Re: Regarding performance issues with the Emacs 25.1 Windows-build

[Eli Zaretskii]

> From: Noam Postavsky <address@hidden>
> Date: Wed, 9 Nov 2016 11:55:04 -0500
> Cc: address@hidden, Emacs developers <address@hidden>
> 
> I think the problem is that the 25.1 build is not optimized: I did M-x
> report-emacs-bug in each, notice that 25.1 has a setting for CFLAGS
> which doesn't include -O2, while 24.5 doesn't have one (and hence uses
> the default, which I believe does include -O2).
> 
> In GNU Emacs 25.1.1 (x86_64-w64-mingw32)
>  of 2016-09-17 built on LAPHROAIG
> Configured using:
>  'configure --without-dbus --without-compress-install CFLAGS=-static'
> 
> In GNU Emacs 24.5.1 (i686-pc-mingw32)
>  of 2015-04-11 on LEG570
> Windowing system distributor `Microsoft Corp.', version 6.3.9600
> Configured using:
>  `configure --prefix=/c/usr --host=i686-pc-mingw32'

That could indeed be the culprit: omitting -O2 makes Emacs 2 to 3
times slower, IME.

Phillip, could you please double-check the value of CFLAGS in the
Makefiles in your build tree?  Does it include any optimization
options?

Thanks.