On Mon, 4 Apr 2016, Jakub Jelinek wrote:
> On Mon, Apr 04, 2016 at 11:24:41AM +0200, Richard Biener wrote:
> > On Fri, 1 Apr 2016, Bernd Schmidt wrote:
> >
> > > On 04/01/2016 11:08 AM, Richard Biener wrote:
> > > > {
> > > > ! if (canon_true_dependence (s_info->mem,
> > > > ! GET_MODE (s_info->mem),
> > > > ! s_info->mem_addr,
> > > > ! mem, mem_addr))
> > > > {
> > > > s_info->rhs = NULL;
> > > > s_info->const_rhs = NULL;
> > > > --- 1609,1617 ----
> > > > the value of store_info. If it is, set the rhs to NULL to
> > > > keep it from being used to remove a load. */
> > > > {
> > > > ! if (canon_output_dependence (s_info->mem, true,
> > > > ! mem, GET_MODE (mem),
> > > > ! mem_addr))
> > > > {
> > > > s_info->rhs = NULL;
> > > > s_info->const_rhs = NULL;
> > >
> > > I think the patch is ok, but there is a comment in that function which
> > > references canon_true_dependence; that should also be fixed up.
> >
> > Done, though I don't understand it at all ... if alias-set was supposed
> > to be zero for all cases we call canon_true_dependence then the issue
> > wouldn't have happened. Maybe there was times where passing mem_addr
> > == NULL_RTX to canon_true_dependence caused it to bail out?
> >
> > Not sure how to adjust that comment now, maybe it would be valid
> > to simply remove the if (spill_alias_set) case and always use
> > the else case?
>
> I believe all of the spill_alias_set stuff is dead for many years.
> In 4.4, a call to dse_record_singleton_alias_set has been removed
> (supposedly related to introduction of IRA). Then in 4.8 you've
> removed the dse_record_singleton_alias_set function, later on Lawrence
> removed other small bits of this.
> E.g. the alias_set_out argument from canon_address, all of spill_alias_set
> handling, alias_set field, clear_alias_set_lookup, clear_alias_mode_holder,
> clear_alias_group, clear_alias_mode_table are all dead IMHO.
True. By simple constant propagation I can remove a lot of code.
I'm going to bootstrap / test the following - is this ok for trunk
now (I'm going to write a better changelog).
Thanks,
Richard.
2016-04-05 Richard Biener <rguent...@suse.de>
* dse.c: Remove dead code.
Index: gcc/dse.c
===================================================================
--- gcc/dse.c (revision 234736)
+++ gcc/dse.c (working copy)
@@ -242,9 +242,6 @@ struct store_info
/* Canonized MEM address for use by canon_true_dependence. */
rtx mem_addr;
- /* If this is non-zero, it is the alias set of a spill location. */
- alias_set_type alias_set;
-
/* The offset of the first and byte before the last byte associated
with the operation. */
HOST_WIDE_INT begin, end;
@@ -306,9 +303,6 @@ struct read_info_type
/* The id of the mem group of the base address. */
int group_id;
- /* If this is non-zero, it is the alias set of a spill location. */
- alias_set_type alias_set;
-
/* The offset of the first and byte after the last byte associated
with the operation. If begin == end == 0, the read did not have
a constant offset. */
@@ -576,19 +570,6 @@ static object_allocator<deferred_change>
static deferred_change *deferred_change_list = NULL;
-/* The group that holds all of the clear_alias_sets. */
-static group_info *clear_alias_group;
-
-/* The modes of the clear_alias_sets. */
-static htab_t clear_alias_mode_table;
-
-/* Hash table element to look up the mode for an alias set. */
-struct clear_alias_mode_holder
-{
- alias_set_type alias_set;
- machine_mode mode;
-};
-
/* 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;
@@ -596,7 +577,6 @@ static bool stores_off_frame_dead_at_ret
/* Counter for stats. */
static int globally_deleted;
static int locally_deleted;
-static int spill_deleted;
static bitmap all_blocks;
@@ -613,22 +593,6 @@ static unsigned int current_position;
----------------------------------------------------------------------------*/
-/* Find the entry associated with ALIAS_SET. */
-
-static struct clear_alias_mode_holder *
-clear_alias_set_lookup (alias_set_type alias_set)
-{
- struct clear_alias_mode_holder tmp_holder;
- void **slot;
-
- tmp_holder.alias_set = alias_set;
- slot = htab_find_slot (clear_alias_mode_table, &tmp_holder, NO_INSERT);
- gcc_assert (*slot);
-
- return (struct clear_alias_mode_holder *) *slot;
-}
-
-
/* Hashtable callbacks for maintaining the "bases" field of
store_group_info, given that the addresses are function invariants. */
@@ -665,37 +629,13 @@ get_group_info (rtx base)
group_info *gi;
group_info **slot;
- if (base)
- {
- /* Find the store_base_info structure for BASE, creating a new one
- if necessary. */
- tmp_gi.rtx_base = base;
- slot = rtx_group_table->find_slot (&tmp_gi, INSERT);
- gi = *slot;
- }
- else
- {
- if (!clear_alias_group)
- {
- clear_alias_group = gi = group_info_pool.allocate ();
- memset (gi, 0, sizeof (struct group_info));
- gi->id = rtx_group_next_id++;
- gi->store1_n = BITMAP_ALLOC (&dse_bitmap_obstack);
- gi->store1_p = BITMAP_ALLOC (&dse_bitmap_obstack);
- gi->store2_n = BITMAP_ALLOC (&dse_bitmap_obstack);
- gi->store2_p = BITMAP_ALLOC (&dse_bitmap_obstack);
- gi->escaped_p = BITMAP_ALLOC (&dse_bitmap_obstack);
- gi->escaped_n = BITMAP_ALLOC (&dse_bitmap_obstack);
- gi->group_kill = BITMAP_ALLOC (&dse_bitmap_obstack);
- gi->process_globally = false;
- gi->offset_map_size_n = 0;
- gi->offset_map_size_p = 0;
- gi->offset_map_n = NULL;
- gi->offset_map_p = NULL;
- rtx_group_vec.safe_push (gi);
- }
- return clear_alias_group;
- }
+ gcc_assert (base != NULL_RTX);
+
+ /* Find the store_base_info structure for BASE, creating a new one
+ if necessary. */
+ tmp_gi.rtx_base = base;
+ slot = rtx_group_table->find_slot (&tmp_gi, INSERT);
+ gi = *slot;
if (gi == NULL)
{
@@ -732,7 +672,6 @@ dse_step0 (void)
{
locally_deleted = 0;
globally_deleted = 0;
- spill_deleted = 0;
bitmap_obstack_initialize (&dse_bitmap_obstack);
gcc_obstack_init (&dse_obstack);
@@ -749,8 +688,6 @@ dse_step0 (void)
stores_off_frame_dead_at_return = !cfun->stdarg;
init_alias_analysis ();
-
- clear_alias_group = NULL;
}
@@ -919,15 +856,8 @@ delete_dead_store_insn (insn_info_t insn
if (!check_for_inc_dec_1 (insn_info))
return;
if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Locally deleting insn %d ",
- INSN_UID (insn_info->insn));
- if (insn_info->store_rec->alias_set)
- fprintf (dump_file, "alias set %d\n",
- (int) insn_info->store_rec->alias_set);
- else
- fprintf (dump_file, "\n");
- }
+ fprintf (dump_file, "Locally deleting insn %d\n",
+ INSN_UID (insn_info->insn));
free_store_info (insn_info);
read_info = insn_info->read_rec;
@@ -1057,13 +987,8 @@ free_read_records (bb_info_t bb_info)
while (*ptr)
{
read_info_t next = (*ptr)->next;
- if ((*ptr)->alias_set == 0)
- {
- read_info_type_pool.remove (*ptr);
- *ptr = next;
- }
- else
- ptr = &(*ptr)->next;
+ read_info_type_pool.remove (*ptr);
+ *ptr = next;
}
}
@@ -1137,7 +1062,6 @@ const_or_frame_p (rtx x)
static bool
canon_address (rtx mem,
- alias_set_type *alias_set_out,
int *group_id,
HOST_WIDE_INT *offset,
cselib_val **base)
@@ -1147,8 +1071,6 @@ canon_address (rtx mem,
rtx expanded_address, address;
int expanded;
- *alias_set_out = 0;
-
cselib_lookup (mem_address, address_mode, 1, GET_MODE (mem));
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1347,7 +1269,6 @@ record_store (rtx body, bb_info_t bb_inf
rtx mem, rhs, const_rhs, mem_addr;
HOST_WIDE_INT offset = 0;
HOST_WIDE_INT width = 0;
- alias_set_type spill_alias_set;
insn_info_t insn_info = bb_info->last_insn;
store_info *store_info = NULL;
int group_id;
@@ -1410,7 +1331,7 @@ record_store (rtx body, bb_info_t bb_inf
if (MEM_VOLATILE_P (mem))
insn_info->cannot_delete = true;
- if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base))
