#include "config.h"
#include "system.h"
#include "tree.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "insn-config.h"
#include "output.h"
#include "function.h"
#include "obstack.h"
#include "cfglayout.h"
extern struct obstack flow_obstack;
static rtx function_tail_eff_head;
static rtx skip_insns_after_block PARAMS ((basic_block));
static void record_effective_endpoints PARAMS ((void));
static rtx label_for_bb PARAMS ((basic_block));
static void fixup_reorder_chain PARAMS ((void));
static void set_block_levels PARAMS ((tree, int));
static void change_scope PARAMS ((rtx, tree, tree));
void verify_insn_chain PARAMS ((void));
static void fixup_fallthru_exit_predecessor PARAMS ((void));
static varray_type insn_scopes;
static rtx
skip_insns_after_block (bb)
basic_block bb;
{
rtx insn, last_insn, next_head, prev;
next_head = NULL_RTX;
if (bb->index + 1 != n_basic_blocks)
next_head = BASIC_BLOCK (bb->index + 1)->head;
for (last_insn = insn = bb->end; (insn = NEXT_INSN (insn)) != 0; )
{
if (insn == next_head)
break;
switch (GET_CODE (insn))
{
case BARRIER:
last_insn = insn;
continue;
case NOTE:
switch (NOTE_LINE_NUMBER (insn))
{
case NOTE_INSN_LOOP_END:
case NOTE_INSN_BLOCK_END:
last_insn = insn;
continue;
case NOTE_INSN_DELETED:
case NOTE_INSN_DELETED_LABEL:
continue;
default:
continue;
break;
}
break;
case CODE_LABEL:
if (NEXT_INSN (insn)
&& GET_CODE (NEXT_INSN (insn)) == JUMP_INSN
&& (GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_VEC
|| GET_CODE (PATTERN (NEXT_INSN (insn))) == ADDR_DIFF_VEC))
{
insn = NEXT_INSN (insn);
last_insn = insn;
continue;
}
break;
default:
break;
}
break;
}
for (insn = last_insn; insn != bb->end; insn = prev)
{
prev = PREV_INSN (insn);
if (GET_CODE (insn) == NOTE)
switch (NOTE_LINE_NUMBER (insn))
{
case NOTE_INSN_LOOP_END:
case NOTE_INSN_BLOCK_END:
case NOTE_INSN_DELETED:
case NOTE_INSN_DELETED_LABEL:
continue;
default:
reorder_insns (insn, insn, last_insn);
}
}
return last_insn;
}
static rtx
label_for_bb (bb)
basic_block bb;
{
rtx label = bb->head;
if (GET_CODE (label) != CODE_LABEL)
{
if (rtl_dump_file)
fprintf (rtl_dump_file, "Emitting label for block %d\n", bb->index);
label = block_label (bb);
if (bb->head == PREV_INSN (RBI (bb)->eff_head))
RBI (bb)->eff_head = label;
}
return label;
}
static void
record_effective_endpoints ()
{
rtx next_insn = get_insns ();
int i;
for (i = 0; i < n_basic_blocks; i++)
{
basic_block bb = BASIC_BLOCK (i);
rtx end;
RBI (bb)->eff_head = next_insn;
end = skip_insns_after_block (bb);
RBI (bb)->eff_end = end;
next_insn = NEXT_INSN (end);
}
function_tail_eff_head = next_insn;
}
void
scope_to_insns_initialize ()
{
tree block = NULL;
rtx insn, next;
VARRAY_TREE_INIT (insn_scopes, get_max_uid (), "insn scopes");
for (insn = get_insns (); insn; insn = next)
{
next = NEXT_INSN (insn);
if (active_insn_p (insn)
&& GET_CODE (PATTERN (insn)) != ADDR_VEC
&& GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC)
