1 /* Compute remainder and a congruent to the quotient.
2 Copyright (C) 1997-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
22 #include <math_private.h>
25 static const double zero = 0.0;
29 __remquo (double x, double y, int *quo)
35 EXTRACT_WORDS64 (hx, x);
36 EXTRACT_WORDS64 (hy, y);
37 sx = hx & UINT64_C(0x8000000000000000);
38 qs = sx ^ (hy & UINT64_C(0x8000000000000000));
39 hy &= UINT64_C(0x7fffffffffffffff);
40 hx &= UINT64_C(0x7fffffffffffffff);
42 /* Purge off exception values. */
43 if (__builtin_expect (hy == 0, 0))
44 return (x * y) / (x * y); /* y = 0 */
45 if (__builtin_expect (hx >= UINT64_C(0x7ff0000000000000) /* x not finite */
46 || hy > UINT64_C(0x7ff0000000000000), 0))/* y is NaN */
47 return (x * y) / (x * y);
49 if (hy <= UINT64_C(0x7fbfffffffffffff))
50 x = __ieee754_fmod (x, 8 * y); /* now x < 8y */
52 if (__builtin_expect (hx == hy, 0))
58 INSERT_WORDS64 (x, hx);
59 INSERT_WORDS64 (y, hy);
73 if (hy < UINT64_C(0x0020000000000000))
88 double y_half = 0.5 * y;
101 *quo = qs ? -cquo : cquo;
107 weak_alias (__remquo, remquo)
108 #ifdef NO_LONG_DOUBLE
109 strong_alias (__remquo, __remquol)
110 weak_alias (__remquo, remquol)