diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 1ecdea052cdb..3c219bb47e99 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -788,11 +788,12 @@ Instruction *InstCombinerImpl::commonIDivTransforms(BinaryOperator &I) { } if ((IsSigned && match(Op0, m_NSWShl(m_Value(X), m_APInt(C1))) && - *C1 != C1->getBitWidth() - 1) || - (!IsSigned && match(Op0, m_NUWShl(m_Value(X), m_APInt(C1))))) { + C1->ult(C1->getBitWidth() - 1)) || + (!IsSigned && match(Op0, m_NUWShl(m_Value(X), m_APInt(C1))) && + C1->ult(C1->getBitWidth()))) { APInt Quotient(C1->getBitWidth(), /*val=*/0ULL, IsSigned); APInt C1Shifted = APInt::getOneBitSet( - C1->getBitWidth(), static_cast(C1->getLimitedValue())); + C1->getBitWidth(), static_cast(C1->getZExtValue())); // (X << C1) / C2 -> X / (C2 >> C1) if C2 is a multiple of 1 << C1. if (isMultiple(*C2, C1Shifted, Quotient, IsSigned)) { diff --git a/llvm/test/Transforms/InstCombine/shift.ll b/llvm/test/Transforms/InstCombine/shift.ll index 2c5c4a7dbe1c..5ecc443d9010 100644 --- a/llvm/test/Transforms/InstCombine/shift.ll +++ b/llvm/test/Transforms/InstCombine/shift.ll @@ -1796,6 +1796,68 @@ define void @ashr_out_of_range_1(i177* %A) { ret void } +; OSS Fuzz #38078 +; https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=38078 +define void @ossfuzz_38078(i32 %arg, i32 %arg1) { +; CHECK-LABEL: @ossfuzz_38078( +; CHECK-NEXT: bb: +; CHECK-NEXT: [[I2:%.*]] = sub i32 0, [[ARG1:%.*]] +; CHECK-NEXT: [[I5:%.*]] = icmp eq i32 [[I2]], [[ARG:%.*]] +; CHECK-NEXT: call void @llvm.assume(i1 [[I5]]) +; CHECK-NEXT: store volatile i32 undef, i32* undef, align 4 +; CHECK-NEXT: br label [[BB:%.*]] +; CHECK: BB: +; CHECK-NEXT: unreachable +; +bb: + %i = or i32 0, -1 + %B24 = urem i32 %i, -2147483648 + %B21 = or i32 %i, %i + %i2 = add nsw i32 %arg, %arg1 + %B7 = or i32 %i, %i2 + %B8 = and i32 %i, %i2 + %B12 = sdiv i32 %i2, %B7 + %B3 = add i32 %i2, %B24 + %B5 = and i32 %i, %B3 + %B18 = and i32 %i, %B8 + %i3 = xor i32 %i2, %B3 + %C1 = icmp ne i32 %B8, %B5 + %i4 = lshr i32 %B5, %i3 + %B29 = shl nuw i32 %B8, %i3 + %B2 = lshr i32 %B12, %i2 + %B16 = add i32 %B2, %i3 + %B = sdiv i32 %B29, %B5 + %B15 = sub i32 %i2, %B5 + %B22 = or i32 %B21, %B29 + %B23 = mul i32 %B15, %B + %C2 = icmp sge i1 %C1, false + %C7 = icmp sle i32 %i3, %B16 + %B20 = xor i32 %B21, %B22 + %G1 = getelementptr i32, i32* undef, i32 %B22 + %B1 = sub i32 %B, undef + %B26 = ashr i32 %B29, undef + %B4 = add i32 undef, %B5 + %B27 = srem i32 %B12, %B21 + %i5 = icmp eq i32 %B20, %B18 + %C11 = icmp ugt i32 %i4, %B4 + call void @llvm.assume(i1 %i5) + store volatile i32 %B4, i32* %G1, align 4 + %B11 = or i32 undef, %B23 + br label %BB + +BB: + store i1 %C7, i1* undef, align 1 + store i32 %B11, i32* undef, align 4 + store i1 %C11, i1* undef, align 1 + store i32 %B1, i32* undef, align 4 + store i32 %B27, i32* undef, align 4 + %C = icmp ne i32 %B26, undef + %B17 = or i1 %C, %C2 + store i1 %B17, i1* undef, align 1 + unreachable +} +declare void @llvm.assume(i1 noundef) + define i8 @lshr_mask_demand(i8 %x) { ; CHECK-LABEL: @lshr_mask_demand( ; CHECK-NEXT: [[S:%.*]] = lshr i8 63, [[X:%.*]]