From owner-freebsd-toolchain@freebsd.org Wed Mar 13 15:05:54 2019 Return-Path: Delivered-To: freebsd-toolchain@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 172581535EF8; Wed, 13 Mar 2019 15:05:54 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "troutmask", Issuer "troutmask" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 09A1C831B0; Wed, 13 Mar 2019 15:05:51 +0000 (UTC) (envelope-from sgk@troutmask.apl.washington.edu) Received: from troutmask.apl.washington.edu (localhost [127.0.0.1]) by troutmask.apl.washington.edu (8.15.2/8.15.2) with ESMTPS id x2DF5n13034668 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Wed, 13 Mar 2019 08:05:49 -0700 (PDT) (envelope-from sgk@troutmask.apl.washington.edu) Received: (from sgk@localhost) by troutmask.apl.washington.edu (8.15.2/8.15.2/Submit) id x2DF5nXT034667; Wed, 13 Mar 2019 08:05:49 -0700 (PDT) (envelope-from sgk) Date: Wed, 13 Mar 2019 08:05:49 -0700 From: Steve Kargl To: freebsd-toolchain@freebsd.org, freebsd-current@freebsd.org Subject: Re: Optimization bug with floating-point? Message-ID: <20190313150548.GA34658@troutmask.apl.washington.edu> Reply-To: sgk@troutmask.apl.washington.edu References: <20190313024506.GA31746@troutmask.apl.washington.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190313024506.GA31746@troutmask.apl.washington.edu> User-Agent: Mutt/1.11.2 (2019-01-07) X-Rspamd-Queue-Id: 09A1C831B0 X-Spamd-Bar: +++ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [3.92 / 15.00]; ARC_NA(0.00)[]; HAS_REPLYTO(0.00)[sgk@troutmask.apl.washington.edu]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_SPAM_MEDIUM(0.68)[0.679,0]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; TO_DN_NONE(0.00)[]; AUTH_NA(1.00)[]; DMARC_NA(0.00)[washington.edu]; RCVD_COUNT_THREE(0.00)[3]; RCVD_TLS_LAST(0.00)[]; NEURAL_SPAM_SHORT(0.60)[0.598,0]; RCVD_IN_DNSWL_MED(-0.20)[21.76.95.128.list.dnswl.org : 127.0.11.2]; MX_GOOD(-0.01)[cached: troutmask.apl.washington.edu]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_SPAM_LONG(0.93)[0.932,0]; R_SPF_NA(0.00)[]; REPLYTO_ADDR_EQ_FROM(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; ASN(0.00)[asn:73, ipnet:128.95.0.0/16, country:US]; MID_RHS_MATCH_FROM(0.00)[]; IP_SCORE(0.02)[ip: (0.09), ipnet: 128.95.0.0/16(0.09), asn: 73(0.01), country: US(-0.07)] X-BeenThere: freebsd-toolchain@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Maintenance of FreeBSD's integrated toolchain List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 13 Mar 2019 15:05:54 -0000 On Tue, Mar 12, 2019 at 07:45:41PM -0700, Steve Kargl wrote: > All, > > There seems to an optimization bug with clang on > > % uname -a > FreeBSD mobile 13.0-CURRENT FreeBSD 13.0-CURRENT r344653 MOBILE i386 > > IOW, if you do numerica work on i386, you may want to check your > results. > > The program demonstrating the issue is at the end of this email. > > gcc8 --version > gcc8 (FreeBSD Ports Collection) 8.3.0 > > gcc8 -fno-builtin -o z a.c -lm && ./z > gcc8 -O -fno-builtin -o z a.c -lm && ./z > gcc8 -O2 -fno-builtin -o z a.c -lm && ./z > gcc8 -O3 -fno-builtin -o z a.c -lm && ./z > > Max ULP: 2.297073 > Count: 0 (# of ULP that exceed 21) > The above results do not change if one add -ffloat-store to the command line. > cc -O -fno-builtin -o z a.c -lm && ./z > cc -O2 -fno-builtin -o z a.c -lm && ./z > cc -O3 -fno-builtin -o z a.c -lm && ./z > > Max ULP: 23.061242 > Count: 39 (# of ULP that exceeds 21) Clang doesn't support -ffloat-store, so the above does not change. -- Steve