Cleanup modref interfaces.

* ipa-fnsummary.c (refs_local_or_readonly_memory_p): New function.
	(points_to_local_or_readonly_memory_p): New function.
	* ipa-fnsummary.h (refs_local_or_readonly_memory_p): Declare.
	(points_to_local_or_readonly_memory_p): Declare.
	* ipa-modref.c (record_access_p): Use refs_local_or_readonly_memory_p.
	* ipa-pure-const.c (check_op): Likewise.

	* gcc.dg/tree-ssa/local-pure-const.c: Update template.

gcc/ipa-fnsummary.c

@@ -2430,6 +2430,47 @@ fp_expression_p (gimple *stmt)
   return false;
 }
 
+/* Return true if T references memory location that is local
+   for the function (that means, dead after return) or read-only.  */
+
+bool
+refs_local_or_readonly_memory_p (tree t)
+{
+  /* Non-escaping memory is fine.  */
+  t = get_base_address (t);
+  if ((TREE_CODE (t) == MEM_REF
+      || TREE_CODE (t) == TARGET_MEM_REF))
+    return points_to_local_or_readonly_memory_p (TREE_OPERAND (t, 0));
+
+  /* Automatic variables are fine.  */
+  if (DECL_P (t)
+      && auto_var_in_fn_p (t, current_function_decl))
+    return true;
+
+  /* Read-only variables are fine.  */
+  if (DECL_P (t) && TREE_READONLY (t))
+    return true;
+
+  return false;
+}
+
+/* Return true if T is a pointer pointing to memory location that is local
+   for the function (that means, dead after return) or read-only.  */
+
+bool
+points_to_local_or_readonly_memory_p (tree t)
+{
+  /* See if memory location is clearly invalid.  */
+  if (integer_zerop (t))
+    return flag_delete_null_pointer_checks;
+  if (TREE_CODE (t) == SSA_NAME)
+    return !ptr_deref_may_alias_global_p (t);
+  if (TREE_CODE (t) == ADDR_EXPR)
+    return refs_local_or_readonly_memory_p (TREE_OPERAND (t, 0));
+  return false;
+}
+
+
 /* Analyze function body for NODE.
    EARLY indicates run from early optimization pipeline.  */
 

gcc/ipa-fnsummary.h

@@ -357,6 +357,8 @@ void estimate_ipcp_clone_size_and_time (struct cgraph_node *,
 void ipa_merge_fn_summary_after_inlining (struct cgraph_edge *edge);
 void ipa_update_overall_fn_summary (struct cgraph_node *node, bool reset = true);
 void compute_fn_summary (struct cgraph_node *, bool);
+bool refs_local_or_readonly_memory_p (tree);
+bool points_to_local_or_readonly_memory_p (tree);
 
 
 void evaluate_properties_for_edge (struct cgraph_edge *e,

gcc/ipa-modref.c

@@ -62,6 +62,9 @@ along with GCC; see the file COPYING3.  If not see
 #include "calls.h"
 #include "ipa-modref-tree.h"
 #include "ipa-modref.h"
+#include "value-range.h"
+#include "ipa-prop.h"
+#include "ipa-fnsummary.h"
 
 /* Class (from which there is one global instance) that holds modref summaries
    for all analyzed functions.  */
@@ -347,36 +350,12 @@ record_access_lto (modref_records_lto *tt, ao_ref *ref)
 static bool
 record_access_p (tree expr)
 {
-  /* Non-escaping memory is fine  */
-  tree t = get_base_address (expr);
-  if (t && (INDIRECT_REF_P (t)
-	    || TREE_CODE (t) == MEM_REF
-	    || TREE_CODE (t) == TARGET_MEM_REF)
-	&& TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME
-	&& !ptr_deref_may_alias_global_p (TREE_OPERAND (t, 0)))
+  if (refs_local_or_readonly_memory_p (expr))
     {
       if (dump_file)
-	fprintf (dump_file, "   - Non-escaping memory, ignoring.\n");
+	fprintf (dump_file, "   - Read-only or local, ignoring.\n");
       return false;
     }
-
-  /* Automatic variables are fine.  */
-  if (DECL_P (t)
-      && auto_var_in_fn_p (t, current_function_decl))
-    {
-      if (dump_file)
-	fprintf (dump_file, "   - Automatic variable, ignoring.\n");
-      return false;
-    }
-
-  /* Read-only variables are fine.  */
-  if (DECL_P (t) && TREE_READONLY (t))
-    {
-      if (dump_file)
-	fprintf (dump_file, "   - Read-only variable, ignoring.\n");
-      return false;
-    }
-
   return true;
 }
 

gcc/ipa-pure-const.c

@@ -381,13 +381,11 @@ check_op (funct_state local, tree t, bool checking_write)
 	fprintf (dump_file, "    Volatile indirect ref is not const/pure\n");
       return;
     }
-  else if (t
-  	   && (INDIRECT_REF_P (t) || TREE_CODE (t) == MEM_REF)
-	   && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME
-	   && !ptr_deref_may_alias_global_p (TREE_OPERAND (t, 0)))
+  else if (refs_local_or_readonly_memory_p (t))
     {
       if (dump_file)
-	fprintf (dump_file, "    Indirect ref to local memory is OK\n");
+	fprintf (dump_file, "    Indirect ref to local or readonly "
+		 "memory is OK\n");
       return;
     }
   else if (checking_write)

gcc/testsuite/gcc.dg/tree-ssa/local-pure-const.c

@@ -12,5 +12,5 @@ t(int a, int b, int c)
     p = &c;
   return *p;
 }
-/* { dg-final { scan-tree-dump-times "local memory is OK" 1 "local-pure-const1"} } */
+/* { dg-final { scan-tree-dump-times "local or readonly memory is OK" 1 "local-pure-const1"} } */
 /* { dg-final { scan-tree-dump-times "found to be const" 1 "local-pure-const1"} } */