This patch fixes bug 16539, spurious underflow exceptions from x86 /
x86-64 expm1l. The problem is that the computation of a base-2
exponent with extra precision involves spurious underflows for
arguments that are small but not subnormal, so a check is added to
just return the argument in those cases. (If the argument *is*
subnormal, underflowing is correct and the existing code will always
underflow, so it suffices to keep using the existing code in that
case; some expm1 implementations have a bug (bug 16353) with missing
underflow exceptions, but I don't think there's such a bug in this
particular version.)
Tested x86_64 and x86; no ulps updates needed.
(auto-libm-test-out diffs omitted below.)
[BZ #16539]
* sysdeps/i386/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]: Just
return the argument for normal arguments with exponent below -64.
* sysdeps/x86_64/fpu/e_expl.S (IEEE754_EXPL) [USE_AS_EXPM1L]:
Likewise.
* math/auto-libm-test-in: Add another test of expm1.
* math/auto-libm-test-out: Regenerated.
This patch fixes bug 16287, spurious underflows from ldbl-128 erfl
arising from it calling erfcl for arguments with absolute value at
least 1.0, although for large positive arguments erfcl correctly
underflows but erfl shouldn't. The fix is simply to avoid calling
erfcl, and just return 1, for arguments above a cut-off large enough
that erfl correctly rounds to-nearest as 1 but not so large that erfcl
underflows.
Tested mips64. Also tested x86_64 and x86 to confirm the new tests
(taken from the tests of erfc) don't cause any problems there; no ulps
updates needed.
[BZ #16287]
* sysdeps/ieee754/ldbl-128/s_erfl.c (__erfl): Return 1 without
calling __erfcl for arguments at least 16.
* math/auto-libm-test-in: Add more tests of erf.
* math/auto-libm-test-out: Regenerated.
Continuing the process of making non-ex-ports architectures follow the
preferred sysdeps practices followed by ex-ports architectures - that
is, putting things in architecture-specific sysdeps files rather than
having architecture-specific cases in architecture-independent files -
this patch moves architecture cases out of
sysdeps/unix/sysv/linux/configure.ac into (new or existing) configure
fragments for each architecture. (In the case of the
arch_minimum_kernel setting for x32,
sysdeps/unix/sysv/linux/x86_64/x32/configure already has such a
setting so the setting in sysdeps/unix/sysv/linux/configure.ac was a
duplicate that could just be removed - though I haven't tested for
x32.)
Tested for x86_64 and x86 that the patch causes no changes to the
installed shared libraries or ldd (or any part of the installation
except for the parts that always change because the files contain
timestamps - nscd and static libraries).
* sysdeps/unix/sysv/linux/configure.ac: Remove cases for
individual architectures.
* sysdeps/unix/sysv/linux/configure: Regenerated.
* sysdeps/unix/sysv/linux/i386/configure.ac: New file.
* sysdeps/unix/sysv/linux/i386/configure: New generated file.
* sysdeps/unix/sysv/linux/powerpc/configure.ac
(ldd_rewrite_script): Define variable.
* sysdeps/unix/sysv/linux/powerpc/configure: Regenerated.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/configure.ac: New
file.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/configure: New
generated file.
* sysdeps/unix/sysv/linux/s390/configure.ac: New file.
* sysdeps/unix/sysv/linux/s390/configure: New generated file.
* sysdeps/unix/sysv/linux/sh/configure.ac: New file.
* sysdeps/unix/sysv/linux/sh/configure: New generated file.
* sysdeps/unix/sysv/linux/sparc/configure.ac: New file.
* sysdeps/unix/sysv/linux/sparc/configure: New generated file.
* sysdeps/unix/sysv/linux/x86_64/configure.ac: New file.
* sysdeps/unix/sysv/linux/x86_64/configure: New generated file.
Improve fesetenv to use an optimized implementation similar to
feupdateenv.
2014-06-24 Wilco <wdijkstr@arm.com>
* sysdeps/arm/fesetenv.c (fesetenv): Optimize implementation.
This patch rewrites feupdateenv to improve performance by avoiding
unnecessary FPSCR reads/writes. It fixes bug 16918 by passing the
correct return value.
2014-06-24 Wilco <wdijkstr@arm.com>
[BZ #16918]
* sysdeps/arm/feupdateenv.c (feupdateenv):
Rewrite to reduce FPSCR accesses and fix return value.
rather than duplicating functionality. To make this work for softfp builds,
ensure functions in fenv_private are not conditionally compiled.
2014-06-24 Wilco <wdijkstr@arm.com>
* sysdeps/arm/fegetround.c (fegetround): Call get_rounding_mode.
* sysdeps/arm/feholdexcpt.c (feholdexcept): Call libc_feholdexcept_vfp.
* sysdeps/arm/fesetround.c (fesetround): Call libc_fesetround_vfp.
* sysdeps/arm/fgetexcptflg.c (fegetexceptflag):
Call libc_fetestexcept_vfp.
* sysdeps/arm/ftestexcept.c (fetestexcept): Call libc_fetestexcept_vfp.
* sysdeps/arm/fenv_private.h: Move libc_*_vfp functions outside of
__SOFTFP__ ifdef so that they can be built for softfp.
The first argument of elision_adapt and that of ELISION_*LOCK have
different signs since __elision_rwcount is signed char * and the
argument of elision_adapt is uint8_t *. Modified elision_adapt to
accept signed char * instead of uint8_t *.
This patch fixes bug 16354, spurious underflows from cosh when a tiny
argument is passed to expm1 and expm1 correctly underflows although
the final result of cosh should be 1. As noted in that bug, some
cases are latent because of expm1 implementations not raising
underflow (bug 16353), but all the implementations are fixed
similarly. They already contained checks for tiny arguments, but the
checks were too late to avoid underflow from expm1 (although they
would avoid underflow from subsequent squaring of the result of
expm1); they are moved before the expm1 calls.
The thresholds used for considering arguments tiny are not
particularly consistent in how they relate to the precision of the
floating-point format in question. They are, however, all sufficient
to ensure that the round-to-nearest result of cosh is indeed 1 below
the threshold (although sometimes they are smaller than necessary).
But the previous logic did not return 1, but the previously computed 1
+ expm1(abs(x)) value. And the thresholds in the ldbl-128 and
ldbl-128ibm code (0x1p-71L - I suspect 0x3f8b was intended in the code
instead of 0x3fb8 - and (roughly) 0x1p-55L) are not sufficient for
that value to be 1. So by moving the test for tiny arguments, and
consequently returning 1 directly now the expm1 value hasn't been
computed by that point, this patch also fixes bug 17061, the (large
number of ulps) inaccuracy for small arguments in those
implementations. Tests for that bug are duly added.
Tested x86_64 and x86 and ulps updated accordingly. Also tested for
mips64 and powerpc32 to validate the ldbl-128 and ldbl-128ibm changes.
[BZ #16354]
[BZ #17061]
* sysdeps/ieee754/dbl-64/e_cosh.c (__ieee754_cosh): Check for
small arguments before calling __expm1.
* sysdeps/ieee754/flt-32/e_coshf.c (__ieee754_coshf): Check for
small arguments before calling __expm1f.
* sysdeps/ieee754/ldbl-128/e_coshl.c (__ieee754_coshl): Check for
small arguments before calling __expm1l.
* sysdeps/ieee754/ldbl-128ibm/e_coshl.c (__ieee754_coshl):
Likewise.
* sysdeps/ieee754/ldbl-96/e_coshl.c (__ieee754_coshl): Likewise.
* math/auto-libm-test-in: Add more cosh tests. Do not allow
spurious underflow for some cosh tests.
* math/auto-libm-test-out: Regenerated.
* sysdeps/i386/fpu/libm-test-ulps: Update.
This patch fixes bug 17050, missing errno setting for y1 overflow (for
small positive arguments). An appropriate check is added for overflow
directly in the __ieee754_y1 implementation, similar to the check
present for yn (doing it there rather than in the wrapper also avoids
yn needing to repeat the check when called for order 1 or -1 and it
uses __ieee754_y1).
Tested x86_64 and x86; no ulps update needed. Also tested for mips64
to verify the ldbl-128 fix (the ldbl-128ibm code just #includes the
ldbl-128 file).
[BZ #17050]
* sysdeps/ieee754/dbl-64/e_j1.c: Include <errno.h>.
(__ieee754_y1): Set errno if return value overflows.
* sysdeps/ieee754/flt-32/e_j1f.c: Include <errno.h>.
(__ieee754_y1f): Set errno if return value overflows.
* sysdeps/ieee754/ldbl-128/e_j1l.c: Include <errno.h>.
(__ieee754_y1l): Set errno if return value overflows.
* sysdeps/ieee754/ldbl-96/e_j1l.c: Include <errno.h>.
(__ieee754_y1l): Set errno if return value overflows.
