[Bug ipa/83506] [8 Regression] ICE: Segmentation fault in force_nonfallthru_and_redirect

["prathamesh3492 at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83506

--- Comment #5 from prathamesh3492 at gcc dot gnu.org ---
(In reply to Jakub Jelinek from comment #4)
> Though, I guess the real bug is that ipa_free_fn_summary (); is no longer
> called for -fno-ipa-pure-const.  While the ipa_inline pass had unconditional
> gate and so it was freed always if !flag_wpa, ipa-pure-const has a
> non-trivial gate and thus it frees only sometimes.  Calling
> ipa_free_fn_summary () in ipa-inline.c if if (!flag_wpa &&
> !flag_ipa_pure_const && !in_lto_p) is not nice, as it duplicates the
> ipa-pure-const.c gate.  So, we can do something like:
> --- gcc/ipa.c.jj	2017-09-01 09:26:37.000000000 +0200
> +++ gcc/ipa.c	2017-12-20 11:22:57.915226765 +0100
> @@ -1270,6 +1270,11 @@ ipa_single_use (void)
>    varpool_node *var;
>    hash_map<varpool_node *, cgraph_node *> single_user_map;
>  
> +  /* In WPA we use inline summaries for partitioning process.  Otherwise,
> +     free it if earlier IPA passes have not done so yet.  */
> +  if (!flag_wpa)
> +    ipa_free_fn_summary ();
> +
>    FOR_EACH_DEFINED_VARIABLE (var)
>      if (!var->all_refs_explicit_p ())
>        var->aux = BOTTOM;
> But I think I have a cleaner patch than that.

Hi Jakub,
Thanks for the fix! In r254140, I removed the call to ipa_free_fn_summary()
gated on !flag_wpa from inline pass since ipa-pure-const required it for
propagating malloc attribute, which unfortunately caused the above bug.

Regards,
Prathamesh