projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 051b1e55 DF |
1 | /* |
| 2 | * Copyright (c) 1980 Regents of the University of California. | |
| 3 | * All rights reserved. The Berkeley software License Agreement | |
| 4 | * specifies the terms and conditions for redistribution. | |
| 5 | */ | |
| 6 | ||
| 7 | #ifndef lint | |
| 8 | static char sccsid[] = "@(#)pow.c 5.1 (Berkeley) %G%"; | |
| 9 | #endif not lint | |
| 3be90705 SL |
10 | |
| 11 | #include <mp.h> | |
| 12 | pow(a,b,c,d) MINT *a,*b,*c,*d; | |
| 13 | { int i,j,n; | |
| 14 | MINT x,y; | |
| 15 | x.len=y.len=0; | |
| 16 | xfree(d); | |
| 17 | d->len=1; | |
| 18 | d->val=xalloc(1,"pow"); | |
| 19 | *d->val=1; | |
| 20 | for(j=0;j<b->len;j++) | |
| 21 | { n=b->val[b->len-j-1]; | |
| 22 | for(i=0;i<15;i++) | |
| 23 | { mult(d,d,&x); | |
| 24 | mdiv(&x,c,&y,d); | |
| 25 | if((n=n<<1)&0100000) | |
| 26 | { mult(a,d,&x); | |
| 27 | mdiv(&x,c,&y,d); | |
| 28 | } | |
| 29 | } | |
| 30 | } | |
| 31 | xfree(&x); | |
| 32 | xfree(&y); | |
| 33 | return; | |
| 34 | } | |
| 35 | rpow(a,n,b) MINT *a,*b; | |
| 36 | { MINT x,y; | |
| 37 | int i; | |
| 38 | x.len=1; | |
| 39 | x.val=xalloc(1,"rpow"); | |
| 40 | *x.val=n; | |
| 41 | y.len=n*a->len+4; | |
| 42 | y.val=xalloc(y.len,"rpow2"); | |
| 43 | for(i=0;i<y.len;i++) y.val[i]=0; | |
| 44 | y.val[y.len-1]=010000; | |
| 45 | xfree(b); | |
| 46 | pow(a,&x,&y,b); | |
| 47 | xfree(&x); | |
| 48 | xfree(&y); | |
| 49 | return; | |
| 50 | } |