2 Copyright (C) 2012 Free Software Foundation, Inc.
4 This program is free software: you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 remainder (double x, double y)
25 double q = - round (x / y);
26 double r = fma (q, y, x); /* = x + q * y, computed in one step */
27 /* Correct possible rounding errors in the quotient x / y. */
28 double half_y = 0.5L * y;
31 /* Expect -y/2 <= r <= y/2. */
33 q -= 1, r = fma (q, y, x);
34 else if (r < - half_y)
35 q += 1, r = fma (q, y, x);
39 /* Expect y/2 <= r <= -y/2. */
41 q += 1, r = fma (q, y, x);
43 q -= 1, r = fma (q, y, x);