X-Recipient: archive-cygwin AT delorie DOT com DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:in-reply-to:references:from:date :message-id:subject:to:content-type; q=dns; s=default; b=sC+4lU+ pCJnJzqTazLSQYqN9Y+lJTz2CJE8eercPtZJEMcYPGDlP/mlGQEGrlEi54zRCbsz Svrw7c6l0rdPwkL6ywt/ivqsxR3cQQI0cFlIEqeFrG5BrHdcU2WxBuVTVxf4SZo4 YP8JEV9DvyyChcZeAXWMi07XMdO4oVLTQa3s= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:mime-version:in-reply-to:references:from:date :message-id:subject:to:content-type; s=default; bh=9LnOVgouD59J4 i50fES1gQ5zGYI=; b=Hrj249ib/5vyw+JQZJwoVLZVXjyb0sO+oN+RUwxzebv3/ COiNdXgsvKzTEiTTFhrWrCoC6PMdBQEm3/cRLslyFYw7JXwy9E0md6xJTfUz+bTt IsDgAmFPs/7SoyOetfDsWgB9ykMRkqH0/re7UVyJGoG38nP0k9Af1jreCTCkaw= Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.3 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,SPF_PASS autolearn=no version=3.3.2 spammy= X-HELO: mail-yb0-f180.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=0oVEPdL9/93T8dF+7H9FXjovm3Zzt5ZnOdYxWtNnQgk=; b=ASyxCiMMn5FeCe/RFttrBIFQWKVnJbKS2Ba2Pf9dFu9CsEjZYl9OrXRAKGsetMjSSe Q2a+w1Bnk6SYhsfm9LGauO7FLqyzefyE7MLrqL9radrCwyYIVZ4R1bhEU/A/0OSVSha6 NyaXwtxMGWVCFEagCtNWvb+k498hZ7TbqvoumRP5pa+T35v/KcRFJI8PuIX2gUZlsnOU Hdkk/roChddiuuoRxRHVIDXzE70LBydPyUafozAca9SWTgQX9Wxm7yjsHk6BgHbnglxM VdZNIx0y+Y+/Dy7R/K5eoAvxz7agw5Gxc6t7f3HIW9CPp3S4zKIrsutVWtJiIn2rMa+8 BXKA== X-Gm-Message-State: AODbwcCYKVXw2ZvbBeTLNUfB8XL/CwosNBQTo712F3dA6ljF1yR31eI0 6Q46DtXF0biw1Bk6+xSa6nyePqps6Z8V X-Received: by 10.37.180.154 with SMTP id o26mr10089552ybj.10.1495794511607; Fri, 26 May 2017 03:28:31 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <6f28f46906804c6f8f6b4b861e202492 AT CASMBX02 DOT oslo DOT ngi DOT no> From: Erik Bray Date: Fri, 26 May 2017 12:28:31 +0200 Message-ID: Subject: Re: bug in lrint [was: FW: Printing long int in C program under cygwin64] To: cygwin AT cygwin DOT com Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes On Wed, May 24, 2017 at 6:57 PM, Eric Blake wrote: > On 05/24/2017 11:53 AM, Erik Bray wrote: > >>>> dropping down to assembly; it could very well be that the assembly code >>>> is incorrectly truncating things at 32 bits (where it is just fine for >>>> 32-bit Cygwin, but wrong for 64-bit): >>>> >>>> long lrint (double x) >>>> { >>>> long retval = 0L; >>>> #if defined(_AMD64_) || defined(__x86_64__) || defined(_X86_) || >>>> defined(__i386__) >>>> __asm__ __volatile__ ("fistpl %0" : "=m" (retval) : "t" (x) : "st"); > >> Actually, I take it back. gdb/objdump (and presumably binutils in >> general) was being deceptive to me about the nature of that mov >> instruction. And in fact the fistpl should be fistpq. That fixes it. > > Is fistpq right on 32-bit, or is this a case where we need different > assembly for 32-bit (fistpl) vs. 64-bit (fistql) to match the size of > long that we are converting to? Right. I didn't read that pre-processer line past the first couple defines. Really this should be fistpq on 64-bit and fistpl on 32-bit. And if llrint has the same bug then it should be fixed there too. The discussion about printf format specifiers is orthogonal to this. I can submit a patch for l(l)rint if you'd like. Erik -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple