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Re: Reservation unit as FIFO
- From: "Vladimir N. Makarov" <vmakarov at redhat dot com>
- To: Joern Rennecke <joern dot rennecke at superh dot com>
- Cc: Jan Hubicka <jh at suse dot cz>, gcc at gcc dot gnu dot org
- Date: Fri, 29 Nov 2002 13:37:57 -0500
- Subject: Re: Reservation unit as FIFO
- References: <3DE7B07C.851C015@superh.com>
Joern Rennecke wrote:
> > Yes, it is interesting. In general, to model FIFO we need more
> > powerful model than DFA and regular expressions. But regular expression
>
> You could just pretrend you are scheduling two instructions instead of one.
> One for the part that is done before and in the FIFO, and another one
> that does the work after the FIFO, and data-dependent on the former.
>
An interesting approach too. But the insn scheduler has no such
infrastructure. Even if the insn could be splitted in two insns, the
scheduler can create a big gap between the two insns. That is wrong. So we
need to differ such dependencies. In general it is a big work. Although this
infrastructure could be used for other insn scheduling problems too.
Vlad