On 04/02/2018 10:52 AM, Dennis wrote:
```For these examples, I'll use the D programming language compiler that
is currently under development. (...)
But what if bar is pure?
pure int bar(int);
int foo(int i)
{
return bar(i) + bar(i);
}
Now the assembler output is:
push EAX ; save argument i on stack
call bar ; call bar(i)
add EAX,EAX ; double result
pop ECX ; clean stack
ret ; return to caller
bar(i) is called only once```
I've checked whether multiple calls to pure functions get optimized, and
it seems like they *never* do. I've tried different versions of dmd with
optimizaiton flags on/off, and also LDC/GDC.
The function also needs the `nothrow` attribute. And you have to compile
with `-O -release`.
https://run.dlang.io/is/GWnUPH
