diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineSelect.cpp | 4 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/select-crash.ll | 17 |
2 files changed, 21 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp index bdd97a8..291e800 100644 --- a/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -881,12 +881,16 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) { if (SelectInst *TrueSI = dyn_cast<SelectInst>(TrueVal)) { if (TrueSI->getCondition() == CondVal) { + if (SI.getTrueValue() == TrueSI->getTrueValue()) + return 0; SI.setOperand(1, TrueSI->getTrueValue()); return &SI; } } if (SelectInst *FalseSI = dyn_cast<SelectInst>(FalseVal)) { if (FalseSI->getCondition() == CondVal) { + if (SI.getFalseValue() == FalseSI->getFalseValue()) + return 0; SI.setOperand(2, FalseSI->getFalseValue()); return &SI; } diff --git a/test/Transforms/InstCombine/select-crash.ll b/test/Transforms/InstCombine/select-crash.ll index 18af152..946ea2b 100644 --- a/test/Transforms/InstCombine/select-crash.ll +++ b/test/Transforms/InstCombine/select-crash.ll @@ -30,3 +30,20 @@ define <4 x float> @foo(i1 %b, <4 x float> %x, <4 x float> %y, <4 x float> %z) { %sel = select i1 %b, <4 x float> %a, <4 x float> %sub ret <4 x float> %sel } + +; CHECK: @test3 +define i32 @test3(i1 %bool, i32 %a) { +entry: + %cond = or i1 %bool, true + br i1 %cond, label %return, label %xpto + +; technically reachable, but this malformed IR may appear as a result of constant propagation +xpto: + %select = select i1 %bool, i32 %a, i32 %select + %select2 = select i1 %bool, i32 %select2, i32 %a + %sum = add i32 %select, %select2 + ret i32 %sum + +return: + ret i32 7 +} |