The csqrt implementations in glibc can miss underflow exceptions when
the real or imaginary part of the result becomes tiny in the course of
scaling down (in particular, multiplication by 0.5) and that scaling
is exact although the relevant part of the mathematical result isn't.
This patch forces the exception in a similar way to previous fixes.
Tested for x86_64 and x86.
[BZ #18370]
* math/s_csqrt.c (__csqrt): Force underflow exception for results
whose real or imaginary part has small absolute value.
* math/s_csqrtf.c (__csqrtf): Likewise.
* math/s_csqrtl.c (__csqrtl): Likewise.
* math/auto-libm-test-in: Add more tests of csqrt.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
This patch adds extra inline functions to change the Program Priority
Register from ISA 2.07.
2015-08-19 Gabriel F. T. Gomes <gftg@linux.vnet.ibm.com>
* sysdeps/powerpc/sys/platform/ppc.h (__ppc_set_ppr_med_high,
__ppc_set_ppr_very_low): New functions.
* manual/platform.texi: Add documentation about
__ppc_set_ppr_med_high and __ppc_set_ppr_very_low.
Fix the bind-now case when DT_REL and DT_JMPREL sections are separate
and there is a gap between them.
[BZ #14341]
* elf/dynamic-link.h (elf_machine_lazy_rel): Properly handle the
case when there is a gap between DT_REL and DT_JMPREL sections.
* sysdeps/x86_64/Makefile (tests): Add tst-split-dynreloc.
(LDFLAGS-tst-split-dynreloc): New.
(tst-split-dynreloc-ENV): Likewise.
* sysdeps/x86_64/tst-split-dynreloc.c: New file.
* sysdeps/x86_64/tst-split-dynreloc.lds: Likewise.
__xstat_conv, __xstat64_conv and __xstat32_conv are internal to glibc.
They should be marked as hidden so that they can't be called without
PLT.
[BZ #18822]
* sysdeps/unix/sysv/linux/xstatconv.h (__xstat_conv): Add
attribute_hidden.
(__xstat64_conv): Likewise.
(__xstat32_conv): Likewise.
Since _dl_x86_cpu_features is always available, we can use x86-64
cacheinfo.c and sysconf.c for both i386 and x86-64.
* sysdeps/i386/i686/Makefile
[$(subdir) == string] (sysdep_routines): Moved to ...
* sysdeps/i386/Makefile: Here.
* sysdeps/i386/i686/cacheinfo.c: Moved to ...
* sysdeps/i386/cacheinfo.c: Here.
* sysdeps/unix/sysv/linux/i386/sysconf.c: Removed.
* sysdeps/unix/sysv/linux/i386/i686/sysconf.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/sysconf.c: Moved to ...
* sysdeps/unix/sysv/linux/x86/sysconf.c: Here.
To remove -Wno-error=undef, we need to fix the remaining cases where
there are -Wundef warnings in the testsuite. One of those places is
in elf/tst-execstack.c.
tst-execstack.c tests USE_PTHREADS with #if. nptl/tst-execstack.c
defines USE_PTHREADS to 1 before including ../elf/tst-execstack.c,
while elf/tst-execstack.c, when compiled directly, leaves it
undefined.
This patch adds a setting of CPPFLAGS-tst-execstack.c to
elf/Makefile. An alternative approach would be to rename
tst-execstack.c to tst-execstack-main.c and have two different
tst-execstack.c files include it, each with an appropriate
USE_PTHREADS #define.
Tested for x86_64.
* elf/Makefile [$(have-z-execstack) = yes]
(CPPFLAGS-tst-execstack.c): New variable.
To remove -Wno-error=undef, we need to fix the remaining cases where
there are -Wundef warnings in the testsuite. One of those places is
in login/tst-utmp.c.
