[LoopSimplify] Preserve LCSSA when removing edges from unreachable blocks.
This fixes PR30454.
llvm-svn: 287379
diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index 3ad5f58..01a5579 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -1369,12 +1369,13 @@
return NumDeadInst;
}
-unsigned llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap) {
+unsigned llvm::changeToUnreachable(Instruction *I, bool UseLLVMTrap,
+ bool PreserveLCSSA) {
BasicBlock *BB = I->getParent();
// Loop over all of the successors, removing BB's entry from any PHI
// nodes.
for (BasicBlock *Successor : successors(BB))
- Successor->removePredecessor(BB);
+ Successor->removePredecessor(BB, PreserveLCSSA);
// Insert a call to llvm.trap right before this. This turns the undefined
// behavior into a hard fail instead of falling through into random code.