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Add profiling support for IVOPTS

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* tree-ssa-loop-ivopts.c (get_computation_cost_at): Scale
	computed costs by frequency of BB they belong to.
	(get_scaled_computation_cost_at): New function.

From-SVN: r236888
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Martin Liska 2016-05-30 18:04:50 +02:00 committed by Martin Liska
parent 69be8c9124
commit 83e0b73912
2 changed files with 52 additions and 16 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2016-05-30 Martin Liska <mliska@suse.cz>
* tree-ssa-loop-ivopts.c (get_computation_cost_at): Scale
computed costs by frequency of BB they belong to.
(get_scaled_computation_cost_at): New function.
2016-05-30 Alexander Monakov <amonakov@ispras.ru>
Marc Glisse <marc.glisse@inria.fr>

62
gcc/tree-ssa-loop-ivopts.c
View File

@ -4794,7 +4794,33 @@ get_loop_invariant_expr (struct ivopts_data *data, tree ubase,
return record_inv_expr (data, expr);
}
/* Scale (multiply) the computed COST (except scratch part that should be
hoisted out a loop) by header->frequency / AT->frequency,
which makes expected cost more accurate. */
static comp_cost
get_scaled_computation_cost_at (ivopts_data *data, gimple *at, iv_cand *cand,
comp_cost cost)
{
int loop_freq = data->current_loop->header->frequency;
int bb_freq = at->bb->frequency;
if (loop_freq != 0)
{
gcc_assert (cost.scratch <= cost.cost);
int scaled_cost
= cost.scratch + (cost.cost - cost.scratch) * bb_freq / loop_freq;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Scaling iv_use based on cand %d "
"by %2.2f: %d (scratch: %d) -> %d (%d/%d)\n",
cand->id, 1.0f * bb_freq / loop_freq, cost.cost,
cost.scratch, scaled_cost, bb_freq, loop_freq);
cost.cost = scaled_cost;
}
return cost;
}
/* Determines the cost of the computation by that USE is expressed
from induction variable CAND. If ADDRESS_P is true, we just need
@ -4982,18 +5008,21 @@ get_computation_cost_at (struct ivopts_data *data,
(symbol/var1/const parts may be omitted). If we are looking for an
address, find the cost of addressing this. */
if (address_p)
return cost + get_address_cost (symbol_present, var_present,
offset, ratio, cstepi,
mem_mode,
TYPE_ADDR_SPACE (TREE_TYPE (utype)),
speed, stmt_is_after_inc, can_autoinc);
{
cost += get_address_cost (symbol_present, var_present,
offset, ratio, cstepi,
mem_mode,
TYPE_ADDR_SPACE (TREE_TYPE (utype)),
speed, stmt_is_after_inc, can_autoinc);
return get_scaled_computation_cost_at (data, at, cand, cost);
}
/* Otherwise estimate the costs for computing the expression. */
if (!symbol_present && !var_present && !offset)
{
if (ratio != 1)
cost += mult_by_coeff_cost (ratio, TYPE_MODE (ctype), speed);
return cost;
return get_scaled_computation_cost_at (data, at, cand, cost);
}
/* Symbol + offset should be compile-time computable so consider that they
@ -5012,24 +5041,25 @@ get_computation_cost_at (struct ivopts_data *data,
aratio = ratio > 0 ? ratio : -ratio;
if (aratio != 1)
cost += mult_by_coeff_cost (aratio, TYPE_MODE (ctype), speed);
return cost;
return get_scaled_computation_cost_at (data, at, cand, cost);
fallback:
if (can_autoinc)
*can_autoinc = false;
{
/* Just get the expression, expand it and measure the cost. */
tree comp = get_computation_at (data->current_loop, use, cand, at);
/* Just get the expression, expand it and measure the cost. */
tree comp = get_computation_at (data->current_loop, use, cand, at);
if (!comp)
return infinite_cost;
if (!comp)
return infinite_cost;
if (address_p)
comp = build_simple_mem_ref (comp);
if (address_p)
comp = build_simple_mem_ref (comp);
return comp_cost (computation_cost (comp, speed), 0);
}
cost = comp_cost (computation_cost (comp, speed), 0);
return get_scaled_computation_cost_at (data, at, cand, cost);
}
/* Determines the cost of the computation by that USE is expressed