From: Michael Matz <matz@suse.de>
To: Jan Hubicka <hubicka@ucw.cz>
Cc: Richard Biener <richard.guenther@gmail.com>,
Alexander Monakov <amonakov@ispras.ru>,
gcc-patches@gcc.gnu.org
Subject: Re: [x86-64] RFC: Add nosse abi attribute
Date: Tue, 11 Jul 2023 14:00:03 +0000 (UTC) [thread overview]
Message-ID: <alpine.LSU.2.20.2307111358060.13548@wotan.suse.de> (raw)
In-Reply-To: <ZK1XcSChStVjpnGF@kam.mff.cuni.cz>
Hello,
On Tue, 11 Jul 2023, Jan Hubicka wrote:
> > > > When a function doesn't contain calls to
> > > > unknown functions we can be a bit more lenient: we can make it so that
> > > > GCC simply doesn't touch xmm8-15 at all, then no save/restore is
> > > > necessary.
>
> One may also take into account that first 8 registers are cheaper to
> encode than the later 8, so perhaps we may want to choose range that
> contains both.
There is actually none in the low range that's usable. xmm0/1 are used
for return values and xmm2-7 are used for argument passing. Arguments are
by default callee clobbered, and we do not want to change this (or limit
the number of register arguments for the alternate ABI).
Ciao,
Michael.
next prev parent reply other threads:[~2023-07-11 14:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-10 15:55 Michael Matz
2023-07-10 17:28 ` Richard Biener
2023-07-10 19:07 ` Alexander Monakov
2023-07-10 20:33 ` Alexander Monakov
2023-07-11 6:42 ` Richard Biener
2023-07-11 8:53 ` Jan Hubicka
2023-07-11 9:07 ` Richard Biener
2023-07-11 13:00 ` Richard Biener
2023-07-11 13:21 ` Jan Hubicka
2023-07-11 14:00 ` Michael Matz [this message]
2023-07-11 13:59 ` Alexander Monakov
2023-07-11 14:57 ` Michael Matz
2023-07-11 15:17 ` Alexander Monakov
2023-07-11 15:34 ` Michael Matz
2023-07-11 16:53 ` Alexander Monakov
2023-07-17 23:00 ` Richard Sandiford
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