You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301, USA. */
/* References:
bool
tree_predicted_by_p (basic_block bb, enum br_predictor predictor)
{
- struct edge_prediction *i = bb_ann (bb)->predictions;
- for (i = bb_ann (bb)->predictions; i; i = i->next)
- if (i->predictor == predictor)
+ struct edge_prediction *i;
+ for (i = bb->predictions; i; i = i->ep_next)
+ if (i->ep_predictor == predictor)
return true;
return false;
}
void
tree_predict_edge (edge e, enum br_predictor predictor, int probability)
{
- struct edge_prediction *i = ggc_alloc (sizeof (struct edge_prediction));
+ gcc_assert (profile_status != PROFILE_GUESSED);
+ if ((e->src != ENTRY_BLOCK_PTR && EDGE_COUNT (e->src->succs) > 1)
+ && flag_guess_branch_prob && optimize)
+ {
+ struct edge_prediction *i = ggc_alloc (sizeof (struct edge_prediction));
+
+ i->ep_next = e->src->predictions;
+ e->src->predictions = i;
+ i->ep_probability = probability;
+ i->ep_predictor = predictor;
+ i->ep_edge = e;
+ }
+}
- i->next = bb_ann (e->src)->predictions;
- bb_ann (e->src)->predictions = i;
- i->probability = probability;
- i->predictor = predictor;
- i->edge = e;
+/* Remove all predictions on given basic block that are attached
+ to edge E. */
+void
+remove_predictions_associated_with_edge (edge e)
+{
+ if (e->src->predictions)
+ {
+ struct edge_prediction **prediction = &e->src->predictions;
+ while (*prediction)
+ {
+ if ((*prediction)->ep_edge == e)
+ *prediction = (*prediction)->ep_next;
+ else
+ prediction = &((*prediction)->ep_next);
+ }
+ }
}
/* Return true when we can store prediction on insn INSN.
Remove now useless prediction entries. */
static void
-combine_predictions_for_bb (FILE *file, basic_block bb)
+combine_predictions_for_bb (basic_block bb)
{
int best_probability = PROB_EVEN;
int best_predictor = END_PREDICTORS;
{
if (!bb->count)
set_even_probabilities (bb);
- bb_ann (bb)->predictions = NULL;
- if (file)
- fprintf (file, "%i edges in bb %i predicted to even probabilities\n",
+ bb->predictions = NULL;
+ if (dump_file)
+ fprintf (dump_file, "%i edges in bb %i predicted to even probabilities\n",
nedges, bb->index);
return;
}
- if (file)
- fprintf (file, "Predictions for bb %i\n", bb->index);
+ if (dump_file)
+ fprintf (dump_file, "Predictions for bb %i\n", bb->index);
/* We implement "first match" heuristics and use probability guessed
by predictor with smallest index. */
- for (pred = bb_ann (bb)->predictions; pred; pred = pred->next)
+ for (pred = bb->predictions; pred; pred = pred->ep_next)
{
- int predictor = pred->predictor;
- int probability = pred->probability;
+ int predictor = pred->ep_predictor;
+ int probability = pred->ep_probability;
- if (pred->edge != first)
+ if (pred->ep_edge != first)
probability = REG_BR_PROB_BASE - probability;
found = true;
first_match = true;
if (!found)
- dump_prediction (file, PRED_NO_PREDICTION, combined_probability, bb, true);
+ dump_prediction (dump_file, PRED_NO_PREDICTION, combined_probability, bb, true);
else
{
- dump_prediction (file, PRED_DS_THEORY, combined_probability, bb,
+ dump_prediction (dump_file, PRED_DS_THEORY, combined_probability, bb,
!first_match);
- dump_prediction (file, PRED_FIRST_MATCH, best_probability, bb,
+ dump_prediction (dump_file, PRED_FIRST_MATCH, best_probability, bb,
first_match);
}
if (first_match)
combined_probability = best_probability;
- dump_prediction (file, PRED_COMBINED, combined_probability, bb, true);
+ dump_prediction (dump_file, PRED_COMBINED, combined_probability, bb, true);
- for (pred = bb_ann (bb)->predictions; pred; pred = pred->next)
+ for (pred = bb->predictions; pred; pred = pred->ep_next)
{
- int predictor = pred->predictor;
- int probability = pred->probability;
+ int predictor = pred->ep_predictor;
+ int probability = pred->ep_probability;
- if (pred->edge != EDGE_SUCC (bb, 0))
+ if (pred->ep_edge != EDGE_SUCC (bb, 0))
probability = REG_BR_PROB_BASE - probability;
- dump_prediction (file, predictor, probability, bb,
+ dump_prediction (dump_file, predictor, probability, bb,
!first_match || best_predictor == predictor);
}
- bb_ann (bb)->predictions = NULL;
+ bb->predictions = NULL;
