TS 18661-1 defines an fetestexceptflag function to test the exception
state saved in an fexcept_t object by fegetexceptflag.
This patch implements this function for glibc. Almost all
architectures save exception state in such a way that it can be
directly ANDed with exception flag bits, so rather than having lots of
fetestexceptflag implementations that all do the same thing, the math/
implementation is made to use this generic logic (which is also OK in
the fallback case where FE_ALL_EXCEPT is zero). The only architecture
that seems to need anything different is s390.
(fegetexceptflag and fesetexceptflag use abbreviated filenames
fgetexcptflg.c and fsetexcptflg.c. Because we are no longer concerned
by 14-character filename limits, fetestexceptflag uses the obvious
filename fetestexceptflag.c.)
The NEWS entry is intended to be expanded along the lines given in
<https://sourceware.org/ml/libc-alpha/2016-08/msg00356.html> when
fegetmode and fesetmode are added.
Tested for x86_64, x86, mips64 and powerpc.
* math/fetestexceptflag.c: New file.
* sysdeps/s390/fpu/fetestexceptflag.c: Likewise. Comment by
Stefan Liebler.
* math/fenv.h [__GLIBC_USE (IEC_60559_BFP_EXT)]
(fetestexceptflag): New function declaration.
* manual/arith.texi (fetestexceptflag): Document function.
* math/Versions (fetestexceptflag): New libm symbol at version
GLIBC_2.25.
* math/Makefile (libm-support): Add fetestexceptflag.
(tests): Add test-fetestexceptflag.
* math/test-fetestexceptflag.c: New file.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.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/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
TS 18661-1 defines an fesetexcept function for setting floating-point
exception flags without the side-effect of causing enabled traps to be
taken.
This patch series implements this function for glibc. The present
patch adds the fallback stub implementation, x86 and x86_64
implementations, documentation, tests and ABI baseline updates. The
remaining patches, some of them untested, add implementations for
other architectures. The implementations generally follow those of
the fesetexceptflag function.
As for fesetexceptflag, the approach taken for architectures where
setting flags causes enabled traps to be taken is to set the flags
(and potentially cause traps) rather than refusing to set the flags
and returning an error. Since ISO C and TS 18661 provide no way to
enable traps, this is formally in accordance with the standards.
The NEWS entry should be considered a placeholder, since this patch
series is intended to be followed by further such series adding other
TS 18661-1 features, so that the NEWS entry would end up looking more
like
* New <fenv.h> features from TS 18661-1:2014 are added to libm: the
fesetexcept, fetestexceptflag, fegetmode and fesetmode functions,
the femode_t type and the FE_DFL_MODE macro.
with hopefully more such entries for other features, rather than
having an entry for a single function in the end.
I believe we have consensus for adding TS 18661-1 interfaces as per
<https://sourceware.org/ml/libc-alpha/2016-06/msg00421.html>.
Tested for x86_64, x86, mips64 (hard float, and soft float to test the
fallback version), arm (hard float) and powerpc (hard float, soft
float and e500).
* math/fesetexcept.c: New file.
* sysdeps/i386/fpu/fesetexcept.c: Likewise.
* sysdeps/x86_64/fpu/fesetexcept.c: Likewise.
* math/fenv.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
[__GLIBC_USE (IEC_60559_BFP_EXT)] (fesetexcept): New function
declaration.
* manual/arith.texi (fesetexcept): Document function.
* math/Versions (fesetexcept): New libm symbol at version
GLIBC_2.25.
* math/Makefile (libm-support): Add fesetexcept.
(tests): Add test-fesetexcept and test-fesetexcept-traps.
* math/test-fesetexcept.c: New file.
* math/test-fesetexcept-traps.c: Likewise.
* sysdeps/nacl/libm.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.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/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
This patch implements support for the __STDC_WANT_IEC_60559_BFP_EXT__
feature test macro from ISO/IEC 18661-1:2014, following the
__GLIBC_USE approach now used for __STDC_WANT_LIB_EXT2__. For this
macro, the relevant consideration is whether it is defined or
undefined when an affected header is included (not what its value is
if defined, and not whether it's defined or undefined when any other
unaffected system header is included).
