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SimplifyCFG: Avoid miscompilations due to removed lifetime intrinsics #19

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SimplifyCFG: Avoid miscompilations due to removed lifetime intrinsics #19

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2 changes: 1 addition & 1 deletion lib/Transforms/Utils/SimplifyCFG.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4011,7 +4011,7 @@ 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;
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6 changes: 3 additions & 3 deletions test/Transforms/SimplifyCFG/lifetime.ll
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@@ -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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