+ if (!canon_address (mem, &group_id, &offset, &base))
{
clear_rhs_from_active_local_stores ();
return 0;
@@ -1421,26 +1342,7 @@ record_store (rtx body, bb_info_t bb_inf
else
width = GET_MODE_SIZE (GET_MODE (mem));
- if (spill_alias_set)
- {
- bitmap store1 = clear_alias_group->store1_p;
- bitmap store2 = clear_alias_group->store2_p;
-
- gcc_assert (GET_MODE (mem) != BLKmode);
-
- if (!bitmap_set_bit (store1, spill_alias_set))
- bitmap_set_bit (store2, spill_alias_set);
-
- if (clear_alias_group->offset_map_size_p < spill_alias_set)
- clear_alias_group->offset_map_size_p = spill_alias_set;
-
- store_info = rtx_store_info_pool.allocate ();
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " processing spill store %d(%s)\n",
- (int) spill_alias_set, GET_MODE_NAME (GET_MODE (mem)));
- }
- else if (group_id >= 0)
+ if (group_id >= 0)
{
/* In the restrictive case where the base is a constant or the
frame pointer we can do global analysis. */
@@ -1506,21 +1408,16 @@ record_store (rtx body, bb_info_t bb_inf
last = NULL;
redundant_reason = NULL;
mem = canon_rtx (mem);
- /* For alias_set != 0 canon_true_dependence should be never called. */
- if (spill_alias_set)
- mem_addr = NULL_RTX;
+
+ if (group_id < 0)
+ mem_addr = base->val_rtx;
else
{
- if (group_id < 0)
- mem_addr = base->val_rtx;
- else
- {
- group_info *group = rtx_group_vec[group_id];
- mem_addr = group->canon_base_addr;
- }
- if (offset)
- mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset);
+ group_info *group = rtx_group_vec[group_id];
+ mem_addr = group->canon_base_addr;
}
+ if (offset)
+ mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset);
while (ptr)
{
@@ -1534,29 +1431,8 @@ record_store (rtx body, bb_info_t bb_inf
while (!s_info->is_set)
s_info = s_info->next;
- if (s_info->alias_set != spill_alias_set)
- del = false;
- else if (s_info->alias_set)
- {
- struct clear_alias_mode_holder *entry
- = clear_alias_set_lookup (s_info->alias_set);
- /* Generally, spills cannot be processed if and of the
- references to the slot have a different mode. But if
- we are in the same block and mode is exactly the same
- between this store and one before in the same block,
- we can still delete it. */
- if ((GET_MODE (mem) == GET_MODE (s_info->mem))
- && (GET_MODE (mem) == entry->mode))
- {
- del = true;
- set_all_positions_unneeded (s_info);
- }
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " trying spill store in insn=%d
alias_set=%d\n",
- INSN_UID (ptr->insn), (int) s_info->alias_set);
- }
- else if ((s_info->group_id == group_id)
- && (s_info->cse_base == base))
+ if ((s_info->group_id == group_id)
+ && (s_info->cse_base == base))
{
HOST_WIDE_INT i;
if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1646,7 +1522,6 @@ record_store (rtx body, bb_info_t bb_inf
store_info->next = insn_info->store_rec;
insn_info->store_rec = store_info;
store_info->mem = mem;
- store_info->alias_set = spill_alias_set;
store_info->mem_addr = mem_addr;
store_info->cse_base = base;
if (width > HOST_BITS_PER_WIDE_INT)
@@ -2070,7 +1945,6 @@ check_mem_read_rtx (rtx *loc, bb_info_t
insn_info_t insn_info;
HOST_WIDE_INT offset = 0;
HOST_WIDE_INT width = 0;
- alias_set_type spill_alias_set = 0;
cselib_val *base = NULL;
int group_id;
read_info_t read_info;
@@ -2092,7 +1966,7 @@ check_mem_read_rtx (rtx *loc, bb_info_t
if (MEM_READONLY_P (mem))
return;
- if (!canon_address (mem, &spill_alias_set, &group_id, &offset, &base))
+ if (!canon_address (mem, &group_id, &offset, &base))
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " adding wild read, canon_address failure.\n");
@@ -2108,64 +1982,21 @@ check_mem_read_rtx (rtx *loc, bb_info_t
read_info = read_info_type_pool.allocate ();
read_info->group_id = group_id;
read_info->mem = mem;
- read_info->alias_set = spill_alias_set;
