From: "Soegtrop, Michael" <michael.soegtrop@intel.com>
To: "dank@kegel.com" <dank@kegel.com>,
"cygwin@cygwin.com" <cygwin@cygwin.com>
Subject: RE: Floating point exception in strtod()
Date: Sun, 08 Apr 2018 12:57:00 -0000 [thread overview]
Message-ID: <0F7D3B1B3C4B894D824F5B822E3E5A177861A345@IRSMSX102.ger.corp.intel.com> (raw)
In-Reply-To: <CAPF-yOboiR8Dg+QtrHCCR55vPGysMxQ=Wbpa4QGaJ=i5PoqtkQ@mail.gmail.com>
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1175 bytes --]
> Probably doesn't fit precisely into a double. Does strtold behave
> better?
actually both numbers can be represented exactly as IEEE double. In Maxima:
(%i1) factor(121645100408832000);
(%o1) 2^16*3^8*5^3*7^2*11*13*17*19
(%i2) float(log(3^8*5^3*7^2*11*13*17*19)/log(2));
(%o2) 40.75545582601886
(%i3) factor(221645100408832000);
(%o3) 2^16*5^3*31*41*1361*15641
(%i4) float(log(5^3*31*41*1361*15641)/log(2));
(%o4) 41.62102908434535
So the first number has 41 bits and the second 42 after removing powers of 2. The significand size of a double is 53 bits (including the implicit 1).
Best regards,
Michael
Intel Deutschland GmbH
Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Christin Eisenschmid, Christian Lamprechter
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
\x03BKCB\x1cØ\x19[H\x1c\^[Ü\x1cÎ\b\b\b\b\b\b\x1a\x1d\x1d\x1c\x0eËØÞYÝÚ[ÛÛKÜ\x1cØ\x19[\Ë\x1d^[[\x03BTN\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\b\x1a\x1d\x1d\x1c\x0eËØÞYÝÚ[ÛÛKÙ\KÃB^[ØÝ[Y[\x18]\x1a[Û\b\b\b\b\b\b\b\b\x1a\x1d\x1d\x1c\x0eËØÞYÝÚ[ÛÛKÙ^[ØÜË\x1d^[[\x03B[ÝXØÜXH\x1a[Î\b\b\b\b\b\x1a\x1d\x1d\x1c\x0eËØÞYÝÚ[ÛÛKÛ[\vÈÝ[ÝXØÜXK\Ú[\^[\x19CBB
next prev parent reply other threads:[~2018-04-08 12:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-07 17:40 Ken Brown
2018-04-07 20:52 ` Dan Kegel
2018-04-08 12:57 ` Soegtrop, Michael [this message]
2018-04-07 20:56 ` Eliot Moss
2018-04-08 3:12 ` Duncan Roe
2018-04-08 10:25 ` Hans-Bernhard Bröker
2018-04-09 9:47 ` Corinna Vinschen
2018-04-09 12:09 ` Ken Brown
2018-04-09 12:51 ` Corinna Vinschen
2018-04-09 14:46 ` Soegtrop, Michael
2018-04-09 15:33 ` Corinna Vinschen
2018-04-09 15:55 ` Soegtrop, Michael
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=0F7D3B1B3C4B894D824F5B822E3E5A177861A345@IRSMSX102.ger.corp.intel.com \
--to=michael.soegtrop@intel.com \
--cc=cygwin@cygwin.com \
--cc=dank@kegel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).