gdc or ldc for faster programs?

[Siarhei Siamashka]

On Monday, 31 January 2022 at 08:54:16 UTC, Patrick Schluter 
wrote:
> -O3 often chooses longer code and unrollsmore agressively 
> inducing higher miss rates in the instruction caches.
> -O2 can beat -O3 in some cases when code size is important.

One of the historical reasons for favoring -O2 optimization level 
over -O3 was the necessity for Linux distributions to fit on a CD 
or DVD. Also if everyone is using -O2 optimizations, then -O3 
optimizations get a lot less testing coverage and are more likely 
to have compiler bugs. This makes -O2 even more attractive for 
those, who prefer safety and stability...

I think that it's a good thing that LDC is breaking out of this 
-O2 vs. -O3 dilemma by just mapping "-O" option to -O3 
("aggressive optimizations"):

     Setting the optimization level:
       -O                                   - Equivalent to -O3
       --O0                                  - No optimizations 
(default)
       --O1                                  - Simple optimizations
       --O2                                  - Good optimizations
       --O3                                  - Aggressive 
optimizations
       --O4                                  - Equivalent to -O3
       --O5                                  - Equivalent to -O3
       --Os                                  - Like -O2 with extra 
optimizations for size
       --Oz                                  - Like -Os but 
reduces code size further

I wonder if GDC can do the same?