Process all uses first before defs to accurately capture register liveness. rdar://10449480
llvm-svn: 144770
diff --git a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
index e2fd007..2e5111d 100644
--- a/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -1115,6 +1115,7 @@
MCID.isTerminator())
// Don't move pass calls, etc.
return false;
+ SmallVector<unsigned, 2> OtherDefs;
for (unsigned i = 0, e = OtherMI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = OtherMI->getOperand(i);
if (!MO.isReg())
@@ -1131,15 +1132,20 @@
// Don't want to extend other live ranges and update kills.
return false;
} else {
- if (Uses.count(MOReg))
- return false;
- if (TargetRegisterInfo::isPhysicalRegister(MOReg) &&
- LiveDefs.count(MOReg))
- return false;
- // Physical register def is seen.
- Defs.erase(MOReg);
+ OtherDefs.push_back(MOReg);
}
}
+
+ for (unsigned i = 0, e = OtherDefs.size(); i != e; ++i) {
+ unsigned MOReg = OtherDefs[i];
+ if (Uses.count(MOReg))
+ return false;
+ if (TargetRegisterInfo::isPhysicalRegister(MOReg) &&
+ LiveDefs.count(MOReg))
+ return false;
+ // Physical register def is seen.
+ Defs.erase(MOReg);
+ }
}
// Move the old kill above MI, don't forget to move debug info as well.