glibc/sysdeps/x86/bits/floatn.h

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Add float128 support for x86_64, x86. This patch enables float128 support for x86_64 and x86. All GCC versions that can build glibc provide the required support, but since GCC 6 and before don't provide __builtin_nanq / __builtin_nansq, sNaN tests and some tests of NaN payloads need to be disabled with such compilers (this does not affect the generated glibc binaries at all, just the tests). bits/floatn.h declares float128 support to be available for GCC versions that provide the required libgcc support (4.3 for x86_64, 4.4 for i386 GNU/Linux, 4.5 for i386 GNU/Hurd); compilation-only support was present some time before then, but not really useful without the libgcc functions. fenv_private.h needed updating to avoid trying to put _Float128 values in registers. I make no assertion of optimality of the math_opt_barrier / math_force_eval definitions for this case; they are simply intended to be sufficient to work correctly. Tested for x86_64 and x86, with GCC 7 and GCC 6. (Testing for x32 was compilation tests only with build-many-glibcs.py to verify the ABI baseline updates. I have not done any testing for Hurd, although the float128 support is enabled there as for GNU/Linux.) * sysdeps/i386/Implies: Add ieee754/float128. * sysdeps/x86_64/Implies: Likewise. * sysdeps/x86/bits/floatn.h: New file. * sysdeps/x86/float128-abi.h: Likewise. * manual/math.texi (Mathematics): Document support for _Float128 on x86_64 and x86. * sysdeps/i386/fpu/fenv_private.h: Include <bits/floatn.h>. (math_opt_barrier): Do not put _Float128 values in floating-point registers. (math_force_eval): Likewise. [__x86_64__] (SET_RESTORE_ROUNDF128): New macro. * sysdeps/x86/fpu/Makefile [$(subdir) = math] (CPPFLAGS): Append to Makefile variable. * sysdeps/x86/fpu/e_sqrtf128.c: New file. * sysdeps/x86/fpu/sfp-machine.h: Likewise. Based on libgcc. * sysdeps/x86/math-tests.h: New file. * math/libm-test-support.h (XFAIL_FLOAT128_PAYLOAD): New macro. * math/libm-test-getpayload.inc (getpayload_test_data): Use XFAIL_FLOAT128_PAYLOAD. * math/libm-test-setpayload.inc (setpayload_test_data): Likewise. * math/libm-test-totalorder.inc (totalorder_test_data): Likewise. * math/libm-test-totalordermag.inc (totalordermag_test_data): Likewise. * sysdeps/unix/sysv/linux/i386/libc.abilist: Update. * sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise. * sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise. * sysdeps/i386/fpu/libm-test-ulps: Likewise. * sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
2017-06-26 22:01:27 +00:00
/* 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
#endif
#endif /* _BITS_FLOATN_H */