[llvm] [X86] Resolve FIXME: Copy kill flag for eflags (PR #82411)
via llvm-commits
llvm-commits at lists.llvm.org
Thu Feb 29 09:06:57 PST 2024
https://github.com/AtariDreams updated https://github.com/llvm/llvm-project/pull/82411
>From dc06306ba4ddbd0f14ec850217bde99468de5e86 Mon Sep 17 00:00:00 2001
From: Rose <83477269+AtariDreams at users.noreply.github.com>
Date: Tue, 20 Feb 2024 14:29:42 -0500
Subject: [PATCH] [X86] Resolve FIXME: Copy kill flag for eflags
We now mark the last eflags usage as kill if the def was also kill.
---
llvm/lib/CodeGen/MachineCombiner.cpp | 15 ++++--
llvm/lib/CodeGen/ModuloSchedule.cpp | 7 ++-
llvm/lib/CodeGen/PeepholeOptimizer.cpp | 2 +-
llvm/lib/CodeGen/RegisterCoalescer.cpp | 4 +-
.../lib/CodeGen/TwoAddressInstructionPass.cpp | 6 ++-
llvm/lib/Target/X86/X86FlagsCopyLowering.cpp | 49 +++++++++++++++----
llvm/lib/Target/X86/X86InstrInfo.cpp | 39 +++++++++------
.../X86/X86SpeculativeLoadHardening.cpp | 10 ++--
8 files changed, 93 insertions(+), 39 deletions(-)
diff --git a/llvm/lib/CodeGen/MachineCombiner.cpp b/llvm/lib/CodeGen/MachineCombiner.cpp
index c65937935ed820..4e31d036c25150 100644
--- a/llvm/lib/CodeGen/MachineCombiner.cpp
+++ b/llvm/lib/CodeGen/MachineCombiner.cpp
@@ -232,8 +232,10 @@ MachineCombiner::getDepth(SmallVectorImpl<MachineInstr *> &InsInstrs,
assert(DefInstr &&
"There must be a definition for a new virtual register");
DepthOp = InstrDepth[II->second];
- int DefIdx = DefInstr->findRegisterDefOperandIdx(MO.getReg());
- int UseIdx = InstrPtr->findRegisterUseOperandIdx(MO.getReg());
+ int DefIdx =
+ DefInstr->findRegisterDefOperandIdx(MO.getReg(), false, false, TRI);
+ int UseIdx =
+ InstrPtr->findRegisterUseOperandIdx(MO.getReg(), false, TRI);
LatencyOp = TSchedModel.computeOperandLatency(DefInstr, DefIdx,
InstrPtr, UseIdx);
} else {
@@ -244,8 +246,11 @@ MachineCombiner::getDepth(SmallVectorImpl<MachineInstr *> &InsInstrs,
DepthOp = BlockTrace.getInstrCycles(*DefInstr).Depth;
if (!isTransientMI(DefInstr))
LatencyOp = TSchedModel.computeOperandLatency(
- DefInstr, DefInstr->findRegisterDefOperandIdx(MO.getReg()),
- InstrPtr, InstrPtr->findRegisterUseOperandIdx(MO.getReg()));
+ DefInstr,
+ DefInstr->findRegisterDefOperandIdx(MO.getReg(), false, false,
+ TRI),
+ InstrPtr,
+ InstrPtr->findRegisterUseOperandIdx(MO.getReg(), false, TRI));
}
}
IDepth = std::max(IDepth, DepthOp + LatencyOp);
@@ -284,7 +289,7 @@ unsigned MachineCombiner::getLatency(MachineInstr *Root, MachineInstr *NewRoot,
if (UseMO && BlockTrace.isDepInTrace(*Root, *UseMO)) {
LatencyOp = TSchedModel.computeOperandLatency(
NewRoot, NewRoot->findRegisterDefOperandIdx(MO.getReg()), UseMO,
- UseMO->findRegisterUseOperandIdx(MO.getReg()));
+ UseMO->findRegisterUseOperandIdx(MO.getReg(), false, TRI));
} else {
LatencyOp = TSchedModel.computeInstrLatency(NewRoot);
}
diff --git a/llvm/lib/CodeGen/ModuloSchedule.cpp b/llvm/lib/CodeGen/ModuloSchedule.cpp
index 0bef513342ff12..20f4bcd9ab93a9 100644
--- a/llvm/lib/CodeGen/ModuloSchedule.cpp
+++ b/llvm/lib/CodeGen/ModuloSchedule.cpp
@@ -1673,7 +1673,9 @@ void PeelingModuloScheduleExpander::moveStageBetweenBlocks(
// we don't need the phi anymore.
