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.
Some powerpc64 processors (e5500 core for instance) does not provide the
fsqrt instruction, however current check to use in math_private.h is
__WORDSIZE and _ARCH_PWR4 (ISA 2.02). This is patch change it to use
the compiler flag _ARCH_PPCSQ (which is the same condition GCC uses to
decide whether to generate fsqrt instruction).
It fixes BZ#16576.
GLIBC memset optimization for POWER8 uses the '.machine power8'
directive, which is only supported officially on binutils 2.24+. This
causes a build failure on older binutils.
Since the requirement of .machine power8 is to correctly assembly the
'mtvsrd' instruction and it is already handled by the MTVSRD_V1_R4
macro, there is no really needed of using it.
The patch replaces the power8 with power7 for .machine directive.
It fixes BZ#17869.
This patch fix the elf/ifuncmain6pie failure when building with GCC
4.9+. For some reason, the compiler removes the branch taken code at
resolve_ifunc (sysdeps/powerpc/powerpc64/dl-machine.h) as dead-code
and thus the testcase fails because the ifunc resolves branches to an
invalid memory location. It fixes by explicit adding a dependency of
value based on odp variable to avoid compiler optimization.
It fixes BZ#17868.
This patch fixes a performance regression on the POWER7/PPC64 memcmp
porting for Little Endian. The LE code uses 'ldbrx' instruction to read
the memory on byte reversed form, however ISA 2.06 just provide the indexed
form which uses a register value as additional index, instead of a fixed value
enconded in the instruction.
And the port strategy for LE uses r0 index value and update the address
value on each compare loop interation. For large compare size values,
it adds 8 more instructions plus some more depending of trailing
size. This patch fixes it by adding pre-calculate indexes to remove the
address update on loops and tailing sizes.
For large sizes it shows a considerable gain, with double performance
pairing with BE.
This patch adds an optimized POWER8 strncmp. The implementation focus
on speeding up unaligned cases follwing the ideas of power8 strcmp.
The algorithm first check the initial 16 bytes, then align the first
function source and uses unaligned loads on second argument only.
Aditional checks for page boundaries are done for unaligned cases
(where sources alignment are different).
This patch optimized the POWER7 trailing check by avoiding using byte
read operations and instead use the doubleword already readed with
bitwise operations.
This patch adds an optimized POWER8 strcmp using unaligned accesses.
The algorithm first check the initial 16 bytes, then align the first
function source and uses unaligned loads on second argument only.
Aditional checks for page boundaries are done for unaligned cases
This patch adds an optimized POWER8 st{r,p}ncpy using unaligned accesses.
It shows 10%-80% improvement over the optimized POWER7 one that uses
only aligned accesses, specially on unaligned inputs.
The algorithm first read and check 16 bytes (if inputs do not cross a 4K
page size). The it realign source to 16-bytes and issue a 16 bytes read
and compare loop to speedup null byte checks for large strings. Also,
different from POWER7 optimization, the null pad is done inline in the
implementation using possible unaligned accesses, instead of realying on
a memset call. Special case is added for page cross reads.
With 3eb38795db (Simplify strncat) the generic algorithms uses
strlen, strnlen, and memcpy. This is faster than POWER7 current
implementation, especially for unaligned strings (where POWER7 code
uses byte-byte operations).
This patch removes the assembly implementation and uses a multiarch
specialization based on default algorithm calling optimized POWER7
symbols.
This patch adds an optimized POWER8 strcpy using unaligned accesses.
For strings up to 16 bytes the implementation first calculate the
string size, like strlen, and issues a memcpy. For larger strings,
source is first aligned to 16 bytes and then tested over a loop that
reads 16 bytes am combine the cmpb results for speedup. Special case is
added for page cross reads.
It shows 30%-60% improvement over the optimized POWER7 one that uses
only aligned accesses.
Linux kernel powerpc documentation states issuing a syscall inside a
transaction is not recommended and may lead to undefined behavior. It
also states syscalls does not abort transactoin neither they run in
transactional state.
