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llvm-mirror/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
Evandro Menezes 44fc35bb88 Add support to optionally limit the size of jump tables. 
Many high-performance processors have a dedicated branch predictor for
indirect branches, commonly used with jump tables.  As sophisticated as such
branch predictors are, they tend to have well defined limits beyond which
their effectiveness is hampered or even nullified.  One such limit is the
number of possible destinations for a given indirect branches that such
branch predictors can handle.

This patch considers a limit that a target may set to the number of
destination addresses in a jump table.

Patch by: Evandro Menezes <e.menezes@samsung.com>, Aditya Kumar
<aditya.k7@samsung.com>, Sebastian Pop <s.pop@samsung.com>.

Differential revision: https://reviews.llvm.org/D21940

llvm-svn: 282412
2016-09-26 15:32:33 +00:00

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358 KiB
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//===-- SelectionDAGBuilder.cpp - Selection-DAG building ------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This implements routines for translating from LLVM IR into SelectionDAG IR.
//
//===----------------------------------------------------------------------===//
#include "SelectionDAGBuilder.h"
#include "SDNodeDbgValue.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Analysis/VectorUtils.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/GCStrategy.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGTargetInfo.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/WinEHFuncInfo.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GetElementPtrTypeIterator.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Statepoint.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetFrameLowering.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetIntrinsicInfo.h"
#include "llvm/Target/TargetLowering.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include <algorithm>
#include <utility>
using namespace llvm;
#define DEBUG_TYPE "isel"
/// LimitFloatPrecision - Generate low-precision inline sequences for
/// some float libcalls (6, 8 or 12 bits).
static unsigned LimitFloatPrecision;
static cl::opt<unsigned, true>
LimitFPPrecision("limit-float-precision",
cl::desc("Generate low-precision inline sequences "
"for some float libcalls"),
cl::location(LimitFloatPrecision),
cl::init(0));
static cl::opt<bool>
EnableFMFInDAG("enable-fmf-dag", cl::init(true), cl::Hidden,
cl::desc("Enable fast-math-flags for DAG nodes"));
/// Minimum jump table density for normal functions.
static cl::opt<unsigned>
JumpTableDensity("jump-table-density", cl::init(10), cl::Hidden,
cl::desc("Minimum density for building a jump table in "
"a normal function"));
/// Minimum jump table density for -Os or -Oz functions.
static cl::opt<unsigned>
OptsizeJumpTableDensity("optsize-jump-table-density", cl::init(40), cl::Hidden,
cl::desc("Minimum density for building a jump table in "
"an optsize function"));
// Limit the width of DAG chains. This is important in general to prevent
// DAG-based analysis from blowing up. For example, alias analysis and
// load clustering may not complete in reasonable time. It is difficult to
// recognize and avoid this situation within each individual analysis, and
// future analyses are likely to have the same behavior. Limiting DAG width is
// the safe approach and will be especially important with global DAGs.
//
// MaxParallelChains default is arbitrarily high to avoid affecting
// optimization, but could be lowered to improve compile time. Any ld-ld-st-st
// sequence over this should have been converted to llvm.memcpy by the
// frontend. It is easy to induce this behavior with .ll code such as:
// %buffer = alloca [4096 x i8]
// %data = load [4096 x i8]* %argPtr
// store [4096 x i8] %data, [4096 x i8]* %buffer
static const unsigned MaxParallelChains = 64;
static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL,
const SDValue *Parts, unsigned NumParts,
MVT PartVT, EVT ValueVT, const Value *V);
/// getCopyFromParts - Create a value that contains the specified legal parts
/// combined into the value they represent. If the parts combine to a type
/// larger than ValueVT then AssertOp can be used to specify whether the extra
/// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT
/// (ISD::AssertSext).
static SDValue getCopyFromParts(SelectionDAG &DAG, const SDLoc &DL,
const SDValue *Parts, unsigned NumParts,
MVT PartVT, EVT ValueVT, const Value *V,
Optional<ISD::NodeType> AssertOp = None) {
if (ValueVT.isVector())
return getCopyFromPartsVector(DAG, DL, Parts, NumParts,
PartVT, ValueVT, V);
assert(NumParts > 0 && "No parts to assemble!");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Val = Parts[0];
if (NumParts > 1) {
// Assemble the value from multiple parts.
if (ValueVT.isInteger()) {
unsigned PartBits = PartVT.getSizeInBits();
unsigned ValueBits = ValueVT.getSizeInBits();
// Assemble the power of 2 part.
unsigned RoundParts = NumParts & (NumParts - 1) ?
1 << Log2_32(NumParts) : NumParts;
unsigned RoundBits = PartBits * RoundParts;
EVT RoundVT = RoundBits == ValueBits ?
ValueVT : EVT::getIntegerVT(*DAG.getContext(), RoundBits);
SDValue Lo, Hi;
EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), RoundBits/2);
if (RoundParts > 2) {
Lo = getCopyFromParts(DAG, DL, Parts, RoundParts / 2,
PartVT, HalfVT, V);
Hi = getCopyFromParts(DAG, DL, Parts + RoundParts / 2,
RoundParts / 2, PartVT, HalfVT, V);
} else {
Lo = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[0]);
Hi = DAG.getNode(ISD::BITCAST, DL, HalfVT, Parts[1]);
}
if (DAG.getDataLayout().isBigEndian())
std::swap(Lo, Hi);
Val = DAG.getNode(ISD::BUILD_PAIR, DL, RoundVT, Lo, Hi);
if (RoundParts < NumParts) {
// Assemble the trailing non-power-of-2 part.
unsigned OddParts = NumParts - RoundParts;
EVT OddVT = EVT::getIntegerVT(*DAG.getContext(), OddParts * PartBits);
Hi = getCopyFromParts(DAG, DL,
Parts + RoundParts, OddParts, PartVT, OddVT, V);
// Combine the round and odd parts.
Lo = Val;
if (DAG.getDataLayout().isBigEndian())
std::swap(Lo, Hi);
EVT TotalVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Hi = DAG.getNode(ISD::ANY_EXTEND, DL, TotalVT, Hi);
Hi =
DAG.getNode(ISD::SHL, DL, TotalVT, Hi,
DAG.getConstant(Lo.getValueSizeInBits(), DL,
TLI.getPointerTy(DAG.getDataLayout())));
Lo = DAG.getNode(ISD::ZERO_EXTEND, DL, TotalVT, Lo);
Val = DAG.getNode(ISD::OR, DL, TotalVT, Lo, Hi);
}
} else if (PartVT.isFloatingPoint()) {
// FP split into multiple FP parts (for ppcf128)
assert(ValueVT == EVT(MVT::ppcf128) && PartVT == MVT::f64 &&
"Unexpected split");
SDValue Lo, Hi;
Lo = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[0]);
Hi = DAG.getNode(ISD::BITCAST, DL, EVT(MVT::f64), Parts[1]);
if (TLI.hasBigEndianPartOrdering(ValueVT, DAG.getDataLayout()))
std::swap(Lo, Hi);
Val = DAG.getNode(ISD::BUILD_PAIR, DL, ValueVT, Lo, Hi);
} else {
// FP split into integer parts (soft fp)
assert(ValueVT.isFloatingPoint() && PartVT.isInteger() &&
!PartVT.isVector() && "Unexpected split");
EVT IntVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits());
Val = getCopyFromParts(DAG, DL, Parts, NumParts, PartVT, IntVT, V);
}
}
// There is now one part, held in Val. Correct it to match ValueVT.
// PartEVT is the type of the register class that holds the value.
// ValueVT is the type of the inline asm operation.
EVT PartEVT = Val.getValueType();
if (PartEVT == ValueVT)
return Val;
if (PartEVT.isInteger() && ValueVT.isFloatingPoint() &&
ValueVT.bitsLT(PartEVT)) {
// For an FP value in an integer part, we need to truncate to the right
// width first.
PartEVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits());
Val = DAG.getNode(ISD::TRUNCATE, DL, PartEVT, Val);
}
// Handle types that have the same size.
if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits())
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
// Handle types with different sizes.
if (PartEVT.isInteger() && ValueVT.isInteger()) {
if (ValueVT.bitsLT(PartEVT)) {
// For a truncate, see if we have any information to
// indicate whether the truncated bits will always be
// zero or sign-extension.
if (AssertOp.hasValue())
Val = DAG.getNode(*AssertOp, DL, PartEVT, Val,
DAG.getValueType(ValueVT));
return DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
}
return DAG.getNode(ISD::ANY_EXTEND, DL, ValueVT, Val);
}
if (PartEVT.isFloatingPoint() && ValueVT.isFloatingPoint()) {
// FP_ROUND's are always exact here.
if (ValueVT.bitsLT(Val.getValueType()))
return DAG.getNode(
ISD::FP_ROUND, DL, ValueVT, Val,
DAG.getTargetConstant(1, DL, TLI.getPointerTy(DAG.getDataLayout())));
return DAG.getNode(ISD::FP_EXTEND, DL, ValueVT, Val);
}
llvm_unreachable("Unknown mismatch!");
}
static void diagnosePossiblyInvalidConstraint(LLVMContext &Ctx, const Value *V,
const Twine &ErrMsg) {
const Instruction *I = dyn_cast_or_null<Instruction>(V);
if (!V)
return Ctx.emitError(ErrMsg);
const char *AsmError = ", possible invalid constraint for vector type";
if (const CallInst *CI = dyn_cast<CallInst>(I))
if (isa<InlineAsm>(CI->getCalledValue()))
return Ctx.emitError(I, ErrMsg + AsmError);
return Ctx.emitError(I, ErrMsg);
}
/// getCopyFromPartsVector - Create a value that contains the specified legal
/// parts combined into the value they represent. If the parts combine to a
/// type larger than ValueVT then AssertOp can be used to specify whether the
/// extra bits are known to be zero (ISD::AssertZext) or sign extended from
/// ValueVT (ISD::AssertSext).
static SDValue getCopyFromPartsVector(SelectionDAG &DAG, const SDLoc &DL,
const SDValue *Parts, unsigned NumParts,
MVT PartVT, EVT ValueVT, const Value *V) {
assert(ValueVT.isVector() && "Not a vector value");
assert(NumParts > 0 && "No parts to assemble!");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Val = Parts[0];
// Handle a multi-element vector.
if (NumParts > 1) {
EVT IntermediateVT;
MVT RegisterVT;
unsigned NumIntermediates;
unsigned NumRegs =
TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT, IntermediateVT,
NumIntermediates, RegisterVT);
assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!");
NumParts = NumRegs; // Silence a compiler warning.
assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!");
assert(RegisterVT.getSizeInBits() ==
Parts[0].getSimpleValueType().getSizeInBits() &&
"Part type sizes don't match!");
// Assemble the parts into intermediate operands.
SmallVector<SDValue, 8> Ops(NumIntermediates);
if (NumIntermediates == NumParts) {
// If the register was not expanded, truncate or copy the value,
// as appropriate.
for (unsigned i = 0; i != NumParts; ++i)
Ops[i] = getCopyFromParts(DAG, DL, &Parts[i], 1,
PartVT, IntermediateVT, V);
} else if (NumParts > 0) {
// If the intermediate type was expanded, build the intermediate
// operands from the parts.
assert(NumParts % NumIntermediates == 0 &&
"Must expand into a divisible number of parts!");
unsigned Factor = NumParts / NumIntermediates;
for (unsigned i = 0; i != NumIntermediates; ++i)
Ops[i] = getCopyFromParts(DAG, DL, &Parts[i * Factor], Factor,
PartVT, IntermediateVT, V);
}
// Build a vector with BUILD_VECTOR or CONCAT_VECTORS from the
// intermediate operands.
Val = DAG.getNode(IntermediateVT.isVector() ? ISD::CONCAT_VECTORS
: ISD::BUILD_VECTOR,
DL, ValueVT, Ops);
}
// There is now one part, held in Val. Correct it to match ValueVT.
EVT PartEVT = Val.getValueType();
if (PartEVT == ValueVT)
return Val;
if (PartEVT.isVector()) {
// If the element type of the source/dest vectors are the same, but the
// parts vector has more elements than the value vector, then we have a
// vector widening case (e.g. <2 x float> -> <4 x float>). Extract the
// elements we want.
if (PartEVT.getVectorElementType() == ValueVT.getVectorElementType()) {
assert(PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements() &&
"Cannot narrow, it would be a lossy transformation");
return DAG.getNode(
ISD::EXTRACT_SUBVECTOR, DL, ValueVT, Val,
DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout())));
}
// Vector/Vector bitcast.
if (ValueVT.getSizeInBits() == PartEVT.getSizeInBits())
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
assert(PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements() &&
"Cannot handle this kind of promotion");
// Promoted vector extract
return DAG.getAnyExtOrTrunc(Val, DL, ValueVT);
}
// Trivial bitcast if the types are the same size and the destination
// vector type is legal.
if (PartEVT.getSizeInBits() == ValueVT.getSizeInBits() &&
TLI.isTypeLegal(ValueVT))
return DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
// Handle cases such as i8 -> <1 x i1>
if (ValueVT.getVectorNumElements() != 1) {
diagnosePossiblyInvalidConstraint(*DAG.getContext(), V,
"non-trivial scalar-to-vector conversion");
return DAG.getUNDEF(ValueVT);
}
if (ValueVT.getVectorNumElements() == 1 &&
ValueVT.getVectorElementType() != PartEVT)
Val = DAG.getAnyExtOrTrunc(Val, DL, ValueVT.getScalarType());
return DAG.getNode(ISD::BUILD_VECTOR, DL, ValueVT, Val);
}
static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &dl,
SDValue Val, SDValue *Parts, unsigned NumParts,
MVT PartVT, const Value *V);
/// getCopyToParts - Create a series of nodes that contain the specified value
/// split into legal parts. If the parts contain more bits than Val, then, for
/// integers, ExtendKind can be used to specify how to generate the extra bits.
static void getCopyToParts(SelectionDAG &DAG, const SDLoc &DL, SDValue Val,
SDValue *Parts, unsigned NumParts, MVT PartVT,
const Value *V,
ISD::NodeType ExtendKind = ISD::ANY_EXTEND) {
EVT ValueVT = Val.getValueType();
// Handle the vector case separately.
if (ValueVT.isVector())
return getCopyToPartsVector(DAG, DL, Val, Parts, NumParts, PartVT, V);
unsigned PartBits = PartVT.getSizeInBits();
unsigned OrigNumParts = NumParts;
assert(DAG.getTargetLoweringInfo().isTypeLegal(PartVT) &&
"Copying to an illegal type!");
if (NumParts == 0)
return;
assert(!ValueVT.isVector() && "Vector case handled elsewhere");
EVT PartEVT = PartVT;
if (PartEVT == ValueVT) {
assert(NumParts == 1 && "No-op copy with multiple parts!");
Parts[0] = Val;
return;
}
if (NumParts * PartBits > ValueVT.getSizeInBits()) {
// If the parts cover more bits than the value has, promote the value.
if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) {
assert(NumParts == 1 && "Do not know what to promote to!");
Val = DAG.getNode(ISD::FP_EXTEND, DL, PartVT, Val);
} else {
if (ValueVT.isFloatingPoint()) {
// FP values need to be bitcast, then extended if they are being put
// into a larger container.
ValueVT = EVT::getIntegerVT(*DAG.getContext(), ValueVT.getSizeInBits());
Val = DAG.getNode(ISD::BITCAST, DL, ValueVT, Val);
}
assert((PartVT.isInteger() || PartVT == MVT::x86mmx) &&
ValueVT.isInteger() &&
"Unknown mismatch!");
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ExtendKind, DL, ValueVT, Val);
if (PartVT == MVT::x86mmx)
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
}
} else if (PartBits == ValueVT.getSizeInBits()) {
// Different types of the same size.
assert(NumParts == 1 && PartEVT != ValueVT);
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
} else if (NumParts * PartBits < ValueVT.getSizeInBits()) {
// If the parts cover less bits than value has, truncate the value.
assert((PartVT.isInteger() || PartVT == MVT::x86mmx) &&
ValueVT.isInteger() &&
"Unknown mismatch!");
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
if (PartVT == MVT::x86mmx)
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
}
// The value may have changed - recompute ValueVT.
ValueVT = Val.getValueType();
assert(NumParts * PartBits == ValueVT.getSizeInBits() &&
"Failed to tile the value with PartVT!");
if (NumParts == 1) {
if (PartEVT != ValueVT) {
diagnosePossiblyInvalidConstraint(*DAG.getContext(), V,
"scalar-to-vector conversion failed");
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
}
Parts[0] = Val;
return;
}
// Expand the value into multiple parts.
if (NumParts & (NumParts - 1)) {
// The number of parts is not a power of 2. Split off and copy the tail.
assert(PartVT.isInteger() && ValueVT.isInteger() &&
"Do not know what to expand to!");
unsigned RoundParts = 1 << Log2_32(NumParts);
unsigned RoundBits = RoundParts * PartBits;
unsigned OddParts = NumParts - RoundParts;
SDValue OddVal = DAG.getNode(ISD::SRL, DL, ValueVT, Val,
DAG.getIntPtrConstant(RoundBits, DL));
getCopyToParts(DAG, DL, OddVal, Parts + RoundParts, OddParts, PartVT, V);
if (DAG.getDataLayout().isBigEndian())
// The odd parts were reversed by getCopyToParts - unreverse them.
std::reverse(Parts + RoundParts, Parts + NumParts);
NumParts = RoundParts;
ValueVT = EVT::getIntegerVT(*DAG.getContext(), NumParts * PartBits);
Val = DAG.getNode(ISD::TRUNCATE, DL, ValueVT, Val);
}
// The number of parts is a power of 2. Repeatedly bisect the value using
// EXTRACT_ELEMENT.
Parts[0] = DAG.getNode(ISD::BITCAST, DL,
EVT::getIntegerVT(*DAG.getContext(),
ValueVT.getSizeInBits()),
Val);
for (unsigned StepSize = NumParts; StepSize > 1; StepSize /= 2) {
for (unsigned i = 0; i < NumParts; i += StepSize) {
unsigned ThisBits = StepSize * PartBits / 2;
EVT ThisVT = EVT::getIntegerVT(*DAG.getContext(), ThisBits);
SDValue &Part0 = Parts[i];
SDValue &Part1 = Parts[i+StepSize/2];
Part1 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL,
ThisVT, Part0, DAG.getIntPtrConstant(1, DL));
Part0 = DAG.getNode(ISD::EXTRACT_ELEMENT, DL,
ThisVT, Part0, DAG.getIntPtrConstant(0, DL));
if (ThisBits == PartBits && ThisVT != PartVT) {
Part0 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part0);
Part1 = DAG.getNode(ISD::BITCAST, DL, PartVT, Part1);
}
}
}
if (DAG.getDataLayout().isBigEndian())
std::reverse(Parts, Parts + OrigNumParts);
}
/// getCopyToPartsVector - Create a series of nodes that contain the specified
/// value split into legal parts.
static void getCopyToPartsVector(SelectionDAG &DAG, const SDLoc &DL,
SDValue Val, SDValue *Parts, unsigned NumParts,
MVT PartVT, const Value *V) {
EVT ValueVT = Val.getValueType();
assert(ValueVT.isVector() && "Not a vector");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (NumParts == 1) {
EVT PartEVT = PartVT;
if (PartEVT == ValueVT) {
// Nothing to do.
} else if (PartVT.getSizeInBits() == ValueVT.getSizeInBits()) {
// Bitconvert vector->vector case.
Val = DAG.getNode(ISD::BITCAST, DL, PartVT, Val);
} else if (PartVT.isVector() &&
PartEVT.getVectorElementType() == ValueVT.getVectorElementType() &&
PartEVT.getVectorNumElements() > ValueVT.getVectorNumElements()) {
EVT ElementVT = PartVT.getVectorElementType();
// Vector widening case, e.g. <2 x float> -> <4 x float>. Shuffle in
// undef elements.
SmallVector<SDValue, 16> Ops;
for (unsigned i = 0, e = ValueVT.getVectorNumElements(); i != e; ++i)
Ops.push_back(DAG.getNode(
ISD::EXTRACT_VECTOR_ELT, DL, ElementVT, Val,
DAG.getConstant(i, DL, TLI.getVectorIdxTy(DAG.getDataLayout()))));
for (unsigned i = ValueVT.getVectorNumElements(),
e = PartVT.getVectorNumElements(); i != e; ++i)
Ops.push_back(DAG.getUNDEF(ElementVT));
Val = DAG.getNode(ISD::BUILD_VECTOR, DL, PartVT, Ops);
// FIXME: Use CONCAT for 2x -> 4x.
//SDValue UndefElts = DAG.getUNDEF(VectorTy);
//Val = DAG.getNode(ISD::CONCAT_VECTORS, DL, PartVT, Val, UndefElts);
} else if (PartVT.isVector() &&
PartEVT.getVectorElementType().bitsGE(
ValueVT.getVectorElementType()) &&
PartEVT.getVectorNumElements() == ValueVT.getVectorNumElements()) {
// Promoted vector extract
Val = DAG.getAnyExtOrTrunc(Val, DL, PartVT);
} else{
// Vector -> scalar conversion.
assert(ValueVT.getVectorNumElements() == 1 &&
"Only trivial vector-to-scalar conversions should get here!");
Val = DAG.getNode(
ISD::EXTRACT_VECTOR_ELT, DL, PartVT, Val,
DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout())));
Val = DAG.getAnyExtOrTrunc(Val, DL, PartVT);
}
Parts[0] = Val;
return;
}
// Handle a multi-element vector.
EVT IntermediateVT;
MVT RegisterVT;
unsigned NumIntermediates;
unsigned NumRegs = TLI.getVectorTypeBreakdown(*DAG.getContext(), ValueVT,
IntermediateVT,
NumIntermediates, RegisterVT);
unsigned NumElements = ValueVT.getVectorNumElements();
assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!");
NumParts = NumRegs; // Silence a compiler warning.
assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!");
// Split the vector into intermediate operands.
SmallVector<SDValue, 8> Ops(NumIntermediates);
for (unsigned i = 0; i != NumIntermediates; ++i) {
if (IntermediateVT.isVector())
Ops[i] =
DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, IntermediateVT, Val,
DAG.getConstant(i * (NumElements / NumIntermediates), DL,
TLI.getVectorIdxTy(DAG.getDataLayout())));
else
Ops[i] = DAG.getNode(
ISD::EXTRACT_VECTOR_ELT, DL, IntermediateVT, Val,
DAG.getConstant(i, DL, TLI.getVectorIdxTy(DAG.getDataLayout())));
}
// Split the intermediate operands into legal parts.
if (NumParts == NumIntermediates) {
// If the register was not expanded, promote or copy the value,
// as appropriate.
for (unsigned i = 0; i != NumParts; ++i)
getCopyToParts(DAG, DL, Ops[i], &Parts[i], 1, PartVT, V);
} else if (NumParts > 0) {
// If the intermediate type was expanded, split each the value into
// legal parts.
assert(NumIntermediates != 0 && "division by zero");
assert(NumParts % NumIntermediates == 0 &&
"Must expand into a divisible number of parts!");
unsigned Factor = NumParts / NumIntermediates;
for (unsigned i = 0; i != NumIntermediates; ++i)
getCopyToParts(DAG, DL, Ops[i], &Parts[i*Factor], Factor, PartVT, V);
}
}
RegsForValue::RegsForValue() {}
RegsForValue::RegsForValue(const SmallVector<unsigned, 4> &regs, MVT regvt,
EVT valuevt)
: ValueVTs(1, valuevt), RegVTs(1, regvt), Regs(regs) {}
RegsForValue::RegsForValue(LLVMContext &Context, const TargetLowering &TLI,
const DataLayout &DL, unsigned Reg, Type *Ty) {
ComputeValueVTs(TLI, DL, Ty, ValueVTs);
for (EVT ValueVT : ValueVTs) {
unsigned NumRegs = TLI.getNumRegisters(Context, ValueVT);
MVT RegisterVT = TLI.getRegisterType(Context, ValueVT);
for (unsigned i = 0; i != NumRegs; ++i)
Regs.push_back(Reg + i);
RegVTs.push_back(RegisterVT);
Reg += NumRegs;
}
}
/// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from
/// this value and returns the result as a ValueVT value. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG,
FunctionLoweringInfo &FuncInfo,
const SDLoc &dl, SDValue &Chain,
SDValue *Flag, const Value *V) const {
// A Value with type {} or [0 x %t] needs no registers.
if (ValueVTs.empty())
return SDValue();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// Assemble the legal parts into the final values.
SmallVector<SDValue, 4> Values(ValueVTs.size());
SmallVector<SDValue, 8> Parts;
for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) {
// Copy the legal parts from the registers.
EVT ValueVT = ValueVTs[Value];
unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVT);
MVT RegisterVT = RegVTs[Value];
Parts.resize(NumRegs);
for (unsigned i = 0; i != NumRegs; ++i) {
SDValue P;
if (!Flag) {
P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT);
} else {
P = DAG.getCopyFromReg(Chain, dl, Regs[Part+i], RegisterVT, *Flag);
*Flag = P.getValue(2);
}
Chain = P.getValue(1);
Parts[i] = P;
// If the source register was virtual and if we know something about it,
// add an assert node.
if (!TargetRegisterInfo::isVirtualRegister(Regs[Part+i]) ||
!RegisterVT.isInteger() || RegisterVT.isVector())
continue;
const FunctionLoweringInfo::LiveOutInfo *LOI =
FuncInfo.GetLiveOutRegInfo(Regs[Part+i]);
if (!LOI)
continue;
unsigned RegSize = RegisterVT.getSizeInBits();
unsigned NumSignBits = LOI->NumSignBits;
unsigned NumZeroBits = LOI->KnownZero.countLeadingOnes();
if (NumZeroBits == RegSize) {
// The current value is a zero.
// Explicitly express that as it would be easier for
// optimizations to kick in.
Parts[i] = DAG.getConstant(0, dl, RegisterVT);
continue;
}
// FIXME: We capture more information than the dag can represent. For
// now, just use the tightest assertzext/assertsext possible.
bool isSExt = true;
EVT FromVT(MVT::Other);
if (NumSignBits == RegSize) {
isSExt = true; // ASSERT SEXT 1
FromVT = MVT::i1;
} else if (NumZeroBits >= RegSize - 1) {
isSExt = false; // ASSERT ZEXT 1
FromVT = MVT::i1;
} else if (NumSignBits > RegSize - 8) {
isSExt = true; // ASSERT SEXT 8
FromVT = MVT::i8;
} else if (NumZeroBits >= RegSize - 8) {
isSExt = false; // ASSERT ZEXT 8
FromVT = MVT::i8;
} else if (NumSignBits > RegSize - 16) {
isSExt = true; // ASSERT SEXT 16
FromVT = MVT::i16;
} else if (NumZeroBits >= RegSize - 16) {
isSExt = false; // ASSERT ZEXT 16
FromVT = MVT::i16;
} else if (NumSignBits > RegSize - 32) {
isSExt = true; // ASSERT SEXT 32
FromVT = MVT::i32;
} else if (NumZeroBits >= RegSize - 32) {
isSExt = false; // ASSERT ZEXT 32
FromVT = MVT::i32;
} else {
continue;
}
// Add an assertion node.
assert(FromVT != MVT::Other);
Parts[i] = DAG.getNode(isSExt ? ISD::AssertSext : ISD::AssertZext, dl,
RegisterVT, P, DAG.getValueType(FromVT));
}
Values[Value] = getCopyFromParts(DAG, dl, Parts.begin(),
NumRegs, RegisterVT, ValueVT, V);
Part += NumRegs;
Parts.clear();
}
return DAG.getNode(ISD::MERGE_VALUES, dl, DAG.getVTList(ValueVTs), Values);
}
/// getCopyToRegs - Emit a series of CopyToReg nodes that copies the
/// specified value into the registers specified by this object. This uses
/// Chain/Flag as the input and updates them for the output Chain/Flag.
/// If the Flag pointer is NULL, no flag is used.
void RegsForValue::getCopyToRegs(SDValue Val, SelectionDAG &DAG,
const SDLoc &dl, SDValue &Chain, SDValue *Flag,
const Value *V,
ISD::NodeType PreferredExtendType) const {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
ISD::NodeType ExtendKind = PreferredExtendType;
// Get the list of the values's legal parts.
unsigned NumRegs = Regs.size();
SmallVector<SDValue, 8> Parts(NumRegs);
for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) {
EVT ValueVT = ValueVTs[Value];
unsigned NumParts = TLI.getNumRegisters(*DAG.getContext(), ValueVT);
MVT RegisterVT = RegVTs[Value];
if (ExtendKind == ISD::ANY_EXTEND && TLI.isZExtFree(Val, RegisterVT))
ExtendKind = ISD::ZERO_EXTEND;
getCopyToParts(DAG, dl, Val.getValue(Val.getResNo() + Value),
&Parts[Part], NumParts, RegisterVT, V, ExtendKind);
Part += NumParts;
}
// Copy the parts into the registers.
SmallVector<SDValue, 8> Chains(NumRegs);
for (unsigned i = 0; i != NumRegs; ++i) {
SDValue Part;
if (!Flag) {
Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i]);
} else {
Part = DAG.getCopyToReg(Chain, dl, Regs[i], Parts[i], *Flag);
*Flag = Part.getValue(1);
}
Chains[i] = Part.getValue(0);
}
if (NumRegs == 1 || Flag)
// If NumRegs > 1 && Flag is used then the use of the last CopyToReg is
// flagged to it. That is the CopyToReg nodes and the user are considered
// a single scheduling unit. If we create a TokenFactor and return it as
// chain, then the TokenFactor is both a predecessor (operand) of the
// user as well as a successor (the TF operands are flagged to the user).
// c1, f1 = CopyToReg
// c2, f2 = CopyToReg
// c3 = TokenFactor c1, c2
// ...
// = op c3, ..., f2
Chain = Chains[NumRegs-1];
else
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Chains);
}
/// AddInlineAsmOperands - Add this value to the specified inlineasm node
/// operand list. This adds the code marker and includes the number of
/// values added into it.
void RegsForValue::AddInlineAsmOperands(unsigned Code, bool HasMatching,
unsigned MatchingIdx, const SDLoc &dl,
SelectionDAG &DAG,
std::vector<SDValue> &Ops) const {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned Flag = InlineAsm::getFlagWord(Code, Regs.size());
if (HasMatching)
Flag = InlineAsm::getFlagWordForMatchingOp(Flag, MatchingIdx);
else if (!Regs.empty() &&
TargetRegisterInfo::isVirtualRegister(Regs.front())) {
// Put the register class of the virtual registers in the flag word. That
// way, later passes can recompute register class constraints for inline
// assembly as well as normal instructions.
// Don't do this for tied operands that can use the regclass information
// from the def.
const MachineRegisterInfo &MRI = DAG.getMachineFunction().getRegInfo();
const TargetRegisterClass *RC = MRI.getRegClass(Regs.front());
Flag = InlineAsm::getFlagWordForRegClass(Flag, RC->getID());
}
SDValue Res = DAG.getTargetConstant(Flag, dl, MVT::i32);
Ops.push_back(Res);
unsigned SP = TLI.getStackPointerRegisterToSaveRestore();
for (unsigned Value = 0, Reg = 0, e = ValueVTs.size(); Value != e; ++Value) {
unsigned NumRegs = TLI.getNumRegisters(*DAG.getContext(), ValueVTs[Value]);
MVT RegisterVT = RegVTs[Value];
for (unsigned i = 0; i != NumRegs; ++i) {
assert(Reg < Regs.size() && "Mismatch in # registers expected");
unsigned TheReg = Regs[Reg++];
Ops.push_back(DAG.getRegister(TheReg, RegisterVT));
if (TheReg == SP && Code == InlineAsm::Kind_Clobber) {
// If we clobbered the stack pointer, MFI should know about it.
assert(DAG.getMachineFunction().getFrameInfo().hasOpaqueSPAdjustment());
}
}
}
}
void SelectionDAGBuilder::init(GCFunctionInfo *gfi, AliasAnalysis &aa,
const TargetLibraryInfo *li) {
AA = &aa;
GFI = gfi;
LibInfo = li;
DL = &DAG.getDataLayout();
Context = DAG.getContext();
LPadToCallSiteMap.clear();
}
/// clear - Clear out the current SelectionDAG and the associated
/// state and prepare this SelectionDAGBuilder object to be used
/// for a new block. This doesn't clear out information about
/// additional blocks that are needed to complete switch lowering
/// or PHI node updating; that information is cleared out as it is
/// consumed.
void SelectionDAGBuilder::clear() {
NodeMap.clear();
UnusedArgNodeMap.clear();
PendingLoads.clear();
PendingExports.clear();
CurInst = nullptr;
HasTailCall = false;
SDNodeOrder = LowestSDNodeOrder;
StatepointLowering.clear();
}
/// clearDanglingDebugInfo - Clear the dangling debug information
/// map. This function is separated from the clear so that debug
/// information that is dangling in a basic block can be properly
/// resolved in a different basic block. This allows the
/// SelectionDAG to resolve dangling debug information attached
/// to PHI nodes.
void SelectionDAGBuilder::clearDanglingDebugInfo() {
DanglingDebugInfoMap.clear();
}
/// getRoot - Return the current virtual root of the Selection DAG,
/// flushing any PendingLoad items. This must be done before emitting
/// a store or any other node that may need to be ordered after any
/// prior load instructions.
///
SDValue SelectionDAGBuilder::getRoot() {
if (PendingLoads.empty())
return DAG.getRoot();
if (PendingLoads.size() == 1) {
SDValue Root = PendingLoads[0];
DAG.setRoot(Root);
PendingLoads.clear();
return Root;
}
// Otherwise, we have to make a token factor node.
SDValue Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other,
PendingLoads);
PendingLoads.clear();
DAG.setRoot(Root);
return Root;
}
/// getControlRoot - Similar to getRoot, but instead of flushing all the
/// PendingLoad items, flush all the PendingExports items. It is necessary
/// to do this before emitting a terminator instruction.
///
SDValue SelectionDAGBuilder::getControlRoot() {
SDValue Root = DAG.getRoot();
if (PendingExports.empty())
return Root;
// Turn all of the CopyToReg chains into one factored node.
if (Root.getOpcode() != ISD::EntryToken) {
unsigned i = 0, e = PendingExports.size();
for (; i != e; ++i) {
assert(PendingExports[i].getNode()->getNumOperands() > 1);
if (PendingExports[i].getNode()->getOperand(0) == Root)
break; // Don't add the root if we already indirectly depend on it.
}
if (i == e)
PendingExports.push_back(Root);
}
Root = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other,
PendingExports);
PendingExports.clear();
DAG.setRoot(Root);
return Root;
}
/// Copy swift error to the final virtual register at end of a basic block, as
/// specified by SwiftErrorWorklist, if necessary.
static void copySwiftErrorsToFinalVRegs(SelectionDAGBuilder &SDB) {
const TargetLowering &TLI = SDB.DAG.getTargetLoweringInfo();
if (!TLI.supportSwiftError())
return;
if (!SDB.FuncInfo.SwiftErrorWorklist.count(SDB.FuncInfo.MBB))
return;
// Go through entries in SwiftErrorWorklist, and create copy as necessary.
FunctionLoweringInfo::SwiftErrorVRegs &WorklistEntry =
SDB.FuncInfo.SwiftErrorWorklist[SDB.FuncInfo.MBB];
FunctionLoweringInfo::SwiftErrorVRegs &MapEntry =
SDB.FuncInfo.SwiftErrorMap[SDB.FuncInfo.MBB];
for (unsigned I = 0, E = WorklistEntry.size(); I < E; I++) {
unsigned WorkReg = WorklistEntry[I];
// Find the swifterror virtual register for the value in SwiftErrorMap.
unsigned MapReg = MapEntry[I];
assert(TargetRegisterInfo::isVirtualRegister(MapReg) &&
"Entries in SwiftErrorMap should be virtual registers");
if (WorkReg == MapReg)
continue;
// Create copy from SwiftErrorMap to SwiftWorklist.
auto &DL = SDB.DAG.getDataLayout();
SDValue CopyNode = SDB.DAG.getCopyToReg(
SDB.getRoot(), SDB.getCurSDLoc(), WorkReg,
SDB.DAG.getRegister(MapReg, EVT(TLI.getPointerTy(DL))));
MapEntry[I] = WorkReg;
SDB.DAG.setRoot(CopyNode);
}
}
void SelectionDAGBuilder::visit(const Instruction &I) {
// Set up outgoing PHI node register values before emitting the terminator.
if (isa<TerminatorInst>(&I)) {
copySwiftErrorsToFinalVRegs(*this);
HandlePHINodesInSuccessorBlocks(I.getParent());
}
++SDNodeOrder;
CurInst = &I;
visit(I.getOpcode(), I);
if (!isa<TerminatorInst>(&I) && !HasTailCall &&
!isStatepoint(&I)) // statepoints handle their exports internally
CopyToExportRegsIfNeeded(&I);
CurInst = nullptr;
}
void SelectionDAGBuilder::visitPHI(const PHINode &) {
llvm_unreachable("SelectionDAGBuilder shouldn't visit PHI nodes!");
}
void SelectionDAGBuilder::visit(unsigned Opcode, const User &I) {
// Note: this doesn't use InstVisitor, because it has to work with
// ConstantExpr's in addition to instructions.
switch (Opcode) {
default: llvm_unreachable("Unknown instruction type encountered!");
// Build the switch statement using the Instruction.def file.
#define HANDLE_INST(NUM, OPCODE, CLASS) \
case Instruction::OPCODE: visit##OPCODE((const CLASS&)I); break;
#include "llvm/IR/Instruction.def"
}
}
// resolveDanglingDebugInfo - if we saw an earlier dbg_value referring to V,
// generate the debug data structures now that we've seen its definition.
void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
SDValue Val) {
DanglingDebugInfo &DDI = DanglingDebugInfoMap[V];
if (DDI.getDI()) {
const DbgValueInst *DI = DDI.getDI();
DebugLoc dl = DDI.getdl();
unsigned DbgSDNodeOrder = DDI.getSDNodeOrder();
DILocalVariable *Variable = DI->getVariable();
DIExpression *Expr = DI->getExpression();
assert(Variable->isValidLocationForIntrinsic(dl) &&
"Expected inlined-at fields to agree");
uint64_t Offset = DI->getOffset();
SDDbgValue *SDV;
if (Val.getNode()) {
if (!EmitFuncArgumentDbgValue(V, Variable, Expr, dl, Offset, false,
Val)) {
SDV = getDbgValue(Val, Variable, Expr, Offset, dl, DbgSDNodeOrder);
DAG.AddDbgValue(SDV, Val.getNode(), false);
}
} else
DEBUG(dbgs() << "Dropping debug info for " << *DI << "\n");
DanglingDebugInfoMap[V] = DanglingDebugInfo();
}
}
/// getCopyFromRegs - If there was virtual register allocated for the value V
/// emit CopyFromReg of the specified type Ty. Return empty SDValue() otherwise.
SDValue SelectionDAGBuilder::getCopyFromRegs(const Value *V, Type *Ty) {
DenseMap<const Value *, unsigned>::iterator It = FuncInfo.ValueMap.find(V);
SDValue Result;
if (It != FuncInfo.ValueMap.end()) {
unsigned InReg = It->second;
RegsForValue RFV(*DAG.getContext(), DAG.getTargetLoweringInfo(),
DAG.getDataLayout(), InReg, Ty);
SDValue Chain = DAG.getEntryNode();
Result = RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V);
resolveDanglingDebugInfo(V, Result);
}
return Result;
}
/// getValue - Return an SDValue for the given Value.
SDValue SelectionDAGBuilder::getValue(const Value *V) {
// If we already have an SDValue for this value, use it. It's important
// to do this first, so that we don't create a CopyFromReg if we already
// have a regular SDValue.
SDValue &N = NodeMap[V];
if (N.getNode()) return N;
// If there's a virtual register allocated and initialized for this
// value, use it.
if (SDValue copyFromReg = getCopyFromRegs(V, V->getType()))
return copyFromReg;
// Otherwise create a new SDValue and remember it.
SDValue Val = getValueImpl(V);
NodeMap[V] = Val;
resolveDanglingDebugInfo(V, Val);
return Val;
}
// Return true if SDValue exists for the given Value
bool SelectionDAGBuilder::findValue(const Value *V) const {
return (NodeMap.find(V) != NodeMap.end()) ||
(FuncInfo.ValueMap.find(V) != FuncInfo.ValueMap.end());
}
/// getNonRegisterValue - Return an SDValue for the given Value, but
/// don't look in FuncInfo.ValueMap for a virtual register.
SDValue SelectionDAGBuilder::getNonRegisterValue(const Value *V) {
// If we already have an SDValue for this value, use it.
SDValue &N = NodeMap[V];
if (N.getNode()) {
if (isa<ConstantSDNode>(N) || isa<ConstantFPSDNode>(N)) {
// Remove the debug location from the node as the node is about to be used
// in a location which may differ from the original debug location. This
// is relevant to Constant and ConstantFP nodes because they can appear
// as constant expressions inside PHI nodes.
N->setDebugLoc(DebugLoc());
}
return N;
}
// Otherwise create a new SDValue and remember it.
SDValue Val = getValueImpl(V);
NodeMap[V] = Val;
resolveDanglingDebugInfo(V, Val);
return Val;
}
/// getValueImpl - Helper function for getValue and getNonRegisterValue.
/// Create an SDValue for the given value.
SDValue SelectionDAGBuilder::getValueImpl(const Value *V) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (const Constant *C = dyn_cast<Constant>(V)) {
EVT VT = TLI.getValueType(DAG.getDataLayout(), V->getType(), true);
if (const ConstantInt *CI = dyn_cast<ConstantInt>(C))
return DAG.getConstant(*CI, getCurSDLoc(), VT);
if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
return DAG.getGlobalAddress(GV, getCurSDLoc(), VT);
if (isa<ConstantPointerNull>(C)) {
unsigned AS = V->getType()->getPointerAddressSpace();
return DAG.getConstant(0, getCurSDLoc(),
TLI.getPointerTy(DAG.getDataLayout(), AS));
}
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C))
return DAG.getConstantFP(*CFP, getCurSDLoc(), VT);
if (isa<UndefValue>(C) && !V->getType()->isAggregateType())
return DAG.getUNDEF(VT);
if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
visit(CE->getOpcode(), *CE);
SDValue N1 = NodeMap[V];
assert(N1.getNode() && "visit didn't populate the NodeMap!");
return N1;
}
if (isa<ConstantStruct>(C) || isa<ConstantArray>(C)) {
SmallVector<SDValue, 4> Constants;
for (User::const_op_iterator OI = C->op_begin(), OE = C->op_end();
OI != OE; ++OI) {
SDNode *Val = getValue(*OI).getNode();
// If the operand is an empty aggregate, there are no values.
if (!Val) continue;
// Add each leaf value from the operand to the Constants list
// to form a flattened list of all the values.
for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i)
Constants.push_back(SDValue(Val, i));
}
return DAG.getMergeValues(Constants, getCurSDLoc());
}
if (const ConstantDataSequential *CDS =
dyn_cast<ConstantDataSequential>(C)) {
SmallVector<SDValue, 4> Ops;
for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
SDNode *Val = getValue(CDS->getElementAsConstant(i)).getNode();
// Add each leaf value from the operand to the Constants list
// to form a flattened list of all the values.
for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i)
Ops.push_back(SDValue(Val, i));
}
if (isa<ArrayType>(CDS->getType()))
return DAG.getMergeValues(Ops, getCurSDLoc());
return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, getCurSDLoc(),
VT, Ops);
}
if (C->getType()->isStructTy() || C->getType()->isArrayTy()) {
assert((isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) &&
"Unknown struct or array constant!");
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, DAG.getDataLayout(), C->getType(), ValueVTs);
unsigned NumElts = ValueVTs.size();
if (NumElts == 0)
return SDValue(); // empty struct
SmallVector<SDValue, 4> Constants(NumElts);
for (unsigned i = 0; i != NumElts; ++i) {
EVT EltVT = ValueVTs[i];
if (isa<UndefValue>(C))
Constants[i] = DAG.getUNDEF(EltVT);
else if (EltVT.isFloatingPoint())
Constants[i] = DAG.getConstantFP(0, getCurSDLoc(), EltVT);
else
Constants[i] = DAG.getConstant(0, getCurSDLoc(), EltVT);
}
return DAG.getMergeValues(Constants, getCurSDLoc());
}
if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
return DAG.getBlockAddress(BA, VT);
VectorType *VecTy = cast<VectorType>(V->getType());
unsigned NumElements = VecTy->getNumElements();
// Now that we know the number and type of the elements, get that number of
// elements into the Ops array based on what kind of constant it is.
