Re: [PATCH] Support multi-versioning on self-recursive function (ipa/92133)

[Jan Hubicka <hubicka@ucw.cz>]

> 2019-11-15  Feng Xue <fxue@os.amperecomputing.com>
> 
>         PR ipa/92133
>         * doc/invoke.texi (ipa-cp-max-recursive-depth): Document new option.
>         (ipa-cp-min-recursive-probability): Likewise.
>         * params.opt (ipa-cp-max-recursive-depth): New.
>         (ipa-cp-min-recursive-probability): Likewise.
>         * ipa-cp.c (ipcp_lattice<valtype>::add_value): Add two new parameters
>         val_p and unlimited.
>         (self_recursively_generated_p): New function.
>         (get_val_across_arith_op): Likewise.
>         (propagate_vals_across_arith_jfunc): Add constant propagation for
>         self-recursive function.
>         (incorporate_penalties): Do not penalize pure self-recursive function.
>         (good_cloning_opportunity_p): Dump node_is_self_scc flag.
>         (propagate_constants_topo): Set node_is_self_scc flag for cgraph node.
>         (get_info_about_necessary_edges): Relax hotness check for edge to
>         self-recursive function.
>         * ipa-prop.h (ipa_node_params): Add new field node_is_self_scc.

OK, thanks!
do you have some plans on the better cost model for the recursive
cloning? Also it would be nice to have this info available in recursive
inliner and give it a higher priority when inlining is going to turn
previously recrusive call into non-recursive.

Honza