/* Control flow graph building code for GNU compiler.
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
This file is part of GCC.
- CFG construction
find_basic_blocks
- Local CFG construction
- find_sub_basic_blocks
- */
+ find_sub_basic_blocks */
\f
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "tree.h"
#include "rtl.h"
#include "hard-reg-set.h"
#include "toplev.h"
#include "timevar.h"
-#include "obstack.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, int, int, int));
+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));
+\f
+/* Return true if insn is something that should be contained inside basic
+ block. */
+
+bool
+inside_basic_block_p (insn)
+ 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
+ || (GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_VEC
+ && GET_CODE (PATTERN (NEXT_INSN (insn))) != ADDR_DIFF_VEC));
+
+ case JUMP_INSN:
+ return (GET_CODE (PATTERN (insn)) != ADDR_VEC
+ && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
+
+ case CALL_INSN:
+ case INSN:
+ return true;
+
+ case BARRIER:
+ case NOTE:
+ return false;
+
+ default:
+ abort ();
+ }
+}
+
+/* Return true if INSN may cause control flow transfer, so it should be last in
+ the basic block. */
+
+bool
+control_flow_insn_p (insn)
+ rtx insn;
+{
+ rtx note;
+
+ switch (GET_CODE (insn))
+ {
+ case NOTE:
+ case CODE_LABEL:
+ return false;
+
+ case JUMP_INSN:
+ /* Jump insn always causes control transfer except for tablejumps. */
+ return (GET_CODE (PATTERN (insn)) != ADDR_VEC
+ && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC);
+
+ case CALL_INSN:
+ /* Call insn may return to the nonlocal goto handler. */
+ return ((nonlocal_goto_handler_labels
+ && (0 == (note = find_reg_note (insn, REG_EH_REGION,
+ NULL_RTX))
+ || INTVAL (XEXP (note, 0)) >= 0))
+ /* Or may trap. */
+ || can_throw_internal (insn));
+
+ case INSN:
+ return (flag_non_call_exceptions && can_throw_internal (insn));
+
+ case BARRIER:
+ /* It is nonsence to reach barrier when looking for the
+ end of basic block, but before dead code is eliminated
+ this may happen. */
+ return false;
+
+ default:
+ abort ();
+ }
+}
/* Count the basic blocks of the function. */
count_basic_blocks (f)
rtx f;
{
- register rtx insn;
- register RTX_CODE prev_code;
- register int count = 0;
- int saw_abnormal_edge = 0;
+ int count = 0;
+ bool saw_insn = false;
+ rtx insn;
- prev_code = JUMP_INSN;
for (insn = f; insn; insn = NEXT_INSN (insn))
{
- enum rtx_code code = GET_CODE (insn);
-
- if (code == CODE_LABEL
- || (GET_RTX_CLASS (code) == 'i'
- && (prev_code == JUMP_INSN
- || prev_code == BARRIER
- || saw_abnormal_edge)))
- {
- saw_abnormal_edge = 0;
- count++;
- }
-
- /* Record whether this insn created an edge. */
- if (code == CALL_INSN)
- {
- rtx note;
-
- /* If there is a nonlocal goto label and the specified
- region number isn't -1, we have an edge. */
- if (nonlocal_goto_handler_labels
- && ((note = find_reg_note (insn, REG_EH_REGION, NULL_RTX)) == 0
- || INTVAL (XEXP (note, 0)) >= 0))
- saw_abnormal_edge = 1;
-
- else if (can_throw_internal (insn))
- saw_abnormal_edge = 1;
- }
- else if (flag_non_call_exceptions
- && code == INSN
- && can_throw_internal (insn))
- saw_abnormal_edge = 1;
-
- if (code != NOTE)
- prev_code = code;
+ /* 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)
+ && saw_insn)
+ count++, saw_insn = false;
+
+ /* Start basic block if needed. */
+ if (!saw_insn && inside_basic_block_p (insn))
+ saw_insn = true;
+
+ /* Control flow insn causes current basic block to be terminated. */
+ if (saw_insn && control_flow_insn_p (insn))
+ count++, saw_insn = false;
}
+ if (saw_insn)
+ count++;
+
/* The rest of the compiler works a bit smoother when we don't have to
check for the edge case of do-nothing functions with no basic blocks. */
if (count == 0)
/* 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 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))
+ && GET_CODE (next) == JUMP_INSN
+ && (GET_CODE (PATTERN (next)) == ADDR_VEC
+ || GET_CODE (PATTERN (next)) == ADDR_DIFF_VEC))
;
else if (GET_CODE (lab) == NOTE)
;
basic_block src;
rtx insn;
{
- int is_call = (GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0);
+ int is_call = GET_CODE (insn) == CALL_INSN ? EDGE_ABNORMAL_CALL : 0;
rtx handlers, i;
handlers = reachable_handlers (insn);
free_INSN_LIST_list (&handlers);
}
+
/* Identify the edges between basic blocks MIN to MAX.
NONLOCAL_LABEL_LIST is a list of non-local labels in the function. Blocks
static void
make_edges (label_value_list, min, max, update_p)
rtx label_value_list;
- int min, max, update_p;
+ basic_block min, max;
+ int update_p;
{
- int i;
+ basic_block bb;
sbitmap *edge_cache = NULL;
/* Assume no computed jump; revise as we create edges. */
/* 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)
+ if (forced_labels || label_value_list || cfun->max_jumptable_ents > 100)
{
- edge_cache = sbitmap_vector_alloc (n_basic_blocks, n_basic_blocks);
- sbitmap_vector_zero (edge_cache, n_basic_blocks);
+ edge_cache = sbitmap_vector_alloc (last_basic_block, last_basic_block);
+ sbitmap_vector_zero (edge_cache, last_basic_block);
if (update_p)
- for (i = min; i <= max; ++i)
+ FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
{
edge e;
- for (e = BASIC_BLOCK (i)->succ; e ; e = e->succ_next)
+
+ for (e = bb->succ; e ; e = e->succ_next)
if (e->dest != EXIT_BLOCK_PTR)
- SET_BIT (edge_cache[i], e->dest->index);
+ SET_BIT (edge_cache[bb->index], e->dest->index);
}
}
- /* By nature of the way these get numbered, block 0 is always the entry. */
- cached_make_edge (edge_cache, ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU);
+ /* 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);
- for (i = min; i <= max; ++i)
+ FOR_BB_BETWEEN (bb, min, max->next_bb, next_bb)
{
- basic_block bb = BASIC_BLOCK (i);
rtx insn, x;
enum rtx_code code;
int force_fallthru = 0;
- if (GET_CODE (bb->head) == CODE_LABEL
- && LABEL_ALTERNATE_NAME (bb->head))
+ if (GET_CODE (bb->head) == CODE_LABEL && LABEL_ALT_ENTRY_P (bb->head))
cached_make_edge (NULL, ENTRY_BLOCK_PTR, bb, 0);
/* Examine the last instruction of the block, and discover the
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 sibling call insn, then this is in effect a
- combined call and return, and so we need an edge to the
- exit block. No need to worry about EH edges, since we
- wouldn't have created the sibling call in the first place. */
-
+ /* If this is a sibling call insn, then this is in effect a combined call
+ and return, and so we need an edge to the exit block. No need to
+ worry about EH edges, since we wouldn't have created the sibling call
+ 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);
+ cached_make_edge (edge_cache, bb, EXIT_BLOCK_PTR, EDGE_SIBCALL);
/* 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
exceptions then any insn can reach any of the active handlers.
-
Also mark the CALL_INSN as reaching any nonlocal goto handler. */
-
else if (code == CALL_INSN || flag_non_call_exceptions)
{
/* Add any appropriate EH edges. */
{
/* ??? This could be made smarter: in some cases it's possible
to tell that certain calls will not do a nonlocal goto.
-
For example, if the nested functions that do the nonlocal
gotos do not have their addresses taken, then only calls to
those functions or to other nested functions that use them
could possibly do nonlocal gotos. */
+
/* We do know that a REG_EH_REGION note with a value less
than 0 is guaranteed not to perform a non-local goto. */
rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
+
if (!note || INTVAL (XEXP (note, 0)) >= 0)
for (x = nonlocal_goto_handler_labels; x; x = XEXP (x, 1))
make_label_edge (edge_cache, bb, XEXP (x, 0),
}
/* Find out if we can drop through to the next block. */
- insn = next_nonnote_insn (insn);
- if (!insn || (i + 1 == n_basic_blocks && force_fallthru))
+ insn = NEXT_INSN (insn);
+ while (insn
+ && GET_CODE (insn) == NOTE
+ && 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 (i + 1 < n_basic_blocks)
+ else if (bb->next_bb != EXIT_BLOCK_PTR)
{
- rtx tmp = BLOCK_HEAD (i + 1);
- if (GET_CODE (tmp) == NOTE)
- tmp = next_nonnote_insn (tmp);
- if (force_fallthru || insn == tmp)
- cached_make_edge (edge_cache, bb, BASIC_BLOCK (i + 1), EDGE_FALLTHRU);
+ if (force_fallthru || insn == bb->next_bb->head)
+ cached_make_edge (edge_cache, bb, bb->next_bb, EDGE_FALLTHRU);
}
}
find_basic_blocks_1 (f)
rtx f;
{
- register rtx insn, next;
- int i = 0;
+ 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;
/* We process the instructions in a slightly different way than we did
previously. This is so that we see a NOTE_BASIC_BLOCK after we have
next = NEXT_INSN (insn);
+ if ((GET_CODE (insn) == CODE_LABEL || GET_CODE (insn) == BARRIER)
+ && head)
+ {
+ prev = create_basic_block_structure (head, end, bb_note, prev);
+ head = end = NULL_RTX;
+ bb_note = NULL_RTX;
+ }
+
+ if (inside_basic_block_p (insn))
+ {
+ if (head == NULL_RTX)
+ head = insn;
+ end = insn;
+ }
+
+ if (head && control_flow_insn_p (insn))
+ {
+ prev = create_basic_block_structure (head, end, bb_note, prev);
+ head = end = NULL_RTX;
+ bb_note = NULL_RTX;
+ }
+
switch (code)
{
case NOTE:
}
case CODE_LABEL:
- /* A basic block starts at a label. If we've closed one off due
- to a barrier or some such, no need to do it again. */
- if (head != NULL_RTX)
- {
- create_basic_block_structure (i++, head, end, bb_note);
- bb_note = NULL_RTX;
- }
-
- head = end = insn;
- break;
-
case JUMP_INSN:
- /* A basic block ends at a jump. */
- if (head == NULL_RTX)
- head = insn;
- else
- {
- /* ??? Make a special check for table jumps. The way this
- happens is truly and amazingly gross. We are about to
- create a basic block that contains just a code label and
- an addr*vec jump insn. Worse, an addr_diff_vec creates
- its own natural loop.
-
- Prevent this bit of brain damage, pasting things together
- correctly in make_edges.
-
- The correct solution involves emitting the table directly
- on the tablejump instruction as a note, or JUMP_LABEL. */
-
- if (GET_CODE (PATTERN (insn)) == ADDR_VEC
- || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
- {
- head = end = NULL;
- n_basic_blocks--;
- break;
- }
- }
- end = insn;
- goto new_bb_inclusive;
-
+ case INSN:
case BARRIER:
- /* A basic block ends at a barrier. It may be that an unconditional
- jump already closed the basic block -- no need to do it again. */
- if (head == NULL_RTX)
- break;
- goto new_bb_exclusive;
+ break;
case CALL_INSN:
- {
- /* Record whether this call created an edge. */
- rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
- int region = (note ? INTVAL (XEXP (note, 0)) : 0);
-
- 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);
- }
-
- /* A basic block ends at a call that can either throw or
- do a non-local goto. */
- if ((nonlocal_goto_handler_labels && region >= 0)
- || can_throw_internal (insn))
- {
- new_bb_inclusive:
- if (head == NULL_RTX)
- head = insn;
- end = insn;
-
- new_bb_exclusive:
- create_basic_block_structure (i++, head, end, bb_note);
- head = end = NULL_RTX;
- bb_note = NULL_RTX;
- break;
- }
- }
- /* Fall through. */
-
- case INSN:
- /* Non-call exceptions generate new blocks just like calls. */
- if (flag_non_call_exceptions && can_throw_internal (insn))
- goto new_bb_inclusive;
-
- if (head == NULL_RTX)
- head = insn;
- end = 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:
}
if (head != NULL_RTX)
- create_basic_block_structure (i++, head, end, bb_note);
+ create_basic_block_structure (head, end, bb_note, prev);
else if (bb_note)
delete_insn (bb_note);
- if (i != n_basic_blocks)
+ if (last_basic_block != n_basic_blocks)
abort ();
label_value_list = lvl;
tail_recursion_label_list = trll;
+ clear_aux_for_blocks ();
}
int nregs ATTRIBUTE_UNUSED;
FILE *file ATTRIBUTE_UNUSED;
{
- int max_uid;
- timevar_push (TV_CFG);
+ basic_block bb;
- basic_block_for_insn = 0;
+ timevar_push (TV_CFG);
/* Flush out existing data. */
if (basic_block_info != NULL)
{
- int i;
-
clear_edges ();
/* Clear bb->aux on all extant basic blocks. We'll use this as a
tag for reuse during create_basic_block, just in case some pass
copies around basic block notes improperly. */
- for (i = 0; i < n_basic_blocks; ++i)
- BASIC_BLOCK (i)->aux = NULL;
+ FOR_EACH_BB (bb)
+ bb->aux = NULL;
VARRAY_FREE (basic_block_info);
}
n_basic_blocks = count_basic_blocks (f);
+ last_basic_block = 0;
+ ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR;
+ EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR;
/* Size the basic block table. The actual structures will be allocated
by find_basic_blocks_1, since we want to keep the structure pointers
find_basic_blocks_1 (f);
- /* Record the block to which an insn belongs. */
- /* ??? This should be done another way, by which (perhaps) a label is
- tagged directly with the basic block that it starts. It is used for
- more than that currently, but IMO that is the only valid use. */
-
- max_uid = get_max_uid ();
-#ifdef AUTO_INC_DEC
- /* Leave space for insns life_analysis makes in some cases for auto-inc.
- These cases are rare, so we don't need too much space. */
- max_uid += max_uid / 10;
-#endif
-
- compute_bb_for_insn (max_uid);
-
/* Discover the edges of our cfg. */
- make_edges (label_value_list, 0, n_basic_blocks - 1, 0);
+ make_edges (label_value_list, 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. */
timevar_pop (TV_CFG);
}
\f
-/* Assume that someone emitted code with control flow instructions to the
- basic block. Update the data structure. */
-void
-find_sub_basic_blocks (bb)
+/* State of basic block as seen by find_sub_basic_blocks. */
+enum state {BLOCK_NEW = 0, BLOCK_ORIGINAL, BLOCK_TO_SPLIT};
+
+#define STATE(BB) (enum state) ((size_t) (BB)->aux)
+#define SET_STATE(BB, STATE) ((BB)->aux = (void *) (size_t) (STATE))
+
+/* Scan basic block BB for possible BB boundaries inside the block
+ and create new basic blocks in the progress. */
+
+static void
+find_bb_boundaries (bb)
basic_block bb;
{
rtx insn = bb->head;
rtx end = bb->end;
rtx flow_transfer_insn = NULL_RTX;
edge fallthru = NULL;
- basic_block first_bb = bb;
- int i;
if (insn == bb->end)
return;
{
enum rtx_code code = GET_CODE (insn);
- switch (code)
+ /* On code label, split current basic block. */
+ if (code == CODE_LABEL)
{
- case BARRIER:
- if (!flow_transfer_insn)
- abort ();
- break;
-
- /* On code label, split current basic block. */
- case CODE_LABEL:
fallthru = split_block (bb, PREV_INSN (insn));
if (flow_transfer_insn)
bb->end = flow_transfer_insn;
+
bb = fallthru->dest;
remove_edge (fallthru);
flow_transfer_insn = NULL_RTX;
- if (LABEL_ALTERNATE_NAME (insn))
+ if (LABEL_ALT_ENTRY_P (insn))
make_edge (ENTRY_BLOCK_PTR, bb, 0);
- break;
-
- case INSN:
- case JUMP_INSN:
- case CALL_INSN:
- /* In case we've previously split an insn that effects a control
- flow transfer, move the block header to proper place. */
- if (flow_transfer_insn)
- {
- fallthru = split_block (bb, PREV_INSN (insn));
- bb->end = flow_transfer_insn;
- bb = fallthru->dest;
- remove_edge (fallthru);
- flow_transfer_insn = NULL_RTX;
- }
-
- /* We need some special care for those expressions. */
- if (code == JUMP_INSN)
- {
- if (GET_CODE (PATTERN (insn)) == ADDR_VEC
- || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC)
- abort();
- flow_transfer_insn = insn;
- }
- else if (code == CALL_INSN)
- {
- rtx note;
- if (nonlocal_goto_handler_labels
- && (!(note = find_reg_note (insn, REG_EH_REGION, NULL_RTX))
- || INTVAL (XEXP (note, 0)) >= 0))
- flow_transfer_insn = insn;
- else if (can_throw_internal (insn))
- flow_transfer_insn = insn;
- else if (SIBLING_CALL_P (insn))
- flow_transfer_insn = insn;
- else if (find_reg_note (insn, REG_NORETURN, 0))
- flow_transfer_insn = insn;
- }
- else if (flag_non_call_exceptions && can_throw_internal (insn))
- flow_transfer_insn = insn;
- break;
+ }
- default:
- break;
+ /* In case we've previously seen an insn that effects a control
+ flow transfer, split the block. */
+ if (flow_transfer_insn && inside_basic_block_p (insn))
+ {
+ fallthru = split_block (bb, PREV_INSN (insn));
+ bb->end = flow_transfer_insn;
+ bb = fallthru->dest;
+ remove_edge (fallthru);
+ flow_transfer_insn = NULL_RTX;
}
+
+ if (control_flow_insn_p (insn))
+ flow_transfer_insn = insn;
if (insn == end)
break;
insn = NEXT_INSN (insn);
followed by cleanup at fallthru edge, so the outgoing edges may
be dead. */
purge_dead_edges (bb);
+}
+
+/* Assume that frequency of basic block B is known. Compute frequencies
+ and probabilities of outgoing edges. */
+
+static void
+compute_outgoing_frequencies (b)
+ basic_block b;
+{
+ edge e, f;
+
+ if (b->succ && b->succ->succ_next && !b->succ->succ_next->succ_next)
+ {
+ rtx note = find_reg_note (b->end, 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 (b->succ && !b->succ->succ_next)
+ {
+ e = b->succ;
+ e->probability = REG_BR_PROB_BASE;
+ e->count = b->count;
+ }
+}
+
+/* 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;
+{
+ basic_block bb, min, max;
+
+ FOR_EACH_BB (bb)
+ SET_STATE (bb,
+ TEST_BIT (blocks, bb->index) ? BLOCK_TO_SPLIT : BLOCK_ORIGINAL);
+
+ FOR_EACH_BB (bb)
+ if (STATE (bb) == BLOCK_TO_SPLIT)
+ find_bb_boundaries (bb);
+
+ FOR_EACH_BB (bb)
+ if (STATE (bb) != BLOCK_ORIGINAL)
+ break;
+
+ min = max = bb;
+ for (; bb != EXIT_BLOCK_PTR; bb = bb->next_bb)
+ if (STATE (bb) != BLOCK_ORIGINAL)
+ max = 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);
+
+ /* 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 (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);
+ }
+ }
+
+ 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;
+{
+ basic_block min, max, b;
+ basic_block next = bb->next_bb;
+
+ min = bb;
+ find_bb_boundaries (bb);
+ max = next->prev_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, first_bb->index, bb->index, 1);
+ make_edges (NULL, min, max, 1);
/* Update branch probabilities. Expect only (un)conditional jumps
to be created with only the forward edges. */
- for (i = first_bb->index; i <= bb->index; i++)
+ FOR_BB_BETWEEN (b, min, max->next_bb, next_bb)
{
- edge e,f;
- basic_block b = BASIC_BLOCK (i);
- if (b != first_bb)
+ edge e;
+
+ if (b != min)
{
b->count = 0;
b->frequency = 0;
- for (e = b->pred; e; e=e->pred_next)
+ for (e = b->pred; e; e = e->pred_next)
{
b->count += e->count;
b->frequency += EDGE_FREQUENCY (e);
}
}
- if (b->succ && b->succ->succ_next && !b->succ->succ_next->succ_next)
- {
- rtx note = find_reg_note (b->end, REG_BR_PROB, NULL);
- int probability;
-
- if (!note)
- continue;
- 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 (b->succ && !b->succ->succ_next)
- {
- e = b->succ;
- e->probability = REG_BR_PROB_BASE;
- e->count = b->count;
- }
+
+ compute_outgoing_frequencies (b);
}
}
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