Sorry for the slow reply.
Omar Tahir <omar.ta...@arm.com> writes:
>> Omar Tahir <omar.ta...@arm.com> writes:
>> > Hi Richard,
>> >
>> > From: Richard Sandiford <richard.sandif...@arm.com>
>> >> > @@ -3719,6 +3722,7 @@ static unsigned int rest_of_handle_sched (void)
>> >> > { #ifdef INSN_SCHEDULING
>> >> > + first_moveable_pseudo = last_moveable_pseudo;
>> >> > if (flag_selective_scheduling
>> >> > && ! maybe_skip_selective_scheduling ())
>> >> > run_selective_scheduling ();
>> >>
>> >> I think instead we should zero out both variables at the end of IRA.
>> >> There are other places besides the scheduler that call into the IRA code,
>> >> so tackling the problem there seems more general.
>> >
>> > If you zero first_moveable_pseudo and last_moveable_pseudo after IRA then
>> > they'll be zero for the second scheduler pass, which uses them.
>>
>> Are you sure? It shouldn't be doing that, since there are no pseudos
>> left when the second scheduling pass runs. RA replaces all pseudos
>> with hard registers.
>>
>> So if the values in the variables has a noticeable effect on sched2,
>> I think that's even more reason to clear them after IRA :-)
>
> That's a good point. A few other passes call functions that make use of
> the moveable pseudo variables. But if they're before IRA then they should
> be zero, and as you say if they're after IRA then there are no pseudos left!
>
> I've moved the reset to the end of move_unallocated_pseudos. Unfortunately I
> can't inline the patch as there's a form feed (^L) that's mangling the text,
> not sure how to get around that.
Thanks, pushed to master.
Richard
