From e0cba6fbc2045cf0e403c4f22b7dd0849699b91a Mon Sep 17 00:00:00 2001
From: Tom Stellard <thomas.stellard@amd.com>
Date: Tue, 17 Mar 2015 20:42:08 +0000
Subject: [PATCH] Merging r214336:
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r214336 | rafael.espindola | 2014-07-30 17:04:00 -0400 (Wed, 30 Jul 2014) | 9 lines
SimplifyCFG: Avoid miscompilations due to removed lifetime intrinsics.
The lifetime intrinsics need some work in order to make it clear which
optimizations are or are not valid.
For now dropping this optimization avoids a miscompilation.
Patch by Björn Steinbrink.
------------------------------------------------------------------------
llvm-svn: 232544
---
llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 2 +-
llvm/test/Transforms/SimplifyCFG/lifetime.ll | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index 24bb63bb60a5..1c62559739f9 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4008,7 +4008,7 @@ bool SimplifyCFGOpt::SimplifyUncondBranch(BranchInst *BI, IRBuilder<> &Builder){
return true;
// If the Terminator is the only non-phi instruction, simplify the block.
- BasicBlock::iterator I = BB->getFirstNonPHIOrDbgOrLifetime();
+ BasicBlock::iterator I = BB->getFirstNonPHIOrDbg();
if (I->isTerminator() && BB != &BB->getParent()->getEntryBlock() &&
TryToSimplifyUncondBranchFromEmptyBlock(BB))
return true;
diff --git a/llvm/test/Transforms/SimplifyCFG/lifetime.ll b/llvm/test/Transforms/SimplifyCFG/lifetime.ll
index b79422172530..7c66be529500 100644
--- a/llvm/test/Transforms/SimplifyCFG/lifetime.ll
+++ b/llvm/test/Transforms/SimplifyCFG/lifetime.ll
@@ -1,11 +1,11 @@
; RUN: opt < %s -simplifycfg -S | FileCheck %s
-; Test that a lifetime intrinsic doesn't prevent us from simplifying this.
+; Test that a lifetime intrinsic isn't removed because that would change semantics
; CHECK: foo
; CHECK: entry:
-; CHECK-NOT: bb0:
-; CHECK-NOT: bb1:
+; CHECK: bb0:
+; CHECK: bb1:
; CHECK: ret
define void @foo(i1 %x) {
entry:
--
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