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* [Bug math/16677] New: nextafter incorrect in directed rounding modes
@ 2014-03-08 0:52 jsm28 at gcc dot gnu.org
2014-03-08 14:09 ` [Bug math/16677] " cvs-commit at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: jsm28 at gcc dot gnu.org @ 2014-03-08 0:52 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16677
Bug ID: 16677
Summary: nextafter incorrect in directed rounding modes
Product: glibc
Version: 2.19
Status: NEW
Severity: normal
Priority: P2
Component: math
Assignee: unassigned at sourceware dot org
Reporter: jsm28 at gcc dot gnu.org
At least some nextafter implementations compute an overflowing result as x + x
to raise the overflow exception. However, the result must be independent of
the rounding mode (C11 F.10.8.3); the exception is correct, the finite value in
some rounding modes isn't. E.g., on x86_64 for float:
testing float (without inline functions)
Failure: Test: nextafter_downward (max_value, inf)
Result:
is: 3.40282346638528859811e+38 0x1.fffffe00000000000000p+127
should be: inf inf
Failure: Test: nextafter_towardzero (max_value, inf)
Result:
is: 3.40282346638528859811e+38 0x1.fffffe00000000000000p+127
should be: inf inf
Failure: Test: nextafter_towardzero (-max_value, -inf)
Result:
is: -3.40282346638528859811e+38 -0x1.fffffe00000000000000p+127
should be: -inf -inf
Failure: Test: nextafter_upward (-max_value, -inf)
Result:
is: -3.40282346638528859811e+38 -0x1.fffffe00000000000000p+127
should be: -inf -inf
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^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug math/16677] nextafter incorrect in directed rounding modes
2014-03-08 0:52 [Bug math/16677] New: nextafter incorrect in directed rounding modes jsm28 at gcc dot gnu.org
@ 2014-03-08 14:09 ` cvs-commit at gcc dot gnu.org
2014-03-11 22:25 ` jsm28 at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2014-03-08 14:09 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16677
--- Comment #1 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 e9996ef750d845b46bc7d743c730c73f044720af (commit)
from 5c7808498e9e1fd3df43aa2bd84fd47dc8e6ab7c (commit)
Those revisions listed above that are new to this repository have
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- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=e9996ef750d845b46bc7d743c730c73f044720af
commit e9996ef750d845b46bc7d743c730c73f044720af
Author: Joseph Myers <joseph@codesourcery.com>
Date: Sat Mar 8 14:08:38 2014 +0000
Add libm-test.inc macro for all-rounding-modes testing.
This patch adds support in libm-test.inc for automatically running
tests of a function in all rounding modes, in the form of a macro
ALL_RM_TEST to loop over all rounding modes when running tests of a
function, and uses it for functions whose results should always be
independent of the rounding mode.
Conversion of tests of nextafter to ALL_RM_TEST was deferred because
trying that conversion showed up bug 16677. (Finding such a bug of
course illustrates the point of testing more systematically in all
rounding modes rather than only reactively when bugs get reported in a
particular function in a non-default mode.) Conversion of tests where
results can depend on the rounding mode will follow once I add
gen-libm-test.pl support for using different initializers for the
expected results for different rounding modes (again, some conversions
may need deferring until bugs are fixed, depending on how
straightforward they are to XFAIL in a particular context).
Some existing tests get run five times rather than four, with
round-to-nearest tests both run in that as default rounding mode and
also with it explicitly set with fesetround (FE_TONEAREST). This
duplication doesn't seem particularly useful, so ALL_RM_TEST only runs
tests four times.
Tested x86_64 and x86.
* math/libm-test.inc (ALL_RM_TEST): New macro.
(ceil_test): Use ALL_RM_TEST.
(cimag_test): Likewise.
(conj_test): Likewise.
(copysign_test): Likewise.
(cproj_test): Likewise.
(creal_test): Likewise.
(fabs_test): Likewise.
(floor_test): Likewise.
(fmax_test): Likewise.
(fmin_test): Likewise.
(fmod_test): Likewise.
(fpclassify_test): Likewise.
(frexp_test): Likewise.
(ilogb_test): Likewise.
(isfinite_test): Likewise.
(finite_test): Likewise.
(isgreater_test): Likewise.
(isgreaterequal_test): Likewise.
(isinf_test): Likewise.
(isless_test): Likewise.
(islessequal_test): Likewise.
