C2X adds new <math.h> functions for floating-point maximum and
minimum, corresponding to the new operations that were added in IEEE
754-2019 because of concerns about the old operations not being
associative in the presence of signaling NaNs. fmaximum and fminimum
handle NaNs like most <math.h> functions (any NaN argument means the
result is a quiet NaN). fmaximum_num and fminimum_num handle both
quiet and signaling NaNs the way fmax and fmin handle quiet NaNs (if
one argument is a number and the other is a NaN, return the number),
but still raise "invalid" for a signaling NaN argument, making them
exceptions to the normal rule that a function with a floating-point
result raising "invalid" also returns a quiet NaN. fmaximum_mag,
fminimum_mag, fmaximum_mag_num and fminimum_mag_num are corresponding
functions returning the argument with greatest or least absolute
value. All these functions also treat +0 as greater than -0. There
are also corresponding <tgmath.h> type-generic macros.
Add these functions to glibc. The implementations use type-generic
templates based on those for fmax, fmin, fmaxmag and fminmag, and test
inputs are based on those for those functions with appropriate
adjustments to the expected results. The RISC-V maintainers might
wish to add optimized versions of fmaximum_num and fminimum_num (for
float and double), since RISC-V (F extension version 2.2 and later)
provides instructions corresponding to those functions - though it
might be at least as useful to add architecture-independent built-in
functions to GCC and teach the RISC-V back end to expand those
functions inline, which is what you generally want for functions that
can be implemented with a single instruction.
Tested for x86_64 and x86, and with build-many-glibcs.py.
This patch adds the narrowing fused multiply-add functions from TS
18661-1 / TS 18661-3 / C2X to glibc's libm: ffma, ffmal, dfmal,
f32fmaf64, f32fmaf32x, f32xfmaf64 for all configurations; f32fmaf64x,
f32fmaf128, f64fmaf64x, f64fmaf128, f32xfmaf64x, f32xfmaf128,
f64xfmaf128 for configurations with _Float64x and _Float128;
__f32fmaieee128 and __f64fmaieee128 aliases in the powerpc64le case
(for calls to ffmal and dfmal when long double is IEEE binary128).
Corresponding tgmath.h macro support is also added.
The changes are mostly similar to those for the other narrowing
functions previously added, especially that for sqrt, so the
description of those generally applies to this patch as well. As with
sqrt, I reused the same test inputs in auto-libm-test-in as for
non-narrowing fma rather than adding extra or separate inputs for
narrowing fma. The tests in libm-test-narrow-fma.inc also follow
those for non-narrowing fma.
The non-narrowing fma has a known bug (bug 6801) that it does not set
errno on errors (overflow, underflow, Inf * 0, Inf - Inf). Rather
than fixing this or having narrowing fma check for errors when
non-narrowing does not (complicating the cases when narrowing fma can
otherwise be an alias for a non-narrowing function), this patch does
not attempt to check for errors from narrowing fma and set errno; the
CHECK_NARROW_FMA macro is still present, but as a placeholder that
does nothing, and this missing errno setting is considered to be
covered by the existing bug rather than needing a separate open bug.
missing-errno annotations are duly added to many of the
auto-libm-test-in test inputs for fma.
This completes adding all the new functions from TS 18661-1 to glibc,
so will be followed by corresponding stdc-predef.h changes to define
__STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__, as the support
for TS 18661-1 will be at a similar level to that for C standard
floating-point facilities up to C11 (pragmas not implemented, but
library functions done). (There are still further changes to be done
to implement changes to the types of fromfp functions from N2548.)
Tested as followed: natively with the full glibc testsuite for x86_64
(GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC
11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32
hard float, mips64 (all three ABIs, both hard and soft float). The
different GCC versions are to cover the different cases in tgmath.h
and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in
glibc headers, GCC 7 has proper _Float* support, GCC 8 adds
__builtin_tgmath).
This patch adds the narrowing square root functions from TS 18661-1 /
TS 18661-3 / C2X to glibc's libm: fsqrt, fsqrtl, dsqrtl, f32sqrtf64,
f32sqrtf32x, f32xsqrtf64 for all configurations; f32sqrtf64x,
f32sqrtf128, f64sqrtf64x, f64sqrtf128, f32xsqrtf64x, f32xsqrtf128,
f64xsqrtf128 for configurations with _Float64x and _Float128;
__f32sqrtieee128 and __f64sqrtieee128 aliases in the powerpc64le case
(for calls to fsqrtl and dsqrtl when long double is IEEE binary128).
