🚀 go-pugleaf

> ==========Michael Elizabeth Chastain, 11/25/95==========

> I say 'may have to' because every processor I know can implement
> variable-sized stack frames by subtracting an appropriate value from
> the stack pointer at the appropriate time.  But what about processors I
> don't know about?  Are there truly any processors in use which don't
> support subtracting a computed value from the stack pointer?

Subtract implies stack direction.  There have been machines with
stacks that increased in address instead of decreased in address.
Have they all really disappeared from heavy use?  I am rusty
on current machine architectures, but an amazing variety of
architectures have existed, including some for which the address
of a memory location varied according to the width of the access.

Also, how about the case of several of these in one stack frame.
The "start" (i.e., address) of some is affected by the size of others
rather than just being an offset into the stack frame from the frame
pointer.  That makes the solution messier to do and starts favoring
the various heap schemes for this as preserving fixed frame offsets
is usually a very good thing to do.

Good Day
Dick
Dick.Menninger@DaytonOH.ATTGIS.COM
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