Commit bfdade77 by Richard Kenner Committed by Richard Kenner

* predict.c: Reformatting and minor cleanups.

From-SVN: r48269
parent 6c7d86ec
Sat Dec 22 08:59:50 2001 Richard Kenner <kenner@vlsi1.ultra.nyu.edu> Sat Dec 22 08:59:50 2001 Richard Kenner <kenner@vlsi1.ultra.nyu.edu>
* predict.c: Reformatting and minor cleanups.
* expr.c (expand_expr, case ADDR_EXPR): Handling taking address of * expr.c (expand_expr, case ADDR_EXPR): Handling taking address of
SAVE_EXPR. SAVE_EXPR.
* function.c (gen_mem_addressof): Add missing tests for SAVE_EXPR. * function.c (gen_mem_addressof): Add missing tests for SAVE_EXPR.
......
/* Branch prediction routines for the GNU compiler. /* Branch prediction routines for the GNU compiler.
Copyright (C) 2000, 2001 Free Software Foundation, Inc. Copyright (C) 2000, 2001 Free Software Foundation, Inc.
This file is part of GCC. This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it GCC is free software; you can redistribute it and/or modify it under
under the terms of the GNU General Public License as published by the terms of the GNU General Public License as published by the Free
the Free Software Foundation; either version 2, or (at your option) Software Foundation; either version 2, or (at your option) any later
any later version. version.
GCC is distributed in the hope that it will be useful, but WITHOUT GCC is distributed in the hope that it will be useful, but WITHOUT ANY
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY WARRANTY; without even the implied warranty of MERCHANTABILITY or
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
License for more details. for more details.
You should have received a copy of the GNU General Public License 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 along with GCC; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */ 02111-1307, USA. */
/* References: /* References:
...@@ -25,9 +25,7 @@ ...@@ -25,9 +25,7 @@
[2] "Static Branch Frequency and Program Profile Analysis" [2] "Static Branch Frequency and Program Profile Analysis"
Wu and Larus; MICRO-27. Wu and Larus; MICRO-27.
[3] "Corpus-based Static Branch Prediction" [3] "Corpus-based Static Branch Prediction"
Calder, Grunwald, Lindsay, Martin, Mozer, and Zorn; PLDI '95. Calder, Grunwald, Lindsay, Martin, Mozer, and Zorn; PLDI '95. */
*/
#include "config.h" #include "config.h"
...@@ -67,6 +65,7 @@ static void counts_to_freqs PARAMS ((void)); ...@@ -67,6 +65,7 @@ static void counts_to_freqs PARAMS ((void));
/* Information we hold about each branch predictor. /* Information we hold about each branch predictor.
Filled using information from predict.def. */ Filled using information from predict.def. */
struct predictor_info struct predictor_info
{ {
const char *const name; /* Name used in the debugging dumps. */ const char *const name; /* Name used in the debugging dumps. */
...@@ -81,10 +80,10 @@ struct predictor_info ...@@ -81,10 +80,10 @@ struct predictor_info
/* Recompute hitrate in percent to our representation. */ /* Recompute hitrate in percent to our representation. */
#define HITRATE(VAL) ((int)((VAL) * REG_BR_PROB_BASE + 50) / 100) #define HITRATE(VAL) ((int) ((VAL) * REG_BR_PROB_BASE + 50) / 100)
#define DEF_PREDICTOR(ENUM, NAME, HITRATE, FLAGS) {NAME, HITRATE, FLAGS}, #define DEF_PREDICTOR(ENUM, NAME, HITRATE, FLAGS) {NAME, HITRATE, FLAGS},
static const struct predictor_info predictor_info[] = { static const struct predictor_info predictor_info[]= {
#include "predict.def" #include "predict.def"
/* Upper bound on predictors. */ /* Upper bound on predictors. */
...@@ -100,6 +99,7 @@ predict_insn (insn, predictor, probability) ...@@ -100,6 +99,7 @@ predict_insn (insn, predictor, probability)
{ {
if (!any_condjump_p (insn)) if (!any_condjump_p (insn))
abort (); abort ();
REG_NOTES (insn) REG_NOTES (insn)
= gen_rtx_EXPR_LIST (REG_BR_PRED, = gen_rtx_EXPR_LIST (REG_BR_PRED,
gen_rtx_CONCAT (VOIDmode, gen_rtx_CONCAT (VOIDmode,
...@@ -109,6 +109,7 @@ predict_insn (insn, predictor, probability) ...@@ -109,6 +109,7 @@ predict_insn (insn, predictor, probability)
} }
