[PATCH] Add support for ARM modified immediate syntax

[Tim Northover]

Hi Mihai,

> I found a way to avoid having a big switch that converts opcodes between ri
> and rii. Basically, I am assigning all the rii instructions to a new
> DecoderNamespace.

Hmm. Interesting approach.

We may need an umpire soon (or pistols at dawn?). I took a stab at the
one-instruction-to-rule-them-all approach (in the MC layer so far)
over the weekend: http://llvm-reviews.chandlerc.com/D1432

> Now, surprisingly I am having problems with step 1!
> Although the two immediates are always the final inputs, they are not the
> final MCOperands, nor the final immediate MCOperands.

This is because of the predicate and flag-setting operands (usually
imm:14 and reg:0)? If so, couldn't you count from the back rather than
the front of the list? Or is there some even more evil mangling going
on?

Cheers.

Tim.