| | | 1 | | //======================================================================= |
| | | 2 | | // Signed320.cs |
| | | 3 | | //======================================================================= |
| | | 4 | | // MIT License, Copyright (c) 2024–present David Oravsky (mrdav30) |
| | | 5 | | // See LICENSE file in the project root for full license information. |
| | | 6 | | //======================================================================= |
| | | 7 | | |
| | | 8 | | using System.Runtime.CompilerServices; |
| | | 9 | | |
| | | 10 | | namespace FixedMathSharp; |
| | | 11 | | |
| | | 12 | | /// <summary> |
| | | 13 | | /// A signed five-word value used by exact geometry for products and |
| | | 14 | | /// differences of three-component dot products. |
| | | 15 | | /// </summary> |
| | | 16 | | internal readonly struct Signed320 |
| | | 17 | | { |
| | 1 | 18 | | public static readonly Signed320 One = ExtendValue(Signed192.One); |
| | | 19 | | |
| | | 20 | | internal readonly ulong Word4; |
| | | 21 | | internal readonly ulong Word3; |
| | | 22 | | internal readonly ulong Word2; |
| | | 23 | | internal readonly ulong Word1; |
| | | 24 | | internal readonly ulong Word0; |
| | | 25 | | |
| | | 26 | | internal Signed320(ulong word4, ulong word3, ulong word2, ulong word1, ulong word0) |
| | | 27 | | { |
| | 6542638 | 28 | | Word4 = word4; |
| | 6542638 | 29 | | Word3 = word3; |
| | 6542638 | 30 | | Word2 = word2; |
| | 6542638 | 31 | | Word1 = word1; |
| | 6542638 | 32 | | Word0 = word0; |
| | 6542638 | 33 | | } |
| | | 34 | | |
| | 5200426 | 35 | | internal bool IsZero => (Word4 | Word3 | Word2 | Word1 | Word0) == 0UL; |
| | | 36 | | |
| | 5083569 | 37 | | internal int Sign => IsZero ? 0 : (Word4 & (1UL << 63)) != 0UL ? -1 : 1; |
| | | 38 | | |
| | | 39 | | /// <summary> |
| | | 40 | | /// Narrow a Signed576 value to a Signed320 value, discarding the upper 256 bits. |
| | | 41 | | /// </summary> |
| | | 42 | | internal static Signed320 NarrowValue(Signed576 value) => |
| | 84554 | 43 | | new(value.Word4, |
| | 84554 | 44 | | value.Word3, |
| | 84554 | 45 | | value.Word2, |
| | 84554 | 46 | | value.Word1, |
| | 84554 | 47 | | value.Word0); |
| | | 48 | | |
| | | 49 | | [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| | | 50 | | internal static bool TryNarrowSigned(Signed576 value, out Signed320 result) |
| | | 51 | | { |
| | 417026 | 52 | | ulong extension = (value.Word4 & (1UL << 63)) != 0UL ? ulong.MaxValue : 0UL; |
| | 417026 | 53 | | if (value.Word8 != extension || value.Word7 != extension |
| | 417026 | 54 | | || value.Word6 != extension || value.Word5 != extension) |
| | | 55 | | { |
| | 71564 | 56 | | result = default; |
| | 71564 | 57 | | return false; |
| | | 58 | | } |
| | | 59 | | |
| | 345462 | 60 | | result = new Signed320(value.Word4, value.Word3, value.Word2, value.Word1, value.Word0); |
| | 345462 | 61 | | return true; |
| | | 62 | | } |
| | | 63 | | |
| | | 64 | | /// <summary> |
| | | 65 | | /// Sign-extends an exact three-word value to five words. |
| | | 66 | | /// </summary> |
| | | 67 | | [MethodImpl(MethodImplOptions.AggressiveInlining)] |
| | | 68 | | internal static Signed320 ExtendValue(Signed192 value) |
| | | 69 | | { |
| | 1453860 | 70 | | ulong extension = value.Sign < 0 ? ulong.MaxValue : 0UL; |
| | 1453860 | 71 | | return new Signed320(extension, extension, value.High, value.Middle, value.Low); |
| | | 72 | | } |
| | | 73 | | |
| | | 74 | | internal bool Equals(Signed320 other) => |
| | 16213 | 75 | | ((Word4 ^ other.Word4) |
| | 16213 | 76 | | | (Word3 ^ other.Word3) |
| | 16213 | 77 | | | (Word2 ^ other.Word2) |
| | 16213 | 78 | | | (Word1 ^ other.Word1) |
| | 16213 | 79 | | | (Word0 ^ other.Word0)) == 0UL; |
| | | 80 | | } |