When included from tst-utmpx.c, <utmpx.h> is included instead of
<utmp.h>, meaning the _HAVE_UT_* macros are not defined. The test is
prepared for them not being defined, in that all the relevant
conditionals also include "defined UTMPX". However, they test the
_HAVE_UT_* macros first, so resulting in -Wundef warnings.
This patch does the minimal fix of swapping the || operands. This is
logically correct - avoiding checking a macro we know will not be
defined in the case where it is not defined. It won't fix such
warnings for the case where the toplevel bits/utmp.h is used and most
_HAVE_UT_* aren't defined at all even when <utmp.h> is included, but
that case doesn't apply to any current glibc configuration. Fixing it
would also be tricky in that, while glibc itself consistently uses
_HAVE_UT_* in ways that would work with 0 instead of undefined,
external packages that use the macros expect defined / undefined
instead of 1 / 0 (codesearch.debian.net shows uses by util-linux,
python-utmp, libsys-utmp-perl).
Tested for x86_64.
* login/tst-utmp.c [_HAVE_UT_TYPE || defined UTMPX]: Change
conditional to [defined UTMPX || _HAVE_UT_TYPE].
[_HAVE_UT_TV || defined UTMPX]: Change conditional to [defined
UTMPX || _HAVE_UT_TV].
[_HAVE_UT_TV - 0 || defined UTMPX]: Change conditional to [defined
UTMPX || _HAVE_UT_TV - 0].
This patch fixes -Wundef warnings relating to __mips_isa_rev being
undefined.
Tested for mips64 (all three ABIs) that there is a clean build and
testsuite run with -Wno-error=undef removed (and my other -Wundef
patches applied).
* sysdeps/mips/dl-machine.h [__mips_isa_rev < 6]: Change
conditionals to [!defined __mips_isa_rev || __mips_isa_rev < 6].
* sysdeps/mips/machine-gmon.h [__mips_isa_rev < 6]: Likewise.
Some features in hwcap.h do not have matching string descriptors
to be displayed when LD_SHOW_AUXV=1. This patch fixes the problem.
2015-08-13 Carlos Eduardo Seo <cseo@linux.vnet.ibm.com>
* sysdeps/powerpc/dl-procinfo.c:
(_dl_powerpc_cap_flags): Added missing strings for some
hwcap features.
* sysdeps/powerpc/dl-procinfo.h: Updated hwcap bit count.
cpuid, i586 and i686 instructions are available if the processor
specified by -march= supports them. We can use this information
to determine whether those instructions can be used safely.
* sysdeps/x86/cpu-features.c (init_cpu_features): Check
whether cpuid is available only if HAS_CPUID is 0.
* sysdeps/x86/cpu-features.h (HAS_CPUID): New.
(HAS_I586): Likewise.
(HAS_I686): Likewise.
lang_lib (which reflects ISO 639-2/B (bibliographic) codes) and
lang_term (which reflects ISO 639-2/T (terminology) codes) should be
identical except for those languages for which ISO 639-2 specifies
separate bibliographic/terminology values.
I used this Library of Congress page as the source:
http://www.loc.gov/standards/iso639-2/php/code_list.php
This brings hppa inline with all the other arches and main code where we
require TLS support everywhere. That means dropping the defines USE_TLS
and USE___THREAD, and dropping the binutils check (since we already have
a version requirement that is new enough).
The csqrt functions scale up small arguments to avoid underflows when
calling hypot functions. However, even when hypot does not underflow,
a subsequent calculation of 0.5 * hypot can underflow. This patch
duly increases the threshold and scale factor to avoid such underflows
as well.
Tested for x86_64, x86 and mips64.
[BZ #18823]
* math/s_csqrt.c (__csqrt): Increase threshold and scale factor
for scaling up small arguments.
* math/s_csqrtf.c (__csqrtf): Likewise.
* math/s_csqrtl.c (__csqrtl): Likewise.
* math/auto-libm-test-in: Add more tests of csqrt.
* math/auto-libm-test-out: Regenerated.
