1 /* Copyright (c) 1979 Regents of the University of California */ 2 3 static char sccsid[] = "@(#)PACK.c 1.2 03/07/81"; 4 5 #include "h01errs.h" 6 7 /* 8 * pack(a,i,z) 9 * 10 * with: a: array[m..n] of t 11 * z: packed array[u..v] of t 12 * 13 * semantics: for j := u to v do 14 * z[j] := a[j-u+i]; 15 * 16 * need to check: 17 * 1. i >= m 18 * 2. i+(v-u) <= n (i.e. i-m <= (n-m)-(v-u)) 19 * 20 * on stack: lv(z), lv(a), rv(i) (len 4) 21 * 22 * move w(t)*(v-u+1) bytes from lv(a)+w(t)*(i-m) to lv(z) 23 */ 24 25 PACK(i, a, z, size_a, lb_a, ub_a, size_z) 26 27 long i; /* subscript into a to begin packing */ 28 char *a; /* pointer to structure a */ 29 char *z; /* pointer to structure z */ 30 long size_a; /* sizeof(a_type) */ 31 long lb_a; /* lower bound of structure a */ 32 long ub_a; /* (upper bound of a) - (lb_a + sizeof(z_type)) */ 33 long size_z; /* sizeof(z_type) */ 34 { 35 int subscr; 36 register char *cp; 37 register char *zp = z; 38 register char *limit; 39 40 subscr = i - lb_a; 41 if (subscr < 0 || subscr > ub_a) { 42 ERROR(EPACK, i); 43 return; 44 } 45 cp = &a[subscr * size_a]; 46 limit = cp + size_z; 47 do { 48 *zp++ = *cp++; 49 } while (cp < limit); 50 } 51