SmallVector<SDValue, 16> Ops;
if (const ConstantVector *CV = dyn_cast<ConstantVector>(C)) {
for (unsigned i = 0; i != NumElements; ++i)
Ops.push_back(getValue(CV->getOperand(i)));
} else {
assert(isa<ConstantAggregateZero>(C) && "Unknown vector constant!");
EVT EltVT =
TLI.getValueType(DAG.getDataLayout(), VecTy->getElementType());
SDValue Op;
if (EltVT.isFloatingPoint())
Op = DAG.getConstantFP(0, getCurSDLoc(), EltVT);
else
Op = DAG.getConstant(0, getCurSDLoc(), EltVT);
Ops.assign(NumElements, Op);
}
// Create a BUILD_VECTOR node.
return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, getCurSDLoc(), VT, Ops);
}
// If this is a static alloca, generate it as the frameindex instead of
// computation.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end())
return DAG.getFrameIndex(SI->second,
TLI.getPointerTy(DAG.getDataLayout()));
}
// If this is an instruction which fast-isel has deferred, select it now.
if (const Instruction *Inst = dyn_cast<Instruction>(V)) {
unsigned InReg = FuncInfo.InitializeRegForValue(Inst);
RegsForValue RFV(*DAG.getContext(), TLI, DAG.getDataLayout(), InReg,
Inst->getType());
SDValue Chain = DAG.getEntryNode();
return RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V);
}
llvm_unreachable("Can't get register for value!");
}
void SelectionDAGBuilder::visitCatchPad(const CatchPadInst &I) {
auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn());
bool IsMSVCCXX = Pers == EHPersonality::MSVC_CXX;
bool IsCoreCLR = Pers == EHPersonality::CoreCLR;
MachineBasicBlock *CatchPadMBB = FuncInfo.MBB;
// In MSVC C++ and CoreCLR, catchblocks are funclets and need prologues.
if (IsMSVCCXX || IsCoreCLR)
CatchPadMBB->setIsEHFuncletEntry();
DAG.setRoot(DAG.getNode(ISD::CATCHPAD, getCurSDLoc(), MVT::Other, getControlRoot()));
}
void SelectionDAGBuilder::visitCatchRet(const CatchReturnInst &I) {
// Update machine-CFG edge.
MachineBasicBlock *TargetMBB = FuncInfo.MBBMap[I.getSuccessor()];
FuncInfo.MBB->addSuccessor(TargetMBB);
auto Pers = classifyEHPersonality(FuncInfo.Fn->getPersonalityFn());
bool IsSEH = isAsynchronousEHPersonality(Pers);
if (IsSEH) {
// If this is not a fall-through branch or optimizations are switched off,
// emit the branch.
if (TargetMBB != NextBlock(FuncInfo.MBB) ||
TM.getOptLevel() == CodeGenOpt::None)
DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other,
getControlRoot(), DAG.getBasicBlock(TargetMBB)));
return;
}
// Figure out the funclet membership for the catchret's successor.
// This will be used by the FuncletLayout pass to determine how to order the
// BB's.
// A 'catchret' returns to the outer scope's color.
Value *ParentPad = I.getCatchSwitchParentPad();
const BasicBlock *SuccessorColor;
if (isa<ConstantTokenNone>(ParentPad))
SuccessorColor = &FuncInfo.Fn->getEntryBlock();
else
SuccessorColor = cast<Instruction>(ParentPad)->getParent();
assert(SuccessorColor && "No parent funclet for catchret!");
MachineBasicBlock *SuccessorColorMBB = FuncInfo.MBBMap[SuccessorColor];
assert(SuccessorColorMBB && "No MBB for SuccessorColor!");
// Create the terminator node.
SDValue Ret = DAG.getNode(ISD::CATCHRET, getCurSDLoc(), MVT::Other,
getControlRoot(), DAG.getBasicBlock(TargetMBB),
DAG.getBasicBlock(SuccessorColorMBB));
DAG.setRoot(Ret);
}
void SelectionDAGBuilder::visitCleanupPad(const CleanupPadInst &CPI) {
// Don't emit any special code for the cleanuppad instruction. It just marks
// the start of a funclet.
FuncInfo.MBB->setIsEHFuncletEntry();
FuncInfo.MBB->setIsCleanupFuncletEntry();
}
/// When an invoke or a cleanupret unwinds to the next EH pad, there are
/// many places it could ultimately go. In the IR, we have a single unwind
/// destination, but in the machine CFG, we enumerate all the possible blocks.
/// This function skips over imaginary basic blocks that hold catchswitch
/// instructions, and finds all the "real" machine
/// basic block destinations. As those destinations may not be successors of
/// EHPadBB, here we also calculate the edge probability to those destinations.
/// The passed-in Prob is the edge probability to EHPadBB.
static void findUnwindDestinations(
FunctionLoweringInfo &FuncInfo, const BasicBlock *EHPadBB,
BranchProbability Prob,
SmallVectorImpl<std::pair<MachineBasicBlock *, BranchProbability>>
&UnwindDests) {
EHPersonality Personality =
classifyEHPersonality(FuncInfo.Fn->getPersonalityFn());
bool IsMSVCCXX = Personality == EHPersonality::MSVC_CXX;
bool IsCoreCLR = Personality == EHPersonality::CoreCLR;
while (EHPadBB) {
const Instruction *Pad = EHPadBB->getFirstNonPHI();
BasicBlock *NewEHPadBB = nullptr;
if (isa<LandingPadInst>(Pad)) {
// Stop on landingpads. They are not funclets.
UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob);
break;
} else if (isa<CleanupPadInst>(Pad)) {
// Stop on cleanup pads. Cleanups are always funclet entries for all known
// personalities.
UnwindDests.emplace_back(FuncInfo.MBBMap[EHPadBB], Prob);
UnwindDests.back().first->setIsEHFuncletEntry();
break;
} else if (auto *CatchSwitch = dyn_cast<CatchSwitchInst>(Pad)) {
// Add the catchpad handlers to the possible destinations.
for (const BasicBlock *CatchPadBB : CatchSwitch->handlers()) {
UnwindDests.emplace_back(FuncInfo.MBBMap[CatchPadBB], Prob);
// For MSVC++ and the CLR, catchblocks are funclets and need prologues.
if (IsMSVCCXX || IsCoreCLR)
UnwindDests.back().first->setIsEHFuncletEntry();
}
NewEHPadBB = CatchSwitch->getUnwindDest();
} else {
continue;
}
BranchProbabilityInfo *BPI = FuncInfo.BPI;
if (BPI && NewEHPadBB)
Prob *= BPI->getEdgeProbability(EHPadBB, NewEHPadBB);
EHPadBB = NewEHPadBB;
}
}
void SelectionDAGBuilder::visitCleanupRet(const CleanupReturnInst &I) {
// Update successor info.
SmallVector<std::pair<MachineBasicBlock *, BranchProbability>, 1> UnwindDests;
auto UnwindDest = I.getUnwindDest();
BranchProbabilityInfo *BPI = FuncInfo.BPI;
BranchProbability UnwindDestProb =
(BPI && UnwindDest)
? BPI->getEdgeProbability(FuncInfo.MBB->getBasicBlock(), UnwindDest)
: BranchProbability::getZero();
findUnwindDestinations(FuncInfo, UnwindDest, UnwindDestProb, UnwindDests);
for (auto &UnwindDest : UnwindDests) {
UnwindDest.first->setIsEHPad();
addSuccessorWithProb(FuncInfo.MBB, UnwindDest.first, UnwindDest.second);
}
FuncInfo.MBB->normalizeSuccProbs();
// Create the terminator node.
SDValue Ret =
DAG.getNode(ISD::CLEANUPRET, getCurSDLoc(), MVT::Other, getControlRoot());
DAG.setRoot(Ret);
}
void SelectionDAGBuilder::visitCatchSwitch(const CatchSwitchInst &CSI) {
report_fatal_error("visitCatchSwitch not yet implemented!");
}
void SelectionDAGBuilder::visitRet(const ReturnInst &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
auto &DL = DAG.getDataLayout();
SDValue Chain = getControlRoot();
SmallVector<ISD::OutputArg, 8> Outs;
SmallVector<SDValue, 8> OutVals;
// Calls to @llvm.experimental.deoptimize don't generate a return value, so
// lower
//
// %val = call <ty> @llvm.experimental.deoptimize()
// ret <ty> %val
//
// differently.
if (I.getParent()->getTerminatingDeoptimizeCall()) {
LowerDeoptimizingReturn();
return;
}
if (!FuncInfo.CanLowerReturn) {
unsigned DemoteReg = FuncInfo.DemoteRegister;
const Function *F = I.getParent()->getParent();
// Emit a store of the return value through the virtual register.
// Leave Outs empty so that LowerReturn won't try to load return
// registers the usual way.
SmallVector<EVT, 1> PtrValueVTs;
ComputeValueVTs(TLI, DL, PointerType::getUnqual(F->getReturnType()),
PtrValueVTs);
SDValue RetPtr = DAG.getCopyFromReg(DAG.getEntryNode(), getCurSDLoc(),
DemoteReg, PtrValueVTs[0]);
SDValue RetOp = getValue(I.getOperand(0));
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(TLI, DL, I.getOperand(0)->getType(), ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
// An aggregate return value cannot wrap around the address space, so
// offsets to its parts don't wrap either.
SDNodeFlags Flags;
Flags.setNoUnsignedWrap(true);
SmallVector<SDValue, 4> Chains(NumValues);
for (unsigned i = 0; i != NumValues; ++i) {
SDValue Add = DAG.getNode(ISD::ADD, getCurSDLoc(),
RetPtr.getValueType(), RetPtr,
DAG.getIntPtrConstant(Offsets[i],
getCurSDLoc()),
&Flags);
Chains[i] = DAG.getStore(Chain, getCurSDLoc(),
SDValue(RetOp.getNode(), RetOp.getResNo() + i),
// FIXME: better loc info would be nice.
Add, MachinePointerInfo());
}
Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(),
MVT::Other, Chains);
} else if (I.getNumOperands() != 0) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, DL, I.getOperand(0)->getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues) {
SDValue RetOp = getValue(I.getOperand(0));
const Function *F = I.getParent()->getParent();
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (F->getAttributes().hasAttribute(AttributeSet::ReturnIndex,
Attribute::SExt))
ExtendKind = ISD::SIGN_EXTEND;
else if (F->getAttributes().hasAttribute(AttributeSet::ReturnIndex,
Attribute::ZExt))
ExtendKind = ISD::ZERO_EXTEND;
LLVMContext &Context = F->getContext();
bool RetInReg = F->getAttributes().hasAttribute(AttributeSet::ReturnIndex,
Attribute::InReg);
for (unsigned j = 0; j != NumValues; ++j) {
EVT VT = ValueVTs[j];
if (ExtendKind != ISD::ANY_EXTEND && VT.isInteger())
VT = TLI.getTypeForExtReturn(Context, VT, ExtendKind);
unsigned NumParts = TLI.getNumRegisters(Context, VT);
MVT PartVT = TLI.getRegisterType(Context, VT);
SmallVector<SDValue, 4> Parts(NumParts);
getCopyToParts(DAG, getCurSDLoc(),
SDValue(RetOp.getNode(), RetOp.getResNo() + j),
&Parts[0], NumParts, PartVT, &I, ExtendKind);
// 'inreg' on function refers to return value
ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
if (RetInReg)
Flags.setInReg();
// Propagate extension type if any
if (ExtendKind == ISD::SIGN_EXTEND)
Flags.setSExt();
else if (ExtendKind == ISD::ZERO_EXTEND)
Flags.setZExt();
for (unsigned i = 0; i < NumParts; ++i) {
Outs.push_back(ISD::OutputArg(Flags, Parts[i].getValueType(),
VT, /*isfixed=*/true, 0, 0));
OutVals.push_back(Parts[i]);
}
}
}
}
// Push in swifterror virtual register as the last element of Outs. This makes
// sure swifterror virtual register will be returned in the swifterror
// physical register.
const Function *F = I.getParent()->getParent();
if (TLI.supportSwiftError() &&
F->getAttributes().hasAttrSomewhere(Attribute::SwiftError)) {
ISD::ArgFlagsTy Flags = ISD::ArgFlagsTy();
Flags.setSwiftError();
Outs.push_back(ISD::OutputArg(Flags, EVT(TLI.getPointerTy(DL)) /*vt*/,
EVT(TLI.getPointerTy(DL)) /*argvt*/,
true /*isfixed*/, 1 /*origidx*/,
0 /*partOffs*/));
// Create SDNode for the swifterror virtual register.
OutVals.push_back(DAG.getRegister(FuncInfo.SwiftErrorMap[FuncInfo.MBB][0],
EVT(TLI.getPointerTy(DL))));
}
bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg();
CallingConv::ID CallConv =
DAG.getMachineFunction().getFunction()->getCallingConv();
Chain = DAG.getTargetLoweringInfo().LowerReturn(
Chain, CallConv, isVarArg, Outs, OutVals, getCurSDLoc(), DAG);
// Verify that the target's LowerReturn behaved as expected.
assert(Chain.getNode() && Chain.getValueType() == MVT::Other &&
"LowerReturn didn't return a valid chain!");
// Update the DAG with the new chain value resulting from return lowering.
DAG.setRoot(Chain);
}
/// CopyToExportRegsIfNeeded - If the given value has virtual registers
/// created for it, emit nodes to copy the value into the virtual
/// registers.
void SelectionDAGBuilder::CopyToExportRegsIfNeeded(const Value *V) {
// Skip empty types
if (V->getType()->isEmptyTy())
return;
DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
if (VMI != FuncInfo.ValueMap.end()) {
assert(!V->use_empty() && "Unused value assigned virtual registers!");
CopyValueToVirtualRegister(V, VMI->second);
}
}
/// ExportFromCurrentBlock - If this condition isn't known to be exported from
/// the current basic block, add it to ValueMap now so that we'll get a
/// CopyTo/FromReg.
void SelectionDAGBuilder::ExportFromCurrentBlock(const Value *V) {
// No need to export constants.
if (!isa<Instruction>(V) && !isa<Argument>(V)) return;
// Already exported?
if (FuncInfo.isExportedInst(V)) return;
unsigned Reg = FuncInfo.InitializeRegForValue(V);
CopyValueToVirtualRegister(V, Reg);
}
bool SelectionDAGBuilder::isExportableFromCurrentBlock(const Value *V,
const BasicBlock *FromBB) {
// The operands of the setcc have to be in this block. We don't know
// how to export them from some other block.
if (const Instruction *VI = dyn_cast<Instruction>(V)) {
// Can export from current BB.
if (VI->getParent() == FromBB)
return true;
// Is already exported, noop.
return FuncInfo.isExportedInst(V);
}
// If this is an argument, we can export it if the BB is the entry block or
// if it is already exported.
if (isa<Argument>(V)) {
if (FromBB == &FromBB->getParent()->getEntryBlock())
return true;
// Otherwise, can only export this if it is already exported.
return FuncInfo.isExportedInst(V);
}
// Otherwise, constants can always be exported.
return true;
}
/// Return branch probability calculated by BranchProbabilityInfo for IR blocks.
BranchProbability
SelectionDAGBuilder::getEdgeProbability(const MachineBasicBlock *Src,
const MachineBasicBlock *Dst) const {
BranchProbabilityInfo *BPI = FuncInfo.BPI;
const BasicBlock *SrcBB = Src->getBasicBlock();
const BasicBlock *DstBB = Dst->getBasicBlock();
if (!BPI) {
// If BPI is not available, set the default probability as 1 / N, where N is
// the number of successors.
auto SuccSize = std::max<uint32_t>(
std::distance(succ_begin(SrcBB), succ_end(SrcBB)), 1);
return BranchProbability(1, SuccSize);
}
return BPI->getEdgeProbability(SrcBB, DstBB);
}
void SelectionDAGBuilder::addSuccessorWithProb(MachineBasicBlock *Src,
MachineBasicBlock *Dst,
BranchProbability Prob) {
if (!FuncInfo.BPI)
Src->addSuccessorWithoutProb(Dst);
else {
if (Prob.isUnknown())
Prob = getEdgeProbability(Src, Dst);
Src->addSuccessor(Dst, Prob);
}
}
static bool InBlock(const Value *V, const BasicBlock *BB) {
if (const Instruction *I = dyn_cast<Instruction>(V))
return I->getParent() == BB;
return true;
}
/// EmitBranchForMergedCondition - Helper method for FindMergedConditions.
/// This function emits a branch and is used at the leaves of an OR or an
/// AND operator tree.
///
void
SelectionDAGBuilder::EmitBranchForMergedCondition(const Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB,
BranchProbability TProb,
BranchProbability FProb) {
const BasicBlock *BB = CurBB->getBasicBlock();
// If the leaf of the tree is a comparison, merge the condition into
// the caseblock.
if (const CmpInst *BOp = dyn_cast<CmpInst>(Cond)) {
// The operands of the cmp have to be in this block. We don't know
// how to export them from some other block. If this is the first block
// of the sequence, no exporting is needed.
if (CurBB == SwitchBB ||
(isExportableFromCurrentBlock(BOp->getOperand(0), BB) &&
isExportableFromCurrentBlock(BOp->getOperand(1), BB))) {
ISD::CondCode Condition;
if (const ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) {
Condition = getICmpCondCode(IC->getPredicate());
} else {
const FCmpInst *FC = cast<FCmpInst>(Cond);
Condition = getFCmpCondCode(FC->getPredicate());
if (TM.Options.NoNaNsFPMath)
Condition = getFCmpCodeWithoutNaN(Condition);
}
CaseBlock CB(Condition, BOp->getOperand(0), BOp->getOperand(1), nullptr,
TBB, FBB, CurBB, TProb, FProb);
SwitchCases.push_back(CB);
return;
}
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, Cond, ConstantInt::getTrue(*DAG.getContext()),
nullptr, TBB, FBB, CurBB, TProb, FProb);
SwitchCases.push_back(CB);
}
/// FindMergedConditions - If Cond is an expression like
void SelectionDAGBuilder::FindMergedConditions(const Value *Cond,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
MachineBasicBlock *CurBB,
MachineBasicBlock *SwitchBB,
Instruction::BinaryOps Opc,
BranchProbability TProb,
BranchProbability FProb) {
// If this node is not part of the or/and tree, emit it as a branch.
const Instruction *BOp = dyn_cast<Instruction>(Cond);
if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) ||
(unsigned)BOp->getOpcode() != Opc || !BOp->hasOneUse() ||
BOp->getParent() != CurBB->getBasicBlock() ||
!InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) ||
!InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) {
EmitBranchForMergedCondition(Cond, TBB, FBB, CurBB, SwitchBB,
TProb, FProb);
return;
}
// Create TmpBB after CurBB.
MachineFunction::iterator BBI(CurBB);
MachineFunction &MF = DAG.getMachineFunction();
MachineBasicBlock *TmpBB = MF.CreateMachineBasicBlock(CurBB->getBasicBlock());
CurBB->getParent()->insert(++BBI, TmpBB);
if (Opc == Instruction::Or) {
// Codegen X | Y as:
// BB1:
// jmp_if_X TBB
// jmp TmpBB
// TmpBB:
// jmp_if_Y TBB
// jmp FBB
//
// We have flexibility in setting Prob for BB1 and Prob for TmpBB.
// The requirement is that
// TrueProb for BB1 + (FalseProb for BB1 * TrueProb for TmpBB)
// = TrueProb for original BB.
// Assuming the original probabilities are A and B, one choice is to set
// BB1's probabilities to A/2 and A/2+B, and set TmpBB's probabilities to
// A/(1+B) and 2B/(1+B). This choice assumes that
// TrueProb for BB1 == FalseProb for BB1 * TrueProb for TmpBB.
// Another choice is to assume TrueProb for BB1 equals to TrueProb for
// TmpBB, but the math is more complicated.
auto NewTrueProb = TProb / 2;
auto NewFalseProb = TProb / 2 + FProb;
// Emit the LHS condition.
FindMergedConditions(BOp->getOperand(0), TBB, TmpBB, CurBB, SwitchBB, Opc,
NewTrueProb, NewFalseProb);
// Normalize A/2 and B to get A/(1+B) and 2B/(1+B).
SmallVector<BranchProbability, 2> Probs{TProb / 2, FProb};
BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end());
// Emit the RHS condition into TmpBB.
FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc,
Probs[0], Probs[1]);
} else {
assert(Opc == Instruction::And && "Unknown merge op!");
// Codegen X & Y as:
// BB1:
// jmp_if_X TmpBB
// jmp FBB
// TmpBB:
// jmp_if_Y TBB
// jmp FBB
//
// This requires creation of TmpBB after CurBB.
// We have flexibility in setting Prob for BB1 and Prob for TmpBB.
// The requirement is that
// FalseProb for BB1 + (TrueProb for BB1 * FalseProb for TmpBB)
// = FalseProb for original BB.
// Assuming the original probabilities are A and B, one choice is to set
// BB1's probabilities to A+B/2 and B/2, and set TmpBB's probabilities to
// 2A/(1+A) and B/(1+A). This choice assumes that FalseProb for BB1 ==
// TrueProb for BB1 * FalseProb for TmpBB.
auto NewTrueProb = TProb + FProb / 2;
auto NewFalseProb = FProb / 2;
// Emit the LHS condition.
FindMergedConditions(BOp->getOperand(0), TmpBB, FBB, CurBB, SwitchBB, Opc,
NewTrueProb, NewFalseProb);
// Normalize A and B/2 to get 2A/(1+A) and B/(1+A).
SmallVector<BranchProbability, 2> Probs{TProb, FProb / 2};
BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end());
// Emit the RHS condition into TmpBB.
FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, SwitchBB, Opc,
Probs[0], Probs[1]);
}
}
/// If the set of cases should be emitted as a series of branches, return true.
/// If we should emit this as a bunch of and/or'd together conditions, return
/// false.
bool
SelectionDAGBuilder::ShouldEmitAsBranches(const std::vector<CaseBlock> &Cases) {
if (Cases.size() != 2) return true;
// If this is two comparisons of the same values or'd or and'd together, they
// will get folded into a single comparison, so don't emit two blocks.
if ((Cases[0].CmpLHS == Cases[1].CmpLHS &&
Cases[0].CmpRHS == Cases[1].CmpRHS) ||
(Cases[0].CmpRHS == Cases[1].CmpLHS &&
Cases[0].CmpLHS == Cases[1].CmpRHS)) {
return false;
}
// Handle: (X != null) | (Y != null) --> (X|Y) != 0
// Handle: (X == null) & (Y == null) --> (X|Y) == 0
if (Cases[0].CmpRHS == Cases[1].CmpRHS &&
Cases[0].CC == Cases[1].CC &&
isa<Constant>(Cases[0].CmpRHS) &&
cast<Constant>(Cases[0].CmpRHS)->isNullValue()) {
if (Cases[0].CC == ISD::SETEQ && Cases[0].TrueBB == Cases[1].ThisBB)
return false;
if (Cases[0].CC == ISD::SETNE && Cases[0].FalseBB == Cases[1].ThisBB)
return false;
}
return true;
}
void SelectionDAGBuilder::visitBr(const BranchInst &I) {
MachineBasicBlock *BrMBB = FuncInfo.MBB;
// Update machine-CFG edges.
MachineBasicBlock *Succ0MBB = FuncInfo.MBBMap[I.getSuccessor(0)];
if (I.isUnconditional()) {
// Update machine-CFG edges.
BrMBB->addSuccessor(Succ0MBB);
// If this is not a fall-through branch or optimizations are switched off,
// emit the branch.
if (Succ0MBB != NextBlock(BrMBB) || TM.getOptLevel() == CodeGenOpt::None)
DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(),
MVT::Other, getControlRoot(),
DAG.getBasicBlock(Succ0MBB)));
return;
}
// If this condition is one of the special cases we handle, do special stuff
// now.
const Value *CondVal = I.getCondition();
MachineBasicBlock *Succ1MBB = FuncInfo.MBBMap[I.getSuccessor(1)];
// If this is a series of conditions that are or'd or and'd together, emit
// this as a sequence of branches instead of setcc's with and/or operations.
// As long as jumps are not expensive, this should improve performance.
// For example, instead of something like:
// cmp A, B
// C = seteq
// cmp D, E
// F = setle
// or C, F
// jnz foo
// Emit:
// cmp A, B
// je foo
// cmp D, E
// jle foo
//
if (const BinaryOperator *BOp = dyn_cast<BinaryOperator>(CondVal)) {
Instruction::BinaryOps Opcode = BOp->getOpcode();
if (!DAG.getTargetLoweringInfo().isJumpExpensive() && BOp->hasOneUse() &&
!I.getMetadata(LLVMContext::MD_unpredictable) &&
(Opcode == Instruction::And || Opcode == Instruction::Or)) {
FindMergedConditions(BOp, Succ0MBB, Succ1MBB, BrMBB, BrMBB,
Opcode,
getEdgeProbability(BrMBB, Succ0MBB),
getEdgeProbability(BrMBB, Succ1MBB));
// If the compares in later blocks need to use values not currently
// exported from this block, export them now. This block should always
// be the first entry.
assert(SwitchCases[0].ThisBB == BrMBB && "Unexpected lowering!");
// Allow some cases to be rejected.
if (ShouldEmitAsBranches(SwitchCases)) {
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) {
ExportFromCurrentBlock(SwitchCases[i].CmpLHS);
ExportFromCurrentBlock(SwitchCases[i].CmpRHS);
}
// Emit the branch for this block.
visitSwitchCase(SwitchCases[0], BrMBB);
SwitchCases.erase(SwitchCases.begin());
return;
}
// Okay, we decided not to do this, remove any inserted MBB's and clear
// SwitchCases.
for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i)
FuncInfo.MF->erase(SwitchCases[i].ThisBB);
SwitchCases.clear();
}
}
// Create a CaseBlock record representing this branch.
CaseBlock CB(ISD::SETEQ, CondVal, ConstantInt::getTrue(*DAG.getContext()),
nullptr, Succ0MBB, Succ1MBB, BrMBB);
// Use visitSwitchCase to actually insert the fast branch sequence for this
// cond branch.
visitSwitchCase(CB, BrMBB);
}
/// visitSwitchCase - Emits the necessary code to represent a single node in
/// the binary search tree resulting from lowering a switch instruction.
void SelectionDAGBuilder::visitSwitchCase(CaseBlock &CB,
MachineBasicBlock *SwitchBB) {
SDValue Cond;
SDValue CondLHS = getValue(CB.CmpLHS);
SDLoc dl = getCurSDLoc();
// Build the setcc now.
if (!CB.CmpMHS) {
// Fold "(X == true)" to X and "(X == false)" to !X to
// handle common cases produced by branch lowering.
if (CB.CmpRHS == ConstantInt::getTrue(*DAG.getContext()) &&
CB.CC == ISD::SETEQ)
Cond = CondLHS;
else if (CB.CmpRHS == ConstantInt::getFalse(*DAG.getContext()) &&
CB.CC == ISD::SETEQ) {
SDValue True = DAG.getConstant(1, dl, CondLHS.getValueType());
Cond = DAG.getNode(ISD::XOR, dl, CondLHS.getValueType(), CondLHS, True);
} else
Cond = DAG.getSetCC(dl, MVT::i1, CondLHS, getValue(CB.CmpRHS), CB.CC);
} else {
assert(CB.CC == ISD::SETLE && "Can handle only LE ranges now");
const APInt& Low = cast<ConstantInt>(CB.CmpLHS)->getValue();
const APInt& High = cast<ConstantInt>(CB.CmpRHS)->getValue();
SDValue CmpOp = getValue(CB.CmpMHS);
EVT VT = CmpOp.getValueType();
if (cast<ConstantInt>(CB.CmpLHS)->isMinValue(true)) {
Cond = DAG.getSetCC(dl, MVT::i1, CmpOp, DAG.getConstant(High, dl, VT),
ISD::SETLE);
} else {
SDValue SUB = DAG.getNode(ISD::SUB, dl,
VT, CmpOp, DAG.getConstant(Low, dl, VT));
Cond = DAG.getSetCC(dl, MVT::i1, SUB,
DAG.getConstant(High-Low, dl, VT), ISD::SETULE);
}
}
// Update successor info
addSuccessorWithProb(SwitchBB, CB.TrueBB, CB.TrueProb);
// TrueBB and FalseBB are always different unless the incoming IR is
// degenerate. This only happens when running llc on weird IR.
if (CB.TrueBB != CB.FalseBB)
addSuccessorWithProb(SwitchBB, CB.FalseBB, CB.FalseProb);
SwitchBB->normalizeSuccProbs();
// If the lhs block is the next block, invert the condition so that we can
// fall through to the lhs instead of the rhs block.
if (CB.TrueBB == NextBlock(SwitchBB)) {
std::swap(CB.TrueBB, CB.FalseBB);
SDValue True = DAG.getConstant(1, dl, Cond.getValueType());
Cond = DAG.getNode(ISD::XOR, dl, Cond.getValueType(), Cond, True);
}
SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, getControlRoot(), Cond,
DAG.getBasicBlock(CB.TrueBB));
// Insert the false branch. Do this even if it's a fall through branch,
// this makes it easier to do DAG optimizations which require inverting
// the branch condition.
BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond,
DAG.getBasicBlock(CB.FalseBB));
DAG.setRoot(BrCond);
}
/// visitJumpTable - Emit JumpTable node in the current MBB
void SelectionDAGBuilder::visitJumpTable(JumpTable &JT) {
// Emit the code for the jump table
assert(JT.Reg != -1U && "Should lower JT Header first!");
EVT PTy = DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout());
SDValue Index = DAG.getCopyFromReg(getControlRoot(), getCurSDLoc(),
JT.Reg, PTy);
SDValue Table = DAG.getJumpTable(JT.JTI, PTy);
SDValue BrJumpTable = DAG.getNode(ISD::BR_JT, getCurSDLoc(),
MVT::Other, Index.getValue(1),
Table, Index);
DAG.setRoot(BrJumpTable);
}
/// visitJumpTableHeader - This function emits necessary code to produce index
/// in the JumpTable from switch case.
void SelectionDAGBuilder::visitJumpTableHeader(JumpTable &JT,
JumpTableHeader &JTH,
MachineBasicBlock *SwitchBB) {
SDLoc dl = getCurSDLoc();
// Subtract the lowest switch case value from the value being switched on and
// conditional branch to default mbb if the result is greater than the
// difference between smallest and largest cases.
SDValue SwitchOp = getValue(JTH.SValue);
EVT VT = SwitchOp.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp,
DAG.getConstant(JTH.First, dl, VT));
// The SDNode we just created, which holds the value being switched on minus
// the smallest case value, needs to be copied to a virtual register so it
// can be used as an index into the jump table in a subsequent basic block.
// This value may be smaller or larger than the target's pointer type, and
// therefore require extension or truncating.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SwitchOp = DAG.getZExtOrTrunc(Sub, dl, TLI.getPointerTy(DAG.getDataLayout()));
unsigned JumpTableReg =
FuncInfo.CreateReg(TLI.getPointerTy(DAG.getDataLayout()));
SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl,
JumpTableReg, SwitchOp);
JT.Reg = JumpTableReg;
// Emit the range check for the jump table, and branch to the default block
// for the switch statement if the value being switched on exceeds the largest
// case in the switch.
SDValue CMP = DAG.getSetCC(
dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(),
Sub.getValueType()),
Sub, DAG.getConstant(JTH.Last - JTH.First, dl, VT), ISD::SETUGT);
SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, CopyTo, CMP,
DAG.getBasicBlock(JT.Default));
// Avoid emitting unnecessary branches to the next block.
if (JT.MBB != NextBlock(SwitchBB))
BrCond = DAG.getNode(ISD::BR, dl, MVT::Other, BrCond,
DAG.getBasicBlock(JT.MBB));
DAG.setRoot(BrCond);
}
/// Create a LOAD_STACK_GUARD node, and let it carry the target specific global
/// variable if there exists one.
static SDValue getLoadStackGuard(SelectionDAG &DAG, const SDLoc &DL,
SDValue &Chain) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
MachineFunction &MF = DAG.getMachineFunction();
Value *Global = TLI.getSDagStackGuard(*MF.getFunction()->getParent());
MachineSDNode *Node =
DAG.getMachineNode(TargetOpcode::LOAD_STACK_GUARD, DL, PtrTy, Chain);
if (Global) {
MachinePointerInfo MPInfo(Global);
MachineInstr::mmo_iterator MemRefs = MF.allocateMemRefsArray(1);
auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant |
MachineMemOperand::MODereferenceable;
*MemRefs = MF.getMachineMemOperand(MPInfo, Flags, PtrTy.getSizeInBits() / 8,
DAG.getEVTAlignment(PtrTy));
Node->setMemRefs(MemRefs, MemRefs + 1);
}
return SDValue(Node, 0);
}
/// Codegen a new tail for a stack protector check ParentMBB which has had its
/// tail spliced into a stack protector check success bb.
///
/// For a high level explanation of how this fits into the stack protector
/// generation see the comment on the declaration of class
/// StackProtectorDescriptor.
void SelectionDAGBuilder::visitSPDescriptorParent(StackProtectorDescriptor &SPD,
MachineBasicBlock *ParentBB) {
// First create the loads to the guard/stack slot for the comparison.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
MachineFrameInfo &MFI = ParentBB->getParent()->getFrameInfo();
int FI = MFI.getStackProtectorIndex();
SDValue Guard;
SDLoc dl = getCurSDLoc();
SDValue StackSlotPtr = DAG.getFrameIndex(FI, PtrTy);
const Module &M = *ParentBB->getParent()->getFunction()->getParent();
unsigned Align = DL->getPrefTypeAlignment(Type::getInt8PtrTy(M.getContext()));
// Generate code to load the content of the guard slot.
SDValue StackSlot = DAG.getLoad(
PtrTy, dl, DAG.getEntryNode(), StackSlotPtr,
MachinePointerInfo::getFixedStack(DAG.getMachineFunction(), FI), Align,
MachineMemOperand::MOVolatile);
// Retrieve guard check function, nullptr if instrumentation is inlined.
if (const Value *GuardCheck = TLI.getSSPStackGuardCheck(M)) {
// The target provides a guard check function to validate the guard value.
// Generate a call to that function with the content of the guard slot as
// argument.
auto *Fn = cast<Function>(GuardCheck);
FunctionType *FnTy = Fn->getFunctionType();
assert(FnTy->getNumParams() == 1 && "Invalid function signature");
TargetLowering::ArgListTy Args;
TargetLowering::ArgListEntry Entry;
Entry.Node = StackSlot;
Entry.Ty = FnTy->getParamType(0);
if (Fn->hasAttribute(1, Attribute::AttrKind::InReg))
Entry.isInReg = true;
Args.push_back(Entry);
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(getCurSDLoc())
.setChain(DAG.getEntryNode())
.setCallee(Fn->getCallingConv(), FnTy->getReturnType(),
getValue(GuardCheck), std::move(Args));
std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI);
DAG.setRoot(Result.second);
return;
}
// If useLoadStackGuardNode returns true, generate LOAD_STACK_GUARD.
// Otherwise, emit a volatile load to retrieve the stack guard value.
SDValue Chain = DAG.getEntryNode();
if (TLI.useLoadStackGuardNode()) {
Guard = getLoadStackGuard(DAG, dl, Chain);
} else {
const Value *IRGuard = TLI.getSDagStackGuard(M);
SDValue GuardPtr = getValue(IRGuard);
Guard =
DAG.getLoad(PtrTy, dl, Chain, GuardPtr, MachinePointerInfo(IRGuard, 0),
Align, MachineMemOperand::MOVolatile);
}
// Perform the comparison via a subtract/getsetcc.
EVT VT = Guard.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, Guard, StackSlot);
SDValue Cmp = DAG.getSetCC(dl, TLI.getSetCCResultType(DAG.getDataLayout(),
*DAG.getContext(),
Sub.getValueType()),
Sub, DAG.getConstant(0, dl, VT), ISD::SETNE);
// If the sub is not 0, then we know the guard/stackslot do not equal, so
// branch to failure MBB.
SDValue BrCond = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, StackSlot.getOperand(0),
Cmp, DAG.getBasicBlock(SPD.getFailureMBB()));
// Otherwise branch to success MBB.
SDValue Br = DAG.getNode(ISD::BR, dl,
MVT::Other, BrCond,
DAG.getBasicBlock(SPD.getSuccessMBB()));
DAG.setRoot(Br);
}
/// Codegen the failure basic block for a stack protector check.
///
/// A failure stack protector machine basic block consists simply of a call to
/// __stack_chk_fail().
///
/// For a high level explanation of how this fits into the stack protector
/// generation see the comment on the declaration of class
/// StackProtectorDescriptor.
void
SelectionDAGBuilder::visitSPDescriptorFailure(StackProtectorDescriptor &SPD) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Chain =
TLI.makeLibCall(DAG, RTLIB::STACKPROTECTOR_CHECK_FAIL, MVT::isVoid,
None, false, getCurSDLoc(), false, false).second;
DAG.setRoot(Chain);
}
/// visitBitTestHeader - This function emits necessary code to produce value
/// suitable for "bit tests"
void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B,
MachineBasicBlock *SwitchBB) {
SDLoc dl = getCurSDLoc();
// Subtract the minimum value
SDValue SwitchOp = getValue(B.SValue);
EVT VT = SwitchOp.getValueType();
SDValue Sub = DAG.getNode(ISD::SUB, dl, VT, SwitchOp,
DAG.getConstant(B.First, dl, VT));
// Check range
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue RangeCmp = DAG.getSetCC(
dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(),
Sub.getValueType()),
Sub, DAG.getConstant(B.Range, dl, VT), ISD::SETUGT);
// Determine the type of the test operands.
bool UsePtrType = false;
if (!TLI.isTypeLegal(VT))
UsePtrType = true;
else {
for (unsigned i = 0, e = B.Cases.size(); i != e; ++i)
if (!isUIntN(VT.getSizeInBits(), B.Cases[i].Mask)) {
// Switch table case range are encoded into series of masks.
// Just use pointer type, it's guaranteed to fit.
UsePtrType = true;
break;
}
}
if (UsePtrType) {
VT = TLI.getPointerTy(DAG.getDataLayout());
Sub = DAG.getZExtOrTrunc(Sub, dl, VT);
}
B.RegVT = VT.getSimpleVT();
B.Reg = FuncInfo.CreateReg(B.RegVT);
SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), dl, B.Reg, Sub);
MachineBasicBlock* MBB = B.Cases[0].ThisBB;
addSuccessorWithProb(SwitchBB, B.Default, B.DefaultProb);
addSuccessorWithProb(SwitchBB, MBB, B.Prob);
SwitchBB->normalizeSuccProbs();
SDValue BrRange = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, CopyTo, RangeCmp,
DAG.getBasicBlock(B.Default));
// Avoid emitting unnecessary branches to the next block.
if (MBB != NextBlock(SwitchBB))
BrRange = DAG.getNode(ISD::BR, dl, MVT::Other, BrRange,
DAG.getBasicBlock(MBB));
DAG.setRoot(BrRange);
}
/// visitBitTestCase - this function produces one "bit test"
void SelectionDAGBuilder::visitBitTestCase(BitTestBlock &BB,
MachineBasicBlock* NextMBB,
BranchProbability BranchProbToNext,
unsigned Reg,
BitTestCase &B,
MachineBasicBlock *SwitchBB) {
SDLoc dl = getCurSDLoc();
MVT VT = BB.RegVT;
SDValue ShiftOp = DAG.getCopyFromReg(getControlRoot(), dl, Reg, VT);
SDValue Cmp;
unsigned PopCount = countPopulation(B.Mask);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (PopCount == 1) {
// Testing for a single bit; just compare the shift count with what it
// would need to be to shift a 1 bit in that position.
Cmp = DAG.getSetCC(
dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT),
ShiftOp, DAG.getConstant(countTrailingZeros(B.Mask), dl, VT),
ISD::SETEQ);
} else if (PopCount == BB.Range) {
// There is only one zero bit in the range, test for it directly.
Cmp = DAG.getSetCC(
dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT),
ShiftOp, DAG.getConstant(countTrailingOnes(B.Mask), dl, VT),
ISD::SETNE);
} else {
// Make desired shift
SDValue SwitchVal = DAG.getNode(ISD::SHL, dl, VT,
DAG.getConstant(1, dl, VT), ShiftOp);
// Emit bit tests and jumps
SDValue AndOp = DAG.getNode(ISD::AND, dl,
VT, SwitchVal, DAG.getConstant(B.Mask, dl, VT));
Cmp = DAG.getSetCC(
dl, TLI.getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT),
AndOp, DAG.getConstant(0, dl, VT), ISD::SETNE);
}
// The branch probability from SwitchBB to B.TargetBB is B.ExtraProb.
addSuccessorWithProb(SwitchBB, B.TargetBB, B.ExtraProb);
// The branch probability from SwitchBB to NextMBB is BranchProbToNext.
addSuccessorWithProb(SwitchBB, NextMBB, BranchProbToNext);
// It is not guaranteed that the sum of B.ExtraProb and BranchProbToNext is
// one as they are relative probabilities (and thus work more like weights),
// and hence we need to normalize them to let the sum of them become one.
SwitchBB->normalizeSuccProbs();
SDValue BrAnd = DAG.getNode(ISD::BRCOND, dl,
MVT::Other, getControlRoot(),
Cmp, DAG.getBasicBlock(B.TargetBB));
// Avoid emitting unnecessary branches to the next block.
if (NextMBB != NextBlock(SwitchBB))
BrAnd = DAG.getNode(ISD::BR, dl, MVT::Other, BrAnd,
DAG.getBasicBlock(NextMBB));
DAG.setRoot(BrAnd);
}
void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
MachineBasicBlock *InvokeMBB = FuncInfo.MBB;
// Retrieve successors. Look through artificial IR level blocks like
// catchswitch for successors.