To avoid side-effects being visible outside transactions, GLIBC with
lock elision enabled will issue a transaction abort instruction just
before all syscalls if hardware supports hardware transactions.
This patch optimizes strcpy for ppc64/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 word aligned optimization is also removed, since the new unaligned
code path shows better results handling word-aligned strings.
More combination of unaligned inputs is also added in benchtest
to measure the improvement.The new optimization shows 2 to 80% of
performance improvement for longer string though it does not show
big difference on string size less than 16 due to additional checks.
Use of strftime, a C90 function, ends up bringing in wcschr, which is
not a C90 function. Although not a conformance bug (C90 reserves
wcs*), this is still contrary to glibc practice of avoiding relying on
those reservations; this patch arranges for the internal uses to use
__wcschr instead, with wcschr being a weak alias. This is more
complicated than some such patches because of the various IFUNC
definitions of wcschr (which include code redefining libc_hidden_def
in a way that involves creating __GI_wcschr manually and so also needs
to create __GI___wcschr after the change of internal uses to use
__wcschr).
Tested for x86_64 and 32-bit x86 (testsuite, and that disassembly of
installed shared libraries is unchanged by the patch).
2014-12-10 Joseph Myers <joseph@codesourcery.com>
Adhemerval Zanella <azanella@linux.vnet.ibm.com>
[BZ #17634]
* wcsmbs/wcschr.c [!WCSCHR] (wcschr): Define as __wcschr.
Undefine after defining function. Define as weak alias of
__wcschr. Use libc_hidden_weak.
* include/wchar.h (__wcschr): Declare. Use libc_hidden_proto.
* sysdeps/i386/i686/multiarch/wcschr-c.c [IS_IN (libc) && SHARED]
(libc_hidden_def): Also define __GI___wcschr alias.
* sysdeps/i386/i686/multiarch/wcschr.S (wcschr): Rename to
__wcschr and define as weak alias of __wcschr.
* sysdeps/powerpc/power6/wcschr.c [!WCSCHR] (WCSCHR): Define as
__wcschr.
[!WCSCHR] (DEFAULT_WCSCHR): Define.
[DEFAULT_WCSCHR] (__wcschr): Use libc_hidden_def.
[DEFAULT_WCSCHR] (wcschr): Define as weak alias of __wcschr. Use
libc_hidden_weak. Do not use libc_hidden_def.
* sysdeps/powerpc/powerpc32/power4/multiarch/wcschr-ppc32.c
[IS_IN (libc) && SHARED] (libc_hidden_def): Also define
__GI___wcschr alias.
* sysdeps/powerpc/powerpc32/power4/multiarch/wcschr.c
[IS_IN (libc)] (wcschr): Define as macro expanding to
__redirect_wcschr.
[IS_IN (libc)] (__wcschr_ppc): Use __redirect_wcschr in typeof.
[IS_IN (libc)] (__wcschr_power6): Likewise.
[IS_IN (libc)] (__wcschr_power7): Likewise.
[IS_IN (libc)] (__libc_wcschr): New. Define with libc_ifunc
instead of wcschr.
[IS_IN (libc)] (wcschr): Undefine and define as weak alias of
__libc_wcschr.
[!IS_IN (libc)] (libc_hidden_def): Do not undefine and redefine.
* sysdeps/powerpc/powerpc64/multiarch/wcschr.c (wcschr): Rename to
__wcschr and define as weak alias of __wcschr. Use
libc_hidden_builtin_def.
* sysdeps/x86_64/wcschr.S (wcschr): Rename to __wcschr and define
as weak alias of __wcschr. Use libc_hidden_weak.
* time/alt_digit.c (_nl_get_walt_digit): Use __wcschr instead of
wcschr.
* time/era.c (_nl_init_era_entries): Likewise.
* conform/Makefile (test-xfail-ISO/time.h/linknamespace): Remove
variable.
(test-xfail-XPG3/time.h/linknamespace): Likewise.
(test-xfail-XPG4/time.h/linknamespace): Likewise.
This patch makes the POWER7 optimized strpbrk generic by using
default doubleword stores to zero the hash, instead of VSX
instructions. Performance on POWER7/POWER8 does not change.
