#include "config.h"
#include "system.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "timevar.h"
#include "output.h"
#include "insn-config.h"
#include "flags.h"
#include "recog.h"
#include "toplev.h"
#include "cselib.h"
#include "tm_p.h"
#include "target.h"
enum bb_flags
{
BB_FORWARDER_BLOCK = 1,
BB_NONTHREADABLE_BLOCK = 2
};
#define BB_FLAGS(BB) (enum bb_flags) (BB)->aux
#define BB_SET_FLAG(BB, FLAG) \
(BB)->aux = (void *) (long) ((enum bb_flags) (BB)->aux | (FLAG))
#define BB_CLEAR_FLAG(BB, FLAG) \
(BB)->aux = (void *) (long) ((enum bb_flags) (BB)->aux & ~(FLAG))
#define FORWARDER_BLOCK_P(BB) (BB_FLAGS (BB) & BB_FORWARDER_BLOCK)
static bool try_crossjump_to_edge PARAMS ((int, edge, edge));
static bool try_crossjump_bb PARAMS ((int, basic_block));
static bool outgoing_edges_match PARAMS ((int,
basic_block, basic_block));
static int flow_find_cross_jump PARAMS ((int, basic_block, basic_block,
rtx *, rtx *));
static bool insns_match_p PARAMS ((int, rtx, rtx));
static bool label_is_jump_target_p PARAMS ((rtx, rtx));
static bool tail_recursion_label_p PARAMS ((rtx));
static void merge_blocks_move_predecessor_nojumps PARAMS ((basic_block,
basic_block));
static void merge_blocks_move_successor_nojumps PARAMS ((basic_block,
basic_block));
static bool merge_blocks PARAMS ((edge,basic_block,basic_block,
int));
static bool try_optimize_cfg PARAMS ((int));
static bool try_simplify_condjump PARAMS ((basic_block));
static bool try_forward_edges PARAMS ((int, basic_block));
static edge thread_jump PARAMS ((int, edge, basic_block));
static bool mark_effect PARAMS ((rtx, bitmap));
static void notice_new_block PARAMS ((basic_block));
static void update_forwarder_flag PARAMS ((basic_block));
static int mentions_nonequal_regs PARAMS ((rtx *, void *));
static bool has_dont_shorten_note PARAMS ((basic_block));
static void
notice_new_block (bb)
basic_block bb;
{
if (!bb)
return;
if (forwarder_block_p (bb))
BB_SET_FLAG (bb, BB_FORWARDER_BLOCK);
}
static void
update_forwarder_flag (bb)
basic_block bb;
{
if (forwarder_block_p (bb))
BB_SET_FLAG (bb, BB_FORWARDER_BLOCK);
else
BB_CLEAR_FLAG (bb, BB_FORWARDER_BLOCK);
}
static bool
try_simplify_condjump (cbranch_block)
basic_block cbranch_block;
{
basic_block jump_block, jump_dest_block, cbranch_dest_block;
edge cbranch_jump_edge, cbranch_fallthru_edge;
rtx cbranch_insn;
if (has_dont_shorten_note (cbranch_block))
return false;
if (!cbranch_block->succ
|| !cbranch_block->succ->succ_next
|| cbranch_block->succ->succ_next->succ_next)
return false;
cbranch_insn = cbranch_block->end;
if (!any_condjump_p (cbranch_insn))
return false;
cbranch_fallthru_edge = FALLTHRU_EDGE (cbranch_block);
cbranch_jump_edge = BRANCH_EDGE (cbranch_block);
jump_block = cbranch_fallthru_edge->dest;
if (jump_block->pred->pred_next
|| jump_block->next_bb == EXIT_BLOCK_PTR
|| !FORWARDER_BLOCK_P (jump_block))
return false;
jump_dest_block = jump_block->succ->dest;
cbranch_dest_block = cbranch_jump_edge->dest;
if (!can_fallthru (jump_block, cbranch_dest_block))
return false;
if (!invert_jump (cbranch_insn, block_label (jump_dest_block), 0))
return false;
if (rtl_dump_file)
fprintf (rtl_dump_file, "Simplifying condjump %i around jump %i\n",
INSN_UID (cbranch_insn), INSN_UID (jump_block->end));
cbranch_jump_edge = redirect_edge_succ_nodup (cbranch_jump_edge,
cbranch_dest_block);
cbranch_fallthru_edge = redirect_edge_succ_nodup (cbranch_fallthru_edge,
jump_dest_block);
cbranch_jump_edge->flags |= EDGE_FALLTHRU;
cbranch_fallthru_edge->flags &= ~EDGE_FALLTHRU;
update_br_prob_note (cbranch_block);
flow_delete_block (jump_block);
tidy_fallthru_edge (cbranch_jump_edge, cbranch_block, cbranch_dest_block);
return true;
}
static bool
mark_effect (exp, nonequal)
