Re: insert evaluation for multi-ifields broken

On Thu, Feb 22, 2007 at 11:55:57AM -0500, Dave Brolley
wrote:
> Joern Rennecke wrote:
> 
> >When I want to put a constant into a multi-ifield,
the
> >exact instructions how to set the subfields are
apparently ignored, and the
> >total value is copied into the subfields.
> > 
> >
> This does appear to be broken. This is probably the
first time someone 
> has attempted this, since you could use f-a and f-c
directly.

The real code is much more complex (80 KB .cpu file,
generating - among
other things - three decode*.c files in excess of 700 KB
each).
The multi-ifield is usually used for a register operand. 
However, there
are some special instructions where this operand is not
needed, so a
bunch of them can be encoded by using different values in
this field  -
I implemented this with a normal-insn-enum, which uses the
multi-ifield.
Individual values of this enum are then placed in the format
of the
the separate insns, whcih is equivalent to putting a
constant into the
field.

Joern Rennecke wrote:
> The real code is much more complex (80 KB .cpu file,
generating - among
> other things - three decode*.c files in excess of 700
KB each).
> The multi-ifield is usually used for a register
operand.  However, there
> are some special instructions where this operand is not
needed, so a
> bunch of them can be encoded by using different values
in this field  -
> I implemented this with a normal-insn-enum, which uses
the multi-ifield.
> Individual values of this enum are then placed in the
format of the
> the separate insns, whcih is equivalent to putting a
constant into the
> field.
>   
Understood and quite reasonable, but unfortunately broken.
Your choices 
would seem to be to fix the bug or try the workaround.

Dave