[llvm] r215647 - [Reassociation] Add support for reassociation with unsafe algebra.
Mehdi Amini
joker.eph at gmail.com
Wed Nov 5 23:09:38 PST 2014
Hi Chad,
This commit does not only bring reassociation but also factorization,
which I am not sure is allowed for floating point even in fast-math.
The attached patch disables floating point refactorization while keeping
reassociation.
Moreover I have a crash currently when mixing fast and regular
operation, see test/Transforms/Reassociate/mixed-fast-nonfast-fp.ll in
the patch.
Best,
Mehdi
On 8/14/14, 8:23 AM, Chad Rosier wrote:
> Author: mcrosier
> Date: Thu Aug 14 10:23:01 2014
> New Revision: 215647
>
> URL: http://llvm.org/viewvc/llvm-project?rev=215647&view=rev
> Log:
> [Reassociation] Add support for reassociation with unsafe algebra.
>
> Vector instructions are (still) not supported for either integer or floating
> point. Hopefully, that work will be landed shortly.
>
> Added:
> llvm/trunk/test/Transforms/Reassociate/fast-AgressiveSubMove.ll
> llvm/trunk/test/Transforms/Reassociate/fast-ArrayOutOfBounds.ll
> llvm/trunk/test/Transforms/Reassociate/fast-MissedTree.ll
> llvm/trunk/test/Transforms/Reassociate/fast-ReassociateVector.ll
> llvm/trunk/test/Transforms/Reassociate/fast-SubReassociate.ll
> llvm/trunk/test/Transforms/Reassociate/fast-basictest.ll
> llvm/trunk/test/Transforms/Reassociate/fast-fp-commute.ll
> llvm/trunk/test/Transforms/Reassociate/fast-mightymul.ll
> llvm/trunk/test/Transforms/Reassociate/fast-multistep.ll
> Modified:
> llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp
>
> Modified: llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp?rev=215647&r1=215646&r2=215647&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp (original)
> +++ llvm/trunk/lib/Transforms/Scalar/Reassociate.cpp Thu Aug 14 10:23:01 2014
> @@ -240,6 +240,15 @@ static BinaryOperator *isReassociableOp(
> return nullptr;
> }
>
> +static BinaryOperator *isReassociableOp(Value *V, unsigned Opcode1,
> + unsigned Opcode2) {
> + if (V->hasOneUse() && isa<Instruction>(V) &&
> + (cast<Instruction>(V)->getOpcode() == Opcode1 ||
> + cast<Instruction>(V)->getOpcode() == Opcode2))
> + return cast<BinaryOperator>(V);
> + return nullptr;
> +}
> +
> static bool isUnmovableInstruction(Instruction *I) {
> switch (I->getOpcode()) {
> case Instruction::PHI:
> @@ -304,8 +313,10 @@ unsigned Reassociate::getRank(Value *V)
>
> // If this is a not or neg instruction, do not count it for rank. This
> // assures us that X and ~X will have the same rank.
> - if (!I->getType()->isIntegerTy() ||
> - (!BinaryOperator::isNot(I) && !BinaryOperator::isNeg(I)))
> + Type *Ty = V->getType();
> + if ((!Ty->isIntegerTy() && !Ty->isFloatingPointTy()) ||
> + (!BinaryOperator::isNot(I) && !BinaryOperator::isNeg(I) &&
> + !BinaryOperator::isFNeg(I)))
> ++Rank;
>
> //DEBUG(dbgs() << "Calculated Rank[" << V->getName() << "] = "
> @@ -314,14 +325,50 @@ unsigned Reassociate::getRank(Value *V)
> return ValueRankMap[I] = Rank;
> }
>
> +static BinaryOperator *CreateAdd(Value *S1, Value *S2, const Twine &Name,
> + Instruction *InsertBefore, Value *FlagsOp) {
> + if (S1->getType()->isIntegerTy())
> + return BinaryOperator::CreateAdd(S1, S2, Name, InsertBefore);
> + else {
> + BinaryOperator *Res =
> + BinaryOperator::CreateFAdd(S1, S2, Name, InsertBefore);
> + Res->setFastMathFlags(cast<FPMathOperator>(FlagsOp)->getFastMathFlags());
> + return Res;
> + }
> +}
> +
> +static BinaryOperator *CreateMul(Value *S1, Value *S2, const Twine &Name,
> + Instruction *InsertBefore, Value *FlagsOp) {
> + if (S1->getType()->isIntegerTy())
> + return BinaryOperator::CreateMul(S1, S2, Name, InsertBefore);
> + else {
> + BinaryOperator *Res =
> + BinaryOperator::CreateFMul(S1, S2, Name, InsertBefore);
> + Res->setFastMathFlags(cast<FPMathOperator>(FlagsOp)->getFastMathFlags());
> + return Res;
> + }
> +}
> +
> +static BinaryOperator *CreateNeg(Value *S1, const Twine &Name,
> + Instruction *InsertBefore, Value *FlagsOp) {
> + if (S1->getType()->isIntegerTy())
> + return BinaryOperator::CreateNeg(S1, Name, InsertBefore);
> + else {
> + BinaryOperator *Res = BinaryOperator::CreateFNeg(S1, Name, InsertBefore);
> + Res->setFastMathFlags(cast<FPMathOperator>(FlagsOp)->getFastMathFlags());
> + return Res;
> + }
> +}
> +
> /// LowerNegateToMultiply - Replace 0-X with X*-1.
> ///
> static BinaryOperator *LowerNegateToMultiply(Instruction *Neg) {
> - Constant *Cst = Constant::getAllOnesValue(Neg->getType());
> + Type *Ty = Neg->getType();
> + Constant *NegOne = Ty->isIntegerTy() ? ConstantInt::getAllOnesValue(Ty)
> + : ConstantFP::get(Ty, -1.0);
>
> - BinaryOperator *Res =
> - BinaryOperator::CreateMul(Neg->getOperand(1), Cst, "",Neg);
> - Neg->setOperand(1, Constant::getNullValue(Neg->getType())); // Drop use of op.
> + BinaryOperator *Res = CreateMul(Neg->getOperand(1), NegOne, "", Neg, Neg);
> + Neg->setOperand(1, Constant::getNullValue(Ty)); // Drop use of op.
> Res->takeName(Neg);
> Neg->replaceAllUsesWith(Res);
> Res->setDebugLoc(Neg->getDebugLoc());
> @@ -377,13 +424,14 @@ static void IncorporateWeight(APInt &LHS
> LHS = 0; // 1 + 1 === 0 modulo 2.
> return;
> }
> - if (Opcode == Instruction::Add) {
> + if (Opcode == Instruction::Add || Opcode == Instruction::FAdd) {
> // TODO: Reduce the weight by exploiting nsw/nuw?
> LHS += RHS;
> return;
> }
>
> - assert(Opcode == Instruction::Mul && "Unknown associative operation!");
> + assert((Opcode == Instruction::Mul || Opcode == Instruction::FMul) &&
> + "Unknown associative operation!");
> unsigned Bitwidth = LHS.getBitWidth();
> // If CM is the Carmichael number then a weight W satisfying W >= CM+Bitwidth
> // can be replaced with W-CM. That's because x^W=x^(W-CM) for every Bitwidth
> @@ -499,8 +547,7 @@ static bool LinearizeExprTree(BinaryOper
> DEBUG(dbgs() << "LINEARIZE: " << *I << '\n');
> unsigned Bitwidth = I->getType()->getScalarType()->getPrimitiveSizeInBits();
> unsigned Opcode = I->getOpcode();
> - assert(Instruction::isAssociative(Opcode) &&
> - Instruction::isCommutative(Opcode) &&
> + assert(I->isAssociative() && I->isCommutative() &&
> "Expected an associative and commutative operation!");
>
> // Visit all operands of the expression, keeping track of their weight (the
> @@ -619,15 +666,16 @@ static bool LinearizeExprTree(BinaryOper
>
> // If this is a multiply expression, turn any internal negations into
> // multiplies by -1 so they can be reassociated.
