Initial PollardRho implementation for GPU. Added pool for accelerator streams shared across the threads. GPU processing performance and stabilization improvements. GpuUInt128.BinaryGcd switched to the version which outperformed other in benchmarks.

PerfectNumbers.Core/PrimeOrderCalculator.Gpu.cs

@@ -1,3 +1,5 @@
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using ILGPU;
 using ILGPU.Runtime;
@@ -37,19 +39,21 @@ internal static partial class PrimeOrderCalculator
 		
 		entries.Sort(entries, static (a, b) => a.Key.CompareTo(b.Key));
 
-		AcceleratorStream stream = gpu.Stream!;
+		// AcceleratorStream stream = gpu.Stream!;
 		gpu.EnsureCapacity(entryCount, 1);
+
+		GpuPrimeWorkLimiter.Acquire();
+		AcceleratorStream stream = AcceleratorStreamPool.Rent(gpu.Accelerator);
 		gpu.Pow2ModEntriesToTestOnDevice.View.CopyFromCPU(stream, entries);
 
 		ulong order = phi;
 		var kernel = gpu.CheckFactorsKernel;
 		stream.Synchronize();
 
-		GpuPrimeWorkLimiter.Acquire();
-
-		kernel.Launch(stream, 1, entryCount, phi, gpu.Pow2ModEntriesToTestOnDevice.View, divisorData, gpu.Output.View);
-		gpu.Output.View.CopyToCPU(stream, ref order, 1);
+		kernel.Launch(stream, 1, entryCount, phi, gpu.Pow2ModEntriesToTestOnDevice.View, divisorData, gpu.OutputUlong.View);
+		gpu.OutputUlong.View.CopyToCPU(stream, ref order, 1);
 		stream.Synchronize();
+		AcceleratorStreamPool.Return(stream);
 
 		GpuPrimeWorkLimiter.Release();
 		return order;
@@ -186,5 +190,34 @@ internal static partial class PrimeOrderCalculator
 		GpuPrimeWorkLimiter.Release();
 		return result != 0;
 	}
+
+	private static bool TryPollardRhoGpu(Pow2MontgomeryAccelerator gpu, ulong n, out ulong factor)
+	{
+		// var stream = gpu.Stream!;
+		Span<ulong> randomStateSpan = stackalloc ulong[1]; 
+		randomStateSpan[0] = ThreadStaticDeterministicRandomGpu.Exclusive.State;
+
+		AcceleratorStream stream = AcceleratorStreamPool.Rent(gpu.Accelerator);
+		gpu.Input.View.CopyFromCPU(stream, randomStateSpan);
+
+		Span<byte> factoredSpan = stackalloc byte[1];
+		Span<ulong> factorSpan = stackalloc ulong[1];
+		var kernelLauncher = gpu.PollardRhoKernel.CreateLauncherDelegate<Action<AcceleratorStream, ulong, int, ArrayView1D<ulong, Stride1D.Dense>, ArrayView1D<byte, Stride1D.Dense>, ArrayView1D<ulong, Stride1D.Dense>>>();
+
+		kernelLauncher(stream, n, 1, gpu.Input.View, gpu.OutputByte.View, gpu.OutputUlong.View);
+
+		gpu.OutputByte.View.CopyToCPU(stream, factoredSpan);
+		gpu.OutputUlong.View.CopyToCPU(stream, factorSpan);
+		gpu.Input.View.CopyToCPU(stream, randomStateSpan);
+		stream.Synchronize();
+
+		AcceleratorStreamPool.Return(stream);
+		ThreadStaticDeterministicRandomGpu.Exclusive.SetState(randomStateSpan[0]);
+
+		bool factored = factoredSpan[0] != 0;
+		factor = factored ? factorSpan[0] : 0UL;
+		return factored;
+	}
+	
 }