# # Copyright (c) 1987 University of Maryland Department of Computer Science. # All rights reserved. Permission to copy for any purpose is hereby granted # so long as this copyright notice remains intact. # rcsid: .asciz "$Header: bcopy.s,v 1.2 87/06/16 18:27:33 chris Exp $" # bcopy (from, to, count) char *from, *to; int count; # # Copy "count" bytes from "from" to "to"; not guaranteed to # work if "from" and "to" overlap. .align 2 .globl _bcopy _bcopy: .word 0 movl 4(ap),r1 # r1 = from movl 8(ap),r3 # r3 = to brb 2f 1: subl2 r0,12(ap) # count-=65535 (bytes moved this time) movc3 r0,(r1),(r3) # r1, r3 magically point to next 65K 2: movzwl $65535,r0 cmpl 12(ap),r0 # <= 65535 bytes to move? jgtr 1b # brif not, move 65535 and try again movc3 12(ap),(r1),(r3) # move up to 65535 bytes ret