From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/14648 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: [PATCH] mips: add single-instruction math functions Date: Wed, 11 Sep 2019 07:46:55 -0400 Message-ID: <20190911114655.GT9017@brightrain.aerifal.cx> References: <20190911103224.504A15C44C@mx7.valuehost.ru> Reply-To: musl@lists.openwall.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="217964"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mutt/1.5.21 (2010-09-15) To: musl@lists.openwall.com Original-X-From: musl-return-14664-gllmg-musl=m.gmane.org@lists.openwall.com Wed Sep 11 13:47:11 2019 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.89) (envelope-from ) id 1i815a-000uca-Qq for gllmg-musl@m.gmane.org; Wed, 11 Sep 2019 13:47:10 +0200 Original-Received: (qmail 14230 invoked by uid 550); 11 Sep 2019 11:47:08 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 14209 invoked from network); 11 Sep 2019 11:47:07 -0000 Content-Disposition: inline In-Reply-To: <20190911103224.504A15C44C@mx7.valuehost.ru> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:14648 Archived-At: On Wed, Sep 11, 2019 at 01:05:04PM +0300, info@mobile-stream.com wrote: > > non-commit text: > gcc puts annoying nop into the delay slot for these functions, e.g.: > abs.d $f0,$f12 > jr $ra > nop > is there any way to get rid of this without using pure .S? I think you don't want to get rid of it anyway, since if FPU emulation is in use, emulation of floating point instructions in branch delay slots is really problematic and requires nasty hacks with executable stacks and whatnot. It would be nice if we could tell GCC not to put the fpu instructions it generates in branch delay slots either, but I don't know a way to do that. Rich