AbsNode * CfsMgr::constructAbsLoop(
IN IRBB * entry,
IN AbsNode * parent,
IN BitSet * cur_region,
IN Graph & cur_graph,
IN OUT BitSet & visited)
{
DUMMYUSE(cur_region);
ASSERT0(cur_region == NULL || cur_region->is_contain(BB_id(entry)));
IR_CFG * cfg = m_ru->getCFG();
LI<IRBB> * li = cfg->mapBB2LabelInfo(entry);
ASSERT0(li != NULL && LI_loop_head(li) == entry);
AbsNode * node = new_abs_node(ABS_LOOP);
set_map_bb2abs(entry, node);
ABS_NODE_parent(node) = parent;
ABS_NODE_loop_head(node) = entry;
IRBB * body_start;
cfg->getKidOfLoop(entry, NULL, &body_start);
ASSERT0(body_start != NULL);
CFS_INFO * ci = map_ir2cfsinfo(cfg->get_last_xr(entry));
CHECK_DUMMYUSE(ci);
ASSERT0(CFS_INFO_head(ci) == entry);
ASSERT0(CFS_INFO_loop_body(ci)->is_contain(*LI_bb_set(li)));
BitSet loc_visited;
ABS_NODE_loop_body(node) = constructAbsTree(body_start, node,
LI_bb_set(li), cur_graph, loc_visited);
visited.bunion(loc_visited);
visited.bunion(BB_id(entry));
return node;
}
AbsNode * CfsMgr::constructAbsTree(
IN IRBB * entry,
IN AbsNode * parent,
IN BitSet * cur_region,
IN Graph & cur_graph,
IN OUT BitSet & visited)
{
IR_CFG * cfg = m_ru->getCFG();
AbsNode * lst = NULL;
IRBB * 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.removeVertex(v);
}
}
BitSet loc_visited;
while (bb != NULL &&
(cur_region == NULL ||
cur_region->is_contain(BB_id(bb)))) {
AbsNode * node = NULL;
loc_visited.clean();
LI<IRBB> * li = cfg->mapBB2LabelInfo(bb);
if (li != NULL) {
node = constructAbsLoop(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->isConditionalBr()) {
ASSERT0(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(BB_id(bb));
DUMMYUSE(ipdom);
ASSERT(ipdom > 0, ("bb does not have ipdom"));
node = constructAbsIf(bb, parent, g, loc_visited);
} else {
node = constructAbsBB(bb, parent);
loc_visited.bunion(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.removeVertex(v);
}
IRBB * cand = NULL;
for (v = g.get_first_vertex(c); v != NULL; v = g.get_next_vertex(c)) {
if (g.get_in_degree(v) == 0) {
ASSERT(cand == NULL, ("multiple immediate-post-dominators"));
cand = cfg->getBB(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;
}