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.
