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From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Re: [PATCH 1/1] Stop using legacy -ffat-lto-objects flag
Date: Mon, 09 Nov 2020 17:59:02 +0200
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Cc: evan@eklitzke.org, emacs-devel@gnu.org
To: Andrea Corallo <akrl@sdf.org>
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 Nov 2020 08:57:51 +0000)
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> From: Andrea Corallo <akrl@sdf.org>
> Cc: Evan Klitzke <evan@eklitzke.org>,  emacs-devel@gnu.org
> Date: Mon, 09 Nov 2020 08:57:51 +0000
> 
> >> Currently when Emacs is configured using the 
> >> --enable-link-time-optimization configure flag, the build will use the 
> >> -ffat-lto-objects flag if the host compiler is GCC (but not Clang). 
> >> According to the comments in configure.ac this is to work around an 
> >> issue with LTO builds in GCC 4.9.0. This flag makes builds take much 
> >> longer (and produces much larger object files), so I suggest removing it 
> >> as GCC 4.x is quite old at this point and doesn't have great LTO support 
> >> anyway.
> >
> > I think this is too soon: fencepost.gnu.org, which runs Trisquel LTS,
> > still has GCC 4.8.4.
> >
> > Thanks.
> 
> Couldn't we check and decide based on the GCC version?  IIUC we already
> do something like this using gl_GCC_VERSION_IFELSE.

That'd be fine with me, thanks.