/* Instruction scheduling pass.
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ Free Software Foundation, Inc.
Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by,
and currently maintained by, Jim Wilson (wilson@cygnus.com)
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
+Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
for more details.
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
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
\f
#include "config.h"
#include "system.h"
#include "rtl.h"
#include "tm_p.h"
#include "hard-reg-set.h"
-#include "basic-block.h"
#include "regs.h"
#include "function.h"
#include "flags.h"
#include "params.h"
#include "sched-int.h"
#include "target.h"
+#include "output.h"
+
\f
-/* The number of insns to be scheduled in total. */
-static int target_n_insns;
+#ifdef INSN_SCHEDULING
+
/* The number of insns scheduled so far. */
static int sched_n_insns;
+/* The number of insns to be scheduled in total. */
+static int n_insns;
+
+/* Set of blocks, that already have their dependencies calculated. */
+static bitmap_head dont_calc_deps;
+
+/* Last basic block in current ebb. */
+static basic_block last_bb;
+
/* Implementations of the sched_info functions for region scheduling. */
-static void init_ready_list (struct ready_list *);
-static int can_schedule_ready_p (rtx);
-static int new_ready (rtx);
+static void init_ready_list (void);
+static void begin_schedule_ready (rtx, rtx);
static int schedule_more_p (void);
static const char *ebb_print_insn (rtx, int);
static int rank (rtx, rtx);
static basic_block earliest_block_with_similiar_load (basic_block, rtx);
static void add_deps_for_risky_insns (rtx, rtx);
static basic_block schedule_ebb (rtx, rtx);
-static basic_block fix_basic_block_boundaries (basic_block, basic_block, rtx,
- rtx);
-static void add_missing_bbs (rtx, basic_block, basic_block);
+
+static void add_remove_insn (rtx, int);
+static void add_block1 (basic_block, basic_block);
+static basic_block advance_target_bb (basic_block, rtx);
+static void fix_recovery_cfg (int, int, int);
/* Return nonzero if there are more insns that should be scheduled. */
static int
schedule_more_p (void)
{
- return sched_n_insns < target_n_insns;
+ return sched_n_insns < n_insns;
+}
+
+/* Print dependency information about ebb between HEAD and TAIL. */
+static void
+debug_ebb_dependencies (rtx head, rtx tail)
+{
+ fprintf (sched_dump,
+ ";; --------------- forward dependences: ------------ \n");
+
+ fprintf (sched_dump, "\n;; --- EBB Dependences --- from bb%d to bb%d \n",
+ BLOCK_NUM (head), BLOCK_NUM (tail));
+
+ debug_dependencies (head, tail);
}
/* Add all insns that are initially ready to the ready list READY. Called
once before scheduling a set of insns. */
static void
-init_ready_list (struct ready_list *ready)
+init_ready_list (void)
{
+ int n = 0;
rtx prev_head = current_sched_info->prev_head;
rtx next_tail = current_sched_info->next_tail;
rtx insn;
- target_n_insns = 0;
sched_n_insns = 0;
-#if 0
/* Print debugging information. */
if (sched_verbose >= 5)
- debug_dependencies ();
-#endif
+ debug_ebb_dependencies (NEXT_INSN (prev_head), PREV_INSN (next_tail));
/* Initialize ready list with all 'ready' insns in target block.
