#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "toplev.h"
#include "rtl.h"
#include "tm_p.h"
#include "hard-reg-set.h"
#include "regs.h"
#include "function.h"
#include "flags.h"
#include "insn-config.h"
#include "insn-attr.h"
#include "except.h"
#include "recog.h"
#include "sched-int.h"
#include "target.h"
#include "cfglayout.h"
#include "cfgloop.h"
#include "sbitmap.h"
#include "expr.h"
#include "bitmap.h"
#include "df.h"
#include "ddg.h"
#ifdef ENABLE_LLVM
#undef INSN_SCHEDULING
#endif
#ifdef INSN_SCHEDULING
enum edge_flag {NOT_IN_SCC = 0, IN_SCC};
static void add_backarc_to_ddg (ddg_ptr, ddg_edge_ptr);
static void add_backarc_to_scc (ddg_scc_ptr, ddg_edge_ptr);
static void add_scc_to_ddg (ddg_all_sccs_ptr, ddg_scc_ptr);
static void create_ddg_dependence (ddg_ptr, ddg_node_ptr, ddg_node_ptr, rtx);
static void create_ddg_dep_no_link (ddg_ptr, ddg_node_ptr, ddg_node_ptr,
dep_type, dep_data_type, int);
static ddg_edge_ptr create_ddg_edge (ddg_node_ptr, ddg_node_ptr, dep_type,
dep_data_type, int, int);
static void add_edge_to_ddg (ddg_ptr g, ddg_edge_ptr);
static bool mem_ref_p;
static int
mark_mem_use (rtx *x, void *data ATTRIBUTE_UNUSED)
{
if (MEM_P (*x))
mem_ref_p = true;
return 0;
}
static void
mark_mem_use_1 (rtx *x, void *data)
{
for_each_rtx (x, mark_mem_use, data);
}
static bool
mem_read_insn_p (rtx insn)
{
mem_ref_p = false;
note_uses (&PATTERN (insn), mark_mem_use_1, NULL);
return mem_ref_p;
}
static void
mark_mem_store (rtx loc, rtx setter ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED)
{
if (MEM_P (loc))
mem_ref_p = true;
}
static bool
mem_write_insn_p (rtx insn)
{
mem_ref_p = false;
note_stores (PATTERN (insn), mark_mem_store, NULL);
return mem_ref_p;
}
static bool
rtx_mem_access_p (rtx x)
{
int i, j;
const char *fmt;
enum rtx_code code;
if (x == 0)
return false;
if (MEM_P (x))
return true;
code = GET_CODE (x);
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
if (rtx_mem_access_p (XEXP (x, i)))
return true;
}
else if (fmt[i] == 'E')
for (j = 0; j < XVECLEN (x, i); j++)
{
if (rtx_mem_access_p (XVECEXP (x, i, j)))
return true;
}
}
return false;
}
static bool
mem_access_insn_p (rtx insn)
{
return rtx_mem_access_p (PATTERN (insn));
}
static void
create_ddg_dependence (ddg_ptr g, ddg_node_ptr src_node,
ddg_node_ptr dest_node, rtx link)
{
ddg_edge_ptr e;
int latency, distance = 0;
int interloop = (src_node->cuid >= dest_node->cuid);
dep_type t = TRUE_DEP;
dep_data_type dt = (mem_access_insn_p (src_node->insn)
&& mem_access_insn_p (dest_node->insn) ? MEM_DEP
: REG_DEP);
if (interloop)
distance = 1;
gcc_assert (link);
if (REG_NOTE_KIND (link) == REG_DEP_ANTI)
t = ANTI_DEP;
else if (REG_NOTE_KIND (link) == REG_DEP_OUTPUT)
t = OUTPUT_DEP;
latency = insn_cost (src_node->insn, link, dest_node->insn);
e = create_ddg_edge (src_node, dest_node, t, dt, latency, distance);
if (interloop)
{
if (!(t == OUTPUT_DEP && src_node == dest_node)
&& !(t == ANTI_DEP && dt == REG_DEP))
add_backarc_to_ddg (g, e);
else
free (e);
}
else if (t == ANTI_DEP && dt == REG_DEP)
free (e);
else
add_edge_to_ddg (g, e);
}
static void
create_ddg_dep_no_link (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to,
dep_type d_t, dep_data_type d_dt, int distance)
{
ddg_edge_ptr e;
int l;
rtx link = alloc_INSN_LIST (to->insn, NULL_RTX);
if (d_t == ANTI_DEP)
PUT_REG_NOTE_KIND (link, REG_DEP_ANTI);
else if (d_t == OUTPUT_DEP)
PUT_REG_NOTE_KIND (link, REG_DEP_OUTPUT);
l = insn_cost (from->insn, link, to->insn);
free_INSN_LIST_node (link);
e = create_ddg_edge (from, to, d_t, d_dt, l, distance);
if (distance > 0)
add_backarc_to_ddg (g, e);
else
add_edge_to_ddg (g, e);
}
static void
add_deps_for_def (ddg_ptr g, struct df *df, struct df_ref *rd)
{
int regno = DF_REF_REGNO (rd);
struct df_ru_bb_info *bb_info = DF_RU_BB_INFO (df, g->bb);
struct df_link *r_use;
int use_before_def = false;
rtx def_insn = DF_REF_INSN (rd);
ddg_node_ptr src_node = get_node_of_insn (g, def_insn);
for (r_use = DF_REF_CHAIN (rd); r_use != NULL; r_use = r_use->next)
{
if (bitmap_bit_p (bb_info->gen, r_use->ref->id))
{
rtx use_insn = DF_REF_INSN (r_use->ref);
ddg_node_ptr dest_node = get_node_of_insn (g, use_insn);
gcc_assert (src_node && dest_node);
use_before_def = true;
create_ddg_dep_no_link (g, src_node, dest_node, TRUE_DEP,
REG_DEP, 1);
}
}
if (! use_before_def)
{
struct df_ref *def = df_bb_regno_first_def_find (df, g->bb, regno);
int i;
ddg_node_ptr dest_node;
if (!def || rd->id == def->id)
return;
for (i = src_node->cuid + 1; i < g->num_nodes; i++)
if (df_find_use (df, g->nodes[i].insn, rd->reg))
return;
dest_node = get_node_of_insn (g, def->insn);
create_ddg_dep_no_link (g, src_node, dest_node, OUTPUT_DEP, REG_DEP, 1);
}
}
static void
add_deps_for_use (ddg_ptr g, struct df *df, struct df_ref *use)
{
int i;
int regno = DF_REF_REGNO (use);
struct df_ref *first_def = df_bb_regno_first_def_find (df, g->bb, regno);
ddg_node_ptr use_node;
ddg_node_ptr def_node;
struct df_rd_bb_info *bb_info;
bb_info = DF_RD_BB_INFO (df, g->bb);
if (!first_def)
return;
use_node = get_node_of_insn (g, use->insn);
def_node = get_node_of_insn (g, first_def->insn);
gcc_assert (use_node && def_node);
for (i = use_node->cuid + 1; i < g->num_nodes; i++)
if (df_find_def (df, g->nodes[i].insn, use->reg))
return;
if (! bitmap_bit_p (bb_info->gen, first_def->id))
create_ddg_dep_no_link (g, use_node, def_node, ANTI_DEP, REG_DEP, 1);
}
static void
build_inter_loop_deps (ddg_ptr g, struct df *df)
{
unsigned rd_num, u_num;
struct df_rd_bb_info *rd_bb_info;
struct df_ru_bb_info *ru_bb_info;
bitmap_iterator bi;
rd_bb_info = DF_RD_BB_INFO (df, g->bb);
EXECUTE_IF_SET_IN_BITMAP (rd_bb_info->gen, 0, rd_num, bi)
{
struct df_ref *rd = DF_DEFS_GET (df, rd_num);
add_deps_for_def (g, df, rd);
}
ru_bb_info = DF_RU_BB_INFO (df, g->bb);
EXECUTE_IF_SET_IN_BITMAP (ru_bb_info->kill, 0, u_num, bi)
{
struct df_ref *use = DF_USES_GET (df, u_num);
if (BLOCK_FOR_INSN (use->insn) == g->bb)
add_deps_for_use (g, df, use);
}
}
static void
add_inter_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to)
{
if (mem_write_insn_p (from->insn))
{
if (mem_read_insn_p (to->insn))
create_ddg_dep_no_link (g, from, to, TRUE_DEP, MEM_DEP, 1);
else if (from->cuid != to->cuid)
create_ddg_dep_no_link (g, from, to, OUTPUT_DEP, MEM_DEP, 1);
}
else
{
if (mem_read_insn_p (to->insn))
return;
else if (from->cuid != to->cuid)
{
create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 1);
create_ddg_dep_no_link (g, to, from, TRUE_DEP, MEM_DEP, 1);
}
}
}
static void
build_intra_loop_deps (ddg_ptr g)
{
int i;
struct deps tmp_deps;
rtx head, tail, link;
init_deps_global ();
init_deps (&tmp_deps);
get_ebb_head_tail (g->bb, g->bb, &head, &tail);
sched_analyze (&tmp_deps, head, tail);
for (i = 0; i < g->num_nodes; i++)
{
ddg_node_ptr dest_node = &g->nodes[i];
if (! INSN_P (dest_node->insn))
continue;
for (link = LOG_LINKS (dest_node->insn); link; link = XEXP (link, 1))
{
ddg_node_ptr src_node = get_node_of_insn (g, XEXP (link, 0));
if (!src_node)
continue;
add_forw_dep (dest_node->insn, link);
create_ddg_dependence (g, src_node, dest_node,
INSN_DEPEND (src_node->insn));
}
if (mem_access_insn_p (dest_node->insn))
{
int j;
for (j = 0; j <= i; j++)
{
ddg_node_ptr j_node = &g->nodes[j];
if (mem_access_insn_p (j_node->insn))
if (! TEST_BIT (dest_node->successors, j))
add_inter_loop_mem_dep (g, dest_node, j_node);
}
}
}
finish_deps_global ();
free_deps (&tmp_deps);
}
ddg_ptr
create_ddg (basic_block bb, struct df *df, int closing_branch_deps)
{
ddg_ptr g;
rtx insn, first_note;
int i;
int num_nodes = 0;
g = (ddg_ptr) xcalloc (1, sizeof (struct ddg));
g->bb = bb;
g->closing_branch_deps = closing_branch_deps;
for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
insn = NEXT_INSN (insn))
{
if (! INSN_P (insn) || GET_CODE (PATTERN (insn)) == USE)
continue;
if (mem_read_insn_p (insn))
g->num_loads++;
if (mem_write_insn_p (insn))
g->num_stores++;
num_nodes++;
}
if (num_nodes <= 1)
{
free (g);
return NULL;
}
g->num_nodes = num_nodes;
g->nodes = (ddg_node_ptr) xcalloc (num_nodes, sizeof (struct ddg_node));
g->closing_branch = NULL;
i = 0;
first_note = NULL_RTX;
for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
insn = NEXT_INSN (insn))
{
if (! INSN_P (insn))
{
if (! first_note && NOTE_P (insn)
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_BASIC_BLOCK)
first_note = insn;
continue;
}
if (JUMP_P (insn))
{
gcc_assert (!g->closing_branch);
g->closing_branch = &g->nodes[i];
}
else if (GET_CODE (PATTERN (insn)) == USE)
{
if (! first_note)
first_note = insn;
continue;
}
g->nodes[i].cuid = i;
g->nodes[i].successors = sbitmap_alloc (num_nodes);
sbitmap_zero (g->nodes[i].successors);
g->nodes[i].predecessors = sbitmap_alloc (num_nodes);
sbitmap_zero (g->nodes[i].predecessors);
g->nodes[i].first_note = (first_note ? first_note : insn);
g->nodes[i++].insn = insn;
first_note = NULL_RTX;
}
gcc_assert (g->closing_branch);
build_intra_loop_deps (g);
build_inter_loop_deps (g, df);
return g;
}
void
free_ddg (ddg_ptr g)
{
int i;
if (!g)
return;
for (i = 0; i < g->num_nodes; i++)
{
ddg_edge_ptr e = g->nodes[i].out;
while (e)
{
ddg_edge_ptr next = e->next_out;
free (e);
e = next;
}
sbitmap_free (g->nodes[i].successors);
sbitmap_free (g->nodes[i].predecessors);
}
if (g->num_backarcs > 0)
free (g->backarcs);
free (g->nodes);
free (g);
}
void
print_ddg_edge (FILE *file, ddg_edge_ptr e)
{
char dep_c;
switch (e->type) {
case OUTPUT_DEP :
dep_c = 'O';
break;
case ANTI_DEP :
dep_c = 'A';
break;
default:
dep_c = 'T';
}
fprintf (file, " [%d -(%c,%d,%d)-> %d] ", INSN_UID (e->src->insn),
dep_c, e->latency, e->distance, INSN_UID (e->dest->insn));
}
void
print_ddg (FILE *file, ddg_ptr g)
{
int i;
for (i = 0; i < g->num_nodes; i++)
{
ddg_edge_ptr e;
print_rtl_single (file, g->nodes[i].insn);
fprintf (file, "OUT ARCS: ");
for (e = g->nodes[i].out; e; e = e->next_out)
print_ddg_edge (file, e);
fprintf (file, "\nIN ARCS: ");
for (e = g->nodes[i].in; e; e = e->next_in)
print_ddg_edge (file, e);
fprintf (file, "\n");
}
}
void
vcg_print_ddg (FILE *file, ddg_ptr g)
{
int src_cuid;
fprintf (file, "graph: {\n");
for (src_cuid = 0; src_cuid < g->num_nodes; src_cuid++)
{
ddg_edge_ptr e;
int src_uid = INSN_UID (g->nodes[src_cuid].insn);
fprintf (file, "node: {title: \"%d_%d\" info1: \"", src_cuid, src_uid);
print_rtl_single (file, g->nodes[src_cuid].insn);
fprintf (file, "\"}\n");
for (e = g->nodes[src_cuid].out; e; e = e->next_out)
{
int dst_uid = INSN_UID (e->dest->insn);
int dst_cuid = e->dest->cuid;
if (e->distance > 0)
fprintf (file, "backedge: {color: red ");
else
fprintf (file, "edge: { ");
fprintf (file, "sourcename: \"%d_%d\" ", src_cuid, src_uid);
fprintf (file, "targetname: \"%d_%d\" ", dst_cuid, dst_uid);
fprintf (file, "label: \"%d_%d\"}\n", e->latency, e->distance);
}
}
fprintf (file, "}\n");
}
static ddg_edge_ptr
create_ddg_edge (ddg_node_ptr src, ddg_node_ptr dest,
dep_type t, dep_data_type dt, int l, int d)
{
ddg_edge_ptr e = (ddg_edge_ptr) xmalloc (sizeof (struct ddg_edge));
e->src = src;
e->dest = dest;
e->type = t;
e->data_type = dt;
e->latency = l;
e->distance = d;
e->next_in = e->next_out = NULL;
e->aux.info = 0;
return e;
}
static void
add_edge_to_ddg (ddg_ptr g ATTRIBUTE_UNUSED, ddg_edge_ptr e)
{
ddg_node_ptr src = e->src;
ddg_node_ptr dest = e->dest;
gcc_assert (src->successors && dest->predecessors);
SET_BIT (src->successors, dest->cuid);
SET_BIT (dest->predecessors, src->cuid);
e->next_in = dest->in;
dest->in = e;
e->next_out = src->out;
src->out = e;
}
static void
set_recurrence_length (ddg_scc_ptr scc, ddg_ptr g)
{
int j;
int result = -1;
for (j = 0; j < scc->num_backarcs; j++)
{
ddg_edge_ptr backarc = scc->backarcs[j];
int length;
int distance = backarc->distance;
ddg_node_ptr src = backarc->dest;
ddg_node_ptr dest = backarc->src;
length = longest_simple_path (g, src->cuid, dest->cuid, scc->nodes);
if (length < 0 )
{
continue;
}
length += backarc->latency;
result = MAX (result, (length / distance));
}
scc->recurrence_length = result;
}
static ddg_scc_ptr
create_scc (ddg_ptr g, sbitmap nodes)
{
ddg_scc_ptr scc;
unsigned int u = 0;
sbitmap_iterator sbi;
scc = (ddg_scc_ptr) xmalloc (sizeof (struct ddg_scc));
scc->backarcs = NULL;
scc->num_backarcs = 0;
scc->nodes = sbitmap_alloc (g->num_nodes);
sbitmap_copy (scc->nodes, nodes);
EXECUTE_IF_SET_IN_SBITMAP (nodes, 0, u, sbi)
{
ddg_edge_ptr e;
ddg_node_ptr n = &g->nodes[u];
for (e = n->out; e; e = e->next_out)
if (TEST_BIT (nodes, e->dest->cuid))
{
e->aux.count = IN_SCC;
if (e->distance > 0)
add_backarc_to_scc (scc, e);
}
}
set_recurrence_length (scc, g);
return scc;
}
static void
free_scc (ddg_scc_ptr scc)
{
if (!scc)
return;
sbitmap_free (scc->nodes);
if (scc->num_backarcs > 0)
free (scc->backarcs);
free (scc);
}
static void
add_backarc_to_ddg (ddg_ptr g, ddg_edge_ptr e)
{
int size = (g->num_backarcs + 1) * sizeof (ddg_edge_ptr);
add_edge_to_ddg (g, e);
g->backarcs = (ddg_edge_ptr *) xrealloc (g->backarcs, size);
g->backarcs[g->num_backarcs++] = e;
}
static void
add_backarc_to_scc (ddg_scc_ptr scc, ddg_edge_ptr e)
{
int size = (scc->num_backarcs + 1) * sizeof (ddg_edge_ptr);
scc->backarcs = (ddg_edge_ptr *) xrealloc (scc->backarcs, size);
scc->backarcs[scc->num_backarcs++] = e;
}
static void
add_scc_to_ddg (ddg_all_sccs_ptr g, ddg_scc_ptr scc)
{
int size = (g->num_sccs + 1) * sizeof (ddg_scc_ptr);
g->sccs = (ddg_scc_ptr *) xrealloc (g->sccs, size);
g->sccs[g->num_sccs++] = scc;
}
ddg_node_ptr
get_node_of_insn (ddg_ptr g, rtx insn)
{
int i;
for (i = 0; i < g->num_nodes; i++)
if (insn == g->nodes[i].insn)
return &g->nodes[i];
return NULL;
}
void
find_successors (sbitmap succ, ddg_ptr g, sbitmap ops)
{
unsigned int i = 0;
sbitmap_iterator sbi;
EXECUTE_IF_SET_IN_SBITMAP (ops, 0, i, sbi)
{
const sbitmap node_succ = NODE_SUCCESSORS (&g->nodes[i]);
sbitmap_a_or_b (succ, succ, node_succ);
};
sbitmap_difference (succ, succ, ops);
}
void
find_predecessors (sbitmap preds, ddg_ptr g, sbitmap ops)
{
unsigned int i = 0;
sbitmap_iterator sbi;
EXECUTE_IF_SET_IN_SBITMAP (ops, 0, i, sbi)
{
const sbitmap node_preds = NODE_PREDECESSORS (&g->nodes[i]);
sbitmap_a_or_b (preds, preds, node_preds);
};
sbitmap_difference (preds, preds, ops);
}
static int
compare_sccs (const void *s1, const void *s2)
{
int rec_l1 = (*(ddg_scc_ptr *)s1)->recurrence_length;
int rec_l2 = (*(ddg_scc_ptr *)s2)->recurrence_length;
return ((rec_l2 > rec_l1) - (rec_l2 < rec_l1));
}
static void
order_sccs (ddg_all_sccs_ptr g)
{
qsort (g->sccs, g->num_sccs, sizeof (ddg_scc_ptr),
(int (*) (const void *, const void *)) compare_sccs);
}
ddg_all_sccs_ptr
create_ddg_all_sccs (ddg_ptr g)
{
int i;
int num_nodes = g->num_nodes;
sbitmap from = sbitmap_alloc (num_nodes);
sbitmap to = sbitmap_alloc (num_nodes);
sbitmap scc_nodes = sbitmap_alloc (num_nodes);
ddg_all_sccs_ptr sccs = (ddg_all_sccs_ptr)
xmalloc (sizeof (struct ddg_all_sccs));
sccs->ddg = g;
sccs->sccs = NULL;
sccs->num_sccs = 0;
for (i = 0; i < g->num_backarcs; i++)
{
ddg_scc_ptr scc;
ddg_edge_ptr backarc = g->backarcs[i];
ddg_node_ptr src = backarc->src;
ddg_node_ptr dest = backarc->dest;
if (backarc->aux.count == IN_SCC)
continue;
sbitmap_zero (from);
sbitmap_zero (to);
SET_BIT (from, dest->cuid);
SET_BIT (to, src->cuid);
if (find_nodes_on_paths (scc_nodes, g, from, to))
{
scc = create_scc (g, scc_nodes);
add_scc_to_ddg (sccs, scc);
}
}
order_sccs (sccs);
sbitmap_free (from);
sbitmap_free (to);
sbitmap_free (scc_nodes);
return sccs;
}
void
free_ddg_all_sccs (ddg_all_sccs_ptr all_sccs)
{
int i;
if (!all_sccs)
return;
for (i = 0; i < all_sccs->num_sccs; i++)
free_scc (all_sccs->sccs[i]);
free (all_sccs);
}
int
find_nodes_on_paths (sbitmap result, ddg_ptr g, sbitmap from, sbitmap to)
{
int answer;
int change;
unsigned int u = 0;
int num_nodes = g->num_nodes;
sbitmap_iterator sbi;
sbitmap workset = sbitmap_alloc (num_nodes);
sbitmap reachable_from = sbitmap_alloc (num_nodes);
sbitmap reach_to = sbitmap_alloc (num_nodes);
sbitmap tmp = sbitmap_alloc (num_nodes);
sbitmap_copy (reachable_from, from);
sbitmap_copy (tmp, from);
change = 1;
while (change)
{
change = 0;
sbitmap_copy (workset, tmp);
sbitmap_zero (tmp);
EXECUTE_IF_SET_IN_SBITMAP (workset, 0, u, sbi)
{
ddg_edge_ptr e;
ddg_node_ptr u_node = &g->nodes[u];
for (e = u_node->out; e != (ddg_edge_ptr) 0; e = e->next_out)
{
ddg_node_ptr v_node = e->dest;
int v = v_node->cuid;
if (!TEST_BIT (reachable_from, v))
{
SET_BIT (reachable_from, v);
SET_BIT (tmp, v);
change = 1;
}
}
}
}
sbitmap_copy (reach_to, to);
sbitmap_copy (tmp, to);
change = 1;
while (change)
{
change = 0;
sbitmap_copy (workset, tmp);
sbitmap_zero (tmp);
EXECUTE_IF_SET_IN_SBITMAP (workset, 0, u, sbi)
{
ddg_edge_ptr e;
ddg_node_ptr u_node = &g->nodes[u];
for (e = u_node->in; e != (ddg_edge_ptr) 0; e = e->next_in)
{
ddg_node_ptr v_node = e->src;
int v = v_node->cuid;
if (!TEST_BIT (reach_to, v))
{
SET_BIT (reach_to, v);
SET_BIT (tmp, v);
change = 1;
}
}
}
}
answer = sbitmap_a_and_b_cg (result, reachable_from, reach_to);
sbitmap_free (workset);
sbitmap_free (reachable_from);
sbitmap_free (reach_to);
sbitmap_free (tmp);
return answer;
}
static int
update_dist_to_successors (ddg_node_ptr u_node, sbitmap nodes, sbitmap tmp)
{
ddg_edge_ptr e;
int result = 0;
for (e = u_node->out; e; e = e->next_out)
{
ddg_node_ptr v_node = e->dest;
int v = v_node->cuid;
if (TEST_BIT (nodes, v)
&& (e->distance == 0)
&& (v_node->aux.count < u_node->aux.count + e->latency))
{
v_node->aux.count = u_node->aux.count + e->latency;
SET_BIT (tmp, v);
result = 1;
}
}
return result;
}
int
longest_simple_path (struct ddg * g, int src, int dest, sbitmap nodes)
{
int i;
unsigned int u = 0;
int change = 1;
int result;
int num_nodes = g->num_nodes;
sbitmap workset = sbitmap_alloc (num_nodes);
sbitmap tmp = sbitmap_alloc (num_nodes);
for (i = 0; i < g->num_nodes; i++)
g->nodes[i].aux.count = -1;
g->nodes[src].aux.count = 0;
sbitmap_zero (tmp);
SET_BIT (tmp, src);
while (change)
{
sbitmap_iterator sbi;
change = 0;
sbitmap_copy (workset, tmp);
sbitmap_zero (tmp);
EXECUTE_IF_SET_IN_SBITMAP (workset, 0, u, sbi)
{
ddg_node_ptr u_node = &g->nodes[u];
change |= update_dist_to_successors (u_node, nodes, tmp);
}
}
result = g->nodes[dest].aux.count;
sbitmap_free (workset);
sbitmap_free (tmp);
return result;
}
#endif