glibc/include/float.h
Joseph Myers 13c92696d2 Use __f128 to define FLT128_* constants in include/float.h for old GCC.
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.
2017-10-17 20:16:01 +00:00

38 lines
1.1 KiB
C

#ifndef _LIBC_FLOAT_H
#define _LIBC_FLOAT_H
#define __GLIBC_INTERNAL_STARTING_HEADER_IMPLEMENTATION
#include <bits/libc-header-start.h>
#ifndef _ISOMAC
# define __STDC_WANT_IEC_60559_TYPES_EXT__
#endif
#include_next <float.h>
/* Supplement float.h macros for _Float128 for older compilers
which do not yet support the type. These are described in
TS 18661-3. */
#include <features.h>
#include <bits/floatn.h>
#if !__GNUC_PREREQ (7, 0) \
&& __HAVE_FLOAT128 && __GLIBC_USE (IEC_60559_TYPES_EXT)
# define FLT128_MANT_DIG 113
# define FLT128_DECIMAL_DIG 36
# define FLT128_DIG 33
# define FLT128_MIN_EXP (-16381)
# define FLT128_MIN_10_EXP (-4931)
# define FLT128_MAX_EXP 16384
# define FLT128_MAX_10_EXP 4932
# define FLT128_MAX \
__f128 (1.18973149535723176508575932662800702e+4932)
# define FLT128_EPSILON \
__f128 (1.92592994438723585305597794258492732e-34)
# define FLT128_MIN \
__f128 (3.36210314311209350626267781732175260e-4932)
# define FLT128_TRUE_MIN \
__f128 (6.47517511943802511092443895822764655e-4966)
#endif
#endif /* _LIBC_FLOAT_H */