Re: The Emacs master is much slower than the emacs-27 branch.

[Stephen Berman]

On Fri, 04 Dec 2020 21:47:53 +0100 Óscar Fuentes <ofv@wanadoo.es> wrote:

> Stephen Berman <stephen.berman@gmx.net> writes:
>
>> Well, I went ahead and configured emacs-27 --with-cairo --without-xft,
>> rebuilt and ran the benchmark, and it still took ~60 seconds.  I've
>> attached the profile because it is considerably longer than the other
>> emacs-27 profiles, though in general it seems similar to me, but maybe
>> an expert will spot a significant difference.
>
> What happens if you build with CFLAGS='-O2' ?

Gregory Heytings found the answer:

  I bisected this, and the origin of the regression is commit
  365dad197bac5deec9244fd9c189d23c46c99b31, which changes the default to
  "use 'static' instead of 'extern inline' [in C headers] because
  'static' typically has better performance for Emacs".  With -Og or
  -O0, the benchmark takes 67 seconds, with -O1 or above (-O2 is the
  default) it takes 25 seconds.

Steve Berman