This patch adds support for symbol __kernel_getcpu in vDSO,
which is available with kernel 4.5.
Now sched_getcpu is using this symbol if available in mapped vDSO
by defining macro HAVE_GETCPU_VSYSCALL. If not available at runtime,
the former syscall is used.
Move sysdeps/x86_64/cacheinfo.c to sysdeps/x86. No code changes on x86
and x86_64.
* sysdeps/i386/cacheinfo.c: Include <sysdeps/x86/cacheinfo.c>
instead of <sysdeps/x86_64/cacheinfo.c>.
* sysdeps/x86_64/cacheinfo.c: Moved to ...
* sysdeps/x86/cacheinfo.c: Here.
* sysdeps/pthread/aio_misc.c (__aio_enqueue_request): Do not write
`running` field of `newp` when a thread was started to process it,
since that thread will not take `__aio_requests_mutex`, and the field
already has the proper value actually.
The file sysdeps/powerpc/sysdeps.h defines aliases for condition register
operands. E.g.: 'cr7' means condition register 7. On the one hand, this
increases readability, as it makes it easier for readers to know whether the
operand is a condition register, a general purpose register or an immediate.
On the other hand, this permits that condition registers be written as if they
were general purpose, and vice-versa, thus reducing the readability of the
code.
This commit removes some of these unintentional misuses.
The changes have no effect on the final code. Checked with objdump.
Instead, we store the data we need from the return value of
readdir in an object of the new type struct readdir_result.
This type is independent of the layout of struct dirent.
This patch fixes the clone CLONE_VM change from 0cb313f (BZ#19957)
where the commit changed the register that contains the save flags
argument to compare with (from r28 to r29). This patch changes
back to correct register.
Tested on powerpc32 (thanks to Tulio Magno Quites Machado Filho).
* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S (__clone): Fix
flags CLONE_VM compare.
As discussed in libc-alpha [1] current clone with CLONE_VM (without
CLONE_THREAD set) will reset the pthread pid/tid fields to -1. The
issue is since memory is shared between the parent and child it will
clobber parent's cached pid/tid leading to internal inconsistencies
if the value is not restored.
And even it is restored it may lead to racy conditions when between
set/restore a thread might invoke pthread function that validate the
pthread with INVALID_TD_P/INVALID_NOT_TERMINATED_TD_P and thus get
wrong results.
As stated in BZ19957, previously reports of this behaviour was close
with EWONTFIX due the fact usage of clone outside glibc is tricky
since glibc requires consistent internal pthread, while using clone
directly may not provide it. However since now posix_spawn uses
clone (CLONE_VM) to fixes various issues related to previous vfork
usage this issue requires fixing.
The vfork implementation also does something similar, but instead
it negates and restores only the *pid* field and functions that
might access its value know to handle such case (getpid, raise
and pthread ones that uses INVALID_TD_P/INVALID_NOT_TERMINATED_TD_P
macros that check only *tid* field). Also vfork does not call
__clone directly, instead calling either __NR_vfork or __NR_clone
directly.
So this patch removes this clone behavior by avoiding setting
the pthread pid/tid field for CLONE_VM. There is no need to
check for CLONE_THREAD, since the minimum supported kernel in all
architecture implies that CLONE_VM must be used with CLONE_THREAD,
otherwise clone returns EINVAL.
Instead of current approach of:
int clone(int (*fn)(void *), void *child_stack, int flags, ...)
[...]
if (flags & CLONE_THREAD)
goto do_syscall;
pid_t new_value;
if (flags & CLONE_VM)
new_value = -1;
else
new_value = getpid ();
THREAD_SETMEM (THREAD_SELF, pid, new_value);
THREAD_SETMEM (THREAD_SELF, tid, new_value);
do_syscall:
[...]
The new approach uses:
int clone(int (*fn)(void *), void *child_stack, int flags, ...)
[...]
if (flags & CLONE_VM)
goto do_syscall;
pid_t new_value = getpid ();
THREAD_SETMEM (THREAD_SELF, pid, new_value);
THREAD_SETMEM (THREAD_SELF, tid, new_value);
do_syscall:
[...]
