[m68k] Add ffssi2 pattern for MCF528x

[Peter Barada]

> Well, I guess.  But really you want to add ctz patterns.  I suggest
>
> (define_insn "*ff1"
>   [(set (match_operand:SI 0 "register_operand" "=d")
>         (ctz:SI (not:SI (match_operand:SI 1 "register_operand" "0"))))]
>   ""
>   "ff1%.l %0")
>
> (define_expand "ctxsi2"
>   [(set (match_dup 2)
> 	(not:SI (match_operand:SI 1 "register_operand" "")))
>    (set (match_operand:SI 0 "register_operand" "=d")
>         (ctz:SI (not:SI (match_dup 2))))]
>   ""
> {
>   operands[2] = gen_reg_rtx (SImode);
> })
>
>> Then add a ffssi2 expander that uses these patterns.
>
>Unfortunately, I can't test on a 528x. Peter, what do you think?

I don't have a 528x either :-)
I'll look it over, compare it to some of hte other .md files and code
it up.  Give me a few days.

-- 
Peter Barada
peter@baradas.org