/* Basic block reordering routines for the GNU compiler.
Copyright (C) 2000 Free Software Foundation, Inc.
- This file is part of GNU CC.
+ This file is part of GCC.
- 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
+ GCC 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.
+ GCC 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. */
+ along with GCC; see the file COPYING. If not, write to the Free
+ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+ 02111-1307, USA. */
/* References:
#include "system.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 "toplev.h"
-#include "recog.h"
-#include "expr.h"
-#include "obstack.h"
-
+#include "cfglayout.h"
#ifndef HAVE_epilogue
#define HAVE_epilogue 0
#endif
-
-/* 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 flow_obstack;
-
-
-/* Structure to hold information about lexical scopes. */
-typedef struct scope_def
-{
- int level;
-
- /* The NOTE_INSN_BLOCK_BEG that started this scope. */
- rtx note_beg;
-
- /* The NOTE_INSN_BLOCK_END that ended this scope. */
- rtx note_end;
-
- /* The bb containing note_beg (if any). */
- basic_block bb_beg;
-
- /* The bb containing note_end (if any). */
- basic_block bb_end;
-
- /* List of basic blocks contained within this scope. */
- basic_block *bbs;
-
- /* Number of blocks contained within this scope. */
- int num_bbs;
-
- /* The outer scope or NULL if outermost scope. */
- struct scope_def *outer;
-
- /* The first inner scope or NULL if innermost scope. */
- struct scope_def *inner;
-
- /* The last inner scope or NULL if innermost scope. */
- struct scope_def *inner_last;
-
- /* Link to the next (sibling) scope. */
- struct scope_def *next;
-} *scope;
-
-
-/* Structure to hold information about the scope forest. */
-typedef struct
-{
- /* Number of trees in forest. */
- int num_trees;
-
- /* List of tree roots. */
- scope *trees;
-} scope_forest_info;
-
-/* Structure to hold information about the blocks during reordering. */
-typedef struct reorder_block_def
-{
- rtx eff_head;
- rtx eff_end;
- scope scope;
- basic_block next;
- int index;
- int visited;
-} *reorder_block_def;
-
-#define RBI(BB) ((reorder_block_def) (BB)->aux)
-
-
/* Local function prototypes. */
-static rtx skip_insns_after_block PARAMS ((basic_block));
-static void record_effective_endpoints PARAMS ((void));
static void make_reorder_chain PARAMS ((void));
static basic_block make_reorder_chain_1 PARAMS ((basic_block, basic_block));
-static rtx label_for_bb PARAMS ((basic_block));
-static rtx emit_jump_to_block_after PARAMS ((basic_block, rtx));
-static void fixup_reorder_chain PARAMS ((void));
-static void relate_bbs_with_scopes PARAMS ((scope));
-static scope make_new_scope PARAMS ((int, rtx));
-static void build_scope_forest PARAMS ((scope_forest_info *));
-static void remove_scope_notes PARAMS ((void));
-static void insert_intra_1 PARAMS ((scope, rtx *));
-static void insert_intra_bb_scope_notes PARAMS ((basic_block));
-static void insert_inter_bb_scope_notes PARAMS ((basic_block, basic_block));
-static void rebuild_scope_notes PARAMS ((scope_forest_info *));
-static void free_scope_forest_1 PARAMS ((scope));
-static void free_scope_forest PARAMS ((scope_forest_info *));
-void dump_scope_forest PARAMS ((scope_forest_info *));
-static void dump_scope_forest_1 PARAMS ((scope, int));
-static rtx get_next_bb_note PARAMS ((rtx));
-static rtx get_prev_bb_note PARAMS ((rtx));
-
-void verify_insn_chain PARAMS ((void));
\f
-/* Skip over inter-block insns occurring after BB which are typically
- associated with BB (e.g., barriers). If there are any such insns,
- we return the last one. Otherwise, we return the end of BB. */
-
-static rtx
-skip_insns_after_block (bb)
- basic_block bb;
-{
- rtx insn, last_insn, next_head;
-
- next_head = NULL_RTX;
- if (bb->index + 1 != n_basic_blocks)
- next_head = BASIC_BLOCK (bb->index + 1)->head;
-
- for (last_insn = bb->end; (insn = NEXT_INSN (last_insn)); last_insn = insn)
- {
- if (insn == next_head)
- break;
-
- switch (GET_CODE (insn))
- {
- case BARRIER:
- continue;
-
- case 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:
- 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);
- continue;
- }
- break;
-
- default:
- break;
- }
-
- break;
- }
-
- return last_insn;
-}
-
-
-/* Locate the effective beginning and end of the insn chain for each
- block, as defined by skip_insns_after_block above. */
-
-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);
- }
-}
-
-
/* Compute an ordering for a subgraph beginning with block BB. Record the
ordering in RBI()->index and chained through RBI()->next. */
basic_block last_block = NULL;
basic_block prev = NULL;
int nbb_m1 = n_basic_blocks - 1;
+ basic_block next;
/* If we've not got epilogue in RTL, we must fallthru to the exit.
