This patch implements roundtoint and convertoint for s390
by using the load-fp-integer and convert-to-fixed instructions.
Both functions are using "round to nearest with ties away from zero"
rounding mode and do not raise inexact exceptions.
This patch updates the s390 specific functions fegetround,
fesetround, feholdexcept, fesetenv, feupdateenv, fegetexceptflag,
fetestexcept, fesetexceptflag, fetestexceptflag.
Now those functions are using the libc_fe* macros if possible.
Furthermore fegetexceptflag is now returning the exception from
dxc field shifted to the usual exception-flags.
Thus a special fetestexceptflag implementation is not needed anymore.
This patch provides the s390 specific implementation for
libc_feholdexcept, libc_fesetround, libc_feholdexcept_setround,
libc_fetestexcept, libc_fesetenv, libc_feupdateenv_test,
libc_feupdateenv, libc_feholdsetround_ctx, libc_feresetround_ctx,
libc_feholdsetround_noex_ctx and libc_feresetround_noex_ctx.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement llround, llroundf, llroundl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement lround, lroundf, lroundl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement llrint, llrintf, llrintl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the convert-to-fixed instruction
is used to implement lrint, lrintf, lrintl.
Otherwise the common-code implementation is used.
If compiled with z196 zarch support, the load-fp-integer instruction
is used to implement roundeven, roundevenf, roundevenl.
Otherwise the common-code implementation is used.
This patch is always using the corresponding GCC builtin for copysignf, copysign,
and is using the builtin for copysignl, copysignf128 if the USE_FUNCTION_BUILTIN
macros are defined to one in math-use-builtins.h.
Altough the long double version is enabled by default we still need
the macro and the alternative implementation as the _Float128 version
of the builtin is not available with all supported GCC versions.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for roundf, round,
roundl and roundf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for truncf, trunc,
truncl and truncf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for ceilf, ceil,
ceill and ceilf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for floorf, floor,
floorl and floorf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for rintf, rint,
rintl and rintf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch is using the corresponding GCC builtin for nearbyintf, nearbyint,
nearbintl and nearbyintf128 if the USE_FUNCTION_BUILTIN macros are defined to one
in math-use-builtins.h.
This is the case for s390 if build with at least --march=z196 --mzarch.
Otherwise the generic implementation is used. The code of the generic
implementation is not changed.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
If the specified needle crosses a page-boundary, the s390-z15 ifunc variant of
strstr truncates the needle which results in invalid results.
This is fixed by loading the needle beyond the page boundary to v18 instead of v16.
The bug is sometimes observable in test-strstr.c in check1 and check2 as the
haystack and needle is stored on stack. Thus the needle can be on a page boundary.
check2 is now extended to test haystack / needles located on stack, at end of page
and on two pages.
This bug was introduced with commit 6f47401bd5
("S390: Add arch13 strstr ifunc variant.") and is already released in glibc 2.30.
This patch adds a default pthreadtypes-arch.h, the idea is to simpify
new ports inclusion and an override is required only if the architecture
adds some arch-specific extensions or requirement.
The default values on the new generic header are based on current
architecture define value and they are not optimal compared to current
code requirements as below.
- On 64 bits __SIZEOF_PTHREAD_BARRIER_T is defined as 32 while is
sizeof (struct pthread_barrier) is 20 bytes.
- On 32 bits __SIZEOF_PTHREAD_ATTR_T is defined as 36 while
sizeof (struct pthread_attr) is 32.
The default values are not changed so the generic header could be
used by some architectures.
Checked with a build on affected abis.
Change-Id: Ie0cd586258a2650f715c1af0c9fe4e7063b0409a
This patch adds a new generic __pthread_rwlock_arch_t definition meant
to be used by new ports. Its layout mimics the current usage on some
64 bits ports and it allows some ports to use the generic definition.
The arch __pthread_rwlock_arch_t definition is moved from
pthreadtypes-arch.h to another arch-specific header (struct_rwlock.h).
Also the static intialization macro for pthread_rwlock_t is set to use
an arch defined on (__PTHREAD_RWLOCK_INITIALIZER) which simplifies its
implementation.
The default pthread_rwlock_t layout differs from current ports with:
1. Internal layout is the same for 32 bits and 64 bits.
2. Internal flag is an unsigned short so it should not required
additional padding to align for word boundary (if it is the case
for the ABI).
Checked with a build on affected abis.
