1 files changed, 43 insertions, 0 deletions
diff --git a/sys/gio/nspp/sysint/packum.x b/sys/gio/nspp/sysint/packum.x
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+++ b/sys/gio/nspp/sysint/packum.x
@@ -0,0 +1,43 @@
+# 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