From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from majordomo@localhost) by oss.sgi.com (8.11.2/8.11.3) id g2EIXjA16481 for linux-mips-outgoing; Thu, 14 Mar 2002 10:33:45 -0800 Received: from hell (buserror-extern.convergence.de [212.84.236.66]) by oss.sgi.com (8.11.2/8.11.3) with SMTP id g2EIXe916478 for ; Thu, 14 Mar 2002 10:33:40 -0800 Received: from js by hell with local (Exim 3.35 #1 (Debian)) id 16la3c-0001XZ-00; Thu, 14 Mar 2002 19:34:32 +0100 Date: Thu, 14 Mar 2002 19:34:32 +0100 From: Johannes Stezenbach To: Thiemo Seufer Cc: linux-mips@oss.sgi.com Subject: Re: Q: -mcpu= vs. -march= for VR41xx specific instructions Message-ID: <20020314183432.GA5802@convergence.de> Mail-Followup-To: Johannes Stezenbach , Thiemo Seufer , linux-mips@oss.sgi.com References: <20020314172502.GA5365@convergence.de> <20020314181031.GC398@rembrandt.csv.ica.uni-stuttgart.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020314181031.GC398@rembrandt.csv.ica.uni-stuttgart.de> User-Agent: Mutt/1.3.27i Sender: owner-linux-mips@oss.sgi.com Precedence: bulk On Thu, Mar 14, 2002 at 07:10:31PM +0100, Thiemo Seufer wrote: > Johannes Stezenbach wrote: > > GCCFLAGS += -Wa,-march=vr4100 -mips2 -Wa,--trap > > > > This works, but I am unshure what the effects of the > > missing -mcpu switch are wrt the code generated by gcc. > > AFAICS the kernel still works, but is the generated > > code slower or subtly incorrect? > > I don't know what the compiler does then. I assume it defaults to > r3000 scheduling/opcodes. How bad is that compared to -mcpu=vr4100? > I would suggest the syntax > > .set march=vr4100 > > This is in my TODO list for gas, but don't hold your breath. OK. > The real fix is to use a newer compiler (gcc >= 3). :-) Not too long ago people here told me that gcc 3.x is still not ready for production use. Or is gcc-3.1-pre from CVS ready for prime time? Thanks, Johannes