On 9 August 2017 at 17:52, Antoine Pitrou <solip...@pitrou.net> wrote: > On Wed, 9 Aug 2017 13:36:28 +1000 > Nick Coghlan <ncogh...@gmail.com> wrote: >> On 8 August 2017 at 10:12, Gregory P. Smith <g...@krypto.org> wrote: >> > I don't know whether it is beneficial or not - but having the capability to >> > build LTO without PGO seems reasonable. I can review any pull requests >> > altering configure.ac and Makefile.pre.in to make such a change. >> >> Being able to separate them seems useful even if it's just from the >> performance research perspective of comparing "PGO only", "LTO only" >> and "PGO+LTO". > > That does not mean "LTO only" deserves a configure option, though. PGO > is difficult to set up manually so it's fair that we provide dedicated > build support for it. LTO should just be a matter of tweaking CFLAGS > and LDFLAGS.
I wouldn't be confident in my own ability to get those right for gcc, let alone getting them right for clang as well. Whereas if the "--with-lto" configure option just works, then I'd never need to worry about it :) It also means that if folks *do* investigate this, it eliminates a class of configuration bugs (i.e. "you didn't actually enable LTO correctly in your testing"). Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com