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Re: [tree-ssa] Write to global memory not hoisted out of loop

From: Daniel Berlin <dberlin at dberlin dot org>
To: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>
Cc: gcc at gcc dot gnu dot org,Steven Bosscher <stevenb at suse dot de>,Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>
Date: Fri, 30 Apr 2004 18:22:09 -0400
Subject: Re: [tree-ssa] Write to global memory not hoisted out of loop
References: <Pine.LNX.4.53.0404301458020.8230@bellatrix.tat.physik.uni-tuebingen.de> <20040430205758.GA12071@atrey.karlin.mff.cuni.cz>

On Apr 30, 2004, at 4:57 PM, Zdenek Dvorak wrote:

Hello,
Writes to global memory are not hoisted out of a computation loop.
Try this with the LNO branch, iirc it can do this.
Not as of gcc (GCC) 3.5-tree-ssa-lno 20040430 (merged 20040425) (-O2
-ftree-loop-optimize -ffast-math), neither with static nor without.
tree-ssa aliasing probably does not take restricted pointers into
account, since it decides that all the accesses in the loop may alias.

points-to *does* take restricted pointers into account, but he said it didn't help, IIRC. I can look into why.

Follow-Ups:
- Re: [tree-ssa] Write to global memory not hoisted out of loop
  - From: Diego Novillo

References:
- Re: [tree-ssa] Write to global memory not hoisted out of loop
  - From: Richard Guenther
- Re: [tree-ssa] Write to global memory not hoisted out of loop
  - From: Zdenek Dvorak

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