static sreal real_zero, real_one, real_almost_one, real_br_prob_base,
real_inv_br_prob_base, real_one_half, real_bb_freq_max;
-/* Random guesstimation given names.
+/* Random guesstimation given names.
PROV_VERY_UNLIKELY should be small enough so basic block predicted
by it gets bellow HOT_BB_FREQUENCY_FRANCTION. */
#define PROB_VERY_UNLIKELY (REG_BR_PROB_BASE / 2000 - 1)
static void combine_predictions_for_insn (rtx, basic_block);
static void dump_prediction (FILE *, enum br_predictor, int, basic_block, int);
static void predict_paths_leading_to (basic_block, enum br_predictor, enum prediction);
-static void compute_function_frequency (void);
static void choose_function_section (void);
static bool can_predict_insn_p (const_rtx);
static inline bool
maybe_hot_frequency_p (int freq)
{
+ struct cgraph_node *node = cgraph_node (current_function_decl);
if (!profile_info || !flag_branch_probabilities)
{
- if (cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
+ if (node->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)
return false;
- if (cfun->function_frequency == FUNCTION_FREQUENCY_HOT)
+ if (node->frequency == NODE_FREQUENCY_HOT)
return true;
}
if (profile_status == PROFILE_ABSENT)
return true;
+ if (node->frequency == NODE_FREQUENCY_EXECUTED_ONCE
+ && freq <= (ENTRY_BLOCK_PTR->frequency * 2 / 3))
+ return false;
if (freq < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION))
return false;
return true;
&& (edge->count
<= profile_info->sum_max / PARAM_VALUE (HOT_BB_COUNT_FRACTION)))
return false;
- if (lookup_attribute ("cold", DECL_ATTRIBUTES (edge->callee->decl))
- || lookup_attribute ("cold", DECL_ATTRIBUTES (edge->caller->decl)))
+ if (edge->caller->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED
+ || edge->callee->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)
+ return false;
+ if (optimize_size)
return false;
- if (lookup_attribute ("hot", DECL_ATTRIBUTES (edge->caller->decl)))
+ if (edge->caller->frequency == NODE_FREQUENCY_HOT)
return true;
+ if (edge->caller->frequency == NODE_FREQUENCY_EXECUTED_ONCE
+ && edge->frequency < CGRAPH_FREQ_BASE * 3 / 2)
+ return false;
if (flag_guess_branch_prob
&& edge->frequency <= (CGRAPH_FREQ_BASE
/ PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)))
if (profile_info && flag_branch_probabilities)
return ((bb->count + profile_info->runs / 2) / profile_info->runs) == 0;
if ((!profile_info || !flag_branch_probabilities)
- && cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
+ && cgraph_node (current_function_decl)->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)
return true;
return false;
}
optimize_function_for_size_p (struct function *fun)
{
return (optimize_size
- || (fun && (fun->function_frequency
- == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)));
+ || (fun && fun->decl
+ && (cgraph_node (fun->decl)->frequency
+ == NODE_FREQUENCY_UNLIKELY_EXECUTED)));
}
/* Return true when current function should always be optimized for speed. */
if (!preds)
return false;
-
+
for (i = (struct edge_prediction *) *preds; i; i = i->ep_next)
if (i->ep_predictor == predictor)
return true;
}
/* Return true when the probability of edge is reliable.
-
+
The profile guessing code is good at predicting branch outcome (ie.
taken/not taken), that is predicted right slightly over 75% of time.
It is however notoriously poor on predicting the probability itself.
remove_predictions_associated_with_edge (edge e)
{
void **preds;
-
+
if (!bb_predictions)
return;
first = e;
}
- /* When there is no successor or only one choice, prediction is easy.
+ /* When there is no successor or only one choice, prediction is easy.
We are lazy for now and predict only basic blocks with two outgoing
edges. It is possible to predict generic case too, but we have to
if (pred2->ep_edge != first)
probability2 = REG_BR_PROB_BASE - probability2;
- if ((probability < REG_BR_PROB_BASE / 2) !=
+ if ((probability < REG_BR_PROB_BASE / 2) !=
(probability2 < REG_BR_PROB_BASE / 2))
break;
EDGE_PROBABILITY_RELIABLE from trusting the branch prediction
as this was causing regression in perl benchmark containing such
a wide loop. */
-
+
int probability = ((REG_BR_PROB_BASE
- predictor_info [(int) PRED_LOOP_EXIT].hitrate)
/ n_exits);
predict_edge (e, PRED_LOOP_EXIT, probability);
}
}
-
+
/* Free basic blocks from get_loop_body. */
free (bbs);
}
return NULL;
}
-/* Return constant EXPR will likely have at execution time, NULL if unknown.
