/* Control flow graph building code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
This file is part of GCC.
#include "toplev.h"
#include "timevar.h"
-static int count_basic_blocks PARAMS ((rtx));
-static void find_basic_blocks_1 PARAMS ((rtx));
-static rtx find_label_refs PARAMS ((rtx, rtx));
-static void make_edges PARAMS ((rtx, basic_block,
- basic_block, int));
-static void make_label_edge PARAMS ((sbitmap *, basic_block,
- rtx, int));
-static void make_eh_edge PARAMS ((sbitmap *, basic_block, rtx));
-static void find_bb_boundaries PARAMS ((basic_block));
-static void compute_outgoing_frequencies PARAMS ((basic_block));
+static int count_basic_blocks (rtx);
+static void find_basic_blocks_1 (rtx);
+static void make_edges (basic_block, basic_block, int);
+static void make_label_edge (sbitmap *, basic_block, rtx, int);
+static void find_bb_boundaries (basic_block);
+static void compute_outgoing_frequencies (basic_block);
\f
/* Return true if insn is something that should be contained inside basic
block. */
bool
-inside_basic_block_p (insn)
- rtx insn;
+inside_basic_block_p (rtx insn)
{
switch (GET_CODE (insn))
{
case CODE_LABEL:
/* Avoid creating of basic block for jumptables. */
return (NEXT_INSN (insn) == 0
- || GET_CODE (NEXT_INSN (insn)) != JUMP_INSN
+ || !JUMP_P (NEXT_INSN (insn))
|| (GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_VEC
&& GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_DIFF_VEC));
return false;
default:
- abort ();
+ gcc_unreachable ();
}
}
the basic block. */
bool
-control_flow_insn_p (insn)
- rtx insn;
+control_flow_insn_p (rtx insn)
{
rtx note;
&& GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
case CALL_INSN:
+ /* Noreturn and sibling call instructions terminate the basic blocks
+ (but only if they happen unconditionally). */
+ if ((SIBLING_CALL_P (insn)
+ || find_reg_note (insn, REG_NORETURN, 0))
+ && GET_CODE (PATTERN (insn)) != COND_EXEC)
+ return true;
/* Call insn may return to the nonlocal goto handler. */
return ((nonlocal_goto_handler_labels
&& (0 == (note = find_reg_note (insn, REG_EH_REGION,
return (flag_non_call_exceptions && can_throw_internal (insn));
case BARRIER:
- /* It is nonsence to reach barrier when looking for the
+ /* It is nonsense to reach barrier when looking for the
end of basic block, but before dead code is eliminated
this may happen. */
return false;
default:
- abort ();
+ gcc_unreachable ();
}
}
/* Count the basic blocks of the function. */
static int
-count_basic_blocks (f)
- rtx f;
+count_basic_blocks (rtx f)
{
int count = 0;
bool saw_insn = false;
{
/* Code labels and barriers causes current basic block to be
terminated at previous real insn. */
- if ((GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == BARRIER)
+ if ((LABEL_P (insn) || BARRIER_P (insn))
&& saw_insn)
count++, saw_insn = false;
return count;
}
-
-/* Scan a list of insns for labels referred to other than by jumps.
- This is used to scan the alternatives of a call placeholder. */
-
-static rtx
-find_label_refs (f, lvl)
- rtx f;
- rtx lvl;
-{
- rtx insn;
-
- for (insn = f; insn; insn = NEXT_INSN (insn))
- if (INSN_P (insn) && GET_CODE (insn) != JUMP_INSN)
- {
- rtx note;
-
- /* Make a list of all labels referred to other than by jumps
- (which just don't have the REG_LABEL notes).
-
- Make a special exception for labels followed by an ADDR*VEC,
- as this would be a part of the tablejump setup code.
