[Bug rtl-optimization/21527] BYTEmark bitmap test: Regression with Profiled Optimization

jbucata at tulsaconnect dot com gcc-bugzilla@gcc.gnu.org
Mon Jul 18 05:17:00 GMT 2005


------- Additional Comments From jbucata at tulsaconnect dot com  2005-07-18 04:42 -------
For me, with -march=athlon-xp, -funroll-loops on 4.0.0 did indeed pessimize
slightly.  However, -fprofile-{generate,use} pessimized more on top of that.  So
there's still a problem with regard to the PO.

I tried it again with your -march=i686 and it went from 9.5s => 13.5s user with
plain -funroll-loops.  The PO made it a tidge worse from there.  IOW, consistent
with what you saw.

Further, I tried -funroll-loops w/o the PO on 3.3.5 and 3.4.3 and it improved
run times for both--moreso in 3.4.3 than in 3.3.5.  So it looks like that's
another regression in 4.0.0, in -funroll-loops by itself!

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21527



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