//------------------------------create_new_if_for_predicate------------------------
// Create a new if below new_entry for the predicate to be cloned (IGVN optimization)
ProjNode* PhaseIterGVN::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
Deoptimization::DeoptReason reason) {
assert(new_entry != 0, "only used for clone predicate");
assert(PhaseIdealLoop::is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!");
IfNode* iff = cont_proj->in(0)->as_If();
ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con);
Node *rgn = uncommon_proj->unique_ctrl_out();
assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct");
uint proj_index = 1; // region's edge corresponding to uncommon_proj
if (!rgn->is_Region()) { // create a region to guard the call
assert(rgn->is_Call(), "must be call uct");
CallNode* call = rgn->as_Call();
rgn = new (C) RegionNode(1);
register_new_node_with_optimizer(rgn);
rgn->add_req(uncommon_proj);
hash_delete(call);
call->set_req(0, rgn);
} else {
// Find region's edge corresponding to uncommon_proj
for (; proj_index < rgn->req(); proj_index++)
if (rgn->in(proj_index) == uncommon_proj) break;
assert(proj_index < rgn->req(), "sanity");
}
// Create new_iff in new location.
IfNode *new_iff = iff->clone()->as_If();
new_iff->set_req(0, new_entry);
register_new_node_with_optimizer(new_iff);
Node *if_cont = new (C) IfTrueNode(new_iff);
Node *if_uct = new (C) IfFalseNode(new_iff);
if (cont_proj->is_IfFalse()) {
// Swap
Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp;
}
register_new_node_with_optimizer(if_cont);
register_new_node_with_optimizer(if_uct);
// if_uct to rgn
hash_delete(rgn);
rgn->add_req(if_uct);
// If rgn has phis add corresponding new edges which has the same
// value as on original uncommon_proj pass.
assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last");
bool has_phi = false;
for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) {
Node* use = rgn->fast_out(i);
if (use->is_Phi() && use->outcnt() > 0) {
rehash_node_delayed(use);
use->add_req(use->in(proj_index));
has_phi = true;
}
}
assert(!has_phi || rgn->req() > 3, "no phis when region is created");
return if_cont->as_Proj();
}
//------------------------------create_new_if_for_predicate------------------------
// create a new if above the uct_if_pattern for the predicate to be promoted.
//
// before after
// ---------- ----------
// ctrl ctrl
// | |
// | |
// v v
// iff new_iff
// / \ / \
// / \ / \
// v v v v
// uncommon_proj cont_proj if_uct if_cont
// \ | | | |
// \ | | | |
// v v v | v
// rgn loop | iff
// | | / \
// | | / \
// v | v v
// uncommon_trap | uncommon_proj cont_proj
// \ \ | |
// \ \ | |
// v v v v
// rgn loop
// |
// |
// v
// uncommon_trap
//
//
// We will create a region to guard the uct call if there is no one there.
// The true projecttion (if_cont) of the new_iff is returned.
// This code is also used to clone predicates to clonned loops.
ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry,
Deoptimization::DeoptReason reason) {
assert(is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!");
IfNode* iff = cont_proj->in(0)->as_If();
ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con);
Node *rgn = uncommon_proj->unique_ctrl_out();
assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct");
uint proj_index = 1; // region's edge corresponding to uncommon_proj
if (!rgn->is_Region()) { // create a region to guard the call
assert(rgn->is_Call(), "must be call uct");
CallNode* call = rgn->as_Call();
IdealLoopTree* loop = get_loop(call);
rgn = new (C) RegionNode(1);
rgn->add_req(uncommon_proj);
register_control(rgn, loop, uncommon_proj);
_igvn.hash_delete(call);
call->set_req(0, rgn);
// When called from beautify_loops() idom is not constructed yet.
if (_idom != NULL) {
set_idom(call, rgn, dom_depth(rgn));
}
} else {
// Find region's edge corresponding to uncommon_proj
for (; proj_index < rgn->req(); proj_index++)
if (rgn->in(proj_index) == uncommon_proj) break;
assert(proj_index < rgn->req(), "sanity");
}
Node* entry = iff->in(0);
if (new_entry != NULL) {
// Clonning the predicate to new location.
entry = new_entry;
}
// Create new_iff
IdealLoopTree* lp = get_loop(entry);
IfNode *new_iff = iff->clone()->as_If();
new_iff->set_req(0, entry);
register_control(new_iff, lp, entry);
Node *if_cont = new (C) IfTrueNode(new_iff);
Node *if_uct = new (C) IfFalseNode(new_iff);
if (cont_proj->is_IfFalse()) {
// Swap
Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp;
}
register_control(if_cont, lp, new_iff);
register_control(if_uct, get_loop(rgn), new_iff);
// if_uct to rgn
_igvn.hash_delete(rgn);
rgn->add_req(if_uct);
// When called from beautify_loops() idom is not constructed yet.
if (_idom != NULL) {
Node* ridom = idom(rgn);
Node* nrdom = dom_lca(ridom, new_iff);
set_idom(rgn, nrdom, dom_depth(rgn));
}
// If rgn has phis add new edges which has the same
// value as on original uncommon_proj pass.
assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last");
bool has_phi = false;
for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) {
Node* use = rgn->fast_out(i);
if (use->is_Phi() && use->outcnt() > 0) {
assert(use->in(0) == rgn, "");
_igvn.rehash_node_delayed(use);
use->add_req(use->in(proj_index));
has_phi = true;
}
}
assert(!has_phi || rgn->req() > 3, "no phis when region is created");
if (new_entry == NULL) {
// Attach if_cont to iff
_igvn.hash_delete(iff);
iff->set_req(0, if_cont);
if (_idom != NULL) {
set_idom(iff, if_cont, dom_depth(iff));
}
}
return if_cont->as_Proj();
}