rtx exp;
regset nonequal;
{
int regno;
rtx dest;
switch (GET_CODE (exp))
{
case CLOBBER:
if (REG_P (XEXP (exp, 0)))
{
dest = XEXP (exp, 0);
regno = REGNO (dest);
CLEAR_REGNO_REG_SET (nonequal, regno);
if (regno < FIRST_PSEUDO_REGISTER)
{
int n = HARD_REGNO_NREGS (regno, GET_MODE (dest));
while (--n > 0)
CLEAR_REGNO_REG_SET (nonequal, regno + n);
}
}
return false;
case SET:
if (rtx_equal_for_cselib_p (SET_DEST (exp), SET_SRC (exp)))
return false;
dest = SET_DEST (exp);
if (dest == pc_rtx)
return false;
if (!REG_P (dest))
return true;
regno = REGNO (dest);
SET_REGNO_REG_SET (nonequal, regno);
if (regno < FIRST_PSEUDO_REGISTER)
{
int n = HARD_REGNO_NREGS (regno, GET_MODE (dest));
while (--n > 0)
SET_REGNO_REG_SET (nonequal, regno + n);
}
return false;
default:
return false;
}
}
static int
mentions_nonequal_regs (x, data)
rtx *x;
void *data;
{
regset nonequal = (regset) data;
if (REG_P (*x))
{
int regno;
regno = REGNO (*x);
if (REGNO_REG_SET_P (nonequal, regno))
return 1;
if (regno < FIRST_PSEUDO_REGISTER)
{
int n = HARD_REGNO_NREGS (regno, GET_MODE (*x));
while (--n > 0)
if (REGNO_REG_SET_P (nonequal, regno + n))
return 1;
}
}
return 0;
}
static edge
thread_jump (mode, e, b)
int mode;
edge e;
basic_block b;
{
rtx set1, set2, cond1, cond2, insn;
enum rtx_code code1, code2, reversed_code2;
bool reverse1 = false;
int i;
regset nonequal;
bool failed = false;
if (BB_FLAGS (b) & BB_NONTHREADABLE_BLOCK)
return NULL;
if (!e->src->succ->succ_next || e->src->succ->succ_next->succ_next)
return NULL;
if (!b->succ || !b->succ->succ_next || b->succ->succ_next->succ_next)
{
BB_SET_FLAG (b, BB_NONTHREADABLE_BLOCK);
return NULL;
}
if (!any_condjump_p (e->src->end))
return NULL;
if (!any_condjump_p (b->end) || !onlyjump_p (b->end))
{
BB_SET_FLAG (b, BB_NONTHREADABLE_BLOCK);
return NULL;
}
set1 = pc_set (e->src->end);
set2 = pc_set (b->end);
if (((e->flags & EDGE_FALLTHRU) != 0)
!= (XEXP (SET_SRC (set1), 1) == pc_rtx))
reverse1 = true;
cond1 = XEXP (SET_SRC (set1), 0);
cond2 = XEXP (SET_SRC (set2), 0);
if (reverse1)
code1 = reversed_comparison_code (cond1, e->src->end);
else
code1 = GET_CODE (cond1);
code2 = GET_CODE (cond2);
reversed_code2 = reversed_comparison_code (cond2, b->end);
if (!comparison_dominates_p (code1, code2)
&& !comparison_dominates_p (code1, reversed_code2))
return NULL;
if (!rtx_equal_p (XEXP (cond1, 0), XEXP (cond2, 0))
|| !rtx_equal_p (XEXP (cond1, 1), XEXP (cond2, 1)))
return NULL;
for (insn = NEXT_INSN (b->head); insn != NEXT_INSN (b->end);
insn = NEXT_INSN (insn))
if (INSN_P (insn) && side_effects_p (PATTERN (insn)))
{
BB_SET_FLAG (b, BB_NONTHREADABLE_BLOCK);
return NULL;
}
cselib_init ();
for (insn = NEXT_INSN (e->src->head); insn != NEXT_INSN (e->src->end);
insn = NEXT_INSN (insn))
if (INSN_P (insn))
cselib_process_insn (insn);
nonequal = BITMAP_XMALLOC();
CLEAR_REG_SET (nonequal);
for (insn = NEXT_INSN (b->head); insn != NEXT_INSN (b->end) && !failed;
insn = NEXT_INSN (insn))
{
if (INSN_P (insn))
{
rtx pat = PATTERN (insn);
if (GET_CODE (pat) == PARALLEL)
{
for (i = 0; i < XVECLEN (pat, 0); i++)
failed |= mark_effect (XVECEXP (pat, 0, i), nonequal);
}
else
failed |= mark_effect (pat, nonequal);
}
cselib_process_insn (insn);
}
if (failed)
{
BB_SET_FLAG (b, BB_NONTHREADABLE_BLOCK);
goto failed_exit;
}
if (for_each_rtx (&cond2, mentions_nonequal_regs, nonequal))
goto failed_exit;
if (mode & CLEANUP_UPDATE_LIFE)
AND_REG_SET (nonequal, b->global_live_at_end);
EXECUTE_IF_SET_IN_REG_SET (nonequal, 0, i, goto failed_exit;);
BITMAP_XFREE (nonequal);
cselib_finish ();
if ((comparison_dominates_p (code1, code2) != 0)
!= (XEXP (SET_SRC (set2), 1) == pc_rtx))
return BRANCH_EDGE (b);
else
return FALLTHRU_EDGE (b);
failed_exit:
BITMAP_XFREE (nonequal);
