#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "insn-config.h"
#include "regs.h"
#include "flags.h"
#include "output.h"
#include "function.h"
#include "except.h"
#include "toplev.h"
#include "recog.h"
#include "expr.h"
#include "predict.h"
#include "coverage.h"
#include "sreal.h"
#include "params.h"
#include "target.h"
#include "cfgloop.h"
#include "tree-flow.h"
#include "ggc.h"
#include "tree-dump.h"
#include "tree-pass.h"
#include "timevar.h"
#include "tree-scalar-evolution.h"
#include "cfgloop.h"
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;
#define PROB_VERY_UNLIKELY (REG_BR_PROB_BASE / 100 - 1)
#define PROB_EVEN (REG_BR_PROB_BASE / 2)
#define PROB_VERY_LIKELY (REG_BR_PROB_BASE - PROB_VERY_UNLIKELY)
#define PROB_ALWAYS (REG_BR_PROB_BASE)
static void combine_predictions_for_insn (rtx, basic_block);
static void dump_prediction (FILE *, enum br_predictor, int, basic_block, int);
static void estimate_loops_at_level (struct loop *, bitmap);
static void propagate_freq (struct loop *, bitmap);
static void estimate_bb_frequencies (struct loops *);
static void predict_paths_leading_to (basic_block, int *, enum br_predictor, enum prediction);
static bool last_basic_block_p (basic_block);
static void compute_function_frequency (void);
static void choose_function_section (void);
static bool can_predict_insn_p (rtx);
struct predictor_info
{
const char *const name;
const int hitrate;
const int flags;
};
#define PRED_FLAG_FIRST_MATCH 1
#define HITRATE(VAL) ((int) ((VAL) * REG_BR_PROB_BASE + 50) / 100)
#define DEF_PREDICTOR(ENUM, NAME, HITRATE, FLAGS) {NAME, HITRATE, FLAGS},
static const struct predictor_info predictor_info[]= {
#include "predict.def"
{NULL, 0, 0}
};
#undef DEF_PREDICTOR
bool
maybe_hot_bb_p (basic_block bb)
{
if (profile_info && flag_branch_probabilities
&& (bb->count
< profile_info->sum_max / PARAM_VALUE (HOT_BB_COUNT_FRACTION)))
return false;
if (bb->frequency < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION))
return false;
return true;
}
bool
probably_cold_bb_p (basic_block bb)
{
if (profile_info && flag_branch_probabilities
&& (bb->count
< profile_info->sum_max / PARAM_VALUE (HOT_BB_COUNT_FRACTION)))
return true;
if (bb->frequency < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION))
return true;
return false;
}
bool
probably_never_executed_bb_p (basic_block bb)
{
if (profile_info && flag_branch_probabilities)
return (bb->count == 0);
return false;
}
bool
rtl_predicted_by_p (basic_block bb, enum br_predictor predictor)
{
rtx note;
if (!INSN_P (BB_END (bb)))
return false;
for (note = REG_NOTES (BB_END (bb)); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_BR_PRED
&& INTVAL (XEXP (XEXP (note, 0), 0)) == (int)predictor)
return true;
return false;
}
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)
return true;
return false;
}
static void
predict_insn (rtx insn, enum br_predictor predictor, int probability)
{
if (!any_condjump_p (insn))
abort ();
if (!flag_guess_branch_prob)
return;
REG_NOTES (insn)
= gen_rtx_EXPR_LIST (REG_BR_PRED,
gen_rtx_CONCAT (VOIDmode,
GEN_INT ((int) predictor),
GEN_INT ((int) probability)),
REG_NOTES (insn));
}
void
predict_insn_def (rtx insn, enum br_predictor predictor,
enum prediction taken)
{
int probability = predictor_info[(int) predictor].hitrate;
if (taken != TAKEN)
probability = REG_BR_PROB_BASE - probability;
predict_insn (insn, predictor, probability);
}
void
rtl_predict_edge (edge e, enum br_predictor predictor, int probability)
{
rtx last_insn;
last_insn = BB_END (e->src);
if (!any_condjump_p (last_insn))
return;
if (e->flags & EDGE_FALLTHRU)
probability = REG_BR_PROB_BASE - probability;
predict_insn (last_insn, predictor, probability);
}
void
tree_predict_edge (edge e, enum br_predictor predictor, int probability)
{
struct edge_prediction *i = ggc_alloc (sizeof (struct edge_prediction));
i->next = bb_ann (e->src)->predictions;
bb_ann (e->src)->predictions = i;
i->probability = probability;
i->predictor = predictor;
i->edge = e;
}
static bool
can_predict_insn_p (rtx insn)
{
return (JUMP_P (insn)
&& any_condjump_p (insn)
&& EDGE_COUNT (BLOCK_FOR_INSN (insn)->succs) >= 2);
}
void
