This tries to more clearly separate per-SSA name held information
from per-DECL held information during update-ssa. We already have
a global array of SSA name informations so it is pointless to
have a hashtable mapping SSA names to yet another piece of information
(a bitmap). This patch simply puts the bitmap into that SSA name
auxiliar vector. Lifetime is managed by using a separate obstack
and the aux vector age.
Bootstrap and regtest pending on x86_64-unknown-linux-gnu.
Richard.
2012-07-27 Richard Guenther <rguent...@suse.de>
* tree-cfg.c (gimple_can_merge_blocks_p): Do more fine-grained
check whether SSA form is not up-to-date.
* tree-flow.h (name_mappings_registered_p): Remove.
* tree-into-ssa.c (struct repl_map_d): Remove.
(repl_tbl): Likewise.
(struct ssa_name_info): Add repl_set member.
(update_ssa_obstack): New static global.
(get_ssa_name_ann): Initialize repl_set.
(clear_ssa_name_info): Assert age did not wrap.
(repl_map_hash, repl_map_eq, repl_map_free): Remove.
(names_replaced_by): Adjust.
(add_to_repl_tbl): Likewise.
(dump_tree_ssa_stats): Likewise.
(init_update_ssa): Initialize update_ssa_obstack.
(delete_update_ssa): Free update_ssa_obstack.
(name_mappings_registered_p): Remove.
(update_ssa): Adjust.
Index: trunk/gcc/tree-cfg.c
===================================================================
*** trunk.orig/gcc/tree-cfg.c 2012-07-26 10:46:43.000000000 +0200
--- trunk/gcc/tree-cfg.c 2012-07-27 13:40:30.603790938 +0200
*************** gimple_can_merge_blocks_p (basic_block a
*** 1449,1455 ****
{
gimple stmt;
gimple_stmt_iterator gsi;
- gimple_seq phis;
if (!single_succ_p (a))
return false;
--- 1449,1454 ----
*************** gimple_can_merge_blocks_p (basic_block a
*** 1499,1508 ****
/* It must be possible to eliminate all phi nodes in B. If ssa form
is not up-to-date and a name-mapping is registered, we cannot eliminate
any phis. Symbols marked for renaming are never a problem though. */
! phis = phi_nodes (b);
! if (!gimple_seq_empty_p (phis)
! && name_mappings_registered_p ())
! return false;
/* When not optimizing, don't merge if we'd lose goto_locus. */
if (!optimize
--- 1498,1510 ----
/* It must be possible to eliminate all phi nodes in B. If ssa form
is not up-to-date and a name-mapping is registered, we cannot eliminate
any phis. Symbols marked for renaming are never a problem though. */
! for (gsi = gsi_start_phis (b); !gsi_end_p (gsi); gsi_next (&gsi))
! {
! gimple phi = gsi_stmt (gsi);
! /* Technically only new names matter. */
! if (name_registered_for_update_p (PHI_RESULT (phi)))
! return false;
! }
/* When not optimizing, don't merge if we'd lose goto_locus. */
if (!optimize
Index: trunk/gcc/tree-flow.h
===================================================================
*** trunk.orig/gcc/tree-flow.h 2012-07-27 12:46:26.000000000 +0200
--- trunk/gcc/tree-flow.h 2012-07-27 13:40:41.441790559 +0200
*************** void delete_update_ssa (void);
*** 570,576 ****
void register_new_name_mapping (tree, tree);
tree create_new_def_for (tree, gimple, def_operand_p);
bool need_ssa_update_p (struct function *);
- bool name_mappings_registered_p (void);
bool name_registered_for_update_p (tree);
void release_ssa_name_after_update_ssa (tree);
void compute_global_livein (bitmap, bitmap);
--- 570,575 ----
Index: trunk/gcc/tree-into-ssa.c
===================================================================
*** trunk.orig/gcc/tree-into-ssa.c 2012-07-27 12:52:09.000000000 +0200
--- trunk/gcc/tree-into-ssa.c 2012-07-27 14:00:30.533749404 +0200
*************** static bitmap blocks_with_phis_to_rewrit
*** 128,145 ****
strategy. */
#define NAME_SETS_GROWTH_FACTOR (MAX (3, num_ssa_names / 3))
- /* Tuple used to represent replacement mappings. */
- struct repl_map_d
- {
- tree name;
- bitmap set;
- };
-
-
- /* NEW -> OLD_SET replacement table. If we are replacing several
- existing SSA names O_1, O_2, ..., O_j with a new name N_i,
- then REPL_TBL[N_i] = { O_1, O_2, ..., O_j }. */
- static htab_t repl_tbl;
/* The function the SSA updating data structures have been initialized for.
