Add comment to describe cleverness.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179806 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Basic/TargetInfo.cpp b/lib/Basic/TargetInfo.cpp
index 699f7d4b3f9290db019154ac7186ca24f26e4547..ff72f495c8ba1ff06075808f689ec8554c18e713 100644 (file)
--- a/lib/Basic/TargetInfo.cpp
+++ b/lib/Basic/TargetInfo.cpp
@@ -373,6 +373,8 @@ bool TargetInfo::validateOutputConstraint(ConstraintInfo &Info) const {
     Name++;
   }
 
+  // If a constraint allows neither memory nor register operands it contains
+  // only modifiers. Reject it.
   return Info.allowsMemory() || Info.allowsRegister();
 }