MachineBasicBlock *Return = FuncInfo.MBBMap[I.getSuccessor(0)];
const BasicBlock *EHPadBB = I.getSuccessor(1);
// Deopt bundles are lowered in LowerCallSiteWithDeoptBundle, and we don't
// have to do anything here to lower funclet bundles.
assert(!I.hasOperandBundlesOtherThan(
{LLVMContext::OB_deopt, LLVMContext::OB_funclet}) &&
"Cannot lower invokes with arbitrary operand bundles yet!");
const Value *Callee(I.getCalledValue());
const Function *Fn = dyn_cast<Function>(Callee);
if (isa<InlineAsm>(Callee))
visitInlineAsm(&I);
else if (Fn && Fn->isIntrinsic()) {
switch (Fn->getIntrinsicID()) {
default:
llvm_unreachable("Cannot invoke this intrinsic");
case Intrinsic::donothing:
// Ignore invokes to @llvm.donothing: jump directly to the next BB.
break;
case Intrinsic::experimental_patchpoint_void:
case Intrinsic::experimental_patchpoint_i64:
visitPatchpoint(&I, EHPadBB);
break;
case Intrinsic::experimental_gc_statepoint:
LowerStatepoint(ImmutableStatepoint(&I), EHPadBB);
break;
}
} else if (I.countOperandBundlesOfType(LLVMContext::OB_deopt)) {
// Currently we do not lower any intrinsic calls with deopt operand bundles.
// Eventually we will support lowering the @llvm.experimental.deoptimize
// intrinsic, and right now there are no plans to support other intrinsics
// with deopt state.
LowerCallSiteWithDeoptBundle(&I, getValue(Callee), EHPadBB);
} else {
LowerCallTo(&I, getValue(Callee), false, EHPadBB);
}
// If the value of the invoke is used outside of its defining block, make it
// available as a virtual register.
// We already took care of the exported value for the statepoint instruction
// during call to the LowerStatepoint.
if (!isStatepoint(I)) {
CopyToExportRegsIfNeeded(&I);
}
SmallVector<std::pair<MachineBasicBlock *, BranchProbability>, 1> UnwindDests;
BranchProbabilityInfo *BPI = FuncInfo.BPI;
BranchProbability EHPadBBProb =
BPI ? BPI->getEdgeProbability(InvokeMBB->getBasicBlock(), EHPadBB)
: BranchProbability::getZero();
findUnwindDestinations(FuncInfo, EHPadBB, EHPadBBProb, UnwindDests);
// Update successor info.
addSuccessorWithProb(InvokeMBB, Return);
for (auto &UnwindDest : UnwindDests) {
UnwindDest.first->setIsEHPad();
addSuccessorWithProb(InvokeMBB, UnwindDest.first, UnwindDest.second);
}
InvokeMBB->normalizeSuccProbs();
// Drop into normal successor.
DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(),
MVT::Other, getControlRoot(),
DAG.getBasicBlock(Return)));
}
void SelectionDAGBuilder::visitResume(const ResumeInst &RI) {
llvm_unreachable("SelectionDAGBuilder shouldn't visit resume instructions!");
}
void SelectionDAGBuilder::visitLandingPad(const LandingPadInst &LP) {
assert(FuncInfo.MBB->isEHPad() &&
"Call to landingpad not in landing pad!");
MachineBasicBlock *MBB = FuncInfo.MBB;
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
AddLandingPadInfo(LP, MMI, MBB);
// If there aren't registers to copy the values into (e.g., during SjLj
// exceptions), then don't bother to create these DAG nodes.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
const Constant *PersonalityFn = FuncInfo.Fn->getPersonalityFn();
if (TLI.getExceptionPointerRegister(PersonalityFn) == 0 &&
TLI.getExceptionSelectorRegister(PersonalityFn) == 0)
return;
// If landingpad's return type is token type, we don't create DAG nodes
// for its exception pointer and selector value. The extraction of exception
// pointer or selector value from token type landingpads is not currently
// supported.
if (LP.getType()->isTokenTy())
return;
SmallVector<EVT, 2> ValueVTs;
SDLoc dl = getCurSDLoc();
ComputeValueVTs(TLI, DAG.getDataLayout(), LP.getType(), ValueVTs);
assert(ValueVTs.size() == 2 && "Only two-valued landingpads are supported");
// Get the two live-in registers as SDValues. The physregs have already been
// copied into virtual registers.
SDValue Ops[2];
if (FuncInfo.ExceptionPointerVirtReg) {
Ops[0] = DAG.getZExtOrTrunc(
DAG.getCopyFromReg(DAG.getEntryNode(), dl,
FuncInfo.ExceptionPointerVirtReg,
TLI.getPointerTy(DAG.getDataLayout())),
dl, ValueVTs[0]);
} else {
Ops[0] = DAG.getConstant(0, dl, TLI.getPointerTy(DAG.getDataLayout()));
}
Ops[1] = DAG.getZExtOrTrunc(
DAG.getCopyFromReg(DAG.getEntryNode(), dl,
FuncInfo.ExceptionSelectorVirtReg,
TLI.getPointerTy(DAG.getDataLayout())),
dl, ValueVTs[1]);
// Merge into one.
SDValue Res = DAG.getNode(ISD::MERGE_VALUES, dl,
DAG.getVTList(ValueVTs), Ops);
setValue(&LP, Res);
}
void SelectionDAGBuilder::sortAndRangeify(CaseClusterVector &Clusters) {
#ifndef NDEBUG
for (const CaseCluster &CC : Clusters)
assert(CC.Low == CC.High && "Input clusters must be single-case");
#endif
std::sort(Clusters.begin(), Clusters.end(),
[](const CaseCluster &a, const CaseCluster &b) {
return a.Low->getValue().slt(b.Low->getValue());
});
// Merge adjacent clusters with the same destination.
const unsigned N = Clusters.size();
unsigned DstIndex = 0;
for (unsigned SrcIndex = 0; SrcIndex < N; ++SrcIndex) {
CaseCluster &CC = Clusters[SrcIndex];
const ConstantInt *CaseVal = CC.Low;
MachineBasicBlock *Succ = CC.MBB;
if (DstIndex != 0 && Clusters[DstIndex - 1].MBB == Succ &&
(CaseVal->getValue() - Clusters[DstIndex - 1].High->getValue()) == 1) {
// If this case has the same successor and is a neighbour, merge it into
// the previous cluster.
Clusters[DstIndex - 1].High = CaseVal;
Clusters[DstIndex - 1].Prob += CC.Prob;
} else {
std::memmove(&Clusters[DstIndex++], &Clusters[SrcIndex],
sizeof(Clusters[SrcIndex]));
}
}
Clusters.resize(DstIndex);
}
void SelectionDAGBuilder::UpdateSplitBlock(MachineBasicBlock *First,
MachineBasicBlock *Last) {
// Update JTCases.
for (unsigned i = 0, e = JTCases.size(); i != e; ++i)
if (JTCases[i].first.HeaderBB == First)
JTCases[i].first.HeaderBB = Last;
// Update BitTestCases.
for (unsigned i = 0, e = BitTestCases.size(); i != e; ++i)
if (BitTestCases[i].Parent == First)
BitTestCases[i].Parent = Last;
}
void SelectionDAGBuilder::visitIndirectBr(const IndirectBrInst &I) {
MachineBasicBlock *IndirectBrMBB = FuncInfo.MBB;
// Update machine-CFG edges with unique successors.
SmallSet<BasicBlock*, 32> Done;
for (unsigned i = 0, e = I.getNumSuccessors(); i != e; ++i) {
BasicBlock *BB = I.getSuccessor(i);
bool Inserted = Done.insert(BB).second;
if (!Inserted)
continue;
MachineBasicBlock *Succ = FuncInfo.MBBMap[BB];
addSuccessorWithProb(IndirectBrMBB, Succ);
}
IndirectBrMBB->normalizeSuccProbs();
DAG.setRoot(DAG.getNode(ISD::BRIND, getCurSDLoc(),
MVT::Other, getControlRoot(),
getValue(I.getAddress())));
}
void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {
if (DAG.getTarget().Options.TrapUnreachable)
DAG.setRoot(
DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot()));
}
void SelectionDAGBuilder::visitFSub(const User &I) {
// -0.0 - X --> fneg
Type *Ty = I.getType();
if (isa<Constant>(I.getOperand(0)) &&
I.getOperand(0) == ConstantFP::getZeroValueForNegation(Ty)) {
SDValue Op2 = getValue(I.getOperand(1));
setValue(&I, DAG.getNode(ISD::FNEG, getCurSDLoc(),
Op2.getValueType(), Op2));
return;
}
visitBinary(I, ISD::FSUB);
}
/// Checks if the given instruction performs a vector reduction, in which case
/// we have the freedom to alter the elements in the result as long as the
/// reduction of them stays unchanged.
static bool isVectorReductionOp(const User *I) {
const Instruction *Inst = dyn_cast<Instruction>(I);
if (!Inst || !Inst->getType()->isVectorTy())
return false;
auto OpCode = Inst->getOpcode();
switch (OpCode) {
case Instruction::Add:
case Instruction::Mul:
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
break;
case Instruction::FAdd:
case Instruction::FMul:
if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(Inst))
if (FPOp->getFastMathFlags().unsafeAlgebra())
break;
LLVM_FALLTHROUGH;
default:
return false;
}
unsigned ElemNum = Inst->getType()->getVectorNumElements();
unsigned ElemNumToReduce = ElemNum;
// Do DFS search on the def-use chain from the given instruction. We only
// allow four kinds of operations during the search until we reach the
// instruction that extracts the first element from the vector:
//
// 1. The reduction operation of the same opcode as the given instruction.
//
// 2. PHI node.
//
// 3. ShuffleVector instruction together with a reduction operation that
// does a partial reduction.
//
// 4. ExtractElement that extracts the first element from the vector, and we
// stop searching the def-use chain here.
//
// 3 & 4 above perform a reduction on all elements of the vector. We push defs
// from 1-3 to the stack to continue the DFS. The given instruction is not
// a reduction operation if we meet any other instructions other than those
// listed above.
SmallVector<const User *, 16> UsersToVisit{Inst};
SmallPtrSet<const User *, 16> Visited;
bool ReduxExtracted = false;
while (!UsersToVisit.empty()) {
auto User = UsersToVisit.back();
UsersToVisit.pop_back();
if (!Visited.insert(User).second)
continue;
for (const auto &U : User->users()) {
auto Inst = dyn_cast<Instruction>(U);
if (!Inst)
return false;
if (Inst->getOpcode() == OpCode || isa<PHINode>(U)) {
if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(Inst))
if (!isa<PHINode>(FPOp) && !FPOp->getFastMathFlags().unsafeAlgebra())
return false;
UsersToVisit.push_back(U);
} else if (const ShuffleVectorInst *ShufInst =
dyn_cast<ShuffleVectorInst>(U)) {
// Detect the following pattern: A ShuffleVector instruction together
// with a reduction that do partial reduction on the first and second
// ElemNumToReduce / 2 elements, and store the result in
// ElemNumToReduce / 2 elements in another vector.
unsigned ResultElements = ShufInst->getType()->getVectorNumElements();
if (ResultElements < ElemNum)
return false;
if (ElemNumToReduce == 1)
return false;
if (!isa<UndefValue>(U->getOperand(1)))
return false;
for (unsigned i = 0; i < ElemNumToReduce / 2; ++i)
if (ShufInst->getMaskValue(i) != int(i + ElemNumToReduce / 2))
return false;
for (unsigned i = ElemNumToReduce / 2; i < ElemNum; ++i)
if (ShufInst->getMaskValue(i) != -1)
return false;
// There is only one user of this ShuffleVector instruction, which
// must be a reduction operation.
if (!U->hasOneUse())
return false;
auto U2 = dyn_cast<Instruction>(*U->user_begin());
if (!U2 || U2->getOpcode() != OpCode)
return false;
// Check operands of the reduction operation.
if ((U2->getOperand(0) == U->getOperand(0) && U2->getOperand(1) == U) ||
(U2->getOperand(1) == U->getOperand(0) && U2->getOperand(0) == U)) {
UsersToVisit.push_back(U2);
ElemNumToReduce /= 2;
} else
return false;
} else if (isa<ExtractElementInst>(U)) {
// At this moment we should have reduced all elements in the vector.
if (ElemNumToReduce != 1)
return false;
const ConstantInt *Val = dyn_cast<ConstantInt>(U->getOperand(1));
if (!Val || Val->getZExtValue() != 0)
return false;
ReduxExtracted = true;
} else
return false;
}
}
return ReduxExtracted;
}
void SelectionDAGBuilder::visitBinary(const User &I, unsigned OpCode) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
bool nuw = false;
bool nsw = false;
bool exact = false;
bool vec_redux = false;
FastMathFlags FMF;
if (const OverflowingBinaryOperator *OFBinOp =
dyn_cast<const OverflowingBinaryOperator>(&I)) {
nuw = OFBinOp->hasNoUnsignedWrap();
nsw = OFBinOp->hasNoSignedWrap();
}
if (const PossiblyExactOperator *ExactOp =
dyn_cast<const PossiblyExactOperator>(&I))
exact = ExactOp->isExact();
if (const FPMathOperator *FPOp = dyn_cast<const FPMathOperator>(&I))
FMF = FPOp->getFastMathFlags();
if (isVectorReductionOp(&I)) {
vec_redux = true;
DEBUG(dbgs() << "Detected a reduction operation:" << I << "\n");
}
SDNodeFlags Flags;
Flags.setExact(exact);
Flags.setNoSignedWrap(nsw);
Flags.setNoUnsignedWrap(nuw);
Flags.setVectorReduction(vec_redux);
if (EnableFMFInDAG) {
Flags.setAllowReciprocal(FMF.allowReciprocal());
Flags.setNoInfs(FMF.noInfs());
Flags.setNoNaNs(FMF.noNaNs());
Flags.setNoSignedZeros(FMF.noSignedZeros());
Flags.setUnsafeAlgebra(FMF.unsafeAlgebra());
}
SDValue BinNodeValue = DAG.getNode(OpCode, getCurSDLoc(), Op1.getValueType(),
Op1, Op2, &Flags);
setValue(&I, BinNodeValue);
}
void SelectionDAGBuilder::visitShift(const User &I, unsigned Opcode) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
EVT ShiftTy = DAG.getTargetLoweringInfo().getShiftAmountTy(
Op2.getValueType(), DAG.getDataLayout());
// Coerce the shift amount to the right type if we can.
if (!I.getType()->isVectorTy() && Op2.getValueType() != ShiftTy) {
unsigned ShiftSize = ShiftTy.getSizeInBits();
unsigned Op2Size = Op2.getValueSizeInBits();
SDLoc DL = getCurSDLoc();
// If the operand is smaller than the shift count type, promote it.
if (ShiftSize > Op2Size)
Op2 = DAG.getNode(ISD::ZERO_EXTEND, DL, ShiftTy, Op2);
// If the operand is larger than the shift count type but the shift
// count type has enough bits to represent any shift value, truncate
// it now. This is a common case and it exposes the truncate to
// optimization early.
else if (ShiftSize >= Log2_32_Ceil(Op2.getValueSizeInBits()))
Op2 = DAG.getNode(ISD::TRUNCATE, DL, ShiftTy, Op2);
// Otherwise we'll need to temporarily settle for some other convenient
// type. Type legalization will make adjustments once the shiftee is split.
else
Op2 = DAG.getZExtOrTrunc(Op2, DL, MVT::i32);
}
bool nuw = false;
bool nsw = false;
bool exact = false;
if (Opcode == ISD::SRL || Opcode == ISD::SRA || Opcode == ISD::SHL) {
if (const OverflowingBinaryOperator *OFBinOp =
dyn_cast<const OverflowingBinaryOperator>(&I)) {
nuw = OFBinOp->hasNoUnsignedWrap();
nsw = OFBinOp->hasNoSignedWrap();
}
if (const PossiblyExactOperator *ExactOp =
dyn_cast<const PossiblyExactOperator>(&I))
exact = ExactOp->isExact();
}
SDNodeFlags Flags;
Flags.setExact(exact);
Flags.setNoSignedWrap(nsw);
Flags.setNoUnsignedWrap(nuw);
SDValue Res = DAG.getNode(Opcode, getCurSDLoc(), Op1.getValueType(), Op1, Op2,
&Flags);
setValue(&I, Res);
}
void SelectionDAGBuilder::visitSDiv(const User &I) {
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
SDNodeFlags Flags;
Flags.setExact(isa<PossiblyExactOperator>(&I) &&
cast<PossiblyExactOperator>(&I)->isExact());
setValue(&I, DAG.getNode(ISD::SDIV, getCurSDLoc(), Op1.getValueType(), Op1,
Op2, &Flags));
}
void SelectionDAGBuilder::visitICmp(const User &I) {
ICmpInst::Predicate predicate = ICmpInst::BAD_ICMP_PREDICATE;
if (const ICmpInst *IC = dyn_cast<ICmpInst>(&I))
predicate = IC->getPredicate();
else if (const ConstantExpr *IC = dyn_cast<ConstantExpr>(&I))
predicate = ICmpInst::Predicate(IC->getPredicate());
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
ISD::CondCode Opcode = getICmpCondCode(predicate);
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Opcode));
}
void SelectionDAGBuilder::visitFCmp(const User &I) {
FCmpInst::Predicate predicate = FCmpInst::BAD_FCMP_PREDICATE;
if (const FCmpInst *FC = dyn_cast<FCmpInst>(&I))
predicate = FC->getPredicate();
else if (const ConstantExpr *FC = dyn_cast<ConstantExpr>(&I))
predicate = FCmpInst::Predicate(FC->getPredicate());
SDValue Op1 = getValue(I.getOperand(0));
SDValue Op2 = getValue(I.getOperand(1));
ISD::CondCode Condition = getFCmpCondCode(predicate);
// FIXME: Fcmp instructions have fast-math-flags in IR, so we should use them.
// FIXME: We should propagate the fast-math-flags to the DAG node itself for
// further optimization, but currently FMF is only applicable to binary nodes.
if (TM.Options.NoNaNsFPMath)
Condition = getFCmpCodeWithoutNaN(Condition);
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getSetCC(getCurSDLoc(), DestVT, Op1, Op2, Condition));
}
// Check if the condition of the select has one use or two users that are both
// selects with the same condition.
static bool hasOnlySelectUsers(const Value *Cond) {
return all_of(Cond->users(), [](const Value *V) {
return isa<SelectInst>(V);
});
}
void SelectionDAGBuilder::visitSelect(const User &I) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), I.getType(),
ValueVTs);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0) return;
SmallVector<SDValue, 4> Values(NumValues);
SDValue Cond = getValue(I.getOperand(0));
SDValue LHSVal = getValue(I.getOperand(1));
SDValue RHSVal = getValue(I.getOperand(2));
auto BaseOps = {Cond};
ISD::NodeType OpCode = Cond.getValueType().isVector() ?
ISD::VSELECT : ISD::SELECT;
// Min/max matching is only viable if all output VTs are the same.
if (std::equal(ValueVTs.begin(), ValueVTs.end(), ValueVTs.begin())) {
EVT VT = ValueVTs[0];
LLVMContext &Ctx = *DAG.getContext();
auto &TLI = DAG.getTargetLoweringInfo();
// We care about the legality of the operation after it has been type
// legalized.
while (TLI.getTypeAction(Ctx, VT) != TargetLoweringBase::TypeLegal &&
VT != TLI.getTypeToTransformTo(Ctx, VT))
VT = TLI.getTypeToTransformTo(Ctx, VT);
// If the vselect is legal, assume we want to leave this as a vector setcc +
// vselect. Otherwise, if this is going to be scalarized, we want to see if
// min/max is legal on the scalar type.
bool UseScalarMinMax = VT.isVector() &&
!TLI.isOperationLegalOrCustom(ISD::VSELECT, VT);
Value *LHS, *RHS;
auto SPR = matchSelectPattern(const_cast<User*>(&I), LHS, RHS);
ISD::NodeType Opc = ISD::DELETED_NODE;
switch (SPR.Flavor) {
case SPF_UMAX: Opc = ISD::UMAX; break;
case SPF_UMIN: Opc = ISD::UMIN; break;
case SPF_SMAX: Opc = ISD::SMAX; break;
case SPF_SMIN: Opc = ISD::SMIN; break;
case SPF_FMINNUM:
switch (SPR.NaNBehavior) {
case SPNB_NA: llvm_unreachable("No NaN behavior for FP op?");
case SPNB_RETURNS_NAN: Opc = ISD::FMINNAN; break;
case SPNB_RETURNS_OTHER: Opc = ISD::FMINNUM; break;
case SPNB_RETURNS_ANY: {
if (TLI.isOperationLegalOrCustom(ISD::FMINNUM, VT))
Opc = ISD::FMINNUM;
else if (TLI.isOperationLegalOrCustom(ISD::FMINNAN, VT))
Opc = ISD::FMINNAN;
else if (UseScalarMinMax)
Opc = TLI.isOperationLegalOrCustom(ISD::FMINNUM, VT.getScalarType()) ?
ISD::FMINNUM : ISD::FMINNAN;
break;
}
}
break;
case SPF_FMAXNUM:
switch (SPR.NaNBehavior) {
case SPNB_NA: llvm_unreachable("No NaN behavior for FP op?");
case SPNB_RETURNS_NAN: Opc = ISD::FMAXNAN; break;
case SPNB_RETURNS_OTHER: Opc = ISD::FMAXNUM; break;
case SPNB_RETURNS_ANY:
if (TLI.isOperationLegalOrCustom(ISD::FMAXNUM, VT))
Opc = ISD::FMAXNUM;
else if (TLI.isOperationLegalOrCustom(ISD::FMAXNAN, VT))
Opc = ISD::FMAXNAN;
else if (UseScalarMinMax)
Opc = TLI.isOperationLegalOrCustom(ISD::FMAXNUM, VT.getScalarType()) ?
ISD::FMAXNUM : ISD::FMAXNAN;
break;
}
break;
default: break;
}
if (Opc != ISD::DELETED_NODE &&
(TLI.isOperationLegalOrCustom(Opc, VT) ||
(UseScalarMinMax &&
TLI.isOperationLegalOrCustom(Opc, VT.getScalarType()))) &&
// If the underlying comparison instruction is used by any other
// instruction, the consumed instructions won't be destroyed, so it is
// not profitable to convert to a min/max.
hasOnlySelectUsers(cast<SelectInst>(I).getCondition())) {
OpCode = Opc;
LHSVal = getValue(LHS);
RHSVal = getValue(RHS);
BaseOps = {};
}
}
for (unsigned i = 0; i != NumValues; ++i) {
SmallVector<SDValue, 3> Ops(BaseOps.begin(), BaseOps.end());
Ops.push_back(SDValue(LHSVal.getNode(), LHSVal.getResNo() + i));
Ops.push_back(SDValue(RHSVal.getNode(), RHSVal.getResNo() + i));
Values[i] = DAG.getNode(OpCode, getCurSDLoc(),
LHSVal.getNode()->getValueType(LHSVal.getResNo()+i),
Ops);
}
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(),
DAG.getVTList(ValueVTs), Values));
}
void SelectionDAGBuilder::visitTrunc(const User &I) {
// TruncInst cannot be a no-op cast because sizeof(src) > sizeof(dest).
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitZExt(const User &I) {
// ZExt cannot be a no-op cast because sizeof(src) < sizeof(dest).
// ZExt also can't be a cast to bool for same reason. So, nothing much to do
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::ZERO_EXTEND, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitSExt(const User &I) {
// SExt cannot be a no-op cast because sizeof(src) < sizeof(dest).
// SExt also can't be a cast to bool for same reason. So, nothing much to do
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::SIGN_EXTEND, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPTrunc(const User &I) {
// FPTrunc is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
SDLoc dl = getCurSDLoc();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType());
setValue(&I, DAG.getNode(ISD::FP_ROUND, dl, DestVT, N,
DAG.getTargetConstant(
0, dl, TLI.getPointerTy(DAG.getDataLayout()))));
}
void SelectionDAGBuilder::visitFPExt(const User &I) {
// FPExt is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::FP_EXTEND, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPToUI(const User &I) {
// FPToUI is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::FP_TO_UINT, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitFPToSI(const User &I) {
// FPToSI is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::FP_TO_SINT, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitUIToFP(const User &I) {
// UIToFP is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::UINT_TO_FP, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitSIToFP(const User &I) {
// SIToFP is never a no-op cast, no need to check
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getNode(ISD::SINT_TO_FP, getCurSDLoc(), DestVT, N));
}
void SelectionDAGBuilder::visitPtrToInt(const User &I) {
// What to do depends on the size of the integer and the size of the pointer.
// We can either truncate, zero extend, or no-op, accordingly.
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT));
}
void SelectionDAGBuilder::visitIntToPtr(const User &I) {
// What to do depends on the size of the integer and the size of the pointer.
// We can either truncate, zero extend, or no-op, accordingly.
SDValue N = getValue(I.getOperand(0));
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
setValue(&I, DAG.getZExtOrTrunc(N, getCurSDLoc(), DestVT));
}
void SelectionDAGBuilder::visitBitCast(const User &I) {
SDValue N = getValue(I.getOperand(0));
SDLoc dl = getCurSDLoc();
EVT DestVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType());
// BitCast assures us that source and destination are the same size so this is
// either a BITCAST or a no-op.
if (DestVT != N.getValueType())
setValue(&I, DAG.getNode(ISD::BITCAST, dl,
DestVT, N)); // convert types.
// Check if the original LLVM IR Operand was a ConstantInt, because getValue()
// might fold any kind of constant expression to an integer constant and that
// is not what we are looking for. Only regcognize a bitcast of a genuine
// constant integer as an opaque constant.
else if(ConstantInt *C = dyn_cast<ConstantInt>(I.getOperand(0)))
setValue(&I, DAG.getConstant(C->getValue(), dl, DestVT, /*isTarget=*/false,
/*isOpaque*/true));
else
setValue(&I, N); // noop cast.
}
void SelectionDAGBuilder::visitAddrSpaceCast(const User &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
const Value *SV = I.getOperand(0);
SDValue N = getValue(SV);
EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType());
unsigned SrcAS = SV->getType()->getPointerAddressSpace();
unsigned DestAS = I.getType()->getPointerAddressSpace();
if (!TLI.isNoopAddrSpaceCast(SrcAS, DestAS))
N = DAG.getAddrSpaceCast(getCurSDLoc(), DestVT, N, SrcAS, DestAS);
setValue(&I, N);
}
void SelectionDAGBuilder::visitInsertElement(const User &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue InVec = getValue(I.getOperand(0));
SDValue InVal = getValue(I.getOperand(1));
SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(2)), getCurSDLoc(),
TLI.getVectorIdxTy(DAG.getDataLayout()));
setValue(&I, DAG.getNode(ISD::INSERT_VECTOR_ELT, getCurSDLoc(),
TLI.getValueType(DAG.getDataLayout(), I.getType()),
InVec, InVal, InIdx));
}
void SelectionDAGBuilder::visitExtractElement(const User &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue InVec = getValue(I.getOperand(0));
SDValue InIdx = DAG.getSExtOrTrunc(getValue(I.getOperand(1)), getCurSDLoc(),
TLI.getVectorIdxTy(DAG.getDataLayout()));
setValue(&I, DAG.getNode(ISD::EXTRACT_VECTOR_ELT, getCurSDLoc(),
TLI.getValueType(DAG.getDataLayout(), I.getType()),
InVec, InIdx));
}
void SelectionDAGBuilder::visitShuffleVector(const User &I) {
SDValue Src1 = getValue(I.getOperand(0));
SDValue Src2 = getValue(I.getOperand(1));
SDLoc DL = getCurSDLoc();
SmallVector<int, 8> Mask;
ShuffleVectorInst::getShuffleMask(cast<Constant>(I.getOperand(2)), Mask);
unsigned MaskNumElts = Mask.size();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType());
EVT SrcVT = Src1.getValueType();
unsigned SrcNumElts = SrcVT.getVectorNumElements();
if (SrcNumElts == MaskNumElts) {
setValue(&I, DAG.getVectorShuffle(VT, DL, Src1, Src2, Mask));
return;
}
// Normalize the shuffle vector since mask and vector length don't match.
if (SrcNumElts < MaskNumElts) {
// Mask is longer than the source vectors. We can use concatenate vector to
// make the mask and vectors lengths match.
if (MaskNumElts % SrcNumElts == 0) {
// Mask length is a multiple of the source vector length.
// Check if the shuffle is some kind of concatenation of the input
// vectors.
unsigned NumConcat = MaskNumElts / SrcNumElts;
bool IsConcat = true;
SmallVector<int, 8> ConcatSrcs(NumConcat, -1);
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
if (Idx < 0)
continue;
// Ensure the indices in each SrcVT sized piece are sequential and that
// the same source is used for the whole piece.
if ((Idx % SrcNumElts != (i % SrcNumElts)) ||
(ConcatSrcs[i / SrcNumElts] >= 0 &&
ConcatSrcs[i / SrcNumElts] != (int)(Idx / SrcNumElts))) {
IsConcat = false;
break;
}
// Remember which source this index came from.
ConcatSrcs[i / SrcNumElts] = Idx / SrcNumElts;
}
// The shuffle is concatenating multiple vectors together. Just emit
// a CONCAT_VECTORS operation.
if (IsConcat) {
SmallVector<SDValue, 8> ConcatOps;
for (auto Src : ConcatSrcs) {
if (Src < 0)
ConcatOps.push_back(DAG.getUNDEF(SrcVT));
else if (Src == 0)
ConcatOps.push_back(Src1);
else
ConcatOps.push_back(Src2);
}
setValue(&I, DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, ConcatOps));
return;
}
}
unsigned PaddedMaskNumElts = alignTo(MaskNumElts, SrcNumElts);
unsigned NumConcat = PaddedMaskNumElts / SrcNumElts;
EVT PaddedVT = EVT::getVectorVT(*DAG.getContext(), VT.getScalarType(),
PaddedMaskNumElts);
// Pad both vectors with undefs to make them the same length as the mask.
SDValue UndefVal = DAG.getUNDEF(SrcVT);
SmallVector<SDValue, 8> MOps1(NumConcat, UndefVal);
SmallVector<SDValue, 8> MOps2(NumConcat, UndefVal);
MOps1[0] = Src1;
MOps2[0] = Src2;
Src1 = Src1.isUndef()
? DAG.getUNDEF(PaddedVT)
: DAG.getNode(ISD::CONCAT_VECTORS, DL, PaddedVT, MOps1);
Src2 = Src2.isUndef()
? DAG.getUNDEF(PaddedVT)
: DAG.getNode(ISD::CONCAT_VECTORS, DL, PaddedVT, MOps2);
// Readjust mask for new input vector length.
SmallVector<int, 8> MappedOps(PaddedMaskNumElts, -1);
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
if (Idx >= (int)SrcNumElts)
Idx -= SrcNumElts - PaddedMaskNumElts;
MappedOps[i] = Idx;
}
SDValue Result = DAG.getVectorShuffle(PaddedVT, DL, Src1, Src2, MappedOps);
// If the concatenated vector was padded, extract a subvector with the
// correct number of elements.
if (MaskNumElts != PaddedMaskNumElts)
Result = DAG.getNode(
ISD::EXTRACT_SUBVECTOR, DL, VT, Result,
DAG.getConstant(0, DL, TLI.getVectorIdxTy(DAG.getDataLayout())));
setValue(&I, Result);
return;
}
if (SrcNumElts > MaskNumElts) {
// Analyze the access pattern of the vector to see if we can extract
// two subvectors and do the shuffle. The analysis is done by calculating
// the range of elements the mask access on both vectors.
int MinRange[2] = { static_cast<int>(SrcNumElts),
static_cast<int>(SrcNumElts)};
int MaxRange[2] = {-1, -1};
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
unsigned Input = 0;
if (Idx < 0)
continue;
if (Idx >= (int)SrcNumElts) {
Input = 1;
Idx -= SrcNumElts;
}
if (Idx > MaxRange[Input])
MaxRange[Input] = Idx;
if (Idx < MinRange[Input])
MinRange[Input] = Idx;
}
// Check if the access is smaller than the vector size and can we find
// a reasonable extract index.
int RangeUse[2] = { -1, -1 }; // 0 = Unused, 1 = Extract, -1 = Can not
// Extract.
int StartIdx[2]; // StartIdx to extract from
for (unsigned Input = 0; Input < 2; ++Input) {
if (MinRange[Input] >= (int)SrcNumElts && MaxRange[Input] < 0) {
RangeUse[Input] = 0; // Unused
StartIdx[Input] = 0;
continue;
}
// Find a good start index that is a multiple of the mask length. Then
// see if the rest of the elements are in range.
StartIdx[Input] = (MinRange[Input]/MaskNumElts)*MaskNumElts;
if (MaxRange[Input] - StartIdx[Input] < (int)MaskNumElts &&
StartIdx[Input] + MaskNumElts <= SrcNumElts)
RangeUse[Input] = 1; // Extract from a multiple of the mask length.
}
if (RangeUse[0] == 0 && RangeUse[1] == 0) {
setValue(&I, DAG.getUNDEF(VT)); // Vectors are not used.
return;
}
if (RangeUse[0] >= 0 && RangeUse[1] >= 0) {
// Extract appropriate subvector and generate a vector shuffle
for (unsigned Input = 0; Input < 2; ++Input) {
SDValue &Src = Input == 0 ? Src1 : Src2;
if (RangeUse[Input] == 0)
Src = DAG.getUNDEF(VT);
else {
Src = DAG.getNode(
ISD::EXTRACT_SUBVECTOR, DL, VT, Src,
DAG.getConstant(StartIdx[Input], DL,
TLI.getVectorIdxTy(DAG.getDataLayout())));
}
}
// Calculate new mask.
SmallVector<int, 8> MappedOps;
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
if (Idx >= 0) {
if (Idx < (int)SrcNumElts)
Idx -= StartIdx[0];
else
Idx -= SrcNumElts + StartIdx[1] - MaskNumElts;
}
MappedOps.push_back(Idx);
}
setValue(&I, DAG.getVectorShuffle(VT, DL, Src1, Src2, MappedOps));
return;
}
}
// We can't use either concat vectors or extract subvectors so fall back to
// replacing the shuffle with extract and build vector.
// to insert and build vector.
EVT EltVT = VT.getVectorElementType();
EVT IdxVT = TLI.getVectorIdxTy(DAG.getDataLayout());
SmallVector<SDValue,8> Ops;
for (unsigned i = 0; i != MaskNumElts; ++i) {
int Idx = Mask[i];
SDValue Res;
if (Idx < 0) {
Res = DAG.getUNDEF(EltVT);
} else {
SDValue &Src = Idx < (int)SrcNumElts ? Src1 : Src2;
if (Idx >= (int)SrcNumElts) Idx -= SrcNumElts;
Res = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, DL,
EltVT, Src, DAG.getConstant(Idx, DL, IdxVT));
}
Ops.push_back(Res);
}
setValue(&I, DAG.getNode(ISD::BUILD_VECTOR, DL, VT, Ops));
}
void SelectionDAGBuilder::visitInsertValue(const InsertValueInst &I) {
const Value *Op0 = I.getOperand(0);
const Value *Op1 = I.getOperand(1);
Type *AggTy = I.getType();
Type *ValTy = Op1->getType();
bool IntoUndef = isa<UndefValue>(Op0);
bool FromUndef = isa<UndefValue>(Op1);
unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices());
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SmallVector<EVT, 4> AggValueVTs;
ComputeValueVTs(TLI, DAG.getDataLayout(), AggTy, AggValueVTs);
SmallVector<EVT, 4> ValValueVTs;
ComputeValueVTs(TLI, DAG.getDataLayout(), ValTy, ValValueVTs);
unsigned NumAggValues = AggValueVTs.size();
unsigned NumValValues = ValValueVTs.size();
SmallVector<SDValue, 4> Values(NumAggValues);
// Ignore an insertvalue that produces an empty object
if (!NumAggValues) {
setValue(&I, DAG.getUNDEF(MVT(MVT::Other)));
return;
}
SDValue Agg = getValue(Op0);
unsigned i = 0;
// Copy the beginning value(s) from the original aggregate.
for (; i != LinearIndex; ++i)
Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
// Copy values from the inserted value(s).
if (NumValValues) {
SDValue Val = getValue(Op1);
for (; i != LinearIndex + NumValValues; ++i)
Values[i] = FromUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Val.getNode(), Val.getResNo() + i - LinearIndex);
}
// Copy remaining value(s) from the original aggregate.
for (; i != NumAggValues; ++i)
Values[i] = IntoUndef ? DAG.getUNDEF(AggValueVTs[i]) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(),
DAG.getVTList(AggValueVTs), Values));
}
void SelectionDAGBuilder::visitExtractValue(const ExtractValueInst &I) {
const Value *Op0 = I.getOperand(0);
Type *AggTy = Op0->getType();
Type *ValTy = I.getType();
bool OutOfUndef = isa<UndefValue>(Op0);
unsigned LinearIndex = ComputeLinearIndex(AggTy, I.getIndices());
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SmallVector<EVT, 4> ValValueVTs;
ComputeValueVTs(TLI, DAG.getDataLayout(), ValTy, ValValueVTs);
unsigned NumValValues = ValValueVTs.size();
// Ignore a extractvalue that produces an empty object
if (!NumValValues) {
setValue(&I, DAG.getUNDEF(MVT(MVT::Other)));
return;
}
SmallVector<SDValue, 4> Values(NumValValues);
SDValue Agg = getValue(Op0);
// Copy out the selected value(s).
for (unsigned i = LinearIndex; i != LinearIndex + NumValValues; ++i)
Values[i - LinearIndex] =
OutOfUndef ?
DAG.getUNDEF(Agg.getNode()->getValueType(Agg.getResNo() + i)) :
SDValue(Agg.getNode(), Agg.getResNo() + i);
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, getCurSDLoc(),
DAG.getVTList(ValValueVTs), Values));
}
void SelectionDAGBuilder::visitGetElementPtr(const User &I) {
Value *Op0 = I.getOperand(0);
// Note that the pointer operand may be a vector of pointers. Take the scalar
// element which holds a pointer.
unsigned AS = Op0->getType()->getScalarType()->getPointerAddressSpace();
SDValue N = getValue(Op0);
SDLoc dl = getCurSDLoc();
// Normalize Vector GEP - all scalar operands should be converted to the
// splat vector.
unsigned VectorWidth = I.getType()->isVectorTy() ?
cast<VectorType>(I.getType())->getVectorNumElements() : 0;
if (VectorWidth && !N.getValueType().isVector()) {
LLVMContext &Context = *DAG.getContext();
EVT VT = EVT::getVectorVT(Context, N.getValueType(), VectorWidth);
SmallVector<SDValue, 16> Ops(VectorWidth, N);
N = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
}
for (gep_type_iterator GTI = gep_type_begin(&I), E = gep_type_end(&I);
GTI != E; ++GTI) {
const Value *Idx = GTI.getOperand();
if (StructType *StTy = dyn_cast<StructType>(*GTI)) {
unsigned Field = cast<Constant>(Idx)->getUniqueInteger().getZExtValue();
if (Field) {
// N = N + Offset
uint64_t Offset = DL->getStructLayout(StTy)->getElementOffset(Field);
// In an inbouds GEP with an offset that is nonnegative even when
// interpreted as signed, assume there is no unsigned overflow.
SDNodeFlags Flags;
if (int64_t(Offset) >= 0 && cast<GEPOperator>(I).isInBounds())
Flags.setNoUnsignedWrap(true);
N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N,
DAG.getConstant(Offset, dl, N.getValueType()), &Flags);
}
} else {
MVT PtrTy =
DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout(), AS);
unsigned PtrSize = PtrTy.getSizeInBits();
APInt ElementSize(PtrSize, DL->getTypeAllocSize(GTI.getIndexedType()));
// If this is a scalar constant or a splat vector of constants,
// handle it quickly.
const auto *CI = dyn_cast<ConstantInt>(Idx);
if (!CI && isa<ConstantDataVector>(Idx) &&
cast<ConstantDataVector>(Idx)->getSplatValue())
CI = cast<ConstantInt>(cast<ConstantDataVector>(Idx)->getSplatValue());
if (CI) {
if (CI->isZero())
continue;
APInt Offs = ElementSize * CI->getValue().sextOrTrunc(PtrSize);
LLVMContext &Context = *DAG.getContext();
SDValue OffsVal = VectorWidth ?
DAG.getConstant(Offs, dl, EVT::getVectorVT(Context, PtrTy, VectorWidth)) :
DAG.getConstant(Offs, dl, PtrTy);
// In an inbouds GEP with an offset that is nonnegative even when
// interpreted as signed, assume there is no unsigned overflow.
SDNodeFlags Flags;
if (Offs.isNonNegative() && cast<GEPOperator>(I).isInBounds())
Flags.setNoUnsignedWrap(true);
N = DAG.getNode(ISD::ADD, dl, N.getValueType(), N, OffsVal, &Flags);
continue;
}
// N = N + Idx * ElementSize;
SDValue IdxN = getValue(Idx);
if (!IdxN.getValueType().isVector() && VectorWidth) {
MVT VT = MVT::getVectorVT(IdxN.getValueType().getSimpleVT(), VectorWidth);
SmallVector<SDValue, 16> Ops(VectorWidth, IdxN);
IdxN = DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
}
// If the index is smaller or larger than intptr_t, truncate or extend
// it.
IdxN = DAG.getSExtOrTrunc(IdxN, dl, N.getValueType());
// If this is a multiply by a power of two, turn it into a shl
// immediately. This is a very common case.
if (ElementSize != 1) {
if (ElementSize.isPowerOf2()) {
unsigned Amt = ElementSize.logBase2();
IdxN = DAG.getNode(ISD::SHL, dl,
N.getValueType(), IdxN,
DAG.getConstant(Amt, dl, IdxN.getValueType()));
} else {
SDValue Scale = DAG.getConstant(ElementSize, dl, IdxN.getValueType());
IdxN = DAG.getNode(ISD::MUL, dl,
N.getValueType(), IdxN, Scale);
}
}
N = DAG.getNode(ISD::ADD, dl,
N.getValueType(), N, IdxN);
}
}
setValue(&I, N);
}
void SelectionDAGBuilder::visitAlloca(const AllocaInst &I) {
// If this is a fixed sized alloca in the entry block of the function,
// allocate it statically on the stack.
if (FuncInfo.StaticAllocaMap.count(&I))
return; // getValue will auto-populate this.
SDLoc dl = getCurSDLoc();
Type *Ty = I.getAllocatedType();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
auto &DL = DAG.getDataLayout();
uint64_t TySize = DL.getTypeAllocSize(Ty);
unsigned Align =
std::max((unsigned)DL.getPrefTypeAlignment(Ty), I.getAlignment());
SDValue AllocSize = getValue(I.getArraySize());
EVT IntPtr = TLI.getPointerTy(DAG.getDataLayout());
if (AllocSize.getValueType() != IntPtr)
AllocSize = DAG.getZExtOrTrunc(AllocSize, dl, IntPtr);
AllocSize = DAG.getNode(ISD::MUL, dl, IntPtr,
AllocSize,
DAG.getConstant(TySize, dl, IntPtr));
// Handle alignment. If the requested alignment is less than or equal to
// the stack alignment, ignore it. If the size is greater than or equal to
// the stack alignment, we note this in the DYNAMIC_STACKALLOC node.
unsigned StackAlign =
DAG.getSubtarget().getFrameLowering()->getStackAlignment();
if (Align <= StackAlign)
Align = 0;
// Round the size of the allocation up to the stack alignment size
// by add SA-1 to the size. This doesn't overflow because we're computing
// an address inside an alloca.