Change-Id: I776a6a986c23199929d28a3dcd30272db21cd1d0
The current way of defining the common mutex definition for POSIX and
C11 on pthreadtypes-arch.h (added by commit 06be6368da) is
not really the best options for newer ports. It requires define some
misleading flags that should be always defined as 0
(__PTHREAD_COMPAT_PADDING_MID and __PTHREAD_COMPAT_PADDING_END), it
exposes options used solely for linuxthreads compat mode
(__PTHREAD_MUTEX_USE_UNION and __PTHREAD_MUTEX_NUSERS_AFTER_KIND), and
requires newer ports to explicit define them (adding more boilerplate
code).
This patch adds a new default __pthread_mutex_s definition meant to
be used by newer ports. Its layout mimics the current usage on both
32 and 64 bits ports and it allows most ports to use the generic
definition. Only ports that use some arch-specific definition (such
as hardware lock-elision or linuxthreads compat) requires specific
headers.
For 32 bit, the generic definitions mimic the other 32-bit ports
of using an union to define the fields uses on adaptive and robust
mutexes (thus not allowing both usage at same time) and by using a
single linked-list for robust mutexes. Both decisions seemed to
follow what recent ports have done and make the resulting
pthread_mutex_t/mtx_t object smaller.
Also the static intialization macro for pthread_mutex_t is set to use
a macro __PTHREAD_MUTEX_INITIALIZER where the architecture can redefine
in its struct_mutex.h if it requires additional fields to be
initialized.
Checked with a build on affected abis.
Change-Id: I30a22c3e3497805fd6e52994c5925897cffcfe13
The new rwlock implementation added by cc25c8b4c1 (2.25) removed
support for lock-elision. This patch removes remaining the
arch-specific unused definitions.
Checked with a build against all affected ABIs.
Change-Id: I5dec8af50e3cd56d7351c52ceff4aa3771b53cd6
This patch new build tests to check for internal fields offsets for
internal pthread_rwlock_t definition. Althoug the '__data.__flags'
field layout should be preserved due static initializators, the patch
also adds tests for the futexes that may be used in a shared memory
(although using different libc version in such scenario is not really
supported).
Checked with a build against all affected ABIs.
Change-Id: Iccc103d557de13d17e4a3f59a0cad2f4a640c148
The offsets of pthread_mutex_t __data.__nusers, __data.__spins,
__data.elision, __data.list are not required to be constant over
the releases. Only the __data.__kind is used for static
initializers.
This patch also adds an additional size check for __data.__kind.
Checked with a build against affected ABIs.
Change-Id: I7a4e48cc91b4c4ada57e9a5d1b151fb702bfaa9f
The s390 gcc bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77918
"S390: Floating point comparisons don't raise invalid for unordered operands."
is fixed with gcc 10. Thus we conditionally set FIX_COMPARE_INVALID
to 0 or 1.
With only two exceptions (sys/types.h and sys/param.h, both of which
historically might have defined BYTE_ORDER) the public headers that
include <endian.h> only want to be able to test __BYTE_ORDER against
__*_ENDIAN.
This patch creates a new bits/endian.h that can be included by any
header that wants to be able to test __BYTE_ORDER and/or
__FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs
__LONG_LONG_PAIR. It only defines macros in the implementation
namespace.
The existing bits/endian.h (which could not be included independently
of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER)
is renamed to bits/endianness.h. I also took the opportunity to
canonicalize the form of this header, which we are stuck with having
one copy of per architecture. Since they are so short, this means git
doesn’t understand that they were renamed from existing headers, sigh.
endian.h itself is a nonstandard header and its only remaining use
from a standard header is guarded by __USE_MISC, so I dropped the
__USE_MISC conditionals from around all of the public-namespace things
it defines. (This means, an application that requests strict library
conformance but includes endian.h will still see the definition of
BYTE_ORDER.)
A few changes to specific bits/endian(ness).h variants deserve
mention:
- sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to
sysdeps/ia64/bits/endianness.h. If I remember correctly, ia64 did
have selectable endianness, but we have assembly code in
sysdeps/ia64 that assumes it’s little-endian, so there is no reason
to treat the ia64 endianness.h as linux-specific.
- The C-SKY port does not fully support big-endian mode, the compile
will error out if __CSKYBE__ is defined.
- The PowerPC port had extra logic in its bits/endian.h to detect a
broken compiler, which strikes me as unnecessary, so I removed it.
- The only files that defined __FLOAT_WORD_ORDER always defined it to
the same value as __BYTE_ORDER, so I removed those definitions.
