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author | Joseph Myers <joseph@codesourcery.com> | 2017-08-31 16:39:25 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2017-08-31 16:39:25 +0000 |
commit | c0c49d60cfeff3b2aa801d6598143a073989654a (patch) | |
tree | 248bd1a808a8f2e27396ddfd1c04e5362d7e5da2 /sysdeps/ieee754/bits | |
parent | 5ef1b2138d4236bb3616e612c5bc4dc328a9ffb2 (diff) | |
download | glibc-c0c49d60cfeff3b2aa801d6598143a073989654a.tar.gz glibc-c0c49d60cfeff3b2aa801d6598143a073989654a.tar.xz glibc-c0c49d60cfeff3b2aa801d6598143a073989654a.zip |
Simplify NAN definitions.
Similar to my patches for HUGE_VAL and INFINITY. this patch eliminates the bits/nan.h headers. __builtin_nanf ("") is used to define NAN for GCC 3.3 and later; the fallback is (0.0f / 0.0f), which is a constant expression for a quiet NaN of type float, but raises a spurious "invalid" exception outside static initializers, which seems the best that can be done purely in standard C. Again, if anyone actually uses a compiler with its own incompatible extension for producing a constant quiet NaN, we can add compiler conditionals. Tested for x86_64. * math/math.h [__USE_ISOC99] (NAN): Define directly here. Do not include <bits/nan.h>. * math/Makefile (headers): Remove bits/nan.h. * bits/nan.h: Remove. * sysdeps/ieee754/bits/nan.h: Likewise. * sysdeps/mips/bits/nan.h: Likewise.
Diffstat (limited to 'sysdeps/ieee754/bits')
-rw-r--r-- | sysdeps/ieee754/bits/nan.h | 52 |
1 files changed, 0 insertions, 52 deletions
diff --git a/sysdeps/ieee754/bits/nan.h b/sysdeps/ieee754/bits/nan.h deleted file mode 100644 index b6e14f5873..0000000000 --- a/sysdeps/ieee754/bits/nan.h +++ /dev/null @@ -1,52 +0,0 @@ -/* `NAN' constant for IEEE 754 machines. - Copyright (C) 1992-2017 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 _MATH_H -# error "Never use <bits/nan.h> directly; include <math.h> instead." -#endif - - -/* IEEE Not A Number. */ - -#if __GNUC_PREREQ(3,3) - -# define NAN (__builtin_nanf ("")) - -#elif defined __GNUC__ - -# define NAN \ - (__extension__ \ - ((union { unsigned __l __attribute__ ((__mode__ (__SI__))); float __d; }) \ - { __l: 0x7fc00000UL }).__d) - -#else - -# include <endian.h> - -# if __BYTE_ORDER == __BIG_ENDIAN -# define __qnan_bytes { 0x7f, 0xc0, 0, 0 } -# endif -# if __BYTE_ORDER == __LITTLE_ENDIAN -# define __qnan_bytes { 0, 0, 0xc0, 0x7f } -# endif - -static union { unsigned char __c[4]; float __d; } __qnan_union - __attribute__ ((__unused__)) = { __qnan_bytes }; -# define NAN (__qnan_union.__d) - -#endif /* GCC. */ |