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+AS - Assembler Sources
+
+This directory contains any (non-kernel) files which it has proven
+desirable to optimize in assembler. Most of these routines are not
+required for the operation of the system, although considerable gains
+in speed may be possible in some cases. If the autogeneration routines
+cannot find a particular assembler file, the portable routine will
+automatically be used instead.
+
+The following assembler files are required:
+
+ zsvjmp.s (libos.a)
+
+The following should normally be optimized in assembler, particularly if the
+machine has special memory move or bitfield instructions:
+
+ aclr.s clear a block of memory
+ amov.s move a block of memory
+ bitpak.s write into a bit field
+ bitupk.s read from a bit field
+ bytmov.s a variant on amov.s
+ ishift.s bit shift, also iand, ior (used by NCAR/graphics)
+
+The following can be omitted without significant penalty:
+
+ aaddks.s
+ aadds.s
+ aluir.s
+ aluis.s
+ amapr.s
+ amaps.s
+ awsur.s
+ awsus.s
+ cyboow.s