mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-25 20:23:11 +01:00
066460043d
This patch kills off a significant user of the "IsIndirect" field of DBG_VALUE machine insts. Brought up in in PR41675, IsIndirect is techncally redundant as it can be expressed by the DIExpression of a DBG_VALUE inst, and it isn't helpful to have two ways of expressing things. Rather than setting IsIndirect, have DBG_VALUE creators add an extra deref to the insts DIExpression. There should now be no appearences of IsIndirect=True from isel down to LiveDebugVariables / VirtRegRewriter, which is ensured by an assertion in LDVImpl::handleDebugValue. This means we also get to delete the IsIndirect handling in LiveDebugVariables. Tests can be upgraded by for example swapping the following IsIndirect=True DBG_VALUE: DBG_VALUE $somereg, 0, !123, !DIExpression(DW_OP_foo) With one where the indirection is in the DIExpression, by _appending_ a deref: DBG_VALUE $somereg, $noreg, !123, !DIExpression(DW_OP_foo, DW_OP_deref) Which both mean the same thing. Most of the test changes in this patch are updates of that form; also some changes in how the textual assembly printer handles these insts. Differential Revision: https://reviews.llvm.org/D68945 llvm-svn: 374877
1166 lines
46 KiB
C++
1166 lines
46 KiB
C++
//==--- InstrEmitter.cpp - Emit MachineInstrs for the SelectionDAG class ---==//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This implements the Emit routines for the SelectionDAG class, which creates
|
|
// MachineInstrs based on the decisions of the SelectionDAG instruction
|
|
// selection.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "InstrEmitter.h"
|
|
#include "SDNodeDbgValue.h"
|
|
#include "llvm/ADT/Statistic.h"
|
|
#include "llvm/CodeGen/MachineConstantPool.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
#include "llvm/CodeGen/MachineInstrBuilder.h"
|
|
#include "llvm/CodeGen/MachineRegisterInfo.h"
|
|
#include "llvm/CodeGen/StackMaps.h"
|
|
#include "llvm/CodeGen/TargetInstrInfo.h"
|
|
#include "llvm/CodeGen/TargetLowering.h"
|
|
#include "llvm/CodeGen/TargetSubtargetInfo.h"
|
|
#include "llvm/IR/DataLayout.h"
|
|
#include "llvm/IR/DebugInfo.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/ErrorHandling.h"
|
|
#include "llvm/Support/MathExtras.h"
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "instr-emitter"
|
|
|
|
/// MinRCSize - Smallest register class we allow when constraining virtual
|
|
/// registers. If satisfying all register class constraints would require
|
|
/// using a smaller register class, emit a COPY to a new virtual register
|
|
/// instead.
|
|
const unsigned MinRCSize = 4;
|
|
|
|
/// CountResults - The results of target nodes have register or immediate
|
|
/// operands first, then an optional chain, and optional glue operands (which do
|
|
/// not go into the resulting MachineInstr).
|
|
unsigned InstrEmitter::CountResults(SDNode *Node) {
|
|
unsigned N = Node->getNumValues();
|
|
while (N && Node->getValueType(N - 1) == MVT::Glue)
|
|
--N;
|
|
if (N && Node->getValueType(N - 1) == MVT::Other)
|
|
--N; // Skip over chain result.
|
|
return N;
|
|
}
|
|
|
|
/// countOperands - The inputs to target nodes have any actual inputs first,
|
|
/// followed by an optional chain operand, then an optional glue operand.
|
|
/// Compute the number of actual operands that will go into the resulting
|
|
/// MachineInstr.
|
|
///
|
|
/// Also count physreg RegisterSDNode and RegisterMaskSDNode operands preceding
|
|
/// the chain and glue. These operands may be implicit on the machine instr.
|
|
static unsigned countOperands(SDNode *Node, unsigned NumExpUses,
|
|
unsigned &NumImpUses) {
|
|
unsigned N = Node->getNumOperands();
|
|
while (N && Node->getOperand(N - 1).getValueType() == MVT::Glue)
|
|
--N;
|
|
if (N && Node->getOperand(N - 1).getValueType() == MVT::Other)
|
|
--N; // Ignore chain if it exists.
|
|
|
|
// Count RegisterSDNode and RegisterMaskSDNode operands for NumImpUses.
|
|
NumImpUses = N - NumExpUses;
|
|
for (unsigned I = N; I > NumExpUses; --I) {
|
|
if (isa<RegisterMaskSDNode>(Node->getOperand(I - 1)))
|
|
continue;
|
|
if (RegisterSDNode *RN = dyn_cast<RegisterSDNode>(Node->getOperand(I - 1)))
|
|
if (Register::isPhysicalRegister(RN->getReg()))
|
|
continue;
|
|
NumImpUses = N - I;
|
|
break;
|
|
}
|
|
|
|
return N;
|
|
}
|
|
|
|
/// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an
|
|
/// implicit physical register output.
|
|
void InstrEmitter::
|
|
EmitCopyFromReg(SDNode *Node, unsigned ResNo, bool IsClone, bool IsCloned,
|
|
unsigned SrcReg, DenseMap<SDValue, unsigned> &VRBaseMap) {
|
|
unsigned VRBase = 0;
|
|
if (Register::isVirtualRegister(SrcReg)) {
|
|
// Just use the input register directly!
|
|
SDValue Op(Node, ResNo);
|
|
if (IsClone)
|
|
VRBaseMap.erase(Op);
|
|
bool isNew = VRBaseMap.insert(std::make_pair(Op, SrcReg)).second;
|
|
(void)isNew; // Silence compiler warning.
|
|
assert(isNew && "Node emitted out of order - early");
|
|
return;
|
|
}
|
|
|
|
// If the node is only used by a CopyToReg and the dest reg is a vreg, use
|
|
// the CopyToReg'd destination register instead of creating a new vreg.
|
|
bool MatchReg = true;
|
|
const TargetRegisterClass *UseRC = nullptr;
|
|
MVT VT = Node->getSimpleValueType(ResNo);
|
|
|
|
// Stick to the preferred register classes for legal types.
|
|
if (TLI->isTypeLegal(VT))
|
|
UseRC = TLI->getRegClassFor(VT, Node->isDivergent());
|
|
|
|
if (!IsClone && !IsCloned)
|
|
for (SDNode *User : Node->uses()) {
|
|
bool Match = true;
|
|
if (User->getOpcode() == ISD::CopyToReg &&
|
|
User->getOperand(2).getNode() == Node &&
|
|
User->getOperand(2).getResNo() == ResNo) {
|
|
unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
|
|
if (Register::isVirtualRegister(DestReg)) {
|
|
VRBase = DestReg;
|
|
Match = false;
|
|
} else if (DestReg != SrcReg)
|
|
Match = false;
|
|
} else {
|
|
for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
|
|
SDValue Op = User->getOperand(i);
|
|
if (Op.getNode() != Node || Op.getResNo() != ResNo)
|
|
continue;
|
|
MVT VT = Node->getSimpleValueType(Op.getResNo());
|
|
if (VT == MVT::Other || VT == MVT::Glue)
|
|
continue;
|
|
Match = false;
|
|
if (User->isMachineOpcode()) {
|
|
const MCInstrDesc &II = TII->get(User->getMachineOpcode());
|
|
const TargetRegisterClass *RC = nullptr;
|
|
if (i+II.getNumDefs() < II.getNumOperands()) {
|
|
RC = TRI->getAllocatableClass(
|
|
TII->getRegClass(II, i+II.getNumDefs(), TRI, *MF));
|
|
}
|
|
if (!UseRC)
|
|
UseRC = RC;
|
|
else if (RC) {
|
|
const TargetRegisterClass *ComRC =
|
|
TRI->getCommonSubClass(UseRC, RC);
|
|
// If multiple uses expect disjoint register classes, we emit
|
|
// copies in AddRegisterOperand.
