Correctly mark a valno that was previous defined by a PHI node as having an
unknown defining inst after PHI elimination.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49069 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index f89d9f2..6416690 100644
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -845,7 +845,6 @@
}
bool StrongPHIElimination::runOnMachineFunction(MachineFunction &Fn) {
-
LiveIntervals& LI = getAnalysis<LiveIntervals>();
// Compute DFS numbers of each block
@@ -889,17 +888,21 @@
// If this is a dead PHI node, then remove it from LiveIntervals.
unsigned DestReg = PInstr->getOperand(0).getReg();
+ LiveInterval& PI = LI.getInterval(DestReg);
if (PInstr->registerDefIsDead(DestReg)) {
- LiveInterval& PI = LI.getInterval(DestReg);
-
if (PI.containsOneValue()) {
LI.removeInterval(DestReg);
} else {
unsigned idx = LI.getDefIndex(LI.getInstructionIndex(PInstr));
PI.removeRange(*PI.getLiveRangeContaining(idx), true);
}
+ } else {
+ // If the PHI is not dead, then the valno defined by the PHI
+ // now has an unknown def.
+ unsigned idx = LI.getDefIndex(LI.getInstructionIndex(PInstr));
+ PI.getLiveRangeContaining(idx)->valno->def = ~0U;
}
-
+
LI.RemoveMachineInstrFromMaps(PInstr);
PInstr->eraseFromParent();
}