if (getStage(Def) == Stage) {
Register PhiReg = MI.getOperand(0).getReg();
- assert(Def->findRegisterDefOperandIdx(MI.getOperand(1).getReg()) != -1);
+ assert(Def->findRegisterDefOperandIdx(MI.getOperand(1).getReg(), false,
+ false,
+ MRI.getTargetRegisterInfo()) != -1);
MRI.replaceRegWith(MI.getOperand(0).getReg(), MI.getOperand(1).getReg());
MI.getOperand(0).setReg(PhiReg);
PhiToDelete.push_back(&MI);
@@ -1899,7 +1901,8 @@ Register
PeelingModuloScheduleExpander::getEquivalentRegisterIn(Register Reg,
MachineBasicBlock *BB) {
MachineInstr *MI = MRI.getUniqueVRegDef(Reg);
- unsigned OpIdx = MI->findRegisterDefOperandIdx(Reg);
+ unsigned OpIdx = MI->findRegisterDefOperandIdx(Reg, false, false,
+ MRI.getTargetRegisterInfo());
return BlockMIs[{BB, CanonicalMIs[MI]}]->getOperand(OpIdx).getReg();
}
diff --git a/llvm/lib/CodeGen/PeepholeOptimizer.cpp b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
index 1b1f22e827cb1e..c2e3df99e78921 100644
--- a/llvm/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
@@ -1577,7 +1577,7 @@ bool PeepholeOptimizer::findTargetRecurrence(
return false;
MachineInstr &MI = *(MRI->use_instr_nodbg_begin(Reg));
- unsigned Idx = MI.findRegisterUseOperandIdx(Reg);
+ unsigned Idx = MI.findRegisterUseOperandIdx(Reg, false, TRI);
// Only interested in recurrences whose instructions have only one def, which
// is a virtual register.
diff --git a/llvm/lib/CodeGen/RegisterCoalescer.cpp b/llvm/lib/CodeGen/RegisterCoalescer.cpp
index 7e9c992031f8d3..bbb3560b5f5556 100644
--- a/llvm/lib/CodeGen/RegisterCoalescer.cpp
+++ b/llvm/lib/CodeGen/RegisterCoalescer.cpp
@@ -723,7 +723,7 @@ bool RegisterCoalescer::adjustCopiesBackFrom(const CoalescerPair &CP,
// If the source instruction was killing the source register before the
// merge, unset the isKill marker given the live range has been extended.
- int UIdx = ValSEndInst->findRegisterUseOperandIdx(IntB.reg(), true);
+ int UIdx = ValSEndInst->findRegisterUseOperandIdx(IntB.reg(), true, TRI);
if (UIdx != -1) {
ValSEndInst->getOperand(UIdx).setIsKill(false);
}
@@ -848,7 +848,7 @@ RegisterCoalescer::removeCopyByCommutingDef(const CoalescerPair &CP,
return { false, false };
// If DefMI is a two-address instruction then commuting it will change the
// destination register.
- int DefIdx = DefMI->findRegisterDefOperandIdx(IntA.reg());
+ int DefIdx = DefMI->findRegisterDefOperandIdx(IntA.reg(), false, TRI);
assert(DefIdx != -1);
unsigned UseOpIdx;
if (!DefMI->isRegTiedToUseOperand(DefIdx, &UseOpIdx))
diff --git a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
index ebacbc420f8580..863871488032c7 100644
--- a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -1355,8 +1355,10 @@ tryInstructionTransform(MachineBasicBlock::iterator &mi,
<< "2addr: NEW INST: " << *NewMIs[1]);
// Transform the instruction, now that it no longer has a load.
