Subject: bug#24720: closed (Re: bug#24720: Performance impact of -no-pie)

From: [email-masked] (GNU bug Tracking System)
Date: Tue, 18 Oct 2016 16:22:02 +0000

Your bug report

#24720: Performance impact of -no-pie

which was filed against the emacs package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
24720: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=24720
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#24720: Performance impact of -no-pie
From: Paul Eggert <[email-masked]>
To: Glenn Morris <[email-masked]>, Alex <[email-masked]>
Cc: [email-masked]
Date: Tue, 18 Oct 2016 09:21:27 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

On 10/18/2016 08:59 AM, Glenn Morris wrote:
> I'm going to guess that when you set it via CFLAGS, you lost the -O2
> that is otherwise part of the default CFLAGS.

Yes, that sounds quite plausible. Thanks for the diagnosis. Closing the bug.

Subject: Performance impact of -no-pie
From: Paul Eggert <[email-masked]>
To: Emacs bug reports <[email-masked]>
Cc: Alex <[email-masked]>
Date: Mon, 17 Oct 2016 13:18:51 -0700
List-Id: <debbugs-submit.debbugs.gnu.org>

(The rest of this message is copied from Alex's email archived at 
<http://lists.gnu.org/archive/html/emacs-devel/2016-10/msg00451.html>.)

After being forced to add -no-pie to my CFLAGS in order to build Emacs with a recent GCC, my startup time for my whole config (with -nw) has increased from ~1 second to ~2 seconds.

The startup time for `emacs -Q -nw` went up from about 0.07s to 0.14s; again it's about twice as slow.

The -Q time doesn't worry me, but the extra second for my main configuration isn't pleasant.

Is such a performance impact expected? If so, is there a plan to regain the old speed?