It also removes the linux tst-getpid2.c test which expects the previous
behavior and instead add another clone test.
Tested on x86_64, i686, x32, powerpc64le, aarch64, armhf, s390, and
s390x. I also did limited check on mips32 and sparc64 (using the new
added test).
I also got reviews from both m68k, hppa, and tile. So I presume for
these architecture the patch works.
The fixes for alpha, microblaze, sh, ia64, and nio2 have not been
tested.
[1] https://sourceware.org/ml/libc-alpha/2016-04/msg00307.html
* sysdeps/unix/sysv/linux/Makefile [$(subdir) == nptl] (test): Remove
tst-getpid2.
(test): Add tst-clone2.
* sysdeps/unix/sysv/linux/tst-clone2.c: New file.
* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Do not change
pid/tid fields for CLONE_VM.
* sysdeps/unix/sysv/linux/arm/clone.S: Likewise.
* sysdeps/unix/sysv/linux/i386/clone.S: Likewise.
* sysdeps/unix/sysv/linux/mips/clone.S: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/clone.S: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/clone.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/clone.S: Likewise.
* sysdeps/unix/sysv/linux/tst-getpid2.c: Remove file.
Call __memset_power8 to pad, with zeros, the remaining bytes in the
dest string on __strncpy_power8 and __stpncpy_power8. This improves
performance when n is larger than the input string, giving ~30% gain for
larger strings without impacting much shorter strings.
When converting a struct hostent response to struct gaih_addrtuple, the
gethosts macro (which is called from gaih_inet) used alloca, without
malloc fallback for large responses. This commit changes this code to
use calloc unconditionally.
This commit also consolidated a second hostent-to-gaih_addrtuple
conversion loop (in gaih_inet) to use the new conversion function.
this patch adds the missing SOL_IUCV socket level definition
and socket options SO_IPRMDATA_MSG, SO_MSGLIMIT, SO_MSGSIZE
which can be used with get/setsockopt().
SCM_IUCV_TRGCLS is needed to send/receive ancillary data with send/recvmsg().
The defines are copied from kernel-source:
include/net/iucv/af_iucv.h
include/linux/socket.h
This patch optimizes strcasestr function for power >= 8 systems. The average
improvement of this optimization is ~40% and compares 16 bytes at a time
using vector instructions. This patch is tested on powerpc64 and powerpc64le.
Updated from the model numbers of Goldmont and Airmont processors in
Intel64 And IA-32 Processor Architectures Software Developer's Manual
Volume 3 Revision 058.
* sysdeps/x86/cpu-features.c (init_cpu_features): Detect Intel
Goldmont and Airmont processors.
This patch fixes the __ALIGNMENT_{ARG,COUNT} definition for ports that
define __ASSUME_ALIGNED_REGISTER_PAIRS by including the kernel-features.h
(where it is defined if the case).
This was shown on arm with failing cases:
FAIL: debug/tst-chk1
FAIL: debug/tst-chk2
FAIL: debug/tst-chk3
FAIL: debug/tst-chk4
FAIL: debug/tst-chk5
FAIL: debug/tst-chk6
FAIL: debug/tst-lfschk1
FAIL: debug/tst-lfschk2
FAIL: debug/tst-lfschk3
FAIL: debug/tst-lfschk4
FAIL: debug/tst-lfschk5
FAIL: debug/tst-lfschk6
FAIL: posix/tst-preadwrite
FAIL: posix/tst-preadwrite64
The patches fixes it. Tested on armhf.
* sysdeps/unix/sysv/linux/sysdep.h: Include kernel-features.h.
Previously, a thread M invoking fork would acquire locks in this order:
(M1) malloc arena locks (in the registered fork handler)
(M2) libio list lock
A thread F invoking flush (NULL) would acquire locks in this order:
(F1) libio list lock
(F2) individual _IO_FILE locks
A thread G running getdelim would use this order:
(G1) _IO_FILE lock
(G2) malloc arena lock
After executing (M1), (F1), (G1), none of the threads can make progress.
This commit changes the fork lock order to:
(M'1) libio list lock
(M'2) malloc arena locks
It explicitly encodes the lock order in the implementations of fork,
and does not rely on the registration order, thus avoiding the deadlock.
