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Implemented IDCT algorithm with avx/fma, move IDCT code to a different file

pull/1632/head
Dmitry Pentin 5 years ago
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513e86a904
2 changed files with 275 additions and 139 deletions
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  1. 263
      src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.IDCT.cs
  2. 151
      src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.cs

263
src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.IDCT.cs
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@ -0,0 +1,263 @@
// Copyright (c) Six Labors.
// Licensed under the Apache License, Version 2.0.
using System.Numerics;
using System.Runtime.CompilerServices;
#if SUPPORTS_RUNTIME_INTRINSICS
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;
#endif
// ReSharper disable InconsistentNaming
namespace SixLabors.ImageSharp.Formats.Jpeg.Components
{
/// <summary>
/// Contains inaccurate, but fast forward and inverse DCT implementations.
/// </summary>
internal static partial class FastFloatingPointDCT
{
/// <summary>
/// Apply floating point IDCT transformation into dest, using a temporary block 'temp' provided by the caller (optimization).
/// Ported from https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L239
/// </summary>
/// <param name="src">Source</param>
/// <param name="dest">Destination</param>
/// <param name="temp">Temporary block provided by the caller</param>
public static void TransformIDCT(ref Block8x8F src, ref Block8x8F dest, ref Block8x8F temp)
{
src.TransposeInto(ref temp);
IDCT8x8(ref temp, ref dest);
dest.TransposeInto(ref temp);
IDCT8x8(ref temp, ref dest);
// TODO: What if we leave the blocks in a scaled-by-x8 state until final color packing?
dest.MultiplyInPlace(C_0_125);
}
/// <summary>
/// Performs 8x8 matrix Inverse Discrete Cosine Transform
/// </summary>
/// <param name="s">Source</param>
/// <param name="d">Destination</param>
public static void IDCT8x8(ref Block8x8F s, ref Block8x8F d)
{
#if SUPPORTS_RUNTIME_INTRINSICS
if (Avx.IsSupported)
{
IDCT8x8_Avx(ref s, ref d);
}
else
#endif
{
IDCT8x4_LeftPart(ref s, ref d);
IDCT8x4_RightPart(ref s, ref d);
}
}
/// <summary>
/// Do IDCT internal operations on the left part of the block. Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">Destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_LeftPart(ref Block8x8F s, ref Block8x8F d)
{
Vector4 my1 = s.V1L;
Vector4 my7 = s.V7L;
Vector4 mz0 = my1 + my7;
Vector4 my3 = s.V3L;
Vector4 mz2 = my3 + my7;
Vector4 my5 = s.V5L;
Vector4 mz1 = my3 + my5;
Vector4 mz3 = my1 + my5;
Vector4 mz4 = (mz0 + mz1) * C_1_175876;
mz2 = (mz2 * C_1_961571) + mz4;
mz3 = (mz3 * C_0_390181) + mz4;
mz0 = mz0 * C_0_899976;
mz1 = mz1 * C_2_562915;
Vector4 mb3 = (my7 * C_0_298631) + mz0 + mz2;
Vector4 mb2 = (my5 * C_2_053120) + mz1 + mz3;
Vector4 mb1 = (my3 * C_3_072711) + mz1 + mz2;
Vector4 mb0 = (my1 * C_1_501321) + mz0 + mz3;
Vector4 my2 = s.V2L;
Vector4 my6 = s.V6L;
mz4 = (my2 + my6) * C_0_541196;
Vector4 my0 = s.V0L;
Vector4 my4 = s.V4L;
mz0 = my0 + my4;
mz1 = my0 - my4;
mz2 = mz4 + (my6 * C_1_847759);
mz3 = mz4 + (my2 * C_0_765367);
my0 = mz0 + mz3;
my3 = mz0 - mz3;
my1 = mz1 + mz2;
my2 = mz1 - mz2;
d.V0L = my0 + mb0;
d.V7L = my0 - mb0;
d.V1L = my1 + mb1;
d.V6L = my1 - mb1;
d.V2L = my2 + mb2;
d.V5L = my2 - mb2;
d.V3L = my3 + mb3;
d.V4L = my3 - mb3;
}
/// <summary>
/// Do IDCT internal operations on the right part of the block.
/// Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">The destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_RightPart(ref Block8x8F s, ref Block8x8F d)
{
Vector4 my1 = s.V1R;
Vector4 my7 = s.V7R;
Vector4 mz0 = my1 + my7;
Vector4 my3 = s.V3R;
Vector4 mz2 = my3 + my7;
Vector4 my5 = s.V5R;
Vector4 mz1 = my3 + my5;
Vector4 mz3 = my1 + my5;
Vector4 mz4 = (mz0 + mz1) * C_1_175876;
mz2 = (mz2 * C_1_961571) + mz4;
mz3 = (mz3 * C_0_390181) + mz4;
mz0 = mz0 * C_0_899976;
mz1 = mz1 * C_2_562915;
Vector4 mb3 = (my7 * C_0_298631) + mz0 + mz2;
Vector4 mb2 = (my5 * C_2_053120) + mz1 + mz3;
Vector4 mb1 = (my3 * C_3_072711) + mz1 + mz2;
Vector4 mb0 = (my1 * C_1_501321) + mz0 + mz3;
Vector4 my2 = s.V2R;
Vector4 my6 = s.V6R;
mz4 = (my2 + my6) * C_0_541196;
Vector4 my0 = s.V0R;
Vector4 my4 = s.V4R;
mz0 = my0 + my4;
mz1 = my0 - my4;
mz2 = mz4 + (my6 * C_1_847759);
mz3 = mz4 + (my2 * C_0_765367);
my0 = mz0 + mz3;
my3 = mz0 - mz3;
my1 = mz1 + mz2;
my2 = mz1 - mz2;
d.V0R = my0 + mb0;
d.V7R = my0 - mb0;
d.V1R = my1 + mb1;
d.V6R = my1 - mb1;
d.V2R = my2 + mb2;
d.V5R = my2 - mb2;
d.V3R = my3 + mb3;
d.V4R = my3 - mb3;
}
#if SUPPORTS_RUNTIME_INTRINSICS
/// <summary>
/// Do IDCT internal operations on the given block.
/// </summary>
/// <param name="s">Source</param>
/// <param name="d">Destination</param>
public static void IDCT8x8_Avx(ref Block8x8F s, ref Block8x8F d)
{
Vector256<float> my1 = s.V1;
Vector256<float> my7 = s.V7;
Vector256<float> mz0 = Avx.Add(my1, my7);
Vector256<float> my3 = s.V3;
Vector256<float> mz2 = Avx.Add(my3, my7);
Vector256<float> my5 = s.V5;
Vector256<float> mz1 = Avx.Add(my3, my5);
Vector256<float> mz3 = Avx.Add(my1, my5);
Vector256<float> mz4 = Avx.Multiply(Avx.Add(mz0, mz1), w1_1758);
if (Fma.IsSupported)
{
mz2 = Fma.MultiplyAdd(mz2, C_V_n1_9615, mz4);
mz3 = Fma.MultiplyAdd(mz3, C_V_n0_3901, mz4);
}
else
{
mz2 = Avx.Add(Avx.Multiply(mz2, C_V_n1_9615), mz4);
mz3 = Avx.Add(Avx.Multiply(mz3, C_V_n0_3901), mz4);
}
mz0 = Avx.Multiply(mz0, C_V_n0_8999);
mz1 = Avx.Multiply(mz1, C_V_n2_5629);
Unsafe.SkipInit(out Vector256<float> mb3);
Unsafe.SkipInit(out Vector256<float> mb2);
Unsafe.SkipInit(out Vector256<float> mb1);
Unsafe.SkipInit(out Vector256<float> mb0);
if (Fma.IsSupported)
{
mb3 = Avx.Add(Fma.MultiplyAdd(my7, C_V_0_2986, mz0), mz2);
mb2 = Avx.Add(Fma.MultiplyAdd(my5, C_V_2_0531, mz1), mz3);
mb1 = Avx.Add(Fma.MultiplyAdd(my3, C_V_3_0727, mz1), mz2);
mb0 = Avx.Add(Fma.MultiplyAdd(my1, C_V_1_5013, mz0), mz3);
}
else
{
mb3 = Avx.Add(Avx.Add(Avx.Multiply(my7, C_V_0_2986), mz0), mz2);
mb2 = Avx.Add(Avx.Add(Avx.Multiply(my5, C_V_2_0531), mz1), mz3);
mb1 = Avx.Add(Avx.Add(Avx.Multiply(my3, C_V_3_0727), mz1), mz2);
mb0 = Avx.Add(Avx.Add(Avx.Multiply(my1, C_V_1_5013), mz0), mz3);
}
Vector256<float> my2 = s.V2;