predict_edge_def (edge e, enum br_predictor predictor,
enum prediction taken)
{
int probability = predictor_info[(int) predictor].hitrate;
if (taken != TAKEN)
probability = REG_BR_PROB_BASE - probability;
predict_edge (e, predictor, probability);
}
void
invert_br_probabilities (rtx insn)
{
rtx note;
for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_BR_PROB)
XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0)));
else if (REG_NOTE_KIND (note) == REG_BR_PRED)
XEXP (XEXP (note, 0), 1)
= GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (XEXP (note, 0), 1)));
}
static void
dump_prediction (FILE *file, enum br_predictor predictor, int probability,
basic_block bb, int used)
{
edge e;
edge_iterator ei;
if (!file)
return;
FOR_EACH_EDGE (e, ei, bb->succs)
if (! (e->flags & EDGE_FALLTHRU))
break;
fprintf (file, " %s heuristics%s: %.1f%%",
predictor_info[predictor].name,
used ? "" : " (ignored)", probability * 100.0 / REG_BR_PROB_BASE);
if (bb->count)
{
fprintf (file, " exec ");
fprintf (file, HOST_WIDEST_INT_PRINT_DEC, bb->count);
if (e)
{
fprintf (file, " hit ");
fprintf (file, HOST_WIDEST_INT_PRINT_DEC, e->count);
fprintf (file, " (%.1f%%)", e->count * 100.0 / bb->count);
}
}
fprintf (file, "\n");
}
static void
set_even_probabilities (basic_block bb)
{
int nedges = 0;
edge e;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, bb->succs)
if (!(e->flags & (EDGE_EH | EDGE_FAKE)))
nedges ++;
FOR_EACH_EDGE (e, ei, bb->succs)
if (!(e->flags & (EDGE_EH | EDGE_FAKE)))
e->probability = (REG_BR_PROB_BASE + nedges / 2) / nedges;
else
e->probability = 0;
}
static void
combine_predictions_for_insn (rtx insn, basic_block bb)
{
rtx prob_note;
rtx *pnote;
rtx note;
int best_probability = PROB_EVEN;
int best_predictor = END_PREDICTORS;
int combined_probability = REG_BR_PROB_BASE / 2;
int d;
bool first_match = false;
bool found = false;
if (!can_predict_insn_p (insn))
{
set_even_probabilities (bb);
return;
}
prob_note = find_reg_note (insn, REG_BR_PROB, 0);
pnote = ®_NOTES (insn);
if (dump_file)
fprintf (dump_file, "Predictions for insn %i bb %i\n", INSN_UID (insn),
bb->index);
for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_BR_PRED)
{
int predictor = INTVAL (XEXP (XEXP (note, 0), 0));
int probability = INTVAL (XEXP (XEXP (note, 0), 1));
found = true;
if (best_predictor > predictor)
best_probability = probability, best_predictor = predictor;
d = (combined_probability * probability
+ (REG_BR_PROB_BASE - combined_probability)
* (REG_BR_PROB_BASE - probability));
if (d == 0)
combined_probability = REG_BR_PROB_BASE / 2;
else
combined_probability = (((double) combined_probability) * probability
* REG_BR_PROB_BASE / d + 0.5);
}
if (predictor_info [best_predictor].flags & PRED_FLAG_FIRST_MATCH)
first_match = true;
if (!found)
dump_prediction (dump_file, PRED_NO_PREDICTION,
combined_probability, bb, true);
else
{
dump_prediction (dump_file, PRED_DS_THEORY, combined_probability,
bb, !first_match);
dump_prediction (dump_file, PRED_FIRST_MATCH, best_probability,
bb, first_match);
}
if (first_match)
combined_probability = best_probability;
dump_prediction (dump_file, PRED_COMBINED, combined_probability, bb, true);
while (*pnote)
{
if (REG_NOTE_KIND (*pnote) == REG_BR_PRED)
{
int predictor = INTVAL (XEXP (XEXP (*pnote, 0), 0));
int probability = INTVAL (XEXP (XEXP (*pnote, 0), 1));
dump_prediction (dump_file, predictor, probability, bb,
!first_match || best_predictor == predictor);
*pnote = XEXP (*pnote, 1);
}
else
pnote = &XEXP (*pnote, 1);
}
if (!prob_note)
{
REG_NOTES (insn)
= gen_rtx_EXPR_LIST (REG_BR_PROB,
GEN_INT (combined_probability), REG_NOTES (insn));
if (EDGE_COUNT (bb->succs) > 1)
{
BRANCH_EDGE (bb)->probability = combined_probability;
FALLTHRU_EDGE (bb)->probability
= REG_BR_PROB_BASE - combined_probability;
}
}
else if (EDGE_COUNT (bb->succs) > 1)
{
int prob = INTVAL (XEXP (prob_note, 0));
BRANCH_EDGE (bb)->probability = prob;
FALLTHRU_EDGE (bb)->probability = REG_BR_PROB_BASE - prob;
}
else
EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE;
}
static void
combine_predictions_for_bb (FILE *file, basic_block bb)
{
int best_probability = PROB_EVEN;
int best_predictor = END_PREDICTORS;
