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Use Intel AVX2 Code Replacement Library to Generate SIMD Code from MATLAB Algorithms

Note

This workflow requires a MATLAB® Coder™ license and an Embedded Coder® license.

To generate SIMD code from MATLAB System objects, create a coder.config (MATLAB Coder) object, set the CodeReplacementLibrary property to 'DSP Intel AVX2-FMA (Windows)', 'DSP Intel AVX2-FMA (Linux)', or 'DSP Intel AVX2-FMA (Mac)', and use the object with the codegen (MATLAB Coder) command.

Consider this MATLAB function that filters a random multichannel signal using the dsp.FIRFilter System object™.

function y = firsingle()

persistent fir
if isempty(fir)
    b = fir1(250,.4);
    fir = dsp.FIRFilter(b);    
end

frameSize = 512;
numChannels = 8;
numFrames = 1e3;

for k = 1:numFrames
    x = randn(frameSize,numChannels,'single');
    y = fir(x);
end

Generate plain C code executable of this function using the codegen command.

cfg = coder.config('exe');
% provides starter main.c
cfg.GenerateExampleMain = 'GenerateCodeAndCompile'; 
switch computer('arch')
case 'glnxa64'
    codegen firsingle -config cfg -report -o firsingle_std    
case 'win64'
    codegen firsingle -config cfg -report -o firsingle_std.exe
case 'maci64'
    codegen firsingle -config cfg -report -o firsingle_std
case 'maca64'
    codegen firsingle -config cfg -report -o firsingle_std
end

Measure the time it takes to run the generated executable.

tic; 
system('firsingle_std'); 
tplain = toc
tplain =

   1.1700

Generate AVX2 C code executable by setting the CodeReplacementLibrary parameter to either 'DSP Intel AVX2-FMA (Windows)', 'DSP Intel AVX2-FMA (Linux)', or 'DSP Intel AVX2-FMA (Mac)', and calling the codegen command on the coder.config object.

cfg = coder.config('exe');
switch computer('arch')
case 'glnxa64'
    cfg.CodeReplacementLibrary = 'DSP Intel AVX2-FMA (Linux)';
case 'win64' 
    cfg.CodeReplacementLibrary = 'DSP Intel AVX2-FMA (Windows)';
case 'maci64'
    cfg.CodeReplacementLibrary = 'DSP Intel AVX2-FMA (Mac)';
case 'maca64'
    cfg.CodeReplacementLibrary = 'DSP Intel AVX2-FMA (Mac)';
end
cfg.GenerateExampleMain = 'GenerateCodeAndCompile'; % provides starter main.c
switch computer('arch')
case 'glnxa64'
    codegen firsingle -config cfg -report -o firsingle_avx2    
case 'win64'
    codegen firsingle -config cfg -report -o firsingle_avx2.exe
case 'maci64'
    codegen firsingle -config cfg -report -o firsingle_avx2
case 'maca64'
    codegen firsingle -config cfg -report -o firsingle_avx2
end

Measure the time it takes to run the generated executable.

tic; 
system('firsingle_avx2');
tavx2 = toc
tavx2 =

   0.2611

The generated SIMD code is around 4.5x faster compared to the plain C code on a Windows® 10 machine.

tplain/tavx2
 ans = 
4.4815

You can also generate a static library and a dynamic library by specifying the build type as 'lib' and 'dll', respectively.

cfg = coder.config('lib');
cfg.CodeReplacementLibrary = 'DSP Intel AVX2-FMA (Windows)';
codegen MATLABfunctionName -config cfg  

cfg = coder.config('dll');
cfg.CodeReplacementLibrary = 'DSP Intel AVX2-FMA (Windows)';
codegen MATLABfunctionName -config cfg

MATLABfunctionName is the MATLAB function that calls the System object you are trying to generate SIMD code from. For a list of System objects that support SIMD code generation, see System objects in DSP System Toolbox that Support SIMD Code Generation.

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