The overloading approach in the W* macros was incompatible with
integer expressions of a type different from int. Applications
using union wait and these macros will have to migrate to the
POSIX-specified int status type.
The large memcpy micro benchmark in glibc shows that there is a
regression with large data on Haswell machine. non-temporal store in
memcpy on large data can improve performance significantly. This
patch adds a threshold to use non temporal store which is 6 times of
shared cache size. When size is above the threshold, non temporal
store will be used, but avoid non-temporal store if there is overlap
between destination and source since destination may be in cache when
source is loaded.
For size below 8 vector register width, we load all data into registers
and store them together. Only forward and backward loops, which move 4
vector registers at a time, are used to support overlapping addresses.
For forward loop, we load the last 4 vector register width of data and
the first vector register width of data into vector registers before the
loop and store them after the loop. For backward loop, we load the first
4 vector register width of data and the last vector register width of
data into vector registers before the loop and store them after the loop.
[BZ #19928]
* sysdeps/x86_64/cacheinfo.c (__x86_shared_non_temporal_threshold):
New.
(init_cacheinfo): Set __x86_shared_non_temporal_threshold to 6
times of shared cache size.
* sysdeps/x86_64/multiarch/memmove-avx-unaligned-erms.S
(VMOVNT): New.
* sysdeps/x86_64/multiarch/memmove-avx512-unaligned-erms.S
(VMOVNT): Likewise.
* sysdeps/x86_64/multiarch/memmove-sse2-unaligned-erms.S
(VMOVNT): Likewise.
(VMOVU): Changed to movups for smaller code sizes.
(VMOVA): Changed to movaps for smaller code sizes.
* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: Update
comments.
(PREFETCH): New.
(PREFETCH_SIZE): Likewise.
(PREFETCHED_LOAD_SIZE): Likewise.
(PREFETCH_ONE_SET): Likewise.
Rewrite to use forward and backward loops, which move 4 vector
registers at a time, to support overlapping addresses and use
non temporal store if size is above the threshold and there is
no overlap between destination and source.
This patch adds support for using the implementations of gettimeofday()
and clock_gettime() provided by the kernel in the VDSO. The VDSO will
always provide clock_gettime() as CLOCK_{REALTIME,MONOTONIC}_COARSE can
be implemented regardless of platform. CLOCK_{REALTIME,MONOTONIC}, along
with gettimeofday(), are only implemented on platforms which make use of
either the CP0 count or GIC as their clocksource. On other platforms,
the VDSO does not provide the __vdso_gettimeofday symbol, as it is
never useful.
The VDSO functions return ENOSYS when they encounter an unsupported
request, in which case glibc should fall back to the standard syscall.
Tested with upstream kernel 4.5 and QEMU emulating Malta.
./vdsotest gettimeofday bench
gettimeofday: syscall: 1021 nsec/call
gettimeofday: libc: 262 nsec/call
gettimeofday: vdso: 174 nsec/call
* sysdeps/unix/sysv/linux/mips/Makefile (sysdep_routines):
Include dl-vdso.
* sysdeps/unix/sysv/linux/mips/Versions: Add
__vdso_clock_gettime.
* sysdeps/unix/sysv/linux/mips/init-first.c: New file.
* sysdeps/unix/sysv/linux/mips/libc-vdso.h: New file.
* sysdeps/unix/sysv/linux/mips/mips32/sysdep.h:
(INTERNAL_VSYSCALL_CALL): Define to be compatible with MIPS
definitions of INTERNAL_SYSCALL_{ERROR_P,ERRNO}.
(HAVE_CLOCK_GETTIME_VSYSCALL): Define.
(HAVE_GETTIMEOFDAY_VSYSCALL): Define.
* sysdeps/unix/sysv/linux/mips/mips64/n32/sysdep.h: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h: Likewise.
This patch consolidates all the pwrite/pwrite64 implementation for Linux
in only one (sysdeps/unix/sysv/linux/pwrite{64}.c). It also removes the
syscall from the auto-generation using assembly macros.
For pwrite{64} offset argument placement the new SYSCALL_LL{64} macro
is used. For pwrite ports that do not define __NR_pwrite will use
__NR_pwrite64 and for pwrite64 ports that dot define __NR_pwrite64 will
use __NR_pwrite for the syscall.