|
|
if (ComRC)
|
|
UseRC = ComRC;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
MatchReg &= Match;
|
|
if (VRBase)
|
|
break;
|
|
}
|
|
|
|
const TargetRegisterClass *SrcRC = nullptr, *DstRC = nullptr;
|
|
SrcRC = TRI->getMinimalPhysRegClass(SrcReg, VT);
|
|
|
|
// Figure out the register class to create for the destreg.
|
|
if (VRBase) {
|
|
DstRC = MRI->getRegClass(VRBase);
|
|
} else if (UseRC) {
|
|
assert(TRI->isTypeLegalForClass(*UseRC, VT) &&
|
|
"Incompatible phys register def and uses!");
|
|
DstRC = UseRC;
|
|
} else {
|
|
DstRC = TLI->getRegClassFor(VT, Node->isDivergent());
|
|
}
|
|
|
|
// If all uses are reading from the src physical register and copying the
|
|
// register is either impossible or very expensive, then don't create a copy.
|
|
if (MatchReg && SrcRC->getCopyCost() < 0) {
|
|
VRBase = SrcReg;
|
|
} else {
|
|
// Create the reg, emit the copy.
|
|
VRBase = MRI->createVirtualRegister(DstRC);
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
|
|
VRBase).addReg(SrcReg);
|
|
}
|
|
|
|
SDValue Op(Node, ResNo);
|
|
if (IsClone)
|
|
VRBaseMap.erase(Op);
|
|
bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
|
|
(void)isNew; // Silence compiler warning.
|
|
assert(isNew && "Node emitted out of order - early");
|
|
}
|
|
|
|
void InstrEmitter::CreateVirtualRegisters(SDNode *Node,
|
|
MachineInstrBuilder &MIB,
|
|
const MCInstrDesc &II,
|
|
bool IsClone, bool IsCloned,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap) {
|
|
assert(Node->getMachineOpcode() != TargetOpcode::IMPLICIT_DEF &&
|
|
"IMPLICIT_DEF should have been handled as a special case elsewhere!");
|
|
|
|
unsigned NumResults = CountResults(Node);
|
|
for (unsigned i = 0; i < II.getNumDefs(); ++i) {
|
|
// If the specific node value is only used by a CopyToReg and the dest reg
|
|
// is a vreg in the same register class, use the CopyToReg'd destination
|
|
// register instead of creating a new vreg.
|
|
unsigned VRBase = 0;
|
|
const TargetRegisterClass *RC =
|
|
TRI->getAllocatableClass(TII->getRegClass(II, i, TRI, *MF));
|
|
// Always let the value type influence the used register class. The
|
|
// constraints on the instruction may be too lax to represent the value
|
|
// type correctly. For example, a 64-bit float (X86::FR64) can't live in
|
|
// the 32-bit float super-class (X86::FR32).
|
|
if (i < NumResults && TLI->isTypeLegal(Node->getSimpleValueType(i))) {
|
|
const TargetRegisterClass *VTRC = TLI->getRegClassFor(
|
|
Node->getSimpleValueType(i),
|
|
(Node->isDivergent() || (RC && TRI->isDivergentRegClass(RC))));
|
|
if (RC)
|
|
VTRC = TRI->getCommonSubClass(RC, VTRC);
|
|
if (VTRC)
|
|
RC = VTRC;
|
|
}
|
|
|
|
if (II.OpInfo[i].isOptionalDef()) {
|
|
// Optional def must be a physical register.
|
|
VRBase = cast<RegisterSDNode>(Node->getOperand(i-NumResults))->getReg();
|
|
assert(Register::isPhysicalRegister(VRBase));
|
|
MIB.addReg(VRBase, RegState::Define);
|
|
}
|
|
|
|
if (!VRBase && !IsClone && !IsCloned)
|
|
for (SDNode *User : Node->uses()) {
|
|
if (User->getOpcode() == ISD::CopyToReg &&
|
|
User->getOperand(2).getNode() == Node &&
|
|
User->getOperand(2).getResNo() == i) {
|
|
unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
|
|
if (Register::isVirtualRegister(Reg)) {
|
|
const TargetRegisterClass *RegRC = MRI->getRegClass(Reg);
|
|
if (RegRC == RC) {
|
|
VRBase = Reg;
|
|
MIB.addReg(VRBase, RegState::Define);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// Create the result registers for this node and add the result regs to
|
|
// the machine instruction.
|
|
if (VRBase == 0) {
|
|
assert(RC && "Isn't a register operand!");
|
|
VRBase = MRI->createVirtualRegister(RC);
|
|
MIB.addReg(VRBase, RegState::Define);
|
|
}
|
|
|
|
// If this def corresponds to a result of the SDNode insert the VRBase into
|
|
// the lookup map.
|
|
if (i < NumResults) {
|
|
SDValue Op(Node, i);
|
|
if (IsClone)
|
|
VRBaseMap.erase(Op);
|
|
bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
|
|
(void)isNew; // Silence compiler warning.
|
|
assert(isNew && "Node emitted out of order - early");
|
|
}
|
|
}
|
|
}
|
|
|
|
/// getVR - Return the virtual register corresponding to the specified result
|
|
/// of the specified node.
|
|
unsigned InstrEmitter::getVR(SDValue Op,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap) {
|
|
if (Op.isMachineOpcode() &&
|
|
Op.getMachineOpcode() == TargetOpcode::IMPLICIT_DEF) {
|
|
// Add an IMPLICIT_DEF instruction before every use.
|
|
// IMPLICIT_DEF can produce any type of result so its MCInstrDesc
|
|
// does not include operand register class info.
|
|
const TargetRegisterClass *RC = TLI->getRegClassFor(
|
|
Op.getSimpleValueType(), Op.getNode()->isDivergent());
|
|
Register VReg = MRI->createVirtualRegister(RC);
|
|
BuildMI(*MBB, InsertPos, Op.getDebugLoc(),
|
|
TII->get(TargetOpcode::IMPLICIT_DEF), VReg);
|
|
return VReg;
|
|
}
|
|
|
|
DenseMap<SDValue, unsigned>::iterator I = VRBaseMap.find(Op);
|
|
assert(I != VRBaseMap.end() && "Node emitted out of order - late");
|
|
return I->second;
|
|
}
|
|
|
|
|
|
/// AddRegisterOperand - Add the specified register as an operand to the
|
|
/// specified machine instr. Insert register copies if the register is
|
|
/// not in the required register class.
|
|
void
|
|
InstrEmitter::AddRegisterOperand(MachineInstrBuilder &MIB,
|
|
SDValue Op,
|
|
unsigned IIOpNum,
|
|
const MCInstrDesc *II,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap,
|
|
bool IsDebug, bool IsClone, bool IsCloned) {
|
|
assert(Op.getValueType() != MVT::Other &&
|
|
Op.getValueType() != MVT::Glue &&
|
|
"Chain and glue operands should occur at end of operand list!");
|
|
// Get/emit the operand.
