On Fri, Oct 31, 2014 at 10:46:12AM +0000, Richard Biener wrote:
> On Wed, Oct 29, 2014 at 3:39 PM, James Greenhalgh wrote:
> >> I suppose I could port any target with a definition of MOVE_RATIO to
> >> override the default parameter value in their option overriding code,
> >> but that makes this a very large patch set (many targets define
> >> MOVE_RATIO).
> >>
> >> Is this an avenue worth exploring? I agree the very special target
> >> hook is not ideal.
> >
> > Hi,
> >
> > Did you have any further thoughts on this? I'm still unable to come up
> > with a way to set these parameters which allows them to default to their
> > current (MOVE_RATIO derived) values.
> >
> > If the only way to make this work is to add code to
> > TARGET_OPTION_OVERRIDE for all targets that define MOVE_RATIO, then I
> > suppose I can do that, but I'd prefer a neater way to make it work, if
> > you can think of one.
>
> Maybe instead of putting the code in opts.c put it right before we call
> targetm.target_option.override () in toplev.c:process_options. With
> a comment on why it cannot be in opts.c.
Ah, that makes sense. The (much simplified) patch then looks like
this...
Bootstrapped on x86_64, ARM and AArch64 with no issues.
OK?
Thanks,
James
---
gcc/
2014-11-06 James Greenhalgh <james.greenha...@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.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 792f25b..fcc5c89 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -10403,6 +10403,16 @@ 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
diff --git a/gcc/params.def b/gcc/params.def
index beff7e6..7cba3b3 100644
--- a/gcc/params.def
+++ b/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 "
diff --git a/gcc/target.h b/gcc/target.h
index 40d7841..65250ed 100644
--- a/gcc/target.h
+++ b/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;
diff --git a/gcc/targhooks.c b/gcc/targhooks.c
index eef3d45..d798217 100644
--- a/gcc/targhooks.c
+++ b/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;
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 2c570d4..71589f2 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1265,6 +1265,20 @@ 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 ();
diff --git a/gcc/tree-sra.c b/gcc/tree-sra.c
index b723ca5..1e629bc 100644
--- a/gcc/tree-sra.c
+++ b/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))
