LSR: teach isSimplifiedLoopNest to handle PHI IVUsers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153132 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index 308729f..463584d 100644
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -148,7 +148,14 @@
// Only consider IVUsers that are dominated by simplified loop
// headers. Otherwise, SCEVExpander will crash.
- if (!isSimplifiedLoopNest(User->getParent(), DT, LI, SimpleLoopNests))
+ BasicBlock *UseBB = User->getParent();
+ // A phi's use is live out of its predecessor block.
+ if (PHINode *PHI = dyn_cast<PHINode>(User)) {
+ unsigned OperandNo = UI.getOperandNo();
+ unsigned ValNo = PHINode::getIncomingValueNumForOperand(OperandNo);
+ UseBB = PHI->getIncomingBlock(ValNo);
+ }
+ if (!isSimplifiedLoopNest(UseBB, DT, LI, SimpleLoopNests))
return false;
// Descend recursively, but not into PHI nodes outside the current loop.