- unsigned NewDstIdx = NewMIs[1]->findRegisterDefOperandIdx(regA);
- unsigned NewSrcIdx = NewMIs[1]->findRegisterUseOperandIdx(regB);
+ unsigned NewDstIdx =
+ NewMIs[1]->findRegisterDefOperandIdx(regA, false, TRI);
+ unsigned NewSrcIdx =
+ NewMIs[1]->findRegisterUseOperandIdx(regB, false, TRI);
MachineBasicBlock::iterator NewMI = NewMIs[1];
bool TransformResult =
tryInstructionTransform(NewMI, mi, NewSrcIdx, NewDstIdx, Dist, true);
diff --git a/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp b/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
index af25b34fbab995..7debca3b0a1f7f 100644
--- a/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
+++ b/llvm/lib/Target/X86/X86FlagsCopyLowering.cpp
@@ -347,6 +347,31 @@ static X86::CondCode getCondFromFCMOV(unsigned Opcode) {
}
}
+static bool checkEFLAGSLive(MachineInstr *MI) {
+ if (MI->killsRegister(X86::EFLAGS))
+ return false;
+
+ // The EFLAGS operand of MI might be missing a kill marker.
+ // Figure out whether EFLAGS operand should LIVE after MI instruction.
+ MachineBasicBlock *BB = MI->getParent();
+ MachineBasicBlock::iterator ItrMI = MI;
+
+ // Scan forward through BB for a use/def of EFLAGS.
+ for (auto I = std::next(ItrMI), E = BB->end(); I != E; ++I) {
+ if (I->readsRegister(X86::EFLAGS))
+ return true;
+ if (I->definesRegister(X86::EFLAGS))
+ return false;
+ }
+
+ // We hit the end of the block, check whether EFLAGS is live into a successor.
+ for (MachineBasicBlock *Succ : BB->successors())
+ if (Succ->isLiveIn(X86::EFLAGS))
+ return true;
+
+ return false;
+}
+
bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
LLVM_DEBUG(dbgs() << "********** " << getPassName() << " : " << MF.getName()
<< " **********\n");
@@ -442,7 +467,8 @@ bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
llvm::reverse(llvm::make_range(Begin, End)), [&](MachineInstr &MI) {
// Flag any instruction (other than the copy we are
// currently rewriting) that defs EFLAGS.
- return &MI != CopyI && MI.findRegisterDefOperand(X86::EFLAGS);
+ return &MI != CopyI &&
+ MI.findRegisterDefOperand(X86::EFLAGS, false, false, TRI);
});
};
auto HasEFLAGSClobberPath = [&](MachineBasicBlock *BeginMBB,
@@ -500,7 +526,7 @@ bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
auto DefIt = llvm::find_if(
llvm::reverse(llvm::make_range(TestMBB->instr_begin(), TestPos)),
[&](MachineInstr &MI) {
- return MI.findRegisterDefOperand(X86::EFLAGS);
+ return MI.findRegisterDefOperand(X86::EFLAGS, false, false, TRI);
});
if (DefIt.base() != TestMBB->instr_begin()) {
dbgs() << " Using EFLAGS defined by: ";
@@ -562,9 +588,10 @@ bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
break;
}
- MachineOperand *FlagUse = MI.findRegisterUseOperand(X86::EFLAGS);
+ MachineOperand *FlagUse =
+ MI.findRegisterUseOperand(X86::EFLAGS, false, TRI);
if (!FlagUse) {
- if (MI.findRegisterDefOperand(X86::EFLAGS)) {
+ if (MI.findRegisterDefOperand(X86::EFLAGS, false, false, TRI)) {
// If EFLAGS are defined, it's as-if they were killed. We can stop
// scanning here.
//
@@ -614,7 +641,7 @@ bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
rewriteCopy(MI, *FlagUse, CopyDefI);
} else {
// We assume all other instructions that use flags also def them.
