UNIX 7th Ed. - /usr/src/libmp/gcd.c

   1: #include <mp.h>
   2: gcd(a,b,c) MINT *a,*b,*c;
   3: {   MINT x,y,z,w;
   4:     x.len=y.len=z.len=w.len=0;
   5:     move(a,&x);
   6:     move(b,&y);
   7:     while(y.len!=0)
   8:     {   mdiv(&x,&y,&w,&z);
   9:         move(&y,&x);
  10:         move(&z,&y);
  11:     }
  12:     move(&x,c);
  13:     xfree(&x);
  14:     xfree(&y);
  15:     xfree(&z);
  16:     xfree(&w);
  17:     return;
  18: }
  19: invert(a, b, c) MINT *a, *b, *c;
  20: {   MINT x, y, z, w, Anew, Aold;
  21:     int i = 0;
  22:     x.len = y.len = z.len = w.len = Aold.len = 0;
  23:     Anew.len = 1;
  24:     Anew.val = xalloc(1);
  25:     *Anew.val = 1;
  26:     move(b, &x);
  27:     move(a, &y);
  28:     while(y.len != 0)
  29:     {   mdiv(&x, &y, &w, &z);
  30:         move(&Anew, &x);
  31:         mult(&w, &Anew, &Anew);
  32:         madd(&Anew, &Aold, &Anew);
  33:         move(&x, &Aold);
  34:         move(&y, &x);
  35:         move(&z, &y);
  36:         i++;
  37:     }
  38:     move(&Aold, c);
  39:     if( (i&01) == 0) msub(b, c, c);
  40:     xfree(&x);
  41:     xfree(&y);
  42:     xfree(&z);
  43:     xfree(&w);
  44:     xfree(&Aold);
  45:     xfree(&Anew);
  46: }

Defined functions