From ef0e69bc056e517f25de212752b95540e3700e99 Mon Sep 17 00:00:00 2001 From: AZero13 Date: Mon, 11 Aug 2025 12:17:21 -0400 Subject: [PATCH 1/2] Pre-commit tests (NFC) --- .../InstCombine/saturating-add-sub.ll | 302 ++++++++++++++++++ 1 file changed, 302 insertions(+) diff --git a/llvm/test/Transforms/InstCombine/saturating-add-sub.ll b/llvm/test/Transforms/InstCombine/saturating-add-sub.ll index cfd679c0cc592..84cd69f8ebbe1 100644 --- a/llvm/test/Transforms/InstCombine/saturating-add-sub.ll +++ b/llvm/test/Transforms/InstCombine/saturating-add-sub.ll @@ -2351,3 +2351,305 @@ define i8 @fold_add_umax_to_usub_multiuse(i8 %a) { } declare void @usei8(i8) + +define i8 @sadd_sat_uge_int_max(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_uge_int_max( +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 127 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y:%.*]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sge i8 %x, 127 + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_ugt_int_max(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_ugt_int_max( +; CHECK-NEXT: [[R:%.*]] = add i8 [[X:%.*]], [[Y:%.*]] +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sgt i8 %x, 127 + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_eq_int_max(i8 %x) { +; CHECK-LABEL: @sadd_sat_eq_int_max( +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 127 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], 1 +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp eq i8 %x, 127 + %add = add i8 %x, 1 + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_constant(i8 %x) { +; CHECK-LABEL: @sadd_sat_constant( +; CHECK-NEXT: [[TMP1:%.*]] = call i8 @llvm.smin.i8(i8 [[X:%.*]], i8 117) +; CHECK-NEXT: [[R:%.*]] = add nsw i8 [[TMP1]], 10 +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sge i8 %x, 118 + %add = add i8 %x, 10 + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_negative_no_fold(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_negative_no_fold( +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 127 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y:%.*]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sge i8 %x, 127 + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_wrong_predicate(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_wrong_predicate( +; CHECK-NEXT: [[CMP_NOT:%.*]] = icmp eq i8 [[X:%.*]], 127 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[Y:%.*]], 127 +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP_NOT]], i8 [[ADD]], i8 127 +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp slt i8 %x, 127 + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_wrong_constant(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_wrong_constant( +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], 125 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y:%.*]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sge i8 %x, 126 + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define <2 x i8> @sadd_sat_vector(<2 x i8> %x, <2 x i8> %y) { +; CHECK-LABEL: @sadd_sat_vector( +; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i8> [[X:%.*]], splat (i8 127) +; CHECK-NEXT: [[ADD:%.*]] = add <2 x i8> [[X]], [[Y:%.*]] +; CHECK-NEXT: [[R:%.*]] = select <2 x i1> [[CMP]], <2 x i8> splat (i8 127), <2 x i8> [[ADD]] +; CHECK-NEXT: ret <2 x i8> [[R]] +; + %cmp = icmp sge <2 x i8> %x, + %add = add <2 x i8> %x, %y + %r = select <2 x i1> %cmp, <2 x i8> , <2 x i8> %add + ret <2 x i8> %r +} + +define <2 x i8> @sadd_sat_vector_constant(<2 x i8> %x) { +; CHECK-LABEL: @sadd_sat_vector_constant( +; CHECK-NEXT: [[TMP1:%.*]] = call <2 x i8> @llvm.smin.v2i8(<2 x i8> [[X:%.*]], <2 x i8> ) +; CHECK-NEXT: [[R:%.