Corresponding tgmath.h macro support is also added.
The changes are mostly similar to those for the other narrowing
functions previously added, so the description of those generally
applies to this patch as well. However, the not-actually-narrowing
cases (where the two types involved in the function have the same
floating-point format) are aliased to sqrt, sqrtl or sqrtf128 rather
than needing a separately built not-actually-narrowing function such
as was needed for add / sub / mul / div. Thus, there is no
__nldbl_dsqrtl name for ldbl-opt because no such name was needed
(whereas the other functions needed such a name since the only other
name for that entry point was e.g. f32xaddf64, not reserved by TS
18661-1); the headers are made to arrange for sqrt to be called in
that case instead.
The DIAG_* calls in sysdeps/ieee754/soft-fp/s_dsqrtl.c are because
they were observed to be needed in GCC 7 testing of
riscv32-linux-gnu-rv32imac-ilp32. The other sysdeps/ieee754/soft-fp/
files added didn't need such DIAG_* in any configuration I tested with
build-many-glibcs.py, but if they do turn out to be needed in more
files with some other configuration / GCC version, they can always be
added there.
I reused the same test inputs in auto-libm-test-in as for
non-narrowing sqrt rather than adding extra or separate inputs for
narrowing sqrt. The tests in libm-test-narrow-sqrt.inc also follow
those for non-narrowing sqrt.
Tested as followed: natively with the full glibc testsuite for x86_64
(GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC
11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32
hard float, mips64 (all three ABIs, both hard and soft float). The
different GCC versions are to cover the different cases in tgmath.h
and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in
glibc headers, GCC 7 has proper _Float* support, GCC 8 adds
__builtin_tgmath).
The functions in the nexttoward family are special, in the sense that
they always have a long double argument, regardless of their suffix
(i.e.: nexttowardf and nexttoward have a long double argument, besides
the float and double arguments).
On top of that, they are also special because nexttoward functions are
not part of the _FloatN API, hence __nexttowardf128 do not exist.
This patch adds 4 new function implementations for the new long double
format:
__nexttoward_to_ieee128
__nexttowardf_to_ieee128
__nexttowardieee128 (as an alias to __nextafterieee128)
Likewise, rename "long double" "_Float128" in shared ldbl-128
files to ensure correct type is used irrespective of ABI
switches.
Thank you to those who helped out with this patch:
Co-Authored-By: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Move the narrow math aliasing macros into a new sysdep header file
math-narrow-alias-float128.h. Then, provide an override header
to supply the necessary changes to supply the *ieee128 aliases of
these symbols.
This adds ieee128 aliases for faddl, fdivl, fmull, fsubl, daddl, ddivl,
dmull, dsubl.
Reuse the template in order to provide the redirect for
scalbl to __scalbieee128, but avoid any extra aliasing
as this is intended to support long double redirects only.
This patch adds IEEE long double versions of q*cvt* functions for
powerpc64le. Unlike all other long double to/from string conversion
functions, these do not rely on internal functions that can take
floating-point numbers with different formats and act on them
accordingly, instead, the related files are rebuilt with the
-mabi=ieeelongdouble compiler flag set.
Having -mabi=ieeelongdouble passed to the compiler causes the object
files to be marked with a .gnu_attribute that is incompatible with the
.gnu_attribute in files built with -mabi=ibmlongdouble (the default).
The difference causes error messages similar to the following:
ld: libc_pic.a(s_isinfl.os) uses IBM long double,
libc_pic.a(ieee128-qefgcvt_r.os) uses IEEE long double.
collect2: error: ld returned 1 exit status
make[2]: *** [../Makerules:649: libc_pic.os] Error 1
Although this warning is useful in other situations, the library
actually needs to have functions with different long double formats, so
.gnu_attribute generation is explicitly disabled for these files with
the use of -mno-gnu-attribute.
Tested for powerpc64le on the branch that actually enables the
sysdeps/ieee754/ldbl-128ibm-compat for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
In the format string for *scanf functions, the '%as', '%aS', and '%a[]'
modifiers behave differently depending on ISO C99 compatibility. When
_GNU_SOURCE is defined and -std=c89 is passed to the compiler, these
functions behave like ascanf, and the modifiers allocate memory for the
output. Otherwise, the ISO C99 compliant version of these functions is
used, and the modifiers consume a floating-point argument. This patch
adds the IEEE binary128 variant of ISO C99 compliant functions for the
third long double format on powerpc64le.
