On 11/18/14 06:42, Segher Boessenkool wrote:
On Tue, Nov 18, 2014 at 06:38:49AM -0600, Segher Boessenkool wrote:
Does it help pr52714 where we'd like to rip apart a PARALLEL with two
sets, one of which is dead. If so, it might allow us to optimize that
code better.
It does not seem to fix the testcase. I'll investigate why not.
You're talking about the
(parallel [(set (pc) (pc))
(set (X) (sp))])
right? I guess the "set pc pc" is not marked as unused...
The very first thing that is checked for is !(added_sets_2 && i1 == 0)
which matches in this case. I wonder what that condition is supposed
to accomplish -- "optimisation" I suppose?
Hacking that out, it still won't match because the "set pc pc" is not
considered dead. It's a no-op, not the same thing. I'll try to widen
the condition...
Just to be clear, I wouldn't consider fixing this a requirement to get
your change in. I think 5/5 was ready to go as-is. Obviously if you
can improve on it, that's great ;-)
jeff