* math/auto-libm-test-in: Add more tests of y0, y1 and yn.
* math/auto-libm-test-out: Regenerated.
This patch enables testing of cpow in all rounding modes using
ALL_RM_TEST. There were two reasons this was previously deferred:
* MPC has complicated rounding-mode-dependent rules for the signs of
exact zero real or imaginary parts in the result of mpc_pow. Annex
G does not impose any such requirements and I don't think glibc
should try to implement any particular logic here. This patch adds
support for gen-auto-libm-tests passing the IGNORE_ZERO_INF_SIGN
flag to libm-test.inc.
* Error accumulations in some tests in non-default rounding modes
exceed the maximum error permitted in libm-test.inc. This patch
marks the problem tests with xfail-rounding. (It might be possible
to reduce the accumulations a bit by using round-to-nearest when
cpow calls clog, but I don't think there's much point; the
implementation approach for cpow is fundamentally deficient, as
discussed in the existing bug for cpow inaccuracy which can
reasonably be considered to cover these less-inaccurate cases as
well. It's possible that the test "cpow 2 0 10 0" will also need
xfail-rounding on some platforms.)
Tested x86_64 and x86 and ulps updated accordingly.
* math/gen-auto-libm-tests.c: Document use of
ignore-zero-inf-sign.
(input_flag_type): Add value flag_ignore_zero_inf_sign.
(input_flags): Add ignore-zero-inf-sign.
(output_for_one_input_case): Handle flag_ignore_zero_inf_sign.
* math/gen-libm-test.pl (generate_testfile): Handle
ignore-zero-inf-sign.
* math/auto-libm-test-in: Mark some cpow tests with
ignore-zero-inf-sign and some with xfail-rounding.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (cpow_test): Use ALL_RM_TEST.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
This patch fixes bug 16315, bad pow handling of overflow/underflow in
non-default rounding modes. Tests of pow are duly converted to
ALL_RM_TEST to run all tests in all rounding modes.
There are two main issues here. First, various implementations
compute a negative result by negating a positive result, but this
yields inappropriate overflow / underflow values for directed
rounding, so either overflow / underflow results need recomputing in
the correct sign, or the relevant overflowing / underflowing operation
needs to be made to have a result of the correct sign. Second, the
dbl-64 implementation sets FE_TONEAREST internally; in the overflow /
underflow case, the result needs recomputing in the original rounding
mode.
Tested x86_64 and x86 and ulps updated accordingly.
[BZ #16315]
* sysdeps/i386/fpu/e_pow.S (__ieee754_pow): Ensure possibly
overflowing or underflowing operations take place with sign of
result.
* sysdeps/i386/fpu/e_powf.S (__ieee754_powf): Likewise.
* sysdeps/i386/fpu/e_powl.S (__ieee754_powl): Likewise.
* sysdeps/ieee754/dbl-64/e_pow.c: Include <math.h>.
(__ieee754_pow): Recompute overflowing and underflowing results in
original rounding mode.
* sysdeps/x86/fpu/powl_helper.c: Include <stdbool.h>.
(__powl_helper): Allow negative argument X and scale negated value
as needed. Avoid passing value outside [-1, 1] to f2xm1.
* sysdeps/x86_64/fpu/e_powl.S (__ieee754_powl): Ensure possibly
overflowing or underflowing operations take place with sign of
result.
* sysdeps/x86_64/fpu/multiarch/e_pow.c [HAVE_FMA4_SUPPORT]:
Include <math.h>.
* math/auto-libm-test-in: Add more tests of pow.
* math/auto-libm-test-out: Regenerated.
* math/libm-test.inc (pow_test): Use ALL_RM_TEST.
(pow_tonearest_test_data): Remove.
(pow_test_tonearest): Likewise.
(pow_towardzero_test_data): Likewise.
(pow_test_towardzero): Likewise.
(pow_downward_test_data): Likewise.
(pow_test_downward): Likewise.
(pow_upward_test_data): Likewise.
(pow_test_upward): Likewise.
(main): Don't call removed functions.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
This patch adds a generic implementation of HAVE_RM_CTX using standard
fenv calls. As a result math functions using SET_RESTORE_ROUND* macros
do not suffer from a large slowdown on targets which do not implement
optimized libc_fe*_ctx inline functions. Most of the libc_fe* inline
functions are now unused and could be removed in the future (there are
a few math functions left which use a mixture of standard fenv calls
and libc_fe* inline functions - they could be updated to use
SET_RESTORE_ROUND or improved to avoid expensive fenv manipulations
across just a few FP instructions).
libc_feholdsetround*_noex_ctx is added to enable better optimization of
SET_RESTORE_ROUND_NOEX* implementations.