if (!bb->count)
{
niter = desc.niter + 1;
if (niter == 0) /* We might overflow here. */
niter = desc.niter;
+ if (niter
+ > (unsigned int) PARAM_VALUE (PARAM_MAX_PREDICTED_ITERATIONS))
+ niter = PARAM_VALUE (PARAM_MAX_PREDICTED_ITERATIONS);
prob = (REG_BR_PROB_BASE
- (REG_BR_PROB_BASE + niter /2) / niter);
{
tree niter = NULL;
- if (number_of_iterations_exit (loop, exits[j], &niter_desc))
+ if (number_of_iterations_exit (loop, exits[j], &niter_desc, false))
niter = niter_desc.niter;
if (!niter || TREE_CODE (niter_desc.niter) != INTEGER_CST)
niter = loop_niter_by_eval (loop, exits[j]);
if (TREE_CODE (niter) == INTEGER_CST)
{
int probability;
+ int max = PARAM_VALUE (PARAM_MAX_PREDICTED_ITERATIONS);
if (host_integerp (niter, 1)
&& tree_int_cst_lt (niter,
- build_int_cstu (NULL_TREE,
- REG_BR_PROB_BASE - 1)))
+ build_int_cstu (NULL_TREE, max - 1)))
{
HOST_WIDE_INT nitercst = tree_low_cst (niter, 1) + 1;
- probability = (REG_BR_PROB_BASE + nitercst / 2) / nitercst;
+ probability = ((REG_BR_PROB_BASE + nitercst / 2)
+ / nitercst);
}
else
- probability = 1;
+ probability = ((REG_BR_PROB_BASE + max / 2) / max);
predict_edge (exits[j], PRED_LOOP_ITERATIONS, probability);
}
conditional has no loop header successors as not taken. */
if (!header_found)
FOR_EACH_EDGE (e, ei, bb->succs)
- if (e->dest->index < 0
+ if (e->dest->index < NUM_FIXED_BLOCKS
|| !flow_bb_inside_loop_p (loop, e->dest))
predict_edge
(e, PRED_LOOP_EXIT,
}
}
-/* Statically estimate the probability that a branch will be taken and produce
- estimated profile. When profile feedback is present never executed portions
- of function gets estimated. */
-
-void
-estimate_probability (struct loops *loops_info)
-{
- basic_block bb;
-
- connect_infinite_loops_to_exit ();
- calculate_dominance_info (CDI_DOMINATORS);
- calculate_dominance_info (CDI_POST_DOMINATORS);
-
- predict_loops (loops_info, true);
-
- iv_analysis_done ();
-
- /* Attempt to predict conditional jumps using a number of heuristics. */
- FOR_EACH_BB (bb)
- {
- rtx last_insn = BB_END (bb);
- edge e;
- edge_iterator ei;
-
- if (! can_predict_insn_p (last_insn))
- continue;
-
- FOR_EACH_EDGE (e, ei, bb->succs)
- {
- /* Predict early returns to be probable, as we've already taken
- care for error returns and other are often used for fast paths
- trought function. */
- if ((e->dest == EXIT_BLOCK_PTR
- || (single_succ_p (e->dest)
- && single_succ (e->dest) == EXIT_BLOCK_PTR))
- && !predicted_by_p (bb, PRED_NULL_RETURN)
- && !predicted_by_p (bb, PRED_CONST_RETURN)
- && !predicted_by_p (bb, PRED_NEGATIVE_RETURN)
- && !last_basic_block_p (e->dest))
- predict_edge_def (e, PRED_EARLY_RETURN, TAKEN);
-
- /* Look for block we are guarding (i.e. we dominate it,
- but it doesn't postdominate us). */
- if (e->dest != EXIT_BLOCK_PTR && e->dest != bb
- && dominated_by_p (CDI_DOMINATORS, e->dest, e->src)
- && !dominated_by_p (CDI_POST_DOMINATORS, e->src, e->dest))
- {
- rtx insn;
-
- /* The call heuristic claims that a guarded function call
- is improbable. This is because such calls are often used
- to signal exceptional situations such as printing error
- messages. */
- for (insn = BB_HEAD (e->dest); insn != NEXT_INSN (BB_END (e->dest));
- insn = NEXT_INSN (insn))
- if (CALL_P (insn)
- /* Constant and pure calls are hardly used to signalize
- something exceptional. */
- && ! CONST_OR_PURE_CALL_P (insn))
- {
- predict_edge_def (e, PRED_CALL, NOT_TAKEN);
- break;
- }
- }
- }
- bb_estimate_probability_locally (bb);
- }
-
- /* Attach the combined probability to each conditional jump. */
- FOR_EACH_BB (bb)
- combine_predictions_for_insn (BB_END (bb), bb);
-
- remove_fake_edges ();
- estimate_bb_frequencies (loops_info);
- free_dominance_info (CDI_POST_DOMINATORS);
- if (profile_status == PROFILE_ABSENT)
- profile_status = PROFILE_GUESSED;
-}
-
/* Set edge->probability for each successor edge of BB. */
void
guess_outgoing_edge_probabilities (basic_block bb)
op1 = expr_expected_value (TREE_OPERAND (expr, 1), visited);
if (!op1)
return NULL;
- res = fold (build (TREE_CODE (expr), TREE_TYPE (expr), op0, op1));
+ res = fold_build2 (TREE_CODE (expr), TREE_TYPE (expr), op0, op1);
