Maybe expand MAX_RECOG_ALTERNATIVES ?

[Hans-Peter Nilsson]

On Fri, 11 May 2012, Greg McGary wrote:
> On 05/11/12 16:00, Greg McGary wrote:
>
> > My question is this: does it make sense to double MAX_RECOG_ALTERNATIVES so
> > that I can use insn attributes to identify operand signatures, or should I use
> > another approach?
>
> After some exploration, I don't see that another approach is even possible.  The
> predicates in define_insn_reservation must be statically evaluated by genattrtab,
> so I can't use (match_test "...") or (symbol_ref "..."), where "..." is arbitrary
> C code.  Is it true that define_insn_reservation predicates can only use boolean
> expressions on (eq_attr ...), or am I missing something?

Seeing this hasn't been replied to yet, I can't help but stating
the obvious: handle it like MAX_RECOG_OPERANDS.  Trivially, just
count the commas (the alternatives) in define_insn and friends.
(I don't think commas are allowed in constraints; if they are,
you may have to restrict the new max to targets using
define_constraint and friends and let the others stay with 30.)

Patches are welcome but be prepared for a lengthy ping session
as always. :/

brgds, H-P