| /* 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 and |
| Jakub Jelinek <jj@ultra.linux.cz>, 1999. |
| |
| 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 "quadmath-imp.h" |
| |
| static const __float128 zero = 0.0; |
| |
| |
| __float128 |
| remquoq (__float128 x, __float128 y, int *quo) |
| { |
| int64_t hx,hy; |
| uint64_t sx,lx,ly,qs; |
| int cquo; |
| |
| GET_FLT128_WORDS64 (hx, lx, x); |
| GET_FLT128_WORDS64 (hy, ly, y); |
| sx = hx & 0x8000000000000000ULL; |
| qs = sx ^ (hy & 0x8000000000000000ULL); |
| hy &= 0x7fffffffffffffffLL; |
| hx &= 0x7fffffffffffffffLL; |
| |
| /* Purge off exception values. */ |
| if ((hy | ly) == 0) |
| return (x * y) / (x * y); /* y = 0 */ |
| if ((hx >= 0x7fff000000000000LL) /* x not finite */ |
| || ((hy >= 0x7fff000000000000LL) /* y is NaN */ |
| && (((hy - 0x7fff000000000000LL) | ly) != 0))) |
| return (x * y) / (x * y); |
| |
| if (hy <= 0x7ffbffffffffffffLL) |
| x = fmodq (x, 8 * y); /* now x < 8y */ |
| |
| if (((hx - hy) | (lx - ly)) == 0) |
| { |
| *quo = qs ? -1 : 1; |
| return zero * x; |
| } |
| |
| x = fabsq (x); |
| y = fabsq (y); |
| cquo = 0; |
| |
| if (hy <= 0x7ffcffffffffffffLL && x >= 4 * y) |
| { |
| x -= 4 * y; |
| cquo += 4; |
| } |
| if (hy <= 0x7ffdffffffffffffLL && x >= 2 * y) |
| { |
| x -= 2 * y; |
| cquo += 2; |
| } |
| |
| if (hy < 0x0002000000000000LL) |
| { |
| if (x + x > y) |
| { |
| x -= y; |
| ++cquo; |
| if (x + x >= y) |
| { |
| x -= y; |
| ++cquo; |
| } |
| } |
| } |
| else |
| { |
| __float128 y_half = 0.5Q * y; |
| if (x > y_half) |
| { |
| x -= y; |
| ++cquo; |
| if (x >= y_half) |
| { |
| x -= y; |
| ++cquo; |
| } |
| } |
| } |
| |
| *quo = qs ? -cquo : cquo; |
| |
| /* Ensure correct sign of zero result in round-downward mode. */ |
| if (x == 0) |
| x = 0; |
| if (sx) |
| x = -x; |
| return x; |
| } |