Trial golang benchmark.

division.go

package division

// Division is ...
func Division(n float64) float64 {
	return n / 10
}

// Multiplication is ...
func Multiplication(n float64) float64 {
	return n * 0.1
}

division_test.go

package division

import (
	"math/rand"
	"os"
	"testing"
	"time"
)

var values []float64

func TestMain(m *testing.M) {
	rand.Seed(time.Now().UnixNano())
	for i := 0; i < 1000000; i++ {
		values = append(values, float64(rand.Int63n(10000)*10))
	}

	os.Exit(m.Run())
}

func BenchmarkDivision(b *testing.B) {
	for i := 0; i < b.N; i++ {
		b.Log(Division(values[i]))
	}
}

func BenchmarkMultiplication(b *testing.B) {
	for i := 0; i < b.N; i++ {
		b.Log(Multiplication(values[i]))
	}
}