1 /*
2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
28 #include "gc/g1/heapRegion.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/cardTableModRefBS.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "gc/shenandoah/brooksPointer.hpp"
33 #include "gc/shenandoah/shenandoahConnectionMatrix.hpp"
34 #include "gc/shenandoah/shenandoahHeap.hpp"
35 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "opto/addnode.hpp"
38 #include "opto/castnode.hpp"
39 #include "opto/convertnode.hpp"
40 #include "opto/graphKit.hpp"
41 #include "opto/idealKit.hpp"
42 #include "opto/intrinsicnode.hpp"
43 #include "opto/locknode.hpp"
44 #include "opto/machnode.hpp"
45 #include "opto/opaquenode.hpp"
46 #include "opto/parse.hpp"
47 #include "opto/rootnode.hpp"
48 #include "opto/runtime.hpp"
49 #include "opto/shenandoahSupport.hpp"
50 #include "runtime/deoptimization.hpp"
51 #include "runtime/sharedRuntime.hpp"
52
53 //----------------------------GraphKit-----------------------------------------
54 // Main utility constructor.
55 GraphKit::GraphKit(JVMState* jvms)
56 : Phase(Phase::Parser),
57 _env(C->env()),
58 _gvn(*C->initial_gvn())
59 {
60 _exceptions = jvms->map()->next_exception();
61 if (_exceptions != NULL) jvms->map()->set_next_exception(NULL);
62 set_jvms(jvms);
63 }
64
65 // Private constructor for parser.
66 GraphKit::GraphKit()
67 : Phase(Phase::Parser),
68 _env(C->env()),
69 _gvn(*C->initial_gvn())
70 {
71 _exceptions = NULL;
72 set_map(NULL);
73 debug_only(_sp = -99);
74 debug_only(set_bci(-99));
75 }
76
77
78
79 //---------------------------clean_stack---------------------------------------
80 // Clear away rubbish from the stack area of the JVM state.
81 // This destroys any arguments that may be waiting on the stack.
82 void GraphKit::clean_stack(int from_sp) {
83 SafePointNode* map = this->map();
84 JVMState* jvms = this->jvms();
85 int stk_size = jvms->stk_size();
86 int stkoff = jvms->stkoff();
87 Node* top = this->top();
88 for (int i = from_sp; i < stk_size; i++) {
89 if (map->in(stkoff + i) != top) {
90 map->set_req(stkoff + i, top);
91 }
92 }
93 }
94
95
96 //--------------------------------sync_jvms-----------------------------------
97 // Make sure our current jvms agrees with our parse state.
98 JVMState* GraphKit::sync_jvms() const {
99 JVMState* jvms = this->jvms();
100 jvms->set_bci(bci()); // Record the new bci in the JVMState
101 jvms->set_sp(sp()); // Record the new sp in the JVMState
102 assert(jvms_in_sync(), "jvms is now in sync");
103 return jvms;
104 }
105
106 //--------------------------------sync_jvms_for_reexecute---------------------
107 // Make sure our current jvms agrees with our parse state. This version
108 // uses the reexecute_sp for reexecuting bytecodes.
109 JVMState* GraphKit::sync_jvms_for_reexecute() {
110 JVMState* jvms = this->jvms();
111 jvms->set_bci(bci()); // Record the new bci in the JVMState
112 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState
113 return jvms;
114 }
115
116 #ifdef ASSERT
117 bool GraphKit::jvms_in_sync() const {
118 Parse* parse = is_Parse();
119 if (parse == NULL) {
120 if (bci() != jvms()->bci()) return false;
121 if (sp() != (int)jvms()->sp()) return false;
122 return true;
123 }
124 if (jvms()->method() != parse->method()) return false;
125 if (jvms()->bci() != parse->bci()) return false;
126 int jvms_sp = jvms()->sp();
127 if (jvms_sp != parse->sp()) return false;
128 int jvms_depth = jvms()->depth();
129 if (jvms_depth != parse->depth()) return false;
130 return true;
131 }
132
133 // Local helper checks for special internal merge points
134 // used to accumulate and merge exception states.
135 // They are marked by the region's in(0) edge being the map itself.
136 // Such merge points must never "escape" into the parser at large,
137 // until they have been handed to gvn.transform.
138 static bool is_hidden_merge(Node* reg) {
139 if (reg == NULL) return false;
140 if (reg->is_Phi()) {
141 reg = reg->in(0);
142 if (reg == NULL) return false;
143 }
144 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
145 }
146
147 void GraphKit::verify_map() const {
148 if (map() == NULL) return; // null map is OK
149 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
150 assert(!map()->has_exceptions(), "call add_exception_states_from 1st");
151 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
152 }
153
154 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
155 assert(ex_map->next_exception() == NULL, "not already part of a chain");
156 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
157 }
158 #endif
159
160 //---------------------------stop_and_kill_map---------------------------------
161 // Set _map to NULL, signalling a stop to further bytecode execution.
162 // First smash the current map's control to a constant, to mark it dead.
163 void GraphKit::stop_and_kill_map() {
164 SafePointNode* dead_map = stop();
165 if (dead_map != NULL) {
166 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
167 assert(dead_map->is_killed(), "must be so marked");
168 }
169 }
170
171
172 //--------------------------------stopped--------------------------------------
173 // Tell if _map is NULL, or control is top.
174 bool GraphKit::stopped() {
175 if (map() == NULL) return true;
176 else if (control() == top()) return true;
177 else return false;
178 }
179
180
181 //-----------------------------has_ex_handler----------------------------------
182 // Tell if this method or any caller method has exception handlers.
183 bool GraphKit::has_ex_handler() {
184 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
185 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
186 return true;
187 }
188 }
189 return false;
190 }
191
192 //------------------------------save_ex_oop------------------------------------
193 // Save an exception without blowing stack contents or other JVM state.
194 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
195 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
196 ex_map->add_req(ex_oop);
197 debug_only(verify_exception_state(ex_map));
198 }
199
200 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
201 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
202 Node* ex_oop = ex_map->in(ex_map->req()-1);
203 if (clear_it) ex_map->del_req(ex_map->req()-1);
204 return ex_oop;
205 }
206
207 //-----------------------------saved_ex_oop------------------------------------
208 // Recover a saved exception from its map.
209 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
210 return common_saved_ex_oop(ex_map, false);
211 }
212
213 //--------------------------clear_saved_ex_oop---------------------------------
214 // Erase a previously saved exception from its map.
215 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
216 return common_saved_ex_oop(ex_map, true);
217 }
218
219 #ifdef ASSERT
220 //---------------------------has_saved_ex_oop----------------------------------
221 // Erase a previously saved exception from its map.
222 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
223 return ex_map->req() == ex_map->jvms()->endoff()+1;
224 }
225 #endif
226
227 //-------------------------make_exception_state--------------------------------
228 // Turn the current JVM state into an exception state, appending the ex_oop.
229 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
230 sync_jvms();
231 SafePointNode* ex_map = stop(); // do not manipulate this map any more
232 set_saved_ex_oop(ex_map, ex_oop);
233 return ex_map;
234 }
235
236
237 //--------------------------add_exception_state--------------------------------
238 // Add an exception to my list of exceptions.
239 void GraphKit::add_exception_state(SafePointNode* ex_map) {
240 if (ex_map == NULL || ex_map->control() == top()) {
241 return;
242 }
243 #ifdef ASSERT
244 verify_exception_state(ex_map);
245 if (has_exceptions()) {
246 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
247 }
248 #endif
249
250 // If there is already an exception of exactly this type, merge with it.
251 // In particular, null-checks and other low-level exceptions common up here.
252 Node* ex_oop = saved_ex_oop(ex_map);
253 const Type* ex_type = _gvn.type(ex_oop);
254 if (ex_oop == top()) {
255 // No action needed.
256 return;
257 }
258 assert(ex_type->isa_instptr(), "exception must be an instance");
259 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
260 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
261 // We check sp also because call bytecodes can generate exceptions
262 // both before and after arguments are popped!
263 if (ex_type2 == ex_type
264 && e2->_jvms->sp() == ex_map->_jvms->sp()) {
265 combine_exception_states(ex_map, e2);
266 return;
267 }
268 }
269
270 // No pre-existing exception of the same type. Chain it on the list.
271 push_exception_state(ex_map);
272 }
273
274 //-----------------------add_exception_states_from-----------------------------
275 void GraphKit::add_exception_states_from(JVMState* jvms) {
276 SafePointNode* ex_map = jvms->map()->next_exception();
277 if (ex_map != NULL) {
278 jvms->map()->set_next_exception(NULL);
279 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
280 next_map = ex_map->next_exception();
281 ex_map->set_next_exception(NULL);
282 add_exception_state(ex_map);
283 }
284 }
285 }
286
287 //-----------------------transfer_exceptions_into_jvms-------------------------
288 JVMState* GraphKit::transfer_exceptions_into_jvms() {
289 if (map() == NULL) {
290 // We need a JVMS to carry the exceptions, but the map has gone away.
291 // Create a scratch JVMS, cloned from any of the exception states...
292 if (has_exceptions()) {
293 _map = _exceptions;
294 _map = clone_map();
295 _map->set_next_exception(NULL);
296 clear_saved_ex_oop(_map);
297 debug_only(verify_map());
298 } else {
299 // ...or created from scratch
300 JVMState* jvms = new (C) JVMState(_method, NULL);
301 jvms->set_bci(_bci);
302 jvms->set_sp(_sp);
303 jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
304 set_jvms(jvms);
305 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top());
306 set_all_memory(top());
307 while (map()->req() < jvms->endoff()) map()->add_req(top());
308 }
309 // (This is a kludge, in case you didn't notice.)
310 set_control(top());
311 }
312 JVMState* jvms = sync_jvms();
313 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
314 jvms->map()->set_next_exception(_exceptions);
315 _exceptions = NULL; // done with this set of exceptions
316 return jvms;
317 }
318
319 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
320 assert(is_hidden_merge(dstphi), "must be a special merge node");
321 assert(is_hidden_merge(srcphi), "must be a special merge node");
322 uint limit = srcphi->req();
323 for (uint i = PhiNode::Input; i < limit; i++) {
324 dstphi->add_req(srcphi->in(i));
325 }
326 }
327 static inline void add_one_req(Node* dstphi, Node* src) {
328 assert(is_hidden_merge(dstphi), "must be a special merge node");
329 assert(!is_hidden_merge(src), "must not be a special merge node");
330 dstphi->add_req(src);
331 }
332
333 //-----------------------combine_exception_states------------------------------
334 // This helper function combines exception states by building phis on a
335 // specially marked state-merging region. These regions and phis are
336 // untransformed, and can build up gradually. The region is marked by
337 // having a control input of its exception map, rather than NULL. Such
338 // regions do not appear except in this function, and in use_exception_state.
339 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
340 if (failing()) return; // dying anyway...
341 JVMState* ex_jvms = ex_map->_jvms;
342 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
343 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
344 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
345 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
346 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
347 assert(ex_map->req() == phi_map->req(), "matching maps");
348 uint tos = ex_jvms->stkoff() + ex_jvms->sp();
349 Node* hidden_merge_mark = root();
350 Node* region = phi_map->control();
351 MergeMemNode* phi_mem = phi_map->merged_memory();
352 MergeMemNode* ex_mem = ex_map->merged_memory();
353 if (region->in(0) != hidden_merge_mark) {
354 // The control input is not (yet) a specially-marked region in phi_map.
355 // Make it so, and build some phis.
356 region = new RegionNode(2);
357 _gvn.set_type(region, Type::CONTROL);
358 region->set_req(0, hidden_merge_mark); // marks an internal ex-state
359 region->init_req(1, phi_map->control());
360 phi_map->set_control(region);
361 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
362 record_for_igvn(io_phi);
363 _gvn.set_type(io_phi, Type::ABIO);
364 phi_map->set_i_o(io_phi);
365 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
366 Node* m = mms.memory();
367 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
368 record_for_igvn(m_phi);
369 _gvn.set_type(m_phi, Type::MEMORY);
370 mms.set_memory(m_phi);
371 }
372 }
373
374 // Either or both of phi_map and ex_map might already be converted into phis.
375 Node* ex_control = ex_map->control();
376 // if there is special marking on ex_map also, we add multiple edges from src
377 bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
378 // how wide was the destination phi_map, originally?
379 uint orig_width = region->req();
380
381 if (add_multiple) {
382 add_n_reqs(region, ex_control);
383 add_n_reqs(phi_map->i_o(), ex_map->i_o());
384 } else {
385 // ex_map has no merges, so we just add single edges everywhere
386 add_one_req(region, ex_control);
387 add_one_req(phi_map->i_o(), ex_map->i_o());
388 }
389 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
390 if (mms.is_empty()) {
391 // get a copy of the base memory, and patch some inputs into it
392 const TypePtr* adr_type = mms.adr_type(C);
393 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
394 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
395 mms.set_memory(phi);
396 // Prepare to append interesting stuff onto the newly sliced phi:
397 while (phi->req() > orig_width) phi->del_req(phi->req()-1);
398 }
399 // Append stuff from ex_map:
400 if (add_multiple) {
401 add_n_reqs(mms.memory(), mms.memory2());
402 } else {
403 add_one_req(mms.memory(), mms.memory2());
404 }
405 }
406 uint limit = ex_map->req();
407 for (uint i = TypeFunc::Parms; i < limit; i++) {
408 // Skip everything in the JVMS after tos. (The ex_oop follows.)
409 if (i == tos) i = ex_jvms->monoff();
410 Node* src = ex_map->in(i);
411 Node* dst = phi_map->in(i);
412 if (src != dst) {
413 PhiNode* phi;
414 if (dst->in(0) != region) {
415 dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
416 record_for_igvn(phi);
417 _gvn.set_type(phi, phi->type());
418 phi_map->set_req(i, dst);
419 // Prepare to append interesting stuff onto the new phi:
420 while (dst->req() > orig_width) dst->del_req(dst->req()-1);
421 } else {
422 assert(dst->is_Phi(), "nobody else uses a hidden region");
423 phi = dst->as_Phi();
424 }
425 if (add_multiple && src->in(0) == ex_control) {
426 // Both are phis.
427 add_n_reqs(dst, src);
428 } else {
429 while (dst->req() < region->req()) add_one_req(dst, src);
430 }
431 const Type* srctype = _gvn.type(src);
432 if (phi->type() != srctype) {
433 const Type* dsttype = phi->type()->meet_speculative(srctype);
434 if (phi->type() != dsttype) {
435 phi->set_type(dsttype);
436 _gvn.set_type(phi, dsttype);
437 }
438 }
439 }
440 }
441 phi_map->merge_replaced_nodes_with(ex_map);
442 }
443
444 //--------------------------use_exception_state--------------------------------
445 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
446 if (failing()) { stop(); return top(); }
447 Node* region = phi_map->control();
448 Node* hidden_merge_mark = root();
449 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
450 Node* ex_oop = clear_saved_ex_oop(phi_map);
451 if (region->in(0) == hidden_merge_mark) {
452 // Special marking for internal ex-states. Process the phis now.
453 region->set_req(0, region); // now it's an ordinary region
454 set_jvms(phi_map->jvms()); // ...so now we can use it as a map
455 // Note: Setting the jvms also sets the bci and sp.
456 set_control(_gvn.transform(region));
457 uint tos = jvms()->stkoff() + sp();
458 for (uint i = 1; i < tos; i++) {
459 Node* x = phi_map->in(i);
460 if (x->in(0) == region) {
461 assert(x->is_Phi(), "expected a special phi");
462 phi_map->set_req(i, _gvn.transform(x));
463 }
464 }
465 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
466 Node* x = mms.memory();
467 if (x->in(0) == region) {
468 assert(x->is_Phi(), "nobody else uses a hidden region");
469 mms.set_memory(_gvn.transform(x));
470 }
471 }
472 if (ex_oop->in(0) == region) {
473 assert(ex_oop->is_Phi(), "expected a special phi");
474 ex_oop = _gvn.transform(ex_oop);
475 }
476 } else {
477 set_jvms(phi_map->jvms());
478 }
479
480 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
481 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
482 return ex_oop;
483 }
484
485 //---------------------------------java_bc-------------------------------------
486 Bytecodes::Code GraphKit::java_bc() const {
487 ciMethod* method = this->method();
488 int bci = this->bci();
489 if (method != NULL && bci != InvocationEntryBci)
490 return method->java_code_at_bci(bci);
491 else
492 return Bytecodes::_illegal;
493 }
494
495 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
496 bool must_throw) {
497 // if the exception capability is set, then we will generate code
498 // to check the JavaThread.should_post_on_exceptions flag to see
499 // if we actually need to report exception events (for this
500 // thread). If we don't need to report exception events, we will
501 // take the normal fast path provided by add_exception_events. If
502 // exception event reporting is enabled for this thread, we will
503 // take the uncommon_trap in the BuildCutout below.
504
505 // first must access the should_post_on_exceptions_flag in this thread's JavaThread
506 Node* jthread = _gvn.transform(new ThreadLocalNode());
507 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
508 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
509
510 // Test the should_post_on_exceptions_flag vs. 0
511 Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
512 Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
513
514 // Branch to slow_path if should_post_on_exceptions_flag was true
515 { BuildCutout unless(this, tst, PROB_MAX);
516 // Do not try anything fancy if we're notifying the VM on every throw.
517 // Cf. case Bytecodes::_athrow in parse2.cpp.
518 uncommon_trap(reason, Deoptimization::Action_none,
519 (ciKlass*)NULL, (char*)NULL, must_throw);
520 }
521
522 }
523
524 //------------------------------builtin_throw----------------------------------
525 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
526 bool must_throw = true;
527
528 if (env()->jvmti_can_post_on_exceptions()) {
529 // check if we must post exception events, take uncommon trap if so
530 uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
531 // here if should_post_on_exceptions is false
532 // continue on with the normal codegen
533 }
534
535 // If this particular condition has not yet happened at this
536 // bytecode, then use the uncommon trap mechanism, and allow for
537 // a future recompilation if several traps occur here.
538 // If the throw is hot, try to use a more complicated inline mechanism
539 // which keeps execution inside the compiled code.
540 bool treat_throw_as_hot = false;
541 ciMethodData* md = method()->method_data();
542
543 if (ProfileTraps) {
544 if (too_many_traps(reason)) {
545 treat_throw_as_hot = true;
546 }
547 // (If there is no MDO at all, assume it is early in
548 // execution, and that any deopts are part of the
549 // startup transient, and don't need to be remembered.)
550
551 // Also, if there is a local exception handler, treat all throws
552 // as hot if there has been at least one in this method.
553 if (C->trap_count(reason) != 0
554 && method()->method_data()->trap_count(reason) != 0
555 && has_ex_handler()) {
556 treat_throw_as_hot = true;
557 }
558 }
559
560 // If this throw happens frequently, an uncommon trap might cause
561 // a performance pothole. If there is a local exception handler,
562 // and if this particular bytecode appears to be deoptimizing often,
563 // let us handle the throw inline, with a preconstructed instance.
564 // Note: If the deopt count has blown up, the uncommon trap
565 // runtime is going to flush this nmethod, not matter what.
566 if (treat_throw_as_hot
567 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
568 // If the throw is local, we use a pre-existing instance and
569 // punt on the backtrace. This would lead to a missing backtrace
570 // (a repeat of 4292742) if the backtrace object is ever asked
571 // for its backtrace.
572 // Fixing this remaining case of 4292742 requires some flavor of
573 // escape analysis. Leave that for the future.
574 ciInstance* ex_obj = NULL;
575 switch (reason) {
576 case Deoptimization::Reason_null_check:
577 ex_obj = env()->NullPointerException_instance();
578 break;
579 case Deoptimization::Reason_div0_check:
580 ex_obj = env()->ArithmeticException_instance();
581 break;
582 case Deoptimization::Reason_range_check:
583 ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
584 break;
585 case Deoptimization::Reason_class_check:
586 if (java_bc() == Bytecodes::_aastore) {
587 ex_obj = env()->ArrayStoreException_instance();
588 } else {
589 ex_obj = env()->ClassCastException_instance();
590 }
591 break;
592 }
593 if (failing()) { stop(); return; } // exception allocation might fail
594 if (ex_obj != NULL) {
595 // Cheat with a preallocated exception object.
596 if (C->log() != NULL)
597 C->log()->elem("hot_throw preallocated='1' reason='%s'",
598 Deoptimization::trap_reason_name(reason));
599 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj);
600 Node* ex_node = _gvn.transform(ConNode::make(ex_con));
601
602 // Clear the detail message of the preallocated exception object.
603 // Weblogic sometimes mutates the detail message of exceptions
604 // using reflection.
605 int offset = java_lang_Throwable::get_detailMessage_offset();
606 const TypePtr* adr_typ = ex_con->add_offset(offset);
607
608 Node *adr = basic_plus_adr(ex_node, ex_node, offset);
609 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
610 // Conservatively release stores of object references.
611 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
612
613 add_exception_state(make_exception_state(ex_node));
614 return;
615 }
616 }
617
618 // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
619 // It won't be much cheaper than bailing to the interp., since we'll
620 // have to pass up all the debug-info, and the runtime will have to
621 // create the stack trace.
622
623 // Usual case: Bail to interpreter.
624 // Reserve the right to recompile if we haven't seen anything yet.
625
626 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
627 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
628 if (treat_throw_as_hot
629 && (method()->method_data()->trap_recompiled_at(bci(), m)
630 || C->too_many_traps(reason))) {
631 // We cannot afford to take more traps here. Suffer in the interpreter.
