Skip to content

Add 4 Channel Shuffle Intrinsics #1404

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
JimBobSquarePants merged 9 commits into from
Oct 29, 2020
Merged

Add 4 Channel Shuffle Intrinsics #1404

Show file tree
Hide file tree
Changes from 6 commits
Commits
Show all changes
9 commits
Select commit Hold shift + click to select a range
771829d
Add 4 channel float shuffling.
JimBobSquarePants Oct 26, 2020
f659bc3
Add 4 channel byte shuffling
JimBobSquarePants Oct 26, 2020
5625b4b
Don't use static spans for now.
JimBobSquarePants Oct 26, 2020
79a7e8f
Add optimized fallback for existing shuffles.
JimBobSquarePants Oct 27, 2020
deb1800
Unroll loops
JimBobSquarePants Oct 28, 2020
299ea10
Fix coverage
JimBobSquarePants Oct 28, 2020
ab11f4e
Implement new optimized 4 channel shuffle methods.
JimBobSquarePants Oct 28, 2020
aba5d63
Update based on feedback
JimBobSquarePants Oct 28, 2020
dabc237
Fix benchmarks, cleanup.
JimBobSquarePants Oct 29, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
240 changes: 240 additions & 0 deletions src/ImageSharp/Common/Helpers/SimdUtils.HwIntrinsics.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,246 @@ public static class HwIntrinsics

public static ReadOnlySpan<byte> PermuteMaskEvenOdd8x32 => new byte[] { 0, 0, 0, 0, 2, 0, 0, 0, 4, 0, 0, 0, 6, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 5, 0, 0, 0, 7, 0, 0, 0 };

/// <summary>
/// Shuffle single-precision (32-bit) floating-point elements in <paramref name="source"/>
/// using the control and store the results in <paramref name="dest"/>.
/// </summary>
/// <param name="source">The source span of floats.</param>
/// <param name="dest">The destination span of floats.</param>
/// <param name="control">The byte control.</param>
[MethodImpl(InliningOptions.ShortMethod)]
public static void Shuffle4ChannelReduce(
ref ReadOnlySpan<float> source,
ref Span<float> dest,
byte control)
{
if (Avx.IsSupported || Sse.IsSupported)
{
int remainder;
if (Avx.IsSupported)
{
remainder = ImageMaths.ModuloP2(source.Length, Vector256<float>.Count);
}
else
{
remainder = ImageMaths.ModuloP2(source.Length, Vector128<float>.Count);
}

int adjustedCount = source.Length - remainder;

if (adjustedCount > 0)
{
Shuffle4Channel(
source.Slice(0, adjustedCount),
dest.Slice(0, adjustedCount),
control);

source = source.Slice(adjustedCount);
dest = dest.Slice(adjustedCount);
}
}
}

/// <summary>
/// Shuffle 8-bit integers in a within 128-bit lanes in <paramref name="source"/>
/// using the control and store the results in <paramref name="dest"/>.
/// </summary>
/// <param name="source">The source span of bytes.</param>
/// <param name="dest">The destination span of bytes.</param>
/// <param name="control">The byte control.</param>
[MethodImpl(InliningOptions.ShortMethod)]
public static void Shuffle4ChannelReduce(
ref ReadOnlySpan<byte> source,
ref Span<byte> dest,
byte control)
{
if (Avx2.IsSupported || Ssse3.IsSupported)
{
int remainder;
if (Avx2.IsSupported)
{
remainder = ImageMaths.ModuloP2(source.Length, Vector256<byte>.Count);
}
else
{
remainder = ImageMaths.ModuloP2(source.Length, Vector128<byte>.Count);
}
Comment thread
JimBobSquarePants marked this conversation as resolved.
Outdated

int adjustedCount = source.Length - remainder;

if (adjustedCount > 0)
{
Shuffle4Channel(
source.Slice(0, adjustedCount),
dest.Slice(0, adjustedCount),
control);

source = source.Slice(adjustedCount);
dest = dest.Slice(adjustedCount);
}
}
}

[MethodImpl(InliningOptions.ShortMethod)]
private static void Shuffle4Channel(
ReadOnlySpan<float> source,
Span<float> dest,
byte control)
{
if (Avx.IsSupported)
{
ref Vector256<float> sourceBase =
ref Unsafe.As<float, Vector256<float>>(ref MemoryMarshal.GetReference(source));

ref Vector256<float> destBase =
ref Unsafe.As<float, Vector256<float>>(ref MemoryMarshal.GetReference(dest));

int n = dest.Length / Vector256<float>.Count;
int m = ImageMaths.Modulo4(n);
int u = n - m;

for (int i = 0; i < u; i += 4)
{
ref Vector256<float> vd0 = ref Unsafe.Add(ref destBase, i);
ref Vector256<float> vs0 = ref Unsafe.Add(ref sourceBase, i);

vd0 = Avx.Permute(vs0, control);
Unsafe.Add(ref vd0, 1) = Avx.Permute(Unsafe.Add(ref vs0, 1), control);
Unsafe.Add(ref vd0, 2) = Avx.Permute(Unsafe.Add(ref vs0, 2), control);
Unsafe.Add(ref vd0, 3) = Avx.Permute(Unsafe.Add(ref vs0, 3), control);
}

