145 lines
3.9 KiB
C#
145 lines
3.9 KiB
C#
using System.Collections.Generic;
|
|
using BenchmarkDotNet.Attributes;
|
|
using BenchmarkDotNet.Jobs;
|
|
using PerfectNumbers.Core.Gpu;
|
|
|
|
namespace EvenPerfectBitScanner.Benchmarks;
|
|
|
|
[SimpleJob(RuntimeMoniker.Net80)]
|
|
[MemoryDiagnoser]
|
|
public class GpuUInt128MulModByLimbBenchmarks
|
|
{
|
|
private static readonly MulModByLimbInput[] Inputs = new MulModByLimbInput[]
|
|
{
|
|
new(
|
|
new GpuUInt128(0UL, 17UL),
|
|
new GpuUInt128(0UL, 19UL),
|
|
new GpuUInt128(0x0000_0000_0000_0001UL, 0x0000_0000_0000_00FFUL),
|
|
"TinyOperands"),
|
|
new(
|
|
new GpuUInt128(0x0123_4567_89AB_CDEFUL, 0xFEDC_BA98_7654_3210UL),
|
|
new GpuUInt128(0x0F1E_2D3C_4B5A_6978UL, 0x8776_6554_4332_2110UL),
|
|
new GpuUInt128(0x0FFF_FFFF_FFFF_FFFFUL, 0xFFFF_FFFF_FFFF_FFC3UL),
|
|
"MixedMagnitude"),
|
|
new(
|
|
new GpuUInt128(0x8000_0000_0000_0000UL, 0x0000_0000_0000_0001UL),
|
|
new GpuUInt128(0x7FFF_FFFF_FFFF_FFFFUL, 0x8000_0000_0000_0000UL),
|
|
new GpuUInt128(0x7FFF_FFFF_FFFF_FFFFUL, 0xFFFF_FFFF_FFFF_FFF1UL),
|
|
"HighWordDominant"),
|
|
};
|
|
|
|
[ParamsSource(nameof(GetInputs))]
|
|
public MulModByLimbInput Input { get; set; }
|
|
|
|
public static IEnumerable<MulModByLimbInput> GetInputs() => Inputs;
|
|
|
|
[Benchmark(Baseline = true)]
|
|
public GpuUInt128 LegacyAllocating()
|
|
{
|
|
return MulModByLimbLegacy(Input.Left, Input.Right, Input.Modulus);
|
|
}
|
|
|
|
[Benchmark]
|
|
public GpuUInt128 InPlaceReduction()
|
|
{
|
|
GpuUInt128 value = Input.Left;
|
|
value.MulModByLimb(Input.Right, Input.Modulus);
|
|
return value;
|
|
}
|
|
|
|
private static GpuUInt128 MulModByLimbLegacy(GpuUInt128 left, GpuUInt128 right, GpuUInt128 modulus)
|
|
{
|
|
var (p3, p2, p1, p0) = MultiplyFullLegacy(left, right);
|
|
|
|
GpuUInt128 remainder = new(p3, p2);
|
|
while (remainder.CompareTo(modulus) >= 0)
|
|
{
|
|
remainder.Sub(modulus);
|
|
}
|
|
|
|
ulong limb = p1;
|
|
for (int i = 0; i < 2; i++)
|
|
{
|
|
remainder <<= 64;
|
|
remainder = new GpuUInt128(remainder.High, limb);
|
|
while (remainder.CompareTo(modulus) >= 0)
|
|
{
|
|
remainder.Sub(modulus);
|
|
}
|
|
|
|
limb = p0;
|
|
}
|
|
|
|
return remainder;
|
|
}
|
|
|
|
private static (ulong P3, ulong P2, ulong P1, ulong P0) MultiplyFullLegacy(GpuUInt128 left, GpuUInt128 right)
|
|
{
|
|
var (h0, l0) = Mul64Legacy(left.Low, right.Low);
|
|
var (h1, l1) = Mul64Legacy(left.Low, right.High);
|
|
var (h2, l2) = Mul64Legacy(left.High, right.Low);
|
|
var (h3, l3) = Mul64Legacy(left.High, right.High);
|
|
|
|
ulong carry = 0UL;
|
|
ulong sum0 = l0;
|
|
ulong sum1 = h0;
|
|
|
|
sum1 += l1;
|
|
if (sum1 < l1)
|
|
{
|
|
carry++;
|
|
}
|
|
|
|
sum1 += l2;
|
|
if (sum1 < l2)
|
|
{
|
|
carry++;
|
|
}
|
|
|
|
ulong sum2 = h1 + h2;
|
|
ulong carry2 = sum2 < h2 ? 1UL : 0UL;
|
|
sum2 += l3;
|
|
if (sum2 < l3)
|
|
{
|
|
carry2++;
|
|
}
|
|
|
|
sum2 += carry;
|
|
if (sum2 < carry)
|
|
{
|
|
carry2++;
|
|
}
|
|
|
|
ulong p1 = sum1;
|
|
ulong p2 = sum2;
|
|
ulong p3 = h3 + carry2;
|
|
|
|
return (p3, p2, p1, sum0);
|
|
}
|
|
|
|
private static (ulong High, ulong Low) Mul64Legacy(ulong left, ulong right)
|
|
{
|
|
ulong a0 = (uint)left;
|
|
ulong a1 = left >> 32;
|
|
ulong b0 = (uint)right;
|
|
ulong b1 = right >> 32;
|
|
|
|
ulong lo = a0 * b0;
|
|
ulong mid1 = a1 * b0;
|
|
b0 = a0 * b1;
|
|
b1 *= a1;
|
|
|
|
a0 = (lo >> 32) + (uint)mid1 + (uint)b0;
|
|
a1 = (lo & 0xFFFF_FFFFUL) | (a0 << 32);
|
|
b1 += (mid1 >> 32) + (b0 >> 32) + (a0 >> 32);
|
|
|
|
return (b1, a1);
|
|
}
|
|
|
|
public readonly record struct MulModByLimbInput(GpuUInt128 Left, GpuUInt128 Right, GpuUInt128 Modulus, string Name)
|
|
{
|
|
public override string ToString() => Name;
|
|
}
|
|
}
|
|
|