8.5 Assembler Procedures

The next three procedures are written in assembler and run with the processor priority level set to seven. These procedures do not observe the normal procedure entry conventions so that r5 and r6, the environment and stack pointers, are not disturbed during procedure entry and exit.

As has already been noted, “savu” and “retu” can combine to produce the effect of a coroutine jump. The third procedure, “aretu,” when followed by a “return” statement produces the effect of a non-local “goto”.