glibc/sysdeps/x86/bits/floatn.h
Joseph Myers 797ba44ba2 Add bits/floatn.h defines for more _FloatN / _FloatNx types.
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.
2017-10-20 21:42:51 +00:00

107 lines
3.7 KiB
C

/* Macros to control TS 18661-3 glibc features on x86.
Copyright (C) 2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#ifndef _BITS_FLOATN_H
#define _BITS_FLOATN_H
#include <features.h>
/* Defined to 1 if the current compiler invocation provides a
floating-point type with the IEEE 754 binary128 format, and this
glibc includes corresponding *f128 interfaces for it. The required
libgcc support was added some time after the basic compiler
support, for x86_64 and x86. */
#if (defined __x86_64__ \
? __GNUC_PREREQ (4, 3) \
: (defined __GNU__ ? __GNUC_PREREQ (4, 5) : __GNUC_PREREQ (4, 4)))
# define __HAVE_FLOAT128 1
#else
# define __HAVE_FLOAT128 0
#endif
/* Defined to 1 if __HAVE_FLOAT128 is 1 and the type is ABI-distinct
from the default float, double and long double types in this glibc. */
#if __HAVE_FLOAT128
# define __HAVE_DISTINCT_FLOAT128 1
#else
# define __HAVE_DISTINCT_FLOAT128 0
#endif
/* Defined to concatenate the literal suffix to be used with _Float128
types, if __HAVE_FLOAT128 is 1. */
#if __HAVE_FLOAT128
# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
/* The literal suffix f128 exists only since GCC 7.0. */
# define __f128(x) x##q
# else
# define __f128(x) x##f128
# endif
#endif
/* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1. */
#if __HAVE_FLOAT128
# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
/* Add a typedef for older GCC compilers which don't natively support
_Complex _Float128. */
typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
# define __CFLOAT128 __cfloat128
# else
# define __CFLOAT128 _Complex _Float128
# endif
#endif
/* The remaining of this file provides support for older compilers. */
#if __HAVE_FLOAT128
/* The type _Float128 exists only since GCC 7.0. */
# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
typedef __float128 _Float128;
# endif
/* __builtin_huge_valf128 doesn't exist before GCC 7.0. */
# if !__GNUC_PREREQ (7, 0)
# define __builtin_huge_valf128() ((_Float128) __builtin_huge_val ())
# endif
/* Older GCC has only a subset of built-in functions for _Float128 on
x86, and __builtin_infq is not usable in static initializers.
Converting a narrower sNaN to _Float128 produces a quiet NaN, so
attempts to use _Float128 sNaNs will not work properly with older
compilers. */
# if !__GNUC_PREREQ (7, 0)
# define __builtin_copysignf128 __builtin_copysignq
# define __builtin_fabsf128 __builtin_fabsq
# define __builtin_inff128() ((_Float128) __builtin_inf ())
# define __builtin_nanf128(x) ((_Float128) __builtin_nan (x))
# define __builtin_nansf128(x) ((_Float128) __builtin_nans (x))
# endif
/* In math/math.h, __MATH_TG will expand signbit to __builtin_signbit*,
e.g.: __builtin_signbitf128, before GCC 6. However, there has never
been a __builtin_signbitf128 in GCC and the type-generic builtin is
only available since GCC 6. */
# if !__GNUC_PREREQ (6, 0)
# define __builtin_signbitf128 __signbitf128
# endif
#endif
#include <bits/floatn-common.h>
#endif /* _BITS_FLOATN_H */