|
|
unsigned VReg = getVR(Op, VRBaseMap);
|
|
|
|
const MCInstrDesc &MCID = MIB->getDesc();
|
|
bool isOptDef = IIOpNum < MCID.getNumOperands() &&
|
|
MCID.OpInfo[IIOpNum].isOptionalDef();
|
|
|
|
// If the instruction requires a register in a different class, create
|
|
// a new virtual register and copy the value into it, but first attempt to
|
|
// shrink VReg's register class within reason. For example, if VReg == GR32
|
|
// and II requires a GR32_NOSP, just constrain VReg to GR32_NOSP.
|
|
if (II) {
|
|
const TargetRegisterClass *OpRC = nullptr;
|
|
if (IIOpNum < II->getNumOperands())
|
|
OpRC = TII->getRegClass(*II, IIOpNum, TRI, *MF);
|
|
|
|
if (OpRC) {
|
|
const TargetRegisterClass *ConstrainedRC
|
|
= MRI->constrainRegClass(VReg, OpRC, MinRCSize);
|
|
if (!ConstrainedRC) {
|
|
OpRC = TRI->getAllocatableClass(OpRC);
|
|
assert(OpRC && "Constraints cannot be fulfilled for allocation");
|
|
Register NewVReg = MRI->createVirtualRegister(OpRC);
|
|
BuildMI(*MBB, InsertPos, Op.getNode()->getDebugLoc(),
|
|
TII->get(TargetOpcode::COPY), NewVReg).addReg(VReg);
|
|
VReg = NewVReg;
|
|
} else {
|
|
assert(ConstrainedRC->isAllocatable() &&
|
|
"Constraining an allocatable VReg produced an unallocatable class?");
|
|
}
|
|
}
|
|
}
|
|
|
|
// If this value has only one use, that use is a kill. This is a
|
|
// conservative approximation. InstrEmitter does trivial coalescing
|
|
// with CopyFromReg nodes, so don't emit kill flags for them.
|
|
// Avoid kill flags on Schedule cloned nodes, since there will be
|
|
// multiple uses.
|
|
// Tied operands are never killed, so we need to check that. And that
|
|
// means we need to determine the index of the operand.
|
|
bool isKill = Op.hasOneUse() &&
|
|
Op.getNode()->getOpcode() != ISD::CopyFromReg &&
|
|
!IsDebug &&
|
|
!(IsClone || IsCloned);
|
|
if (isKill) {
|
|
unsigned Idx = MIB->getNumOperands();
|
|
while (Idx > 0 &&
|
|
MIB->getOperand(Idx-1).isReg() &&
|
|
MIB->getOperand(Idx-1).isImplicit())
|
|
--Idx;
|
|
bool isTied = MCID.getOperandConstraint(Idx, MCOI::TIED_TO) != -1;
|
|
if (isTied)
|
|
isKill = false;
|
|
}
|
|
|
|
MIB.addReg(VReg, getDefRegState(isOptDef) | getKillRegState(isKill) |
|
|
getDebugRegState(IsDebug));
|
|
}
|
|
|
|
/// AddOperand - Add the specified operand to the specified machine instr. II
|
|
/// specifies the instruction information for the node, and IIOpNum is the
|
|
/// operand number (in the II) that we are adding.
|
|
void InstrEmitter::AddOperand(MachineInstrBuilder &MIB,
|
|
SDValue Op,
|
|
unsigned IIOpNum,
|
|
const MCInstrDesc *II,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap,
|
|
bool IsDebug, bool IsClone, bool IsCloned) {
|
|
if (Op.isMachineOpcode()) {
|
|
AddRegisterOperand(MIB, Op, IIOpNum, II, VRBaseMap,
|
|
IsDebug, IsClone, IsCloned);
|
|
} else if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
|
|
MIB.addImm(C->getSExtValue());
|
|
} else if (ConstantFPSDNode *F = dyn_cast<ConstantFPSDNode>(Op)) {
|
|
MIB.addFPImm(F->getConstantFPValue());
|
|
} else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
|
|
unsigned VReg = R->getReg();
|
|
MVT OpVT = Op.getSimpleValueType();
|
|
const TargetRegisterClass *IIRC =
|
|
II ? TRI->getAllocatableClass(TII->getRegClass(*II, IIOpNum, TRI, *MF))
|
|
: nullptr;
|
|
const TargetRegisterClass *OpRC =
|
|
TLI->isTypeLegal(OpVT)
|
|
? TLI->getRegClassFor(OpVT,
|
|
Op.getNode()->isDivergent() ||
|
|
(IIRC && TRI->isDivergentRegClass(IIRC)))
|
|
: nullptr;
|
|
|
|
if (OpRC && IIRC && OpRC != IIRC && Register::isVirtualRegister(VReg)) {
|
|
Register NewVReg = MRI->createVirtualRegister(IIRC);
|
|
BuildMI(*MBB, InsertPos, Op.getNode()->getDebugLoc(),
|
|
TII->get(TargetOpcode::COPY), NewVReg).addReg(VReg);
|
|
VReg = NewVReg;
|
|
}
|
|
// Turn additional physreg operands into implicit uses on non-variadic
|
|
// instructions. This is used by call and return instructions passing
|
|
// arguments in registers.
|
|
bool Imp = II && (IIOpNum >= II->getNumOperands() && !II->isVariadic());
|
|
MIB.addReg(VReg, getImplRegState(Imp));
|
|
} else if (RegisterMaskSDNode *RM = dyn_cast<RegisterMaskSDNode>(Op)) {
|
|
MIB.addRegMask(RM->getRegMask());
|
|
} else if (GlobalAddressSDNode *TGA = dyn_cast<GlobalAddressSDNode>(Op)) {
|
|
MIB.addGlobalAddress(TGA->getGlobal(), TGA->getOffset(),
|
|
TGA->getTargetFlags());
|
|
} else if (BasicBlockSDNode *BBNode = dyn_cast<BasicBlockSDNode>(Op)) {
|
|
MIB.addMBB(BBNode->getBasicBlock());
|
|
} else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Op)) {
|
|
MIB.addFrameIndex(FI->getIndex());
|
|
} else if (JumpTableSDNode *JT = dyn_cast<JumpTableSDNode>(Op)) {
|
|
MIB.addJumpTableIndex(JT->getIndex(), JT->getTargetFlags());
|
|
} else if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(Op)) {
|
|
int Offset = CP->getOffset();
|
|
unsigned Align = CP->getAlignment();
|
|
Type *Type = CP->getType();
|
|
// MachineConstantPool wants an explicit alignment.
|
|
if (Align == 0) {
|
|
Align = MF->getDataLayout().getPrefTypeAlignment(Type);
|
|
if (Align == 0) {
|
|
// Alignment of vector types. FIXME!
