Re: BUG: non-fixed-length ISAs are unsupported for now

Sergey Belyashov via Cgen <[email protected]> Mon, 27 Apr 2020 20:00:07 +0300
Newsgroups gmane.comp.tools.cgen.devel
Message-ID <CAOe0RDx2ppy3fqVTyWpEaVpXK-PvKeJNMEc4tKtPhqtKcmdUCA@mail.gmail.com>
Hi,
Z80 has istructions from 1 byte (nop for example) up to 4 bytes long (eZ80
up to 6 bytes) including operands 0..2 bytes (eZ80 0..3 bytes). So
base-insn-bitsize is set to 8. And it is not enought for 1-3 bytes (eZ80
1-4) insn code size (w/o immediate operands).

Best regards,
Sergey Belyashov


пн, 27 апр. 2020 г., 19:29 Frank Ch. Eigler <[email protected]>:

> Hi -
>
> > While analyzing code of CGEN I have found next code:
> > [...]
> > Can anybody add support for non-fixed-length ISAs?
>
> I am not expecting major cgen improvements.  However, if your
> base-insn-size is large enough to contain all the opcode-like
> bits of your largest possible instruction, you may not need
> those improvements.
>
> - FChE
>
>