632 if (C->log() != NULL)
633 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
634 Deoptimization::trap_reason_name(reason),
635 C->trap_count(reason));
636 action = Deoptimization::Action_none;
637 }
638
639 // "must_throw" prunes the JVM state to include only the stack, if there
640 // are no local exception handlers. This should cut down on register
641 // allocation time and code size, by drastically reducing the number
642 // of in-edges on the call to the uncommon trap.
643
644 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
645 }
646
647
648 //----------------------------PreserveJVMState---------------------------------
649 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
650 debug_only(kit->verify_map());
651 _kit = kit;
652 _map = kit->map(); // preserve the map
653 _sp = kit->sp();
654 kit->set_map(clone_map ? kit->clone_map() : NULL);
655 #ifdef ASSERT
656 _bci = kit->bci();
657 Parse* parser = kit->is_Parse();
658 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
659 _block = block;
660 #endif
661 }
662 PreserveJVMState::~PreserveJVMState() {
663 GraphKit* kit = _kit;
664 #ifdef ASSERT
665 assert(kit->bci() == _bci, "bci must not shift");
666 Parse* parser = kit->is_Parse();
667 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
668 assert(block == _block, "block must not shift");
669 #endif
670 kit->set_map(_map);
671 kit->set_sp(_sp);
672 }
673
674
675 //-----------------------------BuildCutout-------------------------------------
676 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
677 : PreserveJVMState(kit)
678 {
679 assert(p->is_Con() || p->is_Bool(), "test must be a bool");
680 SafePointNode* outer_map = _map; // preserved map is caller's
681 SafePointNode* inner_map = kit->map();
682 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
683 outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
684 inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
685 }
686 BuildCutout::~BuildCutout() {
687 GraphKit* kit = _kit;
688 assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
689 }
690
691 //---------------------------PreserveReexecuteState----------------------------
692 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
693 assert(!kit->stopped(), "must call stopped() before");
694 _kit = kit;
695 _sp = kit->sp();
696 _reexecute = kit->jvms()->_reexecute;
697 }
698 PreserveReexecuteState::~PreserveReexecuteState() {
699 if (_kit->stopped()) return;
700 _kit->jvms()->_reexecute = _reexecute;
701 _kit->set_sp(_sp);
702 }
703
704 //------------------------------clone_map--------------------------------------
705 // Implementation of PreserveJVMState
706 //
707 // Only clone_map(...) here. If this function is only used in the
708 // PreserveJVMState class we may want to get rid of this extra
709 // function eventually and do it all there.
710
711 SafePointNode* GraphKit::clone_map() {
712 if (map() == NULL) return NULL;
713
714 // Clone the memory edge first
715 Node* mem = MergeMemNode::make(map()->memory());
716 gvn().set_type_bottom(mem);
717
718 SafePointNode *clonemap = (SafePointNode*)map()->clone();
719 JVMState* jvms = this->jvms();
720 JVMState* clonejvms = jvms->clone_shallow(C);
721 clonemap->set_memory(mem);
722 clonemap->set_jvms(clonejvms);
723 clonejvms->set_map(clonemap);
724 record_for_igvn(clonemap);
725 gvn().set_type_bottom(clonemap);
726 return clonemap;
727 }
728
729
730 //-----------------------------set_map_clone-----------------------------------
731 void GraphKit::set_map_clone(SafePointNode* m) {
732 _map = m;
733 _map = clone_map();
734 _map->set_next_exception(NULL);
735 debug_only(verify_map());
736 }
737
738
739 //----------------------------kill_dead_locals---------------------------------
740 // Detect any locals which are known to be dead, and force them to top.
741 void GraphKit::kill_dead_locals() {
742 // Consult the liveness information for the locals. If any
743 // of them are unused, then they can be replaced by top(). This
744 // should help register allocation time and cut down on the size
745 // of the deoptimization information.
746
747 // This call is made from many of the bytecode handling
748 // subroutines called from the Big Switch in do_one_bytecode.
749 // Every bytecode which might include a slow path is responsible
750 // for killing its dead locals. The more consistent we
751 // are about killing deads, the fewer useless phis will be
752 // constructed for them at various merge points.
753
754 // bci can be -1 (InvocationEntryBci). We return the entry
755 // liveness for the method.
756
757 if (method() == NULL || method()->code_size() == 0) {
758 // We are building a graph for a call to a native method.
759 // All locals are live.
760 return;
761 }
762
763 ResourceMark rm;
764
765 // Consult the liveness information for the locals. If any
766 // of them are unused, then they can be replaced by top(). This
767 // should help register allocation time and cut down on the size
768 // of the deoptimization information.
769 MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
770
771 int len = (int)live_locals.size();
772 assert(len <= jvms()->loc_size(), "too many live locals");
773 for (int local = 0; local < len; local++) {
774 if (!live_locals.at(local)) {
775 set_local(local, top());
776 }
777 }
778 }
779
780 #ifdef ASSERT
781 //-------------------------dead_locals_are_killed------------------------------
782 // Return true if all dead locals are set to top in the map.
783 // Used to assert "clean" debug info at various points.
784 bool GraphKit::dead_locals_are_killed() {
785 if (method() == NULL || method()->code_size() == 0) {
786 // No locals need to be dead, so all is as it should be.
787 return true;
788 }
789
790 // Make sure somebody called kill_dead_locals upstream.
791 ResourceMark rm;
792 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
793 if (jvms->loc_size() == 0) continue; // no locals to consult
794 SafePointNode* map = jvms->map();
795 ciMethod* method = jvms->method();
796 int bci = jvms->bci();
797 if (jvms == this->jvms()) {
798 bci = this->bci(); // it might not yet be synched
799 }
800 MethodLivenessResult live_locals = method->liveness_at_bci(bci);
801 int len = (int)live_locals.size();
802 if (!live_locals.is_valid() || len == 0)
803 // This method is trivial, or is poisoned by a breakpoint.
804 return true;
805 assert(len == jvms->loc_size(), "live map consistent with locals map");
806 for (int local = 0; local < len; local++) {
807 if (!live_locals.at(local) && map->local(jvms, local) != top()) {
808 if (PrintMiscellaneous && (Verbose || WizardMode)) {
809 tty->print_cr("Zombie local %d: ", local);
810 jvms->dump();
811 }
812 return false;
813 }
814 }
815 }
816 return true;
817 }
818
819 #endif //ASSERT
820
821 // Helper function for enforcing certain bytecodes to reexecute if
822 // deoptimization happens
823 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
824 ciMethod* cur_method = jvms->method();
825 int cur_bci = jvms->bci();
826 if (cur_method != NULL && cur_bci != InvocationEntryBci) {
827 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
828 return Interpreter::bytecode_should_reexecute(code) ||
829 is_anewarray && code == Bytecodes::_multianewarray;
830 // Reexecute _multianewarray bytecode which was replaced with
831 // sequence of [a]newarray. See Parse::do_multianewarray().
832 //
833 // Note: interpreter should not have it set since this optimization
834 // is limited by dimensions and guarded by flag so in some cases
835 // multianewarray() runtime calls will be generated and
836 // the bytecode should not be reexecutes (stack will not be reset).
837 } else
838 return false;
839 }
840
841 // Helper function for adding JVMState and debug information to node
842 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
843 // Add the safepoint edges to the call (or other safepoint).
844
845 // Make sure dead locals are set to top. This
846 // should help register allocation time and cut down on the size
847 // of the deoptimization information.
848 assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
849
850 // Walk the inline list to fill in the correct set of JVMState's
851 // Also fill in the associated edges for each JVMState.
852
853 // If the bytecode needs to be reexecuted we need to put
854 // the arguments back on the stack.
855 const bool should_reexecute = jvms()->should_reexecute();
856 JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
857
858 // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
859 // undefined if the bci is different. This is normal for Parse but it
860 // should not happen for LibraryCallKit because only one bci is processed.
861 assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
862 "in LibraryCallKit the reexecute bit should not change");
863
864 // If we are guaranteed to throw, we can prune everything but the
865 // input to the current bytecode.
866 bool can_prune_locals = false;
867 uint stack_slots_not_pruned = 0;
868 int inputs = 0, depth = 0;
869 if (must_throw) {
870 assert(method() == youngest_jvms->method(), "sanity");
871 if (compute_stack_effects(inputs, depth)) {
872 can_prune_locals = true;
873 stack_slots_not_pruned = inputs;
874 }
875 }
876
877 if (env()->should_retain_local_variables()) {
878 // At any safepoint, this method can get breakpointed, which would
879 // then require an immediate deoptimization.
880 can_prune_locals = false; // do not prune locals
881 stack_slots_not_pruned = 0;
882 }
883
884 // do not scribble on the input jvms
885 JVMState* out_jvms = youngest_jvms->clone_deep(C);
886 call->set_jvms(out_jvms); // Start jvms list for call node
887
888 // For a known set of bytecodes, the interpreter should reexecute them if
889 // deoptimization happens. We set the reexecute state for them here
890 if (out_jvms->is_reexecute_undefined() && //don't change if already specified
891 should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
892 out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
893 }
894
895 // Presize the call:
896 DEBUG_ONLY(uint non_debug_edges = call->req());
897 call->add_req_batch(top(), youngest_jvms->debug_depth());
898 assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
899
900 // Set up edges so that the call looks like this:
901 // Call [state:] ctl io mem fptr retadr
902 // [parms:] parm0 ... parmN
903 // [root:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
904 // [...mid:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
905 // [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
906 // Note that caller debug info precedes callee debug info.
907
908 // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
909 uint debug_ptr = call->req();
910
911 // Loop over the map input edges associated with jvms, add them
912 // to the call node, & reset all offsets to match call node array.
913 for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
914 uint debug_end = debug_ptr;
915 uint debug_start = debug_ptr - in_jvms->debug_size();
916 debug_ptr = debug_start; // back up the ptr
917
918 uint p = debug_start; // walks forward in [debug_start, debug_end)
919 uint j, k, l;
920 SafePointNode* in_map = in_jvms->map();
921 out_jvms->set_map(call);
922
923 if (can_prune_locals) {
924 assert(in_jvms->method() == out_jvms->method(), "sanity");
925 // If the current throw can reach an exception handler in this JVMS,
926 // then we must keep everything live that can reach that handler.
927 // As a quick and dirty approximation, we look for any handlers at all.
928 if (in_jvms->method()->has_exception_handlers()) {
929 can_prune_locals = false;
930 }
931 }
932
933 // Add the Locals
934 k = in_jvms->locoff();
935 l = in_jvms->loc_size();
936 out_jvms->set_locoff(p);
937 if (!can_prune_locals) {
938 for (j = 0; j < l; j++)
939 call->set_req(p++, in_map->in(k+j));
940 } else {
941 p += l; // already set to top above by add_req_batch
942 }
943
944 // Add the Expression Stack
945 k = in_jvms->stkoff();
946 l = in_jvms->sp();
947 out_jvms->set_stkoff(p);
948 if (!can_prune_locals) {
949 for (j = 0; j < l; j++)
950 call->set_req(p++, in_map->in(k+j));
951 } else if (can_prune_locals && stack_slots_not_pruned != 0) {
952 // Divide stack into {S0,...,S1}, where S0 is set to top.
953 uint s1 = stack_slots_not_pruned;
954 stack_slots_not_pruned = 0; // for next iteration
955 if (s1 > l) s1 = l;
956 uint s0 = l - s1;
957 p += s0; // skip the tops preinstalled by add_req_batch
958 for (j = s0; j < l; j++)
959 call->set_req(p++, in_map->in(k+j));
960 } else {
961 p += l; // already set to top above by add_req_batch
962 }
963
964 // Add the Monitors
965 k = in_jvms->monoff();
966 l = in_jvms->mon_size();
967 out_jvms->set_monoff(p);
968 for (j = 0; j < l; j++)
969 call->set_req(p++, in_map->in(k+j));
970
971 // Copy any scalar object fields.
972 k = in_jvms->scloff();
973 l = in_jvms->scl_size();
974 out_jvms->set_scloff(p);
975 for (j = 0; j < l; j++)
976 call->set_req(p++, in_map->in(k+j));
977
978 // Finish the new jvms.
979 out_jvms->set_endoff(p);
980
981 assert(out_jvms->endoff() == debug_end, "fill ptr must match");
982 assert(out_jvms->depth() == in_jvms->depth(), "depth must match");
983 assert(out_jvms->loc_size() == in_jvms->loc_size(), "size must match");
984 assert(out_jvms->mon_size() == in_jvms->mon_size(), "size must match");
985 assert(out_jvms->scl_size() == in_jvms->scl_size(), "size must match");
986 assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
987
988 // Update the two tail pointers in parallel.
989 out_jvms = out_jvms->caller();
990 in_jvms = in_jvms->caller();
991 }
992
993 assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
994
995 // Test the correctness of JVMState::debug_xxx accessors:
996 assert(call->jvms()->debug_start() == non_debug_edges, "");
997 assert(call->jvms()->debug_end() == call->req(), "");
998 assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
999 }
1000
1001 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1002 Bytecodes::Code code = java_bc();
1003 if (code == Bytecodes::_wide) {
1004 code = method()->java_code_at_bci(bci() + 1);
1005 }
1006
1007 BasicType rtype = T_ILLEGAL;
1008 int rsize = 0;
1009
1010 if (code != Bytecodes::_illegal) {
1011 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1012 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1013 if (rtype < T_CONFLICT)
1014 rsize = type2size[rtype];
1015 }
1016
1017 switch (code) {
1018 case Bytecodes::_illegal:
1019 return false;
1020
1021 case Bytecodes::_ldc:
1022 case Bytecodes::_ldc_w:
1023 case Bytecodes::_ldc2_w:
1024 inputs = 0;
1025 break;
1026
1027 case Bytecodes::_dup: inputs = 1; break;
1028 case Bytecodes::_dup_x1: inputs = 2; break;
1029 case Bytecodes::_dup_x2: inputs = 3; break;
1030 case Bytecodes::_dup2: inputs = 2; break;
1031 case Bytecodes::_dup2_x1: inputs = 3; break;
1032 case Bytecodes::_dup2_x2: inputs = 4; break;
1033 case Bytecodes::_swap: inputs = 2; break;
1034 case Bytecodes::_arraylength: inputs = 1; break;
1035
1036 case Bytecodes::_getstatic:
1037 case Bytecodes::_putstatic:
1038 case Bytecodes::_getfield:
1039 case Bytecodes::_putfield:
1040 {
1041 bool ignored_will_link;
1042 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1043 int size = field->type()->size();
1044 bool is_get = (depth >= 0), is_static = (depth & 1);
1045 inputs = (is_static ? 0 : 1);
1046 if (is_get) {
1047 depth = size - inputs;
1048 } else {
1049 inputs += size; // putxxx pops the value from the stack
1050 depth = - inputs;
1051 }
1052 }
1053 break;
1054
1055 case Bytecodes::_invokevirtual:
1056 case Bytecodes::_invokespecial:
1057 case Bytecodes::_invokestatic:
1058 case Bytecodes::_invokedynamic:
1059 case Bytecodes::_invokeinterface:
1060 {
1061 bool ignored_will_link;
1062 ciSignature* declared_signature = NULL;
1063 ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1064 assert(declared_signature != NULL, "cannot be null");
1065 inputs = declared_signature->arg_size_for_bc(code);
1066 int size = declared_signature->return_type()->size();
1067 depth = size - inputs;
1068 }
1069 break;
1070
1071 case Bytecodes::_multianewarray:
1072 {
1073 ciBytecodeStream iter(method());
1074 iter.reset_to_bci(bci());
1075 iter.next();
1076 inputs = iter.get_dimensions();
1077 assert(rsize == 1, "");
1078 depth = rsize - inputs;
1079 }
1080 break;
1081
1082 case Bytecodes::_ireturn:
1083 case Bytecodes::_lreturn:
1084 case Bytecodes::_freturn:
1085 case Bytecodes::_dreturn:
1086 case Bytecodes::_areturn:
1087 assert(rsize == -depth, "");
1088 inputs = rsize;
1089 break;
1090
1091 case Bytecodes::_jsr:
1092 case Bytecodes::_jsr_w:
1093 inputs = 0;
1094 depth = 1; // S.B. depth=1, not zero
1095 break;
1096
1097 default:
1098 // bytecode produces a typed result
1099 inputs = rsize - depth;
1100 assert(inputs >= 0, "");
1101 break;
1102 }
1103
1104 #ifdef ASSERT
1105 // spot check
1106 int outputs = depth + inputs;
1107 assert(outputs >= 0, "sanity");
1108 switch (code) {
1109 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1110 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break;
1111 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break;
1112 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break;
1113 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break;
1114 }
1115 #endif //ASSERT
1116
1117 return true;
1118 }
1119
1120
1121
1122 //------------------------------basic_plus_adr---------------------------------
1123 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1124 // short-circuit a common case
1125 if (offset == intcon(0)) return ptr;
1126 return _gvn.transform( new AddPNode(base, ptr, offset) );
1127 }
1128
1129 Node* GraphKit::ConvI2L(Node* offset) {
1130 // short-circuit a common case
1131 jint offset_con = find_int_con(offset, Type::OffsetBot);
1132 if (offset_con != Type::OffsetBot) {
1133 return longcon((jlong) offset_con);
1134 }
1135 return _gvn.transform( new ConvI2LNode(offset));
1136 }
1137
1138 Node* GraphKit::ConvI2UL(Node* offset) {
1139 juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1140 if (offset_con != (juint) Type::OffsetBot) {
1141 return longcon((julong) offset_con);
1142 }
1143 Node* conv = _gvn.transform( new ConvI2LNode(offset));
1144 Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1145 return _gvn.transform( new AndLNode(conv, mask) );
1146 }
1147
1148 Node* GraphKit::ConvL2I(Node* offset) {
1149 // short-circuit a common case
1150 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1151 if (offset_con != (jlong)Type::OffsetBot) {
1152 return intcon((int) offset_con);
1153 }
1154 return _gvn.transform( new ConvL2INode(offset));
1155 }
1156
1157 //-------------------------load_object_klass-----------------------------------
1158 Node* GraphKit::load_object_klass(Node* obj) {
1159 // Special-case a fresh allocation to avoid building nodes:
1160 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1161 if (akls != NULL) return akls;
1162 if (ShenandoahVerifyReadsToFromSpace) {
1163 obj = shenandoah_read_barrier(obj);
1164 }
1165 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1166 return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1167 }
1168
1169 //-------------------------load_array_length-----------------------------------
1170 Node* GraphKit::load_array_length(Node* array) {
1171 // Special-case a fresh allocation to avoid building nodes:
1172 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1173 Node *alen;
1174 if (alloc == NULL) {
1175 if (ShenandoahVerifyReadsToFromSpace) {
1176 array = shenandoah_read_barrier(array);
1177 }
1178
1179 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1180 alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1181 } else {
1182 alen = alloc->Ideal_length();
1183 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1184 if (ccast != alen) {
1185 alen = _gvn.transform(ccast);
1186 }
1187 }
1188 return alen;
1189 }
1190
1191 //------------------------------do_null_check----------------------------------
1192 // Helper function to do a NULL pointer check. Returned value is
1193 // the incoming address with NULL casted away. You are allowed to use the
1194 // not-null value only if you are control dependent on the test.
1195 #ifndef PRODUCT
1196 extern int explicit_null_checks_inserted,
1197 explicit_null_checks_elided;
1198 #endif
1199 Node* GraphKit::null_check_common(Node* value, BasicType type,
1200 // optional arguments for variations:
1201 bool assert_null,
1202 Node* *null_control,
1203 bool speculative) {
1204 assert(!assert_null || null_control == NULL, "not both at once");
1205 if (stopped()) return top();
1206 NOT_PRODUCT(explicit_null_checks_inserted++);
1207
1208 // Construct NULL check
1209 Node *chk = NULL;
1210 switch(type) {
1211 case T_LONG : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1212 case T_INT : chk = new CmpINode(value, _gvn.intcon(0)); break;
1213 case T_ARRAY : // fall through
1214 type = T_OBJECT; // simplify further tests
1215 case T_OBJECT : {
1216 const Type *t = _gvn.type( value );
1217
1218 const TypeOopPtr* tp = t->isa_oopptr();
1219 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1220 // Only for do_null_check, not any of its siblings:
1221 && !assert_null && null_control == NULL) {
1222 // Usually, any field access or invocation on an unloaded oop type
1223 // will simply fail to link, since the statically linked class is
1224 // likely also to be unloaded. However, in -Xcomp mode, sometimes
1225 // the static class is loaded but the sharper oop type is not.
1226 // Rather than checking for this obscure case in lots of places,
1227 // we simply observe that a null check on an unloaded class
1228 // will always be followed by a nonsense operation, so we
1229 // can just issue the uncommon trap here.
1230 // Our access to the unloaded class will only be correct
1231 // after it has been loaded and initialized, which requires
1232 // a trip through the interpreter.
1233 #ifndef PRODUCT
1234 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1235 #endif
1236 uncommon_trap(Deoptimization::Reason_unloaded,
1237 Deoptimization::Action_reinterpret,
1238 tp->klass(), "!loaded");
1239 return top();
1240 }
1241
1242 if (assert_null) {
1243 // See if the type is contained in NULL_PTR.
1244 // If so, then the value is already null.
1245 if (t->higher_equal(TypePtr::NULL_PTR)) {
1246 NOT_PRODUCT(explicit_null_checks_elided++);
1247 return value; // Elided null assert quickly!
1248 }
1249 } else {
1250 // See if mixing in the NULL pointer changes type.
1251 // If so, then the NULL pointer was not allowed in the original
1252 // type. In other words, "value" was not-null.
1253 if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1254 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1255 NOT_PRODUCT(explicit_null_checks_elided++);
1256 return value; // Elided null check quickly!
