1*1669Smckusick /* Copyright (c) 1979 Regents of the University of California */ 2*1669Smckusick 3*1669Smckusick static char sccsid[] = "@(#)PACK.c 1.1 10/30/80"; 4*1669Smckusick 5*1669Smckusick #include "h01errs.h" 6*1669Smckusick 7*1669Smckusick /* 8*1669Smckusick * pack(a,i,z) 9*1669Smckusick * 10*1669Smckusick * with: a: array[m..n] of t 11*1669Smckusick * z: packed array[u..v] of t 12*1669Smckusick * 13*1669Smckusick * semantics: for j := u to v do 14*1669Smckusick * z[j] := a[j-u+i]; 15*1669Smckusick * 16*1669Smckusick * need to check: 17*1669Smckusick * 1. i >= m 18*1669Smckusick * 2. i+(v-u) <= n (i.e. i-m <= (n-m)-(v-u)) 19*1669Smckusick * 20*1669Smckusick * on stack: lv(z), lv(a), rv(i) (len 4) 21*1669Smckusick * 22*1669Smckusick * move w(t)*(v-u+1) bytes from lv(a)+w(t)*(i-m) to lv(z) 23*1669Smckusick */ 24*1669Smckusick 25*1669Smckusick PACK(i, a, z, size_a, lb_a, ub_a, size_z) 26*1669Smckusick 27*1669Smckusick int i; /* subscript into a to begin packing */ 28*1669Smckusick char *a; /* pointer to structure a */ 29*1669Smckusick char *z; /* pointer to structure z */ 30*1669Smckusick int size_a; /* sizeof(a_type) */ 31*1669Smckusick int lb_a; /* lower bound of structure a */ 32*1669Smckusick int ub_a; /* (upper bound of a) - (lb_a + sizeof(z_type)) */ 33*1669Smckusick int size_z; /* sizeof(z_type) */ 34*1669Smckusick { 35*1669Smckusick int subscr; 36*1669Smckusick register char *cp; 37*1669Smckusick register char *zp = z; 38*1669Smckusick register char *limit; 39*1669Smckusick 40*1669Smckusick subscr = i - lb_a; 41*1669Smckusick if (subscr < 0 || subscr > ub_a) { 42*1669Smckusick ERROR(EPACK, i); 43*1669Smckusick return; 44*1669Smckusick } 45*1669Smckusick cp = &a[subscr * size_a]; 46*1669Smckusick limit = cp + size_z; 47*1669Smckusick do { 48*1669Smckusick *zp++ = *cp++; 49*1669Smckusick } while (cp < limit); 50*1669Smckusick } 51