Don't consider definitions by other PHIs live-in when trimming a PHI source's
live range after inserting a copy at the end of a block.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174945 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index f046ac9..abad5c1 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -467,7 +467,11 @@
bool isLiveOut = false;
for (MachineBasicBlock::succ_iterator SI = opBlock.succ_begin(),
SE = opBlock.succ_end(); SI != SE; ++SI) {
- if (SrcLI.liveAt(LIS->getMBBStartIdx(*SI))) {
+ SlotIndex startIdx = LIS->getMBBStartIdx(*SI);
+ VNInfo *VNI = SrcLI.getVNInfoAt(startIdx);
+
+ // Definitions by other PHIs are not truly live-in for our purposes.
+ if (VNI && VNI->def != startIdx) {
isLiveOut = true;
break;
}