- assert(MI.findRegisterDefOperand(X86::EFLAGS) &&
+ assert(MI.findRegisterDefOperand(X86::EFLAGS, false, false, TRI) &&
"Expected a def of EFLAGS for this instruction!");
// NB!!! Several arithmetic instructions only *partially* update
@@ -683,6 +710,8 @@ bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
// Now rewrite the jumps that use the flags. These we handle specially
// because if there are multiple jumps in a single basic block we'll have
// to do surgery on the CFG.
+ bool CopyDefIsKill = !checkEFLAGSLive(&CopyDefI);
+ MachineOperand *LastEflagsUse = nullptr;
MachineBasicBlock *LastJmpMBB = nullptr;
for (MachineInstr *JmpI : JmpIs) {
// Past the first jump within a basic block we need to split the blocks
@@ -693,10 +722,12 @@ bool X86FlagsCopyLoweringPass::runOnMachineFunction(MachineFunction &MF) {
LastJmpMBB = JmpI->getParent();
rewriteCondJmp(*TestMBB, TestPos, TestLoc, *JmpI, CondRegs);
+ if (CopyDefIsKill && JmpI->readsRegister(X86::EFLAGS))
+ LastEflagsUse = JmpI->findRegisterUseOperand(X86::EFLAGS, false, TRI);
}
- // FIXME: Mark the last use of EFLAGS before the copy's def as a kill if
- // the copy's def operand is itself a kill.
+ if (LastEflagsUse && CopyDefIsKill)
+ LastEflagsUse->setIsKill(true);
}
#ifndef NDEBUG
@@ -733,7 +764,7 @@ CondRegArray X86FlagsCopyLoweringPass::collectCondsInRegs(
// Stop scanning when we see the first definition of the EFLAGS as prior to
// this we would potentially capture the wrong flag state.
- if (MI.findRegisterDefOperand(X86::EFLAGS))
+ if (MI.findRegisterDefOperand(X86::EFLAGS, false, false, TRI))
break;
}
return CondRegs;
@@ -911,7 +942,7 @@ void X86FlagsCopyLoweringPass::rewriteCondJmp(
// Rewrite the jump to use the !ZF flag from the test, and kill its use of
// flags afterward.
JmpI.getOperand(1).setImm(Inverted ? X86::COND_E : X86::COND_NE);
- JmpI.findRegisterUseOperand(X86::EFLAGS)->setIsKill(true);
+ JmpI.findRegisterUseOperand(X86::EFLAGS, false, TRI)->setIsKill(true);
LLVM_DEBUG(dbgs() << " fixed jCC: "; JmpI.dump());
}
diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
index 0f21880f6df90c..4ea922a9747cc9 100644
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -3711,7 +3711,8 @@ bool X86InstrInfo::analyzeBranchImpl(
// In practice we should never have an undef eflags operand, if we do
// abort here as we are not prepared to preserve the flag.
- if (I->findRegisterUseOperand(X86::EFLAGS)->isUndef())
+ if (I->findRegisterUseOperand(X86::EFLAGS, false, &getRegisterInfo())
+ ->isUndef())
return true;
// Working from the bottom, handle the first conditional branch.
@@ -5455,7 +5456,8 @@ bool X86InstrInfo::optimizeCompareInstr(MachineInstr &CmpInstr, Register SrcReg,
}
// Make sure Sub instruction defines EFLAGS and mark the def live.
- MachineOperand *FlagDef = Sub->findRegisterDefOperand(X86::EFLAGS);
+ MachineOperand *FlagDef = Sub->findRegisterDefOperand(
+ X86::EFLAGS, false, false, &getRegisterInfo());
assert(FlagDef && "Unable to locate a def EFLAGS operand");
FlagDef->setIsDead(false);
@@ -5608,7 +5610,8 @@ bool X86InstrInfo::foldImmediateImpl(MachineInstr &UseMI, MachineInstr *DefMI,
return false;
}
- if (UseMI.findRegisterUseOperand(Reg)->getSubReg())
+ if (UseMI.findRegisterUseOperand(Reg, false, MRI->getTargetRegisterInfo())
+ ->getSubReg())
return false;
// Immediate has larger code size than register. So avoid folding the
// immediate if it has more than 1 use and we are optimizing for size.
