Check bool attribute value in getOptionalBoolLoopAttribute.

Summary:
Check the bool value of the attribute in getOptionalBoolLoopAttribute
not just its existance.
Eliminates the warning noise generated when vectorization is explicitly disabled.

Reviewers: Meinersbur, hfinkel, dmgreen

Subscribers: jlebar, sanjoy, llvm-commits

Differential Revision: https://reviews.llvm.org/D57260

llvm-svn: 352555

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp
index 3d08ce21f31..54cb0fc23cb 100644
--- a/llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -216,7 +216,10 @@ static Optional<bool> getOptionalBoolLoopAttribute(const Loop *TheLoop,
     // When the value is absent it is interpreted as 'attribute set'.
     return true;
   case 2:
-    return mdconst::extract_or_null<ConstantInt>(MD->getOperand(1).get());
+    if (ConstantInt *IntMD =
+            mdconst::extract_or_null<ConstantInt>(MD->getOperand(1).get()))
+      return IntMD->getZExtValue();
+    return true;
   }
   llvm_unreachable("unexpected number of options");
 }