NULL if they need to be initialized by register_new_name_mapping. */
--- 128,133 ----
*************** struct mark_def_sites_global_data
*** 157,174 ****
/* Information stored for SSA names. */
struct ssa_name_info
{
! /* The current reaching definition replacing this SSA name. */
! tree current_def;
/* This field indicates whether or not the variable may need PHI nodes.
See the enum's definition for more detailed information about the
states. */
ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
! /* Age of this record (so that info_for_ssa_name table can be cleared
! quickly); if AGE < CURRENT_INFO_FOR_SSA_NAME_AGE, then the fields
! are assumed to be null. */
! unsigned age;
};
/* The information associated with names. */
--- 145,165 ----
/* Information stored for SSA names. */
struct ssa_name_info
{
! /* Age of this record (so that info_for_ssa_name table can be cleared
! quickly); if AGE < CURRENT_INFO_FOR_SSA_NAME_AGE, then the fields
! are assumed to be null. */
! unsigned age;
/* This field indicates whether or not the variable may need PHI nodes.
See the enum's definition for more detailed information about the
states. */
ENUM_BITFIELD (need_phi_state) need_phi_state : 2;
! /* The current reaching definition replacing this SSA name. */
! tree current_def;
!
! /* Replacement mappings, allocated from update_ssa_obstack. */
! bitmap repl_set;
};
/* The information associated with names. */
*************** DEF_VEC_ALLOC_P (ssa_name_info_p, heap);
*** 179,184 ****
--- 170,177 ----
static VEC(ssa_name_info_p, heap) *info_for_ssa_name;
static unsigned current_info_for_ssa_name_age;
+ static bitmap_obstack update_ssa_obstack;
+
/* The set of blocks affected by update_ssa. */
static bitmap blocks_to_update;
*************** get_ssa_name_ann (tree name)
*** 288,293 ****
--- 281,287 ----
{
info->need_phi_state = NEED_PHI_STATE_UNKNOWN;
info->current_def = NULL_TREE;
+ info->repl_set = NULL;
info->age = current_info_for_ssa_name_age;
}
*************** static void
*** 301,306 ****
--- 295,304 ----
clear_ssa_name_info (void)
{
current_info_for_ssa_name_age++;
+
+ /* If current_info_for_ssa_name_age wraps we use stale information.
+ Asser that this does not happen. */
+ gcc_assert (current_info_for_ssa_name_age != 0);
}
*************** is_new_name (tree name)
*** 573,617 ****
}
- /* Hashing and equality functions for REPL_TBL. */
-
- static hashval_t
- repl_map_hash (const void *p)
- {
- return htab_hash_pointer ((const void *)((const struct repl_map_d
*)p)->name);
- }
-
- static int
- repl_map_eq (const void *p1, const void *p2)
- {
- return ((const struct repl_map_d *)p1)->name
- == ((const struct repl_map_d *)p2)->name;
- }
-
- static void
- repl_map_free (void *p)
- {
- BITMAP_FREE (((struct repl_map_d *)p)->set);
- free (p);
- }
-
-
/* Return the names replaced by NEW_TREE (i.e., REPL_TBL[NEW_TREE].SET). */
static inline bitmap
names_replaced_by (tree new_tree)
{
! struct repl_map_d m;
! void **slot;
!
! m.name = new_tree;
! slot = htab_find_slot (repl_tbl, (void *) &m, NO_INSERT);
!
! /* If N was not registered in the replacement table, return NULL. */
! if (slot == NULL || *slot == NULL)
! return NULL;
!
! return ((struct repl_map_d *) *slot)->set;
}
--- 571,582 ----
}
/* Return the names replaced by NEW_TREE (i.e., REPL_TBL[NEW_TREE].SET). */
static inline bitmap
names_replaced_by (tree new_tree)
{
! return get_ssa_name_ann (new_tree)->repl_set;
}
*************** names_replaced_by (tree new_tree)
*** 620,641 ****
static inline void
add_to_repl_tbl (tree new_tree, tree old)
{
! struct repl_map_d m, *mp;
! void **slot;
!
