Умножение матрицы на вектор, без оптимизаций

process-vectors.go

package main

import (
	"fmt"
	"math"
	"time"
)

type V4 [4]float32
type M4 [16]float32

const (
	numVectors = 8 * 1024 * 1024
)

func M4MultiplyV4(m M4, v V4) V4 {
	return V4{
		v[0]*m[0] + v[1]*m[4] + v[2]*m[8] + v[3]*m[12],
		v[0]*m[1] + v[1]*m[5] + v[2]*m[9] + v[3]*m[13],
		v[0]*m[2] + v[1]*m[6] + v[2]*m[10] + v[3]*m[14],
		v[0]*m[3] + v[1]*m[7] + v[2]*m[11] + v[3]*m[15],
	}
}

func multiply(data []V4, m M4) {
	for i, v := range data {
		data[i] = M4MultiplyV4(m, v)
	}
}

func benchmark(f func()) {
	best := math.MaxFloat64
	for i := 0; i < 100; i++ {
		start := time.Now()
		f()
		end := time.Now()
		elapsed := end.Sub(start).Seconds()
		if elapsed < best {
			best = elapsed
		}
	}
	fmt.Printf("%.0fms\n", best*1000)
}

func main() {
	data := make([]V4, numVectors)

	for i := range data {
		data[i] = V4{1, 2, 3, 4}
	}

	m := M4{
		1, 2, 3, 4,
		5, 6, 7, 8,
		9, 10, 11, 12,
		13, 14, 15, 16,
	}

	benchmark(func() { multiply(data, m) })
}

run.sh

go build -o process-vectors && ./process-vectors