On platforms where long double has IEEE binary128 format as a third
option (initially, only powerpc64le), many exported functions are
redirected to their __*ieee128 equivalents. This redirection is
provided by installed headers such as stdio-ldbl.h, and is supposed to
work correctly with user code.
However, during the build of glibc, similar redirections are employed,
in internal headers, such as include/stdio.h, in order to avoid extra
PLT entries. These redirections conflict with the redirections to
__*ieee128, and must be avoided during the build. This patch protects
the second redirections with a test for __LONG_DOUBLE_USES_FLOAT128, a
new macro that is defined to 1 when functions that deal with long double
typed values reuses the _Float128 implementation (this is currently only
true for powerpc64le).
Tested for powerpc64le, x86_64, and with build-many-glibcs.py.
Co-authored-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Add a new macro __STATFS_MATCHES_STATFS64 that specifies if fsblkcnt_t
matches fsblkcnt64_t and if fsfilcnt_t matches fsfilcnt64_t.
As we don't have the padding we also need to update the overflow checker
to not access the undefined members.
Commit 7532837d7b ("The
-Wstringop-truncation option new in GCC 8 detects common misuses")
added __attribute_nonstring__ to bits/utmp.h, but it did not update
the parallel bits/utmpx.h header. In struct utmp, the nonstring
attribute for ut_id was missing.
C2X (current version in git, postdating the most recent public draft
available as a PDF on the WG14 website) adds the interfaces from TS
18661-4, other than the reduction functions, as unconditionally
required and visible in <math.h> for hosted implementations; the
__STDC_WANT_IEC_60559_FUNCS_EXT__ macro is not included in C2X at all
(as the reduction functions aren't included at all, expected to end up
in a version of the TS updated to be relative to C2X).
This patch updates the glibc headers accordingly, following the same
pattern used for 18661-1 functions. As the only 18661-4 functions
currently supported are the exp10 functions that have been in glibc
for a very long time, this means that in fact __GLIBC_USE
(IEC_60559_FUNCS_EXT) ends up being used only to determine the
definition of __GLIBC_USE_IEC_60559_FUNCS_EXT_C2X, not yet in any
headers other than bits/libc-header-start.h.
(I hope to add the other 18661-4 functions to glibc at some point; the
main complication is the current lack of MPFR support for many of
these functions.)
Tested for x86_64.
* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_FUNCS_EXT):
Update comment.
(__GLIBC_USE_IEC_60559_FUNCS_EXT_C2X): New macro.
* bits/math-finite.h [__GLIBC_USE (IEC_60559_FUNCS_EXT)]: Change
to [__GLIBC_USE (IEC_60559_FUNCS_EXT_C2X)].
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_FUNCS_EXT)]:
Likewise.
The tgkill function is sometimes used in crash handlers.
<bits/signal_ext.h> follows the same approach as <bits/unistd_ext.h>
(which was added for the gettid system call wrapper).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
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>
sysdeps/ia64/fpu/bits/math-finite.h exists and will be installed on
ia64, but during the build, the default math/bits/math-finite.h file
is used, which is wrong.
Fixes commit 0ac5ae2335 ("Optimize
libm").
No functional change; the previous path worked as well, but it
re-added the obsolete sysdeps/generic/bits directory, which was
removed (for the first time) in commit
c72565e5f1.
Fixes commit e47d82c99a ("Provide
<bits/unistd_ext.h> as a sysdeps header exclusively").
glibc support for 64-bit time_t on 32-bit architectures
will involve:
- Using 64-bit times inside glibc, with conversions
to and from 32-bit times taking place as necessary
for interfaces using such times.
- Adding 64-bit-time support in the glibc public API.
This support should be dynamic, i.e. glibc should
provide both 32-bit and 64-bit implementations and
let user code choose at compile time whether to use
the 32-bit or 64-bit interfaces.
This requires a glibc-internal name for a type for times
that are always 64-bit.
Based on __TIMESIZE, a new macro is defined, __TIME64_T_TYPE,
which is always the right __*_T_TYPE to hold a 64-bit-time.
__TIME64_T_TYPE equals __TIME_T_TYPE if __TIMESIZE equals 64
and equals __SQUAD_T_TYPE otherwise.
__time64_t can then replace uses of internal_time_t.
This patch was tested by running 'make check' on branch
master then applying this patch and its predecessor and
running 'make check' again, and checking that both 'make
check' yield identical results. This was done on
x86_64-linux-gnu and i686-linux-gnu.
* bits/time64.h: New file.
* include/time.h: Replace internal_time_t with __time64_t.
* posix/bits/types (__time64_t): Add.
* stdlib/Makefile: Add bits/time64.h to includes.
* time/tzfile.c: Replace internal_time_t with __time64_t.
To determine whether the default time_t interfaces are 32-bit
and so need conversions, or are 64-bit and so are compatible
with the internal 64-bit type without conversions, a macro
giving the size of the default time_t is also required.
This macro is called __TIMESIZE.
This macro can then be used instead of __WORDSIZE in msq-pad.h
and shm-pad.h files, which in turn allows removing their x86
variants, and in sem-pad.h files but keeping the x86 variant.
