Re: Caller/Callee saved Registers

preston@noel.cs.rice.edu (Preston Briggs) writes:
+Steele and Sussman propose an alternative
-resource called "racks". Rather than a set of registers and a stack,
+their machine would have a set of these racks. A rack has 4 operations:
- Assign(R, V) -- make V the current value of the rack R
+ Fetch(R) -- return the current value of the rack R
- Save(R) -- save (probably on an internal stack) the current
+ value of the rack R
- Restore -- restore the current value of the rack R
+So, obviously we can use a bunch of these things as registers, simply
-issuing Saves and Restores around procedure calls.


I haven't considered 'racks' all that carefully, but my first question is
how non-stack environments can be properly handled -- i.e., closures.
I haven't read the paper in some time, but I don't recall a solution
to the problem of closures.


Equally interesting is what happens in the case of non-local returns --
i.e., longjmp & various kinds of signals.
--

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