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llvm-mirror/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
Tony Jiang 7cd663b80c [PowerPC] Expand ISEL instruction into if-then-else sequence. 
Generally, the ISEL is expanded into if-then-else sequence, in some
cases (like when the destination register is the same with the true
or false value register), it may just be expanded into just the if
or else sequence.

llvm-svn: 292154
2017-01-16 20:12:26 +00:00

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//===-- PPCISelDAGToDAG.cpp - PPC --pattern matching inst selector --------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a pattern matching instruction selector for PowerPC,
// converting from a legalized dag to a PPC dag.
//
//===----------------------------------------------------------------------===//
#include "MCTargetDesc/PPCMCTargetDesc.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "PPC.h"
#include "PPCISelLowering.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/CodeGen/FunctionLoweringInfo.h"
#include "llvm/CodeGen/ISDOpcodes.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineValueType.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/CodeGen/SelectionDAGISel.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstrTypes.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.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/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <iterator>
#include <limits>
#include <memory>
#include <new>
#include <tuple>
#include <utility>
using namespace llvm;
#define DEBUG_TYPE "ppc-codegen"
// FIXME: Remove this once the bug has been fixed!
cl::opt<bool> ANDIGlueBug("expose-ppc-andi-glue-bug",
cl::desc("expose the ANDI glue bug on PPC"), cl::Hidden);
static cl::opt<bool>
UseBitPermRewriter("ppc-use-bit-perm-rewriter", cl::init(true),
cl::desc("use aggressive ppc isel for bit permutations"),
cl::Hidden);
static cl::opt<bool> BPermRewriterNoMasking(
"ppc-bit-perm-rewriter-stress-rotates",
cl::desc("stress rotate selection in aggressive ppc isel for "
"bit permutations"),
cl::Hidden);
static cl::opt<bool> EnableBranchHint(
"ppc-use-branch-hint", cl::init(true),
cl::desc("Enable static hinting of branches on ppc"),
cl::Hidden);
namespace {
//===--------------------------------------------------------------------===//
/// PPCDAGToDAGISel - PPC specific code to select PPC machine
/// instructions for SelectionDAG operations.
///
class PPCDAGToDAGISel : public SelectionDAGISel {
const PPCTargetMachine &TM;
const PPCSubtarget *PPCSubTarget;
const PPCTargetLowering *PPCLowering;
unsigned GlobalBaseReg;
public:
explicit PPCDAGToDAGISel(PPCTargetMachine &tm)
: SelectionDAGISel(tm), TM(tm) {}
bool runOnMachineFunction(MachineFunction &MF) override {
// Make sure we re-emit a set of the global base reg if necessary
GlobalBaseReg = 0;
PPCSubTarget = &MF.getSubtarget<PPCSubtarget>();
PPCLowering = PPCSubTarget->getTargetLowering();
SelectionDAGISel::runOnMachineFunction(MF);
if (!PPCSubTarget->isSVR4ABI())
InsertVRSaveCode(MF);
return true;
}
void PreprocessISelDAG() override;
void PostprocessISelDAG() override;
/// getI32Imm - Return a target constant with the specified value, of type
/// i32.
inline SDValue getI32Imm(unsigned Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
}
/// getI64Imm - Return a target constant with the specified value, of type
/// i64.
inline SDValue getI64Imm(uint64_t Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i64);
}
/// getSmallIPtrImm - Return a target constant of pointer type.
inline SDValue getSmallIPtrImm(unsigned Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(
Imm, dl, PPCLowering->getPointerTy(CurDAG->getDataLayout()));
}
/// isRotateAndMask - Returns true if Mask and Shift can be folded into a
/// rotate and mask opcode and mask operation.
static bool isRotateAndMask(SDNode *N, unsigned Mask, bool isShiftMask,
unsigned &SH, unsigned &MB, unsigned &ME);
/// getGlobalBaseReg - insert code into the entry mbb to materialize the PIC
/// base register. Return the virtual register that holds this value.
SDNode *getGlobalBaseReg();
void selectFrameIndex(SDNode *SN, SDNode *N, unsigned Offset = 0);
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
void Select(SDNode *N) override;
bool tryBitfieldInsert(SDNode *N);
bool tryBitPermutation(SDNode *N);
/// SelectCC - Select a comparison of the specified values with the
/// specified condition code, returning the CR# of the expression.
SDValue SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
const SDLoc &dl);
/// SelectAddrImm - Returns true if the address N can be represented by
/// a base register plus a signed 16-bit displacement [r+imm].
bool SelectAddrImm(SDValue N, SDValue &Disp,
SDValue &Base) {
return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, false);
}
/// SelectAddrImmOffs - Return true if the operand is valid for a preinc
/// immediate field. Note that the operand at this point is already the
/// result of a prior SelectAddressRegImm call.
bool SelectAddrImmOffs(SDValue N, SDValue &Out) const {
if (N.getOpcode() == ISD::TargetConstant ||
N.getOpcode() == ISD::TargetGlobalAddress) {
Out = N;
return true;
}
return false;
}
/// SelectAddrIdx - Given the specified addressed, check to see if it can be
/// represented as an indexed [r+r] operation. Returns false if it can
/// be represented by [r+imm], which are preferred.
bool SelectAddrIdx(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering->SelectAddressRegReg(N, Base, Index, *CurDAG);
}
/// SelectAddrIdxOnly - Given the specified addressed, force it to be
/// represented as an indexed [r+r] operation.
bool SelectAddrIdxOnly(SDValue N, SDValue &Base, SDValue &Index) {
return PPCLowering->SelectAddressRegRegOnly(N, Base, Index, *CurDAG);
}
/// SelectAddrImmX4 - Returns true if the address N can be represented by
/// a base register plus a signed 16-bit displacement that is a multiple of 4.
/// Suitable for use by STD and friends.
bool SelectAddrImmX4(SDValue N, SDValue &Disp, SDValue &Base) {
return PPCLowering->SelectAddressRegImm(N, Disp, Base, *CurDAG, true);
}
// Select an address into a single register.
bool SelectAddr(SDValue N, SDValue &Base) {
Base = N;
return true;
}
/// SelectInlineAsmMemoryOperand - Implement addressing mode selection for
/// inline asm expressions. It is always correct to compute the value into
/// a register. The case of adding a (possibly relocatable) constant to a
/// register can be improved, but it is wrong to substitute Reg+Reg for
/// Reg in an asm, because the load or store opcode would have to change.
bool SelectInlineAsmMemoryOperand(const SDValue &Op,
unsigned ConstraintID,
std::vector<SDValue> &OutOps) override {
switch(ConstraintID) {
default:
errs() << "ConstraintID: " << ConstraintID << "\n";
llvm_unreachable("Unexpected asm memory constraint");
case InlineAsm::Constraint_es:
case InlineAsm::Constraint_i:
case InlineAsm::Constraint_m:
case InlineAsm::Constraint_o:
case InlineAsm::Constraint_Q:
case InlineAsm::Constraint_Z:
case InlineAsm::Constraint_Zy:
// We need to make sure that this one operand does not end up in r0
// (because we might end up lowering this as 0(%op)).
const TargetRegisterInfo *TRI = PPCSubTarget->getRegisterInfo();
const TargetRegisterClass *TRC = TRI->getPointerRegClass(*MF, /*Kind=*/1);
SDLoc dl(Op);
SDValue RC = CurDAG->getTargetConstant(TRC->getID(), dl, MVT::i32);
SDValue NewOp =
SDValue(CurDAG->getMachineNode(TargetOpcode::COPY_TO_REGCLASS,
dl, Op.getValueType(),
Op, RC), 0);
OutOps.push_back(NewOp);
return false;
}
return true;
}
void InsertVRSaveCode(MachineFunction &MF);
StringRef getPassName() const override {
return "PowerPC DAG->DAG Pattern Instruction Selection";
}
// Include the pieces autogenerated from the target description.
#include "PPCGenDAGISel.inc"
private:
bool trySETCC(SDNode *N);
void PeepholePPC64();
void PeepholePPC64ZExt();
void PeepholeCROps();
SDValue combineToCMPB(SDNode *N);
void foldBoolExts(SDValue &Res, SDNode *&N);
bool AllUsersSelectZero(SDNode *N);
void SwapAllSelectUsers(SDNode *N);
void transferMemOperands(SDNode *N, SDNode *Result);
};
} // end anonymous namespace
/// InsertVRSaveCode - Once the entire function has been instruction selected,
/// all virtual registers are created and all machine instructions are built,
/// check to see if we need to save/restore VRSAVE. If so, do it.
void PPCDAGToDAGISel::InsertVRSaveCode(MachineFunction &Fn) {
// Check to see if this function uses vector registers, which means we have to
// save and restore the VRSAVE register and update it with the regs we use.
//
// In this case, there will be virtual registers of vector type created
// by the scheduler. Detect them now.
bool HasVectorVReg = false;
for (unsigned i = 0, e = RegInfo->getNumVirtRegs(); i != e; ++i) {
unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
if (RegInfo->getRegClass(Reg) == &PPC::VRRCRegClass) {
HasVectorVReg = true;
break;
}
}
if (!HasVectorVReg) return; // nothing to do.
// If we have a vector register, we want to emit code into the entry and exit
// blocks to save and restore the VRSAVE register. We do this here (instead
// of marking all vector instructions as clobbering VRSAVE) for two reasons:
//
// 1. This (trivially) reduces the load on the register allocator, by not
// having to represent the live range of the VRSAVE register.
// 2. This (more significantly) allows us to create a temporary virtual
// register to hold the saved VRSAVE value, allowing this temporary to be
// register allocated, instead of forcing it to be spilled to the stack.
// Create two vregs - one to hold the VRSAVE register that is live-in to the
// function and one for the value after having bits or'd into it.
unsigned InVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
unsigned UpdatedVRSAVE = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
const TargetInstrInfo &TII = *PPCSubTarget->getInstrInfo();
MachineBasicBlock &EntryBB = *Fn.begin();
DebugLoc dl;
// Emit the following code into the entry block:
// InVRSAVE = MFVRSAVE
// UpdatedVRSAVE = UPDATE_VRSAVE InVRSAVE
// MTVRSAVE UpdatedVRSAVE
MachineBasicBlock::iterator IP = EntryBB.begin(); // Insert Point
BuildMI(EntryBB, IP, dl, TII.get(PPC::MFVRSAVE), InVRSAVE);
BuildMI(EntryBB, IP, dl, TII.get(PPC::UPDATE_VRSAVE),
UpdatedVRSAVE).addReg(InVRSAVE);
BuildMI(EntryBB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(UpdatedVRSAVE);
// Find all return blocks, outputting a restore in each epilog.
for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
if (BB->isReturnBlock()) {
IP = BB->end(); --IP;
// Skip over all terminator instructions, which are part of the return
// sequence.
MachineBasicBlock::iterator I2 = IP;
while (I2 != BB->begin() && (--I2)->isTerminator())
IP = I2;
// Emit: MTVRSAVE InVRSave
BuildMI(*BB, IP, dl, TII.get(PPC::MTVRSAVE)).addReg(InVRSAVE);
}
}
}
/// getGlobalBaseReg - Output the instructions required to put the
/// base address to use for accessing globals into a register.
///
SDNode *PPCDAGToDAGISel::getGlobalBaseReg() {
if (!GlobalBaseReg) {
const TargetInstrInfo &TII = *PPCSubTarget->getInstrInfo();
// Insert the set of GlobalBaseReg into the first MBB of the function
MachineBasicBlock &FirstMBB = MF->front();
MachineBasicBlock::iterator MBBI = FirstMBB.begin();
const Module *M = MF->getFunction()->getParent();
DebugLoc dl;
if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) == MVT::i32) {
if (PPCSubTarget->isTargetELF()) {
GlobalBaseReg = PPC::R30;
if (M->getPICLevel() == PICLevel::SmallPIC) {
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MoveGOTtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
MF->getInfo<PPCFunctionInfo>()->setUsesPICBase(true);
} else {
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
unsigned TempReg = RegInfo->createVirtualRegister(&PPC::GPRCRegClass);
BuildMI(FirstMBB, MBBI, dl,
TII.get(PPC::UpdateGBR), GlobalBaseReg)
.addReg(TempReg, RegState::Define).addReg(GlobalBaseReg);
MF->getInfo<PPCFunctionInfo>()->setUsesPICBase(true);
}
} else {
GlobalBaseReg =
RegInfo->createVirtualRegister(&PPC::GPRC_and_GPRC_NOR0RegClass);
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR), GlobalBaseReg);
}
} else {
GlobalBaseReg = RegInfo->createVirtualRegister(&PPC::G8RC_and_G8RC_NOX0RegClass);
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MovePCtoLR8));
BuildMI(FirstMBB, MBBI, dl, TII.get(PPC::MFLR8), GlobalBaseReg);
}
}
return CurDAG->getRegister(GlobalBaseReg,
PPCLowering->getPointerTy(CurDAG->getDataLayout()))
.getNode();
}
/// isIntS16Immediate - This method tests to see if the node is either a 32-bit
/// or 64-bit immediate, and if the value can be accurately represented as a
/// sign extension from a 16-bit value. If so, this returns true and the
/// immediate.
static bool isIntS16Immediate(SDNode *N, short &Imm) {
if (N->getOpcode() != ISD::Constant)
return false;
Imm = (short)cast<ConstantSDNode>(N)->getZExtValue();
if (N->getValueType(0) == MVT::i32)
return Imm == (int32_t)cast<ConstantSDNode>(N)->getZExtValue();
else
return Imm == (int64_t)cast<ConstantSDNode>(N)->getZExtValue();
}
static bool isIntS16Immediate(SDValue Op, short &Imm) {
return isIntS16Immediate(Op.getNode(), Imm);
}
/// isInt32Immediate - This method tests to see if the node is a 32-bit constant
/// operand. If so Imm will receive the 32-bit value.
static bool isInt32Immediate(SDNode *N, unsigned &Imm) {
if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i32) {
Imm = cast<ConstantSDNode>(N)->getZExtValue();
return true;
}
return false;
}
/// isInt64Immediate - This method tests to see if the node is a 64-bit constant
/// operand. If so Imm will receive the 64-bit value.
static bool isInt64Immediate(SDNode *N, uint64_t &Imm) {
if (N->getOpcode() == ISD::Constant && N->getValueType(0) == MVT::i64) {
Imm = cast<ConstantSDNode>(N)->getZExtValue();
return true;
}
return false;
}
// isInt32Immediate - This method tests to see if a constant operand.
// If so Imm will receive the 32 bit value.
static bool isInt32Immediate(SDValue N, unsigned &Imm) {
return isInt32Immediate(N.getNode(), Imm);
}
static unsigned getBranchHint(unsigned PCC, FunctionLoweringInfo *FuncInfo,
const SDValue &DestMBB) {
assert(isa<BasicBlockSDNode>(DestMBB));
if (!FuncInfo->BPI) return PPC::BR_NO_HINT;
const BasicBlock *BB = FuncInfo->MBB->getBasicBlock();
const TerminatorInst *BBTerm = BB->getTerminator();
if (BBTerm->getNumSuccessors() != 2) return PPC::BR_NO_HINT;
const BasicBlock *TBB = BBTerm->getSuccessor(0);
const BasicBlock *FBB = BBTerm->getSuccessor(1);
auto TProb = FuncInfo->BPI->getEdgeProbability(BB, TBB);
auto FProb = FuncInfo->BPI->getEdgeProbability(BB, FBB);
// We only want to handle cases which are easy to predict at static time, e.g.
// C++ throw statement, that is very likely not taken, or calling never
// returned function, e.g. stdlib exit(). So we set Threshold to filter
// unwanted cases.
//
// Below is LLVM branch weight table, we only want to handle case 1, 2
//
// Case Taken:Nontaken Example
// 1. Unreachable 1048575:1 C++ throw, stdlib exit(),
// 2. Invoke-terminating 1:1048575
// 3. Coldblock 4:64 __builtin_expect
// 4. Loop Branch 124:4 For loop
// 5. PH/ZH/FPH 20:12
const uint32_t Threshold = 10000;
if (std::max(TProb, FProb) / Threshold < std::min(TProb, FProb))
return PPC::BR_NO_HINT;
DEBUG(dbgs() << "Use branch hint for '" << FuncInfo->Fn->getName() << "::"
<< BB->getName() << "'\n"
<< " -> " << TBB->getName() << ": " << TProb << "\n"
<< " -> " << FBB->getName() << ": " << FProb << "\n");
const BasicBlockSDNode *BBDN = cast<BasicBlockSDNode>(DestMBB);
// If Dest BasicBlock is False-BasicBlock (FBB), swap branch probabilities,
// because we want 'TProb' stands for 'branch probability' to Dest BasicBlock
if (BBDN->getBasicBlock()->getBasicBlock() != TBB)
std::swap(TProb, FProb);
return (TProb > FProb) ? PPC::BR_TAKEN_HINT : PPC::BR_NONTAKEN_HINT;
}
// isOpcWithIntImmediate - This method tests to see if the node is a specific
// opcode and that it has a immediate integer right operand.
// If so Imm will receive the 32 bit value.
static bool isOpcWithIntImmediate(SDNode *N, unsigned Opc, unsigned& Imm) {
return N->getOpcode() == Opc
&& isInt32Immediate(N->getOperand(1).getNode(), Imm);
}
void PPCDAGToDAGISel::selectFrameIndex(SDNode *SN, SDNode *N, unsigned Offset) {
SDLoc dl(SN);
int FI = cast<FrameIndexSDNode>(N)->getIndex();
SDValue TFI = CurDAG->getTargetFrameIndex(FI, N->getValueType(0));
unsigned Opc = N->getValueType(0) == MVT::i32 ? PPC::ADDI : PPC::ADDI8;
if (SN->hasOneUse())
CurDAG->SelectNodeTo(SN, Opc, N->getValueType(0), TFI,
getSmallIPtrImm(Offset, dl));
else
ReplaceNode(SN, CurDAG->getMachineNode(Opc, dl, N->getValueType(0), TFI,
getSmallIPtrImm(Offset, dl)));
}
bool PPCDAGToDAGISel::isRotateAndMask(SDNode *N, unsigned Mask,
bool isShiftMask, unsigned &SH,
unsigned &MB, unsigned &ME) {
// Don't even go down this path for i64, since different logic will be
// necessary for rldicl/rldicr/rldimi.
if (N->getValueType(0) != MVT::i32)
return false;
unsigned Shift = 32;
unsigned Indeterminant = ~0; // bit mask marking indeterminant results
unsigned Opcode = N->getOpcode();
if (N->getNumOperands() != 2 ||
!isInt32Immediate(N->getOperand(1).getNode(), Shift) || (Shift > 31))
return false;
if (Opcode == ISD::SHL) {
// apply shift left to mask if it comes first
if (isShiftMask) Mask = Mask << Shift;
// determine which bits are made indeterminant by shift
Indeterminant = ~(0xFFFFFFFFu << Shift);
} else if (Opcode == ISD::SRL) {
// apply shift right to mask if it comes first
if (isShiftMask) Mask = Mask >> Shift;
// determine which bits are made indeterminant by shift
Indeterminant = ~(0xFFFFFFFFu >> Shift);
// adjust for the left rotate
Shift = 32 - Shift;
} else if (Opcode == ISD::ROTL) {
Indeterminant = 0;
} else {
return false;
}
// if the mask doesn't intersect any Indeterminant bits
if (Mask && !(Mask & Indeterminant)) {
SH = Shift & 31;
// make sure the mask is still a mask (wrap arounds may not be)
return isRunOfOnes(Mask, MB, ME);
}
return false;
}
/// Turn an or of two masked values into the rotate left word immediate then
/// mask insert (rlwimi) instruction.
bool PPCDAGToDAGISel::tryBitfieldInsert(SDNode *N) {
SDValue Op0 = N->getOperand(0);
SDValue Op1 = N->getOperand(1);
SDLoc dl(N);
APInt LKZ, LKO, RKZ, RKO;
CurDAG->computeKnownBits(Op0, LKZ, LKO);
CurDAG->computeKnownBits(Op1, RKZ, RKO);
unsigned TargetMask = LKZ.getZExtValue();
unsigned InsertMask = RKZ.getZExtValue();
if ((TargetMask | InsertMask) == 0xFFFFFFFF) {
unsigned Op0Opc = Op0.getOpcode();
unsigned Op1Opc = Op1.getOpcode();
unsigned Value, SH = 0;
TargetMask = ~TargetMask;
InsertMask = ~InsertMask;
// If the LHS has a foldable shift and the RHS does not, then swap it to the
// RHS so that we can fold the shift into the insert.
if (Op0Opc == ISD::AND && Op1Opc == ISD::AND) {
if (Op0.getOperand(0).getOpcode() == ISD::SHL ||
Op0.getOperand(0).getOpcode() == ISD::SRL) {
if (Op1.getOperand(0).getOpcode() != ISD::SHL &&
Op1.getOperand(0).getOpcode() != ISD::SRL) {
std::swap(Op0, Op1);
std::swap(Op0Opc, Op1Opc);
std::swap(TargetMask, InsertMask);
}
}
} else if (Op0Opc == ISD::SHL || Op0Opc == ISD::SRL) {
if (Op1Opc == ISD::AND && Op1.getOperand(0).getOpcode() != ISD::SHL &&
Op1.getOperand(0).getOpcode() != ISD::SRL) {
std::swap(Op0, Op1);
std::swap(Op0Opc, Op1Opc);
std::swap(TargetMask, InsertMask);
}
}
unsigned MB, ME;
if (isRunOfOnes(InsertMask, MB, ME)) {
SDValue Tmp1, Tmp2;
if ((Op1Opc == ISD::SHL || Op1Opc == ISD::SRL) &&
isInt32Immediate(Op1.getOperand(1), Value)) {
Op1 = Op1.getOperand(0);
SH = (Op1Opc == ISD::SHL) ? Value : 32 - Value;
}
if (Op1Opc == ISD::AND) {
// The AND mask might not be a constant, and we need to make sure that
// if we're going to fold the masking with the insert, all bits not
// know to be zero in the mask are known to be one.
