Re: [cc65] ca65 Z80 support

On Mon, Dec 05, 2005 at 09:44:21AM +0100, Gábor Lénárt wrote:
> I've started to code an EvalZ80() function which would parse
> the rest of the line to get with the number of arguments (separated by
> comma), and the type of them. Each handler would call this EvalZ80() first,
> check number of params and types and then decide if it's valid and generate
> code if so. I guess this is not it whould be done ;-) It works well for
> instructions don't need any parameters (TokIsSep() can be used to detect
> if have bogus params). However problem occures to write the real part of my
> EvalZ80(). I would like to classify assembly source line (after opcode name
> itself) in this way:

Please have a look at the ea... modules. They are used to determine the
addressing mode of an instruction and will fill a struct with the results.

> Then handlers can use these MODE_ constants to check if addressing mode
> is valid and if it is what code should be generated (probably in the form
> of having an array contain every valid combination of these constants,
> type byte(s) should emit and the optional variable stuff value and type
> (signed byte, word)).

Once the addressing mode is determined, it is easy to check if it is valid
with a given instruction, since the table entry for the instruction contains a
bit field that encodes the valid addressing modes.

Regards


        Uz


-- 
Ullrich von Bassewitz                                  uz@musoftware.de
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