/* Predict insn by given predictor. */ /* Predict insn by given predictor. */
void void
predict_insn_def (insn, predictor, taken) predict_insn_def (insn, predictor, taken)
rtx insn; rtx insn;
...@@ -116,12 +117,15 @@ predict_insn_def (insn, predictor, taken) ...@@ -116,12 +117,15 @@ predict_insn_def (insn, predictor, taken)
enum prediction taken; enum prediction taken;
{ {
int probability = predictor_info[(int) predictor].hitrate; int probability = predictor_info[(int) predictor].hitrate;
if (taken != TAKEN) if (taken != TAKEN)
probability = REG_BR_PROB_BASE - probability; probability = REG_BR_PROB_BASE - probability;
predict_insn (insn, predictor, probability); predict_insn (insn, predictor, probability);
} }
/* Predict edge E with given probability if possible. */ /* Predict edge E with given probability if possible. */
void void
predict_edge (e, predictor, probability) predict_edge (e, predictor, probability)
edge e; edge e;
...@@ -144,6 +148,7 @@ predict_edge (e, predictor, probability) ...@@ -144,6 +148,7 @@ predict_edge (e, predictor, probability)
} }
/* Predict edge E by given predictor if possible. */ /* Predict edge E by given predictor if possible. */
void void
predict_edge_def (e, predictor, taken) predict_edge_def (e, predictor, taken)
edge e; edge e;
...@@ -154,29 +159,29 @@ predict_edge_def (e, predictor, taken) ...@@ -154,29 +159,29 @@ predict_edge_def (e, predictor, taken)
if (taken != TAKEN) if (taken != TAKEN)
probability = REG_BR_PROB_BASE - probability; probability = REG_BR_PROB_BASE - probability;
predict_edge (e, predictor, probability); predict_edge (e, predictor, probability);
} }
/* Invert all branch predictions or probability notes in the INSN. This needs /* Invert all branch predictions or probability notes in the INSN. This needs
to be done each time we invert the condition used by the jump. */ to be done each time we invert the condition used by the jump. */
void void
invert_br_probabilities (insn) invert_br_probabilities (insn)
rtx insn; rtx insn;
{ {
rtx note = REG_NOTES (insn); rtx note;
while (note) for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
{ if (REG_NOTE_KIND (note) == REG_BR_PROB)
if (REG_NOTE_KIND (note) == REG_BR_PROB) XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0)));
XEXP (note, 0) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (note, 0))); else if (REG_NOTE_KIND (note) == REG_BR_PRED)
else if (REG_NOTE_KIND (note) == REG_BR_PRED) XEXP (XEXP (note, 0), 1)
XEXP (XEXP (note, 0), 1) = GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (XEXP (note, 0), 1)));
= GEN_INT (REG_BR_PROB_BASE - INTVAL (XEXP (XEXP (note, 0), 1)));
note = XEXP (note, 1);
}
} }
/* Dump information about the branch prediction to the output file. */ /* Dump information about the branch prediction to the output file. */
static void static void
dump_prediction (predictor, probability, bb, used) dump_prediction (predictor, probability, bb, used)
enum br_predictor predictor; enum br_predictor predictor;
...@@ -194,25 +199,23 @@ dump_prediction (predictor, probability, bb, used) ...@@ -194,25 +199,23 @@ dump_prediction (predictor, probability, bb, used)
fprintf (rtl_dump_file, " %s heuristics%s: %.1f%%", fprintf (rtl_dump_file, " %s heuristics%s: %.1f%%",
predictor_info[predictor].name, predictor_info[predictor].name,
used ? "" : " (ignored)", used ? "" : " (ignored)", probability * 100.0 / REG_BR_PROB_BASE);
probability * 100.0 / REG_BR_PROB_BASE);
if (bb->count) if (bb->count)
{ {
fprintf (rtl_dump_file, " exec "); fprintf (rtl_dump_file, " exec ");
fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC, fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC, bb->count);
(HOST_WIDEST_INT) bb->count);
fprintf (rtl_dump_file, " hit "); fprintf (rtl_dump_file, " hit ");
fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC, fprintf (rtl_dump_file, HOST_WIDEST_INT_PRINT_DEC, e->count);
(HOST_WIDEST_INT) e->count); fprintf (rtl_dump_file, " (%.1f%%)", e->count * 100.0 / bb->count);
fprintf (rtl_dump_file, " (%.1f%%)",
e->count * 100.0 / bb->count);
} }
fprintf (rtl_dump_file, "\n"); fprintf (rtl_dump_file, "\n");
} }
