/* Basic block reordering routines for the GNU compiler.
- Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2003, 2004 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "function.h"
#include "obstack.h"
#include "cfglayout.h"
+#include "cfgloop.h"
+#include "target.h"
+#include "ggc.h"
+#include "alloc-pool.h"
+#include "flags.h"
/* The contents of the current function definition are allocated
in this obstack, and all are freed at the end of the function. */
extern struct obstack flow_obstack;
/* Holds the interesting trailing notes for the function. */
-static rtx function_tail_eff_head;
+rtx cfg_layout_function_footer, cfg_layout_function_header;
-static rtx skip_insns_after_block PARAMS ((basic_block));
-static void record_effective_endpoints PARAMS ((void));
-static rtx label_for_bb PARAMS ((basic_block));
-static void fixup_reorder_chain PARAMS ((void));
+static rtx skip_insns_after_block (basic_block);
+static void record_effective_endpoints (void);
+static rtx label_for_bb (basic_block);
+static void fixup_reorder_chain (void);
-static void set_block_levels PARAMS ((tree, int));
-static void change_scope PARAMS ((rtx, tree, tree));
+static void set_block_levels (tree, int);
+static void change_scope (rtx, tree, tree);
-void verify_insn_chain PARAMS ((void));
-static void fixup_fallthru_exit_predecessor PARAMS ((void));
-
-/* Map insn uid to lexical block. */
-static varray_type insn_scopes;
+void verify_insn_chain (void);
+static void fixup_fallthru_exit_predecessor (void);
+static tree insn_scope (rtx);
+static void update_unlikely_executed_notes (basic_block);
+\f
+rtx
+unlink_insn_chain (rtx first, rtx last)
+{
+ rtx prevfirst = PREV_INSN (first);
+ rtx nextlast = NEXT_INSN (last);
+
+ PREV_INSN (first) = NULL;
+ NEXT_INSN (last) = NULL;
+ if (prevfirst)
+ NEXT_INSN (prevfirst) = nextlast;
+ if (nextlast)
+ PREV_INSN (nextlast) = prevfirst;
+ else
+ set_last_insn (prevfirst);
+ if (!prevfirst)
+ set_first_insn (nextlast);
+ return first;
+}
\f
/* Skip over inter-block insns occurring after BB which are typically
associated with BB (e.g., barriers). If there are any such insns,
we return the last one. Otherwise, we return the end of BB. */
static rtx
-skip_insns_after_block (bb)
- basic_block bb;
+skip_insns_after_block (basic_block bb)
{
rtx insn, last_insn, next_head, prev;
next_head = NULL_RTX;
- if (bb->index + 1 != n_basic_blocks)
- next_head = BASIC_BLOCK (bb->index + 1)->head;
+ if (bb->next_bb != EXIT_BLOCK_PTR)
+ next_head = BB_HEAD (bb->next_bb);
- for (last_insn = insn = bb->end; (insn = NEXT_INSN (insn)) != 0; )
+ for (last_insn = insn = BB_END (bb); (insn = NEXT_INSN (insn)) != 0; )
{
if (insn == next_head)
break;
last_insn = insn;
continue;
}
- break;
+ break;
default:
break;
}
/* It is possible to hit contradictory sequence. For instance:
-
+
jump_insn
NOTE_INSN_LOOP_BEG
barrier
created by removing the basic block originally following
NOTE_INSN_LOOP_BEG. In such case reorder the notes. */
- for (insn = last_insn; insn != bb->end; insn = prev)
+ for (insn = last_insn; insn != BB_END (bb); insn = prev)
{
prev = PREV_INSN (insn);
if (GET_CODE (insn) == NOTE)
switch (NOTE_LINE_NUMBER (insn))
{
- case NOTE_INSN_LOOP_END:
- case NOTE_INSN_BLOCK_END:
- case NOTE_INSN_DELETED:
- case NOTE_INSN_DELETED_LABEL:
+ case NOTE_INSN_LOOP_END:
+ case NOTE_INSN_BLOCK_END:
+ case NOTE_INSN_DELETED:
+ case NOTE_INSN_DELETED_LABEL:
continue;
- default:
+ default:
reorder_insns (insn, insn, last_insn);
- }
+ }
}
return last_insn;
/* Locate or create a label for a given basic block. */
static rtx
-label_for_bb (bb)
- basic_block bb;
+label_for_bb (basic_block bb)
{
- rtx label = bb->head;
+ rtx label = BB_HEAD (bb);
if (GET_CODE (label) != CODE_LABEL)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Emitting label for block %d\n", bb->index);
+ if (dump_file)
+ fprintf (dump_file, "Emitting label for block %d\n", bb->index);
label = block_label (bb);
- if (bb->head == PREV_INSN (RBI (bb)->eff_head))
- RBI (bb)->eff_head = label;
}
return label;
block, as defined by skip_insns_after_block above. */
static void
-record_effective_endpoints ()
+record_effective_endpoints (void)
{
- rtx next_insn = get_insns ();
- int i;
-
- for (i = 0; i < n_basic_blocks; i++)
+ rtx next_insn;
+ basic_block bb;
+ rtx insn;
+
+ for (insn = get_insns ();
+ insn
+ && GET_CODE (insn) == NOTE
+ && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK;
+ insn = NEXT_INSN (insn))
+ continue;
+ if (!insn)
+ abort (); /* No basic blocks at all? */
+ if (PREV_INSN (insn))
+ cfg_layout_function_header =
+ unlink_insn_chain (get_insns (), PREV_INSN (insn));
+ else
+ cfg_layout_function_header = NULL_RTX;
+
+ next_insn = get_insns ();
+ FOR_EACH_BB (bb)
{
- basic_block bb = BASIC_BLOCK (i);
rtx end;
- RBI (bb)->eff_head = next_insn;
+ if (PREV_INSN (BB_HEAD (bb)) && next_insn != BB_HEAD (bb))
+ bb->rbi->header = unlink_insn_chain (next_insn,
+ PREV_INSN (BB_HEAD (bb)));
end = skip_insns_after_block (bb);
- RBI (bb)->eff_end = end;
- next_insn = NEXT_INSN (end);
+ if (NEXT_INSN (BB_END (bb)) && BB_END (bb) != end)
+ bb->rbi->footer = unlink_insn_chain (NEXT_INSN (BB_END (bb)), end);
+ next_insn = NEXT_INSN (BB_END (bb));
}
- function_tail_eff_head = next_insn;
+ cfg_layout_function_footer = next_insn;
+ if (cfg_layout_function_footer)
+ cfg_layout_function_footer = unlink_insn_chain (cfg_layout_function_footer, get_last_insn ());
}
\f
-/* Build a varray mapping INSN_UID to lexical block. Return it. */
+/* Data structures representing mapping of INSN_LOCATOR into scope blocks, line
+ numbers and files. In order to be GGC friendly we need to use separate
+ varrays. This also slightly improve the memory locality in binary search.
+ The _locs array contains locators where the given property change. The
+ block_locators_blocks contains the scope block that is used for all insn
+ locator greater than corresponding block_locators_locs value and smaller
+ than the following one. Similarly for the other properties. */
+static GTY(()) varray_type block_locators_locs;
+static GTY(()) varray_type block_locators_blocks;
+static GTY(()) varray_type line_locators_locs;
+static GTY(()) varray_type line_locators_lines;
+static GTY(()) varray_type file_locators_locs;
+static GTY(()) varray_type file_locators_files;
+int prologue_locator;
+int epilogue_locator;
+
+/* During the RTL expansion the lexical blocks and line numbers are
+ represented via INSN_NOTEs. Replace them by representation using
+ INSN_LOCATORs. */
void
-scope_to_insns_initialize ()
+insn_locators_initialize (void)
{
tree block = NULL;
+ tree last_block = NULL;
rtx insn, next;
+ int loc = 0;
+ int line_number = 0, last_line_number = 0;
+ char *file_name = NULL, *last_file_name = NULL;
- VARRAY_TREE_INIT (insn_scopes, get_max_uid (), "insn scopes");
+ prologue_locator = epilogue_locator = 0;
+
+ VARRAY_INT_INIT (block_locators_locs, 32, "block_locators_locs");
+ VARRAY_TREE_INIT (block_locators_blocks, 32, "block_locators_blocks");
+ VARRAY_INT_INIT (line_locators_locs, 32, "line_locators_locs");
+ VARRAY_INT_INIT (line_locators_lines, 32, "line_locators_lines");
+ VARRAY_INT_INIT (file_locators_locs, 32, "file_locators_locs");
+ VARRAY_CHAR_PTR_INIT (file_locators_files, 32, "file_locators_files");
for (insn = get_insns (); insn; insn = next)
{
next = NEXT_INSN (insn);
- if (active_insn_p (insn)
- && GET_CODE (PATTERN (insn)) != ADDR_VEC
- && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC)
- VARRAY_TREE (insn_scopes, INSN_UID (insn)) = block;
+ if ((active_insn_p (insn)
+ && GET_CODE (PATTERN (insn)) != ADDR_VEC
+ && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC)
+ || !NEXT_INSN (insn)
+ || (!prologue_locator && file_name))
+ {
+ if (last_block != block)
+ {
+ loc++;
+ VARRAY_PUSH_INT (block_locators_locs, loc);
+ VARRAY_PUSH_TREE (block_locators_blocks, block);
+ last_block = block;
+ }
+ if (last_line_number != line_number)
+ {
+ loc++;
+ VARRAY_PUSH_INT (line_locators_locs, loc);
+ VARRAY_PUSH_INT (line_locators_lines, line_number);
+ last_line_number = line_number;
+ }
+ if (last_file_name != file_name)
+ {
+ loc++;
+ VARRAY_PUSH_INT (file_locators_locs, loc);
+ VARRAY_PUSH_CHAR_PTR (file_locators_files, file_name);
+ last_file_name = file_name;
+ }
+ }
+ if (!prologue_locator && file_name)
+ prologue_locator = loc;
+ if (!NEXT_INSN (insn))
+ epilogue_locator = loc;
+ if (active_insn_p (insn))
+ INSN_LOCATOR (insn) = loc;
else if (GET_CODE (insn) == NOTE)
{
switch (NOTE_LINE_NUMBER (insn))
{
case NOTE_INSN_BLOCK_BEG:
+ if (cfun->dont_emit_block_notes)
+ abort ();
block = NOTE_BLOCK (insn);
delete_insn (insn);
break;
case NOTE_INSN_BLOCK_END:
+ if (cfun->dont_emit_block_notes)
+ abort ();
block = BLOCK_SUPERCONTEXT (block);
+ if (block && TREE_CODE (block) == FUNCTION_DECL)
+ block = 0;
delete_insn (insn);
break;
default:
+ if (NOTE_LINE_NUMBER (insn) > 0)
+ {
+ line_number = NOTE_LINE_NUMBER (insn);
+ file_name = (char *)NOTE_SOURCE_FILE (insn);
+ }
break;
}
}
+
+ if (cfun->dont_emit_block_notes)
+ check_block_change (insn, &block);
}
+
+ /* Tag the blocks with a depth number so that change_scope can find
+ the common parent easily. */
+ set_block_levels (DECL_INITIAL (cfun->decl), 0);
+
+ if (cfun->dont_emit_block_notes)
+ free_block_changes ();
}
/* For each lexical block, set BLOCK_NUMBER to the depth at which it is
found in the block tree. */
