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Re: Empty loop elimination in 4.0 ?

From: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>
To: Michael Veksler <VEKSLER at il dot ibm dot com>
Cc: gcc at gcc dot gnu dot org
Date: Mon, 10 Jan 2005 01:07:21 +0100
Subject: Re: Empty loop elimination in 4.0 ?
References: <OF8E52E8AD.F66BBDC4-ONC2256F84.006EFF07-C2256F84.0070E494@il.ibm.com>

Hello,

> In the days of gcc-2.6.x the documentation of gcc said that empty loops
> were not eliminated. The docs used to say that this was on purpose -
> because empty loops were being used as delay loops.
> 
> Does this ancient and not portable delay-loop hack still work with
> gcc version 4.0.0 20050102 (experimental) ?

yes.  Although I think documentation about this was changed
and it is no longer guaranteed that the empty loops are not
removed.  Also a patch for removing empty loops was submitted.

Zdenek

Follow-Ups:
- Re: Empty loop elimination in 4.0 ?
  - From: Michael Veksler

References:
- Empty loop elimination in 4.0 ?
  - From: Michael Veksler

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