1257 }
1258 }
1259 chk = new CmpPNode( value, null() );
1260 break;
1261 }
1262
1263 default:
1264 fatal("unexpected type: %s", type2name(type));
1265 }
1266 assert(chk != NULL, "sanity check");
1267 chk = _gvn.transform(chk);
1268
1269 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1270 BoolNode *btst = new BoolNode( chk, btest);
1271 Node *tst = _gvn.transform( btst );
1272
1273 //-----------
1274 // if peephole optimizations occurred, a prior test existed.
1275 // If a prior test existed, maybe it dominates as we can avoid this test.
1276 if (tst != btst && type == T_OBJECT) {
1277 // At this point we want to scan up the CFG to see if we can
1278 // find an identical test (and so avoid this test altogether).
1279 Node *cfg = control();
1280 int depth = 0;
1281 while( depth < 16 ) { // Limit search depth for speed
1282 if( cfg->Opcode() == Op_IfTrue &&
1283 cfg->in(0)->in(1) == tst ) {
1284 // Found prior test. Use "cast_not_null" to construct an identical
1285 // CastPP (and hence hash to) as already exists for the prior test.
1286 // Return that casted value.
1287 if (assert_null) {
1288 replace_in_map(value, null());
1289 return null(); // do not issue the redundant test
1290 }
1291 Node *oldcontrol = control();
1292 set_control(cfg);
1293 Node *res = cast_not_null(value);
1294 set_control(oldcontrol);
1295 NOT_PRODUCT(explicit_null_checks_elided++);
1296 return res;
1297 }
1298 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1299 if (cfg == NULL) break; // Quit at region nodes
1300 depth++;
1301 }
1302 }
1303
1304 //-----------
1305 // Branch to failure if null
1306 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen
1307 Deoptimization::DeoptReason reason;
1308 if (assert_null) {
1309 reason = Deoptimization::Reason_null_assert;
1310 } else if (type == T_OBJECT) {
1311 reason = Deoptimization::reason_null_check(speculative);
1312 } else {
1313 reason = Deoptimization::Reason_div0_check;
1314 }
1315 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1316 // ciMethodData::has_trap_at will return a conservative -1 if any
1317 // must-be-null assertion has failed. This could cause performance
1318 // problems for a method after its first do_null_assert failure.
1319 // Consider using 'Reason_class_check' instead?
1320
1321 // To cause an implicit null check, we set the not-null probability
1322 // to the maximum (PROB_MAX). For an explicit check the probability
1323 // is set to a smaller value.
1324 if (null_control != NULL || too_many_traps(reason)) {
1325 // probability is less likely
1326 ok_prob = PROB_LIKELY_MAG(3);
1327 } else if (!assert_null &&
1328 (ImplicitNullCheckThreshold > 0) &&
1329 method() != NULL &&
1330 (method()->method_data()->trap_count(reason)
1331 >= (uint)ImplicitNullCheckThreshold)) {
1332 ok_prob = PROB_LIKELY_MAG(3);
1333 }
1334
1335 if (null_control != NULL) {
1336 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1337 Node* null_true = _gvn.transform( new IfFalseNode(iff));
1338 set_control( _gvn.transform( new IfTrueNode(iff)));
1339 #ifndef PRODUCT
1340 if (null_true == top()) {
1341 explicit_null_checks_elided++;
1342 }
1343 #endif
1344 (*null_control) = null_true;
1345 } else {
1346 BuildCutout unless(this, tst, ok_prob);
1347 // Check for optimizer eliding test at parse time
1348 if (stopped()) {
1349 // Failure not possible; do not bother making uncommon trap.
1350 NOT_PRODUCT(explicit_null_checks_elided++);
1351 } else if (assert_null) {
1352 uncommon_trap(reason,
1353 Deoptimization::Action_make_not_entrant,
1354 NULL, "assert_null");
1355 } else {
1356 replace_in_map(value, zerocon(type));
1357 builtin_throw(reason);
1358 }
1359 }
1360
1361 // Must throw exception, fall-thru not possible?
1362 if (stopped()) {
1363 return top(); // No result
1364 }
1365
1366 if (assert_null) {
1367 // Cast obj to null on this path.
1368 replace_in_map(value, zerocon(type));
1369 return zerocon(type);
1370 }
1371
1372 // Cast obj to not-null on this path, if there is no null_control.
1373 // (If there is a null_control, a non-null value may come back to haunt us.)
1374 if (type == T_OBJECT) {
1375 Node* cast = cast_not_null(value, false);
1376 if (null_control == NULL || (*null_control) == top())
1377 replace_in_map(value, cast);
1378 value = cast;
1379 }
1380
1381 return value;
1382 }
1383
1384
1385 //------------------------------cast_not_null----------------------------------
1386 // Cast obj to not-null on this path
1387 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1388 const Type *t = _gvn.type(obj);
1389 const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1390 // Object is already not-null?
1391 if( t == t_not_null ) return obj;
1392
1393 Node *cast = new CastPPNode(obj,t_not_null);
1394 cast->init_req(0, control());
1395 cast = _gvn.transform( cast );
1396
1397 // Scan for instances of 'obj' in the current JVM mapping.
1398 // These instances are known to be not-null after the test.
1399 if (do_replace_in_map)
1400 replace_in_map(obj, cast);
1401
1402 return cast; // Return casted value
1403 }
1404
1405
1406 //--------------------------replace_in_map-------------------------------------
1407 void GraphKit::replace_in_map(Node* old, Node* neww) {
1408 if (old == neww) {
1409 return;
1410 }
1411
1412 map()->replace_edge(old, neww);
1413
1414 // Note: This operation potentially replaces any edge
1415 // on the map. This includes locals, stack, and monitors
1416 // of the current (innermost) JVM state.
1417
1418 // don't let inconsistent types from profiling escape this
1419 // method
1420
1421 const Type* told = _gvn.type(old);
1422 const Type* tnew = _gvn.type(neww);
1423
1424 if (!tnew->higher_equal(told)) {
1425 return;
1426 }
1427
1428 map()->record_replaced_node(old, neww);
1429 }
1430
1431
1432 //=============================================================================
1433 //--------------------------------memory---------------------------------------
1434 Node* GraphKit::memory(uint alias_idx) {
1435 MergeMemNode* mem = merged_memory();
1436 Node* p = mem->memory_at(alias_idx);
1437 _gvn.set_type(p, Type::MEMORY); // must be mapped
1438 return p;
1439 }
1440
1441 //-----------------------------reset_memory------------------------------------
1442 Node* GraphKit::reset_memory() {
1443 Node* mem = map()->memory();
1444 // do not use this node for any more parsing!
1445 debug_only( map()->set_memory((Node*)NULL) );
1446 return _gvn.transform( mem );
1447 }
1448
1449 //------------------------------set_all_memory---------------------------------
1450 void GraphKit::set_all_memory(Node* newmem) {
1451 Node* mergemem = MergeMemNode::make(newmem);
1452 gvn().set_type_bottom(mergemem);
1453 map()->set_memory(mergemem);
1454 }
1455
1456 //------------------------------set_all_memory_call----------------------------
1457 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1458 Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1459 set_all_memory(newmem);
1460 }
1461
1462 //=============================================================================
1463 //
1464 // parser factory methods for MemNodes
1465 //
1466 // These are layered on top of the factory methods in LoadNode and StoreNode,
1467 // and integrate with the parser's memory state and _gvn engine.
1468 //
1469
1470 // factory methods in "int adr_idx"
1471 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1472 int adr_idx,
1473 MemNode::MemOrd mo,
1474 LoadNode::ControlDependency control_dependency,
1475 bool require_atomic_access,
1476 bool unaligned,
1477 bool mismatched) {
1478 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1479 const TypePtr* adr_type = NULL; // debug-mode-only argument
1480 debug_only(adr_type = C->get_adr_type(adr_idx));
1481 Node* mem = memory(adr_idx);
1482 Node* ld;
1483 if (require_atomic_access && bt == T_LONG) {
1484 ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1485 } else if (require_atomic_access && bt == T_DOUBLE) {
1486 ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1487 } else {
1488 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1489 }
1490 ld = _gvn.transform(ld);
1491 if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1492 // Improve graph before escape analysis and boxing elimination.
1493 record_for_igvn(ld);
1494 }
1495 return ld;
1496 }
1497
1498 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1499 int adr_idx,
1500 MemNode::MemOrd mo,
1501 bool require_atomic_access,
1502 bool unaligned,
1503 bool mismatched) {
1504 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1505 const TypePtr* adr_type = NULL;
1506 debug_only(adr_type = C->get_adr_type(adr_idx));
1507 Node *mem = memory(adr_idx);
1508 Node* st;
1509 if (require_atomic_access && bt == T_LONG) {
1510 st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1511 } else if (require_atomic_access && bt == T_DOUBLE) {
1512 st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1513 } else {
1514 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1515 }
1516 if (unaligned) {
1517 st->as_Store()->set_unaligned_access();
1518 }
1519 if (mismatched) {
1520 st->as_Store()->set_mismatched_access();
1521 }
1522 st = _gvn.transform(st);
1523 set_memory(st, adr_idx);
1524 // Back-to-back stores can only remove intermediate store with DU info
1525 // so push on worklist for optimizer.
1526 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1527 record_for_igvn(st);
1528
1529 return st;
1530 }
1531
1532
1533 Node* GraphKit::pre_barrier(bool do_load,
1534 Node* ctl,
1535 Node* obj,
1536 Node* adr,
1537 uint adr_idx,
1538 Node* val,
1539 const TypeOopPtr* val_type,
1540 Node* pre_val,
1541 BasicType bt) {
1542
1543 BarrierSet* bs = Universe::heap()->barrier_set();
1544 set_control(ctl);
1545 switch (bs->kind()) {
1546 case BarrierSet::G1SATBCTLogging:
1547 g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1548 return val;
1549 case BarrierSet::ShenandoahBarrierSet:
1550 return shenandoah_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1551 break;
1552
1553 case BarrierSet::CardTableForRS:
1554 case BarrierSet::CardTableExtension:
1555 case BarrierSet::ModRef:
1556 break;
1557
1558 default :
1559 ShouldNotReachHere();
1560
1561 }
1562 return val;
1563 }
1564
1565 bool GraphKit::can_move_pre_barrier() const {
1566 BarrierSet* bs = Universe::heap()->barrier_set();
1567 switch (bs->kind()) {
1568 case BarrierSet::G1SATBCTLogging:
1569 case BarrierSet::ShenandoahBarrierSet:
1570 return true; // Can move it if no safepoint
1571
1572 case BarrierSet::CardTableForRS:
1573 case BarrierSet::CardTableExtension:
1574 case BarrierSet::ModRef:
1575 return true; // There is no pre-barrier
1576
1577 default :
1578 ShouldNotReachHere();
1579 }
1580 return false;
1581 }
1582
1583 void GraphKit::post_barrier(Node* ctl,
1584 Node* store,
1585 Node* obj,
1586 Node* adr,
1587 uint adr_idx,
1588 Node* val,
1589 BasicType bt,
1590 bool use_precise) {
1591 BarrierSet* bs = Universe::heap()->barrier_set();
1592 set_control(ctl);
1593 switch (bs->kind()) {
1594 case BarrierSet::G1SATBCTLogging:
1595 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1596 break;
1597
1598 case BarrierSet::CardTableForRS:
1599 case BarrierSet::CardTableExtension:
1600 write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1601 break;
1602
1603 case BarrierSet::ModRef:
1604 case BarrierSet::ShenandoahBarrierSet:
1605 break;
1606
1607 default :
1608 ShouldNotReachHere();
1609
1610 }
1611 }
1612
1613 Node* GraphKit::store_oop(Node* ctl,
1614 Node* obj,
1615 Node* adr,
1616 const TypePtr* adr_type,
1617 Node* val,
1618 const TypeOopPtr* val_type,
1619 BasicType bt,
1620 bool use_precise,
1621 MemNode::MemOrd mo,
1622 bool mismatched) {
1623 // Transformation of a value which could be NULL pointer (CastPP #NULL)
1624 // could be delayed during Parse (for example, in adjust_map_after_if()).
1625 // Execute transformation here to avoid barrier generation in such case.
1626 if (_gvn.type(val) == TypePtr::NULL_PTR)
1627 val = _gvn.makecon(TypePtr::NULL_PTR);
1628
1629 set_control(ctl);
1630 if (stopped()) return top(); // Dead path ?
1631
1632 assert(bt == T_OBJECT, "sanity");
1633 assert(val != NULL, "not dead path");
1634 uint adr_idx = C->get_alias_index(adr_type);
1635 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1636
1637 val = pre_barrier(true /* do_load */,
1638 control(), obj, adr, adr_idx, val, val_type,
1639 NULL /* pre_val */,
1640 bt);
1641
1642 Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1643 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1644 return store;
1645 }
1646
1647 // Could be an array or object we don't know at compile time (unsafe ref.)
1648 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1649 Node* obj, // containing obj
1650 Node* adr, // actual adress to store val at
1651 const TypePtr* adr_type,
1652 Node* val,
1653 BasicType bt,
1654 MemNode::MemOrd mo,
1655 bool mismatched) {
1656 Compile::AliasType* at = C->alias_type(adr_type);
1657 const TypeOopPtr* val_type = NULL;
1658 if (adr_type->isa_instptr()) {
1659 if (at->field() != NULL) {
1660 // known field. This code is a copy of the do_put_xxx logic.
1661 ciField* field = at->field();
1662 if (!field->type()->is_loaded()) {
1663 val_type = TypeInstPtr::BOTTOM;
1664 } else {
1665 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1666 }
1667 }
1668 } else if (adr_type->isa_aryptr()) {
1669 val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1670 }
1671 if (val_type == NULL) {
1672 val_type = TypeInstPtr::BOTTOM;
1673 }
1674 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1675 }
1676
1677
1678 //-------------------------array_element_address-------------------------
1679 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1680 const TypeInt* sizetype, Node* ctrl) {
1681 uint shift = exact_log2(type2aelembytes(elembt));
1682 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1683
1684 // short-circuit a common case (saves lots of confusing waste motion)
1685 jint idx_con = find_int_con(idx, -1);
1686 if (idx_con >= 0) {
1687 intptr_t offset = header + ((intptr_t)idx_con << shift);
1688 return basic_plus_adr(ary, offset);
1689 }
1690
1691 // must be correct type for alignment purposes
1692 Node* base = basic_plus_adr(ary, header);
1693 idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1694 Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1695 return basic_plus_adr(ary, base, scale);
1696 }
1697
1698 //-------------------------load_array_element-------------------------
1699 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1700 const Type* elemtype = arytype->elem();
1701 BasicType elembt = elemtype->array_element_basic_type();
1702 Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1703 if (elembt == T_NARROWOOP) {
1704 elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1705 }
1706 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1707 return ld;
1708 }
1709
1710 //-------------------------set_arguments_for_java_call-------------------------
1711 // Arguments (pre-popped from the stack) are taken from the JVMS.
1712 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1713 // Add the call arguments:
1714 uint nargs = call->method()->arg_size();
1715 for (uint i = 0; i < nargs; i++) {
1716 Node* arg = argument(i);
1717 if (ShenandoahVerifyReadsToFromSpace && call->is_CallDynamicJava() && i == 0) {
1718 arg = shenandoah_read_barrier(arg);
1719 }
1720 call->init_req(i + TypeFunc::Parms, arg);
1721 }
1722 }
1723
1724 //---------------------------set_edges_for_java_call---------------------------
1725 // Connect a newly created call into the current JVMS.
1726 // A return value node (if any) is returned from set_edges_for_java_call.
1727 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1728
1729 // Add the predefined inputs:
1730 call->init_req( TypeFunc::Control, control() );
1731 call->init_req( TypeFunc::I_O , i_o() );
1732 call->init_req( TypeFunc::Memory , reset_memory() );
1733 call->init_req( TypeFunc::FramePtr, frameptr() );
1734 call->init_req( TypeFunc::ReturnAdr, top() );
1735
1736 add_safepoint_edges(call, must_throw);
1737
1738 Node* xcall = _gvn.transform(call);
1739
1740 if (xcall == top()) {
1741 set_control(top());
1742 return;
1743 }
1744 assert(xcall == call, "call identity is stable");
1745
1746 // Re-use the current map to produce the result.
1747
1748 set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1749 set_i_o( _gvn.transform(new ProjNode(call, TypeFunc::I_O , separate_io_proj)));
1750 set_all_memory_call(xcall, separate_io_proj);
1751
1752 //return xcall; // no need, caller already has it
1753 }
1754
1755 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1756 if (stopped()) return top(); // maybe the call folded up?
1757
1758 // Capture the return value, if any.
1759 Node* ret;
1760 if (call->method() == NULL ||
1761 call->method()->return_type()->basic_type() == T_VOID)
1762 ret = top();
1763 else ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1764
1765 // Note: Since any out-of-line call can produce an exception,
1766 // we always insert an I_O projection from the call into the result.
1767
1768 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1769
1770 if (separate_io_proj) {
1771 // The caller requested separate projections be used by the fall
1772 // through and exceptional paths, so replace the projections for
1773 // the fall through path.
1774 set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1775 set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1776 }
1777 return ret;
1778 }
1779
1780 //--------------------set_predefined_input_for_runtime_call--------------------
1781 // Reading and setting the memory state is way conservative here.
1782 // The real problem is that I am not doing real Type analysis on memory,
1783 // so I cannot distinguish card mark stores from other stores. Across a GC
1784 // point the Store Barrier and the card mark memory has to agree. I cannot
1785 // have a card mark store and its barrier split across the GC point from
1786 // either above or below. Here I get that to happen by reading ALL of memory.
1787 // A better answer would be to separate out card marks from other memory.
1788 // For now, return the input memory state, so that it can be reused
1789 // after the call, if this call has restricted memory effects.
1790 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1791 // Set fixed predefined input arguments
1792 Node* memory = reset_memory();
1793 call->init_req( TypeFunc::Control, control() );
1794 call->init_req( TypeFunc::I_O, top() ); // does no i/o
1795 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs
1796 call->init_req( TypeFunc::FramePtr, frameptr() );
1797 call->init_req( TypeFunc::ReturnAdr, top() );
1798 return memory;
1799 }
1800
1801 //-------------------set_predefined_output_for_runtime_call--------------------
1802 // Set control and memory (not i_o) from the call.
1803 // If keep_mem is not NULL, use it for the output state,
1804 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1805 // If hook_mem is NULL, this call produces no memory effects at all.
1806 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1807 // then only that memory slice is taken from the call.
1808 // In the last case, we must put an appropriate memory barrier before
1809 // the call, so as to create the correct anti-dependencies on loads
1810 // preceding the call.
1811 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1812 Node* keep_mem,
1813 const TypePtr* hook_mem) {
1814 // no i/o
1815 set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1816 if (keep_mem) {
1817 // First clone the existing memory state
1818 set_all_memory(keep_mem);
1819 if (hook_mem != NULL) {
1820 // Make memory for the call
1821 Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1822 // Set the RawPtr memory state only. This covers all the heap top/GC stuff
1823 // We also use hook_mem to extract specific effects from arraycopy stubs.
1824 set_memory(mem, hook_mem);
1825 }
1826 // ...else the call has NO memory effects.
1827
1828 // Make sure the call advertises its memory effects precisely.
1829 // This lets us build accurate anti-dependences in gcm.cpp.
1830 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1831 "call node must be constructed correctly");
1832 } else {
1833 assert(hook_mem == NULL, "");
1834 // This is not a "slow path" call; all memory comes from the call.
1835 set_all_memory_call(call);
1836 }
1837 }
1838
1839
1840 // Replace the call with the current state of the kit.
1841 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1842 JVMState* ejvms = NULL;
1843 if (has_exceptions()) {
1844 ejvms = transfer_exceptions_into_jvms();
1845 }
1846
1847 ReplacedNodes replaced_nodes = map()->replaced_nodes();
1848 ReplacedNodes replaced_nodes_exception;
1849 Node* ex_ctl = top();
1850
1851 SafePointNode* final_state = stop();
1852
1853 // Find all the needed outputs of this call
1854 CallProjections callprojs;
1855 call->extract_projections(&callprojs, true);
1856
1857 Node* init_mem = call->in(TypeFunc::Memory);
1858 Node* final_mem = final_state->in(TypeFunc::Memory);
1859 Node* final_ctl = final_state->in(TypeFunc::Control);
1860 Node* final_io = final_state->in(TypeFunc::I_O);
1861
1862 // Replace all the old call edges with the edges from the inlining result
1863 if (callprojs.fallthrough_catchproj != NULL) {
1864 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1865 }
1866 if (callprojs.fallthrough_memproj != NULL) {
1867 if (final_mem->is_MergeMem()) {
1868 // Parser's exits MergeMem was not transformed but may be optimized
1869 final_mem = _gvn.transform(final_mem);
1870 }
1871 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem);
1872 }
1873 if (callprojs.fallthrough_ioproj != NULL) {
1874 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io);
1875 }
1876
1877 // Replace the result with the new result if it exists and is used
1878 if (callprojs.resproj != NULL && result != NULL) {
1879 C->gvn_replace_by(callprojs.resproj, result);
1880 }
1881
1882 if (ejvms == NULL) {
1883 // No exception edges to simply kill off those paths
1884 if (callprojs.catchall_catchproj != NULL) {
1885 C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1886 }
1887 if (callprojs.catchall_memproj != NULL) {
1888 C->gvn_replace_by(callprojs.catchall_memproj, C->top());
1889 }
1890 if (callprojs.catchall_ioproj != NULL) {
1891 C->gvn_replace_by(callprojs.catchall_ioproj, C->top());
1892 }
1893 // Replace the old exception object with top
1894 if (callprojs.exobj != NULL) {
1895 C->gvn_replace_by(callprojs.exobj, C->top());
1896 }
1897 } else {
1898 GraphKit ekit(ejvms);
1899
1900 // Load my combined exception state into the kit, with all phis transformed:
1901 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1902 replaced_nodes_exception = ex_map->replaced_nodes();
1903
1904 Node* ex_oop = ekit.use_exception_state(ex_map);
1905
1906 if (callprojs.catchall_catchproj != NULL) {
1907 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1908 ex_ctl = ekit.control();
1909 }
1910 if (callprojs.catchall_memproj != NULL) {
1911 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory());
1912 }
1913 if (callprojs.catchall_ioproj != NULL) {
1914 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o());
1915 }
1916
1917 // Replace the old exception object with the newly created one
1918 if (callprojs.exobj != NULL) {
1919 C->gvn_replace_by(callprojs.exobj, ex_oop);
1920 }
1921 }
1922
1923 // Disconnect the call from the graph
1924 call->disconnect_inputs(NULL, C);
1925 C->gvn_replace_by(call, C->top());
1926
1927 // Clean up any MergeMems that feed other MergeMems since the
1928 // optimizer doesn't like that.
