diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -275,6 +275,15 @@ } } + // abs(X) * abs(X) -> X * X + // nabs(X) * nabs(X) -> X * X + if (Op0 == Op1) { + Value *X, *Y; + SelectPatternFlavor SPF = matchSelectPattern(Op0, X, Y).Flavor; + if (SPF == SPF_ABS || SPF == SPF_NABS) + return BinaryOperator::CreateMul(X, X); + } + // -X * C --> X * -C Value *X, *Y; Constant *Op1C; diff --git a/llvm/test/Transforms/InstCombine/mul.ll b/llvm/test/Transforms/InstCombine/mul.ll --- a/llvm/test/Transforms/InstCombine/mul.ll +++ b/llvm/test/Transforms/InstCombine/mul.ll @@ -610,10 +610,7 @@ ; fold mul(abs(x),abs(x)) -> mul(x,x) define i31 @combine_mul_abs_i31(i31 %0) { ; CHECK-LABEL: @combine_mul_abs_i31( -; CHECK-NEXT: [[C:%.*]] = icmp slt i31 [[TMP0:%.*]], 0 -; CHECK-NEXT: [[S:%.*]] = sub nsw i31 0, [[TMP0]] -; CHECK-NEXT: [[R:%.*]] = select i1 [[C]], i31 [[S]], i31 [[TMP0]] -; CHECK-NEXT: [[M:%.*]] = mul i31 [[R]], [[R]] +; CHECK-NEXT: [[M:%.*]] = mul i31 [[TMP0:%.*]], [[TMP0]] ; CHECK-NEXT: ret i31 [[M]] ; %c = icmp slt i31 %0, 0 @@ -625,10 +622,7 @@ define i32 @combine_mul_abs_i32(i32 %0) { ; CHECK-LABEL: @combine_mul_abs_i32( -; CHECK-NEXT: [[C:%.*]] = icmp slt i32 [[TMP0:%.*]], 0 -; CHECK-NEXT: [[S:%.*]] = sub nsw i32 0, [[TMP0]] -; CHECK-NEXT: [[R:%.*]] = select i1 [[C]], i32 [[S]], i32 [[TMP0]] -; CHECK-NEXT: [[M:%.*]] = mul i32 [[R]], [[R]] +; CHECK-NEXT: [[M:%.*]] = mul i32 [[TMP0:%.*]], [[TMP0]] ; CHECK-NEXT: ret i32 [[M]] ; %c = icmp slt i32 %0, 0 @@ -640,10 +634,7 @@ define <4 x i32> @combine_mul_abs_v4i32(<4 x i32> %0) { ; CHECK-LABEL: @combine_mul_abs_v4i32( -; CHECK-NEXT: [[C:%.*]] = icmp slt <4 x i32> [[TMP0:%.*]], zeroinitializer -; CHECK-NEXT: [[S:%.*]] = sub nsw <4 x i32> zeroinitializer, [[TMP0]] -; CHECK-NEXT: [[R:%.*]] = select <4 x i1> [[C]], <4 x i32> [[S]], <4 x i32> [[TMP0]] -; CHECK-NEXT: [[M:%.*]] = mul <4 x i32> [[R]], [[R]] +; CHECK-NEXT: [[M:%.*]] = mul <4 x i32> [[TMP0:%.*]], [[TMP0]] ; CHECK-NEXT: ret <4 x i32> [[M]] ; %c = icmp slt <4 x i32> %0, zeroinitializer @@ -656,10 +647,7 @@ ; fold mul(nabs(x),nabs(x)) -> mul(x,x) define i31 @combine_mul_nabs_i31(i31 %0) { ; CHECK-LABEL: @combine_mul_nabs_i31( -; CHECK-NEXT: [[C:%.*]] = icmp slt i31 [[TMP0:%.*]], 0 -; CHECK-NEXT: [[S:%.*]] = sub nsw i31 0, [[TMP0]] -; CHECK-NEXT: [[R:%.*]] = select i1 [[C]], i31 [[TMP0]], i31 [[S]] -; CHECK-NEXT: [[M:%.*]] = mul i31 [[R]], [[R]] +; CHECK-NEXT: [[M:%.*]] = mul i31 [[TMP0:%.*]], [[TMP0]] ; CHECK-NEXT: ret i31 [[M]] ; %c = icmp slt i31 %0, 0 @@ -671,10 +659,7 @@ define i32 @combine_mul_nabs_i32(i32 %0) { ; CHECK-LABEL: @combine_mul_nabs_i32( -; CHECK-NEXT: [[C:%.*]] = icmp slt i32 [[TMP0:%.*]], 0 -; CHECK-NEXT: [[S:%.*]] = sub nsw i32 0, [[TMP0]] -; CHECK-NEXT: [[R:%.*]] = select i1 [[C]], i32 [[TMP0]], i32 [[S]] -; CHECK-NEXT: [[M:%.*]] = mul i32 [[R]], [[R]] +; CHECK-NEXT: [[M:%.*]] = mul i32 [[TMP0:%.*]], [[TMP0]] ; CHECK-NEXT: ret i32 [[M]] ; %c = icmp slt i32 %0, 0 @@ -686,10 +671,7 @@ define <4 x i32> @combine_mul_nabs_v4i32(<4 x i32> %0) { ; CHECK-LABEL: @combine_mul_nabs_v4i32( -; CHECK-NEXT: [[C:%.*]] = icmp slt <4 x i32> [[TMP0:%.*]], zeroinitializer -; CHECK-NEXT: [[S:%.*]] = sub nsw <4 x i32> zeroinitializer, [[TMP0]] -; CHECK-NEXT: [[R:%.*]] = select <4 x i1> [[C]], <4 x i32> [[TMP0]], <4 x i32> [[S]] -; CHECK-NEXT: [[M:%.*]] = mul <4 x i32> [[R]], [[R]] +; CHECK-NEXT: [[M:%.*]] = mul <4 x i32> [[TMP0:%.*]], [[TMP0]] ; CHECK-NEXT: ret <4 x i32> [[M]] ; %c = icmp slt <4 x i32> %0, zeroinitializer