read_info->begin = offset;
read_info->end = offset + width;
read_info->next = insn_info->read_rec;
insn_info->read_rec = read_info;
- /* For alias_set != 0 canon_true_dependence should be never called. */
- if (spill_alias_set)
- mem_addr = NULL_RTX;
+ if (group_id < 0)
+ mem_addr = base->val_rtx;
else
{
- if (group_id < 0)
- mem_addr = base->val_rtx;
- else
- {
- group_info *group = rtx_group_vec[group_id];
- mem_addr = group->canon_base_addr;
- }
- if (offset)
- mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset);
+ group_info *group = rtx_group_vec[group_id];
+ mem_addr = group->canon_base_addr;
}
+ if (offset)
+ mem_addr = plus_constant (get_address_mode (mem), mem_addr, offset);
- /* We ignore the clobbers in store_info. The is mildly aggressive,
- but there really should not be a clobber followed by a read. */
-
- if (spill_alias_set)
- {
- insn_info_t i_ptr = active_local_stores;
- insn_info_t last = NULL;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " processing spill load %d\n",
- (int) spill_alias_set);
-
- while (i_ptr)
- {
- store_info *store_info = i_ptr->store_rec;
-
- /* Skip the clobbers. */
- while (!store_info->is_set)
- store_info = store_info->next;
-
- if (store_info->alias_set == spill_alias_set)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- dump_insn_info ("removing from active", i_ptr);
-
- active_local_stores_len--;
- if (last)
- last->next_local_store = i_ptr->next_local_store;
- else
- active_local_stores = i_ptr->next_local_store;
- }
- else
- last = i_ptr;
- i_ptr = i_ptr->next_local_store;
- }
- }
- else if (group_id >= 0)
+ if (group_id >= 0)
{
/* This is the restricted case where the base is a constant or
the frame pointer and offset is a constant. */
@@ -2293,11 +2124,10 @@ check_mem_read_rtx (rtx *loc, bb_info_t
bb_info->regs_live))
return;
- if (!store_info->alias_set)
- remove = canon_true_dependence (store_info->mem,
- GET_MODE (store_info->mem),
- store_info->mem_addr,
- mem, mem_addr);
+ remove = canon_true_dependence (store_info->mem,
+ GET_MODE (store_info->mem),
+ store_info->mem_addr,
+ mem, mem_addr);
if (remove)
{
@@ -2730,16 +2560,13 @@ dse_step1 (void)
/* Skip the clobbers. */
while (!store_info->is_set)
store_info = store_info->next;
- if (store_info->alias_set && !i_ptr->cannot_delete)
- delete_dead_store_insn (i_ptr);
- else
- if (store_info->group_id >= 0)
- {
- group_info *group
+ if (store_info->group_id >= 0)
+ {
+ group_info *group
= rtx_group_vec[store_info->group_id];
- if (group->frame_related && !i_ptr->cannot_delete)
- delete_dead_store_insn (i_ptr);
- }
+ if (group->frame_related && !i_ptr->cannot_delete)
+ delete_dead_store_insn (i_ptr);
+ }
i_ptr = i_ptr->next_local_store;
}
@@ -2883,9 +2710,6 @@ dse_step2_nospill (void)
bitmap_iterator bi;
unsigned int j;
- if (group == clear_alias_group)
- continue;
-
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);
@@ -2968,30 +2792,6 @@ scan_stores_nospill (store_info *store_i
}
-/* Process the STORE_INFOs into the bitmaps into GEN and KILL. KILL
- may be NULL. */
-
-static void
-scan_stores_spill (store_info *store_info, bitmap gen, bitmap kill)
-{
- while (store_info)
- {
- if (store_info->alias_set)
- {
- int index = get_bitmap_index (clear_alias_group,
- store_info->alias_set);
- if (index != 0)
- {
- bitmap_set_bit (gen, index);
- if (kill)
- bitmap_clear_bit (kill, index);
- }
- }
- store_info = store_info->next;
- }
-}
-
-
/* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL
may be NULL. */
@@ -3086,30 +2886,6 @@ scan_reads_nospill (insn_info_t insn_inf
}
}
-/* Process the READ_INFOs into the bitmaps into GEN and KILL. KILL
- may be NULL. */
-
-static void
-scan_reads_spill (read_info_t read_info, bitmap gen, bitmap kill)
-{
- while (read_info)
- {
- if (read_info->alias_set)
- {
- int index = get_bitmap_index (clear_alias_group,