-
- Make a special exception to registers loaded with label
- values just before jump insns that use them. */
-
- for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
- if (REG_NOTE_KIND (note) == REG_LABEL)
- {
- rtx lab = XEXP (note, 0), next;
-
- if ((next = next_nonnote_insn (lab)) != NULL
- && GET_CODE (next) == JUMP_INSN
- && (GET_CODE (PATTERN (next)) == ADDR_VEC
- || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC))
- ;
- else if (GET_CODE (lab) == NOTE)
- ;
- else if (GET_CODE (NEXT_INSN (insn)) == JUMP_INSN
- && find_reg_note (NEXT_INSN (insn), REG_LABEL, lab))
- ;
- else
- lvl = alloc_EXPR_LIST (0, XEXP (note, 0), lvl);
- }
- }
-
- return lvl;
-}
\f
/* Create an edge between two basic blocks. FLAGS are auxiliary information
about the edge that is accumulated between calls. */
/* Create an edge from a basic block to a label. */
static void
-make_label_edge (edge_cache, src, label, flags)
- sbitmap *edge_cache;
- basic_block src;
- rtx label;
- int flags;
+make_label_edge (sbitmap *edge_cache, basic_block src, rtx label, int flags)
{
- if (GET_CODE (label) != CODE_LABEL)
- abort ();
+ gcc_assert (LABEL_P (label));
/* If the label was never emitted, this insn is junk, but avoid a
crash trying to refer to BLOCK_FOR_INSN (label). This can happen
/* Create the edges generated by INSN in REGION. */
-static void
-make_eh_edge (edge_cache, src, insn)
- sbitmap *edge_cache;
- basic_block src;
- rtx insn;
+void
+rtl_make_eh_edge (sbitmap *edge_cache, basic_block src, rtx insn)
{
- int is_call = GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0;
+ int is_call = CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0;
rtx handlers, i;
handlers = reachable_handlers (insn);
the list of exception regions active at the end of the basic block. */
static void
-make_edges (label_value_list, min, max, update_p)
- rtx label_value_list;
- basic_block min, max;
- int update_p;
+make_edges (basic_block min, basic_block max, int update_p)
{
basic_block bb;
sbitmap *edge_cache = NULL;
/* Assume no computed jump; revise as we create edges. */
current_function_has_computed_jump = 0;
+ /* If we are partitioning hot and cold basic blocks into separate
+ sections, we cannot assume there is no computed jump (partitioning
+ sometimes requires the use of indirect jumps; see comments about
+ partitioning at the top of bb-reorder.c:partition_hot_cold_basic_blocks
+ for complete details). */
+
+ if (flag_reorder_blocks_and_partition)
+ current_function_has_computed_jump = 1;
+
/* Heavy use of computed goto in machine-generated code can lead to
nearly fully-connected CFGs. In that case we spend a significant
amount of time searching the edge lists for duplicates. */
- if (forced_labels || label_value_list || cfun->max_jumptable_ents > 100)
+ if (forced_labels || cfun->max_jumptable_ents > 100)
{
edge_cache = sbitmap_vector_alloc (last_basic_block, last_basic_block);
sbitmap_vector_zero (edge_cache, last_basic_block);
FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
{
edge e;
+ edge_iterator ei;
- for (e = bb->succ; e ; e = e->succ_next)
+ FOR_EACH_EDGE (e, ei, bb->succs)
if (e->dest != EXIT_BLOCK_PTR)
SET_BIT (edge_cache[bb->index], e->dest->index);
}
rtx insn, x;
enum rtx_code code;
int force_fallthru = 0;
+ edge e;
+ edge_iterator ei;
- if (GET_CODE (bb->head) == CODE_LABEL && LABEL_ALT_ENTRY_P (bb->head))
+ if (LABEL_P (BB_HEAD (bb))
+ && LABEL_ALT_ENTRY_P (BB_HEAD (bb)))
cached_make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
/* Examine the last instruction of the block, and discover the
ways we can leave the block. */
- insn = bb->end;
+ insn = BB_END (bb);
code = GET_CODE (insn);
/* A branch. */
/* Recognize exception handling placeholders. */
if (GET_CODE (PATTERN (insn)) == RESX)
- make_eh_edge (edge_cache, bb, insn);
+ rtl_make_eh_edge (edge_cache, bb, insn);
/* Recognize a non-local goto as a branch outside the
current function. */
else if (find_reg_note (insn, REG_NON_LOCAL_GOTO, NULL_RTX))
;
- /* ??? Recognize a tablejump and do the right thing. */
- else if ((tmp = JUMP_LABEL (insn)) != NULL_RTX
- && (tmp = NEXT_INSN (tmp)) != NULL_RTX
- && GET_CODE (tmp) == JUMP_INSN
- && (GET_CODE (PATTERN (tmp)) == ADDR_VEC
- || GET_CODE (PATTERN (tmp)) == ADDR_DIFF_VEC))
+ /* Recognize a tablejump and do the right thing. */
+ else if (tablejump_p (insn, NULL, &tmp))
{
rtvec vec;
int j;
}
/* If this is a computed jump, then mark it as reaching
- everything on the label_value_list and forced_labels list. */
+ everything on the forced_labels list. */
else if (computed_jump_p (insn))
{
current_function_has_computed_jump = 1;
- for (x = label_value_list; x; x = XEXP (x, 1))
- make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL);
-
for (x = forced_labels; x; x = XEXP (x, 1))
make_label_edge (edge_cache, bb, XEXP (x, 0), EDGE_ABNORMAL);
}
/* Otherwise, we have a plain conditional or unconditional jump. */
else
{
- if (! JUMP_LABEL (insn))
- abort ();
+ gcc_assert (JUMP_LABEL (insn));
make_label_edge (edge_cache, bb, JUMP_LABEL (insn), 0);
}
}
in the first place. */
if (code == CALL_INSN && SIBLING_CALL_P (insn))
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR,
- EDGE_ABNORMAL | EDGE_ABNORMAL_CALL);
+ EDGE_SIBCALL | EDGE_ABNORMAL);
/* If this is a CALL_INSN, then mark it as reaching the active EH
handler for this CALL_INSN. If we're handling non-call
else if (code == CALL_INSN || flag_non_call_exceptions)
{
/* Add any appropriate EH edges. */
- make_eh_edge (edge_cache, bb, insn);
+ rtl_make_eh_edge (edge_cache, bb, insn);
if (code == CALL_INSN && nonlocal_goto_handler_labels)
{
}
/* Find out if we can drop through to the next block. */
- insn = next_nonnote_insn (insn);
+ insn = NEXT_INSN (insn);
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->dest == EXIT_BLOCK_PTR && e->flags & EDGE_FALLTHRU)
+ {
+ insn = 0;
+ break;
+ }
+ while (insn
+ && NOTE_P (insn)
+ && NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK)
+ insn = NEXT_INSN (insn);
+
if (!insn || (bb->next_bb == EXIT_BLOCK_PTR && force_fallthru))
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
else if (bb->next_bb != EXIT_BLOCK_PTR)
{
- rtx tmp = bb->next_bb->head;
- if (GET_CODE (tmp) == NOTE)
- tmp = next_nonnote_insn (tmp);
- if (force_fallthru || insn == tmp)
+ if (force_fallthru || insn == BB_HEAD (bb->next_bb))
cached_make_edge (edge_cache, bb, bb->next_bb, EDGE_FALLTHRU);
}
}
will be used in make_edges for use with computed gotos. */
static void
-find_basic_blocks_1 (f)
- rtx f;
+find_basic_blocks_1 (rtx f)
{
rtx insn, next;
rtx bb_note = NULL_RTX;
- rtx lvl = NULL_RTX;
- rtx trll = NULL_RTX;
rtx head = NULL_RTX;
rtx end = NULL_RTX;
basic_block prev = ENTRY_BLOCK_PTR;
next = NEXT_INSN (insn);
- if ((GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == BARRIER)
+ if ((LABEL_P (insn) || BARRIER_P (insn))
&& head)
{
prev = create_basic_block_structure (head, end, bb_note, prev);
case CODE_LABEL:
case JUMP_INSN:
+ case CALL_INSN:
case INSN:
case BARRIER:
break;
- case CALL_INSN:
- if (GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
- {
- /* Scan each of the alternatives for label refs. */
- lvl = find_label_refs (XEXP (PATTERN (insn), 0), lvl);
- lvl = find_label_refs (XEXP (PATTERN (insn), 1), lvl);
- lvl = find_label_refs (XEXP (PATTERN (insn), 2), lvl);
- /* Record its tail recursion label, if any. */
- if (XEXP (PATTERN (insn), 3) != NULL_RTX)
- trll = alloc_EXPR_LIST (0, XEXP (PATTERN (insn), 3), trll);
- }
- break;
-
default:
- abort ();
- }
-
- if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN)
- {
- rtx note;
-
- /* Make a list of all labels referred to other than by jumps.
-
- Make a special exception for labels followed by an ADDR*VEC,
- as this would be a part of the tablejump setup code.
-
- Make a special exception to registers loaded with label
- values just before jump insns that use them. */
-
- for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
- if (REG_NOTE_KIND (note) == REG_LABEL)
- {
- rtx lab = XEXP (note, 0), next;
-
- if ((next = next_nonnote_insn (lab)) != NULL
- && GET_CODE (next) == JUMP_INSN
- && (GET_CODE (PATTERN (next)) == ADDR_VEC
- || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC))
- ;
- else if (GET_CODE (lab) == NOTE)
- ;
- else if (GET_CODE (NEXT_INSN (insn)) == JUMP_INSN
- && find_reg_note (NEXT_INSN (insn), REG_LABEL, lab))
- ;
- else
- lvl = alloc_EXPR_LIST (0, XEXP (note, 0), lvl);
- }
+ gcc_unreachable ();
}
}
else if (bb_note)
delete_insn (bb_note);
- if (last_basic_block != n_basic_blocks)
- abort ();
+ gcc_assert (last_basic_block == n_basic_blocks);
- label_value_list = lvl;
- tail_recursion_label_list = trll;
clear_aux_for_blocks ();
}
numbers in use. */
void
-find_basic_blocks (f, nregs, file)
- rtx f;
- int nregs ATTRIBUTE_UNUSED;
- FILE *file ATTRIBUTE_UNUSED;
+find_basic_blocks (rtx f, int nregs ATTRIBUTE_UNUSED,
+ FILE *file ATTRIBUTE_UNUSED)
{
basic_block bb;
tag for reuse during create_basic_block, just in case some pass
copies around basic block notes improperly. */
FOR_EACH_BB (bb)
- bb->aux = NULL;
+ bb->aux = NULL;
- VARRAY_FREE (basic_block_info);
+ basic_block_info = NULL;
}
n_basic_blocks = count_basic_blocks (f);
find_basic_blocks_1 (f);
+ profile_status = PROFILE_ABSENT;
+
/* Discover the edges of our cfg. */
- make_edges (label_value_list, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, 0);
+ make_edges (ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR->prev_bb, 0);
/* Do very simple cleanup now, for the benefit of code that runs between
here and cleanup_cfg, e.g. thread_prologue_and_epilogue_insns. */
and create new basic blocks in the progress. */
static void
-find_bb_boundaries (bb)
- basic_block bb;
+find_bb_boundaries (basic_block bb)
{
- rtx insn = bb->head;
- rtx end = bb->end;
+ rtx insn = BB_HEAD (bb);
+ rtx end = BB_END (bb);
rtx flow_transfer_insn = NULL_RTX;
edge fallthru = NULL;
- if (insn == bb->end)
+ if (insn == BB_END (bb))
return;
- if (GET_CODE (insn) == CODE_LABEL)
+ if (LABEL_P (insn))
insn = NEXT_INSN (insn);
/* Scan insn chain and try to find new basic block boundaries. */
{
fallthru = split_block (bb, PREV_INSN (insn));
if (flow_transfer_insn)
- bb->end = flow_transfer_insn;
+ BB_END (bb) = flow_transfer_insn;
bb = fallthru->dest;
remove_edge (fallthru);
if (flow_transfer_insn && inside_basic_block_p (insn))
{
fallthru = split_block (bb, PREV_INSN (insn));
- bb->end = flow_transfer_insn;
+ BB_END (bb) = flow_transfer_insn;
bb = fallthru->dest;
remove_edge (fallthru);
flow_transfer_insn = NULL_RTX;
return and barrier, or possibly other sequence not behaving like
ordinary jump, we need to take care and move basic block boundary. */
if (flow_transfer_insn)
- bb->end = flow_transfer_insn;
+ BB_END (bb) = flow_transfer_insn;
/* We've possibly replaced the conditional jump by conditional jump
followed by cleanup at fallthru edge, so the outgoing edges may
and probabilities of outgoing edges. */
static void
-compute_outgoing_frequencies (b)
- basic_block b;
+compute_outgoing_frequencies (basic_block b)
{
edge e, f;
+ edge_iterator ei;
