Index: llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp =================================================================== --- llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -1814,6 +1814,19 @@ return nullptr; } +Instruction *InstCombiner::foldIntrinsicWithOverflowCommon(IntrinsicInst *II) { + OverflowCheckFlavor OCF = + IntrinsicIDToOverflowCheckFlavor(II->getIntrinsicID()); + assert(OCF != OCF_INVALID && "unexpected!"); + + Value *OperationResult = nullptr; + Constant *OverflowResult = nullptr; + if (OptimizeOverflowCheck(OCF, II->getArgOperand(0), II->getArgOperand(1), + *II, OperationResult, OverflowResult)) + return CreateOverflowTuple(II, OperationResult, OverflowResult); + return nullptr; +} + /// CallInst simplification. This mostly only handles folding of intrinsic /// instructions. For normal calls, it allows visitCallBase to do the heavy /// lifting. @@ -2016,8 +2029,31 @@ return &CI; break; } + case Intrinsic::sadd_with_overflow: { + if (Instruction *I = canonicalizeConstantArg0ToArg1(CI)) + return I; + if (Instruction *I = foldIntrinsicWithOverflowCommon(II)) + return I; + + // `add nsw` + `sadd.with.overflow` with constants should fold. + Value *X; + const APInt *RHS, *LHS; + Value *Arg0 = II->getArgOperand(0); + Value *Arg1 = II->getArgOperand(1); + if (match(Arg0, m_NSWAdd(m_Value(X), m_APInt(LHS))) && + match(Arg1, m_APInt(RHS))) { + bool Overflow; + APInt NewC = RHS->sadd_ov(*LHS, Overflow); + if (!Overflow) + return replaceInstUsesWith( + *II, Builder.CreateBinaryIntrinsic( + Intrinsic::sadd_with_overflow, X, + ConstantInt::get(Arg1->getType(), NewC))); + } + + break; + } case Intrinsic::uadd_with_overflow: - case Intrinsic::sadd_with_overflow: case Intrinsic::umul_with_overflow: case Intrinsic::smul_with_overflow: if (Instruction *I = canonicalizeConstantArg0ToArg1(CI)) @@ -2026,15 +2062,8 @@ case Intrinsic::usub_with_overflow: case Intrinsic::ssub_with_overflow: { - OverflowCheckFlavor OCF = - IntrinsicIDToOverflowCheckFlavor(II->getIntrinsicID()); - assert(OCF != OCF_INVALID && "unexpected!"); - - Value *OperationResult = nullptr; - Constant *OverflowResult = nullptr; - if (OptimizeOverflowCheck(OCF, II->getArgOperand(0), II->getArgOperand(1), - *II, OperationResult, OverflowResult)) - return CreateOverflowTuple(II, OperationResult, OverflowResult); + if (Instruction *I = foldIntrinsicWithOverflowCommon(II)) + return I; break; } Index: llvm/lib/Transforms/InstCombine/InstCombineInternal.h =================================================================== --- llvm/lib/Transforms/InstCombine/InstCombineInternal.h +++ llvm/lib/Transforms/InstCombine/InstCombineInternal.h @@ -592,6 +592,8 @@ Value *matchSelectFromAndOr(Value *A, Value *B, Value *C, Value *D); Value *getSelectCondition(Value *A, Value *B); + Instruction *foldIntrinsicWithOverflowCommon(IntrinsicInst *II); + public: /// Inserts an instruction \p New before instruction \p Old /// Index: llvm/test/Transforms/InstCombine/sadd-with-overflow.ll =================================================================== --- llvm/test/Transforms/InstCombine/sadd-with-overflow.ll +++ llvm/test/Transforms/InstCombine/sadd-with-overflow.ll @@ -9,9 +9,8 @@ define { i32, i1 } @simple_fold(i32) { ; CHECK-LABEL: @simple_fold( -; CHECK-NEXT: [[TMP2:%.*]] = add nsw i32 [[TMP0:%.*]], 7 -; CHECK-NEXT: [[TMP3:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[TMP2]], i32 13) -; CHECK-NEXT: ret { i32, i1 } [[TMP3]] +; CHECK-NEXT: [[TMP2:%.*]] = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[TMP0:%.*]], i32 20) +; CHECK-NEXT: ret { i32, i1 } [[TMP2]] ; %2 = add nsw i32 %0, 7 %3 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %2, i32 13) @@ -20,9 +19,8 @@ define { i32, i1 } @fold_mixed_signs(i32) { ; CHECK-LABEL: @fold_mixed_signs( -; CHECK-NEXT: [[TMP2:%.*]] = add nsw i32 [[TMP0:%.*]], 13 -; CHECK-NEXT: [[TMP3:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[TMP2]], i32 -7) -; CHECK-NEXT: ret { i32, i1 } [[TMP3]] +; CHECK-NEXT: [[TMP2:%.*]] = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[TMP0:%.*]], i32 6) +; CHECK-NEXT: ret { i32, i1 } [[TMP2]] ; %2 = add nsw i32 %0, 13 %3 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %2, i32 -7) @@ -42,9 +40,8 @@ define { <2 x i32>, <2 x i1> } @fold_simple_splat_constant(<2 x i32>) { ; CHECK-LABEL: @fold_simple_splat_constant( -; CHECK-NEXT: [[TMP2:%.*]] = add nsw <2 x i32> [[TMP0:%.*]], -; CHECK-NEXT: [[TMP3:%.*]] = tail call { <2 x i32>, <2 x i1> } @llvm.sadd.with.overflow.v2i32(<2 x i32> [[TMP2]], <2 x i32> ) -; CHECK-NEXT: ret { <2 x i32>, <2 x i1> } [[TMP3]] +; CHECK-NEXT: [[TMP2:%.*]] = call { <2 x i32>, <2 x i1> } @llvm.sadd.with.overflow.v2i32(<2 x i32> [[TMP0:%.*]], <2 x i32> ) +; CHECK-NEXT: ret { <2 x i32>, <2 x i1> } [[TMP2]] ; %2 = add nsw <2 x i32> %0, %3 = tail call { <2 x i32>, <2 x i1> } @llvm.sadd.with.overflow.v2i32(<2 x i32> %2, <2 x i32> ) @@ -75,9 +72,8 @@ define { i32, i1 } @fold_nuwnsw(i32) { ; CHECK-LABEL: @fold_nuwnsw( -; CHECK-NEXT: [[TMP2:%.*]] = add nuw nsw i32 [[TMP0:%.*]], 12 -; CHECK-NEXT: [[TMP3:%.*]] = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[TMP2]], i32 30) -; CHECK-NEXT: ret { i32, i1 } [[TMP3]] +; CHECK-NEXT: [[TMP2:%.*]] = call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 [[TMP0:%.*]], i32 42) +; CHECK-NEXT: ret { i32, i1 } [[TMP2]] ; %2 = add nuw nsw i32 %0, 12 %3 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %2, i32 30)