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Re: Using LTO-enabled libgfortran
- From: Richard Biener <richard dot guenther at gmail dot com>
- To: Thomas Koenig <tkoenig at netcologne dot de>,gcc mailing list <gcc at gcc dot gnu dot org>,"fortran at gcc dot gnu dot org" <fortran at gcc dot gnu dot org>
- Date: Tue, 16 Aug 2016 20:57:55 +0200
- Subject: Re: Using LTO-enabled libgfortran
- Authentication-results: sourceware.org; auth=none
- References: <2a3f69d5-f3fe-2eef-9b8d-7b23ca963632@netcologne.de>
On August 16, 2016 7:11:26 PM GMT+02:00, Thomas Koenig <tkoenig@netcologne.de> wrote:
>What would it take to use an LTO-enabled version of gfortran?
>
>It could turn out to be quite useful for speeding up programs,
>especially where I/O or array intrinsics are used.
>
>I also expect many issues to surface where libgfortran is
>playing with types in a way that could break LTO, so I
>would not expect this to be an easy thing.
>
>So, ideas anybody? I don't think any other library included
>with gcc does this, correct?
Correct. My advice is to simply try. Note this will work only for static libgfortran. Also note that since the LTO option scheme changed to preserve compile-time optimization and target attributes LTOing libgfortran will be less useful than before (you won't get any advantage from extra available ISAs).
Richard.
>Regards
>
> Thomas