int combined_probability = REG_BR_PROB_BASE / 2;
int d;
bool first_match = false;
bool found = false;
struct edge_prediction *pred;
int nedges = 0;
edge e, first = NULL, second = NULL;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, bb->succs)
if (!(e->flags & (EDGE_EH | EDGE_FAKE)))
{
nedges ++;
if (first && !second)
second = e;
if (!first)
first = e;
}
if (nedges != 2)
{
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",
nedges, bb->index);
return;
}
if (file)
fprintf (file, "Predictions for bb %i\n", bb->index);
for (pred = bb_ann (bb)->predictions; pred; pred = pred->next)
{
int predictor = pred->predictor;
int probability = pred->probability;
if (pred->edge != first)
probability = REG_BR_PROB_BASE - probability;
found = true;
if (best_predictor > predictor)
best_probability = probability, best_predictor = predictor;
d = (combined_probability * probability
+ (REG_BR_PROB_BASE - combined_probability)
* (REG_BR_PROB_BASE - probability));
if (d == 0)
combined_probability = REG_BR_PROB_BASE / 2;
else
combined_probability = (((double) combined_probability) * probability
* REG_BR_PROB_BASE / d + 0.5);
}
if (predictor_info [best_predictor].flags & PRED_FLAG_FIRST_MATCH)
first_match = true;
if (!found)
dump_prediction (file, PRED_NO_PREDICTION, combined_probability, bb, true);
else
{
dump_prediction (file, PRED_DS_THEORY, combined_probability, bb,
!first_match);
dump_prediction (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);
for (pred = bb_ann (bb)->predictions; pred; pred = pred->next)
{
int predictor = pred->predictor;
int probability = pred->probability;
if (pred->edge != EDGE_SUCC (bb, 0))
probability = REG_BR_PROB_BASE - probability;
dump_prediction (file, predictor, probability, bb,
!first_match || best_predictor == predictor);
}
bb_ann (bb)->predictions = NULL;
if (!bb->count)
{
first->probability = combined_probability;
second->probability = REG_BR_PROB_BASE - combined_probability;
}
}
static void
predict_loops (struct loops *loops_info, bool rtlsimpleloops)
{
unsigned i;
if (!rtlsimpleloops)
scev_initialize (loops_info);
for (i = 1; i < loops_info->num; i++)
{
basic_block bb, *bbs;
unsigned j;
int exits;
struct loop *loop = loops_info->parray[i];
struct niter_desc desc;
unsigned HOST_WIDE_INT niter;
flow_loop_scan (loop, LOOP_EXIT_EDGES);
exits = loop->num_exits;
if (rtlsimpleloops)
{
iv_analysis_loop_init (loop);
find_simple_exit (loop, &desc);
if (desc.simple_p && desc.const_iter)
{
int prob;
niter = desc.niter + 1;
if (niter == 0)
niter = desc.niter;
prob = (REG_BR_PROB_BASE
- (REG_BR_PROB_BASE + niter /2) / niter);
if (prob == REG_BR_PROB_BASE)
prob = REG_BR_PROB_BASE - 1;
predict_edge (desc.in_edge, PRED_LOOP_ITERATIONS,
prob);
}
}
else
{
edge *exits;
unsigned j, n_exits;
struct tree_niter_desc niter_desc;
exits = get_loop_exit_edges (loop, &n_exits);
for (j = 0; j < n_exits; j++)
{
tree niter = NULL;
if (number_of_iterations_exit (loop, exits[j], &niter_desc))
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;
if (host_integerp (niter, 1)
&& tree_int_cst_lt (niter,
build_int_cstu (NULL_TREE,
REG_BR_PROB_BASE - 1)))
{
HOST_WIDE_INT nitercst = tree_low_cst (niter, 1) + 1;
probability = (REG_BR_PROB_BASE + nitercst / 2) / nitercst;
}
else
probability = 1;
predict_edge (exits[j], PRED_LOOP_ITERATIONS, probability);
}
}
free (exits);
}
bbs = get_loop_body (loop);
for (j = 0; j < loop->num_nodes; j++)
{
int header_found = 0;
edge e;
edge_iterator ei;
bb = bbs[j];
if ((rtlsimpleloops && !can_predict_insn_p (BB_END (bb)))
|| predicted_by_p (bb, PRED_CONTINUE))
continue;
if (bb == loop->latch)
{
e = find_edge (loop->latch, loop->header);
if (e)
{
header_found = 1;
predict_edge_def (e, PRED_LOOP_BRANCH, TAKEN);
}
}
if (!header_found)
FOR_EACH_EDGE (e, ei, bb->succs)
if (e->dest->index < 0
|| !flow_bb_inside_loop_p (loop, e->dest))
predict_edge
(e, PRED_LOOP_EXIT,
(REG_BR_PROB_BASE
- predictor_info [(int) PRED_LOOP_EXIT].hitrate)
/ exits);
}
free (bbs);
}
if (rtlsimpleloops)
iv_analysis_done ();
if (!rtlsimpleloops)
scev_finalize ();
}
static void
bb_estimate_probability_locally (basic_block bb)
{
rtx last_insn = BB_END (bb);
rtx cond;
if (! can_predict_insn_p (last_insn))