> - BinaryOperator *BO = dyn_cast<BinaryOperator>(Op);
> - if (Opcode == Instruction::Mul && BO && BinaryOperator::isNeg(BO)) {
> - DEBUG(dbgs() << "MORPH LEAF: " << *Op << " (" << Weight << ") TO ");
> - BO = LowerNegateToMultiply(BO);
> - DEBUG(dbgs() << *BO << 'n');
> - Worklist.push_back(std::make_pair(BO, Weight));
> - MadeChange = true;
> - continue;
> - }
> + if (BinaryOperator *BO = dyn_cast<BinaryOperator>(Op))
> + if ((Opcode == Instruction::Mul && BinaryOperator::isNeg(BO)) ||
> + (Opcode == Instruction::FMul && BinaryOperator::isFNeg(BO))) {
> + DEBUG(dbgs() << "MORPH LEAF: " << *Op << " (" << Weight << ") TO ");
> + BO = LowerNegateToMultiply(BO);
> + DEBUG(dbgs() << *BO << '\n');
> + Worklist.push_back(std::make_pair(BO, Weight));
> + MadeChange = true;
> + continue;
> + }
>
> // Failed to morph into an expression of the right type. This really is
> // a leaf.
> @@ -798,6 +846,8 @@ void Reassociate::RewriteExprTree(Binary
> Constant *Undef = UndefValue::get(I->getType());
> NewOp = BinaryOperator::Create(Instruction::BinaryOps(Opcode),
> Undef, Undef, "", I);
> + if (NewOp->getType()->isFloatingPointTy())
> + NewOp->setFastMathFlags(I->getFastMathFlags());
> } else {
> NewOp = NodesToRewrite.pop_back_val();
> }
> @@ -817,7 +867,14 @@ void Reassociate::RewriteExprTree(Binary
> // expression tree is dominated by all of Ops.
> if (ExpressionChanged)
> do {
> - ExpressionChanged->clearSubclassOptionalData();
> + // Preserve FastMathFlags.
> + if (isa<FPMathOperator>(I)) {
> + FastMathFlags Flags = I->getFastMathFlags();
> + ExpressionChanged->clearSubclassOptionalData();
> + ExpressionChanged->setFastMathFlags(Flags);
> + } else
> + ExpressionChanged->clearSubclassOptionalData();
> +
> if (ExpressionChanged == I)
> break;
> ExpressionChanged->moveBefore(I);
> @@ -834,6 +891,8 @@ void Reassociate::RewriteExprTree(Binary
> /// version of the value is returned, and BI is left pointing at the instruction
> /// that should be processed next by the reassociation pass.
> static Value *NegateValue(Value *V, Instruction *BI) {
> + if (ConstantFP *C = dyn_cast<ConstantFP>(V))
> + return ConstantExpr::getFNeg(C);
> if (Constant *C = dyn_cast<Constant>(V))
> return ConstantExpr::getNeg(C);
>
> @@ -846,7 +905,8 @@ static Value *NegateValue(Value *V, Inst
> // the constants. We assume that instcombine will clean up the mess later if
> // we introduce tons of unnecessary negation instructions.
> //
> - if (BinaryOperator *I = isReassociableOp(V, Instruction::Add)) {
> + if (BinaryOperator *I =
> + isReassociableOp(V, Instruction::Add, Instruction::FAdd)) {
> // Push the negates through the add.
> I->setOperand(0, NegateValue(I->getOperand(0), BI));
> I->setOperand(1, NegateValue(I->getOperand(1), BI));
> @@ -864,7 +924,8 @@ static Value *NegateValue(Value *V, Inst
> // Okay, we need to materialize a negated version of V with an instruction.
> // Scan the use lists of V to see if we have one already.
> for (User *U : V->users()) {
> - if (!BinaryOperator::isNeg(U)) continue;
> + if (!BinaryOperator::isNeg(U) && !BinaryOperator::isFNeg(U))
> + continue;
>
> // We found one! Now we have to make sure that the definition dominates
> // this use. We do this by moving it to the entry block (if it is a
> @@ -894,27 +955,30 @@ static Value *NegateValue(Value *V, Inst
>
> // Insert a 'neg' instruction that subtracts the value from zero to get the
> // negation.
> - return BinaryOperator::CreateNeg(V, V->getName() + ".neg", BI);
> + return CreateNeg(V, V->getName() + ".neg", BI, BI);
> }
>
> /// ShouldBreakUpSubtract - Return true if we should break up this subtract of
> /// X-Y into (X + -Y).
> static bool ShouldBreakUpSubtract(Instruction *Sub) {
> // If this is a negation, we can't split it up!
> - if (BinaryOperator::isNeg(Sub))
> + if (BinaryOperator::isNeg(Sub) || BinaryOperator::isFNeg(Sub))
> return false;
>
> // Don't bother to break this up unless either the LHS is an associable add or
> // subtract or if this is only used by one.
> - if (isReassociableOp(Sub->getOperand(0), Instruction::Add) ||
> - isReassociableOp(Sub->getOperand(0), Instruction::Sub))
> + Value *V0 = Sub->getOperand(0);
> + if (isReassociableOp(V0, Instruction::Add, Instruction::FAdd) ||
> + isReassociableOp(V0, Instruction::Sub, Instruction::FSub))
> return true;
> - if (isReassociableOp(Sub->getOperand(1), Instruction::Add) ||
> - isReassociableOp(Sub->getOperand(1), Instruction::Sub))
> + Value *V1 = Sub->getOperand(1);
> + if (isReassociableOp(V1, Instruction::Add, Instruction::FAdd) ||
> + isReassociableOp(V1, Instruction::Sub, Instruction::FSub))
> return true;
> + Value *VB = Sub->user_back();
> if (Sub->hasOneUse() &&
> - (isReassociableOp(Sub->user_back(), Instruction::Add) ||
> - isReassociableOp(Sub->user_back(), Instruction::Sub)))
> + (isReassociableOp(VB, Instruction::Add, Instruction::FAdd) ||
> + isReassociableOp(VB, Instruction::Sub, Instruction::FSub)))
> return true;
>
> return false;
> @@ -931,8 +995,7 @@ static BinaryOperator *BreakUpSubtract(I
> // and set it as the RHS of the add instruction we just made.
> //
> Value *NegVal = NegateValue(Sub->getOperand(1), Sub);
> - BinaryOperator *New =
> - BinaryOperator::CreateAdd(Sub->getOperand(0), NegVal, "", Sub);
> + BinaryOperator *New = CreateAdd(Sub->getOperand(0), NegVal, "", Sub, Sub);
> Sub->setOperand(0, Constant::getNullValue(Sub->getType())); // Drop use of op.
> Sub->setOperand(1, Constant::getNullValue(Sub->getType())); // Drop use of op.
> New->takeName(Sub);
> @@ -988,15 +1051,16 @@ static Value *EmitAddTreeOfValues(Instru
> Value *V1 = Ops.back();
> Ops.pop_back();
> Value *V2 = EmitAddTreeOfValues(I, Ops);
> - return BinaryOperator::CreateAdd(V2, V1, "tmp", I);
> + return CreateAdd(V2, V1, "tmp", I, I);
> }
>
> /// RemoveFactorFromExpression - If V is an expression tree that is a
> /// multiplication sequence, and if this sequence contains a multiply by Factor,
> /// remove Factor from the tree and return the new tree.
> Value *Reassociate::RemoveFactorFromExpression(Value *V, Value *Factor) {
> - BinaryOperator *BO = isReassociableOp(V, Instruction::Mul);
> - if (!BO) return nullptr;
> + BinaryOperator *BO = isReassociableOp(V, Instruction::Mul, Instruction::FMul);
> + if (!BO)
> + return nullptr;
>
> SmallVector<RepeatedValue, 8> Tree;
> MadeChange |= LinearizeExprTree(BO, Tree);
> @@ -1018,13 +1082,25 @@ Value *Reassociate::RemoveFactorFromExpr
> }
>
> // If this is a negative version of this factor, remove it.