(islessgreater_test): Likewise.
(isnan_test): Likewise.
(isnormal_test): Likewise.
(issignaling_test): Likewise.
(isunordered_test): Likewise.
(logb_test): Likewise.
(logb_downward_test_data): Remove.
(logb_test_downward): Likewise.
(lround_test): Use ALL_RM_TEST.
(llround_test): Likewise.
(modf_test): Likewise.
(nexttoward_test): Likewise.
(remainder_test): Likewise.
(drem_test): Likewise.
(remainder_tonearest_test_data): Likewise.
(remainder_test_tonearest): Likewise.
(drem_test_tonearest): Likewise.
(remainder_towardzero_test_data): Likewise.
(remainder_test_towardzero): Likewise.
(drem_test_towardzero): Likewise.
(remainder_downward_test_data): Likewise.
(remainder_test_downward): Likewise.
(drem_test_downward): Likewise.
(remainder_upward_test_data): Likewise.
(remainder_test_upward): Likewise.
(drem_test_upward): Likewise.
(remquo_test): Use ALL_RM_TEST. Remove comment about x.
(round_test): Use ALL_RM_TEST.
(signbit_test): Likewise.
(trunc_test): Likewise.
(significand_test): Likewise.
(main): Don't call removed functions.
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 57 ++++++++
math/libm-test.inc | 398 ++++++++++------------------------------------------
2 files changed, 130 insertions(+), 325 deletions(-)
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^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug math/16677] nextafter incorrect in directed rounding modes
2014-03-08 0:52 [Bug math/16677] New: nextafter incorrect in directed rounding modes jsm28 at gcc dot gnu.org
2014-03-08 14:09 ` [Bug math/16677] " cvs-commit at gcc dot gnu.org
@ 2014-03-11 22:25 ` jsm28 at gcc dot gnu.org
2014-03-11 22:25 ` cvs-commit at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: jsm28 at gcc dot gnu.org @ 2014-03-11 22:25 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16677
Joseph Myers <jsm28 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--- Comment #3 from Joseph Myers <jsm28 at gcc dot gnu.org> ---
Fixed for 2.20.
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^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug math/16677] nextafter incorrect in directed rounding modes
2014-03-08 0:52 [Bug math/16677] New: nextafter incorrect in directed rounding modes jsm28 at gcc dot gnu.org
2014-03-08 14:09 ` [Bug math/16677] " cvs-commit at gcc dot gnu.org
2014-03-11 22:25 ` jsm28 at gcc dot gnu.org
@ 2014-03-11 22:25 ` cvs-commit at gcc dot gnu.org
2014-06-13 6:36 ` fweimer at redhat dot com
2015-10-02 17:12 ` cvs-commit at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2014-03-11 22:25 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16677
--- Comment #2 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 600fa36158cd741d897b2d22c735c60247b982e0 (commit)
from d7706c32589ef32f4bed3122a2f5c861b214149e (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=600fa36158cd741d897b2d22c735c60247b982e0
commit 600fa36158cd741d897b2d22c735c60247b982e0
Author: Joseph Myers <joseph@codesourcery.com>
Date: Tue Mar 11 22:24:00 2014 +0000
Fix nextafter overflow in non-default rounding modes (bug 16677).
ISO C requires the result of nextafter to be independent of the
rounding mode, even when underflow or overflow occurs. This patch
fixes the bug in various nextafter implementations that, having done
an overflowing computation to force an overflow exception (correct),
they then return the result of that computation rather than an
infinity computed some other way (incorrect, when the overflowing
result of arithmetic with that sign and rounding mode is finite but
the correct result is infinite) - generally by falling through to
existing code to return a value that in fact is correct for this case
(but was computed by an integer increment and so without generating
the exceptions required). Having fixed the bug, the previously
deferred conversion of nextafter testing in libm-test.inc to
ALL_RM_TEST is also included.
Tested x86_64 and x86; also spot-checked results of nextafter tests
for powerpc32 and mips64 to test the ldbl-128ibm and ldbl-128
changes. (The m68k change is untested.)
[BZ #16677]
* math/s_nextafter.c (__nextafter): Do not return value from
overflowing computation.
* sysdeps/i386/fpu/s_nextafterl.c (__nextafterl): Likewise.
* sysdeps/ieee754/flt-32/s_nextafterf.c (__nextafterf): Likewise.
