Reduce lookup_attribute memory footprint.

2017-09-12  Martin Liska  <mliska@suse.cz>

	* attribs.c (private_lookup_attribute): New function.
	* attribs.h (private_lookup_attribute): Declared here.
	(lookup_attribute): Called from this place.

From-SVN: r252022

gcc/ChangeLog

+2017-09-12  Martin Liska  <mliska@suse.cz>
+
+	* attribs.c (private_lookup_attribute): New function.
+	* attribs.h (private_lookup_attribute): Declared here.
+	(lookup_attribute): Called from this place.
+
 2017-09-12  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/82157

gcc/attribs.c

@@ -1584,3 +1584,25 @@ attribute_list_contained (const_tree l1, const_tree l2)
 
   return 1;
 }
+
+/* The backbone of lookup_attribute().  ATTR_LEN is the string length
+   of ATTR_NAME, and LIST is not NULL_TREE.
+
+   The function is called from lookup_attribute in order to optimize
+   for size.  */
+
+tree
+private_lookup_attribute (const char *attr_name, size_t attr_len, tree list)
+{
+  while (list)
+    {
+      tree attr = get_attribute_name (list);
+      size_t ident_len = IDENTIFIER_LENGTH (attr);
+      if (cmp_attribs (attr_name, attr_len, IDENTIFIER_POINTER (attr),
+		       ident_len))
+	break;
+      list = TREE_CHAIN (list);
+    }
+
+  return list;
+}

gcc/attribs.h

@@ -87,6 +87,14 @@ extern tree handle_dll_attribute (tree *, tree, tree, int, bool *);
 extern int attribute_list_equal (const_tree, const_tree);
 extern int attribute_list_contained (const_tree, const_tree);
 
+/* The backbone of lookup_attribute().  ATTR_LEN is the string length
+   of ATTR_NAME, and LIST is not NULL_TREE.
+
+   The function is called from lookup_attribute in order to optimize
+   for size.  */
+extern tree private_lookup_attribute (const char *attr_name, size_t attr_len,
+				      tree list);
+
 /* For a given IDENTIFIER_NODE, strip leading and trailing '_' characters
    so that we have a canonical form of attribute names.  */
 
@@ -151,17 +159,7 @@ lookup_attribute (const char *attr_name, tree list)
       /* Do the strlen() before calling the out-of-line implementation.
 	 In most cases attr_name is a string constant, and the compiler
 	 will optimize the strlen() away.  */
-      while (list)
-	{
-	  tree attr = get_attribute_name (list);
-	  size_t ident_len = IDENTIFIER_LENGTH (attr);
-	  if (cmp_attribs (attr_name, attr_len, IDENTIFIER_POINTER (attr),
-			   ident_len))
-	    break;
-	  list = TREE_CHAIN (list);
-	}
-
-      return list;
+      return private_lookup_attribute (attr_name, attr_len, list);
     }
 }