projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| b374846a KB |
1 | /* |
| 2 | * Copyright (c) 1990 Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * This code is derived from software contributed to Berkeley by | |
| 6 | * Chris Torek. | |
| 7 | * | |
| 8 | * %sccs.include.redist.c% | |
| 9 | */ | |
| 10 | ||
| 11 | #if defined(LIBC_SCCS) && !defined(lint) | |
| 12 | static char sccsid[] = "@(#)div.c 5.1 (Berkeley) %G%"; | |
| 13 | #endif /* LIBC_SCCS and not lint */ | |
| 14 | ||
| 15 | #include <stdlib.h> /* div_t */ | |
| 16 | ||
| 17 | /* | |
| 18 | * I AM NOT SURE THIS IS COMPLETELY PORTABLE | |
| 19 | * (or that it is even right) | |
| 20 | */ | |
| 21 | div_t | |
| 22 | div(num, denom) | |
| 23 | int num, denom; | |
| 24 | { | |
| 25 | div_t r; | |
| 26 | ||
| 27 | /* avoid deep thought */ | |
| 28 | if (num > 0 && denom < 0) { | |
| 29 | num = -num; | |
| 30 | denom = -denom; | |
| 31 | } | |
| 32 | r.quot = num / denom; | |
| 33 | r.rem = num % denom; | |
| 34 | if (num < 0 && denom > 0) { | |
| 35 | /* | |
| 36 | * Machine division and remainer may work either way. The | |
| 37 | * ANSI standard says that |r.quot| < |n/d| (where n/d | |
| 38 | * computed in infinite precision). If the remainder is | |
| 39 | * positive, we got the `wrong' answer, so fix it. | |
| 40 | */ | |
| 41 | if (r.rem > 0) { | |
| 42 | r.quot++; | |
| 43 | r.rem -= denom; | |
| 44 | } | |
| 45 | } | |
| 46 | return (r); | |
| 47 | } |