Tested for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Similarly to what has been done for printf-like functions, more
specifically to the internal implementation in __vfprintf_internal, this
patch extends __vstrfmon_l_internal to deal with long double values with
binary128 format (as a third format option and reusing the float128
implementation).
Tested for powerpc64le, powerpc64, x86_64, and with build-many-glibcs.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Similarly to __vfprintf_internal and __vfscanf_internal, the internal
implementation of syslog functions (__vsyslog_internal) takes a
'mode_flags' parameter used to select the format of long double
parameters. This patch adds variants of the syslog functions that set
'mode_flags' to PRINTF_LDBL_USES_FLOAT128, thus enabling the correct
printing of long double values on powerpc64le, when long double has IEEE
binary128 format (-mabi=ieeelongdouble).
Tested for powerpc64le.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Joseph Myers <joseph@codesourcery.com>
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Similarly to the functions from the *printf family, this patch adds
implementations for __obstack_*printf* functions that set the
'mode_flags' parameter to PRINTF_LDBL_USES_FLOAT128, before making calls
to __vfprintf_internal (indirectly through __obstack_vprintf_internal).
Tested for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Use the recently added, internal functions, __error_at_line_internal and
__error_internal, to provide error.h functions that can take long double
arguments with IEEE binary128 format on platforms where long double can
also take double format or some non-IEEE format (currently, this means
powerpc64le).
Tested for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Use the recently added, internal functions, __vwarnx_internal and
__vwarn_internal, to provide err.h functions that can take long double
arguments with IEEE binary128 format on platforms where long double can
also take double format or some non-IEEE format (currently, this means
powerpc64le).
Tested for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Use the recently added, internal functions, __argp_error_internal and
__argp_failure_internal, to provide argp_error and argp_failure that can
take long double arguments with IEEE binary128 format on platforms where
long double can also take double format or some non-IEEE format
(currently, this means powerpc64le).
Tested for powerpc64le.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
Similarly to what was done for regular character scanning functions,
this patch uses the new mode mask, SCANF_LDBL_USES_FLOAT128, in the
'mode' argument of the wide characters scanning function,
__vfwscanf_internal (which is also extended to support scanning
floating-point values with IEEE binary128, by redirecting calls to
__wcstold_internal to __wcstof128_internal).
Tested for powerpc64le.
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
The 'mode' argument to __vfscanf_internal allows the selection of the
long double format for all long double arguments requested by the format
string. Currently, there are two possibilities: long double with the
same format as double or long double as something else. The 'something
else' format varies between architectures, and on powerpc64le, it means
IBM Extended Precision format.
In preparation for the third option of long double format on
powerpc64le, this patch uses the new mode mask,
SCANF_LDBL_USES_FLOAT128, which tells __vfscanf_internal to call
__strtof128_internal, instead of __strtold_internal, and save the output
into a _Float128 variable.
Tested for powerpc64le.
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
Similarly to what was done for the regular character, fortified printing
functions, this patch combines the mode masks PRINTF_LDBL_USES_FLOAT128
and PRINTF_FORTIFY to provide wide character versions of fortified
printf functions. It also adds two flavors of test cases: one that
explicitly calls the fortified functions, and another that reuses the
non-fortified test, but defining _FORTIFY_SOURCE as 2. The first
guarantees that the implementations are actually being tested
(independently of what's in bits/wchar2.h), whereas the second
guarantees that the redirections calls the correct function in the IBM
and IEEE long double cases.
Tested for powerpc64le.
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
Since the introduction of internal functions with explicit flags for the
printf family of functions, the 'mode' parameter can be used to select
which format long double parameters have (with the mode flags:
PRINTF_LDBL_IS_DBL and PRINTF_LDBL_USES_FLOAT128), as well as to select
whether to check for overflows (mode flag: PRINTF_FORTIFY).
This patch combines PRINTF_LDBL_USES_FLOAT128 and PRINTF_FORTIFY to
provide the IEEE binary128 version of printf-like function for platforms
where long double can take this format, in addition to the double format
and to some non-ieee format (currently, this means powerpc64le).