static void
-set_block_levels (block, level)
- tree block;
- int level;
+set_block_levels (tree block, int level)
{
while (block)
{
block = BLOCK_CHAIN (block);
}
}
-
+\f
+/* Return sope resulting from combination of S1 and S2. */
+tree
+choose_inner_scope (tree s1, tree s2)
+{
+ if (!s1)
+ return s2;
+ if (!s2)
+ return s1;
+ if (BLOCK_NUMBER (s1) > BLOCK_NUMBER (s2))
+ return s1;
+ return s2;
+}
+\f
/* Emit lexical block notes needed to change scope from S1 to S2. */
static void
-change_scope (orig_insn, s1, s2)
- rtx orig_insn;
- tree s1, s2;
+change_scope (rtx orig_insn, tree s1, tree s2)
{
rtx insn = orig_insn;
tree com = NULL_TREE;
}
}
+/* Return lexical scope block insn belong to. */
+static tree
+insn_scope (rtx insn)
+{
+ int max = VARRAY_ACTIVE_SIZE (block_locators_locs);
+ int min = 0;
+ int loc = INSN_LOCATOR (insn);
+
+ /* When block_locators_locs was initialized, the pro- and epilogue
+ insns didn't exist yet and can therefore not be found this way.
+ But we know that they belong to the outer most block of the
+ current function.
+ Without this test, the prologue would be put inside the block of
+ the first valid instruction in the function and when that first
+ insn is part of an inlined function then the low_pc of that
+ inlined function is messed up. Likewise for the epilogue and
+ the last valid instruction. */
+ if (loc == prologue_locator || loc == epilogue_locator)
+ return DECL_INITIAL (cfun->decl);
+
+ if (!max || !loc)
+ return NULL;
+ while (1)
+ {
+ int pos = (min + max) / 2;
+ int tmp = VARRAY_INT (block_locators_locs, pos);
+
+ if (tmp <= loc && min != pos)
+ min = pos;
+ else if (tmp > loc && max != pos)
+ max = pos;
+ else
+ {
+ min = pos;
+ break;
+ }
+ }
+ return VARRAY_TREE (block_locators_blocks, min);
+}
+
+/* Return line number of the statement specified by the locator. */
+int
+locator_line (int loc)
+{
+ int max = VARRAY_ACTIVE_SIZE (line_locators_locs);
+ int min = 0;
+
+ if (!max || !loc)
+ return 0;
+ while (1)
+ {
+ int pos = (min + max) / 2;
+ int tmp = VARRAY_INT (line_locators_locs, pos);
+
+ if (tmp <= loc && min != pos)
+ min = pos;
+ else if (tmp > loc && max != pos)
+ max = pos;
+ else
+ {
+ min = pos;
+ break;
+ }
+ }
+ return VARRAY_INT (line_locators_lines, min);
+}
+
+/* Return line number of the statement that produced this insn. */
+int
+insn_line (rtx insn)
+{
+ return locator_line (INSN_LOCATOR (insn));
+}
+
+/* Return source file of the statement specified by LOC. */
+const char *
+locator_file (int loc)
+{
+ int max = VARRAY_ACTIVE_SIZE (file_locators_locs);
+ int min = 0;
+
+ if (!max || !loc)
+ return NULL;
+ while (1)
+ {
+ int pos = (min + max) / 2;
+ int tmp = VARRAY_INT (file_locators_locs, pos);
+
+ if (tmp <= loc && min != pos)
+ min = pos;
+ else if (tmp > loc && max != pos)
+ max = pos;
+ else
+ {
+ min = pos;
+ break;
+ }
+ }
+ return VARRAY_CHAR_PTR (file_locators_files, min);
+}
+
+/* Return source file of the statement that produced this insn. */
+const char *
+insn_file (rtx insn)
+{
+ return locator_file (INSN_LOCATOR (insn));
+}
+
/* Rebuild all the NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes based
on the scope tree and the newly reordered instructions. */
void
-scope_to_insns_finalize ()
+reemit_insn_block_notes (void)
{
tree cur_block = DECL_INITIAL (cfun->decl);
rtx insn, note;
- /* Tag the blocks with a depth number so that change_scope can find
- the common parent easily. */
- set_block_levels (cur_block, 0);
-
- for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
+ insn = get_insns ();
+ if (!active_insn_p (insn))
+ insn = next_active_insn (insn);
+ for (; insn; insn = next_active_insn (insn))
{
tree this_block;
- if ((size_t) INSN_UID (insn) >= insn_scopes->num_elements)
- continue;
- this_block = VARRAY_TREE (insn_scopes, INSN_UID (insn));
+ this_block = insn_scope (insn);
+ /* For sequences compute scope resulting from merging all scopes
+ of instructions nested inside. */
+ if (GET_CODE (PATTERN (insn)) == SEQUENCE)
+ {
+ int i;
+ rtx body = PATTERN (insn);
+
+ this_block = NULL;
+ for (i = 0; i < XVECLEN (body, 0); i++)
+ this_block = choose_inner_scope (this_block,
+ insn_scope (XVECEXP (body, 0, i)));
+ }
if (! this_block)
continue;
}
}
- VARRAY_FREE (insn_scopes);
-
/* change_scope emits before the insn, not after. */
- note = emit_note (NULL, NOTE_INSN_DELETED);
+ note = emit_note (NOTE_INSN_DELETED);
change_scope (note, cur_block, DECL_INITIAL (cfun->decl));
delete_insn (note);
/* Given a reorder chain, rearrange the code to match. */
static void
-fixup_reorder_chain ()
+fixup_reorder_chain (void)
{
- basic_block bb, last_bb;
+ basic_block bb, prev_bb;
int index;
- rtx insn;
- int old_n_basic_blocks = n_basic_blocks;
+ rtx insn = NULL;
+
+ if (cfg_layout_function_header)
+ {
+ set_first_insn (cfg_layout_function_header);
+ insn = cfg_layout_function_header;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ }
/* First do the bulk reordering -- rechain the blocks without regard to
the needed changes to jumps and labels. */
- for (last_bb = BASIC_BLOCK (0), bb = RBI (last_bb)->next, index = 1;
+ for (bb = ENTRY_BLOCK_PTR->next_bb, index = 0;
bb != 0;
- last_bb = bb, bb = RBI (bb)->next, index++)
+ bb = bb->rbi->next, index++)
{
- rtx last_e = RBI (last_bb)->eff_end;
- rtx curr_h = RBI (bb)->eff_head;
-
- NEXT_INSN (last_e) = curr_h;
- PREV_INSN (curr_h) = last_e;
+ if (bb->rbi->header)
+ {
+ if (insn)
+ NEXT_INSN (insn) = bb->rbi->header;
+ else
+ set_first_insn (bb->rbi->header);
+ PREV_INSN (bb->rbi->header) = insn;
+ insn = bb->rbi->header;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ }
+ if (insn)
+ NEXT_INSN (insn) = BB_HEAD (bb);
+ else
+ set_first_insn (BB_HEAD (bb));
+ PREV_INSN (BB_HEAD (bb)) = insn;
+ insn = BB_END (bb);
+ if (bb->rbi->footer)
+ {
+ NEXT_INSN (insn) = bb->rbi->footer;
+ PREV_INSN (bb->rbi->footer) = insn;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ }
}
if (index != n_basic_blocks)
abort ();
- insn = RBI (last_bb)->eff_end;
- NEXT_INSN (insn) = function_tail_eff_head;
- if (function_tail_eff_head)
- PREV_INSN (function_tail_eff_head) = insn;
+ NEXT_INSN (insn) = cfg_layout_function_footer;
+ if (cfg_layout_function_footer)
+ PREV_INSN (cfg_layout_function_footer) = insn;
while (NEXT_INSN (insn))
insn = NEXT_INSN (insn);
#ifdef ENABLE_CHECKING
verify_insn_chain ();
#endif
+ delete_dead_jumptables ();
/* Now add jumps and labels as needed to match the blocks new
outgoing edges. */
- for (bb = BASIC_BLOCK (0); bb ; bb = RBI (bb)->next)
+ for (bb = ENTRY_BLOCK_PTR->next_bb; bb ; bb = bb->rbi->next)
{
edge e_fall, e_taken, e;
rtx bb_end_insn;
basic_block nb;
+ basic_block old_bb;
if (bb->succ == NULL)
continue;
else if (! (e->flags & EDGE_EH))
e_taken = e;
- bb_end_insn = bb->end;
+ bb_end_insn = BB_END (bb);
if (GET_CODE (bb_end_insn) == JUMP_INSN)
{
if (any_condjump_p (bb_end_insn))
{
/* If the old fallthru is still next, nothing to do. */
- if (RBI (bb)->next == e_fall->dest
- || (!RBI (bb)->next
+ if (bb->rbi->next == e_fall->dest
+ || (!bb->rbi->next
&& e_fall->dest == EXIT_BLOCK_PTR))
continue;
+ /* The degenerated case of conditional jump jumping to the next
+ instruction can happen on target having jumps with side
+ effects.
+
+ Create temporarily the duplicated edge representing branch.
+ It will get unidentified by force_nonfallthru_and_redirect
+ that would otherwise get confused by fallthru edge not pointing
+ to the next basic block. */
+ if (!e_taken)
+ {
+ rtx note;
+ edge e_fake;
+
+ e_fake = unchecked_make_edge (bb, e_fall->dest, 0);
+
+ if (!redirect_jump (BB_END (bb), block_label (bb), 0))
+ abort ();
+ note = find_reg_note (BB_END (bb), REG_BR_PROB, NULL_RTX);
+ if (note)
+ {
+ int prob = INTVAL (XEXP (note, 0));
+
+ e_fake->probability = prob;
+ e_fake->count = e_fall->count * prob / REG_BR_PROB_BASE;
+ e_fall->probability -= e_fall->probability;
+ e_fall->count -= e_fake->count;
+ if (e_fall->probability < 0)
+ e_fall->probability = 0;
+ if (e_fall->count < 0)
+ e_fall->count = 0;
+ }
+ }
/* There is one special case: if *neither* block is next,
such as happens at the very end of a function, then we'll
need to add a new unconditional jump. Choose the taken
edge based on known or assumed probability. */
- if (RBI (bb)->next != e_taken->dest)
+ else if (bb->rbi->next != e_taken->dest)
{
rtx note = find_reg_note (bb_end_insn, REG_BR_PROB, 0);
if (note
&& INTVAL (XEXP (note, 0)) < REG_BR_PROB_BASE / 2
&& invert_jump (bb_end_insn,
- label_for_bb (e_fall->dest), 0))
+ (e_fall->dest == EXIT_BLOCK_PTR
+ ? NULL_RTX
+ : label_for_bb (e_fall->dest)), 0))
{
e_fall->flags &= ~EDGE_FALLTHRU;
+#ifdef ENABLE_CHECKING
+ if (!could_fall_through (e_taken->src, e_taken->dest))
+ abort ();
+#endif
e_taken->flags |= EDGE_FALLTHRU;
+ update_br_prob_note (bb);
e = e_fall, e_fall = e_taken, e_taken = e;
}
}
- /* Otherwise we can try to invert the jump. This will
+ /* If the "jumping" edge is a crossing edge, and the fall
+ through edge is non-crossing, leave things as they are. */
+ else if (e_taken->crossing_edge && !e_fall->crossing_edge)
+ continue;
+
+ /* Otherwise we can try to invert the jump. This will
basically never fail, however, keep up the pretense. */
else if (invert_jump (bb_end_insn,
- label_for_bb (e_fall->dest), 0))
+ (e_fall->dest == EXIT_BLOCK_PTR
+ ? NULL_RTX
+ : label_for_bb (e_fall->dest)), 0))
{
e_fall->flags &= ~EDGE_FALLTHRU;
+#ifdef ENABLE_CHECKING
+ if (!could_fall_through (e_taken->src, e_taken->dest))
+ abort ();
+#endif
e_taken->flags |= EDGE_FALLTHRU;
+ update_br_prob_note (bb);
continue;
}
}
#ifdef CASE_DROPS_THROUGH
/* Except for VAX. Since we didn't have predication for the
tablejump, the fallthru block should not have moved. */
- if (RBI (bb)->next == e_fall->dest)
+ if (bb->rbi->next == e_fall->dest)
continue;
bb_end_insn = skip_insns_after_block (bb);
#else
continue;
/* If the fallthru block is still next, nothing to do. */
- if (RBI (bb)->next == e_fall->dest)
+ if (bb->rbi->next == e_fall->dest)
continue;
/* A fallthru to exit block. */
- if (!RBI (bb)->next && e_fall->dest == EXIT_BLOCK_PTR)
+ if (e_fall->dest == EXIT_BLOCK_PTR)
continue;
}
nb = force_nonfallthru (e_fall);
if (nb)
{
- alloc_aux_for_block (nb, sizeof (struct reorder_block_def));
- RBI (nb)->eff_head = nb->head;
- RBI (nb)->eff_end = NEXT_INSN (nb->end);
- RBI (nb)->visited = 1;
- RBI (nb)->next = RBI (bb)->next;
- RBI (bb)->next = nb;
+ initialize_bb_rbi (nb);
+ nb->rbi->visited = 1;
+ nb->rbi->next = bb->rbi->next;
+ bb->rbi->next = nb;
/* Don't process this new block. */
+ old_bb = bb;
bb = nb;
+
+ /* Make sure new bb is tagged for correct section (same as
+ fall-thru source). */
+ e_fall->src->partition = bb->pred->src->partition;
+ if (flag_reorder_blocks_and_partition)
+ {
+ if (bb->pred->src->partition == COLD_PARTITION)
+ {
+ rtx new_note;
+ rtx note = BB_HEAD (e_fall->src);
+
+ while (!INSN_P (note)
+ && note != BB_END (e_fall->src))
+ note = NEXT_INSN (note);
+
+ new_note = emit_note_before
+ (NOTE_INSN_UNLIKELY_EXECUTED_CODE,
+ note);
+ NOTE_BASIC_BLOCK (new_note) = bb;
+ }
+ if (GET_CODE (BB_END (bb)) == JUMP_INSN
+ && !any_condjump_p (BB_END (bb))
+ && bb->succ->crossing_edge )
+ REG_NOTES (BB_END (bb)) = gen_rtx_EXPR_LIST
+ (REG_CROSSING_JUMP, NULL_RTX, REG_NOTES (BB_END (bb)));
+ }
}
}
/* Put basic_block_info in the new order. */
- bb = BASIC_BLOCK (0);
- index = 0;
-
- if (rtl_dump_file)
- fprintf (rtl_dump_file, "Reordered sequence:\n");
- for (; bb; bb = RBI (bb)->next, index++)
+ if (dump_file)
{
- if (rtl_dump_file)
- fprintf (rtl_dump_file, " %i %sbb %i freq %i\n", index,
- bb->index >= old_n_basic_blocks ? "compensation " : "",
- bb->index,
- bb->frequency);
+ fprintf (dump_file, "Reordered sequence:\n");
+ for (bb = ENTRY_BLOCK_PTR->next_bb, index = 0;
+ bb;
+ bb = bb->rbi->next, index++)
+ {
+ fprintf (dump_file, " %i ", index);
+ if (bb->rbi->original)
+ fprintf (dump_file, "duplicate of %i ",
+ bb->rbi->original->index);
+ else if (forwarder_block_p (bb)
+ && GET_CODE (BB_HEAD (bb)) != CODE_LABEL)
+ fprintf (dump_file, "compensation ");
+ else
+ fprintf (dump_file, "bb %i ", bb->index);
+ fprintf (dump_file, " [%i]\n", bb->frequency);
+ }
+ }
+
+ prev_bb = ENTRY_BLOCK_PTR;
+ bb = ENTRY_BLOCK_PTR->next_bb;
+ index = 0;
+ for (; bb; prev_bb = bb, bb = bb->rbi->next, index ++)
+ {
bb->index = index;
BASIC_BLOCK (index) = bb;
+
+ update_unlikely_executed_notes (bb);
+
+ bb->prev_bb = prev_bb;
+ prev_bb->next_bb = bb;
+ }
+ prev_bb->next_bb = EXIT_BLOCK_PTR;
+ EXIT_BLOCK_PTR->prev_bb = prev_bb;
+
+ /* Annoying special case - jump around dead jumptables left in the code. */
+ FOR_EACH_BB (bb)
+ {
+ edge e;
+ for (e = bb->succ; e && !(e->flags & EDGE_FALLTHRU); e = e->succ_next)
+ continue;
+ if (e && !can_fallthru (e->src, e->dest))
+ force_nonfallthru (e);
}
}
\f
+/* Update the basic block number information in any
+ NOTE_INSN_UNLIKELY_EXECUTED_CODE notes within the basic block. */
+
+static void
+update_unlikely_executed_notes (basic_block bb)
+{
+ rtx cur_insn;
+
+ for (cur_insn = BB_HEAD (bb); cur_insn != BB_END (bb);
+ cur_insn = NEXT_INSN (cur_insn))
+ if (GET_CODE (cur_insn) == NOTE
+ && NOTE_LINE_NUMBER (cur_insn) == NOTE_INSN_UNLIKELY_EXECUTED_CODE)
+ NOTE_BASIC_BLOCK (cur_insn) = bb;
+}
+\f
/* Perform sanity checks on the insn chain.
1. Check that next/prev pointers are consistent in both the forward and
reverse direction.
3. Check that get_last_insn () returns the actual end of chain. */
void
-verify_insn_chain ()
+verify_insn_chain (void)
{
rtx x, prevx, nextx;
int insn_cnt1, insn_cnt2;
if (insn_cnt1 != insn_cnt2)
abort ();
}
-
-/* The block falling through to exit must be the last one in the reordered
- chain. Ensure it is. */
-
+\f
+/* If we have assembler epilogues, the block falling through to exit must
+ be the last one in the reordered chain when we reach final. Ensure
+ that this condition is met. */
static void
-fixup_fallthru_exit_predecessor ()
+fixup_fallthru_exit_predecessor (void)
{
edge e;
basic_block bb = NULL;
+ /* This transformation is not valid before reload, because we might separate
+ a call from the instruction that copies the return value. */
+ if (! reload_completed)
+ abort ();
+
for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
if (e->flags & EDGE_FALLTHRU)
bb = e->src;
- if (bb && RBI (bb)->next)
+ if (bb && bb->rbi->next)
+ {
+ basic_block c = ENTRY_BLOCK_PTR->next_bb;
+
+ /* If the very first block is the one with the fall-through exit
+ edge, we have to split that block. */
+ if (c == bb)
+ {
+ bb = split_block (bb, NULL)->dest;
+ initialize_bb_rbi (bb);
+ bb->rbi->next = c->rbi->next;
+ c->rbi->next = bb;
+ bb->rbi->footer = c->rbi->footer;
+ c->rbi->footer = NULL;
+ }
+
+ while (c->rbi->next != bb)
+ c = c->rbi->next;
+
+ c->rbi->next = bb->rbi->next;
+ while (c->rbi->next)
+ c = c->rbi->next;
+
+ c->rbi->next = bb;
+ bb->rbi->next = NULL;
+ }
+}
+\f
+/* Return true in case it is possible to duplicate the basic block BB. */
+
+/* We do not want to declare the function in a header file, since it should
+ only be used through the cfghooks interface, and we do not want to move
+ it to cfgrtl.c since it would require also moving quite a lot of related
+ code. */
+extern bool cfg_layout_can_duplicate_bb_p (basic_block);
+
+bool
+cfg_layout_can_duplicate_bb_p (basic_block bb)
+{
+ /* Do not attempt to duplicate tablejumps, as we need to unshare
+ the dispatch table. This is difficult to do, as the instructions
+ computing jump destination may be hoisted outside the basic block. */
+ if (tablejump_p (BB_END (bb), NULL, NULL))
+ return false;
+
+ /* Do not duplicate blocks containing insns that can't be copied. */
+ if (targetm.cannot_copy_insn_p)
+ {
+ rtx insn = BB_HEAD (bb);
+ while (1)
+ {
+ if (INSN_P (insn) && targetm.cannot_copy_insn_p (insn))
+ return false;
+ if (insn == BB_END (bb))
+ break;
+ insn = NEXT_INSN (insn);
+ }
+ }
+
+ return true;
+}
+
+rtx
+duplicate_insn_chain (rtx from, rtx to)
+{
+ rtx insn, last;
+
+ /* Avoid updating of boundaries of previous basic block. The
+ note will get removed from insn stream in fixup. */
+ last = emit_note (NOTE_INSN_DELETED);
+
+ /* Create copy at the end of INSN chain. The chain will
+ be reordered later. */
+ for (insn = from; insn != NEXT_INSN (to); insn = NEXT_INSN (insn))
{
- basic_block c = BASIC_BLOCK (0);
+ switch (GET_CODE (insn))
+ {
+ case INSN:
+ case CALL_INSN:
+ case JUMP_INSN:
+ /* Avoid copying of dispatch tables. We never duplicate
+ tablejumps, so this can hit only in case the table got
+ moved far from original jump. */
+ if (GET_CODE (PATTERN (insn)) == ADDR_VEC
+ || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
+ break;
+ emit_copy_of_insn_after (insn, get_last_insn ());
+ break;
+
+ case CODE_LABEL:
+ break;
+
+ case BARRIER:
+ emit_barrier ();
+ break;
+
+ case NOTE:
+ switch (NOTE_LINE_NUMBER (insn))
+ {
+ /* In case prologue is empty and function contain label
+ in first BB, we may want to copy the block. */
+ case NOTE_INSN_PROLOGUE_END:
+
+ case NOTE_INSN_LOOP_VTOP:
+ case NOTE_INSN_LOOP_CONT:
+ case NOTE_INSN_LOOP_BEG:
+ case NOTE_INSN_LOOP_END:
+ /* Strip down the loop notes - we don't really want to keep
+ them consistent in loop copies. */
+ case NOTE_INSN_DELETED:
+ case NOTE_INSN_DELETED_LABEL:
+ /* No problem to strip these. */
+ case NOTE_INSN_EPILOGUE_BEG:
+ case NOTE_INSN_FUNCTION_END:
+ /* Debug code expect these notes to exist just once.
+ Keep them in the master copy.
+ ??? It probably makes more sense to duplicate them for each
+ epilogue copy. */
+ case NOTE_INSN_FUNCTION_BEG:
+ /* There is always just single entry to function. */
+ case NOTE_INSN_BASIC_BLOCK:
+ break;
+
+ /* There is no purpose to duplicate prologue. */
+ case NOTE_INSN_BLOCK_BEG:
+ case NOTE_INSN_BLOCK_END:
+ /* The BLOCK_BEG/BLOCK_END notes should be eliminated when BB
+ reordering is in the progress. */
+ case NOTE_INSN_EH_REGION_BEG:
+ case NOTE_INSN_EH_REGION_END:
+ /* Should never exist at BB duplication time. */
+ abort ();
+ break;
+ case NOTE_INSN_REPEATED_LINE_NUMBER:
+ case NOTE_INSN_UNLIKELY_EXECUTED_CODE:
+ emit_note_copy (insn);
+ break;
+
+ default:
+ if (NOTE_LINE_NUMBER (insn) < 0)
+ abort ();
+ /* It is possible that no_line_number is set and the note
+ won't be emitted. */
+ emit_note_copy (insn);
+ }
+ break;
+ default:
+ abort ();
+ }
+ }
+ insn = NEXT_INSN (last);
+ delete_insn (last);
+ return insn;
+}
+/* Create a duplicate of the basic block BB. */
+
+/* We do not want to declare the function in a header file, since it should
+ only be used through the cfghooks interface, and we do not want to move
+ it to cfgrtl.c since it would require also moving quite a lot of related
+ code. */
+extern basic_block cfg_layout_duplicate_bb (basic_block);
+
+basic_block
+cfg_layout_duplicate_bb (basic_block bb)
+{
+ rtx insn;
+ basic_block new_bb;
+
+ insn = duplicate_insn_chain (BB_HEAD (bb), BB_END (bb));
+ new_bb = create_basic_block (insn,
+ insn ? get_last_insn () : NULL,
+ EXIT_BLOCK_PTR->prev_bb);
- while (RBI (c)->next != bb)
- c = RBI (c)->next;
+ if (bb->rbi->header)
+ {
+ insn = bb->rbi->header;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ insn = duplicate_insn_chain (bb->rbi->header, insn);
+ if (insn)
+ new_bb->rbi->header = unlink_insn_chain (insn, get_last_insn ());
+ }
- RBI (c)->next = RBI (bb)->next;
- while (RBI (c)->next)
- c = RBI (c)->next;
+ if (bb->rbi->footer)
+ {
+ insn = bb->rbi->footer;
+ while (NEXT_INSN (insn))
+ insn = NEXT_INSN (insn);
+ insn = duplicate_insn_chain (bb->rbi->footer, insn);
+ if (insn)
+ new_bb->rbi->footer = unlink_insn_chain (insn, get_last_insn ());
+ }
- RBI (c)->next = bb;
- RBI (bb)->next = NULL;
+ if (bb->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, bb->global_live_at_start);
+ COPY_REG_SET (new_bb->global_live_at_end, bb->global_live_at_end);
}
+
+ return new_bb;
}
\f
-/* Main entry point to this module: initialize the datastructures for CFG
- layout changes. */
+/* Main entry point to this module - initialize the data structures for
+ CFG layout changes. It keeps LOOPS up-to-date if not null. */
void
-cfg_layout_initialize ()
+cfg_layout_initialize (void)
{
- alloc_aux_for_blocks (sizeof (struct reorder_block_def));
+ basic_block bb;
+
+ /* Our algorithm depends on fact that there are no dead jumptables
+ around the code. */
+ alloc_rbi_pool ();
+
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ initialize_bb_rbi (bb);
- scope_to_insns_initialize ();
+ cfg_layout_rtl_register_cfg_hooks ();
record_effective_endpoints ();
+
+ cleanup_cfg (CLEANUP_CFGLAYOUT);
+}
+
+/* Splits superblocks. */
+void
+break_superblocks (void)
+{
+ sbitmap superblocks;
+ bool need = false;
+ basic_block bb;
+
+ superblocks = sbitmap_alloc (last_basic_block);
+ sbitmap_zero (superblocks);
+
+ FOR_EACH_BB (bb)
+ if (bb->flags & BB_SUPERBLOCK)
+ {
+ bb->flags &= ~BB_SUPERBLOCK;
+ SET_BIT (superblocks, bb->index);
+ need = true;
+ }
+
+ if (need)
+ {
+ rebuild_jump_labels (get_insns ());
+ find_many_sub_basic_blocks (superblocks);
+ }
+
+ free (superblocks);
}
/* Finalize the changes: reorder insn list according to the sequence, enter
compensation code, rebuild scope forest. */
void
-cfg_layout_finalize ()
+cfg_layout_finalize (void)
{
- fixup_fallthru_exit_predecessor ();
+ basic_block bb;
+
+#ifdef ENABLE_CHECKING
+ verify_flow_info ();
+#endif
+ rtl_register_cfg_hooks ();
+ if (reload_completed
+#ifdef HAVE_epilogue
+ && !HAVE_epilogue
+#endif
+ )
+ fixup_fallthru_exit_predecessor ();
fixup_reorder_chain ();
#ifdef ENABLE_CHECKING
verify_insn_chain ();
#endif
- scope_to_insns_finalize ();
+ free_rbi_pool ();
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb)
+ bb->rbi = NULL;
- free_aux_for_blocks ();
+ break_superblocks ();
#ifdef ENABLE_CHECKING
verify_flow_info ();
#endif
}
+
+/* Checks whether all N blocks in BBS array can be copied. */
+bool
+can_copy_bbs_p (basic_block *bbs, unsigned n)
+{
+ unsigned i;
+ edge e;
+ int ret = true;
+
+ for (i = 0; i < n; i++)
+ bbs[i]->rbi->duplicated = 1;
+
+ for (i = 0; i < n; i++)
+ {
+ /* In case we should redirect abnormal edge during duplication, fail. */
+ for (e = bbs[i]->succ; e; e = e->succ_next)
+ if ((e->flags & EDGE_ABNORMAL)
+ && e->dest->rbi->duplicated)
+ {
+ ret = false;
+ goto end;
+ }
+
+ if (!can_duplicate_block_p (bbs[i]))
+ {
+ ret = false;
+ break;
+ }
+ }
+
+end:
+ for (i = 0; i < n; i++)
+ bbs[i]->rbi->duplicated = 0;
+
+ return ret;
+}
+
+/* Duplicates N basic blocks stored in array BBS. Newly created basic blocks
+ are placed into array NEW_BBS in the same order. Edges from basic blocks
+ in BBS are also duplicated and copies of those of them
+ that lead into BBS are redirected to appropriate newly created block. The
+ function assigns bbs into loops (copy of basic block bb is assigned to
+ bb->loop_father->copy loop, so this must be set up correctly in advance)
+ and updates dominators locally (LOOPS structure that contains the information
+ about dominators is passed to enable this).
+
+ BASE is the superloop to that basic block belongs; if its header or latch
+ is copied, we do not set the new blocks as header or latch.
+
+ Created copies of N_EDGES edges in array EDGES are stored in array NEW_EDGES,
+ also in the same order. */
+
+void
+copy_bbs (basic_block *bbs, unsigned n, basic_block *new_bbs,
+ edge *edges, unsigned n_edges, edge *new_edges,
+ struct loop *base)
+{
+ unsigned i, j;
+ basic_block bb, new_bb, dom_bb;
+ edge e;
+
+ /* Duplicate bbs, update dominators, assign bbs to loops. */
+ for (i = 0; i < n; i++)
+ {
+ /* Duplicate. */
+ bb = bbs[i];
+ new_bb = new_bbs[i] = duplicate_block (bb, NULL);
+ bb->rbi->duplicated = 1;
+ /* Add to loop. */
+ add_bb_to_loop (new_bb, bb->loop_father->copy);
+ /* Possibly set header. */
+ if (bb->loop_father->header == bb && bb->loop_father != base)
+ new_bb->loop_father->header = new_bb;
+ /* Or latch. */
+ if (bb->loop_father->latch == bb && bb->loop_father != base)
+ new_bb->loop_father->latch = new_bb;
+ }
+
+ /* Set dominators. */
+ for (i = 0; i < n; i++)
+ {
+ bb = bbs[i];
+ new_bb = new_bbs[i];
+
+ dom_bb = get_immediate_dominator (CDI_DOMINATORS, bb);
+ if (dom_bb->rbi->duplicated)
+ {
+ dom_bb = dom_bb->rbi->copy;
+ set_immediate_dominator (CDI_DOMINATORS, new_bb, dom_bb);
+ }
+ }
+
+ /* Redirect edges. */
+ for (j = 0; j < n_edges; j++)
+ new_edges[j] = NULL;
+ for (i = 0; i < n; i++)
+ {
+ new_bb = new_bbs[i];
+ bb = bbs[i];
+
+ for (e = new_bb->succ; e; e = e->succ_next)
+ {
+ for (j = 0; j < n_edges; j++)
+ if (edges[j] && edges[j]->src == bb && edges[j]->dest == e->dest)
+ new_edges[j] = e;
+
+ if (!e->dest->rbi->duplicated)
+ continue;
+ redirect_edge_and_branch_force (e, e->dest->rbi->copy);
+ }
+ }
+
+ /* Clear information about duplicates. */
+ for (i = 0; i < n; i++)
+ bbs[i]->rbi->duplicated = 0;
+}
+
+#include "gt-cfglayout.h"
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