[llvm-commits] [llvm] r69121 - /llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp

[Evan Cheng]

Author: evancheng
Date: Tue Apr 14 19:43:54 2009
New Revision: 69121

URL: http://llvm.org/viewvc/llvm-project?rev=69121&view=rev
Log:
Avoid making the transformation enabled by my last patch if the new destinations have phi nodes.

Modified:
    llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp?rev=69121&r1=69120&r2=69121&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/CondPropagate.cpp Tue Apr 14 19:43:54 2009
@@ -267,11 +267,21 @@
     // Change FromBr to branch to the new destination.
     FromBr->setSuccessor(0, ToBB);
   } else {
+    BasicBlock *Succ0 = BI->getSuccessor(0);
+    // Do not perform transform if the new destination has PHI nodes. The
+    // transform will add new preds to the PHI's.
+    if (isa<PHINode>(Succ0->begin()))
+      return false;
+
+    BasicBlock *Succ1 = BI->getSuccessor(1);
+    if (isa<PHINode>(Succ1->begin()))
+      return false;
+
     // Insert the new conditional branch.
-    BranchInst::Create(BI->getSuccessor(0), BI->getSuccessor(1), Cond, FromBr);
+    BranchInst::Create(Succ0, Succ1, Cond, FromBr);
 
-    FoldSingleEntryPHINodes(BI->getSuccessor(0));
-    FoldSingleEntryPHINodes(BI->getSuccessor(1));
+    FoldSingleEntryPHINodes(Succ0);
+    FoldSingleEntryPHINodes(Succ1);
 
     // Update PHI nodes in OldSucc to know that FromBB no longer branches to it.
     OldSucc->removePredecessor(FromBB);