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path: root/lib/CodeGen/PeepholeOptimizer.cpp
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Diffstat (limited to 'lib/CodeGen/PeepholeOptimizer.cpp')
-rw-r--r--lib/CodeGen/PeepholeOptimizer.cpp32
1 files changed, 15 insertions, 17 deletions
diff --git a/lib/CodeGen/PeepholeOptimizer.cpp b/lib/CodeGen/PeepholeOptimizer.cpp
index 0f2ba41..75f453a 100644
--- a/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/lib/CodeGen/PeepholeOptimizer.cpp
@@ -82,8 +82,7 @@ namespace {
}
private:
- bool OptimizeCmpInstr(MachineInstr *MI, MachineBasicBlock *MBB,
- MachineBasicBlock::iterator &MII);
+ bool OptimizeCmpInstr(MachineInstr *MI, MachineBasicBlock *MBB);
bool OptimizeExtInstr(MachineInstr *MI, MachineBasicBlock *MBB,
SmallPtrSet<MachineInstr*, 8> &LocalMIs);
};
@@ -112,12 +111,10 @@ FunctionPass *llvm::createPeepholeOptimizerPass() {
bool PeepholeOptimizer::
OptimizeExtInstr(MachineInstr *MI, MachineBasicBlock *MBB,
SmallPtrSet<MachineInstr*, 8> &LocalMIs) {
- LocalMIs.insert(MI);
-
unsigned SrcReg, DstReg, SubIdx;
if (!TII->isCoalescableExtInstr(*MI, SrcReg, DstReg, SubIdx))
return false;
-
+
if (TargetRegisterInfo::isPhysicalRegister(DstReg) ||
TargetRegisterInfo::isPhysicalRegister(SrcReg))
return false;
@@ -242,8 +239,7 @@ OptimizeExtInstr(MachineInstr *MI, MachineBasicBlock *MBB,
/// set) the same flag as the compare, then we can remove the comparison and use
/// the flag from the previous instruction.
bool PeepholeOptimizer::OptimizeCmpInstr(MachineInstr *MI,
- MachineBasicBlock *MBB,
- MachineBasicBlock::iterator &NextIter){
+ MachineBasicBlock *MBB){
// If this instruction is a comparison against zero and isn't comparing a
// physical register, we can try to optimize it.
unsigned SrcReg;
@@ -253,7 +249,7 @@ bool PeepholeOptimizer::OptimizeCmpInstr(MachineInstr *MI,
return false;
// Attempt to optimize the comparison instruction.
- if (TII->OptimizeCompareInstr(MI, SrcReg, CmpMask, CmpValue, MRI, NextIter)) {
+ if (TII->OptimizeCompareInstr(MI, SrcReg, CmpMask, CmpValue, MRI)) {
++NumEliminated;
return true;
}
@@ -262,6 +258,9 @@ bool PeepholeOptimizer::OptimizeCmpInstr(MachineInstr *MI,
}
bool PeepholeOptimizer::runOnMachineFunction(MachineFunction &MF) {
+ if (DisablePeephole)
+ return false;
+
TM = &MF.getTarget();
TII = TM->getInstrInfo();
MRI = &MF.getRegInfo();
@@ -276,17 +275,16 @@ bool PeepholeOptimizer::runOnMachineFunction(MachineFunction &MF) {
for (MachineBasicBlock::iterator
MII = I->begin(), MIE = I->end(); MII != MIE; ) {
- MachineInstr *MI = &*MII;
-
- if (MI->getDesc().isCompare() &&
- !MI->getDesc().hasUnmodeledSideEffects()) {
- if (!DisablePeephole && OptimizeCmpInstr(MI, MBB, MII))
- Changed = true;
- else
- ++MII;
+ MachineInstr *MI = &*MII++;
+ LocalMIs.insert(MI);
+
+ if (MI->getDesc().hasUnmodeledSideEffects())
+ continue;
+
+ if (MI->getDesc().isCompare()) {
+ Changed |= OptimizeCmpInstr(MI, MBB);
} else {
Changed |= OptimizeExtInstr(MI, MBB, LocalMIs);
- ++MII;
}
}
}