> - if (ConstantInt *FC1 = dyn_cast<ConstantInt>(Factor))
> + if (ConstantInt *FC1 = dyn_cast<ConstantInt>(Factor)) {
> if (ConstantInt *FC2 = dyn_cast<ConstantInt>(Factors[i].Op))
> if (FC1->getValue() == -FC2->getValue()) {
> FoundFactor = NeedsNegate = true;
> Factors.erase(Factors.begin()+i);
> break;
> }
> + } else if (ConstantFP *FC1 = dyn_cast<ConstantFP>(Factor)) {
> + if (ConstantFP *FC2 = dyn_cast<ConstantFP>(Factors[i].Op)) {
> + APFloat F1(FC1->getValueAPF());
> + APFloat F2(FC2->getValueAPF());
> + F2.changeSign();
> + if (F1.compare(F2) == APFloat::cmpEqual) {
> + FoundFactor = NeedsNegate = true;
> + Factors.erase(Factors.begin() + i);
> + break;
> + }
> + }
> + }
> }
>
> if (!FoundFactor) {
> @@ -1046,7 +1122,7 @@ Value *Reassociate::RemoveFactorFromExpr
> }
>
> if (NeedsNegate)
> - V = BinaryOperator::CreateNeg(V, "neg", InsertPt);
> + V = CreateNeg(V, "neg", InsertPt, BO);
>
> return V;
> }
> @@ -1058,7 +1134,7 @@ Value *Reassociate::RemoveFactorFromExpr
> static void FindSingleUseMultiplyFactors(Value *V,
> SmallVectorImpl<Value*> &Factors,
> const SmallVectorImpl<ValueEntry> &Ops) {
> - BinaryOperator *BO = isReassociableOp(V, Instruction::Mul);
> + BinaryOperator *BO = isReassociableOp(V, Instruction::Mul, Instruction::FMul);
> if (!BO) {
> Factors.push_back(V);
> return;
> @@ -1389,13 +1465,15 @@ Value *Reassociate::OptimizeAdd(Instruct
> ++NumFactor;
>
> // Insert a new multiply.
> - Value *Mul = ConstantInt::get(cast<IntegerType>(I->getType()), NumFound);
> - Mul = BinaryOperator::CreateMul(TheOp, Mul, "factor", I);
> + Type *Ty = TheOp->getType();
> + Constant *C = Ty->isIntegerTy() ? ConstantInt::get(Ty, NumFound)
> + : ConstantFP::get(Ty, NumFound);
> + Instruction *Mul = CreateMul(TheOp, C, "factor", I, I);
>
> // Now that we have inserted a multiply, optimize it. This allows us to
> // handle cases that require multiple factoring steps, such as this:
> // (X*2) + (X*2) + (X*2) -> (X*2)*3 -> X*6
> - RedoInsts.insert(cast<Instruction>(Mul));
> + RedoInsts.insert(Mul);
>
> // If every add operand was a duplicate, return the multiply.
> if (Ops.empty())
> @@ -1412,11 +1490,12 @@ Value *Reassociate::OptimizeAdd(Instruct
> }
>
> // Check for X and -X or X and ~X in the operand list.
> - if (!BinaryOperator::isNeg(TheOp) && !BinaryOperator::isNot(TheOp))
> + if (!BinaryOperator::isNeg(TheOp) && !BinaryOperator::isFNeg(TheOp) &&
> + !BinaryOperator::isNot(TheOp))
> continue;
>
> Value *X = nullptr;
> - if (BinaryOperator::isNeg(TheOp))
> + if (BinaryOperator::isNeg(TheOp) || BinaryOperator::isFNeg(TheOp))
> X = BinaryOperator::getNegArgument(TheOp);
> else if (BinaryOperator::isNot(TheOp))
> X = BinaryOperator::getNotArgument(TheOp);
> @@ -1426,7 +1505,8 @@ Value *Reassociate::OptimizeAdd(Instruct
> continue;
>
> // Remove X and -X from the operand list.
> - if (Ops.size() == 2 && BinaryOperator::isNeg(TheOp))
> + if (Ops.size() == 2 &&
> + (BinaryOperator::isNeg(TheOp) || BinaryOperator::isFNeg(TheOp)))
> return Constant::getNullValue(X->getType());
>
> // Remove X and ~X from the operand list.
> @@ -1463,7 +1543,8 @@ Value *Reassociate::OptimizeAdd(Instruct
> unsigned MaxOcc = 0;
> Value *MaxOccVal = nullptr;
> for (unsigned i = 0, e = Ops.size(); i != e; ++i) {
> - BinaryOperator *BOp = isReassociableOp(Ops[i].Op, Instruction::Mul);
> + BinaryOperator *BOp =
> + isReassociableOp(Ops[i].Op, Instruction::Mul, Instruction::FMul);
> if (!BOp)
> continue;
>
> @@ -1476,23 +1557,43 @@ Value *Reassociate::OptimizeAdd(Instruct
> SmallPtrSet<Value*, 8> Duplicates;
> for (unsigned i = 0, e = Factors.size(); i != e; ++i) {
> Value *Factor = Factors[i];
> - if (!Duplicates.insert(Factor)) continue;
> + if (!Duplicates.insert(Factor))
> + continue;
>
> unsigned Occ = ++FactorOccurrences[Factor];
> - if (Occ > MaxOcc) { MaxOcc = Occ; MaxOccVal = Factor; }
> + if (Occ > MaxOcc) {
> + MaxOcc = Occ;
> + MaxOccVal = Factor;
> + }
>
> // If Factor is a negative constant, add the negated value as a factor
> // because we can percolate the negate out. Watch for minint, which
> // cannot be positivified.
> - if (ConstantInt *CI = dyn_cast<ConstantInt>(Factor))
> + if (ConstantInt *CI = dyn_cast<ConstantInt>(Factor)) {
> if (CI->isNegative() && !CI->isMinValue(true)) {
> Factor = ConstantInt::get(CI->getContext(), -CI->getValue());
> assert(!Duplicates.count(Factor) &&
> "Shouldn't have two constant factors, missed a canonicalize");
> -
> unsigned Occ = ++FactorOccurrences[Factor];
> - if (Occ > MaxOcc) { MaxOcc = Occ; MaxOccVal = Factor; }
> + if (Occ > MaxOcc) {
> + MaxOcc = Occ;
> + MaxOccVal = Factor;
> + }
> }
> + } else if (ConstantFP *CF = dyn_cast<ConstantFP>(Factor)) {
> + if (CF->isNegative()) {
> + APFloat F(CF->getValueAPF());
> + F.changeSign();
> + Factor = ConstantFP::get(CF->getContext(), F);
> + assert(!Duplicates.count(Factor) &&
> + "Shouldn't have two constant factors, missed a canonicalize");
> + unsigned Occ = ++FactorOccurrences[Factor];
> + if (Occ > MaxOcc) {
> + MaxOcc = Occ;
> + MaxOccVal = Factor;
> + }
> + }
> + }
> }
> }
>
> @@ -1505,11 +1606,16 @@ Value *Reassociate::OptimizeAdd(Instruct
> // this, we could otherwise run into situations where removing a factor
> // from an expression will drop a use of maxocc, and this can cause
> // RemoveFactorFromExpression on successive values to behave differently.
> - Instruction *DummyInst = BinaryOperator::CreateAdd(MaxOccVal, MaxOccVal);
> + Instruction *DummyInst =
> + I->getType()->isIntegerTy()
> + ? BinaryOperator::CreateAdd(MaxOccVal, MaxOccVal)
> + : BinaryOperator::CreateFAdd(MaxOccVal, MaxOccVal);
> +
> SmallVector<WeakVH, 4> NewMulOps;
> for (unsigned i = 0; i != Ops.size(); ++i) {
> // Only try to remove factors from expressions we're allowed to.
> - BinaryOperator *BOp = isReassociableOp(Ops[i].Op, Instruction::Mul);
> + BinaryOperator *BOp =
> + isReassociableOp(Ops[i].Op, Instruction::Mul, Instruction::FMul);
> if (!BOp)
> continue;
>
> @@ -1542,7 +1648,7 @@ Value *Reassociate::OptimizeAdd(Instruct
> RedoInsts.insert(VI);
>
> // Create the multiply.
> - Instruction *V2 = BinaryOperator::CreateMul(V, MaxOccVal, "tmp", I);
> + Instruction *V2 = CreateMul(V, MaxOccVal, "tmp", I, I);
>
> // Rerun associate on the multiply in case the inner expression turned into
> // a multiply. We want to make sure that we keep things in canonical form.
