Tiny cleanup

This commit is contained in:
Marek Lemańczyk committed 2025-09-21 09:51:05 +02:00
1 parent 2c2bc62cb2
commit 860d64baba
1 file changed
+121 -121
@@ -9,11 +9,11 @@ namespace PerfectNumbers.Core.Gpu;
public sealed class MersenneNumberDivisorGpuTester
{
private readonly ConcurrentDictionary<Accelerator, Action<Index1D, ulong, GpuUInt128, ArrayView<byte>>> _kernelCache = new();
private readonly ConcurrentDictionary<Accelerator, MemoryBuffer1D<byte, Stride1D.Dense>> _resultBuffers = new();
private readonly ConcurrentDictionary<Accelerator, Action<Index1D, ulong, GpuUInt128, ArrayView<byte>>> _kernelCache = new();
private readonly ConcurrentDictionary<Accelerator, MemoryBuffer1D<byte, Stride1D.Dense>> _resultBuffers = new();
private Action<Index1D, ulong, GpuUInt128, ArrayView<byte>> GetKernel(Accelerator accelerator) =>
_kernelCache.GetOrAdd(accelerator, acc => acc.LoadAutoGroupedStreamKernel<Index1D, ulong, GpuUInt128, ArrayView<byte>>(Kernel));
private Action<Index1D, ulong, GpuUInt128, ArrayView<byte>> GetKernel(Accelerator accelerator) =>
_kernelCache.GetOrAdd(accelerator, acc => acc.LoadAutoGroupedStreamKernel<Index1D, ulong, GpuUInt128, ArrayView<byte>>(Kernel));
public static void BuildDivisorCandidates()
{
@@ -32,137 +32,137 @@ public sealed class MersenneNumberDivisorGpuTester
list[count++] = ((ulong)i, cycle);
}
_divisorCandidates = count == 0 ? Array.Empty<(ulong divisor, uint cycle)>() : list[..count].ToArray();
}
_divisorCandidates = count == 0 ? [] : list[..count];
}
public bool IsDivisible(ulong exponent, UInt128 divisor)
{
var gpu = GpuContextPool.RentPreferred(preferCpu: false);
var accelerator = gpu.Accelerator;
var kernel = GetKernel(accelerator);
var resultBuffer = _resultBuffers.GetOrAdd(accelerator, acc => acc.Allocate1D<byte>(1));
resultBuffer.MemSetToZero();
kernel(1, exponent, (GpuUInt128)divisor, resultBuffer.View);
accelerator.Synchronize();
Span<byte> result = stackalloc byte[1];
resultBuffer.View.CopyToCPU(ref result[0], 1);
bool divisible = result[0] != 0;
result[0] = 0;
resultBuffer.View.CopyFromCPU(ref result[0], 1);
accelerator.Synchronize();
gpu.Dispose();
return divisible;
}
public bool IsDivisible(ulong exponent, UInt128 divisor)
{
var gpu = GpuContextPool.RentPreferred(preferCpu: false);
var accelerator = gpu.Accelerator;
var kernel = GetKernel(accelerator);
var resultBuffer = _resultBuffers.GetOrAdd(accelerator, acc => acc.Allocate1D<byte>(1));
resultBuffer.MemSetToZero();
kernel(1, exponent, (GpuUInt128)divisor, resultBuffer.View);
accelerator.Synchronize();
Span<byte> result = stackalloc byte[1];
resultBuffer.View.CopyToCPU(ref result[0], 1);
bool divisible = result[0] != 0;
result[0] = 0;
resultBuffer.View.CopyFromCPU(ref result[0], 1);
accelerator.Synchronize();
gpu.Dispose();
return divisible;
}
private static (ulong divisor, uint cycle)[]? _divisorCandidates = Array.Empty<(ulong divisor, uint cycle)>();
private static (ulong divisor, uint cycle)[]? _divisorCandidates = Array.Empty<(ulong divisor, uint cycle)>();
public bool IsPrime(ulong p, UInt128 d, ulong divisorCyclesSearchLimit, out bool divisorsExhausted)
{
if (d != UInt128.Zero)
{
if (IsDivisible(p, d))
{
divisorsExhausted = true;
return false;
}
public bool IsPrime(ulong p, UInt128 d, ulong divisorCyclesSearchLimit, out bool divisorsExhausted)
{
if (d != UInt128.Zero)
{
if (IsDivisible(p, d))
{
divisorsExhausted = true;
return false;
}
divisorsExhausted = false;
return true;
}
divisorsExhausted = false;
return true;
}
if (_divisorCandidates is { Length: > 0 } candidates)
{
int len = candidates.Length;
