HP 3000 Manuals HP 3000 Manuals
HP C/XL MOVEB Function: Move Bytes
/*************************************************************
MOVEB SPL MOVE BYTES
This emulates the MOVE statement in SPL for byte moves with
no information removed from the stack, for example:
MOVE B1 := B2, (CNT), 0
LEN := tos;
@S1 := tos;
@D1 := tos;
This may be converted to C with:
LEN := MOVEB(B1,B2,CNT,0,&S1,&D1);
The parameters to MOVEB are:
to -- The address to be moved to.
from -- The address to be moved from.
count -- Number of bytes to be moved. A positive value
means left to right move, negative means
right to left.
sdec -- The SPL stack decrement. In this context, the
value of this parameter will determine if
the function accesses the last two
parameters, as follows:
sdec = 3 -- Ignore the last two parameters
(in SPL, this is the default
case, deleting 3 stack words).
sdec = 2 -- Expect only one parameter
after this, dest_addr.
sdec = 1 -- Expect two parameters after
this, dest_addr and source_addr.
sdec = 0 -- Same as 1. This is never a
meaningful operation in SPL,
as the TOS, or count value,
is always zero after the MOVE
instruction.
source_addr -- The address of the next char of "from" beyond
the final character moved.
dest_addr -- The address of the next char of "to" beyond the
final character moved.
The return value of the function is the number of bytes moved
***************************************************************/
short int MOVEB(to,from,count,sdec,source_addr,dest_addr)
char *to, *from, **source_addr, **dest_addr;
int count, sdec;
{
int c;
c = 0;
if (count>0) /* left-to-right move */
do *to++ = *from++; while (++c < count);
else if (count<0) /* right-to-left move */
{
count = -count;
do *to-- = = *from--; while (++c < count);
}
switch (sdec) {
case 0: ; /* fall through to case 1 */
case 1: *source_addr = from;
case 2: *dest_addr = to;
case 3: ; /* nil */
}
return(c);
}