> @@ -1632,7 +1738,10 @@ static Value *buildMultiplyTree(IRBuilde
>
> Value *LHS = Ops.pop_back_val();
> do {
> - LHS = Builder.CreateMul(LHS, Ops.pop_back_val());
> + if (LHS->getType()->isIntegerTy())
> + LHS = Builder.CreateMul(LHS, Ops.pop_back_val());
> + else
> + LHS = Builder.CreateFMul(LHS, Ops.pop_back_val());
> } while (!Ops.empty());
>
> return LHS;
> @@ -1765,11 +1874,13 @@ Value *Reassociate::OptimizeExpression(B
> break;
>
> case Instruction::Add:
> + case Instruction::FAdd:
> if (Value *Result = OptimizeAdd(I, Ops))
> return Result;
> break;
>
> case Instruction::Mul:
> + case Instruction::FMul:
> if (Value *Result = OptimizeMul(I, Ops))
> return Result;
> break;
> @@ -1810,8 +1921,7 @@ void Reassociate::OptimizeInst(Instructi
> if (!isa<BinaryOperator>(I))
> return;
>
> - if (I->getOpcode() == Instruction::Shl &&
> - isa<ConstantInt>(I->getOperand(1)))
> + if (I->getOpcode() == Instruction::Shl && isa<ConstantInt>(I->getOperand(1)))
> // If an operand of this shift is a reassociable multiply, or if the shift
> // is used by a reassociable multiply or add, turn into a multiply.
> if (isReassociableOp(I->getOperand(0), Instruction::Mul) ||
> @@ -1824,28 +1934,33 @@ void Reassociate::OptimizeInst(Instructi
> I = NI;
> }
>
> - // Floating point binary operators are not associative, but we can still
> - // commute (some) of them, to canonicalize the order of their operands.
> - // This can potentially expose more CSE opportunities, and makes writing
> - // other transformations simpler.
> - if ((I->getType()->isFloatingPointTy() || I->getType()->isVectorTy())) {
> - // FAdd and FMul can be commuted.
> - if (I->getOpcode() != Instruction::FMul &&
> - I->getOpcode() != Instruction::FAdd)
> - return;
> + // Commute floating point binary operators, to canonicalize the order of their
> + // operands. This can potentially expose more CSE opportunities, and makes
> + // writing other transformations simpler.
> + if (I->getType()->isFloatingPointTy() || I->getType()->isVectorTy()) {
>
> - Value *LHS = I->getOperand(0);
> - Value *RHS = I->getOperand(1);
> - unsigned LHSRank = getRank(LHS);
> - unsigned RHSRank = getRank(RHS);
> -
> - // Sort the operands by rank.
> - if (RHSRank < LHSRank) {
> - I->setOperand(0, RHS);
> - I->setOperand(1, LHS);
> + // FAdd and FMul can be commuted.
> + if (I->getOpcode() == Instruction::FMul ||
> + I->getOpcode() == Instruction::FAdd) {
> + Value *LHS = I->getOperand(0);
> + Value *RHS = I->getOperand(1);
> + unsigned LHSRank = getRank(LHS);
> + unsigned RHSRank = getRank(RHS);
> +
> + // Sort the operands by rank.
> + if (RHSRank < LHSRank) {
> + I->setOperand(0, RHS);
> + I->setOperand(1, LHS);
> + }
> }
>
> - return;
> + // FIXME: We should commute vector instructions as well. However, this
> + // requires further analysis to determine the effect on later passes.
> +
> + // Don't try to optimize vector instructions or anything that doesn't have
> + // unsafe algebra.
> + if (I->getType()->isVectorTy() || !I->hasUnsafeAlgebra())
> + return;
> }
>
> // Do not reassociate boolean (i1) expressions. We want to preserve the
> @@ -1877,6 +1992,24 @@ void Reassociate::OptimizeInst(Instructi
> I = NI;
> }
> }
> + } else if (I->getOpcode() == Instruction::FSub) {
> + if (ShouldBreakUpSubtract(I)) {
> + Instruction *NI = BreakUpSubtract(I);
> + RedoInsts.insert(I);
> + MadeChange = true;
> + I = NI;
> + } else if (BinaryOperator::isFNeg(I)) {
> + // Otherwise, this is a negation. See if the operand is a multiply tree
> + // and if this is not an inner node of a multiply tree.
> + if (isReassociableOp(I->getOperand(1), Instruction::FMul) &&
> + (!I->hasOneUse() ||
> + !isReassociableOp(I->user_back(), Instruction::FMul))) {
> + Instruction *NI = LowerNegateToMultiply(I);
> + RedoInsts.insert(I);
> + MadeChange = true;
> + I = NI;
> + }
> + }
> }
>
> // If this instruction is an associative binary operator, process it.
> @@ -1894,11 +2027,16 @@ void Reassociate::OptimizeInst(Instructi
> if (BO->hasOneUse() && BO->getOpcode() == Instruction::Add &&
> cast<Instruction>(BO->user_back())->getOpcode() == Instruction::Sub)
> return;
> + if (BO->hasOneUse() && BO->getOpcode() == Instruction::FAdd &&
> + cast<Instruction>(BO->user_back())->getOpcode() == Instruction::FSub)
> + return;
>
> ReassociateExpression(BO);
> }
>
> void Reassociate::ReassociateExpression(BinaryOperator *I) {
> + assert(!I->getType()->isVectorTy() &&
> + "Reassociation of vector instructions is not supported.");
>
> // First, walk the expression tree, linearizing the tree, collecting the
> // operand information.
> @@ -1943,12 +2081,21 @@ void Reassociate::ReassociateExpression(
> // this is a multiply tree used only by an add, and the immediate is a -1.
> // In this case we reassociate to put the negation on the outside so that we
> // can fold the negation into the add: (-X)*Y + Z -> Z-X*Y
> - if (I->getOpcode() == Instruction::Mul && I->hasOneUse() &&
> - cast<Instruction>(I->user_back())->getOpcode() == Instruction::Add &&
> - isa<ConstantInt>(Ops.back().Op) &&
> - cast<ConstantInt>(Ops.back().Op)->isAllOnesValue()) {
> - ValueEntry Tmp = Ops.pop_back_val();
> - Ops.insert(Ops.begin(), Tmp);
> + if (I->hasOneUse()) {
> + if (I->getOpcode() == Instruction::Mul &&
> + cast<Instruction>(I->user_back())->getOpcode() == Instruction::Add &&
> + isa<ConstantInt>(Ops.back().Op) &&
> + cast<ConstantInt>(Ops.back().Op)->isAllOnesValue()) {
> + ValueEntry Tmp = Ops.pop_back_val();
> + Ops.insert(Ops.begin(), Tmp);
> + } else if (I->getOpcode() == Instruction::FMul &&
> + cast<Instruction>(I->user_back())->getOpcode() ==
> + Instruction::FAdd &&
> + isa<ConstantFP>(Ops.back().Op) &&
> + cast<ConstantFP>(Ops.back().Op)->isExactlyValue(-1.0)) {
> + ValueEntry Tmp = Ops.pop_back_val();
> + Ops.insert(Ops.begin(), Tmp);
> + }
> }
>
> DEBUG(dbgs() << "RAOut:\t"; PrintOps(I, Ops); dbgs() << '\n');
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-AgressiveSubMove.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-AgressiveSubMove.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-AgressiveSubMove.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-AgressiveSubMove.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,24 @@
> +; RUN: opt < %s -reassociate -S | FileCheck %s
> +
> +define float @test1(float %A) {
> +; CHECK-LABEL: test1
> +; CHECK-NEXT: %X = fadd float 1.000000e+00, %A
> +; CHECK-NEXT: %Y = fadd float 1.000000e+00, %A
> +; CHECK-NEXT: %r = fsub float %X, %Y
> +; CHECK-NEXT: ret float %r
> +
> + %X = fadd float %A, 1.000000e+00
> + %Y = fadd float %A, 1.000000e+00
> + %r = fsub float %X, %Y
> + ret float %r
> +}
> +
> +define float @test2(float %A) {
> +; CHECK-LABEL: test2
> +; CHECK-NEXT: ret float 0.000000e+00
> +
> + %X = fadd fast float 1.000000e+00, %A
> + %Y = fadd fast float 1.000000e+00, %A
> + %r = fsub fast float %X, %Y
> + ret float %r
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-ArrayOutOfBounds.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-ArrayOutOfBounds.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-ArrayOutOfBounds.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-ArrayOutOfBounds.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,65 @@
> +; RUN: opt < %s -reassociate -instcombine -S | FileCheck %s
> +
> +; Not marked as fast, so must not change.