*]] = add <2 x i8> [[TMP1]], +; CHECK-NEXT: ret <2 x i8> [[R]] +; + %cmp = icmp sge <2 x i8> %x, + %add = add <2 x i8> %x, + %r = select <2 x i1> %cmp, <2 x i8> , <2 x i8> %add + ret <2 x i8> %r +} + +define i8 @sadd_sat_int_max_minus_x(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x( +; CHECK-NEXT: [[SUB:%.*]] = sub i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[SUB]], [[Y:%.*]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub i8 127, %x + %cmp = icmp slt i8 %sub, %y + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_commuted(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_commuted( +; CHECK-NEXT: [[SUB:%.*]] = sub i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[Y:%.*]], [[SUB]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub i8 127, %x + %cmp = icmp sgt i8 %y, %sub + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_nonstrict(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_nonstrict( +; CHECK-NEXT: [[SUB:%.*]] = sub i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP_NOT:%.*]] = icmp sgt i8 [[SUB]], [[Y:%.*]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP_NOT]], i8 [[ADD]], i8 127 +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub i8 127, %x + %cmp = icmp sle i8 %sub, %y + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_commuted_nonstrict(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_commuted_nonstrict( +; CHECK-NEXT: [[SUB:%.*]] = sub i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP_NOT:%.*]] = icmp slt i8 [[Y:%.*]], [[SUB]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP_NOT]], i8 [[ADD]], i8 127 +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub i8 127, %x + %cmp = icmp sge i8 %y, %sub + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_wrong_constant(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_wrong_constant( +; CHECK-NEXT: [[SUB:%.*]] = sub i8 126, [[X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[SUB]], [[Y:%.*]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub i8 126, %x + %cmp = icmp slt i8 %sub, %y + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_wrong_predicate(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_wrong_predicate( +; CHECK-NEXT: [[SUB:%.*]] = sub i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[SUB]], [[Y:%.*]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub i8 127, %x + %cmp = icmp sgt i8 %sub, %y + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define <2 x i8> @sadd_sat_int_max_minus_x_vector(<2 x i8> %x, <2 x i8> %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_vector( +; CHECK-NEXT: [[SUB:%.*]] = sub <2 x i8> splat (i8 127), [[X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt <2 x i8> [[SUB]], [[Y:%.*]] +; CHECK-NEXT: [[ADD:%.*]] = add <2 x i8> [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select <2 x i1> [[CMP]], <2 x i8> splat (i8 127), <2 x i8> [[ADD]] +; CHECK-NEXT: ret <2 x i8> [[R]] +; + %sub = sub <2 x i8> , %x + %cmp = icmp slt <2 x i8> %sub, %y + %add = add <2 x i8> %x, %y + %r = select <2 x i1> %cmp, <2 x i8> , <2 x i8> %add + ret <2 x i8> %r +} + +define i8 @sadd_sat_commuted_select(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_commuted_select( +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 127 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[Y:%.*]], 127 +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 [[ADD]], i8 127 +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sge i8 %x, 127 + %add = add i8 %x, %y + %r = select i1 %cmp, i8 %add, i8 127 + ret i8 %r +} + +define i8 @sadd_sat_commuted_add(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_commuted_add( +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 127 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[Y:%.