Message-ID: <55930D24.4040105@zytor.com>
Date: Tue, 30 Jun 2015 14:41:56 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Jakub Jelinek <jakub@redhat.com>, Andy Lutomirski <luto@kernel.org>
CC: gcc@gcc.gnu.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
        Vladimir Makarov <vmakarov@redhat.com>
Subject: Re: gcc feature request / RFC: extra clobbered regs
References: <CALCETrX6j9vBZR7RirXf8usz1Y4f-1TnVaYTVg0_PgQCeWZnRg@mail.gmail.com> <20150630213736.GQ10247@tucnak.redhat.com>
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On 06/30/2015 02:37 PM, Jakub Jelinek wrote:
> I'd say the most natural API for this would be to allow
> f{fixed,call-{used,saved}}-REG in target attribute.

Either that or

	__attribute__((fixed(rbp,rcx),used(rax,rbx),saved(r11)))

... just to be shorter.  Either way, I would consider this to be
desirable -- I have myself used this to good effect in a past life
(*cough* Transmeta *cough*) -- but not a high priority feature.

	-hpa


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