From d49981a9bbeb49626389119ebec3b0626337b233 Mon Sep 17 00:00:00 2001
From: Nuno Lopes <nunoplopes@sapo.pt>
Date: Mon, 16 Jul 2012 22:49:40 +0000
Subject: [PATCH] fix PR13339 (remove the predecessor from the unwind BB when
 removing an invoke)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160325 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/SimplifyCFGPass.cpp |  1 +
 test/Transforms/SimplifyCFG/invoke.ll     | 22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index 91158b429ea..99e236f5433 100644
--- a/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -165,6 +165,7 @@ static bool MarkAliveBlocks(BasicBlock *BB,
         if (II->use_empty() && II->onlyReadsMemory()) {
           // jump to the normal destination branch.
           BranchInst::Create(II->getNormalDest(), II);
+          II->getUnwindDest()->removePredecessor(II->getParent());
           II->eraseFromParent();
         } else
           ChangeToCall(II);
diff --git a/test/Transforms/SimplifyCFG/invoke.ll b/test/Transforms/SimplifyCFG/invoke.ll
index ddced6b94df..10dc41b44bc 100644
--- a/test/Transforms/SimplifyCFG/invoke.ll
+++ b/test/Transforms/SimplifyCFG/invoke.ll
@@ -3,6 +3,7 @@ target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f3
 
 declare i32 @__gxx_personality_v0(...)
 declare void @__cxa_call_unexpected(i8*)
+declare void @purefn() nounwind readnone
 declare i32 @read_only() nounwind readonly
 declare i32 @nounwind_fn() nounwind
 declare i32 @fn()
@@ -115,3 +116,24 @@ lpad:
   tail call void @__cxa_call_unexpected(i8* %phi2) noreturn nounwind
   unreachable
 }
+
+; CHECK: @f6
+define void @f6() {
+entry:
+  invoke void @purefn()
+          to label %invoke.cont1 unwind label %lpad
+
+invoke.cont1:
+  %foo = invoke i32 @fn()
+          to label %invoke.cont2 unwind label %lpad
+
+invoke.cont2:
+  ret void
+
+lpad:
+; CHECK-NOT: phi
+  %tmp = phi i8* [ null, %invoke.cont1 ], [ null, %entry ]
+  landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*)
+          cleanup
+  ret void
+}