if (m > 0)
{
for (int i = u; i < n; i++)
{
Unsafe.Add(ref destBase, i) = Avx.Permute(Unsafe.Add(ref sourceBase, i), control);
}
}
}
else
{
// Sse
ref Vector128<float> sourceBase =
ref Unsafe.As<float, Vector128<float>>(ref MemoryMarshal.GetReference(source));

ref Vector128<float> destBase =
ref Unsafe.As<float, Vector128<float>>(ref MemoryMarshal.GetReference(dest));

int n = dest.Length / Vector128<float>.Count;
int m = ImageMaths.Modulo4(n);
int u = n - m;

for (int i = 0; i < u; i += 4)
{
ref Vector128<float> vd0 = ref Unsafe.Add(ref destBase, i);
ref Vector128<float> vs0 = ref Unsafe.Add(ref sourceBase, i);

vd0 = Sse.Shuffle(vs0, vs0, control);

Vector128<float> vs1 = Unsafe.Add(ref vs0, 1);
Unsafe.Add(ref vd0, 1) = Sse.Shuffle(vs1, vs1, control);

Vector128<float> vs2 = Unsafe.Add(ref vs0, 2);
Unsafe.Add(ref vd0, 2) = Sse.Shuffle(vs2, vs2, control);

Vector128<float> vs3 = Unsafe.Add(ref vs0, 3);
Unsafe.Add(ref vd0, 3) = Sse.Shuffle(vs3, vs3, control);
}

if (m > 0)
{
for (int i = u; i < n; i++)
{
Vector128<float> vs = Unsafe.Add(ref sourceBase, i);
Unsafe.Add(ref destBase, i) = Sse.Shuffle(vs, vs, control);
}
}
}
}

[MethodImpl(InliningOptions.ShortMethod)]
private static void Shuffle4Channel(
ReadOnlySpan<byte> source,
Span<byte> dest,
byte control)
{
if (Avx2.IsSupported)
{
// I've chosen to do this for convenience while we determine what
// shuffle controls to add to the library.
// We can add static ROS instances if need be in the future.
Span<byte> bytes = stackalloc byte[Vector256<byte>.Count];
Shuffle.MmShuffleSpan(ref bytes, control);
Vector256<byte> vcm = Unsafe.As<byte, Vector256<byte>>(ref MemoryMarshal.GetReference(bytes));

ref Vector256<byte> sourceBase =
ref Unsafe.As<byte, Vector256<byte>>(ref MemoryMarshal.GetReference(source));

ref Vector256<byte> destBase =
ref Unsafe.As<byte, Vector256<byte>>(ref MemoryMarshal.GetReference(dest));

int n = dest.Length / Vector256<byte>.Count;
int m = ImageMaths.Modulo4(n);
int u = n - m;

for (int i = 0; i < u; i += 4)
{
ref Vector256<byte> vs0 = ref Unsafe.Add(ref sourceBase, i);
ref Vector256<byte> vd0 = ref Unsafe.Add(ref destBase, i);

vd0 = Avx2.Shuffle(vs0, vcm);
Unsafe.Add(ref vd0, 1) = Avx2.Shuffle(Unsafe.Add(ref vs0, 1), vcm);
Unsafe.Add(ref vd0, 2) = Avx2.Shuffle(Unsafe.Add(ref vs0, 2), vcm);
Unsafe.Add(ref vd0, 3) = Avx2.Shuffle(Unsafe.Add(ref vs0, 3), vcm);
}

if (m > 0)
{
for (int i = u; i < n; i++)
{
Unsafe.Add(ref destBase, i) = Avx2.Shuffle(Unsafe.Add(ref sourceBase, i), vcm);
}
}
}
else
{
// Ssse3
Span<byte> bytes = stackalloc byte[Vector128<byte>.Count];
Shuffle.MmShuffleSpan(ref bytes, control);
Vector128<byte> vcm = Unsafe.As<byte, Vector128<byte>>(ref MemoryMarshal.GetReference(bytes));

ref Vector128<byte> sourceBase =
ref Unsafe.As<byte, Vector128<byte>>(ref MemoryMarshal.GetReference(source));

ref Vector128<byte> destBase =
ref Unsafe.As<byte, Vector128<byte>>(ref MemoryMarshal.GetReference(dest));

int n = dest.Length / Vector128<byte>.Count;
int m = ImageMaths.Modulo4(n);
int u = n - m;

for (int i = 0; i < u; i += 4)
{
ref Vector128<byte> vs0 = ref Unsafe.Add(ref sourceBase, i);
ref Vector128<byte> vd0 = ref Unsafe.Add(ref destBase, i);

vd0 = Ssse3.Shuffle(vs0, vcm);
Unsafe.Add(ref vd0, 1) = Ssse3.Shuffle(Unsafe.Add(ref vs0, 1), vcm);
Unsafe.Add(ref vd0, 2) = Ssse3.Shuffle(Unsafe.Add(ref vs0, 2), vcm);
Unsafe.Add(ref vd0, 3) = Ssse3.Shuffle(Unsafe.Add(ref vs0, 3), vcm);
}

if (m > 0)
{
for (int i = u; i < n; i++)
{
Unsafe.Add(ref destBase, i) = Ssse3.Shuffle(Unsafe.Add(ref sourceBase, i), vcm);
}
}
}
}

/// <summary>
/// Performs a multiplication and an addition of the <see cref="Vector256{T}"/>.
/// </summary>
Expand Down
Loading
⚡