chore: Split SoftFallback into multiple partial class parts

2026-04-17 03:32:54 +00:00 · 2025-07-03 23:20:32 -05:00
parent 83502494d9
commit 342c811aca
10 changed files with 737 additions and 692 deletions
--- a/src/ARMeilleure/Instructions/SoftFallback/SoftFallback.Sha256.cs
+++ b/src/ARMeilleure/Instructions/SoftFallback/SoftFallback.Sha256.cs
@@ -0,0 +1,140 @@
+using ARMeilleure.State;
+using System.Runtime.InteropServices;
+
+namespace ARMeilleure.Instructions
+{
+    static partial class SoftFallback
+    {
+        [UnmanagedCallersOnly]
+        public static V128 HashLower(V128 hash_abcd, V128 hash_efgh, V128 wk)
+        {
+            return Sha256Hash(hash_abcd, hash_efgh, wk, part1: true);
+        }
+
+        [UnmanagedCallersOnly]
+        public static V128 HashUpper(V128 hash_abcd, V128 hash_efgh, V128 wk)
+        {
+            return Sha256Hash(hash_abcd, hash_efgh, wk, part1: false);
+        }
+
+        [UnmanagedCallersOnly]
+        public static V128 Sha256SchedulePart1(V128 w0_3, V128 w4_7)
+        {
+            V128 result = new();
+
+            for (int e = 0; e <= 3; e++)
+            {
+                uint elt = (e <= 2 ? w0_3 : w4_7).Extract<uint>(e <= 2 ? e + 1 : 0);
+
+                elt = elt.Ror(7) ^ elt.Ror(18) ^ elt.Lsr(3);
+
+                elt += w0_3.Extract<uint>(e);
+
+                result.Insert(e, elt);
+            }
+
+            return result;
+        }
+
+        [UnmanagedCallersOnly]
+        public static V128 Sha256SchedulePart2(V128 w0_3, V128 w8_11, V128 w12_15)
+        {
+            V128 result = new();
+
+            ulong t1 = w12_15.Extract<ulong>(1);
+
+            for (int e = 0; e <= 1; e++)
+            {
+                uint elt = t1.ULongPart(e);
+
+                elt = elt.Ror(17) ^ elt.Ror(19) ^ elt.Lsr(10);
+
+                elt += w0_3.Extract<uint>(e) + w8_11.Extract<uint>(e + 1);
+
+                result.Insert(e, elt);
+            }
+
+            t1 = result.Extract<ulong>(0);
+
+            for (int e = 2; e <= 3; e++)
+            {
+                uint elt = t1.ULongPart(e - 2);
+
+                elt = elt.Ror(17) ^ elt.Ror(19) ^ elt.Lsr(10);
+
+                elt += w0_3.Extract<uint>(e) + (e == 2 ? w8_11 : w12_15).Extract<uint>(e == 2 ? 3 : 0);
+
+                result.Insert(e, elt);
+            }
+
+            return result;
+        }
+
+        private static V128 Sha256Hash(V128 x, V128 y, V128 w, bool part1)
+        {
+            for (int e = 0; e <= 3; e++)
+            {
+                uint chs = ShaChoose(y.Extract<uint>(0),
+                                     y.Extract<uint>(1),
+                                     y.Extract<uint>(2));
+
+                uint maj = ShaMajority(x.Extract<uint>(0),
+                                       x.Extract<uint>(1),
+                                       x.Extract<uint>(2));
+
+                uint t1 = y.Extract<uint>(3) + ShaHashSigma1(y.Extract<uint>(0)) + chs + w.Extract<uint>(e);
+
+                uint t2 = t1 + x.Extract<uint>(3);
+
+                x.Insert(3, t2);
+
+                t2 = t1 + ShaHashSigma0(x.Extract<uint>(0)) + maj;
+
+                y.Insert(3, t2);
+
+                Rol32_256(ref y, ref x);
+            }
+
+            return part1 ? x : y;
+        }
+
+        private static void Rol32_256(ref V128 y, ref V128 x)
+        {
+            uint yE3 = y.Extract<uint>(3);
+            uint xE3 = x.Extract<uint>(3);
+
+            y <<= 32;
+            x <<= 32;
+
+            y.Insert(0, xE3);
+            x.Insert(0, yE3);
+        }
+
+        private static uint ShaHashSigma0(uint x)
+        {
+            return x.Ror(2) ^ x.Ror(13) ^ x.Ror(22);
+        }
+
+        private static uint ShaHashSigma1(uint x)
+        {
+            return x.Ror(6) ^ x.Ror(11) ^ x.Ror(25);
+        }
+
+        private static uint Ror(this uint value, int count)
+        {
+            return (value >> count) | (value << (32 - count));
+        }
+
+        private static uint Lsr(this uint value, int count)
+        {
+            return value >> count;
+        }
+
+        private static uint ULongPart(this ulong value, int part)
+        {
+            return part == 0
+                ? (uint)(value & 0xFFFFFFFFUL)
+                : (uint)(value >> 32);
+        }
+    }
+}