static deferred_change_t deferred_change_list = NULL;
-/* This are used to hold the alias sets of spill variables. Since
- these are never aliased and there may be a lot of them, it makes
- sense to treat them specially. This bitvector is only allocated in
- calls from dse_record_singleton_alias_set which currently is only
- made during reload1. So when dse is called before reload this
- mechanism does nothing. */
-
-static bitmap clear_alias_sets = NULL;
-
-/* The set of clear_alias_sets that have been disqualified because
- there are loads or stores using a different mode than the alias set
- was registered with. */
-static bitmap disqualified_clear_alias_sets = NULL;
-
/* The group that holds all of the clear_alias_sets. */
static group_info_t clear_alias_group;
enum machine_mode mode;
};
-static alloc_pool clear_alias_mode_pool;
-
/* This is true except if cfun->stdarg -- i.e. we cannot do
this for vararg functions because they play games with the frame. */
static bool stores_off_frame_dead_at_return;
init_alias_analysis ();
- if (clear_alias_sets)
- clear_alias_group = get_group_info (NULL);
- else
- clear_alias_group = NULL;
+ clear_alias_group = NULL;
}
rtx expanded_address, address;
int expanded;
- /* Make sure that cselib is has initialized all of the operands of
- the address before asking it to do the subst. */
-
- if (clear_alias_sets)
- {
- /* If this is a spill, do not do any further processing. */
- alias_set_type alias_set = MEM_ALIAS_SET (mem);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "found alias set %d\n", (int) alias_set);
- if (bitmap_bit_p (clear_alias_sets, alias_set))
- {
- struct clear_alias_mode_holder *entry
- = clear_alias_set_lookup (alias_set);
-
- /* If the modes do not match, we cannot process this set. */
- if (entry->mode != GET_MODE (mem))
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file,
- "disqualifying alias set %d, (%s) != (%s)\n",
- (int) alias_set, GET_MODE_NAME (entry->mode),
- GET_MODE_NAME (GET_MODE (mem)));
-
- bitmap_set_bit (disqualified_clear_alias_sets, alias_set);
- return false;
- }
-
- *alias_set_out = alias_set;
- *group_id = clear_alias_group->id;
- return true;
- }
- }
-
*alias_set_out = 0;
cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem));
}
-/* Init the offset tables for the spill case. */
-
-static bool
-dse_step2_spill (void)
-{
- unsigned int j;
- group_info_t group = clear_alias_group;
- bitmap_iterator bi;
-
- /* Position 0 is unused because 0 is used in the maps to mean
- unused. */
- current_position = 1;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- bitmap_print (dump_file, clear_alias_sets,
- "clear alias sets ", "\n");
- bitmap_print (dump_file, disqualified_clear_alias_sets,
- "disqualified clear alias sets ", "\n");
- }
-
- memset (group->offset_map_n, 0, sizeof(int) * group->offset_map_size_n);
- memset (group->offset_map_p, 0, sizeof(int) * group->offset_map_size_p);
- bitmap_clear (group->group_kill);
-
- /* Remove the disqualified positions from the store2_p set. */
- bitmap_and_compl_into (group->store2_p, disqualified_clear_alias_sets);
-
- /* We do not need to process the store2_n set because
- alias_sets are always positive. */
- EXECUTE_IF_SET_IN_BITMAP (group->store2_p, 0, j, bi)
- {
- bitmap_set_bit (group->group_kill, current_position);
- group->offset_map_p[j] = current_position++;
- group->process_globally = true;
- }
-
- return current_position != 1;
-}
-
-
\f
/*----------------------------------------------------------------------------
Third step.
}
-static void
-dse_step5_spill (void)
-{
- basic_block bb;
- FOR_EACH_BB (bb)
- {
- bb_info_t bb_info = bb_table[bb->index];
- insn_info_t insn_info = bb_info->last_insn;
- bitmap v = bb_info->out;
-
- while (insn_info)
- {
- bool deleted = false;
- /* There may have been code deleted by the dce pass run before
- this phase. */
- if (insn_info->insn
- && INSN_P (insn_info->insn)
- && (!insn_info->cannot_delete)
- && (!bitmap_empty_p (v)))
- {
- /* Try to delete the current insn. */
- store_info_t store_info = insn_info->store_rec;
- deleted = true;
-
- while (store_info)
- {
- if (store_info->alias_set)
- {
- int index = get_bitmap_index (clear_alias_group,
- store_info->alias_set);
- if (index == 0 || !bitmap_bit_p (v, index))
- {
- deleted = false;
- break;
- }
- }
- else
- deleted = false;
- store_info = store_info->next;
- }
- if (deleted && dbg_cnt (dse)
- && check_for_inc_dec_1 (insn_info))
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Spill deleting insn %d\n",
- INSN_UID (insn_info->insn));
- delete_insn (insn_info->insn);
- spill_deleted++;
- insn_info->insn = NULL;
- }
- }
-
- if (insn_info->insn
- && INSN_P (insn_info->insn)
- && (!deleted))
- {
- scan_stores_spill (insn_info->store_rec, v, NULL);
- scan_reads_spill (insn_info->read_rec, v, NULL);
- }
-
- insn_info = insn_info->prev_insn;
- }
- }
-}
-
-
\f
/*----------------------------------------------------------------------------
Sixth step.
bitmap_obstack_release (&dse_bitmap_obstack);
obstack_free (&dse_obstack, NULL);
- if (clear_alias_sets)
- {
- BITMAP_FREE (clear_alias_sets);
- BITMAP_FREE (disqualified_clear_alias_sets);
- free_alloc_pool (clear_alias_mode_pool);
- htab_delete (clear_alias_mode_table);
- }
-
end_alias_analysis ();
free (bb_table);
rtx_group_table.dispose ();
static unsigned int
rest_of_handle_dse (void)
{
- bool did_global = false;
-
df_set_flags (DF_DEFER_INSN_RESCAN);
/* Need the notes since we must track live hardregs in the forwards
{
df_set_flags (DF_LR_RUN_DCE);
df_analyze ();
- did_global = true;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "doing global processing\n");
dse_step3 (false);
dse_step5_nospill ();
}
- /* For the instance of dse that runs after reload, we make a special
- pass to process the spills. These are special in that they are
- totally transparent, i.e, there is no aliasing issues that need
- to be considered. This means that the wild reads that kill
- everything else do not apply here. */
- if (clear_alias_sets && dse_step2_spill ())
- {
- if (!did_global)
- {
- df_set_flags (DF_LR_RUN_DCE);
- df_analyze ();
- }
- did_global = true;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "doing global spill processing\n");
- dse_step3 (true);
- dse_step4 ();
- dse_step5_spill ();
- }
-
dse_step6 ();
dse_step7 ();
projects / gcc.git / commitdiff