/* Combine all REG_BR_PRED notes into single probability and attach REG_BR_PROB /* Combine all REG_BR_PRED notes into single probability and attach REG_BR_PROB
note if not already present. Remove now useless REG_BR_PRED notes. */ note if not already present. Remove now useless REG_BR_PRED notes. */
static void static void
combine_predictions_for_insn (insn, bb) combine_predictions_for_insn (insn, bb)
rtx insn; rtx insn;
...@@ -220,7 +223,7 @@ combine_predictions_for_insn (insn, bb) ...@@ -220,7 +223,7 @@ combine_predictions_for_insn (insn, bb)
{ {
rtx prob_note = find_reg_note (insn, REG_BR_PROB, 0); rtx prob_note = find_reg_note (insn, REG_BR_PROB, 0);
rtx *pnote = &REG_NOTES (insn); rtx *pnote = &REG_NOTES (insn);
rtx note = REG_NOTES (insn); rtx note;
int best_probability = PROB_EVEN; int best_probability = PROB_EVEN;
int best_predictor = END_PREDICTORS; int best_predictor = END_PREDICTORS;
int combined_probability = REG_BR_PROB_BASE / 2; int combined_probability = REG_BR_PROB_BASE / 2;
...@@ -235,29 +238,27 @@ combine_predictions_for_insn (insn, bb) ...@@ -235,29 +238,27 @@ combine_predictions_for_insn (insn, bb)
/* We implement "first match" heuristics and use probability guessed /* We implement "first match" heuristics and use probability guessed
by predictor with smallest index. In the future we will use better by predictor with smallest index. In the future we will use better
probability combination techniques. */ probability combination techniques. */
while (note) for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
{ if (REG_NOTE_KIND (note) == REG_BR_PRED)
if (REG_NOTE_KIND (note) == REG_BR_PRED) {
{ int predictor = INTVAL (XEXP (XEXP (note, 0), 0));
int predictor = INTVAL (XEXP (XEXP (note, 0), 0)); int probability = INTVAL (XEXP (XEXP (note, 0), 1));
int probability = INTVAL (XEXP (XEXP (note, 0), 1));
found = true;
found = true; if (best_predictor > predictor)
if (best_predictor > predictor) best_probability = probability, best_predictor = predictor;
best_probability = probability, best_predictor = predictor;
d = (combined_probability * probability
d = (combined_probability * probability + (REG_BR_PROB_BASE - combined_probability)
+ (REG_BR_PROB_BASE - combined_probability) * (REG_BR_PROB_BASE - probability));
* (REG_BR_PROB_BASE - probability));
/* An FP math to avoid overflows of 32bit integers. */ /* Use FP math to avoid overflows of 32bit integers. */
combined_probability = (((double)combined_probability) * probability combined_probability = (((double) combined_probability) * probability
* REG_BR_PROB_BASE / d + 0.5); * REG_BR_PROB_BASE / d + 0.5);
} }
note = XEXP (note, 1);
} /* Decide which heuristic to use. In case we didn't match anything,
use no_prediction heuristic, in case we did match, use either
/* Decide heuristic to use. In case we didn't match anything, use
no_prediction heuristic, in case we did match, use either
first match or Dempster-Shaffer theory depending on the flags. */ first match or Dempster-Shaffer theory depending on the flags. */
if (predictor_info [best_predictor].flags & PRED_FLAG_FIRST_MATCH) if (predictor_info [best_predictor].flags & PRED_FLAG_FIRST_MATCH)
...@@ -267,8 +268,7 @@ combine_predictions_for_insn (insn, bb) ...@@ -267,8 +268,7 @@ combine_predictions_for_insn (insn, bb)
dump_prediction (PRED_NO_PREDICTION, combined_probability, bb, true); dump_prediction (PRED_NO_PREDICTION, combined_probability, bb, true);
else else
{ {
dump_prediction (PRED_DS_THEORY, combined_probability, bb, dump_prediction (PRED_DS_THEORY, combined_probability, bb, !first_match);
!first_match);
dump_prediction (PRED_FIRST_MATCH, best_probability, bb, first_match); dump_prediction (PRED_FIRST_MATCH, best_probability, bb, first_match);
} }
...@@ -290,17 +290,20 @@ combine_predictions_for_insn (insn, bb) ...@@ -290,17 +290,20 @@ combine_predictions_for_insn (insn, bb)
else else
pnote = &XEXP (*pnote, 1); pnote = &XEXP (*pnote, 1);
} }
if (!prob_note) if (!prob_note)
{ {
REG_NOTES (insn) REG_NOTES (insn)
= gen_rtx_EXPR_LIST (REG_BR_PROB, = gen_rtx_EXPR_LIST (REG_BR_PROB,
GEN_INT (combined_probability), REG_NOTES (insn)); GEN_INT (combined_probability), REG_NOTES (insn));
