Initial commit.

PerfectNumbers.Core.Tests/Gpu/NttBackendConfigTests.cs

@@ -0,0 +1,78 @@
+using FluentAssertions;
+using PerfectNumbers.Core.Gpu;
+using Xunit;
+
+namespace PerfectNumbers.Core.Tests.Gpu;
+
+[Collection("GpuNtt")]
+public class NttBackendConfigTests
+{
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void ForwardInverseGpu_reference_backend_matches_cpu_on_small_input()
+    {
+        var original = NttGpuMath.GpuTransformBackend;
+        try
+        {
+            Span<GpuUInt128> input = stackalloc GpuUInt128[8];
+            for (ulong i = 0; i < (ulong)input.Length; i++)
+            {
+                input[(int)i] = new GpuUInt128(0UL, i + 1UL);
+            }
+
+            var modulus = new GpuUInt128(0UL, 17UL);
+            var primitiveRoot = new GpuUInt128(0UL, 3UL);
+
+            NttGpuMath.GpuTransformBackend = NttBackend.Reference;
+            Span<GpuUInt128> gpu = stackalloc GpuUInt128[input.Length];
+            input.CopyTo(gpu);
+            NttGpuMath.ForwardGpu(gpu, modulus, primitiveRoot);
+            NttGpuMath.InverseGpu(gpu, modulus, primitiveRoot);
+
+            Span<GpuUInt128> cpu = stackalloc GpuUInt128[input.Length];
+            input.CopyTo(cpu);
+            NttGpuMath.Forward(cpu, modulus, primitiveRoot);
+            NttGpuMath.Inverse(cpu, modulus, primitiveRoot);
+            gpu.ToArray().Should().Equal(cpu.ToArray());
+        }
+        finally
+        {
+            NttGpuMath.GpuTransformBackend = original;
+        }
+    }
+
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void ForwardInverseGpu_staged_backend_matches_cpu_on_small_input()
+    {
+        var original = NttGpuMath.GpuTransformBackend;
+        try
+        {
+            Span<GpuUInt128> input = stackalloc GpuUInt128[8];
+            for (ulong i = 0; i < (ulong)input.Length; i++)
+            {
+                input[(int)i] = new GpuUInt128(0UL, i + 1UL);
+            }
+
+            var modulus = new GpuUInt128(0UL, 17UL);
+            var primitiveRoot = new GpuUInt128(0UL, 3UL);
+
+            NttGpuMath.GpuTransformBackend = NttBackend.Staged;
+            Span<GpuUInt128> gpu = stackalloc GpuUInt128[input.Length];
+            input.CopyTo(gpu);
+            NttGpuMath.ForwardGpu(gpu, modulus, primitiveRoot);
+            NttGpuMath.InverseGpu(gpu, modulus, primitiveRoot);
+
+            Span<GpuUInt128> cpu = stackalloc GpuUInt128[input.Length];
+            input.CopyTo(cpu);
+            NttGpuMath.Forward(cpu, modulus, primitiveRoot);
+            NttGpuMath.Inverse(cpu, modulus, primitiveRoot);
+            gpu.ToArray().Should().Equal(cpu.ToArray());
+        }
+        finally
+        {
+            NttGpuMath.GpuTransformBackend = original;
+        }
+    }
+}
+