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Re: Rerunning CSE after GCSE
- To: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- Subject: Re: Rerunning CSE after GCSE
- From: Jeffrey A Law <law at redhat dot com>
- Date: Mon, 19 Feb 2001 20:10:05 -0700
- cc: gcc at gcc dot gnu dot org
- Reply-To: law at redhat dot com
In message <10102200216.AA19911@vlsi1.ultra.nyu.edu>you write:
> Yea, it worked by keeping state for each block and re-using that to spe
> ed
> up skip-blocks, follow-jumps, etc etc if I recall.
>
> I would like to see if we still *need* skip-blocks and follow-jumps now
> that we have gcse.
That's a good question. And I don't have an answer.
However, consider that cse.c has more code to handle costing, more
simplifications, etc than gcse.c Also consider that gcse.c doesn't work
at all on hard regs -- it seems them and gives up.
jeff