/* Save the prediction into CFG in case we are seeing non-degenerated /* Save the prediction into CFG in case we are seeing non-degenerated
conditional jump. */ conditional jump. */
if (bb->succ->succ_next) if (bb->succ->succ_next)
{ {
BRANCH_EDGE (bb)->probability = combined_probability; BRANCH_EDGE (bb)->probability = combined_probability;
FALLTHRU_EDGE (bb)->probability = REG_BR_PROB_BASE - combined_probability; FALLTHRU_EDGE (bb)->probability
= REG_BR_PROB_BASE - combined_probability;
} }
} }
} }
...@@ -335,37 +338,34 @@ estimate_probability (loops_info) ...@@ -335,37 +338,34 @@ estimate_probability (loops_info)
flow_loop_scan (loops_info, loop, LOOP_EXIT_EDGES); flow_loop_scan (loops_info, loop, LOOP_EXIT_EDGES);
exits = loop->num_exits; exits = loop->num_exits;
for (j = loop->first->index; for (j = loop->first->index; j <= loop->last->index; ++j)
j <= loop->last->index; if (TEST_BIT (loop->nodes, j))
++j) {
{ int header_found = 0;
if (TEST_BIT (loop->nodes, j)) edge e;
{
int header_found = 0; /* Loop branch heuristics - predict an edge back to a
edge e; loop's head as taken. */
for (e = BASIC_BLOCK(j)->succ; e; e = e->succ_next)
/* Loop branch heuristics - predict as taken an edge back to if (e->dest == loop->header
a loop's head. */ && e->src == loop->latch)
{
header_found = 1;
predict_edge_def (e, PRED_LOOP_BRANCH, TAKEN);
}
/* Loop exit heuristics - predict an edge exiting the loop if the
conditinal has no loop header successors as not taken. */
if (!header_found)
for (e = BASIC_BLOCK(j)->succ; e; e = e->succ_next) for (e = BASIC_BLOCK(j)->succ; e; e = e->succ_next)
if (e->dest == loop->header if (e->dest->index < 0
&& e->src == loop->latch) || !TEST_BIT (loop->nodes, e->dest->index))
{ predict_edge
header_found = 1; (e, PRED_LOOP_EXIT,
predict_edge_def (e, PRED_LOOP_BRANCH, TAKEN); (REG_BR_PROB_BASE
} - predictor_info [(int)PRED_LOOP_EXIT].hitrate)
/* Loop exit heuristics - predict as not taken an edge / exits);
exiting the loop if the conditinal has no loop header }
successors. */
if (!header_found)
for (e = BASIC_BLOCK(j)->succ; e; e = e->succ_next)
if (e->dest->index < 0
|| !TEST_BIT (loop->nodes, e->dest->index))
predict_edge (e, PRED_LOOP_EXIT,
(REG_BR_PROB_BASE
- predictor_info [(int)PRED_LOOP_EXIT].hitrate)
/ exits);
}
}
} }
/* Attempt to predict conditional jumps using a number of heuristics. */ /* Attempt to predict conditional jumps using a number of heuristics. */
...@@ -376,30 +376,27 @@ estimate_probability (loops_info) ...@@ -376,30 +376,27 @@ estimate_probability (loops_info)
rtx cond, earliest; rtx cond, earliest;
edge e; edge e;
/* If block has no successor, predict all possible paths to /* If block has no successor, predict all possible paths to it as
it as improbable, as the block contains a call to a noreturn improbable, as the block contains a call to a noreturn function and
function and thus can be executed only once. */ thus can be executed only once. */
if (bb->succ == NULL && !found_noreturn) if (bb->succ == NULL && !found_noreturn)
{ {
int y; int y;
/* ??? Postdominator claims each noreturn block to be postdominated /* ??? Postdominator claims each noreturn block to be postdominated
by each, so we need to run only once. This needs to be changed by each, so we need to run only once. This needs to be changed
once postdominace algorithm is updated to say something more sane. once postdominace algorithm is updated to say something more
*/ sane. */
found_noreturn = 1; found_noreturn = 1;
for (y = 0; y < n_basic_blocks; y++) for (y = 0; y < n_basic_blocks; y++)
if (!TEST_BIT (post_dominators[y], i)) if (!TEST_BIT (post_dominators[y], i))
{ for (e = BASIC_BLOCK (y)->succ; e; e = e->succ_next)
for (e = BASIC_BLOCK (y)->succ; e; e = e->succ_next)
if (e->dest->index >= 0 if (e->dest->index >= 0
&& TEST_BIT (post_dominators[e->dest->index], i)) && TEST_BIT (post_dominators[e->dest->index], i))
predict_edge_def (e, PRED_NORETURN, NOT_TAKEN); predict_edge_def (e, PRED_NORETURN, NOT_TAKEN);
}
} }
if (GET_CODE (last_insn) != JUMP_INSN if (GET_CODE (last_insn) != JUMP_INSN || ! any_condjump_p (last_insn))
