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Re: [wwwdocs] Document in changes.html -fcode-hoisting, -fipa-bit-cp, -fipa-vrp, -fsplit-loops, GCJ removal, x86 ISA additions, -fshrink-wrap-separate etc.
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Kyrill Tkachov <kyrylo dot tkachov at foss dot arm dot com>
- Cc: gcc-patches at gcc dot gnu dot org, Richard Biener <rguenther at suse dot de>, Uros Bizjak <ubizjak at gmail dot com>, Andrew Senkevich <andrew dot n dot senkevich at gmail dot com>, Segher Boessenkool <segher at kernel dot crashing dot org>
- Date: Fri, 27 Jan 2017 17:38:17 +0100
- Subject: Re: [wwwdocs] Document in changes.html -fcode-hoisting, -fipa-bit-cp, -fipa-vrp, -fsplit-loops, GCJ removal, x86 ISA additions, -fshrink-wrap-separate etc.
- Authentication-results: sourceware.org; auth=none
- References: <20170127163051.GW1867@tucnak> <588B76AD.9050300@foss.arm.com>
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
On Fri, Jan 27, 2017 at 04:34:53PM +0000, Kyrill Tkachov wrote:
> > +
> > <h3 id="powerpc">PowerPC / PowerPC64 / RS6000</h3>
> > <ul>
> > <li>The PowerPC port now uses LRA by default.</li>
> > <li>GCC now diagnoses inline assembly that clobbers register r2.
> > This has always been invalid code, and is no longer quietly
> > tolerated.</li>
> > + <li>Shrink-wrapping optimization can now separate portions of
> > + prologues and epilogues to improve performance if some of the
> > + work done traditionally by prologues and epilogues is not needed
> > + on certain paths. This is controlled by the
> > + <code>-fshrink-wrap-separate</code> option, enabled by default.</li>
> > </ul>
>
> AArch64 also implements these hooks and so benefits from the optimisation as well.
> Perhaps move this to the general optimizer improvements section and mention it's only
> enabled for powerpc and aarch64 for the moment?
Yeah, I've also noticed that, but not sure what is better, as it is only 2
targets that support it, so it is not really generic enough. It is unclear what
is better.
Jakub
- References:
- [wwwdocs] Document in changes.html -fcode-hoisting, -fipa-bit-cp, -fipa-vrp, -fsplit-loops, GCJ removal, x86 ISA additions, -fshrink-wrap-separate etc.
- Re: [wwwdocs] Document in changes.html -fcode-hoisting, -fipa-bit-cp, -fipa-vrp, -fsplit-loops, GCJ removal, x86 ISA additions, -fshrink-wrap-separate etc.