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* [Bug math/18245] New: sqrtl(1.1L) raises the inexact flag
@ 2015-04-10 12:29 nszabolcs at gmail dot com
2015-06-23 17:27 ` [Bug math/18245] " cvs-commit at gcc dot gnu.org
2015-06-23 17:28 ` jsm28 at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: nszabolcs at gmail dot com @ 2015-04-10 12:29 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=18245
Bug ID: 18245
Summary: sqrtl(1.1L) raises the inexact flag
Product: glibc
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: math
Assignee: unassigned at sourceware dot org
Reporter: nszabolcs at gmail dot com
sqrt should not raise inexact when the result is nan.
the following code prints (x86_64 and aarch64 as well):
sqrtl(-1.1) = nan invalid=1 inexact=1 want inexact=0
#include <fenv.h>
#include <math.h>
#include <stdio.h>
int main()
{
#pragma STDC FENV_ACCESS ON
long double x = -1.1L;
long double r;
feclearexcept(FE_ALL_EXCEPT);
r = sqrtl(x);
if (fetestexcept(FE_INEXACT))
printf("sqrtl(%Lg) = %La invalid=%d inexact=%d want inexact=0\n", x,
r, !!fetestexcept(FE_INVALID), !!fetestexcept(FE_INEXACT));
}
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* [Bug math/18245] sqrtl(1.1L) raises the inexact flag
2015-04-10 12:29 [Bug math/18245] New: sqrtl(1.1L) raises the inexact flag nszabolcs at gmail dot com
@ 2015-06-23 17:27 ` cvs-commit at gcc dot gnu.org
2015-06-23 17:28 ` jsm28 at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2015-06-23 17:27 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=18245
--- 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 8b1bab5ffa235bc494c33fdbe4c9994202936cfc (commit)
from c47ca9647f9b72692e62f94fe468cd5568f49129 (commit)
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- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8b1bab5ffa235bc494c33fdbe4c9994202936cfc
commit 8b1bab5ffa235bc494c33fdbe4c9994202936cfc
Author: Joseph Myers <joseph@codesourcery.com>
Date: Tue Jun 23 17:26:46 2015 +0000
Fix spurious "inexact" exceptions from __kernel_standard_l (bug 18245, bug
18583).
__kernel_standard_l converts long double arguments to double for use
in SVID "struct exception". This has special-case handling for when
that conversion would overflow or underflow but the original long
double function wouldn't. However, it turns out that "inexact"
exceptions can be spurious here as well, when the function is exactly
determined and __kernel_standard_l is being called for a domain error.
This patch fixes this by using feholdexcept / fesetenv to avoid
exceptions from the conversion, replacing the previous special-case
logic for overflow and underflow (this covers all functions using
__kernel_standard_l, not just those that actually need a change, since
there doesn't seem to be much point in restricting things just to the
functions that mustn't get "inexact" here).
Tested for x86_64 and x86.
[BZ #18245]
[BZ #18583]
* sysdeps/ieee754/k_standardl.c: Include <fenv.h>.
(__kernel_standard_l): Use feholdexcept and fesetenv around
conversion to double instead of special-casing overflow and
underflow.
* math/libm-test.inc (fmod_test_data): Add more tests.
(remainder_test_data): Likewise.
(sqrt_test_data): Likewise.
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 12 ++++++++++++
NEWS | 12 ++++++------
math/libm-test.inc | 9 +++++++++
sysdeps/ieee754/k_standardl.c | 34 +++++++++-------------------------
4 files changed, 36 insertions(+), 31 deletions(-)
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* [Bug math/18245] sqrtl(1.1L) raises the inexact flag
2015-04-10 12:29 [Bug math/18245] New: sqrtl(1.1L) raises the inexact flag nszabolcs at gmail dot com
2015-06-23 17:27 ` [Bug math/18245] " cvs-commit at gcc dot gnu.org
@ 2015-06-23 17:28 ` jsm28 at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: jsm28 at gcc dot gnu.org @ 2015-06-23 17:28 UTC (permalink / raw)
To: glibc-bugs
https://sourceware.org/bugzilla/show_bug.cgi?id=18245
Joseph Myers <jsm28 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |FIXED
--- Comment #2 from Joseph Myers <jsm28 at gcc dot gnu.org> ---
Fixed for 2.22.
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2015-04-10 12:29 [Bug math/18245] New: sqrtl(1.1L) raises the inexact flag nszabolcs at gmail dot com
2015-06-23 17:27 ` [Bug math/18245] " cvs-commit at gcc dot gnu.org
2015-06-23 17:28 ` jsm28 at gcc dot gnu.org
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