On Mon, Jul 13, 2015 at 02:47:23PM +0200, Paolo Bonzini wrote: > > > On 13/07/2015 14:34, Martin Jambor wrote: > > You might want to use Martin's shiny new > > function_summary class in symbol-summary.c. That is a mechanism > > specifically designed to append to a cgraph_node information specific > > to an optimization pass (or two, as ipa-cp and ipa-inline already both > > use a few of them). Unfortunately, the class is not very well > > documented but you should be able to figure out how to use it from > > other code using them. > > > > If you then always deallocate everything there at the end of > > ipa-inline analysis, you'll get exactly the right life-time for the > > data. > > Good. I might as well merge func_body_info and ipa_node_params then, so > I already have ipa_node_params_sum. WDYT?
Well, perhaps but I am not so sure. I have made a conscious decision to make func_body_info a separate structure and not a part of ipa_node_params exactly because of their different life-times. func_body_info is something only used during intra-procedural stage of IPA analysis and should be thrown away as soon as it is over. ipa_node_params is a structure which contains results of that analysis, which are streamed to disk during LTO and then read back for the actual intEr-procedural propagation of information. Yes, it also contains quite a few fields that are used only during the IPA stage and so perhaps a few more bits used only during the intra-stage might be OK too. But Honza recently told me the ipa-structures are beginning to show in memory footprint of LTOing Firefox, so allocating more unused memory for each and every function in Firefox and all its clones is not really such a good idea. I also tend to think that coding the deallocation is going to be easier for you if you just use another summary. For an analysis-stage-only summary, you do not need to implement any of the hooks (i.e. insert, remove, duplicate), for example. Those should never happen during intraprocedural phase, or so I believe :-), so just put gcc_unreachable into them and that should be it. I'm sorry for making this so complicated :-) Martin
