The dbl-64/wordsize-64 remquo implementation follows similar logic to
various other implementations, but where that logic computes some
absolute values, it wrongly uses a previously computed bit-pattern for
the absolute value of the first argument, where actually it needs the
absolute value of the first argument mod 8 times the second. This
patch fixes it to compute the correct absolute value.
The integer quotient result of remquo is only specified mod 8
(including its sign); architecture-specific versions may well vary in
what results they give for higher bits of that result (and indeed bug
17569 gives an example correct result from __builtin_remquo giving 9
for that result, where the particular glibc implementation used in
that bug report would give 1 after this fix). Thus, this patch adapts
the tests of remquo to test that result only mod 8, to allow for such
variation when tests with higher quotient are included.
Tested for x86_64 and x86.
[BZ #17569]
* sysdeps/ieee754/dbl-64/wordsize-64/s_remquo.c (__remquo):
Compute absolute value of x as modified by fmod, not original
value of x.
* math/libm-test.inc (RUN_TEST_ffI_f1): Rename to
RUN_TEST_ffI_f1_mod8. Check extra return value mod 8.
(RUN_TEST_LOOP_ffI_f1): Rename to RUN_TEST_LOOP_ffI_f1_mod8. Call
RUN_TEST_ffI_f1_mod8.
(remquo_test_data): Add more tests.
Similarly to sqrt in
<https://sourceware.org/ml/libc-alpha/2015-02/msg00353.html>, the
powerpc sqrtf implementation for when _ARCH_PPCSQ is not defined also
relies on a * b + c being contracted into a fused multiply-add.
Although this contraction is not explicitly disabled for e_sqrtf.c, it
still seems appropriate to make the file explicit about its
requirements by using __builtin_fmaf; this patch does so.
Furthermore, it turns out that doing so fixes the observed inaccuracy
and missing exceptions (that is, that without explicit __builtin_fmaf
usage, it was not being compiled as intended).
Tested for powerpc32 (hard float).
[BZ #17967]
* sysdeps/powerpc/fpu/e_sqrtf.c (__slow_ieee754_sqrtf): Use
__builtin_fmaf instead of relying on contraction of a * b + c.
As Adhemerval noted in
<https://sourceware.org/ml/libc-alpha/2015-01/msg00451.html>, the
powerpc sqrt implementation for when _ARCH_PPCSQ is not defined is
inaccurate in some cases.
The problem is that this code relies on fused multiply-add, and relies
on the compiler contracting a * b + c to get a fused operation. But
sysdeps/ieee754/dbl-64/Makefile disables contraction for e_sqrt.c,
because the implementation in that directory relies on *not* having
contracted operations.
While it would be possible to arrange makefiles so that an earlier
sysdeps directory can disable the setting in
sysdeps/ieee754/dbl-64/Makefile, it seems a lot cleaner to make the
dependence on fused operations explicit in the .c file. GCC 4.6
introduced support for __builtin_fma on powerpc and other
architectures with such instructions, so we can rely on that; this
patch duly makes the code use __builtin_fma for all such fused
operations.
Tested for powerpc32 (hard float).
2015-02-12 Joseph Myers <joseph@codesourcery.com>
[BZ #17964]
* sysdeps/powerpc/fpu/e_sqrt.c (__slow_ieee754_sqrt): Use
__builtin_fma instead of relying on contraction of a * b + c.
The tv_sec is of type time_t in both struct timeval and struct timespec.
This matches the implementation and also the relevant standard (checked
C11 for timespec and opengroup for timeval).
This patch fixes the remaining part of bug 16560, spurious underflows
from exp2 of arguments close to 0 (when the result is close to 1, so
should not underflow), by just using 1+x instead of a more complicated
calculation when the argument is sufficiently small.
Tested for x86_64, x86 and mips64.
[BZ #16560]
* math/e_exp2l.c [LDBL_MANT_DIG == 106] (LDBL_EPSILON): Undefine
and redefine.
(__ieee754_exp2l): Do not multiply small fractional parts by
M_LN2l.
* sysdeps/i386/fpu/e_exp2l.S (__ieee754_exp2l): Just add 1 to
small argument.
* 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 (__ieee754_exp2l): Likewise.
* math/auto-libm-test-in: Add more tests of exp2.
* math/auto-libm-test-out: Regenerated.
This patch optimizes strncpy for power7 for unaligned source or
destination address. The source or destination address is aligned
to doubleword and data is shifted based on the alignment and
added with the previous loaded data to be written as a doubleword.
For each load, cmpb instruction is used for faster null check.
The new optimization shows 10 to 70% of performance improvement
for longer string though it does not show big difference on string
size less than 16 due to additional checks.Hence this new algorithm
is restricted to string greater than 16.
pthread_mutexattr_settype adds PTHREAD_MUTEX_NO_ELISION_NP to kind,
which is an internal flag that pthread_mutexattr_gettype shouldn't
expose, since pthread_mutexattr_settype wouldn't accept it.
and revert the corresponding part of ba90e05 which was making the fix
necessary.
* abi-tags: Revert ae20c9a: rename back gnu into gnu-gnu.
* configure.ac, configure: Revert ba90e05: modify gnu-* host_os back
into gnu-gnu, and update comment to refer to abi-tags.
This patch makes sincos set errno to EDOM when passed an infinity,
similarly to sin and cos.
Tested for x86_64, x86, powerpc and mips64. I don't know if the
architecture-specific implementations for ia64 and m68k might need
corresponding fixes.
2015-02-11 Joseph Myers <joseph@codesourcery.com>
[BZ #15467]
* sysdeps/ieee754/dbl-64/s_sincos.c: Include <errno.h>.
(__sincos): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/flt-32/s_sincosf.c: Include <errno.h>.
(SINCOSF_FUNC): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/ldbl-128/s_sincosl.c: Include <errno.h>.
(__sincosl): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/ldbl-128ibm/s_sincosl.c: Include <errno.h>.
(__sincosl): Set errno to EDOM for infinite argument.
* sysdeps/ieee754/ldbl-96/s_sincosl.c: Include <errno.h>.
(__sincosl): Set errno to EDOM for infinite argument.
* math/libm-test.inc (sincos_test_data): Test errno setting.
As noted in
<https://sourceware.org/ml/libc-alpha/2014-10/msg00369.html>, soft-fp
sysdeps subdirectories (and more generally, subdirectories where
sysdeps/foo/Implies contains foo/bar) are unnecessary and should be
eliminated. This patch does so for MIPS.
Tested for MIPS64 (all three ABIs, soft-float) that installed stripped
shared libraries are unchanged by this patch.
* sysdeps/mips/soft-fp/sfp-machine.h: Move to ....
* sysdeps/mips/mips32/sfp-machine.h: ... here.
* sysdeps/mips/mips64/soft-fp/Makefile: Move to ....
* sysdeps/mips/mips64/Makefile: ... here.
* sysdeps/mips/mips64/soft-fp/e_sqrtl.c: Move to ....
* sysdeps/mips/mips64/e_sqrtl.c: ... here.
* sysdeps/mips/mips64/soft-fp/sfp-machine.h: Move to ....
* sysdeps/mips/mips64/sfp-machine.h: ... here.
* sysdeps/mips/mips32/Implies: Remove mips/soft-fp.
* sysdeps/mips/mips64/n32/Implies: Remove mips/mips64/soft-fp.
* sysdeps/mips/mips64/n64/Implies: Likewise.
Current minimum binutils supported (2.22) has ".machine altivec" support
as default, so there is no need to add a configure check for such
functionality. This patches removes the configure checks for it.
This patch cleanup some multiarch code related to memmmove
optimization. Initial IFUNC support added specialized wordcopy
symbols which turned in local IFUNC calls used by memmove default
implementation. The patch removes the internal IFUNC for wordcopy
symbols and uses local branches in the memmmove optimization instead.
This patch cleanup some multiarch code related to memmmove
optimization. Initial IFUNC support added specialized wordcopy
symbols which turned in local IFUNC calls used by memmove default
implementation.
This change by removing then and used the optimized memmove instead
for supported chips.
This patch simplify the default bcopy symbol for powerpc64 by just using
memmove instead of implementing using the default bcopy. Since the
symbol is deprecated, it trades speed by code size.
This removes code which actually never happens, and is already taken
care of in the function.
This is in the second part of select, when the __mach_msg() function
over the portset has returned something else than MACH_MSG_SUCCESS. I
guess in the past the value returned by __mach_msg() was stored in err,
so this code was necessary to set back err to 0, but now it is stored in
msgerr, so err is already still 0 by default. It can thus never contain
MACH_RCV_TIMED_OUT, i.e. the code is dead. The first case mentioned in
the comment is already handled: on time out with no message, err is
already still the default 0. On time out due to poll, err would still be
0, unless some of the io_select RPCs has returned EINTR, in which case
it contains EINTR. If any other io_select RPCs had returned a proper
answer, got!=0, and thus err is set to 0 just below. The code is thus
indeed not useful any more.
It looks like _hurd_thread_sigstate used to return with the sigstate
lock held long ago, but since that's no longer the case, don't unlock
something that isn't locked.
Note that it's unlikely this change fixes anything in practice since
its current implementation (on i386) makes this call a nop.