|
|
Align = MF->getDataLayout().getTypeAllocSize(Type);
|
|
}
|
|
}
|
|
|
|
unsigned Idx;
|
|
MachineConstantPool *MCP = MF->getConstantPool();
|
|
if (CP->isMachineConstantPoolEntry())
|
|
Idx = MCP->getConstantPoolIndex(CP->getMachineCPVal(), Align);
|
|
else
|
|
Idx = MCP->getConstantPoolIndex(CP->getConstVal(), Align);
|
|
MIB.addConstantPoolIndex(Idx, Offset, CP->getTargetFlags());
|
|
} else if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Op)) {
|
|
MIB.addExternalSymbol(ES->getSymbol(), ES->getTargetFlags());
|
|
} else if (auto *SymNode = dyn_cast<MCSymbolSDNode>(Op)) {
|
|
MIB.addSym(SymNode->getMCSymbol());
|
|
} else if (BlockAddressSDNode *BA = dyn_cast<BlockAddressSDNode>(Op)) {
|
|
MIB.addBlockAddress(BA->getBlockAddress(),
|
|
BA->getOffset(),
|
|
BA->getTargetFlags());
|
|
} else if (TargetIndexSDNode *TI = dyn_cast<TargetIndexSDNode>(Op)) {
|
|
MIB.addTargetIndex(TI->getIndex(), TI->getOffset(), TI->getTargetFlags());
|
|
} else {
|
|
assert(Op.getValueType() != MVT::Other &&
|
|
Op.getValueType() != MVT::Glue &&
|
|
"Chain and glue operands should occur at end of operand list!");
|
|
AddRegisterOperand(MIB, Op, IIOpNum, II, VRBaseMap,
|
|
IsDebug, IsClone, IsCloned);
|
|
}
|
|
}
|
|
|
|
unsigned InstrEmitter::ConstrainForSubReg(unsigned VReg, unsigned SubIdx,
|
|
MVT VT, bool isDivergent, const DebugLoc &DL) {
|
|
const TargetRegisterClass *VRC = MRI->getRegClass(VReg);
|
|
const TargetRegisterClass *RC = TRI->getSubClassWithSubReg(VRC, SubIdx);
|
|
|
|
// RC is a sub-class of VRC that supports SubIdx. Try to constrain VReg
|
|
// within reason.
|
|
if (RC && RC != VRC)
|
|
RC = MRI->constrainRegClass(VReg, RC, MinRCSize);
|
|
|
|
// VReg has been adjusted. It can be used with SubIdx operands now.
|
|
if (RC)
|
|
return VReg;
|
|
|
|
// VReg couldn't be reasonably constrained. Emit a COPY to a new virtual
|
|
// register instead.
|
|
RC = TRI->getSubClassWithSubReg(TLI->getRegClassFor(VT, isDivergent), SubIdx);
|
|
assert(RC && "No legal register class for VT supports that SubIdx");
|
|
Register NewReg = MRI->createVirtualRegister(RC);
|
|
BuildMI(*MBB, InsertPos, DL, TII->get(TargetOpcode::COPY), NewReg)
|
|
.addReg(VReg);
|
|
return NewReg;
|
|
}
|
|
|
|
/// EmitSubregNode - Generate machine code for subreg nodes.
|
|
///
|
|
void InstrEmitter::EmitSubregNode(SDNode *Node,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap,
|
|
bool IsClone, bool IsCloned) {
|
|
unsigned VRBase = 0;
|
|
unsigned Opc = Node->getMachineOpcode();
|
|
|
|
// If the node is only used by a CopyToReg and the dest reg is a vreg, use
|
|
// the CopyToReg'd destination register instead of creating a new vreg.
|
|
for (SDNode *User : Node->uses()) {
|
|
if (User->getOpcode() == ISD::CopyToReg &&
|
|
User->getOperand(2).getNode() == Node) {
|
|
unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
|
|
if (Register::isVirtualRegister(DestReg)) {
|
|
VRBase = DestReg;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (Opc == TargetOpcode::EXTRACT_SUBREG) {
|
|
// EXTRACT_SUBREG is lowered as %dst = COPY %src:sub. There are no
|
|
// constraints on the %dst register, COPY can target all legal register
|
|
// classes.
|
|
unsigned SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
|
|
const TargetRegisterClass *TRC =
|
|
TLI->getRegClassFor(Node->getSimpleValueType(0), Node->isDivergent());
|
|
|
|
unsigned Reg;
|
|
MachineInstr *DefMI;
|
|
RegisterSDNode *R = dyn_cast<RegisterSDNode>(Node->getOperand(0));
|
|
if (R && Register::isPhysicalRegister(R->getReg())) {
|
|
Reg = R->getReg();
|
|
DefMI = nullptr;
|
|
} else {
|
|
Reg = R ? R->getReg() : getVR(Node->getOperand(0), VRBaseMap);
|
|
DefMI = MRI->getVRegDef(Reg);
|
|
}
|
|
|
|
unsigned SrcReg, DstReg, DefSubIdx;
|
|
if (DefMI &&
|
|
TII->isCoalescableExtInstr(*DefMI, SrcReg, DstReg, DefSubIdx) &&
|
|
SubIdx == DefSubIdx &&
|
|
TRC == MRI->getRegClass(SrcReg)) {
|
|
// Optimize these:
|
|
// r1025 = s/zext r1024, 4
|
|
// r1026 = extract_subreg r1025, 4
|
|
// to a copy
|
|
// r1026 = copy r1024
|
|
VRBase = MRI->createVirtualRegister(TRC);
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
|
|
TII->get(TargetOpcode::COPY), VRBase).addReg(SrcReg);
|
|
MRI->clearKillFlags(SrcReg);
|
|
} else {
|
|
// Reg may not support a SubIdx sub-register, and we may need to
|
|
// constrain its register class or issue a COPY to a compatible register
|
|
// class.
|
|
if (Register::isVirtualRegister(Reg))
|
|
Reg = ConstrainForSubReg(Reg, SubIdx,
|
|
Node->getOperand(0).getSimpleValueType(),
|
|
Node->isDivergent(), Node->getDebugLoc());
|
|
// Create the destreg if it is missing.
|
|
if (VRBase == 0)
|
|
VRBase = MRI->createVirtualRegister(TRC);
|
|
|
|
// Create the extract_subreg machine instruction.
|
|
MachineInstrBuilder CopyMI =
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
|
|
TII->get(TargetOpcode::COPY), VRBase);
|
|
if (Register::isVirtualRegister(Reg))
|
|
CopyMI.addReg(Reg, 0, SubIdx);
|
|
else
|
|
CopyMI.addReg(TRI->getSubReg(Reg, SubIdx));
|
|
}
|
|
} else if (Opc == TargetOpcode::INSERT_SUBREG ||
|
|
Opc == TargetOpcode::SUBREG_TO_REG) {
|
|
SDValue N0 = Node->getOperand(0);
|
|
SDValue N1 = Node->getOperand(1);
|
|
SDValue N2 = Node->getOperand(2);
|
|
unsigned SubIdx = cast<ConstantSDNode>(N2)->getZExtValue();
|
|
|
|
// Figure out the register class to create for the destreg. It should be
|
|
// the largest legal register class supporting SubIdx sub-registers.
|
|
// RegisterCoalescer will constrain it further if it decides to eliminate
|
|
// the INSERT_SUBREG instruction.
|
|
//
|
|
// %dst = INSERT_SUBREG %src, %sub, SubIdx
|
|
//
|
|
// is lowered by TwoAddressInstructionPass to:
|
|
//
|
|
// %dst = COPY %src
|
|
// %dst:SubIdx = COPY %sub
|
|
//
|
|
// There is no constraint on the %src register class.
|
|
//
|
|
const TargetRegisterClass *SRC =
|
|
TLI->getRegClassFor(Node->getSimpleValueType(0), Node->isDivergent());
|
|
SRC = TRI->getSubClassWithSubReg(SRC, SubIdx);
|
|
assert(SRC && "No register class supports VT and SubIdx for INSERT_SUBREG");
|
|
|
|
if (VRBase == 0 || !SRC->hasSubClassEq(MRI->getRegClass(VRBase)))
|
|
VRBase = MRI->createVirtualRegister(SRC);
|
|
|
|
// Create the insert_subreg or subreg_to_reg machine instruction.