return;
cond = get_condition (last_insn, NULL, false, false);
if (! cond)
return;
if (COMPARISON_P (cond)
&& ((REG_P (XEXP (cond, 0)) && REG_POINTER (XEXP (cond, 0)))
|| (REG_P (XEXP (cond, 1)) && REG_POINTER (XEXP (cond, 1)))))
{
if (GET_CODE (cond) == EQ)
predict_insn_def (last_insn, PRED_POINTER, NOT_TAKEN);
else if (GET_CODE (cond) == NE)
predict_insn_def (last_insn, PRED_POINTER, TAKEN);
}
else
switch (GET_CODE (cond))
{
case CONST_INT:
predict_insn_def (last_insn, PRED_UNCONDITIONAL,
cond == const0_rtx ? NOT_TAKEN : TAKEN);
break;
case EQ:
case UNEQ:
if (FLOAT_MODE_P (GET_MODE (XEXP (cond, 0))))
;
else if (XEXP (cond, 1) == const0_rtx
|| XEXP (cond, 0) == const0_rtx)
;
else
predict_insn_def (last_insn, PRED_OPCODE_NONEQUAL, NOT_TAKEN);
break;
case NE:
case LTGT:
if (FLOAT_MODE_P (GET_MODE (XEXP (cond, 0))))
;
else if (XEXP (cond, 1) == const0_rtx
|| XEXP (cond, 0) == const0_rtx)
;
else
predict_insn_def (last_insn, PRED_OPCODE_NONEQUAL, TAKEN);
break;
case ORDERED:
predict_insn_def (last_insn, PRED_FPOPCODE, TAKEN);
break;
case UNORDERED:
predict_insn_def (last_insn, PRED_FPOPCODE, NOT_TAKEN);
break;
case LE:
case LT:
if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 1) == const1_rtx
|| XEXP (cond, 1) == constm1_rtx)
predict_insn_def (last_insn, PRED_OPCODE_POSITIVE, NOT_TAKEN);
break;
case GE:
case GT:
if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 1) == const1_rtx
|| XEXP (cond, 1) == constm1_rtx)
predict_insn_def (last_insn, PRED_OPCODE_POSITIVE, TAKEN);
break;
default:
break;
}
}
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 ();
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)
{
if ((e->dest == EXIT_BLOCK_PTR
|| (EDGE_COUNT (e->dest->succs) == 1
&& EDGE_SUCC (e->dest, 0)->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);
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;
for (insn = BB_HEAD (e->dest); insn != NEXT_INSN (BB_END (e->dest));
insn = NEXT_INSN (insn))
if (CALL_P (insn)
&& ! CONST_OR_PURE_CALL_P (insn))
{
predict_edge_def (e, PRED_CALL, NOT_TAKEN);
break;
}
}
}
bb_estimate_probability_locally (bb);
}
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;
}
void
guess_outgoing_edge_probabilities (basic_block bb)
{
bb_estimate_probability_locally (bb);
combine_predictions_for_insn (BB_END (bb), bb);
}
static tree
expr_expected_value (tree expr, bitmap visited)
{
if (TREE_CONSTANT (expr))
return expr;
else if (TREE_CODE (expr) == SSA_NAME)
{
tree def = SSA_NAME_DEF_STMT (expr);
if (bitmap_bit_p (visited, SSA_NAME_VERSION (expr)))
return NULL;
bitmap_set_bit (visited, SSA_NAME_VERSION (expr));
if (TREE_CODE (def) == PHI_NODE)
{
int i;
tree val = NULL, new_val;
for (i = 0; i < PHI_NUM_ARGS (def); i++)
{
tree arg = PHI_ARG_DEF (def, i);
if (arg == PHI_RESULT (def))
continue;
new_val = expr_expected_value (arg, visited);
if (!new_val)
return NULL;
if (!val)
val = new_val;
else if (!operand_equal_p (val, new_val, false))
return NULL;
}
return val;
}
if (TREE_CODE (def) != MODIFY_EXPR || TREE_OPERAND (def, 0) != expr)
return NULL;
return expr_expected_value (TREE_OPERAND (def, 1), visited);
}
else if (TREE_CODE (expr) == CALL_EXPR)
{
tree decl = get_callee_fndecl (expr);
if (!decl)
return NULL;
if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
&& DECL_FUNCTION_CODE (decl) == BUILT_IN_EXPECT)
{
tree arglist = TREE_OPERAND (expr, 1);
tree val;
if (arglist == NULL_TREE
|| TREE_CHAIN (arglist) == NULL_TREE)
return NULL;
val = TREE_VALUE (TREE_CHAIN (TREE_OPERAND (expr, 1)));
if (TREE_CONSTANT (val))
return val;
return TREE_VALUE (TREE_CHAIN (TREE_OPERAND (expr, 1)));
}
}
if (BINARY_CLASS_P (expr) || COMPARISON_CLASS_P (expr))
{
tree op0, op1, res;
op0 = expr_expected_value (TREE_OPERAND (expr, 0), visited);
if (!op0)
return NULL;
op1 = expr_expected_value (TREE_OPERAND (expr, 1), visited);
if (!op1)
return NULL;
res = fold (build (TREE_CODE (expr), TREE_TYPE (expr), op0, op1));
if (TREE_CONSTANT (res))
return res;
return NULL;
}
if (UNARY_CLASS_P (expr))
{
tree op0, res;
op0 = expr_expected_value (TREE_OPERAND (expr, 0), visited);
if (!op0)
return NULL;
res = fold (build1 (TREE_CODE (expr), TREE_TYPE (expr), op0));
