Re: anonymous ifields

[Ben Elliston <bje at redhat dot com>]

>>>>> "Frank" == Frank Ch Eigler <fche@redhat.com> writes:

  Frank> How frequently does each of these anonymous ifields occur in your new
  Frank> port?  If the ifields in question are used more than once, then a
  Frank> pmacro-based declaration plus "f-0" type references would be about as
  Frank> compact than an anonymous declaration in situ.

In some cases, they occur dozens of times -- perhaps in 30% of the
entire instruction set.

  Frank> If you don't like having to declare the ifields explicitly, we could
  Frank> get cgen to automagically declare a bunch of ifields for all
  Frank> contiguous bitfields in an instruction word.  (O(N**2) of them for N
  Frank> bits.)

In some ways, I think that would be *worse*.  Things happening
implicitly just gets confusing.  Is what I'm proposing really deemed
to be that bad?  I can understand it from the perspective of
increasing cgen's syntax.

I'm going to try using pmacros to implement what I'm after and we'll
see how useful it ends up being.

Ben