This patch was tested by running 'make check' on branch master
then applying this patch and running 'make check' again, and
checking that both 'make check' yield identical results.
This was done on x86_64-linux-gnu and i686-linux-gnu.
* bits/timesize.h: New file.
* stdlib/Makefile (headers): Add bits/timesize.h.
* sysdeps/unix/sysv/linux/bits/msq-pad.h
(__MSQ_PAD_AFTER_TIME): Use __TIMESIZE instead of __WORDSIZE.
* sysdeps/unix/sysv/linux/bits/sem-pad.h
(__SEM_PAD_AFTER_TIME): Likewise.
* sysdeps/unix/sysv/linux/bits/shm-pad.h
(__SHM_PAD_AFTER_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
* sysdeps/unix/sysv/linux/mips/bits/msq-pad.h
(__MSQ_PAD_AFTER_TIME, __MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/x86/bits/msq-pad.h: Delete file.
* sysdeps/unix/sysv/linux/x86/bits/shm-pad.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/timesize.h: New file.
Add <bits/indirect-return.h> and include it in <ucontext.h>.
__INDIRECT_RETURN defined in <bits/indirect-return.h> indicates if
swapcontext requires special compiler treatment. The default
__INDIRECT_RETURN is empty.
On x86, when shadow stack is enabled, __INDIRECT_RETURN is defined
with indirect_return attribute, which has been added to GCC 9, to
indicate that swapcontext returns via indirect branch. Otherwise
__INDIRECT_RETURN is defined with returns_twice attribute.
When shadow stack is enabled, remove always_inline attribute from
prepare_test_buffer in string/tst-xbzero-opt.c to avoid:
tst-xbzero-opt.c: In function ‘prepare_test_buffer’:
tst-xbzero-opt.c:105:1: error: function ‘prepare_test_buffer’ can never be inlined because it uses setjmp
prepare_test_buffer (unsigned char *buf)
when indirect_return attribute isn't available.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* bits/indirect-return.h: New file.
* misc/sys/cdefs.h (__glibc_has_attribute): New.
* sysdeps/x86/bits/indirect-return.h: Likewise.
* stdlib/Makefile (headers): Add bits/indirect-return.h.
* stdlib/ucontext.h: Include <bits/indirect-return.h>.
(swapcontext): Add __INDIRECT_RETURN.
* string/tst-xbzero-opt.c (ALWAYS_INLINE): New.
(prepare_test_buffer): Use it.
When compiling C++ code with -mabi=ieeelongdouble, KCtype is
unavailable and the long double type should be used instead.
This is also providing macro __HAVE_FLOAT128_UNLIKE_LDBL in order to
identify the kind of long double type is being used in the current
compilation unit.
Notice that bits/floatn.h cannot benefit from the new macro due to order
of header inclusion.
* bits/floatn-common.h: Define __HAVE_FLOAT128_UNLIKE_LDBL.
* math/math.h: Restrict the prototype definition for the functions
issignaling(_Float128) and iszero(_Float128); and template
__iseqsig_type<_Float128>, from __HAVE_DISTINCT_FLOAT128 to
__HAVE_FLOAT128_UNLIKE_LDBL.
* sysdeps/powerpc/bits/floatn.h [__HAVE_FLOAT128
&& (!__GNUC_PREREQ (7, 0) || defined __cplusplus)
&& __LDBL_MANT_DIG__ == 113]: Use long double suffix for
__f128() constants; define the type _Float128 as long double;
and reuse long double in __CFLOAT128.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
As for sysctl, ustat has been deprecated in favor of {f}statfs. Also
some newer ports which uses generic interface builds a stub version that
returns ENOSYS.
This patch deprecates ustat interface by removing ustat.h related headers,
adding a compatibility symbol, and avoiding new ports to build and provide
the symbol.
Checked on x86_64-linux-gnu and i686-linux-gnu. Also checked with a
check-abi on all affected ABIs.
* NEWS: Add ustat.h deprecation entry.
* bits/ustat.h: Remove file.
* misc/sys/ustat.h: Likewise.
* misc/ustat.h: Likewise.
* sysdeps/unix/sysv/linux/generic/ustat.c: Likewise.
* misc/Makefile (headers): Remove ustat.h and sys/ustat.h.
* misc/ustat.c (__ustat): Rename to __old_ustat and export only in
compatibility mode.
* sysdeps/unix/sysv/linux/ustat.c (__ustat): Likewise.
* sysdeps/unix/sysv/linux/mips/ustat.c: Define DEV_TO_KDEV and use
generic Linux implementation.
* bits/sched.h: Include <bits/types/struct_sched_param.h> and move struct
sched_param definition to it.
* sysdeps/unix/sysv/linux/bits/sched.h: Likewise.
* bits/types/struct_sched_param.h: New file.
* sysdeps/htl/bits/types/struct___pthread_attr.h: Include
<bits/types/struct_sched_param.h> instead of <sched.h>.
* posix/Makefile (headers): Add bits/types/struct_sched_param.h.
* bits/in.h [!__USE_MISC]: Do not define struct ip_opts.
* conform/data/netinet/in.h-data: Allow sin_ and sin6_ prefix.