1929 if (final_mem->is_MergeMem()) {
1930 Node_List wl;
1931 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1932 Node* m = i.get();
1933 if (m->is_MergeMem() && !wl.contains(m)) {
1934 wl.push(m);
1935 }
1936 }
1937 while (wl.size() > 0) {
1938 _gvn.transform(wl.pop());
1939 }
1940 }
1941
1942 if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1943 replaced_nodes.apply(C, final_ctl);
1944 }
1945 if (!ex_ctl->is_top() && do_replaced_nodes) {
1946 replaced_nodes_exception.apply(C, ex_ctl);
1947 }
1948 }
1949
1950
1951 //------------------------------increment_counter------------------------------
1952 // for statistics: increment a VM counter by 1
1953
1954 void GraphKit::increment_counter(address counter_addr) {
1955 Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1956 increment_counter(adr1);
1957 }
1958
1959 void GraphKit::increment_counter(Node* counter_addr) {
1960 int adr_type = Compile::AliasIdxRaw;
1961 Node* ctrl = control();
1962 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1963 Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1964 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1965 }
1966
1967
1968 //------------------------------uncommon_trap----------------------------------
1969 // Bail out to the interpreter in mid-method. Implemented by calling the
1970 // uncommon_trap blob. This helper function inserts a runtime call with the
1971 // right debug info.
1972 void GraphKit::uncommon_trap(int trap_request,
1973 ciKlass* klass, const char* comment,
1974 bool must_throw,
1975 bool keep_exact_action) {
1976 if (failing()) stop();
1977 if (stopped()) return; // trap reachable?
1978
1979 // Note: If ProfileTraps is true, and if a deopt. actually
1980 // occurs here, the runtime will make sure an MDO exists. There is
1981 // no need to call method()->ensure_method_data() at this point.
1982
1983 // Set the stack pointer to the right value for reexecution:
1984 set_sp(reexecute_sp());
1985
1986 #ifdef ASSERT
1987 if (!must_throw) {
1988 // Make sure the stack has at least enough depth to execute
1989 // the current bytecode.
1990 int inputs, ignored_depth;
1991 if (compute_stack_effects(inputs, ignored_depth)) {
1992 assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1993 Bytecodes::name(java_bc()), sp(), inputs);
1994 }
1995 }
1996 #endif
1997
1998 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1999 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2000
2001 switch (action) {
2002 case Deoptimization::Action_maybe_recompile:
2003 case Deoptimization::Action_reinterpret:
2004 // Temporary fix for 6529811 to allow virtual calls to be sure they
2005 // get the chance to go from mono->bi->mega
2006 if (!keep_exact_action &&
2007 Deoptimization::trap_request_index(trap_request) < 0 &&
2008 too_many_recompiles(reason)) {
2009 // This BCI is causing too many recompilations.
2010 if (C->log() != NULL) {
2011 C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2012 Deoptimization::trap_reason_name(reason),
2013 Deoptimization::trap_action_name(action));
2014 }
2015 action = Deoptimization::Action_none;
2016 trap_request = Deoptimization::make_trap_request(reason, action);
2017 } else {
2018 C->set_trap_can_recompile(true);
2019 }
2020 break;
2021 case Deoptimization::Action_make_not_entrant:
2022 C->set_trap_can_recompile(true);
2023 break;
2024 #ifdef ASSERT
2025 case Deoptimization::Action_none:
2026 case Deoptimization::Action_make_not_compilable:
2027 break;
2028 default:
2029 fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2030 break;
2031 #endif
2032 }
2033
2034 if (TraceOptoParse) {
2035 char buf[100];
2036 tty->print_cr("Uncommon trap %s at bci:%d",
2037 Deoptimization::format_trap_request(buf, sizeof(buf),
2038 trap_request), bci());
2039 }
2040
2041 CompileLog* log = C->log();
2042 if (log != NULL) {
2043 int kid = (klass == NULL)? -1: log->identify(klass);
2044 log->begin_elem("uncommon_trap bci='%d'", bci());
2045 char buf[100];
2046 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2047 trap_request));
2048 if (kid >= 0) log->print(" klass='%d'", kid);
2049 if (comment != NULL) log->print(" comment='%s'", comment);
2050 log->end_elem();
2051 }
2052
2053 // Make sure any guarding test views this path as very unlikely
2054 Node *i0 = control()->in(0);
2055 if (i0 != NULL && i0->is_If()) { // Found a guarding if test?
2056 IfNode *iff = i0->as_If();
2057 float f = iff->_prob; // Get prob
2058 if (control()->Opcode() == Op_IfTrue) {
2059 if (f > PROB_UNLIKELY_MAG(4))
2060 iff->_prob = PROB_MIN;
2061 } else {
2062 if (f < PROB_LIKELY_MAG(4))
2063 iff->_prob = PROB_MAX;
2064 }
2065 }
2066
2067 // Clear out dead values from the debug info.
2068 kill_dead_locals();
2069
2070 // Now insert the uncommon trap subroutine call
2071 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2072 const TypePtr* no_memory_effects = NULL;
2073 // Pass the index of the class to be loaded
2074 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2075 (must_throw ? RC_MUST_THROW : 0),
2076 OptoRuntime::uncommon_trap_Type(),
2077 call_addr, "uncommon_trap", no_memory_effects,
2078 intcon(trap_request));
2079 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2080 "must extract request correctly from the graph");
2081 assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2082
2083 call->set_req(TypeFunc::ReturnAdr, returnadr());
2084 // The debug info is the only real input to this call.
2085
2086 // Halt-and-catch fire here. The above call should never return!
2087 HaltNode* halt = new HaltNode(control(), frameptr());
2088 _gvn.set_type_bottom(halt);
2089 root()->add_req(halt);
2090
2091 stop_and_kill_map();
2092 }
2093
2094
2095 //--------------------------just_allocated_object------------------------------
2096 // Report the object that was just allocated.
2097 // It must be the case that there are no intervening safepoints.
2098 // We use this to determine if an object is so "fresh" that
2099 // it does not require card marks.
2100 Node* GraphKit::just_allocated_object(Node* current_control) {
2101 if (C->recent_alloc_ctl() == current_control)
2102 return C->recent_alloc_obj();
2103 return NULL;
2104 }
2105
2106
2107 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2108 // (Note: TypeFunc::make has a cache that makes this fast.)
2109 const TypeFunc* tf = TypeFunc::make(dest_method);
2110 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2111 for (int j = 0; j < nargs; j++) {
2112 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2113 if( targ->basic_type() == T_DOUBLE ) {
2114 // If any parameters are doubles, they must be rounded before
2115 // the call, dstore_rounding does gvn.transform
2116 Node *arg = argument(j);
2117 arg = dstore_rounding(arg);
2118 set_argument(j, arg);
2119 }
2120 }
2121 }
2122
2123 /**
2124 * Record profiling data exact_kls for Node n with the type system so
2125 * that it can propagate it (speculation)
2126 *
2127 * @param n node that the type applies to
2128 * @param exact_kls type from profiling
2129 * @param maybe_null did profiling see null?
2130 *
2131 * @return node with improved type
2132 */
2133 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2134 const Type* current_type = _gvn.type(n);
2135 assert(UseTypeSpeculation, "type speculation must be on");
2136
2137 const TypePtr* speculative = current_type->speculative();
2138
2139 // Should the klass from the profile be recorded in the speculative type?
2140 if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2141 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2142 const TypeOopPtr* xtype = tklass->as_instance_type();
2143 assert(xtype->klass_is_exact(), "Should be exact");
2144 // Any reason to believe n is not null (from this profiling or a previous one)?
2145 const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2146 // record the new speculative type's depth
2147 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2148 speculative = speculative->with_inline_depth(jvms()->depth());
2149 } else if (current_type->would_improve_ptr(maybe_null)) {
2150 // Profiling report that null was never seen so we can change the
2151 // speculative type to non null ptr.
2152 assert(!maybe_null, "nothing to improve");
2153 if (speculative == NULL) {
2154 speculative = TypePtr::NOTNULL;
2155 } else {
2156 const TypePtr* ptr = TypePtr::NOTNULL;
2157 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2158 }
2159 }
2160
2161 if (speculative != current_type->speculative()) {
2162 // Build a type with a speculative type (what we think we know
2163 // about the type but will need a guard when we use it)
2164 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2165 // We're changing the type, we need a new CheckCast node to carry
2166 // the new type. The new type depends on the control: what
2167 // profiling tells us is only valid from here as far as we can
2168 // tell.
2169 Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2170 cast = _gvn.transform(cast);
2171 replace_in_map(n, cast);
2172 n = cast;
2173 }
2174
2175 return n;
2176 }
2177
2178 /**
2179 * Record profiling data from receiver profiling at an invoke with the
2180 * type system so that it can propagate it (speculation)
2181 *
2182 * @param n receiver node
2183 *
2184 * @return node with improved type
2185 */
2186 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2187 if (!UseTypeSpeculation) {
2188 return n;
2189 }
2190 ciKlass* exact_kls = profile_has_unique_klass();
2191 bool maybe_null = true;
2192 if (java_bc() == Bytecodes::_checkcast ||
2193 java_bc() == Bytecodes::_instanceof ||
2194 java_bc() == Bytecodes::_aastore) {
2195 ciProfileData* data = method()->method_data()->bci_to_data(bci());
2196 maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2197 }
2198 return record_profile_for_speculation(n, exact_kls, maybe_null);
2199 }
2200
2201 /**
2202 * Record profiling data from argument profiling at an invoke with the
2203 * type system so that it can propagate it (speculation)
2204 *
2205 * @param dest_method target method for the call
2206 * @param bc what invoke bytecode is this?
2207 */
2208 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2209 if (!UseTypeSpeculation) {
2210 return;
2211 }
2212 const TypeFunc* tf = TypeFunc::make(dest_method);
2213 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2214 int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2215 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2216 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2217 if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2218 bool maybe_null = true;
2219 ciKlass* better_type = NULL;
2220 if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2221 record_profile_for_speculation(argument(j), better_type, maybe_null);
2222 }
2223 i++;
2224 }
2225 }
2226 }
2227
2228 /**
2229 * Record profiling data from parameter profiling at an invoke with
2230 * the type system so that it can propagate it (speculation)
2231 */
2232 void GraphKit::record_profiled_parameters_for_speculation() {
2233 if (!UseTypeSpeculation) {
2234 return;
2235 }
2236 for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2237 if (_gvn.type(local(i))->isa_oopptr()) {
2238 bool maybe_null = true;
2239 ciKlass* better_type = NULL;
2240 if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2241 record_profile_for_speculation(local(i), better_type, maybe_null);
2242 }
2243 j++;
2244 }
2245 }
2246 }
2247
2248 /**
2249 * Record profiling data from return value profiling at an invoke with
2250 * the type system so that it can propagate it (speculation)
2251 */
2252 void GraphKit::record_profiled_return_for_speculation() {
2253 if (!UseTypeSpeculation) {
2254 return;
2255 }
2256 bool maybe_null = true;
2257 ciKlass* better_type = NULL;
2258 if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2259 // If profiling reports a single type for the return value,
2260 // feed it to the type system so it can propagate it as a
2261 // speculative type
2262 record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2263 }
2264 }
2265
2266 void GraphKit::round_double_result(ciMethod* dest_method) {
2267 // A non-strict method may return a double value which has an extended
2268 // exponent, but this must not be visible in a caller which is 'strict'
2269 // If a strict caller invokes a non-strict callee, round a double result
2270
2271 BasicType result_type = dest_method->return_type()->basic_type();
2272 assert( method() != NULL, "must have caller context");
2273 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2274 // Destination method's return value is on top of stack
2275 // dstore_rounding() does gvn.transform
2276 Node *result = pop_pair();
2277 result = dstore_rounding(result);
2278 push_pair(result);
2279 }
2280 }
2281
2282 // rounding for strict float precision conformance
2283 Node* GraphKit::precision_rounding(Node* n) {
2284 return UseStrictFP && _method->flags().is_strict()
2285 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2286 ? _gvn.transform( new RoundFloatNode(0, n) )
2287 : n;
2288 }
2289
2290 // rounding for strict double precision conformance
2291 Node* GraphKit::dprecision_rounding(Node *n) {
2292 return UseStrictFP && _method->flags().is_strict()
2293 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2294 ? _gvn.transform( new RoundDoubleNode(0, n) )
2295 : n;
2296 }
2297
2298 // rounding for non-strict double stores
2299 Node* GraphKit::dstore_rounding(Node* n) {
2300 return Matcher::strict_fp_requires_explicit_rounding
2301 && UseSSE <= 1
2302 ? _gvn.transform( new RoundDoubleNode(0, n) )
2303 : n;
2304 }
2305
2306 //=============================================================================
2307 // Generate a fast path/slow path idiom. Graph looks like:
2308 // [foo] indicates that 'foo' is a parameter
2309 //
2310 // [in] NULL
2311 // \ /
2312 // CmpP
2313 // Bool ne
2314 // If
2315 // / \
2316 // True False-<2>
2317 // / |
2318 // / cast_not_null
2319 // Load | | ^
2320 // [fast_test] | |
2321 // gvn to opt_test | |
2322 // / \ | <1>
2323 // True False |
2324 // | \\ |
2325 // [slow_call] \[fast_result]
2326 // Ctl Val \ \
2327 // | \ \
2328 // Catch <1> \ \
2329 // / \ ^ \ \
2330 // Ex No_Ex | \ \
2331 // | \ \ | \ <2> \
2332 // ... \ [slow_res] | | \ [null_result]
2333 // \ \--+--+--- | |
2334 // \ | / \ | /
2335 // --------Region Phi
2336 //
2337 //=============================================================================
2338 // Code is structured as a series of driver functions all called 'do_XXX' that
2339 // call a set of helper functions. Helper functions first, then drivers.
2340
2341 //------------------------------null_check_oop---------------------------------
2342 // Null check oop. Set null-path control into Region in slot 3.
2343 // Make a cast-not-nullness use the other not-null control. Return cast.
2344 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2345 bool never_see_null,
2346 bool safe_for_replace,
2347 bool speculative) {
2348 // Initial NULL check taken path
2349 (*null_control) = top();
2350 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2351
2352 // Generate uncommon_trap:
2353 if (never_see_null && (*null_control) != top()) {
2354 // If we see an unexpected null at a check-cast we record it and force a
2355 // recompile; the offending check-cast will be compiled to handle NULLs.
2356 // If we see more than one offending BCI, then all checkcasts in the
2357 // method will be compiled to handle NULLs.
2358 PreserveJVMState pjvms(this);
2359 set_control(*null_control);
2360 replace_in_map(value, null());
2361 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2362 uncommon_trap(reason,
2363 Deoptimization::Action_make_not_entrant);
2364 (*null_control) = top(); // NULL path is dead
2365 }
2366 if ((*null_control) == top() && safe_for_replace) {
2367 replace_in_map(value, cast);
2368 }
2369
2370 // Cast away null-ness on the result
2371 return cast;
2372 }
2373
2374 //------------------------------opt_iff----------------------------------------
2375 // Optimize the fast-check IfNode. Set the fast-path region slot 2.
2376 // Return slow-path control.
2377 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2378 IfNode *opt_iff = _gvn.transform(iff)->as_If();
2379
2380 // Fast path taken; set region slot 2
2381 Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2382 region->init_req(2,fast_taken); // Capture fast-control
2383
2384 // Fast path not-taken, i.e. slow path
2385 Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2386 return slow_taken;
2387 }
2388
2389 //-----------------------------make_runtime_call-------------------------------
2390 Node* GraphKit::make_runtime_call(int flags,
2391 const TypeFunc* call_type, address call_addr,
2392 const char* call_name,
2393 const TypePtr* adr_type,
2394 // The following parms are all optional.
2395 // The first NULL ends the list.
2396 Node* parm0, Node* parm1,
2397 Node* parm2, Node* parm3,
2398 Node* parm4, Node* parm5,
2399 Node* parm6, Node* parm7) {
2400 // Slow-path call
2401 bool is_leaf = !(flags & RC_NO_LEAF);
2402 bool has_io = (!is_leaf && !(flags & RC_NO_IO));
2403 if (call_name == NULL) {
2404 assert(!is_leaf, "must supply name for leaf");
2405 call_name = OptoRuntime::stub_name(call_addr);
2406 }
2407 CallNode* call;
2408 if (!is_leaf) {
2409 call = new CallStaticJavaNode(call_type, call_addr, call_name,
2410 bci(), adr_type);
2411 } else if (flags & RC_NO_FP) {
2412 call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2413 } else {
2414 call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2415 }
2416
2417 // The following is similar to set_edges_for_java_call,
2418 // except that the memory effects of the call are restricted to AliasIdxRaw.
2419
2420 // Slow path call has no side-effects, uses few values
2421 bool wide_in = !(flags & RC_NARROW_MEM);
2422 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2423
2424 Node* prev_mem = NULL;
2425 if (wide_in) {
2426 prev_mem = set_predefined_input_for_runtime_call(call);
2427 } else {
2428 assert(!wide_out, "narrow in => narrow out");
2429 Node* narrow_mem = memory(adr_type);
2430 prev_mem = reset_memory();
2431 map()->set_memory(narrow_mem);
2432 set_predefined_input_for_runtime_call(call);
2433 }
2434
2435 // Hook each parm in order. Stop looking at the first NULL.
2436 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2437 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2438 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2439 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2440 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2441 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2442 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2443 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2444 /* close each nested if ===> */ } } } } } } } }
2445 assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2446
2447 if (!is_leaf) {
2448 // Non-leaves can block and take safepoints:
2449 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2450 }
2451 // Non-leaves can throw exceptions:
2452 if (has_io) {
2453 call->set_req(TypeFunc::I_O, i_o());
2454 }
2455
2456 if (flags & RC_UNCOMMON) {
2457 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency.
2458 // (An "if" probability corresponds roughly to an unconditional count.
2459 // Sort of.)
2460 call->set_cnt(PROB_UNLIKELY_MAG(4));
2461 }
2462
2463 Node* c = _gvn.transform(call);
2464 assert(c == call, "cannot disappear");
2465
2466 if (wide_out) {
2467 // Slow path call has full side-effects.
2468 set_predefined_output_for_runtime_call(call);
2469 } else {
2470 // Slow path call has few side-effects, and/or sets few values.
2471 set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2472 }
2473
2474 if (has_io) {
2475 set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2476 }
2477 return call;
2478
2479 }
2480
2481 //------------------------------merge_memory-----------------------------------
2482 // Merge memory from one path into the current memory state.
2483 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2484 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2485 Node* old_slice = mms.force_memory();
2486 Node* new_slice = mms.memory2();
2487 if (old_slice != new_slice) {
2488 PhiNode* phi;
2489 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2490 if (mms.is_empty()) {
2491 // clone base memory Phi's inputs for this memory slice
2492 assert(old_slice == mms.base_memory(), "sanity");
2493 phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2494 _gvn.set_type(phi, Type::MEMORY);
2495 for (uint i = 1; i < phi->req(); i++) {
2496 phi->init_req(i, old_slice->in(i));
2497 }
2498 } else {
2499 phi = old_slice->as_Phi(); // Phi was generated already
2500 }
2501 } else {
2502 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2503 _gvn.set_type(phi, Type::MEMORY);
2504 }
2505 phi->set_req(new_path, new_slice);
2506 mms.set_memory(phi);
2507 }
2508 }
2509 }
2510
2511 //------------------------------make_slow_call_ex------------------------------
2512 // Make the exception handler hookups for the slow call
2513 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2514 if (stopped()) return;
2515
2516 // Make a catch node with just two handlers: fall-through and catch-all
2517 Node* i_o = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2518 Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2519 Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2520 Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) );
2521
2522 { PreserveJVMState pjvms(this);
2523 set_control(excp);
2524 set_i_o(i_o);
2525
2526 if (excp != top()) {
2527 if (deoptimize) {
2528 // Deoptimize if an exception is caught. Don't construct exception state in this case.
2529 uncommon_trap(Deoptimization::Reason_unhandled,
2530 Deoptimization::Action_none);
2531 } else {
2532 // Create an exception state also.
2533 // Use an exact type if the caller has specified a specific exception.
2534 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2535 Node* ex_oop = new CreateExNode(ex_type, control(), i_o);
2536 add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2537 }
2538 }
2539 }
2540
2541 // Get the no-exception control from the CatchNode.
