early vs late referencing benchmark

ref_test.go

package ref_test

import (
	"testing"
)

type s struct {
	ss string
}

func lateRef() *s {
	i := s{ss: "sssss"}
	i.ss = "bitch please"
	return &i
}

func earlyRef() *s {
	i := &s{ss: "sssss"}
	i.ss = "bitch please"
	return i
}

func noRef() s {
	i := s{ss: "sssss"}
	i.ss = "bitch please"
	return i
}

func BenchmarkEarlyRef(b *testing.B) {
	var i *s
	b.ReportAllocs()
	for n := 0; n < b.N; n++ {
		i = earlyRef()
	}
	_ = i
}
func BenchmarkLateRef(b *testing.B) {
	var i *s
	b.ReportAllocs()
	for n := 0; n < b.N; n++ {
		i = lateRef()
	}
	_ = i
}
func BenchmarkNoRef(b *testing.B) {
	var i s
	b.ReportAllocs()
	for n := 0; n < b.N; n++ {
		i = noRef()
	}
	_ = i
}

result.txt

goos: darwin
goarch: amd64
pkg: ref
BenchmarkEarlyRef-4     50000000                25.5 ns/op            16 B/op          1 allocs/op
BenchmarkLateRef-4      50000000                26.8 ns/op            16 B/op          1 allocs/op
BenchmarkNoRef-4        2000000000               0.32 ns/op            0 B/op          0 allocs/op
PASS
ok      ref 3.372s