[Bug ipa/97292] [11 Regression] dealII from SPECCPU 2016 no longer terminates after g:c34db4b6f8a5d80367c709309f9b00cb32630054

[hubicka at ucw dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97292

--- Comment #6 from Jan Hubicka <hubicka at ucw dot cz> ---
Hi,
the following patch should let us to pinpoint the wrong disambiguation.
With -fdump-tree-all-details we should also see the difference in dump
file.

Honza

diff --git a/gcc/dbgcnt.def b/gcc/dbgcnt.def
index cf8775b2b66..07946a85ecc 100644
--- a/gcc/dbgcnt.def
+++ b/gcc/dbgcnt.def
@@ -171,6 +171,7 @@ DEBUG_COUNTER (if_after_reload)
 DEBUG_COUNTER (if_conversion)
 DEBUG_COUNTER (if_conversion_tree)
 DEBUG_COUNTER (ipa_cp_bits)
+DEBUG_COUNTER (ipa_mod_ref)
 DEBUG_COUNTER (ipa_sra_params)
 DEBUG_COUNTER (ipa_sra_retvalues)
 DEBUG_COUNTER (ira_move)
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 97dc4ac8814..ba208604c30 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -2470,6 +2470,9 @@ modref_may_conflict (const gimple *stmt,
   if (tt->every_base)
     return true;

+  if (!dbg_cnt (ipa_mod_ref))
+    return true;
+
   base_set = ao_ref_base_alias_set (ref);

   ref_set = ao_ref_alias_set (ref);