From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/4874 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 11:51:48 -0400 Message-ID: <20140411155148.GT26358@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> <20140411154813.GS26358@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 1397231531 2587 80.91.229.3 (11 Apr 2014 15:52:11 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 11 Apr 2014 15:52:11 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-4878-gllmg-musl=m.gmane.org@lists.openwall.com Fri Apr 11 17:52:04 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 1WYdkJ-0007nw-F5 for gllmg-musl@plane.gmane.org; Fri, 11 Apr 2014 17:52:03 +0200 Original-Received: (qmail 19529 invoked by uid 550); 11 Apr 2014 15:52:00 -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 19516 invoked from network); 11 Apr 2014 15:52:00 -0000 Content-Disposition: inline In-Reply-To: <20140411154813.GS26358@brightrain.aerifal.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Xref: news.gmane.org gmane.linux.lib.musl.general:4874 Archived-At: On Fri, Apr 11, 2014 at 11:48:13AM -0400, Rich Felker wrote: > 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. Maybe we're unclear on what one another are saying. I'm talking about strtod and family here, not printf. Rich