1 /*
2 * Copyright (c) 2001, 2017, 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 "ci/ciValueKlass.hpp"
28 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
29 #include "gc/g1/heapRegion.hpp"
30 #include "gc/shared/barrierSet.hpp"
31 #include "gc/shared/cardTableModRefBS.hpp"
32 #include "gc/shared/collectedHeap.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "opto/addnode.hpp"
35 #include "opto/castnode.hpp"
36 #include "opto/convertnode.hpp"
37 #include "opto/graphKit.hpp"
38 #include "opto/idealKit.hpp"
39 #include "opto/intrinsicnode.hpp"
40 #include "opto/locknode.hpp"
41 #include "opto/machnode.hpp"
42 #include "opto/opaquenode.hpp"
43 #include "opto/parse.hpp"
44 #include "opto/rootnode.hpp"
45 #include "opto/runtime.hpp"
46 #include "opto/valuetypenode.hpp"
47 #include "runtime/deoptimization.hpp"
48 #include "runtime/sharedRuntime.hpp"
49
50 //----------------------------GraphKit-----------------------------------------
51 // Main utility constructor.
52 GraphKit::GraphKit(JVMState* jvms, PhaseGVN* gvn)
53 : Phase(Phase::Parser),
54 _env(C->env()),
55 _gvn((gvn != NULL) ? *gvn : *C->initial_gvn())
56 {
57 _exceptions = jvms->map()->next_exception();
58 if (_exceptions != NULL) jvms->map()->set_next_exception(NULL);
59 set_jvms(jvms);
60 #ifdef ASSERT
61 if (_gvn.is_IterGVN() != NULL) {
62 // Save the initial size of _for_igvn worklist for verification (see ~GraphKit)
63 _worklist_size = _gvn.C->for_igvn()->size();
64 }
65 #endif
66 }
67
68 // Private constructor for parser.
69 GraphKit::GraphKit()
70 : Phase(Phase::Parser),
71 _env(C->env()),
72 _gvn(*C->initial_gvn())
73 {
74 _exceptions = NULL;
75 set_map(NULL);
76 debug_only(_sp = -99);
77 debug_only(set_bci(-99));
78 }
79
80
81
82 //---------------------------clean_stack---------------------------------------
83 // Clear away rubbish from the stack area of the JVM state.
84 // This destroys any arguments that may be waiting on the stack.
85 void GraphKit::clean_stack(int from_sp) {
86 SafePointNode* map = this->map();
87 JVMState* jvms = this->jvms();
88 int stk_size = jvms->stk_size();
89 int stkoff = jvms->stkoff();
90 Node* top = this->top();
91 for (int i = from_sp; i < stk_size; i++) {
92 if (map->in(stkoff + i) != top) {
93 map->set_req(stkoff + i, top);
94 }
95 }
96 }
97
98
99 //--------------------------------sync_jvms-----------------------------------
100 // Make sure our current jvms agrees with our parse state.
101 JVMState* GraphKit::sync_jvms() const {
102 JVMState* jvms = this->jvms();
103 jvms->set_bci(bci()); // Record the new bci in the JVMState
104 jvms->set_sp(sp()); // Record the new sp in the JVMState
105 assert(jvms_in_sync(), "jvms is now in sync");
106 return jvms;
107 }
108
109 //--------------------------------sync_jvms_for_reexecute---------------------
110 // Make sure our current jvms agrees with our parse state. This version
111 // uses the reexecute_sp for reexecuting bytecodes.
112 JVMState* GraphKit::sync_jvms_for_reexecute() {
113 JVMState* jvms = this->jvms();
114 jvms->set_bci(bci()); // Record the new bci in the JVMState
115 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState
116 return jvms;
117 }
118
119 #ifdef ASSERT
120 bool GraphKit::jvms_in_sync() const {
121 Parse* parse = is_Parse();
122 if (parse == NULL) {
123 if (bci() != jvms()->bci()) return false;
124 if (sp() != (int)jvms()->sp()) return false;
125 return true;
126 }
127 if (jvms()->method() != parse->method()) return false;
128 if (jvms()->bci() != parse->bci()) return false;
129 int jvms_sp = jvms()->sp();
130 if (jvms_sp != parse->sp()) return false;
131 int jvms_depth = jvms()->depth();
132 if (jvms_depth != parse->depth()) return false;
133 return true;
134 }
135
136 // Local helper checks for special internal merge points
137 // used to accumulate and merge exception states.
138 // They are marked by the region's in(0) edge being the map itself.
139 // Such merge points must never "escape" into the parser at large,
140 // until they have been handed to gvn.transform.
141 static bool is_hidden_merge(Node* reg) {
142 if (reg == NULL) return false;
143 if (reg->is_Phi()) {
144 reg = reg->in(0);
145 if (reg == NULL) return false;
146 }
147 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
148 }
149
150 void GraphKit::verify_map() const {
151 if (map() == NULL) return; // null map is OK
152 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
153 assert(!map()->has_exceptions(), "call add_exception_states_from 1st");
154 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
155 }
156
157 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
158 assert(ex_map->next_exception() == NULL, "not already part of a chain");
159 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
160 }
161 #endif
162
163 //---------------------------stop_and_kill_map---------------------------------
164 // Set _map to NULL, signalling a stop to further bytecode execution.
165 // First smash the current map's control to a constant, to mark it dead.
166 void GraphKit::stop_and_kill_map() {
167 SafePointNode* dead_map = stop();
168 if (dead_map != NULL) {
169 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
170 assert(dead_map->is_killed(), "must be so marked");
171 }
172 }
173
174
175 //--------------------------------stopped--------------------------------------
176 // Tell if _map is NULL, or control is top.
177 bool GraphKit::stopped() {
178 if (map() == NULL) return true;
179 else if (control() == top()) return true;
180 else return false;
181 }
182
183
184 //-----------------------------has_ex_handler----------------------------------
185 // Tell if this method or any caller method has exception handlers.
186 bool GraphKit::has_ex_handler() {
187 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
188 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
189 return true;
190 }
191 }
192 return false;
193 }
194
195 //------------------------------save_ex_oop------------------------------------
196 // Save an exception without blowing stack contents or other JVM state.
197 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
198 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
199 ex_map->add_req(ex_oop);
200 debug_only(verify_exception_state(ex_map));
201 }
202
203 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
204 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
205 Node* ex_oop = ex_map->in(ex_map->req()-1);
206 if (clear_it) ex_map->del_req(ex_map->req()-1);
207 return ex_oop;
208 }
209
210 //-----------------------------saved_ex_oop------------------------------------
211 // Recover a saved exception from its map.
212 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
213 return common_saved_ex_oop(ex_map, false);
214 }
215
216 //--------------------------clear_saved_ex_oop---------------------------------
217 // Erase a previously saved exception from its map.
218 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
219 return common_saved_ex_oop(ex_map, true);
220 }
221
222 #ifdef ASSERT
223 //---------------------------has_saved_ex_oop----------------------------------
224 // Erase a previously saved exception from its map.
225 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
226 return ex_map->req() == ex_map->jvms()->endoff()+1;
227 }
228 #endif
229
230 //-------------------------make_exception_state--------------------------------
231 // Turn the current JVM state into an exception state, appending the ex_oop.
232 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
233 sync_jvms();
234 SafePointNode* ex_map = stop(); // do not manipulate this map any more
235 set_saved_ex_oop(ex_map, ex_oop);
236 return ex_map;
237 }
238
239
240 //--------------------------add_exception_state--------------------------------
241 // Add an exception to my list of exceptions.
242 void GraphKit::add_exception_state(SafePointNode* ex_map) {
243 if (ex_map == NULL || ex_map->control() == top()) {
244 return;
245 }
246 #ifdef ASSERT
247 verify_exception_state(ex_map);
248 if (has_exceptions()) {
249 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
250 }
251 #endif
252
253 // If there is already an exception of exactly this type, merge with it.
254 // In particular, null-checks and other low-level exceptions common up here.
255 Node* ex_oop = saved_ex_oop(ex_map);
256 const Type* ex_type = _gvn.type(ex_oop);
257 if (ex_oop == top()) {
258 // No action needed.
259 return;
260 }
261 assert(ex_type->isa_instptr(), "exception must be an instance");
262 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
263 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
264 // We check sp also because call bytecodes can generate exceptions
265 // both before and after arguments are popped!
266 if (ex_type2 == ex_type
267 && e2->_jvms->sp() == ex_map->_jvms->sp()) {
268 combine_exception_states(ex_map, e2);
269 return;
270 }
271 }
272
273 // No pre-existing exception of the same type. Chain it on the list.
274 push_exception_state(ex_map);
275 }
276
277 //-----------------------add_exception_states_from-----------------------------
278 void GraphKit::add_exception_states_from(JVMState* jvms) {
279 SafePointNode* ex_map = jvms->map()->next_exception();
280 if (ex_map != NULL) {
281 jvms->map()->set_next_exception(NULL);
282 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
283 next_map = ex_map->next_exception();
284 ex_map->set_next_exception(NULL);
285 add_exception_state(ex_map);
286 }
287 }
288 }
289
290 //-----------------------transfer_exceptions_into_jvms-------------------------
291 JVMState* GraphKit::transfer_exceptions_into_jvms() {
292 if (map() == NULL) {
293 // We need a JVMS to carry the exceptions, but the map has gone away.
294 // Create a scratch JVMS, cloned from any of the exception states...
295 if (has_exceptions()) {
296 _map = _exceptions;
297 _map = clone_map();
298 _map->set_next_exception(NULL);
299 clear_saved_ex_oop(_map);
300 debug_only(verify_map());
301 } else {
302 // ...or created from scratch
303 JVMState* jvms = new (C) JVMState(_method, NULL);
304 jvms->set_bci(_bci);
305 jvms->set_sp(_sp);
306 jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
307 set_jvms(jvms);
308 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top());
309 set_all_memory(top());
310 while (map()->req() < jvms->endoff()) map()->add_req(top());
311 }
312 // (This is a kludge, in case you didn't notice.)