SDNodeFlags Flags;
Flags.setNoUnsignedWrap(true);
AllocSize = DAG.getNode(ISD::ADD, dl,
AllocSize.getValueType(), AllocSize,
DAG.getIntPtrConstant(StackAlign - 1, dl), &Flags);
// Mask out the low bits for alignment purposes.
AllocSize = DAG.getNode(ISD::AND, dl,
AllocSize.getValueType(), AllocSize,
DAG.getIntPtrConstant(~(uint64_t)(StackAlign - 1),
dl));
SDValue Ops[] = { getRoot(), AllocSize, DAG.getIntPtrConstant(Align, dl) };
SDVTList VTs = DAG.getVTList(AllocSize.getValueType(), MVT::Other);
SDValue DSA = DAG.getNode(ISD::DYNAMIC_STACKALLOC, dl, VTs, Ops);
setValue(&I, DSA);
DAG.setRoot(DSA.getValue(1));
assert(FuncInfo.MF->getFrameInfo().hasVarSizedObjects());
}
void SelectionDAGBuilder::visitLoad(const LoadInst &I) {
if (I.isAtomic())
return visitAtomicLoad(I);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
const Value *SV = I.getOperand(0);
if (TLI.supportSwiftError()) {
// Swifterror values can come from either a function parameter with
// swifterror attribute or an alloca with swifterror attribute.
if (const Argument *Arg = dyn_cast<Argument>(SV)) {
if (Arg->hasSwiftErrorAttr())
return visitLoadFromSwiftError(I);
}
if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(SV)) {
if (Alloca->isSwiftError())
return visitLoadFromSwiftError(I);
}
}
SDValue Ptr = getValue(SV);
Type *Ty = I.getType();
bool isVolatile = I.isVolatile();
bool isNonTemporal = I.getMetadata(LLVMContext::MD_nontemporal) != nullptr;
bool isInvariant = I.getMetadata(LLVMContext::MD_invariant_load) != nullptr;
bool isDereferenceable = isDereferenceablePointer(SV, DAG.getDataLayout());
unsigned Alignment = I.getAlignment();
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range);
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(TLI, DAG.getDataLayout(), Ty, ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0)
return;
SDValue Root;
bool ConstantMemory = false;
if (isVolatile || NumValues > MaxParallelChains)
// Serialize volatile loads with other side effects.
Root = getRoot();
else if (AA->pointsToConstantMemory(MemoryLocation(
SV, DAG.getDataLayout().getTypeStoreSize(Ty), AAInfo))) {
// Do not serialize (non-volatile) loads of constant memory with anything.
Root = DAG.getEntryNode();
ConstantMemory = true;
} else {
// Do not serialize non-volatile loads against each other.
Root = DAG.getRoot();
}
SDLoc dl = getCurSDLoc();
if (isVolatile)
Root = TLI.prepareVolatileOrAtomicLoad(Root, dl, DAG);
// An aggregate load cannot wrap around the address space, so offsets to its
// parts don't wrap either.
SDNodeFlags Flags;
Flags.setNoUnsignedWrap(true);
SmallVector<SDValue, 4> Values(NumValues);
SmallVector<SDValue, 4> Chains(std::min(MaxParallelChains, NumValues));
EVT PtrVT = Ptr.getValueType();
unsigned ChainI = 0;
for (unsigned i = 0; i != NumValues; ++i, ++ChainI) {
// Serializing loads here may result in excessive register pressure, and
// TokenFactor places arbitrary choke points on the scheduler. SD scheduling
// could recover a bit by hoisting nodes upward in the chain by recognizing
// they are side-effect free or do not alias. The optimizer should really
// avoid this case by converting large object/array copies to llvm.memcpy
// (MaxParallelChains should always remain as failsafe).
if (ChainI == MaxParallelChains) {
assert(PendingLoads.empty() && "PendingLoads must be serialized first");
SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
Root = Chain;
ChainI = 0;
}
SDValue A = DAG.getNode(ISD::ADD, dl,
PtrVT, Ptr,
DAG.getConstant(Offsets[i], dl, PtrVT),
&Flags);
auto MMOFlags = MachineMemOperand::MONone;
if (isVolatile)
MMOFlags |= MachineMemOperand::MOVolatile;
if (isNonTemporal)
MMOFlags |= MachineMemOperand::MONonTemporal;
if (isInvariant)
MMOFlags |= MachineMemOperand::MOInvariant;
if (isDereferenceable)
MMOFlags |= MachineMemOperand::MODereferenceable;
SDValue L = DAG.getLoad(ValueVTs[i], dl, Root, A,
MachinePointerInfo(SV, Offsets[i]), Alignment,
MMOFlags, AAInfo, Ranges);
Values[i] = L;
Chains[ChainI] = L.getValue(1);
}
if (!ConstantMemory) {
SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
if (isVolatile)
DAG.setRoot(Chain);
else
PendingLoads.push_back(Chain);
}
setValue(&I, DAG.getNode(ISD::MERGE_VALUES, dl,
DAG.getVTList(ValueVTs), Values));
}
void SelectionDAGBuilder::visitStoreToSwiftError(const StoreInst &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
assert(TLI.supportSwiftError() &&
"call visitStoreToSwiftError when backend supports swifterror");
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
const Value *SrcV = I.getOperand(0);
ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(),
SrcV->getType(), ValueVTs, &Offsets);
assert(ValueVTs.size() == 1 && Offsets[0] == 0 &&
"expect a single EVT for swifterror");
SDValue Src = getValue(SrcV);
// Create a virtual register, then update the virtual register.
auto &DL = DAG.getDataLayout();
const TargetRegisterClass *RC = TLI.getRegClassFor(TLI.getPointerTy(DL));
unsigned VReg = FuncInfo.MF->getRegInfo().createVirtualRegister(RC);
// Chain, DL, Reg, N or Chain, DL, Reg, N, Glue
// Chain can be getRoot or getControlRoot.
SDValue CopyNode = DAG.getCopyToReg(getRoot(), getCurSDLoc(), VReg,
SDValue(Src.getNode(), Src.getResNo()));
DAG.setRoot(CopyNode);
FuncInfo.setSwiftErrorVReg(FuncInfo.MBB, I.getOperand(1), VReg);
}
void SelectionDAGBuilder::visitLoadFromSwiftError(const LoadInst &I) {
assert(DAG.getTargetLoweringInfo().supportSwiftError() &&
"call visitLoadFromSwiftError when backend supports swifterror");
assert(!I.isVolatile() &&
I.getMetadata(LLVMContext::MD_nontemporal) == nullptr &&
I.getMetadata(LLVMContext::MD_invariant_load) == nullptr &&
"Support volatile, non temporal, invariant for load_from_swift_error");
const Value *SV = I.getOperand(0);
Type *Ty = I.getType();
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
assert(!AA->pointsToConstantMemory(MemoryLocation(
SV, DAG.getDataLayout().getTypeStoreSize(Ty), AAInfo)) &&
"load_from_swift_error should not be constant memory");
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(), Ty,
ValueVTs, &Offsets);
assert(ValueVTs.size() == 1 && Offsets[0] == 0 &&
"expect a single EVT for swifterror");
// Chain, DL, Reg, VT, Glue or Chain, DL, Reg, VT
SDValue L = DAG.getCopyFromReg(getRoot(), getCurSDLoc(),
FuncInfo.findSwiftErrorVReg(FuncInfo.MBB, SV),
ValueVTs[0]);
setValue(&I, L);
}
void SelectionDAGBuilder::visitStore(const StoreInst &I) {
if (I.isAtomic())
return visitAtomicStore(I);
const Value *SrcV = I.getOperand(0);
const Value *PtrV = I.getOperand(1);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (TLI.supportSwiftError()) {
// Swifterror values can come from either a function parameter with
// swifterror attribute or an alloca with swifterror attribute.
if (const Argument *Arg = dyn_cast<Argument>(PtrV)) {
if (Arg->hasSwiftErrorAttr())
return visitStoreToSwiftError(I);
}
if (const AllocaInst *Alloca = dyn_cast<AllocaInst>(PtrV)) {
if (Alloca->isSwiftError())
return visitStoreToSwiftError(I);
}
}
SmallVector<EVT, 4> ValueVTs;
SmallVector<uint64_t, 4> Offsets;
ComputeValueVTs(DAG.getTargetLoweringInfo(), DAG.getDataLayout(),
SrcV->getType(), ValueVTs, &Offsets);
unsigned NumValues = ValueVTs.size();
if (NumValues == 0)
return;
// Get the lowered operands. Note that we do this after
// checking if NumResults is zero, because with zero results
// the operands won't have values in the map.
SDValue Src = getValue(SrcV);
SDValue Ptr = getValue(PtrV);
SDValue Root = getRoot();
SmallVector<SDValue, 4> Chains(std::min(MaxParallelChains, NumValues));
SDLoc dl = getCurSDLoc();
EVT PtrVT = Ptr.getValueType();
unsigned Alignment = I.getAlignment();
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
auto MMOFlags = MachineMemOperand::MONone;
if (I.isVolatile())
MMOFlags |= MachineMemOperand::MOVolatile;
if (I.getMetadata(LLVMContext::MD_nontemporal) != nullptr)
MMOFlags |= MachineMemOperand::MONonTemporal;
// An aggregate load cannot wrap around the address space, so offsets to its
// parts don't wrap either.
SDNodeFlags Flags;
Flags.setNoUnsignedWrap(true);
unsigned ChainI = 0;
for (unsigned i = 0; i != NumValues; ++i, ++ChainI) {
// See visitLoad comments.
if (ChainI == MaxParallelChains) {
SDValue Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
Root = Chain;
ChainI = 0;
}
SDValue Add = DAG.getNode(ISD::ADD, dl, PtrVT, Ptr,
DAG.getConstant(Offsets[i], dl, PtrVT), &Flags);
SDValue St = DAG.getStore(
Root, dl, SDValue(Src.getNode(), Src.getResNo() + i), Add,
MachinePointerInfo(PtrV, Offsets[i]), Alignment, MMOFlags, AAInfo);
Chains[ChainI] = St;
}
SDValue StoreNode = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
makeArrayRef(Chains.data(), ChainI));
DAG.setRoot(StoreNode);
}
void SelectionDAGBuilder::visitMaskedStore(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// llvm.masked.store.*(Src0, Ptr, alignment, Mask)
Value *PtrOperand = I.getArgOperand(1);
SDValue Ptr = getValue(PtrOperand);
SDValue Src0 = getValue(I.getArgOperand(0));
SDValue Mask = getValue(I.getArgOperand(3));
EVT VT = Src0.getValueType();
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(2)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(PtrOperand),
MachineMemOperand::MOStore, VT.getStoreSize(),
Alignment, AAInfo);
SDValue StoreNode = DAG.getMaskedStore(getRoot(), sdl, Src0, Ptr, Mask, VT,
MMO, false);
DAG.setRoot(StoreNode);
setValue(&I, StoreNode);
}
// Get a uniform base for the Gather/Scatter intrinsic.
// The first argument of the Gather/Scatter intrinsic is a vector of pointers.
// We try to represent it as a base pointer + vector of indices.
// Usually, the vector of pointers comes from a 'getelementptr' instruction.
// The first operand of the GEP may be a single pointer or a vector of pointers
// Example:
// %gep.ptr = getelementptr i32, <8 x i32*> %vptr, <8 x i32> %ind
// or
// %gep.ptr = getelementptr i32, i32* %ptr, <8 x i32> %ind
// %res = call <8 x i32> @llvm.masked.gather.v8i32(<8 x i32*> %gep.ptr, ..
//
// When the first GEP operand is a single pointer - it is the uniform base we
// are looking for. If first operand of the GEP is a splat vector - we
// extract the spalt value and use it as a uniform base.
// In all other cases the function returns 'false'.
//
static bool getUniformBase(const Value *& Ptr, SDValue& Base, SDValue& Index,
SelectionDAGBuilder* SDB) {
SelectionDAG& DAG = SDB->DAG;
LLVMContext &Context = *DAG.getContext();
assert(Ptr->getType()->isVectorTy() && "Uexpected pointer type");
const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(Ptr);
if (!GEP || GEP->getNumOperands() > 2)
return false;
const Value *GEPPtr = GEP->getPointerOperand();
if (!GEPPtr->getType()->isVectorTy())
Ptr = GEPPtr;
else if (!(Ptr = getSplatValue(GEPPtr)))
return false;
Value *IndexVal = GEP->getOperand(1);
// The operands of the GEP may be defined in another basic block.
// In this case we'll not find nodes for the operands.
if (!SDB->findValue(Ptr) || !SDB->findValue(IndexVal))
return false;
Base = SDB->getValue(Ptr);
Index = SDB->getValue(IndexVal);
// Suppress sign extension.
if (SExtInst* Sext = dyn_cast<SExtInst>(IndexVal)) {
if (SDB->findValue(Sext->getOperand(0))) {
IndexVal = Sext->getOperand(0);
Index = SDB->getValue(IndexVal);
}
}
if (!Index.getValueType().isVector()) {
unsigned GEPWidth = GEP->getType()->getVectorNumElements();
EVT VT = EVT::getVectorVT(Context, Index.getValueType(), GEPWidth);
SmallVector<SDValue, 16> Ops(GEPWidth, Index);
Index = DAG.getNode(ISD::BUILD_VECTOR, SDLoc(Index), VT, Ops);
}
return true;
}
void SelectionDAGBuilder::visitMaskedScatter(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// llvm.masked.scatter.*(Src0, Ptrs, alignemt, Mask)
const Value *Ptr = I.getArgOperand(1);
SDValue Src0 = getValue(I.getArgOperand(0));
SDValue Mask = getValue(I.getArgOperand(3));
EVT VT = Src0.getValueType();
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(2)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
SDValue Base;
SDValue Index;
const Value *BasePtr = Ptr;
bool UniformBase = getUniformBase(BasePtr, Base, Index, this);
const Value *MemOpBasePtr = UniformBase ? BasePtr : nullptr;
MachineMemOperand *MMO = DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(MemOpBasePtr),
MachineMemOperand::MOStore, VT.getStoreSize(),
Alignment, AAInfo);
if (!UniformBase) {
Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy(DAG.getDataLayout()));
Index = getValue(Ptr);
}
SDValue Ops[] = { getRoot(), Src0, Mask, Base, Index };
SDValue Scatter = DAG.getMaskedScatter(DAG.getVTList(MVT::Other), VT, sdl,
Ops, MMO);
DAG.setRoot(Scatter);
setValue(&I, Scatter);
}
void SelectionDAGBuilder::visitMaskedLoad(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// @llvm.masked.load.*(Ptr, alignment, Mask, Src0)
Value *PtrOperand = I.getArgOperand(0);
SDValue Ptr = getValue(PtrOperand);
SDValue Src0 = getValue(I.getArgOperand(3));
SDValue Mask = getValue(I.getArgOperand(2));
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType());
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(1)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range);
// Do not serialize masked loads of constant memory with anything.
bool AddToChain = !AA->pointsToConstantMemory(MemoryLocation(
PtrOperand, DAG.getDataLayout().getTypeStoreSize(I.getType()), AAInfo));
SDValue InChain = AddToChain ? DAG.getRoot() : DAG.getEntryNode();
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(PtrOperand),
MachineMemOperand::MOLoad, VT.getStoreSize(),
Alignment, AAInfo, Ranges);
SDValue Load = DAG.getMaskedLoad(VT, sdl, InChain, Ptr, Mask, Src0, VT, MMO,
ISD::NON_EXTLOAD);
if (AddToChain) {
SDValue OutChain = Load.getValue(1);
DAG.setRoot(OutChain);
}
setValue(&I, Load);
}
void SelectionDAGBuilder::visitMaskedGather(const CallInst &I) {
SDLoc sdl = getCurSDLoc();
// @llvm.masked.gather.*(Ptrs, alignment, Mask, Src0)
const Value *Ptr = I.getArgOperand(0);
SDValue Src0 = getValue(I.getArgOperand(3));
SDValue Mask = getValue(I.getArgOperand(2));
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType());
unsigned Alignment = (cast<ConstantInt>(I.getArgOperand(1)))->getZExtValue();
if (!Alignment)
Alignment = DAG.getEVTAlignment(VT);
AAMDNodes AAInfo;
I.getAAMetadata(AAInfo);
const MDNode *Ranges = I.getMetadata(LLVMContext::MD_range);
SDValue Root = DAG.getRoot();
SDValue Base;
SDValue Index;
const Value *BasePtr = Ptr;
bool UniformBase = getUniformBase(BasePtr, Base, Index, this);
bool ConstantMemory = false;
if (UniformBase &&
AA->pointsToConstantMemory(MemoryLocation(
BasePtr, DAG.getDataLayout().getTypeStoreSize(I.getType()),
AAInfo))) {
// Do not serialize (non-volatile) loads of constant memory with anything.
Root = DAG.getEntryNode();
ConstantMemory = true;
}
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(UniformBase ? BasePtr : nullptr),
MachineMemOperand::MOLoad, VT.getStoreSize(),
Alignment, AAInfo, Ranges);
if (!UniformBase) {
Base = DAG.getTargetConstant(0, sdl, TLI.getPointerTy(DAG.getDataLayout()));
Index = getValue(Ptr);
}
SDValue Ops[] = { Root, Src0, Mask, Base, Index };
SDValue Gather = DAG.getMaskedGather(DAG.getVTList(VT, MVT::Other), VT, sdl,
Ops, MMO);
SDValue OutChain = Gather.getValue(1);
if (!ConstantMemory)
PendingLoads.push_back(OutChain);
setValue(&I, Gather);
}
void SelectionDAGBuilder::visitAtomicCmpXchg(const AtomicCmpXchgInst &I) {
SDLoc dl = getCurSDLoc();
AtomicOrdering SuccessOrder = I.getSuccessOrdering();
AtomicOrdering FailureOrder = I.getFailureOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
MVT MemVT = getValue(I.getCompareOperand()).getSimpleValueType();
SDVTList VTs = DAG.getVTList(MemVT, MVT::i1, MVT::Other);
SDValue L = DAG.getAtomicCmpSwap(
ISD::ATOMIC_CMP_SWAP_WITH_SUCCESS, dl, MemVT, VTs, InChain,
getValue(I.getPointerOperand()), getValue(I.getCompareOperand()),
getValue(I.getNewValOperand()), MachinePointerInfo(I.getPointerOperand()),
/*Alignment=*/ 0, SuccessOrder, FailureOrder, Scope);
SDValue OutChain = L.getValue(2);
setValue(&I, L);
DAG.setRoot(OutChain);
}
void SelectionDAGBuilder::visitAtomicRMW(const AtomicRMWInst &I) {
SDLoc dl = getCurSDLoc();
ISD::NodeType NT;
switch (I.getOperation()) {
default: llvm_unreachable("Unknown atomicrmw operation");
case AtomicRMWInst::Xchg: NT = ISD::ATOMIC_SWAP; break;
case AtomicRMWInst::Add: NT = ISD::ATOMIC_LOAD_ADD; break;
case AtomicRMWInst::Sub: NT = ISD::ATOMIC_LOAD_SUB; break;
case AtomicRMWInst::And: NT = ISD::ATOMIC_LOAD_AND; break;
case AtomicRMWInst::Nand: NT = ISD::ATOMIC_LOAD_NAND; break;
case AtomicRMWInst::Or: NT = ISD::ATOMIC_LOAD_OR; break;
case AtomicRMWInst::Xor: NT = ISD::ATOMIC_LOAD_XOR; break;
case AtomicRMWInst::Max: NT = ISD::ATOMIC_LOAD_MAX; break;
case AtomicRMWInst::Min: NT = ISD::ATOMIC_LOAD_MIN; break;
case AtomicRMWInst::UMax: NT = ISD::ATOMIC_LOAD_UMAX; break;
case AtomicRMWInst::UMin: NT = ISD::ATOMIC_LOAD_UMIN; break;
}
AtomicOrdering Order = I.getOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
SDValue L =
DAG.getAtomic(NT, dl,
getValue(I.getValOperand()).getSimpleValueType(),
InChain,
getValue(I.getPointerOperand()),
getValue(I.getValOperand()),
I.getPointerOperand(),
/* Alignment=*/ 0, Order, Scope);
SDValue OutChain = L.getValue(1);
setValue(&I, L);
DAG.setRoot(OutChain);
}
void SelectionDAGBuilder::visitFence(const FenceInst &I) {
SDLoc dl = getCurSDLoc();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDValue Ops[3];
Ops[0] = getRoot();
Ops[1] = DAG.getConstant((unsigned)I.getOrdering(), dl,
TLI.getPointerTy(DAG.getDataLayout()));
Ops[2] = DAG.getConstant(I.getSynchScope(), dl,
TLI.getPointerTy(DAG.getDataLayout()));
DAG.setRoot(DAG.getNode(ISD::ATOMIC_FENCE, dl, MVT::Other, Ops));
}
void SelectionDAGBuilder::visitAtomicLoad(const LoadInst &I) {
SDLoc dl = getCurSDLoc();
AtomicOrdering Order = I.getOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType());
if (I.getAlignment() < VT.getSizeInBits() / 8)
report_fatal_error("Cannot generate unaligned atomic load");
MachineMemOperand *MMO =
DAG.getMachineFunction().
getMachineMemOperand(MachinePointerInfo(I.getPointerOperand()),
MachineMemOperand::MOVolatile |
MachineMemOperand::MOLoad,
VT.getStoreSize(),
I.getAlignment() ? I.getAlignment() :
DAG.getEVTAlignment(VT));
InChain = TLI.prepareVolatileOrAtomicLoad(InChain, dl, DAG);
SDValue L =
DAG.getAtomic(ISD::ATOMIC_LOAD, dl, VT, VT, InChain,
getValue(I.getPointerOperand()), MMO,
Order, Scope);
SDValue OutChain = L.getValue(1);
setValue(&I, L);
DAG.setRoot(OutChain);
}
void SelectionDAGBuilder::visitAtomicStore(const StoreInst &I) {
SDLoc dl = getCurSDLoc();
AtomicOrdering Order = I.getOrdering();
SynchronizationScope Scope = I.getSynchScope();
SDValue InChain = getRoot();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT VT =
TLI.getValueType(DAG.getDataLayout(), I.getValueOperand()->getType());
if (I.getAlignment() < VT.getSizeInBits() / 8)
report_fatal_error("Cannot generate unaligned atomic store");
SDValue OutChain =
DAG.getAtomic(ISD::ATOMIC_STORE, dl, VT,
InChain,
getValue(I.getPointerOperand()),
getValue(I.getValueOperand()),
I.getPointerOperand(), I.getAlignment(),
Order, Scope);
DAG.setRoot(OutChain);
}
/// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC
/// node.
void SelectionDAGBuilder::visitTargetIntrinsic(const CallInst &I,
unsigned Intrinsic) {
bool HasChain = !I.doesNotAccessMemory();
bool OnlyLoad = HasChain && I.onlyReadsMemory();
// Build the operand list.
SmallVector<SDValue, 8> Ops;
if (HasChain) { // If this intrinsic has side-effects, chainify it.
if (OnlyLoad) {
// We don't need to serialize loads against other loads.
Ops.push_back(DAG.getRoot());
} else {
Ops.push_back(getRoot());
}
}
// Info is set by getTgtMemInstrinsic
TargetLowering::IntrinsicInfo Info;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
bool IsTgtIntrinsic = TLI.getTgtMemIntrinsic(Info, I, Intrinsic);
// Add the intrinsic ID as an integer operand if it's not a target intrinsic.
if (!IsTgtIntrinsic || Info.opc == ISD::INTRINSIC_VOID ||
Info.opc == ISD::INTRINSIC_W_CHAIN)
Ops.push_back(DAG.getTargetConstant(Intrinsic, getCurSDLoc(),
TLI.getPointerTy(DAG.getDataLayout())));
// Add all operands of the call to the operand list.
for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
SDValue Op = getValue(I.getArgOperand(i));
Ops.push_back(Op);
}
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(TLI, DAG.getDataLayout(), I.getType(), ValueVTs);
if (HasChain)
ValueVTs.push_back(MVT::Other);
SDVTList VTs = DAG.getVTList(ValueVTs);
// Create the node.
SDValue Result;
if (IsTgtIntrinsic) {
// This is target intrinsic that touches memory
Result = DAG.getMemIntrinsicNode(Info.opc, getCurSDLoc(),
VTs, Ops, Info.memVT,
MachinePointerInfo(Info.ptrVal, Info.offset),
Info.align, Info.vol,
Info.readMem, Info.writeMem, Info.size);
} else if (!HasChain) {
Result = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, getCurSDLoc(), VTs, Ops);
} else if (!I.getType()->isVoidTy()) {
Result = DAG.getNode(ISD::INTRINSIC_W_CHAIN, getCurSDLoc(), VTs, Ops);
} else {
Result = DAG.getNode(ISD::INTRINSIC_VOID, getCurSDLoc(), VTs, Ops);
}
if (HasChain) {
SDValue Chain = Result.getValue(Result.getNode()->getNumValues()-1);
if (OnlyLoad)
PendingLoads.push_back(Chain);
else
DAG.setRoot(Chain);
}
if (!I.getType()->isVoidTy()) {
if (VectorType *PTy = dyn_cast<VectorType>(I.getType())) {
EVT VT = TLI.getValueType(DAG.getDataLayout(), PTy);
Result = DAG.getNode(ISD::BITCAST, getCurSDLoc(), VT, Result);
} else
Result = lowerRangeToAssertZExt(DAG, I, Result);
setValue(&I, Result);
}
}
/// GetSignificand - Get the significand and build it into a floating-point
/// number with exponent of 1:
///
/// Op = (Op & 0x007fffff) | 0x3f800000;
///
/// where Op is the hexadecimal representation of floating point value.
static SDValue GetSignificand(SelectionDAG &DAG, SDValue Op, const SDLoc &dl) {
SDValue t1 = DAG.getNode(ISD::AND, dl, MVT::i32, Op,
DAG.getConstant(0x007fffff, dl, MVT::i32));
SDValue t2 = DAG.getNode(ISD::OR, dl, MVT::i32, t1,
DAG.getConstant(0x3f800000, dl, MVT::i32));
return DAG.getNode(ISD::BITCAST, dl, MVT::f32, t2);
}
/// GetExponent - Get the exponent:
///
/// (float)(int)(((Op & 0x7f800000) >> 23) - 127);
///
/// where Op is the hexadecimal representation of floating point value.
static SDValue GetExponent(SelectionDAG &DAG, SDValue Op,
const TargetLowering &TLI, const SDLoc &dl) {
SDValue t0 = DAG.getNode(ISD::AND, dl, MVT::i32, Op,
DAG.getConstant(0x7f800000, dl, MVT::i32));
SDValue t1 = DAG.getNode(
ISD::SRL, dl, MVT::i32, t0,
DAG.getConstant(23, dl, TLI.getPointerTy(DAG.getDataLayout())));
SDValue t2 = DAG.getNode(ISD::SUB, dl, MVT::i32, t1,
DAG.getConstant(127, dl, MVT::i32));
return DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, t2);
}
/// getF32Constant - Get 32-bit floating point constant.
static SDValue getF32Constant(SelectionDAG &DAG, unsigned Flt,
const SDLoc &dl) {
return DAG.getConstantFP(APFloat(APFloat::IEEEsingle, APInt(32, Flt)), dl,
MVT::f32);
}
static SDValue getLimitedPrecisionExp2(SDValue t0, const SDLoc &dl,
SelectionDAG &DAG) {
// TODO: What fast-math-flags should be set on the floating-point nodes?
// IntegerPartOfX = ((int32_t)(t0);
SDValue IntegerPartOfX = DAG.getNode(ISD::FP_TO_SINT, dl, MVT::i32, t0);
// FractionalPartOfX = t0 - (float)IntegerPartOfX;
SDValue t1 = DAG.getNode(ISD::SINT_TO_FP, dl, MVT::f32, IntegerPartOfX);
SDValue X = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0, t1);
// IntegerPartOfX <<= 23;
IntegerPartOfX = DAG.getNode(
ISD::SHL, dl, MVT::i32, IntegerPartOfX,
DAG.getConstant(23, dl, DAG.getTargetLoweringInfo().getPointerTy(
DAG.getDataLayout())));
SDValue TwoToFractionalPartOfX;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// TwoToFractionalPartOfX =
// 0.997535578f +
// (0.735607626f + 0.252464424f * x) * x;
//
// error 0.0144103317, which is 6 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3e814304, dl));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f3c50c8, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f7f5e7e, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// TwoToFractionalPartOfX =
// 0.999892986f +
// (0.696457318f +
// (0.224338339f + 0.792043434e-1f * x) * x) * x;
//
// error 0.000107046256, which is 13 to 14 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3da235e3, dl));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3e65b8f3, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f324b07, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3f7ff8fd, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// TwoToFractionalPartOfX =
// 0.999999982f +
// (0.693148872f +
// (0.240227044f +
// (0.554906021e-1f +
// (0.961591928e-2f +
// (0.136028312e-2f + 0.157059148e-3f *x)*x)*x)*x)*x)*x;
// error 2.47208000*10^(-7), which is better than 18 bits
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3924b03e, dl));
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3ab24b87, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3c1d8c17, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3d634a1d, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3e75fe14, dl));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
SDValue t11 = DAG.getNode(ISD::FADD, dl, MVT::f32, t10,
getF32Constant(DAG, 0x3f317234, dl));
SDValue t12 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t11, X);
TwoToFractionalPartOfX = DAG.getNode(ISD::FADD, dl, MVT::f32, t12,
getF32Constant(DAG, 0x3f800000, dl));
}
// Add the exponent into the result in integer domain.
SDValue t13 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, TwoToFractionalPartOfX);
return DAG.getNode(ISD::BITCAST, dl, MVT::f32,
DAG.getNode(ISD::ADD, dl, MVT::i32, t13, IntegerPartOfX));
}
/// expandExp - Lower an exp intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandExp(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
// Put the exponent in the right bit position for later addition to the
// final result:
//
// #define LOG2OFe 1.4426950f
// t0 = Op * LOG2OFe
// TODO: What fast-math-flags should be set here?
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, Op,
getF32Constant(DAG, 0x3fb8aa3b, dl));
return getLimitedPrecisionExp2(t0, dl, DAG);
}
// No special expansion.
return DAG.getNode(ISD::FEXP, dl, Op.getValueType(), Op);
}
/// expandLog - Lower a log intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
// TODO: What fast-math-flags should be set on the floating-point nodes?
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Scale the exponent by log(2) [0.69314718f].
SDValue Exp = GetExponent(DAG, Op1, TLI, dl);
SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp,
getF32Constant(DAG, 0x3f317218, dl));
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
SDValue LogOfMantissa;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// LogofMantissa =
// -1.1609546f +
// (1.4034025f - 0.23903021f * x) * x;
//
// error 0.0034276066, which is better than 8 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbe74c456, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3fb3a2b1, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f949a29, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// LogOfMantissa =
// -1.7417939f +
// (2.8212026f +
// (-1.4699568f +
// (0.44717955f - 0.56570851e-1f * x) * x) * x) * x;
//
// error 0.000061011436, which is 14 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbd67b6d6, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3ee4f4b8, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fbc278b, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40348e95, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3fdef31a, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// LogOfMantissa =
// -2.1072184f +
// (4.2372794f +
// (-3.7029485f +
// (2.2781945f +
// (-0.87823314f +
// (0.19073739f - 0.17809712e-1f * x) * x) * x) * x) * x)*x;
//
// error 0.0000023660568, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbc91e5ac, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e4350aa, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f60d3e3, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x4011cdf0, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x406cfd1c, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x408797cb, dl));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
LogOfMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10,
getF32Constant(DAG, 0x4006dcab, dl));
}
return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, LogOfMantissa);
}
// No special expansion.
return DAG.getNode(ISD::FLOG, dl, Op.getValueType(), Op);
}
/// expandLog2 - Lower a log2 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
// TODO: What fast-math-flags should be set on the floating-point nodes?
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Get the exponent.
SDValue LogOfExponent = GetExponent(DAG, Op1, TLI, dl);
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
// Different possible minimax approximations of significand in
// floating-point for various degrees of accuracy over [1,2].
SDValue Log2ofMantissa;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// Log2ofMantissa = -1.6749035f + (2.0246817f - .34484768f * x) * x;
//
// error 0.0049451742, which is more than 7 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbeb08fe0, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x40019463, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fd6633d, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// Log2ofMantissa =
// -2.51285454f +
// (4.07009056f +
// (-2.12067489f +
// (.645142248f - 0.816157886e-1f * x) * x) * x) * x;
//
// error 0.0000876136000, which is better than 13 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbda7262e, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3f25280b, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x4007b923, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40823e2f, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x4020d29c, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// Log2ofMantissa =
// -3.0400495f +
// (6.1129976f +
// (-5.3420409f +
// (3.2865683f +
// (-1.2669343f +
// (0.27515199f -
// 0.25691327e-1f * x) * x) * x) * x) * x) * x;
//
// error 0.0000018516, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbcd2769e, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e8ce0b9, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3fa22ae7, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FADD, dl, MVT::f32, t4,
getF32Constant(DAG, 0x40525723, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t6,
getF32Constant(DAG, 0x40aaf200, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
SDValue t9 = DAG.getNode(ISD::FADD, dl, MVT::f32, t8,
getF32Constant(DAG, 0x40c39dad, dl));
SDValue t10 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t9, X);
Log2ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t10,
getF32Constant(DAG, 0x4042902c, dl));
}
return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log2ofMantissa);
}
// No special expansion.
return DAG.getNode(ISD::FLOG2, dl, Op.getValueType(), Op);
}
/// expandLog10 - Lower a log10 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandLog10(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
// TODO: What fast-math-flags should be set on the floating-point nodes?
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
SDValue Op1 = DAG.getNode(ISD::BITCAST, dl, MVT::i32, Op);
// Scale the exponent by log10(2) [0.30102999f].
SDValue Exp = GetExponent(DAG, Op1, TLI, dl);
SDValue LogOfExponent = DAG.getNode(ISD::FMUL, dl, MVT::f32, Exp,
getF32Constant(DAG, 0x3e9a209a, dl));
// Get the significand and build it into a floating-point number with
// exponent of 1.
SDValue X = GetSignificand(DAG, Op1, dl);
SDValue Log10ofMantissa;
if (LimitFloatPrecision <= 6) {
// For floating-point precision of 6:
//
// Log10ofMantissa =
// -0.50419619f +
// (0.60948995f - 0.10380950f * x) * x;
//
// error 0.0014886165, which is 6 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0xbdd49a13, dl));
SDValue t1 = DAG.getNode(ISD::FADD, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3f1c0789, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f011300, dl));
} else if (LimitFloatPrecision <= 12) {
// For floating-point precision of 12:
//
// Log10ofMantissa =
// -0.64831180f +
// (0.91751397f +
// (-0.31664806f + 0.47637168e-1f * x) * x) * x;
//
// error 0.00019228036, which is better than 12 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3d431f31, dl));
SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3ea21fb2, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3f6ae232, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f25f7c3, dl));
} else { // LimitFloatPrecision <= 18
// For floating-point precision of 18:
//
// Log10ofMantissa =
// -0.84299375f +
// (1.5327582f +
// (-1.0688956f +
// (0.49102474f +
// (-0.12539807f + 0.13508273e-1f * x) * x) * x) * x) * x;
//
// error 0.0000037995730, which is better than 18 bits
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, X,
getF32Constant(DAG, 0x3c5d51ce, dl));
SDValue t1 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t0,
getF32Constant(DAG, 0x3e00685a, dl));
SDValue t2 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t1, X);
SDValue t3 = DAG.getNode(ISD::FADD, dl, MVT::f32, t2,
getF32Constant(DAG, 0x3efb6798, dl));
SDValue t4 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t3, X);
SDValue t5 = DAG.getNode(ISD::FSUB, dl, MVT::f32, t4,
getF32Constant(DAG, 0x3f88d192, dl));
SDValue t6 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t5, X);
SDValue t7 = DAG.getNode(ISD::FADD, dl, MVT::f32, t6,
getF32Constant(DAG, 0x3fc4316c, dl));
SDValue t8 = DAG.getNode(ISD::FMUL, dl, MVT::f32, t7, X);
Log10ofMantissa = DAG.getNode(ISD::FSUB, dl, MVT::f32, t8,
getF32Constant(DAG, 0x3f57ce70, dl));
}
return DAG.getNode(ISD::FADD, dl, MVT::f32, LogOfExponent, Log10ofMantissa);
}
// No special expansion.
return DAG.getNode(ISD::FLOG10, dl, Op.getValueType(), Op);
}
/// expandExp2 - Lower an exp2 intrinsic. Handles the special sequences for
/// limited-precision mode.
static SDValue expandExp2(const SDLoc &dl, SDValue Op, SelectionDAG &DAG,
const TargetLowering &TLI) {
if (Op.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18)
return getLimitedPrecisionExp2(Op, dl, DAG);
// No special expansion.
return DAG.getNode(ISD::FEXP2, dl, Op.getValueType(), Op);
}
/// visitPow - Lower a pow intrinsic. Handles the special sequences for
/// limited-precision mode with x == 10.0f.
static SDValue expandPow(const SDLoc &dl, SDValue LHS, SDValue RHS,
SelectionDAG &DAG, const TargetLowering &TLI) {
bool IsExp10 = false;
if (LHS.getValueType() == MVT::f32 && RHS.getValueType() == MVT::f32 &&
LimitFloatPrecision > 0 && LimitFloatPrecision <= 18) {
if (ConstantFPSDNode *LHSC = dyn_cast<ConstantFPSDNode>(LHS)) {
APFloat Ten(10.0f);
IsExp10 = LHSC->isExactlyValue(Ten);
}
}
// TODO: What fast-math-flags should be set on the FMUL node?
if (IsExp10) {
// Put the exponent in the right bit position for later addition to the
// final result:
//
// #define LOG2OF10 3.3219281f
// t0 = Op * LOG2OF10;
SDValue t0 = DAG.getNode(ISD::FMUL, dl, MVT::f32, RHS,
getF32Constant(DAG, 0x40549a78, dl));
return getLimitedPrecisionExp2(t0, dl, DAG);
}
// No special expansion.
return DAG.getNode(ISD::FPOW, dl, LHS.getValueType(), LHS, RHS);
}
/// ExpandPowI - Expand a llvm.powi intrinsic.
static SDValue ExpandPowI(const SDLoc &DL, SDValue LHS, SDValue RHS,
SelectionDAG &DAG) {
// If RHS is a constant, we can expand this out to a multiplication tree,
// otherwise we end up lowering to a call to __powidf2 (for example). When
// optimizing for size, we only want to do this if the expansion would produce
// a small number of multiplies, otherwise we do the full expansion.
if (ConstantSDNode *RHSC = dyn_cast<ConstantSDNode>(RHS)) {
// Get the exponent as a positive value.
unsigned Val = RHSC->getSExtValue();
if ((int)Val < 0) Val = -Val;
// powi(x, 0) -> 1.0
if (Val == 0)
return DAG.getConstantFP(1.0, DL, LHS.getValueType());
const Function *F = DAG.getMachineFunction().getFunction();
if (!F->optForSize() ||
// If optimizing for size, don't insert too many multiplies.
// This inserts up to 5 multiplies.
countPopulation(Val) + Log2_32(Val) < 7) {
// We use the simple binary decomposition method to generate the multiply
// sequence. There are more optimal ways to do this (for example,
// powi(x,15) generates one more multiply than it should), but this has
// the benefit of being both really simple and much better than a libcall.
SDValue Res; // Logically starts equal to 1.0
SDValue CurSquare = LHS;
// TODO: Intrinsics should have fast-math-flags that propagate to these
// nodes.
while (Val) {
if (Val & 1) {
if (Res.getNode())
Res = DAG.getNode(ISD::FMUL, DL,Res.getValueType(), Res, CurSquare);
else
Res = CurSquare; // 1.0*CurSquare.
}
CurSquare = DAG.getNode(ISD::FMUL, DL, CurSquare.getValueType(),
CurSquare, CurSquare);
Val >>= 1;
}
// If the original was negative, invert the result, producing 1/(x*x*x).
if (RHSC->getSExtValue() < 0)
Res = DAG.getNode(ISD::FDIV, DL, LHS.getValueType(),
DAG.getConstantFP(1.0, DL, LHS.getValueType()), Res);
return Res;
}
}
// Otherwise, expand to a libcall.
return DAG.getNode(ISD::FPOWI, DL, LHS.getValueType(), LHS, RHS);
}
// getUnderlyingArgReg - Find underlying register used for a truncated or
// bitcasted argument.
static unsigned getUnderlyingArgReg(const SDValue &N) {
switch (N.getOpcode()) {
case ISD::CopyFromReg:
return cast<RegisterSDNode>(N.getOperand(1))->getReg();
case ISD::BITCAST:
case ISD::AssertZext:
case ISD::AssertSext:
case ISD::TRUNCATE:
return getUnderlyingArgReg(N.getOperand(0));
default:
return 0;
}
}
/// EmitFuncArgumentDbgValue - If the DbgValueInst is a dbg_value of a function
/// argument, create the corresponding DBG_VALUE machine instruction for it now.
/// At the end of instruction selection, they will be inserted to the entry BB.
bool SelectionDAGBuilder::EmitFuncArgumentDbgValue(
const Value *V, DILocalVariable *Variable, DIExpression *Expr,
DILocation *DL, int64_t Offset, bool IsIndirect, const SDValue &N) {
const Argument *Arg = dyn_cast<Argument>(V);
if (!Arg)
return false;
MachineFunction &MF = DAG.getMachineFunction();
const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo();
// Ignore inlined function arguments here.
//
// FIXME: Should we be checking DL->inlinedAt() to determine this?
if (!Variable->getScope()->getSubprogram()->describes(MF.getFunction()))
return false;
Optional<MachineOperand> Op;
// Some arguments' frame index is recorded during argument lowering.
if (int FI = FuncInfo.getArgumentFrameIndex(Arg))
Op = MachineOperand::CreateFI(FI);
if (!Op && N.getNode()) {
unsigned Reg = getUnderlyingArgReg(N);
if (Reg && TargetRegisterInfo::isVirtualRegister(Reg)) {
MachineRegisterInfo &RegInfo = MF.getRegInfo();
unsigned PR = RegInfo.getLiveInPhysReg(Reg);
if (PR)
Reg = PR;
}
if (Reg)
Op = MachineOperand::CreateReg(Reg, false);
}
if (!Op) {
// Check if ValueMap has reg number.
DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
if (VMI != FuncInfo.ValueMap.end())
Op = MachineOperand::CreateReg(VMI->second, false);
}
if (!Op && N.getNode())
// Check if frame index is available.
if (LoadSDNode *LNode = dyn_cast<LoadSDNode>(N.getNode()))
if (FrameIndexSDNode *FINode =
dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()))
Op = MachineOperand::CreateFI(FINode->getIndex());
if (!Op)
return false;
assert(Variable->isValidLocationForIntrinsic(DL) &&
"Expected inlined-at fields to agree");
if (Op->isReg())
FuncInfo.ArgDbgValues.push_back(
BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsIndirect,
Op->getReg(), Offset, Variable, Expr));
else
FuncInfo.ArgDbgValues.push_back(
BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE))
.addOperand(*Op)
.addImm(Offset)
.addMetadata(Variable)
.addMetadata(Expr));
return true;
}
/// Return the appropriate SDDbgValue based on N.
SDDbgValue *SelectionDAGBuilder::getDbgValue(SDValue N,
DILocalVariable *Variable,
DIExpression *Expr, int64_t Offset,
DebugLoc dl,
unsigned DbgSDNodeOrder) {
SDDbgValue *SDV;
auto *FISDN = dyn_cast<FrameIndexSDNode>(N.getNode());
if (FISDN && Expr->startsWithDeref()) {
// Construct a FrameIndexDbgValue for FrameIndexSDNodes so we can describe
// stack slot locations as such instead of as indirectly addressed
// locations.
ArrayRef<uint64_t> TrailingElements(Expr->elements_begin() + 1,
Expr->elements_end());
DIExpression *DerefedDIExpr =
DIExpression::get(*DAG.getContext(), TrailingElements);
int FI = FISDN->getIndex();
SDV = DAG.getFrameIndexDbgValue(Variable, DerefedDIExpr, FI, 0, dl,
DbgSDNodeOrder);
} else {
SDV = DAG.getDbgValue(Variable, Expr, N.getNode(), N.getResNo(), false,
Offset, dl, DbgSDNodeOrder);
}
return SDV;
}
// VisualStudio defines setjmp as _setjmp
#if defined(_MSC_VER) && defined(setjmp) && \
!defined(setjmp_undefined_for_msvc)
# pragma push_macro("setjmp")
# undef setjmp
# define setjmp_undefined_for_msvc
#endif
/// visitIntrinsicCall - Lower the call to the specified intrinsic function. If
/// we want to emit this as a call to a named external function, return the name
/// otherwise lower it and return null.
const char *
SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SDLoc sdl = getCurSDLoc();
DebugLoc dl = getCurDebugLoc();
SDValue Res;
switch (Intrinsic) {
default:
// By default, turn this into a target intrinsic node.
visitTargetIntrinsic(I, Intrinsic);
return nullptr;
case Intrinsic::vastart: visitVAStart(I); return nullptr;
case Intrinsic::vaend: visitVAEnd(I); return nullptr;
case Intrinsic::vacopy: visitVACopy(I); return nullptr;
case Intrinsic::returnaddress:
setValue(&I, DAG.getNode(ISD::RETURNADDR, sdl,
TLI.getPointerTy(DAG.getDataLayout()),
getValue(I.getArgOperand(0))));
return nullptr;
case Intrinsic::frameaddress:
setValue(&I, DAG.getNode(ISD::FRAMEADDR, sdl,
TLI.getPointerTy(DAG.getDataLayout()),
getValue(I.getArgOperand(0))));
return nullptr;
case Intrinsic::read_register: {
Value *Reg = I.getArgOperand(0);
SDValue Chain = getRoot();
SDValue RegName =
DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata()));
EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType());
Res = DAG.getNode(ISD::READ_REGISTER, sdl,
DAG.getVTList(VT, MVT::Other), Chain, RegName);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return nullptr;
}
case Intrinsic::write_register: {
Value *Reg = I.getArgOperand(0);
Value *RegValue = I.getArgOperand(1);
SDValue Chain = getRoot();
SDValue RegName =
DAG.getMDNode(cast<MDNode>(cast<MetadataAsValue>(Reg)->getMetadata()));
DAG.setRoot(DAG.getNode(ISD::WRITE_REGISTER, sdl, MVT::Other, Chain,
RegName, getValue(RegValue)));
return nullptr;
}
case Intrinsic::setjmp:
return &"_setjmp"[!TLI.usesUnderscoreSetJmp()];
case Intrinsic::longjmp:
return &"_longjmp"[!TLI.usesUnderscoreLongJmp()];
case Intrinsic::memcpy: {
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
if (!Align)
Align = 1; // @llvm.memcpy defines 0 and 1 to both mean no alignment.
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
SDValue MC = DAG.getMemcpy(getRoot(), sdl, Op1, Op2, Op3, Align, isVol,
false, isTC,
MachinePointerInfo(I.getArgOperand(0)),
MachinePointerInfo(I.getArgOperand(1)));
updateDAGForMaybeTailCall(MC);
return nullptr;
}
case Intrinsic::memset: {
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
if (!Align)
Align = 1; // @llvm.memset defines 0 and 1 to both mean no alignment.
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
SDValue MS = DAG.getMemset(getRoot(), sdl, Op1, Op2, Op3, Align, isVol,
isTC, MachinePointerInfo(I.getArgOperand(0)));
updateDAGForMaybeTailCall(MS);
return nullptr;
}
case Intrinsic::memmove: {
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDValue Op3 = getValue(I.getArgOperand(2));
unsigned Align = cast<ConstantInt>(I.getArgOperand(3))->getZExtValue();
if (!Align)
Align = 1; // @llvm.memmove defines 0 and 1 to both mean no alignment.
bool isVol = cast<ConstantInt>(I.getArgOperand(4))->getZExtValue();
bool isTC = I.isTailCall() && isInTailCallPosition(&I, DAG.getTarget());
SDValue MM = DAG.getMemmove(getRoot(), sdl, Op1, Op2, Op3, Align, isVol,
isTC, MachinePointerInfo(I.getArgOperand(0)),
MachinePointerInfo(I.getArgOperand(1)));
updateDAGForMaybeTailCall(MM);
return nullptr;
}
case Intrinsic::dbg_declare: {
const DbgDeclareInst &DI = cast<DbgDeclareInst>(I);
DILocalVariable *Variable = DI.getVariable();
DIExpression *Expression = DI.getExpression();
const Value *Address = DI.getAddress();
assert(Variable && "Missing variable");
if (!Address) {
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
return nullptr;
}
// Check if address has undef value.
if (isa<UndefValue>(Address) ||
(Address->use_empty() && !isa<Argument>(Address))) {
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
return nullptr;
}
SDValue &N = NodeMap[Address];
if (!N.getNode() && isa<Argument>(Address))
// Check unused arguments map.
N = UnusedArgNodeMap[Address];
SDDbgValue *SDV;
if (N.getNode()) {
if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
Address = BCI->getOperand(0);
// Parameters are handled specially.
bool isParameter = Variable->isParameter() || isa<Argument>(Address);
auto FINode = dyn_cast<FrameIndexSDNode>(N.getNode());
if (isParameter && FINode) {
// Byval parameter. We have a frame index at this point.
SDV = DAG.getFrameIndexDbgValue(Variable, Expression,
FINode->getIndex(), 0, dl, SDNodeOrder);
} else if (isa<Argument>(Address)) {
// Address is an argument, so try to emit its dbg value using
// virtual register info from the FuncInfo.ValueMap.
EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false,
N);
return nullptr;
} else {
SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
true, 0, dl, SDNodeOrder);
}
DAG.AddDbgValue(SDV, N.getNode(), isParameter);
} else {
// If Address is an argument then try to emit its dbg value using
// virtual register info from the FuncInfo.ValueMap.
if (!EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false,
N)) {
// If variable is pinned by a alloca in dominating bb then
// use StaticAllocaMap.
if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
if (AI->getParent() != DI.getParent()) {
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI != FuncInfo.StaticAllocaMap.end()) {
SDV = DAG.getFrameIndexDbgValue(Variable, Expression, SI->second,
0, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
return nullptr;
}
}
}
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
}
}
return nullptr;
}
case Intrinsic::dbg_value: {
const DbgValueInst &DI = cast<DbgValueInst>(I);
assert(DI.getVariable() && "Missing variable");
DILocalVariable *Variable = DI.getVariable();
DIExpression *Expression = DI.getExpression();
uint64_t Offset = DI.getOffset();
const Value *V = DI.getValue();
if (!V)
return nullptr;
SDDbgValue *SDV;
if (isa<ConstantInt>(V) || isa<ConstantFP>(V) || isa<UndefValue>(V)) {
SDV = DAG.getConstantDbgValue(Variable, Expression, V, Offset, dl,
SDNodeOrder);
DAG.AddDbgValue(SDV, nullptr, false);
} else {
// Do not use getValue() in here; we don't want to generate code at
// this point if it hasn't been done yet.
SDValue N = NodeMap[V];
if (!N.getNode() && isa<Argument>(V))
// Check unused arguments map.
N = UnusedArgNodeMap[V];
if (N.getNode()) {
if (!EmitFuncArgumentDbgValue(V, Variable, Expression, dl, Offset,
false, N)) {
SDV = getDbgValue(N, Variable, Expression, Offset, dl, SDNodeOrder);
DAG.AddDbgValue(SDV, N.getNode(), false);
}
} else if (!V->use_empty() ) {
// Do not call getValue(V) yet, as we don't want to generate code.
// Remember it for later.
DanglingDebugInfo DDI(&DI, dl, SDNodeOrder);
DanglingDebugInfoMap[V] = DDI;
} else {
// We may expand this to cover more cases. One case where we have no
// data available is an unreferenced parameter.
DEBUG(dbgs() << "Dropping debug info for " << DI << "\n");
}
}
// Build a debug info table entry.
if (const BitCastInst *BCI = dyn_cast<BitCastInst>(V))
V = BCI->getOperand(0);
const AllocaInst *AI = dyn_cast<AllocaInst>(V);
// Don't handle byval struct arguments or VLAs, for example.
if (!AI) {
DEBUG(dbgs() << "Dropping debug location info for:\n " << DI << "\n");
DEBUG(dbgs() << " Last seen at:\n " << *V << "\n");
return nullptr;
}
DenseMap<const AllocaInst*, int>::iterator SI =
FuncInfo.StaticAllocaMap.find(AI);
if (SI == FuncInfo.StaticAllocaMap.end())
return nullptr; // VLAs.
return nullptr;
}
case Intrinsic::eh_typeid_for: {
// Find the type id for the given typeinfo.
GlobalValue *GV = ExtractTypeInfo(I.getArgOperand(0));
unsigned TypeID = DAG.getMachineFunction().getMMI().getTypeIDFor(GV);
Res = DAG.getConstant(TypeID, sdl, MVT::i32);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::eh_return_i32:
case Intrinsic::eh_return_i64:
DAG.getMachineFunction().getMMI().setCallsEHReturn(true);
DAG.setRoot(DAG.getNode(ISD::EH_RETURN, sdl,
MVT::Other,
getControlRoot(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
case Intrinsic::eh_unwind_init:
DAG.getMachineFunction().getMMI().setCallsUnwindInit(true);
return nullptr;
case Intrinsic::eh_dwarf_cfa: {
setValue(&I, DAG.getNode(ISD::EH_DWARF_CFA, sdl,
TLI.getPointerTy(DAG.getDataLayout()),
getValue(I.getArgOperand(0))));
return nullptr;
}
case Intrinsic::eh_sjlj_callsite: {
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(0));
assert(CI && "Non-constant call site value in eh.sjlj.callsite!");
assert(MMI.getCurrentCallSite() == 0 && "Overlapping call sites!");
MMI.setCurrentCallSite(CI->getZExtValue());
return nullptr;
}
case Intrinsic::eh_sjlj_functioncontext: {
// Get and store the index of the function context.
MachineFrameInfo &MFI = DAG.getMachineFunction().getFrameInfo();
AllocaInst *FnCtx =
cast<AllocaInst>(I.getArgOperand(0)->stripPointerCasts());
int FI = FuncInfo.StaticAllocaMap[FnCtx];
MFI.setFunctionContextIndex(FI);
return nullptr;
}
case Intrinsic::eh_sjlj_setjmp: {
SDValue Ops[2];
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
SDValue Op = DAG.getNode(ISD::EH_SJLJ_SETJMP, sdl,
DAG.getVTList(MVT::i32, MVT::Other), Ops);
setValue(&I, Op.getValue(0));
DAG.setRoot(Op.getValue(1));
return nullptr;
}
case Intrinsic::eh_sjlj_longjmp: {
DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_LONGJMP, sdl, MVT::Other,
getRoot(), getValue(I.getArgOperand(0))));
return nullptr;
}
case Intrinsic::eh_sjlj_setup_dispatch: {
DAG.setRoot(DAG.getNode(ISD::EH_SJLJ_SETUP_DISPATCH, sdl, MVT::Other,
getRoot()));
return nullptr;
}
case Intrinsic::masked_gather:
visitMaskedGather(I);
return nullptr;
case Intrinsic::masked_load:
visitMaskedLoad(I);
return nullptr;
case Intrinsic::masked_scatter:
visitMaskedScatter(I);
return nullptr;
case Intrinsic::masked_store:
visitMaskedStore(I);
return nullptr;
case Intrinsic::x86_mmx_pslli_w:
case Intrinsic::x86_mmx_pslli_d:
case Intrinsic::x86_mmx_pslli_q:
case Intrinsic::x86_mmx_psrli_w:
case Intrinsic::x86_mmx_psrli_d:
case Intrinsic::x86_mmx_psrli_q:
case Intrinsic::x86_mmx_psrai_w:
case Intrinsic::x86_mmx_psrai_d: {
SDValue ShAmt = getValue(I.getArgOperand(1));
if (isa<ConstantSDNode>(ShAmt)) {
visitTargetIntrinsic(I, Intrinsic);
return nullptr;
}
unsigned NewIntrinsic = 0;
EVT ShAmtVT = MVT::v2i32;
switch (Intrinsic) {
case Intrinsic::x86_mmx_pslli_w:
NewIntrinsic = Intrinsic::x86_mmx_psll_w;
break;
case Intrinsic::x86_mmx_pslli_d:
NewIntrinsic = Intrinsic::x86_mmx_psll_d;
break;
case Intrinsic::x86_mmx_pslli_q:
NewIntrinsic = Intrinsic::x86_mmx_psll_q;
break;
case Intrinsic::x86_mmx_psrli_w:
NewIntrinsic = Intrinsic::x86_mmx_psrl_w;
break;
case Intrinsic::x86_mmx_psrli_d:
NewIntrinsic = Intrinsic::x86_mmx_psrl_d;
break;
case Intrinsic::x86_mmx_psrli_q:
NewIntrinsic = Intrinsic::x86_mmx_psrl_q;
break;
case Intrinsic::x86_mmx_psrai_w:
NewIntrinsic = Intrinsic::x86_mmx_psra_w;
break;
case Intrinsic::x86_mmx_psrai_d:
NewIntrinsic = Intrinsic::x86_mmx_psra_d;
break;
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
}
// The vector shift intrinsics with scalars uses 32b shift amounts but
// the sse2/mmx shift instructions reads 64 bits. Set the upper 32 bits
// to be zero.
// We must do this early because v2i32 is not a legal type.
SDValue ShOps[2];
ShOps[0] = ShAmt;
ShOps[1] = DAG.getConstant(0, sdl, MVT::i32);
ShAmt = DAG.getNode(ISD::BUILD_VECTOR, sdl, ShAmtVT, ShOps);
EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType());
ShAmt = DAG.getNode(ISD::BITCAST, sdl, DestVT, ShAmt);
Res = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, sdl, DestVT,
DAG.getConstant(NewIntrinsic, sdl, MVT::i32),
getValue(I.getArgOperand(0)), ShAmt);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::convertff:
case Intrinsic::convertfsi:
case Intrinsic::convertfui:
case Intrinsic::convertsif:
case Intrinsic::convertuif:
case Intrinsic::convertss:
case Intrinsic::convertsu:
case Intrinsic::convertus:
case Intrinsic::convertuu: {
ISD::CvtCode Code = ISD::CVT_INVALID;
switch (Intrinsic) {
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
case Intrinsic::convertff: Code = ISD::CVT_FF; break;
case Intrinsic::convertfsi: Code = ISD::CVT_FS; break;
case Intrinsic::convertfui: Code = ISD::CVT_FU; break;
case Intrinsic::convertsif: Code = ISD::CVT_SF; break;
case Intrinsic::convertuif: Code = ISD::CVT_UF; break;
case Intrinsic::convertss: Code = ISD::CVT_SS; break;
case Intrinsic::convertsu: Code = ISD::CVT_SU; break;
case Intrinsic::convertus: Code = ISD::CVT_US; break;
case Intrinsic::convertuu: Code = ISD::CVT_UU; break;
}
EVT DestVT = TLI.getValueType(DAG.getDataLayout(), I.getType());
const Value *Op1 = I.getArgOperand(0);
Res = DAG.getConvertRndSat(DestVT, sdl, getValue(Op1),
DAG.getValueType(DestVT),
DAG.getValueType(getValue(Op1).getValueType()),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2)),
Code);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::powi:
setValue(&I, ExpandPowI(sdl, getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)), DAG));
return nullptr;
case Intrinsic::log:
setValue(&I, expandLog(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::log2:
setValue(&I, expandLog2(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::log10:
setValue(&I, expandLog10(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::exp:
setValue(&I, expandExp(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::exp2:
setValue(&I, expandExp2(sdl, getValue(I.getArgOperand(0)), DAG, TLI));
return nullptr;
case Intrinsic::pow:
setValue(&I, expandPow(sdl, getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)), DAG, TLI));
return nullptr;
case Intrinsic::sqrt:
case Intrinsic::fabs:
case Intrinsic::sin:
case Intrinsic::cos:
case Intrinsic::floor:
case Intrinsic::ceil:
case Intrinsic::trunc:
case Intrinsic::rint:
case Intrinsic::nearbyint:
case Intrinsic::round:
case Intrinsic::canonicalize: {
unsigned Opcode;
switch (Intrinsic) {
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
case Intrinsic::sqrt: Opcode = ISD::FSQRT; break;
case Intrinsic::fabs: Opcode = ISD::FABS; break;
case Intrinsic::sin: Opcode = ISD::FSIN; break;
case Intrinsic::cos: Opcode = ISD::FCOS; break;
case Intrinsic::floor: Opcode = ISD::FFLOOR; break;
case Intrinsic::ceil: Opcode = ISD::FCEIL; break;
case Intrinsic::trunc: Opcode = ISD::FTRUNC; break;
case Intrinsic::rint: Opcode = ISD::FRINT; break;
case Intrinsic::nearbyint: Opcode = ISD::FNEARBYINT; break;
case Intrinsic::round: Opcode = ISD::FROUND; break;
case Intrinsic::canonicalize: Opcode = ISD::FCANONICALIZE; break;
}
setValue(&I, DAG.getNode(Opcode, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return nullptr;
}
case Intrinsic::minnum: {
auto VT = getValue(I.getArgOperand(0)).getValueType();
unsigned Opc =
I.hasNoNaNs() && TLI.isOperationLegalOrCustom(ISD::FMINNAN, VT)
? ISD::FMINNAN
: ISD::FMINNUM;
setValue(&I, DAG.getNode(Opc, sdl, VT,
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
}
case Intrinsic::maxnum: {
auto VT = getValue(I.getArgOperand(0)).getValueType();
unsigned Opc =
I.hasNoNaNs() && TLI.isOperationLegalOrCustom(ISD::FMAXNAN, VT)
? ISD::FMAXNAN
: ISD::FMAXNUM;
setValue(&I, DAG.getNode(Opc, sdl, VT,
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
}
case Intrinsic::copysign:
setValue(&I, DAG.getNode(ISD::FCOPYSIGN, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1))));
return nullptr;
case Intrinsic::fma:
setValue(&I, DAG.getNode(ISD::FMA, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2))));
return nullptr;
case Intrinsic::fmuladd: {
EVT VT = TLI.getValueType(DAG.getDataLayout(), I.getType());
if (TM.Options.AllowFPOpFusion != FPOpFusion::Strict &&
TLI.isFMAFasterThanFMulAndFAdd(VT)) {
setValue(&I, DAG.getNode(ISD::FMA, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
getValue(I.getArgOperand(2))));
} else {
// TODO: Intrinsic calls should have fast-math-flags.
SDValue Mul = DAG.getNode(ISD::FMUL, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)));
SDValue Add = DAG.getNode(ISD::FADD, sdl,
getValue(I.getArgOperand(0)).getValueType(),
Mul,
getValue(I.getArgOperand(2)));
setValue(&I, Add);
}
return nullptr;
}
case Intrinsic::convert_to_fp16:
setValue(&I, DAG.getNode(ISD::BITCAST, sdl, MVT::i16,
DAG.getNode(ISD::FP_ROUND, sdl, MVT::f16,
getValue(I.getArgOperand(0)),
DAG.getTargetConstant(0, sdl,
MVT::i32))));
return nullptr;
case Intrinsic::convert_from_fp16:
setValue(&I, DAG.getNode(ISD::FP_EXTEND, sdl,
TLI.getValueType(DAG.getDataLayout(), I.getType()),
DAG.getNode(ISD::BITCAST, sdl, MVT::f16,
getValue(I.getArgOperand(0)))));
return nullptr;
case Intrinsic::pcmarker: {
SDValue Tmp = getValue(I.getArgOperand(0));
DAG.setRoot(DAG.getNode(ISD::PCMARKER, sdl, MVT::Other, getRoot(), Tmp));
return nullptr;
}
case Intrinsic::readcyclecounter: {
SDValue Op = getRoot();
Res = DAG.getNode(ISD::READCYCLECOUNTER, sdl,
DAG.getVTList(MVT::i64, MVT::Other), Op);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return nullptr;
}
case Intrinsic::bitreverse:
setValue(&I, DAG.getNode(ISD::BITREVERSE, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return nullptr;
case Intrinsic::bswap:
setValue(&I, DAG.getNode(ISD::BSWAP, sdl,
getValue(I.getArgOperand(0)).getValueType(),
getValue(I.getArgOperand(0))));
return nullptr;
case Intrinsic::cttz: {
SDValue Arg = getValue(I.getArgOperand(0));
ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTTZ : ISD::CTTZ_ZERO_UNDEF,
sdl, Ty, Arg));
return nullptr;
}
case Intrinsic::ctlz: {
SDValue Arg = getValue(I.getArgOperand(0));
ConstantInt *CI = cast<ConstantInt>(I.getArgOperand(1));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(CI->isZero() ? ISD::CTLZ : ISD::CTLZ_ZERO_UNDEF,
sdl, Ty, Arg));
return nullptr;
}
case Intrinsic::ctpop: {
SDValue Arg = getValue(I.getArgOperand(0));
EVT Ty = Arg.getValueType();
setValue(&I, DAG.getNode(ISD::CTPOP, sdl, Ty, Arg));
return nullptr;
}
case Intrinsic::stacksave: {
SDValue Op = getRoot();
Res = DAG.getNode(
ISD::STACKSAVE, sdl,
DAG.getVTList(TLI.getPointerTy(DAG.getDataLayout()), MVT::Other), Op);
setValue(&I, Res);
DAG.setRoot(Res.getValue(1));
return nullptr;
}
case Intrinsic::stackrestore: {
Res = getValue(I.getArgOperand(0));
DAG.setRoot(DAG.getNode(ISD::STACKRESTORE, sdl, MVT::Other, getRoot(), Res));
return nullptr;
}
case Intrinsic::get_dynamic_area_offset: {
SDValue Op = getRoot();
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
EVT ResTy = TLI.getValueType(DAG.getDataLayout(), I.getType());
// Result type for @llvm.get.dynamic.area.offset should match PtrTy for
// target.
if (PtrTy != ResTy)
report_fatal_error("Wrong result type for @llvm.get.dynamic.area.offset"
" intrinsic!");
Res = DAG.getNode(ISD::GET_DYNAMIC_AREA_OFFSET, sdl, DAG.getVTList(ResTy),
Op);
DAG.setRoot(Op);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::stackguard: {
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
MachineFunction &MF = DAG.getMachineFunction();
const Module &M = *MF.getFunction()->getParent();
SDValue Chain = getRoot();
if (TLI.useLoadStackGuardNode()) {
Res = getLoadStackGuard(DAG, sdl, Chain);
} else {
const Value *Global = TLI.getSDagStackGuard(M);
unsigned Align = DL->getPrefTypeAlignment(Global->getType());
Res = DAG.getLoad(PtrTy, sdl, Chain, getValue(Global),
MachinePointerInfo(Global, 0), Align,
MachineMemOperand::MOVolatile);
}
DAG.setRoot(Chain);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::stackprotector: {
// Emit code into the DAG to store the stack guard onto the stack.
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo &MFI = MF.getFrameInfo();
EVT PtrTy = TLI.getPointerTy(DAG.getDataLayout());
SDValue Src, Chain = getRoot();
if (TLI.useLoadStackGuardNode())
Src = getLoadStackGuard(DAG, sdl, Chain);
else
Src = getValue(I.getArgOperand(0)); // The guard's value.
AllocaInst *Slot = cast<AllocaInst>(I.getArgOperand(1));
int FI = FuncInfo.StaticAllocaMap[Slot];
MFI.setStackProtectorIndex(FI);
SDValue FIN = DAG.getFrameIndex(FI, PtrTy);
// Store the stack protector onto the stack.
Res = DAG.getStore(Chain, sdl, Src, FIN, MachinePointerInfo::getFixedStack(
DAG.getMachineFunction(), FI),
/* Alignment = */ 0, MachineMemOperand::MOVolatile);
setValue(&I, Res);
DAG.setRoot(Res);
return nullptr;
}
case Intrinsic::objectsize: {
// If we don't know by now, we're never going to know.
ConstantInt *CI = dyn_cast<ConstantInt>(I.getArgOperand(1));
assert(CI && "Non-constant type in __builtin_object_size?");
SDValue Arg = getValue(I.getCalledValue());
EVT Ty = Arg.getValueType();
if (CI->isZero())
Res = DAG.getConstant(-1ULL, sdl, Ty);
else
Res = DAG.getConstant(0, sdl, Ty);
setValue(&I, Res);
return nullptr;
}
case Intrinsic::annotation:
case Intrinsic::ptr_annotation:
// Drop the intrinsic, but forward the value
setValue(&I, getValue(I.getOperand(0)));
return nullptr;
case Intrinsic::assume:
case Intrinsic::var_annotation:
// Discard annotate attributes and assumptions
return nullptr;
case Intrinsic::init_trampoline: {
const Function *F = cast<Function>(I.getArgOperand(1)->stripPointerCasts());
SDValue Ops[6];
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
Ops[2] = getValue(I.getArgOperand(1));
Ops[3] = getValue(I.getArgOperand(2));
Ops[4] = DAG.getSrcValue(I.getArgOperand(0));
Ops[5] = DAG.getSrcValue(F);
Res = DAG.getNode(ISD::INIT_TRAMPOLINE, sdl, MVT::Other, Ops);
DAG.setRoot(Res);
return nullptr;
}
case Intrinsic::adjust_trampoline: {
setValue(&I, DAG.getNode(ISD::ADJUST_TRAMPOLINE, sdl,
TLI.getPointerTy(DAG.getDataLayout()),
getValue(I.getArgOperand(0))));
return nullptr;
}
case Intrinsic::gcroot: {
MachineFunction &MF = DAG.getMachineFunction();
const Function *F = MF.getFunction();
(void)F;
assert(F->hasGC() &&
"only valid in functions with gc specified, enforced by Verifier");
assert(GFI && "implied by previous");
const Value *Alloca = I.getArgOperand(0)->stripPointerCasts();
const Constant *TypeMap = cast<Constant>(I.getArgOperand(1));
FrameIndexSDNode *FI = cast<FrameIndexSDNode>(getValue(Alloca).getNode());
GFI->addStackRoot(FI->getIndex(), TypeMap);
return nullptr;
}
case Intrinsic::gcread:
case Intrinsic::gcwrite:
llvm_unreachable("GC failed to lower gcread/gcwrite intrinsics!");
case Intrinsic::flt_rounds:
setValue(&I, DAG.getNode(ISD::FLT_ROUNDS_, sdl, MVT::i32));
return nullptr;
case Intrinsic::expect: {
// Just replace __builtin_expect(exp, c) with EXP.
setValue(&I, getValue(I.getArgOperand(0)));
return nullptr;
}
case Intrinsic::debugtrap:
case Intrinsic::trap: {
StringRef TrapFuncName =
I.getAttributes()
.getAttribute(AttributeSet::FunctionIndex, "trap-func-name")
.getValueAsString();
if (TrapFuncName.empty()) {
ISD::NodeType Op = (Intrinsic == Intrinsic::trap) ?
ISD::TRAP : ISD::DEBUGTRAP;
DAG.setRoot(DAG.getNode(Op, sdl,MVT::Other, getRoot()));
return nullptr;
}
TargetLowering::ArgListTy Args;
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(sdl).setChain(getRoot()).setCallee(
CallingConv::C, I.getType(),
DAG.getExternalSymbol(TrapFuncName.data(),
TLI.getPointerTy(DAG.getDataLayout())),
std::move(Args));
std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI);
DAG.setRoot(Result.second);
return nullptr;
}
case Intrinsic::uadd_with_overflow:
case Intrinsic::sadd_with_overflow:
case Intrinsic::usub_with_overflow:
case Intrinsic::ssub_with_overflow:
case Intrinsic::umul_with_overflow:
case Intrinsic::smul_with_overflow: {
ISD::NodeType Op;
switch (Intrinsic) {
default: llvm_unreachable("Impossible intrinsic"); // Can't reach here.
case Intrinsic::uadd_with_overflow: Op = ISD::UADDO; break;
case Intrinsic::sadd_with_overflow: Op = ISD::SADDO; break;
case Intrinsic::usub_with_overflow: Op = ISD::USUBO; break;
case Intrinsic::ssub_with_overflow: Op = ISD::SSUBO; break;
case Intrinsic::umul_with_overflow: Op = ISD::UMULO; break;
case Intrinsic::smul_with_overflow: Op = ISD::SMULO; break;
}
SDValue Op1 = getValue(I.getArgOperand(0));
SDValue Op2 = getValue(I.getArgOperand(1));
SDVTList VTs = DAG.getVTList(Op1.getValueType(), MVT::i1);
setValue(&I, DAG.getNode(Op, sdl, VTs, Op1, Op2));
return nullptr;
}
case Intrinsic::prefetch: {
SDValue Ops[5];
unsigned rw = cast<ConstantInt>(I.getArgOperand(1))->getZExtValue();
Ops[0] = getRoot();
Ops[1] = getValue(I.getArgOperand(0));
Ops[2] = getValue(I.getArgOperand(1));
Ops[3] = getValue(I.getArgOperand(2));
Ops[4] = getValue(I.getArgOperand(3));
DAG.setRoot(DAG.getMemIntrinsicNode(ISD::PREFETCH, sdl,
DAG.getVTList(MVT::Other), Ops,
EVT::getIntegerVT(*Context, 8),
MachinePointerInfo(I.getArgOperand(0)),
0, /* align */
false, /* volatile */
rw==0, /* read */
rw==1)); /* write */
return nullptr;
}
case Intrinsic::lifetime_start:
case Intrinsic::lifetime_end: {
bool IsStart = (Intrinsic == Intrinsic::lifetime_start);
// Stack coloring is not enabled in O0, discard region information.
if (TM.getOptLevel() == CodeGenOpt::None)
return nullptr;
SmallVector<Value *, 4> Allocas;
GetUnderlyingObjects(I.getArgOperand(1), Allocas, *DL);
for (SmallVectorImpl<Value*>::iterator Object = Allocas.begin(),
E = Allocas.end(); Object != E; ++Object) {
AllocaInst *LifetimeObject = dyn_cast_or_null<AllocaInst>(*Object);
// Could not find an Alloca.
if (!LifetimeObject)
continue;
// First check that the Alloca is static, otherwise it won't have a
// valid frame index.
auto SI = FuncInfo.StaticAllocaMap.find(LifetimeObject);
if (SI == FuncInfo.StaticAllocaMap.end())
return nullptr;
int FI = SI->second;
SDValue Ops[2];
Ops[0] = getRoot();
Ops[1] =
DAG.getFrameIndex(FI, TLI.getPointerTy(DAG.getDataLayout()), true);
unsigned Opcode = (IsStart ? ISD::LIFETIME_START : ISD::LIFETIME_END);
Res = DAG.getNode(Opcode, sdl, MVT::Other, Ops);
DAG.setRoot(Res);
}
return nullptr;
}
case Intrinsic::invariant_start:
// Discard region information.
setValue(&I, DAG.getUNDEF(TLI.getPointerTy(DAG.getDataLayout())));
return nullptr;
case Intrinsic::invariant_end:
// Discard region information.
return nullptr;
case Intrinsic::clear_cache:
return TLI.getClearCacheBuiltinName();
case Intrinsic::donothing:
// ignore
return nullptr;
case Intrinsic::experimental_stackmap: {
visitStackmap(I);
return nullptr;
}
case Intrinsic::experimental_patchpoint_void:
case Intrinsic::experimental_patchpoint_i64: {
visitPatchpoint(&I);
return nullptr;
}
case Intrinsic::experimental_gc_statepoint: {
LowerStatepoint(ImmutableStatepoint(&I));
return nullptr;
}
case Intrinsic::experimental_gc_result: {
visitGCResult(cast<GCResultInst>(I));
return nullptr;
}
case Intrinsic::experimental_gc_relocate: {
visitGCRelocate(cast<GCRelocateInst>(I));
return nullptr;
}
case Intrinsic::instrprof_increment:
llvm_unreachable("instrprof failed to lower an increment");
case Intrinsic::instrprof_value_profile:
llvm_unreachable("instrprof failed to lower a value profiling call");
case Intrinsic::localescape: {
MachineFunction &MF = DAG.getMachineFunction();
const TargetInstrInfo *TII = DAG.getSubtarget().getInstrInfo();
// Directly emit some LOCAL_ESCAPE machine instrs. Label assignment emission
// is the same on all targets.
for (unsigned Idx = 0, E = I.getNumArgOperands(); Idx < E; ++Idx) {
Value *Arg = I.getArgOperand(Idx)->stripPointerCasts();
if (isa<ConstantPointerNull>(Arg))
continue; // Skip null pointers. They represent a hole in index space.
AllocaInst *Slot = cast<AllocaInst>(Arg);
assert(FuncInfo.StaticAllocaMap.count(Slot) &&
"can only escape static allocas");
int FI = FuncInfo.StaticAllocaMap[Slot];
MCSymbol *FrameAllocSym =
MF.getMMI().getContext().getOrCreateFrameAllocSymbol(
GlobalValue::getRealLinkageName(MF.getName()), Idx);
BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, dl,
TII->get(TargetOpcode::LOCAL_ESCAPE))
.addSym(FrameAllocSym)
.addFrameIndex(FI);
}
return nullptr;
}
case Intrinsic::localrecover: {
// i8* @llvm.localrecover(i8* %fn, i8* %fp, i32 %idx)
MachineFunction &MF = DAG.getMachineFunction();
MVT PtrVT = TLI.getPointerTy(DAG.getDataLayout(), 0);
// Get the symbol that defines the frame offset.
auto *Fn = cast<Function>(I.getArgOperand(0)->stripPointerCasts());
auto *Idx = cast<ConstantInt>(I.getArgOperand(2));
unsigned IdxVal = unsigned(Idx->getLimitedValue(INT_MAX));
MCSymbol *FrameAllocSym =
MF.getMMI().getContext().getOrCreateFrameAllocSymbol(
GlobalValue::getRealLinkageName(Fn->getName()), IdxVal);
// Create a MCSymbol for the label to avoid any target lowering
// that would make this PC relative.
SDValue OffsetSym = DAG.getMCSymbol(FrameAllocSym, PtrVT);
SDValue OffsetVal =
DAG.getNode(ISD::LOCAL_RECOVER, sdl, PtrVT, OffsetSym);
// Add the offset to the FP.
Value *FP = I.getArgOperand(1);
SDValue FPVal = getValue(FP);
SDValue Add = DAG.getNode(ISD::ADD, sdl, PtrVT, FPVal, OffsetVal);
setValue(&I, Add);
return nullptr;
}
case Intrinsic::eh_exceptionpointer:
case Intrinsic::eh_exceptioncode: {
// Get the exception pointer vreg, copy from it, and resize it to fit.
const auto *CPI = cast<CatchPadInst>(I.getArgOperand(0));
MVT PtrVT = TLI.getPointerTy(DAG.getDataLayout());
const TargetRegisterClass *PtrRC = TLI.getRegClassFor(PtrVT);
unsigned VReg = FuncInfo.getCatchPadExceptionPointerVReg(CPI, PtrRC);
SDValue N =
DAG.getCopyFromReg(DAG.getEntryNode(), getCurSDLoc(), VReg, PtrVT);
if (Intrinsic == Intrinsic::eh_exceptioncode)
N = DAG.getZExtOrTrunc(N, getCurSDLoc(), MVT::i32);
setValue(&I, N);
return nullptr;
}
case Intrinsic::experimental_deoptimize:
LowerDeoptimizeCall(&I);
return nullptr;
}
}
std::pair<SDValue, SDValue>
SelectionDAGBuilder::lowerInvokable(TargetLowering::CallLoweringInfo &CLI,
const BasicBlock *EHPadBB) {
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
MCSymbol *BeginLabel = nullptr;
if (EHPadBB) {
// Insert a label before the invoke call to mark the try range. This can be
// used to detect deletion of the invoke via the MachineModuleInfo.
BeginLabel = MMI.getContext().createTempSymbol();
// For SjLj, keep track of which landing pads go with which invokes
// so as to maintain the ordering of pads in the LSDA.
unsigned CallSiteIndex = MMI.getCurrentCallSite();
if (CallSiteIndex) {
MMI.setCallSiteBeginLabel(BeginLabel, CallSiteIndex);
LPadToCallSiteMap[FuncInfo.MBBMap[EHPadBB]].push_back(CallSiteIndex);
// Now that the call site is handled, stop tracking it.
MMI.setCurrentCallSite(0);
}
// Both PendingLoads and PendingExports must be flushed here;
// this call might not return.
(void)getRoot();
DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getControlRoot(), BeginLabel));
CLI.setChain(getRoot());
}
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
std::pair<SDValue, SDValue> Result = TLI.LowerCallTo(CLI);
assert((CLI.IsTailCall || Result.second.getNode()) &&
"Non-null chain expected with non-tail call!");
assert((Result.second.getNode() || !Result.first.getNode()) &&
"Null value expected with tail call!");
if (!Result.second.getNode()) {
// As a special case, a null chain means that a tail call has been emitted
// and the DAG root is already updated.
HasTailCall = true;
// Since there's no actual continuation from this block, nothing can be
// relying on us setting vregs for them.
PendingExports.clear();
} else {
DAG.setRoot(Result.second);
}
if (EHPadBB) {
// Insert a label at the end of the invoke call to mark the try range. This
// can be used to detect deletion of the invoke via the MachineModuleInfo.
MCSymbol *EndLabel = MMI.getContext().createTempSymbol();
DAG.setRoot(DAG.getEHLabel(getCurSDLoc(), getRoot(), EndLabel));
// Inform MachineModuleInfo of range.
if (MMI.hasEHFunclets()) {
assert(CLI.CS);
WinEHFuncInfo *EHInfo = DAG.getMachineFunction().getWinEHFuncInfo();
EHInfo->addIPToStateRange(cast<InvokeInst>(CLI.CS->getInstruction()),
BeginLabel, EndLabel);
} else {
MMI.addInvoke(FuncInfo.MBBMap[EHPadBB], BeginLabel, EndLabel);
}
}
return Result;
}
void SelectionDAGBuilder::LowerCallTo(ImmutableCallSite CS, SDValue Callee,
bool isTailCall,
const BasicBlock *EHPadBB) {
auto &DL = DAG.getDataLayout();
FunctionType *FTy = CS.getFunctionType();
Type *RetTy = CS.getType();
TargetLowering::ArgListTy Args;
TargetLowering::ArgListEntry Entry;
Args.reserve(CS.arg_size());
const Value *SwiftErrorVal = nullptr;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
for (ImmutableCallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end();
i != e; ++i) {
const Value *V = *i;
// Skip empty types
if (V->getType()->isEmptyTy())
continue;
SDValue ArgNode = getValue(V);
Entry.Node = ArgNode; Entry.Ty = V->getType();
// Skip the first return-type Attribute to get to params.
Entry.setAttributes(&CS, i - CS.arg_begin() + 1);
// Use swifterror virtual register as input to the call.
if (Entry.isSwiftError && TLI.supportSwiftError()) {
SwiftErrorVal = V;
// We find the virtual register for the actual swifterror argument.
// Instead of using the Value, we use the virtual register instead.
Entry.Node = DAG.getRegister(
FuncInfo.findSwiftErrorVReg(FuncInfo.MBB, V),
EVT(TLI.getPointerTy(DL)));
}
Args.push_back(Entry);
// If we have an explicit sret argument that is an Instruction, (i.e., it
// might point to function-local memory), we can't meaningfully tail-call.
if (Entry.isSRet && isa<Instruction>(V))
isTailCall = false;
}
// Check if target-independent constraints permit a tail call here.
// Target-dependent constraints are checked within TLI->LowerCallTo.
if (isTailCall && !isInTailCallPosition(CS, DAG.getTarget()))
isTailCall = false;
// Disable tail calls if there is an swifterror argument. Targets have not
// been updated to support tail calls.
if (TLI.supportSwiftError() && SwiftErrorVal)
isTailCall = false;
TargetLowering::CallLoweringInfo CLI(DAG);
CLI.setDebugLoc(getCurSDLoc())
.setChain(getRoot())
.setCallee(RetTy, FTy, Callee, std::move(Args), CS)
.setTailCall(isTailCall)
.setConvergent(CS.isConvergent());
std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB);
if (Result.first.getNode()) {
const Instruction *Inst = CS.getInstruction();
Result.first = lowerRangeToAssertZExt(DAG, *Inst, Result.first);
setValue(Inst, Result.first);
}
// The last element of CLI.InVals has the SDValue for swifterror return.
// Here we copy it to a virtual register and update SwiftErrorMap for
// book-keeping.
if (SwiftErrorVal && TLI.supportSwiftError()) {
// Get the last element of InVals.
SDValue Src = CLI.InVals.back();
const TargetRegisterClass *RC = TLI.getRegClassFor(TLI.getPointerTy(DL));
unsigned VReg = FuncInfo.MF->getRegInfo().createVirtualRegister(RC);
SDValue CopyNode = CLI.DAG.getCopyToReg(Result.second, CLI.DL, VReg, Src);
// We update the virtual register for the actual swifterror argument.