2542 set_control(norm);
2543 }
2544
2545 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2546 Node* cmp = NULL;
2547 switch(bt) {
2548 case T_INT: cmp = new CmpINode(in1, in2); break;
2549 case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2550 default: fatal("unexpected comparison type %s", type2name(bt));
2551 }
2552 gvn->transform(cmp);
2553 Node* bol = gvn->transform(new BoolNode(cmp, test));
2554 IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2555 gvn->transform(iff);
2556 if (!bol->is_Con()) gvn->record_for_igvn(iff);
2557 return iff;
2558 }
2559
2560
2561 //-------------------------------gen_subtype_check-----------------------------
2562 // Generate a subtyping check. Takes as input the subtype and supertype.
2563 // Returns 2 values: sets the default control() to the true path and returns
2564 // the false path. Only reads invariant memory; sets no (visible) memory.
2565 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2566 // but that's not exposed to the optimizer. This call also doesn't take in an
2567 // Object; if you wish to check an Object you need to load the Object's class
2568 // prior to coming here.
2569 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2570 Compile* C = gvn->C;
2571
2572 if ((*ctrl)->is_top()) {
2573 return C->top();
2574 }
2575
2576 // Fast check for identical types, perhaps identical constants.
2577 // The types can even be identical non-constants, in cases
2578 // involving Array.newInstance, Object.clone, etc.
2579 if (subklass == superklass)
2580 return C->top(); // false path is dead; no test needed.
2581
2582 if (gvn->type(superklass)->singleton()) {
2583 ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2584 ciKlass* subk = gvn->type(subklass)->is_klassptr()->klass();
2585
2586 // In the common case of an exact superklass, try to fold up the
2587 // test before generating code. You may ask, why not just generate
2588 // the code and then let it fold up? The answer is that the generated
2589 // code will necessarily include null checks, which do not always
2590 // completely fold away. If they are also needless, then they turn
2591 // into a performance loss. Example:
2592 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2593 // Here, the type of 'fa' is often exact, so the store check
2594 // of fa[1]=x will fold up, without testing the nullness of x.
2595 switch (C->static_subtype_check(superk, subk)) {
2596 case Compile::SSC_always_false:
2597 {
2598 Node* always_fail = *ctrl;
2599 *ctrl = gvn->C->top();
2600 return always_fail;
2601 }
2602 case Compile::SSC_always_true:
2603 return C->top();
2604 case Compile::SSC_easy_test:
2605 {
2606 // Just do a direct pointer compare and be done.
2607 IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2608 *ctrl = gvn->transform(new IfTrueNode(iff));
2609 return gvn->transform(new IfFalseNode(iff));
2610 }
2611 case Compile::SSC_full_test:
2612 break;
2613 default:
2614 ShouldNotReachHere();
2615 }
2616 }
2617
2618 // %%% Possible further optimization: Even if the superklass is not exact,
2619 // if the subklass is the unique subtype of the superklass, the check
2620 // will always succeed. We could leave a dependency behind to ensure this.
2621
2622 // First load the super-klass's check-offset
2623 Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2624 Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2625 Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2626 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2627 bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2628
2629 // Load from the sub-klass's super-class display list, or a 1-word cache of
2630 // the secondary superclass list, or a failing value with a sentinel offset
2631 // if the super-klass is an interface or exceptionally deep in the Java
2632 // hierarchy and we have to scan the secondary superclass list the hard way.
2633 // Worst-case type is a little odd: NULL is allowed as a result (usually
2634 // klass loads can never produce a NULL).
2635 Node *chk_off_X = chk_off;
2636 #ifdef _LP64
2637 chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2638 #endif
2639 Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2640 // For some types like interfaces the following loadKlass is from a 1-word
2641 // cache which is mutable so can't use immutable memory. Other
2642 // types load from the super-class display table which is immutable.
2643 m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2644 Node *kmem = might_be_cache ? m : C->immutable_memory();
2645 Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2646
2647 // Compile speed common case: ARE a subtype and we canNOT fail
2648 if( superklass == nkls )
2649 return C->top(); // false path is dead; no test needed.
2650
2651 // See if we get an immediate positive hit. Happens roughly 83% of the
2652 // time. Test to see if the value loaded just previously from the subklass
2653 // is exactly the superklass.
2654 IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2655 Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2656 *ctrl = gvn->transform(new IfFalseNode(iff1));
2657
2658 // Compile speed common case: Check for being deterministic right now. If
2659 // chk_off is a constant and not equal to cacheoff then we are NOT a
2660 // subklass. In this case we need exactly the 1 test above and we can
2661 // return those results immediately.
2662 if (!might_be_cache) {
2663 Node* not_subtype_ctrl = *ctrl;
2664 *ctrl = iftrue1; // We need exactly the 1 test above
2665 return not_subtype_ctrl;
2666 }
2667
2668 // Gather the various success & failures here
2669 RegionNode *r_ok_subtype = new RegionNode(4);
2670 gvn->record_for_igvn(r_ok_subtype);
2671 RegionNode *r_not_subtype = new RegionNode(3);
2672 gvn->record_for_igvn(r_not_subtype);
2673
2674 r_ok_subtype->init_req(1, iftrue1);
2675
2676 // Check for immediate negative hit. Happens roughly 11% of the time (which
2677 // is roughly 63% of the remaining cases). Test to see if the loaded
2678 // check-offset points into the subklass display list or the 1-element
2679 // cache. If it points to the display (and NOT the cache) and the display
2680 // missed then it's not a subtype.
2681 Node *cacheoff = gvn->intcon(cacheoff_con);
2682 IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2683 r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2684 *ctrl = gvn->transform(new IfFalseNode(iff2));
2685
2686 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2687 // No performance impact (too rare) but allows sharing of secondary arrays
2688 // which has some footprint reduction.
2689 IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2690 r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2691 *ctrl = gvn->transform(new IfFalseNode(iff3));
2692
2693 // -- Roads not taken here: --
2694 // We could also have chosen to perform the self-check at the beginning
2695 // of this code sequence, as the assembler does. This would not pay off
2696 // the same way, since the optimizer, unlike the assembler, can perform
2697 // static type analysis to fold away many successful self-checks.
2698 // Non-foldable self checks work better here in second position, because
2699 // the initial primary superclass check subsumes a self-check for most
2700 // types. An exception would be a secondary type like array-of-interface,
2701 // which does not appear in its own primary supertype display.
2702 // Finally, we could have chosen to move the self-check into the
2703 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2704 // dependent manner. But it is worthwhile to have the check here,
2705 // where it can be perhaps be optimized. The cost in code space is
2706 // small (register compare, branch).
2707
2708 // Now do a linear scan of the secondary super-klass array. Again, no real
2709 // performance impact (too rare) but it's gotta be done.
2710 // Since the code is rarely used, there is no penalty for moving it
2711 // out of line, and it can only improve I-cache density.
2712 // The decision to inline or out-of-line this final check is platform
2713 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2714 Node* psc = gvn->transform(
2715 new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2716
2717 IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2718 r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2719 r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2720
2721 // Return false path; set default control to true path.
2722 *ctrl = gvn->transform(r_ok_subtype);
2723 return gvn->transform(r_not_subtype);
2724 }
2725
2726 // Profile-driven exact type check:
2727 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2728 float prob,
2729 Node* *casted_receiver) {
2730 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2731 Node* recv_klass = load_object_klass(receiver);
2732 Node* want_klass = makecon(tklass);
2733 Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2734 Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2735 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2736 set_control( _gvn.transform( new IfTrueNode (iff) ));
2737 Node* fail = _gvn.transform( new IfFalseNode(iff) );
2738
2739 const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2740 assert(recv_xtype->klass_is_exact(), "");
2741
2742 // Subsume downstream occurrences of receiver with a cast to
2743 // recv_xtype, since now we know what the type will be.
2744 Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2745 (*casted_receiver) = _gvn.transform(cast);
2746 // (User must make the replace_in_map call.)
2747
2748 return fail;
2749 }
2750
2751
2752 //------------------------------seems_never_null-------------------------------
2753 // Use null_seen information if it is available from the profile.
2754 // If we see an unexpected null at a type check we record it and force a
2755 // recompile; the offending check will be recompiled to handle NULLs.
2756 // If we see several offending BCIs, then all checks in the
2757 // method will be recompiled.
2758 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2759 speculating = !_gvn.type(obj)->speculative_maybe_null();
2760 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2761 if (UncommonNullCast // Cutout for this technique
2762 && obj != null() // And not the -Xcomp stupid case?
2763 && !too_many_traps(reason)
2764 ) {
2765 if (speculating) {
2766 return true;
2767 }
2768 if (data == NULL)
2769 // Edge case: no mature data. Be optimistic here.
2770 return true;
2771 // If the profile has not seen a null, assume it won't happen.
2772 assert(java_bc() == Bytecodes::_checkcast ||
2773 java_bc() == Bytecodes::_instanceof ||
2774 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2775 return !data->as_BitData()->null_seen();
2776 }
2777 speculating = false;
2778 return false;
2779 }
2780
2781 //------------------------maybe_cast_profiled_receiver-------------------------
2782 // If the profile has seen exactly one type, narrow to exactly that type.
2783 // Subsequent type checks will always fold up.
2784 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2785 ciKlass* require_klass,
2786 ciKlass* spec_klass,
2787 bool safe_for_replace) {
2788 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2789
2790 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2791
2792 // Make sure we haven't already deoptimized from this tactic.
2793 if (too_many_traps(reason) || too_many_recompiles(reason))
2794 return NULL;
2795
2796 // (No, this isn't a call, but it's enough like a virtual call
2797 // to use the same ciMethod accessor to get the profile info...)
2798 // If we have a speculative type use it instead of profiling (which
2799 // may not help us)
2800 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2801 if (exact_kls != NULL) {// no cast failures here
2802 if (require_klass == NULL ||
2803 C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2804 // If we narrow the type to match what the type profile sees or
2805 // the speculative type, we can then remove the rest of the
2806 // cast.
2807 // This is a win, even if the exact_kls is very specific,
2808 // because downstream operations, such as method calls,
2809 // will often benefit from the sharper type.
2810 Node* exact_obj = not_null_obj; // will get updated in place...
2811 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2812 &exact_obj);
2813 { PreserveJVMState pjvms(this);
2814 set_control(slow_ctl);
2815 uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2816 }
2817 if (safe_for_replace) {
2818 replace_in_map(not_null_obj, exact_obj);
2819 }
2820 return exact_obj;
2821 }
2822 // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2823 }
2824
2825 return NULL;
2826 }
2827
2828 /**
2829 * Cast obj to type and emit guard unless we had too many traps here
2830 * already
2831 *
2832 * @param obj node being casted
2833 * @param type type to cast the node to
2834 * @param not_null true if we know node cannot be null
2835 */
2836 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2837 ciKlass* type,
2838 bool not_null) {
2839 if (stopped()) {
2840 return obj;
2841 }
2842
2843 // type == NULL if profiling tells us this object is always null
2844 if (type != NULL) {
2845 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2846 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2847
2848 if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2849 !too_many_traps(class_reason) &&
2850 !too_many_recompiles(class_reason)) {
2851 Node* not_null_obj = NULL;
2852 // not_null is true if we know the object is not null and
2853 // there's no need for a null check
2854 if (!not_null) {
2855 Node* null_ctl = top();
2856 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2857 assert(null_ctl->is_top(), "no null control here");
2858 } else {
2859 not_null_obj = obj;
2860 }
2861
2862 Node* exact_obj = not_null_obj;
2863 ciKlass* exact_kls = type;
2864 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2865 &exact_obj);
2866 {
2867 PreserveJVMState pjvms(this);
2868 set_control(slow_ctl);
2869 uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2870 }
2871 replace_in_map(not_null_obj, exact_obj);
2872 obj = exact_obj;
2873 }
2874 } else {
2875 if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2876 !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2877 Node* exact_obj = null_assert(obj);
2878 replace_in_map(obj, exact_obj);
2879 obj = exact_obj;
2880 }
2881 }
2882 return obj;
2883 }
2884
2885 //-------------------------------gen_instanceof--------------------------------
2886 // Generate an instance-of idiom. Used by both the instance-of bytecode
2887 // and the reflective instance-of call.
2888 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2889 kill_dead_locals(); // Benefit all the uncommon traps
2890 assert( !stopped(), "dead parse path should be checked in callers" );
2891 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2892 "must check for not-null not-dead klass in callers");
2893
2894 // Make the merge point
2895 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2896 RegionNode* region = new RegionNode(PATH_LIMIT);
2897 Node* phi = new PhiNode(region, TypeInt::BOOL);
2898 C->set_has_split_ifs(true); // Has chance for split-if optimization
2899
2900 ciProfileData* data = NULL;
2901 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode
2902 data = method()->method_data()->bci_to_data(bci());
2903 }
2904 bool speculative_not_null = false;
2905 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile
2906 && seems_never_null(obj, data, speculative_not_null));
2907
2908 // Null check; get casted pointer; set region slot 3
2909 Node* null_ctl = top();
2910 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2911
2912 // If not_null_obj is dead, only null-path is taken
2913 if (stopped()) { // Doing instance-of on a NULL?
2914 set_control(null_ctl);
2915 return intcon(0);
2916 }
2917 region->init_req(_null_path, null_ctl);
2918 phi ->init_req(_null_path, intcon(0)); // Set null path value
2919 if (null_ctl == top()) {
2920 // Do this eagerly, so that pattern matches like is_diamond_phi
2921 // will work even during parsing.
2922 assert(_null_path == PATH_LIMIT-1, "delete last");
2923 region->del_req(_null_path);
2924 phi ->del_req(_null_path);
2925 }
2926
2927 // Do we know the type check always succeed?
2928 bool known_statically = false;
2929 if (_gvn.type(superklass)->singleton()) {
2930 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2931 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2932 if (subk != NULL && subk->is_loaded()) {
2933 int static_res = C->static_subtype_check(superk, subk);
2934 known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2935 }
2936 }
2937
2938 if (known_statically && UseTypeSpeculation) {
2939 // If we know the type check always succeeds then we don't use the
2940 // profiling data at this bytecode. Don't lose it, feed it to the
2941 // type system as a speculative type.
2942 not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2943 } else {
2944 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2945 // We may not have profiling here or it may not help us. If we
2946 // have a speculative type use it to perform an exact cast.
2947 ciKlass* spec_obj_type = obj_type->speculative_type();
2948 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2949 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2950 if (stopped()) { // Profile disagrees with this path.
2951 set_control(null_ctl); // Null is the only remaining possibility.
2952 return intcon(0);
2953 }
2954 if (cast_obj != NULL) {
2955 not_null_obj = cast_obj;
2956 }
2957 }
2958 }
2959
2960 if (ShenandoahVerifyReadsToFromSpace) {
2961 not_null_obj = shenandoah_read_barrier(not_null_obj);
2962 }
2963
2964 // Load the object's klass
2965 Node* obj_klass = load_object_klass(not_null_obj);
2966
2967 // Generate the subtype check
2968 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2969
2970 // Plug in the success path to the general merge in slot 1.
2971 region->init_req(_obj_path, control());
2972 phi ->init_req(_obj_path, intcon(1));
2973
2974 // Plug in the failing path to the general merge in slot 2.
2975 region->init_req(_fail_path, not_subtype_ctrl);
2976 phi ->init_req(_fail_path, intcon(0));
2977
2978 // Return final merged results
2979 set_control( _gvn.transform(region) );
2980 record_for_igvn(region);
2981 return _gvn.transform(phi);
2982 }
2983
2984 //-------------------------------gen_checkcast---------------------------------
2985 // Generate a checkcast idiom. Used by both the checkcast bytecode and the
2986 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the
2987 // uncommon-trap paths work. Adjust stack after this call.
2988 // If failure_control is supplied and not null, it is filled in with
2989 // the control edge for the cast failure. Otherwise, an appropriate
2990 // uncommon trap or exception is thrown.
2991 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2992 Node* *failure_control) {
2993 kill_dead_locals(); // Benefit all the uncommon traps
2994 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2995 const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2996
2997 // Fast cutout: Check the case that the cast is vacuously true.
2998 // This detects the common cases where the test will short-circuit
2999 // away completely. We do this before we perform the null check,
3000 // because if the test is going to turn into zero code, we don't
3001 // want a residual null check left around. (Causes a slowdown,
3002 // for example, in some objArray manipulations, such as a[i]=a[j].)
3003 if (tk->singleton()) {
3004 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3005 if (objtp != NULL && objtp->klass() != NULL) {
3006 switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3007 case Compile::SSC_always_true:
3008 // If we know the type check always succeed then we don't use
3009 // the profiling data at this bytecode. Don't lose it, feed it
3010 // to the type system as a speculative type.
3011 return record_profiled_receiver_for_speculation(obj);
3012 case Compile::SSC_always_false:
3013 // It needs a null check because a null will *pass* the cast check.
3014 // A non-null value will always produce an exception.
3015 return null_assert(obj);
3016 }
3017 }
3018 }
3019
3020 ciProfileData* data = NULL;
3021 bool safe_for_replace = false;
3022 if (failure_control == NULL) { // use MDO in regular case only
3023 assert(java_bc() == Bytecodes::_aastore ||
3024 java_bc() == Bytecodes::_checkcast,
3025 "interpreter profiles type checks only for these BCs");
3026 data = method()->method_data()->bci_to_data(bci());
3027 safe_for_replace = true;
3028 }
3029
3030 // Make the merge point
3031 enum { _obj_path = 1, _null_path, PATH_LIMIT };
3032 RegionNode* region = new RegionNode(PATH_LIMIT);
3033 Node* phi = new PhiNode(region, toop);
3034 C->set_has_split_ifs(true); // Has chance for split-if optimization
3035
3036 // Use null-cast information if it is available
3037 bool speculative_not_null = false;
3038 bool never_see_null = ((failure_control == NULL) // regular case only
3039 && seems_never_null(obj, data, speculative_not_null));
3040
3041 // Null check; get casted pointer; set region slot 3
3042 Node* null_ctl = top();
3043 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3044
3045 if (ShenandoahVerifyReadsToFromSpace) {
3046 not_null_obj = shenandoah_read_barrier(not_null_obj);
3047 }
3048
3049 // If not_null_obj is dead, only null-path is taken
3050 if (stopped()) { // Doing instance-of on a NULL?
3051 set_control(null_ctl);
3052 return null();
3053 }
3054 region->init_req(_null_path, null_ctl);
3055 phi ->init_req(_null_path, null()); // Set null path value
3056 if (null_ctl == top()) {
3057 // Do this eagerly, so that pattern matches like is_diamond_phi
3058 // will work even during parsing.
3059 assert(_null_path == PATH_LIMIT-1, "delete last");
3060 region->del_req(_null_path);
3061 phi ->del_req(_null_path);
3062 }
3063
3064 Node* cast_obj = NULL;
3065 if (tk->klass_is_exact()) {
3066 // The following optimization tries to statically cast the speculative type of the object
3067 // (for example obtained during profiling) to the type of the superklass and then do a
3068 // dynamic check that the type of the object is what we expect. To work correctly
3069 // for checkcast and aastore the type of superklass should be exact.
3070 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3071 // We may not have profiling here or it may not help us. If we have
3072 // a speculative type use it to perform an exact cast.
3073 ciKlass* spec_obj_type = obj_type->speculative_type();
3074 if (spec_obj_type != NULL || data != NULL) {
3075 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3076 if (cast_obj != NULL) {
3077 if (failure_control != NULL) // failure is now impossible
3078 (*failure_control) = top();
3079 // adjust the type of the phi to the exact klass:
3080 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3081 }
3082 }
3083 }
3084
3085 if (cast_obj == NULL) {
3086 // Load the object's klass
3087 Node* obj_klass = load_object_klass(not_null_obj);
3088
3089 // Generate the subtype check
3090 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3091
3092 // Plug in success path into the merge
3093 cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3094 // Failure path ends in uncommon trap (or may be dead - failure impossible)
3095 if (failure_control == NULL) {
3096 if (not_subtype_ctrl != top()) { // If failure is possible
3097 PreserveJVMState pjvms(this);
3098 set_control(not_subtype_ctrl);
3099 builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3100 }
3101 } else {
3102 (*failure_control) = not_subtype_ctrl;
3103 }
3104 }
3105
3106 region->init_req(_obj_path, control());
3107 phi ->init_req(_obj_path, cast_obj);
3108
3109 // A merge of NULL or Casted-NotNull obj
3110 Node* res = _gvn.transform(phi);
3111
3112 // Note I do NOT always 'replace_in_map(obj,result)' here.
3113 // if( tk->klass()->can_be_primary_super() )
3114 // This means that if I successfully store an Object into an array-of-String
3115 // I 'forget' that the Object is really now known to be a String. I have to
3116 // do this because we don't have true union types for interfaces - if I store
3117 // a Baz into an array-of-Interface and then tell the optimizer it's an
3118 // Interface, I forget that it's also a Baz and cannot do Baz-like field
3119 // references to it. FIX THIS WHEN UNION TYPES APPEAR!
3120 // replace_in_map( obj, res );
3121
3122 // Return final merged results
3123 set_control( _gvn.transform(region) );
3124 record_for_igvn(region);
3125 return res;
3126 }
3127
3128 //------------------------------next_monitor-----------------------------------
3129 // What number should be given to the next monitor?
3130 int GraphKit::next_monitor() {
3131 int current = jvms()->monitor_depth()* C->sync_stack_slots();
3132 int next = current + C->sync_stack_slots();
3133 // Keep the toplevel high water mark current:
3134 if (C->fixed_slots() < next) C->set_fixed_slots(next);
3135 return current;
3136 }
3137
3138 //------------------------------insert_mem_bar---------------------------------
3139 // Memory barrier to avoid floating things around
3140 // The membar serves as a pinch point between both control and all memory slices.
