struct iv_use
{
unsigned id; /* The id of the use. */
+ unsigned sub_id; /* The id of the sub use. */
enum use_type type; /* Type of the use. */
struct iv *iv; /* The induction variable it is based on. */
gimple stmt; /* Statement in that it occurs. */
struct iv_cand *selected;
/* The selected candidate. */
+
+ struct iv_use *next; /* The next sub use. */
+ tree addr_base; /* Base address with const offset stripped. */
+ unsigned HOST_WIDE_INT addr_offset;
+ /* Const offset stripped from base address. */
};
/* The position where the iv is computed. */
void
dump_use (FILE *file, struct iv_use *use)
{
- fprintf (file, "use %d\n", use->id);
+ fprintf (file, "use %d", use->id);
+ if (use->sub_id)
+ fprintf (file, ".%d", use->sub_id);
+
+ fprintf (file, "\n");
switch (use->type)
{
for (i = 0; i < n_iv_uses (data); i++)
{
use = iv_use (data, i);
-
- dump_use (file, use);
+ do
+ {
+ dump_use (file, use);
+ use = use->next;
+ }
+ while (use);
fprintf (file, "\n");
}
}
return true;
}
-/* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV. */
+/* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV.
+ For address type use, ADDR_BASE is the stripped IV base, ADDR_OFFSET
+ is the const offset stripped from IV base. For uses of other types,
+ ADDR_BASE and ADDR_OFFSET are zero by default. */
static struct iv_use *
record_use (struct ivopts_data *data, tree *use_p, struct iv *iv,
- gimple stmt, enum use_type use_type)
+ gimple stmt, enum use_type use_type, tree addr_base = NULL,
+ unsigned HOST_WIDE_INT addr_offset = 0)
{
struct iv_use *use = XCNEW (struct iv_use);
use->id = n_iv_uses (data);
+ use->sub_id = 0;
use->type = use_type;
use->iv = iv;
use->stmt = stmt;
use->op_p = use_p;
use->related_cands = BITMAP_ALLOC (NULL);
+ use->next = NULL;
+ use->addr_base = addr_base;
+ use->addr_offset = addr_offset;
/* To avoid showing ssa name in the dumps, if it was not reset by the
caller. */
iv->ssa_name = NULL_TREE;
- if (dump_file && (dump_flags & TDF_DETAILS))
- dump_use (dump_file, use);
-
data->iv_uses.safe_push (use);
return use;
}
+/* Records a sub use of type USE_TYPE at *USE_P in STMT whose value is IV.
+ The sub use is recorded under the one whose use id is ID_GROUP. */
+
+static struct iv_use *
+record_sub_use (struct ivopts_data *data, tree *use_p,
+ struct iv *iv, gimple stmt, enum use_type use_type,
+ tree addr_base, unsigned HOST_WIDE_INT addr_offset,
+ unsigned int id_group)
+{
+ struct iv_use *use = XCNEW (struct iv_use);
+ struct iv_use *group = iv_use (data, id_group);
+
+ use->id = group->id;
+ use->sub_id = 0;
+ use->type = use_type;
+ use->iv = iv;
+ use->stmt = stmt;
+ use->op_p = use_p;
+ use->related_cands = NULL;
+ use->addr_base = addr_base;
+ use->addr_offset = addr_offset;
+
+ /* Sub use list is maintained in offset ascending order. */
+ if (addr_offset <= group->addr_offset)
+ {
+ use->related_cands = group->related_cands;
+ group->related_cands = NULL;
+ use->next = group;
+ data->iv_uses[id_group] = use;
+ }
+ else
+ {
+ struct iv_use *pre;
+ do
+ {
+ pre = group;
+ group = group->next;
+ }
+ while (group && addr_offset > group->addr_offset);
+ use->next = pre->next;
+ pre->next = use;
+ }
+
+ /* To avoid showing ssa name in the dumps, if it was not reset by the
+ caller. */
+ iv->ssa_name = NULL_TREE;
+
+ return use;
+}
+
/* Checks whether OP is a loop-level invariant and if so, records it.