313 set_control(top());
314 }
315 JVMState* jvms = sync_jvms();
316 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
317 jvms->map()->set_next_exception(_exceptions);
318 _exceptions = NULL; // done with this set of exceptions
319 return jvms;
320 }
321
322 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
323 assert(is_hidden_merge(dstphi), "must be a special merge node");
324 assert(is_hidden_merge(srcphi), "must be a special merge node");
325 uint limit = srcphi->req();
326 for (uint i = PhiNode::Input; i < limit; i++) {
327 dstphi->add_req(srcphi->in(i));
328 }
329 }
330 static inline void add_one_req(Node* dstphi, Node* src) {
331 assert(is_hidden_merge(dstphi), "must be a special merge node");
332 assert(!is_hidden_merge(src), "must not be a special merge node");
333 dstphi->add_req(src);
334 }
335
336 //-----------------------combine_exception_states------------------------------
337 // This helper function combines exception states by building phis on a
338 // specially marked state-merging region. These regions and phis are
339 // untransformed, and can build up gradually. The region is marked by
340 // having a control input of its exception map, rather than NULL. Such
341 // regions do not appear except in this function, and in use_exception_state.
342 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
343 if (failing()) return; // dying anyway...
344 JVMState* ex_jvms = ex_map->_jvms;
345 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
346 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
347 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
348 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
349 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
350 assert(ex_map->req() == phi_map->req(), "matching maps");
351 uint tos = ex_jvms->stkoff() + ex_jvms->sp();
352 Node* hidden_merge_mark = root();
353 Node* region = phi_map->control();
354 MergeMemNode* phi_mem = phi_map->merged_memory();
355 MergeMemNode* ex_mem = ex_map->merged_memory();
356 if (region->in(0) != hidden_merge_mark) {
357 // The control input is not (yet) a specially-marked region in phi_map.
358 // Make it so, and build some phis.
359 region = new RegionNode(2);
360 _gvn.set_type(region, Type::CONTROL);
361 region->set_req(0, hidden_merge_mark); // marks an internal ex-state
362 region->init_req(1, phi_map->control());
363 phi_map->set_control(region);
364 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
365 record_for_igvn(io_phi);
366 _gvn.set_type(io_phi, Type::ABIO);
367 phi_map->set_i_o(io_phi);
368 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
369 Node* m = mms.memory();
370 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
371 record_for_igvn(m_phi);
372 _gvn.set_type(m_phi, Type::MEMORY);
373 mms.set_memory(m_phi);
374 }
375 }
376
377 // Either or both of phi_map and ex_map might already be converted into phis.
378 Node* ex_control = ex_map->control();
379 // if there is special marking on ex_map also, we add multiple edges from src
380 bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
381 // how wide was the destination phi_map, originally?
382 uint orig_width = region->req();
383
384 if (add_multiple) {
385 add_n_reqs(region, ex_control);
386 add_n_reqs(phi_map->i_o(), ex_map->i_o());
387 } else {
388 // ex_map has no merges, so we just add single edges everywhere
389 add_one_req(region, ex_control);
390 add_one_req(phi_map->i_o(), ex_map->i_o());
391 }
392 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
393 if (mms.is_empty()) {
394 // get a copy of the base memory, and patch some inputs into it
395 const TypePtr* adr_type = mms.adr_type(C);
396 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
397 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
398 mms.set_memory(phi);
399 // Prepare to append interesting stuff onto the newly sliced phi:
400 while (phi->req() > orig_width) phi->del_req(phi->req()-1);
401 }
402 // Append stuff from ex_map:
403 if (add_multiple) {
404 add_n_reqs(mms.memory(), mms.memory2());
405 } else {
406 add_one_req(mms.memory(), mms.memory2());
407 }
408 }
409 uint limit = ex_map->req();
410 for (uint i = TypeFunc::Parms; i < limit; i++) {
411 // Skip everything in the JVMS after tos. (The ex_oop follows.)
412 if (i == tos) i = ex_jvms->monoff();
413 Node* src = ex_map->in(i);
414 Node* dst = phi_map->in(i);
415 if (src != dst) {
416 PhiNode* phi;
417 if (dst->in(0) != region) {
418 dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
419 record_for_igvn(phi);
420 _gvn.set_type(phi, phi->type());
421 phi_map->set_req(i, dst);
422 // Prepare to append interesting stuff onto the new phi:
423 while (dst->req() > orig_width) dst->del_req(dst->req()-1);
424 } else {
425 assert(dst->is_Phi(), "nobody else uses a hidden region");
426 phi = dst->as_Phi();
427 }
428 if (add_multiple && src->in(0) == ex_control) {
429 // Both are phis.
430 add_n_reqs(dst, src);
431 } else {
432 while (dst->req() < region->req()) add_one_req(dst, src);
433 }
434 const Type* srctype = _gvn.type(src);
435 if (phi->type() != srctype) {
436 const Type* dsttype = phi->type()->meet_speculative(srctype);
437 if (phi->type() != dsttype) {
438 phi->set_type(dsttype);
439 _gvn.set_type(phi, dsttype);
440 }
441 }
442 }
443 }
444 phi_map->merge_replaced_nodes_with(ex_map);
445 }
446
447 //--------------------------use_exception_state--------------------------------
448 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
449 if (failing()) { stop(); return top(); }
450 Node* region = phi_map->control();
451 Node* hidden_merge_mark = root();
452 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
453 Node* ex_oop = clear_saved_ex_oop(phi_map);
454 if (region->in(0) == hidden_merge_mark) {
455 // Special marking for internal ex-states. Process the phis now.
456 region->set_req(0, region); // now it's an ordinary region
457 set_jvms(phi_map->jvms()); // ...so now we can use it as a map
458 // Note: Setting the jvms also sets the bci and sp.
459 set_control(_gvn.transform(region));
460 uint tos = jvms()->stkoff() + sp();
461 for (uint i = 1; i < tos; i++) {
462 Node* x = phi_map->in(i);
463 if (x->in(0) == region) {
464 assert(x->is_Phi(), "expected a special phi");
465 phi_map->set_req(i, _gvn.transform(x));
466 }
467 }
468 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
469 Node* x = mms.memory();
470 if (x->in(0) == region) {
471 assert(x->is_Phi(), "nobody else uses a hidden region");
472 mms.set_memory(_gvn.transform(x));
473 }
474 }
475 if (ex_oop->in(0) == region) {
476 assert(ex_oop->is_Phi(), "expected a special phi");
477 ex_oop = _gvn.transform(ex_oop);
478 }
479 } else {
480 set_jvms(phi_map->jvms());
481 }
482
483 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
484 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
485 return ex_oop;
486 }
487
488 //---------------------------------java_bc-------------------------------------
489 Bytecodes::Code GraphKit::java_bc() const {
490 ciMethod* method = this->method();
491 int bci = this->bci();
492 if (method != NULL && bci != InvocationEntryBci)
493 return method->java_code_at_bci(bci);
494 else
495 return Bytecodes::_illegal;
496 }
497
498 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
499 bool must_throw) {
500 // if the exception capability is set, then we will generate code
501 // to check the JavaThread.should_post_on_exceptions flag to see
502 // if we actually need to report exception events (for this
503 // thread). If we don't need to report exception events, we will
504 // take the normal fast path provided by add_exception_events. If
505 // exception event reporting is enabled for this thread, we will
506 // take the uncommon_trap in the BuildCutout below.
507
508 // first must access the should_post_on_exceptions_flag in this thread's JavaThread
509 Node* jthread = _gvn.transform(new ThreadLocalNode());
510 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
511 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
512
513 // Test the should_post_on_exceptions_flag vs. 0
514 Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
515 Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
516
517 // Branch to slow_path if should_post_on_exceptions_flag was true
518 { BuildCutout unless(this, tst, PROB_MAX);
519 // Do not try anything fancy if we're notifying the VM on every throw.
520 // Cf. case Bytecodes::_athrow in parse2.cpp.
521 uncommon_trap(reason, Deoptimization::Action_none,
522 (ciKlass*)NULL, (char*)NULL, must_throw);
523 }
524
525 }
526
527 //------------------------------builtin_throw----------------------------------
528 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
529 bool must_throw = true;
530
531 if (env()->jvmti_can_post_on_exceptions()) {
532 // check if we must post exception events, take uncommon trap if so
533 uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
534 // here if should_post_on_exceptions is false
535 // continue on with the normal codegen
536 }
537
538 // If this particular condition has not yet happened at this
539 // bytecode, then use the uncommon trap mechanism, and allow for
540 // a future recompilation if several traps occur here.
541 // If the throw is hot, try to use a more complicated inline mechanism
542 // which keeps execution inside the compiled code.
543 bool treat_throw_as_hot = false;
544 ciMethodData* md = method()->method_data();
545
546 if (ProfileTraps) {
547 if (too_many_traps(reason)) {
548 treat_throw_as_hot = true;
549 }
550 // (If there is no MDO at all, assume it is early in
551 // execution, and that any deopts are part of the
552 // startup transient, and don't need to be remembered.)
553
554 // Also, if there is a local exception handler, treat all throws
555 // as hot if there has been at least one in this method.
556 if (C->trap_count(reason) != 0
557 && method()->method_data()->trap_count(reason) != 0
558 && has_ex_handler()) {
559 treat_throw_as_hot = true;
560 }
561 }
562
563 // If this throw happens frequently, an uncommon trap might cause
564 // a performance pothole. If there is a local exception handler,
565 // and if this particular bytecode appears to be deoptimizing often,
566 // let us handle the throw inline, with a preconstructed instance.
567 // Note: If the deopt count has blown up, the uncommon trap
568 // runtime is going to flush this nmethod, not matter what.
569 if (treat_throw_as_hot
570 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
571 // If the throw is local, we use a pre-existing instance and
572 // punt on the backtrace. This would lead to a missing backtrace
573 // (a repeat of 4292742) if the backtrace object is ever asked
574 // for its backtrace.
575 // Fixing this remaining case of 4292742 requires some flavor of
576 // escape analysis. Leave that for the future.
577 ciInstance* ex_obj = NULL;
578 switch (reason) {
579 case Deoptimization::Reason_null_check:
580 ex_obj = env()->NullPointerException_instance();
581 break;
582 case Deoptimization::Reason_div0_check:
583 ex_obj = env()->ArithmeticException_instance();
584 break;
585 case Deoptimization::Reason_range_check:
586 ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
587 break;
588 case Deoptimization::Reason_class_check:
589 if (java_bc() == Bytecodes::_aastore || java_bc() == Bytecodes::_vastore) {
590 ex_obj = env()->ArrayStoreException_instance();
591 } else {
592 ex_obj = env()->ClassCastException_instance();
593 }
594 break;
595 default:
596 break;
597 }
598 if (failing()) { stop(); return; } // exception allocation might fail
599 if (ex_obj != NULL) {
600 // Cheat with a preallocated exception object.
601 if (C->log() != NULL)
602 C->log()->elem("hot_throw preallocated='1' reason='%s'",
603 Deoptimization::trap_reason_name(reason));
604 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj);
605 Node* ex_node = _gvn.transform(ConNode::make(ex_con));
606
607 // Clear the detail message of the preallocated exception object.
608 // Weblogic sometimes mutates the detail message of exceptions
609 // using reflection.
610 int offset = java_lang_Throwable::get_detailMessage_offset();
611 const TypePtr* adr_typ = ex_con->add_offset(offset);
612
613 Node *adr = basic_plus_adr(ex_node, ex_node, offset);
614 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
615 // Conservatively release stores of object references.
616 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
617
618 add_exception_state(make_exception_state(ex_node));
619 return;
620 }
621 }
622
623 // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
624 // It won't be much cheaper than bailing to the interp., since we'll
625 // have to pass up all the debug-info, and the runtime will have to
626 // create the stack trace.
627
628 // Usual case: Bail to interpreter.
629 // Reserve the right to recompile if we haven't seen anything yet.
630
631 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
632 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
633 if (treat_throw_as_hot
634 && (method()->method_data()->trap_recompiled_at(bci(), m)
635 || C->too_many_traps(reason))) {
636 // We cannot afford to take more traps here. Suffer in the interpreter.
637 if (C->log() != NULL)
638 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
639 Deoptimization::trap_reason_name(reason),
640 C->trap_count(reason));
641 action = Deoptimization::Action_none;
642 }
643
644 // "must_throw" prunes the JVM state to include only the stack, if there
645 // are no local exception handlers. This should cut down on register
646 // allocation time and code size, by drastically reducing the number
647 // of in-edges on the call to the uncommon trap.
648
649 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
650 }
651
652
653 //----------------------------PreserveJVMState---------------------------------
654 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
655 debug_only(kit->verify_map());
656 _kit = kit;
657 _map = kit->map(); // preserve the map
658 _sp = kit->sp();
659 kit->set_map(clone_map ? kit->clone_map() : NULL);
660 #ifdef ASSERT
661 _bci = kit->bci();
662 Parse* parser = kit->is_Parse();
663 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
664 _block = block;
665 #endif
666 }
667 PreserveJVMState::~PreserveJVMState() {
668 GraphKit* kit = _kit;
669 #ifdef ASSERT
670 assert(kit->bci() == _bci, "bci must not shift");
671 Parse* parser = kit->is_Parse();
672 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
673 assert(block == _block, "block must not shift");
674 #endif
675 kit->set_map(_map);
676 kit->set_sp(_sp);
677 }
678
679
680 //-----------------------------BuildCutout-------------------------------------
681 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
682 : PreserveJVMState(kit)
683 {
684 assert(p->is_Con() || p->is_Bool(), "test must be a bool");
685 SafePointNode* outer_map = _map; // preserved map is caller's
686 SafePointNode* inner_map = kit->map();
687 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
688 outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
689 inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
690 }
691 BuildCutout::~BuildCutout() {
692 GraphKit* kit = _kit;
693 assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
694 }
695
696 //---------------------------PreserveReexecuteState----------------------------
697 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
698 assert(!kit->stopped(), "must call stopped() before");
699 _kit = kit;
700 _sp = kit->sp();
701 _reexecute = kit->jvms()->_reexecute;
702 }
703 PreserveReexecuteState::~PreserveReexecuteState() {
704 if (_kit->stopped()) return;
705 _kit->jvms()->_reexecute = _reexecute;
706 _kit->set_sp(_sp);
707 }
708
709 //------------------------------clone_map--------------------------------------
710 // Implementation of PreserveJVMState
711 //
712 // Only clone_map(...) here. If this function is only used in the
713 // PreserveJVMState class we may want to get rid of this extra
714 // function eventually and do it all there.
715
716 SafePointNode* GraphKit::clone_map() {
717 if (map() == NULL) return NULL;
718
719 // Clone the memory edge first
720 Node* mem = MergeMemNode::make(map()->memory());
721 gvn().set_type_bottom(mem);
722
723 SafePointNode *clonemap = (SafePointNode*)map()->clone();
724 JVMState* jvms = this->jvms();
725 JVMState* clonejvms = jvms->clone_shallow(C);
726 clonemap->set_memory(mem);
727 clonemap->set_jvms(clonejvms);
728 clonejvms->set_map(clonemap);
729 record_for_igvn(clonemap);
730 gvn().set_type_bottom(clonemap);
731 return clonemap;
732 }
733
734
735 //-----------------------------set_map_clone-----------------------------------
736 void GraphKit::set_map_clone(SafePointNode* m) {
737 _map = m;
738 _map = clone_map();
739 _map->set_next_exception(NULL);
740 debug_only(verify_map());
741 }
742
743
744 //----------------------------kill_dead_locals---------------------------------
745 // Detect any locals which are known to be dead, and force them to top.
746 void GraphKit::kill_dead_locals() {
747 // Consult the liveness information for the locals. If any
748 // of them are unused, then they can be replaced by top(). This
749 // should help register allocation time and cut down on the size
750 // of the deoptimization information.
751
752 // This call is made from many of the bytecode handling
753 // subroutines called from the Big Switch in do_one_bytecode.
754 // Every bytecode which might include a slow path is responsible
755 // for killing its dead locals. The more consistent we
756 // are about killing deads, the fewer useless phis will be
757 // constructed for them at various merge points.
758
759 // bci can be -1 (InvocationEntryBci). We return the entry
760 // liveness for the method.
761
762 if (method() == NULL || method()->code_size() == 0) {
763 // We are building a graph for a call to a native method.
764 // All locals are live.
765 return;
766 }
767
768 ResourceMark rm;
769
770 // Consult the liveness information for the locals. If any
771 // of them are unused, then they can be replaced by top(). This
772 // should help register allocation time and cut down on the size
773 // of the deoptimization information.
774 MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
775
776 int len = (int)live_locals.size();
777 assert(len <= jvms()->loc_size(), "too many live locals");
778 for (int local = 0; local < len; local++) {
779 if (!live_locals.at(local)) {
780 set_local(local, top());
781 }
782 }
783 }
784
785 #ifdef ASSERT
786 //-------------------------dead_locals_are_killed------------------------------
787 // Return true if all dead locals are set to top in the map.
788 // Used to assert "clean" debug info at various points.
789 bool GraphKit::dead_locals_are_killed() {
790 if (method() == NULL || method()->code_size() == 0) {
791 // No locals need to be dead, so all is as it should be.
792 return true;
793 }
794
795 // Make sure somebody called kill_dead_locals upstream.
796 ResourceMark rm;
797 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
798 if (jvms->loc_size() == 0) continue; // no locals to consult
799 SafePointNode* map = jvms->map();
800 ciMethod* method = jvms->method();
801 int bci = jvms->bci();
802 if (jvms == this->jvms()) {
803 bci = this->bci(); // it might not yet be synched
804 }
805 MethodLivenessResult live_locals = method->liveness_at_bci(bci);
806 int len = (int)live_locals.size();
807 if (!live_locals.is_valid() || len == 0)
808 // This method is trivial, or is poisoned by a breakpoint.
809 return true;
810 assert(len == jvms->loc_size(), "live map consistent with locals map");
811 for (int local = 0; local < len; local++) {
812 if (!live_locals.at(local) && map->local(jvms, local) != top()) {
813 if (PrintMiscellaneous && (Verbose || WizardMode)) {
814 tty->print_cr("Zombie local %d: ", local);
815 jvms->dump();
816 }
817 return false;
818 }
819 }
820 }
821 return true;
822 }
823
824 #endif //ASSERT
825
826 // Helper function for adding JVMState and debug information to node
827 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
828 // Add the safepoint edges to the call (or other safepoint).
829
830 // Make sure dead locals are set to top. This
831 // should help register allocation time and cut down on the size
832 // of the deoptimization information.
833 assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
834
835 // Walk the inline list to fill in the correct set of JVMState's
836 // Also fill in the associated edges for each JVMState.
837
838 // If the bytecode needs to be reexecuted we need to put
839 // the arguments back on the stack.
840 const bool should_reexecute = jvms()->should_reexecute();
841 JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
842
843 // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
844 // undefined if the bci is different. This is normal for Parse but it
845 // should not happen for LibraryCallKit because only one bci is processed.
846 assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
847 "in LibraryCallKit the reexecute bit should not change");
848
849 // If we are guaranteed to throw, we can prune everything but the
850 // input to the current bytecode.
851 bool can_prune_locals = false;
852 uint stack_slots_not_pruned = 0;
853 int inputs = 0, depth = 0;
854 if (must_throw) {
855 assert(method() == youngest_jvms->method(), "sanity");
856 if (compute_stack_effects(inputs, depth)) {
857 can_prune_locals = true;
858 stack_slots_not_pruned = inputs;
859 }
860 }
861
862 if (env()->should_retain_local_variables()) {
863 // At any safepoint, this method can get breakpointed, which would
864 // then require an immediate deoptimization.