Count number of insns in the target block being scheduled. */
for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn))
{
- if (INSN_DEP_COUNT (insn) == 0)
- ready_add (ready, insn);
- target_n_insns++;
+ try_ready (insn);
+ n++;
}
-}
-/* Called after taking INSN from the ready list. Returns nonzero if this
- insn can be scheduled, nonzero if we should silently discard it. */
+ gcc_assert (n == n_insns);
+}
-static int
-can_schedule_ready_p (rtx insn ATTRIBUTE_UNUSED)
+/* INSN is being scheduled after LAST. Update counters. */
+static void
+begin_schedule_ready (rtx insn, rtx last)
{
sched_n_insns++;
- return 1;
-}
-/* Called after INSN has all its dependencies resolved. Return nonzero
- if it should be moved to the ready list or the queue, or zero if we
- should silently discard it. */
-static int
-new_ready (rtx next ATTRIBUTE_UNUSED)
-{
- return 1;
+ if (BLOCK_FOR_INSN (insn) == last_bb
+ /* INSN is a jump in the last block, ... */
+ && control_flow_insn_p (insn)
+ /* that is going to be moved over some instructions. */
+ && last != PREV_INSN (insn))
+ {
+ edge e;
+ edge_iterator ei;
+ basic_block bb;
+
+ /* An obscure special case, where we do have partially dead
+ instruction scheduled after last control flow instruction.
+ In this case we can create new basic block. It is
+ always exactly one basic block last in the sequence. */
+
+ FOR_EACH_EDGE (e, ei, last_bb->succs)
+ if (e->flags & EDGE_FALLTHRU)
+ break;
+
+#ifdef ENABLE_CHECKING
+ gcc_assert (!e || !(e->flags & EDGE_COMPLEX));
+
+ gcc_assert (BLOCK_FOR_INSN (insn) == last_bb
+ && !IS_SPECULATION_CHECK_P (insn)
+ && BB_HEAD (last_bb) != insn
+ && BB_END (last_bb) == insn);
+
+ {
+ rtx x;
+
+ x = NEXT_INSN (insn);
+ if (e)
+ gcc_assert (NOTE_P (x) || LABEL_P (x));
+ else
+ gcc_assert (BARRIER_P (x));
+ }
+#endif
+
+ if (e)
+ {
+ bb = split_edge (e);
+ gcc_assert (NOTE_INSN_BASIC_BLOCK_P (BB_END (bb)));
+ }
+ else
+ /* Create an empty unreachable block after the INSN. */
+ bb = create_basic_block (NEXT_INSN (insn), NULL_RTX, last_bb);
+
+ /* split_edge () creates BB before E->DEST. Keep in mind, that
+ this operation extends scheduling region till the end of BB.
+ Hence, we need to shift NEXT_TAIL, so haifa-sched.c won't go out
+ of the scheduling region. */
+ current_sched_info->next_tail = NEXT_INSN (BB_END (bb));
+ gcc_assert (current_sched_info->next_tail);
+
+ add_block (bb, last_bb);
+ gcc_assert (last_bb == bb);
+ }
}
/* Return a string that contains the insn uid and optionally anything else
it may guard the fallthrough block from using a value that has
conditionally overwritten that of the main codepath. So we
consider that it restores the value of the main codepath. */
- bitmap_and (set, e->dest->global_live_at_start, cond_set);
+ bitmap_and (set, df_get_live_in (e->dest), cond_set);
else
- bitmap_ior_into (used, e->dest->global_live_at_start);
+ bitmap_ior_into (used, df_get_live_in (e->dest));
}
/* Used in schedule_insns to initialize current_sched_info for scheduling
static struct sched_info ebb_sched_info =
{
init_ready_list,
- can_schedule_ready_p,
+ NULL,
schedule_more_p,
- new_ready,
+ NULL,
rank,
ebb_print_insn,
contributes_to_priority,
NULL, NULL,
NULL, NULL,
- 0, 1, 0
+ 0, 1, 0,
+
+ add_remove_insn,
+ begin_schedule_ready,
+ add_block1,
+ advance_target_bb,
+ fix_recovery_cfg,
+ SCHED_EBB
+ /* We can create new blocks in begin_schedule_ready (). */
+ | NEW_BBS
};
\f
-/* It is possible that ebb scheduling eliminated some blocks.