if (TREE_CONSTANT (res))
return res;
return NULL;
op0 = expr_expected_value (TREE_OPERAND (expr, 0), visited);
if (!op0)
return NULL;
- res = fold (build1 (TREE_CODE (expr), TREE_TYPE (expr), op0));
+ res = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr), op0);
if (TREE_CONSTANT (res))
return res;
return NULL;
&& TREE_CHAIN (arglist))
{
TREE_OPERAND (stmt, 1) = TREE_VALUE (arglist);
- modify_stmt (stmt);
+ update_stmt (stmt);
}
}
}
static void
apply_return_prediction (int *heads)
{
- tree return_stmt;
+ tree return_stmt = NULL;
tree return_val;
edge e;
tree phi;
basic_block bb;
int *heads;
- heads = xmalloc (sizeof (int) * last_basic_block);
- memset (heads, -1, sizeof (int) * last_basic_block);
+ heads = XNEWVEC (int, last_basic_block);
+ memset (heads, ENTRY_BLOCK, sizeof (int) * last_basic_block);
heads[ENTRY_BLOCK_PTR->next_bb->index] = last_basic_block;
apply_return_prediction (heads);
}
/* Predict branch probabilities and estimate profile of the tree CFG. */
-static void
+static unsigned int
tree_estimate_probability (void)
{
basic_block bb;
{
/* Predict early returns to be probable, as we've already taken
care for error returns and other cases are often used for
- fast paths trought function. */
+ fast paths through function. */
if (e->dest == EXIT_BLOCK_PTR
&& TREE_CODE (last_stmt (bb)) == RETURN_EXPR
&& !single_pred_p (bb))
tree_predict_by_opcode (bb);
}
FOR_EACH_BB (bb)
- combine_predictions_for_bb (dump_file, bb);
+ combine_predictions_for_bb (bb);
- if (0) /* FIXME: Enable once we are pass down the profile to RTL level. */
- strip_builtin_expect ();
+ strip_builtin_expect ();
estimate_bb_frequencies (&loops_info);
free_dominance_info (CDI_POST_DOMINATORS);
remove_fake_exit_edges ();
dump_tree_cfg (dump_file, dump_flags);
if (profile_status == PROFILE_ABSENT)
profile_status = PROFILE_GUESSED;
+ return 0;
}
\f
/* __builtin_expect dropped tokens into the insn stream describing expected
edge_iterator ei;
int y;
- if (heads[bb->index] < 0)
+ if (heads[bb->index] == ENTRY_BLOCK)
{
/* This is first time we need this field in heads array; so
find first dominator that we do not post-dominate (we are
basic_block next_ai = get_immediate_dominator (CDI_DOMINATORS, bb);
int head;
- while (heads[next_ai->index] < 0)
+ while (heads[next_ai->index] == ENTRY_BLOCK)
{
if (!dominated_by_p (CDI_POST_DOMINATORS, next_ai, bb))
break;
while (next_ai != bb)
{
next_ai = ai;
- if (heads[ai->index] == ENTRY_BLOCK)
- ai = ENTRY_BLOCK_PTR;
- else
- ai = BASIC_BLOCK (heads[ai->index]);
+ ai = BASIC_BLOCK (heads[ai->index]);
heads[next_ai->index] = head;
}
}
if (y == last_basic_block)
return;
FOR_EACH_EDGE (e, ei, BASIC_BLOCK (y)->succs)
- if (e->dest->index >= 0
+ if (e->dest->index >= NUM_FIXED_BLOCKS
&& dominated_by_p (CDI_POST_DOMINATORS, e->dest, bb))
predict_edge_def (e, pred, taken);
}
/* Similar information for edges. */
typedef struct edge_info_def
{
- /* In case edge is an loopback edge, the probability edge will be reached
+ /* In case edge is a loopback edge, the probability edge will be reached
in case header is. Estimated number of iterations of the loop can be
then computed as 1 / (1 - back_edge_prob). */
sreal back_edge_prob;
- /* True if the edge is an loopback edge in the natural loop. */
+ /* True if the edge is a loopback edge in the natural loop. */
unsigned int back_edge:1;
} *edge_info;
/* The outermost "loop" includes the exit block, which we can not
look up via BASIC_BLOCK. Detect this and use EXIT_BLOCK_PTR
directly. Do the same for the entry block. */
- if (i == (unsigned)ENTRY_BLOCK)
- bb = ENTRY_BLOCK_PTR;
- else if (i == (unsigned)EXIT_BLOCK)
- bb = EXIT_BLOCK_PTR;
- else
- bb = BASIC_BLOCK (i);
+ bb = BASIC_BLOCK (i);
FOR_EACH_EDGE (e, ei, bb->preds)
{
UNLIKELY_EXECUTED_TEXT_SECTION_NAME);
}
+static bool
+gate_estimate_probability (void)
+{
+ return flag_guess_branch_prob;
+}
struct tree_opt_pass pass_profile =
{
"profile", /* name */
- NULL, /* gate */
+ gate_estimate_probability, /* gate */
tree_estimate_probability, /* execute */
NULL, /* sub */
NULL, /* next */
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