865 can_prune_locals = false; // do not prune locals
866 stack_slots_not_pruned = 0;
867 }
868
869 C->add_safepoint_edges(call, youngest_jvms, can_prune_locals, stack_slots_not_pruned);
870 }
871
872 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
873 Bytecodes::Code code = java_bc();
874 if (code == Bytecodes::_wide) {
875 code = method()->java_code_at_bci(bci() + 1);
876 }
877
878 BasicType rtype = T_ILLEGAL;
879 int rsize = 0;
880
881 if (code != Bytecodes::_illegal) {
882 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
883 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
884 if (rtype < T_CONFLICT)
885 rsize = type2size[rtype];
886 }
887
888 switch (code) {
889 case Bytecodes::_illegal:
890 return false;
891
892 case Bytecodes::_ldc:
893 case Bytecodes::_ldc_w:
894 case Bytecodes::_ldc2_w:
895 inputs = 0;
896 break;
897
898 case Bytecodes::_dup: inputs = 1; break;
899 case Bytecodes::_dup_x1: inputs = 2; break;
900 case Bytecodes::_dup_x2: inputs = 3; break;
901 case Bytecodes::_dup2: inputs = 2; break;
902 case Bytecodes::_dup2_x1: inputs = 3; break;
903 case Bytecodes::_dup2_x2: inputs = 4; break;
904 case Bytecodes::_swap: inputs = 2; break;
905 case Bytecodes::_arraylength: inputs = 1; break;
906
907 case Bytecodes::_getstatic:
908 case Bytecodes::_putstatic:
909 case Bytecodes::_getfield:
910 case Bytecodes::_putfield:
911 {
912 bool ignored_will_link;
913 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
914 int size = field->type()->size();
915 bool is_get = (depth >= 0), is_static = (depth & 1);
916 inputs = (is_static ? 0 : 1);
917 if (is_get) {
918 depth = size - inputs;
919 } else {
920 inputs += size; // putxxx pops the value from the stack
921 depth = - inputs;
922 }
923 }
924 break;
925
926 case Bytecodes::_invokevirtual:
927 case Bytecodes::_invokespecial:
928 case Bytecodes::_invokestatic:
929 case Bytecodes::_invokedynamic:
930 case Bytecodes::_invokeinterface:
931 {
932 bool ignored_will_link;
933 ciSignature* declared_signature = NULL;
934 ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
935 assert(declared_signature != NULL, "cannot be null");
936 inputs = declared_signature->arg_size_for_bc(code);
937 int size = declared_signature->return_type()->size();
938 depth = size - inputs;
939 }
940 break;
941
942 case Bytecodes::_multianewarray:
943 {
944 ciBytecodeStream iter(method());
945 iter.reset_to_bci(bci());
946 iter.next();
947 inputs = iter.get_dimensions();
948 assert(rsize == 1, "");
949 depth = rsize - inputs;
950 }
951 break;
952
953 case Bytecodes::_vwithfield: {
954 bool ignored_will_link;
955 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
956 int size = field->type()->size();
957 inputs = size+1;
958 depth = rsize - inputs;
959 break;
960 }
961
962 case Bytecodes::_ireturn:
963 case Bytecodes::_lreturn:
964 case Bytecodes::_freturn:
965 case Bytecodes::_dreturn:
966 case Bytecodes::_areturn:
967 case Bytecodes::_vreturn:
968 assert(rsize == -depth, "");
969 inputs = rsize;
970 break;
971
972 case Bytecodes::_jsr:
973 case Bytecodes::_jsr_w:
974 inputs = 0;
975 depth = 1; // S.B. depth=1, not zero
976 break;
977
978 default:
979 // bytecode produces a typed result
980 inputs = rsize - depth;
981 assert(inputs >= 0, "");
982 break;
983 }
984
985 #ifdef ASSERT
986 // spot check
987 int outputs = depth + inputs;
988 assert(outputs >= 0, "sanity");
989 switch (code) {
990 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
991 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break;
992 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break;
993 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break;
994 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break;
995 default: break;
996 }
997 #endif //ASSERT
998
999 return true;
1000 }
1001
1002
1003
1004 //------------------------------basic_plus_adr---------------------------------
1005 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1006 // short-circuit a common case
1007 if (offset == intcon(0)) return ptr;
1008 return _gvn.transform( new AddPNode(base, ptr, offset) );
1009 }
1010
1011 Node* GraphKit::ConvI2L(Node* offset) {
1012 // short-circuit a common case
1013 jint offset_con = find_int_con(offset, Type::OffsetBot);
1014 if (offset_con != Type::OffsetBot) {
1015 return longcon((jlong) offset_con);
1016 }
1017 return _gvn.transform( new ConvI2LNode(offset));
1018 }
1019
1020 Node* GraphKit::ConvI2UL(Node* offset) {
1021 juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1022 if (offset_con != (juint) Type::OffsetBot) {
1023 return longcon((julong) offset_con);
1024 }
1025 Node* conv = _gvn.transform( new ConvI2LNode(offset));
1026 Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1027 return _gvn.transform( new AndLNode(conv, mask) );
1028 }
1029
1030 Node* GraphKit::ConvL2I(Node* offset) {
1031 // short-circuit a common case
1032 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1033 if (offset_con != (jlong)Type::OffsetBot) {
1034 return intcon((int) offset_con);
1035 }
1036 return _gvn.transform( new ConvL2INode(offset));
1037 }
1038
1039 //-------------------------load_object_klass-----------------------------------
1040 Node* GraphKit::load_object_klass(Node* obj) {
1041 // Special-case a fresh allocation to avoid building nodes:
1042 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1043 if (akls != NULL) return akls;
1044 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1045 return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1046 }
1047
1048 //-------------------------load_array_length-----------------------------------
1049 Node* GraphKit::load_array_length(Node* array) {
1050 // Special-case a fresh allocation to avoid building nodes:
1051 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1052 Node *alen;
1053 if (alloc == NULL) {
1054 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1055 alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1056 } else {
1057 alen = alloc->Ideal_length();
1058 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1059 if (ccast != alen) {
1060 alen = _gvn.transform(ccast);
1061 }
1062 }
1063 return alen;
1064 }
1065
1066 //------------------------------do_null_check----------------------------------
1067 // Helper function to do a NULL pointer check. Returned value is
1068 // the incoming address with NULL casted away. You are allowed to use the
1069 // not-null value only if you are control dependent on the test.
1070 #ifndef PRODUCT
1071 extern int explicit_null_checks_inserted,
1072 explicit_null_checks_elided;
1073 #endif
1074 Node* GraphKit::null_check_common(Node* value, BasicType type,
1075 // optional arguments for variations:
1076 bool assert_null,
1077 Node* *null_control,
1078 bool speculative) {
1079 assert(!assert_null || null_control == NULL, "not both at once");
1080 if (stopped()) return top();
1081 NOT_PRODUCT(explicit_null_checks_inserted++);
1082
1083 // Construct NULL check
1084 Node *chk = NULL;
1085 switch(type) {
1086 case T_LONG : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1087 case T_INT : chk = new CmpINode(value, _gvn.intcon(0)); break;
1088 case T_VALUETYPE : // fall through
1089 case T_ARRAY : // fall through
1090 type = T_OBJECT; // simplify further tests
1091 case T_OBJECT : {
1092 const Type *t = _gvn.type( value );
1093
1094 const TypeOopPtr* tp = t->isa_oopptr();
1095 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1096 // Only for do_null_check, not any of its siblings:
1097 && !assert_null && null_control == NULL) {
1098 // Usually, any field access or invocation on an unloaded oop type
1099 // will simply fail to link, since the statically linked class is
1100 // likely also to be unloaded. However, in -Xcomp mode, sometimes
1101 // the static class is loaded but the sharper oop type is not.
1102 // Rather than checking for this obscure case in lots of places,
1103 // we simply observe that a null check on an unloaded class
1104 // will always be followed by a nonsense operation, so we
1105 // can just issue the uncommon trap here.
1106 // Our access to the unloaded class will only be correct
1107 // after it has been loaded and initialized, which requires
1108 // a trip through the interpreter.
1109 #ifndef PRODUCT
1110 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1111 #endif
1112 uncommon_trap(Deoptimization::Reason_unloaded,
1113 Deoptimization::Action_reinterpret,
1114 tp->klass(), "!loaded");
1115 return top();
1116 }
1117
1118 if (assert_null) {
1119 // See if the type is contained in NULL_PTR.
1120 // If so, then the value is already null.
1121 if (t->higher_equal(TypePtr::NULL_PTR)) {
1122 NOT_PRODUCT(explicit_null_checks_elided++);
1123 return value; // Elided null assert quickly!
1124 }
1125 } else {
1126 // See if mixing in the NULL pointer changes type.
1127 // If so, then the NULL pointer was not allowed in the original
1128 // type. In other words, "value" was not-null.
1129 if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1130 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1131 NOT_PRODUCT(explicit_null_checks_elided++);
1132 return value; // Elided null check quickly!
1133 }
1134 }
1135 chk = new CmpPNode( value, null() );
1136 break;
1137 }
1138
1139 default:
1140 fatal("unexpected type: %s", type2name(type));
1141 }
1142 assert(chk != NULL, "sanity check");
1143 chk = _gvn.transform(chk);
1144
1145 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1146 BoolNode *btst = new BoolNode( chk, btest);
1147 Node *tst = _gvn.transform( btst );
1148
1149 //-----------
1150 // if peephole optimizations occurred, a prior test existed.
1151 // If a prior test existed, maybe it dominates as we can avoid this test.
1152 if (tst != btst && type == T_OBJECT) {
1153 // At this point we want to scan up the CFG to see if we can
1154 // find an identical test (and so avoid this test altogether).
1155 Node *cfg = control();
1156 int depth = 0;
1157 while( depth < 16 ) { // Limit search depth for speed
1158 if( cfg->Opcode() == Op_IfTrue &&
1159 cfg->in(0)->in(1) == tst ) {
1160 // Found prior test. Use "cast_not_null" to construct an identical
1161 // CastPP (and hence hash to) as already exists for the prior test.
1162 // Return that casted value.
1163 if (assert_null) {
1164 replace_in_map(value, null());
1165 return null(); // do not issue the redundant test
1166 }
1167 Node *oldcontrol = control();
1168 set_control(cfg);
1169 Node *res = cast_not_null(value);
1170 set_control(oldcontrol);
1171 NOT_PRODUCT(explicit_null_checks_elided++);
1172 return res;
1173 }
1174 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1175 if (cfg == NULL) break; // Quit at region nodes
1176 depth++;
1177 }
1178 }
1179
1180 //-----------
1181 // Branch to failure if null
1182 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen
1183 Deoptimization::DeoptReason reason;
1184 if (assert_null) {
1185 reason = Deoptimization::reason_null_assert(speculative);
1186 } else if (type == T_OBJECT) {
1187 reason = Deoptimization::reason_null_check(speculative);
1188 } else {
1189 reason = Deoptimization::Reason_div0_check;
1190 }
1191 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1192 // ciMethodData::has_trap_at will return a conservative -1 if any
1193 // must-be-null assertion has failed. This could cause performance
1194 // problems for a method after its first do_null_assert failure.
1195 // Consider using 'Reason_class_check' instead?
1196
1197 // To cause an implicit null check, we set the not-null probability
1198 // to the maximum (PROB_MAX). For an explicit check the probability
1199 // is set to a smaller value.
1200 if (null_control != NULL || too_many_traps(reason)) {
1201 // probability is less likely
1202 ok_prob = PROB_LIKELY_MAG(3);
1203 } else if (!assert_null &&
1204 (ImplicitNullCheckThreshold > 0) &&
1205 method() != NULL &&
1206 (method()->method_data()->trap_count(reason)
1207 >= (uint)ImplicitNullCheckThreshold)) {
1208 ok_prob = PROB_LIKELY_MAG(3);
1209 }
1210
1211 if (null_control != NULL) {
1212 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1213 Node* null_true = _gvn.transform( new IfFalseNode(iff));
1214 set_control( _gvn.transform( new IfTrueNode(iff)));
1215 #ifndef PRODUCT
1216 if (null_true == top()) {
1217 explicit_null_checks_elided++;
1218 }
1219 #endif
1220 (*null_control) = null_true;
1221 } else {
1222 BuildCutout unless(this, tst, ok_prob);
1223 // Check for optimizer eliding test at parse time
1224 if (stopped()) {
1225 // Failure not possible; do not bother making uncommon trap.
