Very nice investigation.
So, this proves that working against interfaces (rather than direct calls)
has more burden to the compiler that, in turns, affects the overall
program's execution speed?
Well, i would guess that someday when duke (from java) meets gopher (from
golang) they both will agree that they do to much on our behalves,
especially providing the "late binding" (or whatever you may call it)
mechanics.
El lunes, 12 de noviembre de 2018, 9:24:35 (UTC-3), Sergey Kamardin
escribió:
>
> Hello gophers,
>
> Does Go compiler has some optimizations for function and *method* calls
> with `variadic` arguments? For example, this simple benchmark:
>
> ```
> package main
>
> import "testing"
>
> func Do(xs ...int) (s int) {
> for i, x := range xs {
> s += i + x
> }
> return s
> }
>
> func BenchmarkDo(b *testing.B) {
> for i := 0; i < b.N; i++ {
> Do(i, i, i, i)
> }
> }
> ```
>
> Provides these results:
>
> ```
> BenchmarkDo-8 300000000 4.29 ns/op 0 B/op 0
> allocs/op
> ```
>
> That is, no allocation for slice of arguments is done. I may assume that
> it is made by preparing `xs` slice on stack of `Do()`.
>
> But, this example:
>
>
> ```
> package main
>
> import "testing"
>
> type Doer interface {
> Do(...int) int
> }
>
> type impl struct {}
>
> func (impl) Do(xs ...int) (s int) {
> for i, x := range xs {
> s += i + x
> }
> return s
> }
>
> func BenchmarkDo(b *testing.B) {
> var d Doer = impl{}
> for i := 0; i < b.N; i++ {
> d.Do(i, i, i, i)
> }
> }
> ```
>
> Provides different results:
>
> ```
> BenchmarkDo-8 300000000 25.8 ns/op 32 B/op 1
> allocs/op
> ```
>
> That is, I assume that this allocation is made for the slice of arguments.
>
> Also, I may assume that this because the compiler does not knows exactly
> which function it will call in a runtime.
>
> Am I understand it right and are there any plans for preparing such
> optimizations?
>
> Regards,
> Sergey.
>
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