if (TREE_CONSTANT (res))
return res;
return NULL;
}
return NULL;
}
static void
strip_builtin_expect (void)
{
basic_block bb;
FOR_EACH_BB (bb)
{
block_stmt_iterator bi;
for (bi = bsi_start (bb); !bsi_end_p (bi); bsi_next (&bi))
{
tree stmt = bsi_stmt (bi);
tree fndecl;
tree arglist;
if (TREE_CODE (stmt) == MODIFY_EXPR
&& TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR
&& (fndecl = get_callee_fndecl (TREE_OPERAND (stmt, 1)))
&& DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
&& DECL_FUNCTION_CODE (fndecl) == BUILT_IN_EXPECT
&& (arglist = TREE_OPERAND (TREE_OPERAND (stmt, 1), 1))
&& TREE_CHAIN (arglist))
{
TREE_OPERAND (stmt, 1) = TREE_VALUE (arglist);
modify_stmt (stmt);
}
}
}
}
static void
tree_predict_by_opcode (basic_block bb)
{
tree stmt = last_stmt (bb);
edge then_edge;
tree cond;
tree op0;
tree type;
tree val;
bitmap visited;
edge_iterator ei;
if (!stmt || TREE_CODE (stmt) != COND_EXPR)
return;
FOR_EACH_EDGE (then_edge, ei, bb->succs)
if (then_edge->flags & EDGE_TRUE_VALUE)
break;
cond = TREE_OPERAND (stmt, 0);
if (!COMPARISON_CLASS_P (cond))
return;
op0 = TREE_OPERAND (cond, 0);
type = TREE_TYPE (op0);
visited = BITMAP_ALLOC (NULL);
val = expr_expected_value (cond, visited);
BITMAP_FREE (visited);
if (val)
{
if (integer_zerop (val))
predict_edge_def (then_edge, PRED_BUILTIN_EXPECT, NOT_TAKEN);
else
predict_edge_def (then_edge, PRED_BUILTIN_EXPECT, TAKEN);
return;
}
if (POINTER_TYPE_P (type))
{
if (TREE_CODE (cond) == EQ_EXPR)
predict_edge_def (then_edge, PRED_TREE_POINTER, NOT_TAKEN);
else if (TREE_CODE (cond) == NE_EXPR)
predict_edge_def (then_edge, PRED_TREE_POINTER, TAKEN);
}
else
switch (TREE_CODE (cond))
{
case EQ_EXPR:
case UNEQ_EXPR:
if (FLOAT_TYPE_P (type))
;
else if (integer_zerop (op0)
|| integer_zerop (TREE_OPERAND (cond, 1)))
;
else
predict_edge_def (then_edge, PRED_TREE_OPCODE_NONEQUAL, NOT_TAKEN);
break;
case NE_EXPR:
case LTGT_EXPR:
if (FLOAT_TYPE_P (type))
;
else if (integer_zerop (op0)
|| integer_zerop (TREE_OPERAND (cond, 1)))
;
else
predict_edge_def (then_edge, PRED_TREE_OPCODE_NONEQUAL, TAKEN);
break;
case ORDERED_EXPR:
predict_edge_def (then_edge, PRED_TREE_FPOPCODE, TAKEN);
break;
case UNORDERED_EXPR:
predict_edge_def (then_edge, PRED_TREE_FPOPCODE, NOT_TAKEN);
break;
case LE_EXPR:
case LT_EXPR:
if (integer_zerop (TREE_OPERAND (cond, 1))
|| integer_onep (TREE_OPERAND (cond, 1))
|| integer_all_onesp (TREE_OPERAND (cond, 1))
|| real_zerop (TREE_OPERAND (cond, 1))
|| real_onep (TREE_OPERAND (cond, 1))
|| real_minus_onep (TREE_OPERAND (cond, 1)))
predict_edge_def (then_edge, PRED_TREE_OPCODE_POSITIVE, NOT_TAKEN);
break;
case GE_EXPR:
case GT_EXPR:
if (integer_zerop (TREE_OPERAND (cond, 1))
|| integer_onep (TREE_OPERAND (cond, 1))
|| integer_all_onesp (TREE_OPERAND (cond, 1))
|| real_zerop (TREE_OPERAND (cond, 1))
|| real_onep (TREE_OPERAND (cond, 1))
|| real_minus_onep (TREE_OPERAND (cond, 1)))
predict_edge_def (then_edge, PRED_TREE_OPCODE_POSITIVE, TAKEN);
break;
default:
break;
}
}
static enum br_predictor
return_prediction (tree val, enum prediction *prediction)
{
if (!val)
return PRED_NO_PREDICTION;
if (POINTER_TYPE_P (TREE_TYPE (val)))
{
if (integer_zerop (val))
{
*prediction = NOT_TAKEN;
return PRED_NULL_RETURN;
}
}
else if (INTEGRAL_TYPE_P (TREE_TYPE (val)))
{
if (TREE_CODE (val) == INTEGER_CST
&& tree_int_cst_sgn (val) < 0)
{
*prediction = NOT_TAKEN;
return PRED_NEGATIVE_RETURN;
}
if (TREE_CONSTANT (val)
&& (!integer_zerop (val) && !integer_onep (val)))
{
*prediction = TAKEN;
return PRED_NEGATIVE_RETURN;
}
}
return PRED_NO_PREDICTION;
}
static void
apply_return_prediction (int *heads)
{
tree return_stmt;
tree return_val;
edge e;
tree phi;
int phi_num_args, i;
enum br_predictor pred;
enum prediction direction;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
{
return_stmt = last_stmt (e->src);
if (TREE_CODE (return_stmt) == RETURN_EXPR)
break;
}
if (!e)
return;
return_val = TREE_OPERAND (return_stmt, 0);
if (!return_val)
return;
if (TREE_CODE (return_val) == MODIFY_EXPR)
return_val = TREE_OPERAND (return_val, 1);
if (TREE_CODE (return_val) != SSA_NAME
|| !SSA_NAME_DEF_STMT (return_val)
|| TREE_CODE (SSA_NAME_DEF_STMT (return_val)) != PHI_NODE)