- Place blocks from FIRST to LAST before BEFORE. */
-
-static void
-add_missing_bbs (rtx before, basic_block first, basic_block last)
-{
- for (; last != first->prev_bb; last = last->prev_bb)
- {
- before = emit_note_before (NOTE_INSN_BASIC_BLOCK, before);
- NOTE_BASIC_BLOCK (before) = last;
- BB_HEAD (last) = before;
- BB_END (last) = before;
- update_bb_for_insn (last);
- }
-}
-
-/* Fixup the CFG after EBB scheduling. Re-recognize the basic
- block boundaries in between HEAD and TAIL and update basic block
- structures between BB and LAST. */
-
-static basic_block
-fix_basic_block_boundaries (basic_block bb, basic_block last, rtx head,
- rtx tail)
-{
- rtx insn = head;
- rtx last_inside = BB_HEAD (bb);
- rtx aftertail = NEXT_INSN (tail);
-
- head = BB_HEAD (bb);
-
- for (; insn != aftertail; insn = NEXT_INSN (insn))
- {
- gcc_assert (!LABEL_P (insn));
- /* Create new basic blocks just before first insn. */
- if (inside_basic_block_p (insn))
- {
- if (!last_inside)
- {
- rtx note;
-
- /* Re-emit the basic block note for newly found BB header. */
- if (LABEL_P (insn))
- {
- note = emit_note_after (NOTE_INSN_BASIC_BLOCK, insn);
- head = insn;
- last_inside = note;
- }
- else
- {
- note = emit_note_before (NOTE_INSN_BASIC_BLOCK, insn);
- head = note;
- last_inside = insn;
- }
- }
- else
- last_inside = insn;
- }
- /* Control flow instruction terminate basic block. It is possible
- that we've eliminated some basic blocks (made them empty).
- Find the proper basic block using BLOCK_FOR_INSN and arrange things in
- a sensible way by inserting empty basic blocks as needed. */
- if (control_flow_insn_p (insn) || (insn == tail && last_inside))
- {
- basic_block curr_bb = BLOCK_FOR_INSN (insn);
- rtx note;
-
- if (!control_flow_insn_p (insn))
- curr_bb = last;
- if (bb == last->next_bb)
- {
- edge f;
- rtx h;
- edge_iterator ei;
-
- /* An obscure special case, where we do have partially dead
- instruction scheduled after last control flow instruction.
- In this case we can create new basic block. It is
- always exactly one basic block last in the sequence. Handle
- it by splitting the edge and repositioning the block.
- This is somewhat hackish, but at least avoid cut&paste
-
- A safer solution can be to bring the code into sequence,
- do the split and re-emit it back in case this will ever
- trigger problem. */
-
- FOR_EACH_EDGE (f, ei, bb->prev_bb->succs)
- if (f->flags & EDGE_FALLTHRU)
- break;
-
- if (f)
- {
- last = curr_bb = split_edge (f);
- h = BB_HEAD (curr_bb);
- BB_HEAD (curr_bb) = head;
- BB_END (curr_bb) = insn;
- /* Edge splitting created misplaced BASIC_BLOCK note, kill
- it. */
- delete_insn (h);
- }
- /* It may happen that code got moved past unconditional jump in
- case the code is completely dead. Kill it. */
- else
- {
- rtx next = next_nonnote_insn (insn);
- delete_insn_chain (head, insn);
- /* We keep some notes in the way that may split barrier from the
