[Bug gcov-profile/55674] [4.8 Regression] >20% size increase of lto/pgo binaries since r193747

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55674

--- Comment #17 from Jan Hubicka <hubicka at ucw dot cz> 2012-12-18 17:25:37 UTC ---
> I did some measurements with tramp3d and in this case
> the default (999) gives the best performance:
> 
> par. size    time
> --------------------
> 999  955859  3.71752
> 990  933390  3.73969
> 980  904718  3.84547
> ...    "        "
> 750  904718  3.84769
> 740  837654  7.67177
> 600  836024  8.80879

Yep, tramp3d is unforutnately quite special case: we measure the number of
instructions prior
late optimization, while in tramp3d over 90% of code disappear as a result of
inlining and further
simplification, so we get GIGO problem...

I am not sure how to handle these things in any resonable way....

I will test couple of values on spec2k this week and lets see how things scale
elsewhere.

Honza