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8sa1-gcc/gcc/bb-reorder.c
Richard Henderson d1bfc5ad46 bb-reorder.c (fixup_reorder_chain): Don't look up new block again. 
* bb-reorder.c (fixup_reorder_chain): Don't look up new block again.
        (reorder_basic_blocks): If no epilogue in rtl, force last block last.

From-SVN: r33221
2000-04-17 18:32:43 -07:00

896 lines
22 KiB
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/* Basic block reordering routines for the GNU compiler.
Copyright (C) 2000 Free Software Foundation, Inc.
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* References:
"Profile Guided Code Positioning"
Pettis and Hanson; PLDI '90.
*/
#include "config.h"
#include "system.h"
#include "tree.h"
#include "rtl.h"
#include "tm_p.h"
#include "basic-block.h"
#include "insn-config.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "flags.h"
#include "output.h"
#include "function.h"
#include "except.h"
#include "toplev.h"
#include "recog.h"
#include "insn-flags.h"
#include "expr.h"
#include "obstack.h"
/* The contents of the current function definition are allocated
in this obstack, and all are freed at the end of the function.
For top-level functions, this is temporary_obstack.
Separate obstacks are made for nested functions. */
extern struct obstack *function_obstack;
typedef struct reorder_block_def {
int flags;
int index;
basic_block add_jump;
edge succ;
rtx end;
int block_begin;
int block_end;
rtx eff_head;
rtx eff_end;
} *reorder_block_def;
static struct reorder_block_def rbd_init
= {
0, /* flags */
0, /* index */
NULL, /* add_jump */
NULL, /* succ */
NULL_RTX, /* end */
0, /* block_begin */
0, /* block_end */
NULL_RTX, /* eff_head */
NULL_RTX /* eff_end */
};
#define REORDER_BLOCK_HEAD 0x1
#define REORDER_BLOCK_VISITED 0x2
#define REORDER_BLOCK_FLAGS(bb) \
((reorder_block_def) (bb)->aux)->flags
#define REORDER_BLOCK_INDEX(bb) \
((reorder_block_def) (bb)->aux)->index
#define REORDER_BLOCK_ADD_JUMP(bb) \
((reorder_block_def) (bb)->aux)->add_jump
#define REORDER_BLOCK_SUCC(bb) \
((reorder_block_def) (bb)->aux)->succ
#define REORDER_BLOCK_OLD_END(bb) \
((reorder_block_def) (bb)->aux)->end
#define REORDER_BLOCK_BEGIN(bb) \
((reorder_block_def) (bb)->aux)->block_begin
#define REORDER_BLOCK_END(bb) \
((reorder_block_def) (bb)->aux)->block_end
#define REORDER_BLOCK_EFF_HEAD(bb) \
((reorder_block_def) (bb)->aux)->eff_head
#define REORDER_BLOCK_EFF_END(bb) \
((reorder_block_def) (bb)->aux)->eff_end
static int reorder_index;
static basic_block reorder_last_visited;
enum reorder_skip_type {REORDER_SKIP_BEFORE, REORDER_SKIP_AFTER,
REORDER_SKIP_BLOCK_END};
/* Local function prototypes. */
static rtx skip_insns_between_block PARAMS ((basic_block,
enum reorder_skip_type));
static basic_block get_common_dest PARAMS ((basic_block, basic_block));
static basic_block chain_reorder_blocks PARAMS ((edge, basic_block));
static void make_reorder_chain PARAMS ((basic_block));
static void fixup_reorder_chain PARAMS ((void));
#ifdef ENABLE_CHECKING
static void verify_insn_chain PARAMS ((void));
#endif
/* Skip over insns BEFORE or AFTER BB which are typically associated with
basic block BB. */
static rtx
skip_insns_between_block (bb, skip_type)
