This is the mail archive of the
cgen@sources.redhat.com
mailing list for the CGEN project.
field splitting
- To: Eric Christopher <echristo at cygnus dot com>
- Subject: field splitting
- From: Doug Evans <dje at transmeta dot com>
- Date: Thu, 26 Oct 2000 16:41:28 -0700 (PDT)
- Cc: cgen at sources dot redhat dot com
- References: <39F8C211.315933D9@cygnus.com>
Eric Christopher writes:
> I have an instruction that looks something like this:
>
> [opcode][4-bits][src][12-bits]
>
> Where the 4 and 12-bit fields are really a part of the same 16-bit
> offset. I've been unable to think of any way to define the field in
> such a way that I can make it a 16-bit operand that just happens to
> contain bits at different spots.
>
> Currently the field is just defined as 2 separate fields.
>
> Any ideas?
This is what multi-ifields are for.
grep for multi-ifield in doc/rtl.texi and *.cpu.