VARRAY_TREE (insn_scopes, INSN_UID (insn)) = block;
else if (GET_CODE (insn) == NOTE)
{
switch (NOTE_LINE_NUMBER (insn))
{
case NOTE_INSN_BLOCK_BEG:
block = NOTE_BLOCK (insn);
delete_insn (insn);
break;
case NOTE_INSN_BLOCK_END:
block = BLOCK_SUPERCONTEXT (block);
delete_insn (insn);
break;
default:
break;
}
}
}
}
static void
set_block_levels (block, level)
tree block;
int level;
{
while (block)
{
BLOCK_NUMBER (block) = level;
set_block_levels (BLOCK_SUBBLOCKS (block), level + 1);
block = BLOCK_CHAIN (block);
}
}
static void
change_scope (orig_insn, s1, s2)
rtx orig_insn;
tree s1, s2;
{
rtx insn = orig_insn;
tree com = NULL_TREE;
tree ts1 = s1, ts2 = s2;
tree s;
while (ts1 != ts2)
{
if (ts1 == NULL || ts2 == NULL)
abort ();
if (BLOCK_NUMBER (ts1) > BLOCK_NUMBER (ts2))
ts1 = BLOCK_SUPERCONTEXT (ts1);
else if (BLOCK_NUMBER (ts1) < BLOCK_NUMBER (ts2))
ts2 = BLOCK_SUPERCONTEXT (ts2);
else
{
ts1 = BLOCK_SUPERCONTEXT (ts1);
ts2 = BLOCK_SUPERCONTEXT (ts2);
}
}
com = ts1;
s = s1;
while (s != com)
{
rtx note = emit_note_before (NOTE_INSN_BLOCK_END, insn);
NOTE_BLOCK (note) = s;
s = BLOCK_SUPERCONTEXT (s);
}
s = s2;
while (s != com)
{
insn = emit_note_before (NOTE_INSN_BLOCK_BEG, insn);
NOTE_BLOCK (insn) = s;
s = BLOCK_SUPERCONTEXT (s);
}
}
void
scope_to_insns_finalize ()
{
tree cur_block = DECL_INITIAL (cfun->decl);
rtx insn, note;
set_block_levels (cur_block, 0);
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
{
tree this_block;
if ((size_t) INSN_UID (insn) >= insn_scopes->num_elements)
continue;
this_block = VARRAY_TREE (insn_scopes, INSN_UID (insn));
if (! this_block)
continue;
if (this_block != cur_block)
{
change_scope (insn, cur_block, this_block);
cur_block = this_block;
}
}
VARRAY_FREE (insn_scopes);
note = emit_note (NULL, NOTE_INSN_DELETED);
change_scope (note, cur_block, DECL_INITIAL (cfun->decl));
delete_insn (note);
reorder_blocks ();
}
static void
fixup_reorder_chain ()
{
basic_block bb, last_bb;
int index;
rtx insn;
int old_n_basic_blocks = n_basic_blocks;
for (last_bb = BASIC_BLOCK (0), bb = RBI (last_bb)->next, index = 1;
bb != 0;
last_bb = bb, bb = RBI (bb)->next, index++)
{
rtx last_e = RBI (last_bb)->eff_end;
rtx curr_h = RBI (bb)->eff_head;
NEXT_INSN (last_e) = curr_h;
PREV_INSN (curr_h) = last_e;
}
if (index != n_basic_blocks)
abort ();
insn = RBI (last_bb)->eff_end;
NEXT_INSN (insn) = function_tail_eff_head;
if (function_tail_eff_head)
PREV_INSN (function_tail_eff_head) = insn;
while (NEXT_INSN (insn))
insn = NEXT_INSN (insn);
set_last_insn (insn);
#ifdef ENABLE_CHECKING
verify_insn_chain ();
#endif
for (bb = BASIC_BLOCK (0); bb ; bb = RBI (bb)->next)
{
edge e_fall, e_taken, e;
rtx bb_end_insn;
basic_block nb;
if (bb->succ == NULL)
continue;
e_taken = e_fall = NULL;
for (e = bb->succ; e ; e = e->succ_next)
if (e->flags & EDGE_FALLTHRU)
e_fall = e;
else if (! (e->flags & EDGE_EH))
e_taken = e;
bb_end_insn = bb->end;
if (GET_CODE (bb_end_insn) == JUMP_INSN)
