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Come up with jump_table ratio constants used in jump_table_cluster.

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2018-06-28  Martin Liska  <mliska@suse.cz>

	* tree-switch-conversion.c (jump_table_cluster::can_be_handled):
        Use newly introduced constants.
	* tree-switch-conversion.h (struct jump_table_cluster):
        Define max_ratio_for_size and max_ratio_for_speed.

From-SVN: r262212
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Martin Liska 2018-06-28 09:15:55 +02:00 • committed by Martin Liska
parent df7c79742a
commit 1aabb71d13
3 changed files with 15 additions and 1 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2018-06-28 Martin Liska <mliska@suse.cz>
* tree-switch-conversion.c (jump_table_cluster::can_be_handled):
Use newly introduced constants.
* tree-switch-conversion.h (struct jump_table_cluster):
Define max_ratio_for_size and max_ratio_for_speed.
2018-06-28 Martin Liska <mliska@suse.cz>
* tree-switch-conversion.c (jump_table_cluster::find_jump_tables):

3
gcc/tree-switch-conversion.c
View file

@ -1180,7 +1180,8 @@ jump_table_cluster::can_be_handled (const vec<cluster *> &clusters,
if (start == end)
return true;
unsigned HOST_WIDE_INT max_ratio = optimize_insn_for_size_p () ? 3 : 8;
unsigned HOST_WIDE_INT max_ratio
= optimize_insn_for_size_p () ? max_ratio_for_size : max_ratio_for_speed;
unsigned HOST_WIDE_INT range = get_range (clusters[start]->get_low (),
clusters[end]->get_high ());
/* Check overflow. */

6
gcc/tree-switch-conversion.h
View file

@ -257,6 +257,12 @@ struct jump_table_cluster: public group_cluster
/* Return whether jump table expansion is allowed. */
static bool is_enabled (void);
/* Max growth ratio for code that is optimized for size. */
static const unsigned HOST_WIDE_INT max_ratio_for_size = 3;
/* Max growth ratio for code that is optimized for speed. */
static const unsigned HOST_WIDE_INT max_ratio_for_speed = 8;
};
/* A GIMPLE switch statement can be expanded to a short sequence of bit-wise