MLIR  19.0.0git
QuasiPolynomial.h
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1 //===- QuasiPolynomial.h - QuasiPolynomial Class ----------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Definition of the QuasiPolynomial class for Barvinok's algorithm,
10 // which represents a single-valued function on a set of parameters.
11 // It is an expression of the form
12 // f(x) = \sum_i c_i * \prod_j ⌊g_{ij}(x)⌋
13 // where c_i \in Q and
14 // g_{ij} : Q^d -> Q are affine functionals over d parameters.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef MLIR_ANALYSIS_PRESBURGER_QUASIPOLYNOMIAL_H
19 #define MLIR_ANALYSIS_PRESBURGER_QUASIPOLYNOMIAL_H
20 
23 
24 namespace mlir {
25 namespace presburger {
26 
27 // A class to describe quasi-polynomials.
28 // A quasipolynomial consists of a set of terms.
29 // The ith term is a constant `coefficients[i]`, multiplied
30 // by the product of a set of affine functions on n parameters.
31 // Represents functions f : Q^n -> Q of the form
32 //
33 // f(x) = \sum_i c_i * \prod_j ⌊g_{ij}(x)⌋
34 //
35 // where c_i \in Q and
36 // g_{ij} : Q^n -> Q are affine functionals.
38 public:
39  QuasiPolynomial(unsigned numVars, ArrayRef<Fraction> coeffs = {},
41 
42  QuasiPolynomial(unsigned numVars, const Fraction &constant);
43 
44  // Find the number of inputs (numDomain) to the polynomial.
45  // numSymbols is set to zero.
46  unsigned getNumInputs() const {
48  }
49 
50  const SmallVector<Fraction> &getCoefficients() const { return coefficients; }
51 
52  const std::vector<std::vector<SmallVector<Fraction>>> &getAffine() const {
53  return affine;
54  }
55 
56  // Arithmetic operations.
60  QuasiPolynomial operator/(const Fraction &x) const;
61 
62  // Removes terms which evaluate to zero from the expression
63  // and folds affine functions which are constant into the
64  // constant coefficients.
66 
67  // Group together like terms in the expression.
69 
71 
72 private:
73  SmallVector<Fraction> coefficients;
74  std::vector<std::vector<SmallVector<Fraction>>> affine;
75 };
76 
77 } // namespace presburger
78 } // namespace mlir
79 
80 #endif // MLIR_ANALYSIS_PRESBURGER_QUASIPOLYNOMIAL_H
PresburgerSpace is the space of all possible values of a tuple of integer valued variables/variables.
QuasiPolynomial operator/(const Fraction &x) const
QuasiPolynomial(unsigned numVars, ArrayRef< Fraction > coeffs={}, ArrayRef< std::vector< SmallVector< Fraction >>> aff={})
QuasiPolynomial operator-(const QuasiPolynomial &x) const
QuasiPolynomial operator+(const QuasiPolynomial &x) const
const std::vector< std::vector< SmallVector< Fraction > > > & getAffine() const
QuasiPolynomial operator*(const QuasiPolynomial &x) const
const SmallVector< Fraction > & getCoefficients() const
Include the generated interface declarations.
A class to represent fractions.
Definition: Fraction.h:28