projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| 0ecb606c JJ |
1 | /* Compute remainder and a congruent to the quotient. |
| 2 | Copyright (C) 1997,1999,2002,2004,2006 Free Software Foundation, Inc. | |
| 3 | This file is part of the GNU C Library. | |
| 4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and | |
| 5 | Jakub Jelinek <jj@ultra.linux.cz>, 1999. | |
| 6 | ||
| 7 | The GNU C Library is free software; you can redistribute it and/or | |
| 8 | modify it under the terms of the GNU Lesser General Public | |
| 9 | License as published by the Free Software Foundation; either | |
| 10 | version 2.1 of the License, or (at your option) any later version. | |
| 11 | ||
| 12 | The GNU C Library is distributed in the hope that it will be useful, | |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 15 | Lesser General Public License for more details. | |
| 16 | ||
| 17 | You should have received a copy of the GNU Lesser General Public | |
| 18 | License along with the GNU C Library; if not, write to the Free | |
| 19 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
| 20 | 02111-1307 USA. */ | |
| 21 | ||
| 22 | #include <math.h> | |
| 23 | ||
| 24 | #include "math_private.h" | |
| 25 | #include <math_ldbl_opt.h> | |
| 26 | ||
| 27 | ||
| 28 | static const long double zero = 0.0; | |
| 29 | ||
| 30 | ||
| 31 | long double | |
| 32 | __remquol (long double x, long double y, int *quo) | |
| 33 | { | |
| 34 | int64_t hx,hy; | |
| 35 | u_int64_t sx,lx,ly,qs; | |
| 36 | int cquo; | |
| 37 | ||
| 38 | GET_LDOUBLE_WORDS64 (hx, lx, x); | |
| 39 | GET_LDOUBLE_WORDS64 (hy, ly, y); | |
| 40 | sx = hx & 0x8000000000000000ULL; | |
| 41 | qs = sx ^ (hy & 0x8000000000000000ULL); | |
| 42 | hy &= 0x7fffffffffffffffLL; | |
| 43 | hx &= 0x7fffffffffffffffLL; | |
| 44 | ||
| 45 | /* Purge off exception values. */ | |
| 46 | if ((hy | (ly & 0x7fffffffffffffff)) == 0) | |
| 47 | return (x * y) / (x * y); /* y = 0 */ | |
| 48 | if ((hx >= 0x7ff0000000000000LL) /* x not finite */ | |
| 49 | || ((hy >= 0x7ff0000000000000LL) /* y is NaN */ | |
| 50 | && (((hy - 0x7ff0000000000000LL) | ly) != 0))) | |
| 51 | return (x * y) / (x * y); | |
| 52 | ||
| 53 | if (hy <= 0x7fbfffffffffffffLL) | |
| 54 | x = __ieee754_fmodl (x, 8 * y); /* now x < 8y */ | |
| 55 | ||
| 56 | if (((hx - hy) | (lx - ly)) == 0) | |
| 57 | { | |
| 58 | *quo = qs ? -1 : 1; | |
| 59 | return zero * x; | |
| 60 | } | |
| 61 | ||
| 62 | x = fabsl (x); | |
| 63 | y = fabsl (y); | |
| 64 | cquo = 0; | |
| 65 | ||
| 66 | if (x >= 4 * y) | |
| 67 | { | |
| 68 | x -= 4 * y; | |
| 69 | cquo += 4; | |
| 70 | } | |
| 71 | if (x >= 2 * y) | |
| 72 | { | |
| 73 | x -= 2 * y; | |
| 74 | cquo += 2; | |
| 75 | } | |
| 76 | ||
| 77 | if (hy < 0x0020000000000000LL) | |
| 78 | { | |
| 79 | if (x + x > y) | |
| 80 | { | |
| 81 | x -= y; | |
| 82 | ++cquo; | |
| 83 | if (x + x >= y) | |
| 84 | { | |
| 85 | x -= y; | |
| 86 | ++cquo; | |
| 87 | } | |
| 88 | } | |
| 89 | } | |
| 90 | else | |
| 91 | { | |
| 92 | long double y_half = 0.5L * y; | |
| 93 | if (x > y_half) | |
| 94 | { | |
| 95 | x -= y; | |
| 96 | ++cquo; | |
| 97 | if (x >= y_half) | |
| 98 | { | |
| 99 | x -= y; | |
| 100 | ++cquo; | |
| 101 | } | |
| 102 | } | |
| 103 | } | |
| 104 | ||
| 105 | *quo = qs ? -cquo : cquo; | |
| 106 | ||
| 107 | if (sx) | |
| 108 | x = -x; | |
| 109 | return x; | |
| 110 | } | |
| 111 | long_double_symbol (libm, __remquol, remquol); |