[Bug tree-optimization/64330] [5 Regression] IPA-ICF merges const exported vars that could be addressable in other TUs

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64330

--- Comment #8 from Martin Liška <marxin at gcc dot gnu.org> ---
Thank you for the missing externally visible attribute.

I've been testing following patch:

diff --git a/gcc/ipa-icf.c b/gcc/ipa-icf.c
index b193200..0685019 100644
--- a/gcc/ipa-icf.c
+++ b/gcc/ipa-icf.c
@@ -1131,8 +1131,12 @@ sem_variable::parse (varpool_node *node, bitmap_obstack
*stack)
   tree decl = node->decl;

   bool readonly = TYPE_P (decl) ? TYPE_READONLY (decl) : TREE_READONLY (decl);
-  bool can_handle = readonly && (DECL_VIRTUAL_P (decl)
-                                || !TREE_ADDRESSABLE (decl));
+  if (!readonly)
+    return NULL;
+
+  bool can_handle = DECL_VIRTUAL_P (decl)
+                   || flag_merge_constants >= 2
+                   || (!TREE_ADDRESSABLE (decl) && !node->externally_visible);

   if (!can_handle)
     return NULL;

As soon as tests finish, I will send it to ML.

Martin