assign_parm_setup_block handling of parallels

[Eric Botcazou]

> In my limited understanding of the problem I think we can allow the
> optimization for one-member parallels iff the hard register will span
> more than one register.  I think this will satisfy both PPC64 and
> Sparc64.

SPARC64 :-)

> Do you folks agree?

I don't understand what you're trying to optimize: what's the problem with

(parallel:DF [
        (expr_list:REG_DEP_TRUE (reg:DI 3 3)
            (const_int 0 [0x0]))
    ])

for your port?  Does (reg:DI 3 3) not span consecutive regs?

IIRC the optimization was precisely aimed at multi-member parallels, as 
indicated in the comment.

-- 
Eric Botcazou