Force the last block to be at the end. */
do
{
int i;
- basic_block next = NULL;
+
+ next = NULL;
/* Find the next unplaced block. */
/* ??? Get rid of this loop, and track which blocks are not yet
remove from the list as we place. The head of that list is
what we're looking for here. */
- for (i = 0; i <= nbb_m1; ++i)
+ for (i = 0; i <= nbb_m1 && !next; ++i)
{
basic_block bb = BASIC_BLOCK (i);
if (! RBI (bb)->visited)
- {
- next = bb;
- break;
- }
+ next = bb;
}
- if (! next)
- abort ();
-
- prev = make_reorder_chain_1 (next, prev);
+ if (next)
+ prev = make_reorder_chain_1 (next, prev);
}
- while (RBI (prev)->index < nbb_m1);
+ while (next);
/* Terminate the chain. */
if (! HAVE_epilogue)
{
RBI (prev)->next = last_block;
- RBI (last_block)->index = RBI (prev)->index + 1;
prev = last_block;
}
RBI (prev)->next = NULL;
/* Mark this block visited. */
if (prev)
{
- int new_index;
-
restart:
RBI (prev)->next = bb;
- new_index = RBI (prev)->index + 1;
- RBI (bb)->index = new_index;
if (rtl_dump_file && prev->index + 1 != bb->index)
- fprintf (rtl_dump_file, "Reordering block %d (%d) after %d (%d)\n",
- bb->index, RBI (bb)->index, prev->index, RBI (prev)->index);
+ fprintf (rtl_dump_file, "Reordering block %d after %d\n",
+ bb->index, prev->index);
}
else
- RBI (bb)->index = 0;
+ {
+ if (bb->index != 0)
+ abort ();
+ }
RBI (bb)->visited = 1;
prev = bb;
return prev;
}
-
-/* Locate or create a label for a given basic block. */
-
-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 (%d)\n",
- bb->index, RBI (bb)->index);
-
- label = emit_label_before (gen_label_rtx (), label);
- if (bb->head == RBI (bb)->eff_head)
- RBI (bb)->eff_head = label;
- bb->head = label;
- }
-
- return label;
-}
-
-
-/* Emit a jump to BB after insn AFTER. */
-
-static rtx
-emit_jump_to_block_after (bb, after)
- basic_block bb;
- rtx after;
-{
- rtx jump;
-
- if (bb != EXIT_BLOCK_PTR)
- {
- rtx label = label_for_bb (bb);
- jump = emit_jump_insn_after (gen_jump (label), after);
- JUMP_LABEL (jump) = label;
- LABEL_NUSES (label) += 1;
-
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Emitting jump to block %d (%d)\n",
- bb->index, RBI (bb)->index);
- }
- else
- {
-#ifdef HAVE_return
- if (! HAVE_return)
- abort ();
- jump = emit_jump_insn_after (gen_return (), after);
-
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Emitting return\n");
-#else
- abort ();
-#endif
- }
-
- return jump;
-}
-
-
-/* Given a reorder chain, rearrange the code to match. */
-
-static void
-fixup_reorder_chain ()
-{
- basic_block bb, last_bb;
-
- /* First do the bulk reordering -- rechain the blocks without regard to
- the needed changes to jumps and labels. */
-
- last_bb = BASIC_BLOCK (0);
- bb = RBI (last_bb)->next;
- while (bb)
- {
- 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;
-
- last_bb = bb;
- bb = RBI (bb)->next;
- }
- NEXT_INSN (RBI (last_bb)->eff_end) = NULL_RTX;