FuncInfo.setSwiftErrorVReg(FuncInfo.MBB, SwiftErrorVal, VReg);
DAG.setRoot(CopyNode);
}
}
/// IsOnlyUsedInZeroEqualityComparison - Return true if it only matters that the
/// value is equal or not-equal to zero.
static bool IsOnlyUsedInZeroEqualityComparison(const Value *V) {
for (const User *U : V->users()) {
if (const ICmpInst *IC = dyn_cast<ICmpInst>(U))
if (IC->isEquality())
if (const Constant *C = dyn_cast<Constant>(IC->getOperand(1)))
if (C->isNullValue())
continue;
// Unknown instruction.
return false;
}
return true;
}
static SDValue getMemCmpLoad(const Value *PtrVal, MVT LoadVT,
Type *LoadTy,
SelectionDAGBuilder &Builder) {
// Check to see if this load can be trivially constant folded, e.g. if the
// input is from a string literal.
if (const Constant *LoadInput = dyn_cast<Constant>(PtrVal)) {
// Cast pointer to the type we really want to load.
LoadInput = ConstantExpr::getBitCast(const_cast<Constant *>(LoadInput),
PointerType::getUnqual(LoadTy));
if (const Constant *LoadCst = ConstantFoldLoadFromConstPtr(
const_cast<Constant *>(LoadInput), LoadTy, *Builder.DL))
return Builder.getValue(LoadCst);
}
// Otherwise, we have to emit the load. If the pointer is to unfoldable but
// still constant memory, the input chain can be the entry node.
SDValue Root;
bool ConstantMemory = false;
// Do not serialize (non-volatile) loads of constant memory with anything.
if (Builder.AA->pointsToConstantMemory(PtrVal)) {
Root = Builder.DAG.getEntryNode();
ConstantMemory = true;
} else {
// Do not serialize non-volatile loads against each other.
Root = Builder.DAG.getRoot();
}
SDValue Ptr = Builder.getValue(PtrVal);
SDValue LoadVal = Builder.DAG.getLoad(LoadVT, Builder.getCurSDLoc(), Root,
Ptr, MachinePointerInfo(PtrVal),
/* Alignment = */ 1);
if (!ConstantMemory)
Builder.PendingLoads.push_back(LoadVal.getValue(1));
return LoadVal;
}
/// processIntegerCallValue - Record the value for an instruction that
/// produces an integer result, converting the type where necessary.
void SelectionDAGBuilder::processIntegerCallValue(const Instruction &I,
SDValue Value,
bool IsSigned) {
EVT VT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType(), true);
if (IsSigned)
Value = DAG.getSExtOrTrunc(Value, getCurSDLoc(), VT);
else
Value = DAG.getZExtOrTrunc(Value, getCurSDLoc(), VT);
setValue(&I, Value);
}
/// visitMemCmpCall - See if we can lower a call to memcmp in an optimized form.
/// If so, return true and lower it, otherwise return false and it will be
/// lowered like a normal call.
bool SelectionDAGBuilder::visitMemCmpCall(const CallInst &I) {
// Verify that the prototype makes sense. int memcmp(void*,void*,size_t)
if (I.getNumArgOperands() != 3)
return false;
const Value *LHS = I.getArgOperand(0), *RHS = I.getArgOperand(1);
if (!LHS->getType()->isPointerTy() || !RHS->getType()->isPointerTy() ||
!I.getArgOperand(2)->getType()->isIntegerTy() ||
!I.getType()->isIntegerTy())
return false;
const Value *Size = I.getArgOperand(2);
const ConstantInt *CSize = dyn_cast<ConstantInt>(Size);
if (CSize && CSize->getZExtValue() == 0) {
EVT CallVT = DAG.getTargetLoweringInfo().getValueType(DAG.getDataLayout(),
I.getType(), true);
setValue(&I, DAG.getConstant(0, getCurSDLoc(), CallVT));
return true;
}
const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForMemcmp(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(LHS), getValue(RHS), getValue(Size),
MachinePointerInfo(LHS),
MachinePointerInfo(RHS));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, true);
PendingLoads.push_back(Res.second);
return true;
}
// memcmp(S1,S2,2) != 0 -> (*(short*)LHS != *(short*)RHS) != 0
// memcmp(S1,S2,4) != 0 -> (*(int*)LHS != *(int*)RHS) != 0
if (CSize && IsOnlyUsedInZeroEqualityComparison(&I)) {
bool ActuallyDoIt = true;
MVT LoadVT;
Type *LoadTy;
switch (CSize->getZExtValue()) {
default:
LoadVT = MVT::Other;
LoadTy = nullptr;
ActuallyDoIt = false;
break;
case 2:
LoadVT = MVT::i16;
LoadTy = Type::getInt16Ty(CSize->getContext());
break;
case 4:
LoadVT = MVT::i32;
LoadTy = Type::getInt32Ty(CSize->getContext());
break;
case 8:
LoadVT = MVT::i64;
LoadTy = Type::getInt64Ty(CSize->getContext());
break;
/*
case 16:
LoadVT = MVT::v4i32;
LoadTy = Type::getInt32Ty(CSize->getContext());
LoadTy = VectorType::get(LoadTy, 4);
break;
*/
}
// This turns into unaligned loads. We only do this if the target natively
// supports the MVT we'll be loading or if it is small enough (<= 4) that
// we'll only produce a small number of byte loads.
// Require that we can find a legal MVT, and only do this if the target
// supports unaligned loads of that type. Expanding into byte loads would
// bloat the code.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (ActuallyDoIt && CSize->getZExtValue() > 4) {
unsigned DstAS = LHS->getType()->getPointerAddressSpace();
unsigned SrcAS = RHS->getType()->getPointerAddressSpace();
// TODO: Handle 5 byte compare as 4-byte + 1 byte.
// TODO: Handle 8 byte compare on x86-32 as two 32-bit loads.
// TODO: Check alignment of src and dest ptrs.
if (!TLI.isTypeLegal(LoadVT) ||
!TLI.allowsMisalignedMemoryAccesses(LoadVT, SrcAS) ||
!TLI.allowsMisalignedMemoryAccesses(LoadVT, DstAS))
ActuallyDoIt = false;
}
if (ActuallyDoIt) {
SDValue LHSVal = getMemCmpLoad(LHS, LoadVT, LoadTy, *this);
SDValue RHSVal = getMemCmpLoad(RHS, LoadVT, LoadTy, *this);
SDValue Res = DAG.getSetCC(getCurSDLoc(), MVT::i1, LHSVal, RHSVal,
ISD::SETNE);
processIntegerCallValue(I, Res, false);
return true;
}
}
return false;
}
/// visitMemChrCall -- See if we can lower a memchr call into an optimized
/// form. If so, return true and lower it, otherwise return false and it
/// will be lowered like a normal call.
bool SelectionDAGBuilder::visitMemChrCall(const CallInst &I) {
// Verify that the prototype makes sense. void *memchr(void *, int, size_t)
if (I.getNumArgOperands() != 3)
return false;
const Value *Src = I.getArgOperand(0);
const Value *Char = I.getArgOperand(1);
const Value *Length = I.getArgOperand(2);
if (!Src->getType()->isPointerTy() ||
!Char->getType()->isIntegerTy() ||
!Length->getType()->isIntegerTy() ||
!I.getType()->isPointerTy())
return false;
const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForMemchr(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Src), getValue(Char), getValue(Length),
MachinePointerInfo(Src));
if (Res.first.getNode()) {
setValue(&I, Res.first);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
///
/// visitMemPCpyCall -- lower a mempcpy call as a memcpy followed by code to
/// to adjust the dst pointer by the size of the copied memory.
bool SelectionDAGBuilder::visitMemPCpyCall(const CallInst &I) {
// Verify argument count: void *mempcpy(void *, const void *, size_t)
if (I.getNumArgOperands() != 3)
return false;
SDValue Dst = getValue(I.getArgOperand(0));
SDValue Src = getValue(I.getArgOperand(1));
SDValue Size = getValue(I.getArgOperand(2));
unsigned DstAlign = DAG.InferPtrAlignment(Dst);
unsigned SrcAlign = DAG.InferPtrAlignment(Src);
unsigned Align = std::min(DstAlign, SrcAlign);
if (Align == 0) // Alignment of one or both could not be inferred.
Align = 1; // 0 and 1 both specify no alignment, but 0 is reserved.
bool isVol = false;
SDLoc sdl = getCurSDLoc();
// In the mempcpy context we need to pass in a false value for isTailCall
// because the return pointer needs to be adjusted by the size of
// the copied memory.
SDValue MC = DAG.getMemcpy(getRoot(), sdl, Dst, Src, Size, Align, isVol,
false, /*isTailCall=*/false,
MachinePointerInfo(I.getArgOperand(0)),
MachinePointerInfo(I.getArgOperand(1)));
assert(MC.getNode() != nullptr &&
"** memcpy should not be lowered as TailCall in mempcpy context **");
DAG.setRoot(MC);
// Check if Size needs to be truncated or extended.
Size = DAG.getSExtOrTrunc(Size, sdl, Dst.getValueType());
// Adjust return pointer to point just past the last dst byte.
SDValue DstPlusSize = DAG.getNode(ISD::ADD, sdl, Dst.getValueType(),
Dst, Size);
setValue(&I, DstPlusSize);
return true;
}
/// visitStrCpyCall -- See if we can lower a strcpy or stpcpy call into an
/// optimized form. If so, return true and lower it, otherwise return false
/// and it will be lowered like a normal call.
bool SelectionDAGBuilder::visitStrCpyCall(const CallInst &I, bool isStpcpy) {
// Verify that the prototype makes sense. char *strcpy(char *, char *)
if (I.getNumArgOperands() != 2)
return false;
const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
if (!Arg0->getType()->isPointerTy() ||
!Arg1->getType()->isPointerTy() ||
!I.getType()->isPointerTy())
return false;
const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrcpy(DAG, getCurSDLoc(), getRoot(),
getValue(Arg0), getValue(Arg1),
MachinePointerInfo(Arg0),
MachinePointerInfo(Arg1), isStpcpy);
if (Res.first.getNode()) {
setValue(&I, Res.first);
DAG.setRoot(Res.second);
return true;
}
return false;
}
/// visitStrCmpCall - See if we can lower a call to strcmp in an optimized form.
/// If so, return true and lower it, otherwise return false and it will be
/// lowered like a normal call.
bool SelectionDAGBuilder::visitStrCmpCall(const CallInst &I) {
// Verify that the prototype makes sense. int strcmp(void*,void*)
if (I.getNumArgOperands() != 2)
return false;
const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
if (!Arg0->getType()->isPointerTy() ||
!Arg1->getType()->isPointerTy() ||
!I.getType()->isIntegerTy())
return false;
const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrcmp(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Arg0), getValue(Arg1),
MachinePointerInfo(Arg0),
MachinePointerInfo(Arg1));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, true);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
/// visitStrLenCall -- See if we can lower a strlen call into an optimized
/// form. If so, return true and lower it, otherwise return false and it
/// will be lowered like a normal call.
bool SelectionDAGBuilder::visitStrLenCall(const CallInst &I) {
// Verify that the prototype makes sense. size_t strlen(char *)
if (I.getNumArgOperands() != 1)
return false;
const Value *Arg0 = I.getArgOperand(0);
if (!Arg0->getType()->isPointerTy() || !I.getType()->isIntegerTy())
return false;
const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrlen(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Arg0), MachinePointerInfo(Arg0));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, false);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
/// visitStrNLenCall -- See if we can lower a strnlen call into an optimized
/// form. If so, return true and lower it, otherwise return false and it
/// will be lowered like a normal call.
bool SelectionDAGBuilder::visitStrNLenCall(const CallInst &I) {
// Verify that the prototype makes sense. size_t strnlen(char *, size_t)
if (I.getNumArgOperands() != 2)
return false;
const Value *Arg0 = I.getArgOperand(0), *Arg1 = I.getArgOperand(1);
if (!Arg0->getType()->isPointerTy() ||
!Arg1->getType()->isIntegerTy() ||
!I.getType()->isIntegerTy())
return false;
const SelectionDAGTargetInfo &TSI = DAG.getSelectionDAGInfo();
std::pair<SDValue, SDValue> Res =
TSI.EmitTargetCodeForStrnlen(DAG, getCurSDLoc(), DAG.getRoot(),
getValue(Arg0), getValue(Arg1),
MachinePointerInfo(Arg0));
if (Res.first.getNode()) {
processIntegerCallValue(I, Res.first, false);
PendingLoads.push_back(Res.second);
return true;
}
return false;
}
/// visitUnaryFloatCall - If a call instruction is a unary floating-point
/// operation (as expected), translate it to an SDNode with the specified opcode
/// and return true.
bool SelectionDAGBuilder::visitUnaryFloatCall(const CallInst &I,
unsigned Opcode) {
// Sanity check that it really is a unary floating-point call.
if (I.getNumArgOperands() != 1 ||
!I.getArgOperand(0)->getType()->isFloatingPointTy() ||
I.getType() != I.getArgOperand(0)->getType() ||
!I.onlyReadsMemory())
return false;
SDValue Tmp = getValue(I.getArgOperand(0));
setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), Tmp.getValueType(), Tmp));
return true;
}
/// visitBinaryFloatCall - If a call instruction is a binary floating-point
/// operation (as expected), translate it to an SDNode with the specified opcode
/// and return true.
bool SelectionDAGBuilder::visitBinaryFloatCall(const CallInst &I,
unsigned Opcode) {
// Sanity check that it really is a binary floating-point call.
if (I.getNumArgOperands() != 2 ||
!I.getArgOperand(0)->getType()->isFloatingPointTy() ||
I.getType() != I.getArgOperand(0)->getType() ||
I.getType() != I.getArgOperand(1)->getType() ||
!I.onlyReadsMemory())
return false;
SDValue Tmp0 = getValue(I.getArgOperand(0));
SDValue Tmp1 = getValue(I.getArgOperand(1));
EVT VT = Tmp0.getValueType();
setValue(&I, DAG.getNode(Opcode, getCurSDLoc(), VT, Tmp0, Tmp1));
return true;
}
void SelectionDAGBuilder::visitCall(const CallInst &I) {
// Handle inline assembly differently.
if (isa<InlineAsm>(I.getCalledValue())) {
visitInlineAsm(&I);
return;
}
MachineModuleInfo &MMI = DAG.getMachineFunction().getMMI();
ComputeUsesVAFloatArgument(I, &MMI);
const char *RenameFn = nullptr;
if (Function *F = I.getCalledFunction()) {
if (F->isDeclaration()) {
if (const TargetIntrinsicInfo *II = TM.getIntrinsicInfo()) {
if (unsigned IID = II->getIntrinsicID(F)) {
RenameFn = visitIntrinsicCall(I, IID);
if (!RenameFn)
return;
}
}
if (Intrinsic::ID IID = F->getIntrinsicID()) {
RenameFn = visitIntrinsicCall(I, IID);
if (!RenameFn)
return;
}
}
// Check for well-known libc/libm calls. If the function is internal, it
// can't be a library call. Don't do the check if marked as nobuiltin for
// some reason.
LibFunc::Func Func;
if (!I.isNoBuiltin() && !F->hasLocalLinkage() && F->hasName() &&
LibInfo->getLibFunc(F->getName(), Func) &&
LibInfo->hasOptimizedCodeGen(Func)) {
switch (Func) {
default: break;
case LibFunc::copysign:
case LibFunc::copysignf:
case LibFunc::copysignl:
if (I.getNumArgOperands() == 2 && // Basic sanity checks.
I.getArgOperand(0)->getType()->isFloatingPointTy() &&
I.getType() == I.getArgOperand(0)->getType() &&
I.getType() == I.getArgOperand(1)->getType() &&
I.onlyReadsMemory()) {
SDValue LHS = getValue(I.getArgOperand(0));
SDValue RHS = getValue(I.getArgOperand(1));
setValue(&I, DAG.getNode(ISD::FCOPYSIGN, getCurSDLoc(),
LHS.getValueType(), LHS, RHS));
return;
}
break;
case LibFunc::fabs:
case LibFunc::fabsf:
case LibFunc::fabsl:
if (visitUnaryFloatCall(I, ISD::FABS))
return;
break;
case LibFunc::fmin:
case LibFunc::fminf:
case LibFunc::fminl:
if (visitBinaryFloatCall(I, ISD::FMINNUM))
return;
break;
case LibFunc::fmax:
case LibFunc::fmaxf:
case LibFunc::fmaxl:
if (visitBinaryFloatCall(I, ISD::FMAXNUM))
return;
break;
case LibFunc::sin:
case LibFunc::sinf:
case LibFunc::sinl:
if (visitUnaryFloatCall(I, ISD::FSIN))
return;
break;
case LibFunc::cos:
case LibFunc::cosf:
case LibFunc::cosl:
if (visitUnaryFloatCall(I, ISD::FCOS))
return;
break;
case LibFunc::sqrt:
case LibFunc::sqrtf:
case LibFunc::sqrtl:
case LibFunc::sqrt_finite:
case LibFunc::sqrtf_finite:
case LibFunc::sqrtl_finite:
if (visitUnaryFloatCall(I, ISD::FSQRT))
return;
break;
case LibFunc::floor:
case LibFunc::floorf:
case LibFunc::floorl:
if (visitUnaryFloatCall(I, ISD::FFLOOR))
return;
break;
case LibFunc::nearbyint:
case LibFunc::nearbyintf:
case LibFunc::nearbyintl:
if (visitUnaryFloatCall(I, ISD::FNEARBYINT))
return;
break;
case LibFunc::ceil:
case LibFunc::ceilf:
case LibFunc::ceill:
if (visitUnaryFloatCall(I, ISD::FCEIL))
return;
break;
case LibFunc::rint:
case LibFunc::rintf:
case LibFunc::rintl:
if (visitUnaryFloatCall(I, ISD::FRINT))
return;
break;
case LibFunc::round:
case LibFunc::roundf:
case LibFunc::roundl:
if (visitUnaryFloatCall(I, ISD::FROUND))
return;
break;
case LibFunc::trunc:
case LibFunc::truncf:
case LibFunc::truncl:
if (visitUnaryFloatCall(I, ISD::FTRUNC))
return;
break;
case LibFunc::log2:
case LibFunc::log2f:
case LibFunc::log2l:
if (visitUnaryFloatCall(I, ISD::FLOG2))
return;
break;
case LibFunc::exp2:
case LibFunc::exp2f:
case LibFunc::exp2l:
if (visitUnaryFloatCall(I, ISD::FEXP2))
return;
break;
case LibFunc::memcmp:
if (visitMemCmpCall(I))
return;
break;
case LibFunc::mempcpy:
if (visitMemPCpyCall(I))
return;
break;
case LibFunc::memchr:
if (visitMemChrCall(I))
return;
break;
case LibFunc::strcpy:
if (visitStrCpyCall(I, false))
return;
break;
case LibFunc::stpcpy:
if (visitStrCpyCall(I, true))
return;
break;
case LibFunc::strcmp:
if (visitStrCmpCall(I))
return;
break;
case LibFunc::strlen:
if (visitStrLenCall(I))
return;
break;
case LibFunc::strnlen:
if (visitStrNLenCall(I))
return;
break;
}
}
}
SDValue Callee;
if (!RenameFn)
Callee = getValue(I.getCalledValue());
else
Callee = DAG.getExternalSymbol(
RenameFn,
DAG.getTargetLoweringInfo().getPointerTy(DAG.getDataLayout()));
// Deopt bundles are lowered in LowerCallSiteWithDeoptBundle, and we don't
// have to do anything here to lower funclet bundles.
assert(!I.hasOperandBundlesOtherThan(
{LLVMContext::OB_deopt, LLVMContext::OB_funclet}) &&
"Cannot lower calls with arbitrary operand bundles!");
if (I.countOperandBundlesOfType(LLVMContext::OB_deopt))
LowerCallSiteWithDeoptBundle(&I, Callee, nullptr);
else
// Check if we can potentially perform a tail call. More detailed checking
// is be done within LowerCallTo, after more information about the call is
// known.
LowerCallTo(&I, Callee, I.isTailCall());
}
namespace {
/// AsmOperandInfo - This contains information for each constraint that we are
/// lowering.
class SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo {
public:
/// CallOperand - If this is the result output operand or a clobber
/// this is null, otherwise it is the incoming operand to the CallInst.
/// This gets modified as the asm is processed.
SDValue CallOperand;
/// AssignedRegs - If this is a register or register class operand, this
/// contains the set of register corresponding to the operand.
RegsForValue AssignedRegs;
explicit SDISelAsmOperandInfo(const TargetLowering::AsmOperandInfo &info)
: TargetLowering::AsmOperandInfo(info), CallOperand(nullptr,0) {
}
/// Whether or not this operand accesses memory
bool hasMemory(const TargetLowering &TLI) const {
// Indirect operand accesses access memory.
if (isIndirect)
return true;
for (const auto &Code : Codes)
if (TLI.getConstraintType(Code) == TargetLowering::C_Memory)
return true;
return false;
}
/// getCallOperandValEVT - Return the EVT of the Value* that this operand
/// corresponds to. If there is no Value* for this operand, it returns
/// MVT::Other.
EVT getCallOperandValEVT(LLVMContext &Context, const TargetLowering &TLI,
const DataLayout &DL) const {
if (!CallOperandVal) return MVT::Other;
if (isa<BasicBlock>(CallOperandVal))
return TLI.getPointerTy(DL);
llvm::Type *OpTy = CallOperandVal->getType();
// FIXME: code duplicated from TargetLowering::ParseConstraints().
// If this is an indirect operand, the operand is a pointer to the
// accessed type.
if (isIndirect) {
llvm::PointerType *PtrTy = dyn_cast<PointerType>(OpTy);
if (!PtrTy)
report_fatal_error("Indirect operand for inline asm not a pointer!");
OpTy = PtrTy->getElementType();
}
// Look for vector wrapped in a struct. e.g. { <16 x i8> }.
if (StructType *STy = dyn_cast<StructType>(OpTy))
if (STy->getNumElements() == 1)
OpTy = STy->getElementType(0);
// If OpTy is not a single value, it may be a struct/union that we
// can tile with integers.
if (!OpTy->isSingleValueType() && OpTy->isSized()) {
unsigned BitSize = DL.getTypeSizeInBits(OpTy);
switch (BitSize) {
default: break;
case 1:
case 8:
case 16:
case 32:
case 64:
case 128:
OpTy = IntegerType::get(Context, BitSize);
break;
}
}
return TLI.getValueType(DL, OpTy, true);
}
};
typedef SmallVector<SDISelAsmOperandInfo,16> SDISelAsmOperandInfoVector;
} // end anonymous namespace
/// Make sure that the output operand \p OpInfo and its corresponding input
/// operand \p MatchingOpInfo have compatible constraint types (otherwise error
/// out).
static void patchMatchingInput(const SDISelAsmOperandInfo &OpInfo,
SDISelAsmOperandInfo &MatchingOpInfo,
SelectionDAG &DAG) {
if (OpInfo.ConstraintVT == MatchingOpInfo.ConstraintVT)
return;
const TargetRegisterInfo *TRI = DAG.getSubtarget().getRegisterInfo();
const auto &TLI = DAG.getTargetLoweringInfo();
std::pair<unsigned, const TargetRegisterClass *> MatchRC =
TLI.getRegForInlineAsmConstraint(TRI, OpInfo.ConstraintCode,
OpInfo.ConstraintVT);
std::pair<unsigned, const TargetRegisterClass *> InputRC =
TLI.getRegForInlineAsmConstraint(TRI, MatchingOpInfo.ConstraintCode,
MatchingOpInfo.ConstraintVT);
if ((OpInfo.ConstraintVT.isInteger() !=
MatchingOpInfo.ConstraintVT.isInteger()) ||
(MatchRC.second != InputRC.second)) {
// FIXME: error out in a more elegant fashion
report_fatal_error("Unsupported asm: input constraint"
" with a matching output constraint of"
" incompatible type!");
}
MatchingOpInfo.ConstraintVT = OpInfo.ConstraintVT;
}
/// Get a direct memory input to behave well as an indirect operand.
/// This may introduce stores, hence the need for a \p Chain.
/// \return The (possibly updated) chain.
static SDValue getAddressForMemoryInput(SDValue Chain, const SDLoc &Location,
SDISelAsmOperandInfo &OpInfo,
SelectionDAG &DAG) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
// If we don't have an indirect input, put it in the constpool if we can,
// otherwise spill it to a stack slot.
// TODO: This isn't quite right. We need to handle these according to
// the addressing mode that the constraint wants. Also, this may take
// an additional register for the computation and we don't want that
// either.
// If the operand is a float, integer, or vector constant, spill to a
// constant pool entry to get its address.
const Value *OpVal = OpInfo.CallOperandVal;
if (isa<ConstantFP>(OpVal) || isa<ConstantInt>(OpVal) ||
isa<ConstantVector>(OpVal) || isa<ConstantDataVector>(OpVal)) {
OpInfo.CallOperand = DAG.getConstantPool(
cast<Constant>(OpVal), TLI.getPointerTy(DAG.getDataLayout()));
return Chain;
}
// Otherwise, create a stack slot and emit a store to it before the asm.
Type *Ty = OpVal->getType();
auto &DL = DAG.getDataLayout();
uint64_t TySize = DL.getTypeAllocSize(Ty);
unsigned Align = DL.getPrefTypeAlignment(Ty);
MachineFunction &MF = DAG.getMachineFunction();
int SSFI = MF.getFrameInfo().CreateStackObject(TySize, Align, false);
SDValue StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy(DL));
Chain = DAG.getStore(Chain, Location, OpInfo.CallOperand, StackSlot,
MachinePointerInfo::getFixedStack(MF, SSFI));
OpInfo.CallOperand = StackSlot;
return Chain;
}
/// GetRegistersForValue - Assign registers (virtual or physical) for the
/// specified operand. We prefer to assign virtual registers, to allow the
/// register allocator to handle the assignment process. However, if the asm
/// uses features that we can't model on machineinstrs, we have SDISel do the
/// allocation. This produces generally horrible, but correct, code.
///
/// OpInfo describes the operand.
///
static void GetRegistersForValue(SelectionDAG &DAG, const TargetLowering &TLI,
const SDLoc &DL,
SDISelAsmOperandInfo &OpInfo) {
LLVMContext &Context = *DAG.getContext();
MachineFunction &MF = DAG.getMachineFunction();
SmallVector<unsigned, 4> Regs;
// If this is a constraint for a single physreg, or a constraint for a
// register class, find it.
std::pair<unsigned, const TargetRegisterClass *> PhysReg =
TLI.getRegForInlineAsmConstraint(MF.getSubtarget().getRegisterInfo(),
OpInfo.ConstraintCode,
OpInfo.ConstraintVT);
unsigned NumRegs = 1;
if (OpInfo.ConstraintVT != MVT::Other) {
// If this is a FP input in an integer register (or visa versa) insert a bit
// cast of the input value. More generally, handle any case where the input
// value disagrees with the register class we plan to stick this in.
if (OpInfo.Type == InlineAsm::isInput &&
PhysReg.second && !PhysReg.second->hasType(OpInfo.ConstraintVT)) {
// Try to convert to the first EVT that the reg class contains. If the
// types are identical size, use a bitcast to convert (e.g. two differing
// vector types).
MVT RegVT = *PhysReg.second->vt_begin();
if (RegVT.getSizeInBits() == OpInfo.CallOperand.getValueSizeInBits()) {
OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL,
RegVT, OpInfo.CallOperand);
OpInfo.ConstraintVT = RegVT;
} else if (RegVT.isInteger() && OpInfo.ConstraintVT.isFloatingPoint()) {
// If the input is a FP value and we want it in FP registers, do a
// bitcast to the corresponding integer type. This turns an f64 value
// into i64, which can be passed with two i32 values on a 32-bit
// machine.
RegVT = MVT::getIntegerVT(OpInfo.ConstraintVT.getSizeInBits());
OpInfo.CallOperand = DAG.getNode(ISD::BITCAST, DL,
RegVT, OpInfo.CallOperand);
OpInfo.ConstraintVT = RegVT;
}
}
NumRegs = TLI.getNumRegisters(Context, OpInfo.ConstraintVT);
}
MVT RegVT;
EVT ValueVT = OpInfo.ConstraintVT;
// If this is a constraint for a specific physical register, like {r17},
// assign it now.
if (unsigned AssignedReg = PhysReg.first) {
const TargetRegisterClass *RC = PhysReg.second;
if (OpInfo.ConstraintVT == MVT::Other)
ValueVT = *RC->vt_begin();
// Get the actual register value type. This is important, because the user
// may have asked for (e.g.) the AX register in i32 type. We need to
// remember that AX is actually i16 to get the right extension.
RegVT = *RC->vt_begin();
// This is a explicit reference to a physical register.
Regs.push_back(AssignedReg);
// If this is an expanded reference, add the rest of the regs to Regs.
if (NumRegs != 1) {
TargetRegisterClass::iterator I = RC->begin();
for (; *I != AssignedReg; ++I)
assert(I != RC->end() && "Didn't find reg!");
// Already added the first reg.
--NumRegs; ++I;
for (; NumRegs; --NumRegs, ++I) {
assert(I != RC->end() && "Ran out of registers to allocate!");
Regs.push_back(*I);
}
}
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
return;
}
// Otherwise, if this was a reference to an LLVM register class, create vregs
// for this reference.
if (const TargetRegisterClass *RC = PhysReg.second) {
RegVT = *RC->vt_begin();
if (OpInfo.ConstraintVT == MVT::Other)
ValueVT = RegVT;
// Create the appropriate number of virtual registers.
MachineRegisterInfo &RegInfo = MF.getRegInfo();
for (; NumRegs; --NumRegs)
Regs.push_back(RegInfo.createVirtualRegister(RC));
OpInfo.AssignedRegs = RegsForValue(Regs, RegVT, ValueVT);
return;
}
// Otherwise, we couldn't allocate enough registers for this.
}
static unsigned
findMatchingInlineAsmOperand(unsigned OperandNo,
const std::vector<SDValue> &AsmNodeOperands) {
// Scan until we find the definition we already emitted of this operand.
unsigned CurOp = InlineAsm::Op_FirstOperand;
for (; OperandNo; --OperandNo) {
// Advance to the next operand.
unsigned OpFlag =
cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue();
assert((InlineAsm::isRegDefKind(OpFlag) ||
InlineAsm::isRegDefEarlyClobberKind(OpFlag) ||
InlineAsm::isMemKind(OpFlag)) &&
"Skipped past definitions?");
CurOp += InlineAsm::getNumOperandRegisters(OpFlag) + 1;
}
return CurOp;
}
/// Fill \p Regs with \p NumRegs new virtual registers of type \p RegVT
/// \return true if it has succeeded, false otherwise
static bool createVirtualRegs(SmallVector<unsigned, 4> &Regs, unsigned NumRegs,
MVT RegVT, SelectionDAG &DAG) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
MachineRegisterInfo &RegInfo = DAG.getMachineFunction().getRegInfo();
for (unsigned i = 0, e = NumRegs; i != e; ++i) {
if (const TargetRegisterClass *RC = TLI.getRegClassFor(RegVT))
Regs.push_back(RegInfo.createVirtualRegister(RC));
else
return false;
}
return true;
}
class ExtraFlags {
unsigned Flags = 0;
public:
explicit ExtraFlags(ImmutableCallSite CS) {
const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
if (IA->hasSideEffects())
Flags |= InlineAsm::Extra_HasSideEffects;
if (IA->isAlignStack())
Flags |= InlineAsm::Extra_IsAlignStack;
if (CS.isConvergent())
Flags |= InlineAsm::Extra_IsConvergent;
Flags |= IA->getDialect() * InlineAsm::Extra_AsmDialect;
}
void update(const llvm::TargetLowering::AsmOperandInfo &OpInfo) {
// Ideally, we would only check against memory constraints. However, the
// meaning of an Other constraint can be target-specific and we can't easily
// reason about it. Therefore, be conservative and set MayLoad/MayStore
// for Other constraints as well.
if (OpInfo.ConstraintType == TargetLowering::C_Memory ||
OpInfo.ConstraintType == TargetLowering::C_Other) {
if (OpInfo.Type == InlineAsm::isInput)
Flags |= InlineAsm::Extra_MayLoad;
else if (OpInfo.Type == InlineAsm::isOutput)
Flags |= InlineAsm::Extra_MayStore;
else if (OpInfo.Type == InlineAsm::isClobber)
Flags |= (InlineAsm::Extra_MayLoad | InlineAsm::Extra_MayStore);
}
}
unsigned get() const { return Flags; }
};
/// visitInlineAsm - Handle a call to an InlineAsm object.
///
void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
/// ConstraintOperands - Information about all of the constraints.
SDISelAsmOperandInfoVector ConstraintOperands;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
TargetLowering::AsmOperandInfoVector TargetConstraints = TLI.ParseConstraints(
DAG.getDataLayout(), DAG.getSubtarget().getRegisterInfo(), CS);
bool hasMemory = false;
// Remember the HasSideEffect, AlignStack, AsmDialect, MayLoad and MayStore
ExtraFlags ExtraInfo(CS);
unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
unsigned ResNo = 0; // ResNo - The result number of the next output.
for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
ConstraintOperands.push_back(SDISelAsmOperandInfo(TargetConstraints[i]));
SDISelAsmOperandInfo &OpInfo = ConstraintOperands.back();
MVT OpVT = MVT::Other;
// Compute the value type for each operand.
if (OpInfo.Type == InlineAsm::isInput ||
(OpInfo.Type == InlineAsm::isOutput && OpInfo.isIndirect)) {
OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
// Process the call argument. BasicBlocks are labels, currently appearing
// only in asm's.
if (const BasicBlock *BB = dyn_cast<BasicBlock>(OpInfo.CallOperandVal)) {
OpInfo.CallOperand = DAG.getBasicBlock(FuncInfo.MBBMap[BB]);
} else {
OpInfo.CallOperand = getValue(OpInfo.CallOperandVal);
}
OpVT =
OpInfo
.getCallOperandValEVT(*DAG.getContext(), TLI, DAG.getDataLayout())
.getSimpleVT();
}
if (OpInfo.Type == InlineAsm::isOutput && !OpInfo.isIndirect) {
// The return value of the call is this value. As such, there is no
// corresponding argument.
assert(!CS.getType()->isVoidTy() && "Bad inline asm!");
if (StructType *STy = dyn_cast<StructType>(CS.getType())) {
OpVT = TLI.getSimpleValueType(DAG.getDataLayout(),
STy->getElementType(ResNo));
} else {
assert(ResNo == 0 && "Asm only has one result!");
OpVT = TLI.getSimpleValueType(DAG.getDataLayout(), CS.getType());
}
++ResNo;
}
OpInfo.ConstraintVT = OpVT;
if (!hasMemory)
hasMemory = OpInfo.hasMemory(TLI);
// Determine if this InlineAsm MayLoad or MayStore based on the constraints.
// FIXME: Could we compute this on OpInfo rather than TargetConstraints[i]?
auto TargetConstraint = TargetConstraints[i];
// Compute the constraint code and ConstraintType to use.
TLI.ComputeConstraintToUse(TargetConstraint, SDValue());
ExtraInfo.update(TargetConstraint);
}
SDValue Chain, Flag;
// We won't need to flush pending loads if this asm doesn't touch
// memory and is nonvolatile.
if (hasMemory || IA->hasSideEffects())
Chain = getRoot();
else
Chain = DAG.getRoot();
// Second pass over the constraints: compute which constraint option to use
// and assign registers to constraints that want a specific physreg.
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
// If this is an output operand with a matching input operand, look up the
// matching input. If their types mismatch, e.g. one is an integer, the
// other is floating point, or their sizes are different, flag it as an
// error.
if (OpInfo.hasMatchingInput()) {
SDISelAsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
patchMatchingInput(OpInfo, Input, DAG);
}
// Compute the constraint code and ConstraintType to use.
TLI.ComputeConstraintToUse(OpInfo, OpInfo.CallOperand, &DAG);
if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
OpInfo.Type == InlineAsm::isClobber)
continue;
// If this is a memory input, and if the operand is not indirect, do what we
// need to to provide an address for the memory input.
if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
!OpInfo.isIndirect) {
assert((OpInfo.isMultipleAlternative ||
(OpInfo.Type == InlineAsm::isInput)) &&
"Can only indirectify direct input operands!");
// Memory operands really want the address of the value.
Chain = getAddressForMemoryInput(Chain, getCurSDLoc(), OpInfo, DAG);
// There is no longer a Value* corresponding to this operand.
OpInfo.CallOperandVal = nullptr;
// It is now an indirect operand.
OpInfo.isIndirect = true;
}
// If this constraint is for a specific register, allocate it before
// anything else.
if (OpInfo.ConstraintType == TargetLowering::C_Register)
GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo);
}
// Third pass - Loop over all of the operands, assigning virtual or physregs
// to register class operands.
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
// C_Register operands have already been allocated, Other/Memory don't need
// to be.
if (OpInfo.ConstraintType == TargetLowering::C_RegisterClass)
GetRegistersForValue(DAG, TLI, getCurSDLoc(), OpInfo);
}
// AsmNodeOperands - The operands for the ISD::INLINEASM node.
std::vector<SDValue> AsmNodeOperands;
AsmNodeOperands.push_back(SDValue()); // reserve space for input chain
AsmNodeOperands.push_back(DAG.getTargetExternalSymbol(
IA->getAsmString().c_str(), TLI.getPointerTy(DAG.getDataLayout())));
// If we have a !srcloc metadata node associated with it, we want to attach
// this to the ultimately generated inline asm machineinstr. To do this, we
// pass in the third operand as this (potentially null) inline asm MDNode.
const MDNode *SrcLoc = CS.getInstruction()->getMetadata("srcloc");
AsmNodeOperands.push_back(DAG.getMDNode(SrcLoc));
// Remember the HasSideEffect, AlignStack, AsmDialect, MayLoad and MayStore
// bits as operand 3.
AsmNodeOperands.push_back(DAG.getTargetConstant(
ExtraInfo.get(), getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout())));
// Loop over all of the inputs, copying the operand values into the
// appropriate registers and processing the output regs.
RegsForValue RetValRegs;
// IndirectStoresToEmit - The set of stores to emit after the inline asm node.
std::vector<std::pair<RegsForValue, Value*> > IndirectStoresToEmit;
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
switch (OpInfo.Type) {
case InlineAsm::isOutput: {
if (OpInfo.ConstraintType != TargetLowering::C_RegisterClass &&
OpInfo.ConstraintType != TargetLowering::C_Register) {
// Memory output, or 'other' output (e.g. 'X' constraint).
assert(OpInfo.isIndirect && "Memory output must be indirect operand");
unsigned ConstraintID =
TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode);
assert(ConstraintID != InlineAsm::Constraint_Unknown &&
"Failed to convert memory constraint code to constraint id.");
// Add information to the INLINEASM node to know about this output.
unsigned OpFlags = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
OpFlags = InlineAsm::getFlagWordForMem(OpFlags, ConstraintID);
AsmNodeOperands.push_back(DAG.getTargetConstant(OpFlags, getCurSDLoc(),
MVT::i32));
AsmNodeOperands.push_back(OpInfo.CallOperand);
break;
}
// Otherwise, this is a register or register class output.
// Copy the output from the appropriate register. Find a register that
// we can use.
if (OpInfo.AssignedRegs.Regs.empty()) {
emitInlineAsmError(
CS, "couldn't allocate output register for constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
// If this is an indirect operand, store through the pointer after the
// asm.
if (OpInfo.isIndirect) {
IndirectStoresToEmit.push_back(std::make_pair(OpInfo.AssignedRegs,
OpInfo.CallOperandVal));
} else {
// This is the result value of the call.
assert(!CS.getType()->isVoidTy() && "Bad inline asm!");
// Concatenate this output onto the outputs list.
RetValRegs.append(OpInfo.AssignedRegs);
}
// Add information to the INLINEASM node to know that this register is
// set.
OpInfo.AssignedRegs
.AddInlineAsmOperands(OpInfo.isEarlyClobber
? InlineAsm::Kind_RegDefEarlyClobber
: InlineAsm::Kind_RegDef,
false, 0, getCurSDLoc(), DAG, AsmNodeOperands);
break;
}
case InlineAsm::isInput: {
SDValue InOperandVal = OpInfo.CallOperand;
if (OpInfo.isMatchingInputConstraint()) {
// If this is required to match an output register we have already set,
// just use its register.
auto CurOp = findMatchingInlineAsmOperand(OpInfo.getMatchedOperand(),
AsmNodeOperands);
unsigned OpFlag =
cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getZExtValue();
if (InlineAsm::isRegDefKind(OpFlag) ||
InlineAsm::isRegDefEarlyClobberKind(OpFlag)) {
// Add (OpFlag&0xffff)>>3 registers to MatchedRegs.
if (OpInfo.isIndirect) {
// This happens on gcc/testsuite/gcc.dg/pr8788-1.c
emitInlineAsmError(CS, "inline asm not supported yet:"
" don't know how to handle tied "
"indirect register inputs");
return;
}
MVT RegVT = AsmNodeOperands[CurOp+1].getSimpleValueType();
SmallVector<unsigned, 4> Regs;
if (!createVirtualRegs(Regs,
InlineAsm::getNumOperandRegisters(OpFlag),
RegVT, DAG)) {
emitInlineAsmError(CS, "inline asm error: This value type register "
"class is not natively supported!");
return;
}
RegsForValue MatchedRegs(Regs, RegVT, InOperandVal.getValueType());
SDLoc dl = getCurSDLoc();
// Use the produced MatchedRegs object to
MatchedRegs.getCopyToRegs(InOperandVal, DAG, dl,
Chain, &Flag, CS.getInstruction());
MatchedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse,
true, OpInfo.getMatchedOperand(), dl,
DAG, AsmNodeOperands);
break;
}
assert(InlineAsm::isMemKind(OpFlag) && "Unknown matching constraint!");
assert(InlineAsm::getNumOperandRegisters(OpFlag) == 1 &&
"Unexpected number of operands");
// Add information to the INLINEASM node to know about this input.
// See InlineAsm.h isUseOperandTiedToDef.
