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mlir/Presburger: optimize to avoid creating copies (#97897)
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Optimize the Presburger library to avoid unnecessarily creating copies.
While at it, fix some other minor issues in the codebase.
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@artagnon
artagnon authored Jul 15, 2024
1 parent 148d907 commit 266a5a9
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Showing 9 changed files with 123 additions and 111 deletions.
10 changes: 5 additions & 5 deletions mlir/include/mlir/Analysis/Presburger/QuasiPolynomial.h
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Original file line number Diff line number Diff line change
Expand Up @@ -36,10 +36,10 @@ namespace presburger {
// g_{ij} : Q^n -> Q are affine functionals.
class QuasiPolynomial : public PresburgerSpace {
public:
QuasiPolynomial(unsigned numVars, SmallVector<Fraction> coeffs = {},
std::vector<std::vector<SmallVector<Fraction>>> aff = {});
QuasiPolynomial(unsigned numVars, ArrayRef<Fraction> coeffs = {},
ArrayRef<std::vector<SmallVector<Fraction>>> aff = {});

QuasiPolynomial(unsigned numVars, Fraction constant);
QuasiPolynomial(unsigned numVars, const Fraction &constant);

// Find the number of inputs (numDomain) to the polynomial.
// numSymbols is set to zero.
Expand All @@ -57,7 +57,7 @@ class QuasiPolynomial : public PresburgerSpace {
QuasiPolynomial operator+(const QuasiPolynomial &x) const;
QuasiPolynomial operator-(const QuasiPolynomial &x) const;
QuasiPolynomial operator*(const QuasiPolynomial &x) const;
QuasiPolynomial operator/(const Fraction x) const;
QuasiPolynomial operator/(const Fraction &x) const;

// Removes terms which evaluate to zero from the expression
// and folds affine functions which are constant into the
Expand All @@ -77,4 +77,4 @@ class QuasiPolynomial : public PresburgerSpace {
} // namespace presburger
} // namespace mlir

#endif // MLIR_ANALYSIS_PRESBURGER_QUASIPOLYNOMIAL_H
#endif // MLIR_ANALYSIS_PRESBURGER_QUASIPOLYNOMIAL_H
41 changes: 21 additions & 20 deletions mlir/lib/Analysis/Presburger/Barvinok.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -361,7 +361,7 @@ mlir::presburger::detail::computePolytopeGeneratingFunction(
continue;
// If this subset corresponds to a vertex that has not been considered,
// store it.
vertices.push_back(*vertex);
vertices.emplace_back(*vertex);

// If a vertex is formed by the intersection of more than d facets, we
// assume that any d-subset of these facets can be solved to obtain its
Expand Down Expand Up @@ -472,10 +472,10 @@ mlir::presburger::detail::computePolytopeGeneratingFunction(
Point mlir::presburger::detail::getNonOrthogonalVector(
ArrayRef<Point> vectors) {
unsigned dim = vectors[0].size();
assert(
llvm::all_of(vectors,
[&](const Point &vector) { return vector.size() == dim; }) &&
"all vectors need to be the same size!");
assert(llvm::all_of(
vectors,
[&dim](const Point &vector) { return vector.size() == dim; }) &&
"all vectors need to be the same size!");

SmallVector<Fraction> newPoint = {Fraction(1, 1)};
Fraction maxDisallowedValue = -Fraction(1, 0),
Expand All @@ -493,7 +493,7 @@ Point mlir::presburger::detail::getNonOrthogonalVector(
// Find the biggest such value
maxDisallowedValue = std::max(maxDisallowedValue, disallowedValue);
}
newPoint.push_back(maxDisallowedValue + 1);
newPoint.emplace_back(maxDisallowedValue + 1);
}
return newPoint;
}
Expand All @@ -519,19 +519,20 @@ QuasiPolynomial mlir::presburger::detail::getCoefficientInRationalFunction(
unsigned numParam = num[0].getNumInputs();
// We use the `isEqual` method of PresburgerSpace, which QuasiPolynomial
// inherits from.
assert(
llvm::all_of(
num, [&](const QuasiPolynomial &qp) { return num[0].isEqual(qp); }) &&
"the quasipolynomials should all belong to the same space!");
assert(llvm::all_of(num,
[&num](const QuasiPolynomial &qp) {
return num[0].isEqual(qp);
}) &&
"the quasipolynomials should all belong to the same space!");

std::vector<QuasiPolynomial> coefficients;
coefficients.reserve(power + 1);

coefficients.push_back(num[0] / den[0]);
coefficients.emplace_back(num[0] / den[0]);
for (unsigned i = 1; i <= power; ++i) {
// If the power is not there in the numerator, the coefficient is zero.
coefficients.push_back(i < num.size() ? num[i]
: QuasiPolynomial(numParam, 0));
coefficients.emplace_back(i < num.size() ? num[i]
: QuasiPolynomial(numParam, 0));