The SH bits/endian(ness).h had comments inconsistent with the
actual setting of __FLOAT_WORD_ORDER, which I also removed.
- I *removed* copyright boilerplate from the few bits/endian(ness).h
headers that had it; these files record a single fact in a fashion
dictated by an external spec, so I do not think they are copyrightable.
As long as I was changing every copy of ieee754.h in the tree, I
noticed that only the MIPS variant includes float.h, because it uses
LDBL_MANT_DIG to decide among three different versions of
ieee854_long_double. This patch makes it not include float.h when
GCC’s intrinsic __LDBL_MANT_DIG__ is available.
* string/endian.h: Unconditionally define LITTLE_ENDIAN,
BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER. Condition byteswapping
macros only on !__ASSEMBLER__. Move the definitions of
__BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER,
and __LONG_LONG_PAIR to...
* string/bits/endian.h: ...this new file, which includes
the renamed header bits/endianness.h for the definition of
__BYTE_ORDER and possibly __FLOAT_WORD_ORDER.
* string/Makefile: Install bits/endianness.h.
* include/bits/endian.h: New wrapper.
* bits/endian.h: Rename to bits/endianness.h.
Add multiple-include guard. Rewrite the comment explaining what
the machine-specific variants of this file should do.
* sysdeps/unix/sysv/linux/ia64/bits/endian.h:
Move to sysdeps/ia64.
* sysdeps/aarch64/bits/endian.h
* sysdeps/alpha/bits/endian.h
* sysdeps/arm/bits/endian.h
* sysdeps/csky/bits/endian.h
* sysdeps/hppa/bits/endian.h
* sysdeps/ia64/bits/endian.h
* sysdeps/m68k/bits/endian.h
* sysdeps/microblaze/bits/endian.h
* sysdeps/mips/bits/endian.h
* sysdeps/nios2/bits/endian.h
* sysdeps/powerpc/bits/endian.h
* sysdeps/riscv/bits/endian.h
* sysdeps/s390/bits/endian.h
* sysdeps/sh/bits/endian.h
* sysdeps/sparc/bits/endian.h
* sysdeps/x86/bits/endian.h:
Rename to endianness.h; canonicalize form of file; remove
redundant definitions of __FLOAT_WORD_ORDER.
* sysdeps/powerpc/bits/endianness.h: Remove logic to check for
broken compilers.
* ctype/ctype.h
* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
* sysdeps/csky/nptl/bits/pthreadtypes-arch.h
* sysdeps/ia64/ieee754.h
* sysdeps/ieee754/ieee754.h
* sysdeps/ieee754/ldbl-128/ieee754.h
* sysdeps/ieee754/ldbl-128ibm/ieee754.h
* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
* sysdeps/mips/ieee754/ieee754.h
* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
* sysdeps/nptl/pthread.h
* sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
* sysdeps/sparc/sparc32/ieee754.h
* sysdeps/unix/sysv/linux/generic/bits/stat.h
* sysdeps/unix/sysv/linux/generic/bits/statfs.h
* sysdeps/unix/sysv/linux/sys/acct.h
* wctype/bits/wctype-wchar.h:
Include bits/endian.h, not endian.h.
* sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h.
* sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__
in ifdefs, instead of LDBL_MANT_DIG. Only include float.h
when __LDBL_MANT_DIG__ is not predefined, in which case
define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.
Use macro _HP_TIMING_S390_H instead of _HP_TIMING_H
in s390 specific hp-timing.h
ChangeLog:
* sysdeps/s390/hp-timing.h (_HP_TIMING_H): Undefine.
(_HP_TIMING_S390_H): Define.
This patch adds support for HP_TIMING_NOW if we build at least
with -march=z10 -mzarch. Otherwise we are still using the
generic hp-timing.h.
ChangeLog:
* sysdeps/s390/hp-timing.h: New file.
This patch introduces the new arch13 ifunc variant for memmem.
For needles longer than 9 bytes it is relying on the common-code
implementation. For shorter needles it is using the new vstrs instruction
which is able to search a substring within a vector register.
ChangeLog:
* sysdeps/s390/Makefile (sysdep_routines): Add memmem-arch13.
* sysdeps/s390/ifunc-memmem.h (HAVE_MEMMEM_ARCH13, MEMMEM_ARCH13,
MEMMEM_Z13_ONLY_USED_AS_FALLBACK, HAVE_MEMMEM_IFUNC_AND_ARCH13_SUPPORT):
New defines.