1226 NOT_PRODUCT(explicit_null_checks_elided++);
1227 } else if (assert_null) {
1228 uncommon_trap(reason,
1229 Deoptimization::Action_make_not_entrant,
1230 NULL, "assert_null");
1231 } else {
1232 replace_in_map(value, zerocon(type));
1233 builtin_throw(reason);
1234 }
1235 }
1236
1237 // Must throw exception, fall-thru not possible?
1238 if (stopped()) {
1239 return top(); // No result
1240 }
1241
1242 if (assert_null) {
1243 // Cast obj to null on this path.
1244 replace_in_map(value, zerocon(type));
1245 return zerocon(type);
1246 }
1247
1248 // Cast obj to not-null on this path, if there is no null_control.
1249 // (If there is a null_control, a non-null value may come back to haunt us.)
1250 if (type == T_OBJECT) {
1251 Node* cast = cast_not_null(value, false);
1252 if (null_control == NULL || (*null_control) == top())
1253 replace_in_map(value, cast);
1254 value = cast;
1255 }
1256
1257 return value;
1258 }
1259
1260
1261 //------------------------------cast_not_null----------------------------------
1262 // Cast obj to not-null on this path
1263 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1264 const Type *t = _gvn.type(obj);
1265 const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1266 // Object is already not-null?
1267 if( t == t_not_null ) return obj;
1268
1269 Node *cast = new CastPPNode(obj,t_not_null);
1270 cast->init_req(0, control());
1271 cast = _gvn.transform( cast );
1272
1273 // Scan for instances of 'obj' in the current JVM mapping.
1274 // These instances are known to be not-null after the test.
1275 if (do_replace_in_map)
1276 replace_in_map(obj, cast);
1277
1278 return cast; // Return casted value
1279 }
1280
1281 // Sometimes in intrinsics, we implicitly know an object is not null
1282 // (there's no actual null check) so we can cast it to not null. In
1283 // the course of optimizations, the input to the cast can become null.
1284 // In that case that data path will die and we need the control path
1285 // to become dead as well to keep the graph consistent. So we have to
1286 // add a check for null for which one branch can't be taken. It uses
1287 // an Opaque4 node that will cause the check to be removed after loop
1288 // opts so the test goes away and the compiled code doesn't execute a
1289 // useless check.
1290 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1291 Node* chk = _gvn.transform(new CmpPNode(value, null()));
1292 Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1293 Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1294 IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1295 _gvn.set_type(iff, iff->Value(&_gvn));
1296 Node *if_f = _gvn.transform(new IfFalseNode(iff));
1297 Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1298 Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1299 C->root()->add_req(halt);
1300 Node *if_t = _gvn.transform(new IfTrueNode(iff));
1301 set_control(if_t);
1302 return cast_not_null(value, do_replace_in_map);
1303 }
1304
1305
1306 //--------------------------replace_in_map-------------------------------------
1307 void GraphKit::replace_in_map(Node* old, Node* neww) {
1308 if (old == neww) {
1309 return;
1310 }
1311
1312 map()->replace_edge(old, neww);
1313
1314 // Note: This operation potentially replaces any edge
1315 // on the map. This includes locals, stack, and monitors
1316 // of the current (innermost) JVM state.
1317
1318 // don't let inconsistent types from profiling escape this
1319 // method
1320
1321 const Type* told = _gvn.type(old);
1322 const Type* tnew = _gvn.type(neww);
1323
1324 if (!tnew->higher_equal(told)) {
1325 return;
1326 }
1327
1328 map()->record_replaced_node(old, neww);
1329 }
1330
1331
1332 //=============================================================================
1333 //--------------------------------memory---------------------------------------
1334 Node* GraphKit::memory(uint alias_idx) {
1335 MergeMemNode* mem = merged_memory();
1336 Node* p = mem->memory_at(alias_idx);
1337 _gvn.set_type(p, Type::MEMORY); // must be mapped
1338 return p;
1339 }
1340
1341 //-----------------------------reset_memory------------------------------------
1342 Node* GraphKit::reset_memory() {
1343 Node* mem = map()->memory();
1344 // do not use this node for any more parsing!
1345 debug_only( map()->set_memory((Node*)NULL) );
1346 return _gvn.transform( mem );
1347 }
1348
1349 //------------------------------set_all_memory---------------------------------
1350 void GraphKit::set_all_memory(Node* newmem) {
1351 Node* mergemem = MergeMemNode::make(newmem);
1352 gvn().set_type_bottom(mergemem);
1353 map()->set_memory(mergemem);
1354 }
1355
1356 //------------------------------set_all_memory_call----------------------------
1357 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1358 Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1359 set_all_memory(newmem);
1360 }
1361
1362 //=============================================================================
1363 //
1364 // parser factory methods for MemNodes
1365 //
1366 // These are layered on top of the factory methods in LoadNode and StoreNode,
1367 // and integrate with the parser's memory state and _gvn engine.
1368 //
1369
1370 // factory methods in "int adr_idx"
1371 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1372 int adr_idx,
1373 MemNode::MemOrd mo,
1374 LoadNode::ControlDependency control_dependency,
1375 bool require_atomic_access,
1376 bool unaligned,
1377 bool mismatched) {
1378 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1379 const TypePtr* adr_type = NULL; // debug-mode-only argument
1380 debug_only(adr_type = C->get_adr_type(adr_idx));
1381 Node* mem = memory(adr_idx);
1382 Node* ld;
1383 if (require_atomic_access && bt == T_LONG) {
1384 ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1385 } else if (require_atomic_access && bt == T_DOUBLE) {
1386 ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1387 } else {
1388 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1389 }
1390 ld = _gvn.transform(ld);
1391 if (bt == T_VALUETYPE) {
1392 // Loading a non-flattened value type from memory requires a null check.
1393 ld = ValueTypeNode::make(this, ld, true /* null check */);
1394 } else if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1395 // Improve graph before escape analysis and boxing elimination.
1396 record_for_igvn(ld);
1397 }
1398 return ld;
1399 }
1400
1401 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1402 int adr_idx,
1403 MemNode::MemOrd mo,
1404 bool require_atomic_access,
1405 bool unaligned,
1406 bool mismatched) {
1407 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1408 const TypePtr* adr_type = NULL;
1409 debug_only(adr_type = C->get_adr_type(adr_idx));
1410 Node *mem = memory(adr_idx);
1411 Node* st;
1412 if (require_atomic_access && bt == T_LONG) {
1413 st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1414 } else if (require_atomic_access && bt == T_DOUBLE) {
1415 st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1416 } else {
1417 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1418 }
1419 if (unaligned) {
1420 st->as_Store()->set_unaligned_access();
1421 }
1422 if (mismatched) {
1423 st->as_Store()->set_mismatched_access();
1424 }
1425 st = _gvn.transform(st);
1426 set_memory(st, adr_idx);
1427 // Back-to-back stores can only remove intermediate store with DU info
1428 // so push on worklist for optimizer.
1429 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1430 record_for_igvn(st);
1431
1432 return st;
1433 }
1434
1435
1436 void GraphKit::pre_barrier(bool do_load,
1437 Node* ctl,
1438 Node* obj,
1439 Node* adr,
1440 uint adr_idx,
1441 Node* val,
1442 const TypeOopPtr* val_type,
1443 Node* pre_val,
1444 BasicType bt) {
1445
1446 BarrierSet* bs = Universe::heap()->barrier_set();
1447 set_control(ctl);
1448 switch (bs->kind()) {
1449 case BarrierSet::G1SATBCTLogging:
1450 g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1451 break;
1452
1453 case BarrierSet::CardTableForRS:
1454 case BarrierSet::CardTableExtension:
1455 case BarrierSet::ModRef:
1456 break;
1457
1458 default :
1459 ShouldNotReachHere();
1460
1461 }
1462 }
1463
1464 bool GraphKit::can_move_pre_barrier() const {
1465 BarrierSet* bs = Universe::heap()->barrier_set();
1466 switch (bs->kind()) {
1467 case BarrierSet::G1SATBCTLogging:
1468 return true; // Can move it if no safepoint
1469
1470 case BarrierSet::CardTableForRS:
1471 case BarrierSet::CardTableExtension:
1472 case BarrierSet::ModRef:
1473 return true; // There is no pre-barrier
1474
1475 default :
1476 ShouldNotReachHere();
1477 }
1478 return false;
1479 }
1480
1481 void GraphKit::post_barrier(Node* ctl,
1482 Node* store,
1483 Node* obj,
1484 Node* adr,
1485 uint adr_idx,
1486 Node* val,
1487 BasicType bt,
1488 bool use_precise) {
1489 BarrierSet* bs = Universe::heap()->barrier_set();
1490 set_control(ctl);
1491 switch (bs->kind()) {
1492 case BarrierSet::G1SATBCTLogging:
1493 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1494 break;
1495
1496 case BarrierSet::CardTableForRS:
1497 case BarrierSet::CardTableExtension:
1498 write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1499 break;
1500
1501 case BarrierSet::ModRef:
1502 break;
1503
1504 default :
1505 ShouldNotReachHere();
1506
1507 }
1508 }
1509
1510 Node* GraphKit::store_oop(Node* ctl,
1511 Node* obj,
1512 Node* adr,
1513 const TypePtr* adr_type,
1514 Node* val,
1515 const TypeOopPtr* val_type,
1516 BasicType bt,
1517 bool use_precise,
1518 MemNode::MemOrd mo,
1519 bool mismatched) {
1520 // Transformation of a value which could be NULL pointer (CastPP #NULL)
1521 // could be delayed during Parse (for example, in adjust_map_after_if()).
1522 // Execute transformation here to avoid barrier generation in such case.
1523 if (_gvn.type(val) == TypePtr::NULL_PTR)
1524 val = _gvn.makecon(TypePtr::NULL_PTR);
1525
1526 set_control(ctl);
1527 if (stopped()) return top(); // Dead path ?
1528
1529 assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1530 assert(val != NULL, "not dead path");
1531 uint adr_idx = C->get_alias_index(adr_type);
1532 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1533
1534 if (val->is_ValueType()) {
1535 // Allocate value type and get oop
1536 val = val->as_ValueType()->allocate(this)->get_oop();
1537 }
1538
1539 pre_barrier(true /* do_load */,
1540 control(), obj, adr, adr_idx, val, val_type,
1541 NULL /* pre_val */,
1542 bt);
1543
1544 Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1545 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1546 return store;
1547 }
1548
1549 // Could be an array or object we don't know at compile time (unsafe ref.)