> +define float @test1(float %a0, float %a1, float %a2, float %a3, float %a4) {
> +; CHECK-LABEL: test1
> +; CHECK-NEXT: %tmp.2 = fadd float %a3, %a4
> +; CHECK-NEXT: %tmp.4 = fadd float %tmp.2, %a2
> +; CHECK-NEXT: %tmp.6 = fadd float %tmp.4, %a1
> +; CHECK-NEXT: %tmp.8 = fadd float %tmp.6, %a0
> +; CHECK-NEXT: %tmp.11 = fadd float %a2, %a3
> +; CHECK-NEXT: %tmp.13 = fadd float %tmp.11, %a1
> +; CHECK-NEXT: %tmp.15 = fadd float %tmp.13, %a0
> +; CHECK-NEXT: %tmp.18 = fadd float %a1, %a2
> +; CHECK-NEXT: %tmp.20 = fadd float %tmp.18, %a0
> +; CHECK-NEXT: %tmp.23 = fadd float %a0, %a1
> +; CHECK-NEXT: %tmp.26 = fsub float %tmp.8, %tmp.15
> +; CHECK-NEXT: %tmp.28 = fadd float %tmp.20, %tmp.26
> +; CHECK-NEXT: %tmp.30 = fsub float %tmp.28, %tmp.23
> +; CHECK-NEXT: %tmp.32 = fsub float %tmp.30, %a4
> +; CHECK-NEXT: %tmp.34 = fsub float %tmp.32, %a2
> +; CHECK-NEXT: %T = fmul float %tmp.34, %tmp.34
> +; CHECK-NEXT: ret float %T
> +
> + %tmp.2 = fadd float %a4, %a3
> + %tmp.4 = fadd float %tmp.2, %a2
> + %tmp.6 = fadd float %tmp.4, %a1
> + %tmp.8 = fadd float %tmp.6, %a0
> + %tmp.11 = fadd float %a3, %a2
> + %tmp.13 = fadd float %tmp.11, %a1
> + %tmp.15 = fadd float %tmp.13, %a0
> + %tmp.18 = fadd float %a2, %a1
> + %tmp.20 = fadd float %tmp.18, %a0
> + %tmp.23 = fadd float %a1, %a0
> + %tmp.26 = fsub float %tmp.8, %tmp.15
> + %tmp.28 = fadd float %tmp.26, %tmp.20
> + %tmp.30 = fsub float %tmp.28, %tmp.23
> + %tmp.32 = fsub float %tmp.30, %a4
> + %tmp.34 = fsub float %tmp.32, %a2
> + %T = fmul float %tmp.34, %tmp.34
> + ret float %T
> +}
> +
> +; Should be able to eliminate everything.
> +define float @test2(float %a0, float %a1, float %a2, float %a3, float %a4) {
> +; CHECK-LABEL: test2
> +; CHECK: ret float 0.000000e+00
> +
> + %tmp.2 = fadd fast float %a4, %a3
> + %tmp.4 = fadd fast float %tmp.2, %a2
> + %tmp.6 = fadd fast float %tmp.4, %a1
> + %tmp.8 = fadd fast float %tmp.6, %a0
> + %tmp.11 = fadd fast float %a3, %a2
> + %tmp.13 = fadd fast float %tmp.11, %a1
> + %tmp.15 = fadd fast float %tmp.13, %a0
> + %tmp.18 = fadd fast float %a2, %a1
> + %tmp.20 = fadd fast float %tmp.18, %a0
> + %tmp.23 = fadd fast float %a1, %a0
> + %tmp.26 = fsub fast float %tmp.8, %tmp.15
> + %tmp.28 = fadd fast float %tmp.26, %tmp.20
> + %tmp.30 = fsub fast float %tmp.28, %tmp.23
> + %tmp.32 = fsub fast float %tmp.30, %a4
> + %tmp.34 = fsub fast float %tmp.32, %a2
> + %T = fmul fast float %tmp.34, %tmp.34
> + ret float %T
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-MissedTree.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-MissedTree.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-MissedTree.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-MissedTree.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,11 @@
> +; RUN: opt < %s -reassociate -instcombine -S | FileCheck %s
> +
> +define float @test1(float %A, float %B) {
> +; CHECK-LABEL: test1
> +; CHECK: %Z = fadd fast float %A, %B
> +; CHECK: ret float %Z
> + %W = fadd fast float %B, -5.0
> + %Y = fadd fast float %A, 5.0
> + %Z = fadd fast float %W, %Y
> + ret float %Z
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-ReassociateVector.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-ReassociateVector.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-ReassociateVector.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-ReassociateVector.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,25 @@
> +; RUN: opt < %s -reassociate -S | FileCheck %s
> +
> +; Don't handle floating point vector operations.
> +define <4 x float> @test1() {
> +; CHECK-LABEL: test1
> +; CHECK-NEXT: %tmp1 = fsub fast <4 x float> zeroinitializer, zeroinitializer
> +; CHECK-NEXT: %tmp2 = fmul fast <4 x float> zeroinitializer, %tmp1
> +
> + %tmp1 = fsub fast <4 x float> zeroinitializer, zeroinitializer
> + %tmp2 = fmul fast <4 x float> zeroinitializer, %tmp1
> + ret <4 x float> %tmp2
> +}
> +
> +; We don't currently commute integer vector operations.
> +define <2 x i32> @test2(<2 x i32> %x, <2 x i32> %y) {
> +; CHECK-LABEL: test2
> +; CHECK-NEXT: %tmp1 = add <2 x i32> %x, %y
> +; CHECK-NEXT: %tmp2 = add <2 x i32> %y, %x
> +; CHECK-NEXT: %tmp3 = add <2 x i32> %tmp1, %tmp2
> +
> + %tmp1 = add <2 x i32> %x, %y
> + %tmp2 = add <2 x i32> %y, %x
> + %tmp3 = add <2 x i32> %tmp1, %tmp2
> + ret <2 x i32> %tmp3
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-SubReassociate.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-SubReassociate.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-SubReassociate.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-SubReassociate.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,70 @@
> +; RUN: opt < %s -reassociate -constprop -instcombine -S | FileCheck %s
> +
> +define float @test1(float %A, float %B) {
> +; CHECK-LABEL: test1
> +; CHECK-NEXT: %W = fadd float %B, 5.000000e+00
> +; CHECK-NEXT: %X = fadd float %A, -7.000000e+00
> +; CHECK-NEXT: %Y = fsub float %X, %W
> +; CHECK-NEXT: %Z = fadd float %Y, 1.200000e+01
> +; CHECK-NEXT: ret float %Z
> +
> + %W = fadd float 5.0, %B
> + %X = fadd float -7.0, %A
> + %Y = fsub float %X, %W
> + %Z = fadd float %Y, 12.0
> + ret float %Z
> +}
> +
> +; With sub reassociation, constant folding can eliminate all of the constants.
> +define float @test2(float %A, float %B) {
> +; CHECK-LABEL: test2
> +; CHECK-NEXT: %Z = fsub fast float %A, %B
> +; CHECK-NEXT: ret float %Z
> +
> + %W = fadd fast float %B, 5.000000e+00
> + %X = fadd fast float %A, -7.000000e+00
> + %Y = fsub fast float %X, %W
> + %Z = fadd fast float %Y, 1.200000e+01
> + ret float %Z
> +
> +}
> +
> +define float @test3(float %A, float %B, float %C, float %D) {
> +; CHECK-LABEL: test3
> +; CHECK-NEXT: %M = fadd float %A, 1.200000e+01
> +; CHECK-NEXT: %N = fadd float %M, %B
> +; CHECK-NEXT: %O = fadd float %N, %C
> +; CHECK-NEXT: %P = fsub float %D, %O
> +; CHECK-NEXT: %Q = fadd float %P, 1.200000e+01
> +; CHECK-NEXT: ret float %Q
> +
> + %M = fadd float %A, 1.200000e+01
> + %N = fadd float %M, %B
> + %O = fadd float %N, %C
> + %P = fsub float %D, %O
> + %Q = fadd float %P, 1.200000e+01
> + ret float %Q
> +}
> +
> +; With sub reassociation, constant folding can eliminate the two 12 constants.
