Re: [lto] Refactor streamer (1/N) (issue4809083)

[Michael Matz]

Hi,

On Fri, 26 Aug 2011, Jakub Jelinek wrote:

> While you are touching it, I think we should also optimize it as in the 
> patch below.  I'm afraid no string length optimization would be able to 
> figure out that it doesn't have to call strlen twice, because the 
> htab_find_slot isn't pure.

Sure.  Regstrapped the below patch and checked in as r178118.


Ciao,
Michael.
-- 
Index: lto-streamer-in.c
===================================================================
--- lto-streamer-in.c   (revision 178117)
+++ lto-streamer-in.c   (revision 178118)
@@ -98,21 +98,22 @@ canon_file_name (const char *string)
 {
   void **slot;
   struct string_slot s_slot;
+  size_t len = strlen (string);
+
   s_slot.s = string;
-  s_slot.len = strlen (string);
+  s_slot.len = len;

   slot = htab_find_slot (file_name_hash_table, &s_slot, INSERT);
   if (*slot == NULL)
     {
-      size_t len;
       char *saved_string;
       struct string_slot *new_slot;

-      len = strlen (string);
       saved_string = (char *) xmalloc (len + 1);
       new_slot = XCNEW (struct string_slot);
-      strcpy (saved_string, string);
+      memcpy (saved_string, string, len + 1);
       new_slot->s = saved_string;
+      new_slot->len = len;
       *slot = new_slot;
       return saved_string;
     }