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Re: [patch, commited] Do not prefetch loops that do not roll
- From: Richard Guenther <rguenther at suse dot de>
- To: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>
- Cc: gcc-patches at gcc dot gnu dot org, dmueller at suse dot de
- Date: Fri, 2 Mar 2007 10:06:33 +0100 (CET)
- Subject: Re: [patch, commited] Do not prefetch loops that do not roll
- References: <20070301215801.GA3660@atrey.karlin.mff.cuni.cz>
On Thu, 1 Mar 2007, Zdenek Dvorak wrote:
> Hello,
>
> this patch makes us avoid issuing prefetches in loops that are finished
> in less time than what the prefetch instruction takes (such prefetches
> are obviously useless, and only would introduce unnecessary overhead).
>
> Bootstrapped & regtested on i686 (without -fprefetch-loop-arrays, as
> the bootstrap with -fprefetch-loop-arrays currently fails because of the
> warnings introduced by the "compile time array subscript checking" patch),
> commited.
Do you happen to have a testcase (or remember the file that triggered
the warning)?
Thanks,
Richard.