* sysdeps/s390/memmem-arch13.S: New file.
* sysdeps/s390/memmem-vx.c: Omit GI symbol for z13 memmem ifunc variant
if it is only used as fallback.
* sysdeps/s390/memmem.c (memmem): Add arch13 variant in ifunc selector.
* sysdeps/s390/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add ifunc variant for arch13 memmem.
This patch introduces the new arch13 ifunc variant for strstr.
For needles longer than 9 charachters it is relying on the common-code
implementation. For shorter needles it is using the new vstrs instruction
which is able to search a substring within a vector register.
ChangeLog:
* sysdeps/s390/Makefile (sysdep_routines): Add strstr-arch13.
* sysdeps/s390/ifunc-strstr.h (HAVE_STRSTR_ARCH13, STRSTR_ARCH13,
STRSTR_Z13_ONLY_USED_AS_FALLBACK, HAVE_STRSTR_IFUNC_AND_ARCH13_SUPPORT):
New defines.
* sysdeps/s390/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add ifunc variant for arch13 strstr.
* sysdeps/s390/strstr-arch13.S: New file.
* sysdeps/s390/strstr-vx.c: Omit GI symbol for z13 strstr ifunc variant
if it is only used as fallback.
* sysdeps/s390/strstr.c (strstr): Add arch13 variant in ifunc selector.
This patch introduces the new arch13 ifunc variant for memmove.
For the forward or non-overlapping case it is just using memcpy.
For the backward case it relies on the new instruction mvcrl.
The instruction copies up to 256 bytes at once.
In case of an overlap, it copies the bytes like copying them
one by one starting from right to left.
ChangeLog:
* sysdeps/s390/ifunc-memcpy.h (HAVE_MEMMOVE_ARCH13, MEMMOVE_ARCH13
HAVE_MEMMOVE_IFUNC_AND_ARCH13_SUPPORT): New defines.
* sysdeps/s390/memcpy-z900.S: Add arch13 memmove implementation.
* sysdeps/s390/memmove.c (memmove): Add arch13 variant in
ifunc selector.
* sysdeps/s390/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add ifunc variant for arch13 memmove.
* sysdeps/s390/multiarch/ifunc-resolve.h (S390_STFLE_BITS_ARCH13_MIE3,
S390_IS_ARCH13_MIE3): New defines.
Add two configure checks which detect if arch13 is supported
by the assembler at all - by explicitely setting the machine -
and if it is supported with default settings.
ChangeLog:
* config.h.in (HAVE_S390_MIN_ARCH13_ZARCH_ASM_SUPPORT,
HAVE_S390_ARCH13_ASM_SUPPORT): New undefine.
* sysdeps/s390/configure.ac: Add checks for arch13 support.
* sysdeps/s390/configure: Regenerated.
This patch adds vx and vxe as important hwcaps
which allows one to provide shared libraries
tuned for platforms with non-vx/-vxe, vx or vxe.
ChangeLog:
* sysdeps/s390/dl-procinfo.h (HWCAP_IMPORTANT):
Add HWCAP_S390_VX and HWCAP_S390_VXE.
The stub implementations are turned into compat symbols.
Linux actually has two reserved system call numbers (for getpmsg
and putpmsg), but these system calls have never been implemented,
and there are no plans to implement them, so this patch replaces
the wrappers with the generic stubs.
According to <https://bugzilla.redhat.com/show_bug.cgi?id=436349>,
the presence of the XSI STREAMS declarations is a minor portability
hazard because they are not actually implemented.
This commit does not change the TIRPC support code in
sunrpc/rpc_svcout.c. It uses additional XTI functionality and
therefore never worked with glibc.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Set the default function alignment to 16 bytes in order to
get rid of some unwanted performance effects.
Please see also GCC commit "S/390: Set default function
alignment to 16." (Subversion revision 262817)
ChangeLog:
* sysdeps/s390/s390-64/sysdep.h(ENTRY): Use alignment of 16byte.
* sysdeps/s390/s390-32/sysdep.h: Likewise.
The recent commit 81a1443941
has introduced __wcscpy, __GI___wcscpy and the weak alias wcscpy.
This patch also introduces those symbols if glibc is build
with CFLAGS="-march=z13" where the ifunc is omitted.
