Re: [dev] [dwm] [st] benefits (or not) of -march=x86-64-v3 and gcc optimizations

From: Petr Šabata <contyk_AT_redhat.com>
Date: Tue, 7 Feb 2023 09:46:57 +0100

It's extremely unlikely you could observe any difference using these
tools on any remotely modern hardware. In practical terms it doesn't
matter.

But if you want to satisfy your curiosity, you could do some
profiling, I guess; or decompile the binaries and eyeball the
generated instructions. I'd suspect the results would be nearly
identical, however, considering what and how these programs do.

P

On Tue, Feb 7, 2023 at 9:37 AM Κρακ Άουτ <krackout_AT_gmx.com> wrote:
>
> I have compiled dwm & st using -march=x86-64-v3 (tried -march=x86-64-v2 also). To be honest they are both (dwm & st) fast and snappy with their default configuration and I cannot spot any difference when compiled with -march=x86-64-v3 or v2. Is there any point adding them?
>
> Related, would -O2 or -O3 flags give any benefit?
>
> As I mentioned, in practice I don't see any differences. I'm wondering if theoretically there could be some positive effect. People who know how exactly the code works are better suited to supply a definitive answer than me, that's why I'm posting here.
>
>
Received on Tue Feb 07 2023 - 09:46:57 CET