From e1d4fb3c2cf6b71c40293f9f18c92a0a14f29f7a Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Thu, 27 Feb 2003 21:51:38 +0000
Subject: [PATCH] Fix bug: LICM/2003-02-27-PreheaderProblem.ll There may be a
 single outside predecessor and still need a new loop-preheader if the
 predecessor has multiple successors.

llvm-svn: 5656
---
 lib/Analysis/LoopInfo.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index a361e629e1a..035f92c33c3 100644
--- a/lib/Analysis/LoopInfo.cpp
+++ b/lib/Analysis/LoopInfo.cpp
@@ -200,6 +200,13 @@ BasicBlock *Loop::getLoopPreheader() const {
         return 0;             // Multiple predecessors outside the loop
       Out = *PI;
     }
+  
+  // Make sure there is only one exit out of the preheader...
+  succ_iterator SI = succ_begin(Out);
+  ++SI;
+  if (SI != succ_end(Out))
+    return 0;  // Multiple exits from the block, must not be a preheader.
+
 
   // If there is exactly one preheader, return it.  If there was zero, then Out
   // is still null.