Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!ucsd!hub!dougp
From: dougp@voodoo.ucsb.edu
Newsgroups: comp.sys.amiga
Subject: Stack
Message-ID: <2105@hub.UUCP>
Date: 22 Jul 89 03:49:07 GMT
Sender: news@hub.UUCP
Organization: UC, Santa Barbara. Physics Computer Services
Lines: 20

-Message-Text-Follows-

	Is there any particular reasor that no microprocessor has limit
registors for the stack? What I mean by limit registers is a pair of
registors which contains the minimum alowable stack address and the 
maximum alowable stack address, and cause an exception, trap or
interrupt when some code attempts to move the stack pointer out of
the range they discribe.
	Asside from making stack problems much easier to find, this would
make it possible to build code which had a dinamicly sized stack. When
you got a stack overflow, the exception handler could alocate a new 
block of memory, move the stack ponter to this new memory and reset
the limits. The stack underflow would work similarly, freeing the
extra stack space and moving the stack pointer to the previous block.
	Now this could get a bit messy if you were in a tight loop which
was pushing and poping right at the discontinuity of the stack, but
this would cirtainly aleviate the problems with programs that sometimes
need 200000 bytes of stack when you've only alocated 4000.

					Douglas Peale