Re: [cc65] const/volatile

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From: Ullrich von Bassewitz (uz_at_musoftware.de)
Date: 2003-01-19 12:24:21


Hi!

On Thu, Jan 16, 2003 at 11:54:12AM +0100, Christian Krüger wrote:
> if a parameter declared as const, you shouldn't/cannot modify
> its value, so when reusing this value, you don't have
> to fetch it again... - again my sample:

So if I need it, but don't fetch it again, how do I get the value? Values
don't come from nowhere, so I would have to remember the value somewhere. And
since the 6502 doesn't have many registers, there is no place, where a value
can be remembered effectively. Which in turn means that the optimization does
not work on the 6502 architecture. For other machines, it may be possible to
keep values in registers as long as possible, but the 6502 needs any register
it has for actual arithmetics and memory access.

Regards


        Uz


-- 
Ullrich von Bassewitz                                  uz_at_musoftware.de
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