return;
phi = SSA_NAME_DEF_STMT (return_val);
while (phi)
{
tree next = PHI_CHAIN (phi);
if (PHI_RESULT (phi) == return_val)
break;
phi = next;
}
if (!phi)
return;
phi_num_args = PHI_NUM_ARGS (phi);
pred = return_prediction (PHI_ARG_DEF (phi, 0), &direction);
for (i = 1; i < phi_num_args; i++)
if (pred != return_prediction (PHI_ARG_DEF (phi, i), &direction))
break;
if (i != phi_num_args)
for (i = 0; i < phi_num_args; i++)
{
pred = return_prediction (PHI_ARG_DEF (phi, i), &direction);
if (pred != PRED_NO_PREDICTION)
predict_paths_leading_to (PHI_ARG_EDGE (phi, i)->src, heads, pred,
direction);
}
}
static void
tree_bb_level_predictions (void)
{
basic_block bb;
int *heads;
heads = xmalloc (sizeof (int) * last_basic_block);
memset (heads, -1, sizeof (int) * last_basic_block);
heads[ENTRY_BLOCK_PTR->next_bb->index] = last_basic_block;
apply_return_prediction (heads);
FOR_EACH_BB (bb)
{
block_stmt_iterator bsi = bsi_last (bb);
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
{
tree stmt = bsi_stmt (bsi);
switch (TREE_CODE (stmt))
{
case MODIFY_EXPR:
if (TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR)
{
stmt = TREE_OPERAND (stmt, 1);
goto call_expr;
}
break;
case CALL_EXPR:
call_expr:;
if (call_expr_flags (stmt) & ECF_NORETURN)
predict_paths_leading_to (bb, heads, PRED_NORETURN,
NOT_TAKEN);
break;
default:
break;
}
}
}
free (heads);
}
static void
tree_estimate_probability (void)
{
basic_block bb;
struct loops loops_info;
flow_loops_find (&loops_info, LOOP_TREE);
if (dump_file && (dump_flags & TDF_DETAILS))
flow_loops_dump (&loops_info, dump_file, NULL, 0);
add_noreturn_fake_exit_edges ();
connect_infinite_loops_to_exit ();
calculate_dominance_info (CDI_DOMINATORS);
calculate_dominance_info (CDI_POST_DOMINATORS);
tree_bb_level_predictions ();
mark_irreducible_loops (&loops_info);
predict_loops (&loops_info, false);
FOR_EACH_BB (bb)
{
edge e;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, bb->succs)
{
if (e->dest == EXIT_BLOCK_PTR
&& TREE_CODE (last_stmt (bb)) == RETURN_EXPR
&& EDGE_COUNT (bb->preds) > 1)
{
edge e1;
edge_iterator ei1;
FOR_EACH_EDGE (e1, ei1, bb->preds)
if (!predicted_by_p (e1->src, PRED_NULL_RETURN)
&& !predicted_by_p (e1->src, PRED_CONST_RETURN)
&& !predicted_by_p (e1->src, PRED_NEGATIVE_RETURN)
&& !last_basic_block_p (e1->src))
predict_edge_def (e1, PRED_TREE_EARLY_RETURN, NOT_TAKEN);
}
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))
{
block_stmt_iterator bi;
for (bi = bsi_start (e->dest); !bsi_end_p (bi);
bsi_next (&bi))
{
tree stmt = bsi_stmt (bi);
if ((TREE_CODE (stmt) == CALL_EXPR
|| (TREE_CODE (stmt) == MODIFY_EXPR
&& TREE_CODE (TREE_OPERAND (stmt, 1)) == CALL_EXPR))
&& TREE_SIDE_EFFECTS (stmt))
{
predict_edge_def (e, PRED_CALL, NOT_TAKEN);
break;
}
}
}
}
tree_predict_by_opcode (bb);
}
FOR_EACH_BB (bb)
combine_predictions_for_bb (dump_file, bb);
if (0)
strip_builtin_expect ();
estimate_bb_frequencies (&loops_info);
free_dominance_info (CDI_POST_DOMINATORS);
remove_fake_exit_edges ();
flow_loops_free (&loops_info);
if (dump_file && (dump_flags & TDF_DETAILS))
dump_tree_cfg (dump_file, dump_flags);
if (profile_status == PROFILE_ABSENT)
profile_status = PROFILE_GUESSED;
}
void
expected_value_to_br_prob (void)
{
rtx insn, cond, ev = NULL_RTX, ev_reg = NULL_RTX;
for (insn = get_insns (); insn ; insn = NEXT_INSN (insn))
{
switch (GET_CODE (insn))
{
case NOTE:
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EXPECTED_VALUE)
{
ev = NOTE_EXPECTED_VALUE (insn);
ev_reg = XEXP (ev, 0);
delete_insn (insn);
}
continue;
case CODE_LABEL:
ev = NULL_RTX;
continue;
case JUMP_INSN:
if (!JUMP_P (insn) || ev == NULL_RTX
|| ! any_condjump_p (insn))
continue;
break;
default:
if (ev && reg_set_p (ev_reg, insn))
ev = NULL_RTX;
continue;
}
cond = XEXP (SET_SRC (pc_set (insn)), 0);
cond = canonicalize_condition (insn, cond, 0, NULL, ev_reg,
false, false);
if (! cond || XEXP (cond, 0) != ev_reg
|| GET_CODE (XEXP (cond, 1)) != CONST_INT)
continue;
cond = gen_rtx_fmt_ee (GET_CODE (cond), VOIDmode,
XEXP (ev, 1), XEXP (cond, 1));
cond = simplify_rtx (cond);
if (cond != const_true_rtx && cond != const0_rtx)
abort ();
predict_insn_def (insn, PRED_BUILTIN_EXPECT,