There are two flavors of test cases provided with this patch: one that
explicitly calls the fortified functions, for instance __asprintf_chk,
and another that reuses the non-fortified test, but defining
_FORTIFY_SOURCE as 2. The first guarantees that the implementations are
actually being tested (in bits/stdio2.h, vprintf gets redirected to
__vfprintf_chk, which would leave __vprintf_chk untested), whereas the
second guarantees that the redirections calls the correct function in
the IBM and IEEE long double cases.
Tested for powerpc64le.
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
Similarly to what was done for regular character printing functions,
this patch uses the new mode mask, PRINTF_LDBL_USES_FLOAT128, in the
'mode' argument of the wide characters printing function,
__vfwprintf_internal (which is also extended to support printing
floating-point values with IEEE binary128, by saving floating-point
values into variables of type __float128 and adjusting the parameters to
__printf_fp and __printf_fphex as if it was a call from a wide-character
version of strfromf128 (even though such version does not exist)).
Tested for powerpc64le.
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
The 'mode' argument to __vfprintf_internal allows the selection of the
long double format for all long double arguments requested by the format
string. Currently, there are two possibilities: long double with the
same format as double or long double as something else. The 'something
else' format varies between architectures, and on powerpc64le, it means
IBM Extended Precision format.
In preparation for the third option of long double format on
powerpc64le, this patch uses the new mode mask,
PRINTF_LDBL_USES_FLOAT128, which tells __vfprintf_internal to save the
floating-point values into variables of type __float128 and adjusts the
parameters to __printf_fp and __printf_fphex as if it was a call from
strfromf128.
Many files from the stdio-common, wcsmbs, argp, misc, and libio
directories will have IEEE binary128 counterparts. Setting the correct
compiler options to these files (original and counterparts) would
produce a large amount of repetitive Makefile rules. To avoid this
repetition, this patch adds a Makefile routine that iterates over the
files adding or removing the appropriate flags.
Tested for powerpc64le.
Reviewed-By: Florian Weimer <fweimer@redhat.com>
Reviewed-By: Joseph Myers <joseph@codesourcery.com>
Reviewed-By: Paul E. Murphy <murphyp@linux.ibm.com>
Since the addition of the _Float128 API, strfromf128 and printf_size use
__printf_fp to print _Float128 values. This is achieved by setting the
'is_binary128' member of the 'printf_info' structure to one. Now that
the format of long double on powerpc64le is getting a third option, this
mechanism is reused for long double values that have binary128 format
(i.e.: when -mabi=ieeelongdouble).
This patch adds __printf_sizeieee128 as an exported symbol, but doesn't
provide redirections from printf_size, yet. All redirections will be
installed in a future commit, once all other functions that print or
read long double values with binary128 format are ready. In
__printf_fp, when 'is_binary128' is one, the floating-point argument is
treated as if it was of _Float128 type, regardless of the value of
'is_long_double', thus __printf_sizeieee128 sets 'is_binary128' to the
same value of 'is_long_double'. Otherwise, double values would not be
printed correctly.
Tested for powerpc64le.
This patch adds __*ieee128 symbols for strfrom, strtold, strtold_l, wcstold
and wcstold_l functions. Redirection from *l to *ieee128 will be handled
in separate patch once we start building these new files.
2018-06-28 Rajalakshmi Srinivasaraghavan <raji@linux.vnet.ibm.com>
* sysdeps/ieee754/ldbl-128ibm-compat/Versions: Add __strfromieee128,
__strtoieee128, __strtoieee128_l,__wcstoieee128 and __wcstoieee128_l.
* sysdeps/ieee754/ldbl-128ibm-compat/strfromf128.c: New file.
* sysdeps/ieee754/ldbl-128ibm-compat/strtof128.c: New file.
* sysdeps/ieee754/ldbl-128ibm-compat/strtof128_l.c: New file.
* sysdeps/ieee754/ldbl-128ibm-compat/wcstof128.c: New file.
* sysdeps/ieee754/ldbl-128ibm-compat/wcstof128_l.c: New file.
Add a new libm-alias-float128.h in order to provide the __*ieee128
aliases for the existing *f128 that do not have a globally exported
symbol.
* sysdeps/ieee754/ldbl-128ibm-compat/Versions: New file.
* sysdeps/ieee754/ldbl-128ibm-compat/libm-alias-float128.h: New file.