APInt MKZ, MKO;
CurDAG->computeKnownBits(Op1.getOperand(1), MKZ, MKO);
bool CanFoldMask = InsertMask == MKO.getZExtValue();
unsigned SHOpc = Op1.getOperand(0).getOpcode();
if ((SHOpc == ISD::SHL || SHOpc == ISD::SRL) && CanFoldMask &&
isInt32Immediate(Op1.getOperand(0).getOperand(1), Value)) {
// Note that Value must be in range here (less than 32) because
// otherwise there would not be any bits set in InsertMask.
Op1 = Op1.getOperand(0).getOperand(0);
SH = (SHOpc == ISD::SHL) ? Value : 32 - Value;
}
}
SH &= 31;
SDValue Ops[] = { Op0, Op1, getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
ReplaceNode(N, CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops));
return true;
}
}
return false;
}
// Predict the number of instructions that would be generated by calling
// getInt64(N).
static unsigned getInt64CountDirect(int64_t Imm) {
// Assume no remaining bits.
unsigned Remainder = 0;
// Assume no shift required.
unsigned Shift = 0;
// If it can't be represented as a 32 bit value.
if (!isInt<32>(Imm)) {
Shift = countTrailingZeros<uint64_t>(Imm);
int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
// If the shifted value fits 32 bits.
if (isInt<32>(ImmSh)) {
// Go with the shifted value.
Imm = ImmSh;
} else {
// Still stuck with a 64 bit value.
Remainder = Imm;
Shift = 32;
Imm >>= 32;
}
}
// Intermediate operand.
unsigned Result = 0;
// Handle first 32 bits.
unsigned Lo = Imm & 0xFFFF;
// Simple value.
if (isInt<16>(Imm)) {
// Just the Lo bits.
++Result;
} else if (Lo) {
// Handle the Hi bits and Lo bits.
Result += 2;
} else {
// Just the Hi bits.
++Result;
}
// If no shift, we're done.
if (!Shift) return Result;
// If Hi word == Lo word,
// we can use rldimi to insert the Lo word into Hi word.
if ((unsigned)(Imm & 0xFFFFFFFF) == Remainder) {
++Result;
return Result;
}
// Shift for next step if the upper 32-bits were not zero.
if (Imm)
++Result;
// Add in the last bits as required.
if ((Remainder >> 16) & 0xFFFF)
++Result;
if (Remainder & 0xFFFF)
++Result;
return Result;
}
static uint64_t Rot64(uint64_t Imm, unsigned R) {
return (Imm << R) | (Imm >> (64 - R));
}
static unsigned getInt64Count(int64_t Imm) {
unsigned Count = getInt64CountDirect(Imm);
if (Count == 1)
return Count;
for (unsigned r = 1; r < 63; ++r) {
uint64_t RImm = Rot64(Imm, r);
unsigned RCount = getInt64CountDirect(RImm) + 1;
Count = std::min(Count, RCount);
// See comments in getInt64 for an explanation of the logic below.
unsigned LS = findLastSet(RImm);
if (LS != r-1)
continue;
uint64_t OnesMask = -(int64_t) (UINT64_C(1) << (LS+1));
uint64_t RImmWithOnes = RImm | OnesMask;
RCount = getInt64CountDirect(RImmWithOnes) + 1;
Count = std::min(Count, RCount);
}
return Count;
}
// Select a 64-bit constant. For cost-modeling purposes, getInt64Count
// (above) needs to be kept in sync with this function.
static SDNode *getInt64Direct(SelectionDAG *CurDAG, const SDLoc &dl,
int64_t Imm) {
// Assume no remaining bits.
unsigned Remainder = 0;
// Assume no shift required.
unsigned Shift = 0;
// If it can't be represented as a 32 bit value.
if (!isInt<32>(Imm)) {
Shift = countTrailingZeros<uint64_t>(Imm);
int64_t ImmSh = static_cast<uint64_t>(Imm) >> Shift;
// If the shifted value fits 32 bits.
if (isInt<32>(ImmSh)) {
// Go with the shifted value.
Imm = ImmSh;
} else {
// Still stuck with a 64 bit value.
Remainder = Imm;
Shift = 32;
Imm >>= 32;
}
}
// Intermediate operand.
SDNode *Result;
// Handle first 32 bits.
unsigned Lo = Imm & 0xFFFF;
unsigned Hi = (Imm >> 16) & 0xFFFF;
auto getI32Imm = [CurDAG, dl](unsigned Imm) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
};
// Simple value.
if (isInt<16>(Imm)) {
// Just the Lo bits.
Result = CurDAG->getMachineNode(PPC::LI8, dl, MVT::i64, getI32Imm(Lo));
} else if (Lo) {
// Handle the Hi bits.
unsigned OpC = Hi ? PPC::LIS8 : PPC::LI8;
Result = CurDAG->getMachineNode(OpC, dl, MVT::i64, getI32Imm(Hi));
// And Lo bits.
Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Lo));
} else {
// Just the Hi bits.
Result = CurDAG->getMachineNode(PPC::LIS8, dl, MVT::i64, getI32Imm(Hi));
}
// If no shift, we're done.
if (!Shift) return Result;
// If Hi word == Lo word,
// we can use rldimi to insert the Lo word into Hi word.
if ((unsigned)(Imm & 0xFFFFFFFF) == Remainder) {
SDValue Ops[] =
{ SDValue(Result, 0), SDValue(Result, 0), getI32Imm(Shift), getI32Imm(0)};
return CurDAG->getMachineNode(PPC::RLDIMI, dl, MVT::i64, Ops);
}
// Shift for next step if the upper 32-bits were not zero.
if (Imm) {
Result = CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64,
SDValue(Result, 0),
getI32Imm(Shift),
getI32Imm(63 - Shift));
}
// Add in the last bits as required.
if ((Hi = (Remainder >> 16) & 0xFFFF)) {
Result = CurDAG->getMachineNode(PPC::ORIS8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Hi));
}
if ((Lo = Remainder & 0xFFFF)) {
Result = CurDAG->getMachineNode(PPC::ORI8, dl, MVT::i64,
SDValue(Result, 0), getI32Imm(Lo));
}
return Result;
}
static SDNode *getInt64(SelectionDAG *CurDAG, const SDLoc &dl, int64_t Imm) {
unsigned Count = getInt64CountDirect(Imm);
if (Count == 1)
return getInt64Direct(CurDAG, dl, Imm);
unsigned RMin = 0;
int64_t MatImm;
unsigned MaskEnd;
for (unsigned r = 1; r < 63; ++r) {
uint64_t RImm = Rot64(Imm, r);
unsigned RCount = getInt64CountDirect(RImm) + 1;
if (RCount < Count) {
Count = RCount;
RMin = r;
MatImm = RImm;
MaskEnd = 63;
}
// If the immediate to generate has many trailing zeros, it might be
// worthwhile to generate a rotated value with too many leading ones
// (because that's free with li/lis's sign-extension semantics), and then
// mask them off after rotation.
unsigned LS = findLastSet(RImm);
// We're adding (63-LS) higher-order ones, and we expect to mask them off
// after performing the inverse rotation by (64-r). So we need that:
// 63-LS == 64-r => LS == r-1
if (LS != r-1)
continue;
uint64_t OnesMask = -(int64_t) (UINT64_C(1) << (LS+1));
uint64_t RImmWithOnes = RImm | OnesMask;
RCount = getInt64CountDirect(RImmWithOnes) + 1;
if (RCount < Count) {
Count = RCount;
RMin = r;
MatImm = RImmWithOnes;
MaskEnd = LS;
}
}
if (!RMin)
return getInt64Direct(CurDAG, dl, Imm);
auto getI32Imm = [CurDAG, dl](unsigned Imm) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
};
SDValue Val = SDValue(getInt64Direct(CurDAG, dl, MatImm), 0);
return CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64, Val,
getI32Imm(64 - RMin), getI32Imm(MaskEnd));
}
// Select a 64-bit constant.
static SDNode *getInt64(SelectionDAG *CurDAG, SDNode *N) {
SDLoc dl(N);
// Get 64 bit value.
int64_t Imm = cast<ConstantSDNode>(N)->getZExtValue();
return getInt64(CurDAG, dl, Imm);
}
namespace {
class BitPermutationSelector {
struct ValueBit {
SDValue V;
// The bit number in the value, using a convention where bit 0 is the
// lowest-order bit.
unsigned Idx;
enum Kind {
ConstZero,
Variable
} K;
ValueBit(SDValue V, unsigned I, Kind K = Variable)
: V(V), Idx(I), K(K) {}
ValueBit(Kind K = Variable)
: V(SDValue(nullptr, 0)), Idx(UINT32_MAX), K(K) {}
bool isZero() const {
return K == ConstZero;
}
bool hasValue() const {
return K == Variable;
}
SDValue getValue() const {
assert(hasValue() && "Cannot get the value of a constant bit");
return V;
}
unsigned getValueBitIndex() const {
assert(hasValue() && "Cannot get the value bit index of a constant bit");
return Idx;
}
};
// A bit group has the same underlying value and the same rotate factor.
struct BitGroup {
SDValue V;
unsigned RLAmt;
unsigned StartIdx, EndIdx;
// This rotation amount assumes that the lower 32 bits of the quantity are
// replicated in the high 32 bits by the rotation operator (which is done
// by rlwinm and friends in 64-bit mode).
bool Repl32;
// Did converting to Repl32 == true change the rotation factor? If it did,
// it decreased it by 32.
bool Repl32CR;
// Was this group coalesced after setting Repl32 to true?
bool Repl32Coalesced;
BitGroup(SDValue V, unsigned R, unsigned S, unsigned E)
: V(V), RLAmt(R), StartIdx(S), EndIdx(E), Repl32(false), Repl32CR(false),
Repl32Coalesced(false) {
DEBUG(dbgs() << "\tbit group for " << V.getNode() << " RLAmt = " << R <<
" [" << S << ", " << E << "]\n");
}
};
// Information on each (Value, RLAmt) pair (like the number of groups
// associated with each) used to choose the lowering method.
struct ValueRotInfo {
SDValue V;
unsigned RLAmt = std::numeric_limits<unsigned>::max();
unsigned NumGroups = 0;
unsigned FirstGroupStartIdx = std::numeric_limits<unsigned>::max();
bool Repl32 = false;
ValueRotInfo() = default;
// For sorting (in reverse order) by NumGroups, and then by
// FirstGroupStartIdx.
bool operator < (const ValueRotInfo &Other) const {
// We need to sort so that the non-Repl32 come first because, when we're
// doing masking, the Repl32 bit groups might be subsumed into the 64-bit
// masking operation.
if (Repl32 < Other.Repl32)
return true;
else if (Repl32 > Other.Repl32)
return false;
else if (NumGroups > Other.NumGroups)
return true;
else if (NumGroups < Other.NumGroups)
return false;
else if (FirstGroupStartIdx < Other.FirstGroupStartIdx)
return true;
return false;
}
};
using ValueBitsMemoizedValue = std::pair<bool, SmallVector<ValueBit, 64>>;
using ValueBitsMemoizer =
DenseMap<SDValue, std::unique_ptr<ValueBitsMemoizedValue>>;
ValueBitsMemoizer Memoizer;
// Return a pair of bool and a SmallVector pointer to a memoization entry.
// The bool is true if something interesting was deduced, otherwise if we're
// providing only a generic representation of V (or something else likewise
// uninteresting for instruction selection) through the SmallVector.
std::pair<bool, SmallVector<ValueBit, 64> *> getValueBits(SDValue V,
unsigned NumBits) {
auto &ValueEntry = Memoizer[V];
if (ValueEntry)
return std::make_pair(ValueEntry->first, &ValueEntry->second);
ValueEntry.reset(new ValueBitsMemoizedValue());
bool &Interesting = ValueEntry->first;
SmallVector<ValueBit, 64> &Bits = ValueEntry->second;
Bits.resize(NumBits);
switch (V.getOpcode()) {
default: break;
case ISD::ROTL:
if (isa<ConstantSDNode>(V.getOperand(1))) {
unsigned RotAmt = V.getConstantOperandVal(1);
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
for (unsigned i = 0; i < NumBits; ++i)
Bits[i] = LHSBits[i < RotAmt ? i + (NumBits - RotAmt) : i - RotAmt];
return std::make_pair(Interesting = true, &Bits);
}
break;
case ISD::SHL:
if (isa<ConstantSDNode>(V.getOperand(1))) {
unsigned ShiftAmt = V.getConstantOperandVal(1);
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
for (unsigned i = ShiftAmt; i < NumBits; ++i)
Bits[i] = LHSBits[i - ShiftAmt];
for (unsigned i = 0; i < ShiftAmt; ++i)
Bits[i] = ValueBit(ValueBit::ConstZero);
return std::make_pair(Interesting = true, &Bits);
}
break;
case ISD::SRL:
if (isa<ConstantSDNode>(V.getOperand(1))) {
unsigned ShiftAmt = V.getConstantOperandVal(1);
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
for (unsigned i = 0; i < NumBits - ShiftAmt; ++i)
Bits[i] = LHSBits[i + ShiftAmt];
for (unsigned i = NumBits - ShiftAmt; i < NumBits; ++i)
Bits[i] = ValueBit(ValueBit::ConstZero);
return std::make_pair(Interesting = true, &Bits);
}
break;
case ISD::AND:
if (isa<ConstantSDNode>(V.getOperand(1))) {
uint64_t Mask = V.getConstantOperandVal(1);
const SmallVector<ValueBit, 64> *LHSBits;
// Mark this as interesting, only if the LHS was also interesting. This
// prevents the overall procedure from matching a single immediate 'and'
// (which is non-optimal because such an and might be folded with other
// things if we don't select it here).
std::tie(Interesting, LHSBits) = getValueBits(V.getOperand(0), NumBits);
for (unsigned i = 0; i < NumBits; ++i)
if (((Mask >> i) & 1) == 1)
Bits[i] = (*LHSBits)[i];
else
Bits[i] = ValueBit(ValueBit::ConstZero);
return std::make_pair(Interesting, &Bits);
}
break;
case ISD::OR: {
const auto &LHSBits = *getValueBits(V.getOperand(0), NumBits).second;
const auto &RHSBits = *getValueBits(V.getOperand(1), NumBits).second;
bool AllDisjoint = true;
for (unsigned i = 0; i < NumBits; ++i)
if (LHSBits[i].isZero())
Bits[i] = RHSBits[i];
else if (RHSBits[i].isZero())
Bits[i] = LHSBits[i];
else {
AllDisjoint = false;
break;
}
if (!AllDisjoint)
break;
return std::make_pair(Interesting = true, &Bits);
}
}
for (unsigned i = 0; i < NumBits; ++i)
Bits[i] = ValueBit(V, i);
return std::make_pair(Interesting = false, &Bits);
}
// For each value (except the constant ones), compute the left-rotate amount
// to get it from its original to final position.
void computeRotationAmounts() {
HasZeros = false;
RLAmt.resize(Bits.size());
for (unsigned i = 0; i < Bits.size(); ++i)
if (Bits[i].hasValue()) {
unsigned VBI = Bits[i].getValueBitIndex();
if (i >= VBI)
RLAmt[i] = i - VBI;
else
RLAmt[i] = Bits.size() - (VBI - i);
} else if (Bits[i].isZero()) {
HasZeros = true;
RLAmt[i] = UINT32_MAX;
} else {
llvm_unreachable("Unknown value bit type");
}
}
// Collect groups of consecutive bits with the same underlying value and
// rotation factor. If we're doing late masking, we ignore zeros, otherwise
// they break up groups.
void collectBitGroups(bool LateMask) {
BitGroups.clear();
unsigned LastRLAmt = RLAmt[0];
SDValue LastValue = Bits[0].hasValue() ? Bits[0].getValue() : SDValue();
unsigned LastGroupStartIdx = 0;
for (unsigned i = 1; i < Bits.size(); ++i) {
unsigned ThisRLAmt = RLAmt[i];
SDValue ThisValue = Bits[i].hasValue() ? Bits[i].getValue() : SDValue();
if (LateMask && !ThisValue) {
ThisValue = LastValue;
ThisRLAmt = LastRLAmt;
// If we're doing late masking, then the first bit group always starts
// at zero (even if the first bits were zero).
if (BitGroups.empty())
LastGroupStartIdx = 0;
}
// If this bit has the same underlying value and the same rotate factor as
// the last one, then they're part of the same group.
if (ThisRLAmt == LastRLAmt && ThisValue == LastValue)
continue;
if (LastValue.getNode())
BitGroups.push_back(BitGroup(LastValue, LastRLAmt, LastGroupStartIdx,
i-1));
LastRLAmt = ThisRLAmt;
LastValue = ThisValue;
LastGroupStartIdx = i;
}
if (LastValue.getNode())
BitGroups.push_back(BitGroup(LastValue, LastRLAmt, LastGroupStartIdx,
Bits.size()-1));
if (BitGroups.empty())
return;
// We might be able to combine the first and last groups.
if (BitGroups.size() > 1) {
// If the first and last groups are the same, then remove the first group
// in favor of the last group, making the ending index of the last group
// equal to the ending index of the to-be-removed first group.
if (BitGroups[0].StartIdx == 0 &&
BitGroups[BitGroups.size()-1].EndIdx == Bits.size()-1 &&
BitGroups[0].V == BitGroups[BitGroups.size()-1].V &&
BitGroups[0].RLAmt == BitGroups[BitGroups.size()-1].RLAmt) {
DEBUG(dbgs() << "\tcombining final bit group with initial one\n");
BitGroups[BitGroups.size()-1].EndIdx = BitGroups[0].EndIdx;
BitGroups.erase(BitGroups.begin());
}
}
}
// Take all (SDValue, RLAmt) pairs and sort them by the number of groups
// associated with each. If there is a degeneracy, pick the one that occurs
// first (in the final value).
void collectValueRotInfo() {
ValueRots.clear();
for (auto &BG : BitGroups) {
unsigned RLAmtKey = BG.RLAmt + (BG.Repl32 ? 64 : 0);
ValueRotInfo &VRI = ValueRots[std::make_pair(BG.V, RLAmtKey)];
VRI.V = BG.V;
VRI.RLAmt = BG.RLAmt;
VRI.Repl32 = BG.Repl32;
VRI.NumGroups += 1;
VRI.FirstGroupStartIdx = std::min(VRI.FirstGroupStartIdx, BG.StartIdx);
}
// Now that we've collected the various ValueRotInfo instances, we need to
// sort them.