- jump. */
- if (BARRIER_P (next))
- {
- emit_barrier_after (prev_nonnote_insn (head));
- delete_insn (next);
- }
- insn = NULL;
- }
- }
- else
- {
- BB_HEAD (curr_bb) = head;
- BB_END (curr_bb) = insn;
- add_missing_bbs (BB_HEAD (curr_bb), bb, curr_bb->prev_bb);
- }
- note = LABEL_P (head) ? NEXT_INSN (head) : head;
- NOTE_BASIC_BLOCK (note) = curr_bb;
- update_bb_for_insn (curr_bb);
- bb = curr_bb->next_bb;
- last_inside = NULL;
- if (!insn)
- break;
- }
- }
- add_missing_bbs (BB_HEAD (last->next_bb), bb, last);
- return bb->prev_bb;
-}
-
/* Returns the earliest block in EBB currently being processed where a
"similar load" 'insn2' is found, and hence LOAD_INSN can move
speculatively into the found block. All the following must hold:
static basic_block
earliest_block_with_similiar_load (basic_block last_block, rtx load_insn)
{
- rtx back_link;
+ sd_iterator_def back_sd_it;
+ dep_t back_dep;
basic_block bb, earliest_block = NULL;
- for (back_link = LOG_LINKS (load_insn);
- back_link;
- back_link = XEXP (back_link, 1))
+ FOR_EACH_DEP (load_insn, SD_LIST_BACK, back_sd_it, back_dep)
{
- rtx insn1 = XEXP (back_link, 0);
+ rtx insn1 = DEP_PRO (back_dep);
- if (GET_MODE (back_link) == VOIDmode)
+ if (DEP_TYPE (back_dep) == REG_DEP_TRUE)
+ /* Found a DEF-USE dependence (insn1, load_insn). */
{
- /* Found a DEF-USE dependence (insn1, load_insn). */
- rtx fore_link;
+ sd_iterator_def fore_sd_it;
+ dep_t fore_dep;
- for (fore_link = INSN_DEPEND (insn1);
- fore_link;
- fore_link = XEXP (fore_link, 1))
+ FOR_EACH_DEP (insn1, SD_LIST_FORW, fore_sd_it, fore_dep)
{
- rtx insn2 = XEXP (fore_link, 0);
+ rtx insn2 = DEP_CON (fore_dep);
basic_block insn2_block = BLOCK_FOR_INSN (insn2);
- if (GET_MODE (fore_link) == VOIDmode)
+ if (DEP_TYPE (fore_dep) == REG_DEP_TRUE)
{
if (earliest_block != NULL
&& earliest_block->index < insn2_block->index)
basic_block last_block = NULL, bb;
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
- if (JUMP_P (insn))
+ if (control_flow_insn_p (insn))
{
bb = BLOCK_FOR_INSN (insn);
bb->aux = last_block;
/* We can not change the mode of the backward
dependency because REG_DEP_ANTI has the lowest
rank. */
- if (add_dependence (insn, prev, REG_DEP_ANTI))
- add_forward_dependence (prev, insn, REG_DEP_ANTI);
+ if (! sched_insns_conditions_mutex_p (insn, prev))
+ {
+ dep_def _dep, *dep = &_dep;
+
+ init_dep (dep, prev, insn, REG_DEP_ANTI);
+
+ if (!(current_sched_info->flags & USE_DEPS_LIST))
+ {
+ enum DEPS_ADJUST_RESULT res;
+
+ res = sd_add_or_update_dep (dep, false);
+
+ /* We can't change an existing dependency with
+ DEP_ANTI. */
+ gcc_assert (res != DEP_CHANGED);
+ }
+ else
+ {
+ if ((current_sched_info->flags & DO_SPECULATION)
+ && (spec_info->mask & BEGIN_CONTROL))
+ DEP_STATUS (dep) = set_dep_weak (DEP_ANTI, BEGIN_CONTROL,
+ MAX_DEP_WEAK);
+
+ sd_add_or_update_dep (dep, false);
+
+ /* Dep_status could have been changed.