* sysdeps/gnu/bits/msq.h (struct msqid_ds): Use __wait_queue struct
instead of wait_queue.
* sysdeps/gnu/bits/shm.h (struct shmid_ds): Use __vm_area_struct
instead of vm_area_struct.
This patch defines _DIRENT_MATCHES_DIRENT64 to either 0 or 1 and adjust its
usage from checking its definition to its value.
Checked on a build for major Linux abis.
* bits/dirent.h (__INO_T_MATCHES_INO64_T): Define regardless whether
__INO_T_MATCHES_INO64_T is defined.
* sysdeps/unix/sysv/linux/bits/dirent.h: Likewise.
* dirent/alphasort.c: Check _DIRENT_MATCHES_DIRENT64 value instead
of definition.
* dirent/alphasort64.c: Likewise.
* dirent/scandir.c: Likewise.
* dirent/scandir64-tail.c: Likewise.
* dirent/scandir64.c: Likewise.
* dirent/scandirat.c: Likewise.
* dirent/scandirat64.c: Likewise.
* dirent/versionsort.c: Likewise.
* dirent/versionsort64.c: Likewise.
* include/dirent.h: Likewise.
so interfaces needing it can get it.
* stdlib/errno.h (error_t): Move definition to...
* bits/types/error_t.h: ... new header.
* stdlib/Makefile (headers): Add bits/types/error_t.h.
* sysdeps/mach/hurd/bits/errno.h (error_t): Move definition to...
* sysdeps/mach/hurd/bits/types/error_t.h: ... new header.
* sysdeps/mach/hurd/errnos.awk (error_t): Likewise.
* hurd/hurd.h: Include <bits/types/error_t.h>
* hurd/hurd/fd.h: Include <bits/types/error_t.h>
* hurd/hurd/id.h: Include <errno.h> and <bits/types/error_t.h>
* hurd/hurd/lookup.h: Include <errno.h> and <bits/types/error_t.h>
* hurd/hurd/resource.h: Include <bits/types/error_t.h>
* hurd/hurd/signal.h: Include <bits/types/error_t.h>
* hurd/hurd/sigpreempt.h: Include <bits/types/error_t.h>
Nearly everything in _G_config.h is either junk or more appropriately
defined elsewhere:
* _G_fpos_t, _G_fpos64_t, and _G_BUFSIZ are already completely unused.
* All remaining uses of _G_va_list have been changed to __gnuc_va_list.
* The definition of _G_HAVE_ST_BLKSIZE/_IO_HAVE_ST_BLKSIZE has
been inlined into its sole use.
* The complete definition of _G_iconv_t has been moved to libio.h and
renamed _IO_iconv_t (all actual users used that name).
* _G_IO_IO_FILE_VERSION is vestigial; some code cares whether
_IO_stdin_used exists, but nothing looks at its value. I've
preserved the value as a hardwired constant in csu/init.c.
This means csu/init.c no longer needs to include anything.
* Many of the headers included by _G_config.h were already being
included directly by either either libio.h or stdio.h; the
remaining ones were moved to libio.h.
* _G_HAVE_MREMAP is still relevant, because mremap genuinely is a
Linux extension; it's not in POSIX and as far as I can tell it's
not available on the Hurd either. I also preserved _G_HAVE_MMAP,
since it's conceivable someone would want to port glibc to a
MMU-less, mmap-less environment in the future. Both are now always
defined to 1/0 as is the current convention, instead of the older
1/undef convention. These are the only symbols still defined in
_G_config.h.
* The actual inclusion of _G_config.h moves from libio.h to libioP.h,
as this is where a potential override of _G_HAVE_MMAP happens.
* The #ifdef logic in libioP.h controlling _IO_JUMPS_OFFSET has been
simplified.
After this patch, the only surviving _G_ symbols are the struct tag
names _G_fpos_t and _G_fpos64_t, which are preserved for the sake of
C++ mangled names in applications, and _G_HAVE_MMAP and _G_HAVE_MREMAP,
which do not seem worth renaming.
Installed stripped libraries are unchanged by this patch.
* bits/_G_config.h: Move back to sysdeps/generic/_G_config.h.
Delete all contents except for definitions of _G_HAVE_MMAP and
_G_HAVE_MREMAP. Add commentary explaining those two symbols.
* sysdeps/unix/sysv/linux/bits/_G_config.h: Move back to
sysdeps/unix/sysv/linux/_G_config.h. Make same content
change as above.
* libio/libio.h: Don't include bits/_G_config.h here.
Include stddef.h with __need_wchar_t defined. Include
bits/types/__mbstate_t.h, bits/types/wint_t.h, and gconv.h.
Define _IO_iconv_t here, directly.
Don't define _IO_HAVE_ST_BLKSIZE.
* libio/libioP.h: Include _G_config.h here. Move include of
shlib-compat.h up with rest of includes. Simplify conditionals
controlling definition of _IO_JUMPS_OFFSET.
* csu/init.c: Remove always-true #if around entire file.
Don't include stdio.h. Set _IO_stdin_used to hardwired
constant 0x20001, and update commentary.
