go-intrin is a Go library that provides a simple interface to SIMD (MMX/SSE/SSE2/AVX/AVX2) instructions.currently supports Intel x86.
go get github.com/octu0/go-intrin import "github.com/octu0/go-intrin/x86" func Add () {a := [4 ]float32 {1.0 ,3.0 ,5.0 ,11.0 }b := [4 ]float32 {2.0 ,4.0 ,6.0 ,8.0 }r := x86 .Float32Add (a ,b )r [0 ]// 3.0 r [1 ]// 7.0 r [2 ]// 11.0 r [3 ]// 19.0 }func Sub () {a := [4 ]float32 {1.0 ,3.0 ,- 5.0 ,- 11.0 }b := [4 ]float32 {2.0 ,- 4.0 ,6.0 ,- 8.0 }r := x86 .Float32Sub (a ,b )r [0 ]// 3.0 r [1 ]// 7.0 r [2 ]// -11.0 r [3 ]// -3 }func Mul () {a := [2 ]float64 {1.0 ,- 1.0 }b := [2 ]float64 {- 2.0 ,- 5.0 }_ = x86 .Float64Mul (a ,b )}func Div () {a := [4 ]float64 {- 1.1 ,5.2 ,3.0 ,4.2 }b := [4 ]float64 {- 100.0 ,20.0 ,2.0 ,2.0 }_ = x86 .Float64Div4 (a ,b )}Int8/Int16/Uint8/Uint16/Int32 import "github.com/octu0/go-intrin/x86" func Add () {a := [16 ]int8 {1 ,2 ,3 ,4 ,5 ,6 ,7 ,8 ,- 1 ,2 ,3 ,- 4 ,- 5 ,- 6 ,- 7 ,- 8 , }b := [16 ]int8 {11 ,12 ,13 ,14 ,15 ,16 ,17 ,18 ,100 ,125 ,126 ,- 128 ,- 124 ,127 ,- 2 ,- 3 , }_ = x86 .Int8Add (a ,b )}func Sub () {a := [8 ]int16 {1 ,2 ,32767 ,- 32768 ,1 ,1 ,- 32768 ,0 }b := [8 ]int16 {1 ,3 ,1 ,1 ,- 32768 ,32767 ,- 1 ,- 1 }_ = x86 .Int16Sub (a ,b )}func Max () {a := [16 ]uint8 {1 ,2 ,3 ,4 ,5 ,6 ,7 ,8 ,255 ,250 ,0 ,255 ,127 ,6 ,7 ,8 , }b := [16 ]uint8 {0 ,1 ,10 ,255 ,254 ,0 ,7 ,8 ,255 ,251 ,255 ,1 ,128 ,7 ,6 ,9 , }_ = x86 .Uint8Max (a ,b )}func Avg () {a := [8 ]uint16 {1 ,2 ,32767 ,65535 ,1 ,65535 ,0 ,0 }b := [8 ]uint16 {1 ,3 ,1 ,1 ,65535 ,65535 ,0 ,1 }_ = x86 .Uint8Avg (a ,b )}func Abs () {a := [8 ]int32 {1 ,- 2 ,- 3 ,- 100 ,- 255 ,1024 ,777 ,- 888 },_ = x86 .Int32Abs (a )}The performance of SIMD benchmarks can vary depending on the execution environment.
Darwin & Core i5
goos: darwingoarch: amd64pkg: github.com/octu0/go-intrin/x86cpu: Intel(R) Core(TM) i5-8210Y CPU @ 1.60GHzBenchmarkInt16BenchmarkInt16/sum/goBenchmarkInt16/sum/go-4 1000000000 0.3100 ns/opBenchmarkInt16/sum/simdBenchmarkInt16/sum/simd-4 1000000000 0.1590 ns/opBenchmarkInt8BenchmarkInt8/sum/goBenchmarkInt8/sum/go-4 1000000000 0.3011 ns/opBenchmarkInt8/sum/simdBenchmarkInt8/sum/simd-4 1000000000 0.08489 ns/opLinux & Xeon
goos: linuxgoarch: amd64pkg: github.com/octu0/go-intrin/x86cpu: Intel(R) Xeon(R) W-11955M CPU @ 2.60GHzBenchmarkFloat32BenchmarkFloat32/sum/goBenchmarkFloat32/sum/go-16 585412603 2.097 ns/opBenchmarkFloat32/sum/simdBenchmarkFloat32/sum/simd-16 1000000000 0.8212 ns/opGo code for Grayscale can improve performance by minimizing cgo calls.
