[PATCH] simple speedup for Darwin's stubs/non-lazy symbol finding

[Andrew Pinski <pinskia at physics dot uc dot edu>]

When I was looking into how I could get PR8361 faster on Mac OS X,
I noticed the top functions were caused by the darwin back-end.
This patch fixes some of the issue dealing with the back-end but
looking into the length of the strings before calling strcmp.
This is faster as we already know the length for the IDENTIFER_NODE,
IDENTIFIER_LENGTH.

Orginal speed on a dual 2.5GHz G5: 18 seconds
After change to machopic_stub_name: 16.650 seconds
After change to machopic_non_lazy_ptr_name: 16.1 seconds.

I have another change to remove machopic_indirect_call_target
but I have not fixed the i386-darwin back-end yet to do the
output right.

With the removal of machopic_indirect_call_target: 14.3 seconds.
(but note this was not a total removal, just of all code in the function).

All measurements were done with CFLAGS="-O2 -g" with the mainline compiler
as the building the compiler.

OK? Bootstrapped on powerpc-apple-darwin with no regressions.

Thanks,
Andrew Pinski

ChangeLog:

	* config/darwin.c (machopic_non_lazy_ptr_name): Check the length of the
	the IDENTIFIER before calling strcmp.
	(machopic_stub_name): Likewise.

Index: darwin.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/darwin.c,v
retrieving revision 1.69
diff -u -p -r1.69 darwin.c
--- darwin.c	3 Jun 2004 22:15:08 -0000	1.69
+++ darwin.c	25 Jun 2004 07:07:32 -0000
@@ -266,6 +266,7 @@ machopic_non_lazy_ptr_name (const char *
 {
   const char *temp_name;
   tree temp, ident = get_identifier (name);
+  int name_len;
 
   for (temp = machopic_non_lazy_pointers;
        temp != NULL_TREE;
@@ -277,16 +278,20 @@ machopic_non_lazy_ptr_name (const char *
 
   name = darwin_strip_name_encoding (name);
 
+  name_len = strlen (name);
+
   /* Try again, but comparing names this time.  */
   for (temp = machopic_non_lazy_pointers;
        temp != NULL_TREE;
        temp = TREE_CHAIN (temp))
     {
+      int tlen;
       if (TREE_VALUE (temp))
 	{
+	  tlen = IDENTIFIER_LENGTH (TREE_VALUE (temp)) - 1;
 	  temp_name = IDENTIFIER_POINTER (TREE_VALUE (temp));
 	  temp_name = darwin_strip_name_encoding (temp_name);
-	  if (strcmp (name, temp_name) == 0)
+	  if (tlen == name_len && strcmp (name, temp_name) == 0)
 	    return IDENTIFIER_POINTER (TREE_PURPOSE (temp));
 	}
     }
@@ -336,19 +341,22 @@ machopic_stub_name (const char *name)
 {
   tree temp, ident = get_identifier (name);
   const char *tname;
+  int name_leng = strlen (name);
 
   for (temp = machopic_stubs;
        temp != NULL_TREE;
        temp = TREE_CHAIN (temp))
     {
+      int tlen;
       if (ident == TREE_VALUE (temp))
 	return IDENTIFIER_POINTER (TREE_PURPOSE (temp));
       tname = IDENTIFIER_POINTER (TREE_VALUE (temp));
-      if (strcmp (name, tname) == 0)
+      tlen = IDENTIFIER_LENGTH (TREE_VALUE (temp)) - 1;
+      if (tlen == name_leng && strcmp (name, tname) == 0)
 	return IDENTIFIER_POINTER (TREE_PURPOSE (temp));
       /* A library call name might not be section-encoded yet, so try
 	 it against a stripped name.  */
-      if (name[0] != '!'
+      if (tlen - 4 == name_leng && name[0] != '!'
 	  && tname[0] == '!'
 	  && strcmp (name, tname + 4) == 0)
 	return IDENTIFIER_POINTER (TREE_PURPOSE (temp));