basic_block bb;
enum reorder_skip_type skip_type;
{
rtx insn, last_insn;
if (skip_type == REORDER_SKIP_BEFORE)
{
if (bb == ENTRY_BLOCK_PTR)
return 0;
last_insn = bb->head;
for (insn = PREV_INSN (bb->head);
insn && insn != BASIC_BLOCK (bb->index - 1)->end;
last_insn = insn, insn = PREV_INSN (insn))
{
if (NEXT_INSN (insn) != last_insn)
break;
if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_END
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_BLOCK_END)
continue;
break;
}
}
else
{
last_insn = bb->end;
if (bb == EXIT_BLOCK_PTR)
return 0;
for (insn = NEXT_INSN (bb->end);
insn;
last_insn = insn, insn = NEXT_INSN (insn))
{
if (bb->index + 1 != n_basic_blocks
&& insn == BASIC_BLOCK (bb->index + 1)->head)
break;
if (GET_CODE (insn) == BARRIER
|| GET_CODE (insn) == JUMP_INSN
|| (GET_CODE (insn) == NOTE
&& (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_END
|| NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)))
continue;
if (GET_CODE (insn) == CODE_LABEL
&& 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);
continue;
}
/* Skip to next non-deleted insn. */
if (GET_CODE (insn) == NOTE
&& (NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED
|| NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED_LABEL))
continue;
break;
}
if (skip_type == REORDER_SKIP_BLOCK_END)
{
int found_block_end = 0;
for (; insn; last_insn = insn, insn = NEXT_INSN (insn))
{
if (bb->index + 1 != n_basic_blocks
&& insn == BASIC_BLOCK (bb->index + 1)->head)
break;
if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
{
found_block_end = 1;
continue;
}
if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED)
continue;
if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) >= 0
&& NEXT_INSN (insn)
&& GET_CODE (NEXT_INSN (insn)) == NOTE
&& (NOTE_LINE_NUMBER (NEXT_INSN (insn))
== NOTE_INSN_BLOCK_END))
continue;
break;
}
if (! found_block_end)
last_insn = 0;
}
}
return last_insn;
}
/* Return common destination for blocks BB0 and BB1. */
static basic_block
get_common_dest (bb0, bb1)
basic_block bb0, bb1;
{
edge e0, e1;
for (e0 = bb0->succ; e0; e0 = e0->succ_next)
{
for (e1 = bb1->succ; e1; e1 = e1->succ_next)
{
if (e0->dest == e1->dest)
{
return e0->dest;
}
}
}
return 0;
}
/* Move the destination block for edge E after chain end block CEB
Adding jumps and labels is deferred until fixup_reorder_chain. */
static basic_block
chain_reorder_blocks (e, ceb)
edge e;
basic_block ceb;
{
basic_block sb = e->src;
basic_block db = e->dest;
rtx cebe_insn, cebbe_insn, dbh_insn, dbe_insn;
edge ee, last_edge;
enum cond_types {NO_COND, PREDICT_THEN_WITH_ELSE, PREDICT_ELSE,
PREDICT_THEN_NO_ELSE, PREDICT_NOT_THEN_NO_ELSE};
enum cond_types cond_type;
enum cond_block_types {NO_COND_BLOCK, THEN_BLOCK, ELSE_BLOCK,
NO_ELSE_BLOCK};
enum cond_block_types cond_block_type;
if (rtl_dump_file)
fprintf (rtl_dump_file,
"Edge from basic block %d to basic block %d last visited %d\n",
sb->index, db->index, ceb->index);
dbh_insn = REORDER_BLOCK_EFF_HEAD (db);
cebe_insn = REORDER_BLOCK_EFF_END (ceb);
cebbe_insn = skip_insns_between_block (ceb, REORDER_SKIP_BLOCK_END);
{
int block_begins = 0;
rtx insn;
for (insn = dbh_insn; insn && insn != db->end; insn = NEXT_INSN (insn))