goos: linuxgoarch: amd64pkg: github.com/octu0/go-intrin/x86cpu: Intel(R) Xeon(R) W-11955M CPU @ 2.60GHzBenchmarkGrayscaleBenchmarkGrayscale/goBenchmarkGrayscale/go-16 1923 596976 ns/opBenchmarkGrayscale/simd/smallBenchmarkGrayscale/simd/small-16 100 10063526 ns/opBenchmarkGrayscale/simd/mediumBenchmarkGrayscale/simd/medium-16 1087 1112508 ns/opBenchmarkGrayscale/simd/fullBenchmarkGrayscale/simd/full-16 3070 382772 ns/opThe Go code is as below:
func Grayscale (src * image.NRGBA )* image.NRGBA {b := src .Bounds ()w ,h := b .Dx (),b .Dy ()out := image .NewNRGBA (b )for y := 0 ;y < h ;y += 1 {for x := 0 ;x < w ;x += 1 {c := src .NRGBAAt (x ,y )// BT.709 gray := byte ((0.2126 * float32 (c .R ))+ (0.7152 * float32 (c .G ))+ (0.0722 * float32 (c .B )))out .SetNRGBA (x ,y , color.NRGBA {R :gray ,G :gray ,B :gray ,A :0xff , }) } }return out }It is called asC.simd_grayscale as follows (this code is used in the simd/full benchmark):
static void simd_grayscale (uint8_t * out ,uint8_t * in ,int size ) {__m128 bt709 = _mm_setr_ps (0.2126f ,0.7152f ,0.0722f ,0.0f );uint8_t gray [8 ];for (int i = 0 ;i < size ;i += 16 ) {__m64 m1 = _mm_setr_pi8 (in [i + 0 ],in [i + 1 ],in [i + 2 ],in [i + 3 ],0 ,0 ,0 ,0 );__m64 m2 = _mm_setr_pi8 (in [i + 4 ],in [i + 5 ],in [i + 6 ],in [i + 7 ],0 ,0 ,0 ,0 );__m64 m3 = _mm_setr_pi8 (in [i + 8 ],in [i + 9 ],in [i + 10 ],in [i + 11 ],0 ,0 ,0 ,0 );__m64 m4 = _mm_setr_pi8 (in [i + 12 ],in [i + 13 ],in [i + 14 ],in [i + 15 ],0 ,0 ,0 ,0 );__m128 rgba1 = _mm_mul_ps (_mm_cvtpu8_ps (m1 ),bt709 );__m128 rgba2 = _mm_mul_ps (_mm_cvtpu8_ps (m2 ),bt709 );__m128 rgba3 = _mm_mul_ps (_mm_cvtpu8_ps (m3 ),bt709 );__m128 rgba4 = _mm_mul_ps (_mm_cvtpu8_ps (m4 ),bt709 );__m128 r = _mm_setr_ps (rgba1 [0 ],rgba2 [0 ],rgba3 [0 ],rgba4 [0 ]);// R __m128 g = _mm_setr_ps (rgba1 [1 ],rgba2 [1 ],rgba3 [1 ],rgba4 [1 ]);// G __m128 b = _mm_setr_ps (rgba1 [2 ],rgba2 [2 ],rgba3 [2 ],rgba4 [2 ]);// B // gray = [rgba1,rgba2,rgba3,rgba4] __m128 gray_float = _mm_add_ps (_mm_add_ps (r ,g ),b );__m64 gray_u8 = _mm_cvtps_pi8 (gray_float );memcpy (& gray ,& gray_u8 ,sizeof (__m64 ));uint8_t tmp [16 ]= {gray [0 ],gray [0 ],gray [0 ],255 ,gray [1 ],gray [1 ],gray [1 ],255 ,gray [2 ],gray [2 ],gray [2 ],255 ,gray [3 ],gray [3 ],gray [3 ],255 };memcpy (out + i ,& tmp ,16 ); }}-mfma cannot be specified for Cgo's CFLAGS by default.
Enable it like the following command.
$ go env -w "CGO_CFLAGS_ALLOW=-mfma"And,go build -tags fma to build
$ go build -tags fma github.com/octu0/go-intrinTesting
$ go test -tags fma -v ./x86/MIT, see LICENSE file for details.