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* [Bug math/15901] New: Bessel functions y0, y1, yn are incorrect on non-positive values
@ 2013-08-27 16:25 vincent-srcware at vinc17 dot net
  2013-12-04 14:40 ` [Bug math/15901] " cvs-commit at gcc dot gnu.org
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: vincent-srcware at vinc17 dot net @ 2013-08-27 16:25 UTC (permalink / raw)
  To: glibc-bugs

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http://sourceware.org/bugzilla/show_bug.cgi?id=15901

            Bug ID: 15901
           Summary: Bessel functions y0, y1, yn are incorrect on
                    non-positive values
           Product: glibc
           Version: 2.17
            Status: NEW
          Severity: normal
          Priority: P2
         Component: math
          Assignee: unassigned at sourceware dot org
          Reporter: vincent-srcware at vinc17 dot net

yn(n,±0.0) on odd negative integer n gives -Inf, while the limit is +Inf. This
incorrect result probably comes from a defect in POSIX[*] and should be
changed.

[*] http://austingroupbugs.net/view.php?id=714

yn(n,x) on negative values x gives -Inf instead of NaN. Though the value -Inf
is currently allowed by POSIX, NaN is a much better result (and the only
expected one according to general rules on undefined math functions), just like
log(negative) or sqrt(negative) is NaN.

I've posted a message about such values in the Austin Group list:

  http://permalink.gmane.org/gmane.comp.standards.posix.austin.general/7982

and replies would appear here:

  http://comments.gmane.org/gmane.comp.standards.posix.austin.general/7982

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From: "berardgui at gmail dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug dynamic-link/15903] New: INITFIRST flag does not change fini order
Date: Tue, 27 Aug 2013 19:49:00 -0000
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https://sourceware.org/bugzilla/show_bug.cgi?id\x15903

            Bug ID: 15903
           Summary: INITFIRST flag does not change fini order
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: dynamic-link
          Assignee: unassigned at sourceware dot org
          Reporter: berardgui at gmail dot com

Created attachment 7169
  --> https://sourceware.org/bugzilla/attachment.cgi?idq69&actioníit
git diff of an idea of a fix

It looks like the INITFIRST flag is read by ld.so only for the init order and
not during sorting the fini order.
For instance, if I build a first library (lib1) with -z initfirst and a second
one without, link an executable with these two libraries, and finally run it
with LD_DEBUG, I have:
     26457:    calling init: ../lib1/lib1.so
     26457:    calling init: /lib64/ld-linux-x86-64.so.2
     26457:    calling init: /lib64/libc.so.6
     26457:    calling init: ../lib2/lib2.so
     26457:    calling fini: ./test [0]
     26457:    calling fini: ../lib1/lib1.so [0]
     26457:    calling fini: ../lib2/lib2.so [0]

According to https://sourceware.org/binutils/docs/ld/Options.html the fini
order should be the reverse order of the init order...

Having a closer look to elf/dl-fini.c it seems that there is no check of the
initfirst flag.

Find attached an idea of a fix.

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^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2014-06-13  9:43 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-08-27 16:25 [Bug math/15901] New: Bessel functions y0, y1, yn are incorrect on non-positive values vincent-srcware at vinc17 dot net
2013-12-04 14:40 ` [Bug math/15901] " cvs-commit at gcc dot gnu.org
2013-12-04 14:42 ` jsm28 at gcc dot gnu.org
2014-06-13  9:43 ` fweimer at redhat dot com

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