cselib_finish ();
return NULL;
}
static bool
try_forward_edges (mode, b)
basic_block b;
int mode;
{
bool changed = false;
edge e, next, *threaded_edges = NULL;
if (has_dont_shorten_note (b))
return false;
for (e = b->succ; e; e = next)
{
basic_block target, first;
int counter;
bool threaded = false;
int nthreaded_edges = 0;
next = e->succ_next;
if (e->flags & EDGE_COMPLEX)
continue;
target = first = e->dest;
counter = 0;
while (counter < n_basic_blocks)
{
basic_block new_target = NULL;
bool new_target_threaded = false;
if (FORWARDER_BLOCK_P (target)
&& target->succ->dest != EXIT_BLOCK_PTR)
{
if (target == target->succ->dest)
counter = n_basic_blocks;
new_target = target->succ->dest;
}
else if (mode & CLEANUP_THREADING)
{
edge t = thread_jump (mode, e, target);
if (t)
{
if (!threaded_edges)
threaded_edges = xmalloc (sizeof (*threaded_edges)
* n_basic_blocks);
else
{
int i;
for (i = 0; i < nthreaded_edges; ++i)
if (threaded_edges[i] == t)
break;
if (i < nthreaded_edges)
{
counter = n_basic_blocks;
break;
}
}
if (t->dest == b)
break;
if (nthreaded_edges >= n_basic_blocks)
abort ();
threaded_edges[nthreaded_edges++] = t;
new_target = t->dest;
new_target_threaded = true;
}
}
if (!new_target)
break;
if ((mode & CLEANUP_PRE_LOOP) && optimize)
{
rtx insn = (target->succ->flags & EDGE_FALLTHRU
? target->head : prev_nonnote_insn (target->end));
if (GET_CODE (insn) != NOTE)
insn = NEXT_INSN (insn);
for (; insn && GET_CODE (insn) != CODE_LABEL && !INSN_P (insn);
insn = NEXT_INSN (insn))
if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
break;
if (GET_CODE (insn) == NOTE)
break;
insn = PREV_INSN (target->head);
if (insn && GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END)
break;
}
counter++;
target = new_target;
threaded |= new_target_threaded;
}
if (counter >= n_basic_blocks)
{
if (rtl_dump_file)
fprintf (rtl_dump_file, "Infinite loop in BB %i.\n",
target->index);
}
else if (target == first)
;
else
{
gcov_type edge_count = e->count;
int edge_probability = e->probability;
int edge_frequency;
int n = 0;
if (threaded && target != EXIT_BLOCK_PTR)
{
notice_new_block (redirect_edge_and_branch_force (e, target));
if (rtl_dump_file)
fprintf (rtl_dump_file, "Conditionals threaded.\n");
}
else if (!redirect_edge_and_branch (e, target))
{
if (rtl_dump_file)
fprintf (rtl_dump_file,
"Forwarding edge %i->%i to %i failed.\n",
b->index, e->dest->index, target->index);
continue;
}
edge_frequency = ((edge_probability * b->frequency
+ REG_BR_PROB_BASE / 2)
/ REG_BR_PROB_BASE);
if (!FORWARDER_BLOCK_P (b) && forwarder_block_p (b))
BB_SET_FLAG (b, BB_FORWARDER_BLOCK);
do
{
edge t;
first->count -= edge_count;
if (first->count < 0)
first->count = 0;
first->frequency -= edge_frequency;
if (first->frequency < 0)
first->frequency = 0;
if (first->succ->succ_next)
{
edge e;
int prob;
if (n >= nthreaded_edges)
abort ();
t = threaded_edges [n++];
if (t->src != first)
abort ();
if (first->frequency)
prob = edge_frequency * REG_BR_PROB_BASE / first->frequency;
else
prob = 0;
if (prob > t->probability)
prob = t->probability;
t->probability -= prob;
prob = REG_BR_PROB_BASE - prob;
if (prob <= 0)
{
first->succ->probability = REG_BR_PROB_BASE;
first->succ->succ_next->probability = 0;
}
else
for (e = first->succ; e; e = e->succ_next)
e->probability = ((e->probability * REG_BR_PROB_BASE)
/ (double) prob);
update_br_prob_note (first);
}
else
{
if (n < nthreaded_edges
&& first == threaded_edges [n]->src)
n++;
t = first->succ;
}
t->count -= edge_count;
if (t->count < 0)
t->count = 0;
first = t->dest;
}
while (first != target);
changed = true;
}
}
if (threaded_edges)
free (threaded_edges);
return changed;
}
static bool
label_is_jump_target_p (label, jump_insn)
rtx label, jump_insn;