- set_last_insn (RBI (last_bb)->eff_end);
-
- /* Now add jumps and labels as needed to match the blocks new
- outgoing edges. */
-
- for (bb = BASIC_BLOCK (0); bb ; bb = RBI (bb)->next)
- {
- edge e_fall, e_taken, e;
- rtx jump_insn, barrier_insn, bb_end_insn;
- basic_block nb;
-
- if (bb->succ == NULL)
- continue;
-
- /* Find the old fallthru edge, and another non-EH edge for
- a taken jump. */
- 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_uncondjump_p (bb_end_insn))
- {
- /* If the destination is still not next, nothing to do. */
- if (RBI (bb)->index + 1 != RBI (e_taken->dest)->index)
- continue;
-
- /* Otherwise, we can remove the jump and cleanup the edge. */
- tidy_fallthru_edge (e_taken, bb, e_taken->dest);
- RBI (bb)->eff_end = skip_insns_after_block (bb);
- RBI (e_taken->dest)->eff_head = NEXT_INSN (RBI (bb)->eff_end);
-
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Removing jump in block %d (%d)\n",
- bb->index, RBI (bb)->index);
- continue;
- }
- else if (any_condjump_p (bb_end_insn))
- {
- /* If the old fallthru is still next, nothing to do. */
- if (RBI (bb)->index + 1 == RBI (e_fall->dest)->index
- || (RBI (bb)->index == n_basic_blocks - 1
- && e_fall->dest == EXIT_BLOCK_PTR))
- continue;
-
- /* There is one special case: if *neither* block is next,
- such as happens at the very end of a function, then we'll
- need to add a new unconditional jump. Choose the taken
- edge based on known or assumed probability. */
- if (RBI (bb)->index + 1 != RBI (e_taken->dest)->index)
- {
- 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;
- e = e_fall, e_fall = e_taken, e_taken = e;
- }
- }
-
- /* Otherwise we can try to invert the jump. This will
- basically never fail, however, keep up the pretense. */
- else if (invert_jump (bb_end_insn,
- label_for_bb (e_fall->dest), 0))
- {
- e_fall->flags &= ~EDGE_FALLTHRU;
- e_taken->flags |= EDGE_FALLTHRU;
- continue;
- }
- }
- else if (returnjump_p (bb_end_insn))
- continue;
- else
- {
- /* Otherwise we have some switch or computed jump. In the
- 99% case, there should not have been a fallthru edge. */
- if (! e_fall)
- continue;
-#ifdef CASE_DROPS_THROUGH
- /* Except for VAX. Since we didn't have predication for the
- tablejump, the fallthru block should not have moved. */
- if (RBI (bb)->index + 1 == RBI (e_fall->dest)->index)
- continue;
- bb_end_insn = skip_insns_after_block (bb);
-#else
- abort ();
-#endif
- }
- }
- else
- {
- /* No fallthru implies a noreturn function with EH edges, or
- something similarly bizarre. In any case, we don't need to
- do anything. */
- if (! e_fall)
- continue;
-
- /* If the fallthru block is still next, nothing to do. */
- if (RBI (bb)->index + 1 == RBI (e_fall->dest)->index
- || (RBI (bb)->index == n_basic_blocks - 1
- && e_fall->dest == EXIT_BLOCK_PTR))
- continue;
-
- /* We need a new jump insn. If the block has only one outgoing
