115 void PhaseIdealLoop::do_unswitching (IdealLoopTree *loop, Node_List &old_new) {
116
117 // Find first invariant test that doesn't exit the loop
118 LoopNode *head = loop->_head->as_Loop();
119
120 IfNode* unswitch_iff = find_unswitching_candidate((const IdealLoopTree *)loop);
121 assert(unswitch_iff != NULL, "should be at least one");
122
123 #ifndef PRODUCT
124 if (TraceLoopOpts) {
125 tty->print("Unswitch %d ", head->unswitch_count()+1);
126 loop->dump_head();
127 }
128 #endif
129
130 // Need to revert back to normal loop
131 if (head->is_CountedLoop() && !head->as_CountedLoop()->is_normal_loop()) {
132 head->as_CountedLoop()->set_normal_loop();
133 }
134
135 ProjNode* proj_true = create_slow_version_of_loop(loop, old_new);
136
137 #ifdef ASSERT
138 Node* uniqc = proj_true->unique_ctrl_out();
139 Node* entry = head->in(LoopNode::EntryControl);
140 Node* predicate = find_predicate(entry);
141 if (predicate != NULL && LoopLimitCheck && UseLoopPredicate) {
142 // We may have two predicates, find first.
143 entry = find_predicate(entry->in(0)->in(0));
144 if (entry != NULL) predicate = entry;
145 }
146 if (predicate != NULL) predicate = predicate->in(0);
147 assert(proj_true->is_IfTrue() &&
148 (predicate == NULL && uniqc == head ||
149 predicate != NULL && uniqc == predicate), "by construction");
150 #endif
151 // Increment unswitch count
152 LoopNode* head_clone = old_new[head->_idx]->as_Loop();
153 int nct = head->unswitch_count() + 1;
154 head->set_unswitch_count(nct);
155 head_clone->set_unswitch_count(nct);
205 Node *n_clone = old_new[n->_idx];
206 _igvn._worklist.push(n_clone);
207 }
208
209 #ifndef PRODUCT
210 if (TraceLoopUnswitching) {
211 tty->print_cr("Loop unswitching orig: %d @ %d new: %d @ %d",
212 head->_idx, unswitch_iff->_idx,
213 old_new[head->_idx]->_idx, unswitch_iff_clone->_idx);
214 }
215 #endif
216
217 C->set_major_progress();
218 }
219
220 //-------------------------create_slow_version_of_loop------------------------
221 // Create a slow version of the loop by cloning the loop
222 // and inserting an if to select fast-slow versions.
223 // Return control projection of the entry to the fast version.
224 ProjNode* PhaseIdealLoop::create_slow_version_of_loop(IdealLoopTree *loop,
225 Node_List &old_new) {
226 LoopNode* head = loop->_head->as_Loop();
227 bool counted_loop = head->is_CountedLoop();
228 Node* entry = head->in(LoopNode::EntryControl);
229 _igvn.rehash_node_delayed(entry);
230 IdealLoopTree* outer_loop = loop->_parent;
231
232 Node *cont = _igvn.intcon(1);
233 set_ctrl(cont, C->root());
234 Node* opq = new Opaque1Node(C, cont);
235 register_node(opq, outer_loop, entry, dom_depth(entry));
236 Node *bol = new Conv2BNode(opq);
237 register_node(bol, outer_loop, entry, dom_depth(entry));
238 IfNode* iff = new IfNode(entry, bol, PROB_MAX, COUNT_UNKNOWN);
239 register_node(iff, outer_loop, entry, dom_depth(entry));
240 ProjNode* iffast = new IfTrueNode(iff);
241 register_node(iffast, outer_loop, iff, dom_depth(iff));
242 ProjNode* ifslow = new IfFalseNode(iff);
243 register_node(ifslow, outer_loop, iff, dom_depth(iff));
244
245 // Clone the loop body. The clone becomes the fast loop. The
246 // original pre-header will (illegally) have 3 control users
247 // (old & new loops & new if).