ValueRotsVec.clear();
for (auto &I : ValueRots) {
ValueRotsVec.push_back(I.second);
}
std::sort(ValueRotsVec.begin(), ValueRotsVec.end());
}
// In 64-bit mode, rlwinm and friends have a rotation operator that
// replicates the low-order 32 bits into the high-order 32-bits. The mask
// indices of these instructions can only be in the lower 32 bits, so they
// can only represent some 64-bit bit groups. However, when they can be used,
// the 32-bit replication can be used to represent, as a single bit group,
// otherwise separate bit groups. We'll convert to replicated-32-bit bit
// groups when possible. Returns true if any of the bit groups were
// converted.
void assignRepl32BitGroups() {
// If we have bits like this:
//
// Indices: 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
// V bits: ... 7 6 5 4 3 2 1 0 31 30 29 28 27 26 25 24
// Groups: | RLAmt = 8 | RLAmt = 40 |
//
// But, making use of a 32-bit operation that replicates the low-order 32
// bits into the high-order 32 bits, this can be one bit group with a RLAmt
// of 8.
auto IsAllLow32 = [this](BitGroup & BG) {
if (BG.StartIdx <= BG.EndIdx) {
for (unsigned i = BG.StartIdx; i <= BG.EndIdx; ++i) {
if (!Bits[i].hasValue())
continue;
if (Bits[i].getValueBitIndex() >= 32)
return false;
}
} else {
for (unsigned i = BG.StartIdx; i < Bits.size(); ++i) {
if (!Bits[i].hasValue())
continue;
if (Bits[i].getValueBitIndex() >= 32)
return false;
}
for (unsigned i = 0; i <= BG.EndIdx; ++i) {
if (!Bits[i].hasValue())
continue;
if (Bits[i].getValueBitIndex() >= 32)
return false;
}
}
return true;
};
for (auto &BG : BitGroups) {
if (BG.StartIdx < 32 && BG.EndIdx < 32) {
if (IsAllLow32(BG)) {
if (BG.RLAmt >= 32) {
BG.RLAmt -= 32;
BG.Repl32CR = true;
}
BG.Repl32 = true;
DEBUG(dbgs() << "\t32-bit replicated bit group for " <<
BG.V.getNode() << " RLAmt = " << BG.RLAmt <<
" [" << BG.StartIdx << ", " << BG.EndIdx << "]\n");
}
}
}
// Now walk through the bit groups, consolidating where possible.
for (auto I = BitGroups.begin(); I != BitGroups.end();) {
// We might want to remove this bit group by merging it with the previous
// group (which might be the ending group).
auto IP = (I == BitGroups.begin()) ?
std::prev(BitGroups.end()) : std::prev(I);
if (I->Repl32 && IP->Repl32 && I->V == IP->V && I->RLAmt == IP->RLAmt &&
I->StartIdx == (IP->EndIdx + 1) % 64 && I != IP) {
DEBUG(dbgs() << "\tcombining 32-bit replicated bit group for " <<
I->V.getNode() << " RLAmt = " << I->RLAmt <<
" [" << I->StartIdx << ", " << I->EndIdx <<
"] with group with range [" <<
IP->StartIdx << ", " << IP->EndIdx << "]\n");
IP->EndIdx = I->EndIdx;
IP->Repl32CR = IP->Repl32CR || I->Repl32CR;
IP->Repl32Coalesced = true;
I = BitGroups.erase(I);
continue;
} else {
// There is a special case worth handling: If there is a single group
// covering the entire upper 32 bits, and it can be merged with both
// the next and previous groups (which might be the same group), then
// do so. If it is the same group (so there will be only one group in
// total), then we need to reverse the order of the range so that it
// covers the entire 64 bits.
if (I->StartIdx == 32 && I->EndIdx == 63) {
assert(std::next(I) == BitGroups.end() &&
"bit group ends at index 63 but there is another?");
auto IN = BitGroups.begin();
if (IP->Repl32 && IN->Repl32 && I->V == IP->V && I->V == IN->V &&
(I->RLAmt % 32) == IP->RLAmt && (I->RLAmt % 32) == IN->RLAmt &&
IP->EndIdx == 31 && IN->StartIdx == 0 && I != IP &&
IsAllLow32(*I)) {
DEBUG(dbgs() << "\tcombining bit group for " <<
I->V.getNode() << " RLAmt = " << I->RLAmt <<
" [" << I->StartIdx << ", " << I->EndIdx <<
"] with 32-bit replicated groups with ranges [" <<
IP->StartIdx << ", " << IP->EndIdx << "] and [" <<
IN->StartIdx << ", " << IN->EndIdx << "]\n");
if (IP == IN) {
// There is only one other group; change it to cover the whole
// range (backward, so that it can still be Repl32 but cover the
// whole 64-bit range).
IP->StartIdx = 31;
IP->EndIdx = 30;
IP->Repl32CR = IP->Repl32CR || I->RLAmt >= 32;
IP->Repl32Coalesced = true;
I = BitGroups.erase(I);
} else {
// There are two separate groups, one before this group and one
// after us (at the beginning). We're going to remove this group,
// but also the group at the very beginning.
IP->EndIdx = IN->EndIdx;
IP->Repl32CR = IP->Repl32CR || IN->Repl32CR || I->RLAmt >= 32;
IP->Repl32Coalesced = true;
I = BitGroups.erase(I);
BitGroups.erase(BitGroups.begin());
}
// This must be the last group in the vector (and we might have
// just invalidated the iterator above), so break here.
break;
}
}
}
++I;
}
}
SDValue getI32Imm(unsigned Imm, const SDLoc &dl) {
return CurDAG->getTargetConstant(Imm, dl, MVT::i32);
}
uint64_t getZerosMask() {
uint64_t Mask = 0;
for (unsigned i = 0; i < Bits.size(); ++i) {
if (Bits[i].hasValue())
continue;
Mask |= (UINT64_C(1) << i);
}
return ~Mask;
}
// Depending on the number of groups for a particular value, it might be
// better to rotate, mask explicitly (using andi/andis), and then or the
// result. Select this part of the result first.
void SelectAndParts32(const SDLoc &dl, SDValue &Res, unsigned *InstCnt) {
if (BPermRewriterNoMasking)
return;
for (ValueRotInfo &VRI : ValueRotsVec) {
unsigned Mask = 0;
for (unsigned i = 0; i < Bits.size(); ++i) {
if (!Bits[i].hasValue() || Bits[i].getValue() != VRI.V)
continue;
if (RLAmt[i] != VRI.RLAmt)
continue;
Mask |= (1u << i);
}
// Compute the masks for andi/andis that would be necessary.
unsigned ANDIMask = (Mask & UINT16_MAX), ANDISMask = Mask >> 16;
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in mask for value bit groups");
bool NeedsRotate = VRI.RLAmt != 0;
// We're trying to minimize the number of instructions. If we have one
// group, using one of andi/andis can break even. If we have three
// groups, we can use both andi and andis and break even (to use both
// andi and andis we also need to or the results together). We need four
// groups if we also need to rotate. To use andi/andis we need to do more
// than break even because rotate-and-mask instructions tend to be easier
// to schedule.
// FIXME: We've biased here against using andi/andis, which is right for
// POWER cores, but not optimal everywhere. For example, on the A2,
// andi/andis have single-cycle latency whereas the rotate-and-mask
// instructions take two cycles, and it would be better to bias toward
// andi/andis in break-even cases.
unsigned NumAndInsts = (unsigned) NeedsRotate +
(unsigned) (ANDIMask != 0) +
(unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0) +
(unsigned) (bool) Res;
DEBUG(dbgs() << "\t\trotation groups for " << VRI.V.getNode() <<
" RL: " << VRI.RLAmt << ":" <<
"\n\t\t\tisel using masking: " << NumAndInsts <<
" using rotates: " << VRI.NumGroups << "\n");
if (NumAndInsts >= VRI.NumGroups)
continue;
DEBUG(dbgs() << "\t\t\t\tusing masking\n");
if (InstCnt) *InstCnt += NumAndInsts;
SDValue VRot;
if (VRI.RLAmt) {
SDValue Ops[] =
{ VRI.V, getI32Imm(VRI.RLAmt, dl), getI32Imm(0, dl),
getI32Imm(31, dl) };
VRot = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32,
Ops), 0);
} else {
VRot = VRI.V;
}
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo, dl, MVT::i32,
VRot, getI32Imm(ANDIMask, dl)), 0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo, dl, MVT::i32,
VRot, getI32Imm(ANDISMask, dl)), 0);
SDValue TotalVal;
if (!ANDIVal)
TotalVal = ANDISVal;
else if (!ANDISVal)
TotalVal = ANDIVal;
else
TotalVal = SDValue(CurDAG->getMachineNode(PPC::OR, dl, MVT::i32,
ANDIVal, ANDISVal), 0);
if (!Res)
Res = TotalVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR, dl, MVT::i32,
Res, TotalVal), 0);
// Now, remove all groups with this underlying value and rotation
// factor.
eraseMatchingBitGroups([VRI](const BitGroup &BG) {
return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt;
});
}
}
// Instruction selection for the 32-bit case.
SDNode *Select32(SDNode *N, bool LateMask, unsigned *InstCnt) {
SDLoc dl(N);
SDValue Res;
if (InstCnt) *InstCnt = 0;
// Take care of cases that should use andi/andis first.
SelectAndParts32(dl, Res, InstCnt);
// If we've not yet selected a 'starting' instruction, and we have no zeros
// to fill in, select the (Value, RLAmt) with the highest priority (largest
// number of groups), and start with this rotated value.
if ((!HasZeros || LateMask) && !Res) {
ValueRotInfo &VRI = ValueRotsVec[0];
if (VRI.RLAmt) {
if (InstCnt) *InstCnt += 1;
SDValue Ops[] =
{ VRI.V, getI32Imm(VRI.RLAmt, dl), getI32Imm(0, dl),
getI32Imm(31, dl) };
Res = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops),
0);
} else {
Res = VRI.V;
}
// Now, remove all groups with this underlying value and rotation factor.
eraseMatchingBitGroups([VRI](const BitGroup &BG) {
return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt;
});
}
if (InstCnt) *InstCnt += BitGroups.size();
// Insert the other groups (one at a time).
for (auto &BG : BitGroups) {
if (!Res) {
SDValue Ops[] =
{ BG.V, getI32Imm(BG.RLAmt, dl),
getI32Imm(Bits.size() - BG.EndIdx - 1, dl),
getI32Imm(Bits.size() - BG.StartIdx - 1, dl) };
Res = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
} else {
SDValue Ops[] =
{ Res, BG.V, getI32Imm(BG.RLAmt, dl),
getI32Imm(Bits.size() - BG.EndIdx - 1, dl),
getI32Imm(Bits.size() - BG.StartIdx - 1, dl) };
Res = SDValue(CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops), 0);
}
}
if (LateMask) {
unsigned Mask = (unsigned) getZerosMask();
unsigned ANDIMask = (Mask & UINT16_MAX), ANDISMask = Mask >> 16;
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in zeros mask?");
if (InstCnt) *InstCnt += (unsigned) (ANDIMask != 0) +
(unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0);
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo, dl, MVT::i32,
Res, getI32Imm(ANDIMask, dl)), 0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo, dl, MVT::i32,
Res, getI32Imm(ANDISMask, dl)), 0);
if (!ANDIVal)
Res = ANDISVal;
else if (!ANDISVal)
Res = ANDIVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR, dl, MVT::i32,
ANDIVal, ANDISVal), 0);
}
return Res.getNode();
}
unsigned SelectRotMask64Count(unsigned RLAmt, bool Repl32,
unsigned MaskStart, unsigned MaskEnd,
bool IsIns) {
// In the notation used by the instructions, 'start' and 'end' are reversed
// because bits are counted from high to low order.
unsigned InstMaskStart = 64 - MaskEnd - 1,
InstMaskEnd = 64 - MaskStart - 1;
if (Repl32)
return 1;
if ((!IsIns && (InstMaskEnd == 63 || InstMaskStart == 0)) ||
InstMaskEnd == 63 - RLAmt)
return 1;
return 2;
}
// For 64-bit values, not all combinations of rotates and masks are
// available. Produce one if it is available.
SDValue SelectRotMask64(SDValue V, const SDLoc &dl, unsigned RLAmt,
bool Repl32, unsigned MaskStart, unsigned MaskEnd,
unsigned *InstCnt = nullptr) {
// In the notation used by the instructions, 'start' and 'end' are reversed
// because bits are counted from high to low order.
unsigned InstMaskStart = 64 - MaskEnd - 1,
InstMaskEnd = 64 - MaskStart - 1;
if (InstCnt) *InstCnt += 1;
if (Repl32) {
// This rotation amount assumes that the lower 32 bits of the quantity
// are replicated in the high 32 bits by the rotation operator (which is
// done by rlwinm and friends).
assert(InstMaskStart >= 32 && "Mask cannot start out of range");
assert(InstMaskEnd >= 32 && "Mask cannot end out of range");
SDValue Ops[] =
{ V, getI32Imm(RLAmt, dl), getI32Imm(InstMaskStart - 32, dl),
getI32Imm(InstMaskEnd - 32, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLWINM8, dl, MVT::i64,
Ops), 0);
}
if (InstMaskEnd == 63) {
SDValue Ops[] =
{ V, getI32Imm(RLAmt, dl), getI32Imm(InstMaskStart, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDICL, dl, MVT::i64, Ops), 0);
}
if (InstMaskStart == 0) {
SDValue Ops[] =
{ V, getI32Imm(RLAmt, dl), getI32Imm(InstMaskEnd, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDICR, dl, MVT::i64, Ops), 0);
}
if (InstMaskEnd == 63 - RLAmt) {
SDValue Ops[] =
{ V, getI32Imm(RLAmt, dl), getI32Imm(InstMaskStart, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDIC, dl, MVT::i64, Ops), 0);
}
// We cannot do this with a single instruction, so we'll use two. The
// problem is that we're not free to choose both a rotation amount and mask
// start and end independently. We can choose an arbitrary mask start and
// end, but then the rotation amount is fixed. Rotation, however, can be
// inverted, and so by applying an "inverse" rotation first, we can get the
// desired result.
if (InstCnt) *InstCnt += 1;
// The rotation mask for the second instruction must be MaskStart.
unsigned RLAmt2 = MaskStart;
// The first instruction must rotate V so that the overall rotation amount
// is RLAmt.
unsigned RLAmt1 = (64 + RLAmt - RLAmt2) % 64;
if (RLAmt1)
V = SelectRotMask64(V, dl, RLAmt1, false, 0, 63);
return SelectRotMask64(V, dl, RLAmt2, false, MaskStart, MaskEnd);
}
// For 64-bit values, not all combinations of rotates and masks are
// available. Produce a rotate-mask-and-insert if one is available.
SDValue SelectRotMaskIns64(SDValue Base, SDValue V, const SDLoc &dl,
unsigned RLAmt, bool Repl32, unsigned MaskStart,
unsigned MaskEnd, unsigned *InstCnt = nullptr) {
// In the notation used by the instructions, 'start' and 'end' are reversed
// because bits are counted from high to low order.
unsigned InstMaskStart = 64 - MaskEnd - 1,
InstMaskEnd = 64 - MaskStart - 1;
if (InstCnt) *InstCnt += 1;
if (Repl32) {
// This rotation amount assumes that the lower 32 bits of the quantity
// are replicated in the high 32 bits by the rotation operator (which is
// done by rlwinm and friends).
assert(InstMaskStart >= 32 && "Mask cannot start out of range");
assert(InstMaskEnd >= 32 && "Mask cannot end out of range");
SDValue Ops[] =
{ Base, V, getI32Imm(RLAmt, dl), getI32Imm(InstMaskStart - 32, dl),
getI32Imm(InstMaskEnd - 32, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLWIMI8, dl, MVT::i64,
Ops), 0);
}
if (InstMaskEnd == 63 - RLAmt) {
SDValue Ops[] =
{ Base, V, getI32Imm(RLAmt, dl), getI32Imm(InstMaskStart, dl) };
return SDValue(CurDAG->getMachineNode(PPC::RLDIMI, dl, MVT::i64, Ops), 0);
}
// We cannot do this with a single instruction, so we'll use two. The
// problem is that we're not free to choose both a rotation amount and mask
// start and end independently. We can choose an arbitrary mask start and
// end, but then the rotation amount is fixed. Rotation, however, can be
// inverted, and so by applying an "inverse" rotation first, we can get the
// desired result.
if (InstCnt) *InstCnt += 1;
// The rotation mask for the second instruction must be MaskStart.
unsigned RLAmt2 = MaskStart;
// The first instruction must rotate V so that the overall rotation amount
// is RLAmt.
unsigned RLAmt1 = (64 + RLAmt - RLAmt2) % 64;
if (RLAmt1)
V = SelectRotMask64(V, dl, RLAmt1, false, 0, 63);
return SelectRotMaskIns64(Base, V, dl, RLAmt2, false, MaskStart, MaskEnd);
}
void SelectAndParts64(const SDLoc &dl, SDValue &Res, unsigned *InstCnt) {
if (BPermRewriterNoMasking)
return;
// The idea here is the same as in the 32-bit version, but with additional
// complications from the fact that Repl32 might be true. Because we
// aggressively convert bit groups to Repl32 form (which, for small
// rotation factors, involves no other change), and then coalesce, it might
// be the case that a single 64-bit masking operation could handle both
// some Repl32 groups and some non-Repl32 groups. If converting to Repl32
// form allowed coalescing, then we must use a 32-bit rotaton in order to
// completely capture the new combined bit group.
for (ValueRotInfo &VRI : ValueRotsVec) {
uint64_t Mask = 0;
// We need to add to the mask all bits from the associated bit groups.