uint cycle;
for (int k = 0; k < len; k++)
{
(ulong dSmall, cycle) = candidates[k];
if (p % cycle != 0UL)
{
continue;
}
if (_divisorCandidates is { Length: > 0 } candidates)
{
int len = candidates.Length;
uint cycle;
for (int k = 0; k < len; k++)
{
(ulong dSmall, cycle) = candidates[k];
if (p % cycle != 0UL)
{
continue;
}
if (IsDivisible(p, dSmall))
{
divisorsExhausted = true;
return false;
}
}
}
if (IsDivisible(p, dSmall))
{
divisorsExhausted = true;
return false;
}
}
}
UInt128 kMul2;
var divisorCycles = MersenneDivisorCycles.Shared;
UInt128 maxK2 = UInt128.MaxValue / ((UInt128)p << 1);
ulong limit = divisorCyclesSearchLimit;
if ((UInt128)limit > maxK2)
{
limit = (ulong)maxK2;
}
UInt128 kMul2;
var divisorCycles = MersenneDivisorCycles.Shared;
UInt128 maxK2 = UInt128.MaxValue / ((UInt128)p << 1);
ulong limit = divisorCyclesSearchLimit;
if ((UInt128)limit > maxK2)
{
limit = (ulong)maxK2;
}
ulong k2;
for (k2 = 1UL; k2 <= limit; k2++)
{
kMul2 = (UInt128)k2 << 1;
UInt128 candidate = checked(kMul2 * p);
d = checked(candidate + UInt128.One);
if (p < 64UL && d == ((UInt128)1 << (int)p) - UInt128.One)
{
continue;
}
ulong k2;
for (k2 = 1UL; k2 <= limit; k2++)
{
kMul2 = (UInt128)k2 << 1;
UInt128 candidate = checked(kMul2 * p);
d = checked(candidate + UInt128.One);
if (p < 64UL && d == ((UInt128)1 << (int)p) - UInt128.One)
{
continue;
}
UInt128 cycle128 = MersenneDivisorCycles.GetCycle(d);
if ((UInt128)p % cycle128 != UInt128.Zero)
{
continue;
}
UInt128 cycle128 = MersenneDivisorCycles.GetCycle(d);
if ((UInt128)p % cycle128 != UInt128.Zero)
{
continue;
}
if (IsDivisible(p, d))
{
divisorsExhausted = true;
return false;
}
}
if (IsDivisible(p, d))
{
divisorsExhausted = true;
return false;
}
}
divisorsExhausted = (UInt128)divisorCyclesSearchLimit >= maxK2;
return true;
}
divisorsExhausted = (UInt128)divisorCyclesSearchLimit >= maxK2;
return true;
}
private static void Kernel(Index1D _, ulong exponent, GpuUInt128 divisor, ArrayView<byte> result)
{
if (divisor.High == 0UL && divisor.Low <= 1UL)
{
result[0] = 0;
return;
}
private static void Kernel(Index1D _, ulong exponent, GpuUInt128 divisor, ArrayView<byte> result)
{
if (divisor.High == 0UL && divisor.Low <= 1UL)
{
result[0] = 0;
return;
}
GpuUInt128 baseVal, mod;
int x = divisor.High == 0UL
? 63 - XMath.LeadingZeroCount(divisor.Low)
: 127 - XMath.LeadingZeroCount(divisor.High);
mod = divisor;
if (x == 0)
{
baseVal = GpuUInt128.Pow2Mod(exponent, mod);
result[0] = baseVal.High == 0UL && baseVal.Low == 1UL ? (byte)1 : (byte)0;
return;
}
GpuUInt128 baseVal, mod;
int x = divisor.High == 0UL
? 63 - XMath.LeadingZeroCount(divisor.Low)
: 127 - XMath.LeadingZeroCount(divisor.High);
mod = divisor;
if (x == 0)
{
baseVal = GpuUInt128.Pow2Mod(exponent, mod);
result[0] = baseVal.High == 0UL && baseVal.Low == 1UL ? (byte)1 : (byte)0;
return;
}
ulong ux = (ulong)x;
if (x >= 64)
{
baseVal = new GpuUInt128(1UL << (x - 64), 0UL);
}
else
{
baseVal = new GpuUInt128(0UL, 1UL << x);
}
ulong ux = (ulong)x;
if (x >= 64)
{
baseVal = new GpuUInt128(1UL << (x - 64), 0UL);
}
else
{
baseVal = new GpuUInt128(0UL, 1UL << x);
}
GpuUInt128 pow = baseVal;
pow.ModPow(exponent / ux, mod);
var part2 = GpuUInt128.Pow2Mod(exponent % ux, mod);
GpuUInt128 product = pow;
product.MulMod(part2, mod);
result[0] = product.High == 0UL && product.Low == 1UL ? (byte)1 : (byte)0;
}
GpuUInt128 pow = baseVal;
pow.ModPow(exponent / ux, mod);
var part2 = GpuUInt128.Pow2Mod(exponent % ux, mod);
GpuUInt128 product = pow;
product.MulMod(part2, mod);
result[0] = product.High == 0UL && product.Low == 1UL ? (byte)1 : (byte)0;
}
}