Currently this macro only affects the issignaling macro and the nextup
and nextdown functions (so they can be enabled by defining this macro,
not just by defining _GNU_SOURCE as previously). Any further features
from this TS added in future would also be conditioned on this macro.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_BFP_EXT): New
macro.
* include/features.h (__STDC_WANT_IEC_60559_BFP_EXT__): Document.
* manual/arith.texi (issignaling): Document as ISO from TS
18661-1:2014.
(nextup): Likewise.
(nextupf): Likewise.
(nextupl): Likewise.
(nextdown): Likewise.
(nextdownf): Likewise.
(nextdownl): Likewise.
* manual/creature.texi (__STDC_WANT_IEC_60559_BFP_EXT__): Document
macro.
* math/math.h: Define
__GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION and include
<bits/libc-header-start.h> instead of including <features.h>.
(issignaling): Define if [__GLIBC_USE (IEC_60559_BFP_EXT)], not
[__USE_GNU].
* math/bits/mathcalls.h (nextdown): Declare if
[__GLIBC_USE (IEC_60559_BFP_EXT)], not [__USE_GNU].
(nextup): Likewise.
(__issignaling): Likewise.
TS 18661 adds nextup and nextdown functions alongside nextafter to provide
support for float128 equivalent to it. This patch adds nextupl, nextup,
nextupf, nextdownl, nextdown and nextdownf to libm before float128 support.
The nextup functions return the next representable value in the direction of
positive infinity and the nextdown functions return the next representable
value in the direction of negative infinity. These are currently enabled
as GNU extensions.
The end of the "Parsing of Floats" subsection currently reads:
The GNU C Library also provides '_l' versions of these functions,
which take an additional argument, the locale to use in conversion.
*Note Parsing of Integers::.
Split the final note as it is unrelated to the above comment and
reference it with "See also" instead.
It is the magnitude of the return value which lies
in [0.5, 1), not the return value itself.
---
2013-05-28 Ben North <ben@redfrontdoor.org>
* manual/arith.texi (frexp): It is the magnitude of the return
value which lies in [0.5, 1), not the return value itself.
2001-07-19 Jakub Jelinek <jakub@redhat.com>
* locales/es_PR (LC_PAPER): Change to Letter.
(LC_MEASUREMENT): Change to 2.
* locales/es_US (LC_PAPER): Change to Letter.
(LC_MEASUREMENT): Change to 2.
2000-10-09 Jakub Jelinek <jakub@redhat.com>
* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): If x == y,
return y not x.
* manual/arith.texi (nextafter): Document it.
* sysdeps/ieee754/ldbl-96/s_nexttoward.c: Fix a comment.
2000-08-17 Ulrich Drepper <drepper@redhat.com>
* stdio-common/printf_fp.c: Fix chars_needed computation.
Patch by Greg McGary <greg@mcgary.org>.
2000-08-17 Jakub Jelinek <jakub@redhat.com>
* elf/dl-load.c (_dl_map_object): Don't crash if both loader and
_dl_loaded are NULL.
2000-08-17 Jakub Jelinek <jakub@redhat.com>
* manual/arith.texi (feholdexcept): Returns 0 on success.
2000-08-17 Andreas Jaeger <aj@suse.de>
* sysdeps/gnu/net/if.h (struct ifreq): Add ifru_newname.
(ifr_newname): New.
Reported by Andi Kleen <ak@suse.de>.
2000-08-17 Jakub Jelinek <jakub@redhat.com>
* sysdeps/alpha/fpu/fedisblxcpt.c: New file.
* sysdeps/alpha/fpu/feenablxcpt.c: New file.
* sysdeps/alpha/fpu/fegetexcept.c: New file.