// If Repl32 is false, we need to add bits from bit groups that have
// Repl32 true, but are trivially convertable to Repl32 false. Such a
// group is trivially convertable if it overlaps only with the lower 32
// bits, and the group has not been coalesced.
auto MatchingBG = [VRI](const BitGroup &BG) {
if (VRI.V != BG.V)
return false;
unsigned EffRLAmt = BG.RLAmt;
if (!VRI.Repl32 && BG.Repl32) {
if (BG.StartIdx < 32 && BG.EndIdx < 32 && BG.StartIdx <= BG.EndIdx &&
!BG.Repl32Coalesced) {
if (BG.Repl32CR)
EffRLAmt += 32;
} else {
return false;
}
} else if (VRI.Repl32 != BG.Repl32) {
return false;
}
return VRI.RLAmt == EffRLAmt;
};
for (auto &BG : BitGroups) {
if (!MatchingBG(BG))
continue;
if (BG.StartIdx <= BG.EndIdx) {
for (unsigned i = BG.StartIdx; i <= BG.EndIdx; ++i)
Mask |= (UINT64_C(1) << i);
} else {
for (unsigned i = BG.StartIdx; i < Bits.size(); ++i)
Mask |= (UINT64_C(1) << i);
for (unsigned i = 0; i <= BG.EndIdx; ++i)
Mask |= (UINT64_C(1) << i);
}
}
// We can use the 32-bit andi/andis technique if the mask does not
// require any higher-order bits. This can save an instruction compared
// to always using the general 64-bit technique.
bool Use32BitInsts = isUInt<32>(Mask);
// Compute the masks for andi/andis that would be necessary.
unsigned ANDIMask = (Mask & UINT16_MAX),
ANDISMask = (Mask >> 16) & UINT16_MAX;
bool NeedsRotate = VRI.RLAmt || (VRI.Repl32 && !isUInt<32>(Mask));
unsigned NumAndInsts = (unsigned) NeedsRotate +
(unsigned) (bool) Res;
if (Use32BitInsts)
NumAndInsts += (unsigned) (ANDIMask != 0) + (unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0);
else
NumAndInsts += getInt64Count(Mask) + /* and */ 1;
unsigned NumRLInsts = 0;
bool FirstBG = true;
bool MoreBG = false;
for (auto &BG : BitGroups) {
if (!MatchingBG(BG)) {
MoreBG = true;
continue;
}
NumRLInsts +=
SelectRotMask64Count(BG.RLAmt, BG.Repl32, BG.StartIdx, BG.EndIdx,
!FirstBG);
FirstBG = false;
}
DEBUG(dbgs() << "\t\trotation groups for " << VRI.V.getNode() <<
" RL: " << VRI.RLAmt << (VRI.Repl32 ? " (32):" : ":") <<
"\n\t\t\tisel using masking: " << NumAndInsts <<
" using rotates: " << NumRLInsts << "\n");
// When we'd use andi/andis, we bias toward using the rotates (andi only
// has a record form, and is cracked on POWER cores). However, when using
// general 64-bit constant formation, bias toward the constant form,
// because that exposes more opportunities for CSE.
if (NumAndInsts > NumRLInsts)
continue;
// When merging multiple bit groups, instruction or is used.
// But when rotate is used, rldimi can inert the rotated value into any
// register, so instruction or can be avoided.
if ((Use32BitInsts || MoreBG) && NumAndInsts == NumRLInsts)
continue;
DEBUG(dbgs() << "\t\t\t\tusing masking\n");
if (InstCnt) *InstCnt += NumAndInsts;
SDValue VRot;
// We actually need to generate a rotation if we have a non-zero rotation
// factor or, in the Repl32 case, if we care about any of the
// higher-order replicated bits. In the latter case, we generate a mask
// backward so that it actually includes the entire 64 bits.
if (VRI.RLAmt || (VRI.Repl32 && !isUInt<32>(Mask)))
VRot = SelectRotMask64(VRI.V, dl, VRI.RLAmt, VRI.Repl32,
VRI.Repl32 ? 31 : 0, VRI.Repl32 ? 30 : 63);
else
VRot = VRI.V;
SDValue TotalVal;
if (Use32BitInsts) {
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in mask when using 32-bit ands for 64-bit value");
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo8, dl, MVT::i64,
VRot, getI32Imm(ANDIMask, dl)), 0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo8, dl, MVT::i64,
VRot, getI32Imm(ANDISMask, dl)), 0);
if (!ANDIVal)
TotalVal = ANDISVal;
else if (!ANDISVal)
TotalVal = ANDIVal;
else
TotalVal = SDValue(CurDAG->getMachineNode(PPC::OR8, dl, MVT::i64,
ANDIVal, ANDISVal), 0);
} else {
TotalVal = SDValue(getInt64(CurDAG, dl, Mask), 0);
TotalVal =
SDValue(CurDAG->getMachineNode(PPC::AND8, dl, MVT::i64,
VRot, TotalVal), 0);
}
if (!Res)
Res = TotalVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR8, dl, MVT::i64,
Res, TotalVal), 0);
// Now, remove all groups with this underlying value and rotation
// factor.
eraseMatchingBitGroups(MatchingBG);
}
}
// Instruction selection for the 64-bit case.
SDNode *Select64(SDNode *N, bool LateMask, unsigned *InstCnt) {
SDLoc dl(N);
SDValue Res;
if (InstCnt) *InstCnt = 0;
// Take care of cases that should use andi/andis first.
SelectAndParts64(dl, Res, InstCnt);
// If we've not yet selected a 'starting' instruction, and we have no zeros
// to fill in, select the (Value, RLAmt) with the highest priority (largest
// number of groups), and start with this rotated value.
if ((!HasZeros || LateMask) && !Res) {
// If we have both Repl32 groups and non-Repl32 groups, the non-Repl32
// groups will come first, and so the VRI representing the largest number
// of groups might not be first (it might be the first Repl32 groups).
unsigned MaxGroupsIdx = 0;
if (!ValueRotsVec[0].Repl32) {
for (unsigned i = 0, ie = ValueRotsVec.size(); i < ie; ++i)
if (ValueRotsVec[i].Repl32) {
if (ValueRotsVec[i].NumGroups > ValueRotsVec[0].NumGroups)
MaxGroupsIdx = i;
break;
}
}
ValueRotInfo &VRI = ValueRotsVec[MaxGroupsIdx];
bool NeedsRotate = false;
if (VRI.RLAmt) {
NeedsRotate = true;
} else if (VRI.Repl32) {
for (auto &BG : BitGroups) {
if (BG.V != VRI.V || BG.RLAmt != VRI.RLAmt ||
BG.Repl32 != VRI.Repl32)
continue;
// We don't need a rotate if the bit group is confined to the lower
// 32 bits.
if (BG.StartIdx < 32 && BG.EndIdx < 32 && BG.StartIdx < BG.EndIdx)
continue;
NeedsRotate = true;
break;
}
}
if (NeedsRotate)
Res = SelectRotMask64(VRI.V, dl, VRI.RLAmt, VRI.Repl32,
VRI.Repl32 ? 31 : 0, VRI.Repl32 ? 30 : 63,
InstCnt);
else
Res = VRI.V;
// Now, remove all groups with this underlying value and rotation factor.
if (Res)
eraseMatchingBitGroups([VRI](const BitGroup &BG) {
return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt &&
BG.Repl32 == VRI.Repl32;
});
}
// Because 64-bit rotates are more flexible than inserts, we might have a
// preference regarding which one we do first (to save one instruction).
if (!Res)
for (auto I = BitGroups.begin(), IE = BitGroups.end(); I != IE; ++I) {
if (SelectRotMask64Count(I->RLAmt, I->Repl32, I->StartIdx, I->EndIdx,
false) <
SelectRotMask64Count(I->RLAmt, I->Repl32, I->StartIdx, I->EndIdx,
true)) {
if (I != BitGroups.begin()) {
BitGroup BG = *I;
BitGroups.erase(I);
BitGroups.insert(BitGroups.begin(), BG);
}
break;
}
}
// Insert the other groups (one at a time).
for (auto &BG : BitGroups) {
if (!Res)
Res = SelectRotMask64(BG.V, dl, BG.RLAmt, BG.Repl32, BG.StartIdx,
BG.EndIdx, InstCnt);
else
Res = SelectRotMaskIns64(Res, BG.V, dl, BG.RLAmt, BG.Repl32,
BG.StartIdx, BG.EndIdx, InstCnt);
}
if (LateMask) {
uint64_t Mask = getZerosMask();
// We can use the 32-bit andi/andis technique if the mask does not
// require any higher-order bits. This can save an instruction compared
// to always using the general 64-bit technique.
bool Use32BitInsts = isUInt<32>(Mask);
// Compute the masks for andi/andis that would be necessary.
unsigned ANDIMask = (Mask & UINT16_MAX),
ANDISMask = (Mask >> 16) & UINT16_MAX;
if (Use32BitInsts) {
assert((ANDIMask != 0 || ANDISMask != 0) &&
"No set bits in mask when using 32-bit ands for 64-bit value");
if (InstCnt) *InstCnt += (unsigned) (ANDIMask != 0) +
(unsigned) (ANDISMask != 0) +
(unsigned) (ANDIMask != 0 && ANDISMask != 0);
SDValue ANDIVal, ANDISVal;
if (ANDIMask != 0)
ANDIVal = SDValue(CurDAG->getMachineNode(PPC::ANDIo8, dl, MVT::i64,
Res, getI32Imm(ANDIMask, dl)), 0);
if (ANDISMask != 0)
ANDISVal = SDValue(CurDAG->getMachineNode(PPC::ANDISo8, dl, MVT::i64,
Res, getI32Imm(ANDISMask, dl)), 0);
if (!ANDIVal)
Res = ANDISVal;
else if (!ANDISVal)
Res = ANDIVal;
else
Res = SDValue(CurDAG->getMachineNode(PPC::OR8, dl, MVT::i64,
ANDIVal, ANDISVal), 0);
} else {
if (InstCnt) *InstCnt += getInt64Count(Mask) + /* and */ 1;
SDValue MaskVal = SDValue(getInt64(CurDAG, dl, Mask), 0);
Res =
SDValue(CurDAG->getMachineNode(PPC::AND8, dl, MVT::i64,
Res, MaskVal), 0);
}
}
return Res.getNode();
}
SDNode *Select(SDNode *N, bool LateMask, unsigned *InstCnt = nullptr) {
// Fill in BitGroups.
collectBitGroups(LateMask);
if (BitGroups.empty())
return nullptr;
// For 64-bit values, figure out when we can use 32-bit instructions.
if (Bits.size() == 64)
assignRepl32BitGroups();
// Fill in ValueRotsVec.
collectValueRotInfo();
if (Bits.size() == 32) {
return Select32(N, LateMask, InstCnt);
} else {
assert(Bits.size() == 64 && "Not 64 bits here?");
return Select64(N, LateMask, InstCnt);
}
return nullptr;
}
void eraseMatchingBitGroups(function_ref<bool(const BitGroup &)> F) {
BitGroups.erase(remove_if(BitGroups, F), BitGroups.end());
}
SmallVector<ValueBit, 64> Bits;
bool HasZeros;
SmallVector<unsigned, 64> RLAmt;
SmallVector<BitGroup, 16> BitGroups;
DenseMap<std::pair<SDValue, unsigned>, ValueRotInfo> ValueRots;
SmallVector<ValueRotInfo, 16> ValueRotsVec;
SelectionDAG *CurDAG;
public:
BitPermutationSelector(SelectionDAG *DAG)
: CurDAG(DAG) {}
// Here we try to match complex bit permutations into a set of
// rotate-and-shift/shift/and/or instructions, using a set of heuristics
// known to produce optimial code for common cases (like i32 byte swapping).
SDNode *Select(SDNode *N) {
Memoizer.clear();
auto Result =
getValueBits(SDValue(N, 0), N->getValueType(0).getSizeInBits());
if (!Result.first)
return nullptr;
Bits = std::move(*Result.second);
DEBUG(dbgs() << "Considering bit-permutation-based instruction"
" selection for: ");
DEBUG(N->dump(CurDAG));
// Fill it RLAmt and set HasZeros.
computeRotationAmounts();
if (!HasZeros)
return Select(N, false);
// We currently have two techniques for handling results with zeros: early
// masking (the default) and late masking. Late masking is sometimes more
// efficient, but because the structure of the bit groups is different, it
// is hard to tell without generating both and comparing the results. With
// late masking, we ignore zeros in the resulting value when inserting each
// set of bit groups, and then mask in the zeros at the end. With early
// masking, we only insert the non-zero parts of the result at every step.
unsigned InstCnt, InstCntLateMask;
DEBUG(dbgs() << "\tEarly masking:\n");
SDNode *RN = Select(N, false, &InstCnt);
DEBUG(dbgs() << "\t\tisel would use " << InstCnt << " instructions\n");
DEBUG(dbgs() << "\tLate masking:\n");
SDNode *RNLM = Select(N, true, &InstCntLateMask);
DEBUG(dbgs() << "\t\tisel would use " << InstCntLateMask <<
" instructions\n");
if (InstCnt <= InstCntLateMask) {
DEBUG(dbgs() << "\tUsing early-masking for isel\n");
return RN;
}
DEBUG(dbgs() << "\tUsing late-masking for isel\n");
return RNLM;
}
};
} // end anonymous namespace
bool PPCDAGToDAGISel::tryBitPermutation(SDNode *N) {
if (N->getValueType(0) != MVT::i32 &&
N->getValueType(0) != MVT::i64)
return false;
if (!UseBitPermRewriter)
return false;
switch (N->getOpcode()) {
default: break;
case ISD::ROTL:
case ISD::SHL:
case ISD::SRL:
case ISD::AND:
case ISD::OR: {
BitPermutationSelector BPS(CurDAG);
if (SDNode *New = BPS.Select(N)) {
ReplaceNode(N, New);
return true;
}
return false;
}
}
return false;
}
/// SelectCC - Select a comparison of the specified values with the specified
/// condition code, returning the CR# of the expression.
SDValue PPCDAGToDAGISel::SelectCC(SDValue LHS, SDValue RHS, ISD::CondCode CC,
const SDLoc &dl) {
// Always select the LHS.
unsigned Opc;
if (LHS.getValueType() == MVT::i32) {
unsigned Imm;
if (CC == ISD::SETEQ || CC == ISD::SETNE) {
if (isInt32Immediate(RHS, Imm)) {
// SETEQ/SETNE comparison with 16-bit immediate, fold it.
if (isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// If this is a 16-bit signed immediate, fold it.
if (isInt<16>((int)Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// For non-equality comparisons, the default code would materialize the
// constant, then compare against it, like this:
// lis r2, 4660
// ori r2, r2, 22136
// cmpw cr0, r3, r2
// Since we are just comparing for equality, we can emit this instead:
// xoris r0,r3,0x1234
// cmplwi cr0,r0,0x5678
// beq cr0,L6
SDValue Xor(CurDAG->getMachineNode(PPC::XORIS, dl, MVT::i32, LHS,
getI32Imm(Imm >> 16, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, Xor,
getI32Imm(Imm & 0xFFFF, dl)), 0);
}
Opc = PPC::CMPLW;
} else if (ISD::isUnsignedIntSetCC(CC)) {
if (isInt32Immediate(RHS, Imm) && isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLWI, dl, MVT::i32, LHS,
getI32Imm(Imm & 0xFFFF, dl)), 0);
Opc = PPC::CMPLW;
} else {
short SImm;
if (isIntS16Immediate(RHS, SImm))
return SDValue(CurDAG->getMachineNode(PPC::CMPWI, dl, MVT::i32, LHS,
getI32Imm((int)SImm & 0xFFFF,
dl)),
0);
Opc = PPC::CMPW;
}
} else if (LHS.getValueType() == MVT::i64) {
uint64_t Imm;
if (CC == ISD::SETEQ || CC == ISD::SETNE) {
if (isInt64Immediate(RHS.getNode(), Imm)) {
// SETEQ/SETNE comparison with 16-bit immediate, fold it.
if (isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// If this is a 16-bit signed immediate, fold it.
if (isInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
getI32Imm(Imm & 0xFFFF, dl)),
0);
// For non-equality comparisons, the default code would materialize the
// constant, then compare against it, like this:
// lis r2, 4660
// ori r2, r2, 22136
// cmpd cr0, r3, r2
// Since we are just comparing for equality, we can emit this instead:
// xoris r0,r3,0x1234
// cmpldi cr0,r0,0x5678
// beq cr0,L6
if (isUInt<32>(Imm)) {
SDValue Xor(CurDAG->getMachineNode(PPC::XORIS8, dl, MVT::i64, LHS,
getI64Imm(Imm >> 16, dl)), 0);
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, Xor,
getI64Imm(Imm & 0xFFFF, dl)),
0);
}
}
Opc = PPC::CMPLD;
} else if (ISD::isUnsignedIntSetCC(CC)) {
if (isInt64Immediate(RHS.getNode(), Imm) && isUInt<16>(Imm))
return SDValue(CurDAG->getMachineNode(PPC::CMPLDI, dl, MVT::i64, LHS,
getI64Imm(Imm & 0xFFFF, dl)), 0);
Opc = PPC::CMPLD;
} else {
short SImm;
if (isIntS16Immediate(RHS, SImm))
return SDValue(CurDAG->getMachineNode(PPC::CMPDI, dl, MVT::i64, LHS,
getI64Imm(SImm & 0xFFFF, dl)),
0);
Opc = PPC::CMPD;
}
} else if (LHS.getValueType() == MVT::f32) {
Opc = PPC::FCMPUS;
} else {
assert(LHS.getValueType() == MVT::f64 && "Unknown vt!");
Opc = PPCSubTarget->hasVSX() ? PPC::XSCMPUDP : PPC::FCMPUD;
}
return SDValue(CurDAG->getMachineNode(Opc, dl, MVT::i32, LHS, RHS), 0);
}
static PPC::Predicate getPredicateForSetCC(ISD::CondCode CC) {
switch (CC) {
case ISD::SETUEQ:
case ISD::SETONE:
case ISD::SETOLE:
case ISD::SETOGE:
llvm_unreachable("Should be lowered by legalize!");
default: llvm_unreachable("Unknown condition!");
case ISD::SETOEQ:
case ISD::SETEQ: return PPC::PRED_EQ;
case ISD::SETUNE:
case ISD::SETNE: return PPC::PRED_NE;
case ISD::SETOLT:
case ISD::SETLT: return PPC::PRED_LT;
case ISD::SETULE:
case ISD::SETLE: return PPC::PRED_LE;
case ISD::SETOGT:
case ISD::SETGT: return PPC::PRED_GT;
case ISD::SETUGE:
case ISD::SETGE: return PPC::PRED_GE;
case ISD::SETO: return PPC::PRED_NU;
case ISD::SETUO: return PPC::PRED_UN;
// These two are invalid for floating point. Assume we have int.
case ISD::SETULT: return PPC::PRED_LT;
case ISD::SETUGT: return PPC::PRED_GT;
}
}
/// getCRIdxForSetCC - Return the index of the condition register field
/// associated with the SetCC condition, and whether or not the field is
/// treated as inverted. That is, lt = 0; ge = 0 inverted.
static unsigned getCRIdxForSetCC(ISD::CondCode CC, bool &Invert) {
Invert = false;
switch (CC) {
default: llvm_unreachable("Unknown condition!");
case ISD::SETOLT:
case ISD::SETLT: return 0; // Bit #0 = SETOLT
case ISD::SETOGT:
case ISD::SETGT: return 1; // Bit #1 = SETOGT
case ISD::SETOEQ:
case ISD::SETEQ: return 2; // Bit #2 = SETOEQ
case ISD::SETUO: return 3; // Bit #3 = SETUO
case ISD::SETUGE:
case ISD::SETGE: Invert = true; return 0; // !Bit #0 = SETUGE
case ISD::SETULE:
case ISD::SETLE: Invert = true; return 1; // !Bit #1 = SETULE
case ISD::SETUNE:
case ISD::SETNE: Invert = true; return 2; // !Bit #2 = SETUNE
case ISD::SETO: Invert = true; return 3; // !Bit #3 = SETO
case ISD::SETUEQ:
case ISD::SETOGE:
case ISD::SETOLE:
case ISD::SETONE:
llvm_unreachable("Invalid branch code: should be expanded by legalize");
// These are invalid for floating point. Assume integer.
case ISD::SETULT: return 0;
case ISD::SETUGT: return 1;
}
}
// getVCmpInst: return the vector compare instruction for the specified
// vector type and condition code. Since this is for altivec specific code,
// only support the altivec types (v16i8, v8i16, v4i32, v2i64, and v4f32).