OpFlag = InlineAsm::convertMemFlagWordToMatchingFlagWord(OpFlag);
OpFlag = InlineAsm::getFlagWordForMatchingOp(OpFlag,
OpInfo.getMatchedOperand());
AsmNodeOperands.push_back(DAG.getTargetConstant(
OpFlag, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout())));
AsmNodeOperands.push_back(AsmNodeOperands[CurOp+1]);
break;
}
// Treat indirect 'X' constraint as memory.
if (OpInfo.ConstraintType == TargetLowering::C_Other &&
OpInfo.isIndirect)
OpInfo.ConstraintType = TargetLowering::C_Memory;
if (OpInfo.ConstraintType == TargetLowering::C_Other) {
std::vector<SDValue> Ops;
TLI.LowerAsmOperandForConstraint(InOperandVal, OpInfo.ConstraintCode,
Ops, DAG);
if (Ops.empty()) {
emitInlineAsmError(CS, "invalid operand for inline asm constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
// Add information to the INLINEASM node to know about this input.
unsigned ResOpType =
InlineAsm::getFlagWord(InlineAsm::Kind_Imm, Ops.size());
AsmNodeOperands.push_back(DAG.getTargetConstant(
ResOpType, getCurSDLoc(), TLI.getPointerTy(DAG.getDataLayout())));
AsmNodeOperands.insert(AsmNodeOperands.end(), Ops.begin(), Ops.end());
break;
}
if (OpInfo.ConstraintType == TargetLowering::C_Memory) {
assert(OpInfo.isIndirect && "Operand must be indirect to be a mem!");
assert(InOperandVal.getValueType() ==
TLI.getPointerTy(DAG.getDataLayout()) &&
"Memory operands expect pointer values");
unsigned ConstraintID =
TLI.getInlineAsmMemConstraint(OpInfo.ConstraintCode);
assert(ConstraintID != InlineAsm::Constraint_Unknown &&
"Failed to convert memory constraint code to constraint id.");
// Add information to the INLINEASM node to know about this input.
unsigned ResOpType = InlineAsm::getFlagWord(InlineAsm::Kind_Mem, 1);
ResOpType = InlineAsm::getFlagWordForMem(ResOpType, ConstraintID);
AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType,
getCurSDLoc(),
MVT::i32));
AsmNodeOperands.push_back(InOperandVal);
break;
}
assert((OpInfo.ConstraintType == TargetLowering::C_RegisterClass ||
OpInfo.ConstraintType == TargetLowering::C_Register) &&
"Unknown constraint type!");
// TODO: Support this.
if (OpInfo.isIndirect) {
emitInlineAsmError(
CS, "Don't know how to handle indirect register inputs yet "
"for constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
// Copy the input into the appropriate registers.
if (OpInfo.AssignedRegs.Regs.empty()) {
emitInlineAsmError(CS, "couldn't allocate input reg for constraint '" +
Twine(OpInfo.ConstraintCode) + "'");
return;
}
SDLoc dl = getCurSDLoc();
OpInfo.AssignedRegs.getCopyToRegs(InOperandVal, DAG, dl,
Chain, &Flag, CS.getInstruction());
OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_RegUse, false, 0,
dl, DAG, AsmNodeOperands);
break;
}
case InlineAsm::isClobber: {
// Add the clobbered value to the operand list, so that the register
// allocator is aware that the physreg got clobbered.
if (!OpInfo.AssignedRegs.Regs.empty())
OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_Clobber,
false, 0, getCurSDLoc(), DAG,
AsmNodeOperands);
break;
}
}
}
// Finish up input operands. Set the input chain and add the flag last.
AsmNodeOperands[InlineAsm::Op_InputChain] = Chain;
if (Flag.getNode()) AsmNodeOperands.push_back(Flag);
Chain = DAG.getNode(ISD::INLINEASM, getCurSDLoc(),
DAG.getVTList(MVT::Other, MVT::Glue), AsmNodeOperands);
Flag = Chain.getValue(1);
// If this asm returns a register value, copy the result from that register
// and set it as the value of the call.
if (!RetValRegs.Regs.empty()) {
SDValue Val = RetValRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(),
Chain, &Flag, CS.getInstruction());
// FIXME: Why don't we do this for inline asms with MRVs?
if (CS.getType()->isSingleValueType() && CS.getType()->isSized()) {
EVT ResultType = TLI.getValueType(DAG.getDataLayout(), CS.getType());
// If any of the results of the inline asm is a vector, it may have the
// wrong width/num elts. This can happen for register classes that can
// contain multiple different value types. The preg or vreg allocated may
// not have the same VT as was expected. Convert it to the right type
// with bit_convert.
if (ResultType != Val.getValueType() && Val.getValueType().isVector()) {
Val = DAG.getNode(ISD::BITCAST, getCurSDLoc(),
ResultType, Val);
} else if (ResultType != Val.getValueType() &&
ResultType.isInteger() && Val.getValueType().isInteger()) {
// If a result value was tied to an input value, the computed result may
// have a wider width than the expected result. Extract the relevant
// portion.
Val = DAG.getNode(ISD::TRUNCATE, getCurSDLoc(), ResultType, Val);
}
assert(ResultType == Val.getValueType() && "Asm result value mismatch!");
}
setValue(CS.getInstruction(), Val);
// Don't need to use this as a chain in this case.
if (!IA->hasSideEffects() && !hasMemory && IndirectStoresToEmit.empty())
return;
}
std::vector<std::pair<SDValue, const Value *> > StoresToEmit;
// Process indirect outputs, first output all of the flagged copies out of
// physregs.
for (unsigned i = 0, e = IndirectStoresToEmit.size(); i != e; ++i) {
RegsForValue &OutRegs = IndirectStoresToEmit[i].first;
const Value *Ptr = IndirectStoresToEmit[i].second;
SDValue OutVal = OutRegs.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(),
Chain, &Flag, IA);
StoresToEmit.push_back(std::make_pair(OutVal, Ptr));
}
// Emit the non-flagged stores from the physregs.
SmallVector<SDValue, 8> OutChains;
for (unsigned i = 0, e = StoresToEmit.size(); i != e; ++i) {
SDValue Val = DAG.getStore(Chain, getCurSDLoc(), StoresToEmit[i].first,
getValue(StoresToEmit[i].second),
MachinePointerInfo(StoresToEmit[i].second));
OutChains.push_back(Val);
}
if (!OutChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, getCurSDLoc(), MVT::Other, OutChains);
DAG.setRoot(Chain);
}
void SelectionDAGBuilder::emitInlineAsmError(ImmutableCallSite CS,
const Twine &Message) {
LLVMContext &Ctx = *DAG.getContext();
Ctx.emitError(CS.getInstruction(), Message);
// Make sure we leave the DAG in a valid state
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
auto VT = TLI.getValueType(DAG.getDataLayout(), CS.getType());
setValue(CS.getInstruction(), DAG.getUNDEF(VT));
}
void SelectionDAGBuilder::visitVAStart(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VASTART, getCurSDLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(0))));
}
void SelectionDAGBuilder::visitVAArg(const VAArgInst &I) {
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
const DataLayout &DL = DAG.getDataLayout();
SDValue V = DAG.getVAArg(TLI.getValueType(DAG.getDataLayout(), I.getType()),
getCurSDLoc(), getRoot(), getValue(I.getOperand(0)),
DAG.getSrcValue(I.getOperand(0)),
DL.getABITypeAlignment(I.getType()));
setValue(&I, V);
DAG.setRoot(V.getValue(1));
}
void SelectionDAGBuilder::visitVAEnd(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VAEND, getCurSDLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(0))));
}
void SelectionDAGBuilder::visitVACopy(const CallInst &I) {
DAG.setRoot(DAG.getNode(ISD::VACOPY, getCurSDLoc(),
MVT::Other, getRoot(),
getValue(I.getArgOperand(0)),
getValue(I.getArgOperand(1)),
DAG.getSrcValue(I.getArgOperand(0)),
DAG.getSrcValue(I.getArgOperand(1))));
}
SDValue SelectionDAGBuilder::lowerRangeToAssertZExt(SelectionDAG &DAG,
const Instruction &I,
SDValue Op) {
const MDNode *Range = I.getMetadata(LLVMContext::MD_range);
if (!Range)
return Op;
Constant *Lo = cast<ConstantAsMetadata>(Range->getOperand(0))->getValue();
if (!Lo->isNullValue())
return Op;
Constant *Hi = cast<ConstantAsMetadata>(Range->getOperand(1))->getValue();
unsigned Bits = cast<ConstantInt>(Hi)->getValue().logBase2();
EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), Bits);
SDLoc SL = getCurSDLoc();
SDValue ZExt = DAG.getNode(ISD::AssertZext, SL, Op.getValueType(),
Op, DAG.getValueType(SmallVT));
unsigned NumVals = Op.getNode()->getNumValues();
if (NumVals == 1)
return ZExt;
SmallVector<SDValue, 4> Ops;
Ops.push_back(ZExt);
for (unsigned I = 1; I != NumVals; ++I)
Ops.push_back(Op.getValue(I));
return DAG.getMergeValues(Ops, SL);
}
/// \brief Populate a CallLowerinInfo (into \p CLI) based on the properties of
/// the call being lowered.
///
/// This is a helper for lowering intrinsics that follow a target calling
/// convention or require stack pointer adjustment. Only a subset of the
/// intrinsic's operands need to participate in the calling convention.
void SelectionDAGBuilder::populateCallLoweringInfo(
TargetLowering::CallLoweringInfo &CLI, ImmutableCallSite CS,
unsigned ArgIdx, unsigned NumArgs, SDValue Callee, Type *ReturnTy,
bool IsPatchPoint) {
TargetLowering::ArgListTy Args;
Args.reserve(NumArgs);
// Populate the argument list.
// Attributes for args start at offset 1, after the return attribute.
for (unsigned ArgI = ArgIdx, ArgE = ArgIdx + NumArgs, AttrI = ArgIdx + 1;
ArgI != ArgE; ++ArgI) {
const Value *V = CS->getOperand(ArgI);
assert(!V->getType()->isEmptyTy() && "Empty type passed to intrinsic.");
TargetLowering::ArgListEntry Entry;
Entry.Node = getValue(V);
Entry.Ty = V->getType();
Entry.setAttributes(&CS, AttrI);
Args.push_back(Entry);
}
CLI.setDebugLoc(getCurSDLoc())
.setChain(getRoot())
.setCallee(CS.getCallingConv(), ReturnTy, Callee, std::move(Args))
.setDiscardResult(CS->use_empty())
.setIsPatchPoint(IsPatchPoint);
}
/// \brief Add a stack map intrinsic call's live variable operands to a stackmap
/// or patchpoint target node's operand list.
///
/// Constants are converted to TargetConstants purely as an optimization to
/// avoid constant materialization and register allocation.
///
/// FrameIndex operands are converted to TargetFrameIndex so that ISEL does not
/// generate addess computation nodes, and so ExpandISelPseudo can convert the
/// TargetFrameIndex into a DirectMemRefOp StackMap location. This avoids
/// address materialization and register allocation, but may also be required
/// for correctness. If a StackMap (or PatchPoint) intrinsic directly uses an
/// alloca in the entry block, then the runtime may assume that the alloca's
/// StackMap location can be read immediately after compilation and that the
/// location is valid at any point during execution (this is similar to the
/// assumption made by the llvm.gcroot intrinsic). If the alloca's location were
/// only available in a register, then the runtime would need to trap when
/// execution reaches the StackMap in order to read the alloca's location.
static void addStackMapLiveVars(ImmutableCallSite CS, unsigned StartIdx,
const SDLoc &DL, SmallVectorImpl<SDValue> &Ops,
SelectionDAGBuilder &Builder) {
for (unsigned i = StartIdx, e = CS.arg_size(); i != e; ++i) {
SDValue OpVal = Builder.getValue(CS.getArgument(i));
if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(OpVal)) {
Ops.push_back(
Builder.DAG.getTargetConstant(StackMaps::ConstantOp, DL, MVT::i64));
Ops.push_back(
Builder.DAG.getTargetConstant(C->getSExtValue(), DL, MVT::i64));
} else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(OpVal)) {
const TargetLowering &TLI = Builder.DAG.getTargetLoweringInfo();
Ops.push_back(Builder.DAG.getTargetFrameIndex(
FI->getIndex(), TLI.getPointerTy(Builder.DAG.getDataLayout())));
} else
Ops.push_back(OpVal);
}
}
/// \brief Lower llvm.experimental.stackmap directly to its target opcode.
void SelectionDAGBuilder::visitStackmap(const CallInst &CI) {
// void @llvm.experimental.stackmap(i32 <id>, i32 <numShadowBytes>,
// [live variables...])
assert(CI.getType()->isVoidTy() && "Stackmap cannot return a value.");
SDValue Chain, InFlag, Callee, NullPtr;
SmallVector<SDValue, 32> Ops;
SDLoc DL = getCurSDLoc();
Callee = getValue(CI.getCalledValue());
NullPtr = DAG.getIntPtrConstant(0, DL, true);
// The stackmap intrinsic only records the live variables (the arguemnts
// passed to it) and emits NOPS (if requested). Unlike the patchpoint
// intrinsic, this won't be lowered to a function call. This means we don't
// have to worry about calling conventions and target specific lowering code.
// Instead we perform the call lowering right here.
//
// chain, flag = CALLSEQ_START(chain, 0)
// chain, flag = STACKMAP(id, nbytes, ..., chain, flag)
// chain, flag = CALLSEQ_END(chain, 0, 0, flag)
//
Chain = DAG.getCALLSEQ_START(getRoot(), NullPtr, DL);
InFlag = Chain.getValue(1);
// Add the <id> and <numBytes> constants.
SDValue IDVal = getValue(CI.getOperand(PatchPointOpers::IDPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(IDVal)->getZExtValue(), DL, MVT::i64));
SDValue NBytesVal = getValue(CI.getOperand(PatchPointOpers::NBytesPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(NBytesVal)->getZExtValue(), DL,
MVT::i32));
// Push live variables for the stack map.
addStackMapLiveVars(&CI, 2, DL, Ops, *this);
// We are not pushing any register mask info here on the operands list,
// because the stackmap doesn't clobber anything.
// Push the chain and the glue flag.
Ops.push_back(Chain);
Ops.push_back(InFlag);
// Create the STACKMAP node.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
SDNode *SM = DAG.getMachineNode(TargetOpcode::STACKMAP, DL, NodeTys, Ops);
Chain = SDValue(SM, 0);
InFlag = Chain.getValue(1);
Chain = DAG.getCALLSEQ_END(Chain, NullPtr, NullPtr, InFlag, DL);
// Stackmaps don't generate values, so nothing goes into the NodeMap.
// Set the root to the target-lowered call chain.
DAG.setRoot(Chain);
// Inform the Frame Information that we have a stackmap in this function.
FuncInfo.MF->getFrameInfo().setHasStackMap();
}
/// \brief Lower llvm.experimental.patchpoint directly to its target opcode.
void SelectionDAGBuilder::visitPatchpoint(ImmutableCallSite CS,
const BasicBlock *EHPadBB) {
// void|i64 @llvm.experimental.patchpoint.void|i64(i64 <id>,
// i32 <numBytes>,
// i8* <target>,
// i32 <numArgs>,
// [Args...],
// [live variables...])
CallingConv::ID CC = CS.getCallingConv();
bool IsAnyRegCC = CC == CallingConv::AnyReg;
bool HasDef = !CS->getType()->isVoidTy();
SDLoc dl = getCurSDLoc();
SDValue Callee = getValue(CS->getOperand(PatchPointOpers::TargetPos));
// Handle immediate and symbolic callees.
if (auto* ConstCallee = dyn_cast<ConstantSDNode>(Callee))
Callee = DAG.getIntPtrConstant(ConstCallee->getZExtValue(), dl,
/*isTarget=*/true);
else if (auto* SymbolicCallee = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(SymbolicCallee->getGlobal(),
SDLoc(SymbolicCallee),
SymbolicCallee->getValueType(0));
// Get the real number of arguments participating in the call <numArgs>
SDValue NArgVal = getValue(CS.getArgument(PatchPointOpers::NArgPos));
unsigned NumArgs = cast<ConstantSDNode>(NArgVal)->getZExtValue();
// Skip the four meta args: <id>, <numNopBytes>, <target>, <numArgs>
// Intrinsics include all meta-operands up to but not including CC.
unsigned NumMetaOpers = PatchPointOpers::CCPos;
assert(CS.arg_size() >= NumMetaOpers + NumArgs &&
"Not enough arguments provided to the patchpoint intrinsic");
// For AnyRegCC the arguments are lowered later on manually.
unsigned NumCallArgs = IsAnyRegCC ? 0 : NumArgs;
Type *ReturnTy =
IsAnyRegCC ? Type::getVoidTy(*DAG.getContext()) : CS->getType();
TargetLowering::CallLoweringInfo CLI(DAG);
populateCallLoweringInfo(CLI, CS, NumMetaOpers, NumCallArgs, Callee, ReturnTy,
true);
std::pair<SDValue, SDValue> Result = lowerInvokable(CLI, EHPadBB);
SDNode *CallEnd = Result.second.getNode();
if (HasDef && (CallEnd->getOpcode() == ISD::CopyFromReg))
CallEnd = CallEnd->getOperand(0).getNode();
/// Get a call instruction from the call sequence chain.
/// Tail calls are not allowed.
assert(CallEnd->getOpcode() == ISD::CALLSEQ_END &&
"Expected a callseq node.");
SDNode *Call = CallEnd->getOperand(0).getNode();
bool HasGlue = Call->getGluedNode();
// Replace the target specific call node with the patchable intrinsic.
SmallVector<SDValue, 8> Ops;
// Add the <id> and <numBytes> constants.
SDValue IDVal = getValue(CS->getOperand(PatchPointOpers::IDPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(IDVal)->getZExtValue(), dl, MVT::i64));
SDValue NBytesVal = getValue(CS->getOperand(PatchPointOpers::NBytesPos));
Ops.push_back(DAG.getTargetConstant(
cast<ConstantSDNode>(NBytesVal)->getZExtValue(), dl,
MVT::i32));
// Add the callee.
Ops.push_back(Callee);
// Adjust <numArgs> to account for any arguments that have been passed on the
// stack instead.
// Call Node: Chain, Target, {Args}, RegMask, [Glue]
unsigned NumCallRegArgs = Call->getNumOperands() - (HasGlue ? 4 : 3);
NumCallRegArgs = IsAnyRegCC ? NumArgs : NumCallRegArgs;
Ops.push_back(DAG.getTargetConstant(NumCallRegArgs, dl, MVT::i32));
// Add the calling convention
Ops.push_back(DAG.getTargetConstant((unsigned)CC, dl, MVT::i32));
// Add the arguments we omitted previously. The register allocator should
// place these in any free register.
if (IsAnyRegCC)
for (unsigned i = NumMetaOpers, e = NumMetaOpers + NumArgs; i != e; ++i)
Ops.push_back(getValue(CS.getArgument(i)));
// Push the arguments from the call instruction up to the register mask.
SDNode::op_iterator e = HasGlue ? Call->op_end()-2 : Call->op_end()-1;
Ops.append(Call->op_begin() + 2, e);
// Push live variables for the stack map.
addStackMapLiveVars(CS, NumMetaOpers + NumArgs, dl, Ops, *this);
// Push the register mask info.
if (HasGlue)
Ops.push_back(*(Call->op_end()-2));
else
Ops.push_back(*(Call->op_end()-1));
// Push the chain (this is originally the first operand of the call, but
// becomes now the last or second to last operand).
Ops.push_back(*(Call->op_begin()));
// Push the glue flag (last operand).
if (HasGlue)
Ops.push_back(*(Call->op_end()-1));
SDVTList NodeTys;
if (IsAnyRegCC && HasDef) {
// Create the return types based on the intrinsic definition
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
SmallVector<EVT, 3> ValueVTs;
ComputeValueVTs(TLI, DAG.getDataLayout(), CS->getType(), ValueVTs);
assert(ValueVTs.size() == 1 && "Expected only one return value type.");
// There is always a chain and a glue type at the end
ValueVTs.push_back(MVT::Other);
ValueVTs.push_back(MVT::Glue);
NodeTys = DAG.getVTList(ValueVTs);
} else
NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
// Replace the target specific call node with a PATCHPOINT node.
MachineSDNode *MN = DAG.getMachineNode(TargetOpcode::PATCHPOINT,
dl, NodeTys, Ops);
// Update the NodeMap.
if (HasDef) {
if (IsAnyRegCC)
setValue(CS.getInstruction(), SDValue(MN, 0));
else
setValue(CS.getInstruction(), Result.first);
}
// Fixup the consumers of the intrinsic. The chain and glue may be used in the
// call sequence. Furthermore the location of the chain and glue can change
// when the AnyReg calling convention is used and the intrinsic returns a
// value.
if (IsAnyRegCC && HasDef) {
SDValue From[] = {SDValue(Call, 0), SDValue(Call, 1)};
SDValue To[] = {SDValue(MN, 1), SDValue(MN, 2)};
DAG.ReplaceAllUsesOfValuesWith(From, To, 2);
} else
DAG.ReplaceAllUsesWith(Call, MN);
DAG.DeleteNode(Call);
// Inform the Frame Information that we have a patchpoint in this function.
FuncInfo.MF->getFrameInfo().setHasPatchPoint();
}
/// Returns an AttributeSet representing the attributes applied to the return
/// value of the given call.
static AttributeSet getReturnAttrs(TargetLowering::CallLoweringInfo &CLI) {
SmallVector<Attribute::AttrKind, 2> Attrs;
if (CLI.RetSExt)
Attrs.push_back(Attribute::SExt);
if (CLI.RetZExt)
Attrs.push_back(Attribute::ZExt);
if (CLI.IsInReg)
Attrs.push_back(Attribute::InReg);
return AttributeSet::get(CLI.RetTy->getContext(), AttributeSet::ReturnIndex,
Attrs);
}
/// TargetLowering::LowerCallTo - This is the default LowerCallTo
/// implementation, which just calls LowerCall.
/// FIXME: When all targets are
/// migrated to using LowerCall, this hook should be integrated into SDISel.
std::pair<SDValue, SDValue>
TargetLowering::LowerCallTo(TargetLowering::CallLoweringInfo &CLI) const {
// Handle the incoming return values from the call.
CLI.Ins.clear();
Type *OrigRetTy = CLI.RetTy;
SmallVector<EVT, 4> RetTys;
SmallVector<uint64_t, 4> Offsets;
auto &DL = CLI.DAG.getDataLayout();
ComputeValueVTs(*this, DL, CLI.RetTy, RetTys, &Offsets);
SmallVector<ISD::OutputArg, 4> Outs;
GetReturnInfo(CLI.RetTy, getReturnAttrs(CLI), Outs, *this, DL);
bool CanLowerReturn =
this->CanLowerReturn(CLI.CallConv, CLI.DAG.getMachineFunction(),
CLI.IsVarArg, Outs, CLI.RetTy->getContext());
SDValue DemoteStackSlot;
int DemoteStackIdx = -100;
if (!CanLowerReturn) {
// FIXME: equivalent assert?
// assert(!CS.hasInAllocaArgument() &&
// "sret demotion is incompatible with inalloca");
uint64_t TySize = DL.getTypeAllocSize(CLI.RetTy);
unsigned Align = DL.getPrefTypeAlignment(CLI.RetTy);
MachineFunction &MF = CLI.DAG.getMachineFunction();
DemoteStackIdx = MF.getFrameInfo().CreateStackObject(TySize, Align, false);
Type *StackSlotPtrType = PointerType::getUnqual(CLI.RetTy);
DemoteStackSlot = CLI.DAG.getFrameIndex(DemoteStackIdx, getPointerTy(DL));
ArgListEntry Entry;
Entry.Node = DemoteStackSlot;
Entry.Ty = StackSlotPtrType;
Entry.isSExt = false;
Entry.isZExt = false;
Entry.isInReg = false;
Entry.isSRet = true;
Entry.isNest = false;
Entry.isByVal = false;
Entry.isReturned = false;
Entry.isSwiftSelf = false;
Entry.isSwiftError = false;
Entry.Alignment = Align;
CLI.getArgs().insert(CLI.getArgs().begin(), Entry);
CLI.RetTy = Type::getVoidTy(CLI.RetTy->getContext());
// sret demotion isn't compatible with tail-calls, since the sret argument
// points into the callers stack frame.
CLI.IsTailCall = false;
} else {
for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
EVT VT = RetTys[I];
MVT RegisterVT = getRegisterType(CLI.RetTy->getContext(), VT);
unsigned NumRegs = getNumRegisters(CLI.RetTy->getContext(), VT);
for (unsigned i = 0; i != NumRegs; ++i) {
ISD::InputArg MyFlags;
MyFlags.VT = RegisterVT;
MyFlags.ArgVT = VT;
MyFlags.Used = CLI.IsReturnValueUsed;
if (CLI.RetSExt)
MyFlags.Flags.setSExt();
if (CLI.RetZExt)
MyFlags.Flags.setZExt();
if (CLI.IsInReg)
MyFlags.Flags.setInReg();
CLI.Ins.push_back(MyFlags);
}
}
}
// We push in swifterror return as the last element of CLI.Ins.
ArgListTy &Args = CLI.getArgs();
if (supportSwiftError()) {
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
if (Args[i].isSwiftError) {
ISD::InputArg MyFlags;
MyFlags.VT = getPointerTy(DL);
MyFlags.ArgVT = EVT(getPointerTy(DL));
MyFlags.Flags.setSwiftError();
CLI.Ins.push_back(MyFlags);
}
}
}
// Handle all of the outgoing arguments.
CLI.Outs.clear();
CLI.OutVals.clear();
for (unsigned i = 0, e = Args.size(); i != e; ++i) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*this, DL, Args[i].Ty, ValueVTs);
Type *FinalType = Args[i].Ty;
if (Args[i].isByVal)
FinalType = cast<PointerType>(Args[i].Ty)->getElementType();
bool NeedsRegBlock = functionArgumentNeedsConsecutiveRegisters(
FinalType, CLI.CallConv, CLI.IsVarArg);
for (unsigned Value = 0, NumValues = ValueVTs.size(); Value != NumValues;
++Value) {
EVT VT = ValueVTs[Value];
Type *ArgTy = VT.getTypeForEVT(CLI.RetTy->getContext());
SDValue Op = SDValue(Args[i].Node.getNode(),
Args[i].Node.getResNo() + Value);
ISD::ArgFlagsTy Flags;
unsigned OriginalAlignment = DL.getABITypeAlignment(ArgTy);
if (Args[i].isZExt)
Flags.setZExt();
if (Args[i].isSExt)
Flags.setSExt();
if (Args[i].isInReg)
Flags.setInReg();
if (Args[i].isSRet)
Flags.setSRet();
if (Args[i].isSwiftSelf)
Flags.setSwiftSelf();
if (Args[i].isSwiftError)
Flags.setSwiftError();
if (Args[i].isByVal)
Flags.setByVal();
if (Args[i].isInAlloca) {
Flags.setInAlloca();
// Set the byval flag for CCAssignFn callbacks that don't know about
// inalloca. This way we can know how many bytes we should've allocated
// and how many bytes a callee cleanup function will pop. If we port
// inalloca to more targets, we'll have to add custom inalloca handling
// in the various CC lowering callbacks.
Flags.setByVal();
}
if (Args[i].isByVal || Args[i].isInAlloca) {
PointerType *Ty = cast<PointerType>(Args[i].Ty);
Type *ElementTy = Ty->getElementType();
Flags.setByValSize(DL.getTypeAllocSize(ElementTy));
// For ByVal, alignment should come from FE. BE will guess if this
// info is not there but there are cases it cannot get right.
unsigned FrameAlign;
if (Args[i].Alignment)
FrameAlign = Args[i].Alignment;
else
FrameAlign = getByValTypeAlignment(ElementTy, DL);
Flags.setByValAlign(FrameAlign);
}
if (Args[i].isNest)
Flags.setNest();
if (NeedsRegBlock)
Flags.setInConsecutiveRegs();
Flags.setOrigAlign(OriginalAlignment);
MVT PartVT = getRegisterType(CLI.RetTy->getContext(), VT);
unsigned NumParts = getNumRegisters(CLI.RetTy->getContext(), VT);
SmallVector<SDValue, 4> Parts(NumParts);
ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
if (Args[i].isSExt)
ExtendKind = ISD::SIGN_EXTEND;
else if (Args[i].isZExt)
ExtendKind = ISD::ZERO_EXTEND;
// Conservatively only handle 'returned' on non-vectors for now
if (Args[i].isReturned && !Op.getValueType().isVector()) {
assert(CLI.RetTy == Args[i].Ty && RetTys.size() == NumValues &&
"unexpected use of 'returned'");
// Before passing 'returned' to the target lowering code, ensure that
// either the register MVT and the actual EVT are the same size or that
// the return value and argument are extended in the same way; in these
// cases it's safe to pass the argument register value unchanged as the
// return register value (although it's at the target's option whether
// to do so)
// TODO: allow code generation to take advantage of partially preserved
// registers rather than clobbering the entire register when the
// parameter extension method is not compatible with the return
// extension method
if ((NumParts * PartVT.getSizeInBits() == VT.getSizeInBits()) ||
(ExtendKind != ISD::ANY_EXTEND &&
CLI.RetSExt == Args[i].isSExt && CLI.RetZExt == Args[i].isZExt))
Flags.setReturned();
}
getCopyToParts(CLI.DAG, CLI.DL, Op, &Parts[0], NumParts, PartVT,
CLI.CS ? CLI.CS->getInstruction() : nullptr, ExtendKind);
for (unsigned j = 0; j != NumParts; ++j) {
// if it isn't first piece, alignment must be 1
ISD::OutputArg MyFlags(Flags, Parts[j].getValueType(), VT,
i < CLI.NumFixedArgs,
i, j*Parts[j].getValueType().getStoreSize());
if (NumParts > 1 && j == 0)
MyFlags.Flags.setSplit();
else if (j != 0) {
MyFlags.Flags.setOrigAlign(1);
if (j == NumParts - 1)
MyFlags.Flags.setSplitEnd();
}
CLI.Outs.push_back(MyFlags);
CLI.OutVals.push_back(Parts[j]);
}
if (NeedsRegBlock && Value == NumValues - 1)
CLI.Outs[CLI.Outs.size() - 1].Flags.setInConsecutiveRegsLast();
}
}
SmallVector<SDValue, 4> InVals;
CLI.Chain = LowerCall(CLI, InVals);
// Update CLI.InVals to use outside of this function.
CLI.InVals = InVals;
// Verify that the target's LowerCall behaved as expected.
assert(CLI.Chain.getNode() && CLI.Chain.getValueType() == MVT::Other &&
"LowerCall didn't return a valid chain!");
assert((!CLI.IsTailCall || InVals.empty()) &&
"LowerCall emitted a return value for a tail call!");
assert((CLI.IsTailCall || InVals.size() == CLI.Ins.size()) &&
"LowerCall didn't emit the correct number of values!");
// For a tail call, the return value is merely live-out and there aren't
// any nodes in the DAG representing it. Return a special value to
// indicate that a tail call has been emitted and no more Instructions
// should be processed in the current block.
if (CLI.IsTailCall) {
CLI.DAG.setRoot(CLI.Chain);
return std::make_pair(SDValue(), SDValue());
}
#ifndef NDEBUG
for (unsigned i = 0, e = CLI.Ins.size(); i != e; ++i) {
assert(InVals[i].getNode() && "LowerCall emitted a null value!");
assert(EVT(CLI.Ins[i].VT) == InVals[i].getValueType() &&
"LowerCall emitted a value with the wrong type!");
}
#endif
SmallVector<SDValue, 4> ReturnValues;
if (!CanLowerReturn) {
// The instruction result is the result of loading from the
// hidden sret parameter.
SmallVector<EVT, 1> PVTs;
Type *PtrRetTy = PointerType::getUnqual(OrigRetTy);
ComputeValueVTs(*this, DL, PtrRetTy, PVTs);
assert(PVTs.size() == 1 && "Pointers should fit in one register");
EVT PtrVT = PVTs[0];
unsigned NumValues = RetTys.size();
ReturnValues.resize(NumValues);
SmallVector<SDValue, 4> Chains(NumValues);
// An aggregate return value cannot wrap around the address space, so
// offsets to its parts don't wrap either.
SDNodeFlags Flags;
Flags.setNoUnsignedWrap(true);
for (unsigned i = 0; i < NumValues; ++i) {
SDValue Add = CLI.DAG.getNode(ISD::ADD, CLI.DL, PtrVT, DemoteStackSlot,
CLI.DAG.getConstant(Offsets[i], CLI.DL,
PtrVT), &Flags);
SDValue L = CLI.DAG.getLoad(
RetTys[i], CLI.DL, CLI.Chain, Add,
MachinePointerInfo::getFixedStack(CLI.DAG.getMachineFunction(),
DemoteStackIdx, Offsets[i]),
/* Alignment = */ 1);
ReturnValues[i] = L;
Chains[i] = L.getValue(1);
}
CLI.Chain = CLI.DAG.getNode(ISD::TokenFactor, CLI.DL, MVT::Other, Chains);
} else {
// Collect the legal value parts into potentially illegal values
// that correspond to the original function's return values.
Optional<ISD::NodeType> AssertOp;
if (CLI.RetSExt)
AssertOp = ISD::AssertSext;
else if (CLI.RetZExt)
AssertOp = ISD::AssertZext;
unsigned CurReg = 0;
for (unsigned I = 0, E = RetTys.size(); I != E; ++I) {
EVT VT = RetTys[I];
MVT RegisterVT = getRegisterType(CLI.RetTy->getContext(), VT);
unsigned NumRegs = getNumRegisters(CLI.RetTy->getContext(), VT);
ReturnValues.push_back(getCopyFromParts(CLI.DAG, CLI.DL, &InVals[CurReg],
NumRegs, RegisterVT, VT, nullptr,
AssertOp));
CurReg += NumRegs;
}
// For a function returning void, there is no return value. We can't create
// such a node, so we just return a null return value in that case. In
// that case, nothing will actually look at the value.
if (ReturnValues.empty())
return std::make_pair(SDValue(), CLI.Chain);
}
SDValue Res = CLI.DAG.getNode(ISD::MERGE_VALUES, CLI.DL,
CLI.DAG.getVTList(RetTys), ReturnValues);
return std::make_pair(Res, CLI.Chain);
}
void TargetLowering::LowerOperationWrapper(SDNode *N,
SmallVectorImpl<SDValue> &Results,
SelectionDAG &DAG) const {
if (SDValue Res = LowerOperation(SDValue(N, 0), DAG))
Results.push_back(Res);
}
SDValue TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
llvm_unreachable("LowerOperation not implemented for this target!");
}
void
SelectionDAGBuilder::CopyValueToVirtualRegister(const Value *V, unsigned Reg) {
SDValue Op = getNonRegisterValue(V);
assert((Op.getOpcode() != ISD::CopyFromReg ||
cast<RegisterSDNode>(Op.getOperand(1))->getReg() != Reg) &&
"Copy from a reg to the same reg!");
assert(!TargetRegisterInfo::isPhysicalRegister(Reg) && "Is a physreg");
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
RegsForValue RFV(V->getContext(), TLI, DAG.getDataLayout(), Reg,
V->getType());
SDValue Chain = DAG.getEntryNode();
ISD::NodeType ExtendType = (FuncInfo.PreferredExtendType.find(V) ==
FuncInfo.PreferredExtendType.end())
? ISD::ANY_EXTEND
: FuncInfo.PreferredExtendType[V];
RFV.getCopyToRegs(Op, DAG, getCurSDLoc(), Chain, nullptr, V, ExtendType);
PendingExports.push_back(Chain);
}
#include "llvm/CodeGen/SelectionDAGISel.h"
/// isOnlyUsedInEntryBlock - If the specified argument is only used in the
/// entry block, return true. This includes arguments used by switches, since
/// the switch may expand into multiple basic blocks.
static bool isOnlyUsedInEntryBlock(const Argument *A, bool FastISel) {
// With FastISel active, we may be splitting blocks, so force creation
// of virtual registers for all non-dead arguments.
if (FastISel)
return A->use_empty();
const BasicBlock &Entry = A->getParent()->front();
for (const User *U : A->users())
if (cast<Instruction>(U)->getParent() != &Entry || isa<SwitchInst>(U))
return false; // Use not in entry block.
return true;
}
void SelectionDAGISel::LowerArguments(const Function &F) {
SelectionDAG &DAG = SDB->DAG;
SDLoc dl = SDB->getCurSDLoc();
const DataLayout &DL = DAG.getDataLayout();
SmallVector<ISD::InputArg, 16> Ins;
if (!FuncInfo->CanLowerReturn) {
// Put in an sret pointer parameter before all the other parameters.
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(*TLI, DAG.getDataLayout(),
PointerType::getUnqual(F.getReturnType()), ValueVTs);
// NOTE: Assuming that a pointer will never break down to more than one VT
// or one register.
ISD::ArgFlagsTy Flags;
Flags.setSRet();
MVT RegisterVT = TLI->getRegisterType(*DAG.getContext(), ValueVTs[0]);
ISD::InputArg RetArg(Flags, RegisterVT, ValueVTs[0], true,
ISD::InputArg::NoArgIndex, 0);
Ins.push_back(RetArg);
}
// Set up the incoming argument description vector.
unsigned Idx = 1;
for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end();
I != E; ++I, ++Idx) {
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*TLI, DAG.getDataLayout(), I->getType(), ValueVTs);
bool isArgValueUsed = !I->use_empty();
unsigned PartBase = 0;
Type *FinalType = I->getType();
if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal))
FinalType = cast<PointerType>(FinalType)->getElementType();
bool NeedsRegBlock = TLI->functionArgumentNeedsConsecutiveRegisters(
FinalType, F.getCallingConv(), F.isVarArg());
for (unsigned Value = 0, NumValues = ValueVTs.size();
Value != NumValues; ++Value) {
EVT VT = ValueVTs[Value];
Type *ArgTy = VT.getTypeForEVT(*DAG.getContext());
ISD::ArgFlagsTy Flags;
unsigned OriginalAlignment = DL.getABITypeAlignment(ArgTy);
if (F.getAttributes().hasAttribute(Idx, Attribute::ZExt))
Flags.setZExt();
if (F.getAttributes().hasAttribute(Idx, Attribute::SExt))
Flags.setSExt();
if (F.getAttributes().hasAttribute(Idx, Attribute::InReg))
Flags.setInReg();
if (F.getAttributes().hasAttribute(Idx, Attribute::StructRet))
Flags.setSRet();
if (F.getAttributes().hasAttribute(Idx, Attribute::SwiftSelf))
Flags.setSwiftSelf();
if (F.getAttributes().hasAttribute(Idx, Attribute::SwiftError))
Flags.setSwiftError();
if (F.getAttributes().hasAttribute(Idx, Attribute::ByVal))
Flags.setByVal();
if (F.getAttributes().hasAttribute(Idx, Attribute::InAlloca)) {
Flags.setInAlloca();
// Set the byval flag for CCAssignFn callbacks that don't know about
// inalloca. This way we can know how many bytes we should've allocated
// and how many bytes a callee cleanup function will pop. If we port
// inalloca to more targets, we'll have to add custom inalloca handling
// in the various CC lowering callbacks.
Flags.setByVal();
}
if (F.getCallingConv() == CallingConv::X86_INTR) {
// IA Interrupt passes frame (1st parameter) by value in the stack.
if (Idx == 1)
Flags.setByVal();
}
if (Flags.isByVal() || Flags.isInAlloca()) {
PointerType *Ty = cast<PointerType>(I->getType());
Type *ElementTy = Ty->getElementType();
Flags.setByValSize(DL.getTypeAllocSize(ElementTy));
// For ByVal, alignment should be passed from FE. BE will guess if
// this info is not there but there are cases it cannot get right.
unsigned FrameAlign;
if (F.getParamAlignment(Idx))
FrameAlign = F.getParamAlignment(Idx);
else
FrameAlign = TLI->getByValTypeAlignment(ElementTy, DL);
Flags.setByValAlign(FrameAlign);
}
if (F.getAttributes().hasAttribute(Idx, Attribute::Nest))
Flags.setNest();
if (NeedsRegBlock)
Flags.setInConsecutiveRegs();
Flags.setOrigAlign(OriginalAlignment);
MVT RegisterVT = TLI->getRegisterType(*CurDAG->getContext(), VT);
unsigned NumRegs = TLI->getNumRegisters(*CurDAG->getContext(), VT);
for (unsigned i = 0; i != NumRegs; ++i) {
ISD::InputArg MyFlags(Flags, RegisterVT, VT, isArgValueUsed,
Idx-1, PartBase+i*RegisterVT.getStoreSize());
if (NumRegs > 1 && i == 0)
MyFlags.Flags.setSplit();
// if it isn't first piece, alignment must be 1
else if (i > 0) {
MyFlags.Flags.setOrigAlign(1);
if (i == NumRegs - 1)
MyFlags.Flags.setSplitEnd();
}
Ins.push_back(MyFlags);
}
if (NeedsRegBlock && Value == NumValues - 1)
Ins[Ins.size() - 1].Flags.setInConsecutiveRegsLast();
PartBase += VT.getStoreSize();
}
}
// Call the target to set up the argument values.
SmallVector<SDValue, 8> InVals;
SDValue NewRoot = TLI->LowerFormalArguments(
DAG.getRoot(), F.getCallingConv(), F.isVarArg(), Ins, dl, DAG, InVals);
// Verify that the target's LowerFormalArguments behaved as expected.
assert(NewRoot.getNode() && NewRoot.getValueType() == MVT::Other &&
"LowerFormalArguments didn't return a valid chain!");
assert(InVals.size() == Ins.size() &&
"LowerFormalArguments didn't emit the correct number of values!");
DEBUG({
for (unsigned i = 0, e = Ins.size(); i != e; ++i) {
assert(InVals[i].getNode() &&
"LowerFormalArguments emitted a null value!");
assert(EVT(Ins[i].VT) == InVals[i].getValueType() &&
"LowerFormalArguments emitted a value with the wrong type!");
}
});
// Update the DAG with the new chain value resulting from argument lowering.
DAG.setRoot(NewRoot);
// Set up the argument values.
unsigned i = 0;
Idx = 1;
if (!FuncInfo->CanLowerReturn) {
// Create a virtual register for the sret pointer, and put in a copy
// from the sret argument into it.
SmallVector<EVT, 1> ValueVTs;
ComputeValueVTs(*TLI, DAG.getDataLayout(),
PointerType::getUnqual(F.getReturnType()), ValueVTs);
MVT VT = ValueVTs[0].getSimpleVT();
MVT RegVT = TLI->getRegisterType(*CurDAG->getContext(), VT);
Optional<ISD::NodeType> AssertOp = None;
SDValue ArgValue = getCopyFromParts(DAG, dl, &InVals[0], 1,
RegVT, VT, nullptr, AssertOp);
MachineFunction& MF = SDB->DAG.getMachineFunction();
MachineRegisterInfo& RegInfo = MF.getRegInfo();
unsigned SRetReg = RegInfo.createVirtualRegister(TLI->getRegClassFor(RegVT));
FuncInfo->DemoteRegister = SRetReg;
NewRoot =
SDB->DAG.getCopyToReg(NewRoot, SDB->getCurSDLoc(), SRetReg, ArgValue);
DAG.setRoot(NewRoot);
// i indexes lowered arguments. Bump it past the hidden sret argument.
// Idx indexes LLVM arguments. Don't touch it.