+ No assertion here. */
+ }
+ }
+
break;
default:
static basic_block
schedule_ebb (rtx head, rtx tail)
{
- int n_insns;
- basic_block b;
+ basic_block first_bb, target_bb;
struct deps tmp_deps;
- basic_block first_bb = BLOCK_FOR_INSN (head);
- basic_block last_bb = BLOCK_FOR_INSN (tail);
+
+ first_bb = BLOCK_FOR_INSN (head);
+ last_bb = BLOCK_FOR_INSN (tail);
if (no_real_insns_p (head, tail))
return BLOCK_FOR_INSN (tail);
- init_deps_global ();
+ gcc_assert (INSN_P (head) && INSN_P (tail));
- /* Compute LOG_LINKS. */
- init_deps (&tmp_deps);
- sched_analyze (&tmp_deps, head, tail);
- free_deps (&tmp_deps);
+ if (!bitmap_bit_p (&dont_calc_deps, first_bb->index))
+ {
+ init_deps_global ();
- /* Compute INSN_DEPEND. */
- compute_forward_dependences (head, tail);
+ /* Compute dependencies. */
+ init_deps (&tmp_deps);
+ sched_analyze (&tmp_deps, head, tail);
+ free_deps (&tmp_deps);
- add_deps_for_risky_insns (head, tail);
+ add_deps_for_risky_insns (head, tail);
- if (targetm.sched.dependencies_evaluation_hook)
- targetm.sched.dependencies_evaluation_hook (head, tail);
+ if (targetm.sched.dependencies_evaluation_hook)
+ targetm.sched.dependencies_evaluation_hook (head, tail);
+
+ finish_deps_global ();
+ }
+ else
+ /* Only recovery blocks can have their dependencies already calculated,
+ and they always are single block ebbs. */
+ gcc_assert (first_bb == last_bb);
/* Set priorities. */
+ current_sched_info->sched_max_insns_priority = 0;
n_insns = set_priorities (head, tail);
+ current_sched_info->sched_max_insns_priority++;
current_sched_info->prev_head = PREV_INSN (head);
current_sched_info->next_tail = NEXT_INSN (tail);
- if (write_symbols != NO_DEBUG)
- {
- save_line_notes (first_bb->index, head, tail);
- rm_line_notes (head, tail);
- }
-
/* rm_other_notes only removes notes which are _inside_ the
block---that is, it won't remove notes before the first real insn
or after the last real insn of the block. So if the first insn
for (note = REG_NOTES (head); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_SAVE_NOTE)
- {
- remove_note (head, note);
- note = XEXP (note, 1);
- remove_note (head, note);
- }
+ remove_note (head, note);
}
/* Remove remaining note insns from the block, save them in
schedule_block (). */
rm_other_notes (head, tail);
+ unlink_bb_notes (first_bb, last_bb);
+
current_sched_info->queue_must_finish_empty = 1;
- schedule_block (-1, n_insns);
+ target_bb = first_bb;
+ schedule_block (&target_bb, n_insns);
+ /* We might pack all instructions into fewer blocks,
+ so we may made some of them empty. Can't assert (b == last_bb). */
+
/* Sanity check: verify that all region insns were scheduled. */
gcc_assert (sched_n_insns == n_insns);
- head = current_sched_info->head;
- tail = current_sched_info->tail;
- if (write_symbols != NO_DEBUG)
- restore_line_notes (head, tail);
- b = fix_basic_block_boundaries (first_bb, last_bb, head, tail);
+ /* Free dependencies. */
+ sched_free_deps (current_sched_info->head, current_sched_info->tail, true);
+
+ gcc_assert (haifa_recovery_bb_ever_added_p
+ || deps_pools_are_empty_p ());
+
+ if (EDGE_COUNT (last_bb->preds) == 0)
+ /* LAST_BB is unreachable. */
+ {
+ gcc_assert (first_bb != last_bb
+ && EDGE_COUNT (last_bb->succs) == 0);
+ last_bb = last_bb->prev_bb;
+ delete_basic_block (last_bb->next_bb);
+ }
- finish_deps_global ();
- return b;
+ return last_bb;
}
-/* The one entry point in this file. DUMP_FILE is the dump file for
- this pass. */
+/* The one entry point in this file. */
void
-schedule_ebbs (FILE *dump_file)
+schedule_ebbs (void)
{
basic_block bb;
int probability_cutoff;
+ rtx tail;
if (profile_info && flag_branch_probabilities)
probability_cutoff = PARAM_VALUE (TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK);
/* Taking care of this degenerate case makes the rest of
this code simpler. */
- if (n_basic_blocks == 0)
+ if (n_basic_blocks == NUM_FIXED_BLOCKS)
return;
- sched_init (dump_file);
-
+ /* We need current_sched_info in init_dependency_caches, which is
+ invoked via sched_init. */
current_sched_info = &ebb_sched_info;
+ df_set_flags (DF_LR_RUN_DCE);
+ df_note_add_problem ();
+ df_analyze ();
+ df_clear_flags (DF_LR_RUN_DCE);
+ regstat_compute_calls_crossed ();
+ sched_init ();
+
compute_bb_for_insn ();
+ /* Initialize DONT_CALC_DEPS and ebb-{start, end} markers. */
+ bitmap_initialize (&dont_calc_deps, 0);
+ bitmap_clear (&dont_calc_deps);
+
/* Schedule every region in the subroutine. */
FOR_EACH_BB (bb)
{
rtx head = BB_HEAD (bb);
- rtx tail;
for (;;)
{
bb = schedule_ebb (head, tail);
}
-
- /* Updating life info can be done by local propagation over the modified
- superblocks. */
+ bitmap_clear (&dont_calc_deps);
/* Reposition the prologue and epilogue notes in case we moved the
prologue/epilogue insns. */
if (reload_completed)
- reposition_prologue_and_epilogue_notes (get_insns ());
-
- if (write_symbols != NO_DEBUG)
- rm_redundant_line_notes ();
+ reposition_prologue_and_epilogue_notes ();
sched_finish ();
+ regstat_free_calls_crossed ();
}
+
+/* INSN has been added to/removed from current ebb. */
+static void
+add_remove_insn (rtx insn ATTRIBUTE_UNUSED, int remove_p)
+{
+ if (!remove_p)
+ n_insns++;
+ else
+ n_insns--;
+}
+
+/* BB was added to ebb after AFTER. */
+static void
+add_block1 (basic_block bb, basic_block after)
+{
+ /* Recovery blocks are always bounded by BARRIERS,
+ therefore, they always form single block EBB,
+ therefore, we can use rec->index to identify such EBBs. */
+ if (after == EXIT_BLOCK_PTR)
+ bitmap_set_bit (&dont_calc_deps, bb->index);
+ else if (after == last_bb)
+ last_bb = bb;
+}
+
+/* Return next block in ebb chain. For parameter meaning please refer to
+ sched-int.h: struct sched_info: advance_target_bb. */
+static basic_block
+advance_target_bb (basic_block bb, rtx insn)
+{
+ if (insn)
+ {
+ if (BLOCK_FOR_INSN (insn) != bb
+ && control_flow_insn_p (insn)
+ /* We handle interblock movement of the speculation check
+ or over a speculation check in
+ haifa-sched.c: move_block_after_check (). */
+ && !IS_SPECULATION_BRANCHY_CHECK_P (insn)
+ && !IS_SPECULATION_BRANCHY_CHECK_P (BB_END (bb)))
+ {
+ /* Assert that we don't move jumps across blocks. */
+ gcc_assert (!control_flow_insn_p (BB_END (bb))
+ && NOTE_INSN_BASIC_BLOCK_P (BB_HEAD (bb->next_bb)));
+ return bb;
+ }
+ else
+ return 0;
+ }
+ else
+ /* Return next non empty block. */
+ {
+ do
+ {
+ gcc_assert (bb != last_bb);
+
+ bb = bb->next_bb;
+ }
+ while (bb_note (bb) == BB_END (bb));
+
+ return bb;
+ }
+}
+
+/* Fix internal data after interblock movement of jump instruction.
+ For parameter meaning please refer to
+ sched-int.h: struct sched_info: fix_recovery_cfg. */
+static void
+fix_recovery_cfg (int bbi ATTRIBUTE_UNUSED, int jump_bbi, int jump_bb_nexti)
+{
+ gcc_assert (last_bb->index != bbi);
+
+ if (jump_bb_nexti == last_bb->index)
+ last_bb = BASIC_BLOCK (jump_bbi);
+}
+
+#endif /* INSN_SCHEDULING */
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