Performance measurements on ARM and x86 of sin() show significant gains
over the current default, fairly close to a highly optimized fenv_private:
ARM x86
no fenv_private : 100% 100%
generic HAVE_RM_CTX : 250% 350%
fenv_private (CTX) : 250% 450%
2014-06-23 Will Newton <will.newton@linaro.org>
Wilco <wdijkstr@arm.com>
* sysdeps/generic/math_private.h: Add generic HAVE_RM_CTX
implementation. Include get-rounding-mode.h.
[!HAVE_RM_CTX]: Define HAVE_RM_CTX to zero.
[!libc_feholdsetround_noex_ctx]: Define
libc_feholdsetround_noex_ctx.
[!libc_feholdsetround_noexf_ctx]: Define
libc_feholdsetround_noexf_ctx.
[!libc_feholdsetround_noexl_ctx]: Define
libc_feholdsetround_noexl_ctx.
(libc_feholdsetround_ctx): New function.
(libc_feresetround_ctx): New function.
(libc_feholdsetround_noex_ctx): New function.
(libc_feresetround_noex_ctx): New function.
This patch updates glibc headers for changes / new definitions in
Linux 3.15. In the course of my review I noticed that
IPV6_PMTUDISC_INTERFACE was absent from glibc despite the inclusion of
IP_PMTUDISC_INTERFACE; I added it along with IP_PMTUDISC_OMIT and
IPV6_PMTUDISC_OMIT. I did not add FALLOC_FL_NO_HIDE_STALE given the
kernel header comment that it is reserved.
Tested x86_64.
* sysdeps/unix/sysv/linux/bits/fcntl-linux.h [__USE_GNU]
(FALLOC_FL_COLLAPSE_RANGE): New macro.
[__USE_GNU] (FALLOC_FL_ZERO_RANGE): Likewise.
* sysdeps/unix/sysv/linux/bits/in.h (IP_PMTUDISC_OMIT): Likewise.
(IPV6_PMTUDISC_INTERFACE): Likewise.
(IPV6_PMTUDISC_OMIT): Likewise.
Linux commit dd58a092c4202f2bd490adab7285b3ff77f8e467 added the
PPC_FEATURE2_VEC_CRYPTO auvx capability to indicate whether to
hardware supports vector crypto hardware instructions. This patch
adds its definition to powerpc hwcap bits.
Convert all uses of __builtin_expect to __glibc_likely and
__glibc_unlikely. Most of these are trivial boolean expressions
but a few were not. In particular the use of __builtin_expect in
the switch expression in do_lookup_x has been removed. Verified
that there are no code changes on x86_64 and ARM aside from line
numbers.
ChangeLog:
2014-06-23 Will Newton <will.newton@linaro.org>
* elf/dl-lookup.c: Use __glibc_unlikely and __glibc_likely
rather than __builtin_expect.
undefined_msg is only used once contrary to the comment.
ChangeLog:
2014-06-23 Will Newton <will.newton@linaro.org>
* elf/dl-lookup.c (undefined_msg): Remove variable.
(_dl_lookup_symbol_x): Replace undefined_msg with string
literal.
Move handling of STB_GNU_UNIQUE symbols to a separate function
from do_lookup_x in order to make the code more readable.
The new function gets inlined with gcc 4.8 on ARM and the
do_lookup_x code becomes a few bytes smaller.
ChangeLog:
2014-06-23 Will Newton <will.newton@linaro.org>
* elf/dl-lookup.c (do_lookup_unique): New function.
(do_lookup_x): Move STB_GNU_UNIQUE handling code
to a separate function.
At the moment the test skeleton uses a mixture of stdout and
stderr for error message output. Using stdout for all test output
keeps all output correctly ordered and properly redirected to the
output file. The suggestion to use stdout is also made on the wiki:
https://sourceware.org/glibc/wiki/Testing/Testsuite#Writing_a_test_case
ChangeLog:
2014-06-23 Will Newton <will.newton@linaro.org>
* test-skeleton.c (signal_handler): Use printf and %m
rather than perror. Use printf rather than fprintf to
stderr. Use puts rather than fputs to stderr.
(main): Likewise.
