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.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@232544 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 24bb63b..1c62559 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -4008,7 +4008,7 @@
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/test/Transforms/SimplifyCFG/lifetime.ll b/test/Transforms/SimplifyCFG/lifetime.ll
index b794221..7c66be5 100644
--- a/test/Transforms/SimplifyCFG/lifetime.ll
+++ b/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:
