/* Control flow graph manipulation code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of GCC.
that are aware of the RTL intermediate language.
Available functionality:
+ - Basic CFG/RTL manipulation API documented in cfghooks.h
- CFG-aware instruction chain manipulation
delete_insn, delete_insn_chain
- - Basic block manipulation
- create_basic_block, flow_delete_block, split_block,
- merge_blocks_nomove
+ - Edge splitting and committing to edges
+ insert_insn_on_edge, commit_edge_insertions
+ - CFG updating after insn simplification
+ purge_dead_edges, purge_all_dead_edges
+
+ Functions not supposed for generic use:
- Infrastructure to determine quickly basic block for insn
compute_bb_for_insn, update_bb_for_insn, set_block_for_insn,
- Edge redirection with updating and optimizing of insn chain
- block_label, redirect_edge_and_branch,
- redirect_edge_and_branch_force, tidy_fallthru_edge, force_nonfallthru
- - Edge splitting and committing to edges
- split_edge, insert_insn_on_edge, commit_edge_insertions
- - Dumping and debugging
- print_rtl_with_bb, dump_bb, debug_bb, debug_bb_n
- - Consistency checking
- verify_flow_info
- - CFG updating after constant propagation
- purge_dead_edges, purge_all_dead_edges */
+ block_label, tidy_fallthru_edge, force_nonfallthru */
\f
#include "config.h"
#include "system.h"
#include "tm_p.h"
#include "obstack.h"
#include "insn-config.h"
+#include "cfglayout.h"
+#include "expr.h"
+#include "target.h"
-/* Stubs in case we don't have a return insn. */
-#ifndef HAVE_return
-#define HAVE_return 0
-#define gen_return() NULL_RTX
-#endif
/* The labels mentioned in non-jump rtl. Valid during find_basic_blocks. */
/* ??? Should probably be using LABEL_NUSES instead. It would take a
bit of surgery to be able to use or co-opt the routines in jump. */
rtx label_value_list;
-rtx tail_recursion_label_list;
-
-static int can_delete_note_p PARAMS ((rtx));
-static int can_delete_label_p PARAMS ((rtx));
-static void commit_one_edge_insertion PARAMS ((edge, int));
-static bool try_redirect_by_replacing_jump PARAMS ((edge, basic_block));
-static rtx last_loop_beg_note PARAMS ((rtx));
-static bool back_edge_of_syntactic_loop_p PARAMS ((basic_block, basic_block));
-basic_block force_nonfallthru_and_redirect PARAMS ((edge, basic_block));
+
+static int can_delete_note_p (rtx);
+static int can_delete_label_p (rtx);
+static void commit_one_edge_insertion (edge, int);
+static rtx last_loop_beg_note (rtx);
+static bool back_edge_of_syntactic_loop_p (basic_block, basic_block);
+static basic_block rtl_split_edge (edge);
+static bool rtl_move_block_after (basic_block, basic_block);
+static int rtl_verify_flow_info (void);
+static basic_block cfg_layout_split_block (basic_block, void *);
+static edge cfg_layout_redirect_edge_and_branch (edge, basic_block);
+static basic_block cfg_layout_redirect_edge_and_branch_force (edge, basic_block);
+static void cfg_layout_delete_block (basic_block);
+static void rtl_delete_block (basic_block);
+static basic_block rtl_redirect_edge_and_branch_force (edge, basic_block);
+static edge rtl_redirect_edge_and_branch (edge, basic_block);
+static basic_block rtl_split_block (basic_block, void *);
+static void rtl_dump_bb (basic_block, FILE *, int);
+static int rtl_verify_flow_info_1 (void);
+static void mark_killed_regs (rtx, rtx, void *);
+static void rtl_make_forwarder_block (edge);
\f
/* Return true if NOTE is not one of the ones that must be kept paired,
so that we may simply delete it. */
static int
-can_delete_note_p (note)
- rtx note;
+can_delete_note_p (rtx note)
{
return (NOTE_LINE_NUMBER (note) == NOTE_INSN_DELETED
|| NOTE_LINE_NUMBER (note) == NOTE_INSN_BASIC_BLOCK
- || NOTE_LINE_NUMBER (note) == NOTE_INSN_PREDICTION);
+ || NOTE_LINE_NUMBER (note) == NOTE_INSN_UNLIKELY_EXECUTED_CODE);
}
/* True if a given label can be deleted. */
static int
-can_delete_label_p (label)
- rtx label;
+can_delete_label_p (rtx label)
{
return (!LABEL_PRESERVE_P (label)
/* User declared labels must be preserved. */
/* Delete INSN by patching it out. Return the next insn. */
rtx
-delete_insn (insn)
- rtx insn;
+delete_insn (rtx insn)
{
rtx next = NEXT_INSN (insn);
rtx note;
bool really_delete = true;
- if (GET_CODE (insn) == CODE_LABEL)
+ if (LABEL_P (insn))
{
/* Some labels can't be directly removed from the INSN chain, as they
might be references via variables, constant pool etc.
really_delete = false;
PUT_CODE (insn, NOTE);
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED_LABEL;
- NOTE_SOURCE_FILE (insn) = name;
+ NOTE_DELETED_LABEL_NAME (insn) = name;
}
remove_node_from_expr_list (insn, &nonlocal_goto_handler_labels);
if (really_delete)
{
/* If this insn has already been deleted, something is very wrong. */
- if (INSN_DELETED_P (insn))
- abort ();
+ gcc_assert (!INSN_DELETED_P (insn));
remove_insn (insn);
INSN_DELETED_P (insn) = 1;
}
/* If deleting a jump, decrement the use count of the label. Deleting
the label itself should happen in the normal course of block merging. */
- if (GET_CODE (insn) == JUMP_INSN
+ if (JUMP_P (insn)
&& JUMP_LABEL (insn)
- && GET_CODE (JUMP_LABEL (insn)) == CODE_LABEL)
+ && LABEL_P (JUMP_LABEL (insn)))
LABEL_NUSES (JUMP_LABEL (insn))--;
/* Also if deleting an insn that references a label. */
- else if ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX
- && GET_CODE (XEXP (note, 0)) == CODE_LABEL)
- LABEL_NUSES (XEXP (note, 0))--;
+ else
+ {
+ while ((note = find_reg_note (insn, REG_LABEL, NULL_RTX)) != NULL_RTX
+ && LABEL_P (XEXP (note, 0)))
+ {
+ LABEL_NUSES (XEXP (note, 0))--;
+ remove_note (insn, note);
+ }
+ }
- if (GET_CODE (insn) == JUMP_INSN
+ if (JUMP_P (insn)
&& (GET_CODE (PATTERN (insn)) == ADDR_VEC
|| GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC))
{
/* When deleting code in bulk (e.g. removing many unreachable
blocks) we can delete a label that's a target of the vector
before deleting the vector itself. */
- if (GET_CODE (label) != NOTE)
+ if (!NOTE_P (label))
LABEL_NUSES (label)--;
}
}
/* Like delete_insn but also purge dead edges from BB. */
rtx
-delete_insn_and_edges (insn)
- rtx insn;
+delete_insn_and_edges (rtx insn)
{
rtx x;
bool purge = false;
if (INSN_P (insn)
&& BLOCK_FOR_INSN (insn)
- && BLOCK_FOR_INSN (insn)->end == insn)
+ && BB_END (BLOCK_FOR_INSN (insn)) == insn)
purge = true;
x = delete_insn (insn);
if (purge)
that must be paired. */
void
-delete_insn_chain (start, finish)
- rtx start, finish;
+delete_insn_chain (rtx start, rtx finish)
{
rtx next;
while (1)
{
next = NEXT_INSN (start);
- if (GET_CODE (start) == NOTE && !can_delete_note_p (start))
+ if (NOTE_P (start) && !can_delete_note_p (start))
;
else
next = delete_insn (start);
/* Like delete_insn but also purge dead edges from BB. */
void
-delete_insn_chain_and_edges (first, last)
- rtx first, last;
+delete_insn_chain_and_edges (rtx first, rtx last)
{
bool purge = false;
if (INSN_P (last)
&& BLOCK_FOR_INSN (last)
- && BLOCK_FOR_INSN (last)->end == last)
+ && BB_END (BLOCK_FOR_INSN (last)) == last)
purge = true;
delete_insn_chain (first, last);
if (purge)
AFTER is the basic block we should be put after. */
basic_block
-create_basic_block_structure (head, end, bb_note, after)
- rtx head, end, bb_note;
- basic_block after;
+create_basic_block_structure (rtx head, rtx end, rtx bb_note, basic_block after)
{
basic_block bb;
if (bb_note
- && ! RTX_INTEGRATED_P (bb_note)
&& (bb = NOTE_BASIC_BLOCK (bb_note)) != NULL
&& bb->aux == NULL)
{
rtx after;
- if (GET_CODE (head) == CODE_LABEL)
+ if (LABEL_P (head))
after = head;
else
{
if (!head && !end)
head = end = bb_note
= emit_note_after (NOTE_INSN_BASIC_BLOCK, get_last_insn ());
- else if (GET_CODE (head) == CODE_LABEL && end)
+ else if (LABEL_P (head) && end)
{
bb_note = emit_note_after (NOTE_INSN_BASIC_BLOCK, head);
if (head == end)
if (NEXT_INSN (end) == bb_note)
end = bb_note;
- bb->head = head;
- bb->end = end;
+ BB_HEAD (bb) = head;
+ BB_END (bb) = end;
bb->index = last_basic_block++;
bb->flags = BB_NEW;
link_block (bb, after);
BASIC_BLOCK (bb->index) = bb;
update_bb_for_insn (bb);
+ BB_SET_PARTITION (bb, BB_UNPARTITIONED);
/* Tag the block so that we know it has been used when considering
other basic block notes. */
create new empty basic block before HEAD. Both END and HEAD can be NULL to
create basic block at the end of INSN chain. */
-basic_block
-create_basic_block (head, end, after)
- rtx head, end;
- basic_block after;
+static basic_block
+rtl_create_basic_block (void *headp, void *endp, basic_block after)
{
+ rtx head = headp, end = endp;
basic_block bb;
- /* Place the new block just after the end. */
- VARRAY_GROW (basic_block_info, last_basic_block+1);
+ /* Grow the basic block array if needed. */
+ if ((size_t) last_basic_block >= VARRAY_SIZE (basic_block_info))
+ {
+ size_t new_size = last_basic_block + (last_basic_block + 3) / 4;
+ VARRAY_GROW (basic_block_info, new_size);
+ }
n_basic_blocks++;
bb->aux = NULL;
return bb;
}
+
+static basic_block
+cfg_layout_create_basic_block (void *head, void *end, basic_block after)
+{
+ basic_block newbb = rtl_create_basic_block (head, end, after);
+
+ initialize_bb_rbi (newbb);
+ return newbb;
+}
\f
/* Delete the insns in a (non-live) block. We physically delete every
non-deleted-note insn, and update the flow graph appropriately.
/* ??? Preserving all such notes strikes me as wrong. It would be nice
to post-process the stream to remove empty blocks, loops, ranges, etc. */
-int
-flow_delete_block_noexpunge (b)
- basic_block b;
+static void
+rtl_delete_block (basic_block b)
{
- int deleted_handler = 0;
rtx insn, end, tmp;
/* If the head of this block is a CODE_LABEL, then it might be the
and remove the associated NOTE_INSN_EH_REGION_BEG and
NOTE_INSN_EH_REGION_END notes. */
- /* Get rid of all NOTE_INSN_PREDICTIONs and NOTE_INSN_LOOP_CONTs
- hanging before the block. */
-
- for (insn = PREV_INSN (b->head); insn; insn = PREV_INSN (insn))
- {
- if (GET_CODE (insn) != NOTE)
- break;
- if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PREDICTION
- || NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_CONT)
- NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
- }
-
- insn = b->head;
-
- never_reached_warning (insn, b->end);
+ insn = BB_HEAD (b);
- if (GET_CODE (insn) == CODE_LABEL)
+ if (LABEL_P (insn))
maybe_remove_eh_handler (insn);
/* Include any jump table following the basic block. */
- end = b->end;
+ end = BB_END (b);
if (tablejump_p (end, NULL, &tmp))
end = tmp;
/* Include any barrier that may follow the basic block. */
tmp = next_nonnote_insn (end);
- if (tmp && GET_CODE (tmp) == BARRIER)
+ if (tmp && BARRIER_P (tmp))
end = tmp;
/* Selectively delete the entire chain. */
- b->head = NULL;
+ BB_HEAD (b) = NULL;
delete_insn_chain (insn, end);
-
- /* Remove the edges into and out of this block. Note that there may
- indeed be edges in, if we are removing an unreachable loop. */
- while (b->pred != NULL)
- remove_edge (b->pred);
- while (b->succ != NULL)
- remove_edge (b->succ);
-
- b->pred = NULL;
- b->succ = NULL;
-
- return deleted_handler;
-}
-
-int
-flow_delete_block (b)
- basic_block b;
-{
- int deleted_handler = flow_delete_block_noexpunge (b);
-
- /* Remove the basic block from the array. */
- expunge_block (b);
-
- return deleted_handler;
}
\f
/* Records the basic block struct in BLOCK_FOR_INSN for every insn. */
void
-compute_bb_for_insn ()
+compute_bb_for_insn (void)
{
basic_block bb;
FOR_EACH_BB (bb)
{
- rtx end = bb->end;
+ rtx end = BB_END (bb);
rtx insn;
- for (insn = bb->head; ; insn = NEXT_INSN (insn))
+ for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn))
{
BLOCK_FOR_INSN (insn) = bb;
if (insn == end)
/* Release the basic_block_for_insn array. */
void
-free_bb_for_insn ()
+free_bb_for_insn (void)
{
rtx insn;
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
- if (GET_CODE (insn) != BARRIER)
+ if (!BARRIER_P (insn))
BLOCK_FOR_INSN (insn) = NULL;
}
+/* Return RTX to emit after when we want to emit code on the entry of function. */
+rtx
+entry_of_function (void)
+{
+ return (n_basic_blocks ? BB_HEAD (ENTRY_BLOCK_PTR->next_bb) : get_insns ());
+}
+
/* Update insns block within BB. */
void
-update_bb_for_insn (bb)
- basic_block bb;
+update_bb_for_insn (basic_block bb)
{
rtx insn;
- for (insn = bb->head; ; insn = NEXT_INSN (insn))
+ for (insn = BB_HEAD (bb); ; insn = NEXT_INSN (insn))
{
- if (GET_CODE (insn) != BARRIER)
+ if (!BARRIER_P (insn))
set_block_for_insn (insn, bb);
- if (insn == bb->end)
+ if (insn == BB_END (bb))
break;
}
}
\f
-/* Split a block BB after insn INSN creating a new fallthru edge.
- Return the new edge. Note that to keep other parts of the compiler happy,
- this function renumbers all the basic blocks so that the new
- one has a number one greater than the block split. */
+/* Creates a new basic block just after basic block B by splitting
+ everything after specified instruction I. */
-edge
-split_block (bb, insn)
- basic_block bb;
- rtx insn;
+static basic_block
+rtl_split_block (basic_block bb, void *insnp)
{
basic_block new_bb;
- edge new_edge;
+ rtx insn = insnp;
edge e;
+ edge_iterator ei;
- /* There is no point splitting the block after its end. */
- if (bb->end == insn)
- return 0;
+ if (!insn)
+ {
+ insn = first_insn_after_basic_block_note (bb);
+
+ if (insn)
+ insn = PREV_INSN (insn);
+ else
+ insn = get_last_insn ();
+ }
+
+ /* We probably should check type of the insn so that we do not create
+ inconsistent cfg. It is checked in verify_flow_info anyway, so do not
+ bother. */
+ if (insn == BB_END (bb))
+ emit_note_after (NOTE_INSN_DELETED, insn);
/* Create the new basic block. */
- new_bb = create_basic_block (NEXT_INSN (insn), bb->end, bb);
- new_bb->count = bb->count;
- new_bb->frequency = bb->frequency;
- new_bb->loop_depth = bb->loop_depth;
- bb->end = insn;
+ new_bb = create_basic_block (NEXT_INSN (insn), BB_END (bb), bb);
+ BB_COPY_PARTITION (new_bb, bb);
+ BB_END (bb) = insn;
/* Redirect the outgoing edges. */
- new_bb->succ = bb->succ;
- bb->succ = NULL;
- for (e = new_bb->succ; e; e = e->succ_next)
+ new_bb->succs = bb->succs;
+ bb->succs = NULL;
+ FOR_EACH_EDGE (e, ei, new_bb->succs)
e->src = new_bb;
- new_edge = make_single_succ_edge (bb, new_bb, EDGE_FALLTHRU);
-
if (bb->global_live_at_start)
{
new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack);
#endif
}
- return new_edge;
+ return new_bb;
}
/* Blocks A and B are to be merged into a single block A. The insns
- are already contiguous, hence `nomove'. */
+ are already contiguous. */
-void
-merge_blocks_nomove (a, b)
- basic_block a, b;
+static void
+rtl_merge_blocks (basic_block a, basic_block b)
{
- rtx b_head = b->head, b_end = b->end, a_end = a->end;
+ rtx b_head = BB_HEAD (b), b_end = BB_END (b), a_end = BB_END (a);
rtx del_first = NULL_RTX, del_last = NULL_RTX;
int b_empty = 0;
- edge e;
/* If there was a CODE_LABEL beginning B, delete it. */
- if (GET_CODE (b_head) == CODE_LABEL)
+ if (LABEL_P (b_head))
{
/* Detect basic blocks with nothing but a label. This can happen
in particular at the end of a function. */
}
/* If there was a jump out of A, delete it. */
- if (GET_CODE (a_end) == JUMP_INSN)
+ if (JUMP_P (a_end))
{
rtx prev;
for (prev = PREV_INSN (a_end); ; prev = PREV_INSN (prev))
- if (GET_CODE (prev) != NOTE
+ if (!NOTE_P (prev)
|| NOTE_LINE_NUMBER (prev) == NOTE_INSN_BASIC_BLOCK
- || prev == a->head)
+ || prev == BB_HEAD (a))
break;
del_first = a_end;
prev = prev_nonnote_insn (prev);
if (!prev)
- prev = a->head;
+ prev = BB_HEAD (a);
del_first = tmp;
}
#endif
a_end = PREV_INSN (del_first);
}
- else if (GET_CODE (NEXT_INSN (a_end)) == BARRIER)
+ else if (BARRIER_P (NEXT_INSN (a_end)))
del_first = NEXT_INSN (a_end);
- /* Normally there should only be one successor of A and that is B, but
- partway though the merge of blocks for conditional_execution we'll
- be merging a TEST block with THEN and ELSE successors. Free the
- whole lot of them and hope the caller knows what they're doing. */
- while (a->succ)
- remove_edge (a->succ);
-
- /* Adjust the edges out of B for the new owner. */
- for (e = b->succ; e; e = e->succ_next)
- e->src = a;
- a->succ = b->succ;
- a->flags |= b->flags;
-
- /* B hasn't quite yet ceased to exist. Attempt to prevent mishap. */
- b->pred = b->succ = NULL;
- a->global_live_at_end = b->global_live_at_end;
-
- expunge_block (b);
-
/* Delete everything marked above as well as crap that might be
hanging out between the two blocks. */
+ BB_HEAD (b) = NULL;
delete_insn_chain (del_first, del_last);
/* Reassociate the insns of B with A. */
a_end = b_end;
}
- a->end = a_end;
+ BB_END (a) = a_end;
+}
+
+/* Return true when block A and B can be merged. */
+static bool
+rtl_can_merge_blocks (basic_block a,basic_block b)
+{
+ /* If we are partitioning hot/cold basic blocks, we don't want to
+ mess up unconditional or indirect jumps that cross between hot
+ and cold sections.
+
+ Basic block partitioning may result in some jumps that appear to
+ be optimizable (or blocks that appear to be mergeable), but which really
+ must be left untouched (they are required to make it safely across
+ partition boundaries). See the comments at the top of
+ bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
+
+ if (flag_reorder_blocks_and_partition
+ && (find_reg_note (BB_END (a), REG_CROSSING_JUMP, NULL_RTX)
+ || find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX)
+ || BB_PARTITION (a) != BB_PARTITION (b)))
+ return false;
+
+ /* There must be exactly one edge in between the blocks. */
+ return (EDGE_COUNT (a->succs) == 1
+ && EDGE_SUCC (a, 0)->dest == b
+ && EDGE_COUNT (b->preds) == 1
+ && a != b
+ /* Must be simple edge. */
+ && !(EDGE_SUCC (a, 0)->flags & EDGE_COMPLEX)
+ && a->next_bb == b
+ && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR
+ /* If the jump insn has side effects,
+ we can't kill the edge. */
+ && (!JUMP_P (BB_END (a))
+ || (reload_completed
+ ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a)))));
}
\f
/* Return the label in the head of basic block BLOCK. Create one if it doesn't
exist. */
rtx
-block_label (block)
- basic_block block;
+block_label (basic_block block)
{
if (block == EXIT_BLOCK_PTR)
return NULL_RTX;
- if (GET_CODE (block->head) != CODE_LABEL)
+ if (!LABEL_P (BB_HEAD (block)))
{
- block->head = emit_label_before (gen_label_rtx (), block->head);
+ BB_HEAD (block) = emit_label_before (gen_label_rtx (), BB_HEAD (block));
}
- return block->head;
+ return BB_HEAD (block);
}
/* Attempt to perform edge redirection by replacing possibly complex jump
apply only if all edges now point to the same block. The parameters and
return values are equivalent to redirect_edge_and_branch. */
-static bool
-try_redirect_by_replacing_jump (e, target)
- edge e;
- basic_block target;
+edge
+try_redirect_by_replacing_jump (edge e, basic_block target, bool in_cfglayout)
{
basic_block src = e->src;
- rtx insn = src->end, kill_from;
+ rtx insn = BB_END (src), kill_from;
edge tmp;
rtx set;
int fallthru = 0;
+ edge_iterator ei;
+
+ /* If we are partitioning hot/cold basic blocks, we don't want to
+ mess up unconditional or indirect jumps that cross between hot
+ and cold sections.
+
+ Basic block partitioning may result in some jumps that appear to
+ be optimizable (or blocks that appear to be mergeable), but which really
+ must be left untouched (they are required to make it safely across
+ partition boundaries). See the comments at the top of
+ bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
+
+ if (flag_reorder_blocks_and_partition
+ && (find_reg_note (insn, REG_CROSSING_JUMP, NULL_RTX)
+ || BB_PARTITION (src) != BB_PARTITION (target)))
+ return NULL;
/* Verify that all targets will be TARGET. */
- for (tmp = src->succ; tmp; tmp = tmp->succ_next)
+ FOR_EACH_EDGE (tmp, ei, src->succs)
if (tmp->dest != target && tmp != e)
break;
if (tmp || !onlyjump_p (insn))
- return false;
- if ((!optimize || flow2_completed) && tablejump_p (insn, NULL, NULL))
- return false;
+ return NULL;
+ if ((!optimize || reload_completed) && tablejump_p (insn, NULL, NULL))
+ return NULL;
/* Avoid removing branch with side effects. */
set = single_set (insn);
if (!set || side_effects_p (set))
- return false;
+ return NULL;
/* In case we zap a conditional jump, we'll need to kill
the cc0 setter too. */
#endif
/* See if we can create the fallthru edge. */
- if (can_fallthru (src, target))
+ if (in_cfglayout || can_fallthru (src, target))
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Removing jump %i.\n", INSN_UID (insn));
+ if (dump_file)
+ fprintf (dump_file, "Removing jump %i.\n", INSN_UID (insn));
fallthru = 1;
/* Selectively unlink whole insn chain. */
- delete_insn_chain (kill_from, PREV_INSN (target->head));
+ if (in_cfglayout)
+ {
+ rtx insn = src->rbi->footer;
+
+ delete_insn_chain (kill_from, BB_END (src));
+
+ /* Remove barriers but keep jumptables. */
+ while (insn)
+ {
+ if (BARRIER_P (insn))
+ {
+ if (PREV_INSN (insn))
+ NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn);
+ else
+ src->rbi->footer = NEXT_INSN (insn);
+ if (NEXT_INSN (insn))
+ PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn);
+ }
+ if (LABEL_P (insn))
+ break;
+ insn = NEXT_INSN (insn);
+ }
+ }
+ else
+ delete_insn_chain (kill_from, PREV_INSN (BB_HEAD (target)));
}
/* If this already is simplejump, redirect it. */
else if (simplejump_p (insn))
{
if (e->dest == target)
- return false;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Redirecting jump %i from %i to %i.\n",
+ return NULL;
+ if (dump_file)
+ fprintf (dump_file, "Redirecting jump %i from %i to %i.\n",
INSN_UID (insn), e->dest->index, target->index);
if (!redirect_jump (insn, block_label (target), 0))
{
- if (target == EXIT_BLOCK_PTR)
- return false;
- abort ();
+ gcc_assert (target == EXIT_BLOCK_PTR);
+ return NULL;
}
}
/* Cannot do anything for target exit block. */
else if (target == EXIT_BLOCK_PTR)
- return false;
+ return NULL;
/* Or replace possibly complicated jump insn by simple jump insn. */
else
rtx target_label = block_label (target);
rtx barrier, label, table;
- emit_jump_insn_after (gen_jump (target_label), insn);
- JUMP_LABEL (src->end) = target_label;
+ emit_jump_insn_after_noloc (gen_jump (target_label), insn);
+ JUMP_LABEL (BB_END (src)) = target_label;
LABEL_NUSES (target_label)++;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Replacing insn %i by jump %i\n",
- INSN_UID (insn), INSN_UID (src->end));
+ if (dump_file)
+ fprintf (dump_file, "Replacing insn %i by jump %i\n",
+ INSN_UID (insn), INSN_UID (BB_END (src)));
delete_insn_chain (kill_from, insn);
if (tablejump_p (insn, &label, &table))
delete_insn_chain (label, table);
- barrier = next_nonnote_insn (src->end);
- if (!barrier || GET_CODE (barrier) != BARRIER)
- emit_barrier_after (src->end);
+ barrier = next_nonnote_insn (BB_END (src));
+ if (!barrier || !BARRIER_P (barrier))
+ emit_barrier_after (BB_END (src));
+ else
+ {
+ if (barrier != NEXT_INSN (BB_END (src)))
+ {
+ /* Move the jump before barrier so that the notes
+ which originally were or were created before jump table are
+ inside the basic block. */
+ rtx new_insn = BB_END (src);
+ rtx tmp;
+
+ for (tmp = NEXT_INSN (BB_END (src)); tmp != barrier;
+ tmp = NEXT_INSN (tmp))
+ set_block_for_insn (tmp, src);
+
+ NEXT_INSN (PREV_INSN (new_insn)) = NEXT_INSN (new_insn);
+ PREV_INSN (NEXT_INSN (new_insn)) = PREV_INSN (new_insn);
+
+ NEXT_INSN (new_insn) = barrier;
+ NEXT_INSN (PREV_INSN (barrier)) = new_insn;
+
+ PREV_INSN (new_insn) = PREV_INSN (barrier);
+ PREV_INSN (barrier) = new_insn;
+ }
+ }
}
/* Keep only one edge out and set proper flags. */
- while (src->succ->succ_next)
- remove_edge (src->succ);
- e = src->succ;
+ while (EDGE_COUNT (src->succs) > 1)
+ remove_edge (e);
+
+ e = EDGE_SUCC (src, 0);
if (fallthru)
e->flags = EDGE_FALLTHRU;
else
/* We don't want a block to end on a line-number note since that has
the potential of changing the code between -g and not -g. */
- while (GET_CODE (e->src->end) == NOTE
- && NOTE_LINE_NUMBER (e->src->end) >= 0)
- delete_insn (e->src->end);
+ while (NOTE_P (BB_END (e->src))
+ && NOTE_LINE_NUMBER (BB_END (e->src)) >= 0)
+ delete_insn (BB_END (e->src));
if (e->dest != target)
redirect_edge_succ (e, target);
- return true;
+ return e;
}
/* Return last loop_beg note appearing after INSN, before start of next
test. */
static rtx
-last_loop_beg_note (insn)
- rtx insn;
+last_loop_beg_note (rtx insn)
{
rtx last = insn;
- for (insn = NEXT_INSN (insn); insn && GET_CODE (insn) == NOTE
+ for (insn = NEXT_INSN (insn); insn && NOTE_P (insn)
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK;
insn = NEXT_INSN (insn))
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
return last;
}
-/* Attempt to change code to redirect edge E to TARGET. Don't do that on
- expense of adding new instructions or reordering basic blocks.
-
- Function can be also called with edge destination equivalent to the TARGET.
- Then it should try the simplifications and do nothing if none is possible.
-
- Return true if transformation succeeded. We still return false in case E
- already destinated TARGET and we didn't managed to simplify instruction
- stream. */
-
-bool
-redirect_edge_and_branch (e, target)
- edge e;
- basic_block target;
+/* Redirect edge representing branch of (un)conditional jump or tablejump,
+ NULL on failure */
+static edge
+redirect_branch_edge (edge e, basic_block target)
{
rtx tmp;
- rtx old_label = e->dest->head;
+ rtx old_label = BB_HEAD (e->dest);
basic_block src = e->src;
- rtx insn = src->end;
-
- if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
- return false;
-
- if (try_redirect_by_replacing_jump (e, target))
- return true;
-
- /* Do this fast path late, as we want above code to simplify for cases
- where called on single edge leaving basic block containing nontrivial
- jump insn. */
- else if (e->dest == target)
- return false;
+ rtx insn = BB_END (src);
/* We can only redirect non-fallthru edges of jump insn. */
if (e->flags & EDGE_FALLTHRU)
- return false;
- else if (GET_CODE (insn) != JUMP_INSN)
- return false;
+ return NULL;
+ else if (!JUMP_P (insn))
+ return NULL;
/* Recognize a tablejump and adjust all matching cases. */
if (tablejump_p (insn, NULL, &tmp))
rtx new_label = block_label (target);
if (target == EXIT_BLOCK_PTR)
- return false;
+ return NULL;
if (GET_CODE (PATTERN (tmp)) == ADDR_VEC)
vec = XVEC (PATTERN (tmp), 0);
else
++LABEL_NUSES (new_label);
}
- /* Handle casesi dispatch insns */
+ /* Handle casesi dispatch insns. */
if ((tmp = single_set (insn)) != NULL
&& SET_DEST (tmp) == pc_rtx
&& GET_CODE (SET_SRC (tmp)) == IF_THEN_ELSE
if (computed_jump_p (insn)
/* A return instruction can't be redirected. */
|| returnjump_p (insn))
- return false;
+ return NULL;
/* If the insn doesn't go where we think, we're confused. */
- if (JUMP_LABEL (insn) != old_label)
- abort ();
+ gcc_assert (JUMP_LABEL (insn) == old_label);
/* If the substitution doesn't succeed, die. This can happen
if the back end emitted unrecognizable instructions or if
target is exit block on some arches. */
if (!redirect_jump (insn, block_label (target), 0))
{
- if (target == EXIT_BLOCK_PTR)
- return false;
- abort ();
+ gcc_assert (target == EXIT_BLOCK_PTR);
+ return NULL;
}
}
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Edge %i->%i redirected to %i\n",
+ if (dump_file)
+ fprintf (dump_file, "Edge %i->%i redirected to %i\n",
e->src->index, e->dest->index, target->index);
if (e->dest != target)
- redirect_edge_succ_nodup (e, target);
+ e = redirect_edge_succ_nodup (e, target);
+ return e;
+}
- return true;
+/* Attempt to change code to redirect edge E to TARGET. Don't do that on
+ expense of adding new instructions or reordering basic blocks.
+
+ Function can be also called with edge destination equivalent to the TARGET.
+ Then it should try the simplifications and do nothing if none is possible.
+
+ Return edge representing the branch if transformation succeeded. Return NULL
+ on failure.
+ We still return NULL in case E already destinated TARGET and we didn't
+ managed to simplify instruction stream. */
+
+static edge
+rtl_redirect_edge_and_branch (edge e, basic_block target)
+{
+ edge ret;
+ basic_block src = e->src;
+
+ if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
+ return NULL;
+
+ if (e->dest == target)
+ return e;
+
+ if ((ret = try_redirect_by_replacing_jump (e, target, false)) != NULL)
+ {
+ src->flags |= BB_DIRTY;
+ return ret;
+ }
+
+ ret = redirect_branch_edge (e, target);
+ if (!ret)
+ return NULL;
+
+ src->flags |= BB_DIRTY;
+ return ret;
}
/* Like force_nonfallthru below, but additionally performs redirection
Used by redirect_edge_and_branch_force. */
-basic_block
-force_nonfallthru_and_redirect (e, target)
- edge e;
- basic_block target;
+static basic_block
+force_nonfallthru_and_redirect (edge e, basic_block target)
{
basic_block jump_block, new_bb = NULL, src = e->src;
rtx note;
/* In the case the last instruction is conditional jump to the next
instruction, first redirect the jump itself and then continue
- by creating an basic block afterwards to redirect fallthru edge. */
+ by creating a basic block afterwards to redirect fallthru edge. */
if (e->src != ENTRY_BLOCK_PTR && e->dest != EXIT_BLOCK_PTR
- && any_condjump_p (e->src->end)
- && JUMP_LABEL (e->src->end) == e->dest->head)
+ && any_condjump_p (BB_END (e->src))
+ /* When called from cfglayout, fallthru edges do not
+ necessarily go to the next block. */
+ && e->src->next_bb == e->dest
+ && JUMP_LABEL (BB_END (e->src)) == BB_HEAD (e->dest))
{
rtx note;
- edge b = make_edge (e->src, target, 0);
+ edge b = unchecked_make_edge (e->src, target, 0);
+ bool redirected;
- if (!redirect_jump (e->src->end, block_label (target), 0))
- abort ();
- note = find_reg_note (e->src->end, REG_BR_PROB, NULL_RTX);
+ redirected = redirect_jump (BB_END (e->src), block_label (target), 0);
+ gcc_assert (redirected);
+
+ note = find_reg_note (BB_END (e->src), REG_BR_PROB, NULL_RTX);
if (note)
{
int prob = INTVAL (XEXP (note, 0));
/* Irritating special case - fallthru edge to the same block as abnormal
edge.
We can't redirect abnormal edge, but we still can split the fallthru
- one and create separate abnormal edge to original destination.
+ one and create separate abnormal edge to original destination.
This allows bb-reorder to make such edge non-fallthru. */
- if (e->dest != target)
- abort ();
+ gcc_assert (e->dest == target);
abnormal_edge_flags = e->flags & ~(EDGE_FALLTHRU | EDGE_CAN_FALLTHRU);
e->flags &= EDGE_FALLTHRU | EDGE_CAN_FALLTHRU;
}
- else if (!(e->flags & EDGE_FALLTHRU))
- abort ();
- else if (e->src == ENTRY_BLOCK_PTR)
+ else
{
- /* We can't redirect the entry block. Create an empty block at the
- start of the function which we use to add the new jump. */
- edge *pe1;
- basic_block bb = create_basic_block (e->dest->head, NULL, ENTRY_BLOCK_PTR);
-
- /* Change the existing edge's source to be the new block, and add
- a new edge from the entry block to the new block. */
- e->src = bb;
- for (pe1 = &ENTRY_BLOCK_PTR->succ; *pe1; pe1 = &(*pe1)->succ_next)
- if (*pe1 == e)
- {
- *pe1 = e->succ_next;
- break;
- }
- e->succ_next = 0;
- bb->succ = e;
- make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU);
+ gcc_assert (e->flags & EDGE_FALLTHRU);
+ if (e->src == ENTRY_BLOCK_PTR)
+ {
+ /* We can't redirect the entry block. Create an empty block
+ at the start of the function which we use to add the new
+ jump. */
+ edge tmp;
+ edge_iterator ei;
+ bool found = false;
+
+ basic_block bb = create_basic_block (BB_HEAD (e->dest), NULL, ENTRY_BLOCK_PTR);
+
+ /* Change the existing edge's source to be the new block, and add
+ a new edge from the entry block to the new block. */
+ e->src = bb;
+ for (ei = ei_start (ENTRY_BLOCK_PTR->succs); (tmp = ei_safe_edge (ei)); )
+ {
+ if (tmp == e)
+ {
+ VEC_unordered_remove (edge, ENTRY_BLOCK_PTR->succs, ei.index);
+ found = true;
+ break;
+ }
+ else
+ ei_next (&ei);
+ }
+
+ gcc_assert (found);
+
+ VEC_safe_push (edge, bb->succs, e);
+ make_single_succ_edge (ENTRY_BLOCK_PTR, bb, EDGE_FALLTHRU);
+ }
}
- if (e->src->succ->succ_next || abnormal_edge_flags)
+ if (EDGE_COUNT (e->src->succs) >= 2 || abnormal_edge_flags)
{
/* Create the new structures. */
+ /* If the old block ended with a tablejump, skip its table
+ by searching forward from there. Otherwise start searching
+ forward from the last instruction of the old block. */
+ if (!tablejump_p (BB_END (e->src), NULL, ¬e))
+ note = BB_END (e->src);
+
/* Position the new block correctly relative to loop notes. */
- note = last_loop_beg_note (e->src->end);
+ note = last_loop_beg_note (note);
note = NEXT_INSN (note);
- /* ... and ADDR_VECs. */
- if (note != NULL
- && GET_CODE (note) == CODE_LABEL
- && NEXT_INSN (note)
- && GET_CODE (NEXT_INSN (note)) == JUMP_INSN
- && (GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_DIFF_VEC
- || GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_VEC))
- note = NEXT_INSN (NEXT_INSN (note));
-
jump_block = create_basic_block (note, NULL, e->src);
jump_block->count = e->count;
jump_block->frequency = EDGE_FREQUENCY (e);
target->global_live_at_start);
}
+ /* Make sure new block ends up in correct hot/cold section. */
+
+ BB_COPY_PARTITION (jump_block, e->src);
+ if (flag_reorder_blocks_and_partition
+ && targetm.have_named_sections)
+ {
+ if (BB_PARTITION (jump_block) == BB_COLD_PARTITION)
+ {
+ rtx bb_note, new_note;
+ for (bb_note = BB_HEAD (jump_block);
+ bb_note && bb_note != NEXT_INSN (BB_END (jump_block));
+ bb_note = NEXT_INSN (bb_note))
+ if (NOTE_P (bb_note)
+ && NOTE_LINE_NUMBER (bb_note) == NOTE_INSN_BASIC_BLOCK)
+ break;
+ new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE,
+ bb_note);
+ NOTE_BASIC_BLOCK (new_note) = jump_block;
+ }
+ if (JUMP_P (BB_END (jump_block))
+ && !any_condjump_p (BB_END (jump_block))
+ && (EDGE_SUCC (jump_block, 0)->flags & EDGE_CROSSING))
+ REG_NOTES (BB_END (jump_block)) = gen_rtx_EXPR_LIST
+ (REG_CROSSING_JUMP, NULL_RTX,
+ REG_NOTES (BB_END (jump_block)));
+ }
+
/* Wire edge in. */
new_edge = make_edge (e->src, jump_block, EDGE_FALLTHRU);
new_edge->probability = e->probability;
e->flags &= ~EDGE_FALLTHRU;
if (target == EXIT_BLOCK_PTR)
{
- if (HAVE_return)
- emit_jump_insn_after (gen_return (), jump_block->end);
- else
- abort ();
+#ifdef HAVE_return
+ emit_jump_insn_after_noloc (gen_return (), BB_END (jump_block));
+#else
+ gcc_unreachable ();
+#endif
}
else
{
rtx label = block_label (target);
- emit_jump_insn_after (gen_jump (label), jump_block->end);
- JUMP_LABEL (jump_block->end) = label;
+ emit_jump_insn_after_noloc (gen_jump (label), BB_END (jump_block));
+ JUMP_LABEL (BB_END (jump_block)) = label;
LABEL_NUSES (label)++;
}
- emit_barrier_after (jump_block->end);
+ emit_barrier_after (BB_END (jump_block));
redirect_edge_succ_nodup (e, target);
if (abnormal_edge_flags)
Return newly created BB or NULL if none. */
basic_block
-force_nonfallthru (e)
- edge e;
+force_nonfallthru (edge e)
{
return force_nonfallthru_and_redirect (e, e->dest);
}
basic block. Return new basic block if created, NULL otherwise.
Abort if conversion is impossible. */
-basic_block
-redirect_edge_and_branch_force (e, target)
- edge e;
- basic_block target;
+static basic_block
+rtl_redirect_edge_and_branch_force (edge e, basic_block target)
{
if (redirect_edge_and_branch (e, target)
|| e->dest == target)
/* The given edge should potentially be a fallthru edge. If that is in
fact true, delete the jump and barriers that are in the way. */
-void
-tidy_fallthru_edge (e, b, c)
- edge e;
- basic_block b, c;
+static void
+rtl_tidy_fallthru_edge (edge e)
{
rtx q;
+ basic_block b = e->src, c = b->next_bb;
+ edge e2;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e2, ei, b->succs)
+ if (e == e2)
+ break;
/* ??? In a late-running flow pass, other folks may have deleted basic
blocks by nopping out blocks, leaving multiple BARRIERs between here
So search through a sequence of barriers, labels, and notes for
the head of block C and assert that we really do fall through. */
- for (q = NEXT_INSN (b->end); q != c->head; q = NEXT_INSN (q))
+ for (q = NEXT_INSN (BB_END (b)); q != BB_HEAD (c); q = NEXT_INSN (q))
if (INSN_P (q))
return;
/* Remove what will soon cease being the jump insn from the source block.
If block B consisted only of this single jump, turn it into a deleted
note. */
- q = b->end;
- if (GET_CODE (q) == JUMP_INSN
+ q = BB_END (b);
+ if (JUMP_P (q)
&& onlyjump_p (q)
&& (any_uncondjump_p (q)
- || (b->succ == e && e->succ_next == NULL)))
+ || (EDGE_SUCC (b, 0) == e && ei.index == EDGE_COUNT (b->succs) - 1)))
{
#ifdef HAVE_cc0
/* If this was a conditional jump, we need to also delete
/* We don't want a block to end on a line-number note since that has
the potential of changing the code between -g and not -g. */
- while (GET_CODE (q) == NOTE && NOTE_LINE_NUMBER (q) >= 0)
+ while (NOTE_P (q) && NOTE_LINE_NUMBER (q) >= 0)
q = PREV_INSN (q);
}
/* Selectively unlink the sequence. */
- if (q != PREV_INSN (c->head))
- delete_insn_chain (NEXT_INSN (q), PREV_INSN (c->head));
+ if (q != PREV_INSN (BB_HEAD (c)))
+ delete_insn_chain (NEXT_INSN (q), PREV_INSN (BB_HEAD (c)));
e->flags |= EDGE_FALLTHRU;
}
-
-/* Fix up edges that now fall through, or rather should now fall through
- but previously required a jump around now deleted blocks. Simplify
- the search by only examining blocks numerically adjacent, since this
- is how find_basic_blocks created them. */
-
-void
-tidy_fallthru_edges ()
-{
- basic_block b, c;
-
- if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR)
- return;
-
- FOR_BB_BETWEEN (b, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, next_bb)
- {
- edge s;
-
- c = b->next_bb;
-
- /* We care about simple conditional or unconditional jumps with
- a single successor.
-
- If we had a conditional branch to the next instruction when
- find_basic_blocks was called, then there will only be one
- out edge for the block which ended with the conditional
- branch (since we do not create duplicate edges).
-
- Furthermore, the edge will be marked as a fallthru because we
- merge the flags for the duplicate edges. So we do not want to
- check that the edge is not a FALLTHRU edge. */
-
- if ((s = b->succ) != NULL
- && ! (s->flags & EDGE_COMPLEX)
- && s->succ_next == NULL
- && s->dest == c
- /* If the jump insn has side effects, we can't tidy the edge. */
- && (GET_CODE (b->end) != JUMP_INSN
- || onlyjump_p (b->end)))
- tidy_fallthru_edge (s, b, c);
- }
-}
\f
/* Helper function for split_edge. Return true in case edge BB2 to BB1
is back edge of syntactic loop. */
static bool
-back_edge_of_syntactic_loop_p (bb1, bb2)
- basic_block bb1, bb2;
+back_edge_of_syntactic_loop_p (basic_block bb1, basic_block bb2)
{
rtx insn;
int count = 0;
if (!bb)
return false;
- for (insn = bb1->end; insn != bb2->head && count >= 0;
+ for (insn = BB_END (bb1); insn != BB_HEAD (bb2) && count >= 0;
insn = NEXT_INSN (insn))
- if (GET_CODE (insn) == NOTE)
+ if (NOTE_P (insn))
{
if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_LOOP_BEG)
count++;
return count >= 0;
}
+/* Should move basic block BB after basic block AFTER. NIY. */
+
+static bool
+rtl_move_block_after (basic_block bb ATTRIBUTE_UNUSED,
+ basic_block after ATTRIBUTE_UNUSED)
+{
+ return false;
+}
+
/* Split a (typically critical) edge. Return the new block.
Abort on abnormal edges.
The case of a block ending in an unconditional jump to a
block with multiple predecessors is not handled optimally. */
-basic_block
-split_edge (edge_in)
- edge edge_in;
+static basic_block
+rtl_split_edge (edge edge_in)
{
basic_block bb;
rtx before;
/* Abnormal edges cannot be split. */
- if ((edge_in->flags & EDGE_ABNORMAL) != 0)
- abort ();
+ gcc_assert (!(edge_in->flags & EDGE_ABNORMAL));
/* We are going to place the new block in front of edge destination.
Avoid existence of fallthru predecessors. */
if ((edge_in->flags & EDGE_FALLTHRU) == 0)
{
edge e;
+ edge_iterator ei;
- for (e = edge_in->dest->pred; e; e = e->pred_next)
+ FOR_EACH_EDGE (e, ei, edge_in->dest->preds)
if (e->flags & EDGE_FALLTHRU)
break;
we confuse the loop optimizer into thinking the loop is a phony. */
if (edge_in->dest != EXIT_BLOCK_PTR
- && PREV_INSN (edge_in->dest->head)
- && GET_CODE (PREV_INSN (edge_in->dest->head)) == NOTE
- && (NOTE_LINE_NUMBER (PREV_INSN (edge_in->dest->head))
+ && PREV_INSN (BB_HEAD (edge_in->dest))
+ && NOTE_P (PREV_INSN (BB_HEAD (edge_in->dest)))
+ && (NOTE_LINE_NUMBER (PREV_INSN (BB_HEAD (edge_in->dest)))
== NOTE_INSN_LOOP_BEG)
&& !back_edge_of_syntactic_loop_p (edge_in->dest, edge_in->src))
- before = PREV_INSN (edge_in->dest->head);
+ before = PREV_INSN (BB_HEAD (edge_in->dest));
else if (edge_in->dest != EXIT_BLOCK_PTR)
- before = edge_in->dest->head;
+ before = BB_HEAD (edge_in->dest);
else
before = NULL_RTX;
- bb = create_basic_block (before, NULL, edge_in->dest->prev_bb);
- bb->count = edge_in->count;
- bb->frequency = EDGE_FREQUENCY (edge_in);
+ /* If this is a fall through edge to the exit block, the blocks might be
+ not adjacent, and the right place is the after the source. */
+ if (edge_in->flags & EDGE_FALLTHRU && edge_in->dest == EXIT_BLOCK_PTR)
+ {
+ before = NEXT_INSN (BB_END (edge_in->src));
+ if (before
+ && NOTE_P (before)
+ && NOTE_LINE_NUMBER (before) == NOTE_INSN_LOOP_END)
+ before = NEXT_INSN (before);
+ bb = create_basic_block (before, NULL, edge_in->src);
+ BB_COPY_PARTITION (bb, edge_in->src);
+ }
+ else
+ {
+ bb = create_basic_block (before, NULL, edge_in->dest->prev_bb);
+ /* ??? Why not edge_in->dest->prev_bb here? */
+ BB_COPY_PARTITION (bb, edge_in->dest);
+ }
/* ??? This info is likely going to be out of date very soon. */
if (edge_in->dest->global_live_at_start)
make_single_succ_edge (bb, edge_in->dest, EDGE_FALLTHRU);
- /* For non-fallthry edges, we must adjust the predecessor's
+ /* For non-fallthru edges, we must adjust the predecessor's
jump instruction to target our new block. */
if ((edge_in->flags & EDGE_FALLTHRU) == 0)
{
- if (!redirect_edge_and_branch (edge_in, bb))
- abort ();
+ edge redirected = redirect_edge_and_branch (edge_in, bb);
+ gcc_assert (redirected);
}
else
redirect_edge_succ (edge_in, bb);
CFG until commit_edge_insertions is called. */
void
-insert_insn_on_edge (pattern, e)
- rtx pattern;
- edge e;
+insert_insn_on_edge (rtx pattern, edge e)
{
/* We cannot insert instructions on an abnormal critical edge.
It will be easier to find the culprit if we die now. */
- if ((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e))
- abort ();
+ gcc_assert (!((e->flags & EDGE_ABNORMAL) && EDGE_CRITICAL_P (e)));
- if (e->insns == NULL_RTX)
+ if (e->insns.r == NULL_RTX)
start_sequence ();
else
- push_to_sequence (e->insns);
+ push_to_sequence (e->insns.r);
emit_insn (pattern);
- e->insns = get_insns ();
+ e->insns.r = get_insns ();
end_sequence ();
}
+/* Called from safe_insert_insn_on_edge through note_stores, marks live
+ registers that are killed by the store. */
+static void
+mark_killed_regs (rtx reg, rtx set ATTRIBUTE_UNUSED, void *data)
+{
+ regset killed = data;
+ int regno, i;
+
+ if (GET_CODE (reg) == SUBREG)
+ reg = SUBREG_REG (reg);
+ if (!REG_P (reg))
+ return;
+ regno = REGNO (reg);
+ if (regno >= FIRST_PSEUDO_REGISTER)
+ SET_REGNO_REG_SET (killed, regno);
+ else
+ {
+ for (i = 0; i < (int) hard_regno_nregs[regno][GET_MODE (reg)]; i++)
+ SET_REGNO_REG_SET (killed, regno + i);
+ }
+}
+
+/* Similar to insert_insn_on_edge, tries to put INSN to edge E. Additionally
+ it checks whether this will not clobber the registers that are live on the
+ edge (i.e. it requires liveness information to be up-to-date) and if there
+ are some, then it tries to save and restore them. Returns true if
+ successful. */
+bool
+safe_insert_insn_on_edge (rtx insn, edge e)
+{
+ rtx x;
+ regset_head killed_head;
+ regset killed = INITIALIZE_REG_SET (killed_head);
+ rtx save_regs = NULL_RTX;
+ unsigned regno;
+ int noccmode;
+ enum machine_mode mode;
+ reg_set_iterator rsi;
+
+#ifdef AVOID_CCMODE_COPIES
+ noccmode = true;
+#else
+ noccmode = false;
+#endif
+
+ for (x = insn; x; x = NEXT_INSN (x))
+ if (INSN_P (x))
+ note_stores (PATTERN (x), mark_killed_regs, killed);
+ bitmap_and_into (killed, e->dest->global_live_at_start);
+
+ EXECUTE_IF_SET_IN_REG_SET (killed, 0, regno, rsi)
+ {
+ mode = regno < FIRST_PSEUDO_REGISTER
+ ? reg_raw_mode[regno]
+ : GET_MODE (regno_reg_rtx[regno]);
+ if (mode == VOIDmode)
+ return false;
+
+ if (noccmode && mode == CCmode)
+ return false;
+
+ save_regs = alloc_EXPR_LIST (0,
+ alloc_EXPR_LIST (0,
+ gen_reg_rtx (mode),
+ gen_raw_REG (mode, regno)),
+ save_regs);
+ }
+
+ if (save_regs)
+ {
+ rtx from, to;
+
+ start_sequence ();
+ for (x = save_regs; x; x = XEXP (x, 1))
+ {
+ from = XEXP (XEXP (x, 0), 1);
+ to = XEXP (XEXP (x, 0), 0);
+ emit_move_insn (to, from);
+ }
+ emit_insn (insn);
+ for (x = save_regs; x; x = XEXP (x, 1))
+ {
+ from = XEXP (XEXP (x, 0), 0);
+ to = XEXP (XEXP (x, 0), 1);
+ emit_move_insn (to, from);
+ }
+ insn = get_insns ();
+ end_sequence ();
+ free_EXPR_LIST_list (&save_regs);
+ }
+ insert_insn_on_edge (insn, e);
+
+ FREE_REG_SET (killed);
+ return true;
+}
+
/* Update the CFG for the instructions queued on edge E. */
static void
-commit_one_edge_insertion (e, watch_calls)
- edge e;
- int watch_calls;
+commit_one_edge_insertion (edge e, int watch_calls)
{
rtx before = NULL_RTX, after = NULL_RTX, insns, tmp, last;
basic_block bb = NULL;
/* Pull the insns off the edge now since the edge might go away. */
- insns = e->insns;
- e->insns = NULL_RTX;
+ insns = e->insns.r;
+ e->insns.r = NULL_RTX;
/* Special case -- avoid inserting code between call and storing
its return value. */
- if (watch_calls && (e->flags & EDGE_FALLTHRU) && !e->dest->pred->pred_next
+ if (watch_calls && (e->flags & EDGE_FALLTHRU)
+ && EDGE_COUNT (e->dest->preds) == 1
&& e->src != ENTRY_BLOCK_PTR
- && GET_CODE (e->src->end) == CALL_INSN)
+ && CALL_P (BB_END (e->src)))
{
- rtx next = next_nonnote_insn (e->src->end);
+ rtx next = next_nonnote_insn (BB_END (e->src));
- after = e->dest->head;
+ after = BB_HEAD (e->dest);
/* The first insn after the call may be a stack pop, skip it. */
while (next
&& keep_with_call_p (next))
{
/* Figure out where to put these things. If the destination has
one predecessor, insert there. Except for the exit block. */
- if (e->dest->pred->pred_next == NULL && e->dest != EXIT_BLOCK_PTR)
+ if (EDGE_COUNT (e->dest->preds) == 1 && e->dest != EXIT_BLOCK_PTR)
{
bb = e->dest;
/* Get the location correct wrt a code label, and "nice" wrt
a basic block note, and before everything else. */
- tmp = bb->head;
- if (GET_CODE (tmp) == CODE_LABEL)
+ tmp = BB_HEAD (bb);
+ if (LABEL_P (tmp))
tmp = NEXT_INSN (tmp);
if (NOTE_INSN_BASIC_BLOCK_P (tmp))
tmp = NEXT_INSN (tmp);
- if (tmp == bb->head)
+ if (tmp
+ && NOTE_P (tmp)
+ && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_UNLIKELY_EXECUTED_CODE)
+ tmp = NEXT_INSN (tmp);
+ if (tmp == BB_HEAD (bb))
before = tmp;
else if (tmp)
after = PREV_INSN (tmp);
/* If the source has one successor and the edge is not abnormal,
insert there. Except for the entry block. */
else if ((e->flags & EDGE_ABNORMAL) == 0
- && e->src->succ->succ_next == NULL
+ && EDGE_COUNT (e->src->succs) == 1
&& e->src != ENTRY_BLOCK_PTR)
{
bb = e->src;
We know this block has a single successor, so we can just emit
the queued insns before the jump. */
- if (GET_CODE (bb->end) == JUMP_INSN)
- for (before = bb->end;
- GET_CODE (PREV_INSN (before)) == NOTE
+ if (JUMP_P (BB_END (bb)))
+ for (before = BB_END (bb);
+ NOTE_P (PREV_INSN (before))
&& NOTE_LINE_NUMBER (PREV_INSN (before)) ==
NOTE_INSN_LOOP_BEG; before = PREV_INSN (before))
;
else
{
- /* We'd better be fallthru, or we've lost track of what's what. */
- if ((e->flags & EDGE_FALLTHRU) == 0)
- abort ();
+ /* We'd better be fallthru, or we've lost track of
+ what's what. */
+ gcc_assert (e->flags & EDGE_FALLTHRU);
- after = bb->end;
+ after = BB_END (bb);
}
}
/* Otherwise we must split the edge. */
else
{
bb = split_edge (e);
- after = bb->end;
+ after = BB_END (bb);
+
+ if (flag_reorder_blocks_and_partition
+ && targetm.have_named_sections
+ && e->src != ENTRY_BLOCK_PTR
+ && BB_PARTITION (e->src) == BB_COLD_PARTITION
+ && !(e->flags & EDGE_CROSSING))
+ {
+ rtx bb_note, new_note, cur_insn;
+
+ bb_note = NULL_RTX;
+ for (cur_insn = BB_HEAD (bb); cur_insn != NEXT_INSN (BB_END (bb));
+ cur_insn = NEXT_INSN (cur_insn))
+ if (NOTE_P (cur_insn)
+ && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_BASIC_BLOCK)
+ {
+ bb_note = cur_insn;
+ break;
+ }
+
+ new_note = emit_note_after (NOTE_INSN_UNLIKELY_EXECUTED_CODE,
+ bb_note);
+ NOTE_BASIC_BLOCK (new_note) = bb;
+ if (JUMP_P (BB_END (bb))
+ && !any_condjump_p (BB_END (bb))
+ && (EDGE_SUCC (bb, 0)->flags & EDGE_CROSSING))
+ REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST
+ (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb)));
+ if (after == bb_note)
+ after = new_note;
+ }
}
}
if (before)
{
- emit_insn_before (insns, before);
+ emit_insn_before_noloc (insns, before);
last = prev_nonnote_insn (before);
}
else
- last = emit_insn_after (insns, after);
+ last = emit_insn_after_noloc (insns, after);
if (returnjump_p (last))
{
for the (single) epilogue, which already has a fallthru edge
to EXIT. */
- e = bb->succ;
- if (e->dest != EXIT_BLOCK_PTR
- || e->succ_next != NULL || (e->flags & EDGE_FALLTHRU) == 0)
- abort ();
+ e = EDGE_SUCC (bb, 0);
+ gcc_assert (e->dest == EXIT_BLOCK_PTR
+ && EDGE_COUNT (bb->succs) == 1 && (e->flags & EDGE_FALLTHRU));
e->flags &= ~EDGE_FALLTHRU;
emit_barrier_after (last);
if (before)
delete_insn (before);
}
- else if (GET_CODE (last) == JUMP_INSN)
- abort ();
+ else
+ gcc_assert (!JUMP_P (last));
/* Mark the basic block for find_sub_basic_blocks. */
bb->aux = &bb->aux;
/* Update the CFG for all queued instructions. */
void
-commit_edge_insertions ()
+commit_edge_insertions (void)
{
basic_block bb;
sbitmap blocks;
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
{
- edge e, next;
+ edge e;
+ edge_iterator ei;
- for (e = bb->succ; e; e = next)
- {
- next = e->succ_next;
- if (e->insns)
- {
- changed = true;
- commit_one_edge_insertion (e, false);
- }
- }
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->insns.r)
+ {
+ changed = true;
+ commit_one_edge_insertion (e, false);
+ }
}
if (!changed)
SET_BIT (blocks, bb->index);
/* Check for forgotten bb->aux values before commit_edge_insertions
call. */
- if (bb->aux != &bb->aux)
- abort ();
+ gcc_assert (bb->aux == &bb->aux);
bb->aux = NULL;
}
find_many_sub_basic_blocks (blocks);
code on edges between call and storing its return value. */
void
-commit_edge_insertions_watch_calls ()
+commit_edge_insertions_watch_calls (void)
{
basic_block bb;
sbitmap blocks;
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb)
{
- edge e, next;
+ edge e;
+ edge_iterator ei;
- for (e = bb->succ; e; e = next)
- {
- next = e->succ_next;
- if (e->insns)
- {
- changed = true;
- commit_one_edge_insertion (e, true);
- }
- }
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->insns.r)
+ {
+ changed = true;
+ commit_one_edge_insertion (e, true);
+ }
}
if (!changed)
SET_BIT (blocks, bb->index);
/* Check for forgotten bb->aux values before commit_edge_insertions
call. */
- if (bb->aux != &bb->aux)
- abort ();
+ gcc_assert (bb->aux == &bb->aux);
bb->aux = NULL;
}
find_many_sub_basic_blocks (blocks);
sbitmap_free (blocks);
}
\f
-/* Print out one basic block with live information at start and end. */
+/* Print out RTL-specific basic block information (live information
+ at start and end). */
-void
-dump_bb (bb, outf)
- basic_block bb;
- FILE *outf;
+static void
+rtl_dump_bb (basic_block bb, FILE *outf, int indent)
{
rtx insn;
rtx last;
- edge e;
-
- fprintf (outf, ";; Basic block %d, loop depth %d, count ",
- bb->index, bb->loop_depth);
- fprintf (outf, HOST_WIDEST_INT_PRINT_DEC, (HOST_WIDEST_INT) bb->count);
- putc ('\n', outf);
+ char *s_indent;
- fputs (";; Predecessors: ", outf);
- for (e = bb->pred; e; e = e->pred_next)
- dump_edge_info (outf, e, 0);
- putc ('\n', outf);
+ s_indent = alloca ((size_t) indent + 1);
+ memset (s_indent, ' ', (size_t) indent);
+ s_indent[indent] = '\0';
- fputs (";; Registers live at start:", outf);
+ fprintf (outf, ";;%s Registers live at start: ", s_indent);
dump_regset (bb->global_live_at_start, outf);
putc ('\n', outf);
- for (insn = bb->head, last = NEXT_INSN (bb->end); insn != last;
+ for (insn = BB_HEAD (bb), last = NEXT_INSN (BB_END (bb)); insn != last;
insn = NEXT_INSN (insn))
print_rtl_single (outf, insn);
- fputs (";; Registers live at end:", outf);
+ fprintf (outf, ";;%s Registers live at end: ", s_indent);
dump_regset (bb->global_live_at_end, outf);
putc ('\n', outf);
-
- fputs (";; Successors: ", outf);
- for (e = bb->succ; e; e = e->succ_next)
- dump_edge_info (outf, e, 1);
- putc ('\n', outf);
}
+\f
+/* Like print_rtl, but also print out live information for the start of each
+ basic block. */
void
-debug_bb (bb)
- basic_block bb;
+print_rtl_with_bb (FILE *outf, rtx rtx_first)
{
- dump_bb (bb, stderr);
-}
-
-basic_block
-debug_bb_n (n)
- int n;
-{
- basic_block bb = BASIC_BLOCK (n);
- dump_bb (bb, stderr);
- return bb;
-}
-\f
-/* Like print_rtl, but also print out live information for the start of each
- basic block. */
-
-void
-print_rtl_with_bb (outf, rtx_first)
- FILE *outf;
- rtx rtx_first;
-{
- rtx tmp_rtx;
+ rtx tmp_rtx;
if (rtx_first == 0)
fprintf (outf, "(nil)\n");
{
enum bb_state { NOT_IN_BB, IN_ONE_BB, IN_MULTIPLE_BB };
int max_uid = get_max_uid ();
- basic_block *start
- = (basic_block *) xcalloc (max_uid, sizeof (basic_block));
- basic_block *end
- = (basic_block *) xcalloc (max_uid, sizeof (basic_block));
- enum bb_state *in_bb_p
- = (enum bb_state *) xcalloc (max_uid, sizeof (enum bb_state));
+ basic_block *start = xcalloc (max_uid, sizeof (basic_block));
+ basic_block *end = xcalloc (max_uid, sizeof (basic_block));
+ enum bb_state *in_bb_p = xcalloc (max_uid, sizeof (enum bb_state));
basic_block bb;
{
rtx x;
- start[INSN_UID (bb->head)] = bb;
- end[INSN_UID (bb->end)] = bb;
- for (x = bb->head; x != NULL_RTX; x = NEXT_INSN (x))
+ start[INSN_UID (BB_HEAD (bb))] = bb;
+ end[INSN_UID (BB_END (bb))] = bb;
+ for (x = BB_HEAD (bb); x != NULL_RTX; x = NEXT_INSN (x))
{
enum bb_state state = IN_MULTIPLE_BB;
state = IN_ONE_BB;
in_bb_p[INSN_UID (x)] = state;
- if (x == bb->end)
+ if (x == BB_END (bb))
break;
}
}
}
if (in_bb_p[INSN_UID (tmp_rtx)] == NOT_IN_BB
- && GET_CODE (tmp_rtx) != NOTE
- && GET_CODE (tmp_rtx) != BARRIER)
+ && !NOTE_P (tmp_rtx)
+ && !BARRIER_P (tmp_rtx))
fprintf (outf, ";; Insn is not within a basic block\n");
else if (in_bb_p[INSN_UID (tmp_rtx)] == IN_MULTIPLE_BB)
fprintf (outf, ";; Insn is in multiple basic blocks\n");
}
\f
void
-update_br_prob_note (bb)
- basic_block bb;
+update_br_prob_note (basic_block bb)
{
rtx note;
- if (GET_CODE (bb->end) != JUMP_INSN)
+ if (!JUMP_P (BB_END (bb)))
return;
- note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX);
+ note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX);
if (!note || INTVAL (XEXP (note, 0)) == BRANCH_EDGE (bb)->probability)
return;
XEXP (note, 0) = GEN_INT (BRANCH_EDGE (bb)->probability);
}
\f
-/* Verify the CFG consistency. This function check some CFG invariants and
- aborts when something is wrong. Hope that this function will help to
- convert many optimization passes to preserve CFG consistent.
+/* Verify the CFG and RTL consistency common for both underlying RTL and
+ cfglayout RTL.
Currently it does following checks:
- test head/end pointers
- overlapping of basic blocks
- - edge list correctness
- headers of basic blocks (the NOTE_INSN_BASIC_BLOCK note)
- tails of basic blocks (ensure that boundary is necessary)
- scans body of the basic block for JUMP_INSN, CODE_LABEL
and NOTE_INSN_BASIC_BLOCK
- - check that all insns are in the basic blocks
- (except the switch handling code, barriers and notes)
- - check that all returns are followed by barriers
+ - verify that no fall_thru edge crosses hot/cold partition boundaries
In future it can be extended check a lot of other stuff as well
(reachability of basic blocks, life information, etc. etc.). */
-void
-verify_flow_info ()
+static int
+rtl_verify_flow_info_1 (void)
{
const int max_uid = get_max_uid ();
- const rtx rtx_first = get_insns ();
rtx last_head = get_last_insn ();
- basic_block *bb_info, *last_visited;
- size_t *edge_checksum;
+ basic_block *bb_info;
rtx x;
- int num_bb_notes, err = 0;
+ int err = 0;
basic_block bb, last_bb_seen;
- bb_info = (basic_block *) xcalloc (max_uid, sizeof (basic_block));
- last_visited = (basic_block *) xcalloc (last_basic_block + 2,
- sizeof (basic_block));
- edge_checksum = (size_t *) xcalloc (last_basic_block + 2, sizeof (size_t));
+ bb_info = xcalloc (max_uid, sizeof (basic_block));
/* Check bb chain & numbers. */
last_bb_seen = ENTRY_BLOCK_PTR;
- FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb, NULL, next_bb)
- {
- if (bb != EXIT_BLOCK_PTR
- && bb != BASIC_BLOCK (bb->index))
- {
- error ("bb %d on wrong place", bb->index);
- err = 1;
- }
-
- if (bb->prev_bb != last_bb_seen)
- {
- error ("prev_bb of %d should be %d, not %d",
- bb->index, last_bb_seen->index, bb->prev_bb->index);
- err = 1;
- }
-
- last_bb_seen = bb;
- }
FOR_EACH_BB_REVERSE (bb)
{
- rtx head = bb->head;
- rtx end = bb->end;
+ rtx head = BB_HEAD (bb);
+ rtx end = BB_END (bb);
/* Verify the end of the basic block is in the INSN chain. */
for (x = last_head; x != NULL_RTX; x = PREV_INSN (x))
FOR_EACH_BB_REVERSE (bb)
{
int n_fallthru = 0, n_eh = 0, n_call = 0, n_abnormal = 0, n_branch = 0;
- edge e;
+ edge e, fallthru = NULL;
rtx note;
+ edge_iterator ei;
- if (INSN_P (bb->end)
- && (note = find_reg_note (bb->end, REG_BR_PROB, NULL_RTX))
- && bb->succ && bb->succ->succ_next
- && any_condjump_p (bb->end))
+ if (INSN_P (BB_END (bb))
+ && (note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX))
+ && EDGE_COUNT (bb->succs) >= 2
+ && any_condjump_p (BB_END (bb)))
{
- if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability)
+ if (INTVAL (XEXP (note, 0)) != BRANCH_EDGE (bb)->probability
+ && profile_status != PROFILE_ABSENT)
{
- error ("verify_flow_info: REG_BR_PROB does not match cfg %i %i",
+ error ("verify_flow_info: REG_BR_PROB does not match cfg %wi %i",
INTVAL (XEXP (note, 0)), BRANCH_EDGE (bb)->probability);
err = 1;
}
}
- if (bb->count < 0)
- {
- error ("verify_flow_info: Wrong count of block %i %i",
- bb->index, (int)bb->count);
- err = 1;
- }
- if (bb->frequency < 0)
- {
- error ("verify_flow_info: Wrong frequency of block %i %i",
- bb->index, bb->frequency);
- err = 1;
- }
- for (e = bb->succ; e; e = e->succ_next)
+ FOR_EACH_EDGE (e, ei, bb->succs)
{
- if (last_visited [e->dest->index + 2] == bb)
- {
- error ("verify_flow_info: Duplicate edge %i->%i",
- e->src->index, e->dest->index);
- err = 1;
- }
- if (e->probability < 0 || e->probability > REG_BR_PROB_BASE)
- {
- error ("verify_flow_info: Wrong probability of edge %i->%i %i",
- e->src->index, e->dest->index, e->probability);
- err = 1;
- }
- if (e->count < 0)
+ if (e->flags & EDGE_FALLTHRU)
{
- error ("verify_flow_info: Wrong count of edge %i->%i %i",
- e->src->index, e->dest->index, (int)e->count);
- err = 1;
+ n_fallthru++, fallthru = e;
+ if ((e->flags & EDGE_CROSSING)
+ || (BB_PARTITION (e->src) != BB_PARTITION (e->dest)
+ && e->src != ENTRY_BLOCK_PTR
+ && e->dest != EXIT_BLOCK_PTR))
+ {
+ error ("Fallthru edge crosses section boundary (bb %i)",
+ e->src->index);
+ err = 1;
+ }
}
- last_visited [e->dest->index + 2] = bb;
-
- if (e->flags & EDGE_FALLTHRU)
- n_fallthru++;
-
- if ((e->flags & ~(EDGE_DFS_BACK | EDGE_CAN_FALLTHRU | EDGE_IRREDUCIBLE_LOOP)) == 0)
+ if ((e->flags & ~(EDGE_DFS_BACK
+ | EDGE_CAN_FALLTHRU
+ | EDGE_IRREDUCIBLE_LOOP
+ | EDGE_LOOP_EXIT
+ | EDGE_CROSSING)) == 0)
n_branch++;
if (e->flags & EDGE_ABNORMAL_CALL)
n_eh++;
else if (e->flags & EDGE_ABNORMAL)
n_abnormal++;
-
- if ((e->flags & EDGE_FALLTHRU)
- && e->src != ENTRY_BLOCK_PTR
- && e->dest != EXIT_BLOCK_PTR)
- {
- rtx insn;
-
- if (e->src->next_bb != e->dest)
- {
- error
- ("verify_flow_info: Incorrect blocks for fallthru %i->%i",
- e->src->index, e->dest->index);
- err = 1;
- }
- else
- for (insn = NEXT_INSN (e->src->end); insn != e->dest->head;
- insn = NEXT_INSN (insn))
- if (GET_CODE (insn) == BARRIER
-#ifndef CASE_DROPS_THROUGH
- || INSN_P (insn)
-#else
- || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn))
-#endif
- )
- {
- error ("verify_flow_info: Incorrect fallthru %i->%i",
- e->src->index, e->dest->index);
- fatal_insn ("wrong insn in the fallthru edge", insn);
- err = 1;
- }
- }
-
- if (e->src != bb)
- {
- error ("verify_flow_info: Basic block %d succ edge is corrupted",
- bb->index);
- fprintf (stderr, "Predecessor: ");
- dump_edge_info (stderr, e, 0);
- fprintf (stderr, "\nSuccessor: ");
- dump_edge_info (stderr, e, 1);
- fprintf (stderr, "\n");
- err = 1;
- }
-
- edge_checksum[e->dest->index + 2] += (size_t) e;
}
- if (n_eh && GET_CODE (PATTERN (bb->end)) != RESX
- && !find_reg_note (bb->end, REG_EH_REGION, NULL_RTX))
+ if (n_eh && GET_CODE (PATTERN (BB_END (bb))) != RESX
+ && !find_reg_note (BB_END (bb), REG_EH_REGION, NULL_RTX))
{
error ("Missing REG_EH_REGION note in the end of bb %i", bb->index);
err = 1;
}
if (n_branch
- && (GET_CODE (bb->end) != JUMP_INSN
- || (n_branch > 1 && (any_uncondjump_p (bb->end)
- || any_condjump_p (bb->end)))))
+ && (!JUMP_P (BB_END (bb))
+ || (n_branch > 1 && (any_uncondjump_p (BB_END (bb))
+ || any_condjump_p (BB_END (bb))))))
{
error ("Too many outgoing branch edges from bb %i", bb->index);
err = 1;
}
- if (n_fallthru && any_uncondjump_p (bb->end))
+ if (n_fallthru && any_uncondjump_p (BB_END (bb)))
{
error ("Fallthru edge after unconditional jump %i", bb->index);
err = 1;
}
- if (n_branch != 1 && any_uncondjump_p (bb->end))
+ if (n_branch != 1 && any_uncondjump_p (BB_END (bb)))
{
error ("Wrong amount of branch edges after unconditional jump %i", bb->index);
err = 1;
}
- if (n_branch != 1 && any_condjump_p (bb->end)
- && JUMP_LABEL (bb->end) != bb->next_bb->head)
+ if (n_branch != 1 && any_condjump_p (BB_END (bb))
+ && JUMP_LABEL (BB_END (bb)) != BB_HEAD (fallthru->dest))
{
error ("Wrong amount of branch edges after conditional jump %i", bb->index);
err = 1;
}
- if (n_call && GET_CODE (bb->end) != CALL_INSN)
+ if (n_call && !CALL_P (BB_END (bb)))
{
error ("Call edges for non-call insn in bb %i", bb->index);
err = 1;
}
if (n_abnormal
- && (GET_CODE (bb->end) != CALL_INSN && n_call != n_abnormal)
- && (GET_CODE (bb->end) != JUMP_INSN
- || any_condjump_p (bb->end)
- || any_uncondjump_p (bb->end)))
+ && (!CALL_P (BB_END (bb)) && n_call != n_abnormal)
+ && (!JUMP_P (BB_END (bb))
+ || any_condjump_p (BB_END (bb))
+ || any_uncondjump_p (BB_END (bb))))
{
error ("Abnormal edges for no purpose in bb %i", bb->index);
err = 1;
}
- if (!n_fallthru)
- {
- rtx insn;
-
- /* Ensure existence of barrier in BB with no fallthru edges. */
- for (insn = bb->end; !insn || GET_CODE (insn) != BARRIER;
- insn = NEXT_INSN (insn))
- if (!insn
- || (GET_CODE (insn) == NOTE
- && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK))
- {
- error ("missing barrier after block %i", bb->index);
- err = 1;
- break;
- }
- }
-
- for (e = bb->pred; e; e = e->pred_next)
- {
- if (e->dest != bb)
- {
- error ("basic block %d pred edge is corrupted", bb->index);
- fputs ("Predecessor: ", stderr);
- dump_edge_info (stderr, e, 0);
- fputs ("\nSuccessor: ", stderr);
- dump_edge_info (stderr, e, 1);
- fputc ('\n', stderr);
- err = 1;
- }
- edge_checksum[e->dest->index + 2] -= (size_t) e;
- }
-
- for (x = bb->head; x != NEXT_INSN (bb->end); x = NEXT_INSN (x))
- if (BLOCK_FOR_INSN (x) != bb)
+ for (x = BB_HEAD (bb); x != NEXT_INSN (BB_END (bb)); x = NEXT_INSN (x))
+ /* We may have a barrier inside a basic block before dead code
+ elimination. There is no BLOCK_FOR_INSN field in a barrier. */
+ if (!BARRIER_P (x) && BLOCK_FOR_INSN (x) != bb)
{
debug_rtx (x);
if (! BLOCK_FOR_INSN (x))
/* OK pointers are correct. Now check the header of basic
block. It ought to contain optional CODE_LABEL followed
by NOTE_BASIC_BLOCK. */
- x = bb->head;
- if (GET_CODE (x) == CODE_LABEL)
+ x = BB_HEAD (bb);
+ if (LABEL_P (x))
{
- if (bb->end == x)
+ if (BB_END (bb) == x)
{
error ("NOTE_INSN_BASIC_BLOCK is missing for block %d",
bb->index);
err = 1;
}
- if (bb->end == x)
+ if (BB_END (bb) == x)
/* Do checks for empty blocks her. e */
;
else
err = 1;
}
- if (x == bb->end)
+ if (x == BB_END (bb))
break;
if (control_flow_insn_p (x))
}
}
- /* Complete edge checksumming for ENTRY and EXIT. */
- {
- edge e;
+ /* Clean up. */
+ free (bb_info);
+ return err;
+}
+
+/* Verify the CFG and RTL consistency common for both underlying RTL and
+ cfglayout RTL.
- for (e = ENTRY_BLOCK_PTR->succ; e ; e = e->succ_next)
- edge_checksum[e->dest->index + 2] += (size_t) e;
+ Currently it does following checks:
+ - all checks of rtl_verify_flow_info_1
+ - check that all insns are in the basic blocks
+ (except the switch handling code, barriers and notes)
+ - check that all returns are followed by barriers
+ - check that all fallthru edge points to the adjacent blocks. */
+static int
+rtl_verify_flow_info (void)
+{
+ basic_block bb;
+ int err = rtl_verify_flow_info_1 ();
+ rtx x;
+ int num_bb_notes;
+ const rtx rtx_first = get_insns ();
+ basic_block last_bb_seen = ENTRY_BLOCK_PTR, curr_bb = NULL;
- for (e = EXIT_BLOCK_PTR->pred; e ; e = e->pred_next)
- edge_checksum[e->dest->index + 2] -= (size_t) e;
- }
+ FOR_EACH_BB_REVERSE (bb)
+ {
+ edge e;
+ edge_iterator ei;
- FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
- if (edge_checksum[bb->index + 2])
- {
- error ("basic block %i edge lists are corrupted", bb->index);
- err = 1;
- }
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->flags & EDGE_FALLTHRU)
+ break;
+ if (!e)
+ {
+ rtx insn;
+
+ /* Ensure existence of barrier in BB with no fallthru edges. */
+ for (insn = BB_END (bb); !insn || !BARRIER_P (insn);
+ insn = NEXT_INSN (insn))
+ if (!insn
+ || (NOTE_P (insn)
+ && NOTE_LINE_NUMBER (insn) == NOTE_INSN_BASIC_BLOCK))
+ {
+ error ("missing barrier after block %i", bb->index);
+ err = 1;
+ break;
+ }
+ }
+ else if (e->src != ENTRY_BLOCK_PTR
+ && e->dest != EXIT_BLOCK_PTR)
+ {
+ rtx insn;
+
+ if (e->src->next_bb != e->dest)
+ {
+ error
+ ("verify_flow_info: Incorrect blocks for fallthru %i->%i",
+ e->src->index, e->dest->index);
+ err = 1;
+ }
+ else
+ for (insn = NEXT_INSN (BB_END (e->src)); insn != BB_HEAD (e->dest);
+ insn = NEXT_INSN (insn))
+ if (BARRIER_P (insn)
+#ifndef CASE_DROPS_THROUGH
+ || INSN_P (insn)
+#else
+ || (INSN_P (insn) && ! JUMP_TABLE_DATA_P (insn))
+#endif
+ )
+ {
+ error ("verify_flow_info: Incorrect fallthru %i->%i",
+ e->src->index, e->dest->index);
+ fatal_insn ("wrong insn in the fallthru edge", insn);
+ err = 1;
+ }
+ }
+ }
num_bb_notes = 0;
last_bb_seen = ENTRY_BLOCK_PTR;
num_bb_notes++;
if (bb != last_bb_seen->next_bb)
- internal_error ("basic blocks not numbered consecutively");
+ internal_error ("basic blocks not laid down consecutively");
- last_bb_seen = bb;
+ curr_bb = last_bb_seen = bb;
}
- if (!bb_info[INSN_UID (x)])
+ if (!curr_bb)
{
switch (GET_CODE (x))
{
break;
case CODE_LABEL:
- /* An addr_vec is placed outside any block block. */
+ /* An addr_vec is placed outside any basic block. */
if (NEXT_INSN (x)
- && GET_CODE (NEXT_INSN (x)) == JUMP_INSN
+ && JUMP_P (NEXT_INSN (x))
&& (GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_DIFF_VEC
|| GET_CODE (PATTERN (NEXT_INSN (x))) == ADDR_VEC))
x = NEXT_INSN (x);
}
if (INSN_P (x)
- && GET_CODE (x) == JUMP_INSN
+ && JUMP_P (x)
&& returnjump_p (x) && ! condjump_p (x)
- && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER))
+ && ! (NEXT_INSN (x) && BARRIER_P (NEXT_INSN (x))))
fatal_insn ("return not followed by barrier", x);
+ if (curr_bb && x == BB_END (curr_bb))
+ curr_bb = NULL;
}
if (num_bb_notes != n_basic_blocks)
("number of bb notes in insn chain (%d) != n_basic_blocks (%d)",
num_bb_notes, n_basic_blocks);
- if (err)
- internal_error ("verify_flow_info failed");
-
- /* Clean up. */
- free (bb_info);
- free (last_visited);
- free (edge_checksum);
+ return err;
}
\f
/* Assume that the preceding pass has possibly eliminated jump instructions
Return true if any edges are eliminated. */
bool
-purge_dead_edges (bb)
- basic_block bb;
+purge_dead_edges (basic_block bb)
{
- edge e, next;
- rtx insn = bb->end, note;
+ edge e;
+ rtx insn = BB_END (bb), note;
bool purged = false;
+ bool found;
+ edge_iterator ei;
/* If this instruction cannot trap, remove REG_EH_REGION notes. */
- if (GET_CODE (insn) == INSN
+ if (NONJUMP_INSN_P (insn)
&& (note = find_reg_note (insn, REG_EH_REGION, NULL)))
{
rtx eqnote;
}
/* Cleanup abnormal edges caused by exceptions or non-local gotos. */
- for (e = bb->succ; e; e = next)
+ for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
{
- next = e->succ_next;
if (e->flags & EDGE_EH)
{
- if (can_throw_internal (bb->end))
- continue;
+ if (can_throw_internal (BB_END (bb)))
+ {
+ ei_next (&ei);
+ continue;
+ }
}
else if (e->flags & EDGE_ABNORMAL_CALL)
{
- if (GET_CODE (bb->end) == CALL_INSN
+ if (CALL_P (BB_END (bb))
&& (! (note = find_reg_note (insn, REG_EH_REGION, NULL))
|| INTVAL (XEXP (note, 0)) >= 0))
- continue;
+ {
+ ei_next (&ei);
+ continue;
+ }
}
else
- continue;
+ {
+ ei_next (&ei);
+ continue;
+ }
remove_edge (e);
bb->flags |= BB_DIRTY;
purged = true;
}
- if (GET_CODE (insn) == JUMP_INSN)
+ if (JUMP_P (insn))
{
rtx note;
edge b,f;
+ edge_iterator ei;
/* We do care only about conditional jumps and simplejumps. */
if (!any_condjump_p (insn)
remove_note (insn, note);
}
- for (e = bb->succ; e; e = next)
+ for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
{
- next = e->succ_next;
-
/* Avoid abnormal flags to leak from computed jumps turned
into simplejumps. */
if ((e->flags & EDGE_FALLTHRU) && any_condjump_p (insn))
/* A conditional jump can fall through into the next
block, so we should keep the edge. */
- continue;
+ {
+ ei_next (&ei);
+ continue;
+ }
else if (e->dest != EXIT_BLOCK_PTR
- && e->dest->head == JUMP_LABEL (insn))
+ && BB_HEAD (e->dest) == JUMP_LABEL (insn))
/* If the destination block is the target of the jump,
keep the edge. */
- continue;
+ {
+ ei_next (&ei);
+ continue;
+ }
else if (e->dest == EXIT_BLOCK_PTR && returnjump_p (insn))
/* If the destination block is the exit block, and this
instruction is a return, then keep the edge. */
- continue;
+ {
+ ei_next (&ei);
+ continue;
+ }
else if ((e->flags & EDGE_EH) && can_throw_internal (insn))
/* Keep the edges that correspond to exceptions thrown by
- this instruction. */
- continue;
+ this instruction and rematerialize the EDGE_ABNORMAL
+ flag we just cleared above. */
+ {
+ e->flags |= EDGE_ABNORMAL;
+ ei_next (&ei);
+ continue;
+ }
/* We do not need this edge. */
bb->flags |= BB_DIRTY;
remove_edge (e);
}
- if (!bb->succ || !purged)
+ if (EDGE_COUNT (bb->succs) == 0 || !purged)
return purged;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Purged edges from bb %i\n", bb->index);
+ if (dump_file)
+ fprintf (dump_file, "Purged edges from bb %i\n", bb->index);
if (!optimize)
return purged;
/* Redistribute probabilities. */
- if (!bb->succ->succ_next)
+ if (EDGE_COUNT (bb->succs) == 1)
{
- bb->succ->probability = REG_BR_PROB_BASE;
- bb->succ->count = bb->count;
+ EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE;
+ EDGE_SUCC (bb, 0)->count = bb->count;
}
else
{
return purged;
}
+ else if (CALL_P (insn) && SIBLING_CALL_P (insn))
+ {
+ /* First, there should not be any EH or ABCALL edges resulting
+ from non-local gotos and the like. If there were, we shouldn't
+ have created the sibcall in the first place. Second, there
+ should of course never have been a fallthru edge. */
+ gcc_assert (EDGE_COUNT (bb->succs) == 1);
+ gcc_assert (EDGE_SUCC (bb, 0)->flags == (EDGE_SIBCALL | EDGE_ABNORMAL));
+
+ return 0;
+ }
/* If we don't see a jump insn, we don't know exactly why the block would
have been broken at this point. Look for a simple, non-fallthru edge,
as these are only created by conditional branches. If we find such an
edge we know that there used to be a jump here and can then safely
remove all non-fallthru edges. */
- for (e = bb->succ; e && (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU));
- e = e->succ_next)
- ;
+ found = false;
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (! (e->flags & (EDGE_COMPLEX | EDGE_FALLTHRU)))
+ {
+ found = true;
+ break;
+ }
- if (!e)
+ if (!found)
return purged;
- for (e = bb->succ; e; e = next)
+ for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
{
- next = e->succ_next;
if (!(e->flags & EDGE_FALLTHRU))
{
bb->flags |= BB_DIRTY;
remove_edge (e);
purged = true;
}
+ else
+ ei_next (&ei);
}
- if (!bb->succ || bb->succ->succ_next)
- abort ();
+ gcc_assert (EDGE_COUNT (bb->succs) == 1);
- bb->succ->probability = REG_BR_PROB_BASE;
- bb->succ->count = bb->count;
+ EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE;
+ EDGE_SUCC (bb, 0)->count = bb->count;
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Purged non-fallthru edges from bb %i\n",
+ if (dump_file)
+ fprintf (dump_file, "Purged non-fallthru edges from bb %i\n",
bb->index);
return purged;
}
true if some edge has been eliminated. */
bool
-purge_all_dead_edges (update_life_p)
- int update_life_p;
+purge_all_dead_edges (int update_life_p)
{
int purged = false;
sbitmap blocks = 0;
sbitmap_free (blocks);
return purged;
}
+
+/* Same as split_block but update cfg_layout structures. */
+
+static basic_block
+cfg_layout_split_block (basic_block bb, void *insnp)
+{
+ rtx insn = insnp;
+ basic_block new_bb = rtl_split_block (bb, insn);
+
+ new_bb->rbi->footer = bb->rbi->footer;
+ bb->rbi->footer = NULL;
+
+ return new_bb;
+}
+
+
+/* Redirect Edge to DEST. */
+static edge
+cfg_layout_redirect_edge_and_branch (edge e, basic_block dest)
+{
+ basic_block src = e->src;
+ edge ret;
+
+ if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))
+ return NULL;
+
+ if (e->dest == dest)
+ return e;
+
+ if (e->src != ENTRY_BLOCK_PTR
+ && (ret = try_redirect_by_replacing_jump (e, dest, true)))
+ {
+ src->flags |= BB_DIRTY;
+ return ret;
+ }
+
+ if (e->src == ENTRY_BLOCK_PTR
+ && (e->flags & EDGE_FALLTHRU) && !(e->flags & EDGE_COMPLEX))
+ {
+ if (dump_file)
+ fprintf (dump_file, "Redirecting entry edge from bb %i to %i\n",
+ e->src->index, dest->index);
+
+ e->src->flags |= BB_DIRTY;
+ redirect_edge_succ (e, dest);
+ return e;
+ }
+
+ /* Redirect_edge_and_branch may decide to turn branch into fallthru edge
+ in the case the basic block appears to be in sequence. Avoid this
+ transformation. */
+
+ if (e->flags & EDGE_FALLTHRU)
+ {
+ /* Redirect any branch edges unified with the fallthru one. */
+ if (JUMP_P (BB_END (src))
+ && label_is_jump_target_p (BB_HEAD (e->dest),
+ BB_END (src)))
+ {
+ edge redirected;
+
+ if (dump_file)
+ fprintf (dump_file, "Fallthru edge unified with branch "
+ "%i->%i redirected to %i\n",
+ e->src->index, e->dest->index, dest->index);
+ e->flags &= ~EDGE_FALLTHRU;
+ redirected = redirect_branch_edge (e, dest);
+ gcc_assert (redirected);
+ e->flags |= EDGE_FALLTHRU;
+ e->src->flags |= BB_DIRTY;
+ return e;
+ }
+ /* In case we are redirecting fallthru edge to the branch edge
+ of conditional jump, remove it. */
+ if (EDGE_COUNT (src->succs) == 2)
+ {
+ bool found = false;
+ unsigned ix = 0;
+ edge tmp, s;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (tmp, ei, src->succs)
+ if (e == tmp)
+ {
+ found = true;
+ ix = ei.index;
+ break;
+ }
+
+ gcc_assert (found);
+
+ if (EDGE_COUNT (src->succs) > (ix + 1))
+ s = EDGE_SUCC (src, ix + 1);
+ else
+ s = EDGE_SUCC (src, 0);
+
+ if (s->dest == dest
+ && any_condjump_p (BB_END (src))
+ && onlyjump_p (BB_END (src)))
+ delete_insn (BB_END (src));
+ }
+ ret = redirect_edge_succ_nodup (e, dest);
+ if (dump_file)
+ fprintf (dump_file, "Fallthru edge %i->%i redirected to %i\n",
+ e->src->index, e->dest->index, dest->index);
+ }
+ else
+ ret = redirect_branch_edge (e, dest);
+
+ /* We don't want simplejumps in the insn stream during cfglayout. */
+ gcc_assert (!simplejump_p (BB_END (src)));
+
+ src->flags |= BB_DIRTY;
+ return ret;
+}
+
+/* Simple wrapper as we always can redirect fallthru edges. */
+static basic_block
+cfg_layout_redirect_edge_and_branch_force (edge e, basic_block dest)
+{
+ edge redirected = cfg_layout_redirect_edge_and_branch (e, dest);
+
+ gcc_assert (redirected);
+ return NULL;
+}
+
+/* Same as delete_basic_block but update cfg_layout structures. */
+
+static void
+cfg_layout_delete_block (basic_block bb)
+{
+ rtx insn, next, prev = PREV_INSN (BB_HEAD (bb)), *to, remaints;
+
+ if (bb->rbi->header)
+ {
+ next = BB_HEAD (bb);
+ if (prev)
+ NEXT_INSN (prev) = bb->rbi->header;
+ else
+ set_first_insn (bb->rbi->header);
+ PREV_INSN (bb->rbi->header) = prev;
+ insn = bb->rbi->header;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ NEXT_INSN (insn) = next;
+ PREV_INSN (next) = insn;
+ }
+ next = NEXT_INSN (BB_END (bb));
+ if (bb->rbi->footer)
+ {
+ insn = bb->rbi->footer;
+ while (insn)
+ {
+ if (BARRIER_P (insn))
+ {
+ if (PREV_INSN (insn))
+ NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn);
+ else
+ bb->rbi->footer = NEXT_INSN (insn);
+ if (NEXT_INSN (insn))
+ PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn);
+ }
+ if (LABEL_P (insn))
+ break;
+ insn = NEXT_INSN (insn);
+ }
+ if (bb->rbi->footer)
+ {
+ insn = BB_END (bb);
+ NEXT_INSN (insn) = bb->rbi->footer;
+ PREV_INSN (bb->rbi->footer) = insn;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ NEXT_INSN (insn) = next;
+ if (next)
+ PREV_INSN (next) = insn;
+ else
+ set_last_insn (insn);
+ }
+ }
+ if (bb->next_bb != EXIT_BLOCK_PTR)
+ to = &bb->next_bb->rbi->header;
+ else
+ to = &cfg_layout_function_footer;
+ rtl_delete_block (bb);
+
+ if (prev)
+ prev = NEXT_INSN (prev);
+ else
+ prev = get_insns ();
+ if (next)
+ next = PREV_INSN (next);
+ else
+ next = get_last_insn ();
+
+ if (next && NEXT_INSN (next) != prev)
+ {
+ remaints = unlink_insn_chain (prev, next);
+ insn = remaints;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ NEXT_INSN (insn) = *to;
+ if (*to)
+ PREV_INSN (*to) = insn;
+ *to = remaints;
+ }
+}
+
+/* Return true when blocks A and B can be safely merged. */
+static bool
+cfg_layout_can_merge_blocks_p (basic_block a, basic_block b)
+{
+ /* If we are partitioning hot/cold basic blocks, we don't want to
+ mess up unconditional or indirect jumps that cross between hot
+ and cold sections.
+
+ Basic block partitioning may result in some jumps that appear to
+ be optimizable (or blocks that appear to be mergeable), but which really
+ must be left untouched (they are required to make it safely across
+ partition boundaries). See the comments at the top of
+ bb-reorder.c:partition_hot_cold_basic_blocks for complete details. */
+
+ if (flag_reorder_blocks_and_partition
+ && (find_reg_note (BB_END (a), REG_CROSSING_JUMP, NULL_RTX)
+ || find_reg_note (BB_END (b), REG_CROSSING_JUMP, NULL_RTX)
+ || BB_PARTITION (a) != BB_PARTITION (b)))
+ return false;
+
+ /* There must be exactly one edge in between the blocks. */
+ return (EDGE_COUNT (a->succs) == 1
+ && EDGE_SUCC (a, 0)->dest == b
+ && EDGE_COUNT (b->preds) == 1
+ && a != b
+ /* Must be simple edge. */
+ && !(EDGE_SUCC (a, 0)->flags & EDGE_COMPLEX)
+ && a != ENTRY_BLOCK_PTR && b != EXIT_BLOCK_PTR
+ /* If the jump insn has side effects,
+ we can't kill the edge. */
+ && (!JUMP_P (BB_END (a))
+ || (reload_completed
+ ? simplejump_p (BB_END (a)) : onlyjump_p (BB_END (a)))));
+}
+
+/* Merge block A and B, abort when it is not possible. */
+static void
+cfg_layout_merge_blocks (basic_block a, basic_block b)
+{
+#ifdef ENABLE_CHECKING
+ gcc_assert (cfg_layout_can_merge_blocks_p (a, b));
+#endif
+
+ /* If there was a CODE_LABEL beginning B, delete it. */
+ if (LABEL_P (BB_HEAD (b)))
+ delete_insn (BB_HEAD (b));
+
+ /* We should have fallthru edge in a, or we can do dummy redirection to get
+ it cleaned up. */
+ if (JUMP_P (BB_END (a)))
+ try_redirect_by_replacing_jump (EDGE_SUCC (a, 0), b, true);
+ gcc_assert (!JUMP_P (BB_END (a)));
+
+ /* Possible line number notes should appear in between. */
+ if (b->rbi->header)
+ {
+ rtx first = BB_END (a), last;
+
+ last = emit_insn_after_noloc (b->rbi->header, BB_END (a));
+ delete_insn_chain (NEXT_INSN (first), last);
+ b->rbi->header = NULL;
+ }
+
+ /* In the case basic blocks are not adjacent, move them around. */
+ if (NEXT_INSN (BB_END (a)) != BB_HEAD (b))
+ {
+ rtx first = unlink_insn_chain (BB_HEAD (b), BB_END (b));
+
+ emit_insn_after_noloc (first, BB_END (a));
+ /* Skip possible DELETED_LABEL insn. */
+ if (!NOTE_INSN_BASIC_BLOCK_P (first))
+ first = NEXT_INSN (first);
+ gcc_assert (NOTE_INSN_BASIC_BLOCK_P (first));
+ BB_HEAD (b) = NULL;
+ delete_insn (first);
+ }
+ /* Otherwise just re-associate the instructions. */
+ else
+ {
+ rtx insn;
+
+ for (insn = BB_HEAD (b);
+ insn != NEXT_INSN (BB_END (b));
+ insn = NEXT_INSN (insn))
+ set_block_for_insn (insn, a);
+ insn = BB_HEAD (b);
+ /* Skip possible DELETED_LABEL insn. */
+ if (!NOTE_INSN_BASIC_BLOCK_P (insn))
+ insn = NEXT_INSN (insn);
+ gcc_assert (NOTE_INSN_BASIC_BLOCK_P (insn));
+ BB_HEAD (b) = NULL;
+ BB_END (a) = BB_END (b);
+ delete_insn (insn);
+ }
+
+ /* Possible tablejumps and barriers should appear after the block. */
+ if (b->rbi->footer)
+ {
+ if (!a->rbi->footer)
+ a->rbi->footer = b->rbi->footer;
+ else
+ {
+ rtx last = a->rbi->footer;
+
+ while (NEXT_INSN (last))
+ last = NEXT_INSN (last);
+ NEXT_INSN (last) = b->rbi->footer;
+ PREV_INSN (b->rbi->footer) = last;
+ }
+ b->rbi->footer = NULL;
+ }
+
+ if (dump_file)
+ fprintf (dump_file, "Merged blocks %d and %d.\n",
+ a->index, b->index);
+}
+
+/* Split edge E. */
+
+static basic_block
+cfg_layout_split_edge (edge e)
+{
+ edge new_e;
+ basic_block new_bb =
+ create_basic_block (e->src != ENTRY_BLOCK_PTR
+ ? NEXT_INSN (BB_END (e->src)) : get_insns (),
+ NULL_RTX, e->src);
+
+ /* ??? This info is likely going to be out of date very soon, but we must
+ create it to avoid getting an ICE later. */
+ if (e->dest->global_live_at_start)
+ {
+ new_bb->global_live_at_start = OBSTACK_ALLOC_REG_SET (&flow_obstack);
+ new_bb->global_live_at_end = OBSTACK_ALLOC_REG_SET (&flow_obstack);
+ COPY_REG_SET (new_bb->global_live_at_start,
+ e->dest->global_live_at_start);
+ COPY_REG_SET (new_bb->global_live_at_end,
+ e->dest->global_live_at_start);
+ }
+
+ new_e = make_edge (new_bb, e->dest, EDGE_FALLTHRU);
+ redirect_edge_and_branch_force (e, new_bb);
+
+ return new_bb;
+}
+
+/* Do postprocessing after making a forwarder block joined by edge FALLTHRU. */
+
+static void
+rtl_make_forwarder_block (edge fallthru ATTRIBUTE_UNUSED)
+{
+}
+
+/* Return 1 if BB ends with a call, possibly followed by some
+ instructions that must stay with the call, 0 otherwise. */
+
+static bool
+rtl_block_ends_with_call_p (basic_block bb)
+{
+ rtx insn = BB_END (bb);
+
+ while (!CALL_P (insn)
+ && insn != BB_HEAD (bb)
+ && keep_with_call_p (insn))
+ insn = PREV_INSN (insn);
+ return (CALL_P (insn));
+}
+
+/* Return 1 if BB ends with a conditional branch, 0 otherwise. */
+
+static bool
+rtl_block_ends_with_condjump_p (basic_block bb)
+{
+ return any_condjump_p (BB_END (bb));
+}
+
+/* Return true if we need to add fake edge to exit.
+ Helper function for rtl_flow_call_edges_add. */
+
+static bool
+need_fake_edge_p (rtx insn)
+{
+ if (!INSN_P (insn))
+ return false;
+
+ if ((CALL_P (insn)
+ && !SIBLING_CALL_P (insn)
+ && !find_reg_note (insn, REG_NORETURN, NULL)
+ && !find_reg_note (insn, REG_ALWAYS_RETURN, NULL)
+ && !CONST_OR_PURE_CALL_P (insn)))
+ return true;
+
+ return ((GET_CODE (PATTERN (insn)) == ASM_OPERANDS
+ && MEM_VOLATILE_P (PATTERN (insn)))
+ || (GET_CODE (PATTERN (insn)) == PARALLEL
+ && asm_noperands (insn) != -1
+ && MEM_VOLATILE_P (XVECEXP (PATTERN (insn), 0, 0)))
+ || GET_CODE (PATTERN (insn)) == ASM_INPUT);
+}
+
+/* Add fake edges to the function exit for any non constant and non noreturn
+ calls, volatile inline assembly in the bitmap of blocks specified by
+ BLOCKS or to the whole CFG if BLOCKS is zero. Return the number of blocks
+ that were split.
+
+ The goal is to expose cases in which entering a basic block does not imply
+ that all subsequent instructions must be executed. */
+
+static int
+rtl_flow_call_edges_add (sbitmap blocks)
+{
+ int i;
+ int blocks_split = 0;
+ int last_bb = last_basic_block;
+ bool check_last_block = false;
+
+ if (n_basic_blocks == 0)
+ return 0;
+
+ if (! blocks)
+ check_last_block = true;
+ else
+ check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index);
+
+ /* In the last basic block, before epilogue generation, there will be
+ a fallthru edge to EXIT. Special care is required if the last insn
+ of the last basic block is a call because make_edge folds duplicate
+ edges, which would result in the fallthru edge also being marked
+ fake, which would result in the fallthru edge being removed by
+ remove_fake_edges, which would result in an invalid CFG.
+
+ Moreover, we can't elide the outgoing fake edge, since the block
+ profiler needs to take this into account in order to solve the minimal
+ spanning tree in the case that the call doesn't return.
+
+ Handle this by adding a dummy instruction in a new last basic block. */
+ if (check_last_block)
+ {
+ basic_block bb = EXIT_BLOCK_PTR->prev_bb;
+ rtx insn = BB_END (bb);
+
+ /* Back up past insns that must be kept in the same block as a call. */
+ while (insn != BB_HEAD (bb)
+ && keep_with_call_p (insn))
+ insn = PREV_INSN (insn);
+
+ if (need_fake_edge_p (insn))
+ {
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->dest == EXIT_BLOCK_PTR)
+ {
+ insert_insn_on_edge (gen_rtx_USE (VOIDmode, const0_rtx), e);
+ commit_edge_insertions ();
+ break;
+ }
+ }
+ }
+
+ /* Now add fake edges to the function exit for any non constant
+ calls since there is no way that we can determine if they will
+ return or not... */
+
+ for (i = 0; i < last_bb; i++)
+ {
+ basic_block bb = BASIC_BLOCK (i);
+ rtx insn;
+ rtx prev_insn;
+
+ if (!bb)
+ continue;
+
+ if (blocks && !TEST_BIT (blocks, i))
+ continue;
+
+ for (insn = BB_END (bb); ; insn = prev_insn)
+ {
+ prev_insn = PREV_INSN (insn);
+ if (need_fake_edge_p (insn))
+ {
+ edge e;
+ rtx split_at_insn = insn;
+
+ /* Don't split the block between a call and an insn that should
+ remain in the same block as the call. */
+ if (CALL_P (insn))
+ while (split_at_insn != BB_END (bb)
+ && keep_with_call_p (NEXT_INSN (split_at_insn)))
+ split_at_insn = NEXT_INSN (split_at_insn);
+
+ /* The handling above of the final block before the epilogue
+ should be enough to verify that there is no edge to the exit
+ block in CFG already. Calling make_edge in such case would
+ cause us to mark that edge as fake and remove it later. */
+
+#ifdef ENABLE_CHECKING
+ if (split_at_insn == BB_END (bb))
+ {
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ gcc_assert (e->dest != EXIT_BLOCK_PTR);
+ }
+#endif
+
+ /* Note that the following may create a new basic block
+ and renumber the existing basic blocks. */
+ if (split_at_insn != BB_END (bb))
+ {
+ e = split_block (bb, split_at_insn);
+ if (e)
+ blocks_split++;
+ }
+
+ make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE);
+ }
+
+ if (insn == BB_HEAD (bb))
+ break;
+ }
+ }
+
+ if (blocks_split)
+ verify_flow_info ();
+
+ return blocks_split;
+}
+
+/* Implementation of CFG manipulation for linearized RTL. */
+struct cfg_hooks rtl_cfg_hooks = {
+ "rtl",
+ rtl_verify_flow_info,
+ rtl_dump_bb,
+ rtl_create_basic_block,
+ rtl_redirect_edge_and_branch,
+ rtl_redirect_edge_and_branch_force,
+ rtl_delete_block,
+ rtl_split_block,
+ rtl_move_block_after,
+ rtl_can_merge_blocks, /* can_merge_blocks_p */
+ rtl_merge_blocks,
+ rtl_predict_edge,
+ rtl_predicted_by_p,
+ NULL, /* can_duplicate_block_p */
+ NULL, /* duplicate_block */
+ rtl_split_edge,
+ rtl_make_forwarder_block,
+ rtl_tidy_fallthru_edge,
+ rtl_block_ends_with_call_p,
+ rtl_block_ends_with_condjump_p,
+ rtl_flow_call_edges_add
+};
+
+/* Implementation of CFG manipulation for cfg layout RTL, where
+ basic block connected via fallthru edges does not have to be adjacent.
+ This representation will hopefully become the default one in future
+ version of the compiler. */
+
+/* We do not want to declare these functions in a header file, since they
+ should only be used through the cfghooks interface, and we do not want to
+ move them here since it would require also moving quite a lot of related
+ code. */
+extern bool cfg_layout_can_duplicate_bb_p (basic_block);
+extern basic_block cfg_layout_duplicate_bb (basic_block);
+
+struct cfg_hooks cfg_layout_rtl_cfg_hooks = {
+ "cfglayout mode",
+ rtl_verify_flow_info_1,
+ rtl_dump_bb,
+ cfg_layout_create_basic_block,
+ cfg_layout_redirect_edge_and_branch,
+ cfg_layout_redirect_edge_and_branch_force,
+ cfg_layout_delete_block,
+ cfg_layout_split_block,
+ rtl_move_block_after,
+ cfg_layout_can_merge_blocks_p,
+ cfg_layout_merge_blocks,
+ rtl_predict_edge,
+ rtl_predicted_by_p,
+ cfg_layout_can_duplicate_bb_p,
+ cfg_layout_duplicate_bb,
+ cfg_layout_split_edge,
+ rtl_make_forwarder_block,
+ NULL,
+ rtl_block_ends_with_call_p,
+ rtl_block_ends_with_condjump_p,
+ rtl_flow_call_edges_add
+};
+
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