cond == const_true_rtx ? TAKEN : NOT_TAKEN);
}
}
static bool
last_basic_block_p (basic_block bb)
{
if (bb == EXIT_BLOCK_PTR)
return false;
return (bb->next_bb == EXIT_BLOCK_PTR
|| (bb->next_bb->next_bb == EXIT_BLOCK_PTR
&& EDGE_COUNT (bb->succs) == 1
&& EDGE_SUCC (bb, 0)->dest->next_bb == EXIT_BLOCK_PTR));
}
static void
predict_paths_leading_to (basic_block bb, int *heads, enum br_predictor pred,
enum prediction taken)
{
edge e;
edge_iterator ei;
int y;
if (heads[bb->index] < 0)
{
basic_block ai = bb;
basic_block next_ai = get_immediate_dominator (CDI_DOMINATORS, bb);
int head;
while (heads[next_ai->index] < 0)
{
if (!dominated_by_p (CDI_POST_DOMINATORS, next_ai, bb))
break;
heads[next_ai->index] = ai->index;
ai = next_ai;
next_ai = get_immediate_dominator (CDI_DOMINATORS, next_ai);
}
if (!dominated_by_p (CDI_POST_DOMINATORS, next_ai, bb))
head = next_ai->index;
else
head = heads[next_ai->index];
while (next_ai != bb)
{
next_ai = ai;
if (heads[ai->index] == ENTRY_BLOCK)
ai = ENTRY_BLOCK_PTR;
else
ai = BASIC_BLOCK (heads[ai->index]);
heads[next_ai->index] = head;
}
}
y = heads[bb->index];
if (y == last_basic_block)
return;
FOR_EACH_EDGE (e, ei, BASIC_BLOCK (y)->succs)
if (e->dest->index >= 0
&& dominated_by_p (CDI_POST_DOMINATORS, e->dest, bb))
predict_edge_def (e, pred, taken);
}
typedef struct block_info_def
{
sreal frequency;
basic_block next;
int npredecessors;
} *block_info;
typedef struct edge_info_def
{
sreal back_edge_prob;
unsigned int back_edge:1;
} *edge_info;
#define BLOCK_INFO(B) ((block_info) (B)->aux)
#define EDGE_INFO(E) ((edge_info) (E)->aux)
static void
propagate_freq (struct loop *loop, bitmap tovisit)
{
basic_block head = loop->header;
basic_block bb;
basic_block last;
unsigned i;
edge e;
basic_block nextbb;
bitmap_iterator bi;
EXECUTE_IF_SET_IN_BITMAP (tovisit, 0, i, bi)
{
edge_iterator ei;
int count = 0;
if (i == (unsigned)ENTRY_BLOCK)
bb = ENTRY_BLOCK_PTR;
else if (i == (unsigned)EXIT_BLOCK)
bb = EXIT_BLOCK_PTR;
else
bb = BASIC_BLOCK (i);
FOR_EACH_EDGE (e, ei, bb->preds)
{
bool visit = bitmap_bit_p (tovisit, e->src->index);
if (visit && !(e->flags & EDGE_DFS_BACK))
count++;
else if (visit && dump_file && !EDGE_INFO (e)->back_edge)
fprintf (dump_file,
"Irreducible region hit, ignoring edge to %i->%i\n",
e->src->index, bb->index);
}
BLOCK_INFO (bb)->npredecessors = count;
}
memcpy (&BLOCK_INFO (head)->frequency, &real_one, sizeof (real_one));
last = head;
for (bb = head; bb; bb = nextbb)
{
edge_iterator ei;
sreal cyclic_probability, frequency;
memcpy (&cyclic_probability, &real_zero, sizeof (real_zero));
memcpy (&frequency, &real_zero, sizeof (real_zero));
nextbb = BLOCK_INFO (bb)->next;
BLOCK_INFO (bb)->next = NULL;
if (bb != head)
{
#ifdef ENABLE_CHECKING
FOR_EACH_EDGE (e, ei, bb->preds)
if (bitmap_bit_p (tovisit, e->src->index)
&& !(e->flags & EDGE_DFS_BACK))
abort ();
#endif
FOR_EACH_EDGE (e, ei, bb->preds)
if (EDGE_INFO (e)->back_edge)
{
sreal_add (&cyclic_probability, &cyclic_probability,
&EDGE_INFO (e)->back_edge_prob);
}
else if (!(e->flags & EDGE_DFS_BACK))
{
sreal tmp;
sreal_init (&tmp, e->probability, 0);
sreal_mul (&tmp, &tmp, &BLOCK_INFO (e->src)->frequency);
sreal_mul (&tmp, &tmp, &real_inv_br_prob_base);
sreal_add (&frequency, &frequency, &tmp);
}
if (sreal_compare (&cyclic_probability, &real_zero) == 0)
{
memcpy (&BLOCK_INFO (bb)->frequency, &frequency,
sizeof (frequency));
}
else
{
if (sreal_compare (&cyclic_probability, &real_almost_one) > 0)
{
memcpy (&cyclic_probability, &real_almost_one,
sizeof (real_almost_one));
}
sreal_sub (&cyclic_probability, &real_one, &cyclic_probability);
sreal_div (&BLOCK_INFO (bb)->frequency,
&frequency, &cyclic_probability);
}
}
bitmap_clear_bit (tovisit, bb->index);
e = find_edge (bb, head);
if (e)
{
sreal tmp;
sreal_init (&tmp, e->probability, 0);
sreal_mul (&tmp, &tmp, &BLOCK_INFO (bb)->frequency);
sreal_mul (&EDGE_INFO (e)->back_edge_prob,
&tmp, &real_inv_br_prob_base);
}
FOR_EACH_EDGE (e, ei, bb->succs)
if (!(e->flags & EDGE_DFS_BACK)
&& BLOCK_INFO (e->dest)->npredecessors)
{
BLOCK_INFO (e->dest)->npredecessors--;
if (!BLOCK_INFO (e->dest)->npredecessors)
{
if (!nextbb)
nextbb = e->dest;
