projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| f964490f | 1 | /* Compute remainder and a congruent to the quotient. |
| b168057a | 2 | Copyright (C) 1997-2015 Free Software Foundation, Inc. |
| f964490f RM |
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 | |
| 59ba27a6 PE |
18 | License along with the GNU C Library; if not, see |
| 19 | <http://www.gnu.org/licenses/>. */ | |
| f964490f RM |
20 | |
| 21 | #include <math.h> | |
| 22 | ||
| 1ed0291c | 23 | #include <math_private.h> |
| f964490f RM |
24 | #include <math_ldbl_opt.h> |
| 25 | ||
| 26 | ||
| 27 | static const long double zero = 0.0; | |
| 28 | ||
| 29 | ||
| 30 | long double | |
| 31 | __remquol (long double x, long double y, int *quo) | |
| 32 | { | |
| 33 | int64_t hx,hy; | |
| 34 | u_int64_t sx,lx,ly,qs; | |
| 35 | int cquo; | |
| 765714ca AM |
36 | double xhi, xlo, yhi, ylo; |
| 37 | ||
| 38 | ldbl_unpack (x, &xhi, &xlo); | |
| 39 | EXTRACT_WORDS64 (hx, xhi); | |
| 40 | EXTRACT_WORDS64 (lx, xlo); | |
| 41 | ldbl_unpack (y, &yhi, &ylo); | |
| 42 | EXTRACT_WORDS64 (hy, yhi); | |
| 43 | EXTRACT_WORDS64 (ly, ylo); | |
| f964490f RM |
44 | sx = hx & 0x8000000000000000ULL; |
| 45 | qs = sx ^ (hy & 0x8000000000000000ULL); | |
| 46 | hy &= 0x7fffffffffffffffLL; | |
| 47 | hx &= 0x7fffffffffffffffLL; | |
| 48 | ||
| 49 | /* Purge off exception values. */ | |
| 765714ca | 50 | if (hy == 0) |
| f964490f RM |
51 | return (x * y) / (x * y); /* y = 0 */ |
| 52 | if ((hx >= 0x7ff0000000000000LL) /* x not finite */ | |
| 765714ca | 53 | || (hy > 0x7ff0000000000000LL)) /* y is NaN */ |
| f964490f RM |
54 | return (x * y) / (x * y); |
| 55 | ||
| 56 | if (hy <= 0x7fbfffffffffffffLL) | |
| 57 | x = __ieee754_fmodl (x, 8 * y); /* now x < 8y */ | |
| 58 | ||
| 59 | if (((hx - hy) | (lx - ly)) == 0) | |
| 60 | { | |
| 61 | *quo = qs ? -1 : 1; | |
| 62 | return zero * x; | |
| 63 | } | |
| 64 | ||
| 65 | x = fabsl (x); | |
| 66 | y = fabsl (y); | |
| 67 | cquo = 0; | |
| 68 | ||
| 69 | if (x >= 4 * y) | |
| 70 | { | |
| 71 | x -= 4 * y; | |
| 72 | cquo += 4; | |
| 73 | } | |
| 74 | if (x >= 2 * y) | |
| 75 | { | |
| 76 | x -= 2 * y; | |
| 77 | cquo += 2; | |
| 78 | } | |
| 79 | ||
| 80 | if (hy < 0x0020000000000000LL) | |
| 81 | { | |
| 82 | if (x + x > y) | |
| 83 | { | |
| 84 | x -= y; | |
| 85 | ++cquo; | |
| 86 | if (x + x >= y) | |
| 87 | { | |
| 88 | x -= y; | |
| 89 | ++cquo; | |
| 90 | } | |
| 91 | } | |
| 92 | } | |
| 93 | else | |
| 94 | { | |
| 95 | long double y_half = 0.5L * y; | |
| 96 | if (x > y_half) | |
| 97 | { | |
| 98 | x -= y; | |
| 99 | ++cquo; | |
| 100 | if (x >= y_half) | |
| 101 | { | |
| 102 | x -= y; | |
| 103 | ++cquo; | |
| 104 | } | |
| 105 | } | |
| 106 | } | |
| 107 | ||
| 108 | *quo = qs ? -cquo : cquo; | |
| 109 | ||
| 110 | if (sx) | |
| 111 | x = -x; | |
| 112 | return x; | |
| 113 | } | |
| 114 | long_double_symbol (libm, __remquol, remquol); |