When using compilers before GCC 7, include/float.h provides fallback
definitions of FLT128_* constants. These definitions use 'Q' constant
suffixes, which works for configurations with _Float128 ABI-distinct
from long double, but not where it has the same ABI as long double.
This patch changes the definitions to use the __f128 macro from
<bits/floatn.h>, so allowing them to work in the non-distinct
_Float128 case (where they are used in building glibc tests, not for
building glibc itself) as well.
Tested (a) with build-many-glibcs.py with GCC 6 (installed stripped
shared libraries unchanged by the patch); (b) with
build-many-glibcs.py with GCC 6 together with the main patch to enable
float128 aliases; (c) for x86_64 with both GCC 6 and GCC 7.
* include/float.h [!__GNUC_PREREQ (7, 0) && __HAVE_FLOAT128 &&
__GLIBC_USE (IEC_60559_TYPES_EXT)] (FLT128_MAX): Define using
__f128.
[!__GNUC_PREREQ (7, 0) && __HAVE_FLOAT128 && __GLIBC_USE
(IEC_60559_TYPES_EXT)] (FLT128_EPSILON): Likewise.
[!__GNUC_PREREQ (7, 0) && __HAVE_FLOAT128 && __GLIBC_USE
(IEC_60559_TYPES_EXT)] (FLT128_MIN): Likewise.
[!__GNUC_PREREQ (7, 0) && __HAVE_FLOAT128 && __GLIBC_USE
(IEC_60559_TYPES_EXT)] (FLT128_TRUE_MIN): Likewise.
The file include/float.h uses the macro __GLIBC_USE to test for TS 18661-3
support. Such macro is provided by bits/libc-header-start.h, so include it
to get the definition.
Tested for powerpc64le and s390x.
* include/float.h: Include libc-header-start.h to get the
definition of __GLIBC_USE.
TS 18661-3 specifies that macros prefixed with FLTN_ can be defined in
float.h, only if __STDC_WANT_IEC_60559_TYPES_EXT__ is defined as a macro
before the inclusion of float.h. Since GCC 7.0, these macros are provided
under this condition, however, for older versions of GCC, these macros are
not provided at all. This patch allows the definitions of such macros in
include/float.h for older compilers, if the condition above is met, and
even if _ISOMAC is defined.
* include/float.h: Allow the definition of macros prefixed with
FLT128 even if _ISOMAC is defined, but provided that
__STDC_WANT_IEC_60559_TYPES_EXT__ is defined as a macro.
Add the necessary bits to the private headers to support
building the _Float128 libm functions.
A local override for float.h is provided to include the
missing *FLT128 macros implied by TS 18661-3 for this
type when compiling prior to GCC 7.
* include/complex.h (__kernel_casinhf128): New declaration.
* include/float.h: New file.
* include/math.h (__finitef128): Add a hidden def.
(__isinff128): Likewise.
(__isnanf128): Likewise.
(__fpclassify): Likewise.
(__issignalling): Likewise.
(__expf128): Likewise.
(__expm1f128): Likewise.
* sysdeps/generic/fix-fp-int-convert-overflow.h:
(FIX_FLT128_LONG_CONVERT_OVERFLOW): New macro.
(FIX_FLT128_LLONG_CONVERT_OVERFLOW): Likewise.
* sysdeps/generic/math-type-macros-float128.h: New file.
* sysdeps/generic/math_private.h: Include bits/floatn.h and
math_private_calls.h for _Float128.
(__isinff128): New inline implementation used when GCC < 7.0,
since in this case __builtin_isinf_sign is broken.
(fabsf128): New inline implementation that calls the builtin.
(__EXPR_FLT128): New macro.
(min_of_type): Optionally include _Float128 types too.
* sysdeps/generic/math_private_calls.h (__kernel_sincos):
Declare for _Float128.
(__kernel_rem_pio2): Likewise.
* sysdeps/ieee754/ldbl-opt/s_sin.c:
(__DECL_SIMD_sincos_disablef128): New macro.