{
rtx tmp = JUMP_LABEL (jump_insn);
if (label == tmp)
return true;
if (tmp != NULL_RTX
&& (tmp = NEXT_INSN (tmp)) != NULL_RTX
&& GET_CODE (tmp) == JUMP_INSN
&& (tmp = PATTERN (tmp),
GET_CODE (tmp) == ADDR_VEC
|| GET_CODE (tmp) == ADDR_DIFF_VEC))
{
rtvec vec = XVEC (tmp, GET_CODE (tmp) == ADDR_DIFF_VEC);
int i, veclen = GET_NUM_ELEM (vec);
for (i = 0; i < veclen; ++i)
if (XEXP (RTVEC_ELT (vec, i), 0) == label)
return true;
}
return false;
}
static bool
tail_recursion_label_p (label)
rtx label;
{
rtx x;
for (x = tail_recursion_label_list; x; x = XEXP (x, 1))
if (label == XEXP (x, 0))
return true;
return false;
}
static void
merge_blocks_move_predecessor_nojumps (a, b)
basic_block a, b;
{
rtx barrier;
barrier = next_nonnote_insn (a->end);
if (GET_CODE (barrier) != BARRIER)
abort ();
delete_insn (barrier);
if (squeeze_notes (&a->head, &a->end))
abort ();
if (a->end != PREV_INSN (b->head))
reorder_insns_nobb (a->head, a->end, PREV_INSN (b->head));
a->flags |= BB_DIRTY;
if (rtl_dump_file)
fprintf (rtl_dump_file, "Moved block %d before %d and merged.\n",
a->index, b->index);
unlink_block (a);
link_block (a, b->prev_bb);
merge_blocks_nomove (a, b);
}
static void
merge_blocks_move_successor_nojumps (a, b)
basic_block a, b;
{
rtx barrier, real_b_end;
real_b_end = b->end;
barrier = NEXT_INSN (b->end);
if (barrier
&& GET_CODE (barrier) == CODE_LABEL
&& NEXT_INSN (barrier)
&& GET_CODE (NEXT_INSN (barrier)) == JUMP_INSN
&& (GET_CODE (PATTERN (NEXT_INSN (barrier))) == ADDR_VEC
|| GET_CODE (PATTERN (NEXT_INSN (barrier))) == ADDR_DIFF_VEC))
{
b->end = NEXT_INSN (barrier);
barrier = NEXT_INSN (b->end);
}
if (barrier && GET_CODE (barrier) == BARRIER)
delete_insn (barrier);
if (squeeze_notes (&b->head, &b->end))
abort ();
reorder_insns_nobb (b->head, b->end, a->end);
b->end = real_b_end;
if (rtl_dump_file)
fprintf (rtl_dump_file, "Moved block %d after %d and merged.\n",
b->index, a->index);
merge_blocks_nomove (a, b);
}
static bool
has_dont_shorten_note (bb)
basic_block bb;
{
rtx cur_insn;
for (cur_insn = bb->head; cur_insn != bb->end; cur_insn = NEXT_INSN (cur_insn))
{
if ((GET_CODE (cur_insn) == NOTE)
&& (NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_DONT_SHORTEN_BRANCH))
return true;
}
return false;
}
static bool
merge_blocks (e, b, c, mode)
edge e;
basic_block b, c;
int mode;
{
if ((mode & CLEANUP_PRE_SIBCALL)
&& GET_CODE (c->head) == CODE_LABEL
&& tail_recursion_label_p (c->head))
return false;
if (has_dont_shorten_note (b))
return false;
if (e->flags & EDGE_FALLTHRU)
{
int b_index = b->index, c_index = c->index;
merge_blocks_nomove (b, c);
update_forwarder_flag (b);
if (rtl_dump_file)
fprintf (rtl_dump_file, "Merged %d and %d without moving.\n",
b_index, c_index);
return true;
}
else if (mode & CLEANUP_EXPENSIVE)
{
edge tmp_edge, b_fallthru_edge;
bool c_has_outgoing_fallthru;
bool b_has_incoming_fallthru;
if (FORWARDER_BLOCK_P (b) || FORWARDER_BLOCK_P (c))
return false;
for (tmp_edge = c->succ; tmp_edge; tmp_edge = tmp_edge->succ_next)
if (tmp_edge->flags & EDGE_FALLTHRU)
break;
c_has_outgoing_fallthru = (tmp_edge != NULL);
for (tmp_edge = b->pred; tmp_edge; tmp_edge = tmp_edge->pred_next)
if (tmp_edge->flags & EDGE_FALLTHRU)
break;
b_has_incoming_fallthru = (tmp_edge != NULL);
b_fallthru_edge = tmp_edge;
if (! c_has_outgoing_fallthru)
{
merge_blocks_move_successor_nojumps (b, c);
return true;
}
if (b_has_incoming_fallthru)
{
basic_block bb;
if (b_fallthru_edge->src == ENTRY_BLOCK_PTR)
return false;
bb = force_nonfallthru (b_fallthru_edge);
if (bb)
notice_new_block (bb);
}
merge_blocks_move_predecessor_nojumps (b, c);
return true;
}
return false;
}
static bool
insns_match_p (mode, i1, i2)
int mode ATTRIBUTE_UNUSED;
rtx i1, i2;
{
rtx p1, p2;