1550 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1551 Node* obj, // containing obj
1552 Node* adr, // actual adress to store val at
1553 const TypePtr* adr_type,
1554 Node* val,
1555 BasicType bt,
1556 MemNode::MemOrd mo,
1557 bool mismatched) {
1558 Compile::AliasType* at = C->alias_type(adr_type);
1559 const TypeOopPtr* val_type = NULL;
1560 if (adr_type->isa_instptr()) {
1561 if (at->field() != NULL) {
1562 // known field. This code is a copy of the do_put_xxx logic.
1563 ciField* field = at->field();
1564 if (!field->type()->is_loaded()) {
1565 val_type = TypeInstPtr::BOTTOM;
1566 } else {
1567 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1568 }
1569 }
1570 } else if (adr_type->isa_aryptr()) {
1571 val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1572 }
1573 if (val_type == NULL) {
1574 val_type = TypeInstPtr::BOTTOM;
1575 }
1576 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1577 }
1578
1579
1580 //-------------------------array_element_address-------------------------
1581 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1582 const TypeInt* sizetype, Node* ctrl) {
1583 uint shift = exact_log2(type2aelembytes(elembt));
1584 ciKlass* arytype_klass = _gvn.type(ary)->is_aryptr()->klass();
1585 if (arytype_klass->is_value_array_klass()) {
1586 ciValueArrayKlass* vak = arytype_klass->as_value_array_klass();
1587 shift = vak->log2_element_size();
1588 }
1589 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1590
1591 // short-circuit a common case (saves lots of confusing waste motion)
1592 jint idx_con = find_int_con(idx, -1);
1593 if (idx_con >= 0) {
1594 intptr_t offset = header + ((intptr_t)idx_con << shift);
1595 return basic_plus_adr(ary, offset);
1596 }
1597
1598 // must be correct type for alignment purposes
1599 Node* base = basic_plus_adr(ary, header);
1600 idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1601 Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1602 return basic_plus_adr(ary, base, scale);
1603 }
1604
1605 //-------------------------load_array_element-------------------------
1606 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1607 const Type* elemtype = arytype->elem();
1608 BasicType elembt = elemtype->array_element_basic_type();
1609 assert(elembt != T_VALUETYPE, "value types are not supported by this method");
1610 Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1611 if (elembt == T_NARROWOOP) {
1612 elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1613 }
1614 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1615 return ld;
1616 }
1617
1618 //-------------------------set_arguments_for_java_call-------------------------
1619 // Arguments (pre-popped from the stack) are taken from the JVMS.
1620 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1621 // Add the call arguments:
1622 const TypeTuple* domain = call->tf()->domain_sig();
1623 uint nargs = domain->cnt();
1624 for (uint i = TypeFunc::Parms, idx = TypeFunc::Parms; i < nargs; i++) {
1625 Node* arg = argument(i-TypeFunc::Parms);
1626 if (ValueTypePassFieldsAsArgs) {
1627 if (arg->is_ValueType()) {
1628 ValueTypeNode* vt = arg->as_ValueType();
1629 if (!domain->field_at(i)->is_valuetypeptr()->is__Value()) {
1630 // We don't pass value type arguments by reference but instead
1631 // pass each field of the value type
1632 idx += vt->pass_fields(call, idx, *this);
1633 // If a value type argument is passed as fields, attach the Method* to the call site
1634 // to be able to access the extended signature later via attached_method_before_pc().
1635 // For example, see CompiledMethod::preserve_callee_argument_oops().
1636 call->set_override_symbolic_info(true);
1637 } else {
1638 arg = arg->as_ValueType()->allocate(this)->get_oop();
1639 call->init_req(idx, arg);
1640 idx++;
1641 }
1642 } else {
1643 call->init_req(idx, arg);
1644 idx++;
1645 }
1646 } else {
1647 if (arg->is_ValueType()) {
1648 // Pass value type argument via oop to callee
1649 arg = arg->as_ValueType()->allocate(this)->get_oop();
1650 }
1651 call->init_req(i, arg);
1652 }
1653 }
1654 }
1655
1656 //---------------------------set_edges_for_java_call---------------------------
1657 // Connect a newly created call into the current JVMS.
1658 // A return value node (if any) is returned from set_edges_for_java_call.
1659 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1660
1661 // Add the predefined inputs:
1662 call->init_req( TypeFunc::Control, control() );
1663 call->init_req( TypeFunc::I_O , i_o() );
1664 call->init_req( TypeFunc::Memory , reset_memory() );
1665 call->init_req( TypeFunc::FramePtr, frameptr() );
1666 call->init_req( TypeFunc::ReturnAdr, top() );
1667
1668 add_safepoint_edges(call, must_throw);
1669
1670 Node* xcall = _gvn.transform(call);
1671
1672 if (xcall == top()) {
1673 set_control(top());
1674 return;
1675 }
1676 assert(xcall == call, "call identity is stable");
1677
1678 // Re-use the current map to produce the result.
1679
1680 set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1681 set_i_o( _gvn.transform(new ProjNode(call, TypeFunc::I_O , separate_io_proj)));
1682 set_all_memory_call(xcall, separate_io_proj);
1683
1684 //return xcall; // no need, caller already has it
1685 }
1686
1687 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1688 if (stopped()) return top(); // maybe the call folded up?
1689
1690 // Note: Since any out-of-line call can produce an exception,
1691 // we always insert an I_O projection from the call into the result.
1692
1693 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1694
1695 if (separate_io_proj) {
1696 // The caller requested separate projections be used by the fall
1697 // through and exceptional paths, so replace the projections for
1698 // the fall through path.
1699 set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1700 set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1701 }
1702
1703 // Capture the return value, if any.
1704 Node* ret;
1705 if (call->method() == NULL ||
1706 call->method()->return_type()->basic_type() == T_VOID) {
1707 ret = top();
1708 } else {
1709 if (!call->tf()->returns_value_type_as_fields()) {
1710 ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1711 } else {
1712 // Return of multiple values (value type fields): we create a
1713 // ValueType node, each field is a projection from the call.
1714 const TypeTuple* range_sig = call->tf()->range_sig();
1715 const Type* t = range_sig->field_at(TypeFunc::Parms);
1716 assert(t->isa_valuetypeptr(), "only value types for multiple return values");
1717 ciValueKlass* vk = t->is_valuetypeptr()->value_type()->value_klass();
1718 Node* ctl = control();
1719 ret = ValueTypeNode::make(_gvn, ctl, merged_memory(), call, vk, TypeFunc::Parms+1, false);
1720 set_control(ctl);
1721 }
1722 }
1723
1724 return ret;
1725 }
1726
1727 //--------------------set_predefined_input_for_runtime_call--------------------
1728 // Reading and setting the memory state is way conservative here.
1729 // The real problem is that I am not doing real Type analysis on memory,
1730 // so I cannot distinguish card mark stores from other stores. Across a GC
1731 // point the Store Barrier and the card mark memory has to agree. I cannot
1732 // have a card mark store and its barrier split across the GC point from
1733 // either above or below. Here I get that to happen by reading ALL of memory.
1734 // A better answer would be to separate out card marks from other memory.
1735 // For now, return the input memory state, so that it can be reused
1736 // after the call, if this call has restricted memory effects.
1737 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1738 // Set fixed predefined input arguments
1739 Node* memory = reset_memory();
1740 call->init_req( TypeFunc::Control, control() );
1741 call->init_req( TypeFunc::I_O, top() ); // does no i/o
1742 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs
1743 call->init_req( TypeFunc::FramePtr, frameptr() );
1744 call->init_req( TypeFunc::ReturnAdr, top() );
1745 return memory;
1746 }
1747
1748 //-------------------set_predefined_output_for_runtime_call--------------------
1749 // Set control and memory (not i_o) from the call.
1750 // If keep_mem is not NULL, use it for the output state,
1751 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1752 // If hook_mem is NULL, this call produces no memory effects at all.
1753 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1754 // then only that memory slice is taken from the call.
1755 // In the last case, we must put an appropriate memory barrier before
1756 // the call, so as to create the correct anti-dependencies on loads
1757 // preceding the call.
1758 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1759 Node* keep_mem,
1760 const TypePtr* hook_mem) {
1761 // no i/o
1762 set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1763 if (keep_mem) {
1764 // First clone the existing memory state
1765 set_all_memory(keep_mem);
1766 if (hook_mem != NULL) {
1767 // Make memory for the call
1768 Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1769 // Set the RawPtr memory state only. This covers all the heap top/GC stuff
1770 // We also use hook_mem to extract specific effects from arraycopy stubs.
1771 set_memory(mem, hook_mem);
1772 }
1773 // ...else the call has NO memory effects.
1774
1775 // Make sure the call advertises its memory effects precisely.
1776 // This lets us build accurate anti-dependences in gcm.cpp.
1777 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1778 "call node must be constructed correctly");
1779 } else {
1780 assert(hook_mem == NULL, "");
1781 // This is not a "slow path" call; all memory comes from the call.
1782 set_all_memory_call(call);
1783 }
1784 }
1785
1786
1787 // Replace the call with the current state of the kit.
