Re: Bootstrap speed

[Óscar Fuentes]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Stefan Monnier <monnier@iro.umontreal.ca>
>> Date: Sun, 02 Jan 2022 00:44:33 -0500
>> 
>> With the native compiler, I get the impression that the compilation from
>> `.el` to `.elc` files is faster but I also see that we spent an insane
>> amount of time in:
>> 
>>     ELC+ELN  emacs-lisp/macroexp.elc
>>     ELC+ELN  emacs-lisp/cconv.elc
>>     ELC+ELN  emacs-lisp/byte-opt.elc
>>     ELC+ELN  emacs-lisp/bytecomp.elc
>>     ELC+ELN  emacs-lisp/comp.elc
>>     ELC+ELN  emacs-lisp/comp-cstr.elc
>> 
>> right after the first dump.
>
> Yes.  See bug#48921.  (comp.el is the worst offender in the above
> group.)  Sadly, we didn't make any tangible progress in that matter
> since the bug was filed.

Is it possible to profile libgccjit on those inputs? Also, searching gcc
bugzilla for "slow" or somesuch could be interesting.

The other-compiler-framework-which-shall-remain-unnamed is very slow on
certain cases (large functions, for instance.) Many algorithms are
slower than O(n) and it shows here and there. I'm pretty sure that GCC
suffers from the same.