From 9dea3a340a8e3db7eab92ea78c20e317ac4c2545 Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Wed, 28 Mar 2007 14:57:43 +0000
Subject: [PATCH] It is not possible to determine dominance between two PHI
 nodes based on their ordering. This is applicable to ETForest::dominates()
 also.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35423 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/VMCore/Dominators.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/VMCore/Dominators.cpp b/lib/VMCore/Dominators.cpp
index 1421cf14e7d..9bd51bf4d91 100644
--- a/lib/VMCore/Dominators.cpp
+++ b/lib/VMCore/Dominators.cpp
@@ -952,6 +952,11 @@ bool ETForestBase::dominates(Instruction *A, Instruction *B) {
   BasicBlock::iterator I = BBA->begin();
   for (; &*I != A && &*I != B; ++I) /*empty*/;
   
+  // It is not possible to determine dominance between two PHI nodes 
+  // based on their ordering.
+  if (isa<PHINode>(A) && isa<PHINode>(B)) 
+    return false;
+
   if(!IsPostDominators) {
     // A dominates B if it is found first in the basic block.
     return &*I == A;
-- 
2.34.1