* include/stdio.h, sysdeps/ieee754/ldbl-opt/nldbl-compat.h:
Replace all uses of _G_va_list with __gnuc_va_list.
* libio/filedoalloc.c: Use #if defined _STATBUF_ST_BLKSIZE
instead of #if _IO_HAVE_ST_BLKSIZE.
* libio/fileops.c: Test _G_HAVE_MREMAP with #if, not #ifdef.
* libio/iofdopen.c, libio/iofopen.c: Test _G_HAVE_MMAP with #if,
not #ifdef.
We shipped 2.27 with libio.h and _G_config.h still installed but
issuing warnings when used. Let's stop installing them early in 2.28
so that we have plenty of time to think of another plan if there are
problems.
The public stdio.h had a genuine dependency on libio.h for the
complete definitions of FILE and cookie_io_functions_t, and a genuine
dependency on _G_config.h for the complete definitions of fpos_t and
fpos64_t; these are moved to single-type headers.
bits/types/struct_FILE.h also provides a handful of accessor and
bitflags macros so that code is not duplicated between bits/stdio.h
and libio.h. All the other _IO_ and _G_ names used by the public
stdio.h can be replaced with either public names or __-names.
In order to minimize the risk of breaking our own compatibility code,
bits/types/struct_FILE.h preserves the _IO_USE_OLD_IO_FILE mechanism
exactly as it was in libio.h, but you have to define _LIBC to use it,
or it'll error out. Similarly, _IO_lock_t_defined is preserved
exactly, but will error out if used without defining _LIBC.
Internally, include/stdio.h continues to include libio.h, and libio.h
scrupulously provides every _IO_* and _G_* name that it always did,
perhaps now defined in terms of the public names. This is how this
patch avoids touching dozens of files throughout glibc and becoming
entangled with the _IO_MTSAFE_IO mess. The remaining patches in this
series eliminate most of the _G_ names.
Tested on x86_64-linux; in addition to the test suite, I installed the
library in a sysroot and verified that a simple program that uses
stdio.h could be compiled against the installed library, and I also
verified that installed stripped libraries are unchanged.
* libio/bits/types/__fpos_t.h, libio/bits/types/__fpos64_t.h:
New single-type headers split from _G_config.h.
* libio/bits/types/cookie_io_functions_t.h
* libio/bits/types/struct_FILE.h
New single-type headers split from libio.h.
* libio/Makefile: Install the above new headers. Don't install
libio.h, _G_config.h, bits/libio.h, bits/_G_config.h, or
bits/libio-ldbl.h.
* libio/_G_config.h, libio/libio.h: Delete file.
* libio/bits/libio.h: Remove improper-inclusion guard.
Include stdio.h and don't repeat anything that it does.
Define _IO_fpos_t as __fpos_t, _IO_fpos64_t as __fpos64_t,
_IO_BUFSIZ as BUFSIZ, _IO_va_list as __gnuc_va_list,
__io_read_fn as cookie_read_function_t,
__io_write_fn as cookie_write_function_t,
__io_seek_fn as cookie_seek_function_t,
__io_close_fn as cookie_close_function_t,
and _IO_cookie_io_functions_t as cookie_io_functions_t.
Define _STDIO_USES_IOSTREAM, __HAVE_COLUMN, and _IO_file_flags
here, in the "compatibility defines" section. Remove an #if 0
block. Use the "body" macros from bits/types/struct_FILE.h to
define _IO_getc_unlocked, _IO_putc_unlocked, _IO_feof_unlocked,
and _IO_ferror_unlocked.
Move prototypes of __uflow and __overflow...
* libio/stdio.h: ...here. Don't include bits/libio.h.
Don't define _STDIO_USES_IOSTREAM. Get __gnuc_va_list
directly from stdarg.h. Include bits/types/__fpos_t.h,
bits/types/__fpos64_t.h, bits/types/struct_FILE.h,
and, when __USE_GNU, bits/types/cookie_io_functions_t.h.
Use __gnuc_va_list, not _G_va_list; __fpos_t, not _G_fpos_t;
__fpos64_t, not _G_fpos64_t; FILE, not struct _IO_FILE;
cookie_io_functions_t, not _IO_cookie_io_functions_t;
__ssize_t, not _IO_ssize_t. Unconditionally define
BUFSIZ as 8192 and EOF as (-1).
* libio/bits/stdio.h: Add multiple-include guard. Use the "body"
macros from bits/types/struct_FILE.h instead of _IO_* macros
from libio.h; use __gnuc_va_list instead of va_list and __ssize_t
instead of _IO_ssize_t.
* libio/bits/stdio2.h: Similarly.
* libio/iolibio.h: Add multiple-include guard.
Include bits/libio.h after stdio.h.
* libio/libioP.h: Add multiple-include guard.
Include stdio.h and bits/libio.h before iolibio.h.
* include/bits/types/__fpos_t.h, include/bits/types/__fpos64_t.h
* include/bits/types/cookie_io_functions_t.h
* include/bits/types/struct_FILE.h: New wrappers.
* bits/_G_config.h, sysdeps/unix/sysv/linux/_G_config.h:
Get definitions of _G_fpos_t and _G_fpos64_t from
bits/types/__fpos_t.h and bits/types/__fpos64_t.h
respectively. Remove improper-inclusion guards.