> +define float @test4(float %A, float %B, float %C, float %D) {
> +; CHECK-LABEL: test4
> +; CHECK-NEXT: %B.neg = fsub fast float -0.000000e+00, %B
> +; CHECK-NEXT: %O.neg = fsub fast float %B.neg, %A
> +; CHECK-NEXT: %P = fsub fast float %O.neg, %C
> +; CHECK-NEXT: %Q = fadd fast float %P, %D
> +; CHECK-NEXT: ret float %Q
> +
> +; FIXME: InstCombine should be able to get us to the following:
> +; %sum = fadd fast float %B, %A
> +; %sum1 = fadd fast float %sum, %C
> +; %Q = fsub fast float %D, %sum1
> +; ret i32 %Q
> +
> + %M = fadd fast float 1.200000e+01, %A
> + %N = fadd fast float %M, %B
> + %O = fadd fast float %N, %C
> + %P = fsub fast float %D, %O
> + %Q = fadd fast float 1.200000e+01, %P
> + ret float %Q
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-basictest.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-basictest.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-basictest.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-basictest.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,285 @@
> +; RUN: opt < %s -reassociate -gvn -instcombine -S | FileCheck %s
> +
> +; With reassociation, constant folding can eliminate the 12 and -12 constants.
> +define float @test1(float %arg) {
> +; CHECK-LABEL: @test1
> +; CHECK-NEXT: fsub fast float -0.000000e+00, %arg
> +; CHECK-NEXT: ret float
> +
> + %tmp1 = fsub fast float -1.200000e+01, %arg
> + %tmp2 = fadd fast float %tmp1, 1.200000e+01
> + ret float %tmp2
> +}
> +
> +define float @test2(float %reg109, float %reg1111) {
> +; CHECK-LABEL: @test2
> +; CHECK-NEXT: fadd float %reg109, -3.000000e+01
> +; CHECK-NEXT: fadd float %reg115, %reg1111
> +; CHECK-NEXT: fadd float %reg116, 3.000000e+01
> +; CHECK-NEXT: ret float
> +
> + %reg115 = fadd float %reg109, -3.000000e+01
> + %reg116 = fadd float %reg115, %reg1111
> + %reg117 = fadd float %reg116, 3.000000e+01
> + ret float %reg117
> +}
> +
> +define float @test3(float %reg109, float %reg1111) {
> +; CHECK-LABEL: @test3
> +; CHECK-NEXT: %reg117 = fadd fast float %reg109, %reg1111
> +; CHECK-NEXT: ret float %reg117
> +
> + %reg115 = fadd fast float %reg109, -3.000000e+01
> + %reg116 = fadd fast float %reg115, %reg1111
> + %reg117 = fadd fast float %reg116, 3.000000e+01
> + ret float %reg117
> +}
> +
> + at fe = external global float
> + at fa = external global float
> + at fb = external global float
> + at fc = external global float
> + at ff = external global float
> +
> +define void @test4() {
> +; CHECK-LABEL: @test4
> +; CHECK: fadd fast float
> +; CHECK: fadd fast float
> +; CHECK-NOT: fadd fast float
> +; CHECK: ret void
> +
> + %A = load float* @fa
> + %B = load float* @fb
> + %C = load float* @fc
> + %t1 = fadd fast float %A, %B
> + %t2 = fadd fast float %t1, %C
> + %t3 = fadd fast float %C, %A
> + %t4 = fadd fast float %t3, %B
> + ; e = (a+b)+c;
> + store float %t2, float* @fe
> + ; f = (a+c)+b
> + store float %t4, float* @ff
> + ret void
> +}
> +
> +define void @test5() {
> +; CHECK-LABEL: @test5
> +; CHECK: fadd fast float
> +; CHECK: fadd fast float
> +; CHECK-NOT: fadd
> +; CHECK: ret void
> +
> + %A = load float* @fa
> + %B = load float* @fb
> + %C = load float* @fc
> + %t1 = fadd fast float %A, %B
> + %t2 = fadd fast float %t1, %C
> + %t3 = fadd fast float %C, %A
> + %t4 = fadd fast float %t3, %B
> + ; e = c+(a+b)
> + store float %t2, float* @fe
> + ; f = (c+a)+b
> + store float %t4, float* @ff
> + ret void
> +}
> +
> +define void @test6() {
> +; CHECK-LABEL: @test6
> +; CHECK: fadd fast float
> +; CHECK: fadd fast float
> +; CHECK-NOT: fadd
> +; CHECK: ret void
> +
> + %A = load float* @fa
> + %B = load float* @fb
> + %C = load float* @fc
> + %t1 = fadd fast float %B, %A
> + %t2 = fadd fast float %t1, %C
> + %t3 = fadd fast float %C, %A
> + %t4 = fadd fast float %t3, %B
> + ; e = c+(b+a)
> + store float %t2, float* @fe
> + ; f = (c+a)+b
> + store float %t4, float* @ff
> + ret void
> +}
> +
> +define float @test7(float %A, float %B, float %C) {
> +; CHECK-LABEL: @test7
> +; CHECK-NEXT: fadd fast float %C, %B
> +; CHECK-NEXT: fmul fast float %A, %A
> +; CHECK-NEXT: fmul fast float %1, %tmp2
> +; CHECK-NEXT: ret float
> +
> + %aa = fmul fast float %A, %A
> + %aab = fmul fast float %aa, %B
> + %ac = fmul fast float %A, %C
> + %aac = fmul fast float %ac, %A
> + %r = fadd fast float %aab, %aac
> + ret float %r
> +}
> +
> +define float @test8(float %X, float %Y, float %Z) {
> +; CHECK-LABEL: @test8
> +; CHECK-NEXT: fmul fast float %Y, %X
> +; CHECK-NEXT: fsub fast float %Z
> +; CHECK-NEXT: ret float
> +
> + %A = fsub fast float 0.0, %X
> + %B = fmul fast float %A, %Y
> + ; (-X)*Y + Z -> Z-X*Y
> + %C = fadd fast float %B, %Z
> + ret float %C
> +}
> +
> +define float @test9(float %X) {
> +; CHECK-LABEL: @test9
> +; CHECK-NEXT: fmul fast float %X, 9.400000e+01
> +; CHECK-NEXT: ret float
> +
> + %Y = fmul fast float %X, 4.700000e+01
> + %Z = fadd fast float %Y, %Y
> + ret float %Z
> +}
> +
> +define float @test10(float %X) {
> +; CHECK-LABEL: @test10
> +; CHECK-NEXT: fmul fast float %X, 3.000000e+00
> +; CHECK-NEXT: ret float
> +
> + %Y = fadd fast float %X ,%X
> + %Z = fadd fast float %Y, %X
> + ret float %Z
> +}
> +
> +define float @test11(float %W) {
> +; CHECK-LABEL: test11
> +; CHECK-NEXT: fmul fast float %W, 3.810000e+02
> +; CHECK-NEXT: ret float
> +
> + %X = fmul fast float %W, 127.0
> + %Y = fadd fast float %X ,%X
> + %Z = fadd fast float %Y, %X
> + ret float %Z
> +}
> +
> +define float @test12(float %X) {
> +; CHECK-LABEL: @test12
> +; CHECK-NEXT: fmul fast float %X, -3.000000e+00
> +; CHECK-NEXT: fadd fast float %factor, 6.000000e+00
> +; CHECK-NEXT: ret float
> +
> + %A = fsub fast float 1.000000e+00, %X
> + %B = fsub fast float 2.000000e+00, %X
> + %C = fsub fast float 3.000000e+00, %X
> + %Y = fadd fast float %A ,%B
> + %Z = fadd fast float %Y, %C
> + ret float %Z
> +}
> +
> +define float @test13(float %X1, float %X2, float %X3) {
> +; CHECK-LABEL: @test13
> +; CHECK-NEXT: fsub fast float %X3, %X2
> +; CHECK-NEXT: fmul fast float {{.*}}, %X1
> +; CHECK-NEXT: ret float
> +
> + %A = fsub fast float 0.000000e+00, %X1
> + %B = fmul fast float %A, %X2 ; -X1*X2
> + %C = fmul fast float %X1, %X3 ; X1*X3
> + %D = fadd fast float %B, %C ; -X1*X2 + X1*X3 -> X1*(X3-X2)
> + ret float %D
> +}
> +
> +define float @test14(float %X1, float %X2) {
> +; CHECK-LABEL: @test14
> +; CHECK-NEXT: fsub fast float %X1, %X2
> +; CHECK-NEXT: fmul fast float %tmp, 4.700000e+01
> +; CHECK-NEXT: ret float
> +
> + %B = fmul fast float %X1, 47. ; X1*47
> + %C = fmul fast float %X2, -47. ; X2*-47
> + %D = fadd fast float %B, %C ; X1*47 + X2*-47 -> 47*(X1-X2)
> + ret float %D
> +}
> +
> +define float @test15(float %arg) {
> +; CHECK-LABEL: test15
> +; CHECK-NEXT: fmul fast float %arg, 1.440000e+02
> +; CHECK-NEXT: ret float %tmp2
> +
> + %tmp1 = fmul fast float 1.200000e+01, %arg
> + %tmp2 = fmul fast float %tmp1, 1.200000e+01
> + ret float %tmp2
> +}
> +
> +; (b+(a+1234))+-a -> b+1234
> +define float @test16(float %b, float %a) {
> +; CHECK-LABEL: @test16
> +; CHECK-NEXT: fadd fast float %b, 1.234000e+03
> +; CHECK-NEXT: ret float
> +
> + %1 = fadd fast float %a, 1234.0
> + %2 = fadd fast float %b, %1
> + %3 = fsub fast float 0.0, %a
> + %4 = fadd fast float %2, %3
> + ret float %4
> +}
> +
> +; Test that we can turn things like X*-(Y*Z) -> X*-1*Y*Z.
