From a16ead8b10ab63e08c91afb852f29b32188b9afb Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sun, 7 Dec 2008 07:22:45 +0000
Subject: [PATCH] fix a bug I introduced in simplifycfg handling single entry
 phi nodes. FoldSingleEntryPHINodes deletes the PHI, so there is no need to
 delete it afterward.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60653 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Utils/SimplifyCFG.cpp                |  1 -
 .../SimplifyCFG/2008-12-06-SingleEntryPhi.ll        | 13 +++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 test/Transforms/SimplifyCFG/2008-12-06-SingleEntryPhi.ll

diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index d6465f599cf..e7bd75e0493 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1102,7 +1102,6 @@ static bool FoldCondBranchOnPHI(BranchInst *BI) {
   // Degenerate case of a single entry PHI.
   if (PN->getNumIncomingValues() == 1) {
     FoldSingleEntryPHINodes(PN->getParent());
-    PN->eraseFromParent();
     return true;    
   }
 
diff --git a/test/Transforms/SimplifyCFG/2008-12-06-SingleEntryPhi.ll b/test/Transforms/SimplifyCFG/2008-12-06-SingleEntryPhi.ll
new file mode 100644
index 00000000000..7b4aee489b5
--- /dev/null
+++ b/test/Transforms/SimplifyCFG/2008-12-06-SingleEntryPhi.ll
@@ -0,0 +1,13 @@
+; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis
+define i32 @test() {
+entry:
+	br label %T
+T:
+	%C = phi i1 [false, %entry] 
+	br i1 %C, label %X, label %Y
+X:
+	ret i32 2
+Y:
+	add i32 1, 2
+	ret i32 1
+}