3141 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3142 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3143 mb->init_req(TypeFunc::Control, control());
3144 mb->init_req(TypeFunc::Memory, reset_memory());
3145 Node* membar = _gvn.transform(mb);
3146 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3147 set_all_memory_call(membar);
3148 return membar;
3149 }
3150
3151 //-------------------------insert_mem_bar_volatile----------------------------
3152 // Memory barrier to avoid floating things around
3153 // The membar serves as a pinch point between both control and memory(alias_idx).
3154 // If you want to make a pinch point on all memory slices, do not use this
3155 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3156 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3157 // When Parse::do_put_xxx updates a volatile field, it appends a series
3158 // of MemBarVolatile nodes, one for *each* volatile field alias category.
3159 // The first membar is on the same memory slice as the field store opcode.
3160 // This forces the membar to follow the store. (Bug 6500685 broke this.)
3161 // All the other membars (for other volatile slices, including AliasIdxBot,
3162 // which stands for all unknown volatile slices) are control-dependent
3163 // on the first membar. This prevents later volatile loads or stores
3164 // from sliding up past the just-emitted store.
3165
3166 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3167 mb->set_req(TypeFunc::Control,control());
3168 if (alias_idx == Compile::AliasIdxBot) {
3169 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3170 } else {
3171 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3172 mb->set_req(TypeFunc::Memory, memory(alias_idx));
3173 }
3174 Node* membar = _gvn.transform(mb);
3175 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3176 if (alias_idx == Compile::AliasIdxBot) {
3177 merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3178 } else {
3179 set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3180 }
3181 return membar;
3182 }
3183
3184 //------------------------------shared_lock------------------------------------
3185 // Emit locking code.
3186 FastLockNode* GraphKit::shared_lock(Node* obj) {
3187 // bci is either a monitorenter bc or InvocationEntryBci
3188 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3189 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3190
3191 if( !GenerateSynchronizationCode )
3192 return NULL; // Not locking things?
3193 if (stopped()) // Dead monitor?
3194 return NULL;
3195
3196 assert(dead_locals_are_killed(), "should kill locals before sync. point");
3197
3198 obj = shenandoah_write_barrier(obj);
3199
3200 // Box the stack location
3201 Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3202 Node* mem = reset_memory();
3203
3204 FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3205 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3206 // Create the counters for this fast lock.
3207 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3208 }
3209
3210 // Create the rtm counters for this fast lock if needed.
3211 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3212
3213 // Add monitor to debug info for the slow path. If we block inside the
3214 // slow path and de-opt, we need the monitor hanging around
3215 map()->push_monitor( flock );
3216
3217 const TypeFunc *tf = LockNode::lock_type();
3218 LockNode *lock = new LockNode(C, tf);
3219
3220 lock->init_req( TypeFunc::Control, control() );
3221 lock->init_req( TypeFunc::Memory , mem );
3222 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3223 lock->init_req( TypeFunc::FramePtr, frameptr() );
3224 lock->init_req( TypeFunc::ReturnAdr, top() );
3225
3226 lock->init_req(TypeFunc::Parms + 0, obj);
3227 lock->init_req(TypeFunc::Parms + 1, box);
3228 lock->init_req(TypeFunc::Parms + 2, flock);
3229 add_safepoint_edges(lock);
3230
3231 lock = _gvn.transform( lock )->as_Lock();
3232
3233 // lock has no side-effects, sets few values
3234 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3235
3236 insert_mem_bar(Op_MemBarAcquireLock);
3237
3238 // Add this to the worklist so that the lock can be eliminated
3239 record_for_igvn(lock);
3240
3241 #ifndef PRODUCT
3242 if (PrintLockStatistics) {
3243 // Update the counter for this lock. Don't bother using an atomic
3244 // operation since we don't require absolute accuracy.
3245 lock->create_lock_counter(map()->jvms());
3246 increment_counter(lock->counter()->addr());
3247 }
3248 #endif
3249
3250 return flock;
3251 }
3252
3253
3254 //------------------------------shared_unlock----------------------------------
3255 // Emit unlocking code.
3256 void GraphKit::shared_unlock(Node* box, Node* obj) {
3257 // bci is either a monitorenter bc or InvocationEntryBci
3258 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3259 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3260
3261 if( !GenerateSynchronizationCode )
3262 return;
3263 if (stopped()) { // Dead monitor?
3264 map()->pop_monitor(); // Kill monitor from debug info
3265 return;
3266 }
3267
3268 // Memory barrier to avoid floating things down past the locked region
3269 insert_mem_bar(Op_MemBarReleaseLock);
3270
3271 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3272 UnlockNode *unlock = new UnlockNode(C, tf);
3273 #ifdef ASSERT
3274 unlock->set_dbg_jvms(sync_jvms());
3275 #endif
3276 uint raw_idx = Compile::AliasIdxRaw;
3277 unlock->init_req( TypeFunc::Control, control() );
3278 unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3279 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3280 unlock->init_req( TypeFunc::FramePtr, frameptr() );
3281 unlock->init_req( TypeFunc::ReturnAdr, top() );
3282
3283 unlock->init_req(TypeFunc::Parms + 0, obj);
3284 unlock->init_req(TypeFunc::Parms + 1, box);
3285 unlock = _gvn.transform(unlock)->as_Unlock();
3286
3287 Node* mem = reset_memory();
3288
3289 // unlock has no side-effects, sets few values
3290 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3291
3292 // Kill monitor from debug info
3293 map()->pop_monitor( );
3294 }
3295
3296 //-------------------------------get_layout_helper-----------------------------
3297 // If the given klass is a constant or known to be an array,
3298 // fetch the constant layout helper value into constant_value
3299 // and return (Node*)NULL. Otherwise, load the non-constant
3300 // layout helper value, and return the node which represents it.
3301 // This two-faced routine is useful because allocation sites
3302 // almost always feature constant types.
3303 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3304 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3305 if (!StressReflectiveCode && inst_klass != NULL) {
3306 ciKlass* klass = inst_klass->klass();
3307 bool xklass = inst_klass->klass_is_exact();
3308 if (xklass || klass->is_array_klass()) {
3309 jint lhelper = klass->layout_helper();
3310 if (lhelper != Klass::_lh_neutral_value) {
3311 constant_value = lhelper;
3312 return (Node*) NULL;
3313 }
3314 }
3315 }
3316 constant_value = Klass::_lh_neutral_value; // put in a known value
3317 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3318 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3319 }
3320
3321 // We just put in an allocate/initialize with a big raw-memory effect.
3322 // Hook selected additional alias categories on the initialization.
3323 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3324 MergeMemNode* init_in_merge,
3325 Node* init_out_raw) {
3326 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3327 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3328
3329 Node* prevmem = kit.memory(alias_idx);
3330 init_in_merge->set_memory_at(alias_idx, prevmem);
3331 kit.set_memory(init_out_raw, alias_idx);
3332 }
3333
3334 //---------------------------set_output_for_allocation-------------------------
3335 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3336 const TypeOopPtr* oop_type,
3337 bool deoptimize_on_exception) {
3338 int rawidx = Compile::AliasIdxRaw;
3339 alloc->set_req( TypeFunc::FramePtr, frameptr() );
3340 add_safepoint_edges(alloc);
3341 Node* allocx = _gvn.transform(alloc);
3342 set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3343 // create memory projection for i_o
3344 set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3345 make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3346
3347 // create a memory projection as for the normal control path
3348 Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3349 set_memory(malloc, rawidx);
3350
3351 // a normal slow-call doesn't change i_o, but an allocation does
3352 // we create a separate i_o projection for the normal control path
3353 set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3354 Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3355
3356 // put in an initialization barrier
3357 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3358 rawoop)->as_Initialize();
3359 assert(alloc->initialization() == init, "2-way macro link must work");
3360 assert(init ->allocation() == alloc, "2-way macro link must work");
3361 {
3362 // Extract memory strands which may participate in the new object's
3363 // initialization, and source them from the new InitializeNode.
3364 // This will allow us to observe initializations when they occur,
3365 // and link them properly (as a group) to the InitializeNode.
3366 assert(init->in(InitializeNode::Memory) == malloc, "");
3367 MergeMemNode* minit_in = MergeMemNode::make(malloc);
3368 init->set_req(InitializeNode::Memory, minit_in);
3369 record_for_igvn(minit_in); // fold it up later, if possible
3370 Node* minit_out = memory(rawidx);
3371 assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3372 if (oop_type->isa_aryptr()) {
3373 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3374 int elemidx = C->get_alias_index(telemref);
3375 hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3376 } else if (oop_type->isa_instptr()) {
3377 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3378 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3379 ciField* field = ik->nonstatic_field_at(i);
3380 if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3381 continue; // do not bother to track really large numbers of fields
3382 // Find (or create) the alias category for this field:
3383 int fieldidx = C->alias_type(field)->index();
3384 hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3385 }
3386 }
3387 }
3388
3389 // Cast raw oop to the real thing...
3390 Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3391 javaoop = _gvn.transform(javaoop);
3392 C->set_recent_alloc(control(), javaoop);
3393 assert(just_allocated_object(control()) == javaoop, "just allocated");
3394
3395 #ifdef ASSERT
3396 { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3397 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3398 "Ideal_allocation works");
3399 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3400 "Ideal_allocation works");
3401 if (alloc->is_AllocateArray()) {
3402 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3403 "Ideal_allocation works");
3404 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3405 "Ideal_allocation works");
3406 } else {
3407 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3408 }
3409 }
3410 #endif //ASSERT
3411
3412 return javaoop;
3413 }
3414
3415 //---------------------------new_instance--------------------------------------
3416 // This routine takes a klass_node which may be constant (for a static type)
3417 // or may be non-constant (for reflective code). It will work equally well
3418 // for either, and the graph will fold nicely if the optimizer later reduces
3419 // the type to a constant.
3420 // The optional arguments are for specialized use by intrinsics:
3421 // - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3422 // - If 'return_size_val', report the the total object size to the caller.
3423 // - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3424 Node* GraphKit::new_instance(Node* klass_node,
3425 Node* extra_slow_test,
3426 Node* *return_size_val,
3427 bool deoptimize_on_exception) {
3428 // Compute size in doublewords
3429 // The size is always an integral number of doublewords, represented
3430 // as a positive bytewise size stored in the klass's layout_helper.
3431 // The layout_helper also encodes (in a low bit) the need for a slow path.
3432 jint layout_con = Klass::_lh_neutral_value;
3433 Node* layout_val = get_layout_helper(klass_node, layout_con);
3434 int layout_is_con = (layout_val == NULL);
3435
3436 if (extra_slow_test == NULL) extra_slow_test = intcon(0);
3437 // Generate the initial go-slow test. It's either ALWAYS (return a
3438 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3439 // case) a computed value derived from the layout_helper.
3440 Node* initial_slow_test = NULL;
3441 if (layout_is_con) {
3442 assert(!StressReflectiveCode, "stress mode does not use these paths");
3443 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3444 initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3445 } else { // reflective case
3446 // This reflective path is used by Unsafe.allocateInstance.
3447 // (It may be stress-tested by specifying StressReflectiveCode.)
3448 // Basically, we want to get into the VM is there's an illegal argument.
3449 Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3450 initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3451 if (extra_slow_test != intcon(0)) {
3452 initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3453 }
3454 // (Macro-expander will further convert this to a Bool, if necessary.)
3455 }
3456
3457 // Find the size in bytes. This is easy; it's the layout_helper.
3458 // The size value must be valid even if the slow path is taken.
3459 Node* size = NULL;
3460 if (layout_is_con) {
3461 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3462 } else { // reflective case
3463 // This reflective path is used by clone and Unsafe.allocateInstance.
3464 size = ConvI2X(layout_val);
3465
3466 // Clear the low bits to extract layout_helper_size_in_bytes:
3467 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3468 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3469 size = _gvn.transform( new AndXNode(size, mask) );
3470 }
3471 if (return_size_val != NULL) {
3472 (*return_size_val) = size;
3473 }
3474
3475 // This is a precise notnull oop of the klass.
3476 // (Actually, it need not be precise if this is a reflective allocation.)
3477 // It's what we cast the result to.
3478 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3479 if (!tklass) tklass = TypeKlassPtr::OBJECT;
3480 const TypeOopPtr* oop_type = tklass->as_instance_type();
3481
3482 // Now generate allocation code
3483
3484 // The entire memory state is needed for slow path of the allocation
3485 // since GC and deoptimization can happened.
3486 Node *mem = reset_memory();
3487 set_all_memory(mem); // Create new memory state
3488
3489 AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3490 control(), mem, i_o(),
3491 size, klass_node,
3492 initial_slow_test);
3493
3494 return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3495 }
3496
3497 //-------------------------------new_array-------------------------------------
3498 // helper for both newarray and anewarray
3499 // The 'length' parameter is (obviously) the length of the array.
3500 // See comments on new_instance for the meaning of the other arguments.
3501 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable)
3502 Node* length, // number of array elements
3503 int nargs, // number of arguments to push back for uncommon trap
3504 Node* *return_size_val,
3505 bool deoptimize_on_exception) {
3506 jint layout_con = Klass::_lh_neutral_value;
3507 Node* layout_val = get_layout_helper(klass_node, layout_con);
3508 int layout_is_con = (layout_val == NULL);
3509
3510 if (!layout_is_con && !StressReflectiveCode &&
3511 !too_many_traps(Deoptimization::Reason_class_check)) {
3512 // This is a reflective array creation site.
3513 // Optimistically assume that it is a subtype of Object[],
3514 // so that we can fold up all the address arithmetic.
3515 layout_con = Klass::array_layout_helper(T_OBJECT);
3516 Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3517 Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3518 { BuildCutout unless(this, bol_lh, PROB_MAX);
3519 inc_sp(nargs);
3520 uncommon_trap(Deoptimization::Reason_class_check,
3521 Deoptimization::Action_maybe_recompile);
3522 }
3523 layout_val = NULL;
3524 layout_is_con = true;
3525 }
3526
3527 // Generate the initial go-slow test. Make sure we do not overflow
3528 // if length is huge (near 2Gig) or negative! We do not need
3529 // exact double-words here, just a close approximation of needed
3530 // double-words. We can't add any offset or rounding bits, lest we
3531 // take a size -1 of bytes and make it positive. Use an unsigned
3532 // compare, so negative sizes look hugely positive.
3533 int fast_size_limit = FastAllocateSizeLimit;
3534 if (layout_is_con) {
3535 assert(!StressReflectiveCode, "stress mode does not use these paths");
3536 // Increase the size limit if we have exact knowledge of array type.
3537 int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3538 fast_size_limit <<= (LogBytesPerLong - log2_esize);
3539 }
3540
3541 Node* initial_slow_cmp = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3542 Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3543
3544 // --- Size Computation ---
3545 // array_size = round_to_heap(array_header + (length << elem_shift));
3546 // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3547 // and round_to(x, y) == ((x + y-1) & ~(y-1))
3548 // The rounding mask is strength-reduced, if possible.
3549 int round_mask = MinObjAlignmentInBytes - 1;
3550 Node* header_size = NULL;
3551 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3552 // (T_BYTE has the weakest alignment and size restrictions...)
3553 if (layout_is_con) {
3554 int hsize = Klass::layout_helper_header_size(layout_con);
3555 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3556 BasicType etype = Klass::layout_helper_element_type(layout_con);
3557 if ((round_mask & ~right_n_bits(eshift)) == 0)
3558 round_mask = 0; // strength-reduce it if it goes away completely
3559 assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3560 assert(header_size_min <= hsize, "generic minimum is smallest");
3561 header_size_min = hsize;
3562 header_size = intcon(hsize + round_mask);
3563 } else {
3564 Node* hss = intcon(Klass::_lh_header_size_shift);
3565 Node* hsm = intcon(Klass::_lh_header_size_mask);
3566 Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3567 hsize = _gvn.transform( new AndINode(hsize, hsm) );
3568 Node* mask = intcon(round_mask);
3569 header_size = _gvn.transform( new AddINode(hsize, mask) );
3570 }
3571
3572 Node* elem_shift = NULL;
3573 if (layout_is_con) {
3574 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3575 if (eshift != 0)
3576 elem_shift = intcon(eshift);
3577 } else {
3578 // There is no need to mask or shift this value.
3579 // The semantics of LShiftINode include an implicit mask to 0x1F.
3580 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3581 elem_shift = layout_val;
3582 }
3583
3584 // Transition to native address size for all offset calculations:
3585 Node* lengthx = ConvI2X(length);
3586 Node* headerx = ConvI2X(header_size);
3587 #ifdef _LP64
3588 { const TypeInt* tilen = _gvn.find_int_type(length);
3589 if (tilen != NULL && tilen->_lo < 0) {
3590 // Add a manual constraint to a positive range. Cf. array_element_address.
3591 jint size_max = fast_size_limit;
3592 if (size_max > tilen->_hi) size_max = tilen->_hi;
3593 const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3594
3595 // Only do a narrow I2L conversion if the range check passed.
3596 IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3597 _gvn.transform(iff);
3598 RegionNode* region = new RegionNode(3);
3599 _gvn.set_type(region, Type::CONTROL);
3600 lengthx = new PhiNode(region, TypeLong::LONG);
3601 _gvn.set_type(lengthx, TypeLong::LONG);
3602
3603 // Range check passed. Use ConvI2L node with narrow type.
3604 Node* passed = IfFalse(iff);
3605 region->init_req(1, passed);
3606 // Make I2L conversion control dependent to prevent it from
3607 // floating above the range check during loop optimizations.
3608 lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3609
3610 // Range check failed. Use ConvI2L with wide type because length may be invalid.
3611 region->init_req(2, IfTrue(iff));
3612 lengthx->init_req(2, ConvI2X(length));
3613
3614 set_control(region);
3615 record_for_igvn(region);
3616 record_for_igvn(lengthx);
3617 }
3618 }
3619 #endif
3620
3621 // Combine header size (plus rounding) and body size. Then round down.
3622 // This computation cannot overflow, because it is used only in two
3623 // places, one where the length is sharply limited, and the other
3624 // after a successful allocation.
3625 Node* abody = lengthx;
3626 if (elem_shift != NULL)
3627 abody = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3628 Node* size = _gvn.transform( new AddXNode(headerx, abody) );
3629 if (round_mask != 0) {
3630 Node* mask = MakeConX(~round_mask);
3631 size = _gvn.transform( new AndXNode(size, mask) );
3632 }
3633 // else if round_mask == 0, the size computation is self-rounding
3634
3635 if (return_size_val != NULL) {
3636 // This is the size
3637 (*return_size_val) = size;
3638 }
3639
3640 // Now generate allocation code
3641
3642 // The entire memory state is needed for slow path of the allocation
3643 // since GC and deoptimization can happened.
3644 Node *mem = reset_memory();
3645 set_all_memory(mem); // Create new memory state
3646
3647 if (initial_slow_test->is_Bool()) {
3648 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3649 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3650 }
3651
3652 // Create the AllocateArrayNode and its result projections
3653 AllocateArrayNode* alloc
3654 = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3655 control(), mem, i_o(),
3656 size, klass_node,
3657 initial_slow_test,
3658 length);
3659
3660 // Cast to correct type. Note that the klass_node may be constant or not,
3661 // and in the latter case the actual array type will be inexact also.
3662 // (This happens via a non-constant argument to inline_native_newArray.)
3663 // In any case, the value of klass_node provides the desired array type.
3664 const TypeInt* length_type = _gvn.find_int_type(length);
3665 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3666 if (ary_type->isa_aryptr() && length_type != NULL) {
3667 // Try to get a better type than POS for the size
3668 ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3669 }
3670
3671 Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3672
3673 // Cast length on remaining path to be as narrow as possible
3674 if (map()->find_edge(length) >= 0) {
3675 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3676 if (ccast != length) {
3677 _gvn.set_type_bottom(ccast);
3678 record_for_igvn(ccast);
3679 replace_in_map(length, ccast);
3680 }
3681 }
3682
3683 return javaoop;
3684 }
3685
3686 // The following "Ideal_foo" functions are placed here because they recognize
3687 // the graph shapes created by the functions immediately above.
3688
3689 //---------------------------Ideal_allocation----------------------------------
3690 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3691 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3692 if (ptr == NULL) { // reduce dumb test in callers
3693 return NULL;
3694 }
3695
3696 // Attempt to see through Shenandoah barriers.
3697 ptr = ShenandoahBarrierNode::skip_through_barrier(ptr);
3698
3699 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3700 ptr = ptr->in(1);
3701 if (ptr == NULL) return NULL;
3702 }
3703 // Return NULL for allocations with several casts:
3704 // j.l.reflect.Array.newInstance(jobject, jint)
3705 // Object.clone()
3706 // to keep more precise type from last cast.
3707 if (ptr->is_Proj()) {
3708 Node* allo = ptr->in(0);
3709 if (allo != NULL && allo->is_Allocate()) {
3710 return allo->as_Allocate();
3711 }
3712 }
3713 // Report failure to match.
3714 return NULL;
3715 }
3716
3717 // Fancy version which also strips off an offset (and reports it to caller).
3718 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3719 intptr_t& offset) {
3720 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3721 if (base == NULL) return NULL;
3722 return Ideal_allocation(base, phase);
3723 }
3724
3725 // Trace Initialize <- Proj[Parm] <- Allocate
3726 AllocateNode* InitializeNode::allocation() {
3727 Node* rawoop = in(InitializeNode::RawAddress);
3728 if (rawoop->is_Proj()) {
3729 Node* alloc = rawoop->in(0);
3730 if (alloc->is_Allocate()) {
3731 return alloc->as_Allocate();
3732 }
3733 }
3734 return NULL;
3735 }
3736
3737 // Trace Allocate -> Proj[Parm] -> Initialize
3738 InitializeNode* AllocateNode::initialization() {
3739 ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3740 if (rawoop == NULL) return NULL;
3741 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3742 Node* init = rawoop->fast_out(i);
3743 if (init->is_Initialize()) {
3744 assert(init->as_Initialize()->allocation() == this, "2-way link");
3745 return init->as_Initialize();
3746 }
3747 }
3748 return NULL;
3749 }
3750
3751 //----------------------------- loop predicates ---------------------------
3752
3753 //------------------------------add_predicate_impl----------------------------
3754 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3755 // Too many traps seen?
3756 if (too_many_traps(reason)) {
3757 #ifdef ASSERT
3758 if (TraceLoopPredicate) {
3759 int tc = C->trap_count(reason);
3760 tty->print("too many traps=%s tcount=%d in ",
3761 Deoptimization::trap_reason_name(reason), tc);
3762 method()->print(); // which method has too many predicate traps
3763 tty->cr();
3764 }
3765 #endif
3766 // We cannot afford to take more traps here,
3767 // do not generate predicate.
3768 return;
3769 }
3770
3771 Node *cont = _gvn.intcon(1);
3772 Node* opq = _gvn.transform(new Opaque1Node(C, cont));
3773 Node *bol = _gvn.transform(new Conv2BNode(opq));
3774 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3775 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3776 C->add_predicate_opaq(opq);
3777 {
3778 PreserveJVMState pjvms(this);
3779 set_control(iffalse);
3780 inc_sp(nargs);
3781 uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3782 }
3783 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3784 set_control(iftrue);
3785 }
3786
3787 //------------------------------add_predicate---------------------------------
3788 void GraphKit::add_predicate(int nargs) {
3789 if (UseLoopPredicate) {
3790 add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3791 }
3792 // loop's limit check predicate should be near the loop.
3793 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3794 }
3795
3796 //----------------------------- store barriers ----------------------------
3797 #define __ ideal.
3798
3799 void GraphKit::sync_kit(IdealKit& ideal) {
3800 set_all_memory(__ merged_memory());
3801 set_i_o(__ i_o());
3802 set_control(__ ctrl());
3803 }
3804
3805 void GraphKit::final_sync(IdealKit& ideal) {
3806 // Final sync IdealKit and graphKit.
3807 sync_kit(ideal);
3808 }
3809
3810 Node* GraphKit::byte_map_base_node() {
3811 // Get base of card map
3812 CardTableModRefBS* ct =
3813 barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3814 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3815 if (ct->byte_map_base != NULL) {
3816 return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3817 } else {
3818 return null();
3819 }
3820 }
3821
3822 // vanilla/CMS post barrier
3823 // Insert a write-barrier store. This is to let generational GC work; we have
3824 // to flag all oop-stores before the next GC point.
3825 void GraphKit::write_barrier_post(Node* oop_store,
3826 Node* obj,
3827 Node* adr,
3828 uint adr_idx,
3829 Node* val,
3830 bool use_precise) {
3831 // No store check needed if we're storing a NULL or an old object
3832 // (latter case is probably a string constant). The concurrent
3833 // mark sweep garbage collector, however, needs to have all nonNull
3834 // oop updates flagged via card-marks.
3835 if (val != NULL && val->is_Con()) {
3836 // must be either an oop or NULL
3837 const Type* t = val->bottom_type();
3838 if (t == TypePtr::NULL_PTR || t == Type::TOP)
3839 // stores of null never (?) need barriers
3840 return;
3841 }
3842
3843 if (use_ReduceInitialCardMarks()
3844 && obj == just_allocated_object(control())) {
3845 // We can skip marks on a freshly-allocated object in Eden.
3846 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3847 // That routine informs GC to take appropriate compensating steps,
3848 // upon a slow-path allocation, so as to make this card-mark
3849 // elision safe.
3850 return;
3851 }
3852
3853 if (!use_precise) {
3854 // All card marks for a (non-array) instance are in one place:
3855 adr = obj;
3856 }
3857 // (Else it's an array (or unknown), and we want more precise card marks.)
3858 assert(adr != NULL, "");
3859
3860 IdealKit ideal(this, true);
3861
3862 // Convert the pointer to an int prior to doing math on it
3863 Node* cast = __ CastPX(__ ctrl(), adr);
3864
3865 // Divide by card size
3866 assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3867 "Only one we handle so far.");
3868 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3869
3870 // Combine card table base and card offset
3871 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3872
3873 // Get the alias_index for raw card-mark memory
3874 int adr_type = Compile::AliasIdxRaw;
3875 Node* zero = __ ConI(0); // Dirty card value
3876 BasicType bt = T_BYTE;
3877
3878 if (UseConcMarkSweepGC && UseCondCardMark) {
3879 insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
3880 __ sync_kit(this);
3881 }
3882
3883 if (UseCondCardMark) {
3884 // The classic GC reference write barrier is typically implemented
3885 // as a store into the global card mark table. Unfortunately
3886 // unconditional stores can result in false sharing and excessive
3887 // coherence traffic as well as false transactional aborts.
3888 // UseCondCardMark enables MP "polite" conditional card mark
3889 // stores. In theory we could relax the load from ctrl() to
3890 // no_ctrl, but that doesn't buy much latitude.
3891 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3892 __ if_then(card_val, BoolTest::ne, zero);
3893 }
3894
3895 // Smash zero into card
3896 if( !UseConcMarkSweepGC ) {
3897 __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3898 } else {
3899 // Specialized path for CM store barrier
3900 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3901 }
3902
3903 if (UseCondCardMark) {
3904 __ end_if();
3905 }
3906
3907 // Final sync IdealKit and GraphKit.
3908 final_sync(ideal);
3909 }
3910 /*
3911 * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3912 * required by SATB to make sure all objects live at the start of the
3913 * marking are kept alive, all reference updates need to any previous
3914 * reference stored before writing.
3915 *
3916 * If the previous value is NULL there is no need to save the old value.
3917 * References that are NULL are filtered during runtime by the barrier
3918 * code to avoid unnecessary queuing.
3919 *
3920 * However in the case of newly allocated objects it might be possible to
3921 * prove that the reference about to be overwritten is NULL during compile
3922 * time and avoid adding the barrier code completely.
3923 *
3924 * The compiler needs to determine that the object in which a field is about
3925 * to be written is newly allocated, and that no prior store to the same field
3926 * has happened since the allocation.
3927 *
3928 * Returns true if the pre-barrier can be removed
3929 */
3930 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3931 BasicType bt, uint adr_idx) {
3932 intptr_t offset = 0;
3933 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3934 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3935
3936 if (offset == Type::OffsetBot) {
3937 return false; // cannot unalias unless there are precise offsets
3938 }
3939
3940 if (alloc == NULL) {
3941 return false; // No allocation found
3942 }
3943
3944 intptr_t size_in_bytes = type2aelembytes(bt);
3945
3946 Node* mem = memory(adr_idx); // start searching here...
3947
3948 for (int cnt = 0; cnt < 50; cnt++) {
3949
3950 if (mem->is_Store()) {
3951
3952 Node* st_adr = mem->in(MemNode::Address);
3953 intptr_t st_offset = 0;
3954 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3955
3956 if (st_base == NULL) {
3957 break; // inscrutable pointer
3958 }
3959
3960 // Break we have found a store with same base and offset as ours so break
3961 if (st_base == base && st_offset == offset) {
3962 break;
3963 }
3964
3965 if (st_offset != offset && st_offset != Type::OffsetBot) {
3966 const int MAX_STORE = BytesPerLong;
3967 if (st_offset >= offset + size_in_bytes ||
3968 st_offset <= offset - MAX_STORE ||
3969 st_offset <= offset - mem->as_Store()->memory_size()) {
3970 // Success: The offsets are provably independent.
3971 // (You may ask, why not just test st_offset != offset and be done?
3972 // The answer is that stores of different sizes can co-exist
3973 // in the same sequence of RawMem effects. We sometimes initialize
3974 // a whole 'tile' of array elements with a single jint or jlong.)
3975 mem = mem->in(MemNode::Memory);
3976 continue; // advance through independent store memory
3977 }
3978 }
3979
3980 if (st_base != base
3981 && MemNode::detect_ptr_independence(base, alloc, st_base,
3982 AllocateNode::Ideal_allocation(st_base, phase),
3983 phase)) {
3984 // Success: The bases are provably independent.
3985 mem = mem->in(MemNode::Memory);
3986 continue; // advance through independent store memory
3987 }
3988 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
3989
3990 InitializeNode* st_init = mem->in(0)->as_Initialize();
3991 AllocateNode* st_alloc = st_init->allocation();
3992
3993 // Make sure that we are looking at the same allocation site.
3994 // The alloc variable is guaranteed to not be null here from earlier check.
3995 if (alloc == st_alloc) {
3996 // Check that the initialization is storing NULL so that no previous store
3997 // has been moved up and directly write a reference
3998 Node* captured_store = st_init->find_captured_store(offset,
3999 type2aelembytes(T_OBJECT),
4000 phase);
4001 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4002 return true;
4003 }
4004 }
4005 }
4006
4007 // Unless there is an explicit 'continue', we must bail out here,
4008 // because 'mem' is an inscrutable memory state (e.g., a call).
4009 break;
4010 }
4011
4012 return false;
4013 }
4014
4015 static void g1_write_barrier_pre_helper(const GraphKit& kit, Node* adr) {
4016 if (UseShenandoahGC && ShenandoahWriteBarrier && adr != NULL) {
4017 Node* c = kit.control();
4018 Node* call = c->in(1)->in(1)->in(1)->in(0);
4019 assert(call->is_g1_wb_pre_call(), "g1_wb_pre call expected");
4020 call->add_req(adr);
4021 }
4022 }
4023
4024 // G1 pre/post barriers
4025 void GraphKit::g1_write_barrier_pre(bool do_load,
4026 Node* obj,
4027 Node* adr,
4028 uint alias_idx,
4029 Node* val,
4030 const TypeOopPtr* val_type,
4031 Node* pre_val,
4032 BasicType bt) {
4033
4034 // Some sanity checks
4035 // Note: val is unused in this routine.
4036
4037 if (do_load) {
4038 // We need to generate the load of the previous value
4039 assert(obj != NULL, "must have a base");
4040 assert(adr != NULL, "where are loading from?");
4041 assert(pre_val == NULL, "loaded already?");
4042 assert(val_type != NULL, "need a type");
4043
4044 if (use_ReduceInitialCardMarks()
4045 && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4046 return;
4047 }
4048
4049 } else {
4050 // In this case both val_type and alias_idx are unused.
4051 assert(pre_val != NULL, "must be loaded already");
4052 // Nothing to be done if pre_val is null.
4053 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4054 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4055 }
4056 assert(bt == T_OBJECT, "or we shouldn't be here");
4057
4058 IdealKit ideal(this, true);
4059
4060 Node* tls = __ thread(); // ThreadLocalStorage
4061
4062 Node* no_ctrl = NULL;
4063 Node* no_base = __ top();
4064 Node* zero = __ ConI(0);
4065 Node* zeroX = __ ConX(0);
4066
4067 float likely = PROB_LIKELY(0.999);
4068 float unlikely = PROB_UNLIKELY(0.999);
4069
4070 BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4071 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4072
4073 // Offsets into the thread
4074 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648
4075 SATBMarkQueue::byte_offset_of_active());
4076 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656
4077 SATBMarkQueue::byte_offset_of_index());
4078 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652
4079 SATBMarkQueue::byte_offset_of_buf());
4080
4081 // Now the actual pointers into the thread
4082 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4083 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4084 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4085
4086 // Now some of the values
4087 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4088
4089 // if (!marking)
4090 __ if_then(marking, BoolTest::ne, zero, unlikely); {
4091 BasicType index_bt = TypeX_X->basic_type();
4092 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4093 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4094
4095 if (do_load) {
4096 // load original value
4097 // alias_idx correct??
4098 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4099 }
4100
4101 // if (pre_val != NULL)
4102 __ if_then(pre_val, BoolTest::ne, null()); {
4103 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4104
4105 // is the queue for this thread full?
4106 __ if_then(index, BoolTest::ne, zeroX, likely); {
4107
4108 // decrement the index
4109 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4110
4111 // Now get the buffer location we will log the previous value into and store it
4112 Node *log_addr = __ AddP(no_base, buffer, next_index);
4113 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4114 // update the index
4115 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4116
4117 } __ else_(); {
4118
4119 // logging buffer is full, call the runtime
4120 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4121 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4122 } __ end_if(); // (!index)
4123 } __ end_if(); // (pre_val != NULL)
4124 } __ end_if(); // (!marking)
4125
4126 // Final sync IdealKit and GraphKit.
4127 final_sync(ideal);
4128 g1_write_barrier_pre_helper(*this, adr);
4129 }
4130
4131 Node* GraphKit::shenandoah_write_barrier_pre(bool do_load,
4132 Node* obj,
4133 Node* adr,
4134 uint alias_idx,
4135 Node* val,
4136 const TypeOopPtr* val_type,
4137 Node* pre_val,
4138 BasicType bt) {
4139
4140 // Some sanity checks
4141 // Note: val is unused in this routine.
4142
4143 if (val == NULL) {
4144 g1_write_barrier_pre(do_load, obj, adr, alias_idx, val, val_type, pre_val, bt);
4145 return NULL;
4146 }
4147
4148 if (! ShenandoahReduceStoreValBarrier) {
4149 val = shenandoah_read_barrier_storeval(val);
4150 shenandoah_update_matrix(adr, val);
4151 g1_write_barrier_pre(do_load, obj, adr, alias_idx, val, val_type, pre_val, bt);
4152 return val;
4153 }
4154
4155 if (do_load) {
4156 // We need to generate the load of the previous value
4157 assert(obj != NULL, "must have a base");
4158 assert(adr != NULL, "where are loading from?");
4159 assert(pre_val == NULL, "loaded already?");
4160 assert(val_type != NULL, "need a type");
4161
4162 if (use_ReduceInitialCardMarks()
4163 && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4164 return shenandoah_read_barrier_storeval(val);
4165 }
4166
4167 } else {
4168 // In this case both val_type and alias_idx are unused.
4169 assert(pre_val != NULL, "must be loaded already");
4170 // Nothing to be done if pre_val is null.
4171 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return val;
4172 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4173 }
4174 assert(bt == T_OBJECT, "or we shouldn't be here");
4175
4176 IdealKit ideal(this, true, true);
4177 IdealVariable ival(ideal);
4178 __ declarations_done();
4179 __ set(ival, val);
4180 Node* tls = __ thread(); // ThreadLocalStorage
4181
4182 Node* no_ctrl = NULL;
4183 Node* no_base = __ top();
4184 Node* zero = __ ConI(0);
4185 Node* zeroX = __ ConX(0);
4186
4187 float likely = PROB_LIKELY(0.999);
4188 float unlikely = PROB_UNLIKELY(0.999);
4189
4190 BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4191 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4192
4193 // Offsets into the thread
4194 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648
4195 SATBMarkQueue::byte_offset_of_active());
4196 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656
4197 SATBMarkQueue::byte_offset_of_index());
4198 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652
4199 SATBMarkQueue::byte_offset_of_buf());
4200
4201 // Now the actual pointers into the thread
4202 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4203 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4204 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4205
4206 // Now some of the values
4207 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4208
4209 // if (!marking)
4210 __ if_then(marking, BoolTest::ne, zero, unlikely); {
4211
4212 Node* storeval = ideal.value(ival);
4213 sync_kit(ideal);
4214 storeval = shenandoah_read_barrier_storeval(storeval);
4215 __ sync_kit(this);
4216 __ set(ival, storeval);
4217
4218 BasicType index_bt = TypeX_X->basic_type();
4219 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4220 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4221
4222 if (do_load) {
4223 // load original value
4224 // alias_idx correct??
4225 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4226 }
4227
4228 // if (pre_val != NULL)
4229 __ if_then(pre_val, BoolTest::ne, null()); {
4230 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4231
4232 // is the queue for this thread full?
4233 __ if_then(index, BoolTest::ne, zeroX, likely); {
4234
4235 // decrement the index
4236 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4237
4238 // Now get the buffer location we will log the previous value into and store it
4239 Node *log_addr = __ AddP(no_base, buffer, next_index);
4240 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4241 // update the index
4242 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4243
4244 } __ else_(); {
4245
4246 // logging buffer is full, call the runtime
4247 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4248 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4249 } __ end_if(); // (!index)
4250 } __ end_if(); // (pre_val != NULL)
4251 } __ end_if(); // (!marking)
4252 Node* new_val = __ value(ival);
4253 // IdealKit generates a Phi with very conservative type, and even
4254 // turns array types into TypeInstPtr (see type.cpp, _const_basic_type[T_ARRAY]).
4255 // We're forcing the result to be the original type.
4256 if (new_val != val) {
4257 const Type* t = _gvn.type(val);
4258 if (new_val->isa_Type()) {
4259 new_val->as_Type()->set_type(t);
4260 }
4261 _gvn.set_type(new_val, t);
4262 }
4263 val = new_val;
4264 __ dead(ival);
4265 // Final sync IdealKit and GraphKit.
4266 final_sync(ideal);
4267 g1_write_barrier_pre_helper(*this, adr);
4268 return val;
4269 }
4270
4271 void GraphKit::shenandoah_update_matrix(Node* adr, Node* val) {
4272 assert(val != NULL, "checked before");
4273 if (adr == NULL) {
4274 return; // Nothing to do
4275 }
4276 assert(adr != NULL, "must not happen");
4277 if (val->bottom_type()->higher_equal(TypePtr::NULL_PTR)) {
4278 // Nothing to do.
4279 return;
4280 }
4281
4282 ShenandoahConnectionMatrix* matrix = ShenandoahHeap::heap()->connection_matrix();
4283
4284 enum { _not_null_path = 1, _null_path, PATH_LIMIT };
4285 RegionNode* region = new RegionNode(PATH_LIMIT);
4286 Node* prev_mem = memory(Compile::AliasIdxRaw);
4287 Node* memphi = PhiNode::make(region, prev_mem, Type::MEMORY, TypeRawPtr::BOTTOM);
4288 Node* null_ctrl = top();
4289 Node* not_null_val = null_check_oop(val, &null_ctrl);
4290
4291 // Null path: nothing to do.
4292 region->init_req(_null_path, null_ctrl);
4293 memphi->init_req(_null_path, prev_mem);
4294
4295 // Not null path. Update the matrix.
4296 Node* heapbase = MakeConX((intx) ShenandoahHeap::heap()->first_region_bottom());
4297 Node* region_size_shift = intcon((jint) ShenandoahHeapRegion::RegionSizeShift);
4298 Node* stride = MakeConX((intx) matrix->stride());
4299 Node* matrix_base = makecon(TypeRawPtr::make(matrix->matrix_addr()));
4300 // Compute region index for adr.
4301 Node* adr_idx = _gvn.transform(new CastP2XNode(control(), adr));
4302 adr_idx = _gvn.transform(new SubXNode(adr_idx, heapbase));
4303 adr_idx = _gvn.transform(new URShiftXNode(adr_idx, region_size_shift));
4304 // Compute region index for val.
4305 Node* val_idx = _gvn.transform(new CastP2XNode(control(), not_null_val));
4306 val_idx = _gvn.transform(new SubXNode(val_idx, heapbase));
4307 val_idx = _gvn.transform(new URShiftXNode(val_idx, region_size_shift));
4308 // Compute matrix index & address.
4309 Node* matrix_idx = _gvn.transform(new MulXNode(adr_idx, stride));
4310 matrix_idx = _gvn.transform(new AddXNode(matrix_idx, val_idx));
4311 Node* matrix_adr = basic_plus_adr(top(), matrix_base, matrix_idx);
4312 // Do the store.
4313 const TypePtr* adr_type = TypeRawPtr::BOTTOM;
4314 Node* store = _gvn.transform(StoreNode::make(_gvn, control(), memory(Compile::AliasIdxRaw), matrix_adr, adr_type, intcon(1), T_BOOLEAN, MemNode::unordered));
4315
4316 region->init_req(_not_null_path, control());
4317 memphi->init_req(_not_null_path, store);
4318
4319 // Merge control flows and memory.
4320 set_control(_gvn.transform(region));
4321 record_for_igvn(region);
4322 set_memory(_gvn.transform(memphi), Compile::AliasIdxRaw);
4323 }
4324
4325 /*
4326 * G1 similar to any GC with a Young Generation requires a way to keep track of
4327 * references from Old Generation to Young Generation to make sure all live
4328 * objects are found. G1 also requires to keep track of object references
4329 * between different regions to enable evacuation of old regions, which is done
4330 * as part of mixed collections. References are tracked in remembered sets and
4331 * is continuously updated as reference are written to with the help of the
4332 * post-barrier.
4333 *
4334 * To reduce the number of updates to the remembered set the post-barrier
4335 * filters updates to fields in objects located in the Young Generation,
4336 * the same region as the reference, when the NULL is being written or
4337 * if the card is already marked as dirty by an earlier write.
4338 *
4339 * Under certain circumstances it is possible to avoid generating the
4340 * post-barrier completely if it is possible during compile time to prove
4341 * the object is newly allocated and that no safepoint exists between the
4342 * allocation and the store.
4343 *
4344 * In the case of slow allocation the allocation code must handle the barrier
4345 * as part of the allocation in the case the allocated object is not located
4346 * in the nursery, this would happen for humongous objects. This is similar to
4347 * how CMS is required to handle this case, see the comments for the method
4348 * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4349 * A deferred card mark is required for these objects and handled in the above
4350 * mentioned methods.