248 clone_loop(loop, old_new, dom_depth(head), iff);
249 assert(old_new[head->_idx]->is_Loop(), "" );
250
251 // Fast (true) control
252 Node* iffast_pred = clone_loop_predicates(entry, iffast, !counted_loop);
253 _igvn.replace_input_of(head, LoopNode::EntryControl, iffast_pred);
254 set_idom(head, iffast_pred, dom_depth(head));
255
256 // Slow (false) control
257 Node* ifslow_pred = clone_loop_predicates(entry, ifslow, !counted_loop);
258 LoopNode* slow_head = old_new[head->_idx]->as_Loop();
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115 void PhaseIdealLoop::do_unswitching (IdealLoopTree *loop, Node_List &old_new) {
116
117 // Find first invariant test that doesn't exit the loop
118 LoopNode *head = loop->_head->as_Loop();
119
120 IfNode* unswitch_iff = find_unswitching_candidate((const IdealLoopTree *)loop);
121 assert(unswitch_iff != NULL, "should be at least one");
122
123 #ifndef PRODUCT
124 if (TraceLoopOpts) {
125 tty->print("Unswitch %d ", head->unswitch_count()+1);
126 loop->dump_head();
127 }
128 #endif
129
130 // Need to revert back to normal loop
131 if (head->is_CountedLoop() && !head->as_CountedLoop()->is_normal_loop()) {
132 head->as_CountedLoop()->set_normal_loop();
133 }
134
135 ProjNode* proj_true = create_slow_version_of_loop(loop, old_new, unswitch_iff->Opcode());
136
137 #ifdef ASSERT
138 Node* uniqc = proj_true->unique_ctrl_out();
139 Node* entry = head->in(LoopNode::EntryControl);
140 Node* predicate = find_predicate(entry);
141 if (predicate != NULL && LoopLimitCheck && UseLoopPredicate) {
142 // We may have two predicates, find first.
143 entry = find_predicate(entry->in(0)->in(0));
144 if (entry != NULL) predicate = entry;
145 }
146 if (predicate != NULL) predicate = predicate->in(0);
147 assert(proj_true->is_IfTrue() &&
148 (predicate == NULL && uniqc == head ||
149 predicate != NULL && uniqc == predicate), "by construction");
150 #endif
151 // Increment unswitch count
152 LoopNode* head_clone = old_new[head->_idx]->as_Loop();
153 int nct = head->unswitch_count() + 1;
154 head->set_unswitch_count(nct);
155 head_clone->set_unswitch_count(nct);
205 Node *n_clone = old_new[n->_idx];
206 _igvn._worklist.push(n_clone);
207 }
208
209 #ifndef PRODUCT
210 if (TraceLoopUnswitching) {
211 tty->print_cr("Loop unswitching orig: %d @ %d new: %d @ %d",
212 head->_idx, unswitch_iff->_idx,
213 old_new[head->_idx]->_idx, unswitch_iff_clone->_idx);
214 }
215 #endif
216
217 C->set_major_progress();
218 }
219
220 //-------------------------create_slow_version_of_loop------------------------
221 // Create a slow version of the loop by cloning the loop
222 // and inserting an if to select fast-slow versions.
223 // Return control projection of the entry to the fast version.
224 ProjNode* PhaseIdealLoop::create_slow_version_of_loop(IdealLoopTree *loop,
225 Node_List &old_new,
226 int opcode) {
227 LoopNode* head = loop->_head->as_Loop();
228 bool counted_loop = head->is_CountedLoop();
229 Node* entry = head->in(LoopNode::EntryControl);
230 _igvn.rehash_node_delayed(entry);
231 IdealLoopTree* outer_loop = loop->_parent;
232
233 Node *cont = _igvn.intcon(1);
234 set_ctrl(cont, C->root());
235 Node* opq = new Opaque1Node(C, cont);
236 register_node(opq, outer_loop, entry, dom_depth(entry));
237 Node *bol = new Conv2BNode(opq);
238 register_node(bol, outer_loop, entry, dom_depth(entry));
239 IfNode* iff = opcode == Op_RangeCheck ? new RangeCheckNode(entry, bol, PROB_MAX, COUNT_UNKNOWN) :
240 new IfNode(entry, bol, PROB_MAX, COUNT_UNKNOWN);
241 register_node(iff, outer_loop, entry, dom_depth(entry));
242 ProjNode* iffast = new IfTrueNode(iff);
243 register_node(iffast, outer_loop, iff, dom_depth(iff));
244 ProjNode* ifslow = new IfFalseNode(iff);
245 register_node(ifslow, outer_loop, iff, dom_depth(iff));
246
247 // Clone the loop body. The clone becomes the fast loop. The
248 // original pre-header will (illegally) have 3 control users
249 // (old & new loops & new if).
250 clone_loop(loop, old_new, dom_depth(head), iff);
251 assert(old_new[head->_idx]->is_Loop(), "" );
252
253 // Fast (true) control
254 Node* iffast_pred = clone_loop_predicates(entry, iffast, !counted_loop);
255 _igvn.replace_input_of(head, LoopNode::EntryControl, iffast_pred);
256 set_idom(head, iffast_pred, dom_depth(head));
257
258 // Slow (false) control
259 Node* ifslow_pred = clone_loop_predicates(entry, ifslow, !counted_loop);
260 LoopNode* slow_head = old_new[head->_idx]->as_Loop();
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