diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 507e6f2a854..ce052f724e8 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -1762,11 +1762,12 @@ bool InstCombiner::SimplifyDemandedBits(Value *V, APInt DemandedMask, APInt KnownZero2(BitWidth, 0), KnownOne2(BitWidth, 0); APInt AllOnes = APInt::getAllOnesValue(BitWidth); - ComputeMaskedBits(I->getOperand(0), AllOnes, - KnownZero2, KnownOne2, Depth+1); + if (SimplifyDemandedBits(I->getOperand(0), AllOnes, + KnownZero2, KnownOne2, Depth+1)) + return true; + uint32_t Leaders = KnownZero2.countLeadingOnes(); - APInt HighZeros = APInt::getHighBitsSet(BitWidth, Leaders); - if (SimplifyDemandedBits(I->getOperand(1), ~HighZeros, + if (SimplifyDemandedBits(I->getOperand(1), AllOnes, KnownZero2, KnownOne2, Depth+1)) return true; diff --git a/test/Transforms/InstCombine/urem-simplify-bug.ll b/test/Transforms/InstCombine/urem-simplify-bug.ll new file mode 100644 index 00000000000..15956f26b69 --- /dev/null +++ b/test/Transforms/InstCombine/urem-simplify-bug.ll @@ -0,0 +1,32 @@ +; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep {= or i32 %x, -5 } + +@.str = internal constant [5 x i8] c"foo\0A\00" ; <[5 x i8]*> [#uses=1] +@.str1 = internal constant [5 x i8] c"bar\0A\00" ; <[5 x i8]*> [#uses=1] + +define i32 @main() nounwind { +entry: + %x = call i32 @func_11( ) nounwind ; [#uses=1] + %tmp3 = or i32 %x, -5 ; [#uses=1] + %tmp5 = urem i32 251, %tmp3 ; [#uses=1] + %tmp6 = icmp ne i32 %tmp5, 0 ; [#uses=1] + %tmp67 = zext i1 %tmp6 to i32 ; [#uses=1] + %tmp9 = urem i32 %tmp67, 95 ; [#uses=1] + %tmp10 = and i32 %tmp9, 1 ; [#uses=1] + %tmp12 = icmp eq i32 %tmp10, 0 ; [#uses=1] + br i1 %tmp12, label %bb14, label %bb + +bb: ; preds = %entry + br label %bb15 + +bb14: ; preds = %entry + br label %bb15 + +bb15: ; preds = %bb14, %bb + %iftmp.0.0 = phi i8* [ getelementptr ([5 x i8]* @.str1, i32 0, i32 0), %bb14 ], [ getelementptr ([5 x i8]* @.str, i32 0, i32 0), %bb ] ; [#uses=1] + %tmp17 = call i32 (i8*, ...)* @printf( i8* %iftmp.0.0 ) nounwind ; [#uses=0] + ret i32 0 +} + +declare i32 @func_11() + +declare i32 @printf(i8*, ...) nounwind