static unsigned int getVCmpInst(MVT VecVT, ISD::CondCode CC,
bool HasVSX, bool &Swap, bool &Negate) {
Swap = false;
Negate = false;
if (VecVT.isFloatingPoint()) {
/* Handle some cases by swapping input operands. */
switch (CC) {
case ISD::SETLE: CC = ISD::SETGE; Swap = true; break;
case ISD::SETLT: CC = ISD::SETGT; Swap = true; break;
case ISD::SETOLE: CC = ISD::SETOGE; Swap = true; break;
case ISD::SETOLT: CC = ISD::SETOGT; Swap = true; break;
case ISD::SETUGE: CC = ISD::SETULE; Swap = true; break;
case ISD::SETUGT: CC = ISD::SETULT; Swap = true; break;
default: break;
}
/* Handle some cases by negating the result. */
switch (CC) {
case ISD::SETNE: CC = ISD::SETEQ; Negate = true; break;
case ISD::SETUNE: CC = ISD::SETOEQ; Negate = true; break;
case ISD::SETULE: CC = ISD::SETOGT; Negate = true; break;
case ISD::SETULT: CC = ISD::SETOGE; Negate = true; break;
default: break;
}
/* We have instructions implementing the remaining cases. */
switch (CC) {
case ISD::SETEQ:
case ISD::SETOEQ:
if (VecVT == MVT::v4f32)
return HasVSX ? PPC::XVCMPEQSP : PPC::VCMPEQFP;
else if (VecVT == MVT::v2f64)
return PPC::XVCMPEQDP;
break;
case ISD::SETGT:
case ISD::SETOGT:
if (VecVT == MVT::v4f32)
return HasVSX ? PPC::XVCMPGTSP : PPC::VCMPGTFP;
else if (VecVT == MVT::v2f64)
return PPC::XVCMPGTDP;
break;
case ISD::SETGE:
case ISD::SETOGE:
if (VecVT == MVT::v4f32)
return HasVSX ? PPC::XVCMPGESP : PPC::VCMPGEFP;
else if (VecVT == MVT::v2f64)
return PPC::XVCMPGEDP;
break;
default:
break;
}
llvm_unreachable("Invalid floating-point vector compare condition");
} else {
/* Handle some cases by swapping input operands. */
switch (CC) {
case ISD::SETGE: CC = ISD::SETLE; Swap = true; break;
case ISD::SETLT: CC = ISD::SETGT; Swap = true; break;
case ISD::SETUGE: CC = ISD::SETULE; Swap = true; break;
case ISD::SETULT: CC = ISD::SETUGT; Swap = true; break;
default: break;
}
/* Handle some cases by negating the result. */
switch (CC) {
case ISD::SETNE: CC = ISD::SETEQ; Negate = true; break;
case ISD::SETUNE: CC = ISD::SETUEQ; Negate = true; break;
case ISD::SETLE: CC = ISD::SETGT; Negate = true; break;
case ISD::SETULE: CC = ISD::SETUGT; Negate = true; break;
default: break;
}
/* We have instructions implementing the remaining cases. */
switch (CC) {
case ISD::SETEQ:
case ISD::SETUEQ:
if (VecVT == MVT::v16i8)
return PPC::VCMPEQUB;
else if (VecVT == MVT::v8i16)
return PPC::VCMPEQUH;
else if (VecVT == MVT::v4i32)
return PPC::VCMPEQUW;
else if (VecVT == MVT::v2i64)
return PPC::VCMPEQUD;
break;
case ISD::SETGT:
if (VecVT == MVT::v16i8)
return PPC::VCMPGTSB;
else if (VecVT == MVT::v8i16)
return PPC::VCMPGTSH;
else if (VecVT == MVT::v4i32)
return PPC::VCMPGTSW;
else if (VecVT == MVT::v2i64)
return PPC::VCMPGTSD;
break;
case ISD::SETUGT:
if (VecVT == MVT::v16i8)
return PPC::VCMPGTUB;
else if (VecVT == MVT::v8i16)
return PPC::VCMPGTUH;
else if (VecVT == MVT::v4i32)
return PPC::VCMPGTUW;
else if (VecVT == MVT::v2i64)
return PPC::VCMPGTUD;
break;
default:
break;
}
llvm_unreachable("Invalid integer vector compare condition");
}
}
bool PPCDAGToDAGISel::trySETCC(SDNode *N) {
SDLoc dl(N);
unsigned Imm;
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(2))->get();
EVT PtrVT =
CurDAG->getTargetLoweringInfo().getPointerTy(CurDAG->getDataLayout());
bool isPPC64 = (PtrVT == MVT::i64);
if (!PPCSubTarget->useCRBits() &&
isInt32Immediate(N->getOperand(1), Imm)) {
// We can codegen setcc op, imm very efficiently compared to a brcond.
// Check for those cases here.
// setcc op, 0
if (Imm == 0) {
SDValue Op = N->getOperand(0);
switch (CC) {
default: break;
case ISD::SETEQ: {
Op = SDValue(CurDAG->getMachineNode(PPC::CNTLZW, dl, MVT::i32, Op), 0);
SDValue Ops[] = { Op, getI32Imm(27, dl), getI32Imm(5, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
case ISD::SETNE: {
if (isPPC64) break;
SDValue AD =
SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(~0U, dl)), 0);
CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, AD, Op, AD.getValue(1));
return true;
}
case ISD::SETLT: {
SDValue Ops[] = { Op, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
case ISD::SETGT: {
SDValue T =
SDValue(CurDAG->getMachineNode(PPC::NEG, dl, MVT::i32, Op), 0);
T = SDValue(CurDAG->getMachineNode(PPC::ANDC, dl, MVT::i32, T, Op), 0);
SDValue Ops[] = { T, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
}
} else if (Imm == ~0U) { // setcc op, -1
SDValue Op = N->getOperand(0);
switch (CC) {
default: break;
case ISD::SETEQ:
if (isPPC64) break;
Op = SDValue(CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(1, dl)), 0);
CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32,
SDValue(CurDAG->getMachineNode(PPC::LI, dl,
MVT::i32,
getI32Imm(0, dl)),
0), Op.getValue(1));
return true;
case ISD::SETNE: {
if (isPPC64) break;
Op = SDValue(CurDAG->getMachineNode(PPC::NOR, dl, MVT::i32, Op, Op), 0);
SDNode *AD = CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
Op, getI32Imm(~0U, dl));
CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, SDValue(AD, 0), Op,
SDValue(AD, 1));
return true;
}
case ISD::SETLT: {
SDValue AD = SDValue(CurDAG->getMachineNode(PPC::ADDI, dl, MVT::i32, Op,
getI32Imm(1, dl)), 0);
SDValue AN = SDValue(CurDAG->getMachineNode(PPC::AND, dl, MVT::i32, AD,
Op), 0);
SDValue Ops[] = { AN, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
case ISD::SETGT: {
SDValue Ops[] = { Op, getI32Imm(1, dl), getI32Imm(31, dl),
getI32Imm(31, dl) };
Op = SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Op, getI32Imm(1, dl));
return true;
}
}
}
}
SDValue LHS = N->getOperand(0);
SDValue RHS = N->getOperand(1);
// Altivec Vector compare instructions do not set any CR register by default and
// vector compare operations return the same type as the operands.
if (LHS.getValueType().isVector()) {
if (PPCSubTarget->hasQPX())
return false;
EVT VecVT = LHS.getValueType();
bool Swap, Negate;
unsigned int VCmpInst = getVCmpInst(VecVT.getSimpleVT(), CC,
PPCSubTarget->hasVSX(), Swap, Negate);
if (Swap)
std::swap(LHS, RHS);
EVT ResVT = VecVT.changeVectorElementTypeToInteger();
if (Negate) {
SDValue VCmp(CurDAG->getMachineNode(VCmpInst, dl, ResVT, LHS, RHS), 0);
CurDAG->SelectNodeTo(N, PPCSubTarget->hasVSX() ? PPC::XXLNOR : PPC::VNOR,
ResVT, VCmp, VCmp);
return true;
}
CurDAG->SelectNodeTo(N, VCmpInst, ResVT, LHS, RHS);
return true;
}
if (PPCSubTarget->useCRBits())
return false;
bool Inv;
unsigned Idx = getCRIdxForSetCC(CC, Inv);
SDValue CCReg = SelectCC(LHS, RHS, CC, dl);
SDValue IntCR;
// Force the ccreg into CR7.
SDValue CR7Reg = CurDAG->getRegister(PPC::CR7, MVT::i32);
SDValue InFlag(nullptr, 0); // Null incoming flag value.
CCReg = CurDAG->getCopyToReg(CurDAG->getEntryNode(), dl, CR7Reg, CCReg,
InFlag).getValue(1);
IntCR = SDValue(CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32, CR7Reg,
CCReg), 0);
SDValue Ops[] = { IntCR, getI32Imm((32 - (3 - Idx)) & 31, dl),
getI32Imm(31, dl), getI32Imm(31, dl) };
if (!Inv) {
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return true;
}
// Get the specified bit.
SDValue Tmp =
SDValue(CurDAG->getMachineNode(PPC::RLWINM, dl, MVT::i32, Ops), 0);
CurDAG->SelectNodeTo(N, PPC::XORI, MVT::i32, Tmp, getI32Imm(1, dl));
return true;
}
void PPCDAGToDAGISel::transferMemOperands(SDNode *N, SDNode *Result) {
// Transfer memoperands.
MachineSDNode::mmo_iterator MemOp = MF->allocateMemRefsArray(1);
MemOp[0] = cast<MemSDNode>(N)->getMemOperand();
cast<MachineSDNode>(Result)->setMemRefs(MemOp, MemOp + 1);
}
// Select - Convert the specified operand from a target-independent to a
// target-specific node if it hasn't already been changed.
void PPCDAGToDAGISel::Select(SDNode *N) {
SDLoc dl(N);
if (N->isMachineOpcode()) {
N->setNodeId(-1);
return; // Already selected.
}
// In case any misguided DAG-level optimizations form an ADD with a
// TargetConstant operand, crash here instead of miscompiling (by selecting
// an r+r add instead of some kind of r+i add).
if (N->getOpcode() == ISD::ADD &&
N->getOperand(1).getOpcode() == ISD::TargetConstant)
llvm_unreachable("Invalid ADD with TargetConstant operand");
// Try matching complex bit permutations before doing anything else.
if (tryBitPermutation(N))
return;
switch (N->getOpcode()) {
default: break;
case ISD::Constant:
if (N->getValueType(0) == MVT::i64) {
ReplaceNode(N, getInt64(CurDAG, N));
return;
}
break;
case ISD::SETCC:
if (trySETCC(N))
return;
break;
case PPCISD::GlobalBaseReg:
ReplaceNode(N, getGlobalBaseReg());
return;
case ISD::FrameIndex:
selectFrameIndex(N, N);
return;
case PPCISD::MFOCRF: {
SDValue InFlag = N->getOperand(1);
ReplaceNode(N, CurDAG->getMachineNode(PPC::MFOCRF, dl, MVT::i32,
N->getOperand(0), InFlag));
return;
}
case PPCISD::READ_TIME_BASE:
ReplaceNode(N, CurDAG->getMachineNode(PPC::ReadTB, dl, MVT::i32, MVT::i32,
MVT::Other, N->getOperand(0)));
return;
case PPCISD::SRA_ADDZE: {
SDValue N0 = N->getOperand(0);
SDValue ShiftAmt =
CurDAG->getTargetConstant(*cast<ConstantSDNode>(N->getOperand(1))->
getConstantIntValue(), dl,
N->getValueType(0));
if (N->getValueType(0) == MVT::i64) {
SDNode *Op =
CurDAG->getMachineNode(PPC::SRADI, dl, MVT::i64, MVT::Glue,
N0, ShiftAmt);
CurDAG->SelectNodeTo(N, PPC::ADDZE8, MVT::i64, SDValue(Op, 0),
SDValue(Op, 1));
return;
} else {
assert(N->getValueType(0) == MVT::i32 &&
"Expecting i64 or i32 in PPCISD::SRA_ADDZE");
SDNode *Op =
CurDAG->getMachineNode(PPC::SRAWI, dl, MVT::i32, MVT::Glue,
N0, ShiftAmt);
CurDAG->SelectNodeTo(N, PPC::ADDZE, MVT::i32, SDValue(Op, 0),
SDValue(Op, 1));
return;
}
}
case ISD::LOAD: {
// Handle preincrement loads.
LoadSDNode *LD = cast<LoadSDNode>(N);
EVT LoadedVT = LD->getMemoryVT();
// Normal loads are handled by code generated from the .td file.
if (LD->getAddressingMode() != ISD::PRE_INC)
break;
SDValue Offset = LD->getOffset();
if (Offset.getOpcode() == ISD::TargetConstant ||
Offset.getOpcode() == ISD::TargetGlobalAddress) {
unsigned Opcode;
bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
if (LD->getValueType(0) != MVT::i64) {
// Handle PPC32 integer and normal FP loads.
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::f64: Opcode = PPC::LFDU; break;
case MVT::f32: Opcode = PPC::LFSU; break;
case MVT::i32: Opcode = PPC::LWZU; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAU : PPC::LHZU; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZU; break;
}
} else {
assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::i64: Opcode = PPC::LDU; break;
case MVT::i32: Opcode = PPC::LWZU8; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAU8 : PPC::LHZU8; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZU8; break;
}
}
SDValue Chain = LD->getChain();
SDValue Base = LD->getBasePtr();
SDValue Ops[] = { Offset, Base, Chain };
SDNode *MN = CurDAG->getMachineNode(
Opcode, dl, LD->getValueType(0),
PPCLowering->getPointerTy(CurDAG->getDataLayout()), MVT::Other, Ops);
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
} else {
unsigned Opcode;
bool isSExt = LD->getExtensionType() == ISD::SEXTLOAD;
if (LD->getValueType(0) != MVT::i64) {
// Handle PPC32 integer and normal FP loads.
assert((!isSExt || LoadedVT == MVT::i16) && "Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::v4f64: Opcode = PPC::QVLFDUX; break; // QPX
case MVT::v4f32: Opcode = PPC::QVLFSUX; break; // QPX
case MVT::f64: Opcode = PPC::LFDUX; break;
case MVT::f32: Opcode = PPC::LFSUX; break;
case MVT::i32: Opcode = PPC::LWZUX; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAUX : PPC::LHZUX; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZUX; break;
}
} else {
assert(LD->getValueType(0) == MVT::i64 && "Unknown load result type!");
assert((!isSExt || LoadedVT == MVT::i16 || LoadedVT == MVT::i32) &&
"Invalid sext update load");
switch (LoadedVT.getSimpleVT().SimpleTy) {
default: llvm_unreachable("Invalid PPC load type!");
case MVT::i64: Opcode = PPC::LDUX; break;
case MVT::i32: Opcode = isSExt ? PPC::LWAUX : PPC::LWZUX8; break;
case MVT::i16: Opcode = isSExt ? PPC::LHAUX8 : PPC::LHZUX8; break;
case MVT::i1:
case MVT::i8: Opcode = PPC::LBZUX8; break;
}
}
SDValue Chain = LD->getChain();
SDValue Base = LD->getBasePtr();
SDValue Ops[] = { Base, Offset, Chain };
SDNode *MN = CurDAG->getMachineNode(
Opcode, dl, LD->getValueType(0),
PPCLowering->getPointerTy(CurDAG->getDataLayout()), MVT::Other, Ops);
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
}
}
case ISD::AND: {
unsigned Imm, Imm2, SH, MB, ME;
uint64_t Imm64;
// If this is an and of a value rotated between 0 and 31 bits and then and'd
// with a mask, emit rlwinm
if (isInt32Immediate(N->getOperand(1), Imm) &&
isRotateAndMask(N->getOperand(0).getNode(), Imm, false, SH, MB, ME)) {
SDValue Val = N->getOperand(0).getOperand(0);
SDValue Ops[] = { Val, getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// If this is just a masked value where the input is not handled above, and
// is not a rotate-left (handled by a pattern in the .td file), emit rlwinm
if (isInt32Immediate(N->getOperand(1), Imm) &&
isRunOfOnes(Imm, MB, ME) &&
N->getOperand(0).getOpcode() != ISD::ROTL) {
SDValue Val = N->getOperand(0);
SDValue Ops[] = { Val, getI32Imm(0, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// If this is a 64-bit zero-extension mask, emit rldicl.
if (isInt64Immediate(N->getOperand(1).getNode(), Imm64) &&
isMask_64(Imm64)) {
SDValue Val = N->getOperand(0);
MB = 64 - countTrailingOnes(Imm64);
SH = 0;
if (Val.getOpcode() == ISD::ANY_EXTEND) {
auto Op0 = Val.getOperand(0);
if ( Op0.getOpcode() == ISD::SRL &&
isInt32Immediate(Op0.getOperand(1).getNode(), Imm) && Imm <= MB) {
auto ResultType = Val.getNode()->getValueType(0);
auto ImDef = CurDAG->getMachineNode(PPC::IMPLICIT_DEF, dl,
ResultType);
SDValue IDVal (ImDef, 0);
Val = SDValue(CurDAG->getMachineNode(PPC::INSERT_SUBREG, dl,
ResultType, IDVal, Op0.getOperand(0),
getI32Imm(1, dl)), 0);
SH = 64 - Imm;
}
}
// If the operand is a logical right shift, we can fold it into this
// instruction: rldicl(rldicl(x, 64-n, n), 0, mb) -> rldicl(x, 64-n, mb)
// for n <= mb. The right shift is really a left rotate followed by a
// mask, and this mask is a more-restrictive sub-mask of the mask implied
// by the shift.
if (Val.getOpcode() == ISD::SRL &&
isInt32Immediate(Val.getOperand(1).getNode(), Imm) && Imm <= MB) {
assert(Imm < 64 && "Illegal shift amount");
Val = Val.getOperand(0);
SH = 64 - Imm;
}
SDValue Ops[] = { Val, getI32Imm(SH, dl), getI32Imm(MB, dl) };
CurDAG->SelectNodeTo(N, PPC::RLDICL, MVT::i64, Ops);
return;
}
// AND X, 0 -> 0, not "rlwinm 32".
if (isInt32Immediate(N->getOperand(1), Imm) && (Imm == 0)) {
ReplaceUses(SDValue(N, 0), N->getOperand(1));
return;
}
// ISD::OR doesn't get all the bitfield insertion fun.
// (and (or x, c1), c2) where isRunOfOnes(~(c1^c2)) might be a
// bitfield insert.
if (isInt32Immediate(N->getOperand(1), Imm) &&
N->getOperand(0).getOpcode() == ISD::OR &&
isInt32Immediate(N->getOperand(0).getOperand(1), Imm2)) {
// The idea here is to check whether this is equivalent to:
// (c1 & m) | (x & ~m)
// where m is a run-of-ones mask. The logic here is that, for each bit in
// c1 and c2:
// - if both are 1, then the output will be 1.
// - if both are 0, then the output will be 0.
// - if the bit in c1 is 0, and the bit in c2 is 1, then the output will
// come from x.
// - if the bit in c1 is 1, and the bit in c2 is 0, then the output will
// be 0.
