From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joel Soete Subject: Re: in ccio_io_pdir_entry(),BUG_ON() seems to break gcc-4.2 optimization? Date: Wed, 02 Jul 2008 18:01:45 +0000 Message-ID: <486BC289.6050405@scarlet.be> References: <20080628202347.GA23898@colo.lackof.org> <4866BA91.9040607@scarlet.be> <20080629205242.GA7629@colo.lackof.org> <486925D4.7090608@scarlet.be> <20080702042821.GB19593@colo.lackof.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: linux-parisc To: Grant Grundler Return-path: In-Reply-To: <20080702042821.GB19593@colo.lackof.org> List-ID: List-Id: linux-parisc.vger.kernel.org Grant Grundler wrote: > On Mon, Jun 30, 2008 at 06:28:36PM +0000, Joel Soete wrote: > ... >> Taken also into account of David remarks, here is the latest stuff tested >> with success: >> >> __asm__ __volatile__ ( >> "lci %%r0(%%sr1, %2), %0\n" >> "\textru %0,19,12,%0\n" >> "\tdepw %0,15,12,%1\n" >> : "=r" (ci), "=r" (pa) >> : "r" (vba) >> ); > > So can you remind me (and Kyle) why this is better than what is > there now? > mmm may be because gcc consider it now as only 1 'volatile' instruction: in -----------< Original code > --------------+------------< New stuff >----------------- 200: 06 80 53 13 lci r0(sr1,r20),r19 | 200: 08 1a 02 54 copy r26,r20 204: d2 73 1a 74 extrw,u r19,19,12,r19 | 204: 06 a0 53 14 lci r0(sr1,r21),r20 208: 08 1a 02 5c copy r26,ret0 | 208: d2 94 1a 74 extrw,u r20,19,12,r20 20c: d7 93 0e 14 depw r19,15,12,ret0 | 20c: d7 94 0e 14 depw r20,15,12,ret0 210: 0e dc 12 80 stw ret0,0(r22) 210: 0e dc 12 80 stw ret0,0(r22) 214: 06 c0 12 80 fdc r0(r22) 214: 06 c0 12 80 fdc r0(r22) 218: 00 00 04 00 sync 218: 00 00 04 00 sync thought? >> Tx to all for kind comments, they learn me a lot ;-) > > welcome! :) > > grant > -- > To unsubscribe from this list: send the line "unsubscribe linux-parisc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >