From: Reid Spencer <rspencer@reidspencer.com>
Date: Mon, 16 Jul 2007 21:03:44 +0000 (+0000)
Subject: Return Undef if the block has no dominator. This was required to allow
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=bde6869ef4bf1c8b1c620c570ea340c8b2d3d269;p=oota-llvm.git

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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@39924 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Utils/LCSSA.cpp b/lib/Transforms/Utils/LCSSA.cpp
index 3f4bad5c513..220241df335 100644
--- a/lib/Transforms/Utils/LCSSA.cpp
+++ b/lib/Transforms/Utils/LCSSA.cpp
@@ -231,6 +231,10 @@ Value *LCSSA::GetValueForBlock(DomTreeNode *BB, Instruction *OrigInst,
 
   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