From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 102744 invoked by alias); 27 May 2017 00:38:10 -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 102728 invoked by uid 89); 27 May 2017 00:38:09 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.6 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 spammy= X-HELO: mx0a-001b2d01.pphosted.com Subject: Re: [PATCH] powerpc: Add a POWER8-optimized version of powf() From: Steven Munroe Reply-To: munroesj@linux.vnet.ibm.com To: Adhemerval Zanella Cc: libc-alpha@sourceware.org In-Reply-To: <9d5740ea-fb29-13d9-b71c-de29290350aa@linaro.org> References: <8c7e16e8-d605-9552-89cc-c658dba81a6f@us.ibm.com> <9d5740ea-fb29-13d9-b71c-de29290350aa@linaro.org> Content-Type: text/plain; charset="UTF-8" Date: Sat, 27 May 2017 00:38:00 -0000 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 17052700-0036-0000-0000-00000214BC17 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007124; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000212; SDB=6.00866058; UDB=6.00430153; IPR=6.00645929; BA=6.00005375; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015601; XFM=3.00000015; UTC=2017-05-27 00:38:08 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17052700-0037-0000-0000-0000407DAB8F Message-Id: <1495845477.31269.11.camel@oc7878010663> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-05-26_15:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1705270009 X-SW-Source: 2017-05/txt/msg00817.txt.bz2 On Fri, 2017-05-26 at 16:55 -0300, Adhemerval Zanella wrote: > > On 25/05/2017 14:47, Paul Clarke wrote: > > This implementation is heavily based on sysdeps/ieee754/flt-32/e_powf.c. > > Most significant changes are code simplification and use of doubles for > > intermediate values. Also, some rearrangement to move early > > non-dependent code later, out of the faster paths. > > > > 2017-05-25 Paul A. Clarke > > > > * sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile > > [$(subdir) = math] (libm-sysdep_routines): Add e_powf-power8 and > > e_powf-ppc64. > > * sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-power8.c: New file. > > * sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf-ppc64.c: Likewise. > > * sysdeps/powerpc/powerpc64/fpu/multiarch/e_powf.c: Likewise. > > * sysdeps/powerpc/powerpc64/power8/fpu/e_powf.c: Likewise. > > This changes seems to be arch independent and I would like to avoid adding > even more arch specific. Is there any reason why this can't be used as > the default implementation? Do you have number on different architecture > for it? > If other platform maintainer what to try this implementation and report that would be OK. But I don't this it is correct or fair to ask Paul to prove a negative. These quests tend to be very labor intensive and usually don't work out (as really common) in the end.