/* 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.
static int count_basic_blocks (rtx);
static void find_basic_blocks_1 (rtx);
-static rtx find_label_refs (rtx, rtx);
-static void make_edges (rtx, basic_block, basic_block, int);
+static void make_edges (basic_block, basic_block, int);
static void make_label_edge (sbitmap *, basic_block, rtx, int);
-static void make_eh_edge (sbitmap *, basic_block, rtx);
static void find_bb_boundaries (basic_block);
static void compute_outgoing_frequencies (basic_block);
\f
&& 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 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 (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 the edges generated by INSN in REGION. */
-static void
-make_eh_edge (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;
rtx handlers, i;
the list of exception regions active at the end of the basic block. */
static void
-make_edges (rtx label_value_list, basic_block min, basic_block 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. */
+
+ 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);
rtx insn, x;
enum rtx_code code;
int force_fallthru = 0;
+ edge e;
- if (GET_CODE (bb->head) == CODE_LABEL && LABEL_ALT_ENTRY_P (bb->head))
+ if (GET_CODE (BB_HEAD (bb)) == CODE_LABEL
+ && 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. */
}
/* 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);
}
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_INSN (insn);
+ for (e = bb->succ; e; e = e->succ_next)
+ if (e->dest == EXIT_BLOCK_PTR && e->flags & EDGE_FALLTHRU)
+ {
+ insn = 0;
+ break;
+ }
while (insn
&& GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK)
cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
else if (bb->next_bb != EXIT_BLOCK_PTR)
{
- if (force_fallthru || insn == bb->next_bb->head)
+ if (force_fallthru || insn == BB_HEAD (bb->next_bb))
cached_make_edge (edge_cache, bb, bb->next_bb, EDGE_FALLTHRU);
}
}
{
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;
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);
- }
- }
}
if (head != NULL_RTX)
if (last_basic_block != n_basic_blocks)
abort ();
- label_value_list = lvl;
- tail_recursion_label_list = trll;
clear_aux_for_blocks ();
}
FOR_EACH_BB (bb)
bb->aux = NULL;
- VARRAY_FREE (basic_block_info);
+ basic_block_info = NULL;
}
n_basic_blocks = count_basic_blocks (f);
find_basic_blocks_1 (f);
/* 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. */
static void
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)
{
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
if (b->succ && b->succ->succ_next && !b->succ->succ_next->succ_next)
{
- 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));
+ probability = INTVAL (XEXP (note, 0));
e = BRANCH_EDGE (b);
e->probability = probability;
e->count = ((b->count * probability + REG_BR_PROB_BASE / 2)
/* 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. */
/* 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. */
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