// If that last condition is never the case, then we can form m from the
// bits that are the same between c1 and c2.
unsigned MB, ME;
if (isRunOfOnes(~(Imm^Imm2), MB, ME) && !(~Imm & Imm2)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
N->getOperand(0).getOperand(1),
getI32Imm(0, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
ReplaceNode(N, CurDAG->getMachineNode(PPC::RLWIMI, dl, MVT::i32, Ops));
return;
}
}
// Other cases are autogenerated.
break;
}
case ISD::OR: {
if (N->getValueType(0) == MVT::i32)
if (tryBitfieldInsert(N))
return;
short Imm;
if (N->getOperand(0)->getOpcode() == ISD::FrameIndex &&
isIntS16Immediate(N->getOperand(1), Imm)) {
APInt LHSKnownZero, LHSKnownOne;
CurDAG->computeKnownBits(N->getOperand(0), LHSKnownZero, LHSKnownOne);
// If this is equivalent to an add, then we can fold it with the
// FrameIndex calculation.
if ((LHSKnownZero.getZExtValue()|~(uint64_t)Imm) == ~0ULL) {
selectFrameIndex(N, N->getOperand(0).getNode(), (int)Imm);
return;
}
}
// Other cases are autogenerated.
break;
}
case ISD::ADD: {
short Imm;
if (N->getOperand(0)->getOpcode() == ISD::FrameIndex &&
isIntS16Immediate(N->getOperand(1), Imm)) {
selectFrameIndex(N, N->getOperand(0).getNode(), (int)Imm);
return;
}
break;
}
case ISD::SHL: {
unsigned Imm, SH, MB, ME;
if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
isRotateAndMask(N, Imm, true, SH, MB, ME)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// Other cases are autogenerated.
break;
}
case ISD::SRL: {
unsigned Imm, SH, MB, ME;
if (isOpcWithIntImmediate(N->getOperand(0).getNode(), ISD::AND, Imm) &&
isRotateAndMask(N, Imm, true, SH, MB, ME)) {
SDValue Ops[] = { N->getOperand(0).getOperand(0),
getI32Imm(SH, dl), getI32Imm(MB, dl),
getI32Imm(ME, dl) };
CurDAG->SelectNodeTo(N, PPC::RLWINM, MVT::i32, Ops);
return;
}
// Other cases are autogenerated.
break;
}
// FIXME: Remove this once the ANDI glue bug is fixed:
case PPCISD::ANDIo_1_EQ_BIT:
case PPCISD::ANDIo_1_GT_BIT: {
if (!ANDIGlueBug)
break;
EVT InVT = N->getOperand(0).getValueType();
assert((InVT == MVT::i64 || InVT == MVT::i32) &&
"Invalid input type for ANDIo_1_EQ_BIT");
unsigned Opcode = (InVT == MVT::i64) ? PPC::ANDIo8 : PPC::ANDIo;
SDValue AndI(CurDAG->getMachineNode(Opcode, dl, InVT, MVT::Glue,
N->getOperand(0),
CurDAG->getTargetConstant(1, dl, InVT)),
0);
SDValue CR0Reg = CurDAG->getRegister(PPC::CR0, MVT::i32);
SDValue SRIdxVal =
CurDAG->getTargetConstant(N->getOpcode() == PPCISD::ANDIo_1_EQ_BIT ?
PPC::sub_eq : PPC::sub_gt, dl, MVT::i32);
CurDAG->SelectNodeTo(N, TargetOpcode::EXTRACT_SUBREG, MVT::i1, CR0Reg,
SRIdxVal, SDValue(AndI.getNode(), 1) /* glue */);
return;
}
case ISD::SELECT_CC: {
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(4))->get();
EVT PtrVT =
CurDAG->getTargetLoweringInfo().getPointerTy(CurDAG->getDataLayout());
bool isPPC64 = (PtrVT == MVT::i64);
// If this is a select of i1 operands, we'll pattern match it.
if (PPCSubTarget->useCRBits() &&
N->getOperand(0).getValueType() == MVT::i1)
break;
// Handle the setcc cases here. select_cc lhs, 0, 1, 0, cc
if (!isPPC64)
if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N->getOperand(1)))
if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N->getOperand(2)))
if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N->getOperand(3)))
if (N1C->isNullValue() && N3C->isNullValue() &&
N2C->getZExtValue() == 1ULL && CC == ISD::SETNE &&
// FIXME: Implement this optzn for PPC64.
N->getValueType(0) == MVT::i32) {
SDNode *Tmp =
CurDAG->getMachineNode(PPC::ADDIC, dl, MVT::i32, MVT::Glue,
N->getOperand(0), getI32Imm(~0U, dl));
CurDAG->SelectNodeTo(N, PPC::SUBFE, MVT::i32, SDValue(Tmp, 0),
N->getOperand(0), SDValue(Tmp, 1));
return;
}
SDValue CCReg = SelectCC(N->getOperand(0), N->getOperand(1), CC, dl);
if (N->getValueType(0) == MVT::i1) {
// An i1 select is: (c & t) | (!c & f).
bool Inv;
unsigned Idx = getCRIdxForSetCC(CC, Inv);
unsigned SRI;
switch (Idx) {
default: llvm_unreachable("Invalid CC index");
case 0: SRI = PPC::sub_lt; break;
case 1: SRI = PPC::sub_gt; break;
case 2: SRI = PPC::sub_eq; break;
case 3: SRI = PPC::sub_un; break;
}
SDValue CCBit = CurDAG->getTargetExtractSubreg(SRI, dl, MVT::i1, CCReg);
SDValue NotCCBit(CurDAG->getMachineNode(PPC::CRNOR, dl, MVT::i1,
CCBit, CCBit), 0);
SDValue C = Inv ? NotCCBit : CCBit,
NotC = Inv ? CCBit : NotCCBit;
SDValue CAndT(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
C, N->getOperand(2)), 0);
SDValue NotCAndF(CurDAG->getMachineNode(PPC::CRAND, dl, MVT::i1,
NotC, N->getOperand(3)), 0);
CurDAG->SelectNodeTo(N, PPC::CROR, MVT::i1, CAndT, NotCAndF);
return;
}
unsigned BROpc = getPredicateForSetCC(CC);
unsigned SelectCCOp;
if (N->getValueType(0) == MVT::i32)
SelectCCOp = PPC::SELECT_CC_I4;
else if (N->getValueType(0) == MVT::i64)
SelectCCOp = PPC::SELECT_CC_I8;
else if (N->getValueType(0) == MVT::f32)
if (PPCSubTarget->hasP8Vector())
SelectCCOp = PPC::SELECT_CC_VSSRC;
else
SelectCCOp = PPC::SELECT_CC_F4;
else if (N->getValueType(0) == MVT::f64)
if (PPCSubTarget->hasVSX())
SelectCCOp = PPC::SELECT_CC_VSFRC;
else
SelectCCOp = PPC::SELECT_CC_F8;
else if (PPCSubTarget->hasQPX() && N->getValueType(0) == MVT::v4f64)
SelectCCOp = PPC::SELECT_CC_QFRC;
else if (PPCSubTarget->hasQPX() && N->getValueType(0) == MVT::v4f32)
SelectCCOp = PPC::SELECT_CC_QSRC;
else if (PPCSubTarget->hasQPX() && N->getValueType(0) == MVT::v4i1)
SelectCCOp = PPC::SELECT_CC_QBRC;
else if (N->getValueType(0) == MVT::v2f64 ||
N->getValueType(0) == MVT::v2i64)
SelectCCOp = PPC::SELECT_CC_VSRC;
else
SelectCCOp = PPC::SELECT_CC_VRRC;
SDValue Ops[] = { CCReg, N->getOperand(2), N->getOperand(3),
getI32Imm(BROpc, dl) };
CurDAG->SelectNodeTo(N, SelectCCOp, N->getValueType(0), Ops);
return;
}
case ISD::VSELECT:
if (PPCSubTarget->hasVSX()) {
SDValue Ops[] = { N->getOperand(2), N->getOperand(1), N->getOperand(0) };
CurDAG->SelectNodeTo(N, PPC::XXSEL, N->getValueType(0), Ops);
return;
}
break;
case ISD::VECTOR_SHUFFLE:
if (PPCSubTarget->hasVSX() && (N->getValueType(0) == MVT::v2f64 ||
N->getValueType(0) == MVT::v2i64)) {
ShuffleVectorSDNode *SVN = cast<ShuffleVectorSDNode>(N);
SDValue Op1 = N->getOperand(SVN->getMaskElt(0) < 2 ? 0 : 1),
Op2 = N->getOperand(SVN->getMaskElt(1) < 2 ? 0 : 1);
unsigned DM[2];
for (int i = 0; i < 2; ++i)
if (SVN->getMaskElt(i) <= 0 || SVN->getMaskElt(i) == 2)
DM[i] = 0;
else
DM[i] = 1;
if (Op1 == Op2 && DM[0] == 0 && DM[1] == 0 &&
Op1.getOpcode() == ISD::SCALAR_TO_VECTOR &&
isa<LoadSDNode>(Op1.getOperand(0))) {
LoadSDNode *LD = cast<LoadSDNode>(Op1.getOperand(0));
SDValue Base, Offset;
if (LD->isUnindexed() && LD->hasOneUse() && Op1.hasOneUse() &&
(LD->getMemoryVT() == MVT::f64 ||
LD->getMemoryVT() == MVT::i64) &&
SelectAddrIdxOnly(LD->getBasePtr(), Base, Offset)) {
SDValue Chain = LD->getChain();
SDValue Ops[] = { Base, Offset, Chain };
CurDAG->SelectNodeTo(N, PPC::LXVDSX, N->getValueType(0), Ops);
return;
}
}
// For little endian, we must swap the input operands and adjust
// the mask elements (reverse and invert them).
if (PPCSubTarget->isLittleEndian()) {
std::swap(Op1, Op2);
unsigned tmp = DM[0];
DM[0] = 1 - DM[1];
DM[1] = 1 - tmp;
}
SDValue DMV = CurDAG->getTargetConstant(DM[1] | (DM[0] << 1), dl,
MVT::i32);
SDValue Ops[] = { Op1, Op2, DMV };
CurDAG->SelectNodeTo(N, PPC::XXPERMDI, N->getValueType(0), Ops);
return;
}
break;
case PPCISD::BDNZ:
case PPCISD::BDZ: {
bool IsPPC64 = PPCSubTarget->isPPC64();
SDValue Ops[] = { N->getOperand(1), N->getOperand(0) };
CurDAG->SelectNodeTo(N, N->getOpcode() == PPCISD::BDNZ
? (IsPPC64 ? PPC::BDNZ8 : PPC::BDNZ)
: (IsPPC64 ? PPC::BDZ8 : PPC::BDZ),
MVT::Other, Ops);
return;
}
case PPCISD::COND_BRANCH: {
// Op #0 is the Chain.
// Op #1 is the PPC::PRED_* number.
// Op #2 is the CR#
// Op #3 is the Dest MBB
// Op #4 is the Flag.
// Prevent PPC::PRED_* from being selected into LI.
unsigned PCC = cast<ConstantSDNode>(N->getOperand(1))->getZExtValue();
if (EnableBranchHint)
PCC |= getBranchHint(PCC, FuncInfo, N->getOperand(3));
SDValue Pred = getI32Imm(PCC, dl);
SDValue Ops[] = { Pred, N->getOperand(2), N->getOperand(3),
N->getOperand(0), N->getOperand(4) };
CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
return;
}
case ISD::BR_CC: {
ISD::CondCode CC = cast<CondCodeSDNode>(N->getOperand(1))->get();
unsigned PCC = getPredicateForSetCC(CC);
if (N->getOperand(2).getValueType() == MVT::i1) {
unsigned Opc;
bool Swap;
switch (PCC) {
default: llvm_unreachable("Unexpected Boolean-operand predicate");
case PPC::PRED_LT: Opc = PPC::CRANDC; Swap = true; break;
case PPC::PRED_LE: Opc = PPC::CRORC; Swap = true; break;
case PPC::PRED_EQ: Opc = PPC::CREQV; Swap = false; break;
case PPC::PRED_GE: Opc = PPC::CRORC; Swap = false; break;
case PPC::PRED_GT: Opc = PPC::CRANDC; Swap = false; break;
case PPC::PRED_NE: Opc = PPC::CRXOR; Swap = false; break;
}
SDValue BitComp(CurDAG->getMachineNode(Opc, dl, MVT::i1,
N->getOperand(Swap ? 3 : 2),
N->getOperand(Swap ? 2 : 3)), 0);
CurDAG->SelectNodeTo(N, PPC::BC, MVT::Other, BitComp, N->getOperand(4),
N->getOperand(0));
return;
}
if (EnableBranchHint)
PCC |= getBranchHint(PCC, FuncInfo, N->getOperand(4));
SDValue CondCode = SelectCC(N->getOperand(2), N->getOperand(3), CC, dl);
SDValue Ops[] = { getI32Imm(PCC, dl), CondCode,
N->getOperand(4), N->getOperand(0) };
CurDAG->SelectNodeTo(N, PPC::BCC, MVT::Other, Ops);
return;
}
case ISD::BRIND: {
// FIXME: Should custom lower this.
SDValue Chain = N->getOperand(0);
SDValue Target = N->getOperand(1);
unsigned Opc = Target.getValueType() == MVT::i32 ? PPC::MTCTR : PPC::MTCTR8;
unsigned Reg = Target.getValueType() == MVT::i32 ? PPC::BCTR : PPC::BCTR8;
Chain = SDValue(CurDAG->getMachineNode(Opc, dl, MVT::Glue, Target,
Chain), 0);
CurDAG->SelectNodeTo(N, Reg, MVT::Other, Chain);
return;
}
case PPCISD::TOC_ENTRY: {
assert ((PPCSubTarget->isPPC64() || PPCSubTarget->isSVR4ABI()) &&
"Only supported for 64-bit ABI and 32-bit SVR4");
if (PPCSubTarget->isSVR4ABI() && !PPCSubTarget->isPPC64()) {
SDValue GA = N->getOperand(0);
SDNode *MN = CurDAG->getMachineNode(PPC::LWZtoc, dl, MVT::i32, GA,
N->getOperand(1));
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
}
// For medium and large code model, we generate two instructions as
// described below. Otherwise we allow SelectCodeCommon to handle this,
// selecting one of LDtoc, LDtocJTI, LDtocCPT, and LDtocBA.
CodeModel::Model CModel = TM.getCodeModel();
if (CModel != CodeModel::Medium && CModel != CodeModel::Large)
break;
// The first source operand is a TargetGlobalAddress or a TargetJumpTable.
// If it must be toc-referenced according to PPCSubTarget, we generate:
// LDtocL(<ga:@sym>, ADDIStocHA(%X2, <ga:@sym>))
// Otherwise we generate:
// ADDItocL(ADDIStocHA(%X2, <ga:@sym>), <ga:@sym>)
SDValue GA = N->getOperand(0);
SDValue TOCbase = N->getOperand(1);
SDNode *Tmp = CurDAG->getMachineNode(PPC::ADDIStocHA, dl, MVT::i64,
TOCbase, GA);
if (isa<JumpTableSDNode>(GA) || isa<BlockAddressSDNode>(GA) ||
CModel == CodeModel::Large) {
SDNode *MN = CurDAG->getMachineNode(PPC::LDtocL, dl, MVT::i64, GA,
SDValue(Tmp, 0));
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
}
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(GA)) {
const GlobalValue *GV = G->getGlobal();
unsigned char GVFlags = PPCSubTarget->classifyGlobalReference(GV);
if (GVFlags & PPCII::MO_NLP_FLAG) {
SDNode *MN = CurDAG->getMachineNode(PPC::LDtocL, dl, MVT::i64, GA,
SDValue(Tmp, 0));
transferMemOperands(N, MN);
ReplaceNode(N, MN);
return;
}
}
ReplaceNode(N, CurDAG->getMachineNode(PPC::ADDItocL, dl, MVT::i64,
SDValue(Tmp, 0), GA));
return;
}
case PPCISD::PPC32_PICGOT:
// Generate a PIC-safe GOT reference.
assert(!PPCSubTarget->isPPC64() && PPCSubTarget->isSVR4ABI() &&
"PPCISD::PPC32_PICGOT is only supported for 32-bit SVR4");
CurDAG->SelectNodeTo(N, PPC::PPC32PICGOT,
PPCLowering->getPointerTy(CurDAG->getDataLayout()),
MVT::i32);
return;
case PPCISD::VADD_SPLAT: {
// This expands into one of three sequences, depending on whether
// the first operand is odd or even, positive or negative.
assert(isa<ConstantSDNode>(N->getOperand(0)) &&
isa<ConstantSDNode>(N->getOperand(1)) &&
"Invalid operand on VADD_SPLAT!");
int Elt = N->getConstantOperandVal(0);
int EltSize = N->getConstantOperandVal(1);
unsigned Opc1, Opc2, Opc3;
EVT VT;
if (EltSize == 1) {
Opc1 = PPC::VSPLTISB;
Opc2 = PPC::VADDUBM;
Opc3 = PPC::VSUBUBM;
VT = MVT::v16i8;
} else if (EltSize == 2) {
Opc1 = PPC::VSPLTISH;
Opc2 = PPC::VADDUHM;
Opc3 = PPC::VSUBUHM;
VT = MVT::v8i16;
} else {
assert(EltSize == 4 && "Invalid element size on VADD_SPLAT!");
Opc1 = PPC::VSPLTISW;
Opc2 = PPC::VADDUWM;
Opc3 = PPC::VSUBUWM;
VT = MVT::v4i32;
}
if ((Elt & 1) == 0) {
// Elt is even, in the range [-32,-18] + [16,30].
//
// Convert: VADD_SPLAT elt, size
// Into: tmp = VSPLTIS[BHW] elt
// VADDU[BHW]M tmp, tmp
// Where: [BHW] = B for size = 1, H for size = 2, W for size = 4
SDValue EltVal = getI32Imm(Elt >> 1, dl);
SDNode *Tmp = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
SDValue TmpVal = SDValue(Tmp, 0);
ReplaceNode(N, CurDAG->getMachineNode(Opc2, dl, VT, TmpVal, TmpVal));
return;
} else if (Elt > 0) {
// Elt is odd and positive, in the range [17,31].
//
// Convert: VADD_SPLAT elt, size
// Into: tmp1 = VSPLTIS[BHW] elt-16
// tmp2 = VSPLTIS[BHW] -16
// VSUBU[BHW]M tmp1, tmp2
SDValue EltVal = getI32Imm(Elt - 16, dl);
SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
EltVal = getI32Imm(-16, dl);
SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
ReplaceNode(N, CurDAG->getMachineNode(Opc3, dl, VT, SDValue(Tmp1, 0),
SDValue(Tmp2, 0)));
return;
} else {
// Elt is odd and negative, in the range [-31,-17].
//
// Convert: VADD_SPLAT elt, size
// Into: tmp1 = VSPLTIS[BHW] elt+16
// tmp2 = VSPLTIS[BHW] -16
// VADDU[BHW]M tmp1, tmp2
SDValue EltVal = getI32Imm(Elt + 16, dl);
SDNode *Tmp1 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
EltVal = getI32Imm(-16, dl);
SDNode *Tmp2 = CurDAG->getMachineNode(Opc1, dl, VT, EltVal);
ReplaceNode(N, CurDAG->getMachineNode(Opc2, dl, VT, SDValue(Tmp1, 0),
SDValue(Tmp2, 0)));
return;
}
}
}
SelectCode(N);
}
// If the target supports the cmpb instruction, do the idiom recognition here.
// We don't do this as a DAG combine because we don't want to do it as nodes
// are being combined (because we might miss part of the eventual idiom). We
// don't want to do it during instruction selection because we want to reuse
// the logic for lowering the masking operations already part of the
// instruction selector.