|
|
MachineInstrBuilder MIB =
|
|
BuildMI(*MF, Node->getDebugLoc(), TII->get(Opc), VRBase);
|
|
|
|
// If creating a subreg_to_reg, then the first input operand
|
|
// is an implicit value immediate, otherwise it's a register
|
|
if (Opc == TargetOpcode::SUBREG_TO_REG) {
|
|
const ConstantSDNode *SD = cast<ConstantSDNode>(N0);
|
|
MIB.addImm(SD->getZExtValue());
|
|
} else
|
|
AddOperand(MIB, N0, 0, nullptr, VRBaseMap, /*IsDebug=*/false,
|
|
IsClone, IsCloned);
|
|
// Add the subregister being inserted
|
|
AddOperand(MIB, N1, 0, nullptr, VRBaseMap, /*IsDebug=*/false,
|
|
IsClone, IsCloned);
|
|
MIB.addImm(SubIdx);
|
|
MBB->insert(InsertPos, MIB);
|
|
} else
|
|
llvm_unreachable("Node is not insert_subreg, extract_subreg, or subreg_to_reg");
|
|
|
|
SDValue Op(Node, 0);
|
|
bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
|
|
(void)isNew; // Silence compiler warning.
|
|
assert(isNew && "Node emitted out of order - early");
|
|
}
|
|
|
|
/// EmitCopyToRegClassNode - Generate machine code for COPY_TO_REGCLASS nodes.
|
|
/// COPY_TO_REGCLASS is just a normal copy, except that the destination
|
|
/// register is constrained to be in a particular register class.
|
|
///
|
|
void
|
|
InstrEmitter::EmitCopyToRegClassNode(SDNode *Node,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap) {
|
|
unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
|
|
|
|
// Create the new VReg in the destination class and emit a copy.
|
|
unsigned DstRCIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
|
|
const TargetRegisterClass *DstRC =
|
|
TRI->getAllocatableClass(TRI->getRegClass(DstRCIdx));
|
|
Register NewVReg = MRI->createVirtualRegister(DstRC);
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
|
|
NewVReg).addReg(VReg);
|
|
|
|
SDValue Op(Node, 0);
|
|
bool isNew = VRBaseMap.insert(std::make_pair(Op, NewVReg)).second;
|
|
(void)isNew; // Silence compiler warning.
|
|
assert(isNew && "Node emitted out of order - early");
|
|
}
|
|
|
|
/// EmitRegSequence - Generate machine code for REG_SEQUENCE nodes.
|
|
///
|
|
void InstrEmitter::EmitRegSequence(SDNode *Node,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap,
|
|
bool IsClone, bool IsCloned) {
|
|
unsigned DstRCIdx = cast<ConstantSDNode>(Node->getOperand(0))->getZExtValue();
|
|
const TargetRegisterClass *RC = TRI->getRegClass(DstRCIdx);
|
|
Register NewVReg = MRI->createVirtualRegister(TRI->getAllocatableClass(RC));
|
|
const MCInstrDesc &II = TII->get(TargetOpcode::REG_SEQUENCE);
|
|
MachineInstrBuilder MIB = BuildMI(*MF, Node->getDebugLoc(), II, NewVReg);
|
|
unsigned NumOps = Node->getNumOperands();
|
|
// If the input pattern has a chain, then the root of the corresponding
|
|
// output pattern will get a chain as well. This can happen to be a
|
|
// REG_SEQUENCE (which is not "guarded" by countOperands/CountResults).
|
|
if (NumOps && Node->getOperand(NumOps-1).getValueType() == MVT::Other)
|
|
--NumOps; // Ignore chain if it exists.
|
|
|
|
assert((NumOps & 1) == 1 &&
|
|
"REG_SEQUENCE must have an odd number of operands!");
|
|
for (unsigned i = 1; i != NumOps; ++i) {
|
|
SDValue Op = Node->getOperand(i);
|
|
if ((i & 1) == 0) {
|
|
RegisterSDNode *R = dyn_cast<RegisterSDNode>(Node->getOperand(i-1));
|
|
// Skip physical registers as they don't have a vreg to get and we'll
|
|
// insert copies for them in TwoAddressInstructionPass anyway.
|
|
if (!R || !Register::isPhysicalRegister(R->getReg())) {
|
|
unsigned SubIdx = cast<ConstantSDNode>(Op)->getZExtValue();
|
|
unsigned SubReg = getVR(Node->getOperand(i-1), VRBaseMap);
|
|
const TargetRegisterClass *TRC = MRI->getRegClass(SubReg);
|
|
const TargetRegisterClass *SRC =
|
|
TRI->getMatchingSuperRegClass(RC, TRC, SubIdx);
|
|
if (SRC && SRC != RC) {
|
|
MRI->setRegClass(NewVReg, SRC);
|
|
RC = SRC;
|
|
}
|
|
}
|
|
}
|
|
AddOperand(MIB, Op, i+1, &II, VRBaseMap, /*IsDebug=*/false,
|
|
IsClone, IsCloned);
|
|
}
|
|
|
|
MBB->insert(InsertPos, MIB);
|
|
SDValue Op(Node, 0);
|
|
bool isNew = VRBaseMap.insert(std::make_pair(Op, NewVReg)).second;
|
|
(void)isNew; // Silence compiler warning.
|
|
assert(isNew && "Node emitted out of order - early");
|
|
}
|
|
|
|
/// EmitDbgValue - Generate machine instruction for a dbg_value node.
|
|
///
|
|
MachineInstr *
|
|
InstrEmitter::EmitDbgValue(SDDbgValue *SD,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap) {
|
|
MDNode *Var = SD->getVariable();
|
|
const DIExpression *Expr = SD->getExpression();
|
|
DebugLoc DL = SD->getDebugLoc();
|
|
assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) &&
|
|
"Expected inlined-at fields to agree");
|
|
|
|
SD->setIsEmitted();
|
|
|
|
if (SD->isInvalidated()) {
|
|
// An invalidated SDNode must generate an undef DBG_VALUE: although the
|
|
// original value is no longer computed, earlier DBG_VALUEs live ranges
|
|
// must not leak into later code.
|
|
auto MIB = BuildMI(*MF, DL, TII->get(TargetOpcode::DBG_VALUE));
|
|
MIB.addReg(0U);
|
|
MIB.addReg(0U, RegState::Debug);
|
|
MIB.addMetadata(Var);
|
|
MIB.addMetadata(Expr);
|
|
return &*MIB;
|
|
}
|
|
|
|
if (SD->getKind() == SDDbgValue::FRAMEIX) {
|
|
// Stack address; this needs to be lowered in target-dependent fashion.
|
|
// EmitTargetCodeForFrameDebugValue is responsible for allocation.
|
|
auto FrameMI = BuildMI(*MF, DL, TII->get(TargetOpcode::DBG_VALUE))
|
|
.addFrameIndex(SD->getFrameIx());
|
|
|
|
if (SD->isIndirect())
|
|
Expr = DIExpression::append(Expr, {dwarf::DW_OP_deref});
|
|
|
|
FrameMI.addReg(0);
|
|
return FrameMI.addMetadata(Var).addMetadata(Expr);
|
|
}
|
|
// Otherwise, we're going to create an instruction here.
