[llvm-commits] [llvm] r39924 - /llvm/trunk/lib/Transforms/Utils/LCSSA.cpp

[Reid Spencer]

Author: reid
Date: Mon Jul 16 16:03:44 2007
New Revision: 39924

URL: http://llvm.org/viewvc/llvm-project?rev=39924&view=rev
Log:
Return Undef if the block has no dominator. This was required to allow
llvm-gcc build to succeed. Without this change it fails in libstdc++
compilation. This causes no regressions in dejagnu tests. However, 
someone who knows this code better might want to review it.

Modified:
    llvm/trunk/lib/Transforms/Utils/LCSSA.cpp

Modified: llvm/trunk/lib/Transforms/Utils/LCSSA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LCSSA.cpp?rev=39924&r1=39923&r2=39924&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LCSSA.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LCSSA.cpp Mon Jul 16 16:03:44 2007
@@ -231,6 +231,10 @@
 
   DomTreeNode *IDom = BB->getIDom();
 
+  // If the block has no dominator, bail
+  if (!IDom)
+    return V = UndefValue::get(OrigInst->getType());
+
   // Otherwise, there are two cases: we either have to insert a PHI node or we
   // don't.  We need to insert a PHI node if this block is not dominated by one
   // of the exit nodes from the loop (the loop could have multiple exits, and