Teach MachineLICM and MachineSink how to clear kill flags conservatively
when they move instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103737 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineLICM.cpp b/lib/CodeGen/MachineLICM.cpp
index b2e757d8d..6120617 100644
--- a/lib/CodeGen/MachineLICM.cpp
+++ b/lib/CodeGen/MachineLICM.cpp
@@ -738,8 +738,10 @@
"Instructions with different phys regs are not identical!");
if (MO.isReg() && MO.isDef() &&
- !TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
+ !TargetRegisterInfo::isPhysicalRegister(MO.getReg())) {
RegInfo->replaceRegWith(MO.getReg(), Dup->getOperand(i).getReg());
+ RegInfo->clearKillFlags(Dup->getOperand(i).getReg());
+ }
}
MI->eraseFromParent();
++NumCSEed;
@@ -784,6 +786,15 @@
// Otherwise, splice the instruction to the preheader.
CurPreheader->splice(CurPreheader->getFirstTerminator(),MI->getParent(),MI);
+ // Clear the kill flags of any register this instruction defines,
+ // since they may need to be live throughout the entire loop
+ // rather than just live for part of it.
+ for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+ MachineOperand &MO = MI->getOperand(i);
+ if (MO.isReg() && MO.isDef() && !MO.isDead())
+ RegInfo->clearKillFlags(MO.getReg());
+ }
+
// Add to the CSE map.
if (CI != CSEMap.end())
CI->second.push_back(MI);