params.def (integer-share-limit): Decrease from 256 to 251, add rationale.

2012-08-17  Richard Guenther  <rguenther@suse.de>

	* params.def (integer-share-limit): Decrease from 256 to 251,
	add rationale.

From-SVN: r190470

gcc/ChangeLog

 2012-08-17  Richard Guenther  <rguenther@suse.de>
 
+	* params.def (integer-share-limit): Decrease from 256 to 251,
+	add rationale.
+
+2012-08-17  Richard Guenther  <rguenther@suse.de>
+
 	* tree-sra.c (modify_function): Free redirect_callers vector.
 	* ipa-split.c (split_function): Free args_to_pass vector.
 	* tree-vect-data-refs.c (vect_peeling_hash_get_lowest_cost): Free

gcc/params.def

@@ -638,11 +638,12 @@ DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
 
 /* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
    {signed,unsigned} integral types.  This determines N.
-   Experimentation shows 256 to be a good value.  */
+   Experimentation shows 251 to be a good value that generates the
+   least amount of garbage for allocating the TREE_VEC storage.  */
 DEFPARAM (PARAM_INTEGER_SHARE_LIMIT,
 	  "integer-share-limit",
 	  "The upper bound for sharing integer constants",
-	  256, 2, 2)
+	  251, 2, 2)
 
 DEFPARAM (PARAM_SSP_BUFFER_SIZE,
 	  "ssp-buffer-size",