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[X86] FixupLEAs, reduce number of calls to getOperand and use X86::AddrBaseReg/AddrIndexReg, etc. instead of hardcoded constants. 

Makes the code a little more readable.

llvm-svn: 349983
This commit is contained in:
Craig Topper 2018-12-22 01:34:47 +00:00
parent 7f41fe3a58
commit 1f02ac3451
1 changed files with 29 additions and 22 deletions
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51
llvm/lib/Target/X86/X86FixupLEAs.cpp
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@ -333,13 +333,12 @@ static inline int getADDriFromLEA(int LEAOpcode, const MachineOperand &Offset) {
static inline bool isLEASimpleIncOrDec(MachineInstr &LEA) {
unsigned SrcReg = LEA.getOperand(1 + X86::AddrBaseReg).getReg();
unsigned DstReg = LEA.getOperand(0).getReg();
unsigned AddrDispOp = 1 + X86::AddrDisp;
const MachineOperand &AddrDisp = LEA.getOperand(1 + X86::AddrDisp);
return SrcReg == DstReg &&
LEA.getOperand(1 + X86::AddrIndexReg).getReg() == 0 &&
LEA.getOperand(1 + X86::AddrSegmentReg).getReg() == 0 &&
LEA.getOperand(AddrDispOp).isImm() &&
(LEA.getOperand(AddrDispOp).getImm() == 1 ||
LEA.getOperand(AddrDispOp).getImm() == -1);
AddrDisp.isImm() &&
(AddrDisp.getImm() == 1 || AddrDisp.getImm() == -1);
}
bool FixupLEAPass::fixupIncDec(MachineBasicBlock::iterator &I,
@ -351,7 +350,7 @@ bool FixupLEAPass::fixupIncDec(MachineBasicBlock::iterator &I,
if (isLEASimpleIncOrDec(MI) && TII->isSafeToClobberEFLAGS(*MFI, I)) {
int NewOpcode;
bool isINC = MI.getOperand(4).getImm() == 1;
bool isINC = MI.getOperand(1 + X86::AddrDisp).getImm() == 1;
switch (Opcode) {
case X86::LEA16r:
NewOpcode = isINC ? X86::INC16r : X86::DEC16r;
@ -368,7 +367,7 @@ bool FixupLEAPass::fixupIncDec(MachineBasicBlock::iterator &I,
MachineInstr *NewMI =
BuildMI(*MFI, I, MI.getDebugLoc(), TII->get(NewOpcode))
.add(MI.getOperand(0))
.add(MI.getOperand(1));
.add(MI.getOperand(1 + X86::AddrBaseReg));
MFI->erase(I);
I = static_cast<MachineBasicBlock::iterator>(NewMI);
return true;
@ -420,15 +419,23 @@ void FixupLEAPass::processInstructionForSlowLEA(MachineBasicBlock::iterator &I,
const int Opcode = MI.getOpcode();
if (!isLEA(Opcode))
return;
if (MI.getOperand(5).getReg() != 0 || !MI.getOperand(4).isImm() ||
const MachineOperand &Dst = MI.getOperand(0);
const MachineOperand &Base = MI.getOperand(1 + X86::AddrBaseReg);
const MachineOperand &Scale = MI.getOperand(1 + X86::AddrScaleAmt);
const MachineOperand &Index = MI.getOperand(1 + X86::AddrIndexReg);
const MachineOperand &Offset = MI.getOperand(1 + X86::AddrDisp);
const MachineOperand &Segment = MI.getOperand(1 + X86::AddrSegmentReg);
if (Segment.getReg() != 0 || !Offset.isImm() ||
!TII->isSafeToClobberEFLAGS(*MFI, I))
return;
const unsigned DstR = MI.getOperand(0).getReg();
const unsigned SrcR1 = MI.getOperand(1).getReg();
const unsigned SrcR2 = MI.getOperand(3).getReg();
const unsigned DstR = Dst.getReg();
const unsigned SrcR1 = Base.getReg();
const unsigned SrcR2 = Index.getReg();
if ((SrcR1 == 0 || SrcR1 != DstR) && (SrcR2 == 0 || SrcR2 != DstR))
return;
if (MI.getOperand(2).getImm() > 1)
if (Scale.getImm() > 1)
return;
LLVM_DEBUG(dbgs() << "FixLEA: Candidate to replace:"; I->dump(););
LLVM_DEBUG(dbgs() << "FixLEA: Replaced by: ";);
@ -436,19 +443,19 @@ void FixupLEAPass::processInstructionForSlowLEA(MachineBasicBlock::iterator &I,
// Make ADD instruction for two registers writing to LEA's destination
if (SrcR1 != 0 && SrcR2 != 0) {
const MCInstrDesc &ADDrr = TII->get(getADDrrFromLEA(Opcode));
const MachineOperand &Src = MI.getOperand(SrcR1 == DstR ? 3 : 1);
const MachineOperand &Src = SrcR1 == DstR ? Index : Base;
NewMI =
BuildMI(*MFI, I, MI.getDebugLoc(), ADDrr, DstR).addReg(DstR).add(Src);
LLVM_DEBUG(NewMI->dump(););
}
// Make ADD instruction for immediate
if (MI.getOperand(4).getImm() != 0) {
if (Offset.getImm() != 0) {
const MCInstrDesc &ADDri =
TII->get(getADDriFromLEA(Opcode, MI.getOperand(4)));
const MachineOperand &SrcR = MI.getOperand(SrcR1 == DstR ? 1 : 3);
TII->get(getADDriFromLEA(Opcode, Offset));
const MachineOperand &SrcR = SrcR1 == DstR ? Base : Index;
NewMI = BuildMI(*MFI, I, MI.getDebugLoc(), ADDri, DstR)
.add(SrcR)
.addImm(MI.getOperand(4).getImm());
.addImm(Offset.getImm());
LLVM_DEBUG(NewMI->dump(););
}
if (NewMI) {
@ -465,12 +472,12 @@ FixupLEAPass::processInstrForSlow3OpLEA(MachineInstr &MI,
if (!isLEA(LEAOpcode))
return nullptr;
const MachineOperand &Dst = MI.getOperand(0);
const MachineOperand &Base = MI.getOperand(1);
const MachineOperand &Scale = MI.getOperand(2);
const MachineOperand &Index = MI.getOperand(3);
const MachineOperand &Offset = MI.getOperand(4);
const MachineOperand &Segment = MI.getOperand(5);
const MachineOperand &Dst = MI.getOperand(0);
const MachineOperand &Base = MI.getOperand(1 + X86::AddrBaseReg);
const MachineOperand &Scale = MI.getOperand(1 + X86::AddrScaleAmt);
const MachineOperand &Index = MI.getOperand(1 + X86::AddrIndexReg);
const MachineOperand &Offset = MI.getOperand(1 + X86::AddrDisp);
const MachineOperand &Segment = MI.getOperand(1 + X86::AddrSegmentReg);
if (!(TII->isThreeOperandsLEA(MI) ||
hasInefficientLEABaseReg(Base, Index)) ||