* sysdeps/ieee754/ldbl-128/s_nextafterl.c (__nextafterl):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c (__nextafterl):
Likewise.
* sysdeps/m68k/m680x0/fpu/s_nextafterl.c (__nextafterl): Likewise.
* math/libm-test.inc (nextafter_test): Use ALL_RM_TEST.
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 14 ++++++++++++++
NEWS | 2 +-
math/libm-test.inc | 5 +----
math/s_nextafter.c | 6 ++----
sysdeps/i386/fpu/s_nextafterl.c | 5 ++++-
sysdeps/ieee754/flt-32/s_nextafterf.c | 6 ++----
sysdeps/ieee754/ldbl-128/s_nextafterl.c | 5 ++++-
sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c | 14 ++++++++++----
sysdeps/m68k/m680x0/fpu/s_nextafterl.c | 5 ++++-
9 files changed, 42 insertions(+), 20 deletions(-)
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^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug math/16677] nextafter incorrect in directed rounding modes
2014-03-08 0:52 [Bug math/16677] New: nextafter incorrect in directed rounding modes jsm28 at gcc dot gnu.org
` (2 preceding siblings ...)
2014-03-11 22:25 ` cvs-commit at gcc dot gnu.org
@ 2014-06-13 6:36 ` fweimer at redhat dot com
2015-10-02 17:12 ` cvs-commit at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: fweimer at redhat dot com @ 2014-06-13 6:36 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16677
Florian Weimer <fweimer at redhat dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Flags| |security-
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^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug math/16677] nextafter incorrect in directed rounding modes
2014-03-08 0:52 [Bug math/16677] New: nextafter incorrect in directed rounding modes jsm28 at gcc dot gnu.org
` (3 preceding siblings ...)
2014-06-13 6:36 ` fweimer at redhat dot com
@ 2015-10-02 17:12 ` cvs-commit at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2015-10-02 17:12 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=16677
--- Comment #5 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 59a63cca1133a8e1e3219970ee95979ac1f810df (commit)
from ef6b619f73e49b6d87c7530e6e9f8a59723b492d (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=59a63cca1133a8e1e3219970ee95979ac1f810df
commit 59a63cca1133a8e1e3219970ee95979ac1f810df
Author: Joseph Myers <joseph@codesourcery.com>
Date: Fri Oct 2 17:11:13 2015 +0000
Fix nexttoward overflow in non-default rounding modes (bug 19059).
ISO C requires overflowing results from nexttoward to be the
appropriate infinity independent of the rounding mode, but some
implementations use a rounding-mode-dependent result (this is the same
issue as was fixed for nextafter in bug 16677). This patch fixes the
problem by making the nexttoward implementations discard the result
from the floating-point computation that forced an overflow exception
and then return the infinity previously computed with integer
arithmetic.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #19059]
* math/s_nexttowardf.c (__nexttowardf): Do not return value from
overflowing computation.
* sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward):
Likewise.
* sysdeps/ieee754/ldbl-128/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
Likewise.
* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Likewise.
* sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf):
Likewise.
* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf):
Likewise.
* math/libm-test.inc (nexttoward_test_data): Add more tests.
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 20 ++++++++++++++++++++
NEWS | 2 +-
math/libm-test.inc | 4 ++++
math/s_nexttowardf.c | 4 ++--
sysdeps/i386/fpu/s_nexttoward.c | 4 ++--
sysdeps/i386/fpu/s_nexttowardf.c | 4 ++--
sysdeps/ieee754/ldbl-128/s_nexttoward.c | 4 ++--
sysdeps/ieee754/ldbl-128/s_nexttowardf.c | 5 ++++-
sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c | 4 ++--
sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c | 4 ++--
sysdeps/ieee754/ldbl-96/s_nexttoward.c | 4 ++--
sysdeps/ieee754/ldbl-96/s_nexttowardf.c | 4 ++--
sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c | 4 ++--
13 files changed, 47 insertions(+), 20 deletions(-)
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2014-03-08 0:52 [Bug math/16677] New: nextafter incorrect in directed rounding modes jsm28 at gcc dot gnu.org
2014-03-08 14:09 ` [Bug math/16677] " cvs-commit at gcc dot gnu.org
2014-03-11 22:25 ` jsm28 at gcc dot gnu.org
2014-03-11 22:25 ` cvs-commit at gcc dot gnu.org
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