| /* Compute remainder and a congruent to the quotient. |
| Copyright (C) 1997-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. |
| |
| 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/>. */ |
| |
| #include <math.h> |
| |
| #include <math_private.h> |
| #include <stdint.h> |
| |
| static const double zero = 0.0; |
| |
| |
| double |
| __remquo (double x, double y, int *quo) |
| { |
| int64_t hx, hy; |
| uint64_t sx, qs; |
| int cquo; |
| |
| EXTRACT_WORDS64 (hx, x); |
| EXTRACT_WORDS64 (hy, y); |
| sx = hx & UINT64_C(0x8000000000000000); |
| qs = sx ^ (hy & UINT64_C(0x8000000000000000)); |
| hy &= UINT64_C(0x7fffffffffffffff); |
| hx &= UINT64_C(0x7fffffffffffffff); |
| |
| /* Purge off exception values. */ |
| if (__builtin_expect (hy == 0, 0)) |
| return (x * y) / (x * y); /* y = 0 */ |
| if (__builtin_expect (hx >= UINT64_C(0x7ff0000000000000) /* x not finite */ |
| || hy > UINT64_C(0x7ff0000000000000), 0))/* y is NaN */ |
| return (x * y) / (x * y); |
| |
| if (hy <= UINT64_C(0x7fbfffffffffffff)) |
| x = __ieee754_fmod (x, 8 * y); /* now x < 8y */ |
| |
| if (__builtin_expect (hx == hy, 0)) |
| { |
| *quo = qs ? -1 : 1; |
| return zero * x; |
| } |
| |
| x = fabs (x); |
| INSERT_WORDS64 (y, hy); |
| cquo = 0; |
| |
| if (x >= 4 * y) |
| { |
| x -= 4 * y; |
| cquo += 4; |
| } |
| if (x >= 2 * y) |
| { |
| x -= 2 * y; |
| cquo += 2; |
| } |
| |
| if (hy < UINT64_C(0x0020000000000000)) |
| { |
| if (x + x > y) |
| { |
| x -= y; |
| ++cquo; |
| if (x + x >= y) |
| { |
| x -= y; |
| ++cquo; |
| } |
| } |
| } |
| else |
| { |
| double y_half = 0.5 * y; |
| if (x > y_half) |
| { |
| x -= y; |
| ++cquo; |
| if (x >= y_half) |
| { |
| x -= y; |
| ++cquo; |
| } |
| } |
| } |
| |
| *quo = qs ? -cquo : cquo; |
| |
| if (sx) |
| x = -x; |
| return x; |
| } |
| weak_alias (__remquo, remquo) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__remquo, __remquol) |
| weak_alias (__remquo, remquol) |
| #endif |
