Hello, On Fri, Sep 04 2026, Martin Jambor wrote: > Hi, > > With profile-feedback, the run-times used for opportunity evaluations > is not currently scaled to the total measured run time of the > program/compilation unit, which is an obvious mistake. This patch > adds such scaling by run-time which is however itself also scaled down > so that the resulting scores rougly fall in line with the scores on > hot loops we get using guessed profile. > > Kugan, please have a look if this helps addressing the issues you see > with AutoFDO (though I have not looked at whether the default value of > ipa-cp-profile-runtime-scaling is appropriate also for AutoFDO). > > I have bootstrapped and tested this on an x86_64-linux in a normal way > and then also did a bootstrap with LTO, PGO and -O3 optimization level. > OK for master? > > Martin > > > > gcc/ChangeLog: > > 2026-05-15 Martin Jambor <[email protected]> > > * ipa-cp.cc (overall_scaled_runtime): New. > (good_cloning_opportunity_p): Scale PGO evaluations by > overall_scaled_runtime. > (ipcp_propagate_stage): Calculate also overall_scaled_runtime and > print it and unscaled time. > (ipa_cp_cc_finalize): Set overall_scaled_runtime to zero. > * params.opt (ipa-cp-profile-runtime-scaling): New. > * doc/params.texi (ipa-cp-profile-runtime-scaling): New.
After this was approved by Honza in person, I have pushed this as commit f9b60a8bd75. Martin