1788 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1789 JVMState* ejvms = NULL;
1790 if (has_exceptions()) {
1791 ejvms = transfer_exceptions_into_jvms();
1792 }
1793
1794 ReplacedNodes replaced_nodes = map()->replaced_nodes();
1795 ReplacedNodes replaced_nodes_exception;
1796 Node* ex_ctl = top();
1797
1798 SafePointNode* final_state = stop();
1799
1800 // Find all the needed outputs of this call
1801 CallProjections callprojs;
1802 call->extract_projections(&callprojs, true);
1803
1804 Node* init_mem = call->in(TypeFunc::Memory);
1805 Node* final_mem = final_state->in(TypeFunc::Memory);
1806 Node* final_ctl = final_state->in(TypeFunc::Control);
1807 Node* final_io = final_state->in(TypeFunc::I_O);
1808
1809 // Replace all the old call edges with the edges from the inlining result
1810 if (callprojs.fallthrough_catchproj != NULL) {
1811 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1812 }
1813 if (callprojs.fallthrough_memproj != NULL) {
1814 if (final_mem->is_MergeMem()) {
1815 // Parser's exits MergeMem was not transformed but may be optimized
1816 final_mem = _gvn.transform(final_mem);
1817 }
1818 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem);
1819 }
1820 if (callprojs.fallthrough_ioproj != NULL) {
1821 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io);
1822 }
1823
1824 // Replace the result with the new result if it exists and is used
1825 if (callprojs.resproj != NULL && result != NULL) {
1826 C->gvn_replace_by(callprojs.resproj, result);
1827 }
1828
1829 if (ejvms == NULL) {
1830 // No exception edges to simply kill off those paths
1831 if (callprojs.catchall_catchproj != NULL) {
1832 C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1833 }
1834 if (callprojs.catchall_memproj != NULL) {
1835 C->gvn_replace_by(callprojs.catchall_memproj, C->top());
1836 }
1837 if (callprojs.catchall_ioproj != NULL) {
1838 C->gvn_replace_by(callprojs.catchall_ioproj, C->top());
1839 }
1840 // Replace the old exception object with top
1841 if (callprojs.exobj != NULL) {
1842 C->gvn_replace_by(callprojs.exobj, C->top());
1843 }
1844 } else {
1845 GraphKit ekit(ejvms);
1846
1847 // Load my combined exception state into the kit, with all phis transformed:
1848 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1849 replaced_nodes_exception = ex_map->replaced_nodes();
1850
1851 Node* ex_oop = ekit.use_exception_state(ex_map);
1852
1853 if (callprojs.catchall_catchproj != NULL) {
1854 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1855 ex_ctl = ekit.control();
1856 }
1857 if (callprojs.catchall_memproj != NULL) {
1858 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory());
1859 }
1860 if (callprojs.catchall_ioproj != NULL) {
1861 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o());
1862 }
1863
1864 // Replace the old exception object with the newly created one
1865 if (callprojs.exobj != NULL) {
1866 C->gvn_replace_by(callprojs.exobj, ex_oop);
1867 }
1868 }
1869
1870 // Disconnect the call from the graph
1871 call->disconnect_inputs(NULL, C);
1872 C->gvn_replace_by(call, C->top());
1873
1874 // Clean up any MergeMems that feed other MergeMems since the
1875 // optimizer doesn't like that.
1876 if (final_mem->is_MergeMem()) {
1877 Node_List wl;
1878 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1879 Node* m = i.get();
1880 if (m->is_MergeMem() && !wl.contains(m)) {
1881 wl.push(m);
1882 }
1883 }
1884 while (wl.size() > 0) {
1885 _gvn.transform(wl.pop());
1886 }
1887 }
1888
1889 if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1890 replaced_nodes.apply(C, final_ctl);
1891 }
1892 if (!ex_ctl->is_top() && do_replaced_nodes) {
1893 replaced_nodes_exception.apply(C, ex_ctl);
1894 }
1895 }
1896
1897
1898 //------------------------------increment_counter------------------------------
1899 // for statistics: increment a VM counter by 1
1900
1901 void GraphKit::increment_counter(address counter_addr) {
1902 Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1903 increment_counter(adr1);
1904 }
1905
1906 void GraphKit::increment_counter(Node* counter_addr) {
1907 int adr_type = Compile::AliasIdxRaw;
1908 Node* ctrl = control();
1909 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1910 Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1911 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1912 }
1913
1914
1915 //------------------------------uncommon_trap----------------------------------
1916 // Bail out to the interpreter in mid-method. Implemented by calling the
1917 // uncommon_trap blob. This helper function inserts a runtime call with the
1918 // right debug info.
1919 void GraphKit::uncommon_trap(int trap_request,
1920 ciKlass* klass, const char* comment,
1921 bool must_throw,
1922 bool keep_exact_action) {
1923 if (failing()) stop();
1924 if (stopped()) return; // trap reachable?
1925
1926 // Note: If ProfileTraps is true, and if a deopt. actually
1927 // occurs here, the runtime will make sure an MDO exists. There is
1928 // no need to call method()->ensure_method_data() at this point.
1929
1930 // Set the stack pointer to the right value for reexecution:
1931 set_sp(reexecute_sp());
1932
1933 #ifdef ASSERT
1934 if (!must_throw) {
1935 // Make sure the stack has at least enough depth to execute
1936 // the current bytecode.
1937 int inputs, ignored_depth;
1938 if (compute_stack_effects(inputs, ignored_depth)) {
1939 assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1940 Bytecodes::name(java_bc()), sp(), inputs);
1941 }
1942 }
1943 #endif
1944
1945 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1946 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1947
1948 switch (action) {
1949 case Deoptimization::Action_maybe_recompile:
1950 case Deoptimization::Action_reinterpret:
1951 // Temporary fix for 6529811 to allow virtual calls to be sure they
1952 // get the chance to go from mono->bi->mega
1953 if (!keep_exact_action &&
1954 Deoptimization::trap_request_index(trap_request) < 0 &&
1955 too_many_recompiles(reason)) {
1956 // This BCI is causing too many recompilations.
1957 if (C->log() != NULL) {
1958 C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
1959 Deoptimization::trap_reason_name(reason),
1960 Deoptimization::trap_action_name(action));
1961 }
1962 action = Deoptimization::Action_none;
1963 trap_request = Deoptimization::make_trap_request(reason, action);
1964 } else {
1965 C->set_trap_can_recompile(true);
1966 }
1967 break;
1968 case Deoptimization::Action_make_not_entrant:
1969 C->set_trap_can_recompile(true);
1970 break;
1971 case Deoptimization::Action_none:
1972 case Deoptimization::Action_make_not_compilable:
1973 break;
1974 default:
1975 #ifdef ASSERT
1976 fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
1977 #endif
1978 break;
1979 }
1980
1981 if (TraceOptoParse) {
1982 char buf[100];
1983 tty->print_cr("Uncommon trap %s at bci:%d",
1984 Deoptimization::format_trap_request(buf, sizeof(buf),
1985 trap_request), bci());
1986 }
1987
1988 CompileLog* log = C->log();
1989 if (log != NULL) {
1990 int kid = (klass == NULL)? -1: log->identify(klass);
1991 log->begin_elem("uncommon_trap bci='%d'", bci());
1992 char buf[100];
1993 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1994 trap_request));
1995 if (kid >= 0) log->print(" klass='%d'", kid);
1996 if (comment != NULL) log->print(" comment='%s'", comment);
1997 log->end_elem();
1998 }
1999
2000 // Make sure any guarding test views this path as very unlikely
2001 Node *i0 = control()->in(0);
2002 if (i0 != NULL && i0->is_If()) { // Found a guarding if test?
2003 IfNode *iff = i0->as_If();
2004 float f = iff->_prob; // Get prob
2005 if (control()->Opcode() == Op_IfTrue) {
2006 if (f > PROB_UNLIKELY_MAG(4))
2007 iff->_prob = PROB_MIN;
2008 } else {
2009 if (f < PROB_LIKELY_MAG(4))
2010 iff->_prob = PROB_MAX;
2011 }
2012 }
2013
2014 // Clear out dead values from the debug info.
2015 kill_dead_locals();
2016
2017 // Now insert the uncommon trap subroutine call
2018 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2019 const TypePtr* no_memory_effects = NULL;
2020 // Pass the index of the class to be loaded
2021 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2022 (must_throw ? RC_MUST_THROW : 0),
2023 OptoRuntime::uncommon_trap_Type(),
2024 call_addr, "uncommon_trap", no_memory_effects,
2025 intcon(trap_request));
2026 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2027 "must extract request correctly from the graph");
2028 assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2029
2030 call->set_req(TypeFunc::ReturnAdr, returnadr());
2031 // The debug info is the only real input to this call.
2032
2033 // Halt-and-catch fire here. The above call should never return!
2034 HaltNode* halt = new HaltNode(control(), frameptr());
2035 _gvn.set_type_bottom(halt);
2036 root()->add_req(halt);
2037
2038 stop_and_kill_map();
2039 }
2040
2041
2042 //--------------------------just_allocated_object------------------------------
2043 // Report the object that was just allocated.
2044 // It must be the case that there are no intervening safepoints.
2045 // We use this to determine if an object is so "fresh" that
2046 // it does not require card marks.
2047 Node* GraphKit::just_allocated_object(Node* current_control) {
2048 if (C->recent_alloc_ctl() == current_control)
2049 return C->recent_alloc_obj();
2050 return NULL;
2051 }
2052
2053
2054 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2055 // (Note: TypeFunc::make has a cache that makes this fast.)
2056 const TypeFunc* tf = TypeFunc::make(dest_method);
2057 int nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2058 for (int j = 0; j < nargs; j++) {
2059 const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2060 if( targ->basic_type() == T_DOUBLE ) {
2061 // If any parameters are doubles, they must be rounded before
2062 // the call, dstore_rounding does gvn.transform
2063 Node *arg = argument(j);
2064 arg = dstore_rounding(arg);
2065 set_argument(j, arg);
2066 }
2067 }
2068 }
2069
2070 /**
2071 * Record profiling data exact_kls for Node n with the type system so
2072 * that it can propagate it (speculation)
2073 *
2074 * @param n node that the type applies to
2075 * @param exact_kls type from profiling
2076 * @param maybe_null did profiling see null?
2077 *
2078 * @return node with improved type
2079 */
2080 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2081 const Type* current_type = _gvn.type(n);
2082 assert(UseTypeSpeculation, "type speculation must be on");
2083
2084 const TypePtr* speculative = current_type->speculative();
2085
2086 // Should the klass from the profile be recorded in the speculative type?
2087 if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2088 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2089 const TypeOopPtr* xtype = tklass->as_instance_type();
2090 assert(xtype->klass_is_exact(), "Should be exact");
2091 // Any reason to believe n is not null (from this profiling or a previous one)?
2092 assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2093 const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2094 // record the new speculative type's depth
2095 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2096 speculative = speculative->with_inline_depth(jvms()->depth());
2097 } else if (current_type->would_improve_ptr(ptr_kind)) {
2098 // Profiling report that null was never seen so we can change the
2099 // speculative type to non null ptr.
2100 if (ptr_kind == ProfileAlwaysNull) {
2101 speculative = TypePtr::NULL_PTR;
2102 } else {
2103 assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2104 const TypePtr* ptr = TypePtr::NOTNULL;
2105 if (speculative != NULL) {
2106 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2107 } else {
2108 speculative = ptr;
2109 }
2110 }
2111 }
2112
2113 if (speculative != current_type->speculative()) {
2114 // Build a type with a speculative type (what we think we know
2115 // about the type but will need a guard when we use it)
2116 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, speculative);
2117 // We're changing the type, we need a new CheckCast node to carry
2118 // the new type. The new type depends on the control: what
2119 // profiling tells us is only valid from here as far as we can
2120 // tell.
