Files
even-perfect-numbers-scanner/PerfectNumbers.Core.Tests/MersenneNumberResidueGpuTesterTests.cs
T

296 lines
9.6 KiB
C#

using System.IO;
using System.Linq;
using System.Reflection;
using FluentAssertions;
using PerfectNumbers.Core;
using PerfectNumbers.Core.Cpu;
using PerfectNumbers.Core.Gpu;
using Xunit;
using UInt128 = System.UInt128;
namespace PerfectNumbers.Core.Tests;
public class MersenneNumberResidueGpuTesterTests
{
private static bool LastDigitIsSeven(ulong exponent) => (exponent & 3UL) == 3UL;
[Theory]
[InlineData(false)]
[InlineData(true)]
[Trait("Category", "Fast")]
public void Scan_handles_various_prime_exponents(bool useGpuOrder)
{
var tester = new MersenneNumberResidueGpuTester(useGpuOrder);
RunCase(tester, 23UL, 2UL, expectedPrime: false);
RunCase(tester, 29UL, 37UL, expectedPrime: false);
RunCase(tester, 31UL, 1_000UL, expectedPrime: true);
RunCase(tester, 89UL, 1_001UL, expectedPrime: true);
RunCase(tester, 107UL, 1_001UL, expectedPrime: true);
RunCase(tester, 127UL, 1_001UL, expectedPrime: true);
}
[Theory]
[InlineData(false)]
[InlineData(true)]
[Trait("Category", "Fast")]
public void Gpu_residue_scan_matches_cpu_for_small_configurations(bool useGpuOrder)
{
var gpuTester = new MersenneNumberResidueGpuTester(useGpuOrder);
var cpuTester = new MersenneNumberResidueCpuTester();
var configurations = new (ulong Exponent, UInt128 PerSetLimit, UInt128 SetCount, UInt128 OverallLimit)[]
{
(31UL, 8UL, 6UL, 48UL),
(61UL, 9UL, 9UL, 81UL),
(89UL, 12UL, 8UL, 96UL),
(107UL, 16UL, 8UL, 128UL),
};
foreach (var (exponent, perSetLimit, setCount, overallLimit) in configurations)
{
bool gpuPrime = true;
bool gpuExhausted = false;
gpuTester.Scan(
exponent,
(UInt128)exponent << 1,
LastDigitIsSeven(exponent),
perSetLimit,
setCount,
overallLimit,
ref gpuPrime,
ref gpuExhausted);
bool cpuPrime = true;
bool cpuExhausted = false;
cpuTester.Scan(
exponent,
(UInt128)exponent << 1,
LastDigitIsSeven(exponent),
perSetLimit,
setCount,
overallLimit,
ref cpuPrime,
ref cpuExhausted);
gpuPrime.Should().Be(cpuPrime, $"GPU residue scan should match CPU for exponent {exponent}");
gpuExhausted.Should().Be(cpuExhausted, $"GPU residue scan should report identical exhaustion for exponent {exponent}");
}
}
[Fact]
[Trait("Category", "Fast")]
public void Scan_residue_gpu_handles_inaccurate_small_cycle_entries()
{
const ulong exponent = 23UL;
const ulong divisor = 47UL; // 47 | M_23
string tempPath = Path.GetTempFileName();
try
{
using (var writer = new BinaryWriter(File.Open(tempPath, FileMode.Create, FileAccess.Write, FileShare.Read)))
{
writer.Write(divisor);
writer.Write((ulong)uint.MaxValue);
}
var cycles = MersenneDivisorCycles.Shared;
var tableField = typeof(MersenneDivisorCycles).GetField("_table", BindingFlags.NonPublic | BindingFlags.Instance)!;
var smallCyclesField = typeof(MersenneDivisorCycles).GetField("_smallCycles", BindingFlags.NonPublic | BindingFlags.Instance)!;
var originalTable = ((List<(ulong Divisor, ulong Cycle)>)tableField.GetValue(cycles)!).Select(x => x).ToList();
var originalSmall = (uint[]?)smallCyclesField.GetValue(cycles);
uint[]? backupSmall = originalSmall is null ? null : (uint[])originalSmall.Clone();
cycles.LoadFrom(tempPath);
GpuContextPool.DisposeAll();
try
{
var tester = new MersenneNumberResidueGpuTester(useGpuOrder: false);
bool isPrime = true;
bool exhausted = false;
tester.Scan(
exponent,
(UInt128)exponent << 1,
lastIsSeven: true,
perSetLimit: (UInt128)10UL,
setCount: UInt128.One,
overallLimit: (UInt128)10UL,
ref isPrime,
ref exhausted);
isPrime.Should().BeFalse();
exhausted.Should().BeTrue();
}
finally
{
tableField.SetValue(cycles, originalTable);
smallCyclesField.SetValue(cycles, backupSmall);
GpuContextPool.DisposeAll();
}
}
finally
{
File.Delete(tempPath);
}
}
[Theory]
[InlineData(false)]
[InlineData(true)]
[Trait("Category", "Fast")]
