[Mlir-commits] [mlir] [MLIR][Presburger] Generating functions and quasi-polynomials for Barvinok's algorithm (PR #75702)

[Arjun P]

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+//===- GeneratingFunction.h - Rational Polynomials over Q^d -----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Definition of the GeneratingFunction class for Barvinok's algorithm,
+// which represents a function over Q^n, parameterized by d parameters.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_ANALYSIS_PRESBURGER_GENERATINGFUNCTION_H
+#define MLIR_ANALYSIS_PRESBURGER_GENERATINGFUNCTION_H
+
+#include "mlir/Analysis/Presburger/Fraction.h"
+#include "mlir/Analysis/Presburger/Matrix.h"
+
+namespace mlir {
+namespace presburger {
+
+// A parametric point is a vector, each of whose elements
+// is an affine function of n parameters. Each row
+// in the matrix represents the affine function and
+// has n+1 elements.
+using ParamPoint = Matrix<Fraction>;
+
+// A point is simply a vector.
+using Point = SmallVector<Fraction>;
+
+// A class to describe the type of generating function
+// used to enumerate the integer points in a polytope.
+// Consists of a set of terms, where the ith term has
+// * a sign, ±1, stored in `signs[i]`
+// * a numerator, of the form x^{n},
+//      where n, stored in `numerators[i]`,
+//      is a parametric point (a vertex).
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Superty wrote:

I would suggest encapsulating by removing these mentions of "vertex" and "generators" from here, this is just a generating function class that represents/allows certain things. I don't think these things give more intuition into understanding the class here, and vertex does not really mean anything in the current context without further explanatino.

https://github.com/llvm/llvm-project/pull/75702