diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp | 105 |
1 files changed, 62 insertions, 43 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index f4d8b79a5311..535a7736454c 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1660,8 +1660,9 @@ Instruction *InstCombinerImpl::visitFAdd(BinaryOperator &I) { Constant *MulC; if (match(&I, m_c_FAdd(m_FMul(m_Value(X), m_ImmConstant(MulC)), m_Deferred(X)))) { - MulC = ConstantExpr::getFAdd(MulC, ConstantFP::get(I.getType(), 1.0)); - return BinaryOperator::CreateFMulFMF(X, MulC, &I); + if (Constant *NewMulC = ConstantFoldBinaryOpOperands( + Instruction::FAdd, MulC, ConstantFP::get(I.getType(), 1.0), DL)) + return BinaryOperator::CreateFMulFMF(X, NewMulC, &I); } if (Value *V = FAddCombine(Builder).simplify(&I)) @@ -1750,6 +1751,52 @@ Value *InstCombinerImpl::OptimizePointerDifference(Value *LHS, Value *RHS, return Builder.CreateIntCast(Result, Ty, true); } +static Instruction *foldSubOfMinMax(BinaryOperator &I, + InstCombiner::BuilderTy &Builder) { + Value *Op0 = I.getOperand(0); + Value *Op1 = I.getOperand(1); + Type *Ty = I.getType(); + auto *MinMax = dyn_cast<MinMaxIntrinsic>(Op1); + if (!MinMax) + return nullptr; + + // sub(add(X,Y), s/umin(X,Y)) --> s/umax(X,Y) + // sub(add(X,Y), s/umax(X,Y)) --> s/umin(X,Y) + Value *X = MinMax->getLHS(); + Value *Y = MinMax->getRHS(); + if (match(Op0, m_c_Add(m_Specific(X), m_Specific(Y))) && + (Op0->hasOneUse() || Op1->hasOneUse())) { + Intrinsic::ID InvID = getInverseMinMaxIntrinsic(MinMax->getIntrinsicID()); + Function *F = Intrinsic::getDeclaration(I.getModule(), InvID, Ty); + return CallInst::Create(F, {X, Y}); + } + + // sub(add(X,Y),umin(Y,Z)) --> add(X,usub.sat(Y,Z)) + // sub(add(X,Z),umin(Y,Z)) --> add(X,usub.sat(Z,Y)) + Value *Z; + if (match(Op1, m_OneUse(m_UMin(m_Value(Y), m_Value(Z))))) { + if (match(Op0, m_OneUse(m_c_Add(m_Specific(Y), m_Value(X))))) { + Value *USub = Builder.CreateIntrinsic(Intrinsic::usub_sat, Ty, {Y, Z}); + return BinaryOperator::CreateAdd(X, USub); + } + if (match(Op0, m_OneUse(m_c_Add(m_Specific(Z), m_Value(X))))) { + Value *USub = Builder.CreateIntrinsic(Intrinsic::usub_sat, Ty, {Z, Y}); + return BinaryOperator::CreateAdd(X, USub); + } + } + + // sub Op0, smin((sub nsw Op0, Z), 0) --> smax Op0, Z + // sub Op0, smax((sub nsw Op0, Z), 0) --> smin Op0, Z + if (MinMax->isSigned() && match(Y, m_ZeroInt()) && + match(X, m_NSWSub(m_Specific(Op0), m_Value(Z)))) { + Intrinsic::ID InvID = getInverseMinMaxIntrinsic(MinMax->getIntrinsicID()); + Function *F = Intrinsic::getDeclaration(I.getModule(), InvID, Ty); + return CallInst::Create(F, {Op0, Z}); + } + + return nullptr; +} + Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) { if (Value *V = simplifySubInst(I.getOperand(0), I.getOperand(1), I.hasNoSignedWrap(), I.hasNoUnsignedWrap(), @@ -1919,14 +1966,12 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) { return