SqMtx.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//

using BenchmarkDotNet.Attributes;
using MicroBenchmarks;

namespace Benchstone.BenchF
{
[BenchmarkCategory(Categories.Runtime, Categories.Benchstones, Categories.JIT, Categories.BenchF)]
public class SqMtx
{
    public const int Iterations = 4000;

    private const int MatrixSize = 40;

    private static T[][] AllocArray<T>(int n1, int n2)
    {
        T[][] a = new T[n1][];
        for (int i = 0; i < n1; ++i)
        {
            a[i] = new T[n2];
        }
        return a;
    }

    [Benchmark(Description = nameof(SqMtx))]
    public bool Test()
    {
        double[][] a = AllocArray<double>(41, 41);
        double[][] c = AllocArray<double>(41, 41);

        int i, j;

        for (i = 1; i <= MatrixSize; i++)
        {
            for (j = 1; j <= MatrixSize; j++)
            {
                a[i][j] = i + j;
            }
        }

        for (i = 1; i <= Iterations; i++)
        {
            Inner(a, c, MatrixSize);
        }

        if (c[1][1] == 23820.0)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    private static void Inner(double[][] a, double[][] c, int n)
    {
        for (int i = 1; i <= n; i++)
        {
            for (int j = 1; j <= n; j++)
            {
                c[i][j] = 0.0;
                for (int k = 1; k <= n; k++)
                {
                    c[i][j] = c[i][j] + a[i][k] * a[k][j];
                }
            }
        }
    }
}
}