@@ -5655,7 +5658,7 @@ bool X86InstrInfo::foldImmediateImpl(MachineInstr &UseMI, MachineInstr *DefMI,
if (!MakeChange)
return true;
UseMI.setDesc(get(X86::MOV32r0));
- UseMI.removeOperand(UseMI.findRegisterUseOperandIdx(Reg));
+ UseMI.removeOperand(UseMI.findRegisterUseOperandIdx(Reg, false, TRI));
UseMI.addOperand(MachineOperand::CreateReg(X86::EFLAGS, /*isDef=*/true,
/*isImp=*/true,
/*isKill=*/false,
@@ -5677,17 +5680,18 @@ bool X86InstrInfo::foldImmediateImpl(MachineInstr &UseMI, MachineInstr *DefMI,
NewOpc == X86::SBB64ri32 || NewOpc == X86::SBB32ri ||
NewOpc == X86::SUB64ri32_ND || NewOpc == X86::SUB32ri_ND ||
NewOpc == X86::SBB64ri32_ND || NewOpc == X86::SBB32ri_ND) &&
- UseMI.findRegisterUseOperandIdx(Reg) != 2)
+ UseMI.findRegisterUseOperandIdx(Reg, false, &getRegisterInfo()) != 2)
return false;
// For CMP instructions the immediate can only be at index 1.
if ((NewOpc == X86::CMP64ri32 || NewOpc == X86::CMP32ri) &&
- UseMI.findRegisterUseOperandIdx(Reg) != 1)
+ UseMI.findRegisterUseOperandIdx(Reg, false, &getRegisterInfo()) != 1)
return false;
using namespace X86;
if (isSHL(Opc) || isSHR(Opc) || isSAR(Opc) || isROL(Opc) || isROR(Opc) ||
isRCL(Opc) || isRCR(Opc)) {
- unsigned RegIdx = UseMI.findRegisterUseOperandIdx(Reg);
+ unsigned RegIdx =
+ UseMI.findRegisterUseOperandIdx(Reg, false, &getRegisterInfo());
if (RegIdx < 2)
return false;
if (!isInt<8>(ImmVal))
@@ -5716,8 +5720,10 @@ bool X86InstrInfo::foldImmediateImpl(MachineInstr &UseMI, MachineInstr *DefMI,
// ==>
// %100 = COPY %101
UseMI.setDesc(get(TargetOpcode::COPY));
- UseMI.removeOperand(UseMI.findRegisterUseOperandIdx(Reg));
- UseMI.removeOperand(UseMI.findRegisterDefOperandIdx(X86::EFLAGS));
+ UseMI.removeOperand(
+ UseMI.findRegisterUseOperandIdx(Reg, false, &getRegisterInfo()));
+ UseMI.removeOperand(UseMI.findRegisterDefOperandIdx(
+ X86::EFLAGS, false, false, &getRegisterInfo()));
UseMI.untieRegOperand(0);
UseMI.clearFlag(MachineInstr::MIFlag::NoSWrap);
UseMI.clearFlag(MachineInstr::MIFlag::NoUWrap);
@@ -9516,7 +9522,8 @@ bool X86InstrInfo::hasReassociableOperands(const MachineInstr &Inst,
// not change anything because rearranging the operands could affect other
// instructions that depend on the exact status flags (zero, sign, etc.)
// that are set by using these particular operands with this operation.
- const MachineOperand *FlagDef = Inst.findRegisterDefOperand(X86::EFLAGS);
+ const MachineOperand *FlagDef = Inst.findRegisterDefOperand(
+ X86::EFLAGS, false, false, &getRegisterInfo());
assert((Inst.getNumDefs() == 1 || FlagDef) && "Implicit def isn't flags?");
if (FlagDef && !FlagDef->isDead())
return false;
@@ -10038,8 +10045,10 @@ void X86InstrInfo::setSpecialOperandAttr(MachineInstr &OldMI1,
MachineInstr &NewMI1,
MachineInstr &NewMI2) const {
// Integer instructions may define an implicit EFLAGS dest register operand.
