qdiv.cpp

   1 //      Divide rational numbers
   2 //
   3 //      Input:          tos-2           dividend
   4 //
   5 //                      tos-1           divisor
   6 //
   7 //      Output:         quotient on stack
   8
   9 #include "stdafx.h"
  10 #include "defs.h"
  11
  12 void
  13 qdiv(void)
  14 {
  15         unsigned int *aa, *bb, *c;
  16
  17         save();
  18
  19         p2 = pop();
  20         p1 = pop();
  21
  22         // zero?
  23
  24         if (MZERO(p2->u.q.a))
  25                 stop("divide by zero");
  26
  27         if (MZERO(p1->u.q.a)) {
  28                 push(zero);
  29                 restore();
  30                 return;
  31         }
  32
  33         aa = mmul(p1->u.q.a, p2->u.q.b);
  34         bb = mmul(p1->u.q.b, p2->u.q.a);
  35
  36         c = mgcd(aa, bb);
  37
  38         MSIGN(c) = MSIGN(bb);
  39
  40         p1 = alloc();
  41
  42         p1->k = NUM;
  43
  44         p1->u.q.a = mdiv(aa, c);
  45         p1->u.q.b = mdiv(bb, c);
  46
  47         mfree(aa);
  48         mfree(bb);
  49         mfree(c);
  50
  51         push(p1);
  52
  53         restore();
  54 }