* conform/data/stdio.h-data: Update expectations of va_list.
* scripts/check-installed-headers.sh: Remove special case for
libio.h and _G_config.h.
We have a general principle of preferring optimizations for library
facilities to use compiler built-in functions rather than being
located in library headers, where the compiler can reasonably optimize
code without needing to know glibc implementation details.
This patch applies this principle to bits/byteswap.h, eliminating all
the architecture-specific variants and bits/byteswap-16.h. The
__bswap_16, __bswap_32 and __bswap_64 interfaces all become inline
functions, never macros, using the GCC built-in functions where
available and otherwise a single architecture-independent definition
using shifts and masking (which compilers may well be able to detect
and optimize; GCC has detection of various byte-swapping idioms).
The __bswap_constant_32 macro needs to stay around because of uses in
static initializers within glibc and its tests, and so for consistency
all __bswap_constant_* are kept rather than just being inlined into
the old-GCC-or-non-GCC parts of the __bswap_* inline function
definitions.
Various open bugs are addressed by this cleanup, with caveats about
exactly what is covered by those bugs and when the bugs applied at
all.
Bug 14508 reports -Wformat warnings building glibc because __bswap_*
sometimes returned the wrong types. Obviously we already don't have
such warnings any more or the build would be failing, given -Werror,
and I suspect that bug was originally for wrong types for x86_64, as
fixed by commit d394eb742a (glibc 2.17).
The only case I saw removed by this patch where the types would still
have been wrong was the non-__GNUC__ case of __bswap_64 in the s390
header (using unsigned long long int, but uint64_t would be unsigned
long int for 64-bit). In any case, the single header consistently
uses __uintN_t types after this patch, thereby eliminating all such
bugs. The existing string/test-endian-types.c test already suffices
to verify that the types are correct with the compiler used to build
glibc and its tests.
Bug 15512 reports an error from __bswap_constant_16 with -Werror
-Wsign-conversion. I am unable to reproduce this with any GCC version
supporting -Wsign-conversion - all seem to be able to avoid warning
for ((x) >> 8) & 0xffu, where x is uint16_t, which while it formally
does involve an implicit conversion from int to unsigned int, is also
a case where it should be easy for the compiler to see that the value
converted is never negative. But in this patch __bswap_constant_16 is
changed to use signed 0xff so that no such implicit conversion occurs
at all, and a test with -Werror -Wsign-conversion is added.
Bug 17082 objects to the use of ({}) statement expressions in these
macros preventing use at file scope (in C, that's in sizeof etc.; in
C++, more generally in static initializers). The particular case of
these interfaces is fixed by this patch as it changes them to inline
functions, eliminating all uses of ({}) in bits/byteswap.h, and a
corresponding testcase is added. The bug tries to raise a more
general policy question about use of ({}) in macros in installed
headers, referring to "many other libc functions" (unspecified which
functions are being considered).
Since such policy questions belong on libc-alpha, and since there
*are* macros in installed headers which can't really avoid using ({})
(where they are type-generic, so can't use an inline function, but
need a temporary variable, and a few where the interface involves
returning memory from alloca so can't use an inline function either),
I propose to consider that bug fixed with this change. That is
without prejudice to any other new bugs anyone wishes to file *for
precisely defined sets of macros* requesting moving away from ({})
*where it is clearly possible for those interfaces*. Where ({}) can
be avoided, typically by use of an inline function, I think that's a
good idea - that inline functions are typically to be preferred to
({}) for header interfaces where such optimizations are useful but the
interface is suited to being defined using an inline function.
Bug 20530 requests use of __builtin_bswap16 when available (GCC 4.8
and later), which this patch implements.
Tested for x86_64, and with build-many-glibcs.py. Also did an x86_64
test with the __GNUC_PREREQ conditionals changed to "#if 0" to verify
the old-GCC/non-GCC case in the headers. (There are already existing
tests for correctness of results of these interfaces.)
[BZ #14508]
[BZ #15512]
[BZ #17082]
[BZ #20530]
* bits/byteswap.h: Update file comment. Do not include
<bits/byteswap-16.h>.
(__bswap_constant_16): Cast result to __uint16_t. Use signed 0xff
constant.
(__bswap_16): Define as inline function.
(__bswap_constant_32): Reformat definition.
(__bswap_32): Always define as inline function, not macro, using
__uint32_t. Use __builtin_bswap32 if [__GNUC_PREREQ (4, 3)],
otherwise __bswap_constant_32.
(__bswap_constant_64): Reformat definition. Do not use
__extension__ here.
(__bswap_64): Always define as inline function, not macro. Use
__extension__ on function definition. Use __builtin_bswap64 if
[__GNUC_PREREQ (4, 3)], otherwise __bswap_constant_64.
* string/test-endian-file-scope.c: New file.
* string/test-endian-sign-conversion.c: Likewise.
* string/Makefile (headers): Remove bits/byteswap-16.h.
(tests): Add test-endian-file-scope and
test-endian-sign-conversion.
(CFLAGS-test-endian-sign-conversion.c): New variable.
