Alan Mackenzie <acm@muc.de> writes:

> 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
On my computer "stock" build from master (28) and 27.1 from Arch repo are at about
same speed. I even posted on Reddit like two days ago.

You can see in screenshots, image 1 and 3 are "stock" versions, 27.1 and
28. Image 2 is my own configured build (no gtk and some other stuff).