Potential of a compiler that creates the executable at once

[rempas]

On Thursday, 10 February 2022 at 20:39:33 UTC, Walter Bright 
wrote:
> This is actually the reason behind why dmd will create a single 
> object file when given multiple source files on the command 
> line. It's also why dmd can create a library directly.
>
> I've toyed with the idea of generating an executable directly 
> many times.

That's nice to hear! However, does DMD generates object files 
directly or "asm" files that are passed to a C compile? If I 
remember correctly, LDC2 needs to pass the output to a C compiler 
as people told me so what's the case from DMD?

I tried to compile a C library (code converted in D to use with 
DMD rather than using "ImportC") using GCC and DMD. And it turns 
out that DMD is about 70-80% faster than GCC which is good but I 
would suppose it could have been better given the design of the D 
as a language and if DMD outputs object files directly.

Do you think that there are any very bad places in DMD's backend? 
Has anyone in the team thought about re-writing the backend (or 
parts of it) from the beginning?