[WarnMissedTransforms] Do not warn about already vectorized loops.

LoopVectorize adds llvm.loop.isvectorized, but leaves
llvm.loop.vectorize.enable. Do not consider such a loop for user-forced
vectorization since vectorization already happened -- by prioritizing
llvm.loop.isvectorized except for TM_SuppressedByUser.

Fixes http://llvm.org/PR40546

Differential Revision: https://reviews.llvm.org/D57542

llvm-svn: 353082

1 files changed, 7 insertions, 7 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp
index 54cb0fc23cb..57af3d1b7e0 100644
--- a/llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -378,17 +378,17 @@ TransformationMode llvm::hasVectorizeTransformation(Loop *L) {
   Optional<int> InterleaveCount =
       getOptionalIntLoopAttribute(L, "llvm.loop.interleave.count");
 
-  if (Enable == true) {
-    // 'Forcing' vector width and interleave count to one effectively disables
-    // this tranformation.
-    if (VectorizeWidth == 1 && InterleaveCount == 1)
-      return TM_SuppressedByUser;
-    return TM_ForcedByUser;
-  }
+  // 'Forcing' vector width and interleave count to one effectively disables
+  // this tranformation.
+  if (Enable == true && VectorizeWidth == 1 && InterleaveCount == 1)
+    return TM_SuppressedByUser;
 
   if (getBooleanLoopAttribute(L, "llvm.loop.isvectorized"))
     return TM_Disable;
 
+  if (Enable == true)
+    return TM_ForcedByUser;
+
   if (VectorizeWidth == 1 && InterleaveCount == 1)
     return TM_Disable;