Fix IVUsers to avoid assuming that the loop has a unique backedge.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86161 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index 543e017fc9dd7907dead8f99680a39de846561f3..20b69f2a7ca2c34edad230e4bdada12741b5e058 100644 (file)
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -151,6 +151,8 @@ static bool IVUseShouldUsePostIncValue(Instruction *User, Instruction *IV,
   if (L->contains(User->getParent())) return false;
 
   BasicBlock *LatchBlock = L->getLoopLatch();
+  if (!LatchBlock)
+    return false;
 
   // Ok, the user is outside of the loop.  If it is dominated by the latch
   // block, use the post-inc value.