if (GET_CODE (i1) != GET_CODE (i2))
return false;
p1 = PATTERN (i1);
p2 = PATTERN (i2);
if (GET_CODE (p1) != GET_CODE (p2))
return false;
if (GET_CODE (i1) == CALL_INSN
&& (!rtx_equal_p (CALL_INSN_FUNCTION_USAGE (i1),
CALL_INSN_FUNCTION_USAGE (i2))
|| SIBLING_CALL_P (i1) != SIBLING_CALL_P (i2)))
return false;
#ifdef STACK_REGS
if ((mode & CLEANUP_POST_REGSTACK) && stack_regs_mentioned (i1))
{
rtx note;
HARD_REG_SET i1_regset, i2_regset;
CLEAR_HARD_REG_SET (i1_regset);
CLEAR_HARD_REG_SET (i2_regset);
for (note = REG_NOTES (i1); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_DEAD && STACK_REG_P (XEXP (note, 0)))
SET_HARD_REG_BIT (i1_regset, REGNO (XEXP (note, 0)));
for (note = REG_NOTES (i2); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_DEAD && STACK_REG_P (XEXP (note, 0)))
SET_HARD_REG_BIT (i2_regset, REGNO (XEXP (note, 0)));
GO_IF_HARD_REG_EQUAL (i1_regset, i2_regset, done);
return false;
done:
;
}
#endif
if (reload_completed
? ! rtx_renumbered_equal_p (p1, p2) : ! rtx_equal_p (p1, p2))
{
rtx equiv1 = find_reg_equal_equiv_note (i1);
rtx equiv2 = find_reg_equal_equiv_note (i2);
if (equiv1 && equiv2
&& (! reload_completed
|| (CONSTANT_P (XEXP (equiv1, 0))
&& rtx_equal_p (XEXP (equiv1, 0), XEXP (equiv2, 0)))))
{
rtx s1 = single_set (i1);
rtx s2 = single_set (i2);
if (s1 != 0 && s2 != 0
&& rtx_renumbered_equal_p (SET_DEST (s1), SET_DEST (s2)))
{
validate_change (i1, &SET_SRC (s1), XEXP (equiv1, 0), 1);
validate_change (i2, &SET_SRC (s2), XEXP (equiv2, 0), 1);
if (! rtx_renumbered_equal_p (p1, p2))
cancel_changes (0);
else if (apply_change_group ())
return true;
}
}
return false;
}
return true;
}
static int
flow_find_cross_jump (mode, bb1, bb2, f1, f2)
int mode ATTRIBUTE_UNUSED;
basic_block bb1, bb2;
rtx *f1, *f2;
{
rtx i1, i2, last1, last2, afterlast1, afterlast2;
int ninsns = 0;
i1 = bb1->end;
last1 = afterlast1 = last2 = afterlast2 = NULL_RTX;
if (onlyjump_p (i1)
|| (returnjump_p (i1) && !side_effects_p (PATTERN (i1))))
{
last1 = i1;
i1 = PREV_INSN (i1);
}
i2 = bb2->end;
if (onlyjump_p (i2)
|| (returnjump_p (i2) && !side_effects_p (PATTERN (i2))))
{
last2 = i2;
if (!simplejump_p (i2) && !returnjump_p (i2) && last1)
ninsns++;
i2 = PREV_INSN (i2);
}
while (true)
{
while (!active_insn_p (i1) && i1 != bb1->head)
i1 = PREV_INSN (i1);
while (!active_insn_p (i2) && i2 != bb2->head)
i2 = PREV_INSN (i2);
if (i1 == bb1->head || i2 == bb2->head)
break;
if (!insns_match_p (mode, i1, i2))
break;
if (active_insn_p (i1))
{
rtx equiv1 = find_reg_equal_equiv_note (i1);
rtx equiv2 = find_reg_equal_equiv_note (i2);
if (equiv1 && !equiv2)
remove_note (i1, equiv1);
else if (!equiv1 && equiv2)
remove_note (i2, equiv2);
else if (equiv1 && equiv2
&& !rtx_equal_p (XEXP (equiv1, 0), XEXP (equiv2, 0)))
{
remove_note (i1, equiv1);
remove_note (i2, equiv2);
}
afterlast1 = last1, afterlast2 = last2;
last1 = i1, last2 = i2;
ninsns++;
}
i1 = PREV_INSN (i1);
i2 = PREV_INSN (i2);
}
#ifdef HAVE_cc0
if (ninsns && reg_mentioned_p (cc0_rtx, last1) && ! sets_cc0_p (last1))
last1 = afterlast1, last2 = afterlast2, ninsns--;
#endif
if (ninsns)
{
while (last1 != bb1->head && !active_insn_p (PREV_INSN (last1)))
last1 = PREV_INSN (last1);
if (last1 != bb1->head && GET_CODE (PREV_INSN (last1)) == CODE_LABEL)
last1 = PREV_INSN (last1);
while (last2 != bb2->head && !active_insn_p (PREV_INSN (last2)))
last2 = PREV_INSN (last2);
if (last2 != bb2->head && GET_CODE (PREV_INSN (last2)) == CODE_LABEL)
last2 = PREV_INSN (last2);
*f1 = last1;
*f2 = last2;
}
return ninsns;
}
static bool
outgoing_edges_match (mode, bb1, bb2)
int mode;
basic_block bb1;
basic_block bb2;
{
int nehedges1 = 0, nehedges2 = 0;
edge fallthru1 = 0, fallthru2 = 0;
edge e1, e2;
if (bb1->succ && !bb1->succ->succ_next
&& (bb1->succ->flags & (EDGE_COMPLEX | EDGE_FAKE)) == 0
&& (GET_CODE (bb1->end) != JUMP_INSN || simplejump_p (bb1->end)))
return (bb2->succ && !bb2->succ->succ_next
&& (bb2->succ->flags & (EDGE_COMPLEX | EDGE_FAKE)) == 0
&& (GET_CODE (bb2->end) != JUMP_INSN || simplejump_p (bb2->end)));
if (bb1->succ
&& bb1->succ->succ_next
&& !bb1->succ->succ_next->succ_next
&& any_condjump_p (bb1->end)
&& onlyjump_p (bb1->end))
{
edge b1, f1, b2, f2;
bool reverse, match;
rtx set1, set2, cond1, cond2;
enum rtx_code code1, code2;
if (!bb2->succ
|| !bb2->succ->succ_next
|| bb2->succ->succ_next->succ_next
|| !any_condjump_p (bb2->end)
|| !onlyjump_p (bb2->end))
return false;
if (bb1->loop_depth != bb2->loop_depth)
return false;
b1 = BRANCH_EDGE (bb1);
b2 = BRANCH_EDGE (bb2);
f1 = FALLTHRU_EDGE (bb1);
f2 = FALLTHRU_EDGE (bb2);
if (FORWARDER_BLOCK_P (f1->dest))
f1 = f1->dest->succ;
if (FORWARDER_BLOCK_P (f2->dest))
f2 = f2->dest->succ;
if (FORWARDER_BLOCK_P (f1->dest)
|| FORWARDER_BLOCK_P (f2->dest)
|| FORWARDER_BLOCK_P (b1->dest)
|| FORWARDER_BLOCK_P (b2->dest))
return false;
if (f1->dest == f2->dest && b1->dest == b2->dest)
reverse = false;
else if (f1->dest == b2->dest && b1->dest == f2->dest)
reverse = true;
else
return false;
set1 = pc_set (bb1->end);
set2 = pc_set (bb2->end);
if ((XEXP (SET_SRC (set1), 1) == pc_rtx)
!= (XEXP (SET_SRC (set2), 1) == pc_rtx))
reverse = !reverse;
cond1 = XEXP (SET_SRC (set1), 0);
cond2 = XEXP (SET_SRC (set2), 0);
code1 = GET_CODE (cond1);
if (reverse)
code2 = reversed_comparison_code (cond2, bb2->end);
else
code2 = GET_CODE (cond2);
if (code2 == UNKNOWN)
return false;
match = ((code1 == code2
&& rtx_renumbered_equal_p (XEXP (cond1, 0), XEXP (cond2, 0))
&& rtx_renumbered_equal_p (XEXP (cond1, 1), XEXP (cond2, 1)))
|| (code1 == swap_condition (code2)
&& rtx_renumbered_equal_p (XEXP (cond1, 1),
XEXP (cond2, 0))
&& rtx_renumbered_equal_p (XEXP (cond1, 0),
XEXP (cond2, 1))));
if (match
&& !optimize_size
&& maybe_hot_bb_p (bb1)
&& maybe_hot_bb_p (bb2))
{
int prob2;
if (b1->dest == b2->dest)
prob2 = b2->probability;
else
prob2 = REG_BR_PROB_BASE - b2->probability;
if (abs (b1->probability - prob2) > REG_BR_PROB_BASE / 2)
{
if (rtl_dump_file)
fprintf (rtl_dump_file,
"Outcomes of branch in bb %i and %i differs to much (%i %i)\n",
bb1->index, bb2->index, b1->probability, prob2);
return false;
}
}
if (rtl_dump_file && match)
fprintf (rtl_dump_file, "Conditionals in bb %i and %i match.\n",
bb1->index, bb2->index);
return match;
}
if (!insns_match_p (mode, bb1->end, bb2->end))
return false;
for (e1 = bb1->succ, e2 = bb2->succ; e1 && e2;
e1 = e1->succ_next, e2 = e2->succ_next)
{
if (e1->flags & EDGE_EH)
nehedges1++;
if (e2->flags & EDGE_EH)
nehedges2++;
if (e1->flags & EDGE_FALLTHRU)
fallthru1 = e1;
if (e2->flags & EDGE_FALLTHRU)
fallthru2 = e2;
}
if (e1 || e2
|| nehedges1 != nehedges2
|| (fallthru1 != 0) != (fallthru2 != 0))
return false;
if (fallthru1)
{
basic_block d1 = (forwarder_block_p (fallthru1->dest)
? fallthru1->dest->succ->dest: fallthru1->dest);
basic_block d2 = (forwarder_block_p (fallthru2->dest)
? fallthru2->dest->succ->dest: fallthru2->dest);
if (d1 != d2)
return false;
}
if (nehedges1)
{
rtx n1 = find_reg_note (bb1->end, REG_EH_REGION, 0);
rtx n2 = find_reg_note (bb2->end, REG_EH_REGION, 0);
if (XEXP (n1, 0) != XEXP (n2, 0))
return false;
}
return true;
}
static bool
try_crossjump_to_edge (mode, e1, e2)
int mode;
edge e1, e2;
{
int nmatch;
basic_block src1 = e1->src, src2 = e2->src;
basic_block redirect_to, redirect_from, to_remove;
rtx newpos1, newpos2;
edge s;
if (src1->pred
&& !src1->pred->pred_next
&& FORWARDER_BLOCK_P (src1))
e1 = src1->pred, src1 = e1->src;
if (src2->pred
&& !src2->pred->pred_next
&& FORWARDER_BLOCK_P (src2))