Checked on x86_64, x32, i386, aarch64, and ppc64le.
* sysdeps/unix/sysv/linux/arm/pwrite.c: Remove file.
* sysdeps/unix/sysv/linux/arm/pwrite64.c: Likewise.
* sysdeps/unix/sysv/linux/generic/wordsize-32/pwrite.c: Likewise.
* sysdeps/unix/sysv/linux/generic/wordsize-32/pwrite64.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/pwrite.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/pwrite64.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/pwrite64.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list (prite): Remove
syscalls generation.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
[__NR_pwrite64] (__NR_write): Remove define.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h
[__NR_pwrite64] (__NR_write): Remove define.
* sysdeps/unix/sysv/linux/pwrite.c [__NR_pwrite64] (__NR_pwrite):
Remove define.
(__libc_pwrite): Use SYSCALL_LL macro on offset argument.
* sysdeps/unix/sysv/linux/pwrite64.c [__NR_pwrite64] (__NR_pwrite):
Remove define.
(__libc_pwrite64): Use SYSCALL_LL64 macro on offset argument.
* sysdeps/unix/sysv/linux/sh/pwrite.c: Rewrite using default
Linux implementation as base.
* sysdeps/unix/sysv/linux/sh/pwrite64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/pwrite.c: Likewise.
* sysdeps/unix/sysv/linux/mips/pwrite64.c: Likewise.
This patch consolidates all the pread/pread64 implementation for Linux
in only one (sysdeps/unix/sysv/linux/pread.c). It also removes the
syscall from the auto-generation using assembly macros.
For pread{64} offset argument placement the new SYSCALL_LL{64} macro
is used. For pread ports that do not define __NR_pread will use
__NR_pread64 and for pread64 ports that dot define __NR_pread64 will
use __NR_pread for the syscall.
Checked on x86_64, x32, i386, aarch64, and ppc64le.
* sysdeps/unix/sysv/linux/arm/pread.c: Remove file.
* sysdeps/unix/sysv/linux/arm/pread64.c: Likewise.
* sysdeps/unix/sysv/linux/generic/wordsize-32/pread.c: Likewise.
* sysdeps/unix/sysv/linux/generic/wordsize-32/pread64.c: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/pread.c: Likewise,
* sysdeps/unix/sysv/linux/powerpc/powerpc32/pread64.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/pread64.c: Likewise.
* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list (pread): Remove
syscall generation.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h
[__NR_pread64] (__NR_pread): Remove define.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h:
[__NR_pread64] (__NR_pread): Likewise.
* sysdeps/unix/sysv/linux/pread.c [__NR_pread64] (__NR_pread): Remove
define.
(__libc_pread): Use SYSCALL_LL macro on offset argument.
* sysdeps/unix/sysv/linux/pread64.c [__NR_pread64] (__NR_pread):
Remove define.
(__libc_pread64): Use SYSCALL_LL64 macro on offset argument.
* sysdeps/unix/sysv/linux/sh/pread.c: Rewrite using default
Linux implementation as base.
* sysdeps/unix/sysv/linux/sh/pread64.c: Likewise.
* sysdeps/unix/sysv/linux/mips/pread.c: Likewise.
* sysdeps/unix/sysv/linux/mips/pread64.c: Likewise.
This patch add three new macros (SYSCALL_LL, SYSCALL_LL64, and
__ASSUME_WORDSIZE64_ILP32) to use along with off_t and off64_t argument
syscalls. The rationale for this change is:
1. Remove multiple implementations for the same syscall for different
architectures (for instance, pread have 6 different implementations).
2. Also remove the requirement to use syscall wrappers for cancellable
entrypoints.
The macro usage should be used along __ALIGNMENT_ARG to follow ABI constrains
for architecture where it applies. For instance, pread can be rewritten as:
return SYSCALL_CANCEL (pread, fd, buf, count,
__ALIGNMENT_ARG SYSCALL_LL (offset));
Another macro, SYSCALL_LL64, is provided for off64_t. The macro
__ASSUME_WORDSIZE64_ILP32 is used by the ABI to define is uses 64-bit register
even if ABI is ILP32 (for instance x32 and mips64-n32).