++i;
}
for (Function::const_arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E;
++I, ++Idx) {
SmallVector<SDValue, 4> ArgValues;
SmallVector<EVT, 4> ValueVTs;
ComputeValueVTs(*TLI, DAG.getDataLayout(), I->getType(), ValueVTs);
unsigned NumValues = ValueVTs.size();
// If this argument is unused then remember its value. It is used to generate
// debugging information.
if (I->use_empty() && NumValues) {
SDB->setUnusedArgValue(&*I, InVals[i]);
// Also remember any frame index for use in FastISel.
if (FrameIndexSDNode *FI =
dyn_cast<FrameIndexSDNode>(InVals[i].getNode()))
FuncInfo->setArgumentFrameIndex(&*I, FI->getIndex());
}
for (unsigned Val = 0; Val != NumValues; ++Val) {
EVT VT = ValueVTs[Val];
MVT PartVT = TLI->getRegisterType(*CurDAG->getContext(), VT);
unsigned NumParts = TLI->getNumRegisters(*CurDAG->getContext(), VT);
if (!I->use_empty()) {
Optional<ISD::NodeType> AssertOp;
if (F.getAttributes().hasAttribute(Idx, Attribute::SExt))
AssertOp = ISD::AssertSext;
else if (F.getAttributes().hasAttribute(Idx, Attribute::ZExt))
AssertOp = ISD::AssertZext;
ArgValues.push_back(getCopyFromParts(DAG, dl, &InVals[i],
NumParts, PartVT, VT,
nullptr, AssertOp));
}
i += NumParts;
}
// We don't need to do anything else for unused arguments.
if (ArgValues.empty())
continue;
// Note down frame index.
if (FrameIndexSDNode *FI =
dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode()))
FuncInfo->setArgumentFrameIndex(&*I, FI->getIndex());
SDValue Res = DAG.getMergeValues(makeArrayRef(ArgValues.data(), NumValues),
SDB->getCurSDLoc());
SDB->setValue(&*I, Res);
if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::BUILD_PAIR) {
if (LoadSDNode *LNode =
dyn_cast<LoadSDNode>(Res.getOperand(0).getNode()))
if (FrameIndexSDNode *FI =
dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()))
FuncInfo->setArgumentFrameIndex(&*I, FI->getIndex());
}
// Update SwiftErrorMap.
if (Res.getOpcode() == ISD::CopyFromReg && TLI->supportSwiftError() &&
F.getAttributes().hasAttribute(Idx, Attribute::SwiftError)) {
unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg();
if (TargetRegisterInfo::isVirtualRegister(Reg))
FuncInfo->SwiftErrorMap[FuncInfo->MBB][0] = Reg;
}
// If this argument is live outside of the entry block, insert a copy from
// wherever we got it to the vreg that other BB's will reference it as.
if (!TM.Options.EnableFastISel && Res.getOpcode() == ISD::CopyFromReg) {
// If we can, though, try to skip creating an unnecessary vreg.
// FIXME: This isn't very clean... it would be nice to make this more
// general. It's also subtly incompatible with the hacks FastISel
// uses with vregs.
unsigned Reg = cast<RegisterSDNode>(Res.getOperand(1))->getReg();
if (TargetRegisterInfo::isVirtualRegister(Reg)) {
FuncInfo->ValueMap[&*I] = Reg;
continue;
}
}
if (!isOnlyUsedInEntryBlock(&*I, TM.Options.EnableFastISel)) {
FuncInfo->InitializeRegForValue(&*I);
SDB->CopyToExportRegsIfNeeded(&*I);
}
}
assert(i == InVals.size() && "Argument register count mismatch!");
// Finally, if the target has anything special to do, allow it to do so.
EmitFunctionEntryCode();
}
/// Handle PHI nodes in successor blocks. Emit code into the SelectionDAG to
/// ensure constants are generated when needed. Remember the virtual registers
/// that need to be added to the Machine PHI nodes as input. We cannot just
/// directly add them, because expansion might result in multiple MBB's for one
/// BB. As such, the start of the BB might correspond to a different MBB than
/// the end.
///
void
SelectionDAGBuilder::HandlePHINodesInSuccessorBlocks(const BasicBlock *LLVMBB) {
const TerminatorInst *TI = LLVMBB->getTerminator();
SmallPtrSet<MachineBasicBlock *, 4> SuccsHandled;
// Check PHI nodes in successors that expect a value to be available from this
// block.
for (unsigned succ = 0, e = TI->getNumSuccessors(); succ != e; ++succ) {
const BasicBlock *SuccBB = TI->getSuccessor(succ);
if (!isa<PHINode>(SuccBB->begin())) continue;
MachineBasicBlock *SuccMBB = FuncInfo.MBBMap[SuccBB];
// If this terminator has multiple identical successors (common for
// switches), only handle each succ once.
if (!SuccsHandled.insert(SuccMBB).second)
continue;
MachineBasicBlock::iterator MBBI = SuccMBB->begin();
// At this point we know that there is a 1-1 correspondence between LLVM PHI
// nodes and Machine PHI nodes, but the incoming operands have not been
// emitted yet.
for (BasicBlock::const_iterator I = SuccBB->begin();
const PHINode *PN = dyn_cast<PHINode>(I); ++I) {
// Ignore dead phi's.
if (PN->use_empty()) continue;
// Skip empty types
if (PN->getType()->isEmptyTy())
continue;
unsigned Reg;
const Value *PHIOp = PN->getIncomingValueForBlock(LLVMBB);
if (const Constant *C = dyn_cast<Constant>(PHIOp)) {
unsigned &RegOut = ConstantsOut[C];
if (RegOut == 0) {
RegOut = FuncInfo.CreateRegs(C->getType());
CopyValueToVirtualRegister(C, RegOut);
}
Reg = RegOut;
} else {
DenseMap<const Value *, unsigned>::iterator I =
FuncInfo.ValueMap.find(PHIOp);
if (I != FuncInfo.ValueMap.end())
Reg = I->second;
else {
assert(isa<AllocaInst>(PHIOp) &&
FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(PHIOp)) &&
"Didn't codegen value into a register!??");
Reg = FuncInfo.CreateRegs(PHIOp->getType());
CopyValueToVirtualRegister(PHIOp, Reg);
}
}
// Remember that this register needs to added to the machine PHI node as
// the input for this MBB.
SmallVector<EVT, 4> ValueVTs;
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
ComputeValueVTs(TLI, DAG.getDataLayout(), PN->getType(), ValueVTs);
for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
EVT VT = ValueVTs[vti];
unsigned NumRegisters = TLI.getNumRegisters(*DAG.getContext(), VT);
for (unsigned i = 0, e = NumRegisters; i != e; ++i)
FuncInfo.PHINodesToUpdate.push_back(
std::make_pair(&*MBBI++, Reg + i));
Reg += NumRegisters;
}
}
}
ConstantsOut.clear();
}
/// Add a successor MBB to ParentMBB< creating a new MachineBB for BB if SuccMBB
/// is 0.
MachineBasicBlock *
SelectionDAGBuilder::StackProtectorDescriptor::
AddSuccessorMBB(const BasicBlock *BB,
MachineBasicBlock *ParentMBB,
bool IsLikely,
MachineBasicBlock *SuccMBB) {
// If SuccBB has not been created yet, create it.
if (!SuccMBB) {
MachineFunction *MF = ParentMBB->getParent();
MachineFunction::iterator BBI(ParentMBB);
SuccMBB = MF->CreateMachineBasicBlock(BB);
MF->insert(++BBI, SuccMBB);
}
// Add it as a successor of ParentMBB.
ParentMBB->addSuccessor(
SuccMBB, BranchProbabilityInfo::getBranchProbStackProtector(IsLikely));
return SuccMBB;
}
MachineBasicBlock *SelectionDAGBuilder::NextBlock(MachineBasicBlock *MBB) {
MachineFunction::iterator I(MBB);
if (++I == FuncInfo.MF->end())
return nullptr;
return &*I;
}
/// During lowering new call nodes can be created (such as memset, etc.).
/// Those will become new roots of the current DAG, but complications arise
/// when they are tail calls. In such cases, the call lowering will update
/// the root, but the builder still needs to know that a tail call has been
/// lowered in order to avoid generating an additional return.
void SelectionDAGBuilder::updateDAGForMaybeTailCall(SDValue MaybeTC) {
// If the node is null, we do have a tail call.
if (MaybeTC.getNode() != nullptr)
DAG.setRoot(MaybeTC);
else
HasTailCall = true;
}
bool SelectionDAGBuilder::isDense(const CaseClusterVector &Clusters,
const SmallVectorImpl<unsigned> &TotalCases,
unsigned First, unsigned Last,
unsigned Density) const {
assert(Last >= First);
assert(TotalCases[Last] >= TotalCases[First]);
const APInt &LowCase = Clusters[First].Low->getValue();
const APInt &HighCase = Clusters[Last].High->getValue();
assert(LowCase.getBitWidth() == HighCase.getBitWidth());
// FIXME: A range of consecutive cases has 100% density, but only requires one
// comparison to lower. We should discriminate against such consecutive ranges
// in jump tables.
uint64_t Diff = (HighCase - LowCase).getLimitedValue((UINT64_MAX - 1) / 100);
uint64_t Range = Diff + 1;
uint64_t NumCases =
TotalCases[Last] - (First == 0 ? 0 : TotalCases[First - 1]);
assert(NumCases < UINT64_MAX / 100);
assert(Range >= NumCases);
return NumCases * 100 >= Range * Density;
}
static inline bool areJTsAllowed(const TargetLowering &TLI,
const SwitchInst *SI) {
const Function *Fn = SI->getParent()->getParent();
if (Fn->getFnAttribute("no-jump-tables").getValueAsString() == "true")
return false;
return TLI.isOperationLegalOrCustom(ISD::BR_JT, MVT::Other) ||
TLI.isOperationLegalOrCustom(ISD::BRIND, MVT::Other);
}
bool SelectionDAGBuilder::buildJumpTable(const CaseClusterVector &Clusters,
unsigned First, unsigned Last,
const SwitchInst *SI,
MachineBasicBlock *DefaultMBB,
CaseCluster &JTCluster) {
assert(First <= Last);
auto Prob = BranchProbability::getZero();
unsigned NumCmps = 0;
std::vector<MachineBasicBlock*> Table;
DenseMap<MachineBasicBlock*, BranchProbability> JTProbs;
// Initialize probabilities in JTProbs.
for (unsigned I = First; I <= Last; ++I)
JTProbs[Clusters[I].MBB] = BranchProbability::getZero();
for (unsigned I = First; I <= Last; ++I) {
assert(Clusters[I].Kind == CC_Range);
Prob += Clusters[I].Prob;
const APInt &Low = Clusters[I].Low->getValue();
const APInt &High = Clusters[I].High->getValue();
NumCmps += (Low == High) ? 1 : 2;
if (I != First) {
// Fill the gap between this and the previous cluster.
const APInt &PreviousHigh = Clusters[I - 1].High->getValue();
assert(PreviousHigh.slt(Low));
uint64_t Gap = (Low - PreviousHigh).getLimitedValue() - 1;
for (uint64_t J = 0; J < Gap; J++)
Table.push_back(DefaultMBB);
}
uint64_t ClusterSize = (High - Low).getLimitedValue() + 1;
for (uint64_t J = 0; J < ClusterSize; ++J)
Table.push_back(Clusters[I].MBB);
JTProbs[Clusters[I].MBB] += Clusters[I].Prob;
}
unsigned NumDests = JTProbs.size();
if (isSuitableForBitTests(NumDests, NumCmps,
Clusters[First].Low->getValue(),
Clusters[Last].High->getValue())) {
// Clusters[First..Last] should be lowered as bit tests instead.
return false;
}
// Create the MBB that will load from and jump through the table.
// Note: We create it here, but it's not inserted into the function yet.
MachineFunction *CurMF = FuncInfo.MF;
MachineBasicBlock *JumpTableMBB =
CurMF->CreateMachineBasicBlock(SI->getParent());
// Add successors. Note: use table order for determinism.
SmallPtrSet<MachineBasicBlock *, 8> Done;
for (MachineBasicBlock *Succ : Table) {
if (Done.count(Succ))
continue;
addSuccessorWithProb(JumpTableMBB, Succ, JTProbs[Succ]);
Done.insert(Succ);
}
JumpTableMBB->normalizeSuccProbs();
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
unsigned JTI = CurMF->getOrCreateJumpTableInfo(TLI.getJumpTableEncoding())
->createJumpTableIndex(Table);
// Set up the jump table info.
JumpTable JT(-1U, JTI, JumpTableMBB, nullptr);
JumpTableHeader JTH(Clusters[First].Low->getValue(),
Clusters[Last].High->getValue(), SI->getCondition(),
nullptr, false);
JTCases.emplace_back(std::move(JTH), std::move(JT));
JTCluster = CaseCluster::jumpTable(Clusters[First].Low, Clusters[Last].High,
JTCases.size() - 1, Prob);
return true;
}
void SelectionDAGBuilder::findJumpTables(CaseClusterVector &Clusters,
const SwitchInst *SI,
MachineBasicBlock *DefaultMBB) {
#ifndef NDEBUG
// Clusters must be non-empty, sorted, and only contain Range clusters.
assert(!Clusters.empty());
for (CaseCluster &C : Clusters)
assert(C.Kind == CC_Range);
for (unsigned i = 1, e = Clusters.size(); i < e; ++i)
assert(Clusters[i - 1].High->getValue().slt(Clusters[i].Low->getValue()));
#endif
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
if (!areJTsAllowed(TLI, SI))
return;
const bool OptForSize = DefaultMBB->getParent()->getFunction()->optForSize();
const int64_t N = Clusters.size();
const unsigned MinJumpTableEntries = TLI.getMinimumJumpTableEntries();
const unsigned MaxJumpTableSize =
OptForSize ? UINT_MAX : TLI.getMaximumJumpTableSize() ?
TLI.getMaximumJumpTableSize() : UINT_MAX;
if (N < 2 || N < MinJumpTableEntries)
return;
// TotalCases[i]: Total nbr of cases in Clusters[0..i].
SmallVector<unsigned, 8> TotalCases(N);
for (unsigned i = 0; i < N; ++i) {
const APInt &Hi = Clusters[i].High->getValue();
const APInt &Lo = Clusters[i].Low->getValue();
TotalCases[i] = (Hi - Lo).getLimitedValue() + 1;
if (i != 0)
TotalCases[i] += TotalCases[i - 1];
}
const unsigned MinDensity =
OptForSize ? OptsizeJumpTableDensity : JumpTableDensity;
// Cheap case: the whole range may be suitable for jump table.
unsigned JumpTableSize = (Clusters[N - 1].High->getValue() -
Clusters[0].Low->getValue())
.getLimitedValue(UINT_MAX - 1) + 1;
if (JumpTableSize <= MaxJumpTableSize &&
isDense(Clusters, TotalCases, 0, N - 1, MinDensity)) {
CaseCluster JTCluster;
if (buildJumpTable(Clusters, 0, N - 1, SI, DefaultMBB, JTCluster)) {
Clusters[0] = JTCluster;
Clusters.resize(1);
return;
}
}
// The algorithm below is not suitable for -O0.
if (TM.getOptLevel() == CodeGenOpt::None)
return;
// Split Clusters into minimum number of dense partitions. The algorithm uses
// the same idea as Kannan & Proebsting "Correction to 'Producing Good Code
// for the Case Statement'" (1994), but builds the MinPartitions array in
// reverse order to make it easier to reconstruct the partitions in ascending
// order. In the choice between two optimal partitionings, it picks the one
// which yields more jump tables.
// MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1].
SmallVector<unsigned, 8> MinPartitions(N);
// LastElement[i] is the last element of the partition starting at i.
SmallVector<unsigned, 8> LastElement(N);
// NumTables[i]: nbr of >= MinJumpTableSize partitions from Clusters[i..N-1].
SmallVector<unsigned, 8> NumTables(N);
// Base case: There is only one way to partition Clusters[N-1].
MinPartitions[N - 1] = 1;
LastElement[N - 1] = N - 1;
NumTables[N - 1] = 0;
// Note: loop indexes are signed to avoid underflow.
for (int64_t i = N - 2; i >= 0; i--) {
// Find optimal partitioning of Clusters[i..N-1].
// Baseline: Put Clusters[i] into a partition on its own.
MinPartitions[i] = MinPartitions[i + 1] + 1;
LastElement[i] = i;
NumTables[i] = NumTables[i + 1];
// Search for a solution that results in fewer partitions.
for (int64_t j = N - 1; j > i; j--) {
// Try building a partition from Clusters[i..j].
JumpTableSize = (Clusters[j].High->getValue() -
Clusters[i].Low->getValue())
.getLimitedValue(UINT_MAX - 1) + 1;
if (JumpTableSize <= MaxJumpTableSize &&
isDense(Clusters, TotalCases, i, j, MinDensity)) {
unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]);
bool IsTable = j - i + 1 >= MinJumpTableEntries;
unsigned Tables = IsTable + (j == N - 1 ? 0 : NumTables[j + 1]);
// If this j leads to fewer partitions, or same number of partitions
// with more lookup tables, it is a better partitioning.
if (NumPartitions < MinPartitions[i] ||
(NumPartitions == MinPartitions[i] && Tables > NumTables[i])) {
MinPartitions[i] = NumPartitions;
LastElement[i] = j;
NumTables[i] = Tables;
}
}
}
}
// Iterate over the partitions, replacing some with jump tables in-place.
unsigned DstIndex = 0;
for (unsigned First = 0, Last; First < N; First = Last + 1) {
Last = LastElement[First];
assert(Last >= First);
assert(DstIndex <= First);
unsigned NumClusters = Last - First + 1;
CaseCluster JTCluster;
if (NumClusters >= MinJumpTableEntries &&
buildJumpTable(Clusters, First, Last, SI, DefaultMBB, JTCluster)) {
Clusters[DstIndex++] = JTCluster;
} else {
for (unsigned I = First; I <= Last; ++I)
std::memmove(&Clusters[DstIndex++], &Clusters[I], sizeof(Clusters[I]));
}
}
Clusters.resize(DstIndex);
}
bool SelectionDAGBuilder::rangeFitsInWord(const APInt &Low, const APInt &High) {
// FIXME: Using the pointer type doesn't seem ideal.
uint64_t BW = DAG.getDataLayout().getPointerSizeInBits();
uint64_t Range = (High - Low).getLimitedValue(UINT64_MAX - 1) + 1;
return Range <= BW;
}
bool SelectionDAGBuilder::isSuitableForBitTests(unsigned NumDests,
unsigned NumCmps,
const APInt &Low,
const APInt &High) {
// FIXME: I don't think NumCmps is the correct metric: a single case and a
// range of cases both require only one branch to lower. Just looking at the
// number of clusters and destinations should be enough to decide whether to
// build bit tests.
// To lower a range with bit tests, the range must fit the bitwidth of a
// machine word.
if (!rangeFitsInWord(Low, High))
return false;
// Decide whether it's profitable to lower this range with bit tests. Each
// destination requires a bit test and branch, and there is an overall range
// check branch. For a small number of clusters, separate comparisons might be
// cheaper, and for many destinations, splitting the range might be better.
return (NumDests == 1 && NumCmps >= 3) ||
(NumDests == 2 && NumCmps >= 5) ||
(NumDests == 3 && NumCmps >= 6);
}
bool SelectionDAGBuilder::buildBitTests(CaseClusterVector &Clusters,
unsigned First, unsigned Last,
const SwitchInst *SI,
CaseCluster &BTCluster) {
assert(First <= Last);
if (First == Last)
return false;
BitVector Dests(FuncInfo.MF->getNumBlockIDs());
unsigned NumCmps = 0;
for (int64_t I = First; I <= Last; ++I) {
assert(Clusters[I].Kind == CC_Range);
Dests.set(Clusters[I].MBB->getNumber());
NumCmps += (Clusters[I].Low == Clusters[I].High) ? 1 : 2;
}
unsigned NumDests = Dests.count();
APInt Low = Clusters[First].Low->getValue();
APInt High = Clusters[Last].High->getValue();
assert(Low.slt(High));
if (!isSuitableForBitTests(NumDests, NumCmps, Low, High))
return false;
APInt LowBound;
APInt CmpRange;
const int BitWidth = DAG.getTargetLoweringInfo()
.getPointerTy(DAG.getDataLayout())
.getSizeInBits();
assert(rangeFitsInWord(Low, High) && "Case range must fit in bit mask!");
// Check if the clusters cover a contiguous range such that no value in the
// range will jump to the default statement.
bool ContiguousRange = true;
for (int64_t I = First + 1; I <= Last; ++I) {
if (Clusters[I].Low->getValue() != Clusters[I - 1].High->getValue() + 1) {
ContiguousRange = false;
break;
}
}
if (Low.isStrictlyPositive() && High.slt(BitWidth)) {
// Optimize the case where all the case values fit in a word without having
// to subtract minValue. In this case, we can optimize away the subtraction.
LowBound = APInt::getNullValue(Low.getBitWidth());
CmpRange = High;
ContiguousRange = false;
} else {
LowBound = Low;
CmpRange = High - Low;
}
CaseBitsVector CBV;
auto TotalProb = BranchProbability::getZero();
for (unsigned i = First; i <= Last; ++i) {
// Find the CaseBits for this destination.
unsigned j;
for (j = 0; j < CBV.size(); ++j)
if (CBV[j].BB == Clusters[i].MBB)
break;
if (j == CBV.size())
CBV.push_back(
CaseBits(0, Clusters[i].MBB, 0, BranchProbability::getZero()));
CaseBits *CB = &CBV[j];
// Update Mask, Bits and ExtraProb.
uint64_t Lo = (Clusters[i].Low->getValue() - LowBound).getZExtValue();
uint64_t Hi = (Clusters[i].High->getValue() - LowBound).getZExtValue();
assert(Hi >= Lo && Hi < 64 && "Invalid bit case!");
CB->Mask |= (-1ULL >> (63 - (Hi - Lo))) << Lo;
CB->Bits += Hi - Lo + 1;
CB->ExtraProb += Clusters[i].Prob;
TotalProb += Clusters[i].Prob;
}
BitTestInfo BTI;
std::sort(CBV.begin(), CBV.end(), [](const CaseBits &a, const CaseBits &b) {
// Sort by probability first, number of bits second.
if (a.ExtraProb != b.ExtraProb)
return a.ExtraProb > b.ExtraProb;
return a.Bits > b.Bits;
});
for (auto &CB : CBV) {
MachineBasicBlock *BitTestBB =
FuncInfo.MF->CreateMachineBasicBlock(SI->getParent());
BTI.push_back(BitTestCase(CB.Mask, BitTestBB, CB.BB, CB.ExtraProb));
}
BitTestCases.emplace_back(std::move(LowBound), std::move(CmpRange),
SI->getCondition(), -1U, MVT::Other, false,
ContiguousRange, nullptr, nullptr, std::move(BTI),
TotalProb);
BTCluster = CaseCluster::bitTests(Clusters[First].Low, Clusters[Last].High,
BitTestCases.size() - 1, TotalProb);
return true;
}
void SelectionDAGBuilder::findBitTestClusters(CaseClusterVector &Clusters,
const SwitchInst *SI) {
// Partition Clusters into as few subsets as possible, where each subset has a
// range that fits in a machine word and has <= 3 unique destinations.
#ifndef NDEBUG
// Clusters must be sorted and contain Range or JumpTable clusters.
assert(!Clusters.empty());
assert(Clusters[0].Kind == CC_Range || Clusters[0].Kind == CC_JumpTable);
for (const CaseCluster &C : Clusters)
assert(C.Kind == CC_Range || C.Kind == CC_JumpTable);
for (unsigned i = 1; i < Clusters.size(); ++i)
assert(Clusters[i-1].High->getValue().slt(Clusters[i].Low->getValue()));
#endif
// The algorithm below is not suitable for -O0.
if (TM.getOptLevel() == CodeGenOpt::None)
return;
// If target does not have legal shift left, do not emit bit tests at all.
const TargetLowering &TLI = DAG.getTargetLoweringInfo();
EVT PTy = TLI.getPointerTy(DAG.getDataLayout());
if (!TLI.isOperationLegal(ISD::SHL, PTy))
return;
int BitWidth = PTy.getSizeInBits();
const int64_t N = Clusters.size();
// MinPartitions[i] is the minimum nbr of partitions of Clusters[i..N-1].
SmallVector<unsigned, 8> MinPartitions(N);
// LastElement[i] is the last element of the partition starting at i.
SmallVector<unsigned, 8> LastElement(N);
// FIXME: This might not be the best algorithm for finding bit test clusters.
// Base case: There is only one way to partition Clusters[N-1].
MinPartitions[N - 1] = 1;
LastElement[N - 1] = N - 1;
// Note: loop indexes are signed to avoid underflow.
for (int64_t i = N - 2; i >= 0; --i) {
// Find optimal partitioning of Clusters[i..N-1].
// Baseline: Put Clusters[i] into a partition on its own.
MinPartitions[i] = MinPartitions[i + 1] + 1;
LastElement[i] = i;
// Search for a solution that results in fewer partitions.
// Note: the search is limited by BitWidth, reducing time complexity.
for (int64_t j = std::min(N - 1, i + BitWidth - 1); j > i; --j) {
// Try building a partition from Clusters[i..j].
// Check the range.
if (!rangeFitsInWord(Clusters[i].Low->getValue(),
Clusters[j].High->getValue()))
continue;
// Check nbr of destinations and cluster types.
// FIXME: This works, but doesn't seem very efficient.
bool RangesOnly = true;
BitVector Dests(FuncInfo.MF->getNumBlockIDs());
for (int64_t k = i; k <= j; k++) {
if (Clusters[k].Kind != CC_Range) {
RangesOnly = false;
break;
}
Dests.set(Clusters[k].MBB->getNumber());
}
if (!RangesOnly || Dests.count() > 3)
break;
// Check if it's a better partition.
unsigned NumPartitions = 1 + (j == N - 1 ? 0 : MinPartitions[j + 1]);
if (NumPartitions < MinPartitions[i]) {
// Found a better partition.
MinPartitions[i] = NumPartitions;
LastElement[i] = j;
}
}
}
// Iterate over the partitions, replacing with bit-test clusters in-place.
unsigned DstIndex = 0;
for (unsigned First = 0, Last; First < N; First = Last + 1) {
Last = LastElement[First];
assert(First <= Last);
assert(DstIndex <= First);
CaseCluster BitTestCluster;
if (buildBitTests(Clusters, First, Last, SI, BitTestCluster)) {
Clusters[DstIndex++] = BitTestCluster;
} else {
size_t NumClusters = Last - First + 1;
std::memmove(&Clusters[DstIndex], &Clusters[First],
sizeof(Clusters[0]) * NumClusters);
DstIndex += NumClusters;
}
}
Clusters.resize(DstIndex);
}
void SelectionDAGBuilder::lowerWorkItem(SwitchWorkListItem W, Value *Cond,
MachineBasicBlock *SwitchMBB,
MachineBasicBlock *DefaultMBB) {
MachineFunction *CurMF = FuncInfo.MF;
MachineBasicBlock *NextMBB = nullptr;
MachineFunction::iterator BBI(W.MBB);
if (++BBI != FuncInfo.MF->end())
NextMBB = &*BBI;
unsigned Size = W.LastCluster - W.FirstCluster + 1;
BranchProbabilityInfo *BPI = FuncInfo.BPI;
if (Size == 2 && W.MBB == SwitchMBB) {
// If any two of the cases has the same destination, and if one value
// is the same as the other, but has one bit unset that the other has set,
// use bit manipulation to do two compares at once. For example:
// "if (X == 6 || X == 4)" -> "if ((X|2) == 6)"
// TODO: This could be extended to merge any 2 cases in switches with 3
// cases.
// TODO: Handle cases where W.CaseBB != SwitchBB.
CaseCluster &Small = *W.FirstCluster;
CaseCluster &Big = *W.LastCluster;
if (Small.Low == Small.High && Big.Low == Big.High &&
Small.MBB == Big.MBB) {
const APInt &SmallValue = Small.Low->getValue();
const APInt &BigValue = Big.Low->getValue();
// Check that there is only one bit different.
APInt CommonBit = BigValue ^ SmallValue;
if (CommonBit.isPowerOf2()) {
SDValue CondLHS = getValue(Cond);
EVT VT = CondLHS.getValueType();
SDLoc DL = getCurSDLoc();
SDValue Or = DAG.getNode(ISD::OR, DL, VT, CondLHS,
DAG.getConstant(CommonBit, DL, VT));
SDValue Cond = DAG.getSetCC(
DL, MVT::i1, Or, DAG.getConstant(BigValue | SmallValue, DL, VT),
ISD::SETEQ);
// Update successor info.
// Both Small and Big will jump to Small.BB, so we sum up the
// probabilities.
addSuccessorWithProb(SwitchMBB, Small.MBB, Small.Prob + Big.Prob);
if (BPI)
addSuccessorWithProb(
SwitchMBB, DefaultMBB,
// The default destination is the first successor in IR.
BPI->getEdgeProbability(SwitchMBB->getBasicBlock(), (unsigned)0));
else
addSuccessorWithProb(SwitchMBB, DefaultMBB);
// Insert the true branch.
SDValue BrCond =
DAG.getNode(ISD::BRCOND, DL, MVT::Other, getControlRoot(), Cond,
DAG.getBasicBlock(Small.MBB));
// Insert the false branch.
BrCond = DAG.getNode(ISD::BR, DL, MVT::Other, BrCond,
DAG.getBasicBlock(DefaultMBB));
DAG.setRoot(BrCond);
return;
}
}
}
if (TM.getOptLevel() != CodeGenOpt::None) {
// Order cases by probability so the most likely case will be checked first.
std::sort(W.FirstCluster, W.LastCluster + 1,
[](const CaseCluster &a, const CaseCluster &b) {
return a.Prob > b.Prob;
});
// Rearrange the case blocks so that the last one falls through if possible
// without without changing the order of probabilities.
for (CaseClusterIt I = W.LastCluster; I > W.FirstCluster; ) {
--I;
if (I->Prob > W.LastCluster->Prob)
break;
if (I->Kind == CC_Range && I->MBB == NextMBB) {
std::swap(*I, *W.LastCluster);
break;
}
}
}
// Compute total probability.
BranchProbability DefaultProb = W.DefaultProb;
BranchProbability UnhandledProbs = DefaultProb;
for (CaseClusterIt I = W.FirstCluster; I <= W.LastCluster; ++I)
UnhandledProbs += I->Prob;
MachineBasicBlock *CurMBB = W.MBB;
for (CaseClusterIt I = W.FirstCluster, E = W.LastCluster; I <= E; ++I) {
MachineBasicBlock *Fallthrough;
if (I == W.LastCluster) {
// For the last cluster, fall through to the default destination.
Fallthrough = DefaultMBB;
} else {
Fallthrough = CurMF->CreateMachineBasicBlock(CurMBB->getBasicBlock());
CurMF->insert(BBI, Fallthrough);
// Put Cond in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(Cond);
}
UnhandledProbs -= I->Prob;
switch (I->Kind) {
case CC_JumpTable: {
// FIXME: Optimize away range check based on pivot comparisons.
JumpTableHeader *JTH = &JTCases[I->JTCasesIndex].first;
JumpTable *JT = &JTCases[I->JTCasesIndex].second;
// The jump block hasn't been inserted yet; insert it here.
MachineBasicBlock *JumpMBB = JT->MBB;
CurMF->insert(BBI, JumpMBB);
auto JumpProb = I->Prob;
auto FallthroughProb = UnhandledProbs;
// If the default statement is a target of the jump table, we evenly
// distribute the default probability to successors of CurMBB. Also
// update the probability on the edge from JumpMBB to Fallthrough.
for (MachineBasicBlock::succ_iterator SI = JumpMBB->succ_begin(),
SE = JumpMBB->succ_end();
SI != SE; ++SI) {
if (*SI == DefaultMBB) {
JumpProb += DefaultProb / 2;
FallthroughProb -= DefaultProb / 2;
JumpMBB->setSuccProbability(SI, DefaultProb / 2);
JumpMBB->normalizeSuccProbs();
break;
}
}
addSuccessorWithProb(CurMBB, Fallthrough, FallthroughProb);
addSuccessorWithProb(CurMBB, JumpMBB, JumpProb);
CurMBB->normalizeSuccProbs();
// The jump table header will be inserted in our current block, do the
// range check, and fall through to our fallthrough block.
JTH->HeaderBB = CurMBB;
JT->Default = Fallthrough; // FIXME: Move Default to JumpTableHeader.
// If we're in the right place, emit the jump table header right now.
if (CurMBB == SwitchMBB) {
visitJumpTableHeader(*JT, *JTH, SwitchMBB);
JTH->Emitted = true;
}
break;
}
case CC_BitTests: {
// FIXME: Optimize away range check based on pivot comparisons.
BitTestBlock *BTB = &BitTestCases[I->BTCasesIndex];
// The bit test blocks haven't been inserted yet; insert them here.
for (BitTestCase &BTC : BTB->Cases)
CurMF->insert(BBI, BTC.ThisBB);
// Fill in fields of the BitTestBlock.
BTB->Parent = CurMBB;
BTB->Default = Fallthrough;
BTB->DefaultProb = UnhandledProbs;
// If the cases in bit test don't form a contiguous range, we evenly
// distribute the probability on the edge to Fallthrough to two
// successors of CurMBB.
if (!BTB->ContiguousRange) {
BTB->Prob += DefaultProb / 2;
BTB->DefaultProb -= DefaultProb / 2;
}
// If we're in the right place, emit the bit test header right now.
if (CurMBB == SwitchMBB) {
visitBitTestHeader(*BTB, SwitchMBB);
BTB->Emitted = true;
}
break;
}
case CC_Range: {
const Value *RHS, *LHS, *MHS;
ISD::CondCode CC;
if (I->Low == I->High) {
// Check Cond == I->Low.
CC = ISD::SETEQ;
LHS = Cond;
RHS=I->Low;
MHS = nullptr;
} else {
// Check I->Low <= Cond <= I->High.
CC = ISD::SETLE;
LHS = I->Low;
MHS = Cond;
RHS = I->High;
}
// The false probability is the sum of all unhandled cases.
CaseBlock CB(CC, LHS, RHS, MHS, I->MBB, Fallthrough, CurMBB, I->Prob,
UnhandledProbs);
if (CurMBB == SwitchMBB)
visitSwitchCase(CB, SwitchMBB);
else
SwitchCases.push_back(CB);
break;
}
}
CurMBB = Fallthrough;
}
}
unsigned SelectionDAGBuilder::caseClusterRank(const CaseCluster &CC,
CaseClusterIt First,
CaseClusterIt Last) {
return std::count_if(First, Last + 1, [&](const CaseCluster &X) {
if (X.Prob != CC.Prob)
return X.Prob > CC.Prob;
// Ties are broken by comparing the case value.
return X.Low->getValue().slt(CC.Low->getValue());
});
}
void SelectionDAGBuilder::splitWorkItem(SwitchWorkList &WorkList,
const SwitchWorkListItem &W,
Value *Cond,
MachineBasicBlock *SwitchMBB) {
assert(W.FirstCluster->Low->getValue().slt(W.LastCluster->Low->getValue()) &&
"Clusters not sorted?");
assert(W.LastCluster - W.FirstCluster + 1 >= 2 && "Too small to split!");
// Balance the tree based on branch probabilities to create a near-optimal (in
// terms of search time given key frequency) binary search tree. See e.g. Kurt
// Mehlhorn "Nearly Optimal Binary Search Trees" (1975).
CaseClusterIt LastLeft = W.FirstCluster;
CaseClusterIt FirstRight = W.LastCluster;
auto LeftProb = LastLeft->Prob + W.DefaultProb / 2;
auto RightProb = FirstRight->Prob + W.DefaultProb / 2;
// Move LastLeft and FirstRight towards each other from opposite directions to
// find a partitioning of the clusters which balances the probability on both
// sides. If LeftProb and RightProb are equal, alternate which side is
// taken to ensure 0-probability nodes are distributed evenly.
unsigned I = 0;
while (LastLeft + 1 < FirstRight) {
if (LeftProb < RightProb || (LeftProb == RightProb && (I & 1)))
LeftProb += (++LastLeft)->Prob;
else
RightProb += (--FirstRight)->Prob;
I++;
}
for (;;) {
// Our binary search tree differs from a typical BST in that ours can have up
// to three values in each leaf. The pivot selection above doesn't take that
// into account, which means the tree might require more nodes and be less
// efficient. We compensate for this here.
unsigned NumLeft = LastLeft - W.FirstCluster + 1;
unsigned NumRight = W.LastCluster - FirstRight + 1;
if (std::min(NumLeft, NumRight) < 3 && std::max(NumLeft, NumRight) > 3) {
// If one side has less than 3 clusters, and the other has more than 3,
// consider taking a cluster from the other side.
if (NumLeft < NumRight) {
// Consider moving the first cluster on the right to the left side.
CaseCluster &CC = *FirstRight;
unsigned RightSideRank = caseClusterRank(CC, FirstRight, W.LastCluster);
unsigned LeftSideRank = caseClusterRank(CC, W.FirstCluster, LastLeft);
if (LeftSideRank <= RightSideRank) {
// Moving the cluster to the left does not demote it.
++LastLeft;
++FirstRight;
continue;
}
} else {
assert(NumRight < NumLeft);
// Consider moving the last element on the left to the right side.
CaseCluster &CC = *LastLeft;
unsigned LeftSideRank = caseClusterRank(CC, W.FirstCluster, LastLeft);
unsigned RightSideRank = caseClusterRank(CC, FirstRight, W.LastCluster);
if (RightSideRank <= LeftSideRank) {
// Moving the cluster to the right does not demot it.
--LastLeft;
--FirstRight;
continue;
}
}
}
break;
}
assert(LastLeft + 1 == FirstRight);
assert(LastLeft >= W.FirstCluster);
assert(FirstRight <= W.LastCluster);
// Use the first element on the right as pivot since we will make less-than
// comparisons against it.
CaseClusterIt PivotCluster = FirstRight;
assert(PivotCluster > W.FirstCluster);
assert(PivotCluster <= W.LastCluster);
CaseClusterIt FirstLeft = W.FirstCluster;
CaseClusterIt LastRight = W.LastCluster;
const ConstantInt *Pivot = PivotCluster->Low;
// New blocks will be inserted immediately after the current one.
MachineFunction::iterator BBI(W.MBB);
++BBI;
// We will branch to the LHS if Value < Pivot. If LHS is a single cluster,
// we can branch to its destination directly if it's squeezed exactly in
// between the known lower bound and Pivot - 1.
MachineBasicBlock *LeftMBB;
if (FirstLeft == LastLeft && FirstLeft->Kind == CC_Range &&
FirstLeft->Low == W.GE &&
(FirstLeft->High->getValue() + 1LL) == Pivot->getValue()) {
LeftMBB = FirstLeft->MBB;
} else {
LeftMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock());
FuncInfo.MF->insert(BBI, LeftMBB);
WorkList.push_back(
{LeftMBB, FirstLeft, LastLeft, W.GE, Pivot, W.DefaultProb / 2});
// Put Cond in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(Cond);
}
// Similarly, we will branch to the RHS if Value >= Pivot. If RHS is a
// single cluster, RHS.Low == Pivot, and we can branch to its destination
// directly if RHS.High equals the current upper bound.
MachineBasicBlock *RightMBB;
if (FirstRight == LastRight && FirstRight->Kind == CC_Range &&
W.LT && (FirstRight->High->getValue() + 1ULL) == W.LT->getValue()) {
RightMBB = FirstRight->MBB;
} else {
RightMBB = FuncInfo.MF->CreateMachineBasicBlock(W.MBB->getBasicBlock());
FuncInfo.MF->insert(BBI, RightMBB);
WorkList.push_back(
{RightMBB, FirstRight, LastRight, Pivot, W.LT, W.DefaultProb / 2});
// Put Cond in a virtual register to make it available from the new blocks.
ExportFromCurrentBlock(Cond);
}
// Create the CaseBlock record that will be used to lower the branch.
CaseBlock CB(ISD::SETLT, Cond, Pivot, nullptr, LeftMBB, RightMBB, W.MBB,
LeftProb, RightProb);
if (W.MBB == SwitchMBB)
visitSwitchCase(CB, SwitchMBB);
else
SwitchCases.push_back(CB);
}
void SelectionDAGBuilder::visitSwitch(const SwitchInst &SI) {
// Extract cases from the switch.
BranchProbabilityInfo *BPI = FuncInfo.BPI;
CaseClusterVector Clusters;
Clusters.reserve(SI.getNumCases());
for (auto I : SI.cases()) {
MachineBasicBlock *Succ = FuncInfo.MBBMap[I.getCaseSuccessor()];
const ConstantInt *CaseVal = I.getCaseValue();
BranchProbability Prob =
BPI ? BPI->getEdgeProbability(SI.getParent(), I.getSuccessorIndex())
: BranchProbability(1, SI.getNumCases() + 1);
Clusters.push_back(CaseCluster::range(CaseVal, CaseVal, Succ, Prob));
}
MachineBasicBlock *DefaultMBB = FuncInfo.MBBMap[SI.getDefaultDest()];
// Cluster adjacent cases with the same destination. We do this at all
// optimization levels because it's cheap to do and will make codegen faster
// if there are many clusters.
sortAndRangeify(Clusters);
if (TM.getOptLevel() != CodeGenOpt::None) {
// Replace an unreachable default with the most popular destination.
// FIXME: Exploit unreachable default more aggressively.
bool UnreachableDefault =
isa<UnreachableInst>(SI.getDefaultDest()->getFirstNonPHIOrDbg());
if (UnreachableDefault && !Clusters.empty()) {
DenseMap<const BasicBlock *, unsigned> Popularity;
unsigned MaxPop = 0;
const BasicBlock *MaxBB = nullptr;
for (auto I : SI.cases()) {
const BasicBlock *BB = I.getCaseSuccessor();
if (++Popularity[BB] > MaxPop) {
MaxPop = Popularity[BB];
MaxBB = BB;
}
}
// Set new default.
assert(MaxPop > 0 && MaxBB);
DefaultMBB = FuncInfo.MBBMap[MaxBB];
// Remove cases that were pointing to the destination that is now the
// default.
CaseClusterVector New;
New.reserve(Clusters.size());
for (CaseCluster &CC : Clusters) {
if (CC.MBB != DefaultMBB)
New.push_back(CC);
}
Clusters = std::move(New);
}
}
// If there is only the default destination, jump there directly.
MachineBasicBlock *SwitchMBB = FuncInfo.MBB;
if (Clusters.empty()) {
SwitchMBB->addSuccessor(DefaultMBB);
if (DefaultMBB != NextBlock(SwitchMBB)) {
DAG.setRoot(DAG.getNode(ISD::BR, getCurSDLoc(), MVT::Other,
getControlRoot(), DAG.getBasicBlock(DefaultMBB)));
}
return;
}
findJumpTables(Clusters, &SI, DefaultMBB);
findBitTestClusters(Clusters, &SI);
DEBUG({
dbgs() << "Case clusters: ";
for (const CaseCluster &C : Clusters) {
if (C.Kind == CC_JumpTable) dbgs() << "JT:";
if (C.Kind == CC_BitTests) dbgs() << "BT:";
C.Low->getValue().print(dbgs(), true);
if (C.Low != C.High) {
dbgs() << '-';
C.High->getValue().print(dbgs(), true);
}
dbgs() << ' ';
}
dbgs() << '\n';
});
assert(!Clusters.empty());
SwitchWorkList WorkList;
CaseClusterIt First = Clusters.begin();
CaseClusterIt Last = Clusters.end() - 1;
auto DefaultProb = getEdgeProbability(SwitchMBB, DefaultMBB);
WorkList.push_back({SwitchMBB, First, Last, nullptr, nullptr, DefaultProb});
while (!WorkList.empty()) {
SwitchWorkListItem W = WorkList.back();
WorkList.pop_back();
unsigned NumClusters = W.LastCluster - W.FirstCluster + 1;
if (NumClusters > 3 && TM.getOptLevel() != CodeGenOpt::None &&
!DefaultMBB->getParent()->getFunction()->optForMinSize()) {
// For optimized builds, lower large range as a balanced binary tree.
splitWorkItem(WorkList, W, SI.getCondition(), SwitchMBB);
continue;
}
lowerWorkItem(W, SI.getCondition(), SwitchMBB, DefaultMBB);
}
}
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