Remove unnecessary isKill properties if a live range has been lengthened due to coalescing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34503 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2007-02-22 23:03:39 +00:00
parent 774b864f0e
commit 30cac02a92
2 changed files with 35 additions and 1 deletions

View File

@ -172,6 +172,13 @@ namespace llvm {
}
private:
/// isRemoved - returns true if the specified machine instr has been
/// removed.
bool isRemoved(MachineInstr* instr) const {
Mi2IndexMap::const_iterator it = mi2iMap_.find(instr);
return it == mi2iMap_.end();
}
/// RemoveMachineInstrFromMaps - This marks the specified machine instr as
/// deleted.
void RemoveMachineInstrFromMaps(MachineInstr *MI) {
@ -256,6 +263,10 @@ namespace llvm {
/// reg between indexes Start and End.
bool hasRegisterUse(unsigned Reg, unsigned Start, unsigned End);
/// unsetRegisterKill - Unset IsKill property of all uses of specific
/// register of the specific instruction.
void unsetRegisterKill(MachineInstr *MI, unsigned Reg);
static LiveInterval createInterval(unsigned Reg);
void removeInterval(unsigned Reg) {

View File

@ -959,10 +959,22 @@ bool LiveIntervals::JoinCopy(MachineInstr *CopyMI,
DOUT << "\n\t\tJoined. Result = "; DestInt.print(DOUT, mri_);
DOUT << "\n";
// If the intervals were swapped by Join, swap them back so that the register
// mapping (in the r2i map) is correct.
if (Swapped) SrcInt.swap(DestInt);
// Live range has been lengthened due to colaescing, eliminate the
// unnecessary kills at the end of the source live ranges.
LiveVariables::VarInfo& vi = lv_->getVarInfo(repSrcReg);
for (unsigned i = 0, e = vi.Kills.size(); i != e; ++i) {
MachineInstr *Kill = vi.Kills[i];
if (Kill == CopyMI || isRemoved(Kill))
continue;
if (DestInt.liveAt(getInstructionIndex(Kill) + InstrSlots::NUM))
unsetRegisterKill(Kill, repSrcReg);
}
removeInterval(repSrcReg);
r2rMap_[repSrcReg] = repDstReg;
@ -1471,6 +1483,17 @@ LiveIntervals::hasRegisterUse(unsigned Reg, unsigned Start, unsigned End) {
return false;
}
/// unsetRegisterKill - Unset IsKill property of all uses of specific register
/// of the specific instruction.
void LiveIntervals::unsetRegisterKill(MachineInstr *MI, unsigned Reg) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isReg() && MO.isUse() && MO.isKill() && MO.getReg() &&
mri_->regsOverlap(rep(MO.getReg()), Reg))
MO.unsetIsKill();
}
}
LiveInterval LiveIntervals::createInterval(unsigned reg) {
float Weight = MRegisterInfo::isPhysicalRegister(reg) ?
HUGE_VALF : 0.0F;