diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -4548,6 +4548,18 @@ } } + // For unsigned predicates / eq / ne: + // icmp pred (x << 1), x --> icmp getSignedPredicate(pred) x, 0 + // icmp pred x, (x << 1) --> icmp getSignedPredicate(pred) 0, x + if (!ICmpInst::isSigned(Pred)) { + if (match(Op0, m_Shl(m_Specific(Op1), m_One()))) + return new ICmpInst(ICmpInst::getSignedPredicate(Pred), Op1, + Constant::getNullValue(Op1->getType())); + else if (match(Op1, m_Shl(m_Specific(Op0), m_One()))) + return new ICmpInst(ICmpInst::getSignedPredicate(Pred), + Constant::getNullValue(Op0->getType()), Op0); + } + if (Value *V = foldMultiplicationOverflowCheck(I)) return replaceInstUsesWith(I, V); diff --git a/llvm/test/Transforms/InstCombine/icmp-shl-1-overflow.ll b/llvm/test/Transforms/InstCombine/icmp-shl-1-overflow.ll --- a/llvm/test/Transforms/InstCombine/icmp-shl-1-overflow.ll +++ b/llvm/test/Transforms/InstCombine/icmp-shl-1-overflow.ll @@ -6,8 +6,7 @@ define i1 @icmp_shl_ugt_1(i8 %x) { ; CHECK-LABEL: @icmp_shl_ugt_1( -; CHECK-NEXT: [[ADD:%.*]] = shl i8 [[X:%.*]], 1 -; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i8 [[ADD]], [[X]] +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], 0 ; CHECK-NEXT: ret i1 [[CMP]] ; %add = shl i8 %x, 1 @@ -18,8 +17,7 @@ define <2 x i1> @icmp_shl_ugt_2(<2 x i32> %_x) { ; CHECK-LABEL: @icmp_shl_ugt_2( ; CHECK-NEXT: [[X:%.*]] = add <2 x i32> [[_X:%.*]], -; CHECK-NEXT: [[ADD:%.*]] = shl <2 x i32> [[X]], -; CHECK-NEXT: [[CMP:%.*]] = icmp ugt <2 x i32> [[X]], [[ADD]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i32> [[X]], zeroinitializer ; CHECK-NEXT: ret <2 x i1> [[CMP]] ; %x = add <2 x i32> , %_x ; thwart complexity-based canonicalization @@ -30,8 +28,7 @@ define <3 x i1> @icmp_shl_uge_1(<3 x i7> %x) { ; CHECK-LABEL: @icmp_shl_uge_1( -; CHECK-NEXT: [[ADD:%.*]] = shl <3 x i7> [[X:%.*]], -; CHECK-NEXT: [[CMP:%.*]] = icmp uge <3 x i7> [[ADD]], [[X]] +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <3 x i7> [[X:%.*]], ; CHECK-NEXT: ret <3 x i1> [[CMP]] ; %add = shl <3 x i7> %x, @@ -42,8 +39,7 @@ define i1 @icmp_shl_uge_2(i5 %_x) { ; CHECK-LABEL: @icmp_shl_uge_2( ; CHECK-NEXT: [[X:%.*]] = add i5 [[_X:%.*]], 10 -; CHECK-NEXT: [[ADD:%.*]] = shl i5 [[X]], 1 -; CHECK-NEXT: [[CMP:%.*]] = icmp uge i5 [[X]], [[ADD]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i5 [[X]], 1 ; CHECK-NEXT: ret i1 [[CMP]] ; %x = add i5 42, %_x ; thwart complexity-based canonicalization @@ -56,7 +52,7 @@ ; CHECK-LABEL: @icmp_shl_ult_1( ; CHECK-NEXT: [[ADD:%.*]] = shl i16 [[X:%.*]], 1 ; CHECK-NEXT: call void @use16(i16 [[ADD]]) -; CHECK-NEXT: [[CMP:%.*]] = icmp ult i16 [[ADD]], [[X]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i16 [[X]], 0 ; CHECK-NEXT: ret i1 [[CMP]] ; %add = shl i16 %x, 1 @@ -70,7 +66,7 @@ ; CHECK-NEXT: [[X:%.*]] = add <4 x i4> [[_X:%.*]], ; CHECK-NEXT: [[ADD:%.*]] = shl <4 x i4> [[X]], ; CHECK-NEXT: call void @usev4(<4 x i4> [[ADD]]) -; CHECK-NEXT: [[CMP:%.