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Re: branch predictions
- To: Jeffrey A Law <law at cygnus dot com>
- Subject: Re: branch predictions
- From: Jason Eckhardt <jle at cygnus dot com>
- Date: Thu, 4 May 2000 06:56:40 -0700 (PDT)
- cc: gcc at gcc dot gnu dot org
On Thu, 4 May 2000, Jeffrey A Law wrote:
>
>
> 3. If we do not have any kind of prediction and one of the blocks
> physically follows the current block, then predict the block which
> physically follows the current block. ie, don't rearrange code
> at random ;-)
>
I forgot to mentioned that this should be okay. But its not clear whether
its any better than a random prediction, at least if we believe the
results in ball/larus' paper (they do a 'random' prediction in this case).
Hopefully this situation arises rarely,
although I haven't done any empirical tests.