BinaryOperator::CreateAdd(X, ConstantExpr::getSub(C, C2)); } + // If there's no chance any bit will need to borrow from an adjacent bit: + // sub C, X --> xor X, C const APInt *Op0C; - if (match(Op0, m_APInt(Op0C)) && Op0C->isMask()) { - // Turn this into a xor if LHS is 2^n-1 and the remaining bits are known - // zero. - KnownBits RHSKnown = computeKnownBits(Op1, 0, &I); - if ((*Op0C | RHSKnown.Zero).isAllOnes()) - return BinaryOperator::CreateXor(Op1, Op0); - } + if (match(Op0, m_APInt(Op0C)) && + (~computeKnownBits(Op1, 0, &I).Zero).isSubsetOf(*Op0C)) + return BinaryOperator::CreateXor(Op1, Op0); { Value *Y; @@ -2016,36 +2061,8 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) { } } - if (auto *II = dyn_cast<MinMaxIntrinsic>(Op1)) { - { - // sub(add(X,Y), s/umin(X,Y)) --> s/umax(X,Y) - // sub(add(X,Y), s/umax(X,Y)) --> s/umin(X,Y) - Value *X = II->getLHS(); - Value *Y = II->getRHS(); - if (match(Op0, m_c_Add(m_Specific(X), m_Specific(Y))) && - (Op0->hasOneUse() || Op1->hasOneUse())) { - Intrinsic::ID InvID = getInverseMinMaxIntrinsic(II->getIntrinsicID()); - Value *InvMaxMin = Builder.CreateBinaryIntrinsic(InvID, X, Y); - return replaceInstUsesWith(I, InvMaxMin); - } - } - - { - // sub(add(X,Y),umin(Y,Z)) --> add(X,usub.sat(Y,Z)) - // sub(add(X,Z),umin(Y,Z)) --> add(X,usub.sat(Z,Y)) - Value *X, *Y, *Z; - if (match(Op1, m_OneUse(m_UMin(m_Value(Y), m_Value(Z))))) { - if (match(Op0, m_OneUse(m_c_Add(m_Specific(Y), m_Value(X))))) - return BinaryOperator::CreateAdd( - X, Builder.CreateIntrinsic(Intrinsic::usub_sat, I.getType(), - {Y, Z})); - if (match(Op0, m_OneUse(m_c_Add(m_Specific(Z), m_Value(X))))) - return BinaryOperator::CreateAdd( - X, Builder.CreateIntrinsic(Intrinsic::usub_sat, I.getType(), - {Z, Y})); - } - } - } + if (Instruction *R = foldSubOfMinMax(I, Builder)) + return R; { // If we have a subtraction between some value and a select between @@ -2437,13 +2454,15 @@ Instruction *InstCombinerImpl::visitFSub(BinaryOperator &I) { // (X * C) - X --> X * (C - 1.0) if (match(Op0, m_FMul(m_Specific(Op1), m_Constant(C)))) { - Constant *CSubOne = ConstantExpr::getFSub(C, ConstantFP::get(Ty, 1.0)); - return BinaryOperator::CreateFMulFMF(Op1, CSubOne, &I); + if (Constant *CSubOne = ConstantFoldBinaryOpOperands( + Instruction::FSub, C, ConstantFP::get(Ty, 1.0), DL)) + return BinaryOperator::CreateFMulFMF(Op1, CSubOne, &I); } // X - (X * C) --> X * (1.0 - C) if (match(Op1, m_FMul(m_Specific(Op0), m_Constant(C)))) { - Constant *OneSubC = ConstantExpr::getFSub(ConstantFP::get(Ty, 1.0), C); - return BinaryOperator::CreateFMulFMF(Op0, OneSubC, &I); + if (Constant *OneSubC = ConstantFoldBinaryOpOperands( + Instruction::FSub, ConstantFP::get(Ty, 1.0), C, DL)) + return BinaryOperator::CreateFMulFMF(Op0, OneSubC, &I); } // Reassociate fsub/fadd sequences to create more fadd instructions and |