qmul.cpp

   1 //      Multiply rational numbers
   2 //
   3 //      Input:          tos-2           multiplicand
   4 //
   5 //                      tos-1           multiplier
   6 //
   7 //      Output:         product on stack
   8
   9 #include "stdafx.h"
  10 #include "defs.h"
  11
  12 void
  13 qmul(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(p1->u.q.a) || MZERO(p2->u.q.a)) {
  25                 push(zero);
  26                 restore();
  27                 return;
  28         }
  29
  30         aa = mmul(p1->u.q.a, p2->u.q.a);
  31         bb = mmul(p1->u.q.b, p2->u.q.b);
  32
  33         c = mgcd(aa, bb);
  34
  35         MSIGN(c) = MSIGN(bb);
  36
  37         p1 = alloc();
  38
  39         p1->k = NUM;
  40
  41         p1->u.q.a = mdiv(aa, c);
  42         p1->u.q.b = mdiv(bb, c);
  43
  44         mfree(aa);
  45         mfree(bb);
  46         mfree(c);
  47
  48         push(p1);
  49
  50         restore();
  51 }