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Extract divisor validator and rename legacy CPU prime helper

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Marek Lemańczyk committed 2025-10-26 18:59:07 +01:00
1 parent 1e5eadac34
commit 3758524450
11 files changed
+67 -61
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PerfectNumbers.Core/DivisorGenerator.cs
+38
View File
@@ -0,0 +1,38 @@
using System.Runtime.CompilerServices;
namespace PerfectNumbers.Core;
internal static class DivisorGenerator
{
private const ushort DecimalMaskWhenLastIsSeven = (1 << 3) | (1 << 7) | (1 << 9);
private const ushort DecimalMaskOtherwise = (1 << 1) | (1 << 3) | (1 << 9);
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static bool IsValidDivisor(
byte remainder10,
byte remainder8,
byte remainder3,
byte remainder5,
byte remainder7,
byte remainder11,
LastDigit lastDigit)
{
ushort decimalMask = lastDigit == LastDigit.Seven ? DecimalMaskWhenLastIsSeven : DecimalMaskOtherwise;
if (((decimalMask >> remainder10) & 1) == 0)
{
return false;
}
if (remainder8 != 1 && remainder8 != 7)
{
return false;
}
if (remainder3 == 0 || remainder5 == 0 || remainder7 == 0 || remainder11 == 0)
{
return false;
}
return true;
}
}
PerfectNumbers.Core/Gpu/MersenneNumberDivisorByDivisorGpuTester.cs
+1 -33
View File
@@ -263,7 +263,7 @@ public sealed class MersenneNumberDivisorByDivisorGpuTester : IMersenneNumberDiv
{
ulong candidate = (ulong)nextDivisor128;
if (CandidatePassesHeuristics(localRemainder10, localRemainder8, localRemainder3, localRemainder5, localRemainder7, localRemainder11, lastDigit))
if (DivisorGenerator.IsValidDivisor(localRemainder10, localRemainder8, localRemainder3, localRemainder5, localRemainder7, localRemainder11, lastDigit))
{
filteredStorage[filteredCount++] = candidate;
}
@@ -378,38 +378,6 @@ public sealed class MersenneNumberDivisorByDivisorGpuTester : IMersenneNumberDiv
return computedCycle;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static bool CandidatePassesHeuristics(
byte remainder10,
byte remainder8,
byte remainder3,
byte remainder5,
byte remainder7,
byte remainder11,
LastDigit lastDigit)
{
const ushort DecimalMaskWhenLastIsSeven = (1 << 3) | (1 << 7) | (1 << 9);
const ushort DecimalMaskOtherwise = (1 << 1) | (1 << 3) | (1 << 9);
ushort decimalMask = lastDigit == LastDigit.Seven ? DecimalMaskWhenLastIsSeven : DecimalMaskOtherwise;
if (((decimalMask >> remainder10) & 1) == 0)
{
return false;
}
if (remainder8 != 1 && remainder8 != 7)
{
return false;
}
if (remainder3 == 0 || remainder5 == 0 || remainder7 == 0 || remainder11 == 0)
{
return false;
}
return true;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
private static byte AddMod(byte value, byte delta, byte modulus)
{
PerfectNumbers.Core/MersenneDivisorCycles.cs
+3 -3
View File
@@ -394,9 +394,9 @@ public class MersenneDivisorCycles
return true;
}
// TODO: Benchmark PrimeTester.IsPrimeCp against Open.Numeric.Primes on the EvenPerfectBitScanner workloads to confirm the faster option for wide composites.
// TODO: Benchmark PrimeTester.IsPrimeCpu against Open.Numeric.Primes on the EvenPerfectBitScanner workloads to confirm the faster option for wide composites.
// if (HeuristicPrimeTester.Exclusive.IsPrimeCpu(remaining, CancellationToken.None))
if (PrimeTester.IsPrimeCp(remaining, CancellationToken.None))
if (PrimeTester.IsPrimeCpu(remaining, CancellationToken.None))
{
AddFactor(counts, remaining);
return true;
@@ -929,7 +929,7 @@ public class MersenneDivisorCycles
}
// if (!skipPrimeOrderHeuristic && HeuristicPrimeTester.Exclusive.IsPrimeCpu(divisor, CancellationToken.None))
if (!skipPrimeOrderHeuristic && PrimeTester.IsPrimeCp(divisor, CancellationToken.None))
if (!skipPrimeOrderHeuristic && PrimeTester.IsPrimeCpu(divisor, CancellationToken.None))
{
ulong computedOrder = PrimeOrderCalculator.Calculate(
divisor,
PerfectNumbers.Core/MersennePrimeFactorTester.cs
+2 -2
View File
@@ -26,7 +26,7 @@ public static class MersennePrimeFactorTester
}
// if (!HeuristicPrimeTester.Exclusive.IsPrimeCpu(q, ct))
if (!PrimeTester.IsPrimeCp(q, ct))
if (!PrimeTester.IsPrimeCpu(q, ct))
{
return false;
}
@@ -235,7 +235,7 @@ public static class MersennePrimeFactorTester
}
// if (HeuristicPrimeTester.Exclusive.IsPrimeCpu(m, ct))
if (PrimeTester.IsPrimeCp(m, ct))
if (PrimeTester.IsPrimeCpu(m, ct))
{
dict[m] = 1;
continue;
PerfectNumbers.Core/PrimeOrderCalculator.Cpu.cs
+13 -13
View File
@@ -516,7 +516,7 @@ internal static partial class PrimeOrderCalculator