- if (b->succ && b->succ->succ_next && !b->succ->succ_next->succ_next)
+ if (EDGE_COUNT (b->succs) == 2)
{
- rtx note = find_reg_note (b->end, REG_BR_PROB, NULL);
+ rtx note = find_reg_note (BB_END (b), REG_BR_PROB, NULL);
int probability;
- if (!note)
- return;
-
- probability = INTVAL (XEXP (find_reg_note (b->end,
- REG_BR_PROB, NULL),
- 0));
- e = BRANCH_EDGE (b);
- e->probability = probability;
- e->count = ((b->count * probability + REG_BR_PROB_BASE / 2)
- / REG_BR_PROB_BASE);
- f = FALLTHRU_EDGE (b);
- f->probability = REG_BR_PROB_BASE - probability;
- f->count = b->count - e->count;
+ if (note)
+ {
+ probability = INTVAL (XEXP (note, 0));
+ e = BRANCH_EDGE (b);
+ e->probability = probability;
+ e->count = ((b->count * probability + REG_BR_PROB_BASE / 2)
+ / REG_BR_PROB_BASE);
+ f = FALLTHRU_EDGE (b);
+ f->probability = REG_BR_PROB_BASE - probability;
+ f->count = b->count - e->count;
+ return;
+ }
}
- if (b->succ && !b->succ->succ_next)
+ if (EDGE_COUNT (b->succs) == 1)
{
- e = b->succ;
+ e = EDGE_SUCC (b, 0);
e->probability = REG_BR_PROB_BASE;
e->count = b->count;
+ return;
}
+ guess_outgoing_edge_probabilities (b);
+ if (b->count)
+ FOR_EACH_EDGE (e, ei, b->succs)
+ e->count = ((b->count * e->probability + REG_BR_PROB_BASE / 2)
+ / REG_BR_PROB_BASE);
}
/* Assume that someone emitted code with control flow instructions to the
basic block. Update the data structure. */
void
-find_many_sub_basic_blocks (blocks)
- sbitmap blocks;
+find_many_sub_basic_blocks (sbitmap blocks)
{
basic_block bb, min, max;
/* Now re-scan and wire in all edges. This expect simple (conditional)
jumps at the end of each new basic blocks. */
- make_edges (NULL, min, max, 1);
+ make_edges (min, max, 1);
/* Update branch probabilities. Expect only (un)conditional jumps
to be created with only the forward edges. */
- FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
- {
- edge e;
+ if (profile_status != PROFILE_ABSENT)
+ FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
+ {
+ edge e;
+ edge_iterator ei;
- if (STATE (bb) == BLOCK_ORIGINAL)
- continue;
- if (STATE (bb) == BLOCK_NEW)
- {
- bb->count = 0;
- bb->frequency = 0;
- for (e = bb->pred; e; e = e->pred_next)
- {
- bb->count += e->count;
- bb->frequency += EDGE_FREQUENCY (e);
- }
- }
+ if (STATE (bb) == BLOCK_ORIGINAL)
+ continue;
+ if (STATE (bb) == BLOCK_NEW)
+ {
+ bb->count = 0;
+ bb->frequency = 0;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ {
+ bb->count += e->count;
+ bb->frequency += EDGE_FREQUENCY (e);
+ }
+ }
- compute_outgoing_frequencies (bb);
- }
+ compute_outgoing_frequencies (bb);
+ }
FOR_EACH_BB (bb)
SET_STATE (bb, 0);
/* Like above but for single basic block only. */
void
-find_sub_basic_blocks (bb)
- basic_block bb;
+find_sub_basic_blocks (basic_block bb)
{
basic_block min, max, b;
basic_block next = bb->next_bb;
/* Now re-scan and wire in all edges. This expect simple (conditional)
jumps at the end of each new basic blocks. */
- make_edges (NULL, min, max, 1);
+ make_edges (min, max, 1);
/* Update branch probabilities. Expect only (un)conditional jumps
to be created with only the forward edges. */
FOR_BB_BETWEEN (b, min, max->next_bb, next_bb)
{
edge e;
+ edge_iterator ei;
if (b != min)
{
b->count = 0;
b->frequency = 0;
- for (e = b->pred; e; e = e->pred_next)
+ FOR_EACH_EDGE (e, ei, b->preds)
{
b->count += e->count;
b->frequency += EDGE_FREQUENCY (e);
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