- edge, then we can stuff the new jump insn in directly. */
- if (bb->succ->succ_next == NULL)
- {
- e_fall->flags &= ~EDGE_FALLTHRU;
-
- jump_insn = emit_jump_to_block_after (e_fall->dest, bb_end_insn);
- bb->end = jump_insn;
- barrier_insn = emit_barrier_after (jump_insn);
- RBI (bb)->eff_end = barrier_insn;
- continue;
- }
- }
-
- /* We got here if we need to add a new jump insn in a new block
- across the edge e_fall. */
-
- jump_insn = emit_jump_to_block_after (e_fall->dest, bb_end_insn);
- barrier_insn = emit_barrier_after (jump_insn);
-
- 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 (&flow_obstack);
- nb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack);
- nb->local_set = 0;
-
- COPY_REG_SET (nb->global_live_at_start, bb->global_live_at_start);
- COPY_REG_SET (nb->global_live_at_end, bb->global_live_at_start);
-
- nb->aux = xmalloc (sizeof (struct reorder_block_def));
- RBI (nb)->eff_head = nb->head;
- RBI (nb)->eff_end = barrier_insn;
- RBI (nb)->scope = RBI (bb)->scope;
- RBI (nb)->index = RBI (bb)->index + 1;
- RBI (nb)->visited = 1;
- RBI (nb)->next = RBI (bb)->next;
- RBI (bb)->next = nb;
-
- /* Link to new block. */
- make_edge (NULL, nb, e_fall->dest, 0);
- redirect_edge_succ (e_fall, nb);
-
- /* Don't process this new block. */
- bb = nb;
-
- /* Fix subsequent reorder block indices to reflect new block. */
- while ((nb = RBI (nb)->next) != NULL)
- RBI (nb)->index += 1;
- }
-
- /* Put basic_block_info in the new order. */
- for (bb = BASIC_BLOCK (0); bb ; bb = RBI (bb)->next)
- {
- bb->index = RBI (bb)->index;
- BASIC_BLOCK (bb->index) = bb;
- }
-}
-
-
-/* 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. */
-
-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 ();
- }
-}
-
-static rtx
-get_next_bb_note (x)
- rtx x;
-{
- while (x)
- {
- if (NOTE_INSN_BASIC_BLOCK_P (x))
- return x;
- x = NEXT_INSN (x);
- }
- return NULL;
-}
-
-
-static rtx
-get_prev_bb_note (x)
- rtx x;
-{
- while (x)
- {
- if (NOTE_INSN_BASIC_BLOCK_P (x))
- return x;
- x = PREV_INSN (x);
- }
- return NULL;
-}
-
-
-/* Determine and record the relationships between basic blocks and
- scopes in scope tree S. */
-
-static void
-relate_bbs_with_scopes (s)
- scope s;
-{
- scope p;
- int i, bbi1, bbi2, bbs_spanned;
- rtx bbnote;
-
- for (p = s->inner; p; p = p->next)
- relate_bbs_with_scopes (p);
-
- bbi1 = bbi2 = -1;
- bbs_spanned = 0;
-
- /* If the begin and end notes are both inside the same basic block,
- or if they are both outside of basic blocks, then we know immediately
- how they are related. Otherwise, we need to poke around to make the
- determination. */
- if (s->bb_beg != s->bb_end)
- {
- if (s->bb_beg && s->bb_end)
- {
- /* Both notes are in different bbs. This implies that all the
- basic blocks spanned by the pair of notes are contained in
- this scope. */
- bbi1 = s->bb_beg->index;
- bbi2 = s->bb_end->index;
- bbs_spanned = 1;
- }
- else if (! s->bb_beg)
