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* [Bug math/13304] New: fma, fmaf, fmal produce wrong results
@ 2011-10-17  2:02 bruno at clisp dot org
  2011-10-17  2:03 ` [Bug math/13304] " bruno at clisp dot org
                   ` (45 more replies)
  0 siblings, 46 replies; 47+ messages in thread
From: bruno at clisp dot org @ 2011-10-17  2:02 UTC (permalink / raw)
  To: glibc-bugs

http://sourceware.org/bugzilla/show_bug.cgi?id=13304

             Bug #: 13304
           Summary: fma, fmaf, fmal produce wrong results
           Product: glibc
           Version: 2.11
            Status: NEW
          Severity: normal
          Priority: P2
         Component: math
        AssignedTo: aj@suse.de
        ReportedBy: bruno@clisp.org
    Classification: Unclassified


Created attachment 5990
  --> http://sourceware.org/bugzilla/attachment.cgi?id=5990
test suite for fma()

The functions fma(), fmaf(), fmal() are defined in POSIX:2008
<http://pubs.opengroup.org/onlinepubs/9699919799/functions/fma.html>:

  "These functions shall compute (x * y) + z, rounded as one ternary operation:
   they shall compute the value (as if) to infinite precision and round once
   to the result format"

Find attached a test suite for fma(), easily adapted for fmaf() or fmal()
through a couple of #defines. I have checked this test suite by running it
against a slow but correct multi-precision implementation of fma().

This test suite gives
  - 7 failures for fma(),
  - 1 more failure for fmaf(),
  - 9 more failures for fmal(),
on a glibc 2.11.3 system where
  - fma() and fmaf() are implemented through a complex floating-point
    instruction rich code,
  - fmal() does just a x*y+z computation.

Find attached the bugs, each in a separate program, to be compiled and linked
with "-lm".

Feel free to add the test suite to glibc. I have a copyright assignment for
glibc on file, and am giving this file to the FSF.

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^ permalink raw reply	[flat|nested] 47+ messages in thread
end of thread, other threads:[~2015-09-25 17:35 UTC | newest]

Thread overview: 47+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2011-10-17  2:02 [Bug math/13304] New: fma, fmaf, fmal produce wrong results bruno at clisp dot org
2011-10-17  2:03 ` [Bug math/13304] " bruno at clisp dot org
2011-10-17  2:05 ` bruno at clisp dot org
2011-10-17  2:05 ` bruno at clisp dot org
2011-10-17  2:05 ` bruno at clisp dot org
2011-10-17  2:06 ` bruno at clisp dot org
2011-10-17  2:06 ` bruno at clisp dot org
2011-10-17  2:07 ` bruno at clisp dot org
2011-10-17  2:08 ` bruno at clisp dot org
2011-10-17  2:08 ` bruno at clisp dot org
2011-10-17  2:08 ` bruno at clisp dot org
2011-10-17  2:09 ` bruno at clisp dot org
2011-10-17  2:10 ` bruno at clisp dot org
2011-10-17  2:10 ` bruno at clisp dot org
2011-10-17  2:11 ` bruno at clisp dot org
2011-10-17  2:11 ` bruno at clisp dot org
2011-10-17  2:11 ` bruno at clisp dot org
2011-10-17  2:11 ` bruno at clisp dot org
2011-10-17  5:54 ` jakub at redhat dot com
2011-10-17  7:19 ` aj at suse dot de
2011-10-17  7:32 ` jakub at redhat dot com
2011-10-17  8:24 ` aj at suse dot de
2011-10-17  9:14 ` bruno at clisp dot org
2011-10-17  9:28 ` jakub at redhat dot com
2011-10-17  9:50 ` bruno at clisp dot org
2011-10-17  9:51 ` bruno at clisp dot org
2011-10-17 12:20 ` jakub at redhat dot com
2011-10-17 14:07 ` joseph at codesourcery dot com
2011-10-17 20:10 ` bruno at clisp dot org
2011-10-17 20:23 ` zimmerma+gcc at loria dot fr
2011-10-17 22:36 ` vincent-srcware at vinc17 dot net
2011-10-17 22:40 ` bruno at clisp dot org
2011-10-17 22:42 ` bruno at clisp dot org
2011-10-17 22:47 ` bruno at clisp dot org
2011-10-17 23:34 ` bruno at clisp dot org
2011-10-18  7:24 ` aj at suse dot de
2011-10-18 16:40 ` bruno at clisp dot org
2012-02-26 17:46 ` jsm28 at gcc dot gnu.org
2012-02-26 17:49 ` jsm28 at gcc dot gnu.org
2012-09-27 20:08 ` law at redhat dot com
2012-09-27 20:26 ` joseph at codesourcery dot com
2012-11-22 17:39 ` jsm28 at gcc dot gnu.org
2013-12-17 14:23 ` jsm28 at gcc dot gnu.org
2014-06-27 11:51 ` fweimer at redhat dot com
2015-09-25 17:30 ` cvs-commit at gcc dot gnu.org
2015-09-25 17:32 ` cvs-commit at gcc dot gnu.org
2015-09-25 17:35 ` jsm28 at gcc dot gnu.org

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