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| author | Chris Lattner <sabre@nondot.org> | 2010-04-10 18:26:57 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-04-10 18:26:57 +0000 |
| commit | 6f285d21053552e5aff9aba74f0425505d6ab61a (patch) | |
| tree | 1da344a5df280258c11143283f30de5cb1e48059 | |
| parent | a2fb234b04eb632fb23aff72e56fd3962aa56e65 (diff) | |
fix PR6743, a case where we'd delete an instruction before using it
in some cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100937 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Transforms/Scalar/JumpThreading.cpp | 4 | ||||
| -rw-r--r-- | test/Transforms/JumpThreading/crash.ll | 17 |
2 files changed, 20 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp index a6489ecc2d..df05b712dc 100644 --- a/lib/Transforms/Scalar/JumpThreading.cpp +++ b/lib/Transforms/Scalar/JumpThreading.cpp @@ -670,8 +670,10 @@ bool JumpThreading::ProcessBranchOnDuplicateCond(BasicBlock *PredBB, Value *OldCond = DestBI->getCondition(); DestBI->setCondition(ConstantInt::get(Type::getInt1Ty(BB->getContext()), BranchDir)); - ConstantFoldTerminator(BB); + // Delete dead instructions before we fold the branch. Folding the branch + // can eliminate edges from the CFG which can end up deleting OldCond. RecursivelyDeleteTriviallyDeadInstructions(OldCond); + ConstantFoldTerminator(BB); return true; } diff --git a/test/Transforms/JumpThreading/crash.ll b/test/Transforms/JumpThreading/crash.ll index c65fd1014b..21620bef9c 100644 --- a/test/Transforms/JumpThreading/crash.ll +++ b/test/Transforms/JumpThreading/crash.ll @@ -324,3 +324,20 @@ A: ; preds = %entry call void undef(i64 ptrtoint (i8* blockaddress(@test11, %A) to i64)) nounwind unreachable } + +; PR6743 +define void @test12() nounwind ssp { +entry: + br label %lbl_51 + +lbl_51: ; preds = %if.then, %entry + %tmp3 = phi i1 [ false, %if.then ], [ undef, %entry ] ; <i1> [#uses=2] + br i1 %tmp3, label %if.end12, label %if.then + +if.then: ; preds = %lbl_51 + br i1 %tmp3, label %lbl_51, label %if.end12 + +if.end12: ; preds = %if.then, %lbl_51 + ret void +} + |