The attached patch removed the unused ‘thread_info_t’ typedef and the
‘thread_info’ variable from nscd.c. The former conflicts with a GNU Mach
typedef, and the latter conflicts with a GNU Mach function declaration:
<https://lists.gnu.org/archive/html/bug-hurd/2014-06/msg00101.html>.
Tested on x86_64-linux-gnu.
This patch removes ARM __ASSUME_SIGFRAME_V2 now that the
2.6.18-and-later signal frame layout can be assumed, renaming the
affected functions accordingly now only one version of them is needed
in glibc. (sigrestorer.S did not in fact include <kernel-features.h>
and it appears that, unlike other such cases, it didn't get the header
indirectly, so the v1 functions would have been compiled in even when
sigaction.c didn't reference them.)
(alpha and hppa also have architecture-specific __ASSUME_* macros that
should now be removed: __ASSUME_FDATASYNC and __ASSUME_LWS_CAS
respectively. I don't have any plans to do anything on that myself.)
Tested on ARM.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_SIGFRAME_V2): Remove macro.
* sysdeps/unix/sysv/linux/arm/sigrestorer.S: Update comment.
[!__ASSUME_SIGFRAME_V2]: Remove conditional code.
(__default_sa_restorer_v2): Rename to __default_sa_restorer.
(__default_rt_sa_restorer_v2): Rename to __default_rt_sa_restorer.
* sysdeps/unix/sysv/linux/arm/sigaction.c (__default_sa_restorer):
Declare as function. Remove conditional macro definitions.
(__default_rt_sa_restorer): Likewise.
(__default_sa_restorer_v1): Remove declaration.
(__default_sa_restorer_v2): Likewise.
(__default_rt_sa_restorer_v1): Likewise.
(__default_rt_sa_restorer_v2): Likewise.
* sysdeps/unix/sysv/linux/arm/Versions (GLIBC_PRIVATE): Remove
__default_sa_restorer_v1, __default_rt_sa_restorer_v1,
__default_sa_restorer_v2 and __default_rt_sa_restorer_v2.
This patch makes files using __ASSUME_* macros include
<kernel-features.h> explicitly, rather than relying on some other
header (such as tls.h, lowlevellock.h or pthreadP.h) to include it
implicitly. (I omitted cases where I've already posted or am testing
the patch that stops the file from needing __ASSUME_* at all.) This
accords with the general principle of making source files include the
headers for anything they use, and also helps make it safe to remove
<kernel-features.h> includes from any file that doesn't use
__ASSUME_* (some of those may be stray includes left behind after
increasing the minimum kernel version, others may never have been
needed or may have become obsolete after some other change).
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* nptl/pthread_cond_wait.c: Include <kernel-features.h>.
* nptl/pthread_rwlock_timedrdlock.c: Likewise.
* nptl/pthread_rwlock_timedwrlock.c: Likewise.
* nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c: Likewise.
* nscd/nscd.c: Likewise.
* sysdeps/i386/nptl/tcb-offsets.sym: Likewise.
* sysdeps/powerpc/nptl/tcb-offsets.sym: Likewise.
* sysdeps/sh/nptl/tcb-offsets.sym: Likewise.
* sysdeps/x86_64/nptl/tcb-offsets.sym: Likewise.
This patch removes conditionals on __ASSUME_SOCK_CLOEXEC, and on
SOCK_CLOEXEC being defined, in Linux-specific code, now that all
supported Linux kernel versions can be assumed to have this
functionality. (The macro is also used in OS-independent code and is
not defined for Hurd.)
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* nptl/sysdeps/unix/sysv/linux/mq_notify.c: Do not include
<kernel-features.h>.
(init_mq_netlink): Remove conditional have_sock_cloexec
definitions. Remove code conditional on have_sock_cloexec < 0.
(init_mq_netlink) [!SOCK_CLOEXEC]: Remove conditional code.
(init_mq_netlink) [!__ASSUME_SOCK_CLOEXEC]: Likewise.
* sysdeps/unix/sysv/linux/opensock.c: Do not include
<kernel-features.h>.
(__opensock) [SOCK_CLOEXEC]: Make code unconditional.
(__opensock) [!__ASSUME_SOCK_CLOEXEC]: Remove conditional code.
This patch adds ifunc tests for x86_64 memset_chk and memset. It also
defines HAS_AVX2 with AVX2_Usable since AVX2 may not be usable even if
processor has AVX2.
* sysdeps/x86_64/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list):
Add tests for memset_chk and memset.
* sysdeps/x86_64/multiarch/init-arch.h (HAS_AVX2): Defined
with AVX2_Usable.