*]] = icmp ult <4 x i4> [[X]], [[ADD]] +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt <4 x i4> [[X]], zeroinitializer ; CHECK-NEXT: ret <4 x i1> [[CMP]] ; %x = add <4 x i4> , %_x ; thwart complexity-based canonicalization @@ -82,8 +78,7 @@ define <2 x i1> @icmp_shl_ule_1(<2 x i8> %x) { ; CHECK-LABEL: @icmp_shl_ule_1( -; CHECK-NEXT: [[ADD:%.*]] = shl <2 x i8> [[X:%.*]], -; CHECK-NEXT: [[CMP:%.*]] = icmp ule <2 x i8> [[ADD]], [[X]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i8> [[X:%.*]], ; CHECK-NEXT: ret <2 x i1> [[CMP]] ; %add = shl <2 x i8> %x, @@ -94,8 +89,7 @@ define i1 @icmp_shl_ule_2(i8 %_x) { ; CHECK-LABEL: @icmp_shl_ule_2( ; CHECK-NEXT: [[X:%.*]] = add i8 [[_X:%.*]], 42 -; CHECK-NEXT: [[ADD:%.*]] = shl i8 [[X]], 1 -; CHECK-NEXT: [[CMP:%.*]] = icmp ule i8 [[X]], [[ADD]] +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[X]], -1 ; CHECK-NEXT: ret i1 [[CMP]] ; %x = add i8 42, %_x ; thwart complexity-based canonicalization @@ -106,8 +100,7 @@ define i1 @icmp_shl_eq_1(i8 %x) { ; CHECK-LABEL: @icmp_shl_eq_1( -; CHECK-NEXT: [[ADD:%.*]] = shl i8 [[X:%.*]], 1 -; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[ADD]], [[X]] +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 0 ; CHECK-NEXT: ret i1 [[CMP]] ; %add = shl i8 %x, 1 @@ -117,12 +110,11 @@ define <2 x i1> @icmp_shl_eq_2(<2 x i8> %_x) { ; CHECK-LABEL: @icmp_shl_eq_2( -; CHECK-NEXT: [[X:%.*]] = add <2 x i8> [[_X:%.*]], -; CHECK-NEXT: [[ADD:%.*]] = shl <2 x i8> [[X]], -; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i8> [[X]], [[ADD]] +; CHECK-NEXT: [[X:%.*]] = sdiv <2 x i8> , [[_X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i8> [[X]], zeroinitializer ; CHECK-NEXT: ret <2 x i1> [[CMP]] ; - %x = add <2 x i8> , %_x ; thwart complexity-based canonicalization + %x = sdiv <2 x i8> , %_x ; thwart complexity-based canonicalization %add = shl <2 x i8> %x, %cmp = icmp eq <2 x i8> %x, %add ret <2 x i1> %cmp @@ -130,8 +122,7 @@ define <2 x i1> @icmp_shl_ne_1(<2 x i8> %x) { ; CHECK-LABEL: @icmp_shl_ne_1( -; CHECK-NEXT: [[ADD:%.*]] = shl <2 x i8> [[X:%.*]], -; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i8> [[ADD]], [[X]] +; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i8> [[X:%.*]], zeroinitializer ; CHECK-NEXT: ret <2 x i1> [[CMP]] ; %add = shl <2 x i8> %x, @@ -141,12 +132,11 @@ define i1 @icmp_shl_ne_2(i8 %_x) { ; CHECK-LABEL: @icmp_shl_ne_2( -; CHECK-NEXT: [[X:%.*]] = add i8 [[_X:%.*]], 42 -; CHECK-NEXT: [[ADD:%.*]] = shl i8 [[X]], 1 -; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X]], [[ADD]] +; CHECK-NEXT: [[X:%.*]] = sdiv i8 42, [[_X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp ne i8 [[X]], 0 ; CHECK-NEXT: ret i1 [[CMP]] ; - %x = add i8 42, %_x ; thwart complexity-based canonicalization + %x = sdiv i8 42, %_x ; thwart complexity-based canonicalization %add = shl i8 %x, 1 %cmp = icmp ne i8 %x, %add ret i1 %cmp