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Split part of isKilled() into a separate function for use elsewhere. 

llvm-svn: 175726
This commit is contained in:
Cameron Zwarich 2013-02-21 07:02:28 +00:00
parent 1c19139ae0
commit c896478f0d
1 changed files with 28 additions and 22 deletions
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50
llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
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@ -330,6 +330,33 @@ static bool isCopyToReg(MachineInstr &MI, const TargetInstrInfo *TII,
return true;
}
/// isPLainlyKilled - Test if the given register value, which is used by the
// given instruction, is killed by the given instruction.
static bool isPlainlyKilled(MachineInstr *MI, unsigned Reg,
LiveIntervals *LIS) {
if (LIS && TargetRegisterInfo::isVirtualRegister(Reg) &&
!LIS->isNotInMIMap(MI)) {
// FIXME: Sometimes tryInstructionTransform() will add instructions and
// test whether they can be folded before keeping them. In this case it
// sets a kill before recursively calling tryInstructionTransform() again.
// If there is no interval available, we assume that this instruction is
// one of those. A kill flag is manually inserted on the operand so the
// check below will handle it.
LiveInterval &LI = LIS->getInterval(Reg);
// This is to match the kill flag version where undefs don't have kill
// flags.
if (!LI.hasAtLeastOneValue())
return false;
SlotIndex useIdx = LIS->getInstructionIndex(MI);
LiveInterval::const_iterator I = LI.find(useIdx);
assert(I != LI.end() && "Reg must be live-in to use.");
return SlotIndex::isSameInstr(I->end, useIdx);
}
return MI->killsRegister(Reg);
}
/// isKilled - Test if the given register value, which is used by the given
/// instruction, is killed by the given instruction. This looks through
/// coalescable copies to see if the original value is potentially not killed.
@ -351,29 +378,8 @@ static bool isKilled(MachineInstr &MI, unsigned Reg,
LiveIntervals *LIS) {
MachineInstr *DefMI = &MI;
for (;;) {
if (LIS && TargetRegisterInfo::isVirtualRegister(Reg) &&
!LIS->isNotInMIMap(DefMI)) {
// FIXME: Sometimes tryInstructionTransform() will add instructions and
// test whether they can be folded before keeping them. In this case it
// sets a kill before recursively calling tryInstructionTransform() again.
// If there is no interval available, we assume that this instruction is
// one of those. A kill flag is manually inserted on the operand so the
// check below will handle it.
LiveInterval &LI = LIS->getInterval(Reg);
// This is to match the kill flag version where undefs don't have kill
// flags.
if (!LI.hasAtLeastOneValue())
return false;
SlotIndex useIdx = LIS->getInstructionIndex(DefMI);
LiveInterval::const_iterator I = LI.find(useIdx);
assert(I != LI.end() && "Reg must be live-in to use.");
if (!SlotIndex::isSameInstr(I->end, useIdx))
return false;
} else if (!DefMI->killsRegister(Reg)) {
if (!isPlainlyKilled(DefMI, Reg, LIS))
return false;
}
if (TargetRegisterInfo::isPhysicalRegister(Reg))
return true;
MachineRegisterInfo::def_iterator Begin = MRI->def_begin(Reg);