I think the last clause of the conditional,
|| __n <= __bos (__dest)
may be backward. The code should call the runtime-checking function
if __n is not constant, or if __n is known to be LARGER than the size
of the destination.
Various fma implementations have logic that, when computing fma (x, y,
z) where z is large (so care needs taking to avoid internal overflow)
but x * y is small, scale x * y up instead of down to avoid internal
underflows resulting from scaling down. (In these cases, x * y is
small enough that only its sign actually matters rather than the exact
value.)
The threshold for scaling up instead of down was correct for "if the
unscaled values were multiplied, the low part of the multiplication
could underflow", and the scaling was sufficient to ensure that the
low part of the multiplication did not underflow (given that cases of
very small x * y - less than half the least subnormal - were
previously dealt with). However, the choice in the functions wasn't
between scaling up or no scaling, but between scaling up and scaling
down (scaling down actually being needed when x * y isn't so small
compared to z and so the exact value does matter). Thus a larger
threshold is needed to ensure that scaling down doesn't produce values
the multiplication of whose low parts underflows. This patch
increases the thresholds accordingly.
Tested for x86_64, x86 and mips64 (with the MIPS version of s_fmal.c
removed so that the ldbl-128 version gets tested instead of the
soft-fp one).
[BZ #18824]
* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Increase threshold for
scaling x * y up instead of down.
* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Likewise.
* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Likewise.
* math/auto-libm-test-in: Add more tests of fma.
* math/auto-libm-test-out: Regenerated.
The change in 0b5395f052 replaced calls
to __get_cpu_features@plt followed by a mov from rax to rdx, with a
single macro LOAD_RTLD_GLOBAL_RO_RDX. It is pretty clear that there
was a typo in s_floorf and __nearbyint due to which the (now incorrect)
mov was not removed. This patch removes that mov.
* sysdeps/x86_64/fpu/multiarch/s_floorf.S (__floorf): Remove
unnecessary movq.
* sysdeps/x86_64/fpu/multiarch/s_nearbyint.S (__nearbyint):
Likewise.
This patch adds more test inputs to various libm functions found
through random generation to have larger ulps errors than previously
listed in libm-test-ulp, on at least one of x86_64 and x86.
Tested for x86_64 and x86.
* math/auto-libm-test-in: Add more tests of acos, acosh, asin,
asinh, atan, atan2, atanh, cabs, cbrt, cosh, csqrt, erf, erfc,
exp, exp2, lgamma, log, log1p, log2, pow, sin, sincos, tan, tanh
and tgamma.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
Similar to various other bugs in this area, some tanh implementations
do not raise the underflow exception for subnormal arguments, when the
result is tiny and inexact. This patch forces the exception in a
similar way to previous fixes.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16520]
* sysdeps/ieee754/dbl-64/s_tanh.c: Include <float.h>.
(__tanh): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/flt-32/s_tanhf.c: Include <float.h>.
(__tanhf): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128/s_tanhl.c: Include <float.h>.
(__tanhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-128ibm/s_tanhl.c: Include <float.h>.
(__tanhl): Force underflow exception for arguments with small
absolute value.
* sysdeps/ieee754/ldbl-96/s_tanhl.c: Include <float.h>.
(__tanhl): Force underflow exception for arguments with small
absolute value.
* math/auto-libm-test-in: Add more tests of tanh.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
Since not all i486 processors support cpuid, we call __get_cpuid_max to
check if cpuid is available before using it if not compiling for i586,
i686 nor x86-64.
* sysdeps/x86/cpu-features.c (init_cpu_features): Call
__get_cpuid_max if not compiling for i586, i686 nor x86-64.
This patch updates x86 elision-conf.c to use the newly defined
HAS_CPU_FEATURE from <cpu-features.h>.
* sysdeps/unix/sysv/linux/x86/elision-conf.c (elision_init):
Replace HAS_RTM with HAS_CPU_FEATURE (RTM).