|| ! any_condjump_p (last_insn))
continue; continue;
for (e = bb->succ; e; e = e->succ_next) for (e = bb->succ; e; e = e->succ_next)
...@@ -413,12 +410,12 @@ estimate_probability (loops_info) ...@@ -413,12 +410,12 @@ estimate_probability (loops_info)
/* Look for block we are guarding (ie we dominate it, /* Look for block we are guarding (ie we dominate it,
but it doesn't postdominate us). */ but it doesn't postdominate us). */
if (e->dest != EXIT_BLOCK_PTR if (e->dest != EXIT_BLOCK_PTR && e->dest != bb
&& e->dest != bb
&& TEST_BIT (dominators[e->dest->index], e->src->index) && TEST_BIT (dominators[e->dest->index], e->src->index)
&& !TEST_BIT (post_dominators[e->src->index], e->dest->index)) && !TEST_BIT (post_dominators[e->src->index], e->dest->index))
{ {
rtx insn; rtx insn;
/* The call heuristic claims that a guarded function call /* The call heuristic claims that a guarded function call
is improbable. This is because such calls are often used is improbable. This is because such calls are often used
to signal exceptional situations such as printing error to signal exceptional situations such as printing error
...@@ -446,18 +443,14 @@ estimate_probability (loops_info) ...@@ -446,18 +443,14 @@ estimate_probability (loops_info)
if (GET_RTX_CLASS (GET_CODE (cond)) == '<' if (GET_RTX_CLASS (GET_CODE (cond)) == '<'
&& ((REG_P (XEXP (cond, 0)) && REG_POINTER (XEXP (cond, 0))) && ((REG_P (XEXP (cond, 0)) && REG_POINTER (XEXP (cond, 0)))
|| (REG_P (XEXP (cond, 1)) && REG_POINTER (XEXP (cond, 1))))) || (REG_P (XEXP (cond, 1)) && REG_POINTER (XEXP (cond, 1)))))
switch (GET_CODE (cond)) {
{ if (GET_CODE (cond) == EQ)
case EQ:
predict_insn_def (last_insn, PRED_POINTER, NOT_TAKEN); predict_insn_def (last_insn, PRED_POINTER, NOT_TAKEN);
break; else if (GET_CODE (cond) == NE)
case NE:
predict_insn_def (last_insn, PRED_POINTER, TAKEN); predict_insn_def (last_insn, PRED_POINTER, TAKEN);
break; }
default:
break;
}
else else
/* Try "opcode heuristic." /* Try "opcode heuristic."
EQ tests are usually false and NE tests are usually true. Also, EQ tests are usually false and NE tests are usually true. Also,
most quantities are positive, so we can make the appropriate guesses most quantities are positive, so we can make the appropriate guesses
...@@ -479,11 +472,13 @@ estimate_probability (loops_info) ...@@ -479,11 +472,13 @@ estimate_probability (loops_info)
; ;
/* Comparisons with 0 are often used for booleans and there is /* Comparisons with 0 are often used for booleans and there is
nothing usefull to predict about them. */ nothing usefull to predict about them. */
else if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 0) == const0_rtx) else if (XEXP (cond, 1) == const0_rtx
|| XEXP (cond, 0) == const0_rtx)
; ;
else else
predict_insn_def (last_insn, PRED_OPCODE_NONEQUAL, NOT_TAKEN); predict_insn_def (last_insn, PRED_OPCODE_NONEQUAL, NOT_TAKEN);
break; break;
case NE: case NE:
case LTGT: case LTGT:
/* Floating point comparisons appears to behave in a very /* Floating point comparisons appears to behave in a very
...@@ -493,23 +488,28 @@ estimate_probability (loops_info) ...@@ -493,23 +488,28 @@ estimate_probability (loops_info)
; ;
/* Comparisons with 0 are often used for booleans and there is /* Comparisons with 0 are often used for booleans and there is
nothing usefull to predict about them. */ nothing usefull to predict about them. */
else if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 0) == const0_rtx) else if (XEXP (cond, 1) == const0_rtx
|| XEXP (cond, 0) == const0_rtx)
; ;
else else
predict_insn_def (last_insn, PRED_OPCODE_NONEQUAL, TAKEN); predict_insn_def (last_insn, PRED_OPCODE_NONEQUAL, TAKEN);
break; break;
case ORDERED: case ORDERED:
predict_insn_def (last_insn, PRED_FPOPCODE, TAKEN); predict_insn_def (last_insn, PRED_FPOPCODE, TAKEN);
break; break;
case UNORDERED: case UNORDERED:
predict_insn_def (last_insn, PRED_FPOPCODE, NOT_TAKEN); predict_insn_def (last_insn, PRED_FPOPCODE, NOT_TAKEN);
break; break;
case LE: case LE:
case LT: case LT:
if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 1) == const1_rtx if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 1) == const1_rtx
|| XEXP (cond, 1) == constm1_rtx) || XEXP (cond, 1) == constm1_rtx)
predict_insn_def (last_insn, PRED_OPCODE_POSITIVE, NOT_TAKEN); predict_insn_def (last_insn, PRED_OPCODE_POSITIVE, NOT_TAKEN);
break; break;
case GE: case GE:
case GT: case GT:
if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 1) == const1_rtx if (XEXP (cond, 1) == const0_rtx || XEXP (cond, 1) == const1_rtx
...@@ -524,23 +524,19 @@ estimate_probability (loops_info) ...@@ -524,23 +524,19 @@ estimate_probability (loops_info)
/* Attach the combined probability to each conditional jump. */ /* Attach the combined probability to each conditional jump. */
for (i = 0; i < n_basic_blocks; i++) for (i = 0; i < n_basic_blocks; i++)
{ if (GET_CODE (BLOCK_END (i)) == JUMP_INSN
rtx last_insn = BLOCK_END (i); && any_condjump_p (BLOCK_END (i)))
combine_predictions_for_insn (BLOCK_END (i), BASIC_BLOCK (i));
if (GET_CODE (last_insn) != JUMP_INSN
|| ! any_condjump_p (last_insn))
continue;
combine_predictions_for_insn (last_insn, BASIC_BLOCK (i));
}
sbitmap_vector_free (post_dominators); sbitmap_vector_free (post_dominators);
sbitmap_vector_free (dominators); sbitmap_vector_free (dominators);
estimate_bb_frequencies (loops_info); estimate_bb_frequencies (loops_info);
} }
/* __builtin_expect dropped tokens into the insn stream describing /* __builtin_expect dropped tokens into the insn stream describing expected
expected values of registers. Generate branch probabilities values of registers. Generate branch probabilities based off these
based off these values. */ values. */
void void
expected_value_to_br_prob () expected_value_to_br_prob ()
...@@ -566,20 +562,19 @@ expected_value_to_br_prob () ...@@ -566,20 +562,19 @@ expected_value_to_br_prob ()
ev = NULL_RTX; ev = NULL_RTX;
continue; continue;
default:
/* Look for insns that clobber the EV register. */
if (ev && reg_set_p (ev_reg, insn))
ev = NULL_RTX;
continue;
case JUMP_INSN: case JUMP_INSN:
/* Look for simple conditional branches. If we haven't got an /* Look for simple conditional branches. If we haven't got an
expected value yet, no point going further. */ expected value yet, no point going further. */
if (GET_CODE (insn) != JUMP_INSN || ev == NULL_RTX) if (GET_CODE (insn) != JUMP_INSN || ev == NULL_RTX
continue; || ! any_condjump_p (insn))
if (! any_condjump_p (insn))
continue; continue;
break; break;
default:
/* Look for insns that clobber the EV register. */
if (ev && reg_set_p (ev_reg, insn))
ev = NULL_RTX;
continue;
} }
/* Collect the branch condition, hopefully relative to EV_REG. */ /* Collect the branch condition, hopefully relative to EV_REG. */
...@@ -593,8 +588,7 @@ expected_value_to_br_prob () ...@@ -593,8 +588,7 @@ expected_value_to_br_prob ()
Could use cselib to try and reduce this further. */ Could use cselib to try and reduce this further. */
cond = XEXP (SET_SRC (pc_set (insn)), 0); cond = XEXP (SET_SRC (pc_set (insn)), 0);
cond = canonicalize_condition (insn, cond, 0, NULL, ev_reg); cond = canonicalize_condition (insn, cond, 0, NULL, ev_reg);
if (! cond if (! cond || XEXP (cond, 0) != ev_reg
|| XEXP (cond, 0) != ev_reg
|| GET_CODE (XEXP (cond, 1)) != CONST_INT) || GET_CODE (XEXP (cond, 1)) != CONST_INT)
continue; continue;
...@@ -650,6 +644,7 @@ typedef struct edge_info_def ...@@ -650,6 +644,7 @@ typedef struct edge_info_def
/* Helper function for estimate_bb_frequencies. /* Helper function for estimate_bb_frequencies.
Propagate the frequencies for loops headed by HEAD. */ Propagate the frequencies for loops headed by HEAD. */
static void static void
propagate_freq (head) propagate_freq (head)
basic_block head; basic_block head;
...@@ -668,6 +663,7 @@ propagate_freq (head) ...@@ -668,6 +663,7 @@ propagate_freq (head)
if (BLOCK_INFO (bb)->tovisit) if (BLOCK_INFO (bb)->tovisit)
{ {
int count = 0; int count = 0;
for (e = bb->pred; e; e = e->pred_next) for (e = bb->pred; e; e = e->pred_next)
if (BLOCK_INFO (e->src)->tovisit && !(e->flags & EDGE_DFS_BACK)) if (BLOCK_INFO (e->src)->tovisit && !(e->flags & EDGE_DFS_BACK))
