>>>>> "AB" == Alan Burlison <[EMAIL PROTECTED]> writes:
AB> Uri Guttman wrote:
>> but indexing directly into a stack frame is effectively a register
>> window. the problem is that you need to do an indirection through the
>> window base for every access and that is slow in software (but free in
>> hardware).
AB> Not quite - a register window system has real registers, it's just
AB> at some point they may end up in memory. That's not the same as
AB> indexing into memory on every access.
what i meant is that the indirection to access a given windowed register
using the window base is free (speed wise) in hardware, but doing the
same thing in software costs.
but comparing the hardware design with a pure software design is not too
useful. the costs and goals are so different. some conceptual analogies
are useful but saying register windows are fast in hardware (BTW that is
risc stuff) but not a speed win in software (where parrot is leaning
towards looking cisc-like) is not relevant.
uri
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Learn Advanced Object Oriented Perl from Damian Conway - Boston, July 10-11
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