diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/s_floor.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/s_floor.c | 98 |
1 files changed, 49 insertions, 49 deletions
diff --git a/sysdeps/ieee754/dbl-64/s_floor.c b/sysdeps/ieee754/dbl-64/s_floor.c index f27c6f3ad2..78325214f4 100644 --- a/sysdeps/ieee754/dbl-64/s_floor.c +++ b/sysdeps/ieee754/dbl-64/s_floor.c @@ -1,4 +1,24 @@ -/* @(#)s_floor.c 5.1 93/09/24 */ +/* Round double to integer away from zero. + Copyright (C) 2011-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 2011. + + 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 + <https://www.gnu.org/licenses/>. */ + +/* Based on a version which carries the following copyright: */ + /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. @@ -10,6 +30,13 @@ * ==================================================== */ +#define NO_MATH_REDIRECT +#include <math.h> +#include <math_private.h> +#include <stdint.h> +#include <libm-alias-double.h> +#include <math-use-builtins.h> + /* * floor(x) * Return x rounded toward -inf to integral value @@ -17,69 +44,42 @@ * Bit twiddling. */ -#include <math.h> -#include <math_private.h> -#include <libm-alias-double.h> double __floor (double x) { - int32_t i0, i1, j0; - uint32_t i, j; - EXTRACT_WORDS (i0, i1, x); - j0 = ((i0 >> 20) & 0x7ff) - 0x3ff; - if (j0 < 20) +#if USE_FLOOR_BUILTIN + return __builtin_floor (x); +#else + /* Use generic implementation. */ + int64_t i0; + EXTRACT_WORDS64 (i0, x); + int32_t j0 = ((i0 >> 52) & 0x7ff) - 0x3ff; + if (__glibc_likely (j0 < 52)) { if (j0 < 0) { - /* return 0*sign(x) if |x|<1 */ + /* return 0 * sign (x) if |x| < 1 */ if (i0 >= 0) - { - i0 = i1 = 0; - } - else if (((i0 & 0x7fffffff) | i1) != 0) - { - i0 = 0xbff00000; i1 = 0; - } + i0 = 0; + else if ((i0 & 0x7fffffffffffffffl) != 0) + i0 = 0xbff0000000000000l; } else { - i = (0x000fffff) >> j0; - if (((i0 & i) | i1) == 0) - return x; /* x is integral */ + uint64_t i = 0x000fffffffffffffl >> j0; + if ((i0 & i) == 0) + return x; /* x is integral */ if (i0 < 0) - i0 += (0x00100000) >> j0; - i0 &= (~i); i1 = 0; - } - } - else if (j0 > 51) - { - if (j0 == 0x400) - return x + x; /* inf or NaN */ - else - return x; /* x is integral */ - } - else - { - i = ((uint32_t) (0xffffffff)) >> (j0 - 20); - if ((i1 & i) == 0) - return x; /* x is integral */ - if (i0 < 0) - { - if (j0 == 20) - i0 += 1; - else - { - j = i1 + (1 << (52 - j0)); - if (j < i1) - i0 += 1; /* got a carry */ - i1 = j; - } + i0 += 0x0010000000000000l >> j0; + i0 &= ~i; } - i1 &= (~i); + INSERT_WORDS64 (x, i0); } - INSERT_WORDS (x, i0, i1); + else if (j0 == 0x400) + return x + x; /* inf or NaN */ return x; +#endif /* ! USE_FLOOR_BUILTIN */ } #ifndef __floor libm_alias_double (__floor, floor) |