From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 111739 invoked by alias); 4 Apr 2016 16:42:21 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 111701 invoked by uid 89); 4 Apr 2016 16:42:20 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 spammy= X-HELO: gate.crashing.org Date: Mon, 04 Apr 2016 16:42:00 -0000 From: Segher Boessenkool To: "Paul E. Murphy" Cc: "libc-alpha@sourceware.org" , Tulio Magno Quites Machado Filho Subject: Re: [PATCHv2] powerpc: Add optimized P8 strspn Message-ID: <20160404164211.GA2517@gate.crashing.org> References: <56FC0008.7030302@linux.vnet.ibm.com> <20160402234040.GA17716@gate.crashing.org> <57027ECE.7070101@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57027ECE.7070101@linux.vnet.ibm.com> User-Agent: Mutt/1.4.2.3i X-SW-Source: 2016-04/txt/msg00055.txt.bz2 On Mon, Apr 04, 2016 at 09:48:46AM -0500, Paul E. Murphy wrote: > >> + lvsr v11, r0, r3 > > > > That is 0, not r0. > > > >> + lvx v0, r0, r3 /* Note, unaligned load ignores lower bits. */ > > > > Same for lvx. > > I'd intentionally used r0 in those cases to explicitly exploit its special > meaning under those instructions. It it customary to explicitly use 0 in > such cases? Yes; the ISA document has many examples of this, see for example 6.4.1 in the Power ISA 3.0 doc. Using "r0" here is quite misleading. Segher