1 files changed, 72 insertions, 155 deletions

diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index a9ae29fa876..c52d75e633b 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -196,7 +196,6 @@ static bitmap_obstack alias_bitmap_obstack;
 
 /* Local functions.  */
 static void compute_flow_insensitive_aliasing (struct alias_info *);
-static void finalize_ref_all_pointers (struct alias_info *);
 static void dump_alias_stats (FILE *);
 static bool may_alias_p (tree, alias_set_type, tree, alias_set_type, bool);
 static tree create_memory_tag (tree type, bool is_type_tag);
@@ -1800,12 +1799,6 @@ compute_may_aliases (void)
      avoid invalid transformations on them.  */
   maybe_create_global_var ();
 
-  /* If the program contains ref-all pointers, finalize may-alias information
-     for them.  This pass needs to be run after call-clobbering information
-     has been computed.  */
-  if (ai->ref_all_symbol_mem_tag)
-    finalize_ref_all_pointers (ai);
-
   /* Compute memory partitions for every memory variable.  */
   compute_memory_partitions ();
 
@@ -2354,7 +2347,6 @@ compute_flow_sensitive_aliasing (struct alias_info *ai)
   for (i = 0; VEC_iterate (tree, ai->processed_ptrs, i, ptr); i++)
     {
       struct ptr_info_def *pi = SSA_NAME_PTR_INFO (ptr);
-      tree tag = symbol_mem_tag (SSA_NAME_VAR (ptr));
 
       /* Set up aliasing information for PTR's name memory tag (if it has
 	 one).  Note that only pointers that have been dereferenced will
@@ -2362,18 +2354,7 @@ compute_flow_sensitive_aliasing (struct alias_info *ai)
       if (pi->name_mem_tag && pi->pt_vars)
 	{
 	  if (!bitmap_empty_p (pi->pt_vars))
-	    {
-	      union_alias_set_into (pi->name_mem_tag, pi->pt_vars);
-	      union_alias_set_into (tag, pi->pt_vars);
-	      bitmap_clear_bit (MTAG_ALIASES (tag), DECL_UID (tag));
-	    
-	      /* It may be the case that this the tag uid was the only
-		 bit we had set in the aliases list, and in this case,
-		 we don't want to keep an empty bitmap, as this
-		 asserts in tree-ssa-operands.c .  */
-	      if (bitmap_empty_p (MTAG_ALIASES (tag)))
-		BITMAP_FREE (MTAG_ALIASES (tag));
-	    }
+	    union_alias_set_into (pi->name_mem_tag, pi->pt_vars);
 	}
     }
   timevar_pop (TV_FLOW_SENSITIVE);
@@ -2390,9 +2371,7 @@ have_common_aliases_p (bitmap tag1aliases, bitmap tag2aliases)
   /* This is the old behavior of have_common_aliases_p, which is to
      return false if both sets are empty, or one set is and the other
      isn't.  */
-     if ((tag1aliases == NULL && tag2aliases != NULL)
-      || (tag2aliases == NULL && tag1aliases != NULL)
-      || (tag1aliases == NULL && tag2aliases == NULL))
+  if (tag1aliases == NULL || tag2aliases == NULL)
     return false;
 
   return bitmap_intersect_p (tag1aliases, tag2aliases);
@@ -2422,10 +2401,6 @@ compute_flow_insensitive_aliasing (struct alias_info *ai)
       tree tag = symbol_mem_tag (p_map->var);
       tree var;
 
-      /* Call-clobbering information is not finalized yet at this point.  */
-      if (PTR_IS_REF_ALL (p_map->var))
-	continue;
-
       for (j = 0; j < ai->num_addressable_vars; j++)
 	{
 	  struct alias_map_d *v_map;
@@ -2487,16 +2462,14 @@ compute_flow_insensitive_aliasing (struct alias_info *ai)
       tree tag1 = symbol_mem_tag (p_map1->var);
       bitmap may_aliases1 = MTAG_ALIASES (tag1);
 
-      if (PTR_IS_REF_ALL (p_map1->var))
-	continue;
-
-      for (j = i + 1; j < ai->num_pointers; j++)
+      for (j = 0; j < ai->num_pointers; j++)
 	{
 	  struct alias_map_d *p_map2 = ai->pointers[j];
 	  tree tag2 = symbol_mem_tag (p_map2->var);
 	  bitmap may_aliases2 = may_aliases (tag2);
 
-	  if (PTR_IS_REF_ALL (p_map2->var))
+	  /* By convention tags don't alias themselves.  */
+	  if (tag1 == tag2)
 	    continue;
 
 	  /* If the pointers may not point to each other, do nothing.  */
@@ -2508,66 +2481,13 @@ compute_flow_insensitive_aliasing (struct alias_info *ai)
 	  if (have_common_aliases_p (may_aliases1, may_aliases2))
 	    continue;
 
