From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/4873 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: Preparing for releases 1.1.0 and 1.0.1 Date: Fri, 11 Apr 2014 11:48:13 -0400 Message-ID: <20140411154813.GS26358@brightrain.aerifal.cx> References: <20140410024045.GA6538@brightrain.aerifal.cx> <20140410131122.GR3034@port70.net> <20140411013911.GQ26358@brightrain.aerifal.cx> <20140411094616.GU3034@port70.net> <20140411130747.GR26358@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1397231314 29783 80.91.229.3 (11 Apr 2014 15:48:34 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 11 Apr 2014 15:48:34 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-4877-gllmg-musl=m.gmane.org@lists.openwall.com Fri Apr 11 17:48:27 2014 Return-path: Envelope-to: gllmg-musl@plane.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1WYdgo-0004Ro-Re for gllmg-musl@plane.gmane.org; Fri, 11 Apr 2014 17:48:26 +0200 Original-Received: (qmail 16159 invoked by uid 550); 11 Apr 2014 15:48:25 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 16146 invoked from network); 11 Apr 2014 15:48:25 -0000 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Xref: news.gmane.org gmane.linux.lib.musl.general:4873 Archived-At: On Fri, Apr 11, 2014 at 11:17:00AM -0400, Morten Welinder wrote: > > Yes but this leads to serious breakage if the compiler does not handle > > the request to drop precision in a conforming way, and it still > > doesn't help the fact that strtod depends on long double semantics. > > Are you sure? > > If the incoming number has at most 53 bits then there will be at most > 24 bits left after the 2^(1+28) reduction. The scalings by 10^9 = 2^9 * 5^9 > require at most log2(5^9) ~ 21 extra bits. > > That ought to fit in valgrind's double. Are you basing this on a reading of how long double is used in the source file, or just generalities? The rounding logic depends on exactly how many places are kept/dropped when a certain addition is performed. Rich