ChangeLog:
* sysdeps/s390/wcscpy-vx.S: Add strong aliases to
__wcscpy, __GI___wcscpy and weak alias to wcscpy.
This patch rewrites wcscat using wcslen and wcscpy. This is similar to
the optimization done on strcat by 6e46de42fe.
The strcpy changes are mainly to add the internal alias to avoid PLT
calls.
Checked on x86_64-linux-gnu and a build against the affected
architectures.
* include/wchar.h (__wcscpy): New prototype.
* sysdeps/powerpc/powerpc32/power4/multiarch/wcscpy-ppc32.c
(__wcscpy): Route internal symbol to generic implementation.
* sysdeps/powerpc/powerpc32/power4/multiarch/wcscpy.c (wcscpy):
Add internal __wcscpy alias.
* sysdeps/powerpc/powerpc64/multiarch/wcscpy.c (wcscpy): Likewise.
* sysdeps/s390/wcscpy.c (wcscpy): Likewise.
* sysdeps/x86_64/multiarch/wcscpy.c (wcscpy): Likewise.
* wcsmbs/wcscpy.c (wcscpy): Add
* sysdeps/x86_64/multiarch/wcscpy-c.c (WCSCPY): Adjust macro to
use generic implementation.
* wcsmbs/wcscat.c (wcscat): Rewrite using wcslen and wcscpy.
This patch fixes -Wimplicit-fallthrough warnings in system-specific
code that show up building glibc with -Wextra, by adding fall-through
comments, or moving existing such comments to the place required for
them to work (immediately before the case label being fallen through).
Tested with build-many-glibcs.py.
* sysdeps/i386/dl-machine.h (elf_machine_rela): Add fall-through
comments.
* sysdeps/m68k/m680x0/fpu/s_cexp_template.c (s(__cexp)): Likewise.
* sysdeps/m68k/memcopy.h (WORD_COPY_FWD): Likewise.
(WORD_COPY_BWD): Likewise.
* sysdeps/mach/hurd/ioctl.c (__ioctl): Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela):
Likewise.
* sysdeps/s390/iso-8859-1_cp037_z900.c (TR_LOOP): Likewise.
* sysdeps/mips/dl-machine.h (elf_machine_reloc): Move fall-through
comment.
* sysdeps/mips/dl-trampoline.c (__dl_runtime_resolve): Likewise.
The recent commit 65f7767a91
has introduced __wmemcmp and the weak alias wmemcmp.
This patch also introduces those symbols if glibc is build
with CFLAGS="-march=z13" where the ifunc is omitted.
ChangeLog:
* sysdeps/s390/wmemcmp-vx.S: Add strong alias to
__wmemcmp and weak alias to wmemcmp.
This fixes the same bug in fnmatch that was fixed by commit 7e2f0d2d77 for
regexp matching. As a side effect it also removes the use of an unbound
VLA.
The ifunc macros s390_vx_libc* are no longer used and
can be removed as all users are now relying on
s390_libc_ifunc_expr.
The same applies to s390_libc_ifunc. The macro
s390_libc_ifunc_init is now renamed to
s390_libc_ifunc_expr_stfle_init and the users are
adjusted accordingly.
ChangeLog:
* sysdeps/s390/multiarch/ifunc-resolve.h
(s390_vx_libc_ifunc, s390_vx_libc_ifunc_redirected,
s390_vx_libc_ifunc2, s390_vx_libc_ifunc_init,
s390_vx_libc_ifunc2_redirected, s390_libc_ifunc):
Delete macro definition.
(s390_libc_ifunc_init): Rename to
s390_libc_ifunc_expr_stfle_init.
* sysdeps/s390/bzero: Use
s390_libc_ifunc_expr_stfle_init instead of
s390_libc_ifunc_init.
* sysdeps/s390/memcmp.c: Likewise.
* sysdeps/s390/memcpy.c: Likewise.
* sysdeps/s390/mempcpy.c: Likewise.
* sysdeps/s390/memset.c: Likewise.
The ifunc handling for various __gconv_transform_* functions
which are using IFUNC on s390x are adjusted in order to omit ifunc
if the minimum architecture level already supports newer CPUs by default.
Instead those functions are just an alias to the vector variants.
Furthermore the ifunc-macro s390_libc_ifunc_expr is now used instead of
s390_vx_libc_ifunc.
ChangeLog:
* sysdeps/s390/multiarch/gconv_simple.c (ICONV_VX_IFUNC):
Define macro dependent on HAVE_S390_MIN_Z13_ZARCH_ASM_SUPPORT.