return false;
}
// if (!PrimeTester.IsPrimeCp(orderFactors.Cofactor, CancellationToken.None))
// if (!PrimeTester.IsPrimeCpu(orderFactors.Cofactor, CancellationToken.None))
if (!orderFactors.CofactorIsPrime)
{
return false;
@@ -1123,8 +1123,8 @@ internal static partial class PrimeOrderCalculator
// }
// bool isPrime = primeTester.HeuristicIsPrimeGpu(composite);
// bool isPrime = PrimeTester.IsPrimeCp(composite, CancellationToken.None);
bool isPrime = PrimeTester.IsPrimeCp(composite, CancellationToken.None);
// bool isPrime = PrimeTester.IsPrimeCpu(composite, CancellationToken.None);
bool isPrime = PrimeTester.IsPrimeCpu(composite, CancellationToken.None);
// bool isPrime = Open.Numeric.Primes.Prime.Numbers.IsPrime(composite);
if (isPrime)
@@ -1186,8 +1186,8 @@ internal static partial class PrimeOrderCalculator
if (!entry.HasKnownPrimality)
{
// bool isPrime = primeTester.HeuristicIsPrimeGpu(composite);
// bool isPrime = PrimeTester.IsPrimeCp(composite, CancellationToken.None);
bool isPrime = PrimeTester.IsPrimeCp(composite, CancellationToken.None);
// bool isPrime = PrimeTester.IsPrimeCpu(composite, CancellationToken.None);
bool isPrime = PrimeTester.IsPrimeCpu(composite, CancellationToken.None);
// bool isPrime = Open.Numeric.Primes.Prime.Numbers.IsPrime(composite);
entry = entry.WithPrimality(isPrime);
@@ -1219,8 +1219,8 @@ internal static partial class PrimeOrderCalculator
else
{
// cofactorIsPrime = primeTester.HeuristicIsPrimeGpu(cofactor);
// cofactorIsPrime = PrimeTester.IsPrimeCp(cofactor, CancellationToken.None);
cofactorIsPrime = PrimeTester.IsPrimeCp(cofactor, CancellationToken.None);
// cofactorIsPrime = PrimeTester.IsPrimeCpu(cofactor, CancellationToken.None);
cofactorIsPrime = PrimeTester.IsPrimeCpu(cofactor, CancellationToken.None);
// cofactorIsPrime = Open.Numeric.Primes.Prime.Numbers.IsPrime(cofactor);
}
@@ -1752,8 +1752,8 @@ internal static partial class PrimeOrderCalculator
PrimeTester primeTester = PrimeTester.Exclusive;
// bool isPrime = primeTester.HeuristicIsPrimeGpu(value);
// bool isPrime = PrimeTester.IsPrimeCp(value, CancellationToken.None);
bool isPrime = PrimeTester.IsPrimeCp(value, CancellationToken.None);
// bool isPrime = PrimeTester.IsPrimeCpu(value, CancellationToken.None);
bool isPrime = PrimeTester.IsPrimeCpu(value, CancellationToken.None);
// bool isPrime = Open.Numeric.Primes.Prime.Numbers.IsPrime(value);
if (!knownComposite && isPrime)
{
@@ -1765,8 +1765,8 @@ internal static partial class PrimeOrderCalculator
ulong quotient = value / factor;
// isPrime = primeTester.HeuristicIsPrimeGpu(factor);
// isPrime = PrimeTester.IsPrimeCp(factor, CancellationToken.None);
isPrime = PrimeTester.IsPrimeCp(factor, CancellationToken.None);
// isPrime = PrimeTester.IsPrimeCpu(factor, CancellationToken.None);
isPrime = PrimeTester.IsPrimeCpu(factor, CancellationToken.None);
// isPrime = Open.Numeric.Primes.Prime.Numbers.IsPrime(factor);
if (isPrime)
{
@@ -1797,8 +1797,8 @@ internal static partial class PrimeOrderCalculator
else
{
// isPrime = primeTester.HeuristicIsPrimeGpu(quotient);
// isPrime = PrimeTester.IsPrimeCp(quotient, CancellationToken.None);
isPrime = PrimeTester.IsPrimeCp(quotient, CancellationToken.None);
// isPrime = PrimeTester.IsPrimeCpu(quotient, CancellationToken.None);
isPrime = PrimeTester.IsPrimeCpu(quotient, CancellationToken.None);
// isPrime = Open.Numeric.Primes.Prime.Numbers.IsPrime(quotient);
}
PerfectNumbers.Core/PrimeOrderCalculator.Shared.cs
+1 -1
View File
@@ -956,7 +956,7 @@ internal static partial class PrimeOrderCalculator
if (value <= ulong.MaxValue)
{
// return HeuristicPrimeTester.Exclusive.IsPrimeCpu((ulong)value, CancellationToken.None);
return PrimeTester.IsPrimeCp((ulong)value, CancellationToken.None);
return PrimeTester.IsPrimeCpu((ulong)value, CancellationToken.None);
}
if ((value & UInt128.One) == UInt128.Zero)
PerfectNumbers.Core/PrimeTester.cs
+2 -2
View File
@@ -93,10 +93,10 @@ public sealed class PrimeTester
bool gpuReportedPrime = !forceCpu && !belowGpuRange && outFlags[0] != 0;
bool requiresCpuFallback = forceCpu || belowGpuRange || !gpuReportedPrime;
return requiresCpuFallback ? IsPrimeCp(n, ct) : true;
return requiresCpuFallback ? IsPrimeCpu(n, ct) : true;
}
public static bool IsPrimeCp(ulong n, CancellationToken ct)
public static bool IsPrimeCpu(ulong n, CancellationToken ct)
{
// Preserve the legacy entry point for callers that bypass the thread-local caches.
return Exclusive.IsPrime(n, ct);