Re: [Qemu-devel] [RFC 01/23] scripts: Add decodetree.py

[Peter Maydell]

On 13 January 2018 at 17:14, Bastian Koppelmann
<address@hidden> wrote:
> Hi Richard,
>
> +# Field examples:
> +#
> +#   %disp   0:s16          -- sextract(i, 0, 16)
> +#   %imm9   16:6 10:3      -- extract(i, 16, 6) << 3 | extract(i, 10, 3)
>
> startindex:endindex for unnamed_field is more intuitive. As any ISA
> manual would specify those.

I find start:len easier to work with personally (and it matches
what we use in QEMU for the extract/deposit APIs, and for what
little it's worth, what RISU data file syntax does). You're probably
right that ISA manuals will tend to give bit positions though.

thanks
-- PMM