46 lines
1.9 KiB
C#
46 lines
1.9 KiB
C#
using PerfectNumbers.Core.Gpu;
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namespace PerfectNumbers.Core;
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internal static partial class PrimeOrderCalculator
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{
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private static bool IsGpuPow2Allowed => s_pow2ModeInitialized && s_allowGpuPow2;
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private const int GpuSmallPrimeFactorSlots = 64;
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private static bool TryPopulateSmallPrimeFactorsGpu(ulong value, uint limit, Dictionary<ulong, int> counts, out ulong remaining)
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{
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ulong[] primeBufferArray = ThreadStaticPools.UlongPool.Rent(GpuSmallPrimeFactorSlots);
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int[] exponentBufferArray = ThreadStaticPools.IntPool.Rent(GpuSmallPrimeFactorSlots);
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Span<ulong> primeBuffer = primeBufferArray.AsSpan(0, GpuSmallPrimeFactorSlots);
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Span<int> exponentBuffer = exponentBufferArray.AsSpan(0, GpuSmallPrimeFactorSlots);
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primeBuffer.Clear();
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exponentBuffer.Clear();
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if (!PrimeOrderGpuHeuristics.TryPartialFactor(value, limit, primeBuffer, exponentBuffer, out int factorCount, out ulong gpuRemaining, out _))
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{
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remaining = value;
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ThreadStaticPools.UlongPool.Return(primeBufferArray);
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ThreadStaticPools.IntPool.Return(exponentBufferArray);
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return false;
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}
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remaining = gpuRemaining;
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for (int i = 0; i < factorCount; i++)
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{
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ulong primeValue = primeBuffer[i];
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int exponent = exponentBuffer[i];
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if (primeValue == 0UL || exponent == 0)
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{
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continue;
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}
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counts[primeValue] = exponent;
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}
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ThreadStaticPools.UlongPool.Return(primeBufferArray);
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ThreadStaticPools.IntPool.Return(exponentBufferArray);
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return true;
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}
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}
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