NONLINEAR_USE is true if the invariant is used in a way we do not
handle specially. */
return false;
}
+static tree
+strip_offset (tree expr, unsigned HOST_WIDE_INT *offset);
+
+/* Record a use of type USE_TYPE at *USE_P in STMT whose value is IV.
+ If there is an existing use which has same stripped iv base and step,
+ this function records this one as a sub use to that; otherwise records
+ it as a normal one. */
+
+static struct iv_use *
+record_group_use (struct ivopts_data *data, tree *use_p,
+ struct iv *iv, gimple stmt, enum use_type use_type)
+{
+ unsigned int i;
+ struct iv_use *use;
+ tree addr_base;
+ unsigned HOST_WIDE_INT addr_offset;
+
+ /* Only support sub use for address type uses, that is, with base
+ object. */
+ if (!iv->base_object)
+ return record_use (data, use_p, iv, stmt, use_type);
+
+ addr_base = strip_offset (iv->base, &addr_offset);
+ for (i = 0; i < n_iv_uses (data); i++)
+ {
+ use = iv_use (data, i);
+ if (use->type != USE_ADDRESS || !use->iv->base_object)
+ continue;
+
+ /* Check if it has the same stripped base and step. */
+ if (operand_equal_p (iv->base_object, use->iv->base_object, 0)
+ && operand_equal_p (iv->step, use->iv->step, 0)
+ && operand_equal_p (addr_base, use->addr_base, 0))
+ break;
+ }
+
+ if (i == n_iv_uses (data))
+ return record_use (data, use_p, iv, stmt,
+ use_type, addr_base, addr_offset);
+ else
+ return record_sub_use (data, use_p, iv, stmt,
+ use_type, addr_base, addr_offset, i);
+}
+
/* Finds addresses in *OP_P inside STMT. */
static void
}
civ = alloc_iv (base, step);
- record_use (data, op_p, civ, stmt, USE_ADDRESS);
+ record_group_use (data, op_p, civ, stmt, USE_ADDRESS);
return;
fail:
free (body);
}
+/* Compute maximum offset of [base + offset] addressing mode
+ for memory reference represented by USE. */
+
+static HOST_WIDE_INT
+compute_max_addr_offset (struct iv_use *use)
+{
+ int width;
+ rtx reg, addr;
+ HOST_WIDE_INT i, off;
+ unsigned list_index, num;
+ addr_space_t as;
+ machine_mode mem_mode, addr_mode;
+ static vec<HOST_WIDE_INT> max_offset_list;
+
+ as = TYPE_ADDR_SPACE (TREE_TYPE (use->iv->base));
+ mem_mode = TYPE_MODE (TREE_TYPE (*use->op_p));
+
+ num = max_offset_list.length ();
+ list_index = (unsigned) as * MAX_MACHINE_MODE + (unsigned) mem_mode;
+ if (list_index >= num)
+ {
+ max_offset_list.safe_grow (list_index + MAX_MACHINE_MODE);
+ for (; num < max_offset_list.length (); num++)
+ max_offset_list[num] = -1;
+ }
+
+ off = max_offset_list[list_index];
+ if (off != -1)
+ return off;
+
+ addr_mode = targetm.addr_space.address_mode (as);
+ reg = gen_raw_REG (addr_mode, LAST_VIRTUAL_REGISTER + 1);
+ addr = gen_rtx_fmt_ee (PLUS, addr_mode, reg, NULL_RTX);
+
+ width = GET_MODE_BITSIZE (addr_mode) - 1;
+ if (width > (HOST_BITS_PER_WIDE_INT - 1))
+ width = HOST_BITS_PER_WIDE_INT - 1;
+
+ for (i = width; i > 0; i--)
+ {
+ off = ((unsigned HOST_WIDE_INT) 1 << i) - 1;
+ XEXP (addr, 1) = gen_int_mode (off, addr_mode);
+ if (memory_address_addr_space_p (mem_mode, addr, as))
+ break;
+
+ /* For some strict-alignment targets, the offset must be naturally
+ aligned. Try an aligned offset if mem_mode is not QImode. */
+ off = ((unsigned HOST_WIDE_INT) 1 << i);
+ if (off > GET_MODE_SIZE (mem_mode) && mem_mode != QImode)
+ {
+ off -= GET_MODE_SIZE (mem_mode);
+ XEXP (addr, 1) = gen_int_mode (off, addr_mode);
+ if (memory_address_addr_space_p (mem_mode, addr, as))
+ break;
+ }
+ }
+ if (i == 0)
+ off = 0;
+
+ max_offset_list[list_index] = off;
+ return off;
+}
+
+/* Check if all small groups should be split. Return true if and
+ only if:
+
+ 1) At least one groups contain two uses with different offsets.