e2 = src2->pred, src2 = e2->src;
if (src1 == ENTRY_BLOCK_PTR || src2 == ENTRY_BLOCK_PTR)
return false;
if (src1 == src2)
return false;
if (FORWARDER_BLOCK_P (e1->dest)
&& FORWARDER_BLOCK_P (e1->dest->succ->dest))
return false;
if (FORWARDER_BLOCK_P (e2->dest)
&& FORWARDER_BLOCK_P (e2->dest->succ->dest))
return false;
if (!src1->pred || !src2->pred)
return false;
if (!outgoing_edges_match (mode, src1, src2))
return false;
nmatch = flow_find_cross_jump (mode, src1, src2, &newpos1, &newpos2);
if (!nmatch)
return false;
if (newpos2 == src2->head)
redirect_to = src2;
else
{
if (rtl_dump_file)
fprintf (rtl_dump_file, "Splitting bb %i before %i insns\n",
src2->index, nmatch);
redirect_to = split_block (src2, PREV_INSN (newpos2))->dest;
}
if (rtl_dump_file)
fprintf (rtl_dump_file,
"Cross jumping from bb %i to bb %i; %i common insns\n",
src1->index, src2->index, nmatch);
redirect_to->count += src1->count;
redirect_to->frequency += src1->frequency;
redirect_to->flags |= BB_DIRTY;
for (s = redirect_to->succ; s; s = s->succ_next)
{
edge s2;
basic_block d = s->dest;
if (FORWARDER_BLOCK_P (d))
d = d->succ->dest;
for (s2 = src1->succ; ; s2 = s2->succ_next)
{
basic_block d2 = s2->dest;
if (FORWARDER_BLOCK_P (d2))
d2 = d2->succ->dest;
if (d == d2)
break;
}
s->count += s2->count;
if (FORWARDER_BLOCK_P (s->dest))
{
s->dest->succ->count += s2->count;
s->dest->count += s2->count;
s->dest->frequency += EDGE_FREQUENCY (s);
}
if (FORWARDER_BLOCK_P (s2->dest))
{
s2->dest->succ->count -= s2->count;
if (s2->dest->succ->count < 0)
s2->dest->succ->count = 0;
s2->dest->count -= s2->count;
s2->dest->frequency -= EDGE_FREQUENCY (s);
if (s2->dest->frequency < 0)
s2->dest->frequency = 0;
if (s2->dest->count < 0)
s2->dest->count = 0;
}
if (!redirect_to->frequency && !src1->frequency)
s->probability = (s->probability + s2->probability) / 2;
else
s->probability
= ((s->probability * redirect_to->frequency +
s2->probability * src1->frequency)
/ (redirect_to->frequency + src1->frequency));
}
update_br_prob_note (redirect_to);
if (GET_CODE (newpos1) == CODE_LABEL)
newpos1 = NEXT_INSN (newpos1);
if (GET_CODE (newpos1) == NOTE)
newpos1 = NEXT_INSN (newpos1);
redirect_from = split_block (src1, PREV_INSN (newpos1))->src;
to_remove = redirect_from->succ->dest;
redirect_edge_and_branch_force (redirect_from->succ, redirect_to);
flow_delete_block (to_remove);
update_forwarder_flag (redirect_from);
return true;
}
static bool
try_crossjump_bb (mode, bb)
int mode;
basic_block bb;
{
edge e, e2, nexte2, nexte, fallthru;
bool changed;
int n = 0;
if (!bb->pred || !bb->pred->pred_next)
return false;
if ((has_dont_shorten_note (bb->pred->src))
|| (has_dont_shorten_note (bb->pred->pred_next->src)))
return false;
for (fallthru = bb->pred; fallthru; fallthru = fallthru->pred_next, n++)
{
if (fallthru->flags & EDGE_FALLTHRU)
break;
if (n > 100)
return false;
}
changed = false;
for (e = bb->pred; e; e = nexte)
{
nexte = e->pred_next;
if (fallthru)
{
if (e == fallthru)
continue;
if (try_crossjump_to_edge (mode, e, fallthru))
{
changed = true;
nexte = bb->pred;
continue;
}
}
if (e->src->succ != e)
continue;
for (e2 = bb->pred; e2; e2 = nexte2)
{
nexte2 = e2->pred_next;
if (e2 == e)
continue;
if (e2 == fallthru)
continue;
if (e->src->index > e2->src->index)
continue;
if (try_crossjump_to_edge (mode, e, e2))
{
changed = true;
nexte = bb->pred;
break;
}
}
}
return changed;
}
static bool
try_optimize_cfg (mode)
int mode;
{
bool changed_overall = false;
bool changed;
int iterations = 0;
basic_block bb, b;
if (mode & CLEANUP_CROSSJUMP)
add_noreturn_fake_exit_edges ();
FOR_EACH_BB (bb)
update_forwarder_flag (bb);
if (mode & CLEANUP_UPDATE_LIFE)
clear_bb_flags ();
if (! (* targetm.cannot_modify_jumps_p) ())
{
