VAX Assembler trivia: "Caution: New Opcodes"

Stephen Crawley scc at cl.cam.ac.uk
Wed Jul 12 13:11:51 AEST 1989


This evening while recompiling an Ultrix 2.2 kernel, the assembler
emitted the following peculiar message for if_ne.c

  Caution: New Opcodes.
  These are not defined for all implementations of the VAX architecture

It turns out that if_ne.c calls functions that are inlined to give the
interlocked queue instructions (insqhi, insqti, remqhi & remqti).
These 4 instructions are labelled in src/bin/as/instrs as NEW.
But my copy of the VAX architecture manual says that the queue
instructions are part of the kernel subset of the VAX instruction set; 
all VAX implementations are supposed to provide these instructions.

Does anyone know if there ever was a member of the VAX architecture 
family that did not implement the interlocked queue instructions?

-- Steve

p.s.	This "New Opcodes" buggette exists in both the Ultrix 2.2
	and 3.0 versions of the assembler.  Not that it makes any
	difference of course.



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