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

[Alan Mackenzie]

Hello, Steve.

On Thu, Dec 03, 2020 at 23:17:18 +0100, Stephen Berman wrote:
> On Thu, 3 Dec 2020 18:15:30 +0000 Alan Mackenzie <acm@muc.de> wrote:

> > Hello, Emacs.

> > I've got pretty much up to date copies of both the master and the
> > emacs-27 branches.

> > When I run my customary benchmark (see below) on master's src/xdisp.c in
> > master, it's taking around 34s.  On emacs-27, it's taking 22s.

> Hm, this is odd: I just ran your benchmark on src/xdisp.c (starting
> Emacs with -Q, both configured with CFLAGS='-Og -g3') and got vastly
> different timings than you did:

> master:   21.785817861557007
> emacs-27: 61.3885281085968

Maybe the emacs-27 is built without optimisation for debugging.

> This is with:

> GNU Emacs 28.0.50 (build 42, x86_64-pc-linux-gnu, GTK+ Version 3.24.17,
> cairo version 1.17.3) of 2020-11-21
> emacs-repository-version: "0a8cd0116204354e95fbb4ebde64c58123502aa2"

> and

> GNU Emacs 27.1.50 (build 18, x86_64-pc-linux-gnu, GTK+ Version 3.24.17)
> of 2020-11-21
> emacs-repository-version: "3ceee398192e312faa3ea073365c49bcce9ef61b"

> Steve Berman

-- 
Alan Mackenzie (Nuremberg, Germany).