-	  if (may_aliases2 && !bitmap_empty_p (may_aliases2))
-	    {
-	      union_alias_set_into (tag1, may_aliases2);
-	    }
-	  else
-	    {
-	      /* Since TAG2 does not have any aliases of its own, add
-		 TAG2 itself to the alias set of TAG1.  */
-	      add_may_alias (tag1, tag2);
-	    }
+	  add_may_alias (tag1, tag2);
 	}
-
     }
   timevar_pop (TV_FLOW_INSENSITIVE);
 }
 
 
-/* Finalize may-alias information for ref-all pointers.  Traverse all
-   the addressable variables found in setup_pointers_and_addressables.
-
-   If flow-sensitive alias analysis has attached a name memory tag to
-   a ref-all pointer, we will use it for the dereferences because that
-   will have more precise aliasing information.  But if there is no
-   name tag, we will use a special symbol tag that aliases all the
-   call-clobbered addressable variables.  */
-
-static void
-finalize_ref_all_pointers (struct alias_info *ai)
-{
-  size_t i;
-
-  /* First add the real call-clobbered variables.  */
-  for (i = 0; i < ai->num_addressable_vars; i++)
-    {
-      tree var = ai->addressable_vars[i]->var;
-      if (is_call_clobbered (var))
-	add_may_alias (ai->ref_all_symbol_mem_tag, var);
-    }
-
-  /* Then add the call-clobbered pointer memory tags.  See
-     compute_flow_insensitive_aliasing for the rationale.  */
-  for (i = 0; i < ai->num_pointers; i++)
-    {
-      tree ptr = ai->pointers[i]->var, tag;
-      /* Avoid adding to self and clean up.  */
-      if (PTR_IS_REF_ALL (ptr))
-	{
-	  struct ptr_info_def *pi = get_ptr_info (ptr);
-	  if (pi->is_dereferenced)
-	    pi->pt_anything = 0;
-	  continue;
-	}
-      tag = symbol_mem_tag (ptr);
-      if (is_call_clobbered (tag))
-	add_may_alias (ai->ref_all_symbol_mem_tag, tag);
-    }
-
-}
-
-
 /* Create a new alias set entry for VAR in AI->ADDRESSABLE_VARS.  */
 
 static void
@@ -2862,74 +2782,85 @@ may_alias_p (tree ptr, alias_set_type mem_alias_set,
       return false;
     }
 
+  /* If the pointed to memory has alias set zero, or the pointer
+     is ref-all, or the pointer decl is marked that no TBAA is to
+     be applied, the MEM can alias VAR.  */
+  if (mem_alias_set == 0
+      || DECL_POINTER_ALIAS_SET (ptr) == 0
+      || TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (ptr))
+      || DECL_NO_TBAA_P (ptr))
+    {
+      alias_stats.alias_mayalias++;
+      alias_stats.simple_resolved++;
+      return true;
+    }
+
   gcc_assert (TREE_CODE (mem) == SYMBOL_MEMORY_TAG);
 
-  if (!DECL_NO_TBAA_P (ptr))
-    {
-      alias_stats.tbaa_queries++;
+  alias_stats.tbaa_queries++;
 
-      /* If the alias sets don't conflict then MEM cannot alias VAR.  */
-      if (!alias_sets_conflict_p (mem_alias_set, var_alias_set))
-	{
-	  alias_stats.alias_noalias++;
-	  alias_stats.tbaa_resolved++;
-	  return false;
-	}
+  /* If the alias sets don't conflict then MEM cannot alias VAR.  */
+  if (mem_alias_set != var_alias_set
+      && !alias_set_subset_of (mem_alias_set, var_alias_set))
+    {
+      alias_stats.alias_noalias++;
+      alias_stats.tbaa_resolved++;
+      return false;
+    }
 
-      /* If VAR is a record or union type, PTR cannot point into VAR
-	 unless there is some explicit address operation in the
-	 program that can reference a field of the type pointed-to by
-	 PTR.  This also assumes that the types of both VAR and PTR
-	 are contained within the compilation unit, and that there is
-	 no fancy addressing arithmetic associated with any of the
-	 types involved.  */
-      if (mem_alias_set != 0 && var_alias_set != 0)
-	{
-	  tree ptr_type = TREE_TYPE (ptr);
-	  tree var_type = TREE_TYPE (var);
+  /* If VAR is a record or union type, PTR cannot point into VAR
+     unless there is some explicit address operation in the
+     program that can reference a field of the type pointed-to by
+     PTR.  This also assumes that the types of both VAR and PTR
+     are contained within the compilation unit, and that there is
+     no fancy addressing arithmetic associated with any of the
+     types involved.  */
+  if (mem_alias_set != 0 && var_alias_set != 0)
+    {
+      tree ptr_type = TREE_TYPE (ptr);
+      tree var_type = TREE_TYPE (var);
       