- MachineOperand *OldFlagDef1 = OldMI1.findRegisterDefOperand(X86::EFLAGS);
- MachineOperand *OldFlagDef2 = OldMI2.findRegisterDefOperand(X86::EFLAGS);
+ MachineOperand *OldFlagDef1 = OldMI1.findRegisterDefOperand(
+ X86::EFLAGS, false, false, &getRegisterInfo());
+ MachineOperand *OldFlagDef2 = OldMI2.findRegisterDefOperand(
+ X86::EFLAGS, false, false, &getRegisterInfo());
assert(!OldFlagDef1 == !OldFlagDef2 &&
"Unexpected instruction type for reassociation");
@@ -10050,8 +10059,10 @@ void X86InstrInfo::setSpecialOperandAttr(MachineInstr &OldMI1,
assert(OldFlagDef1->isDead() && OldFlagDef2->isDead() &&
"Must have dead EFLAGS operand in reassociable instruction");
- MachineOperand *NewFlagDef1 = NewMI1.findRegisterDefOperand(X86::EFLAGS);
- MachineOperand *NewFlagDef2 = NewMI2.findRegisterDefOperand(X86::EFLAGS);
+ MachineOperand *NewFlagDef1 = NewMI1.findRegisterDefOperand(
+ X86::EFLAGS, false, false, &getRegisterInfo());
+ MachineOperand *NewFlagDef2 = NewMI2.findRegisterDefOperand(
+ X86::EFLAGS, false, false, &getRegisterInfo());
assert(NewFlagDef1 && NewFlagDef2 &&
"Unexpected operand in reassociable instruction");
diff --git a/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp b/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp
index 69a54e7667b553..3f0381f5398315 100644
--- a/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp
+++ b/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp
@@ -483,7 +483,7 @@ bool X86SpeculativeLoadHardeningPass::runOnMachineFunction(
PredStateSubReg);
++NumInstsInserted;
MachineOperand *ZeroEFLAGSDefOp =
- ZeroI->findRegisterDefOperand(X86::EFLAGS);
+ ZeroI->findRegisterDefOperand(X86::EFLAGS, false, false, TRI);
assert(ZeroEFLAGSDefOp && ZeroEFLAGSDefOp->isImplicit() &&
"Must have an implicit def of EFLAGS!");
ZeroEFLAGSDefOp->setIsDead(true);
@@ -762,7 +762,8 @@ X86SpeculativeLoadHardeningPass::tracePredStateThroughCFG(
// If this is the last cmov and the EFLAGS weren't originally
// live-in, mark them as killed.
if (!LiveEFLAGS && Cond == Conds.back())
- CMovI->findRegisterUseOperand(X86::EFLAGS)->setIsKill(true);
+ CMovI->findRegisterUseOperand(X86::EFLAGS, false, TRI)
+ ->setIsKill(true);
++NumInstsInserted;
LLVM_DEBUG(dbgs() << " Inserting cmov: "; CMovI->dump();
@@ -1185,7 +1186,7 @@ X86SpeculativeLoadHardeningPass::tracePredStateThroughIndirectBranches(
.addReg(PS->InitialReg)
.addReg(PS->PoisonReg)
.addImm(X86::COND_NE);
- CMovI->findRegisterUseOperand(X86::EFLAGS)->setIsKill(true);
+ CMovI->findRegisterUseOperand(X86::EFLAGS, false, TRI)->setIsKill(true);
++NumInstsInserted;
LLVM_DEBUG(dbgs() << " Inserting cmov: "; CMovI->dump(); dbgs() << "\n");
CMovs.push_back(&*CMovI);
@@ -1213,7 +1214,8 @@ static bool isEFLAGSLive(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
// Check if EFLAGS are alive by seeing if there is a def of them or they
// live-in, and then seeing if that def is in turn used.
for (MachineInstr &MI : llvm::reverse(llvm::make_range(MBB.begin(), I))) {
- if (MachineOperand *DefOp = MI.findRegisterDefOperand(X86::EFLAGS)) {
+ if (MachineOperand *DefOp =
+ MI.findRegisterDefOperand(X86::EFLAGS, false, false, &TRI)) {
// If the def is dead, then EFLAGS is not live.
if (DefOp->isDead())
return false;
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