- {
- /* First note is outside of a bb. If the scope spans more than
- one basic block, then they all are contained within this
- scope. Otherwise, this scope is contained within the basic
- block. */
- bbnote = get_next_bb_note (s->note_beg);
- if (! bbnote)
- abort ();
- if (NOTE_BASIC_BLOCK (bbnote) == s->bb_end)
- {
- bbs_spanned = 0;
- s->bb_beg = NOTE_BASIC_BLOCK (bbnote);
- }
- else
- {
- bbi1 = NOTE_BASIC_BLOCK (bbnote)->index;
- bbi2 = s->bb_end->index;
- s->bb_end = NULL;
- bbs_spanned = 1;
- }
- }
- else /* ! s->bb_end */
- {
- /* Second note is outside of a bb. If the scope spans more than
- one basic block, then they all are contained within this
- scope. Otherwise, this scope is contained within the basic
- block. */
- bbnote = get_prev_bb_note (s->note_end);
- if (! bbnote)
- abort ();
- if (NOTE_BASIC_BLOCK (bbnote) == s->bb_beg)
- {
- bbs_spanned = 0;
- s->bb_end = NOTE_BASIC_BLOCK (bbnote);
- }
- else
- {
- bbi1 = s->bb_beg->index;
- bbi2 = NOTE_BASIC_BLOCK (bbnote)->index;
- s->bb_beg = NULL;
- bbs_spanned = 1;
- }
- }
- }
- else
- {
- if (s->bb_beg)
- /* Both notes are in the same bb, which implies the block
- contains this scope. */
- bbs_spanned = 0;
- else
- {
- rtx x1, x2;
- /* Both notes are outside of any bbs. This implies that all the
- basic blocks spanned by the pair of notes are contained in
- this scope.
- There is a degenerate case to consider. If the notes do not
- span any basic blocks, then it is an empty scope that can
- safely be deleted or ignored. Mark these with level = -1. */
-
- x1 = get_next_bb_note (s->note_beg);
- x2 = get_prev_bb_note (s->note_end);
- if (! (x1 && x2))
- {
- s->level = -1;
- bbs_spanned = 0;
- }
- else
- {
- bbi1 = NOTE_BASIC_BLOCK (x1)->index;
- bbi2 = NOTE_BASIC_BLOCK (x2)->index;
- bbs_spanned = 1;
- }
- }
- }
-
- /* If the scope spans one or more basic blocks, we record them. We
- only record the bbs that are immediately contained within this
- scope. Note that if a scope is contained within a bb, we can tell
- by checking that bb_beg = bb_end and that they are non-null. */
- if (bbs_spanned)
- {
- int j = 0;
-
- s->num_bbs = 0;
- for (i = bbi1; i <= bbi2; i++)
- if (! RBI (BASIC_BLOCK (i))->scope)
- s->num_bbs++;
-
- s->bbs = xmalloc (s->num_bbs * sizeof (basic_block));
- for (i = bbi1; i <= bbi2; i++)
- {
- basic_block curr_bb = BASIC_BLOCK (i);
- if (! RBI (curr_bb)->scope)
- {
- s->bbs[j++] = curr_bb;
- RBI (curr_bb)->scope = s;
- }
- }
- }
- else
- s->num_bbs = 0;
-}
-
-
-/* Allocate and initialize a new scope structure with scope level LEVEL,
- and record the NOTE beginning the scope. */
-
-static scope
-make_new_scope (level, note)
- int level;
- rtx note;
-{
- scope new_scope = xcalloc (1, sizeof (struct scope_def));
- new_scope->level = level;
- new_scope->note_beg = note;
- return new_scope;
-}
-
-
-/* Build a forest representing the scope structure of the function.