count++; count++;
...@@ -683,7 +679,7 @@ propagate_freq (head) ...@@ -683,7 +679,7 @@ propagate_freq (head)
BLOCK_INFO (head)->frequency = 1; BLOCK_INFO (head)->frequency = 1;
for (; bb; bb = nextbb) for (; bb; bb = nextbb)
{ {
volatile double cyclic_probability = 0, frequency = 0; double cyclic_probability = 0, frequency = 0;
nextbb = BLOCK_INFO (bb)->next; nextbb = BLOCK_INFO (bb)->next;
BLOCK_INFO (bb)->next = NULL; BLOCK_INFO (bb)->next = NULL;
...@@ -716,9 +712,9 @@ propagate_freq (head) ...@@ -716,9 +712,9 @@ propagate_freq (head)
/* Compute back edge frequencies. */ /* Compute back edge frequencies. */
for (e = bb->succ; e; e = e->succ_next) for (e = bb->succ; e; e = e->succ_next)
if (e->dest == head) if (e->dest == head)
EDGE_INFO (e)->back_edge_prob = (e->probability EDGE_INFO (e)->back_edge_prob
* BLOCK_INFO (bb)->frequency = ((e->probability * BLOCK_INFO (bb)->frequency)
/ REG_BR_PROB_BASE); / REG_BR_PROB_BASE);
/* Propagate to successor blocks. */ /* Propagate to successor blocks. */
for (e = bb->succ; e; e = e->succ_next) for (e = bb->succ; e; e = e->succ_next)
...@@ -732,6 +728,7 @@ propagate_freq (head) ...@@ -732,6 +728,7 @@ propagate_freq (head)
nextbb = e->dest; nextbb = e->dest;
else else
BLOCK_INFO (last)->next = e->dest; BLOCK_INFO (last)->next = e->dest;
last = e->dest; last = e->dest;
} }
} }
...@@ -739,6 +736,7 @@ propagate_freq (head) ...@@ -739,6 +736,7 @@ propagate_freq (head)
} }
/* Estimate probabilities of loopback edges in loops at same nest level. */ /* Estimate probabilities of loopback edges in loops at same nest level. */
static void static void
estimate_loops_at_level (first_loop) estimate_loops_at_level (first_loop)
struct loop *first_loop; struct loop *first_loop;
...@@ -753,7 +751,8 @@ estimate_loops_at_level (first_loop) ...@@ -753,7 +751,8 @@ estimate_loops_at_level (first_loop)
estimate_loops_at_level (loop->inner); estimate_loops_at_level (loop->inner);
/* Find current loop back edge and mark it. */ /* Find current loop back edge and mark it. */
for (e = loop->latch->succ; e->dest != loop->header; e = e->succ_next); for (e = loop->latch->succ; e->dest != loop->header; e = e->succ_next)
;
EDGE_INFO (e)->back_edge = 1; EDGE_INFO (e)->back_edge = 1;
...@@ -764,6 +763,7 @@ estimate_loops_at_level (first_loop) ...@@ -764,6 +763,7 @@ estimate_loops_at_level (first_loop)
for (l = loop->next; l; l = l->next) for (l = loop->next; l; l = l->next)
if (l->header == loop->header) if (l->header == loop->header)
break; break;
if (l) if (l)
continue; continue;
} }
...@@ -774,11 +774,13 @@ estimate_loops_at_level (first_loop) ...@@ -774,11 +774,13 @@ estimate_loops_at_level (first_loop)
EXECUTE_IF_SET_IN_SBITMAP (l->nodes, 0, n, EXECUTE_IF_SET_IN_SBITMAP (l->nodes, 0, n,
BLOCK_INFO (BASIC_BLOCK (n))->tovisit = 1 BLOCK_INFO (BASIC_BLOCK (n))->tovisit = 1
); );
propagate_freq (loop->header); propagate_freq (loop->header);
} }
} }
/* Convert counts measured by profile driven feedback to frequencies. */ /* Convert counts measured by profile driven feedback to frequencies. */
static void static void
counts_to_freqs () counts_to_freqs ()
{ {
...@@ -786,28 +788,28 @@ counts_to_freqs () ...@@ -786,28 +788,28 @@ counts_to_freqs ()
int i; int i;
for (i = 0; i < n_basic_blocks; i++) for (i = 0; i < n_basic_blocks; i++)
if (BASIC_BLOCK (i)->count > count_max) count_max = MAX (BASIC_BLOCK (i)->count, count_max);
count_max = BASIC_BLOCK (i)->count;
for (i = -2; i < n_basic_blocks; i++) for (i = -2; i < n_basic_blocks; i++)
{ {
basic_block bb; basic_block bb;
if (i == -2) if (i == -2)
bb = ENTRY_BLOCK_PTR; bb = ENTRY_BLOCK_PTR;
else if (i == -1) else if (i == -1)
bb = EXIT_BLOCK_PTR; bb = EXIT_BLOCK_PTR;
else else
bb = BASIC_BLOCK (i); bb = BASIC_BLOCK (i);
bb->frequency = ((bb->count * BB_FREQ_MAX + count_max / 2)
/ count_max); bb->frequency = (bb->count * BB_FREQ_MAX + count_max / 2) / count_max;
} }
} }
/* Return true if function is likely to be expensive, so there is no point /* Return true if function is likely to be expensive, so there is no point to
to optimizer performance of prologue, epilogue or do inlining at the optimize performance of prologue, epilogue or do inlining at the expense
