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* [Bug math/16521] Missing underflow exception from exp2
[not found] <bug-16521-131@http.sourceware.org/bugzilla/>
@ 2014-02-07 7:29 ` zimmerma+gcc at loria dot fr
2014-02-07 7:49 ` zimmerma+gcc at loria dot fr
` (4 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: zimmerma+gcc at loria dot fr @ 2014-02-07 7:29 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16521
--- Comment #1 from Paul Zimmermann <zimmerma+gcc at loria dot fr> ---
same in double precision:
Testing function exp2 for exponent 0 [seed=4342].
rounding mode MPFR_RNDZ:
wrong underflow flag for x=-3.fe0000000003e@2
library gives 3.fffffffff5418@-256
mpfr gives 3.fffffffff5418@-256
underflow: mpfr 1, library 0
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* [Bug math/16521] Missing underflow exception from exp2
[not found] <bug-16521-131@http.sourceware.org/bugzilla/>
2014-02-07 7:29 ` [Bug math/16521] Missing underflow exception from exp2 zimmerma+gcc at loria dot fr
@ 2014-02-07 7:49 ` zimmerma+gcc at loria dot fr
2014-06-13 8:48 ` fweimer at redhat dot com
` (3 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: zimmerma+gcc at loria dot fr @ 2014-02-07 7:49 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16521
--- Comment #2 from Paul Zimmermann <zimmerma+gcc at loria dot fr> ---
same in extended precision:
Testing function exp2 for exponent 0 [seed=8344].
rounding mode MPFR_RNDN:
wrong underflow flag for x=-3.ffe0000000000068@3
library gives 3.ffffffffffedfa68@-4096
mpfr gives 3.ffffffffffedfa68@-4096
underflow: mpfr 1, library 0
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* [Bug math/16521] Missing underflow exception from exp2
[not found] <bug-16521-131@http.sourceware.org/bugzilla/>
2014-02-07 7:29 ` [Bug math/16521] Missing underflow exception from exp2 zimmerma+gcc at loria dot fr
2014-02-07 7:49 ` zimmerma+gcc at loria dot fr
@ 2014-06-13 8:48 ` fweimer at redhat dot com
2015-09-14 22:01 ` cvs-commit at gcc dot gnu.org
` (2 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: fweimer at redhat dot com @ 2014-06-13 8:48 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16521
Florian Weimer <fweimer at redhat dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Flags| |security-
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* [Bug math/16521] Missing underflow exception from exp2
[not found] <bug-16521-131@http.sourceware.org/bugzilla/>
` (2 preceding siblings ...)
2014-06-13 8:48 ` fweimer at redhat dot com
@ 2015-09-14 22:01 ` cvs-commit at gcc dot gnu.org
2015-09-14 22:02 ` jsm28 at gcc dot gnu.org
2015-09-14 22:43 ` jsm28 at gcc dot gnu.org
5 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2015-09-14 22:01 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16521
--- Comment #3 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".
The branch, master has been updated
via 903af5af9a0404c1dfeb7b4db6d5a23a1e45593f (commit)
from ca6be1655bd357bf6ac8857fba9b9dce928edbdc (commit)
Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.
- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=903af5af9a0404c1dfeb7b4db6d5a23a1e45593f
commit 903af5af9a0404c1dfeb7b4db6d5a23a1e45593f
Author: Joseph Myers <joseph@codesourcery.com>
Date: Mon Sep 14 22:00:12 2015 +0000
Fix exp2 missing underflows (bug 16521).
Various exp2 implementations in glibc can miss underflow exceptions
when the scaling down part of the calculation is exact (or, in the x86
case, when the conversion from extended precision to the target
precision is exact). This patch forces the exception in a similar way
to previous fixes.
The x86 exp2f changes may in fact not be needed for this purpose -
it's likely to be the case that no argument of type float has an exp2
result so close to an exact subnormal float value that it equals that
value when rounded to 64 bits (even taking account of variation
between different x86 implementations). However, they are included
for consistency with the changes to exp2 and so as to fix the exp2f
part of bug 18875 by ensuring that excess range and precision is
removed from underflowing return values.