* bits/byteswap-16.h: Remove file.
* sysdeps/ia64/bits/byteswap-16.h: Likewise.
* sysdeps/ia64/bits/byteswap.h: Likewise.
* sysdeps/m68k/bits/byteswap.h: Likewise.
* sysdeps/s390/bits/byteswap-16.h: Likewise.
* sysdeps/s390/bits/byteswap.h: Likewise.
* sysdeps/tile/bits/byteswap.h: Likewise.
* sysdeps/x86/bits/byteswap-16.h: Likewise.
* sysdeps/x86/bits/byteswap.h: Likewise.
In commit cba595c350 and commit
f81ddabffd, ABI compatibility with
applications was broken by increasing the size of the on-stack
allocated __pthread_unwind_buf_t beyond the oringal size.
Applications only have the origianl space available for
__pthread_unwind_register, and __pthread_unwind_next to use,
any increase in the size of __pthread_unwind_buf_t causes these
functions to write beyond the original structure into other
on-stack variables leading to segmentation faults in common
applications like vlc. The only workaround is to version those
functions which operate on the old sized objects, but this must
happen in glibc 2.28.
Thank you to Andrew Senkevich, H.J. Lu, and Aurelien Jarno, for
submitting reports and tracking the issue down.
The commit reverts the above mentioned commits and testing on
x86_64 shows that the ABI compatibility is restored. A tst-cleanup1
regression test linked with an older glibc now passes when run
with the newly built glibc. Previously a tst-cleanup1 linked with
an older glibc would segfault when run with an affected glibc build.
Tested on x86_64 with no regressions.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
libio.h was originally the header for a set of supported GNU
extensions, but they have not been maintained as such in many years,
they are now standing in the way of improvements to stdio, and we
don't think there are any remaining external users. _G_config.h was
never intended for public use, but predates the bits convention.
Move both of these headers into the bits directory and provide stubs
at top level which issue deprecation warnings.
The contents of (bits/)libio.h and (bits/)_G_config.h are still
exposed to external software via stdio.h; changing that requires more
complex surgery than I have time to attempt right now.
* libio/libio.h, libio/_G_config.h: New stub headers which issue a
deprecation warning and then include <bits/libio.h>, <bits/_G_config.h>
respectively.
* libio/libio.h: Rename the original version of this file to
libio/bits/libio.h. Error out if not included by stdio.h or the
stub libio.h.
* include/libio.h: Move to include/bits. Forward to libio/bits/libio.h.
* sysdeps/generic/_G_config.h: Move to top-level bits/. Error out
if not included by bits/libio.h or the stub _G_config.h.
* sysdeps/unix/sysv/linux/_G_config.h: Move to
sysdeps/unix/sysv/linux/bits. Error out if not included by
bits/libio.h or the stub _G_config.h.
* libio/stdio.h: Include bits/libio.h, not libio.h.
* libio/Makefile: Install bits/libio.h and bits/_G_config.h as
well as libio.h and _G_config.h.
* csu/init.c, libio/fmemopen.c, libio/iolibio.h, libio/oldfmemopen.c
* libio/strfile.h, stdio-common/vfscanf.c
* sysdeps/pthread/flockfile.c, sysdeps/pthread/funlockfile.c
Include stdio.h, not _G_config.h nor libio.h.
* libio/iofgetpos.c: Also rename fgetpos64 out of the way.
* libio/iofsetpos.c: Also rename fsetpos64 out of the way.
* scripts/check-installed-headers.sh: Skip libio.h and _G_config.h.
On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer
to support shadow stack in Intel Control-flow Enforcemen Technology.
Since the cancel_jmp_buf array is passed to setjmp and longjmp by
casting it to pointer to struct __jmp_buf_tag, it should be as large
as struct __jmp_buf_tag. Otherwise when shadow stack is enabled,
setjmp and longjmp will write and read beyond cancel_jmp_buf when saving
and restoring shadow stack pointer.
This patch adds bits/types/__cancel_jmp_buf_tag.h to define struct
__cancel_jmp_buf_tag so that Linux/x86 can add saved_mask to
cancel_jmp_buf.
Tested natively on i386, x86_64 and x32. Tested hppa-linux-gnu with
build-many-glibcs.py.
[BZ #22563]
* bits/types/__cancel_jmp_buf_tag.h: New file.
* sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h
* sysdeps/unix/sysv/linux/x86/pthreaddef.h: Likewise.
* sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h: Likewise.
* nptl/Makefile (headers): Add
bits/types/__cancel_jmp_buf_tag.h.
* nptl/descr.h [NEED_SAVED_MASK_IN_CANCEL_JMP_BUF]
(pthread_unwind_buf): Add saved_mask to cancel_jmp_buf.
* sysdeps/nptl/pthread.h: Include
<bits/types/__cancel_jmp_buf_tag.h>.
(__pthread_unwind_buf_t): Use struct __cancel_jmp_buf_tag with
__cancel_jmp_buf.
* sysdeps/unix/sysv/linux/hppa/pthread.h: Likewise.