The changes itself are not currently used in any implementation, so no
code change is expected.
* sysdeps/unix/sysv/linux/generic/sysdep.h (__ALIGNMENT_ARG): Move
definition.
(__ALIGNMENT_COUNT): Likewise.
* sysdeps/unix/sysv/linux/sysdep.h (__ALIGNMENT_ARG): To here.
(__ALIGNMENT_COUNT): Likewise.
(SYSCALL_LL): New define.
(SYSCALL_LL64): Likewise.
* sysdeps/unix/sysv/linux/mips/kernel-features.h:
[_MIPS_SIM == _ABIO32] (__ASSUME_WORDSIZE64_ILP32): Define.
* sysdeps/unix/sysv/linux/x86_64/kernel-features.h:
[ILP32] (__ASUME_WORDSIZE64_ILP32): Likewise.
This patch defines __ASSUME_ALIGNED_REGISTER_PAIRS for the missing
ports that require 64-bit value (e.g., long long) to be aligned to
an even register pair in argument passing.
No code change is expected, tested with builds for powerpc32,
mips-o32, and armhf.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_ALIGNED_REGISTER_PAIRS): Define.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
[_MIPS_SIM == _ABIO32] (__ASSUME_ALIGNED_REGISTER_PAIRS): Likewise.
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
[!__powerpc64__] (__ASSUME_ALIGNED_REGISTER_PAIRS): Likewise.
* sysdeps/generic/ldsodefs.h (struct rtld_global_ro)
[!HAVE_AUX_VECTOR]: Do not define _dl_auxv field.
* misc/getauxval.c (__getauxval) [!HAVE_AUX_VECTOR]: Do not go through
GLRO(dl_auxv) list.
This fixes errors when we inject sse options through CFLAGS and now
that we have -Werror turned on by default this warning turns into an
error on x86:
$ gcc -m32 -march=core2 -mtune=core2 -msse3 -mfpmath=sse -x c /dev/null -S -mno-sse -mno-mmx
/dev/null:1:0: warning: SSE instruction set disabled, using 387 arithmetics
Where as:
$ gcc -m32 -march=core2 -mtune=core2 -msse3 -mfpmath=sse -x c /dev/null -S -mno-sse -mno-mmx -mfpmath=387
Generates no warnings.
bits/termios.h (various versions under sysdeps/unix/sysv/linux)
defines XCASE if defined __USE_MISC || defined __USE_XOPEN. This
macro was removed in the 2001 edition of POSIX, and is not otherwise
reserved, so should not be defined for 2001 and later versions of
POSIX. This patch fixes the conditions accordingly (leaving the macro
defined for __USE_MISC, so still in the default namespace).
Tested for x86_64 and x86 (testsuite, and that installed shared
libraries are unchanged by the patch).
[BZ #19925]
* sysdeps/unix/sysv/linux/alpha/bits/termios.h (XCASE): Do not
define if [!__USE_MISC && __USE_XOPEN2K].
* sysdeps/unix/sysv/linux/bits/termios.h (XCASE): Likewise.
* sysdeps/unix/sysv/linux/mips/bits/termios.h (XCASE): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/termios.h (XCASE):
Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/termios.h (XCASE): Likewise.
* conform/Makefile (test-xfail-XOPEN2K/termios.h/conform): Remove
variable.
(test-xfail-XOPEN2K8/termios.h/conform): Likewise.
This utilizes vectors and bitmasks. For small needle, large
haystack, the performance improvement is upto 8x. For short
strings (0-4B), the cost of computing the bitmask dominates,
and is a tad slower.
Prepare memmove-vec-unaligned-erms.S to make the SSE2 version as the
default memcpy, mempcpy and memmove.
* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S
(MEMCPY_SYMBOL): New.
(MEMPCPY_SYMBOL): Likewise.
(MEMMOVE_CHK_SYMBOL): Likewise.
Replace MEMMOVE_SYMBOL with MEMMOVE_CHK_SYMBOL on __mempcpy_chk
symbols. Replace MEMMOVE_SYMBOL with MEMPCPY_SYMBOL on
__mempcpy symbols. Provide alias for __memcpy_chk in libc.a.
Provide alias for memcpy in libc.a and ld.so.
