direct call/interface/function pointer benchmark

t_test.go

package tt

/*
goos: linux
goarch: amd64
cpu: Intel(R) Core(TM) i3-6100U CPU @ 2.30GHz
BenchmarkInterface-4               	402143721	         2.880 ns/op
BenchmarkTemplate-4                	205737126	         6.119 ns/op
BenchmarkDirect-4                  	1000000000	         0.5869 ns/op
BenchmarkFunctionPointer-4         	166973348	         6.738 ns/op
BenchmarkFunctionPointerStruct-4   	185710765	         6.038 ns/op
PASS
ok  	command-line-arguments	8.509s
*/

import "testing"

type I interface {
	f()
}

type S struct{}

func (S) f() {}

func BenchmarkInterface(b *testing.B) {
	var s I = S{}
	for i := 0; i < b.N; i++ {
		s.f()
	}
}

func f[S I](s S) {
	s.f()
}

func BenchmarkTemplate(b *testing.B) {
	s := S{}
	for i := 0; i < b.N; i++ {
		f(s)
	}
}

func BenchmarkDirect(b *testing.B) {
	s := S{}
	for i := 0; i < b.N; i++ {
		s.f()
	}
}

func BenchmarkFunctionPointer(b *testing.B) {
	s := S{}
	f := s.f
	for i := 0; i < b.N; i++ {
		f()
	}
}

type F struct {
	f func()
}

func BenchmarkFunctionPointerStruct(b *testing.B) {
	s := S{}
	f := F{f: s.f}
	for i := 0; i < b.N; i++ {
		f.f()
	}
}