[tree-profiling] Fix return predictors
Steven Bosscher
stevenb@suse.de
Wed Aug 11 14:24:00 GMT 2004
On Wednesday 11 August 2004 15:29, Jan Hubicka wrote:
> On tree profiloing branch we now get better SPEC scores, faster
> compilation even with the loop disabled, so I will start merging
> remaining neccesary infrastructure bits at the end of week and in the
> case loop won't be replaced for 3.5, we can simply reconstruct the
> profile estimate from REG_BR_PROB notes (I tried that on tree profiling
> branch and it works just as it is written now).
I think we're slow enough as it is, not another pass thank you ;-)
We already have to reconstruct loop notes for the old loop optimizer,
and to hack around loop with profile information too, that's just
stupid. IMHO it is an absolute _must_ that the old loop optimizer can
be removed before GCC 3.5 is released.
The missing bits are, iiuc, strength reduction and prefetching. For
the latter, the tree pass on the LNO branch is already superior.
Strength reduction is a bit of an issue because it needs some hacks
(ie. the REF_ORIGINAL bits) to get alias information right.
Gr.
Steven
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