These machine-dependent inline string functions have never been on by
default, and even if they were a good idea at the time they were
introduced, they haven't really been touched in ten to fifteen years
and probably aren't a good idea on current-gen processors. Current
thinking is that this class of optimization is best left to the
compiler.
* bits/string.h, string/bits/string.h
* sysdeps/aarch64/bits/string.h
* sysdeps/m68k/m680x0/m68020/bits/string.h
* sysdeps/s390/bits/string.h, sysdeps/sparc/bits/string.h
* sysdeps/x86/bits/string.h: Delete file.
* string/string.h: Don't include bits/string.h.
* string/bits/string3.h: Rename to bits/string_fortified.h.
No need to undef various symbols that the removed headers
might have defined as macros.
* string/Makefile (headers): Remove bits/string.h, change
bits/string3.h to bits/string_fortified.h.
* string/string-inlines.c: Update commentary. Remove definitions
of various macros that nothing looks at anymore. Don't directly
include bits/string.h. Set _STRING_INLINE_unaligned here, based on
compiler-predefined macros.
* string/strncat.c: If STRNCAT is not defined, or STRNCAT_PRIMARY
_is_ defined, provide internal hidden alias __strncat.
* include/string.h: Declare internal hidden alias __strncat.
Only forward __stpcpy to __builtin_stpcpy if __NO_STRING_INLINES is
not defined.
* include/bits/string3.h: Rename to bits/string_fortified.h,
update to match above.
* sysdeps/i386/string-inlines.c: Define compat symbols for
everything formerly defined by sysdeps/x86/bits/string.h.
Make existing definitions into compat symbols as well.
Remove some no-longer-necessary messing around with macros.
* sysdeps/powerpc/powerpc32/power4/multiarch/mempcpy.c
* sysdeps/powerpc/powerpc64/multiarch/mempcpy.c
* sysdeps/powerpc/powerpc64/multiarch/stpcpy.c
* sysdeps/s390/multiarch/mempcpy.c
No need to define _HAVE_STRING_ARCH_mempcpy.
Do define __NO_STRING_INLINES and NO_MEMPCPY_STPCPY_REDIRECT.
* sysdeps/i386/i686/multiarch/strncat-c.c
* sysdeps/s390/multiarch/strncat-c.c
* sysdeps/x86_64/multiarch/strncat-c.c
Define STRNCAT_PRIMARY. Don't change definition of libc_hidden_def.
This patch adjusts the s390 specific ifunc helper macros in ifunc-resolve.h to
use the common __ifunc macro, which uses gcc attribute ifunc to get rid of the
false debuginfo. Therefore the redirection construct is applied where needed.
Perhaps in future we can switch some of the internal symbols __GI_* from the
fallback variant to the ifunc function. But this change is not
straightforward due to a segmentation fault while linking libc.so with older
binutils on s390.
ChangeLog:
[BZ #20478]
* sysdeps/s390/multiarch/ifunc-resolve.h
(s390_vx_libc_ifunc2, s390_libc_ifunc): Use __ifunc from libc-symbols.h
to create ifunc symbols.
(s390_vx_libc_ifunc_init, s390_vx_libc_ifunc_redirected
, s390_vx_libc_ifunc2_redirected, s390_libc_ifunc_init): New define.
* sysdeps/s390/multiarch/memchr.c: Redirect ifunced function in header
for using it as type for ifunc function.
* sysdeps/s390/multiarch/mempcpy.c: Likewise.
* sysdeps/s390/multiarch/rawmemchr.c: Likewise.
* sysdeps/s390/multiarch/stpcpy.c: Likewise.
* sysdeps/s390/multiarch/stpncpy.c: Likewise.
* sysdeps/s390/multiarch/strcat.c: Likewise.
* sysdeps/s390/multiarch/strchr.c: Likewise.
* sysdeps/s390/multiarch/strcmp.c: Likewise.
* sysdeps/s390/multiarch/strcpy.c: Likewise.
* sysdeps/s390/multiarch/strcspn.c: Likewise.
* sysdeps/s390/multiarch/strlen.c: Likewise.
* sysdeps/s390/multiarch/strncmp.c: Likewise.
* sysdeps/s390/multiarch/strncpy.c: Likewise.
* sysdeps/s390/multiarch/strnlen.c: Likewise.
* sysdeps/s390/multiarch/strpbrk.c: Likewise.
* sysdeps/s390/multiarch/strrchr.c: Likewise.
* sysdeps/s390/multiarch/strspn.c: Likewise.
* sysdeps/s390/multiarch/wcschr.c: Likewise.
* sysdeps/s390/multiarch/wcscmp.c: Likewise.
* sysdeps/s390/multiarch/wcspbrk.c: Likewise.
* sysdeps/s390/multiarch/wcsspn.c: Likewise.
* sysdeps/s390/multiarch/wmemchr.c: Likewise.
* sysdeps/s390/multiarch/wmemset.c: Likewise.
* sysdeps/s390/s390-32/multiarch/memcmp.c: Likewise.
* sysdeps/s390/s390-32/multiarch/memcpy.c: Likewise.
* sysdeps/s390/s390-32/multiarch/memset.c: Likewise.
* sysdeps/s390/s390-64/multiarch/memcmp.c: Likewise.
* sysdeps/s390/s390-64/multiarch/memcpy.c: Likewise.
* sysdeps/s390/s390-64/multiarch/memset.c: Likewise.
There exist optimized memcpy functions on s390, but no optimized mempcpy.
This patch adds mempcpy entry points in memcpy.S files, which
use the memcpy implementation. Now mempcpy itself is also an IFUNC function
as memcpy is and the variants are listed in ifunc-impl-list.c.
The s390 string.h does not define _HAVE_STRING_ARCH_mempcpy.
Instead mempcpy string/string.h inlines memcpy() + n.
If n is constant and small enough, GCC emits instructions like mvi or mvc
and avoids the function call to memcpy.
If n is not constant, then memcpy is called and n is added afterwards.
If _HAVE_STRING_ARCH_mempcpy would be defined, mempcpy would be called in
every case.
According to PR70140 "Inefficient expansion of __builtin_mempcpy"
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70140) GCC should handle a
call to mempcpy in the same way as memcpy. Then either the mempcpy macro
in string/string.h has to be removed or _HAVE_STRING_ARCH_mempcpy has to
be defined for S390.
ChangeLog:
[BZ #19765]
* sysdeps/s390/mempcpy.S: New File.
* sysdeps/s390/multiarch/mempcpy.c: Likewise.
* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add mempcpy.
* sysdeps/s390/multiarch/ifunc-impl-list.c (__libc_ifunc_impl_list):
Add mempcpy variants.
* sysdeps/s390/s390-32/memcpy.S: Add mempcpy entry point.
(memcpy): Adjust to be usable from mempcpy entry point.
(__memcpy_mvcle): Likewise.
* sysdeps/s390/s390-64/memcpy.S: Likewise.
* sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Add entry points
____mempcpy_z196, ____mempcpy_z10 and add __GI_ symbols for mempcpy.
(__memcpy_z196): Adjust to be usable from mempcpy entry point.
(__memcpy_z10): Likewise.
* sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Likewise.