! m.name = new_tree;
! slot = htab_find_slot (repl_tbl, (void *) &m, INSERT);
! if (*slot == NULL)
! {
! mp = XNEW (struct repl_map_d);
! mp->name = new_tree;
! mp->set = BITMAP_ALLOC (NULL);
! *slot = (void *) mp;
! }
! else
! mp = (struct repl_map_d *) *slot;
!
! bitmap_set_bit (mp->set, SSA_NAME_VERSION (old));
}
--- 585,594 ----
static inline void
add_to_repl_tbl (tree new_tree, tree old)
{
! bitmap *set = &get_ssa_name_ann (new_tree)->repl_set;
! if (!*set)
! *set = BITMAP_ALLOC (&update_ssa_obstack);
! bitmap_set_bit (*set, SSA_NAME_VERSION (old));
}
*************** htab_statistics (FILE *file, htab_t htab
*** 1719,1725 ****
void
dump_tree_ssa_stats (FILE *file)
{
! if (def_blocks || repl_tbl)
fprintf (file, "\nHash table statistics:\n");
if (def_blocks)
--- 1672,1678 ----
void
dump_tree_ssa_stats (FILE *file)
{
! if (def_blocks)
fprintf (file, "\nHash table statistics:\n");
if (def_blocks)
*************** dump_tree_ssa_stats (FILE *file)
*** 1728,1740 ****
htab_statistics (file, def_blocks);
}
! if (repl_tbl)
! {
! fprintf (file, " repl_tbl: ");
! htab_statistics (file, repl_tbl);
! }
!
! if (def_blocks || repl_tbl)
fprintf (file, "\n");
}
--- 1681,1687 ----
htab_statistics (file, def_blocks);
}
! if (def_blocks)
fprintf (file, "\n");
}
*************** init_update_ssa (struct function *fn)
*** 2838,2844 ****
new_ssa_names = sbitmap_alloc (num_ssa_names + NAME_SETS_GROWTH_FACTOR);
sbitmap_zero (new_ssa_names);
! repl_tbl = htab_create (20, repl_map_hash, repl_map_eq, repl_map_free);
names_to_release = NULL;
update_ssa_initialized_fn = fn;
}
--- 2785,2792 ----
new_ssa_names = sbitmap_alloc (num_ssa_names + NAME_SETS_GROWTH_FACTOR);
sbitmap_zero (new_ssa_names);
! bitmap_obstack_initialize (&update_ssa_obstack);
!
names_to_release = NULL;
update_ssa_initialized_fn = fn;
}
*************** delete_update_ssa (void)
*** 2858,2866 ****
sbitmap_free (new_ssa_names);
new_ssa_names = NULL;
- htab_delete (repl_tbl);
- repl_tbl = NULL;
-
bitmap_clear (SYMS_TO_RENAME (update_ssa_initialized_fn));
if (names_to_release)
--- 2806,2811 ----
*************** delete_update_ssa (void)
*** 2885,2890 ****
--- 2830,2838 ----
BITMAP_FREE (blocks_with_phis_to_rewrite);
BITMAP_FREE (blocks_to_update);
+
+ bitmap_obstack_release (&update_ssa_obstack);
+
update_ssa_initialized_fn = NULL;
}
*************** need_ssa_update_p (struct function *fn)
*** 2957,2975 ****
&& !bitmap_empty_p (SYMS_TO_RENAME (fn))));
}
- /* Return true if SSA name mappings have been registered for SSA updating. */
-
- bool
- name_mappings_registered_p (void)
- {
- if (!update_ssa_initialized_fn)
- return false;
-
- gcc_assert (update_ssa_initialized_fn == cfun);
-
- return repl_tbl && htab_elements (repl_tbl) > 0;
- }
-
/* Return true if name N has been registered in the replacement table. */
bool
--- 2905,2910 ----
*************** update_ssa (unsigned update_flags)
*** 3212,3218 ****
{
sbitmap_zero (old_ssa_names);
sbitmap_zero (new_ssa_names);
- htab_empty (repl_tbl);
}
insert_phi_p = (update_flags != TODO_update_ssa_no_phi);
--- 3147,3152 ----