|
|
const MCInstrDesc &II = TII->get(TargetOpcode::DBG_VALUE);
|
|
MachineInstrBuilder MIB = BuildMI(*MF, DL, II);
|
|
if (SD->getKind() == SDDbgValue::SDNODE) {
|
|
SDNode *Node = SD->getSDNode();
|
|
SDValue Op = SDValue(Node, SD->getResNo());
|
|
// It's possible we replaced this SDNode with other(s) and therefore
|
|
// didn't generate code for it. It's better to catch these cases where
|
|
// they happen and transfer the debug info, but trying to guarantee that
|
|
// in all cases would be very fragile; this is a safeguard for any
|
|
// that were missed.
|
|
DenseMap<SDValue, unsigned>::iterator I = VRBaseMap.find(Op);
|
|
if (I==VRBaseMap.end())
|
|
MIB.addReg(0U); // undef
|
|
else
|
|
AddOperand(MIB, Op, (*MIB).getNumOperands(), &II, VRBaseMap,
|
|
/*IsDebug=*/true, /*IsClone=*/false, /*IsCloned=*/false);
|
|
} else if (SD->getKind() == SDDbgValue::VREG) {
|
|
MIB.addReg(SD->getVReg(), RegState::Debug);
|
|
} else if (SD->getKind() == SDDbgValue::CONST) {
|
|
const Value *V = SD->getConst();
|
|
if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
|
|
if (CI->getBitWidth() > 64)
|
|
MIB.addCImm(CI);
|
|
else
|
|
MIB.addImm(CI->getSExtValue());
|
|
} else if (const ConstantFP *CF = dyn_cast<ConstantFP>(V)) {
|
|
MIB.addFPImm(CF);
|
|
} else if (isa<ConstantPointerNull>(V)) {
|
|
// Note: This assumes that all nullptr constants are zero-valued.
|
|
MIB.addImm(0);
|
|
} else {
|
|
// Could be an Undef. In any case insert an Undef so we can see what we
|
|
// dropped.
|
|
MIB.addReg(0U);
|
|
}
|
|
} else {
|
|
// Insert an Undef so we can see what we dropped.
|
|
MIB.addReg(0U);
|
|
}
|
|
|
|
// Indirect addressing is indicated by an Imm as the second parameter.
|
|
if (SD->isIndirect())
|
|
Expr = DIExpression::append(Expr, {dwarf::DW_OP_deref});
|
|
|
|
MIB.addReg(0U, RegState::Debug);
|
|
|
|
MIB.addMetadata(Var);
|
|
MIB.addMetadata(Expr);
|
|
|
|
return &*MIB;
|
|
}
|
|
|
|
MachineInstr *
|
|
InstrEmitter::EmitDbgLabel(SDDbgLabel *SD) {
|
|
MDNode *Label = SD->getLabel();
|
|
DebugLoc DL = SD->getDebugLoc();
|
|
assert(cast<DILabel>(Label)->isValidLocationForIntrinsic(DL) &&
|
|
"Expected inlined-at fields to agree");
|
|
|
|
const MCInstrDesc &II = TII->get(TargetOpcode::DBG_LABEL);
|
|
MachineInstrBuilder MIB = BuildMI(*MF, DL, II);
|
|
MIB.addMetadata(Label);
|
|
|
|
return &*MIB;
|
|
}
|
|
|
|
/// EmitMachineNode - Generate machine code for a target-specific node and
|
|
/// needed dependencies.
|
|
///
|
|
void InstrEmitter::
|
|
EmitMachineNode(SDNode *Node, bool IsClone, bool IsCloned,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap) {
|
|
unsigned Opc = Node->getMachineOpcode();
|
|
|
|
// Handle subreg insert/extract specially
|
|
if (Opc == TargetOpcode::EXTRACT_SUBREG ||
|
|
Opc == TargetOpcode::INSERT_SUBREG ||
|
|
Opc == TargetOpcode::SUBREG_TO_REG) {
|
|
EmitSubregNode(Node, VRBaseMap, IsClone, IsCloned);
|
|
return;
|
|
}
|
|
|
|
// Handle COPY_TO_REGCLASS specially.
|
|
if (Opc == TargetOpcode::COPY_TO_REGCLASS) {
|
|
EmitCopyToRegClassNode(Node, VRBaseMap);
|
|
return;
|
|
}
|
|
|
|
// Handle REG_SEQUENCE specially.
|
|
if (Opc == TargetOpcode::REG_SEQUENCE) {
|
|
EmitRegSequence(Node, VRBaseMap, IsClone, IsCloned);
|
|
return;
|
|
}
|
|
|
|
if (Opc == TargetOpcode::IMPLICIT_DEF)
|
|
// We want a unique VR for each IMPLICIT_DEF use.
|
|
return;
|
|
|
|
const MCInstrDesc &II = TII->get(Opc);
|
|
unsigned NumResults = CountResults(Node);
|
|
unsigned NumDefs = II.getNumDefs();
|
|
const MCPhysReg *ScratchRegs = nullptr;
|
|
|
|
// Handle STACKMAP and PATCHPOINT specially and then use the generic code.
|
|
if (Opc == TargetOpcode::STACKMAP || Opc == TargetOpcode::PATCHPOINT) {
|
|
// Stackmaps do not have arguments and do not preserve their calling
|
|
// convention. However, to simplify runtime support, they clobber the same
|
|
// scratch registers as AnyRegCC.
|
|
unsigned CC = CallingConv::AnyReg;
|
|
if (Opc == TargetOpcode::PATCHPOINT) {
|
|
CC = Node->getConstantOperandVal(PatchPointOpers::CCPos);
|
|
NumDefs = NumResults;
|
|
}
|
|
ScratchRegs = TLI->getScratchRegisters((CallingConv::ID) CC);
|
|
}
|
|
|
|
unsigned NumImpUses = 0;
|
|
unsigned NodeOperands =
|
|
countOperands(Node, II.getNumOperands() - NumDefs, NumImpUses);
|
|
bool HasPhysRegOuts = NumResults > NumDefs && II.getImplicitDefs()!=nullptr;
|
|
#ifndef NDEBUG
|
|
unsigned NumMIOperands = NodeOperands + NumResults;
|
|
if (II.isVariadic())
|
|
assert(NumMIOperands >= II.getNumOperands() &&
|
|
"Too few operands for a variadic node!");
|
|
else
|
|
assert(NumMIOperands >= II.getNumOperands() &&
|
|
NumMIOperands <= II.getNumOperands() + II.getNumImplicitDefs() +
|
|
NumImpUses &&
|
|
"#operands for dag node doesn't match .td file!");
|
|
#endif
|
|
|
|
// Create the new machine instruction.
|
|
MachineInstrBuilder MIB = BuildMI(*MF, Node->getDebugLoc(), II);
|
|
|
|
// Add result register values for things that are defined by this
|
|
// instruction.
