[Mlir-commits] [mlir] [MLIR][Presburger] Definitions for basic functions related to cones (PR #76650)

[Arjun P]

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+//===- Barvinok.h - Barvinok's Algorithm ------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of Barvinok's algorithm and related utility functions.
+// Currently a work in progress.
+// These include functions to manipulate cones (define a cone object, get its
+// dual, and find its index).
+//
+// The implementation is based on:
+// 1. Barvinok, Alexander, and James E. Pommersheim. "An algorithmic theory of
+//    lattice points in polyhedra." New perspectives in algebraic combinatorics
+//    38 (1999): 91-147.
+// 2. Verdoolaege, Sven, et al. "Counting integer points in parametric
+//    polytopes using Barvinok's rational functions." Algorithmica 48 (2007):
+//    37-66.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_ANALYSIS_PRESBURGER_BARVINOK_H
+#define MLIR_ANALYSIS_PRESBURGER_BARVINOK_H
+
+#include "mlir/Analysis/Presburger/IntegerRelation.h"
+#include "mlir/Analysis/Presburger/Matrix.h"
+#include <optional>
+
+namespace mlir {
+namespace presburger {
+namespace detail {
+
+/// A polyhedron in H-representation is a set of inequalities
+/// in d variables with integer coefficients.
+using PolyhedronH = IntegerRelation;
+
+/// A polyhedron in V-representation is a set of rays and points, i.e.,
+/// vectors, stored as rows of a matrix.
+using PolyhedronV = IntMatrix;
+
+/// A cone in either representation is a special case of
+/// a polyhedron in that representation.
+using ConeH = PolyhedronH;
+using ConeV = PolyhedronV;
+
+inline ConeH defineHRep(int num_vars) {
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Superty wrote:

For consistency, if nothing else. I think `unsigned` has been used for these kinds of arguments in this part of the code since before I started contributing.

https://github.com/llvm/llvm-project/pull/76650