{
if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
{
block_begins += 1;
break;
}
}
REORDER_BLOCK_BEGIN (sb) = block_begins;
}
if (cebbe_insn)
{
int block_ends = 0;
rtx insn;
for (insn = cebe_insn; insn; insn = NEXT_INSN (insn))
{
if (PREV_INSN (insn) == cebbe_insn)
break;
if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
{
block_ends += 1;
continue;
}
}
REORDER_BLOCK_END (ceb) = block_ends;
}
/* Blocks are in original order. */
if (sb->index == ceb->index
&& ceb->index + 1 == db->index && NEXT_INSN (cebe_insn))
return db;
/* Get the type of block and type of condition. */
cond_type = NO_COND;
cond_block_type = NO_COND_BLOCK;
if (GET_CODE (sb->end) == JUMP_INSN && ! simplejump_p (sb->end)
&& condjump_p (sb->end))
{
if (e->flags & EDGE_FALLTHRU)
cond_block_type = THEN_BLOCK;
else if (get_common_dest (sb->succ->dest, sb))
cond_block_type = NO_ELSE_BLOCK;
else
cond_block_type = ELSE_BLOCK;
if (sb->succ->succ_next
&& get_common_dest (sb->succ->dest, sb))
{
if (cond_block_type == THEN_BLOCK)
{
if (! (REORDER_BLOCK_FLAGS (sb->succ->succ_next->dest)
& REORDER_BLOCK_VISITED))
cond_type = PREDICT_THEN_NO_ELSE;
else
cond_type = PREDICT_NOT_THEN_NO_ELSE;
}
else if (cond_block_type == NO_ELSE_BLOCK)
{
if (! (REORDER_BLOCK_FLAGS (sb->succ->dest)
& REORDER_BLOCK_VISITED))
cond_type = PREDICT_NOT_THEN_NO_ELSE;
else
cond_type = PREDICT_THEN_NO_ELSE;
}
}
else
{
if (cond_block_type == THEN_BLOCK)
{
if (! (REORDER_BLOCK_FLAGS (sb->succ->succ_next->dest)
& REORDER_BLOCK_VISITED))
cond_type = PREDICT_THEN_WITH_ELSE;
else
cond_type = PREDICT_ELSE;
}
else if (cond_block_type == ELSE_BLOCK
&& sb->succ->dest != EXIT_BLOCK_PTR)
{
if (! (REORDER_BLOCK_FLAGS (sb->succ->dest)
& REORDER_BLOCK_VISITED))
cond_type = PREDICT_ELSE;
else
cond_type = PREDICT_THEN_WITH_ELSE;
}
}
}
if (rtl_dump_file)
{
static const char * cond_type_str [] = {"not cond jump", "predict then",
"predict else",
"predict then w/o else",
"predict not then w/o else"};
static const char * cond_block_type_str [] = {"not then or else block",
"then block",
"else block",
"then w/o else block"};
fprintf (rtl_dump_file, " %s (looking at %s)\n",
cond_type_str[(int)cond_type],
cond_block_type_str[(int)cond_block_type]);
}
/* Reflect that then block will move and we'll jump to it. */
if (cond_block_type != THEN_BLOCK
&& (cond_type == PREDICT_ELSE
|| cond_type == PREDICT_NOT_THEN_NO_ELSE))
{
if (rtl_dump_file)
fprintf (rtl_dump_file,
" then jump from block %d to block %d\n",
sb->index, sb->succ->dest->index);
/* Jump to reordered then block. */
REORDER_BLOCK_ADD_JUMP (sb) = sb->succ->dest;
}
/* Reflect that then block will jump back when we have no else. */
if (cond_block_type != THEN_BLOCK
&& cond_type == PREDICT_NOT_THEN_NO_ELSE)
{
for (ee = sb->succ->dest->succ;
ee && ! (ee->flags & EDGE_FALLTHRU);
ee = ee->succ_next)
continue;
if (ee && ! (GET_CODE (sb->succ->dest->end) == JUMP_INSN
&& ! simplejump_p (sb->succ->dest->end)))
{
REORDER_BLOCK_ADD_JUMP (sb->succ->dest) = ee->dest;
}
}
/* Reflect that else block will jump back. */
if (cond_block_type == ELSE_BLOCK
&& (cond_type == PREDICT_THEN_WITH_ELSE || cond_type == PREDICT_ELSE))
{
last_edge=db->succ;
if (last_edge