+ 2) No group contains more than two uses with different offsets.
+
+ Return false otherwise. We want to split such groups because:
+
+ 1) Small groups don't have much benefit and may interfer with
+ general candidate selection.
+ 2) Size for problem with only small groups is usually small and
+ general algorithm can handle it well.
+
+ TODO -- Above claim may not hold when auto increment is supported. */
+
+static bool
+split_all_small_groups (struct ivopts_data *data)
+{
+ bool split_p = false;
+ unsigned int i, n, distinct;
+ struct iv_use *pre, *use;
+
+ n = n_iv_uses (data);
+ for (i = 0; i < n; i++)
+ {
+ use = iv_use (data, i);
+ if (!use->next)
+ continue;
+
+ distinct = 1;
+ gcc_assert (use->type == USE_ADDRESS);
+ for (pre = use, use = use->next; use; pre = use, use = use->next)
+ {
+ if (pre->addr_offset != use->addr_offset)
+ distinct++;
+
+ if (distinct > 2)
+ return false;
+ }
+ if (distinct == 2)
+ split_p = true;
+ }
+
+ return split_p;
+}
+
+/* For each group of address type uses, this function further groups
+ these uses according to the maximum offset supported by target's
+ [base + offset] addressing mode. */
+
+static void
+group_address_uses (struct ivopts_data *data)
+{
+ HOST_WIDE_INT max_offset = -1;
+ unsigned int i, n, sub_id;
+ struct iv_use *pre, *use;
+ unsigned HOST_WIDE_INT addr_offset_first;
+
+ /* Reset max offset to split all small groups. */
+ if (split_all_small_groups (data))
+ max_offset = 0;
+
+ n = n_iv_uses (data);
+ for (i = 0; i < n; i++)
+ {
+ use = iv_use (data, i);
+ if (!use->next)
+ continue;
+
+ gcc_assert (use->type == USE_ADDRESS);
+ if (max_offset != 0)
+ max_offset = compute_max_addr_offset (use);
+
+ while (use)
+ {
+ sub_id = 0;
+ addr_offset_first = use->addr_offset;
+ /* Only uses with offset that can fit in offset part against
+ the first use can be grouped together. */
+ for (pre = use, use = use->next;
+ use && (use->addr_offset - addr_offset_first
+ <= (unsigned HOST_WIDE_INT) max_offset);
+ pre = use, use = use->next)
+ {
+ use->id = pre->id;
+ use->sub_id = ++sub_id;
+ }
+
+ /* Break the list and create new group. */
+ if (use)
+ {
+ pre->next = NULL;
+ use->id = n_iv_uses (data);
+ use->related_cands = BITMAP_ALLOC (NULL);
+ data->iv_uses.safe_push (use);
+ }
+ }
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ dump_uses (dump_file, data);
+}
+
/* Strips constant offsets from EXPR and stores them to OFFSET. If INSIDE_ADDR
is true, assume we are inside an address. If TOP_COMPREF is true, assume
we are at the top-level of the processed address. */
add_candidate (struct ivopts_data *data,
tree base, tree step, bool important, struct iv_use *use)
{
+ gcc_assert (use == NULL || use->sub_id == 0);
+
if (ip_normal_pos (data->current_loop))
add_candidate_1 (data, base, step, important, IP_NORMAL, use, NULL);
if (ip_end_pos (data->current_loop)
return cost;
}
+/* Returns true if COST is infinite. */
+
+static bool
+infinite_cost_p (comp_cost cost)
+{
+ return cost.cost == INFTY;
+}
+
/* Adds costs COST1 and COST2. */
static comp_cost
add_costs (comp_cost cost1, comp_cost cost2)
{