|
|
if (NumResults) {
|
|
CreateVirtualRegisters(Node, MIB, II, IsClone, IsCloned, VRBaseMap);
|
|
|
|
// Transfer any IR flags from the SDNode to the MachineInstr
|
|
MachineInstr *MI = MIB.getInstr();
|
|
const SDNodeFlags Flags = Node->getFlags();
|
|
if (Flags.hasNoSignedZeros())
|
|
MI->setFlag(MachineInstr::MIFlag::FmNsz);
|
|
|
|
if (Flags.hasAllowReciprocal())
|
|
MI->setFlag(MachineInstr::MIFlag::FmArcp);
|
|
|
|
if (Flags.hasNoNaNs())
|
|
MI->setFlag(MachineInstr::MIFlag::FmNoNans);
|
|
|
|
if (Flags.hasNoInfs())
|
|
MI->setFlag(MachineInstr::MIFlag::FmNoInfs);
|
|
|
|
if (Flags.hasAllowContract())
|
|
MI->setFlag(MachineInstr::MIFlag::FmContract);
|
|
|
|
if (Flags.hasApproximateFuncs())
|
|
MI->setFlag(MachineInstr::MIFlag::FmAfn);
|
|
|
|
if (Flags.hasAllowReassociation())
|
|
MI->setFlag(MachineInstr::MIFlag::FmReassoc);
|
|
|
|
if (Flags.hasNoUnsignedWrap())
|
|
MI->setFlag(MachineInstr::MIFlag::NoUWrap);
|
|
|
|
if (Flags.hasNoSignedWrap())
|
|
MI->setFlag(MachineInstr::MIFlag::NoSWrap);
|
|
|
|
if (Flags.hasExact())
|
|
MI->setFlag(MachineInstr::MIFlag::IsExact);
|
|
|
|
if (Flags.hasFPExcept())
|
|
MI->setFlag(MachineInstr::MIFlag::FPExcept);
|
|
}
|
|
|
|
// Emit all of the actual operands of this instruction, adding them to the
|
|
// instruction as appropriate.
|
|
bool HasOptPRefs = NumDefs > NumResults;
|
|
assert((!HasOptPRefs || !HasPhysRegOuts) &&
|
|
"Unable to cope with optional defs and phys regs defs!");
|
|
unsigned NumSkip = HasOptPRefs ? NumDefs - NumResults : 0;
|
|
for (unsigned i = NumSkip; i != NodeOperands; ++i)
|
|
AddOperand(MIB, Node->getOperand(i), i-NumSkip+NumDefs, &II,
|
|
VRBaseMap, /*IsDebug=*/false, IsClone, IsCloned);
|
|
|
|
// Add scratch registers as implicit def and early clobber
|
|
if (ScratchRegs)
|
|
for (unsigned i = 0; ScratchRegs[i]; ++i)
|
|
MIB.addReg(ScratchRegs[i], RegState::ImplicitDefine |
|
|
RegState::EarlyClobber);
|
|
|
|
// Set the memory reference descriptions of this instruction now that it is
|
|
// part of the function.
|
|
MIB.setMemRefs(cast<MachineSDNode>(Node)->memoperands());
|
|
|
|
// Insert the instruction into position in the block. This needs to
|
|
// happen before any custom inserter hook is called so that the
|
|
// hook knows where in the block to insert the replacement code.
|
|
MBB->insert(InsertPos, MIB);
|
|
|
|
// The MachineInstr may also define physregs instead of virtregs. These
|
|
// physreg values can reach other instructions in different ways:
|
|
//
|
|
// 1. When there is a use of a Node value beyond the explicitly defined
|
|
// virtual registers, we emit a CopyFromReg for one of the implicitly
|
|
// defined physregs. This only happens when HasPhysRegOuts is true.
|
|
//
|
|
// 2. A CopyFromReg reading a physreg may be glued to this instruction.
|
|
//
|
|
// 3. A glued instruction may implicitly use a physreg.
|
|
//
|
|
// 4. A glued instruction may use a RegisterSDNode operand.
|
|
//
|
|
// Collect all the used physreg defs, and make sure that any unused physreg
|
|
// defs are marked as dead.
|
|
SmallVector<Register, 8> UsedRegs;
|
|
|
|
// Additional results must be physical register defs.
|
|
if (HasPhysRegOuts) {
|
|
for (unsigned i = NumDefs; i < NumResults; ++i) {
|
|
Register Reg = II.getImplicitDefs()[i - NumDefs];
|
|
if (!Node->hasAnyUseOfValue(i))
|
|
continue;
|
|
// This implicitly defined physreg has a use.
|
|
UsedRegs.push_back(Reg);
|
|
EmitCopyFromReg(Node, i, IsClone, IsCloned, Reg, VRBaseMap);
|
|
}
|
|
}
|
|
|
|
// Scan the glue chain for any used physregs.
|
|
if (Node->getValueType(Node->getNumValues()-1) == MVT::Glue) {
|
|
for (SDNode *F = Node->getGluedUser(); F; F = F->getGluedUser()) {
|
|
if (F->getOpcode() == ISD::CopyFromReg) {
|
|
UsedRegs.push_back(cast<RegisterSDNode>(F->getOperand(1))->getReg());
|
|
continue;
|
|
} else if (F->getOpcode() == ISD::CopyToReg) {
|
|
// Skip CopyToReg nodes that are internal to the glue chain.
|
|
continue;
|
|
}
|
|
// Collect declared implicit uses.
|
|
const MCInstrDesc &MCID = TII->get(F->getMachineOpcode());
|
|
UsedRegs.append(MCID.getImplicitUses(),
|
|
MCID.getImplicitUses() + MCID.getNumImplicitUses());
|
|
// In addition to declared implicit uses, we must also check for
|
|
// direct RegisterSDNode operands.
|
|
for (unsigned i = 0, e = F->getNumOperands(); i != e; ++i)
|
|
if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(F->getOperand(i))) {
|
|
Register Reg = R->getReg();
|
|
if (Reg.isPhysical())
|
|
UsedRegs.push_back(Reg);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Finally mark unused registers as dead.
|
|
if (!UsedRegs.empty() || II.getImplicitDefs() || II.hasOptionalDef())
|
|
MIB->setPhysRegsDeadExcept(UsedRegs, *TRI);
|
|
|
|
// Run post-isel target hook to adjust this instruction if needed.
|
|
if (II.hasPostISelHook())
|
|
TLI->AdjustInstrPostInstrSelection(*MIB, Node);
|
|
}
|
|
|
|
/// EmitSpecialNode - Generate machine code for a target-independent node and
|
|
/// needed dependencies.
|
|
void InstrEmitter::
|
|
EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
|
|
DenseMap<SDValue, unsigned> &VRBaseMap) {
|
|
switch (Node->getOpcode()) {
|
|
default:
|
|
#ifndef NDEBUG
|
|
Node->dump();
|
|
#endif
|
|
llvm_unreachable("This target-independent node should have been selected!");
|
|
case ISD::EntryToken:
|
|
llvm_unreachable("EntryToken should have been excluded from the schedule!");
|
|
case ISD::MERGE_VALUES:
|
|
case ISD::TokenFactor: // fall thru
|
|
break;
|
|
case ISD::CopyToReg: {
|
|
unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
|
|
SDValue SrcVal = Node->getOperand(2);
|
|
if (Register::isVirtualRegister(DestReg) && SrcVal.isMachineOpcode() &&
|
|
SrcVal.getMachineOpcode() == TargetOpcode::IMPLICIT_DEF) {
|
|
// Instead building a COPY to that vreg destination, build an
|
|
// IMPLICIT_DEF instruction instead.