Tested for x86_64, x86 and mips64.
[BZ #16521]
[BZ #18875]
* math/e_exp2l.c (__ieee754_exp2l): Force underflow exception for
small results.
* sysdeps/i386/fpu/e_exp2.S (dbl_min): New object.
(MO): New macro.
(__ieee754_exp2): For small results, force underflow exception and
remove excess range and precision from return value.
* sysdeps/i386/fpu/e_exp2f.S (flt_min): New object.
(MO): New macro.
(__ieee754_exp2f): For small results, force underflow exception
and remove excess range and precision from return value.
* sysdeps/i386/fpu/e_exp2l.S (ldbl_min): New object.
(MO): New macro.
(__ieee754_exp2l): Force underflow exception for small results.
* sysdeps/ieee754/dbl-64/e_exp2.c (__ieee754_exp2): Likewise.
* sysdeps/ieee754/flt-32/e_exp2f.c (__ieee754_exp2f): Likewise.
* sysdeps/x86_64/fpu/e_exp2l.S (ldbl_min): New object.
(MO): New macro.
(__ieee754_exp2l): Force underflow exception for small results.
* math/auto-libm-test-in: Add more tests or exp2.
* math/auto-libm-test-out: Regenerated.
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 25 ++
NEWS | 8 +-
math/auto-libm-test-in | 23 ++
math/auto-libm-test-out | 575 ++++++++++++++++++++++++++++++++++++++
math/e_exp2l.c | 12 +-
sysdeps/i386/fpu/e_exp2.S | 34 +++-
sysdeps/i386/fpu/e_exp2f.S | 34 +++-
sysdeps/i386/fpu/e_exp2l.S | 29 ++-
sysdeps/ieee754/dbl-64/e_exp2.c | 10 +-
sysdeps/ieee754/flt-32/e_exp2f.c | 10 +-
sysdeps/x86_64/fpu/e_exp2l.S | 25 ++-
11 files changed, 773 insertions(+), 12 deletions(-)
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* [Bug math/16521] Missing underflow exception from exp2
[not found] <bug-16521-131@http.sourceware.org/bugzilla/>
` (3 preceding siblings ...)
2015-09-14 22:01 ` cvs-commit at gcc dot gnu.org
@ 2015-09-14 22:02 ` jsm28 at gcc dot gnu.org
2015-09-14 22:43 ` jsm28 at gcc dot gnu.org
5 siblings, 0 replies; 6+ messages in thread
From: jsm28 at gcc dot gnu.org @ 2015-09-14 22:02 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16521
Joseph Myers <jsm28 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--- Comment #4 from Joseph Myers <jsm28 at gcc dot gnu.org> ---
Fixed for 2.23.
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* [Bug math/16521] Missing underflow exception from exp2
[not found] <bug-16521-131@http.sourceware.org/bugzilla/>
` (4 preceding siblings ...)
2015-09-14 22:02 ` jsm28 at gcc dot gnu.org
@ 2015-09-14 22:43 ` jsm28 at gcc dot gnu.org
5 siblings, 0 replies; 6+ messages in thread
From: jsm28 at gcc dot gnu.org @ 2015-09-14 22:43 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16521
Joseph Myers <jsm28 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |2.23
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[not found] <bug-16521-131@http.sourceware.org/bugzilla/>
2014-02-07 7:29 ` [Bug math/16521] Missing underflow exception from exp2 zimmerma+gcc at loria dot fr
2014-02-07 7:49 ` zimmerma+gcc at loria dot fr
2014-06-13 8:48 ` fweimer at redhat dot com
2015-09-14 22:01 ` cvs-commit at gcc dot gnu.org
2015-09-14 22:02 ` jsm28 at gcc dot gnu.org
2015-09-14 22:43 ` jsm28 at gcc dot gnu.org
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