+ if (infinite_cost_p (cost1) || infinite_cost_p (cost2))
+ return infinite_cost;
+
cost1.cost += cost2.cost;
cost1.complexity += cost2.complexity;
return cost1.cost - cost2.cost;
}
-/* Returns true if COST is infinite. */
-
-static bool
-infinite_cost_p (comp_cost cost)
-{
- return cost.cost == INFTY;
-}
-
/* Sets cost of (USE, CANDIDATE) pair to COST and record that it depends
on invariants DEPENDS_ON and that the value used in expressing it
is VALUE, and in case of iv elimination the comparison operator is COMP. */
cost.cost += add_cost (data->speed, TYPE_MODE (ctype));
}
- if (inv_expr_id)
+ /* Set of invariants depended on by sub use has already been computed
+ for the first use in the group. */
+ if (use->sub_id)
+ {
+ cost.cost = 0;
+ if (depends_on && *depends_on)
+ bitmap_clear (*depends_on);
+ }
+ else if (inv_expr_id)
{
*inv_expr_id =
get_loop_invariant_expr_id (data, ubase, cbase, ratio, address_p);
bitmap depends_on;
bool can_autoinc;
int inv_expr_id = -1;
+ struct iv_use *sub_use;
+ comp_cost sub_cost;
comp_cost cost = get_computation_cost (data, use, cand, true, &depends_on,
&can_autoinc, &inv_expr_id);
else if (cand->pos == IP_AFTER_USE || cand->pos == IP_BEFORE_USE)
cost = infinite_cost;
}
+ for (sub_use = use->next;
+ sub_use && !infinite_cost_p (cost);
+ sub_use = sub_use->next)
+ {
+ sub_cost = get_computation_cost (data, sub_use, cand, true, &depends_on,
+ &can_autoinc, &inv_expr_id);
+ cost = add_costs (cost, sub_cost);
+ }
+
set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE, ERROR_MARK,
inv_expr_id);
/* Rewrites USE (address that is an iv) using candidate CAND. */
static void
-rewrite_use_address (struct ivopts_data *data,
- struct iv_use *use, struct iv_cand *cand)
+rewrite_use_address_1 (struct ivopts_data *data,
+ struct iv_use *use, struct iv_cand *cand)
{
aff_tree aff;
gimple_stmt_iterator bsi = gsi_for_stmt (use->stmt);
*use->op_p = ref;
}
+/* Rewrites USE (address that is an iv) using candidate CAND. If it's the
+ first use of a group, rewrites sub uses in the group too. */
+
+static void
+rewrite_use_address (struct ivopts_data *data,
+ struct iv_use *use, struct iv_cand *cand)
+{
+ struct iv_use *next;
+
+ gcc_assert (use->sub_id == 0);
+ rewrite_use_address_1 (data, use, cand);
+ update_stmt (use->stmt);
+
+ for (next = use->next; next != NULL; next = next->next)
+ {
+ rewrite_use_address_1 (data, next, cand);
+ update_stmt (next->stmt);
+ }
+
+ return;
+}
+
/* Rewrites USE (the condition such that one of the arguments is an iv) using
candidate CAND. */
for (i = 0; i < n_iv_uses (data); i++)
{
struct iv_use *use = iv_use (data, i);
+ struct iv_use *pre = use, *sub = use->next;
+
+ while (sub)
+ {
+ gcc_assert (sub->related_cands == NULL);
+ gcc_assert (sub->n_map_members == 0 && sub->cost_map == NULL);
+
+ free (sub->iv);
+ pre = sub;
+ sub = sub->next;
+ free (pre);
+ }
free (use->iv);
BITMAP_FREE (use->related_cands);
/* Finds interesting uses (item 1). */
find_interesting_uses (data);
+ group_address_uses (data);
if (n_iv_uses (data) > MAX_CONSIDERED_USES)
goto finish;
projects / gcc.git / commitdiff