This patch makes the POWER7 optimized strcspn generic by using
default doubleword stores to zero the hash, instead of VSX
instructions. Performance on POWER7/POWER8 does not change.
This patch makes the POWER7 optimized strspn generic by using
default doubleword stores to zero the hash, instead of VSX
instructions. Performance on POWER7/POWER8 machines does not changed.
This patch optimizes strtok and strtok_r for POWERPC64.
A table of 256 characters is created and marked based on
the 'accept' argument and used to check for any occurance on
the input string.Loop unrolling is also used to gain improvements.
On powerpc, atomic_exchange_and_add is implemented without any
barriers. This patchs adds the missing instruction and memory barrier
for acquire and release semanthics.
This sets __HAVE_64B_ATOMICS if provided. It also sets
USE_ATOMIC_COMPILER_BUILTINS to true if the existing atomic ops use the
__atomic* builtins (aarch64, mips partially) or if this has been
tested (x86_64); otherwise, this is set to false so that C11 atomics will
be based on the existing atomic operations.
This patch fixes the build of C mempcpy and stpcpy by disabling the
redirection to __mempcpy and __stpcpy asm names if
NO_MEMPCPY_STPCPY_REDIRECT is defined, and defining that macro in the
relevant source files.
Tested for powerpc32 that the build is fixed.
* include/string.h [NO_MEMPCPY_STPCPY_REDIRECT] (mempcpy): Do not
redeclare with asm name.
[NO_MEMPCPY_STPCPY_REDIRECT] (stpcpy): Likewise.
* string/mempcpy.c (NO_MEMPCPY_STPCPY_REDIRECT): Define before
including <string.h>.
* string/stpcpy.c (NO_MEMPCPY_STPCPY_REDIRECT): Likewise.
* sysdeps/powerpc/powerpc32/power4/multiarch/mempcpy.c
[!NOT_IN_libc] (NO_MEMPCPY_STPCPY_REDIRECT): Likewise.
* sysdeps/powerpc/powerpc64/multiarch/mempcpy.c
[!NOT_IN_libc] (NO_MEMPCPY_STPCPY_REDIRECT): Likewise.
* sysdeps/powerpc/powerpc64/multiarch/stpcpy.c
[SHARED && !NOT_IN_libc] (NO_MEMPCPY_STPCPY_REDIRECT): Likewise.
Completing the removal of the obsolete INTDEF / INTUSE mechanism, this
patch removes the final use - that for _dl_starting_up - replacing it
by rtld_hidden_def / rtld_hidden_proto. Having removed the last use,
the mechanism itself is also removed.
Tested for x86_64 that installed stripped shared libraries are
unchanged by the patch. (This is not much of a test since this
variable is only defined and used in the !HAVE_INLINED_SYSCALLS case.)
[BZ #14132]
* include/libc-symbols.h (INTUSE): Remove macro.
(INTDEF): Likewise.
(INTVARDEF): Likewise.
(_INTVARDEF): Likewise.
(INTDEF2): Likewise.
(INTVARDEF2): Likewise.
* elf/rtld.c [!HAVE_INLINED_SYSCALLS] (_dl_starting_up): Use
rtld_hidden_def instead of INTVARDEF.
* sysdeps/generic/ldsodefs.h [IS_IN_rtld]
(_dl_starting_up_internal): Remove declaration.
(_dl_starting_up): Use rtld_hidden_proto.
* elf/dl-init.c [!HAVE_INLINED_SYSCALLS] (_dl_starting_up): Remove
declaration.
[!HAVE_INLINED_SYSCALLS] (_dl_starting_up_internal): Likewise.
(_dl_init) [!HAVE_INLINED_SYSCALLS]: Don't use INTUSE with
_dl_starting_up.
* elf/dl-writev.h (_dl_writev): Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.h [!HAVE_INLINED_SYSCALLS]
(DL_STARTING_UP_DEF): Use __GI__dl_starting_up instead of
_dl_starting_up_internal.
