r179806 - Add comment to describe cleverness.

[Benjamin Kramer]

Author: d0k
Date: Thu Apr 18 17:49:48 2013
New Revision: 179806

URL: http://llvm.org/viewvc/llvm-project?rev=179806&view=rev
Log:
Add comment to describe cleverness.

Modified:
    cfe/trunk/lib/Basic/TargetInfo.cpp

Modified: cfe/trunk/lib/Basic/TargetInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/TargetInfo.cpp?rev=179806&r1=179805&r2=179806&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/TargetInfo.cpp (original)
+++ cfe/trunk/lib/Basic/TargetInfo.cpp Thu Apr 18 17:49:48 2013
@@ -373,6 +373,8 @@ bool TargetInfo::validateOutputConstrain
     Name++;
   }
 
+  // If a constraint allows neither memory nor register operands it contains
+  // only modifiers. Reject it.
   return Info.allowsMemory() || Info.allowsRegister();
 }