mirror/gcc
2
0
Fork 0
mirror of git://gcc.gnu.org/git/gcc.git synced 2025-03-21 17:21:03 +08:00
Code Issues Packages Projects Releases Wiki Activity

tree-ssa-loop-ivopts.c (struct comp_cost): New scrach field.

Browse Source 
* tree-ssa-loop-ivopts.c (struct comp_cost): New scrach field.
	(no_cost, infinite_cost): Initialize the new field.
	(get_computation_cost_at): Record setup cost.
	(determine_use_iv_cost_address): Skip cost computation for sub
	uses if we can estimate it without losing accuracy.

From-SVN: r234612
This commit is contained in:
Bin Cheng 2016-03-31 08:57:13 +00:00 committed by Bin Cheng
parent efc3536f46
commit 515558b8ff
2 changed files with 55 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2016-03-31 Bin Cheng <bin.cheng@arm.com>
* tree-ssa-loop-ivopts.c (struct comp_cost): New scrach field.
(no_cost, infinite_cost): Initialize the new field.
(get_computation_cost_at): Record setup cost.
(determine_use_iv_cost_address): Skip cost computation for sub
uses if we can estimate it without losing accuracy.
2016-03-30 Jan Hubicka <hubicka@ucw.cz>
* tree-ssa-loop-niter.c (idx_infer_loop_bounds): We can't get realistic

57
gcc/tree-ssa-loop-ivopts.c
View File

@ -172,10 +172,11 @@ struct comp_cost
the computation (in no concrete units --
complexity field should be larger for more
complex expressions and addressing modes). */
int scratch; /* Scratch used during cost computation. */
};
static const comp_cost no_cost = {0, 0};
static const comp_cost infinite_cost = {INFTY, INFTY};
static const comp_cost no_cost = {0, 0, 0};
static const comp_cost infinite_cost = {INFTY, INFTY, INFTY};
/* The candidate - cost pair. */
struct cost_pair
@ -4953,6 +4954,8 @@ get_computation_cost_at (struct ivopts_data *data,
cost.cost += add_cost (data->speed, TYPE_MODE (ctype));
}
/* Record setup cost in scrach field. */
cost.scratch = cost.cost;
/* Set of invariants depended on by sub use has already been computed
for the first use in the group. */
if (use->sub_id)
@ -5088,12 +5091,12 @@ determine_use_iv_cost_address (struct ivopts_data *data,
struct iv_use *use, struct iv_cand *cand)
{
bitmap depends_on;
bool can_autoinc;
bool can_autoinc, first;
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);
comp_cost sub_cost = cost;
if (cand->ainc_use == use)
{
@ -5105,13 +5108,47 @@ determine_use_iv_cost_address (struct ivopts_data *data,
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)
if (!infinite_cost_p (cost) && use->next)
{
sub_cost = get_computation_cost (data, sub_use, cand, true, NULL,
&can_autoinc, NULL);
cost = add_costs (cost, sub_cost);
first = true;
sub_use = use->next;
/* We don't want to add setup cost for sub-uses. */
sub_cost.cost -= sub_cost.scratch;
/* Add cost for sub uses in group. */
do
{
/* Compute cost for the first sub use with different offset to
the main use and add it afterwards. Costs for these uses
could be quite different. Given below uses in a group:
use 0 : {base + A + offset_0, step}
use 0.1: {base + A + offset_0, step}
use 0.2: {base + A + offset_1, step}
use 0.3: {base + A + offset_2, step}
when we need to compute costs with candidate:
cand 1 : {base + B + offset_0, step}
The first sub use with different offset is use 0.2, its cost
is larger than cost of use 0/0.1 because we need to compute:
A - B + offset_1 - offset_0
rather than:
A - B. */
if (first && use->addr_offset != sub_use->addr_offset)
{
first = false;
sub_cost = get_computation_cost (data, sub_use, cand, true,
NULL, &can_autoinc, NULL);
if (infinite_cost_p (sub_cost))
{
cost = infinite_cost;
break;
}
}
cost = add_costs (cost, sub_cost);
sub_use = sub_use->next;
}
while (sub_use);
}
set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE, ERROR_MARK,