[Bug ipa/105160] [12 regression] ipa modref marks functions with asm volatile as const or pure

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105160

--- Comment #5 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
It is indeed missing logic to merge the side_effect and nondeterministic flag
while updating after inlining.  I am testing the following

diff --git a/gcc/ipa-modref.cc b/gcc/ipa-modref.cc
index acfd7d80ff8..556816ab429 100644
--- a/gcc/ipa-modref.cc
+++ b/gcc/ipa-modref.cc
@@ -5281,6 +5281,29 @@ ipa_merge_modref_summary_after_inlining (cgraph_edge
*edge)
       if (!ignore_stores)
        to_info_lto->stores->collapse ();
     }
+  /* Merge side effects and non-determinism.
+     PURE/CONST flags makes functions deterministic and if there is
+     no LOOPING_CONST_OR_PURE they also have no side effects.  */
+  if (!(flags & (ECF_CONST | ECF_NOVOPS | ECF_PURE))
+      || (flags & ECF_LOOPING_CONST_OR_PURE))
+    {
+      if (to_info)
+       {
+         if (!callee_info || callee_info->side_effects)
+           to_info->side_effects = true;
+         if ((!callee_info || callee_info->nondeterministic)
+             && !ignore_nondeterminism_p (edge->caller->decl, flags))
+           to_info->nondeterministic = true;
+       }
+      if (to_info_lto)
+       {
+         if (!callee_info_lto || callee_info_lto->side_effects)
+           to_info_lto->side_effects = true;
+         if ((!callee_info_lto || callee_info_lto->nondeterministic)
+             && !ignore_nondeterminism_p (edge->caller->decl, flags))
+           to_info_lto->nondeterministic = true;
+       }
+     }
   if (callee_info || callee_info_lto)
     {
       auto_vec <modref_parm_map, 32> parm_map;