Continuing the removal of the obsolete INTDEF / INTUSE mechanism, this
patch replaces its use for _dl_argv with rtld_hidden_data_def and
rtld_hidden_proto. Some places in .S files that previously used
_dl_argv_internal or INTUSE(_dl_argv) now use __GI__dl_argv directly
(there are plenty of existing examples of such direct use of __GI_*).
A single place in rtld.c previously used _dl_argv without INTUSE,
apparently accidentally, while the rtld_hidden_proto mechanism avoids
such accidential omissions. As a consequence, this patch *does*
change the contents of stripped ld.so. However, the installed
stripped shared libraries are identical to those you get if instead of
this patch you change that single _dl_argv use to use INTUSE, without
any other changes.
Tested for x86_64 (testsuite as well as comparison of installed
stripped shared libraries as described above).
[BZ #14132]
* sysdeps/generic/ldsodefs.h (_dl_argv): Use rtld_hidden_proto.
[IS_IN_rtld] (_dl_argv_internal): Do not declare.
(rtld_progname): Make macro definition unconditional.
* elf/rtld.c (_dl_argv): Use rtld_hidden_data_def instead of
INTDEF.
(dlmopen_doit): Do not use INTUSE with _dl_argv.
(dl_main): Likewise.
* elf/dl-sysdep.c (_dl_sysdep_start): Likewise.
* sysdeps/alpha/dl-machine.h (RTLD_START): Use __GI__dl_argv
instead of _dl_argv_internal.
* sysdeps/powerpc/powerpc32/dl-start.S (_dl_start_user): Use
__GI__dl_argv instead of INTUSE(_dl_argv).
* sysdeps/powerpc/powerpc64/dl-machine.h (RTLD_START): Use
__GI__dl_argv instead of _dl_argv_internal.
This patch adds an optimized memset implementation for POWER8. For
sizes from 0 to 255 bytes, a word/doubleword algorithm similar to
POWER7 optimized one is used.
For size higher than 255 two strategies are used:
1. If the constant is different than 0, the memory is written with
altivec vector instruction;
2. If constant is 0, dbcz instructions are used. The loop is unrolled
to clear 512 byte at time.
Using vector instructions increases throughput considerable, with a
double performance for sizes larger than 1024. The dcbz loops unrolls
also shows performance improvement, by doubling throughput for sizes
larger than 8192 bytes.
This patch cleanups the multiarch bzero for powerpc64 by remove
the multiarch objects and use instead the the memset embedded
implementation presented in each multiarch optimization. The
code generate is essentially the same, but the TB_TOCLESS (which
is not essential).
Now that MEMCPY_OK_FOR_FWD_MEMMOVE should be define on memcopy.h there
is no need to specialized powerpc memmove implementation. This patch
moves the define set to powerpc memcopy and cleanup its definition on
powerpc code.
This patch changes power7 memcpy to use VSX instructions only when
memory is aligned to quardword. It is to avoid unaligned kernel traps
on non-cacheable memory (for instance, memory-mapped I/O).
This patch adds an optimized memmove optimization for POWER7/powerpc64.
Basically the idea is to use the memcpy for POWER7 on non-overlapped
memory regions and a optimized backward memcpy for memory regions
that overlap (similar to the idea of string/memmove.c).
The backward memcpy algorithm used is similar the one use for memcpy for
POWER7, with adjustments done for alignment. The difference is memory
is always aligned to 16 bytes before using VSX/altivec instructions.
This patch adds an ifunc power7 strcat symbol that uses the logic on
sysdeps/powerpc/strcat.c but call power7 strlen/strcpy symbols instead
of default ones.
This patch defines ELF_MACHINE_NO_RELA on all architectures. Tested
only on x86_64 to verify that the sources before and after are
identical except for two instructions that pass the current line
number in dl-machine.h to assert_fail.
Optimization is achieved on 8 byte aligned strings with double word
comparison using cmpb instruction. On unaligned strings loop unrolling
is applied for Power7 gain.
This patch fixes the optimized ppc64/power7 strncat strlen call for
static build without ifunc enabled. The strlen symbol to call in such
situation is just strlen, instead of __GI_strlen (since the __GI_
alias is just created for shared objects).