- Return a pointer to a structure describing the forest. */
-
-static void
-build_scope_forest (forest)
- scope_forest_info *forest;
-{
- rtx x;
- int level, bbi, i;
- basic_block curr_bb;
- scope root, curr_scope = 0;
-
- forest->num_trees = 0;
- forest->trees = NULL;
- level = -1;
- root = NULL;
- curr_bb = NULL;
- bbi = 0;
- for (x = get_insns (); x; x = NEXT_INSN (x))
- {
- if (bbi < n_basic_blocks && x == BASIC_BLOCK (bbi)->head)
- curr_bb = BASIC_BLOCK (bbi);
-
- if (GET_CODE (x) == NOTE)
- {
- if (NOTE_LINE_NUMBER (x) == NOTE_INSN_BLOCK_BEG)
- {
- if (root)
- {
- scope new_scope;
- if (! curr_scope)
- abort();
- level++;
- new_scope = make_new_scope (level, x);
- new_scope->outer = curr_scope;
- new_scope->next = NULL;
- if (! curr_scope->inner)
- {
- curr_scope->inner = new_scope;
- curr_scope->inner_last = new_scope;
- }
- else
- {
- curr_scope->inner_last->next = new_scope;
- curr_scope->inner_last = new_scope;
- }
- curr_scope = curr_scope->inner_last;
- }
- else
- {
- int ntrees = forest->num_trees;
- level++;
- curr_scope = make_new_scope (level, x);
- root = curr_scope;
- forest->trees = xrealloc (forest->trees,
- sizeof (scope) * (ntrees + 1));
- forest->trees[forest->num_trees++] = root;
- }
- curr_scope->bb_beg = curr_bb;
- }
- else if (NOTE_LINE_NUMBER (x) == NOTE_INSN_BLOCK_END)
- {
- curr_scope->bb_end = curr_bb;
- curr_scope->note_end = x;
- level--;
- curr_scope = curr_scope->outer;
- if (level == -1)
- root = NULL;
- }
- } /* if note */
-
- if (curr_bb && curr_bb->end == x)
- {
- curr_bb = NULL;
- bbi++;
- }
-
- } /* for */
-
- for (i = 0; i < forest->num_trees; i++)
- relate_bbs_with_scopes (forest->trees[i]);
-}
-
-
-/* Remove all the NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes from
- the insn chain. */
-
-static void
-remove_scope_notes ()
-{
- rtx x, next;
- basic_block currbb = NULL;
-
- for (x = get_insns (); x; x = next)
- {
- next = NEXT_INSN (x);
- if (NOTE_INSN_BASIC_BLOCK_P (x))
- currbb = NOTE_BASIC_BLOCK (x);
-
- if (GET_CODE (x) == NOTE
- && (NOTE_LINE_NUMBER (x) == NOTE_INSN_BLOCK_BEG
- || NOTE_LINE_NUMBER (x) == NOTE_INSN_BLOCK_END))
- {
- /* Check if the scope note happens to be the end of a bb. */
- if (currbb && x == currbb->end)
- currbb->end = PREV_INSN (x);
- if (currbb && x == currbb->head)
- abort ();
-
- if (PREV_INSN (x))
- {
- NEXT_INSN (PREV_INSN (x)) = next;
- PREV_INSN (next) = PREV_INSN (x);
-
- NEXT_INSN (x) = NULL;
- PREV_INSN (x) = NULL;
- }
- else
- abort ();
- }
- }
-}
-
-
-/* Insert scope note pairs for a contained scope tree S after insn IP. */
-
-static void
-insert_intra_1 (s, ip)
- scope s;
- rtx *ip;
-{
- scope p;
-
- if (NOTE_BLOCK (s->note_beg))
- {
- *ip = emit_note_after (NOTE_INSN_BLOCK_BEG, *ip);
- NOTE_BLOCK (*ip) = NOTE_BLOCK (s->note_beg);
- }
-
- for (p = s->inner; p; p = p->next)
- insert_intra_1 (p, ip);
-
- if (NOTE_BLOCK (s->note_beg))
- {