> +
> +define float @test17(float %a, float %b, float %z) {
> +; CHECK-LABEL: test17
> +; CHECK-NEXT: fmul fast float %a, 1.234500e+04
> +; CHECK-NEXT: fmul fast float %e, %b
> +; CHECK-NEXT: fmul fast float %f, %z
> +; CHECK-NEXT: ret float
> +
> + %c = fsub fast float 0.000000e+00, %z
> + %d = fmul fast float %a, %b
> + %e = fmul fast float %c, %d
> + %f = fmul fast float %e, 1.234500e+04
> + %g = fsub fast float 0.000000e+00, %f
> + ret float %g
> +}
> +
> +define float @test18(float %a, float %b, float %z) {
> +; CHECK-LABEL: test18
> +; CHECK-NEXT: fmul fast float %a, 4.000000e+01
> +; CHECK-NEXT: fmul fast float %e, %z
> +; CHECK-NEXT: ret float
> +
> + %d = fmul fast float %z, 4.000000e+01
> + %c = fsub fast float 0.000000e+00, %d
> + %e = fmul fast float %a, %c
> + %f = fsub fast float 0.000000e+00, %e
> + ret float %f
> +}
> +
> +; With sub reassociation, constant folding can eliminate the 12 and -12 constants.
> +define float @test19(float %A, float %B) {
> +; CHECK-LABEL: @test19
> +; CHECK-NEXT: fsub fast float %A, %B
> +; CHECK-NEXT: ret float
> + %X = fadd fast float -1.200000e+01, %A
> + %Y = fsub fast float %X, %B
> + %Z = fadd fast float %Y, 1.200000e+01
> + ret float %Z
> +}
> +
> +; With sub reassociation, constant folding can eliminate the uses of %a.
> +define float @test20(float %a, float %b, float %c) nounwind {
> +; CHECK-LABEL: @test20
> +; CHECK-NEXT: fsub fast float -0.000000e+00, %b
> +; CHECK-NEXT: fsub fast float %b.neg, %c
> +; CHECK-NEXT: ret float
> +
> +; FIXME: Should be able to generate the below, which may expose more
> +; opportunites for FAdd reassociation.
> +; %sum = fadd fast float %c, %b
> +; %tmp7 = fsub fast float 0, %sum
> +
> + %tmp3 = fsub fast float %a, %b
> + %tmp5 = fsub fast float %tmp3, %c
> + %tmp7 = fsub fast float %tmp5, %a
> + ret float %tmp7
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-fp-commute.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-fp-commute.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-fp-commute.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-fp-commute.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,44 @@
> +; RUN: opt -reassociate -S < %s | FileCheck %s
> +
> +declare void @use(float)
> +
> +define void @test1(float %x, float %y) {
> +; CHECK-LABEL: test1
> +; CHECK: fmul fast float %y, %x
> +; CHECK: fmul fast float %y, %x
> +; CHECK: fsub fast float %1, %2
> +; CHECK: call void @use(float %{{.*}})
> +; CHECK: call void @use(float %{{.*}})
> +
> + %1 = fmul fast float %x, %y
> + %2 = fmul fast float %y, %x
> + %3 = fsub fast float %1, %2
> + call void @use(float %1)
> + call void @use(float %3)
> + ret void
> +}
> +
> +define float @test2(float %x, float %y) {
> +; CHECK-LABEL: test2
> +; CHECK-NEXT: fmul fast float %y, %x
> +; CHECK-NEXT: fmul fast float %y, %x
> +; CHECK-NEXT: fsub fast float %1, %2
> +; CHECK-NEXT: ret float %3
> +
> + %1 = fmul fast float %x, %y
> + %2 = fmul fast float %y, %x
> + %3 = fsub fast float %1, %2
> + ret float %3
> +}
> +
> +define float @test3(float %x, float %y) {
> +; CHECK-LABEL: test3
> +; CHECK-NEXT: %factor = fmul fast float 2.000000e+00, %y
> +; CHECK-NEXT: %tmp1 = fmul fast float %factor, %x
> +; CHECK-NEXT: ret float %tmp1
> +
> + %1 = fmul fast float %x, %y
> + %2 = fmul fast float %y, %x
> + %3 = fadd fast float %1, %2
> + ret float %3
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-mightymul.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-mightymul.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-mightymul.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-mightymul.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,35 @@
> +; RUN: opt < %s -reassociate -disable-output
> +; PR13021
> +
> +define float @test2(float %x) {
> + %t0 = fmul fast float %x, %x
> + %t1 = fmul fast float %t0, %t0
> + %t2 = fmul fast float %t1, %t1
> + %t3 = fmul fast float %t2, %t2
> + %t4 = fmul fast float %t3, %t3
> + %t5 = fmul fast float %t4, %t4
> + %t6 = fmul fast float %t5, %t5
> + %t7 = fmul fast float %t6, %t6
> + %t8 = fmul fast float %t7, %t7
> + %t9 = fmul fast float %t8, %t8
> + %t10 = fmul fast float %t9, %t9
> + %t11 = fmul fast float %t10, %t10
> + %t12 = fmul fast float %t11, %t11
> + %t13 = fmul fast float %t12, %t12
> + %t14 = fmul fast float %t13, %t13
> + %t15 = fmul fast float %t14, %t14
> + %t16 = fmul fast float %t15, %t15
> + %t17 = fmul fast float %t16, %t16
> + %t18 = fmul fast float %t17, %t17
> + %t19 = fmul fast float %t18, %t18
> + %t20 = fmul fast float %t19, %t19
> + %t21 = fmul fast float %t20, %t20
> + %t22 = fmul fast float %t21, %t21
> + %t23 = fmul fast float %t22, %t22
> + %t24 = fmul fast float %t23, %t23
> + %t25 = fmul fast float %t24, %t24
> + %t26 = fmul fast float %t25, %t25
> + %t27 = fmul fast float %t26, %t26
> + %t28 = fmul fast float %t27, %t27
> + ret float %t28
> +}
>
> Added: llvm/trunk/test/Transforms/Reassociate/fast-multistep.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Reassociate/fast-multistep.ll?rev=215647&view=auto
> ==============================================================================
> --- llvm/trunk/test/Transforms/Reassociate/fast-multistep.ll (added)
> +++ llvm/trunk/test/Transforms/Reassociate/fast-multistep.ll Thu Aug 14 10:23:01 2014
> @@ -0,0 +1,32 @@
> +; RUN: opt < %s -reassociate -S | FileCheck %s
> +
> +define float @fmultistep1(float %a, float %b, float %c) {
> +; Check that a*a*b+a*a*c is turned into a*(a*(b+c)).