// After den.size(), the coefficients are zero, so we stop
// subtracting at that point (if it is less than i).
Expand Down Expand Up @@ -573,15 +574,15 @@ substituteMuInTerm(unsigned numParams, const ParamPoint &v,
SmallVector<Fraction> coefficients;
coefficients.reserve(numDims);
for (const Point &d : ds)
coefficients.push_back(-dotProduct(mu, d));
coefficients.emplace_back(-dotProduct(mu, d));

// Then, the affine function is a single floor expression, given by the
// corresponding column of v.
ParamPoint vTranspose = v.transpose();
std::vector<std::vector<SmallVector<Fraction>>> affine;
affine.reserve(numDims);
for (unsigned j = 0; j < numDims; ++j)
affine.push_back({SmallVector<Fraction>(vTranspose.getRow(j))});
affine.push_back({SmallVector<Fraction>{vTranspose.getRow(j)}});

QuasiPolynomial num(numParams, coefficients, affine);
num = num.simplify();
Expand All @@ -593,7 +594,7 @@ substituteMuInTerm(unsigned numParams, const ParamPoint &v,
for (const Point &d : ds) {
// This term in the denominator is
// (1 - t^dens.back())
dens.push_back(dotProduct(d, mu));
dens.emplace_back(dotProduct(d, mu));
}

return {num, dens};
Expand Down Expand Up @@ -641,7 +642,7 @@ std::vector<QuasiPolynomial> getBinomialCoefficients(const QuasiPolynomial &n,
coefficients.emplace_back(numParams, 1);
for (unsigned j = 1; j <= r; ++j)
// We use the recursive formula for binomial coefficients here and below.
coefficients.push_back(
coefficients.emplace_back(
(coefficients[j - 1] * (n - QuasiPolynomial(numParams, j - 1)) /
Fraction(j, 1))
.simplify());
Expand All @@ -656,7 +657,7 @@ std::vector<Fraction> getBinomialCoefficients(const Fraction &n,
coefficients.reserve((int64_t)floor(r));
coefficients.emplace_back(1);
for (unsigned j = 1; j <= r; ++j)
coefficients.push_back(coefficients[j - 1] * (n - (j - 1)) / (j));
coefficients.emplace_back(coefficients[j - 1] * (n - (j - 1)) / (j));
return coefficients;
}

Expand Down Expand Up @@ -764,8 +765,8 @@ mlir::presburger::detail::computeNumTerms(const GeneratingFunction &gf) {
eachTermDenCoefficients.reserve(r);
for (const Fraction &den : dens) {
singleTermDenCoefficients = getBinomialCoefficients(den + 1, den + 1);
eachTermDenCoefficients.push_back(
ArrayRef<Fraction>(singleTermDenCoefficients).slice(1));
eachTermDenCoefficients.emplace_back(
ArrayRef<Fraction>(singleTermDenCoefficients).drop_front());
}

// Now we find the coefficients in Q(s) itself
Expand Down
30 changes: 15 additions & 15 deletions mlir/lib/Analysis/Presburger/IntegerRelation.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -511,10 +511,10 @@ void IntegerRelation::getLowerAndUpperBoundIndices(
continue;
if (atIneq(r, pos) >= 1) {
// Lower bound.
lbIndices->push_back(r);
lbIndices->emplace_back(r);
} else if (atIneq(r, pos) <= -1) {
// Upper bound.
ubIndices->push_back(r);
ubIndices->emplace_back(r);
}
}

Expand All @@ -528,7 +528,7 @@ void IntegerRelation::getLowerAndUpperBoundIndices(
continue;
if (containsConstraintDependentOnRange(r, /*isEq=*/true))
continue;
eqIndices->push_back(r);
eqIndices->emplace_back(r);
}
}

Expand Down Expand Up @@ -791,7 +791,7 @@ IntMatrix IntegerRelation::getBoundedDirections() const {
// processes all the inequalities.
for (unsigned i = 0, e = getNumInequalities(); i < e; ++i) {
if (simplex.isBoundedAlongConstraint(i))
boundedIneqs.push_back(i);
boundedIneqs.emplace_back(i);
}

// The direction vector is given by the coefficients and does not include the
Expand Down Expand Up @@ -1981,13 +1981,13 @@ void IntegerRelation::fourierMotzkinEliminate(unsigned pos, bool darkShadow,
for (unsigned r = 0, e = getNumInequalities(); r < e; r++) {
if (atIneq(r, pos) == 0) {
// Var does not appear in bound.
nbIndices.push_back(r);
nbIndices.emplace_back(r);
} else if (atIneq(r, pos) >= 1) {
// Lower bound.
lbIndices.push_back(r);
lbIndices.emplace_back(r);
} else {
// Upper bound.
ubIndices.push_back(r);
ubIndices.emplace_back(r);
}
}

