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Re: GCC DFA Scheduling Query
- From: Jim Wilson <wilson at specifixinc dot com>
- To: Pankaj Dev <panks11 at hotmail dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Wed, 10 Sep 2003 14:53:13 -0700
- Subject: Re: GCC DFA Scheduling Query
- References: <Law10-F110wGCtVWNJa000436d3@hotmail.com>
Pankaj Dev wrote:
I am actually curious about the DFA description of sparclet already in
GCC.
I doubt that anyone has ever looked at this. This is just the obvious
translation of the old pre-DFA description into the new format. Since
the old one was a minimal description, the DFA description is also.
Since there is only one unit available for each FETCH AND DECODE and
WRITE BACK unit so I feel that they should also be included in the
insn_reservation description in the .md file.
This is very unlikely to do anything useful if you think about it. If
every instruction takes 1 cycle in the FETCH AND DECODE unit, then we
don't gain anything by modeling it because there is nothing to schedule.
The important thing here is how long it takes to execute instructions,
and other info is useful to model only if it affects execution time.
--
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com