do
{
changed = false;
iterations++;
if (rtl_dump_file)
fprintf (rtl_dump_file,
"\n\ntry_optimize_cfg iteration %i\n\n",
iterations);
for (b = ENTRY_BLOCK_PTR->next_bb; b != EXIT_BLOCK_PTR;)
{
basic_block c;
edge s;
bool changed_here = false;
while (b->pred == NULL)
{
c = b->prev_bb;
if (rtl_dump_file)
fprintf (rtl_dump_file, "Deleting block %i.\n",
b->index);
flow_delete_block (b);
changed = true;
b = c;
}
if (b->pred->pred_next == NULL
&& (b->pred->flags & EDGE_FALLTHRU)
&& !(b->pred->flags & EDGE_COMPLEX)
&& GET_CODE (b->head) == CODE_LABEL
&& (!(mode & CLEANUP_PRE_SIBCALL)
|| !tail_recursion_label_p (b->head))
&& (b->pred->src == ENTRY_BLOCK_PTR
|| GET_CODE (b->pred->src->end) != JUMP_INSN
|| ! label_is_jump_target_p (b->head,
b->pred->src->end)))
{
rtx label = b->head;
b->head = NEXT_INSN (b->head);
delete_insn_chain (label, label);
if (rtl_dump_file)
fprintf (rtl_dump_file, "Deleted label in block %i.\n",
b->index);
}
if (b->pred->pred_next == NULL
&& (b->pred->flags & EDGE_FALLTHRU)
&& GET_CODE (b->head) != CODE_LABEL
&& FORWARDER_BLOCK_P (b)
&& (b->succ->flags & EDGE_FALLTHRU)
&& n_basic_blocks > 1)
{
if (rtl_dump_file)
fprintf (rtl_dump_file,
"Deleting fallthru block %i.\n",
b->index);
c = b->prev_bb == ENTRY_BLOCK_PTR ? b->next_bb : b->prev_bb;
redirect_edge_succ_nodup (b->pred, b->succ->dest);
flow_delete_block (b);
changed = true;
b = c;
}
while ((s = b->succ) != NULL
&& s->succ_next == NULL
&& !(s->flags & EDGE_COMPLEX)
&& (c = s->dest) != EXIT_BLOCK_PTR
&& c->pred->pred_next == NULL
&& b != c
&& (GET_CODE (b->end) != JUMP_INSN
|| simplejump_p (b->end))
&& merge_blocks (s, b, c, mode))
changed_here = true;
if ((mode & CLEANUP_EXPENSIVE) && try_simplify_condjump (b))
changed_here = true;
if (b->succ
&& ! b->succ->succ_next
&& b->succ->dest != EXIT_BLOCK_PTR
&& onlyjump_p (b->end)
&& ! (has_dont_shorten_note (b))
&& redirect_edge_and_branch (b->succ, b->succ->dest))
{
update_forwarder_flag (b);
changed_here = true;
}
if (try_forward_edges (mode, b))
changed_here = true;
if ((mode & CLEANUP_CROSSJUMP)
&& try_crossjump_bb (mode, b))
changed_here = true;
if (!changed_here)
b = b->next_bb;
else
changed = true;
}
if ((mode & CLEANUP_CROSSJUMP)
&& try_crossjump_bb (mode, EXIT_BLOCK_PTR))
changed = true;
#ifdef ENABLE_CHECKING
if (changed)
verify_flow_info ();
#endif
changed_overall |= changed;
}
while (changed);
}
if (mode & CLEANUP_CROSSJUMP)
remove_fake_edges ();
clear_aux_for_blocks ();
return changed_overall;
}
bool
delete_unreachable_blocks ()
{
bool changed = false;
basic_block b, next_bb;
find_unreachable_blocks ();
for (b = ENTRY_BLOCK_PTR->next_bb; b != EXIT_BLOCK_PTR; b = next_bb)
{
next_bb = b->next_bb;
if (!(b->flags & BB_REACHABLE))
{
flow_delete_block (b);
changed = true;
}
}
if (changed)
tidy_fallthru_edges ();
return changed;
}
bool
cleanup_cfg (mode)
int mode;
{
bool changed = false;
timevar_push (TV_CLEANUP_CFG);
if (delete_unreachable_blocks ())
{
changed = true;
if (!(mode & (CLEANUP_NO_INSN_DEL
| CLEANUP_UPDATE_LIFE | CLEANUP_PRE_SIBCALL))
&& !reload_completed)
delete_trivially_dead_insns (get_insns(), max_reg_num ());
}
compact_blocks ();
while (try_optimize_cfg (mode))
{
delete_unreachable_blocks (), changed = true;
if (mode & CLEANUP_UPDATE_LIFE)
{
if (!update_life_info_in_dirty_blocks (UPDATE_LIFE_GLOBAL_RM_NOTES,
PROP_DEATH_NOTES
| PROP_SCAN_DEAD_CODE
| PROP_KILL_DEAD_CODE
| PROP_LOG_LINKS))
break;
}
else if (!(mode & (CLEANUP_NO_INSN_DEL | CLEANUP_PRE_SIBCALL))
&& (mode & CLEANUP_EXPENSIVE)
&& !reload_completed)
{
if (!delete_trivially_dead_insns (get_insns(), max_reg_num ()))
break;
}
else
break;
delete_dead_jumptables ();
}
free_EXPR_LIST_list (&label_value_list);
timevar_pop (TV_CLEANUP_CFG);
return changed;
}