Expand Down Expand Up @@ -2028,8 +2028,8 @@ void IntegerRelation::fourierMotzkinEliminate(unsigned pos, bool darkShadow,
continue;
assert(lbCoeff >= 1 && ubCoeff >= 1 && "bounds wrongly identified");
DynamicAPInt lcm = llvm::lcm(lbCoeff, ubCoeff);
ineq.push_back(atIneq(ubPos, l) * (lcm / ubCoeff) +
atIneq(lbPos, l) * (lcm / lbCoeff));
ineq.emplace_back(atIneq(ubPos, l) * (lcm / ubCoeff) +
atIneq(lbPos, l) * (lcm / lbCoeff));
assert(lcm > 0 && "lcm should be positive!");
if (lcm != 1)
allLCMsAreOne = false;
Expand Down Expand Up @@ -2057,7 +2057,7 @@ void IntegerRelation::fourierMotzkinEliminate(unsigned pos, bool darkShadow,
for (unsigned l = 0, e = getNumCols(); l < e; l++) {
if (l == pos)
continue;
ineq.push_back(atIneq(nbPos, l));
ineq.emplace_back(atIneq(nbPos, l));
}
newRel.addInequality(ineq);
}
Expand All @@ -2072,7 +2072,7 @@ void IntegerRelation::fourierMotzkinEliminate(unsigned pos, bool darkShadow,
for (unsigned l = 0, e = getNumCols(); l < e; l++) {
if (l == pos)
continue;
eq.push_back(atEq(r, l));
eq.emplace_back(atEq(r, l));
}
newRel.addEquality(eq);
}
Expand Down Expand Up @@ -2264,8 +2264,8 @@ IntegerRelation::unionBoundingBox(const IntegerRelation &otherCst) {
std::negate<DynamicAPInt>());
std::copy(maxUb.begin(), maxUb.end(), newUb.begin() + getNumDimVars());

boundingLbs.push_back(newLb);
boundingUbs.push_back(newUb);
boundingLbs.emplace_back(newLb);
boundingUbs.emplace_back(newUb);
}

// Clear all constraints and add the lower/upper bounds for the bounding box.
Expand Down Expand Up @@ -2309,7 +2309,7 @@ static void getIndependentConstraints(const IntegerRelation &cst, unsigned pos,
break;
}
if (c == pos + num)
nbIneqIndices.push_back(r);
nbIneqIndices.emplace_back(r);
}

for (unsigned r = 0, e = cst.getNumEqualities(); r < e; r++) {
Expand All @@ -2320,7 +2320,7 @@ static void getIndependentConstraints(const IntegerRelation &cst, unsigned pos,
break;
}
if (c == pos + num)
nbEqIndices.push_back(r);
nbEqIndices.emplace_back(r);
}
}

Expand Down
4 changes: 2 additions & 2 deletions mlir/lib/Analysis/Presburger/LinearTransform.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,7 @@ IntegerRelation LinearTransform::applyTo(const IntegerRelation &rel) const {
const DynamicAPInt &c = eq.back();

SmallVector<DynamicAPInt, 8> newEq = preMultiplyWithRow(eq.drop_back());
newEq.push_back(c);
newEq.emplace_back(c);
result.addEquality(newEq);
}

Expand All @@ -61,7 +61,7 @@ IntegerRelation LinearTransform::applyTo(const IntegerRelation &rel) const {
const DynamicAPInt &c = ineq.back();

SmallVector<DynamicAPInt, 8> newIneq = preMultiplyWithRow(ineq.drop_back());
newIneq.push_back(c);
newIneq.emplace_back(c);
result.addInequality(newIneq);
}

Expand Down
6 changes: 3 additions & 3 deletions mlir/lib/Analysis/Presburger/PWMAFunction.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -46,7 +46,7 @@ static SmallVector<DynamicAPInt, 8> subtractExprs(ArrayRef<DynamicAPInt> vecA,
SmallVector<DynamicAPInt, 8> result;
result.reserve(vecA.size());
for (unsigned i = 0, e = vecA.size(); i < e; ++i)
result.push_back(vecA[i] - vecB[i]);
result.emplace_back(vecA[i] - vecB[i]);
return result;
}

Expand Down Expand Up @@ -78,7 +78,7 @@ MultiAffineFunction::valueAt(ArrayRef<DynamicAPInt> point) const {
// function of; we have computed one possible set of values and use them here.
pointHomogenous.reserve(pointHomogenous.size() + divValues.size());
for (const std::optional<DynamicAPInt> &divVal : divValues)
pointHomogenous.push_back(*divVal);
pointHomogenous.emplace_back(*divVal);
// The matrix `output` has an affine expression in the ith row, corresponding
// to the expression for the ith value in the output vector. The last column
// of the matrix contains the constant term. Let v be the input point with
Expand Down Expand Up @@ -295,7 +295,7 @@ void PWMAFunction::addPiece(const Piece &piece) {
assert(piece.isConsistent() && "Piece should be consistent");
assert(piece.domain.intersect(getDomain()).isIntegerEmpty() &&
"Piece should be disjoint from the function");
pieces.push_back(piece);
pieces.emplace_back(piece);
}

void PWMAFunction::print(raw_ostream &os) const {
Expand Down
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