diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp @@ -2723,6 +2723,25 @@ canonicalizeCondSignextOfHighBitExtractToSignextHighBitExtract(I)) return V; + CmpInst::Predicate Pred; + Value *UMul1, *UMul2; + // Check if the OR weakens the overflow condition for umul.with.overflow by + // treating any non-zero result as overflow. In that case, we overflow if both + // umul.with.overflow operands are != 0, as in that case the result can only + // be 0, iff the multiplication overflows. + auto P = m_ICmp(Pred, m_ExtractValue<0>(m_Value(UMul2)), m_SpecificInt(0)); + if (match(&I, m_Or(m_OneUse(m_ExtractValue<1>(m_Value(UMul1))), P)) || + match(&I, m_Or(P, m_OneUse(m_ExtractValue<1>(m_Value(UMul1)))))) { + Value *A, *B; + if (Pred == CmpInst::ICMP_NE && UMul1 == UMul2 && + match(UMul1, m_Intrinsic(m_Value(A), + m_Value(B)))) + + return BinaryOperator::CreateAnd( + Builder.CreateICmpNE(A, ConstantInt::get(A->getType(), 0)), + Builder.CreateICmpNE(A, ConstantInt::get(B->getType(), 0))); + } + return nullptr; } diff --git a/llvm/test/Transforms/InstCombine/umul-signed.ll b/llvm/test/Transforms/InstCombine/umul-signed.ll --- a/llvm/test/Transforms/InstCombine/umul-signed.ll +++ b/llvm/test/Transforms/InstCombine/umul-signed.ll @@ -14,13 +14,10 @@ define i1 @test1(i64 %a, i64* %ptr) { ; CHECK-LABEL: @test1( -; CHECK-NEXT: [[RES:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[A:%.*]], i64 -4775807) -; CHECK-NEXT: [[OVERFLOW:%.*]] = extractvalue { i64, i1 } [[RES]], 1 -; CHECK-NEXT: [[MUL:%.*]] = extractvalue { i64, i1 } [[RES]], 0 -; CHECK-NEXT: [[CMP:%.*]] = icmp ne i64 [[MUL]], 0 -; CHECK-NEXT: [[OVERFLOW_1:%.*]] = or i1 [[OVERFLOW]], [[CMP]] +; CHECK-NEXT: [[MUL:%.*]] = mul i64 [[A:%.*]], -4775807 +; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i64 [[A]], 0 ; CHECK-NEXT: store i64 [[MUL]], i64* [[PTR:%.*]], align 8 -; CHECK-NEXT: ret i1 [[OVERFLOW_1]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 -4775807) %overflow = extractvalue { i64, i1 } %res, 1 @@ -33,13 +30,10 @@ define i1 @test1_or_ops_swapped(i64 %a, i64* %ptr) { ; CHECK-LABEL: @test1_or_ops_swapped( -; CHECK-NEXT: [[RES:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[A:%.*]], i64 -4775807) -; CHECK-NEXT: [[OVERFLOW:%.*]] = extractvalue { i64, i1 } [[RES]], 1 -; CHECK-NEXT: [[MUL:%.*]] = extractvalue { i64, i1 } [[RES]], 0 -; CHECK-NEXT: [[CMP:%.*]] = icmp ne i64 [[MUL]], 0 -; CHECK-NEXT: [[OVERFLOW_1:%.*]] = or i1 [[CMP]], [[OVERFLOW]] +; CHECK-NEXT: [[MUL:%.*]] = mul i64 [[A:%.*]], -4775807 +; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i64 [[A]], 0 ; CHECK-NEXT: store i64 [[MUL]], i64* [[PTR:%.*]], align 8 -; CHECK-NEXT: ret i1 [[OVERFLOW_1]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 -4775807) %overflow = extractvalue { i64, i1 } %res, 1 @@ -53,14 +47,10 @@ define i1 @test2(i64 %a, i64* %ptr) { ; CHECK-LABEL: @test2( -; CHECK-NEXT: [[RES:%.*]] = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 [[A:%.*]], i64 10000) -; CHECK-NEXT: [[OVERFLOW:%.*]] = extractvalue { i64, i1 } [[RES]], 1 -; CHECK-NEXT: [[MUL:%.*]] = extractvalue { i64, i1 } [[RES]], 0 -; CHECK-NEXT: [[CMP:%.*]] = icmp ne i64 [[MUL]], 0 -; CHECK-NEXT: [[OVERFLOW_1:%.*]] = or i1 [[OVERFLOW]], [[CMP]] -; CHECK-NEXT: [[NEG:%.*]] = sub i64 0, [[MUL]] -; CHECK-NEXT: store i64 [[NEG]], i64* [[PTR:%.*]], align 8 -; CHECK-NEXT: ret i1 [[OVERFLOW_1]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ne i64 [[A:%.*]], 0 +; CHECK-NEXT: [[MUL_NEG:%.*]] = mul i64 [[A]], -10000 +; CHECK-NEXT: store i64 [[MUL_NEG]], i64* [[PTR:%.*]], align 8 +; CHECK-NEXT: ret i1 [[TMP1]] ; %res = tail call { i64, i1 } @llvm.umul.with.overflow.i64(i64 %a, i64 10000) %overflow = extractvalue { i64, i1 } %res, 1