108 lines
4.3 KiB
C#
108 lines
4.3 KiB
C#
using System.Numerics;
|
|
using FluentAssertions;
|
|
using PerfectNumbers.Core.Cpu;
|
|
using Xunit;
|
|
|
|
namespace PerfectNumbers.Core.Tests;
|
|
|
|
public class MersenneNumberDivisorCpuTesterTests
|
|
{
|
|
[Fact]
|
|
[Trait("Category", "Fast")]
|
|
public void ByDivisor_tester_tracks_divisors_across_primes()
|
|
{
|
|
var tester = new MersenneNumberDivisorByDivisorCpuTesterWithCpuOrder();
|
|
|
|
ulong[] primes = [5UL, 7UL, 11UL];
|
|
ulong[] allowedMax = new ulong[primes.Length];
|
|
tester.PrepareCandidates(maxPrime: 11UL, primes, allowedMax);
|
|
|
|
tester.ResumeFromState(Path.Combine(Path.GetTempPath(), "bydivisor-cpu-tests.bin"), BigInteger.Zero, BigInteger.One);
|
|
tester.ResetStateTracking();
|
|
|
|
tester.IsPrime(5UL, out bool divisorsExhausted, out BigInteger divisor).Should().BeTrue();
|
|
divisorsExhausted.Should().BeTrue();
|
|
divisor.Should().Be(BigInteger.Zero);
|
|
|
|
tester.IsPrime(7UL, out divisorsExhausted, out divisor).Should().BeTrue();
|
|
divisorsExhausted.Should().BeTrue();
|
|
divisor.Should().Be(BigInteger.Zero);
|
|
|
|
tester.IsPrime(11UL, out divisorsExhausted, out divisor).Should().BeFalse();
|
|
divisorsExhausted.Should().BeTrue();
|
|
divisor.Should().BeGreaterThan(BigInteger.Zero);
|
|
}
|
|
|
|
[Fact]
|
|
[Trait("Category", "Fast")]
|
|
public void ByDivisor_session_checks_divisors_across_primes()
|
|
{
|
|
var session = new MersenneCpuDivisorScanSessionWithCpuOrder();
|
|
|
|
ulong[] primes = [5UL, 7UL, 11UL, 13UL];
|
|
|
|
ulong cycle23 = MersenneDivisorCyclesCpu.CalculateCycleLength(23UL, MontgomeryDivisorData.FromModulus(23UL));
|
|
session.CheckDivisor(23UL, MontgomeryDivisorData.FromModulus(23UL), cycle23, primes).Should().BeTrue();
|
|
|
|
ulong[] primesWithoutHit = [5UL, 7UL, 13UL];
|
|
session.CheckDivisor(23UL, MontgomeryDivisorData.FromModulus(23UL), cycle23, primesWithoutHit).Should().BeFalse();
|
|
|
|
ulong cycle31 = MersenneDivisorCyclesCpu.CalculateCycleLength(31UL, MontgomeryDivisorData.FromModulus(31UL));
|
|
session.CheckDivisor(31UL, MontgomeryDivisorData.FromModulus(31UL), cycle31, primes).Should().BeTrue();
|
|
|
|
ulong[] primesBeforeHit = [7UL, 11UL, 13UL];
|
|
session.CheckDivisor(31UL, MontgomeryDivisorData.FromModulus(31UL), cycle31, primesBeforeHit).Should().BeFalse();
|
|
}
|
|
|
|
[Fact]
|
|
[Trait("Category", "Fast")]
|
|
public void ByDivisor_session_marks_mersenne_numbers_divisible_by_seven_as_composite()
|
|
{
|
|
var session = new MersenneCpuDivisorScanSessionWithCpuOrder();
|
|
|
|
ulong[] exponents = [6UL, 7UL, 9UL, 10UL, 12UL];
|
|
|
|
MontgomeryDivisorData divisorData = MontgomeryDivisorData.FromModulus(7UL);
|
|
ulong cycle = MersenneDivisorCyclesCpu.CalculateCycleLength(7UL, divisorData);
|
|
session.CheckDivisor(7UL, divisorData, cycle, exponents).Should().BeTrue();
|
|
|
|
ulong[] nonDivisibleExponents = [5UL, 11UL];
|
|
session.CheckDivisor(7UL, divisorData, cycle, nonDivisibleExponents).Should().BeFalse();
|
|
}
|
|
|
|
[Fact]
|
|
[Trait("Category", "Fast")]
|
|
public void ByDivisor_session_marks_mersenne_numbers_divisible_by_eleven_as_composite()
|
|
{
|
|
var session = new MersenneCpuDivisorScanSessionWithCpuOrder();
|
|
|
|
ulong[] exponents = [10UL, 11UL, 20UL, 21UL, 30UL];
|
|
|
|
MontgomeryDivisorData divisorData = MontgomeryDivisorData.FromModulus(11UL);
|
|
ulong cycle = MersenneDivisorCyclesCpu.CalculateCycleLength(11UL, divisorData);
|
|
session.CheckDivisor(11UL, divisorData, cycle, exponents).Should().BeTrue();
|
|
|
|
ulong[] nonDivisibleExponents = [5UL, 17UL];
|
|
session.CheckDivisor(11UL, divisorData, cycle, nonDivisibleExponents).Should().BeFalse();
|
|
}
|
|
|
|
[Fact]
|
|
[Trait("Category", "Fast")]
|
|
public void ByDivisor_does_not_mark_mersenne_prime_as_composite_via_self_divisor()
|
|
{
|
|
var tester = new MersenneNumberDivisorByDivisorCpuTesterWithCpuOrder();
|
|
|
|
tester.DivisorLimit = (BigInteger.One << 30) - BigInteger.One;
|
|
BigInteger kSelf = ((BigInteger.One << 31) - 2) / 62; // (2^p - 2) / (2p) for p=31.
|
|
|
|
tester.ResumeFromState(Path.Combine(Path.GetTempPath(), "bydivisor-selfdivisor.bin"), BigInteger.Zero, kSelf);
|
|
tester.ResetStateTracking();
|
|
|
|
tester.IsPrime(31UL, out bool divisorsExhausted, out BigInteger divisor).Should().BeTrue();
|
|
divisorsExhausted.Should().BeTrue();
|
|
divisor.Should().Be(BigInteger.Zero);
|
|
}
|
|
|
|
}
|
|
|