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1D convolution optimization and general codegen tweaks #1477
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@@ Coverage Diff @@
## master #1477 +/- ##
==========================================
- Coverage 83.55% 83.48% -0.08%
==========================================
Files 741 740 -1
Lines 32462 32559 +97
Branches 3648 3652 +4
==========================================
+ Hits 27125 27181 +56
- Misses 4625 4665 +40
- Partials 712 713 +1
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| @@ -90,4 +94,4 @@ public static void Compress(ref Vector4 vector) | |||
| [MethodImpl(InliningOptions.ShortMethod)] | |||
| public static float Compress(float channel) => channel <= 0.0031308F ? 12.92F * channel : (1.055F * MathF.Pow(channel, 0.416666666666667F)) - 0.055F; | |||
JimBobSquarePants
Dec 16, 2020
Member
If we ever figure out how to do an accurate SIMD enable approximation of this we would be laughing.
If we ever figure out how to do an accurate SIMD enable approximation of this we would be laughing.
benaadams
Dec 16, 2020
pow(channel, 0.416666666666667F) => exp(channel * log(0.416666666666667F))
log(0.416666666666667F) == -0.875468737353899935628f
So...
public static void Compress(ref Vector4 vector)
{
var channels = Unsafe.As<Vector4, Vector128<float>>(ref vector);
var log = Vector128.Create(-0.875468737353899935628f);
channels = Sse.Multiply(channels, log);
channels = Exp(channels); // Isn't simd intrinsic
if (Fma.IsSupported)
{
channels = Fma.MultiplyAdd(Vector128.Create(1.055F), channels, Vector128.Create(-0.055F));
}
else
{
channels = Sse.Add(Sse.Multiply(Vector128.Create(1.055F), channels), Vector128.Create(-0.055F));
}
Unsafe.As<Vector4, Vector128<float>>(ref vector) = channels;
}
But Exp isn't a Simd intrinsic; however you can approximate it with these sequences sse_mathfun or avx_mathfun?
pow(channel, 0.416666666666667F) => exp(channel * log(0.416666666666667F))
log(0.416666666666667F) == -0.875468737353899935628f
So...
public static void Compress(ref Vector4 vector)
{
var channels = Unsafe.As<Vector4, Vector128<float>>(ref vector);
var log = Vector128.Create(-0.875468737353899935628f);
channels = Sse.Multiply(channels, log);
channels = Exp(channels); // Isn't simd intrinsic
if (Fma.IsSupported)
{
channels = Fma.MultiplyAdd(Vector128.Create(1.055F), channels, Vector128.Create(-0.055F));
}
else
{
channels = Sse.Add(Sse.Multiply(Vector128.Create(1.055F), channels), Vector128.Create(-0.055F));
}
Unsafe.As<Vector4, Vector128<float>>(ref vector) = channels;
}But Exp isn't a Simd intrinsic; however you can approximate it with these sequences sse_mathfun or avx_mathfun?
...p/Processing/Processors/Convolution/Convolution2PassProcessor{TPixel}.cs
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|
Very, very nice! |
JimBobSquarePants
merged commit f84d525
into
master
8 of 10 checks passed
8 of 10 checks passed
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Prerequisites
Description
This PR does a few things:
Benchmarks
Here's a preview of the current improvements for the gaussian blur benchmark:
And here's some more bokeh blur optimizations compared to master, after #1475 got merged: