ABS_NODE * CFS_MGR::construct_abs_loop(
IN IR_BB * entry,
IN ABS_NODE * parent,
IN BITSET * cur_region,
IN GRAPH & cur_graph,
IN OUT BITSET & visited)
{
IS_TRUE0(cur_region == NULL || cur_region->is_contain(IR_BB_id(entry)));
IR_CFG * cfg = m_ru->get_cfg();
LI<IR_BB> * li = cfg->map_bb2li(entry);
IS_TRUE0(li != NULL && LI_loop_head(li) == entry);
ABS_NODE * node = new_abs_node(ABS_LOOP);
set_map_bb2abs(entry, node);
ABS_NODE_parent(node) = parent;
ABS_NODE_loop_head(node) = entry;
IR_BB * body_start;
cfg->get_loop_two_kids(entry, NULL, &body_start);
IS_TRUE0(body_start != NULL);
CFS_INFO * ci = map_ir2cfsinfo(cfg->get_last_xr(entry));
IS_TRUE0(ci != NULL && CFS_INFO_head(ci) == entry);
IS_TRUE0(CFS_INFO_loop_body(ci)->is_contain(*LI_bb_set(li)));
BITSET loc_visited;
ABS_NODE_loop_body(node) = construct_abs_tree(body_start, node,
LI_bb_set(li),
cur_graph, loc_visited);
visited.bunion(loc_visited);
visited.bunion(IR_BB_id(entry));
return node;
}
ABS_NODE * CFS_MGR::construct_abs_tree(
IN IR_BB * entry,
IN ABS_NODE * parent,
IN BITSET * cur_region,
IN GRAPH & cur_graph,
IN OUT BITSET & visited)
{
IR_CFG * cfg = m_ru->get_cfg();
ABS_NODE * lst = NULL;
IR_BB * bb = entry;
GRAPH g;
g.clone(cur_graph);
VERTEX * next = NULL;
VERTEX * v;
if (cur_region != NULL) {
if (cur_region->get_elem_count() == 0) {
visited.clean();
return NULL;
}
INT c;
for (v = g.get_first_vertex(c); v != NULL; v = next) {
next = g.get_next_vertex(c);
if (cur_region->is_contain(VERTEX_id(v))) {
continue;
}
g.remove_vertex(v);
}
}
BITSET loc_visited;
while (bb != NULL &&
(cur_region == NULL ||
cur_region->is_contain(IR_BB_id(bb)))) {
ABS_NODE * node = NULL;
loc_visited.clean();
LI<IR_BB> * li = cfg->map_bb2li(bb);
if (li != NULL) {
node = construct_abs_loop(bb, parent, LI_bb_set(li),
g, loc_visited);
} else {
IR * last_xr = cfg->get_last_xr(bb);
if (last_xr != NULL && //'bb' is branching node of IF.
last_xr->is_cond_br()) {
IS_TRUE0(map_ir2cfsinfo(last_xr) != NULL);
/* There might not exist ipdom.
e.g:
if (x) //BB1
return 1;
return 2;
BB1 does not have a ipdom.
*/
UINT ipdom = ((DGRAPH*)cfg)->get_ipdom(IR_BB_id(bb));
IS_TRUE(ipdom > 0, ("bb does not have ipdom"));
node = construct_abs_if(bb, parent, g, loc_visited);
} else {
node = construct_abs_bb(bb, parent);
loc_visited.bunion(IR_BB_id(bb));
}
}
insertbefore_one(&lst, lst, node);
visited.bunion(loc_visited);
//Remove visited vertex.
next = NULL;
INT c;
for (v = g.get_first_vertex(c); v != NULL; v = next) {
next = g.get_next_vertex(c);
if (!loc_visited.is_contain(VERTEX_id(v))) {
continue;
}
g.remove_vertex(v);
}
IR_BB * cand = NULL;
for (v = g.get_first_vertex(c); v != NULL; v = g.get_next_vertex(c)) {
if (g.get_in_degree(v) == 0) {
IS_TRUE(cand == NULL, ("multiple immediate-post-dominators"));
cand = cfg->get_bb(VERTEX_id(v));
}
}
if (cand == NULL) {
//Cannot find leading BB, there might be exist cycle in graph.
bb = cfg->get_ipdom(bb);
} else {
bb = cand;
}
if (parent != NULL && bb == ABS_NODE_bb(parent)) {
//Here control-flow is cyclic.
break;
}
}
lst = reverse_list(lst);
return lst;
}