&& last_edge->dest != EXIT_BLOCK_PTR
&& GET_CODE (last_edge->dest->head) == CODE_LABEL
&& ! (GET_CODE (db->end) == JUMP_INSN))
{
if (rtl_dump_file)
fprintf (rtl_dump_file,
" else jump from block %d to block %d\n",
db->index, last_edge->dest->index);
REORDER_BLOCK_ADD_JUMP (db) = last_edge->dest;
}
}
/* This block's successor has already been reordered. This can happen
when we reorder a chain starting at a then or else. */
for (last_edge = db->succ;
last_edge && ! (last_edge->flags & EDGE_FALLTHRU);
last_edge = last_edge->succ_next)
continue;
if (last_edge
&& last_edge->dest != EXIT_BLOCK_PTR
&& (REORDER_BLOCK_FLAGS (last_edge->dest)
& REORDER_BLOCK_VISITED))
{
if (rtl_dump_file)
fprintf (rtl_dump_file,
" end of chain jump from block %d to block %d\n",
db->index, last_edge->dest->index);
REORDER_BLOCK_ADD_JUMP (db) = last_edge->dest;
}
dbh_insn = REORDER_BLOCK_EFF_HEAD (db);
cebe_insn = REORDER_BLOCK_EFF_END (ceb);
dbe_insn = REORDER_BLOCK_EFF_END (db);
/* Leave behind any lexical block markers. */
if (debug_info_level > DINFO_LEVEL_TERSE
&& ceb->index + 1 < db->index)
{
rtx insn, last_insn = get_last_insn ();
insn = NEXT_INSN (ceb->end);
if (! insn)
insn = REORDER_BLOCK_OLD_END (ceb);
if (NEXT_INSN (cebe_insn) == 0)
set_last_insn (cebe_insn);
for (; insn && insn != db->head/*dbh_insn*/;
insn = NEXT_INSN (insn))
{
if (GET_CODE (insn) == NOTE
&& (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG))
{
cebe_insn = emit_note_after (NOTE_INSN_BLOCK_BEG, cebe_insn);
delete_insn (insn);
}
if (GET_CODE (insn) == NOTE
&& (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END))
{
cebe_insn = emit_note_after (NOTE_INSN_BLOCK_END, cebe_insn);
delete_insn (insn);
}
}
set_last_insn (last_insn);
}
/* Rechain predicted block. */
NEXT_INSN (cebe_insn) = dbh_insn;
PREV_INSN (dbh_insn) = cebe_insn;
REORDER_BLOCK_OLD_END (db) = NEXT_INSN (dbe_insn);
if (db->index != n_basic_blocks - 1)
NEXT_INSN (dbe_insn) = 0;
return db;
}
/* Reorder blocks starting at block BB. */
static void
make_reorder_chain (bb)
basic_block bb;
{
edge e;
basic_block visited_edge = NULL;
rtx block_end;
int probability;
if (bb == EXIT_BLOCK_PTR)
return;
/* Find the most probable block. */
e = bb->succ;
block_end = bb->end;
if (GET_CODE (block_end) == JUMP_INSN && condjump_p (block_end))
{
rtx note = find_reg_note (block_end, REG_BR_PROB, 0);
if (note)
probability = INTVAL (XEXP (note, 0));
else
probability = 0;
if (probability >= REG_BR_PROB_BASE / 2)
e = bb->succ->succ_next;
}
/* Add chosen successor to chain and recurse on it. */
if (e && e->dest != EXIT_BLOCK_PTR
&& e->dest != e->src
&& (! (REORDER_BLOCK_FLAGS (e->dest) & REORDER_BLOCK_VISITED)
|| (REORDER_BLOCK_FLAGS (e->dest) == REORDER_BLOCK_HEAD)))
{
if (! (REORDER_BLOCK_FLAGS (bb) & REORDER_BLOCK_VISITED))
{
REORDER_BLOCK_FLAGS (bb) |= REORDER_BLOCK_HEAD;
REORDER_BLOCK_INDEX (bb) = reorder_index++;
REORDER_BLOCK_FLAGS (bb) |= REORDER_BLOCK_VISITED;
}
if (REORDER_BLOCK_FLAGS (e->dest) & REORDER_BLOCK_VISITED)
REORDER_BLOCK_FLAGS (e->dest) &= ~REORDER_BLOCK_HEAD;
REORDER_BLOCK_SUCC (bb) = e;
visited_edge = e->dest;
reorder_last_visited = chain_reorder_blocks (e, bb);
if (e->dest
&& ! (REORDER_BLOCK_FLAGS (e->dest)
& REORDER_BLOCK_VISITED))