-	  /* The star count is -1 if the type at the end of the
-	     pointer_to chain is not a record or union type. */ 
-	  if ((!alias_set_only) && 
-	      ipa_type_escape_star_count_of_interesting_type (var_type) >= 0)
-	    {
-	      int ptr_star_count = 0;
+      /* The star count is -1 if the type at the end of the
+	 pointer_to chain is not a record or union type. */ 
+      if (!alias_set_only
+	  && ipa_type_escape_star_count_of_interesting_type (var_type) >= 0)
+	{
+	  int ptr_star_count = 0;
 	  
-	      /* ipa_type_escape_star_count_of_interesting_type is a
-		 little too restrictive for the pointer type, need to
-		 allow pointers to primitive types as long as those
-		 types cannot be pointers to everything.  */
-	      while (POINTER_TYPE_P (ptr_type))
-		{
-		  /* Strip the *s off.  */ 
-		  ptr_type = TREE_TYPE (ptr_type);
-		  ptr_star_count++;
-		}
+	  /* ipa_type_escape_star_count_of_interesting_type is a
+	     little too restrictive for the pointer type, need to
+	     allow pointers to primitive types as long as those
+	     types cannot be pointers to everything.  */
+	  while (POINTER_TYPE_P (ptr_type))
+	    {
+	      /* Strip the *s off.  */ 
+	      ptr_type = TREE_TYPE (ptr_type);
+	      ptr_star_count++;
+	    }
 	  
-	      /* There does not appear to be a better test to see if
-		 the pointer type was one of the pointer to everything
-		 types.  */
-	      if (ptr_star_count > 0)
-		{
-		  alias_stats.structnoaddress_queries++;
-		  if (ipa_type_escape_field_does_not_clobber_p (var_type, 
-								TREE_TYPE (ptr)))
-		    {
-		      alias_stats.structnoaddress_resolved++;
-		      alias_stats.alias_noalias++;
-		      return false;
-		    }
-		}
-	      else if (ptr_star_count == 0)
+	  /* There does not appear to be a better test to see if
+	     the pointer type was one of the pointer to everything
+	     types.  */
+	  if (ptr_star_count > 0)
+	    {
+	      alias_stats.structnoaddress_queries++;
+	      if (ipa_type_escape_field_does_not_clobber_p (var_type, 
+							    TREE_TYPE (ptr)))
 		{
-		  /* If PTR_TYPE was not really a pointer to type, it cannot 
-		     alias.  */ 
-		  alias_stats.structnoaddress_queries++;
 		  alias_stats.structnoaddress_resolved++;
 		  alias_stats.alias_noalias++;
 		  return false;
 		}
 	    }
+	  else if (ptr_star_count == 0)
+	    {
+	      /* If PTR_TYPE was not really a pointer to type, it cannot 
+		 alias.  */ 
+	      alias_stats.structnoaddress_queries++;
+	      alias_stats.structnoaddress_resolved++;
+	      alias_stats.alias_noalias++;
+	      return false;
+	    }
 	}
     }
 
@@ -3035,12 +2966,6 @@ is_escape_site (tree stmt)
 	     pointer escapes since we can't track the integer.  */
 	  if (POINTER_TYPE_P (from) && !POINTER_TYPE_P (to))
 	    return ESCAPE_BAD_CAST;
-
-	  /* Same if the RHS is a conversion between a regular pointer and a
-	     ref-all pointer since we can't track the SMT of the former.  */
-	  if (POINTER_TYPE_P (from) && !TYPE_REF_CAN_ALIAS_ALL (from)
-	      && POINTER_TYPE_P (to) && TYPE_REF_CAN_ALIAS_ALL (to))
-	    return ESCAPE_BAD_CAST;
 	}
 
       /* If the LHS is an SSA name, it can't possibly represent a non-local
@@ -3146,14 +3071,6 @@ get_smt_for (tree ptr, struct alias_info *ai)
   tree tag_type = TREE_TYPE (TREE_TYPE (ptr));
   alias_set_type tag_set = get_alias_set (tag_type);
 
-  /* We use a unique memory tag for all the ref-all pointers.  */
-  if (PTR_IS_REF_ALL (ptr))
-    {
-      if (!ai->ref_all_symbol_mem_tag)
-	ai->ref_all_symbol_mem_tag = create_memory_tag (void_type_node, true);
-      return ai->ref_all_symbol_mem_tag;
-    }
-
   /* To avoid creating unnecessary memory tags, only create one memory tag
      per alias set class.  Note that it may be tempting to group
      memory tags based on conflicting alias sets instead of