- *ip = emit_note_after (NOTE_INSN_BLOCK_END, *ip);
- NOTE_BLOCK (*ip) = NOTE_BLOCK (s->note_end);
- }
-}
-
-
-/* Insert NOTE_INSN_BLOCK_END notes and NOTE_INSN_BLOCK_BEG notes for
- scopes that are contained within BB. */
-
-static void
-insert_intra_bb_scope_notes (bb)
- basic_block bb;
-{
- scope s = RBI (bb)->scope;
- scope p;
- rtx ip;
-
- if (! s)
- return;
-
- ip = bb->head;
- if (GET_CODE (ip) == CODE_LABEL)
- ip = NEXT_INSN (ip);
-
- for (p = s->inner; p; p = p->next)
- {
- if (p->bb_beg != NULL && p->bb_beg == p->bb_end && p->bb_beg == bb)
- insert_intra_1 (p, &ip);
- }
-}
-
-
-/* Given two consecutive basic blocks BB1 and BB2 with different scopes,
- insert NOTE_INSN_BLOCK_END notes after BB1 and NOTE_INSN_BLOCK_BEG
- notes before BB2 such that the notes are correctly balanced. If BB1 or
- BB2 is NULL, we are inserting scope notes for the first and last basic
- blocks, respectively. */
-
-static void
-insert_inter_bb_scope_notes (bb1, bb2)
- basic_block bb1;
- basic_block bb2;
-{
- rtx ip;
- scope com;
-
- /* It is possible that a basic block is not contained in any scope.
- In that case, we either open or close a scope but not both. */
- if (bb1 && bb2)
- {
- scope s1 = RBI (bb1)->scope;
- scope s2 = RBI (bb2)->scope;
- if (! s1 && ! s2)
- return;
- if (! s1)
- bb1 = NULL;
- else if (! s2)
- bb2 = NULL;
- }
-
- /* Find common ancestor scope. */
- if (bb1 && bb2)
- {
- scope s1 = RBI (bb1)->scope;
- scope s2 = RBI (bb2)->scope;
- while (s1 != s2)
- {
- if (! (s1 && s2))
- abort ();
- if (s1->level > s2->level)
- s1 = s1->outer;
- else if (s2->level > s1->level)
- s2 = s2->outer;
- else
- {
- s1 = s1->outer;
- s2 = s2->outer;
- }
- }
- com = s1;
- }
- else
- com = NULL;
-
- /* Close scopes. */
- if (bb1)
- {
- scope s = RBI (bb1)->scope;
- ip = RBI (bb1)->eff_end;
- while (s != com)
- {
- if (NOTE_BLOCK (s->note_beg))
- {
- ip = emit_note_after (NOTE_INSN_BLOCK_END, ip);
- NOTE_BLOCK (ip) = NOTE_BLOCK (s->note_end);
- }
- s = s->outer;
- }
- }
-
- /* Open scopes. */
- if (bb2)
- {
- scope s = RBI (bb2)->scope;
- ip = bb2->head;
- while (s != com)
- {
- if (NOTE_BLOCK (s->note_beg))
- {
- ip = emit_note_before (NOTE_INSN_BLOCK_BEG, ip);
- NOTE_BLOCK (ip) = NOTE_BLOCK (s->note_beg);
- }
- s = s->outer;
- }
- }
-}
-
-
-/* Rebuild all the NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes based
- on the scope forest and the newly reordered basic blocks. */
-
-static void
-rebuild_scope_notes (forest)
- scope_forest_info *forest;
-{
- int i;
-
- if (forest->num_trees == 0)
- return;
-
- /* Start by opening the scopes before the first basic block. */
- insert_inter_bb_scope_notes (NULL, BASIC_BLOCK (0));
-
- /* Then, open and close scopes as needed between blocks. */
- for (i = 0; i < n_basic_blocks - 1; i++)
- {
- basic_block bb1 = BASIC_BLOCK (i);
- basic_block bb2 = BASIC_BLOCK (i + 1);
- if (RBI (bb1)->scope != RBI (bb2)->scope)