This patch continues filling out TS 18661-3 support by adding *f64 and
*f32x function aliases, supporting _Float64 and _Float32x, as aliases
for double functions. These types are supported for all glibc
configurations. The API corresponds exactly to that for _Float128 and
_Float64x. _Float32 aliases to float functions remain to be added in
subsequent patches to complete this process (then there are a few
miscellaneous functions in TS 18661-3 to implement that aren't simply
versions of existing functions for new types).
The patch enables the feature in bits/floatn-common.h, adds symbol
versions and documentation with updates to ABI baselines, and arranges
for the libm functions for the new types to be tested. As with the
_Float64x changes there are some x86 ulps updates because of header
inlines not used for the new types (and one other change to the
non-multiarch libm-test-ulps, which I suppose comes from using a
different compiler version / configuration from when it was last
regenerated).
Tested for x86_64 and x86, and with build-many-glibcs.py, with both
GCC 6 and GCC 7.
* bits/floatn-common.h (__HAVE_FLOAT64): Define to 1.
(__HAVE_FLOAT32X): Likewise.
* manual/math.texi (Mathematics): Document support for _Float64
and _Float32x.
* math/Makefile (test-types): Add float64 and float32x.
* math/Versions (GLIBC_2.27): Add _Float64 and _Float32x
functions.
* stdlib/Versions (GLIBC_2.27): Likewise.
* wcsmbs/Versions (GLIBC_2.27): Likewise.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Likewise.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
If double, long double and _Float64 all have the same set of values,
TS 18661-3 requires the usual arithmetic conversions on long double
and _Float64 to produce _Float64. For this to be the case when
building with a compiler without a distinct _Float64 type, _Float64
must be a typedef for long double, not for double. (_Float32x,
however, must be double in such a case, not long double, because the
usual arithmetic conversions on _Float32x and double must produce
double.)
This patch adjusts the fallback definition of _Float64 and associated
macros accordingly in that case, to fix the build of test-tgmath3 with
GCC 6 for such a configuration. Tested in conjunction with _Float64
changes with build-many-glibcs.py for arm-linux-gnueabi, to make sure
the issue with test-tgmath3 is fixed. Also tested for x86_64.
* bits/floatn-common.h: Include <bits/long-double.h>.
[__HAVE_FLOAT64 && (!__GNUC_PREREQ (7, 0) || defined __cplusplus)
&& __NO_LONG_DOUBLE_MATH] (__f64): Use suffix 'l'.
[__HAVE_FLOAT64 && (!__GNUC_PREREQ (7, 0) || defined __cplusplus)
&& __NO_LONG_DOUBLE_MATH] (__CFLOAT64): Use _Complex long double.
[__HAVE_FLOAT64 && (!__GNUC_PREREQ (7, 0) || defined __cplusplus)
&& __NO_LONG_DOUBLE_MATH] (_Float64): Use long double.
[__HAVE_FLOAT64 && !__GNUC_PREREQ (7, 0) && __NO_LONG_DOUBLE_MATH]
(__builtin_huge_valf64): Use __builtin_huge_vall.
[__HAVE_FLOAT64 && !__GNUC_PREREQ (7, 0) && __NO_LONG_DOUBLE_MATH]
(__builtin_inff64): Use __builtin_infl.
[__HAVE_FLOAT64 && !__GNUC_PREREQ (7, 0) && __NO_LONG_DOUBLE_MATH]
(__builtin_nanf64): Use __builtin_nanl.
[__HAVE_FLOAT64 && !__GNUC_PREREQ (7, 0) && __NO_LONG_DOUBLE_MATH]
(__builtin_nansf64): Use __builtin_nansl.
This patch continues filling out TS 18661-3 support by adding *f64x
function aliases on platforms with _Float64x support. (It so happens
the set of such platforms is exactly the same as the set of platforms
with _Float128 support, although on x86_64, x86 and ia32 the _Float64x
format is Intel extended rather than binary128.) The API provided
corresponds exactly to that provided for _Float128, mostly coming from
TS 18661-3. As these functions always alias those for another type
(long double, _Float128 or both), __* function names are not provided,
as in other cases of alias types.
Given the preparation done in previous patches, this one just enables
the feature via Makeconfig and bits/floatn.h, adds symbol versions,
and updates documentation and ABI baselines. The symbol versions are
present unconditionally as GLIBC_2.27 in the relevant Versions files,
as it's OK for those to specify versions for functions that may not be
present in some configurations; no additional complexity is needed
unless in future some configuration gains support for this type that
didn't have such support in 2.27. The Makeconfig additions for ia64
and x86 aren't strictly needed, as those configurations also get
float64x-alias-fcts definitions from
sysdeps/ieee754/float128/Makeconfig, but still seem appropriate given
that _Float64x is not _Float128 for those configurations.
A libm-test-ulps update for x86 is included. This is because
bits/mathinline.h does not have _Float64x support added and for two
functions the use of out-of-line functions results in increased ulps
(ifloat64x shares ulps with ildouble / ifloat128 as appropriate).
Given that we'd like generally to eliminate bits/mathinline.h
optimizations, preferring to have such optimizations in GCC instead,
it seems reasonable not to add such support there for new types. GCC
support for _FloatN / _FloatNx built-in functions is limited, but has
been improved in GCC 8, and at some point I hope the full set of libm
built-in functions in GCC, and other optimizations with
per-floating-type aspects, will be enabled for all _FloatN / _FloatNx
types.
