On Monday, 11 July 2022 at 18:15:16 UTC, Ivan Kazmenko wrote:
Hi.
I'm looking at the compiler output of DMD (-O -release), LDC
(-O -release), and GDC (-O3) for a simple array operation:
```
void add1 (int [] a)
{
foreach (i; 0..a.length)
a[i] += 1;
}
```
Here are the outputs: https://godbolt.org/z/GcznbjEaf
From what I gather at the view linked above, DMD does not use
XMM registers for speedup, and does not unroll the loop either.
Switching between 32bit and 64bit doesn't help either.
However, I recall in the past it was capable of at least some
of these optimizations. So, how do I enable them for such a
function?
Ivan Kazmenko.
How long ago is the past? The godbolt.org dmd is quite old.
The dmd backend is ancient, it isn't really capable of these
kinds of loop optimizations.
