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 make_label_edge (sbitmap, basic_block, rtx, int);
static void find_bb_boundaries (basic_block);
static void compute_outgoing_frequencies (basic_block);
\f
/* Create an edge from a basic block to a label. */
static void
-make_label_edge (sbitmap *edge_cache, basic_block src, rtx label, int flags)
+make_label_edge (sbitmap edge_cache, basic_block src, rtx label, int flags)
{
gcc_assert (LABEL_P (label));
/* Create the edges generated by INSN in REGION. */
void
-rtl_make_eh_edge (sbitmap *edge_cache, basic_block src, rtx insn)
+rtl_make_eh_edge (sbitmap edge_cache, basic_block src, rtx insn)
{
int is_call = CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0;
rtx handlers, i;
free_INSN_LIST_list (&handlers);
}
-/* State of basic block as seen by find_many_sub_basic_blocks. */
-enum state {BLOCK_NEW = 0, BLOCK_ORIGINAL, BLOCK_TO_SPLIT};
+/* States of basic block as seen by find_many_sub_basic_blocks. */
+enum state {
+ /* Basic blocks created via split_block belong to this state.
+ make_edges will examine these basic blocks to see if we need to
+ create edges going out of them. */
+ BLOCK_NEW = 0,
+
+ /* Basic blocks that do not need examining belong to this state.
+ These blocks will be left intact. In particular, make_edges will
+ not create edges going out of these basic blocks. */
+ BLOCK_ORIGINAL,
+
+ /* Basic blocks that may need splitting (due to a label appearing in
+ the middle, etc) belong to this state. After splitting them,
+ make_edges will create create edges going out of them as
+ needed. */
+ BLOCK_TO_SPLIT
+};
#define STATE(BB) (enum state) ((size_t) (BB)->aux)
#define SET_STATE(BB, STATE) ((BB)->aux = (void *) (size_t) (STATE))
#define BLOCK_USED_BY_TABLEJUMP 32
#define FULL_STATE(BB) ((size_t) (BB)->aux)
-/* Identify the edges between basic blocks MIN to MAX.
+/* Identify the edges going out of basic blocks between MIN and MAX,
+ inclusive, that have their states set to BLOCK_NEW or
+ BLOCK_TO_SPLIT.
- NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks
- that are otherwise unreachable may be reachable with a non-local goto.
-
- BB_EH_END is an array indexed by basic block number in which we record
- the list of exception regions active at the end of the basic block. */
+ UPDATE_P should be nonzero if we are updating CFG and zero if we
+ are building CFG from scratch. */
static void
make_edges (basic_block min, basic_block max, int update_p)
{
basic_block bb;
- sbitmap *edge_cache = NULL;
+ sbitmap edge_cache = NULL;
/* 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 || cfun->max_jumptable_ents > 100)
- {
- edge_cache = sbitmap_vector_alloc (last_basic_block, last_basic_block);
- sbitmap_vector_zero (edge_cache, last_basic_block);
-
- if (update_p)
- {
- FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
- if (STATE (bb) != BLOCK_ORIGINAL)
- {
- edge e;
- edge_iterator ei;
-
- FOR_EACH_EDGE (e, ei, bb->succs)
- if (e->dest != EXIT_BLOCK_PTR)
- SET_BIT (edge_cache[bb->index], e->dest->index);
- }
- }
- }
+ edge_cache = sbitmap_alloc (last_basic_block);
/* By nature of the way these get numbered, ENTRY_BLOCK_PTR->next_bb block
is always the entry. */
if (min == ENTRY_BLOCK_PTR->next_bb)
- cached_make_edge (edge_cache, ENTRY_BLOCK_PTR, min,
- EDGE_FALLTHRU);
+ make_edge (ENTRY_BLOCK_PTR, min, EDGE_FALLTHRU);
FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
{
rtx insn, x;
enum rtx_code code;
edge e;
+ edge_iterator ei;
if (STATE (bb) == BLOCK_ORIGINAL)
continue;
+ /* If we have an edge cache, cache edges going out of BB. */
+ if (edge_cache)
+ {
+ sbitmap_zero (edge_cache);
+ if (update_p)
+ {
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (e->dest != EXIT_BLOCK_PTR)
+ SET_BIT (edge_cache, e->dest->index);
+ }
+ }
+
if (LABEL_P (BB_HEAD (bb))
&& LABEL_ALT_ENTRY_P (BB_HEAD (bb)))
cached_make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
profile_status = PROFILE_ABSENT;
+ /* Tell make_edges to examine every block for out-going edges. */
FOR_EACH_BB (bb)
SET_STATE (bb, BLOCK_NEW);
}
}
- if (EDGE_COUNT (b->succs) == 1)
+ if (single_succ_p (b))
{
- e = EDGE_SUCC (b, 0);
+ e = single_succ_edge (b);
e->probability = REG_BR_PROB_BASE;
e->count = b->count;
return;
/ REG_BR_PROB_BASE);
}
-/* Assume that someone emitted code with control flow instructions to the
- basic block. Update the data structure. */
+/* Assume that some pass has inserted labels or control flow
+ instructions within a basic block. Split basic blocks as needed
+ and create edges. */
void
find_many_sub_basic_blocks (sbitmap blocks)
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