[fpc-devel] Some Opcodes missing in internal assembler for mips32r2

[Sergei Gorelkin]

29.05.2013 1:26, Michael Ring пишет:
> I did the changes, parts of the opcodes now work fine, I think I have found the problem with the li
> + and + mfc0 op-codes, if last parameter is 0 then the asm statement is generated wrong:
>
> This works:
>      and    $a0,$a0,1
>
> this does not work:
>      and    $a0,$a0,0
>
> result is:
>
> pic32mx1xxfxxxb.s:107: Error: absolute expression required `and $a0,$a0,'
>
So it is the value of operand that matters. I'll try to look at it, probably a bug in the parsing 
part, because the output part doesn't have anything suspicious.

> I am now having troubles with the syntax for mfc0 and mtc0:
>
> mfc0    $t0,$12, 1 //_CP0_STATUS
>
> gets translated to:
>
> mfc0 $t0,$t4,1
>
> which the assembler does not like, it needs $12 and not $t4:
>
> pic32mx1xxfxxxb.s:37: Error: Illegal operands `mfc0 $t0,$t4,1'
>
> Any ideas what to do here?
>
This one is more complicated, we need at least to prevent register name translation (since $12 is a 
coprocessor register, not a general-purpose one), at most handle such registers as a different 
register type.

Regards,
Sergei