1 files changed, 55 insertions, 0 deletions
diff --git a/sys/nmemio/msvfwa.x b/sys/nmemio/msvfwa.x
new file mode 100644
index 00000000..cd3313c5
--- /dev/null
+++ b/sys/nmemio/msvfwa.x
@@ -0,0 +1,55 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include <mach.h>
+
+
+# MSVFWA -- Determine the buffer address which satisfies the maximum alignment
+# criteria, save the buffer fwa in the integer cell immediately preceding
+# this, and return a pointer to the user area of the buffer.
+
+pointer procedure msvfwa (fwa, dtype, nelem, sz_align, fwa_align)
+
+int	fwa, dtype, nelem, sz_align, fwa_align, nbits
+pointer	bufptr, lwl, offset
+
+pointer	mgdptr()
+int	coerce(), sizeof()
+
+include "nmemio.com"
+
+begin
+	# Compute the pointer to the data area which satisfies the desired
+	# alignment criteria.  Store the fwa of the actual OS allocated buffer
+	# in the integer cell preceeding the data area.
+
+	bufptr = mgdptr (fwa, TY_INT, sz_align, fwa_align)
+
+	nbits = sizeof(TY_INT) * 8 * SZB_CHAR
+	if (nbits == 64) {
+	    if (sizeof (dtype) == sizeof (TY_CHAR))
+	        offset = (nelem / SZ_INT + 1)
+	    else if (sizeof (dtype) == sizeof (TY_REAL))
+	        offset = (nelem / SZ_REAL + 1)
+	    else
+	        offset = nelem
+
+	} else if (nbits == 32) { 
+
+	    if (sizeof(dtype) < sz_align)
+	        offset = (nelem / (SZ_INT / sizeof(dtype))) + 1
+	    else
+	        offset = (nelem * sizeof (dtype)) / SZB_CHAR
+	}
+
+	lwl = bufptr + offset
+
+	Memi[bufptr-5] = fwa				# first word address
+	Memi[bufptr-4] = lwl				# last word location
+	Memi[bufptr-3] = dtype				# data type
+	Memi[bufptr-2] = nelem				# no. of elements
+	Memi[bufptr-1] = lsentinal			# lower sentinal
+	Memi[lwl]      = usentinal 			# upper sentinal
+
+	# Return pointer of type dtype to the first cell of the data area.
+	return (coerce (bufptr, TY_INT, dtype))
+end