src/baseparsuif/suifmath/fract.cc

   1 /* file "fract.cc" */
   2
   3 /*  Copyright (c) 1994 Stanford University
   4
   5     All rights reserved.
   6
   7     This software is provided under the terms described in
   8     the "suif_copyright.h" include file. */
   9
  10 #include <suif_copyright.h>
  11
  12 /*  Fraction Implementation */
  13 #define _MODULE_ "libsuifmath.a"
  14 #pragma implementation "fract.h"
  15
  16 #include "suif1.h"
  17 #include "fract.h"
  18
  19
  20 /*  Reduce the fraction.  */
  21
  22 void fract::reduce()
  23 {
  24     if (n == 0) d = 1;
  25     else if (d == 1) ;
  26     else if (n == 1 && d > 0) ;
  27     else reduce_aux();
  28 }
  29
  30
  31
  32 void fract::reduce_aux()
  33 {
  34     /* convert to absolute values */
  35     int mm = (n < 0) ? -n : n;
  36     int nn = (d < 0) ? -d : d;
  37
  38     /* find gcd and divide thru by it */
  39     while (TRUE) {
  40         int rr = mm % nn;
  41         if (rr == 0) break;             /* nn is the answer */
  42         mm = nn;
  43         nn = rr;
  44     }
  45     if (d < 0) nn = -nn;
  46     n /= nn;
  47     d /= nn;
  48 }
  49
  50
  51
  52 fract fract::operator/(const fract &a) const
  53 {
  54     assert(a.num() != 0);
  55
  56     /* get the reciprocal */
  57     fract rcp;
  58     if (a.num() < 0) {
  59         rcp = fract(fneg(a.denom()), fneg(a.num()));
  60     } else {
  61         rcp = fract(a.denom(), a.num());
  62     }
  63
  64     /* multiply by the reciprocal */
  65     return *this * rcp;
  66 }
  67
  68
  69
  70 void fract::print(FILE *f) const
  71 {
  72     if (d == 1) {
  73         fprintf(f, " %d ", n);
  74     } else {
  75         fprintf(f, "%d/%d", n, d);
  76     }
  77     fflush(f);
  78 }