src/Common/src/System/Numerics/Hashing/HashHelpers.cs


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// 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.

namespace System.Numerics.Hashing
{
    // Please change the corresponding file in corefx if this is changed.

    internal static class HashHelpers
    {
        public static readonly int RandomSeed = new Random().Next(int.MinValue, int.MaxValue);

        public static int Combine(int h1, int h2)
        {
            // RyuJIT optimizes this to use the ROL instruction
            // Related GitHub pull request: dotnet/coreclr#1830
            uint rol5 = ((uint)h1 << 5) | ((uint)h1 >> 27);
            return ((int)rol5 + h1) ^ h2;
        }
    }
}