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
|
|
TII->get(TargetOpcode::IMPLICIT_DEF), DestReg);
|
|
break;
|
|
}
|
|
unsigned SrcReg;
|
|
if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(SrcVal))
|
|
SrcReg = R->getReg();
|
|
else
|
|
SrcReg = getVR(SrcVal, VRBaseMap);
|
|
|
|
if (SrcReg == DestReg) // Coalesced away the copy? Ignore.
|
|
break;
|
|
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
|
|
DestReg).addReg(SrcReg);
|
|
break;
|
|
}
|
|
case ISD::CopyFromReg: {
|
|
unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
|
|
EmitCopyFromReg(Node, 0, IsClone, IsCloned, SrcReg, VRBaseMap);
|
|
break;
|
|
}
|
|
case ISD::EH_LABEL:
|
|
case ISD::ANNOTATION_LABEL: {
|
|
unsigned Opc = (Node->getOpcode() == ISD::EH_LABEL)
|
|
? TargetOpcode::EH_LABEL
|
|
: TargetOpcode::ANNOTATION_LABEL;
|
|
MCSymbol *S = cast<LabelSDNode>(Node)->getLabel();
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
|
|
TII->get(Opc)).addSym(S);
|
|
break;
|
|
}
|
|
|
|
case ISD::LIFETIME_START:
|
|
case ISD::LIFETIME_END: {
|
|
unsigned TarOp = (Node->getOpcode() == ISD::LIFETIME_START) ?
|
|
TargetOpcode::LIFETIME_START : TargetOpcode::LIFETIME_END;
|
|
|
|
FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Node->getOperand(1));
|
|
BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TarOp))
|
|
.addFrameIndex(FI->getIndex());
|
|
break;
|
|
}
|
|
|
|
case ISD::INLINEASM:
|
|
case ISD::INLINEASM_BR: {
|
|
unsigned NumOps = Node->getNumOperands();
|
|
if (Node->getOperand(NumOps-1).getValueType() == MVT::Glue)
|
|
--NumOps; // Ignore the glue operand.
|
|
|
|
// Create the inline asm machine instruction.
|
|
unsigned TgtOpc = Node->getOpcode() == ISD::INLINEASM_BR
|
|
? TargetOpcode::INLINEASM_BR
|
|
: TargetOpcode::INLINEASM;
|
|
MachineInstrBuilder MIB =
|
|
BuildMI(*MF, Node->getDebugLoc(), TII->get(TgtOpc));
|
|
|
|
// Add the asm string as an external symbol operand.
|
|
SDValue AsmStrV = Node->getOperand(InlineAsm::Op_AsmString);
|
|
const char *AsmStr = cast<ExternalSymbolSDNode>(AsmStrV)->getSymbol();
|
|
MIB.addExternalSymbol(AsmStr);
|
|
|
|
// Add the HasSideEffect, isAlignStack, AsmDialect, MayLoad and MayStore
|
|
// bits.
|
|
int64_t ExtraInfo =
|
|
cast<ConstantSDNode>(Node->getOperand(InlineAsm::Op_ExtraInfo))->
|
|
getZExtValue();
|
|
MIB.addImm(ExtraInfo);
|
|
|
|
// Remember to operand index of the group flags.
|
|
SmallVector<unsigned, 8> GroupIdx;
|
|
|
|
// Remember registers that are part of early-clobber defs.
|
|
SmallVector<unsigned, 8> ECRegs;
|
|
|
|
// Add all of the operand registers to the instruction.
|
|
for (unsigned i = InlineAsm::Op_FirstOperand; i != NumOps;) {
|
|
unsigned Flags =
|
|
cast<ConstantSDNode>(Node->getOperand(i))->getZExtValue();
|
|
const unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
|
|
|
|
GroupIdx.push_back(MIB->getNumOperands());
|
|
MIB.addImm(Flags);
|
|
++i; // Skip the ID value.
|
|
|
|
switch (InlineAsm::getKind(Flags)) {
|
|
default: llvm_unreachable("Bad flags!");
|
|
case InlineAsm::Kind_RegDef:
|
|
for (unsigned j = 0; j != NumVals; ++j, ++i) {
|
|
unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
|
|
// FIXME: Add dead flags for physical and virtual registers defined.
|
|
// For now, mark physical register defs as implicit to help fast
|
|
// regalloc. This makes inline asm look a lot like calls.
|
|
MIB.addReg(Reg,
|
|
RegState::Define |
|
|
getImplRegState(Register::isPhysicalRegister(Reg)));
|
|
}
|
|
break;
|
|
case InlineAsm::Kind_RegDefEarlyClobber:
|
|
case InlineAsm::Kind_Clobber:
|
|
for (unsigned j = 0; j != NumVals; ++j, ++i) {
|
|
unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
|
|
MIB.addReg(Reg,
|
|
RegState::Define | RegState::EarlyClobber |
|
|
getImplRegState(Register::isPhysicalRegister(Reg)));
|
|
ECRegs.push_back(Reg);
|
|
}
|
|
break;
|
|
case InlineAsm::Kind_RegUse: // Use of register.
|
|
case InlineAsm::Kind_Imm: // Immediate.
|
|
case InlineAsm::Kind_Mem: // Addressing mode.
|
|
// The addressing mode has been selected, just add all of the
|
|
// operands to the machine instruction.
|
|
for (unsigned j = 0; j != NumVals; ++j, ++i)
|
|
AddOperand(MIB, Node->getOperand(i), 0, nullptr, VRBaseMap,
|
|
/*IsDebug=*/false, IsClone, IsCloned);
|
|
|
|
// Manually set isTied bits.
|
|
if (InlineAsm::getKind(Flags) == InlineAsm::Kind_RegUse) {
|
|
unsigned DefGroup = 0;
|
|
if (InlineAsm::isUseOperandTiedToDef(Flags, DefGroup)) {
|
|
unsigned DefIdx = GroupIdx[DefGroup] + 1;
|
|
unsigned UseIdx = GroupIdx.back() + 1;
|
|
for (unsigned j = 0; j != NumVals; ++j)
|
|
MIB->tieOperands(DefIdx + j, UseIdx + j);
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
// GCC inline assembly allows input operands to also be early-clobber
|
|
// output operands (so long as the operand is written only after it's
|
|
// used), but this does not match the semantics of our early-clobber flag.
|
|
// If an early-clobber operand register is also an input operand register,
|
|
// then remove the early-clobber flag.
|
|
for (unsigned Reg : ECRegs) {
|
|
if (MIB->readsRegister(Reg, TRI)) {
|
|
MachineOperand *MO =
|
|
MIB->findRegisterDefOperand(Reg, false, false, TRI);
|
|
assert(MO && "No def operand for clobbered register?");
|
|
MO->setIsEarlyClobber(false);
|
|
}
|
|
}
|
|
|
|
// Get the mdnode from the asm if it exists and add it to the instruction.
|
|
SDValue MDV = Node->getOperand(InlineAsm::Op_MDNode);
|
|
const MDNode *MD = cast<MDNodeSDNode>(MDV)->getMD();
|
|
if (MD)
|
|
MIB.addMetadata(MD);
|
|
|
|
MBB->insert(InsertPos, MIB);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// InstrEmitter - Construct an InstrEmitter and set it to start inserting
|
|
/// at the given position in the given block.
|
|
InstrEmitter::InstrEmitter(MachineBasicBlock *mbb,
|
|
MachineBasicBlock::iterator insertpos)
|
|
: MF(mbb->getParent()), MRI(&MF->getRegInfo()),
|
|
TII(MF->getSubtarget().getInstrInfo()),
|
|
TRI(MF->getSubtarget().getRegisterInfo()),
|
|
TLI(MF->getSubtarget().getTargetLowering()), MBB(mbb),
|
|
InsertPos(insertpos) {}
|