*]], [[X]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sge i8 %x, 127 + %add = add i8 %y, %x + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_commuted_both(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_commuted_both( +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 127 +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[Y:%.*]], 127 +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 [[ADD]], i8 127 +; CHECK-NEXT: ret i8 [[R]] +; + %cmp = icmp sge i8 %x, 127 + %add = add i8 %y, %x + %r = select i1 %cmp, i8 %add, i8 127 + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_nsw_slt(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_nsw_slt( +; CHECK-NEXT: [[SUB:%.*]] = sub nsw i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[SUB]], [[Y:%.*]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub nsw i8 127, %x + %cmp = icmp slt i8 %sub, %y + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_nsw_sge_commuted(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_nsw_sge_commuted( +; CHECK-NEXT: [[SUB:%.*]] = sub nsw i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP_NOT:%.*]] = icmp slt i8 [[Y:%.*]], [[SUB]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP_NOT]], i8 [[ADD]], i8 127 +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub nsw i8 127, %x + %cmp = icmp sge i8 %y, %sub + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} + +define i8 @sadd_sat_int_max_minus_x_no_nsw_neg(i8 %x, i8 %y) { +; CHECK-LABEL: @sadd_sat_int_max_minus_x_no_nsw_neg( +; CHECK-NEXT: [[SUB:%.*]] = sub i8 127, [[X:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[SUB]], [[Y:%.*]] +; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: ret i8 [[R]] +; + %sub = sub i8 127, %x + %cmp = icmp slt i8 %sub, %y + %add = add i8 %x, %y + %r = select i1 %cmp, i8 127, i8 %add + ret i8 %r +} From 339db93ae4ae154d0a36bd4e1fdbc01c3e1c9e69 Mon Sep 17 00:00:00 2001 From: AZero13 Date: Mon, 11 Aug 2025 12:31:50 -0400 Subject: [PATCH 2/2] [InstCombine] Canonicalize signed saturated additions with positive numbers only https://alive2.llvm.org/ce/z/YGT5SN This is tricky because with positive numbers, we only go up, so we can in fact always hit the signed_max boundary. This is important because the intrinsic we use has the behavior of going the OTHER way, aka clamp to INT_MIN if it goes in that direction. And the range checking we do only works for positive numbers. Because of this issue, we can only do this for constants as well. --- .../InstCombine/InstCombineSelect.cpp | 111 +++++++++++++++++- .../InstCombine/canonicalize-const-to-bop.ll | 3 +- .../InstCombine/saturating-add-sub.ll | 44 +++++-- 3 files changed, 137 insertions(+), 21 deletions(-) diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index eb4332fbc0959..c317e738296cf 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1012,10 +1012,9 @@ static Value *canonicalizeSaturatedSubtract(const ICmpInst *ICI, return Result; } -static Value *canonicalizeSaturatedAdd(ICmpInst *Cmp, Value *TVal, Value *FVal, - InstCombiner::BuilderTy &Builder) { - if (!Cmp->hasOneUse()) - return nullptr; +static Value * +canonicalizeSaturatedAddUnsigned(ICmpInst *Cmp, Value *TVal, Value *FVal, + InstCombiner::BuilderTy &Builder) { // Match unsigned saturated add with constant. Value *Cmp0 = Cmp->getOperand(0); @@ -1037,8 +1036,7 @@ static Value *canonicalizeSaturatedAdd(ICmpInst *Cmp, Value *TVal, Value *FVal, // uge -1 is canonicalized to eq -1 and requires special handling // (a == -1) ? -1 : a + 1 -> uadd.sat(a, 1) if (Pred == ICmpInst::ICMP_EQ) { - if (match(FVal, m_Add(m_Specific(Cmp0), m_One())) && - match(Cmp1, m_AllOnes())) { + if (match(FVal, m_Add(m_Specific(Cmp0), m_One())) && Cmp1 == TVal) { return Builder.CreateBinaryIntrinsic( Intrinsic::uadd_sat, Cmp0, ConstantInt::get(Cmp0->getType(), 1)); } @@ -1115,6 +1113,107 @@ static Value *canonicalizeSaturatedAdd(ICmpInst *Cmp, Value *TVal, Value *FVal, return nullptr; } +static Value *canonicalizeSaturatedAddSigned(ICmpInst *Cmp, Value *TVal, + Value *FVal, + InstCombiner::BuilderTy &Builder) { + // Match saturated add with constant. + Value *Cmp0 = Cmp->getOperand(0); + Value *Cmp1 = Cmp->getOperand(1); + ICmpInst::Predicate Pred = Cmp->getPredicate(); + Value *X, *Y; + const APInt *C; + + // Canonicalize INT_MAX to true value of the select. + if (match(FVal, m_MaxSignedValue())) { + std::swap(TVal, FVal); + Pred = CmpInst::getInversePredicate(Pred); + } + if (!match(TVal, m_MaxSignedValue())) + return nullptr; + + // sge maximum signed value is canonicalized to eq minimum signed value and + // requires special handling (a == INT_MAX) ? INT_MAX : a + 1 -> sadd.sat(a, + // 1) + if (Pred == ICmpInst::ICMP_EQ) { + if (match(FVal, m_Add(m_Specific(Cmp0), m_One())) && Cmp1 == TVal) { + return Builder.CreateBinaryIntrinsic( + Intrinsic::sadd_sat, Cmp0, ConstantInt::get(Cmp0->getType(), 1)); + } + return nullptr; + } + + if ((Pred == ICmpInst::ICMP_SGE || Pred == ICmpInst::ICMP_SGT) && + match(FVal, m_Add(m_Specific(Cmp0), m_APIntAllowPoison(C))) && + match(Cmp1, m_SpecificIntAllowPoison( + APInt::getSignedMaxValue( + Cmp1->getType()->getScalarSizeInBits()) - + *C)) && + !C->isNegative()) { + // (X > INT_MAX - C) ? INT_MAX : (X + C) --> sadd.sat(X, C) + // (X >= INT_MAX - C) ? INT_MAX : (X + C) --> sadd.sat(X, C) + return Builder.CreateBinaryIntrinsic(Intrinsic::sadd_sat, Cmp0, + ConstantInt::get(Cmp0->getType(), *C)); + } + + if (Pred == ICmpInst::ICMP_SGT && + match(FVal, m_Add(m_Specific(Cmp0), m_APIntAllowPoison(C))) && + match(Cmp1, m_SpecificIntAllowPoison( + APInt::getSignedMaxValue( + Cmp1->getType()->getScalarSizeInBits()) - + *C - 1)) && + !C->isNegative()) { + // (X > INT_MAX - C - 1) ? INT_MAX : (X + C) --> sadd.sat(X, C) + return Builder.CreateBinaryIntrinsic(Intrinsic::sadd_sat, Cmp0, + ConstantInt::get(Cmp0->getType(), *C)); + } + + // This does not work with 0, or negative numbers as + // (X >= INT_MIN + 0 + 1) ? INT_MAX : (X + 0) is not a saturated add. + if (Pred == ICmpInst::ICMP_SGE && + match(FVal, m_Add(m_Specific(Cmp0), m_APIntAllowPoison(C))) && + match(Cmp1, m_SpecificIntAllowPoison( + APInt::getSignedMinValue( + Cmp1->getType()->getScalarSizeInBits()) - + *C + 1)) && + C->isStrictlyPositive()) { + // (X >= INT_MAX - C + 1) ? INT_MAX : (X + C) --> sadd.sat(X, C) + return Builder.CreateBinaryIntrinsic(Intrinsic::sadd_sat, Cmp0, + ConstantInt::get(Cmp0->getType(), *C)); + } + + // Canonicalize predicate to less-than or less-or-equal-than. + if (Pred == ICmpInst::ICMP_SGT || Pred == ICmpInst::ICMP_SGE) { + std::swap(Cmp0, Cmp1); + Pred = CmpInst::getSwappedPredicate(Pred); + } + + if (Pred != ICmpInst::ICMP_SLT && Pred != ICmpInst::ICMP_SLE) + return nullptr; + + if (match(Cmp0, m_NSWSub(m_MaxSignedValue(), m_Value(X))) && + match(FVal, m_c_Add(m_Specific(X), m_Value(Y))) && Y == Cmp1) { + // (INT_MAX - X s< Y) ? INT_MAX : (X + Y) --> sadd.sat(X, Y) + // (INT_MAX - X s< Y) ? INT_MAX : (Y + X) --> sadd.sat(X, Y) + return Builder.CreateBinaryIntrinsic(Intrinsic::sadd_sat, X, Y); + } + + return nullptr; +} + +static Value *canonicalizeSaturatedAdd(ICmpInst *Cmp, Value *TVal, Value *FVal, + InstCombiner::BuilderTy &Builder) { + if (!Cmp->hasOneUse()) + return nullptr; + + if (Value *V = canonicalizeSaturatedAddUnsigned(Cmp, TVal, FVal, Builder)) + return V; + + if (Value *V = canonicalizeSaturatedAddSigned(Cmp, TVal, FVal, Builder)) + return V; + + return nullptr; +} + /// Try to match patterns with select and subtract as absolute difference. static Value *foldAbsDiff(ICmpInst *Cmp, Value *TVal, Value *FVal, InstCombiner::BuilderTy &Builder) { diff --git a/llvm/test/Transforms/InstCombine/canonicalize-const-to-bop.ll b/llvm/test/Transforms/InstCombine/canonicalize-const-to-bop.ll index b3093a92624ae..f0e40f4ede161 100644 --- a/llvm/test/Transforms/InstCombine/canonicalize-const-to-bop.ll +++ b/llvm/test/Transforms/InstCombine/canonicalize-const-to-bop.ll @@ -123,8 +123,7 @@ define i8 @udiv_slt_exact(i8 %x) { define i8 @canonicalize_icmp_operands(i8 %x) { ; CHECK-LABEL: define i8 @canonicalize_icmp_operands( ; CHECK-SAME: i8 [[X:%.