https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66760
Bug ID: 66760 Summary: [4.9/5/6 Regression] compile time regression in IPA inline analysis on PR26854 testcase Product: gcc Version: 5.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: ipa Assignee: unassigned at gcc dot gnu.org Reporter: bonzini at gnu dot org Target Milestone: --- PR26854 is spending a lot of time in alias stmt walking alias stmt walking : 272.52 (65%) (-O2) alias stmt walking : 116.06 (67%) (-O1) walk_aliased_vdefs has a high % of time spent, but the time is spent in bitmap operations rather than the callbacks! This is because the callback is the trivial mark_modified function. The guilty walk_aliased_vdefs invocation is parm_ref_data_preserved_p, invoked from ipa_load_from_parm_agg and in turn from unmodified_parm_or_parm_agg_item. Memoization via parms_ainfo seems like a plan.