| /* Compute remainder and a congruent to the quotient. |
| Copyright (C) 1997-2018 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 <libm-alias-ldouble.h> |
| |
| |
| static const long double zero = 0.0; |
| |
| |
| long double |
| __remquol (long double x, long double p, int *quo) |
| { |
| int32_t ex,ep,hx,hp; |
| uint32_t sx,lx,lp; |
| int cquo,qs; |
| |
| GET_LDOUBLE_WORDS (ex, hx, lx, x); |
| GET_LDOUBLE_WORDS (ep, hp, lp, p); |
| sx = ex & 0x8000; |
| qs = (sx ^ (ep & 0x8000)) >> 15; |
| ep &= 0x7fff; |
| ex &= 0x7fff; |
| |
| /* Purge off exception values. */ |
| if ((ep | hp | lp) == 0) |
| return (x * p) / (x * p); /* p = 0 */ |
| if ((ex == 0x7fff) /* x not finite */ |
| || ((ep == 0x7fff) /* p is NaN */ |
| && (((hp & 0x7fffffff) | lp) != 0))) |
| return (x * p) / (x * p); |
| |
| if (ep <= 0x7ffb) |
| x = __ieee754_fmodl (x, 8 * p); /* now x < 8p */ |
| |
| if (((ex - ep) | (hx - hp) | (lx - lp)) == 0) |
| { |
| *quo = qs ? -1 : 1; |
| return zero * x; |
| } |
| |
| x = fabsl (x); |
| p = fabsl (p); |
| cquo = 0; |
| |
| if (ep <= 0x7ffc && x >= 4 * p) |
| { |
| x -= 4 * p; |
| cquo += 4; |
| } |
| if (ep <= 0x7ffd && x >= 2 * p) |
| { |
| x -= 2 * p; |
| cquo += 2; |
| } |
| |
| if (ep < 0x0002) |
| { |
| if (x + x > p) |
| { |
| x -= p; |
| ++cquo; |
| if (x + x >= p) |
| { |
| x -= p; |
| ++cquo; |
| } |
| } |
| } |
| else |
| { |
| long double p_half = 0.5 * p; |
| if (x > p_half) |
| { |
| x -= p; |
| ++cquo; |
| if (x >= p_half) |
| { |
| x -= p; |
| ++cquo; |
| } |
| } |
| } |
| |
| *quo = qs ? -cquo : cquo; |
| |
| /* Ensure correct sign of zero result in round-downward mode. */ |
| if (x == 0.0L) |
| x = 0.0L; |
| if (sx) |
| x = -x; |
| return x; |
| } |
| libm_alias_ldouble (__remquo, remquo) |