> +; CHECK-LABEL: @fmultistep1
> +; CHECK-NEXT: fadd fast float %c, %b
> +; CHECK-NEXT: fmul fast float %a, %tmp2
> +; CHECK-NEXT: fmul fast float %tmp3, %a
> +; CHECK-NEXT: ret float
> +
> + %t0 = fmul fast float %a, %b
> + %t1 = fmul fast float %a, %t0 ; a*(a*b)
> + %t2 = fmul fast float %a, %c
> + %t3 = fmul fast float %a, %t2 ; a*(a*c)
> + %t4 = fadd fast float %t1, %t3
> + ret float %t4
> +}
> +
> +define float @fmultistep2(float %a, float %b, float %c, float %d) {
> +; Check that a*b+a*c+d is turned into a*(b+c)+d.
> +; CHECK-LABEL: @fmultistep2
> +; CHECK-NEXT: fadd fast float %c, %b
> +; CHECK-NEXT: fmul fast float %tmp, %a
> +; CHECK-NEXT: fadd fast float %tmp1, %d
> +; CHECK-NEXT: ret float
> +
> + %t0 = fmul fast float %a, %b
> + %t1 = fmul fast float %a, %c
> + %t2 = fadd fast float %t1, %d ; a*c+d
> + %t3 = fadd fast float %t0, %t2 ; a*b+(a*c+d)
> + ret float %t3
> +}
>
>
> _______________________________________________
> llvm-commits mailing list
> llvm-commits at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
-------------- next part --------------
>From aba5fd5fa25a701b840e07a1b17186507112d9fb Mon Sep 17 00:00:00 2001
From: Mehdi Amini <mehdi_amini at apple.com>
Date: Wed, 5 Nov 2014 22:31:24 -0800
Subject: [PATCH] Reassociate: do not refactor floating point, even in
fast-math!
---
lib/Transforms/Scalar/Reassociate.cpp | 5 +++++
test/Transforms/Reassociate/fast-basictest.ll | 6 +++---
test/Transforms/Reassociate/fast-fp-commute.ll | 8 +++++---
test/Transforms/Reassociate/fast-multistep.ll | 21 ++++++++++++---------
.../Transforms/Reassociate/mixed-fast-nonfast-fp.ll | 9 +++++++++
5 files changed, 34 insertions(+), 15 deletions(-)
create mode 100644 test/Transforms/Reassociate/mixed-fast-nonfast-fp.ll
diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp
index 0d5ad73..f317929 100644
--- a/lib/Transforms/Scalar/Reassociate.cpp
+++ b/lib/Transforms/Scalar/Reassociate.cpp
@@ -1547,6 +1547,11 @@ Value *Reassociate::OptimizeAdd(Instruction *I,
}
}
+
+ // Do not refactor floating point
+ if(I->getOpcode() == Instruction::FAdd)
+ return nullptr;
+
// Scan the operand list, checking to see if there are any common factors
// between operands. Consider something like A*A+A*B*C+D. We would like to
// reassociate this to A*(A+B*C)+D, which reduces the number of multiplies.
diff --git a/test/Transforms/Reassociate/fast-basictest.ll b/test/Transforms/Reassociate/fast-basictest.ll
index 67b07f4..ccab442 100644
--- a/test/Transforms/Reassociate/fast-basictest.ll
+++ b/test/Transforms/Reassociate/fast-basictest.ll
@@ -105,12 +105,12 @@ define void @test6() {
}
define float @test7(float %A, float %B, float %C) {
+; Do not factor floating point!
; CHECK-LABEL: @test7
-; CHECK-NEXT: fadd fast float %C, %B
; CHECK-NEXT: fmul fast float %A, %A
-; CHECK-NEXT: fmul fast float %1, %tmp2
+; CHECK-NEXT: fadd fast float %C, %B
+; CHECK-NEXT: fmul fast float %aa, %1
; CHECK-NEXT: ret float
-
%aa = fmul fast float %A, %A
%aab = fmul fast float %aa, %B
%ac = fmul fast float %A, %C
diff --git a/test/Transforms/Reassociate/fast-fp-commute.ll b/test/Transforms/Reassociate/fast-fp-commute.ll
index 71fe7bb..e89d868 100644
--- a/test/Transforms/Reassociate/fast-fp-commute.ll
+++ b/test/Transforms/Reassociate/fast-fp-commute.ll
@@ -32,10 +32,12 @@ define float @test2(float %x, float %y) {
}
define float @test3(float %x, float %y) {
+; Do NOT factor floating point
; CHECK-LABEL: test3
-; CHECK-NEXT: %factor = fmul fast float 2.000000e+00, %y
-; CHECK-NEXT: %tmp1 = fmul fast float %factor, %x
-; CHECK-NEXT: ret float %tmp1
+; CHECK-NEXT: %1 = fmul fast float %y, %x
+; CHECK-NEXT: %2 = fmul fast float %y, %x
+; CHECK-NEXT: %3 = fadd fast float %1, %2
+; CHECK-NEXT: ret float %3
%1 = fmul fast float %x, %y
%2 = fmul fast float %y, %x
diff --git a/test/Transforms/Reassociate/fast-multistep.ll b/test/Transforms/Reassociate/fast-multistep.ll
index 45e15c7..1b6bc61 100644
--- a/test/Transforms/Reassociate/fast-multistep.ll
+++ b/test/Transforms/Reassociate/fast-multistep.ll
@@ -1,12 +1,14 @@
; RUN: opt < %s -reassociate -S | FileCheck %s
define float @fmultistep1(float %a, float %b, float %c) {
-; Check that a*a*b+a*a*c is turned into a*(a*(b+c)).
+; Check that a*a*b+a*a*c is NOT turned into a*(a*(b+c)).
; CHECK-LABEL: @fmultistep1
-; CHECK-NEXT: fadd fast float %c, %b
-; CHECK-NEXT: fmul fast float %a, %tmp2
-; CHECK-NEXT: fmul fast float %tmp3, %a
-; CHECK-NEXT: ret float
+; CHECK-NEXT: %t0 = fmul fast float %a, %a
+; CHECK-NEXT: %t1 = fmul fast float %t0, %b
+; CHECK-NEXT: %t2 = fmul fast float %a, %a
+; CHECK-NEXT: %t3 = fmul fast float %t2, %c
+; CHECK-NEXT: %t4 = fadd fast float %t3, %t1
+; CHECK-NEXT: ret float %t4
%t0 = fmul fast float %a, %b
%t1 = fmul fast float %a, %t0 ; a*(a*b)
@@ -17,11 +19,12 @@ define float @fmultistep1(float %a, float %b, float %c) {
}
define float @fmultistep2(float %a, float %b, float %c, float %d) {
-; Check that a*b+a*c+d is turned into a*(b+c)+d.
+; Check that a*b+a*c+d is NOT turned into a*(b+c)+d.
; CHECK-LABEL: @fmultistep2
-; CHECK-NEXT: fadd fast float %c, %b
-; CHECK-NEXT: fmul fast float %tmp, %a
-; CHECK-NEXT: fadd fast float %tmp1, %d
+; CHECK-NEXT: %t0 = fmul fast float %b, %a
+; CHECK-NEXT: %t1 = fmul fast float %c, %a
+; CHECK-NEXT: %t2 = fadd fast float %d, %t0
+; CHECK-NEXT: %t3 = fadd fast float %t2, %t1
; CHECK-NEXT: ret float
%t0 = fmul fast float %a, %b
diff --git a/test/Transforms/Reassociate/mixed-fast-nonfast-fp.ll b/test/Transforms/Reassociate/mixed-fast-nonfast-fp.ll
new file mode 100644
index 0000000..d4cde04
--- /dev/null
+++ b/test/Transforms/Reassociate/mixed-fast-nonfast-fp.ll
@@ -0,0 +1,9 @@
+; RUN: opt -reassociate %s
+
+define half @agc.main(half %a,half %b, half %c) {
+ %mul1 = fmul half %a, %c
+ %mul2 = fmul half %a, %b
+ %add = fadd fast half %mul1, %mul2
+ ret half %add
+}
+
--
2.1.2
More information about the llvm-commits
mailing list