Golang如何测试函数调用开销_Golang函数调用开销测试实践详解

package main
<p>import "testing"</p><p><span>立即学习</span>“<a href="https://pan.quark.cn/s/00968c3c2c15" style="text-decoration: underline !important; color: blue; font-weight: bolder;" rel="nofollow" target="_blank">go语言免费学习笔记（深入）</a>”；</p><p>func add(a, b int) int {
return a + b
}</p><p>var result int</p><p>func BenchmarkDirectAdd(b *testing.B) {
var r int
for i := 0; i < b.N; i++ {
r = 1 + 2
}
result = r
}</p><p>func BenchmarkFunctionCall(b *testing.B) {
var r int
for i := 0; i < b.N; i++ {
r = add(1, 2)
}
result = r
}

go test -bench=.

BenchmarkDirectAdd       1000000000   0.25 ns/op
BenchmarkFunctionCall    800000000    1.50 ns/op

go build -gcflags="-m" main.go

can inline add

//go:noinline
func add(a, b int) int {
    return a + b
}

type Point struct{ X, Y int }
<p>func distance(p1, p2 Point) float64 {
dx := p1.X - p2.X
dy := p1.Y - p2.Y
return math.Sqrt(float64(dx<em>dx + dy</em>dy))
}</p><p>func BenchmarkStructCall(b *testing.B) {
p1 := Point{1, 2}
p2 := Point{4, 6}
var r float64
for i := 0; i < b.N; i++ {
r = distance(p1, p2)
}
resultFloat64 = r
}

func distancePtr(p1, p2 *Point) float64 {
    dx := p1.X - p2.X
    dy := p1.Y - p2.Y
    return math.Sqrt(float64(dx*dx + dy*dy))
}