Vector256<float> my6 = s.V6;
mz4 = Avx.Multiply(Avx.Add(my2, my6), w0_5411);
Vector256<float> my0 = s.V0;
Vector256<float> my4 = s.V4;
mz0 = Avx.Add(my0, my4);
mz1 = Avx.Subtract(my0, my4);
if (Fma.IsSupported)
{
mz2 = Fma.MultiplyAdd(my6, C_V_n1_8477, mz4);
mz3 = Fma.MultiplyAdd(my2, C_V_0_7653, mz4);
}
else
{
mz2 = Avx.Add(Avx.Multiply(my6, C_V_n1_8477), mz4);
mz3 = Avx.Add(Avx.Multiply(my2, C_V_0_7653), mz4);
}
my0 = Avx.Add(mz0, mz3);
my3 = Avx.Subtract(mz0, mz3);
my1 = Avx.Add(mz1, mz2);
my2 = Avx.Subtract(mz1, mz2);
d.V0 = Avx.Add(my0, mb0);
d.V7 = Avx.Subtract(my0, mb0);
d.V1 = Avx.Add(my1, mb1);
d.V6 = Avx.Subtract(my1, mb1);
d.V2 = Avx.Add(my2, mb2);
d.V5 = Avx.Subtract(my2, mb2);
d.V3 = Avx.Add(my3, mb3);
d.V4 = Avx.Subtract(my3, mb3);
}
#endif
}
}

151
src/ImageSharp/Formats/Jpeg/Components/FastFloatingPointDCT.cs
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@ -14,7 +14,7 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
/// <summary>
/// Contains inaccurate, but fast forward and inverse DCT implementations.
/// </summary>
internal static class FastFloatingPointDCT
internal static partial class FastFloatingPointDCT
{
#pragma warning disable SA1310 // FieldNamesMustNotContainUnderscore
private const float C_1_175876 = 1.175875602f;
@ -51,149 +51,22 @@ namespace SixLabors.ImageSharp.Formats.Jpeg.Components
private static readonly Vector256<float> C_V_1_3870 = Vector256.Create(1.387040f);
private static readonly Vector256<float> C_V_0_2758 = Vector256.Create(0.275899f);
private static readonly Vector256<float> C_V_n1_9615 = Vector256.Create(-1.961570560f);
private static readonly Vector256<float> C_V_n0_3901 = Vector256.Create(-0.390180644f);
private static readonly Vector256<float> C_V_n0_8999 = Vector256.Create(-0.899976223f);
private static readonly Vector256<float> C_V_n2_5629 = Vector256.Create(-2.562915447f);
private static readonly Vector256<float> C_V_0_2986 = Vector256.Create(0.298631336f);
private static readonly Vector256<float> C_V_2_0531 = Vector256.Create(2.053119869f);
private static readonly Vector256<float> C_V_3_0727 = Vector256.Create(3.072711026f);
private static readonly Vector256<float> C_V_1_5013 = Vector256.Create(1.501321110f);
private static readonly Vector256<float> C_V_n1_8477 = Vector256.Create(-1.847759065f);
private static readonly Vector256<float> C_V_0_7653 = Vector256.Create(0.765366865f);
private static Vector256<float> C_V_InvSqrt2 = Vector256.Create(0.707107f);
#endif
#pragma warning restore SA1310 // FieldNamesMustNotContainUnderscore
private static readonly Vector4 InvSqrt2 = new Vector4(0.707107f);
/// <summary>
/// Apply floating point IDCT transformation into dest, using a temporary block 'temp' provided by the caller (optimization).
