public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "dominiq at lps dot ens.fr" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/47558] 163267 breaks exception traceback in xplor-nih
Date: Mon, 07 Feb 2011 23:07:00 -0000	[thread overview]
Message-ID: <bug-47558-4-Altr5DYEX6@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-47558-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47558

--- Comment #69 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2011-02-07 22:58:33 UTC ---
> So, what you are saying is that the system routine produces an answer that
> isn't correct down to the last digit of precision for at least 1 input?

I have not looked in detail to the accuracy of the darwin10 or FSF
implementation in their common range of validity. I am pretty sure that they
are about the same, but even if the darwin10 implementation has a maximum error
twice that of the FSF one, I think this not the reason of PR42333 (it would be
solved by some increase of the tolerance for the comparison). The reason being
that the naive, but fast, algorithm (a+ib)/(c+id)=(a+ib)(c-id)/(c*c+d*d) gives
a sound result only if c*c+d*d does not yield 0.0 nor Inf as it does with the
values in gcc.dg/torture/builtin-math-7.c. 

This is why I think the comments should stress the extended range of validity
for the FSF division rather than a hypothetical accuracy.


  parent reply	other threads:[~2011-02-07 22:58 UTC|newest]

Thread overview: 69+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-31 22:18 [Bug target/47558] New: " howarth at nitro dot med.uc.edu
2011-02-01  0:14 ` [Bug target/47558] " howarth at nitro dot med.uc.edu
2011-02-01  0:32 ` howarth at nitro dot med.uc.edu
2011-02-01  3:55 ` howarth at nitro dot med.uc.edu
2011-02-01  4:02 ` howarth at nitro dot med.uc.edu
2011-02-01  6:10 ` howarth at nitro dot med.uc.edu
2011-02-01  9:09 ` iains at gcc dot gnu.org
2011-02-01 13:25 ` iains at gcc dot gnu.org
2011-02-01 13:52 ` howarth at nitro dot med.uc.edu
2011-02-01 13:53 ` howarth at nitro dot med.uc.edu
2011-02-01 13:56 ` howarth at nitro dot med.uc.edu
2011-02-01 14:37 ` iains at gcc dot gnu.org
2011-02-01 15:12 ` howarth at nitro dot med.uc.edu
2011-02-01 15:26 ` iains at gcc dot gnu.org
2011-02-01 15:50 ` iains at gcc dot gnu.org
2011-02-01 15:57 ` iains at gcc dot gnu.org
2011-02-01 15:59 ` howarth at nitro dot med.uc.edu
2011-02-01 16:32 ` iains at gcc dot gnu.org
2011-02-01 16:40 ` iains at gcc dot gnu.org
2011-02-01 17:05 ` howarth at nitro dot med.uc.edu
2011-02-01 18:07 ` iains at gcc dot gnu.org
2011-02-01 18:51 ` iains at gcc dot gnu.org
2011-02-01 19:56 ` howarth at nitro dot med.uc.edu
2011-02-01 20:33 ` iains at gcc dot gnu.org
2011-02-01 20:57 ` howarth at nitro dot med.uc.edu
2011-02-01 21:27 ` howarth at nitro dot med.uc.edu
2011-02-01 23:53 ` iains at gcc dot gnu.org
2011-02-02  2:23 ` howarth at nitro dot med.uc.edu
2011-02-02  2:55 ` howarth at nitro dot med.uc.edu
2011-02-02  9:13 ` iains at gcc dot gnu.org
2011-02-03 13:57 ` howarth at nitro dot med.uc.edu
2011-02-03 14:21 ` iains at gcc dot gnu.org
2011-02-03 14:29 ` iains at gcc dot gnu.org
2011-02-04  0:30 ` howarth at nitro dot med.uc.edu
2011-02-04  0:44 ` mikestump at comcast dot net
2011-02-04  1:20 ` howarth at nitro dot med.uc.edu
2011-02-04  1:31 ` howarth at nitro dot med.uc.edu
2011-02-04  1:47 ` howarth at nitro dot med.uc.edu
2011-02-04  2:40 ` howarth at nitro dot med.uc.edu
2011-02-04  3:17 ` howarth at nitro dot med.uc.edu
2011-02-04  3:24 ` howarth at nitro dot med.uc.edu
2011-02-04  4:48 ` howarth at nitro dot med.uc.edu
2011-02-04  4:59 ` howarth at nitro dot med.uc.edu
2011-02-04  5:42 ` howarth at nitro dot med.uc.edu
2011-02-04  5:44 ` howarth at nitro dot med.uc.edu
2011-02-04  5:53 ` howarth at nitro dot med.uc.edu
2011-02-04 10:21 ` iains at gcc dot gnu.org
2011-02-04 10:53 ` iains at gcc dot gnu.org
2011-02-04 10:57 ` iains at gcc dot gnu.org
2011-02-04 11:02 ` howarth at nitro dot med.uc.edu
2011-02-04 11:26 ` iains at gcc dot gnu.org
2011-02-04 12:02 ` howarth at nitro dot med.uc.edu
2011-02-04 12:32 ` howarth at nitro dot med.uc.edu
2011-02-04 15:11 ` howarth at nitro dot med.uc.edu
2011-02-04 15:16 ` howarth at nitro dot med.uc.edu
2011-02-05 12:22 ` iains at gcc dot gnu.org
2011-02-05 18:40 ` howarth at nitro dot med.uc.edu
2011-02-05 18:57 ` iains at gcc dot gnu.org
2011-02-05 19:04 ` howarth at nitro dot med.uc.edu
2011-02-05 19:23 ` dominiq at lps dot ens.fr
2011-02-07 20:49 ` mrs at gcc dot gnu.org
2011-02-07 20:53 ` iains at gcc dot gnu.org
2011-02-07 20:56 ` dominiq at lps dot ens.fr
2011-02-07 21:49 ` mrs at gcc dot gnu.org
2011-02-07 22:12 ` mrs at gcc dot gnu.org
2011-02-07 22:27 ` mikestump at comcast dot net
2011-02-07 23:07 ` dominiq at lps dot ens.fr [this message]
2011-02-08  3:58 ` mikestump at comcast dot net
2011-02-08  4:22 ` howarth at nitro dot med.uc.edu

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=bug-47558-4-Altr5DYEX6@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /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).