+/* Return constant EXPR will likely have at execution time, NULL if unknown.
The function is used by builtin_expect branch predictor so the evidence
must come from this construct and additional possible constant folding.
-
+
We may want to implement more involved value guess (such as value range
propagation based prediction), but such tricks shall go to new
implementation. */
if (e)
{
sreal tmp;
-
+
/* EDGE_INFO (e)->back_edge_prob
= ((e->probability * BLOCK_INFO (bb)->frequency)
/ REG_BR_PROB_BASE); */
-
+
sreal_init (&tmp, e->probability, 0);
sreal_mul (&tmp, &tmp, &BLOCK_INFO (bb)->frequency);
sreal_mul (&EDGE_INFO (e)->back_edge_prob,
nextbb = e->dest;
else
BLOCK_INFO (last)->next = e->dest;
-
+
last = e->dest;
}
}
gcov_type count_max, true_count_max = 0;
basic_block bb;
- FOR_EACH_BB (bb)
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
true_count_max = MAX (bb->count, true_count_max);
count_max = MAX (true_count_max, 1);
}
/* Decide whether function is hot, cold or unlikely executed. */
-static void
+void
compute_function_frequency (void)
{
basic_block bb;
+ struct cgraph_node *node = cgraph_node (current_function_decl);
if (!profile_info || !flag_branch_probabilities)
{
+ int flags = flags_from_decl_or_type (current_function_decl);
if (lookup_attribute ("cold", DECL_ATTRIBUTES (current_function_decl))
!= NULL)
- cfun->function_frequency = FUNCTION_FREQUENCY_UNLIKELY_EXECUTED;
+ node->frequency = NODE_FREQUENCY_UNLIKELY_EXECUTED;
else if (lookup_attribute ("hot", DECL_ATTRIBUTES (current_function_decl))
!= NULL)
- cfun->function_frequency = FUNCTION_FREQUENCY_HOT;
+ node->frequency = NODE_FREQUENCY_HOT;
+ else if (flags & ECF_NORETURN)
+ node->frequency = NODE_FREQUENCY_EXECUTED_ONCE;
+ else if (MAIN_NAME_P (DECL_NAME (current_function_decl)))
+ node->frequency = NODE_FREQUENCY_EXECUTED_ONCE;
+ else if (DECL_STATIC_CONSTRUCTOR (current_function_decl)
+ || DECL_STATIC_DESTRUCTOR (current_function_decl))
+ node->frequency = NODE_FREQUENCY_EXECUTED_ONCE;
return;
}
- cfun->function_frequency = FUNCTION_FREQUENCY_UNLIKELY_EXECUTED;
+ node->frequency = NODE_FREQUENCY_UNLIKELY_EXECUTED;
FOR_EACH_BB (bb)
{
if (maybe_hot_bb_p (bb))
{
- cfun->function_frequency = FUNCTION_FREQUENCY_HOT;
+ node->frequency = NODE_FREQUENCY_HOT;
return;
}
if (!probably_never_executed_bb_p (bb))
- cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
+ node->frequency = NODE_FREQUENCY_NORMAL;
}
}
static void
choose_function_section (void)
{
+ struct cgraph_node *node = cgraph_node (current_function_decl);
if (DECL_SECTION_NAME (current_function_decl)
|| !targetm.have_named_sections
/* Theoretically we can split the gnu.linkonce text section too,
if (flag_reorder_blocks_and_partition)
return;
- if (cfun->function_frequency == FUNCTION_FREQUENCY_HOT)
+ if (node->frequency == NODE_FREQUENCY_HOT)
DECL_SECTION_NAME (current_function_decl) =
build_string (strlen (HOT_TEXT_SECTION_NAME), HOT_TEXT_SECTION_NAME);
- if (cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
+ if (node->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)
DECL_SECTION_NAME (current_function_decl) =
build_string (strlen (UNLIKELY_EXECUTED_TEXT_SECTION_NAME),
UNLIKELY_EXECUTED_TEXT_SECTION_NAME);
return predictor_info[predictor].name;
}
-struct gimple_opt_pass pass_profile =
+struct gimple_opt_pass pass_profile =
{
{
GIMPLE_PASS,
}
};
-struct gimple_opt_pass pass_strip_predict_hints =
+struct gimple_opt_pass pass_strip_predict_hints =
{
{
GIMPLE_PASS,
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