From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2102 invoked by alias); 20 Mar 2018 22:59:51 -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 2081 invoked by uid 89); 20 Mar 2018 22:59:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=study, H*u:6.3, H*UA:6.3, HContent-Transfer-Encoding:8bit X-HELO: aserp2130.oracle.com Subject: Re: [PATCH] v12 Improves __ieee754_exp() performance by 6-11% on aarch64/sparc/x86. To: libc-alpha@sourceware.org References: <1521087720-23806-1-git-send-email-patrick.mcgehearty@oracle.com> <10a52463-35af-cc4a-ebcd-ac87ef7f7edf@oracle.com> From: Patrick McGehearty Message-ID: Date: Tue, 20 Mar 2018 22:59:00 -0000 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <10a52463-35af-cc4a-ebcd-ac87ef7f7edf@oracle.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8838 signatures=668695 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=450 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1803200127 X-SW-Source: 2018-03/txt/msg00493.txt.bz2 Further study confirmed that the existing code is as fast or faster on several platforms when not following my code's fast path, but my code runs faster when |x|  < 1.0397. That being the case, I will be submitting a patch with just the fast path added to the existing code. That should give us the best of both approaches until such time as Szabolcs Nagy's investigation gives better results. - patrick