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Re: Defining scheduling resource constraint
On 11/07/2012 12:08 PM, Paulo Matos wrote:
>
>> -----Original Message-----
>> From: Bernd Schmidt [mailto:bernds@codesourcery.com]
>> Sent: 07 November 2012 10:48
>> To: Paulo Matos
>> Cc: gcc@gcc.gnu.org
>> Subject: Re: Defining scheduling resource constraint
>>
>> Yes... I seem to remember the documentation is just wrong for that hook
>> (and the interface is somewhat broken). As you noted, you can't just
>> remove insns from the ready list without moving them somewhere else.
>>
>
> But if I can't remove an insn from the ready list (by 'remove' I mean
> reorder such that gcc understands that the insn should be postponed
> to the next cycle) in the reorder hook, I will give the adjust
> priorities hook a try and maybe here I can ensure that two insns that
> write to the same registers do not have the same priority.
You can effectively remove it by returning zero if all the insns on the
ready list would cause a conflict. The scheduler will then force the
next cycle.
Seriously, all this exists in c6x.c, you just need to copy that code.
Bernd