- insert_inter_bb_scope_notes (bb1, bb2);
- insert_intra_bb_scope_notes (bb1);
- }
-
- /* Finally, close the scopes after the last basic block. */
- insert_inter_bb_scope_notes (BASIC_BLOCK (n_basic_blocks - 1), NULL);
- insert_intra_bb_scope_notes (BASIC_BLOCK (n_basic_blocks - 1));
-}
-
-
-/* Free the storage associated with the scope tree at S. */
-
-static void
-free_scope_forest_1 (s)
- scope s;
-{
- scope p, next;
-
- for (p = s->inner; p; p = next)
- {
- next = p->next;
- free_scope_forest_1 (p);
- }
-
- if (s->bbs)
- free (s->bbs);
- free (s);
-}
-
-
-/* Free the storage associated with the scope forest. */
-
-static void
-free_scope_forest (forest)
- scope_forest_info *forest;
-{
- int i;
- for (i = 0; i < forest->num_trees; i++)
- free_scope_forest_1 (forest->trees[i]);
-}
-
-
-/* Visualize the scope forest. */
-
-void
-dump_scope_forest (forest)
- scope_forest_info *forest;
-{
- if (forest->num_trees == 0)
- fprintf (stderr, "\n< Empty scope forest >\n");
- else
- {
- int i;
- fprintf (stderr, "\n< Scope forest >\n");
- for (i = 0; i < forest->num_trees; i++)
- dump_scope_forest_1 (forest->trees[i], 0);
- }
-}
-
-
-/* Recursive portion of dump_scope_forest. */
-
-static void
-dump_scope_forest_1 (s, indent)
- scope s;
- int indent;
-{
- scope p;
- int i;
-
- if (s->bb_beg != NULL && s->bb_beg == s->bb_end
- && RBI (s->bb_beg)->scope
- && RBI (s->bb_beg)->scope->level + 1 == s->level)
- {
- fprintf (stderr, "%*s", indent, "");
- fprintf (stderr, "BB%d:\n", s->bb_beg->index);
- }
-
- fprintf (stderr, "%*s", indent, "");
- fprintf (stderr, "{ level %d (block %p)\n", s->level,
- (PTR) NOTE_BLOCK (s->note_beg));
-
- fprintf (stderr, "%*s%s", indent, "", "bbs:");
- for (i = 0; i < s->num_bbs; i++)
- fprintf (stderr, " %d", s->bbs[i]->index);
- fprintf (stderr, "\n");
-
- for (p = s->inner; p; p = p->next)
- dump_scope_forest_1 (p, indent + 2);
-
- fprintf (stderr, "%*s", indent, "");
- fprintf (stderr, "}\n");
-}
-
-
/* Reorder basic blocks. The main entry point to this file. */
void
reorder_basic_blocks ()
{
- scope_forest_info forest;
- int i;
-
if (n_basic_blocks <= 1)
return;
- for (i = 0; i < n_basic_blocks; i++)
- BASIC_BLOCK (i)->aux = xcalloc (1, sizeof (struct reorder_block_def));
-
- EXIT_BLOCK_PTR->aux = xcalloc (1, sizeof (struct reorder_block_def));
-
- build_scope_forest (&forest);
- remove_scope_notes ();
+ cfg_layout_initialize ();
- record_effective_endpoints ();
make_reorder_chain ();
- fixup_reorder_chain ();
-#ifdef ENABLE_CHECKING
- verify_insn_chain ();
-#endif
-
- rebuild_scope_notes (&forest);
- free_scope_forest (&forest);
- reorder_blocks ();
-
- for (i = 0; i < n_basic_blocks; i++)
- free (BASIC_BLOCK (i)->aux);
+ if (rtl_dump_file)
+ dump_flow_info (rtl_dump_file);
- free (EXIT_BLOCK_PTR->aux);
-
-#ifdef ENABLE_CHECKING
- verify_flow_info ();
-#endif
+ cfg_layout_finalize ();
}
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