[Patchv3] Control SRA and IPA-SRA by a param rather than MOVE_RATIO

gcc/

	* params.def (sra-max-scalarization-size-Ospeed): New.
	(sra-max-scalarization-size-Osize): Likewise.
	* doc/invoke.texi (sra-max-scalarization-size-Ospeed): Document.
	(sra-max-scalarization-size-Osize): Likewise.
	* toplev.c (process_options): Set default values for new
	parameters.
	* tree-sra.c (analyze_all_variable_accesses): Use new parameters.
	* targhooks.c (get_move_ratio): Remove static designator.
	* target.h (get_move_ratio): Declare.

From-SVN: r217191

gcc/ChangeLog

+2014-11-06  James Greenhalgh  <james.greenhalgh@arm.com>
+
+	* params.def (sra-max-scalarization-size-Ospeed): New.
+	(sra-max-scalarization-size-Osize): Likewise.
+	* doc/invoke.texi (sra-max-scalarization-size-Ospeed): Document.
+	(sra-max-scalarization-size-Osize): Likewise.
+	* toplev.c (process_options): Set default values for new
+	parameters.
+	* tree-sra.c (analyze_all_variable_accesses): Use new parameters.
+	* targhooks.c (get_move_ratio): Remove static designator.
+	* target.h (get_move_ratio): Declare.
+
 2014-11-06  Marek Polacek  <polacek@redhat.com>
 
 	* sanopt.c (sanopt_optimize_walker): Limit removal of the checks.

gcc/doc/invoke.texi

@@ -10401,6 +10401,16 @@ parameters only when their cumulative size is less or equal to
 @option{ipa-sra-ptr-growth-factor} times the size of the original
 pointer parameter.
 
+@item sra-max-scalarization-size-Ospeed
+@item sra-max-scalarization-size-Osize
+The two Scalar Reduction of Aggregates passes (SRA and IPA-SRA) aim to
+replace scalar parts of aggregates with uses of independent scalar
+variables.  These parameters control the maximum size, in storage units,
+of aggregate which will be considered for replacement when compiling for
+speed
+(@option{sra-max-scalarization-size-Ospeed}) or size
+(@option{sra-max-scalarization-size-Osize}) respectively.
+
 @item tm-max-aggregate-size
 When making copies of thread-local variables in a transaction, this
 parameter specifies the size in bytes after which variables are

gcc/params.def

@@ -950,6 +950,18 @@ DEFPARAM (PARAM_TM_MAX_AGGREGATE_SIZE,
 	  "pairs",
 	  9, 0, 0)
 
+DEFPARAM (PARAM_SRA_MAX_SCALARIZATION_SIZE_SPEED,
+	  "sra-max-scalarization-size-Ospeed",
+	  "Maximum size, in storage units, of an aggregate which should be "
+	  "considered for scalarization when compiling for speed",
+	  0, 0, 0)
+
+DEFPARAM (PARAM_SRA_MAX_SCALARIZATION_SIZE_SIZE,
+	  "sra-max-scalarization-size-Osize",
+	  "Maximum size, in storage units, of an aggregate which should be "
+	  "considered for scalarization when compiling for size",
+	  0, 0, 0)
+
 DEFPARAM (PARAM_IPA_CP_VALUE_LIST_SIZE,
 	  "ipa-cp-value-list-size",
 	  "Maximum size of a list of values associated with each parameter for "

gcc/target.h

@@ -102,6 +102,10 @@ extern int elf_record_gcc_switches (print_switch_type type, const char *);
    we disable such optimizations on such targets, using this function.  */
 extern bool target_default_pointer_address_modes_p (void);
 
+/* For hooks which use the MOVE_RATIO macro, this gives the legacy default
+   behaviour.  */
+extern unsigned int get_move_ratio (bool);
+
 struct stdarg_info;
 struct spec_info_def;
 struct hard_reg_set_container;

gcc/targhooks.c

@@ -1409,7 +1409,7 @@ default_register_move_cost (machine_mode mode ATTRIBUTE_UNUSED,
 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
    behaviour.  SPEED_P is true if we are compiling for speed.  */
 
-static unsigned int
+unsigned int
 get_move_ratio (bool speed_p ATTRIBUTE_UNUSED)
 {
   unsigned int move_ratio;

gcc/toplev.c

@@ -1270,6 +1270,20 @@ process_options (void)
      so we can correctly initialize debug output.  */
   no_backend = lang_hooks.post_options (&main_input_filename);
 
+  /* Set default values for parameters relation to the Scalar Reduction
+     of Aggregates passes (SRA and IP-SRA).  We must do this here, rather
+     than in opts.c:default_options_optimization as historically these
+     tuning heuristics have been based on MOVE_RATIO, which on some
+     targets requires other symbols from the backend.  */
+  maybe_set_param_value
+    (PARAM_SRA_MAX_SCALARIZATION_SIZE_SPEED,
+     get_move_ratio (true) * UNITS_PER_WORD,
+     global_options.x_param_values, global_options_set.x_param_values);
+  maybe_set_param_value
+    (PARAM_SRA_MAX_SCALARIZATION_SIZE_SIZE,
+     get_move_ratio (false) * UNITS_PER_WORD,
+     global_options.x_param_values, global_options_set.x_param_values);
+
   /* Some machines may reject certain combinations of options.  */
   targetm.target_option.override ();
 

gcc/tree-sra.c

@@ -2511,10 +2511,12 @@ analyze_all_variable_accesses (void)
   int res = 0;
   bitmap tmp = BITMAP_ALLOC (NULL);
   bitmap_iterator bi;
-  unsigned i, max_total_scalarization_size;
-
-  max_total_scalarization_size = UNITS_PER_WORD * BITS_PER_UNIT
-    * MOVE_RATIO (optimize_function_for_speed_p (cfun));
+  unsigned i;
+  unsigned max_scalarization_size
+    = (optimize_function_for_size_p (cfun)
+	? PARAM_VALUE (PARAM_SRA_MAX_SCALARIZATION_SIZE_SIZE)
+	: PARAM_VALUE (PARAM_SRA_MAX_SCALARIZATION_SIZE_SPEED))
+      * BITS_PER_UNIT;
 
   EXECUTE_IF_SET_IN_BITMAP (candidate_bitmap, 0, i, bi)
     if (bitmap_bit_p (should_scalarize_away_bitmap, i)
@@ -2526,7 +2528,7 @@ analyze_all_variable_accesses (void)
 	    && type_consists_of_records_p (TREE_TYPE (var)))
 	  {
 	    if (tree_to_uhwi (TYPE_SIZE (TREE_TYPE (var)))
-		<= max_total_scalarization_size)
+		<= max_scalarization_size)
 	      {
 		completely_scalarize_var (var);
 		if (dump_file && (dump_flags & TDF_DETAILS))