else
BLOCK_INFO (last)->next = e->dest;
last = e->dest;
}
}
}
}
static void
estimate_loops_at_level (struct loop *first_loop, bitmap tovisit)
{
struct loop *loop;
for (loop = first_loop; loop; loop = loop->next)
{
edge e;
basic_block *bbs;
unsigned i;
estimate_loops_at_level (loop->inner, tovisit);
if (EDGE_COUNT (loop->latch->succs) > 0)
{
e = loop_latch_edge (loop);
EDGE_INFO (e)->back_edge = 1;
}
bbs = get_loop_body (loop);
for (i = 0; i < loop->num_nodes; i++)
bitmap_set_bit (tovisit, bbs[i]->index);
free (bbs);
propagate_freq (loop, tovisit);
}
}
int
counts_to_freqs (void)
{
gcov_type count_max, true_count_max = 0;
basic_block bb;
FOR_EACH_BB (bb)
true_count_max = MAX (bb->count, true_count_max);
count_max = MAX (true_count_max, 1);
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
bb->frequency = (bb->count * BB_FREQ_MAX + count_max / 2) / count_max;
return true_count_max;
}
bool
expensive_function_p (int threshold)
{
unsigned int sum = 0;
basic_block bb;
unsigned int limit;
if (threshold > BB_FREQ_MAX)
abort ();
if (ENTRY_BLOCK_PTR->frequency == 0)
return true;
limit = ENTRY_BLOCK_PTR->frequency * threshold;
FOR_EACH_BB (bb)
{
rtx insn;
for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
insn = NEXT_INSN (insn))
if (active_insn_p (insn))
{
sum += bb->frequency;
if (sum > limit)
return true;
}
}
return false;
}
static void
estimate_bb_frequencies (struct loops *loops)
{
basic_block bb;
sreal freq_max;
if (!flag_branch_probabilities || !counts_to_freqs ())
{
static int real_values_initialized = 0;
bitmap tovisit;
if (!real_values_initialized)
{
real_values_initialized = 1;
sreal_init (&real_zero, 0, 0);
sreal_init (&real_one, 1, 0);
sreal_init (&real_br_prob_base, REG_BR_PROB_BASE, 0);
sreal_init (&real_bb_freq_max, BB_FREQ_MAX, 0);
sreal_init (&real_one_half, 1, -1);
sreal_div (&real_inv_br_prob_base, &real_one, &real_br_prob_base);
sreal_sub (&real_almost_one, &real_one, &real_inv_br_prob_base);
}
mark_dfs_back_edges ();
EDGE_SUCC (ENTRY_BLOCK_PTR, 0)->probability = REG_BR_PROB_BASE;
tovisit = BITMAP_ALLOC (NULL);
alloc_aux_for_blocks (sizeof (struct block_info_def));
alloc_aux_for_edges (sizeof (struct edge_info_def));
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
{
edge e;
edge_iterator ei;
FOR_EACH_EDGE (e, ei, bb->succs)
{
sreal_init (&EDGE_INFO (e)->back_edge_prob, e->probability, 0);
sreal_mul (&EDGE_INFO (e)->back_edge_prob,
&EDGE_INFO (e)->back_edge_prob,
&real_inv_br_prob_base);
}
}
estimate_loops_at_level (loops->tree_root, tovisit);
memcpy (&freq_max, &real_zero, sizeof (real_zero));
FOR_EACH_BB (bb)
if (sreal_compare (&freq_max, &BLOCK_INFO (bb)->frequency) < 0)
memcpy (&freq_max, &BLOCK_INFO (bb)->frequency, sizeof (freq_max));
sreal_div (&freq_max, &real_bb_freq_max, &freq_max);
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
{
sreal tmp;
sreal_mul (&tmp, &BLOCK_INFO (bb)->frequency, &freq_max);
sreal_add (&tmp, &tmp, &real_one_half);
bb->frequency = sreal_to_int (&tmp);
}
free_aux_for_blocks ();
free_aux_for_edges ();
BITMAP_FREE (tovisit);
}
compute_function_frequency ();
if (flag_reorder_functions)
choose_function_section ();
}
static void
compute_function_frequency (void)
{
basic_block bb;
if (!profile_info || !flag_branch_probabilities)
return;
cfun->function_frequency = FUNCTION_FREQUENCY_UNLIKELY_EXECUTED;
FOR_EACH_BB (bb)
{
if (maybe_hot_bb_p (bb))
{
cfun->function_frequency = FUNCTION_FREQUENCY_HOT;
return;
}
if (!probably_never_executed_bb_p (bb))
cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
}
}
static void
choose_function_section (void)
{
if (DECL_SECTION_NAME (current_function_decl)
|| !targetm.have_named_sections
|| DECL_ONE_ONLY (current_function_decl))
return;
if (flag_reorder_blocks_and_partition)
return;
if (cfun->function_frequency == FUNCTION_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)
DECL_SECTION_NAME (current_function_decl) =
build_string (strlen (UNLIKELY_EXECUTED_TEXT_SECTION_NAME),
UNLIKELY_EXECUTED_TEXT_SECTION_NAME);
}
struct tree_opt_pass pass_profile =
{
"profile",
NULL,
tree_estimate_probability,
NULL,
NULL,
0,
TV_BRANCH_PROB,
PROP_cfg,
0,
0,
0,
TODO_ggc_collect | TODO_verify_ssa,
0
};