*]]) { -; CHECK-NEXT: [[TMP1:%.*]] = call i8 @llvm.smin.i8(i8 [[X]], i8 119) -; CHECK-NEXT: [[S:%.*]] = add nsw i8 [[TMP1]], 8 +; CHECK-NEXT: [[S:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[X]], i8 8) ; CHECK-NEXT: ret i8 [[S]] ; %add = add nsw i8 %x, 8 diff --git a/llvm/test/Transforms/InstCombine/saturating-add-sub.ll b/llvm/test/Transforms/InstCombine/saturating-add-sub.ll index 84cd69f8ebbe1..c0ad5818e448a 100644 --- a/llvm/test/Transforms/InstCombine/saturating-add-sub.ll +++ b/llvm/test/Transforms/InstCombine/saturating-add-sub.ll @@ -2378,9 +2378,7 @@ define i8 @sadd_sat_ugt_int_max(i8 %x, i8 %y) { define i8 @sadd_sat_eq_int_max(i8 %x) { ; CHECK-LABEL: @sadd_sat_eq_int_max( -; CHECK-NEXT: [[CMP:%.*]] = icmp eq i8 [[X:%.*]], 127 -; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], 1 -; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[X:%.*]], i8 1) ; CHECK-NEXT: ret i8 [[R]] ; %cmp = icmp eq i8 %x, 127 @@ -2391,8 +2389,7 @@ define i8 @sadd_sat_eq_int_max(i8 %x) { define i8 @sadd_sat_constant(i8 %x) { ; CHECK-LABEL: @sadd_sat_constant( -; CHECK-NEXT: [[TMP1:%.*]] = call i8 @llvm.smin.i8(i8 [[X:%.*]], i8 117) -; CHECK-NEXT: [[R:%.*]] = add nsw i8 [[TMP1]], 10 +; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[X:%.*]], i8 10) ; CHECK-NEXT: ret i8 [[R]] ; %cmp = icmp sge i8 %x, 118 @@ -2611,10 +2608,7 @@ define i8 @sadd_sat_commuted_both(i8 %x, i8 %y) { define i8 @sadd_sat_int_max_minus_x_nsw_slt(i8 %x, i8 %y) { ; CHECK-LABEL: @sadd_sat_int_max_minus_x_nsw_slt( -; CHECK-NEXT: [[SUB:%.*]] = sub nsw i8 127, [[X:%.*]] -; CHECK-NEXT: [[CMP:%.*]] = icmp slt i8 [[SUB]], [[Y:%.*]] -; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP]], i8 127, i8 [[ADD]] +; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]]) ; CHECK-NEXT: ret i8 [[R]] ; %sub = sub nsw i8 127, %x @@ -2626,10 +2620,7 @@ define i8 @sadd_sat_int_max_minus_x_nsw_slt(i8 %x, i8 %y) { define i8 @sadd_sat_int_max_minus_x_nsw_sge_commuted(i8 %x, i8 %y) { ; CHECK-LABEL: @sadd_sat_int_max_minus_x_nsw_sge_commuted( -; CHECK-NEXT: [[SUB:%.*]] = sub nsw i8 127, [[X:%.*]] -; CHECK-NEXT: [[CMP_NOT:%.*]] = icmp slt i8 [[Y:%.*]], [[SUB]] -; CHECK-NEXT: [[ADD:%.*]] = add i8 [[X]], [[Y]] -; CHECK-NEXT: [[R:%.*]] = select i1 [[CMP_NOT]], i8 [[ADD]], i8 127 +; CHECK-NEXT: [[R:%.*]] = call i8 @llvm.sadd.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]]) ; CHECK-NEXT: ret i8 [[R]] ; %sub = sub nsw i8 127, %x @@ -2653,3 +2644,30 @@ define i8 @sadd_sat_int_max_minus_x_no_nsw_neg(i8 %x, i8 %y) { %r = select i1 %cmp, i8 127, i8 %add ret i8 %r } + +define i8 @neg_no_nsw(i8 %x, i8 %y) { +; CHECK-LABEL: @neg_no_nsw( +; CHECK-NEXT: [[ADD:%.*]] = sub i8 127, [[Y:%.*]] +; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i8 [[X:%.*]], [[ADD]] +; CHECK-NEXT: [[D:%.*]] = add i8 [[X]], [[Y]] +; CHECK-NEXT: [[S:%.*]] = select i1 [[CMP]], i8 127, i8 [[D]] +; CHECK-NEXT: ret i8 [[S]] +; + %add = sub i8 127, %y + %cmp = icmp sgt i8 %x, %add + %d = add i8 %x, %y + %s = select i1 %cmp, i8 127, i8 %d + ret i8 %s +} + +define i8 @neg_neg_constant(i8 %x, i8 %y) { +; CHECK-LABEL: @neg_neg_constant( +; CHECK-NEXT: [[TMP1:%.*]] = call i8 @llvm.smin.i8(i8 [[X:%.*]], i8 -1) +; CHECK-NEXT: [[S:%.*]] = and i8 [[TMP1]], 127 +; CHECK-NEXT: ret i8 [[S]] +; + %cmp = icmp sgt i8 %x, -2 + %d = add i8 %x, -128 + %s = select i1 %cmp, i8 127, i8 %d + ret i8 %s +}