SDValue PPCDAGToDAGISel::combineToCMPB(SDNode *N) {
SDLoc dl(N);
assert(N->getOpcode() == ISD::OR &&
"Only OR nodes are supported for CMPB");
SDValue Res;
if (!PPCSubTarget->hasCMPB())
return Res;
if (N->getValueType(0) != MVT::i32 &&
N->getValueType(0) != MVT::i64)
return Res;
EVT VT = N->getValueType(0);
SDValue RHS, LHS;
bool BytesFound[8] = {false, false, false, false, false, false, false, false};
uint64_t Mask = 0, Alt = 0;
auto IsByteSelectCC = [this](SDValue O, unsigned &b,
uint64_t &Mask, uint64_t &Alt,
SDValue &LHS, SDValue &RHS) {
if (O.getOpcode() != ISD::SELECT_CC)
return false;
ISD::CondCode CC = cast<CondCodeSDNode>(O.getOperand(4))->get();
if (!isa<ConstantSDNode>(O.getOperand(2)) ||
!isa<ConstantSDNode>(O.getOperand(3)))
return false;
uint64_t PM = O.getConstantOperandVal(2);
uint64_t PAlt = O.getConstantOperandVal(3);
for (b = 0; b < 8; ++b) {
uint64_t Mask = UINT64_C(0xFF) << (8*b);
if (PM && (PM & Mask) == PM && (PAlt & Mask) == PAlt)
break;
}
if (b == 8)
return false;
Mask |= PM;
Alt |= PAlt;
if (!isa<ConstantSDNode>(O.getOperand(1)) ||
O.getConstantOperandVal(1) != 0) {
SDValue Op0 = O.getOperand(0), Op1 = O.getOperand(1);
if (Op0.getOpcode() == ISD::TRUNCATE)
Op0 = Op0.getOperand(0);
if (Op1.getOpcode() == ISD::TRUNCATE)
Op1 = Op1.getOperand(0);
if (Op0.getOpcode() == ISD::SRL && Op1.getOpcode() == ISD::SRL &&
Op0.getOperand(1) == Op1.getOperand(1) && CC == ISD::SETEQ &&
isa<ConstantSDNode>(Op0.getOperand(1))) {
unsigned Bits = Op0.getValueSizeInBits();
if (b != Bits/8-1)
return false;
if (Op0.getConstantOperandVal(1) != Bits-8)
return false;
LHS = Op0.getOperand(0);
RHS = Op1.getOperand(0);
return true;
}
// When we have small integers (i16 to be specific), the form present
// post-legalization uses SETULT in the SELECT_CC for the
// higher-order byte, depending on the fact that the
// even-higher-order bytes are known to all be zero, for example:
// select_cc (xor $lhs, $rhs), 256, 65280, 0, setult
// (so when the second byte is the same, because all higher-order
// bits from bytes 3 and 4 are known to be zero, the result of the
// xor can be at most 255)
if (Op0.getOpcode() == ISD::XOR && CC == ISD::SETULT &&
isa<ConstantSDNode>(O.getOperand(1))) {
uint64_t ULim = O.getConstantOperandVal(1);
if (ULim != (UINT64_C(1) << b*8))
return false;
// Now we need to make sure that the upper bytes are known to be
// zero.
unsigned Bits = Op0.getValueSizeInBits();
if (!CurDAG->MaskedValueIsZero(
Op0, APInt::getHighBitsSet(Bits, Bits - (b + 1) * 8)))
return false;
LHS = Op0.getOperand(0);
RHS = Op0.getOperand(1);
return true;
}
return false;
}
if (CC != ISD::SETEQ)
return false;
SDValue Op = O.getOperand(0);
if (Op.getOpcode() == ISD::AND) {
if (!isa<ConstantSDNode>(Op.getOperand(1)))
return false;
if (Op.getConstantOperandVal(1) != (UINT64_C(0xFF) << (8*b)))
return false;
SDValue XOR = Op.getOperand(0);
if (XOR.getOpcode() == ISD::TRUNCATE)
XOR = XOR.getOperand(0);
if (XOR.getOpcode() != ISD::XOR)
return false;
LHS = XOR.getOperand(0);
RHS = XOR.getOperand(1);
return true;
} else if (Op.getOpcode() == ISD::SRL) {
if (!isa<ConstantSDNode>(Op.getOperand(1)))
return false;
unsigned Bits = Op.getValueSizeInBits();
if (b != Bits/8-1)
return false;
if (Op.getConstantOperandVal(1) != Bits-8)
return false;
SDValue XOR = Op.getOperand(0);
if (XOR.getOpcode() == ISD::TRUNCATE)
XOR = XOR.getOperand(0);
if (XOR.getOpcode() != ISD::XOR)
return false;
LHS = XOR.getOperand(0);
RHS = XOR.getOperand(1);
return true;
}
return false;
};
SmallVector<SDValue, 8> Queue(1, SDValue(N, 0));
while (!Queue.empty()) {
SDValue V = Queue.pop_back_val();
for (const SDValue &O : V.getNode()->ops()) {
unsigned b;
uint64_t M = 0, A = 0;
SDValue OLHS, ORHS;
if (O.getOpcode() == ISD::OR) {
Queue.push_back(O);
} else if (IsByteSelectCC(O, b, M, A, OLHS, ORHS)) {
if (!LHS) {
LHS = OLHS;
RHS = ORHS;
BytesFound[b] = true;
Mask |= M;
Alt |= A;
} else if ((LHS == ORHS && RHS == OLHS) ||
(RHS == ORHS && LHS == OLHS)) {
BytesFound[b] = true;
Mask |= M;
Alt |= A;
} else {
return Res;
}
} else {
return Res;
}
}
}
unsigned LastB = 0, BCnt = 0;
for (unsigned i = 0; i < 8; ++i)
if (BytesFound[LastB]) {
++BCnt;
LastB = i;
}
if (!LastB || BCnt < 2)
return Res;
// Because we'll be zero-extending the output anyway if don't have a specific
// value for each input byte (via the Mask), we can 'anyext' the inputs.
if (LHS.getValueType() != VT) {
LHS = CurDAG->getAnyExtOrTrunc(LHS, dl, VT);
RHS = CurDAG->getAnyExtOrTrunc(RHS, dl, VT);
}
Res = CurDAG->getNode(PPCISD::CMPB, dl, VT, LHS, RHS);
bool NonTrivialMask = ((int64_t) Mask) != INT64_C(-1);
if (NonTrivialMask && !Alt) {
// Res = Mask & CMPB
Res = CurDAG->getNode(ISD::AND, dl, VT, Res,
CurDAG->getConstant(Mask, dl, VT));
} else if (Alt) {
// Res = (CMPB & Mask) | (~CMPB & Alt)
// Which, as suggested here:
// https://graphics.stanford.edu/~seander/bithacks.html#MaskedMerge
// can be written as:
// Res = Alt ^ ((Alt ^ Mask) & CMPB)
// useful because the (Alt ^ Mask) can be pre-computed.
Res = CurDAG->getNode(ISD::AND, dl, VT, Res,
CurDAG->getConstant(Mask ^ Alt, dl, VT));
Res = CurDAG->getNode(ISD::XOR, dl, VT, Res,
CurDAG->getConstant(Alt, dl, VT));
}
return Res;
}
// When CR bit registers are enabled, an extension of an i1 variable to a i32
// or i64 value is lowered in terms of a SELECT_I[48] operation, and thus
// involves constant materialization of a 0 or a 1 or both. If the result of
// the extension is then operated upon by some operator that can be constant
// folded with a constant 0 or 1, and that constant can be materialized using
// only one instruction (like a zero or one), then we should fold in those
// operations with the select.
void PPCDAGToDAGISel::foldBoolExts(SDValue &Res, SDNode *&N) {
if (!PPCSubTarget->useCRBits())
return;
if (N->getOpcode() != ISD::ZERO_EXTEND &&
N->getOpcode() != ISD::SIGN_EXTEND &&
N->getOpcode() != ISD::ANY_EXTEND)
return;
if (N->getOperand(0).getValueType() != MVT::i1)
return;
if (!N->hasOneUse())
return;
SDLoc dl(N);
EVT VT = N->getValueType(0);
SDValue Cond = N->getOperand(0);
SDValue ConstTrue =
CurDAG->getConstant(N->getOpcode() == ISD::SIGN_EXTEND ? -1 : 1, dl, VT);
SDValue ConstFalse = CurDAG->getConstant(0, dl, VT);
do {
SDNode *User = *N->use_begin();
if (User->getNumOperands() != 2)
break;
auto TryFold = [this, N, User, dl](SDValue Val) {
SDValue UserO0 = User->getOperand(0), UserO1 = User->getOperand(1);
SDValue O0 = UserO0.getNode() == N ? Val : UserO0;
SDValue O1 = UserO1.getNode() == N ? Val : UserO1;
return CurDAG->FoldConstantArithmetic(User->getOpcode(), dl,
User->getValueType(0),
O0.getNode(), O1.getNode());
};
SDValue TrueRes = TryFold(ConstTrue);
if (!TrueRes)
break;
SDValue FalseRes = TryFold(ConstFalse);
if (!FalseRes)
break;
// For us to materialize these using one instruction, we must be able to
// represent them as signed 16-bit integers.
uint64_t True = cast<ConstantSDNode>(TrueRes)->getZExtValue(),
False = cast<ConstantSDNode>(FalseRes)->getZExtValue();
if (!isInt<16>(True) || !isInt<16>(False))
break;
// We can replace User with a new SELECT node, and try again to see if we
// can fold the select with its user.
Res = CurDAG->getSelect(dl, User->getValueType(0), Cond, TrueRes, FalseRes);
N = User;
ConstTrue = TrueRes;
ConstFalse = FalseRes;
} while (N->hasOneUse());
}
void PPCDAGToDAGISel::PreprocessISelDAG() {
SelectionDAG::allnodes_iterator Position(CurDAG->getRoot().getNode());
++Position;
bool MadeChange = false;
while (Position != CurDAG->allnodes_begin()) {
SDNode *N = &*--Position;
if (N->use_empty())
continue;
SDValue Res;
switch (N->getOpcode()) {
default: break;
case ISD::OR:
Res = combineToCMPB(N);
break;
}
if (!Res)
foldBoolExts(Res, N);
if (Res) {
DEBUG(dbgs() << "PPC DAG preprocessing replacing:\nOld: ");
DEBUG(N->dump(CurDAG));
DEBUG(dbgs() << "\nNew: ");
DEBUG(Res.getNode()->dump(CurDAG));
DEBUG(dbgs() << "\n");
CurDAG->ReplaceAllUsesOfValueWith(SDValue(N, 0), Res);
MadeChange = true;
}
}
if (MadeChange)
CurDAG->RemoveDeadNodes();
}
/// PostprocessISelDAG - Perform some late peephole optimizations
/// on the DAG representation.
void PPCDAGToDAGISel::PostprocessISelDAG() {
// Skip peepholes at -O0.
if (TM.getOptLevel() == CodeGenOpt::None)
return;
PeepholePPC64();
PeepholeCROps();
PeepholePPC64ZExt();
}
// Check if all users of this node will become isel where the second operand
// is the constant zero. If this is so, and if we can negate the condition,
// then we can flip the true and false operands. This will allow the zero to
// be folded with the isel so that we don't need to materialize a register
// containing zero.
bool PPCDAGToDAGISel::AllUsersSelectZero(SDNode *N) {
for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
UI != UE; ++UI) {
SDNode *User = *UI;
if (!User->isMachineOpcode())
return false;
if (User->getMachineOpcode() != PPC::SELECT_I4 &&
User->getMachineOpcode() != PPC::SELECT_I8)
return false;
SDNode *Op2 = User->getOperand(2).getNode();
if (!Op2->isMachineOpcode())
return false;
if (Op2->getMachineOpcode() != PPC::LI &&
Op2->getMachineOpcode() != PPC::LI8)
return false;
ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op2->getOperand(0));
if (!C)
return false;
if (!C->isNullValue())
return false;
}
return true;
}
void PPCDAGToDAGISel::SwapAllSelectUsers(SDNode *N) {
SmallVector<SDNode *, 4> ToReplace;
for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end();
UI != UE; ++UI) {
SDNode *User = *UI;
assert((User->getMachineOpcode() == PPC::SELECT_I4 ||
User->getMachineOpcode() == PPC::SELECT_I8) &&
"Must have all select users");
ToReplace.push_back(User);
}
for (SmallVector<SDNode *, 4>::iterator UI = ToReplace.begin(),
UE = ToReplace.end(); UI != UE; ++UI) {
SDNode *User = *UI;
SDNode *ResNode =
CurDAG->getMachineNode(User->getMachineOpcode(), SDLoc(User),
User->getValueType(0), User->getOperand(0),
User->getOperand(2),
User->getOperand(1));
DEBUG(dbgs() << "CR Peephole replacing:\nOld: ");
DEBUG(User->dump(CurDAG));
DEBUG(dbgs() << "\nNew: ");
DEBUG(ResNode->dump(CurDAG));
DEBUG(dbgs() << "\n");
ReplaceUses(User, ResNode);
}
}
void PPCDAGToDAGISel::PeepholeCROps() {
bool IsModified;
do {
IsModified = false;
for (SDNode &Node : CurDAG->allnodes()) {
MachineSDNode *MachineNode = dyn_cast<MachineSDNode>(&Node);
if (!MachineNode || MachineNode->use_empty())
continue;
SDNode *ResNode = MachineNode;
bool Op1Set = false, Op1Unset = false,
Op1Not = false,
Op2Set = false, Op2Unset = false,
Op2Not = false;
unsigned Opcode = MachineNode->getMachineOpcode();
switch (Opcode) {
default: break;
case PPC::CRAND:
case PPC::CRNAND:
case PPC::CROR:
case PPC::CRXOR:
case PPC::CRNOR:
case PPC::CREQV:
case PPC::CRANDC:
case PPC::CRORC: {
SDValue Op = MachineNode->getOperand(1);
if (Op.isMachineOpcode()) {
if (Op.getMachineOpcode() == PPC::CRSET)
Op2Set = true;
else if (Op.getMachineOpcode() == PPC::CRUNSET)
Op2Unset = true;
else if (Op.getMachineOpcode() == PPC::CRNOR &&
Op.getOperand(0) == Op.getOperand(1))
Op2Not = true;
}
LLVM_FALLTHROUGH;
}
case PPC::BC:
case PPC::BCn:
case PPC::SELECT_I4:
case PPC::SELECT_I8:
case PPC::SELECT_F4:
case PPC::SELECT_F8:
case PPC::SELECT_QFRC:
case PPC::SELECT_QSRC:
case PPC::SELECT_QBRC:
case PPC::SELECT_VRRC:
case PPC::SELECT_VSFRC:
case PPC::SELECT_VSSRC:
case PPC::SELECT_VSRC: {
SDValue Op = MachineNode->getOperand(0);
if (Op.isMachineOpcode()) {
if (Op.getMachineOpcode() == PPC::CRSET)
Op1Set = true;
else if (Op.getMachineOpcode() == PPC::CRUNSET)
Op1Unset = true;
else if (Op.getMachineOpcode() == PPC::CRNOR &&
Op.getOperand(0) == Op.getOperand(1))
Op1Not = true;
}
}
break;
}
bool SelectSwap = false;
switch (Opcode) {
default: break;
case PPC::CRAND:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// x & x = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Set)
// 1 & y = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Set)
// x & 1 = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Unset || Op2Unset)
// x & 0 = 0 & y = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Not)
// ~x & y = andc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0).
getOperand(0));
else if (Op2Not)
// x & ~y = andc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRNAND:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// nand(x, x) -> nor(x, x)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Set)
// nand(1, y) -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Set)
// nand(x, 1) -> nor(x, x)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Unset || Op2Unset)
// nand(x, 0) = nand(0, y) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Not)
// nand(~x, y) = ~(~x & y) = x | ~y = orc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// nand(x, ~y) = ~x | y = orc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1).
getOperand(0),
MachineNode->getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CROR:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// x | x = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Set || Op2Set)
// x | 1 = 1 | y = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Unset)
// 0 | y = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Unset)
// x | 0 = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Not)
// ~x | y = orc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0).
getOperand(0));
else if (Op2Not)
// x | ~y = orc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRXOR:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// xor(x, x) = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set)
// xor(1, y) -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Set)
// xor(x, 1) -> nor(x, x)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Unset)
// xor(0, y) = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Unset)
// xor(x, 0) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Not)
// xor(~x, y) = eqv(x, y)
ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// xor(x, ~y) = eqv(x, y)
ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CREQV, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRNOR:
if (Op1Set || Op2Set)
// nor(1, y) -> 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Unset)
// nor(0, y) = ~y -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Unset)
// nor(x, 0) = ~x
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Not)
// nor(~x, y) = andc(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// nor(x, ~y) = andc(y, x)
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1).
getOperand(0),
MachineNode->getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CREQV:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// eqv(x, x) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set)
// eqv(1, y) = y
ResNode = MachineNode->getOperand(1).getNode();
else if (Op2Set)
// eqv(x, 1) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Unset)
// eqv(0, y) = ~y -> nor(y, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op2Unset)
// eqv(x, 0) = ~x
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(0));
else if (Op1Not)
// eqv(~x, y) = xor(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// eqv(x, ~y) = xor(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRXOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1));
SelectSwap = true;
}
break;
case PPC::CRANDC:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// andc(x, x) = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set)
// andc(1, y) = ~y
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op1Unset || Op2Set)
// andc(0, y) = andc(x, 1) = 0
ResNode = CurDAG->getMachineNode(PPC::CRUNSET, SDLoc(MachineNode),
MVT::i1);
else if (Op2Unset)
// andc(x, 0) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Not)
// andc(~x, y) = ~(x | y) = nor(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// andc(x, ~y) = x & y
ResNode = CurDAG->getMachineNode(PPC::CRAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRORC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0));
SelectSwap = true;
}
break;
case PPC::CRORC:
if (MachineNode->getOperand(0) == MachineNode->getOperand(1))
// orc(x, x) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op1Set || Op2Unset)
// orc(1, y) = orc(x, 0) = 1
ResNode = CurDAG->getMachineNode(PPC::CRSET, SDLoc(MachineNode),
MVT::i1);
else if (Op2Set)
// orc(x, 1) = x
ResNode = MachineNode->getOperand(0).getNode();
else if (Op1Unset)
// orc(0, y) = ~y
ResNode = CurDAG->getMachineNode(PPC::CRNOR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(1));
else if (Op1Not)
// orc(~x, y) = ~(x & y) = nand(x, y)
ResNode = CurDAG->getMachineNode(PPC::CRNAND, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1));
else if (Op2Not)
// orc(x, ~y) = x | y
ResNode = CurDAG->getMachineNode(PPC::CROR, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(0),
MachineNode->getOperand(1).
getOperand(0));
else if (AllUsersSelectZero(MachineNode)) {
ResNode = CurDAG->getMachineNode(PPC::CRANDC, SDLoc(MachineNode),
MVT::i1, MachineNode->getOperand(1),
MachineNode->getOperand(0));
SelectSwap = true;
}
break;
case PPC::SELECT_I4:
case PPC::SELECT_I8:
case PPC::SELECT_F4:
case PPC::SELECT_F8:
case PPC::SELECT_QFRC:
case PPC::SELECT_QSRC:
case PPC::SELECT_QBRC:
case PPC::SELECT_VRRC:
case PPC::SELECT_VSFRC:
case PPC::SELECT_VSSRC:
case PPC::SELECT_VSRC:
if (Op1Set)
ResNode = MachineNode->getOperand(1).getNode();
else if (Op1Unset)
ResNode = MachineNode->getOperand(2).getNode();
else if (Op1Not)
ResNode = CurDAG->getMachineNode(MachineNode->getMachineOpcode(),
SDLoc(MachineNode),
MachineNode->getValueType(0),
MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(2),
MachineNode->getOperand(1));
break;
case PPC::BC:
case PPC::BCn:
if (Op1Not)
ResNode = CurDAG->getMachineNode(Opcode == PPC::BC ? PPC::BCn :
PPC::BC,
SDLoc(MachineNode),
MVT::Other,
MachineNode->getOperand(0).
getOperand(0),
MachineNode->getOperand(1),
MachineNode->getOperand(2));
// FIXME: Handle Op1Set, Op1Unset here too.
break;
}
// If we're inverting this node because it is used only by selects that
// we'd like to swap, then swap the selects before the node replacement.
if (SelectSwap)
SwapAllSelectUsers(MachineNode);
if (ResNode != MachineNode) {
DEBUG(dbgs() << "CR Peephole replacing:\nOld: ");
DEBUG(MachineNode->dump(CurDAG));
DEBUG(dbgs() << "\nNew: ");
DEBUG(ResNode->dump(CurDAG));
DEBUG(dbgs() << "\n");
ReplaceUses(MachineNode, ResNode);
IsModified = true;
}
}
if (IsModified)
CurDAG->RemoveDeadNodes();
} while (IsModified);
}
// Gather the set of 32-bit operations that are known to have their
// higher-order 32 bits zero, where ToPromote contains all such operations.
static bool PeepholePPC64ZExtGather(SDValue Op32,
SmallPtrSetImpl<SDNode *> &ToPromote) {
if (!Op32.isMachineOpcode())
return false;
// First, check for the "frontier" instructions (those that will clear the
// higher-order 32 bits.
