[llvm-commits] [llvm] r157522 - /llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

[Benjamin Kramer]

Author: d0k
Date: Sat May 26 16:19:12 2012
New Revision: 157522

URL: http://llvm.org/viewvc/llvm-project?rev=157522&view=rev
Log:
SDAGBuilder: Don't create an invalid iterator when there is only one switch case.

Found by libstdc++'s debug mode.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=157522&r1=157521&r2=157522&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Sat May 26 16:19:12 2012
@@ -1984,10 +1984,10 @@
       }
     }
   }
-
   // Rearrange the case blocks so that the last one falls through if possible.
   Case &BackCase = *(CR.Range.second-1);
-  if (NextBlock && Default != NextBlock && BackCase.BB != NextBlock) {
+  if (Size > 1 &&
+      NextBlock && Default != NextBlock && BackCase.BB != NextBlock) {
     // The last case block won't fall through into 'NextBlock' if we emit the
     // branches in this order.  See if rearranging a case value would help.
     // We start at the bottom as it's the case with the least weight.