expense of code size growth. THRESHOLD is the limit of number of code size growth. THRESHOLD is the limit of number of isntructions
of isntructions function can execute at average to be still considered function can execute at average to be still considered not expensive. */
not expensive. */
bool bool
expensive_function_p (threshold) expensive_function_p (threshold)
int threshold; int threshold;
...@@ -836,19 +838,19 @@ expensive_function_p (threshold) ...@@ -836,19 +838,19 @@ expensive_function_p (threshold)
for (insn = bb->head; insn != NEXT_INSN (bb->end); for (insn = bb->head; insn != NEXT_INSN (bb->end);
insn = NEXT_INSN (insn)) insn = NEXT_INSN (insn))
{ if (active_insn_p (insn))
if (active_insn_p (insn)) {
{ sum += bb->frequency;
sum += bb->frequency; if (sum > limit)
if (sum > limit) return true;
return true;
}
} }
} }
return false; return false;
} }
/* Estimate basic blocks frequency by given branch probabilities. */ /* Estimate basic blocks frequency by given branch probabilities. */
static void static void
estimate_bb_frequencies (loops) estimate_bb_frequencies (loops)
struct loops *loops; struct loops *loops;
...@@ -906,6 +908,7 @@ estimate_bb_frequencies (loops) ...@@ -906,6 +908,7 @@ estimate_bb_frequencies (loops)
fallthru->probability = REG_BR_PROB_BASE - probability; fallthru->probability = REG_BR_PROB_BASE - probability;
} }
} }
ENTRY_BLOCK_PTR->succ->probability = REG_BR_PROB_BASE; ENTRY_BLOCK_PTR->succ->probability = REG_BR_PROB_BASE;
/* Set up block info for each basic block. */ /* Set up block info for each basic block. */
...@@ -922,11 +925,13 @@ estimate_bb_frequencies (loops) ...@@ -922,11 +925,13 @@ estimate_bb_frequencies (loops)
bb = EXIT_BLOCK_PTR; bb = EXIT_BLOCK_PTR;
else else
bb = BASIC_BLOCK (i); bb = BASIC_BLOCK (i);
BLOCK_INFO (bb)->tovisit = 0; BLOCK_INFO (bb)->tovisit = 0;
for (e = bb->succ; e; e = e->succ_next) for (e = bb->succ; e; e = e->succ_next)
EDGE_INFO (e)->back_edge_prob = ((double) e->probability EDGE_INFO (e)->back_edge_prob = ((double) e->probability
/ REG_BR_PROB_BASE); / REG_BR_PROB_BASE);
} }
/* First compute probabilities locally for each loop from innermost /* First compute probabilities locally for each loop from innermost
to outermost to examine probabilities for back edges. */ to outermost to examine probabilities for back edges. */
estimate_loops_at_level (loops->tree_root); estimate_loops_at_level (loops->tree_root);
...@@ -934,6 +939,7 @@ estimate_bb_frequencies (loops) ...@@ -934,6 +939,7 @@ estimate_bb_frequencies (loops)
/* Now fake loop around whole function to finalize probabilities. */ /* Now fake loop around whole function to finalize probabilities. */
for (i = 0; i < n_basic_blocks; i++) for (i = 0; i < n_basic_blocks; i++)
BLOCK_INFO (BASIC_BLOCK (i))->tovisit = 1; BLOCK_INFO (BASIC_BLOCK (i))->tovisit = 1;
BLOCK_INFO (ENTRY_BLOCK_PTR)->tovisit = 1; BLOCK_INFO (ENTRY_BLOCK_PTR)->tovisit = 1;
BLOCK_INFO (EXIT_BLOCK_PTR)->tovisit = 1; BLOCK_INFO (EXIT_BLOCK_PTR)->tovisit = 1;
propagate_freq (ENTRY_BLOCK_PTR); propagate_freq (ENTRY_BLOCK_PTR);
...@@ -941,17 +947,19 @@ estimate_bb_frequencies (loops) ...@@ -941,17 +947,19 @@ estimate_bb_frequencies (loops)
for (i = 0; i < n_basic_blocks; i++) for (i = 0; i < n_basic_blocks; i++)
if (BLOCK_INFO (BASIC_BLOCK (i))->frequency > freq_max) if (BLOCK_INFO (BASIC_BLOCK (i))->frequency > freq_max)
freq_max = BLOCK_INFO (BASIC_BLOCK (i))->frequency; freq_max = BLOCK_INFO (BASIC_BLOCK (i))->frequency;
for (i = -2; i < n_basic_blocks; i++) for (i = -2; i < n_basic_blocks; i++)
{ {
basic_block bb; basic_block bb;
if (i == -2) if (i == -2)
bb = ENTRY_BLOCK_PTR; bb = ENTRY_BLOCK_PTR;
else if (i == -1) else if (i == -1)
bb = EXIT_BLOCK_PTR; bb = EXIT_BLOCK_PTR;
else else
bb = BASIC_BLOCK (i); bb = BASIC_BLOCK (i);
bb->frequency = (BLOCK_INFO (bb)->frequency * BB_FREQ_MAX / freq_max bb->frequency
+ 0.5); = BLOCK_INFO (bb)->frequency * BB_FREQ_MAX / freq_max + 0.5;
} }
free_aux_for_blocks (); free_aux_for_blocks ();
......
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