1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (C) 1992, 1997 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4  */
5 
6 typedef struct {
7 	long    quot;
8 	long    rem;
9 } ldiv_t;
10 /* Return the `ldiv_t' representation of NUMER over DENOM.  */
11 ldiv_t
ldiv(long int numer,long int denom)12 ldiv (long int numer, long int denom)
13 {
14   ldiv_t result;
15 
16   result.quot = numer / denom;
17   result.rem = numer % denom;
18 
19   /* The ANSI standard says that |QUOT| <= |NUMER / DENOM|, where
20      NUMER / DENOM is to be computed in infinite precision.  In
21      other words, we should always truncate the quotient towards
22      zero, never -infinity.  Machine division and remainer may
23      work either way when one or both of NUMER or DENOM is
24      negative.  If only one is negative and QUOT has been
25      truncated towards -infinity, REM will have the same sign as
26      DENOM and the opposite sign of NUMER; if both are negative
27      and QUOT has been truncated towards -infinity, REM will be
28      positive (will have the opposite sign of NUMER).  These are
29      considered `wrong'.  If both are NUM and DENOM are positive,
30      RESULT will always be positive.  This all boils down to: if
31      NUMER >= 0, but REM < 0, we got the wrong answer.  In that
32      case, to get the right answer, add 1 to QUOT and subtract
33      DENOM from REM.  */
34 
35   if (numer >= 0 && result.rem < 0)
36     {
37       ++result.quot;
38       result.rem -= denom;
39     }
40 
41   return result;
42 }
43