// For RLWINM and RLWNM, we need to make sure that the mask does not wrap
// around. If it does not, then these instructions will clear the
// higher-order bits.
if ((Op32.getMachineOpcode() == PPC::RLWINM ||
Op32.getMachineOpcode() == PPC::RLWNM) &&
Op32.getConstantOperandVal(2) <= Op32.getConstantOperandVal(3)) {
ToPromote.insert(Op32.getNode());
return true;
}
// SLW and SRW always clear the higher-order bits.
if (Op32.getMachineOpcode() == PPC::SLW ||
Op32.getMachineOpcode() == PPC::SRW) {
ToPromote.insert(Op32.getNode());
return true;
}
// For LI and LIS, we need the immediate to be positive (so that it is not
// sign extended).
if (Op32.getMachineOpcode() == PPC::LI ||
Op32.getMachineOpcode() == PPC::LIS) {
if (!isUInt<15>(Op32.getConstantOperandVal(0)))
return false;
ToPromote.insert(Op32.getNode());
return true;
}
// LHBRX and LWBRX always clear the higher-order bits.
if (Op32.getMachineOpcode() == PPC::LHBRX ||
Op32.getMachineOpcode() == PPC::LWBRX) {
ToPromote.insert(Op32.getNode());
return true;
}
// CNT[LT]ZW always produce a 64-bit value in [0,32], and so is zero extended.
if (Op32.getMachineOpcode() == PPC::CNTLZW ||
Op32.getMachineOpcode() == PPC::CNTTZW) {
ToPromote.insert(Op32.getNode());
return true;
}
// Next, check for those instructions we can look through.
// Assuming the mask does not wrap around, then the higher-order bits are
// taken directly from the first operand.
if (Op32.getMachineOpcode() == PPC::RLWIMI &&
Op32.getConstantOperandVal(3) <= Op32.getConstantOperandVal(4)) {
SmallPtrSet<SDNode *, 16> ToPromote1;
if (!PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1))
return false;
ToPromote.insert(Op32.getNode());
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
// For OR, the higher-order bits are zero if that is true for both operands.
// For SELECT_I4, the same is true (but the relevant operand numbers are
// shifted by 1).
if (Op32.getMachineOpcode() == PPC::OR ||
Op32.getMachineOpcode() == PPC::SELECT_I4) {
unsigned B = Op32.getMachineOpcode() == PPC::SELECT_I4 ? 1 : 0;
SmallPtrSet<SDNode *, 16> ToPromote1;
if (!PeepholePPC64ZExtGather(Op32.getOperand(B+0), ToPromote1))
return false;
if (!PeepholePPC64ZExtGather(Op32.getOperand(B+1), ToPromote1))
return false;
ToPromote.insert(Op32.getNode());
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
// For ORI and ORIS, we need the higher-order bits of the first operand to be
// zero, and also for the constant to be positive (so that it is not sign
// extended).
if (Op32.getMachineOpcode() == PPC::ORI ||
Op32.getMachineOpcode() == PPC::ORIS) {
SmallPtrSet<SDNode *, 16> ToPromote1;
if (!PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1))
return false;
if (!isUInt<15>(Op32.getConstantOperandVal(1)))
return false;
ToPromote.insert(Op32.getNode());
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
// The higher-order bits of AND are zero if that is true for at least one of
// the operands.
if (Op32.getMachineOpcode() == PPC::AND) {
SmallPtrSet<SDNode *, 16> ToPromote1, ToPromote2;
bool Op0OK =
PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1);
bool Op1OK =
PeepholePPC64ZExtGather(Op32.getOperand(1), ToPromote2);
if (!Op0OK && !Op1OK)
return false;
ToPromote.insert(Op32.getNode());
if (Op0OK)
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
if (Op1OK)
ToPromote.insert(ToPromote2.begin(), ToPromote2.end());
return true;
}
// For ANDI and ANDIS, the higher-order bits are zero if either that is true
// of the first operand, or if the second operand is positive (so that it is
// not sign extended).
if (Op32.getMachineOpcode() == PPC::ANDIo ||
Op32.getMachineOpcode() == PPC::ANDISo) {
SmallPtrSet<SDNode *, 16> ToPromote1;
bool Op0OK =
PeepholePPC64ZExtGather(Op32.getOperand(0), ToPromote1);
bool Op1OK = isUInt<15>(Op32.getConstantOperandVal(1));
if (!Op0OK && !Op1OK)
return false;
ToPromote.insert(Op32.getNode());
if (Op0OK)
ToPromote.insert(ToPromote1.begin(), ToPromote1.end());
return true;
}
return false;
}
void PPCDAGToDAGISel::PeepholePPC64ZExt() {
if (!PPCSubTarget->isPPC64())
return;
// When we zero-extend from i32 to i64, we use a pattern like this:
// def : Pat<(i64 (zext i32:$in)),
// (RLDICL (INSERT_SUBREG (i64 (IMPLICIT_DEF)), $in, sub_32),
// 0, 32)>;
// There are several 32-bit shift/rotate instructions, however, that will
// clear the higher-order bits of their output, rendering the RLDICL
// unnecessary. When that happens, we remove it here, and redefine the
// relevant 32-bit operation to be a 64-bit operation.
SelectionDAG::allnodes_iterator Position(CurDAG->getRoot().getNode());
++Position;
bool MadeChange = false;
while (Position != CurDAG->allnodes_begin()) {
SDNode *N = &*--Position;
// Skip dead nodes and any non-machine opcodes.
if (N->use_empty() || !N->isMachineOpcode())
continue;
if (N->getMachineOpcode() != PPC::RLDICL)
continue;
if (N->getConstantOperandVal(1) != 0 ||
N->getConstantOperandVal(2) != 32)
continue;
SDValue ISR = N->getOperand(0);
if (!ISR.isMachineOpcode() ||
ISR.getMachineOpcode() != TargetOpcode::INSERT_SUBREG)
continue;
if (!ISR.hasOneUse())
continue;
if (ISR.getConstantOperandVal(2) != PPC::sub_32)
continue;
SDValue IDef = ISR.getOperand(0);
if (!IDef.isMachineOpcode() ||
IDef.getMachineOpcode() != TargetOpcode::IMPLICIT_DEF)
continue;
// We now know that we're looking at a canonical i32 -> i64 zext. See if we
// can get rid of it.
SDValue Op32 = ISR->getOperand(1);
if (!Op32.isMachineOpcode())
continue;
// There are some 32-bit instructions that always clear the high-order 32
// bits, there are also some instructions (like AND) that we can look
// through.
SmallPtrSet<SDNode *, 16> ToPromote;
if (!PeepholePPC64ZExtGather(Op32, ToPromote))
continue;
// If the ToPromote set contains nodes that have uses outside of the set
// (except for the original INSERT_SUBREG), then abort the transformation.
bool OutsideUse = false;
for (SDNode *PN : ToPromote) {
for (SDNode *UN : PN->uses()) {
if (!ToPromote.count(UN) && UN != ISR.getNode()) {
OutsideUse = true;
break;
}
}
if (OutsideUse)
break;
}
if (OutsideUse)
continue;
MadeChange = true;
// We now know that this zero extension can be removed by promoting to
// nodes in ToPromote to 64-bit operations, where for operations in the
// frontier of the set, we need to insert INSERT_SUBREGs for their
// operands.
for (SDNode *PN : ToPromote) {
unsigned NewOpcode;
switch (PN->getMachineOpcode()) {
default:
llvm_unreachable("Don't know the 64-bit variant of this instruction");
case PPC::RLWINM: NewOpcode = PPC::RLWINM8; break;
case PPC::RLWNM: NewOpcode = PPC::RLWNM8; break;
case PPC::SLW: NewOpcode = PPC::SLW8; break;
case PPC::SRW: NewOpcode = PPC::SRW8; break;
case PPC::LI: NewOpcode = PPC::LI8; break;
case PPC::LIS: NewOpcode = PPC::LIS8; break;
case PPC::LHBRX: NewOpcode = PPC::LHBRX8; break;
case PPC::LWBRX: NewOpcode = PPC::LWBRX8; break;
case PPC::CNTLZW: NewOpcode = PPC::CNTLZW8; break;
case PPC::CNTTZW: NewOpcode = PPC::CNTTZW8; break;
case PPC::RLWIMI: NewOpcode = PPC::RLWIMI8; break;
case PPC::OR: NewOpcode = PPC::OR8; break;
case PPC::SELECT_I4: NewOpcode = PPC::SELECT_I8; break;
case PPC::ORI: NewOpcode = PPC::ORI8; break;
case PPC::ORIS: NewOpcode = PPC::ORIS8; break;
case PPC::AND: NewOpcode = PPC::AND8; break;
case PPC::ANDIo: NewOpcode = PPC::ANDIo8; break;
case PPC::ANDISo: NewOpcode = PPC::ANDISo8; break;
}
// Note: During the replacement process, the nodes will be in an
// inconsistent state (some instructions will have operands with values
// of the wrong type). Once done, however, everything should be right
// again.
SmallVector<SDValue, 4> Ops;
for (const SDValue &V : PN->ops()) {
if (!ToPromote.count(V.getNode()) && V.getValueType() == MVT::i32 &&
!isa<ConstantSDNode>(V)) {
SDValue ReplOpOps[] = { ISR.getOperand(0), V, ISR.getOperand(2) };
SDNode *ReplOp =
CurDAG->getMachineNode(TargetOpcode::INSERT_SUBREG, SDLoc(V),
ISR.getNode()->getVTList(), ReplOpOps);
Ops.push_back(SDValue(ReplOp, 0));
} else {
Ops.push_back(V);
}
}
// Because all to-be-promoted nodes only have users that are other
// promoted nodes (or the original INSERT_SUBREG), we can safely replace
// the i32 result value type with i64.
SmallVector<EVT, 2> NewVTs;
SDVTList VTs = PN->getVTList();
for (unsigned i = 0, ie = VTs.NumVTs; i != ie; ++i)
if (VTs.VTs[i] == MVT::i32)
NewVTs.push_back(MVT::i64);
else
NewVTs.push_back(VTs.VTs[i]);
DEBUG(dbgs() << "PPC64 ZExt Peephole morphing:\nOld: ");
DEBUG(PN->dump(CurDAG));
CurDAG->SelectNodeTo(PN, NewOpcode, CurDAG->getVTList(NewVTs), Ops);
DEBUG(dbgs() << "\nNew: ");
DEBUG(PN->dump(CurDAG));
DEBUG(dbgs() << "\n");
}
// Now we replace the original zero extend and its associated INSERT_SUBREG
// with the value feeding the INSERT_SUBREG (which has now been promoted to
// return an i64).
DEBUG(dbgs() << "PPC64 ZExt Peephole replacing:\nOld: ");
DEBUG(N->dump(CurDAG));
DEBUG(dbgs() << "\nNew: ");
DEBUG(Op32.getNode()->dump(CurDAG));
DEBUG(dbgs() << "\n");
ReplaceUses(N, Op32.getNode());
}
if (MadeChange)
CurDAG->RemoveDeadNodes();
}
void PPCDAGToDAGISel::PeepholePPC64() {
// These optimizations are currently supported only for 64-bit SVR4.
if (PPCSubTarget->isDarwin() || !PPCSubTarget->isPPC64())
return;
SelectionDAG::allnodes_iterator Position(CurDAG->getRoot().getNode());
++Position;
while (Position != CurDAG->allnodes_begin()) {
SDNode *N = &*--Position;
// Skip dead nodes and any non-machine opcodes.
if (N->use_empty() || !N->isMachineOpcode())
continue;
unsigned FirstOp;
unsigned StorageOpcode = N->getMachineOpcode();
switch (StorageOpcode) {
default: continue;
case PPC::LBZ:
case PPC::LBZ8:
case PPC::LD:
case PPC::LFD:
case PPC::LFS:
case PPC::LHA:
case PPC::LHA8:
case PPC::LHZ:
case PPC::LHZ8:
case PPC::LWA:
case PPC::LWZ:
case PPC::LWZ8:
FirstOp = 0;
break;
case PPC::STB:
case PPC::STB8:
case PPC::STD:
case PPC::STFD:
case PPC::STFS:
case PPC::STH:
case PPC::STH8:
case PPC::STW:
case PPC::STW8:
FirstOp = 1;
break;
}
// If this is a load or store with a zero offset, or within the alignment,
// we may be able to fold an add-immediate into the memory operation.
// The check against alignment is below, as it can't occur until we check
// the arguments to N
if (!isa<ConstantSDNode>(N->getOperand(FirstOp)))
continue;
SDValue Base = N->getOperand(FirstOp + 1);
if (!Base.isMachineOpcode())
continue;
unsigned Flags = 0;
bool ReplaceFlags = true;
// When the feeding operation is an add-immediate of some sort,
// determine whether we need to add relocation information to the
// target flags on the immediate operand when we fold it into the
// load instruction.
//
// For something like ADDItocL, the relocation information is
// inferred from the opcode; when we process it in the AsmPrinter,
// we add the necessary relocation there. A load, though, can receive
// relocation from various flavors of ADDIxxx, so we need to carry
// the relocation information in the target flags.
switch (Base.getMachineOpcode()) {
default: continue;
case PPC::ADDI8:
case PPC::ADDI:
// In some cases (such as TLS) the relocation information
// is already in place on the operand, so copying the operand
// is sufficient.
ReplaceFlags = false;
// For these cases, the immediate may not be divisible by 4, in
// which case the fold is illegal for DS-form instructions. (The
// other cases provide aligned addresses and are always safe.)
if ((StorageOpcode == PPC::LWA ||
StorageOpcode == PPC::LD ||
StorageOpcode == PPC::STD) &&
(!isa<ConstantSDNode>(Base.getOperand(1)) ||
Base.getConstantOperandVal(1) % 4 != 0))
continue;
break;
case PPC::ADDIdtprelL:
Flags = PPCII::MO_DTPREL_LO;
break;
case PPC::ADDItlsldL:
Flags = PPCII::MO_TLSLD_LO;
break;
case PPC::ADDItocL:
Flags = PPCII::MO_TOC_LO;
break;
}
SDValue ImmOpnd = Base.getOperand(1);
// On PPC64, the TOC base pointer is guaranteed by the ABI only to have
// 8-byte alignment, and so we can only use offsets less than 8 (otherwise,
// we might have needed different @ha relocation values for the offset
// pointers).
int MaxDisplacement = 7;
if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
const GlobalValue *GV = GA->getGlobal();
MaxDisplacement = std::min((int) GV->getAlignment() - 1, MaxDisplacement);
}
bool UpdateHBase = false;
SDValue HBase = Base.getOperand(0);
int Offset = N->getConstantOperandVal(FirstOp);
if (ReplaceFlags) {
if (Offset < 0 || Offset > MaxDisplacement) {
// If we have a addi(toc@l)/addis(toc@ha) pair, and the addis has only
// one use, then we can do this for any offset, we just need to also
// update the offset (i.e. the symbol addend) on the addis also.
if (Base.getMachineOpcode() != PPC::ADDItocL)
continue;
if (!HBase.isMachineOpcode() ||
HBase.getMachineOpcode() != PPC::ADDIStocHA)
continue;
if (!Base.hasOneUse() || !HBase.hasOneUse())
continue;
SDValue HImmOpnd = HBase.getOperand(1);
if (HImmOpnd != ImmOpnd)
continue;
UpdateHBase = true;
}
} else {
// If we're directly folding the addend from an addi instruction, then:
// 1. In general, the offset on the memory access must be zero.
// 2. If the addend is a constant, then it can be combined with a
// non-zero offset, but only if the result meets the encoding
// requirements.
if (auto *C = dyn_cast<ConstantSDNode>(ImmOpnd)) {
Offset += C->getSExtValue();
if ((StorageOpcode == PPC::LWA || StorageOpcode == PPC::LD ||
StorageOpcode == PPC::STD) && (Offset % 4) != 0)
continue;
if (!isInt<16>(Offset))
continue;
ImmOpnd = CurDAG->getTargetConstant(Offset, SDLoc(ImmOpnd),
ImmOpnd.getValueType());
} else if (Offset != 0) {
continue;
}
}
// We found an opportunity. Reverse the operands from the add
// immediate and substitute them into the load or store. If
// needed, update the target flags for the immediate operand to
// reflect the necessary relocation information.
DEBUG(dbgs() << "Folding add-immediate into mem-op:\nBase: ");
DEBUG(Base->dump(CurDAG));
DEBUG(dbgs() << "\nN: ");
DEBUG(N->dump(CurDAG));
DEBUG(dbgs() << "\n");
// If the relocation information isn't already present on the
// immediate operand, add it now.
if (ReplaceFlags) {
if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(ImmOpnd)) {
SDLoc dl(GA);
const GlobalValue *GV = GA->getGlobal();
// We can't perform this optimization for data whose alignment
// is insufficient for the instruction encoding.
if (GV->getAlignment() < 4 &&
(StorageOpcode == PPC::LD || StorageOpcode == PPC::STD ||
StorageOpcode == PPC::LWA || (Offset % 4) != 0)) {
DEBUG(dbgs() << "Rejected this candidate for alignment.\n\n");
continue;
}
ImmOpnd = CurDAG->getTargetGlobalAddress(GV, dl, MVT::i64, Offset, Flags);
} else if (ConstantPoolSDNode *CP =
dyn_cast<ConstantPoolSDNode>(ImmOpnd)) {
const Constant *C = CP->getConstVal();
ImmOpnd = CurDAG->getTargetConstantPool(C, MVT::i64,
CP->getAlignment(),
Offset, Flags);
}
}
if (FirstOp == 1) // Store
(void)CurDAG->UpdateNodeOperands(N, N->getOperand(0), ImmOpnd,
Base.getOperand(0), N->getOperand(3));
else // Load
(void)CurDAG->UpdateNodeOperands(N, ImmOpnd, Base.getOperand(0),
N->getOperand(2));
if (UpdateHBase)
(void)CurDAG->UpdateNodeOperands(HBase.getNode(), HBase.getOperand(0),
ImmOpnd);
// The add-immediate may now be dead, in which case remove it.
if (Base.getNode()->use_empty())
CurDAG->RemoveDeadNode(Base.getNode());
}
}
/// createPPCISelDag - This pass converts a legalized DAG into a
/// PowerPC-specific DAG, ready for instruction scheduling.
///
FunctionPass *llvm::createPPCISelDag(PPCTargetMachine &TM) {
return new PPCDAGToDAGISel(TM);
}
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