[llvm] r215647 - [Reassociation] Add support for reassociation with unsafe algebra.
Chad Rosier
mcrosier at codeaurora.org
Thu Aug 14 08:23:01 PDT 2014
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
+}
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