{
if (any_condjump_p (bb_end_insn))
{
if (RBI (bb)->next == e_fall->dest
|| (!RBI (bb)->next
&& e_fall->dest == EXIT_BLOCK_PTR))
continue;
if (RBI (bb)->next != e_taken->dest)
{
rtx note = find_reg_note (bb_end_insn, REG_BR_PROB, 0);
if (note
&& INTVAL (XEXP (note, 0)) < REG_BR_PROB_BASE / 2
&& invert_jump (bb_end_insn,
label_for_bb (e_fall->dest), 0))
{
e_fall->flags &= ~EDGE_FALLTHRU;
e_taken->flags |= EDGE_FALLTHRU;
update_br_prob_note (bb);
e = e_fall, e_fall = e_taken, e_taken = e;
}
}
else if (invert_jump (bb_end_insn,
label_for_bb (e_fall->dest), 0))
{
e_fall->flags &= ~EDGE_FALLTHRU;
e_taken->flags |= EDGE_FALLTHRU;
update_br_prob_note (bb);
continue;
}
}
else if (returnjump_p (bb_end_insn))
continue;
else
{
if (! e_fall)
continue;
#ifdef CASE_DROPS_THROUGH
if (RBI (bb)->next == e_fall->dest)
continue;
bb_end_insn = skip_insns_after_block (bb);
#else
abort ();
#endif
}
}
else
{
if (! e_fall)
continue;
if (RBI (bb)->next == e_fall->dest)
continue;
if (!RBI (bb)->next && e_fall->dest == EXIT_BLOCK_PTR)
continue;
}
nb = force_nonfallthru (e_fall);
if (nb)
{
alloc_aux_for_block (nb, sizeof (struct reorder_block_def));
RBI (nb)->eff_head = nb->head;
RBI (nb)->eff_end = NEXT_INSN (nb->end);
RBI (nb)->visited = 1;
RBI (nb)->next = RBI (bb)->next;
RBI (bb)->next = nb;
bb = nb;
}
}
bb = BASIC_BLOCK (0);
index = 0;
if (rtl_dump_file)
fprintf (rtl_dump_file, "Reordered sequence:\n");
for (; bb; bb = RBI (bb)->next, index++)
{
if (rtl_dump_file)
fprintf (rtl_dump_file, " %i %sbb %i freq %i\n", index,
bb->index >= old_n_basic_blocks ? "compensation " : "",
bb->index,
bb->frequency);
bb->index = index;
BASIC_BLOCK (index) = bb;
}
}
void
verify_insn_chain ()
{
rtx x, prevx, nextx;
int insn_cnt1, insn_cnt2;
for (prevx = NULL, insn_cnt1 = 1, x = get_insns ();
x != 0;
prevx = x, insn_cnt1++, x = NEXT_INSN (x))
if (PREV_INSN (x) != prevx)
abort ();
if (prevx != get_last_insn ())
abort ();
for (nextx = NULL, insn_cnt2 = 1, x = get_last_insn ();
x != 0;
nextx = x, insn_cnt2++, x = PREV_INSN (x))
if (NEXT_INSN (x) != nextx)
abort ();
if (insn_cnt1 != insn_cnt2)
abort ();
}
static void
fixup_fallthru_exit_predecessor ()
{
edge e;
basic_block bb = NULL;
for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
if (e->flags & EDGE_FALLTHRU)
bb = e->src;
if (bb && RBI (bb)->next)
{
basic_block c = BASIC_BLOCK (0);
while (RBI (c)->next != bb)
c = RBI (c)->next;
RBI (c)->next = RBI (bb)->next;
while (RBI (c)->next)
c = RBI (c)->next;
RBI (c)->next = bb;
RBI (bb)->next = NULL;
}
}
void
cfg_layout_initialize ()
{
alloc_aux_for_blocks (sizeof (struct reorder_block_def));
scope_to_insns_initialize ();
record_effective_endpoints ();
}
void
cfg_layout_finalize ()
{
fixup_fallthru_exit_predecessor ();
fixup_reorder_chain ();
#ifdef ENABLE_CHECKING
verify_insn_chain ();
#endif
scope_to_insns_finalize ();
free_aux_for_blocks ();
#ifdef ENABLE_CHECKING
verify_flow_info ();
#endif
}