2000-08-16 Jakub Jelinek <jakub@redhat.com>
* sysdeps/unix/sysv/linux/xstatconv.c (xstat32_conv): Test sizes
of buf->st_ino and kbuf->st_ino, not __st_ino.
If _HAVE_STAT64___ST_INO is not defined, don't use __st_ino at all.
* sysdeps/unix/sysv/linux/getdents64.c: Change path in #include
directive so that only linux/getdents.c is used, not some
architecture specific one.
2000-08-16 Jakub Jelinek <jakub@redhat.com>
* sysdeps/i386/fpu/fegetexcept.c (fegetexcept): Return currently
enabled, not disabled exceptions.
* sysdeps/i386/fpu/fedisblxcpt.c (fedisableexcept): Likewise.
* sysdeps/i386/fpu/feenablxcpt.c (feenableexcept): Likewise.
($(addprefix $(objpfx),$(tests)),
$(addprefix $(objpfx),$(librt-tests))):
* include/link.h: Undo last patches. Hurd now has stat64.
2000-05-28 Ulrich Drepper <drepper@redhat.com>
* manual/arith.texi (Rounding Functions): Fix documentation of trunc.
Patch by Steven G. Johnson <stevenj@gil-galad.mit.edu>.
2000-04-25 Jes Sorensen <Jes.Sorensen@cern.ch>
* shlib-versions: Rename ia64 dynamic linker to ld-linux-ia64.so.1
to avoid name clashes with the ia32 linker.
2000-04-25 Jakub Jelinek <jakub@redhat.com>
* sysdeps/alpha/dl-machine.h (_dl_start_user): Fix the _dl_skip_args
handling.
* manual/string.texi: Document strcasestr, strchrnul, strtoimax,
strtoumax, strfry, and memfrob.
* manual/arith.texi: Document {,u}int*_t types, and strto{i,u}max.
Patch by Bryan Henderson <bryanh@giraffe-data.com>.
1999-10-30 Ulrich Drepper <drepper@cygnus.com>
* manual/time.texi (Formatting Date and Time): Revise comments about
origins of the formats with ISO C99 references.
1999-10-30 Andreas Jaeger <aj@suse.de>
* sysdeps/unix/sysv/linux/ifreq.h: New file.
1999-10-29 Andreas Jaeger <aj@suse.de>
* manual/arith.texi (Parsing of Floats): Document the hexadecimal
input format; mention that strtof and strtold are part of ISO C99.
1999-06-28 Andreas Jaeger <aj@arthur.rhein-neckar.de>
* inet/rcmd.c (__icheckhost): Test for gethostbyname_r result
correctly.
1999-06-25 Andreas Jaeger <aj@arthur.rhein-neckar.de>
* manual/arith.texi (System V Number Conversion): Fix the
description which confused pointer and value to pointer.
Reported by Andries.Brouwer@cwi.nl.
1999-06-28 Andreas Jaeger <aj@arthur.rhein-neckar.de>
* pwd/getpw.c (__getpw): Check for NULL result pointer.
1999-06-29 Andreas Jaeger <aj@arthur.rhein-neckar.de>
* manual/users.texi (Lookup User): Document POSIX return
semantics for getpwuid_r and getgrgid_r.
* manual/socket.texi (Host Names): Document that the result
pointer is null in case of error or host not found and fix a
typo. Give a small example.
1999-06-23 Ulrich Drepper <drepper@cygnus.com>
* manual/arith.texi: Document restriction of ndigit parameter of
ecvt and friends.
* misc/efgcvt.c: Define NDIGIT_MAX.
(gcvt): Limit precision in sprintf call to NDIGIT_MAX.
Do not dynamically allocate the static buffers. They are small enough.
* misc/efgcvt_r.c: Define NDIGIT_MAX.
(fcvt_r): Limit precision in snprintf call to NDIGIT_MAX.
* misc/qefgcvt.c: Define NDIGIT_MAX.
* misc/qefgcvt_r.c: Likewise.
* misc/tst-efgcvt.c (special): Add test for large ndigit parameter.