make_reorder_chain (e->dest);
}
else
{
if (! (REORDER_BLOCK_FLAGS (bb) & REORDER_BLOCK_VISITED))
{
REORDER_BLOCK_INDEX (bb) = reorder_index++;
REORDER_BLOCK_FLAGS (bb) |= REORDER_BLOCK_VISITED;
}
}
/* Recurse on the successors. */
for (e = bb->succ; e; e = e->succ_next)
{
if (e->dest && e->dest == EXIT_BLOCK_PTR)
continue;
if (e->dest
&& e->dest != e->src
&& e->dest != visited_edge
&& ! (REORDER_BLOCK_FLAGS (e->dest)
& REORDER_BLOCK_VISITED))
{
reorder_last_visited
= chain_reorder_blocks (e, reorder_last_visited);
make_reorder_chain (e->dest);
}
}
}
/* Fixup jumps and labels after reordering basic blocks. */
static void
fixup_reorder_chain ()
{
int i, j;
rtx insn;
int orig_num_blocks = n_basic_blocks;
/* Set the new last insn. */
{
int max_val = 0;
int max_index = 0;
for (j = 0; j < n_basic_blocks; j++)
{
int val = REORDER_BLOCK_INDEX (BASIC_BLOCK (j));
if (val > max_val)
{
max_val = val;
max_index = j;
}
}
insn = REORDER_BLOCK_EFF_END (BASIC_BLOCK (max_index));
NEXT_INSN (insn) = NULL_RTX;
set_last_insn (insn);
}
/* Add jumps and labels to fixup blocks. */
for (i = 0; i < orig_num_blocks; i++)
{
int need_block = 0;
basic_block bbi = BASIC_BLOCK (i);
if (REORDER_BLOCK_ADD_JUMP (bbi))
{
rtx label_insn, jump_insn, barrier_insn;
if (GET_CODE (REORDER_BLOCK_ADD_JUMP (bbi)->head) == CODE_LABEL)
label_insn = REORDER_BLOCK_ADD_JUMP (bbi)->head;
else
{
rtx new_label = gen_label_rtx ();
label_insn = emit_label_before (new_label,
REORDER_BLOCK_ADD_JUMP (bbi)->head);
REORDER_BLOCK_ADD_JUMP (bbi)->head = label_insn;
}
if (GET_CODE (bbi->end) != JUMP_INSN)
{
jump_insn = emit_jump_insn_after (gen_jump (label_insn),
bbi->end);
bbi->end = jump_insn;
need_block = 0;
}
else
{
jump_insn = emit_jump_insn_after (gen_jump (label_insn),
REORDER_BLOCK_EFF_END (bbi));
need_block = 1;
}
JUMP_LABEL (jump_insn) = label_insn;
++LABEL_NUSES (label_insn);
barrier_insn = emit_barrier_after (jump_insn);
/* Add block for jump. Typically this is when a then is not
predicted and we are jumping to the moved then block. */
if (need_block)
{
basic_block nb;
VARRAY_GROW (basic_block_info, ++n_basic_blocks);
create_basic_block (n_basic_blocks - 1, jump_insn,
jump_insn, NULL);
nb = BASIC_BLOCK (n_basic_blocks - 1);
nb->global_live_at_start
= OBSTACK_ALLOC_REG_SET (function_obstack);
nb->global_live_at_end
= OBSTACK_ALLOC_REG_SET (function_obstack);
COPY_REG_SET (nb->global_live_at_start,
bbi->global_live_at_start);
COPY_REG_SET (nb->global_live_at_end,
bbi->global_live_at_start);
BASIC_BLOCK (nb->index)->local_set = 0;
nb->aux = xcalloc (1, sizeof (struct reorder_block_def));
REORDER_BLOCK_INDEX (nb) = REORDER_BLOCK_INDEX (bbi) + 1;
/* Relink to new block. */
nb->succ = bbi->succ;
nb->succ->src = nb;
make_edge (NULL, bbi, nb, 0);
bbi->succ->succ_next
= bbi->succ->succ_next->succ_next;
nb->succ->succ_next = 0;
/* Fix reorder block index to reflect new block. */
for (j = 0; j < n_basic_blocks - 1; j++)
{
basic_block bbj = BASIC_BLOCK (j);
if (REORDER_BLOCK_INDEX (bbj)
>= REORDER_BLOCK_INDEX (bbi) + 1)
REORDER_BLOCK_INDEX (bbj)++;
}
}
}
}
}
/* Perform sanity checks on the insn chain.
1. Check that next/prev pointers are consistent in both the forward and
reverse direction.
