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4bbfdf97 EA |
1 | /* `long long int' divison with remainder. |
2 | Copyright (C) 1992, 1996, 1997 Free Software Foundation, Inc. | |
3 | This file is part of the GNU C Library. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
266bdc1f MF |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
4bbfdf97 | 18 | |
4bbfdf97 EA |
19 | #include <features.h> |
20 | #include <stdlib.h> | |
21 | ||
22 | ||
23 | /* Return the `lldiv_t' representation of NUMER over DENOM. */ | |
24 | lldiv_t | |
25 | lldiv (long long int numer, long long int denom) | |
26 | { | |
27 | lldiv_t result; | |
28 | ||
29 | result.quot = numer / denom; | |
30 | result.rem = numer % denom; | |
31 | ||
32 | /* The ANSI standard says that |QUOT| <= |NUMER / DENOM|, where | |
33 | NUMER / DENOM is to be computed in infinite precision. In | |
34 | other words, we should always truncate the quotient towards | |
35 | zero, never -infinity. Machine division and remainer may | |
36 | work either way when one or both of NUMER or DENOM is | |
37 | negative. If only one is negative and QUOT has been | |
38 | truncated towards -infinity, REM will have the same sign as | |
39 | DENOM and the opposite sign of NUMER; if both are negative | |
40 | and QUOT has been truncated towards -infinity, REM will be | |
41 | positive (will have the opposite sign of NUMER). These are | |
42 | considered `wrong'. If both are NUM and DENOM are positive, | |
43 | RESULT will always be positive. This all boils down to: if | |
44 | NUMER >= 0, but REM < 0, we got the wrong answer. In that | |
45 | case, to get the right answer, add 1 to QUOT and subtract | |
46 | DENOM from REM. */ | |
47 | ||
48 | if (numer >= 0 && result.rem < 0) | |
49 | { | |
50 | ++result.quot; | |
51 | result.rem -= denom; | |
52 | } | |
53 | ||
54 | return result; | |
55 | } | |
56 | ||
57 | #if __WORDSIZE != 64 | |
58 | #undef imaxdiv | |
af017216 | 59 | strong_alias(lldiv,imaxdiv) |
4bbfdf97 | 60 | #endif |