Re: [cc65] Zeropage Regbank

Shawn Jefferson kirjoitti:
>
> How difficult, or possible would it be to allow the zeropage regbank 
> size to be specified in the linker config script, or via a pragma 
> command? On the Atari platform there is about 60-70 bytes of free 
> zeropage for use, and I’d like to easily use them for local variables 
> without the complexity of allocating and managing them myself.
>
> I know there is some overhead in saving and restoring the zeropage 
> variables, and at some point doing this negates the benefit you get. 
> It would be nice if the compiler could tell you when that is the case 
> or not as well, but that may be much more difficult.
>

In Atari Lynx target there is already two segments ZEROPAGE and EXTZP 
that is mapped tp ZP and USERZP is free to use.

MEMORY {
USERZP1: start = 0, size = 205, type = rw, define = yes;
USERZP2: start = 0, size = 205, type = rw, define = yes;
ZP: start = 205, size = 51, type = rw, define = yes;
}

SEGMENTS {
ZEROPAGE: load = ZP, type = zp;
EXTZP: load = ZP, type = zp;
USERVAR1: load = USERZP1, type = zp;
USERVAR2: load = USERZP2, type = zp;
}

Copying the USERZP1 segment into conventional memory when swapping from 
one code block to the next would not be so bad.
(And quite simple in my opinion.)

--
Karri

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