From: Jim Grosbach <grosbach@apple.com>
Date: Thu, 19 Nov 2009 02:03:18 +0000 (+0000)
Subject: Eliminate duplicate phi nodes in loops. Loop rotation, for example, can introduce... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d0b552cc5680ae245258598586115d05291b7b19;p=oota-llvm.git

Eliminate duplicate phi nodes in loops. Loop rotation, for example, can introduce these, and it's beneficial to later passes to clean them up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89298 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp
index 2ab09721495..44a2c1f8518 100644
--- a/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/lib/Transforms/Utils/LoopSimplify.cpp
@@ -305,6 +305,12 @@ ReprocessLoop:
     }
   }
 
+  // If there are duplicate phi nodes (for example, from loop rotation),
+  // get rid of them.
+  for (Loop::block_iterator BB = L->block_begin(), E = L->block_end();
+       BB != E; ++BB)
+    EliminateDuplicatePHINodes(*BB);
+
   return Changed;
 }