SPEC / testsuite results for disabling SFTs and the alias-oracle patches

[Diego Novillo]

On 03/05/08 06:48, Richard Guenther wrote:

> you can see that in both cases the runs without SFTs are significantly
> better(!)  Which hints at the fact that we do a poor job with parititoning
> and/or that partitioning triggers earlier with SFTs enabled.

All these differences seem to be less than 1%.  If I'm reading this 
table right, the alias oracle is not really having a significant effect 
on the scores

> The oracle patches are able to slightly improve the results in the non-SFT
> case, but overall there is less difference patched vs. unpatched compared
> to the differences that result if you disable SFTs.

Without the alias oracle you get:

		SFTs (base)	No SFTs (peak)
SPECint		1914		1927 (+0.68%)
SPECfp		2029		2032 (+0.15%)


With the alias oracle you get:

		SFTs (base)	No SFTs (peak)
SPECint		1918		1923 (+0.26%)
SPECfp		2020		2039 (+0.94%)

The good news is that the oracle is not introducing any slowdowns.  So I 
think this is very positive.

> Thus, with the above results I propose we disable generating SFTs by
> default on the mainline (--para max-fields-for-field-sensitive=100
> is still available for comparision).  I will prepare a patch to adjust
> the false negative testcases above to check for optimization outcome
> as well.

Yes, good idea.  Though I think we should just get rid of SFTs outright. 
  They are only going to be a maintenance problem.


Diego.