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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <mach.h>
include <nspp.h>
# PACKUM -- Pack an integer array containing 16 bit quantities into a buffer.
# Each 16 bit input datum occupies one integer; the input integers may be
# any size. This implementation will work on most byte oriented machines,
# but will generate a fatal error on machines with 24, 60, etc. bit words.
procedure packum (a, npix, bp)
int a[ARB] # input array, one 16-bit datum per word
int npix # number of mc words
int bp # LOC pointer to output buffer
int offset, dummy[1]
int loci()
include "nspp.com"
begin
offset = bp - loci (dummy) + 1
# It is necessary to swap the order of the metacode words on some
# machines. Npix is always an even number. The swapping must be
# done here because the NSPP and MCTR code assumes that the bytes
# are ordered in a certain manner (most significant first). Thus,
# when the buffer is flushed FLUSHB will set the magic bits, and
# if we wait and swap upon output rather than here, it will set the
# bits in the wrong word.
if (mbswap == YES) # flag set from graphcap in nsppkern
call mcswap (a, npix)
switch (NBITS_MCWORD) {
case NBITS_SHORT:
call achtis (a, dummy[offset], npix)
case NBITS_INT:
call amovi (a, dummy[offset], npix)
default:
call fatal (1, "gio.ncar.packum: cannot pack metacode")
}
end
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