4351 *
4352 * Returns true if the post barrier can be removed
4353 */
4354 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4355 Node* adr) {
4356 intptr_t offset = 0;
4357 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4358 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4359
4360 if (offset == Type::OffsetBot) {
4361 return false; // cannot unalias unless there are precise offsets
4362 }
4363
4364 if (alloc == NULL) {
4365 return false; // No allocation found
4366 }
4367
4368 // Start search from Store node
4369 Node* mem = store->in(MemNode::Control);
4370 if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4371
4372 InitializeNode* st_init = mem->in(0)->as_Initialize();
4373 AllocateNode* st_alloc = st_init->allocation();
4374
4375 // Make sure we are looking at the same allocation
4376 if (alloc == st_alloc) {
4377 return true;
4378 }
4379 }
4380
4381 return false;
4382 }
4383
4384 //
4385 // Update the card table and add card address to the queue
4386 //
4387 void GraphKit::g1_mark_card(IdealKit& ideal,
4388 Node* card_adr,
4389 Node* oop_store,
4390 uint oop_alias_idx,
4391 Node* index,
4392 Node* index_adr,
4393 Node* buffer,
4394 const TypeFunc* tf) {
4395
4396 Node* zero = __ ConI(0);
4397 Node* zeroX = __ ConX(0);
4398 Node* no_base = __ top();
4399 BasicType card_bt = T_BYTE;
4400 // Smash zero into card. MUST BE ORDERED WRT TO STORE
4401 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4402
4403 // Now do the queue work
4404 __ if_then(index, BoolTest::ne, zeroX); {
4405
4406 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4407 Node* log_addr = __ AddP(no_base, buffer, next_index);
4408
4409 // Order, see storeCM.
4410 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4411 __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4412
4413 } __ else_(); {
4414 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4415 } __ end_if();
4416
4417 }
4418
4419 void GraphKit::g1_write_barrier_post(Node* oop_store,
4420 Node* obj,
4421 Node* adr,
4422 uint alias_idx,
4423 Node* val,
4424 BasicType bt,
4425 bool use_precise) {
4426 // If we are writing a NULL then we need no post barrier
4427
4428 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4429 // Must be NULL
4430 const Type* t = val->bottom_type();
4431 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4432 // No post barrier if writing NULLx
4433 return;
4434 }
4435
4436 if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4437 // We can skip marks on a freshly-allocated object in Eden.
4438 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4439 // That routine informs GC to take appropriate compensating steps,
4440 // upon a slow-path allocation, so as to make this card-mark
4441 // elision safe.
4442 return;
4443 }
4444
4445 if (use_ReduceInitialCardMarks()
4446 && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4447 return;
4448 }
4449
4450 if (!use_precise) {
4451 // All card marks for a (non-array) instance are in one place:
4452 adr = obj;
4453 }
4454 // (Else it's an array (or unknown), and we want more precise card marks.)
4455 assert(adr != NULL, "");
4456
4457 IdealKit ideal(this, true);
4458
4459 Node* tls = __ thread(); // ThreadLocalStorage
4460
4461 Node* no_base = __ top();
4462 float likely = PROB_LIKELY(0.999);
4463 float unlikely = PROB_UNLIKELY(0.999);
4464 Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4465 Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4466 Node* zeroX = __ ConX(0);
4467
4468 // Get the alias_index for raw card-mark memory
4469 const TypePtr* card_type = TypeRawPtr::BOTTOM;
4470
4471 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4472
4473 // Offsets into the thread
4474 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4475 DirtyCardQueue::byte_offset_of_index());
4476 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4477 DirtyCardQueue::byte_offset_of_buf());
4478
4479 // Pointers into the thread
4480
4481 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4482 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4483
4484 // Now some values
4485 // Use ctrl to avoid hoisting these values past a safepoint, which could
4486 // potentially reset these fields in the JavaThread.
4487 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4488 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4489
4490 // Convert the store obj pointer to an int prior to doing math on it
4491 // Must use ctrl to prevent "integerized oop" existing across safepoint
4492 Node* cast = __ CastPX(__ ctrl(), adr);
4493
4494 // Divide pointer by card size
4495 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4496
4497 // Combine card table base and card offset
4498 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4499
4500 // If we know the value being stored does it cross regions?
4501
4502 if (val != NULL) {
4503 // Does the store cause us to cross regions?
4504
4505 // Should be able to do an unsigned compare of region_size instead of
4506 // and extra shift. Do we have an unsigned compare??
4507 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4508 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4509
4510 // if (xor_res == 0) same region so skip
4511 __ if_then(xor_res, BoolTest::ne, zeroX); {
4512
4513 // No barrier if we are storing a NULL
4514 __ if_then(val, BoolTest::ne, null(), unlikely); {
4515
4516 // Ok must mark the card if not already dirty
4517
4518 // load the original value of the card
4519 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4520
4521 __ if_then(card_val, BoolTest::ne, young_card); {
4522 sync_kit(ideal);
4523 // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4524 insert_mem_bar(Op_MemBarVolatile, oop_store);
4525 __ sync_kit(this);
4526
4527 Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4528 __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4529 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4530 } __ end_if();
4531 } __ end_if();
4532 } __ end_if();
4533 } __ end_if();
4534 } else {
4535 // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4536 // We don't need a barrier here if the destination is a newly allocated object
4537 // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4538 // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4539 assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4540 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4541 __ if_then(card_val, BoolTest::ne, young_card); {
4542 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4543 } __ end_if();
4544 }
4545
4546 // Final sync IdealKit and GraphKit.
4547 final_sync(ideal);
4548 }
4549 #undef __
4550
4551
4552 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4553 Node* len = load_array_length(load_String_value(ctrl, str));
4554 Node* coder = load_String_coder(ctrl, str);
4555 // Divide length by 2 if coder is UTF16
4556 return _gvn.transform(new RShiftINode(len, coder));
4557 }
4558
4559 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4560 int value_offset = java_lang_String::value_offset_in_bytes();
4561 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4562 false, NULL, 0);
4563 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4564 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4565 TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4566 ciTypeArrayKlass::make(T_BYTE), true, 0);
4567 int value_field_idx = C->get_alias_index(value_field_type);
4568
4569 if (! ShenandoahOptimizeFinals) {
4570 str = shenandoah_read_barrier(str);
4571 }
4572
4573 Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4574 value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4575 // String.value field is known to be @Stable.
4576 if (UseImplicitStableValues) {
4577 load = cast_array_to_stable(load, value_type);
4578 }
4579 return load;
4580 }
4581
4582 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4583 if (!CompactStrings) {
4584 return intcon(java_lang_String::CODER_UTF16);
4585 }
4586 int coder_offset = java_lang_String::coder_offset_in_bytes();
4587 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4588 false, NULL, 0);
4589 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4590 int coder_field_idx = C->get_alias_index(coder_field_type);
4591
4592 if (! ShenandoahOptimizeFinals) {
4593 str = shenandoah_read_barrier(str);
4594 }
4595
4596 return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4597 TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4598 }
4599
4600 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4601 int value_offset = java_lang_String::value_offset_in_bytes();
4602 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4603 false, NULL, 0);
4604 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4605
4606 str = shenandoah_write_barrier(str);
4607
4608 store_oop_to_object(control(), str, basic_plus_adr(str, value_offset), value_field_type,
4609 value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4610 }
4611
4612 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4613 int coder_offset = java_lang_String::coder_offset_in_bytes();
4614 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4615 false, NULL, 0);
4616
4617 str = shenandoah_write_barrier(str);
4618
4619 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4620 int coder_field_idx = C->get_alias_index(coder_field_type);
4621 store_to_memory(control(), basic_plus_adr(str, coder_offset),
4622 value, T_BYTE, coder_field_idx, MemNode::unordered);
4623 }
4624
4625 // Capture src and dst memory state with a MergeMemNode
4626 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4627 if (src_type == dst_type) {
4628 // Types are equal, we don't need a MergeMemNode
4629 return memory(src_type);
4630 }
4631 MergeMemNode* merge = MergeMemNode::make(map()->memory());
4632 record_for_igvn(merge); // fold it up later, if possible
4633 int src_idx = C->get_alias_index(src_type);
4634 int dst_idx = C->get_alias_index(dst_type);
4635 merge->set_memory_at(src_idx, memory(src_idx));
4636 merge->set_memory_at(dst_idx, memory(dst_idx));
4637 return merge;
4638 }
4639
4640 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4641 assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4642 assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4643 // If input and output memory types differ, capture both states to preserve
4644 // the dependency between preceding and subsequent loads/stores.
4645 // For example, the following program:
4646 // StoreB
4647 // compress_string
4648 // LoadB
4649 // has this memory graph (use->def):
4650 // LoadB -> compress_string -> CharMem
4651 // ... -> StoreB -> ByteMem
4652 // The intrinsic hides the dependency between LoadB and StoreB, causing
4653 // the load to read from memory not containing the result of the StoreB.
4654 // The correct memory graph should look like this:
4655 // LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4656 Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4657 StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4658 Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4659 set_memory(res_mem, TypeAryPtr::BYTES);
4660 return str;
4661 }
4662
4663 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4664 assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4665 assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4666 // Capture src and dst memory (see comment in 'compress_string').
4667 Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4668 StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4669 set_memory(_gvn.transform(str), dst_type);
4670 }
4671
4672 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4673
4674 src = shenandoah_read_barrier(src);
4675 dst = shenandoah_write_barrier(dst);
4676
4677 /**
4678 * int i_char = start;
4679 * for (int i_byte = 0; i_byte < count; i_byte++) {
4680 * dst[i_char++] = (char)(src[i_byte] & 0xff);
4681 * }
4682 */
4683 add_predicate();
4684 RegionNode* head = new RegionNode(3);
4685 head->init_req(1, control());
4686 gvn().set_type(head, Type::CONTROL);
4687 record_for_igvn(head);
4688
4689 Node* i_byte = new PhiNode(head, TypeInt::INT);
4690 i_byte->init_req(1, intcon(0));
4691 gvn().set_type(i_byte, TypeInt::INT);
4692 record_for_igvn(i_byte);
4693
4694 Node* i_char = new PhiNode(head, TypeInt::INT);
4695 i_char->init_req(1, start);
4696 gvn().set_type(i_char, TypeInt::INT);
4697 record_for_igvn(i_char);
4698
4699 Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4700 gvn().set_type(mem, Type::MEMORY);
4701 record_for_igvn(mem);
4702 set_control(head);
4703 set_memory(mem, TypeAryPtr::BYTES);
4704 Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4705 Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4706 AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4707 false, false, true /* mismatched */);
4708
4709 IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4710 head->init_req(2, IfTrue(iff));
4711 mem->init_req(2, st);
4712 i_byte->init_req(2, AddI(i_byte, intcon(1)));
4713 i_char->init_req(2, AddI(i_char, intcon(2)));
4714
4715 set_control(IfFalse(iff));
4716 set_memory(st, TypeAryPtr::BYTES);
4717 }
4718
4719 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4720 if (!field->is_constant()) {
4721 return NULL; // Field not marked as constant.
4722 }
4723 ciInstance* holder = NULL;
4724 if (!field->is_static()) {
4725 ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4726 if (const_oop != NULL && const_oop->is_instance()) {
4727 holder = const_oop->as_instance();
4728 }
4729 }
4730 const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4731 /*is_unsigned_load=*/false);
4732 if (con_type != NULL) {
4733 return makecon(con_type);
4734 }
4735 return NULL;
4736 }
4737
4738 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4739 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4740 // assumption of CCP analysis.
4741 return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4742 }
4743
4744 Node* GraphKit::shenandoah_read_barrier(Node* obj) {
4745 return shenandoah_read_barrier_impl(obj, false, true, true);
4746 }
4747
4748 Node* GraphKit::shenandoah_read_barrier_storeval(Node* obj) {
4749 return shenandoah_read_barrier_impl(obj, true, false, false);
4750 }
4751
4752 Node* GraphKit::shenandoah_read_barrier_impl(Node* obj, bool use_ctrl, bool use_mem, bool allow_fromspace) {
4753
4754 if (UseShenandoahGC && ShenandoahReadBarrier) {
4755 const Type* obj_type = obj->bottom_type();
4756 if (obj_type->higher_equal(TypePtr::NULL_PTR)) {
4757 return obj;
4758 }
4759 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
4760 Node* mem = use_mem ? memory(adr_type) : immutable_memory();
4761
4762 if (! ShenandoahBarrierNode::needs_barrier(&_gvn, NULL, obj, mem, allow_fromspace)) {
4763 // We know it is null, no barrier needed.
4764 return obj;
4765 }
4766
4767
4768 if (obj_type->meet(TypePtr::NULL_PTR) == obj_type->remove_speculative()) {
4769
4770 // We don't know if it's null or not. Need null-check.
4771 enum { _not_null_path = 1, _null_path, PATH_LIMIT };
4772 RegionNode* region = new RegionNode(PATH_LIMIT);
4773 Node* phi = new PhiNode(region, obj_type);
4774 Node* null_ctrl = top();
4775 Node* not_null_obj = null_check_oop(obj, &null_ctrl);
4776
4777 region->init_req(_null_path, null_ctrl);
4778 phi ->init_req(_null_path, zerocon(T_OBJECT));
4779
4780 Node* ctrl = use_ctrl ? control() : NULL;
4781 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, not_null_obj, allow_fromspace);
4782 Node* n = _gvn.transform(rb);
4783
4784 region->init_req(_not_null_path, control());
4785 phi ->init_req(_not_null_path, n);
4786
4787 set_control(_gvn.transform(region));
4788 record_for_igvn(region);
4789 return _gvn.transform(phi);
4790
4791 } else {
4792 // We know it is not null. Simple barrier is sufficient.
4793 Node* ctrl = use_ctrl ? control() : NULL;
4794 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, obj, allow_fromspace);
4795 Node* n = _gvn.transform(rb);
4796 record_for_igvn(n);
4797 return n;
4798 }
4799
4800 } else {
4801 return obj;
4802 }
4803 }
4804
4805 static Node* shenandoah_write_barrier_helper(GraphKit& kit, Node* obj, const TypePtr* adr_type) {
4806 ShenandoahWriteBarrierNode* wb = new ShenandoahWriteBarrierNode(kit.C, kit.control(), kit.memory(adr_type), obj);
4807 Node* n = kit.gvn().transform(wb);
4808 if (n == wb) { // New barrier needs memory projection.
4809 Node* proj = kit.gvn().transform(new ShenandoahWBMemProjNode(n));
4810 kit.set_memory(proj, adr_type);
4811 }
4812
4813 return n;
4814 }
4815
4816 Node* GraphKit::shenandoah_write_barrier(Node* obj) {
4817
4818 if (UseShenandoahGC && ShenandoahWriteBarrier) {
4819
4820 if (! ShenandoahBarrierNode::needs_barrier(&_gvn, NULL, obj, NULL, true)) {
4821 return obj;
4822 }
4823 const Type* obj_type = obj->bottom_type();
4824 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
4825 if (obj_type->meet(TypePtr::NULL_PTR) == obj_type->remove_speculative()) {
4826 // We don't know if it's null or not. Need null-check.
4827 enum { _not_null_path = 1, _null_path, PATH_LIMIT };
4828 RegionNode* region = new RegionNode(PATH_LIMIT);
4829 Node* phi = new PhiNode(region, obj_type);
4830 Node* memphi = PhiNode::make(region, memory(adr_type), Type::MEMORY, C->alias_type(adr_type)->adr_type());
4831
4832 Node* prev_mem = memory(adr_type);
4833 Node* null_ctrl = top();
4834 Node* not_null_obj = null_check_oop(obj, &null_ctrl);
4835
4836 region->init_req(_null_path, null_ctrl);
4837 phi ->init_req(_null_path, zerocon(T_OBJECT));
4838 memphi->init_req(_null_path, prev_mem);
4839
4840 Node* n = shenandoah_write_barrier_helper(*this, not_null_obj, adr_type);
4841
4842 region->init_req(_not_null_path, control());
4843 phi ->init_req(_not_null_path, n);
4844 memphi->init_req(_not_null_path, memory(adr_type));
4845
4846 set_control(_gvn.transform(region));
4847 record_for_igvn(region);
4848 set_memory(_gvn.transform(memphi), adr_type);
4849
4850 Node* res_val = _gvn.transform(phi);
4851 // replace_in_map(obj, res_val);
4852 return res_val;
4853 } else {
4854 // We know it is not null. Simple barrier is sufficient.
4855 Node* n = shenandoah_write_barrier_helper(*this, obj, adr_type);
4856 // replace_in_map(obj, n);
4857 record_for_igvn(n);
4858 return n;
4859 }
4860
4861 } else {
4862 return obj;
4863 }
4864 }
4865
4866 /**
4867 * In Shenandoah, we need barriers on acmp (and similar instructions that compare two
4868 * oops) to avoid false negatives. If it compares a from-space and a to-space
4869 * copy of an object, a regular acmp would return false, even though both are
4870 * the same. The acmp barrier compares the two objects, and when they are
4871 * *not equal* it does a read-barrier on both, and compares them again. When it
4872 * failed because of different copies of the object, we know that the object
4873 * must already have been evacuated (and therefore doesn't require a write-barrier).
4874 */
4875 Node* GraphKit::cmp_objects(Node* a, Node* b) {
4876 // TODO: Refactor into proper GC interface.
4877 if (UseShenandoahGC && ShenandoahAcmpBarrier) {
4878 const Type* a_type = a->bottom_type();
4879 const Type* b_type = b->bottom_type();
4880 if (a_type->higher_equal(TypePtr::NULL_PTR) || b_type->higher_equal(TypePtr::NULL_PTR)) {
4881 // We know one arg is gonna be null. No need for barriers.
4882 return _gvn.transform(new CmpPNode(b, a));
4883 }
4884
4885 const TypePtr* a_adr_type = ShenandoahBarrierNode::brooks_pointer_type(a_type);
4886 const TypePtr* b_adr_type = ShenandoahBarrierNode::brooks_pointer_type(b_type);
4887 if ((! ShenandoahBarrierNode::needs_barrier(&_gvn, NULL, a, memory(a_adr_type), false)) &&
4888 (! ShenandoahBarrierNode::needs_barrier(&_gvn, NULL, b, memory(b_adr_type), false))) {
4889 // We know both args are in to-space already. No acmp barrier needed.
4890 return _gvn.transform(new CmpPNode(b, a));
4891 }
4892
4893 C->set_has_split_ifs(true);
4894
4895 if (ShenandoahVerifyOptoBarriers) {
4896 a = shenandoah_write_barrier(a);
4897 b = shenandoah_write_barrier(b);
4898 return _gvn.transform(new CmpPNode(b, a));
4899 }
4900
4901 enum { _equal = 1, _not_equal, PATH_LIMIT };
4902 RegionNode* region = new RegionNode(PATH_LIMIT);
4903 PhiNode* phiA = PhiNode::make(region, a, _gvn.type(a)->is_oopptr()->cast_to_nonconst());
4904 PhiNode* phiB = PhiNode::make(region, b, _gvn.type(b)->is_oopptr()->cast_to_nonconst());
4905
4906 Node* cmp = _gvn.transform(new CmpPNode(b, a));
4907 Node* tst = _gvn.transform(new BoolNode(cmp, BoolTest::eq));
4908
4909 // TODO: Use profiling data.
4910 IfNode* iff = create_and_map_if(control(), tst, PROB_FAIR, COUNT_UNKNOWN);
4911 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
4912 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
4913
4914 // Equal path: Use original values.
4915 region->init_req(_equal, iftrue);
4916 phiA->init_req(_equal, a);
4917 phiB->init_req(_equal, b);
4918
4919 uint alias_a = C->get_alias_index(a_adr_type);
4920 uint alias_b = C->get_alias_index(b_adr_type);
4921 PhiNode* mem_phi = NULL;
4922 if (alias_a == alias_b) {
4923 mem_phi = PhiNode::make(region, memory(alias_a), Type::MEMORY, C->get_adr_type(alias_a));
4924 } else {
4925 mem_phi = PhiNode::make(region, map()->memory(), Type::MEMORY, TypePtr::BOTTOM);
4926 }
4927
4928 // Unequal path: retry after read barriers.
4929 set_control(iffalse);
4930 if (!iffalse->is_top()) {
4931 Node* mb = NULL;
4932 if (alias_a == alias_b) {
4933 Node* mem = reset_memory();
4934 mb = MemBarNode::make(C, Op_MemBarAcquire, alias_a);
4935 mb->init_req(TypeFunc::Control, control());
4936 mb->init_req(TypeFunc::Memory, mem);
4937 Node* membar = _gvn.transform(mb);
4938 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
4939 Node* newmem = _gvn.transform(new ProjNode(membar, TypeFunc::Memory));
4940 set_all_memory(mem);
4941 set_memory(newmem, alias_a);
4942 } else {
4943 mb = insert_mem_bar(Op_MemBarAcquire);
4944 }
4945 } else {
4946 a = top();
4947 b = top();
4948 }
4949
4950 a = shenandoah_read_barrier_impl(a, true, true, false);
4951 b = shenandoah_read_barrier_impl(b, true, true, false);
4952
4953 region->init_req(_not_equal, control());
4954 phiA->init_req(_not_equal, a);
4955 phiB->init_req(_not_equal, b);
4956 if (alias_a == alias_b) {
4957 mem_phi->init_req(_not_equal, memory(alias_a));
4958 set_memory(mem_phi, alias_a);
4959 } else {
4960 mem_phi->init_req(_not_equal, reset_memory());
4961 set_all_memory(mem_phi);
4962 }
4963 record_for_igvn(mem_phi);
4964 _gvn.set_type(mem_phi, Type::MEMORY);
4965 set_control(_gvn.transform(region));
4966 record_for_igvn(region);
4967
4968 a = _gvn.transform(phiA);
4969 b = _gvn.transform(phiB);
4970 return _gvn.transform(new CmpPNode(b, a));
4971 } else {
4972 return _gvn.transform(new CmpPNode(b, a));
4973 }
4974 }