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Re: "Documentation by paper"
- From: law at redhat dot com
- To: Jamie Lokier <jamie at shareable dot org>
- Cc: Peter Barada <peter at the-baradas dot com>, kenner at vlsi1 dot ultra dot nyu dot edu, paolo dot bonzini at polimi dot it, gcc at gcc dot gnu dot org
- Date: Mon, 09 Feb 2004 11:38:26 -0700
- Subject: Re: "Documentation by paper"
- Reply-to: law at redhat dot com
In message <20040209175301.GB3455@mail.shareable.org>, Jamie Lokier writes:
>Granted, but papers do refer to them as "minimal SSA" et al., and the
>properties are relevant to algorithms. Without being 100% certain
>from memory, I recall some algorithms require some of the "useless"
>PHI nodes to be present.
The claims were that some algorithms may be able to do a better job at
optimizing when those useless PHIs were present. I believe Daniel showed
some evidence that refuted those claims.
I'll also note that our optimizers don't care if they're presented with the
extra PHI nodes or not (which should be true for any SSA optimizer since
otherwise you'd be required to run a DCE pass before entering any SSA
optimizer to remove dead phi nodes).
I'll note that the differences in fully, semi and minimal are also discussed
in a variety of papers and textbooks, though not as far back as the Dragon
book.
jeff