Prepare memset-vec-unaligned-erms.S to make the SSE2 version as the
default memset.
* sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S
(MEMSET_CHK_SYMBOL): New. Define if not defined.
(__bzero): Check VEC_SIZE == 16 instead of USE_MULTIARCH.
Disabled fro now.
Replace MEMSET_SYMBOL with MEMSET_CHK_SYMBOL on __memset_chk
symbols. Properly check USE_MULTIARCH on __memset symbols.
Since memmove and memset in ld.so don't use IFUNC, don't put SSE2, AVX
and AVX512 memmove and memset in ld.so.
* sysdeps/x86_64/multiarch/memmove-avx-unaligned-erms.S: Skip
if not in libc.
* sysdeps/x86_64/multiarch/memmove-avx512-unaligned-erms.S:
Likewise.
* sysdeps/x86_64/multiarch/memset-avx2-unaligned-erms.S:
Likewise.
* sysdeps/x86_64/multiarch/memset-avx512-unaligned-erms.S:
Likewise.
__mempcpy_erms and __memmove_erms can't be placed between __memmove_chk
and __memmove it breaks __memmove_chk.
Don't check source == destination first since it is less common.
* sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:
(__mempcpy_erms, __memmove_erms): Moved before __mempcpy_chk
with unaligned_erms.
(__memmove_erms): Skip if source == destination.
(__memmove_unaligned_erms): Don't check source == destination
first.
Intel Core i3, i5 and i7 processors have fast unaligned copy and
copy backward is ignored. Remove Fast_Copy_Backward from Intel Core
processors to avoid confusion.
* sysdeps/x86/cpu-features.c (init_cpu_features): Don't set
bit_arch_Fast_Copy_Backward for Intel Core proessors.
This patch removes the powerpc64 optimized strspn, strcspn, and
strpbrk assembly implementation now that the default C one
implements the same strategy. On internal glibc benchtests
current implementations shows similar performance with -O2.
Tested on powerpc64le (POWER8).
* sysdeps/powerpc/powerpc64/strcspn.S: Remove file.
* sysdeps/powerpc/powerpc64/strpbrk.S: Remove file.
* sysdeps/powerpc/powerpc64/strspn.S: Remove file.
Improve strcspn performance using a much faster algorithm. It is kept simple
so it works well on most targets. It is generally at least 10 times faster
than the existing implementation on bench-strcspn on a few AArch64
implementations, and for some tests 100 times as fast (repeatedly calling
strchr on a small string is extremely slow...).
In fact the string/bits/string2.h inlines make no longer sense, as GCC
already uses strlen if reject is an empty string, strchrnul is 5 times as
fast as __strcspn_c1, while __strcspn_c2 and __strcspn_c3 are slower than
the strcspn main loop for large strings (though reject length 2-4 could be
special cased in the future to gain even more performance).
Tested on x86_64, i686, and aarch64.
* string/Version (libc): Add GLIBC_2.24.
* string/strcspn.c (strcspn): Rewrite function.
* string/bits/string2.h (strcspn): Use __builtin_strcspn.
(__strcspn_c1): Remove inline function.
(__strcspn_c2): Likewise.
(__strcspn_c3): Likewise.
* string/string-inline.c
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c1): Add
compatibility symbol.
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c2):
Likewise.
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c3):
Likewise.
* sysdeps/i386/string-inlines.c: Include generic string-inlines.c.
This patch uses ahi instead of aghi in 32bit _dl_runtime_resolve
to adjust the stack pointer. This is no functional change,
but a cosmetic one.
ChangeLog:
* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve):
Use ahi instead of aghi to adjust stack pointer.
When the signs differ, the precision of the conversion sometimes
drops below 106 bits. This strategy is identical to the
hexadecimal variant.
I've refactored tst-sprintf3 to enable testing a value with more
than 30 significant digits in order to demonstrate this failure
and its solution.
Additionally, this implicitly fixes a typo in the shift
quantities when subtracting from the high mantissa to compute
the difference.