public void Mersenne_tester_residue_gpu_handles_known_primes_with_many_sets(bool useGpuOrder)
{
var tester = new MersenneNumberTester(
useIncremental: true,
useOrderCache: false,
kernelType: GpuKernelType.Pow2Mod,
useModuloWorkaround: false,
useOrder: false,
useGpuLucas: false,
useGpuScan: true,
useGpuOrder: useGpuOrder,
useResidue: true,
maxK: (UInt128)2_400_000UL,
residueDivisorSets: (UInt128)512UL);
try
{
bool isPrime = tester.IsMersennePrime(127UL, out bool divisorsExhausted);
isPrime.Should().BeTrue();
divisorsExhausted.Should().BeTrue();
}
finally
{
GpuContextPool.DisposeAll();
}
}
[Theory]
[InlineData(false)]
[InlineData(true)]
[Trait("Category", "Fast")]
public void Scan_recognizes_all_known_small_mersenne_primes(bool useGpuOrder)
{
var tester = new MersenneNumberResidueGpuTester(useGpuOrder);
foreach (ulong exponent in MersennePrimeTestData.Exponents)
{
RunCase(tester, exponent, 1UL, expectedPrime: true);
}
}
[Theory]
[InlineData(31UL)]
[Trait("Category", "Fast")]
public void Scan_matches_cli_residue_configuration_for_primes(ulong exponent)
{
RunCliCase(useGpuOrder: false, exponent);
RunCliCase(useGpuOrder: true, exponent);
}
[Theory]
[InlineData(31UL, 1_024UL, 1UL)]
[InlineData(31UL, 256UL, 4UL)]
[InlineData(107UL, 512UL, 1UL)]
[InlineData(107UL, 128UL, 4UL)]
[InlineData(107UL, 15_625UL, 64UL)]
[InlineData(127UL, 512UL, 1UL)]
[InlineData(127UL, 128UL, 4UL)]
[Trait("Category", "Fast")]
public void Scan_handles_multiple_residue_sets_for_known_primes(ulong exponent, ulong perSetLimit, ulong setCount)
{
ulong overallLimit = perSetLimit * setCount;
RunCase(new MersenneNumberResidueGpuTester(useGpuOrder: false), exponent, perSetLimit, setCount, overallLimit, expectedPrime: true);
RunCase(new MersenneNumberResidueGpuTester(useGpuOrder: true), exponent, perSetLimit, setCount, overallLimit, expectedPrime: true);
}
[Theory]
[InlineData(107UL, 1UL, 1_024UL)]
[Trait("Category", "Fast")]
public void Scan_handles_single_lane_sets_for_known_primes(ulong exponent, ulong perSetLimit, ulong overallLimit)
{
ulong setCount = overallLimit;
RunCase(new MersenneNumberResidueGpuTester(useGpuOrder: false), exponent, perSetLimit, setCount, overallLimit, expectedPrime: true);
RunCase(new MersenneNumberResidueGpuTester(useGpuOrder: true), exponent, perSetLimit, setCount, overallLimit, expectedPrime: true);
}
[Theory]
[InlineData(false)]
[InlineData(true)]
[Trait("Category", "Fast")]
public void Scan_handles_multiple_sets_without_false_positives(bool useGpuOrder)
{
var tester = new MersenneNumberResidueGpuTester(useGpuOrder);
bool isPrime = true;
bool exhausted = false;
UInt128 perSetLimit = 1_666_667UL;
UInt128 setCount = 3UL;
UInt128 overallLimit = 5_000_000UL;
tester.Scan(
127UL,
(UInt128)127UL << 1,
LastDigitIsSeven(127UL),
perSetLimit,
setCount,
overallLimit,
ref isPrime,
ref exhausted);
isPrime.Should().BeTrue();
exhausted.Should().BeTrue();
isPrime = true;
exhausted = false;
perSetLimit = 20_000_000UL;
setCount = 5UL;
overallLimit = 100_000_000UL;
tester.Scan(
107UL,
(UInt128)107UL << 1,
LastDigitIsSeven(107UL),
perSetLimit,
setCount,
overallLimit,
ref isPrime,
ref exhausted);
isPrime.Should().BeTrue();
exhausted.Should().BeTrue();
}
private static void RunCliCase(bool useGpuOrder, ulong exponent)
{
var tester = new MersenneNumberResidueGpuTester(useGpuOrder);
RunCase(tester, exponent, 8UL, expectedPrime: true);
}
private static void RunCase(MersenneNumberResidueGpuTester tester, ulong exponent, ulong maxK, bool expectedPrime)
{
RunCase(tester, exponent, maxK, 1UL, maxK, expectedPrime);
}
private static void RunCase(
MersenneNumberResidueGpuTester tester,
ulong exponent,
ulong perSetLimit,
ulong setCount,
ulong overallLimit,
bool expectedPrime)
{
bool isPrime = true;
tester.Scan(exponent, (UInt128)exponent << 1, LastDigitIsSeven(exponent), (UInt128)maxK, ref isPrime);
isPrime.Should().Be(expectedPrime);
}
}