http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54497
--- Comment #2 from Pat Haugen <pthaugen at gcc dot gnu.org> 2012-09-06 21:05:05 UTC --- (In reply to comment #1) > I suppose the loop is no longer predicted to execute enough times? I don't think that's the issue, I'm thinking it's somewhere in the data dependence analysis. Looking at the dump before .pcom (i.e. .dceloop3), both resid_ and resid_.constprop.0 list BB7, the inner loop block, as freq=10000. The .pcom dump has many differences in the data analysis portion between the two procedures, but the main difference is the analysis on resid_.constprop.0 ends with the following: Predictive commoning failed: no suitable chains