Tested for x86_64 and x86, and with build-many-glibcs.py, with both
GCC 6 and GCC 7.
* sysdeps/ia64/Makeconfig (float64x-alias-fcts): New variable.
* sysdeps/ieee754/float128/Makeconfig (float64x-alias-fcts):
Likewise.
* sysdeps/ieee754/ldbl-128/Makeconfig (float64x-alias-fcts):
Likewise.
* sysdeps/x86/Makeconfig: New file.
* bits/floatn-common.h (__HAVE_FLOAT64X): Remove macro.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* bits/floatn.h (__HAVE_FLOAT64X): New macro.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/ia64/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/ieee754/ldbl-128/bits/floatn.h (__HAVE_FLOAT64X):
Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/mips/ieee754/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/powerpc/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/x86/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* manual/math.texi (Mathematics): Document support for _Float64x.
* math/Versions (GLIBC_2.27): Add _Float64x functions.
* stdlib/Versions (GLIBC_2.27): Likewise.
* wcsmbs/Versions (GLIBC_2.27): Likewise.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Likewise.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
Further _FloatN / _FloatNx type alias support will involve making
architecture-specific .S files use the common macros for libm function
aliases. Making them use those macros will also serve to simplify
existing code for aliases / symbol versions in various cases, similar
to such simplifications for ldbl-opt code.
The libm-alias-*.h files sometimes need to include <bits/floatn.h> to
determine which aliases they should define. At present, this does not
work for inclusion from .S files because <bits/floatn.h> can define
typedefs for old compilers. This patch changes all the
<bits/floatn.h> and <bits/floatn-common.h> headers to include
__ASSEMBLER__ conditionals. Those conditionals disable everything
related to C syntax in the __ASSEMBLER__ case, not just the problem
typedefs, as that seemed cleanest. The __HAVE_* definitions remain in
the __ASSEMBLER__ case, as those provide information that is required
to define the correct set of aliases.
Tested with build-many-glibcs.py for a representative set of
configurations (x86_64-linux-gnu i686-linux-gnu ia64-linux-gnu
powerpc64le-linux-gnu mips64-linux-gnu-n64 sparc64-linux-gnu) with GCC
6. Also tested with GCC 6 for i686-linux-gnu in conjunction with
changes to use alias macros in .S files.
* bits/floatn-common.h [!__ASSEMBLER]: Disable everything related
to C syntax instead of availability and properties of types.
* bits/floatn.h [!__ASSEMBLER]: Likewise.
* sysdeps/ia64/bits/floatn.h [!__ASSEMBLER]: Likewise.
* sysdeps/ieee754/ldbl-128/bits/floatn.h [!__ASSEMBLER]: Likewise.
* sysdeps/mips/ieee754/bits/floatn.h [!__ASSEMBLER]: Likewise.
* sysdeps/powerpc/bits/floatn.h [!__ASSEMBLER]: Likewise.
* sysdeps/x86/bits/floatn.h [!__ASSEMBLER]: Likewise.
The bits/floatn.h header currently only has defines relating to
_Float128. This patch adds defines relating to other _FloatN /
_FloatNx types.
The approach taken is to add defines for all _FloatN / _FloatNx types
known to GCC, and to put them in a common bits/floatn-common.h header
included at the end of all the individual bits/floatn.h headers. If
in future some defines become different for different glibc
configurations, they will move out into the separate bits/floatn.h
headers.
Some defines are expected always to be the same across glibc ports.
Corresponding defines are nevertheless put in this header. The intent
is that where there are conditionals (in headers or in non-installed
files) that can just repeat the same or nearly the same logic for each
floating-point type, they should do so, even if in fact the cases for
some types could be unconditionally present or absent because the same
conditionals are true or false for all glibc configurations. This
should make the glibc code with such conditionals easier to read,
because the reader can just see that the same conditionals are
repeated for each type, rather than seeing different conditionals for
different types and needing to reason, at each location with such
differences, why those differences are indeed correct there. (Cases
involving per-format rather than per-type logic are more likely still
to need differences in how they handle different types.)
Having such defines and conditionals also helps in incremental
preparation for adding _Float32 / _Float64 / _Float32x / _Float64x
function aliases. I intend subsequent patches to add such
conditionals corresponding to those already present for _Float128, as
well as making more architecture-specific function implementations use
common macros to define aliases in preparation for adding such _FloatN
/ _FloatNx aliases.
Tested for x86_64.
* bits/floatn-common.h: New file.
* math/Makefile (headers): Add bits/floatn-common.h.
* bits/floatn.h: Include <bits/floatn-common.h>.
* sysdeps/ia64/bits/floatn.h: Likewise.
* sysdeps/ieee754/ldbl-128/bits/floatn.h: Likewise.
* sysdeps/mips/ieee754/bits/floatn.h: Likewise.
* sysdeps/powerpc/bits/floatn.h: Likewise.
* sysdeps/x86/bits/floatn.h: Likewise.
