commit dc3b67b4cad5c18a687edfabd50779c3c656c620
author David Majnemer <david.majnemer@gmail.com> Wed Oct 21 18:22:24 2015 +0000
committer David Majnemer <david.majnemer@gmail.com> Wed Oct 21 18:22:24 2015 +0000
tree e1d19c27f86176fefd1c06125d7ccc5abd95ac47
parent 9d7ccdee0fdfbfa63f6059c2045cdafe89431a48

[SimplifyCFG] Don't use-after-free an SSA value

SimplifyTerminatorOnSelect didn't consider the possibility that the
condition might be related to one of PHI nodes.

This fixes PR25267.

llvm-svn: 250922

llvm/lib/Transforms/Utils/SimplifyCFG.cpp

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index e98f334..e435537 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -2571,7 +2571,8 @@
     else if (Succ == KeepEdge2)
       KeepEdge2 = nullptr;
     else
-      Succ->removePredecessor(OldTerm->getParent());
+      Succ->removePredecessor(OldTerm->getParent(),
+                              /*DontDeleteUselessPHIs=*/true);
   }
 
   IRBuilder<> Builder(OldTerm);