[SCEV] Fix one more caller blindly passing the latch to SCEV's

getSmallConstantTripCount even when it isn't the exiting block.

I missed this in my first audit, very sorry. This was found in LNT and
elsewhere. I don't have a test case, but it was completely obvious from
inspection that this was the problem. I'll see if I can reduce a test
case, but I'm not really hopeful, and the value seems quite low.

llvm-svn: 219562

1 files changed, 1 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 2004f62a80c..d45b8d8a72b 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -5517,8 +5517,7 @@ LoopVectorizationCostModel::selectUnrollFactor(bool OptForSize,
     return 1;
 
   // Do not unroll loops with a relatively small trip count.
-  unsigned TC = SE->getSmallConstantTripCount(TheLoop,
-                                              TheLoop->getLoopLatch());
+  unsigned TC = SE->getSmallConstantTripCount(TheLoop);
   if (TC > 1 && TC < TinyTripCountUnrollThreshold)
     return 1;