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Re: Default compiler optimization level for building dev sources

From: Eli Zaretskii
Subject: Re: Default compiler optimization level for building dev sources
Date: Fri, 22 Apr 2016 17:40:28 +0300

> From: Óscar Fuentes <address@hidden>
> Date: Fri, 22 Apr 2016 16:17:48 +0200
> I'm using Emacs 25.0.92 on Windows and it seems remarkably slower than
> the previous binary. This one was built with a plain config && make
> while the previous one had CFLAGS set to -O3 and other extra
> optimization flags.

So you are saying that -O2 (that's the default) is significantly
slower than -O3?  That's strange, my experience is that -O3 is
generally not faster than -O2 and sometimes slower.

> Maybe the build does not turn on optimizations when it detects that the
> sources are on a repo. Sorry for asking here instead of checking it
> myself but today I have no access to the sources nor the web.

I don't think so.  The default is -O2, so if you want -O3, you need to
request it by saying "CFLAGS='-O3' ./configure ...".

Do you still have the source directory tree where you b uilt the
previous binary?  If so, please tell what configure-time switches you
used and which compiler switches do you see in src/Makefile.

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