- read_info->alias_set);
- if (index != 0)
- {
- if (kill)
- bitmap_set_bit (kill, index);
- bitmap_clear_bit (gen, index);
- }
- }
-
- read_info = read_info->next;
- }
-}
-
/* Return the insn in BB_INFO before the first wild read or if there
are no wild reads in the block, return the last insn. */
@@ -3148,16 +2924,12 @@ find_insn_before_first_wild_read (bb_inf
anything that happens is hidden by the wild read. */
static void
-dse_step3_scan (bool for_spills, basic_block bb)
+dse_step3_scan (basic_block bb)
{
bb_info_t bb_info = bb_table[bb->index];
insn_info_t insn_info;
- if (for_spills)
- /* There are no wild reads in the spill case. */
- insn_info = bb_info->last_insn;
- else
- insn_info = find_insn_before_first_wild_read (bb_info);
+ insn_info = find_insn_before_first_wild_read (bb_info);
/* In the spill case or in the no_spill case if there is no wild
read in the block, we will need a kill set. */
@@ -3178,17 +2950,8 @@ dse_step3_scan (bool for_spills, basic_b
this phase. */
if (insn_info->insn && INSN_P (insn_info->insn))
{
- /* Process the read(s) last. */
- if (for_spills)
- {
- scan_stores_spill (insn_info->store_rec, bb_info->gen,
bb_info->kill);
- scan_reads_spill (insn_info->read_rec, bb_info->gen,
bb_info->kill);
- }
- else
- {
- scan_stores_nospill (insn_info->store_rec, bb_info->gen,
bb_info->kill);
- scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill);
- }
+ scan_stores_nospill (insn_info->store_rec, bb_info->gen,
bb_info->kill);
+ scan_reads_nospill (insn_info, bb_info->gen, bb_info->kill);
}
insn_info = insn_info->prev_insn;
@@ -3243,7 +3006,7 @@ mark_reachable_blocks (sbitmap unreachab
/* Build the transfer functions for the function. */
static void
-dse_step3 (bool for_spills)
+dse_step3 ()
{
basic_block bb;
sbitmap unreachable_blocks = sbitmap_alloc (last_basic_block_for_fn (cfun));
@@ -3266,7 +3029,7 @@ dse_step3 (bool for_spills)
else if (bb->index == EXIT_BLOCK)
dse_step3_exit_block_scan (bb_info);
else
- dse_step3_scan (for_spills, bb);
+ dse_step3_scan (bb);
if (EDGE_COUNT (bb->succs) == 0)
mark_reachable_blocks (unreachable_blocks, bb);
@@ -3502,27 +3265,21 @@ dse_step5_nospill (void)
while (!store_info->is_set)
store_info = store_info->next;
- if (store_info->alias_set)
- deleted = false;
- else
+ HOST_WIDE_INT i;
+ group_info *group_info = rtx_group_vec[store_info->group_id];
+
+ for (i = store_info->begin; i < store_info->end; i++)
{
- HOST_WIDE_INT i;
- group_info *group_info
- = rtx_group_vec[store_info->group_id];
+ int index = get_bitmap_index (group_info, i);
- for (i = store_info->begin; i < store_info->end; i++)
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "i = %d, index = %d\n", (int)i, index);
+ if (index == 0 || !bitmap_bit_p (v, index))
{
- int index = get_bitmap_index (group_info, i);
-
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "i = %d, index = %d\n", (int)i,
index);
- if (index == 0 || !bitmap_bit_p (v, index))
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "failing at i = %d\n", (int)i);
- deleted = false;
- break;
- }
+ fprintf (dump_file, "failing at i = %d\n", (int)i);
+ deleted = false;
+ break;
}
}
if (deleted)
@@ -3672,7 +3429,7 @@ rest_of_handle_dse (void)
df_analyze ();
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "doing global processing\n");
- dse_step3 (false);
+ dse_step3 ();
dse_step4 ();
dse_step5_nospill ();
}
@@ -3681,8 +3438,8 @@ rest_of_handle_dse (void)
dse_step7 ();
if (dump_file)
- fprintf (dump_file, "dse: local deletions = %d, global deletions = %d,
spill deletions = %d\n",
- locally_deleted, globally_deleted, spill_deleted);
+ fprintf (dump_file, "dse: local deletions = %d, global deletions = %d\n",
+ locally_deleted, globally_deleted);
/* DSE can eliminate potentially-trapping MEMs.
Remove any EH edges associated with them. */