2. Count insns in chain, going both directions, and check if equal.
3. Check that get_last_insn () returns the actual end of chain. */
#ifdef ENABLE_CHECKING
static void
verify_insn_chain ()
{
rtx x,
prevx,
nextx;
int insn_cnt1,
insn_cnt2;
prevx = NULL;
insn_cnt1 = 1;
for (x = get_insns (); x; x = NEXT_INSN (x))
{
if (PREV_INSN (x) != prevx)
{
fprintf (stderr, "Forward traversal: insn chain corrupt.\n");
fprintf (stderr, "previous insn:\n");
debug_rtx (prevx);
fprintf (stderr, "current insn:\n");
debug_rtx (x);
abort ();
}
++insn_cnt1;
prevx = x;
}
if (prevx != get_last_insn ())
{
fprintf (stderr, "last_insn corrupt.\n");
abort ();
}
nextx = NULL;
insn_cnt2 = 1;
for (x = get_last_insn (); x; x = PREV_INSN (x))
{
if (NEXT_INSN (x) != nextx)
{
fprintf (stderr, "Reverse traversal: insn chain corrupt.\n");
fprintf (stderr, "current insn:\n");
debug_rtx (x);
fprintf (stderr, "next insn:\n");
debug_rtx (nextx);
abort ();
}
++insn_cnt2;
nextx = x;
}
if (insn_cnt1 != insn_cnt2)
{
fprintf (stderr, "insn_cnt1 (%d) not equal to insn_cnt2 (%d).\n",
insn_cnt1, insn_cnt2);
abort ();
}
}
#endif
/* Reorder basic blocks. */
void
reorder_basic_blocks ()
{
int i, j;
struct loops loops_info;
int num_loops;
if (profile_arc_flag)
return;
if (n_basic_blocks <= 1)
return;
/* Exception edges are not currently handled. */
for (i = 0; i < n_basic_blocks; i++)
{
edge e;
for (e = BASIC_BLOCK (i)->succ; e && ! (e->flags & EDGE_EH);
e = e->succ_next)
continue;
if (e && (e->flags & EDGE_EH))
return;
}
reorder_index = 0;
/* Find natural loops using the CFG. */
num_loops = flow_loops_find (&loops_info);
/* Dump loop information. */
flow_loops_dump (&loops_info, rtl_dump_file, 0);
/* Estimate using heuristics if no profiling info is available. */
if (! flag_branch_probabilities)
estimate_probability (&loops_info);
reorder_last_visited = BASIC_BLOCK (0);
for (i = 0; i < n_basic_blocks; i++)
{
basic_block bbi = BASIC_BLOCK (i);
bbi->aux = xcalloc (1, sizeof (struct reorder_block_def));
*((struct reorder_block_def *)bbi->aux) = rbd_init;
REORDER_BLOCK_EFF_END (bbi)
= skip_insns_between_block (bbi, REORDER_SKIP_AFTER);
if (i == 0)
REORDER_BLOCK_EFF_HEAD (bbi) = get_insns ();
else
{
rtx prev_eff_end = REORDER_BLOCK_EFF_END (BASIC_BLOCK (i - 1));
REORDER_BLOCK_EFF_HEAD (bbi) = NEXT_INSN (prev_eff_end);
}
}
/* If we've not got epilogue in RTL, we must fallthru to the exit.
Force the last block to be at the end. */
/* ??? Some ABIs (e.g. MIPS) require the return insn to be at the
end of the function for stack unwinding purposes. */
#ifndef HAVE_epilogue
#define HAVE_epilogue 0
#endif
if (! HAVE_epilogue)
{
basic_block last = BASIC_BLOCK (n_basic_blocks - 1);
REORDER_BLOCK_INDEX (last) = n_basic_blocks - 1;
REORDER_BLOCK_FLAGS (last) |= REORDER_BLOCK_VISITED;
}
make_reorder_chain (BASIC_BLOCK (0));
fixup_reorder_chain ();
#ifdef ENABLE_CHECKING
verify_insn_chain ();
#endif
/* Put basic_block_info in new order. */
for (i = 0; i < n_basic_blocks - 1; i++)
{
for (j = i; i != REORDER_BLOCK_INDEX (BASIC_BLOCK (j)); j++)
continue;
if (REORDER_BLOCK_INDEX (BASIC_BLOCK (j)) == i
&& i != j)
{
basic_block tempbb;
int temprbi;
int rbi = REORDER_BLOCK_INDEX (BASIC_BLOCK (j));
temprbi = BASIC_BLOCK (rbi)->index;
BASIC_BLOCK (rbi)->index = BASIC_BLOCK (j)->index;
BASIC_BLOCK (j)->index = temprbi;
tempbb = BASIC_BLOCK (rbi);
BASIC_BLOCK (rbi) = BASIC_BLOCK (j);
BASIC_BLOCK (j) = tempbb;
}
}
#ifdef ENABLE_CHECKING
verify_flow_info ();
#endif
for (i = 0; i < n_basic_blocks; i++)
free (BASIC_BLOCK (i)->aux);
/* Free loop information. */
flow_loops_free (&loops_info);
}
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