/// Ported from https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L239
/// </summary>
/// <param name="src">Source</param>
/// <param name="dest">Destination</param>
/// <param name="temp">Temporary block provided by the caller</param>
public static void TransformIDCT(ref Block8x8F src, ref Block8x8F dest, ref Block8x8F temp)
{
src.TransposeInto(ref temp);
IDCT8x4_LeftPart(ref temp, ref dest);
IDCT8x4_RightPart(ref temp, ref dest);
dest.TransposeInto(ref temp);
IDCT8x4_LeftPart(ref temp, ref dest);
IDCT8x4_RightPart(ref temp, ref dest);
// TODO: What if we leave the blocks in a scaled-by-x8 state until final color packing?
dest.MultiplyInPlace(C_0_125);
}
/// <summary>
/// Do IDCT internal operations on the left part of the block. Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">Destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_LeftPart(ref Block8x8F s, ref Block8x8F d)
{
Vector4 my1 = s.V1L;
Vector4 my7 = s.V7L;
Vector4 mz0 = my1 + my7;
Vector4 my3 = s.V3L;
Vector4 mz2 = my3 + my7;
Vector4 my5 = s.V5L;
Vector4 mz1 = my3 + my5;
Vector4 mz3 = my1 + my5;
Vector4 mz4 = (mz0 + mz1) * C_1_175876;
mz2 = (mz2 * C_1_961571) + mz4;
mz3 = (mz3 * C_0_390181) + mz4;
mz0 = mz0 * C_0_899976;
mz1 = mz1 * C_2_562915;
Vector4 mb3 = (my7 * C_0_298631) + mz0 + mz2;
Vector4 mb2 = (my5 * C_2_053120) + mz1 + mz3;
Vector4 mb1 = (my3 * C_3_072711) + mz1 + mz2;
Vector4 mb0 = (my1 * C_1_501321) + mz0 + mz3;
Vector4 my2 = s.V2L;
Vector4 my6 = s.V6L;
mz4 = (my2 + my6) * C_0_541196;
Vector4 my0 = s.V0L;
Vector4 my4 = s.V4L;
mz0 = my0 + my4;
mz1 = my0 - my4;
mz2 = mz4 + (my6 * C_1_847759);
mz3 = mz4 + (my2 * C_0_765367);
my0 = mz0 + mz3;
my3 = mz0 - mz3;
my1 = mz1 + mz2;
my2 = mz1 - mz2;
d.V0L = my0 + mb0;
d.V7L = my0 - mb0;
d.V1L = my1 + mb1;
d.V6L = my1 - mb1;
d.V2L = my2 + mb2;
d.V5L = my2 - mb2;
d.V3L = my3 + mb3;
d.V4L = my3 - mb3;
}
/// <summary>
/// Do IDCT internal operations on the right part of the block.
/// Original src:
/// https://github.com/norishigefukushima/dct_simd/blob/master/dct/dct8x8_simd.cpp#L261
/// </summary>
/// <param name="s">The source block</param>
/// <param name="d">The destination block</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void IDCT8x4_RightPart(ref Block8x8F s, ref Block8x8F d)
{
Vector4 my1 = s.V1R;
Vector4 my7 = s.V7R;
Vector4 mz0 = my1 + my7;
Vector4 my3 = s.V3R;
Vector4 mz2 = my3 + my7;
Vector4 my5 = s.V5R;
Vector4 mz1 = my3 + my5;
Vector4 mz3 = my1 + my5;
Vector4 mz4 = (mz0 + mz1) * C_1_175876;
mz2 = (mz2 * C_1_961571) + mz4;
mz3 = (mz3 * C_0_390181) + mz4;
mz0 = mz0 * C_0_899976;
mz1 = mz1 * C_2_562915;
Vector4 mb3 = (my7 * C_0_298631) + mz0 + mz2;
Vector4 mb2 = (my5 * C_2_053120) + mz1 + mz3;
Vector4 mb1 = (my3 * C_3_072711) + mz1 + mz2;
Vector4 mb0 = (my1 * C_1_501321) + mz0 + mz3;
Vector4 my2 = s.V2R;
Vector4 my6 = s.V6R;
mz4 = (my2 + my6) * C_0_541196;
Vector4 my0 = s.V0R;
Vector4 my4 = s.V4R;
mz0 = my0 + my4;
mz1 = my0 - my4;
mz2 = mz4 + (my6 * C_1_847759);
mz3 = mz4 + (my2 * C_0_765367);
my0 = mz0 + mz3;
my3 = mz0 - mz3;
my1 = mz1 + mz2;
my2 = mz1 - mz2;
d.V0R = my0 + mb0;
d.V7R = my0 - mb0;
d.V1R = my1 + mb1;
d.V6R = my1 - mb1;
d.V2R = my2 + mb2;
d.V5R = my2 - mb2;
d.V3R = my3 + mb3;
d.V4R = my3 - mb3;
}
/// <summary>
/// Original:
/// <see>

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