xref: /llvm-project/mlir/lib/Dialect/Polynomial/IR/Polynomial.cpp (revision db791b278a414fb6df1acc1799adcf11d8fb9169)
1 //===- Polynomial.cpp - MLIR storage type for static Polynomial -*- 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 #include "mlir/Dialect/Polynomial/IR/Polynomial.h"
10 
11 #include "llvm/ADT/SmallVector.h"
12 
13 namespace mlir {
14 namespace polynomial {
15 
16 template <typename PolyT, typename MonomialT>
fromMonomialsImpl(ArrayRef<MonomialT> monomials)17 FailureOr<PolyT> fromMonomialsImpl(ArrayRef<MonomialT> monomials) {
18   // A polynomial's terms are canonically stored in order of increasing degree.
19   auto monomialsCopy = llvm::SmallVector<MonomialT>(monomials);
20   std::sort(monomialsCopy.begin(), monomialsCopy.end());
21 
22   // Ensure non-unique exponents are not present. Since we sorted the list by
23   // exponent, a linear scan of adjancent monomials suffices.
24   if (std::adjacent_find(monomialsCopy.begin(), monomialsCopy.end(),
25                          [](const MonomialT &lhs, const MonomialT &rhs) {
26                            return lhs.getExponent() == rhs.getExponent();
27                          }) != monomialsCopy.end()) {
28     return failure();
29   }
30 
31   return PolyT(monomialsCopy);
32 }
33 
34 FailureOr<IntPolynomial>
fromMonomials(ArrayRef<IntMonomial> monomials)35 IntPolynomial::fromMonomials(ArrayRef<IntMonomial> monomials) {
36   return fromMonomialsImpl<IntPolynomial, IntMonomial>(monomials);
37 }
38 
39 FailureOr<FloatPolynomial>
fromMonomials(ArrayRef<FloatMonomial> monomials)40 FloatPolynomial::fromMonomials(ArrayRef<FloatMonomial> monomials) {
41   return fromMonomialsImpl<FloatPolynomial, FloatMonomial>(monomials);
42 }
43 
44 template <typename PolyT, typename MonomialT, typename CoeffT>
fromCoefficientsImpl(ArrayRef<CoeffT> coeffs)45 PolyT fromCoefficientsImpl(ArrayRef<CoeffT> coeffs) {
46   llvm::SmallVector<MonomialT> monomials;
47   auto size = coeffs.size();
48   monomials.reserve(size);
49   for (size_t i = 0; i < size; i++) {
50     monomials.emplace_back(coeffs[i], i);
51   }
52   auto result = PolyT::fromMonomials(monomials);
53   // Construction guarantees unique exponents, so the failure mode of
54   // fromMonomials can be bypassed.
55   assert(succeeded(result));
56   return result.value();
57 }
58 
fromCoefficients(ArrayRef<int64_t> coeffs)59 IntPolynomial IntPolynomial::fromCoefficients(ArrayRef<int64_t> coeffs) {
60   return fromCoefficientsImpl<IntPolynomial, IntMonomial, int64_t>(coeffs);
61 }
62 
fromCoefficients(ArrayRef<double> coeffs)63 FloatPolynomial FloatPolynomial::fromCoefficients(ArrayRef<double> coeffs) {
64   return fromCoefficientsImpl<FloatPolynomial, FloatMonomial, double>(coeffs);
65 }
66 
67 } // namespace polynomial
68 } // namespace mlir
69