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Re: We're out of tree codes; now what?

From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
To: doug dot gregor at gmail dot com
Cc: dje at watson dot ibm dot com, gcc at gcc dot gnu dot org, stevenb dot gcc at gmail dot com
Date: Mon, 12 Mar 2007 16:52:43 EST
Subject: Re: We're out of tree codes; now what?
References: <doug.gregor@gmail.com> <24b520d20703121113y61cd3911odd9c385ff775dfb9@mail.gmail.com> <200703121835.l2CIZb830240@makai.watson.ibm.com> <571f6b510703121230n73018556g470917c8d9fc6a2a@mail.gmail.com> <24b520d20703121301i6dc3a73fx765b859dabf7e595@mail.gmail.com>

> It's going to have a big performance impact. To extract a 9-bit value,
> the compiler will need to do a lot of masking every time it accesses
> the TREE_CODE.

"a lot masking" means at most two additional instructions, one if we
put it in the right place.  I'd be shocked if we could even measure
this, let alone be a "big" performance impact.

Follow-Ups:
- Re: We're out of tree codes; now what?
  - From: Doug Gregor

References:
- We're out of tree codes; now what?
  - From: Doug Gregor
- Re: We're out of tree codes; now what?
  - From: David Edelsohn
- Re: We're out of tree codes; now what?
  - From: Steven Bosscher
- Re: We're out of tree codes; now what?
  - From: Doug Gregor

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