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Re: Scheduling automaton question
- From: Frédéric RISS <frederic dot riss at gmail dot com>
- To: Bernd Schmidt <bernds at codesourcery dot com>
- Cc: GCC List <gcc at gcc dot gnu dot org>, "Vladimir N. Makarov" <vmakarov at redhat dot com>
- Date: Fri, 11 Feb 2011 19:43:04 +0100
- Subject: Re: Scheduling automaton question
- References: <4D552C9C.6090006@codesourcery.com>
Le vendredi 11 fÃvrier 2011 Ã 13:33 +0100, Bernd Schmidt a Ãcrit :
> Suppose I have two insns, one reserving (A|B|C), and the other reserving
> A. I'm observing that when the first one is scheduled in an otherwise
> empty state, it reserves the A unit and blocks the second one from being
> scheduled in the same cycle. This is a problem when there's an
> anti-dependence of cost 0 between the two instructions.
If you generate a NDFA ( using '(automata_option "ndfa")' ) it should
allow you to schedule both instructions together as this should try all
functional unit alternatives.
Fred