2121 Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2122 cast = _gvn.transform(cast);
2123 replace_in_map(n, cast);
2124 n = cast;
2125 }
2126
2127 return n;
2128 }
2129
2130 /**
2131 * Record profiling data from receiver profiling at an invoke with the
2132 * type system so that it can propagate it (speculation)
2133 *
2134 * @param n receiver node
2135 *
2136 * @return node with improved type
2137 */
2138 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2139 if (!UseTypeSpeculation) {
2140 return n;
2141 }
2142 ciKlass* exact_kls = profile_has_unique_klass();
2143 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2144 if ((java_bc() == Bytecodes::_checkcast ||
2145 java_bc() == Bytecodes::_instanceof ||
2146 java_bc() == Bytecodes::_aastore) &&
2147 method()->method_data()->is_mature()) {
2148 ciProfileData* data = method()->method_data()->bci_to_data(bci());
2149 if (data != NULL) {
2150 if (!data->as_BitData()->null_seen()) {
2151 ptr_kind = ProfileNeverNull;
2152 } else {
2153 assert(data->is_ReceiverTypeData(), "bad profile data type");
2154 ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2155 uint i = 0;
2156 for (; i < call->row_limit(); i++) {
2157 ciKlass* receiver = call->receiver(i);
2158 if (receiver != NULL) {
2159 break;
2160 }
2161 }
2162 ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2163 }
2164 }
2165 }
2166 return record_profile_for_speculation(n, exact_kls, ptr_kind);
2167 }
2168
2169 /**
2170 * Record profiling data from argument profiling at an invoke with the
2171 * type system so that it can propagate it (speculation)
2172 *
2173 * @param dest_method target method for the call
2174 * @param bc what invoke bytecode is this?
2175 */
2176 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2177 if (!UseTypeSpeculation) {
2178 return;
2179 }
2180 const TypeFunc* tf = TypeFunc::make(dest_method);
2181 int nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2182 int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2183 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2184 const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2185 if (targ->isa_oopptr() && !targ->isa_valuetypeptr()) {
2186 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2187 ciKlass* better_type = NULL;
2188 if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2189 record_profile_for_speculation(argument(j), better_type, ptr_kind);
2190 }
2191 i++;
2192 }
2193 }
2194 }
2195
2196 /**
2197 * Record profiling data from parameter profiling at an invoke with
2198 * the type system so that it can propagate it (speculation)
2199 */
2200 void GraphKit::record_profiled_parameters_for_speculation() {
2201 if (!UseTypeSpeculation) {
2202 return;
2203 }
2204 for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2205 if (_gvn.type(local(i))->isa_oopptr()) {
2206 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2207 ciKlass* better_type = NULL;
2208 if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2209 record_profile_for_speculation(local(i), better_type, ptr_kind);
2210 }
2211 j++;
2212 }
2213 }
2214 }
2215
2216 /**
2217 * Record profiling data from return value profiling at an invoke with
2218 * the type system so that it can propagate it (speculation)
2219 */
2220 void GraphKit::record_profiled_return_for_speculation() {
2221 if (!UseTypeSpeculation) {
2222 return;
2223 }
2224 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2225 ciKlass* better_type = NULL;
2226 if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2227 // If profiling reports a single type for the return value,
2228 // feed it to the type system so it can propagate it as a
2229 // speculative type
2230 record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2231 }
2232 }
2233
2234 void GraphKit::round_double_result(ciMethod* dest_method) {
2235 // A non-strict method may return a double value which has an extended
2236 // exponent, but this must not be visible in a caller which is 'strict'
2237 // If a strict caller invokes a non-strict callee, round a double result
2238
2239 BasicType result_type = dest_method->return_type()->basic_type();
2240 assert( method() != NULL, "must have caller context");
2241 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2242 // Destination method's return value is on top of stack
2243 // dstore_rounding() does gvn.transform
2244 Node *result = pop_pair();
2245 result = dstore_rounding(result);
2246 push_pair(result);
2247 }
2248 }
2249
2250 // rounding for strict float precision conformance
2251 Node* GraphKit::precision_rounding(Node* n) {
2252 return UseStrictFP && _method->flags().is_strict()
2253 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2254 ? _gvn.transform( new RoundFloatNode(0, n) )
2255 : n;
2256 }
2257
2258 // rounding for strict double precision conformance
2259 Node* GraphKit::dprecision_rounding(Node *n) {
2260 return UseStrictFP && _method->flags().is_strict()
2261 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2262 ? _gvn.transform( new RoundDoubleNode(0, n) )
2263 : n;
2264 }
2265
2266 // rounding for non-strict double stores
2267 Node* GraphKit::dstore_rounding(Node* n) {
2268 return Matcher::strict_fp_requires_explicit_rounding
2269 && UseSSE <= 1
2270 ? _gvn.transform( new RoundDoubleNode(0, n) )
2271 : n;
2272 }
2273
2274 //=============================================================================
2275 // Generate a fast path/slow path idiom. Graph looks like:
2276 // [foo] indicates that 'foo' is a parameter
2277 //
2278 // [in] NULL
2279 // \ /
2280 // CmpP
2281 // Bool ne
2282 // If
2283 // / \
2284 // True False-<2>
2285 // / |
2286 // / cast_not_null
2287 // Load | | ^
2288 // [fast_test] | |
2289 // gvn to opt_test | |
2290 // / \ | <1>
2291 // True False |
2292 // | \\ |
2293 // [slow_call] \[fast_result]
2294 // Ctl Val \ \
2295 // | \ \
2296 // Catch <1> \ \
2297 // / \ ^ \ \
2298 // Ex No_Ex | \ \
2299 // | \ \ | \ <2> \
2300 // ... \ [slow_res] | | \ [null_result]
2301 // \ \--+--+--- | |
2302 // \ | / \ | /
2303 // --------Region Phi
2304 //
2305 //=============================================================================
2306 // Code is structured as a series of driver functions all called 'do_XXX' that
2307 // call a set of helper functions. Helper functions first, then drivers.
2308
2309 //------------------------------null_check_oop---------------------------------
2310 // Null check oop. Set null-path control into Region in slot 3.
2311 // Make a cast-not-nullness use the other not-null control. Return cast.
2312 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2313 bool never_see_null,
2314 bool safe_for_replace,
2315 bool speculative) {
2316 // Initial NULL check taken path
2317 (*null_control) = top();
2318 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2319
2320 // Generate uncommon_trap:
2321 if (never_see_null && (*null_control) != top()) {
2322 // If we see an unexpected null at a check-cast we record it and force a
2323 // recompile; the offending check-cast will be compiled to handle NULLs.
2324 // If we see more than one offending BCI, then all checkcasts in the
2325 // method will be compiled to handle NULLs.
2326 PreserveJVMState pjvms(this);
2327 set_control(*null_control);
2328 replace_in_map(value, null());
2329 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2330 uncommon_trap(reason,
2331 Deoptimization::Action_make_not_entrant);
2332 (*null_control) = top(); // NULL path is dead
2333 }
2334 if ((*null_control) == top() && safe_for_replace) {
2335 replace_in_map(value, cast);
2336 }
2337
2338 // Cast away null-ness on the result
2339 return cast;
2340 }
2341
2342 //------------------------------opt_iff----------------------------------------
2343 // Optimize the fast-check IfNode. Set the fast-path region slot 2.
2344 // Return slow-path control.
2345 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2346 IfNode *opt_iff = _gvn.transform(iff)->as_If();
2347
2348 // Fast path taken; set region slot 2
2349 Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2350 region->init_req(2,fast_taken); // Capture fast-control
2351
2352 // Fast path not-taken, i.e. slow path
2353 Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2354 return slow_taken;
2355 }
2356
2357 //-----------------------------make_runtime_call-------------------------------
2358 Node* GraphKit::make_runtime_call(int flags,
2359 const TypeFunc* call_type, address call_addr,
2360 const char* call_name,
2361 const TypePtr* adr_type,
2362 // The following parms are all optional.
2363 // The first NULL ends the list.
2364 Node* parm0, Node* parm1,
2365 Node* parm2, Node* parm3,
2366 Node* parm4, Node* parm5,
2367 Node* parm6, Node* parm7) {
2368 // Slow-path call
2369 bool is_leaf = !(flags & RC_NO_LEAF);
2370 bool has_io = (!is_leaf && !(flags & RC_NO_IO));
2371 if (call_name == NULL) {
2372 assert(!is_leaf, "must supply name for leaf");
2373 call_name = OptoRuntime::stub_name(call_addr);
2374 }
2375 CallNode* call;
2376 if (!is_leaf) {
2377 call = new CallStaticJavaNode(call_type, call_addr, call_name,
2378 bci(), adr_type);
2379 } else if (flags & RC_NO_FP) {
2380 call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2381 } else {
2382 call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2383 }
2384
2385 // The following is similar to set_edges_for_java_call,
2386 // except that the memory effects of the call are restricted to AliasIdxRaw.
2387
2388 // Slow path call has no side-effects, uses few values
2389 bool wide_in = !(flags & RC_NARROW_MEM);
2390 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2391
2392 Node* prev_mem = NULL;
2393 if (wide_in) {
2394 prev_mem = set_predefined_input_for_runtime_call(call);
2395 } else {
2396 assert(!wide_out, "narrow in => narrow out");
2397 Node* narrow_mem = memory(adr_type);
2398 prev_mem = reset_memory();
2399 map()->set_memory(narrow_mem);
2400 set_predefined_input_for_runtime_call(call);
2401 }
2402
2403 // Hook each parm in order. Stop looking at the first NULL.
2404 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2405 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2406 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2407 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2408 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2409 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2410 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2411 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2412 /* close each nested if ===> */ } } } } } } } }
2413 assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2414
2415 if (!is_leaf) {
2416 // Non-leaves can block and take safepoints:
2417 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2418 }
2419 // Non-leaves can throw exceptions:
2420 if (has_io) {
2421 call->set_req(TypeFunc::I_O, i_o());
2422 }
2423
2424 if (flags & RC_UNCOMMON) {
2425 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency.
2426 // (An "if" probability corresponds roughly to an unconditional count.
2427 // Sort of.)
2428 call->set_cnt(PROB_UNLIKELY_MAG(4));
2429 }
2430
2431 Node* c = _gvn.transform(call);
2432 assert(c == call, "cannot disappear");
2433
2434 if (wide_out) {
2435 // Slow path call has full side-effects.
2436 set_predefined_output_for_runtime_call(call);
2437 } else {
2438 // Slow path call has few side-effects, and/or sets few values.
2439 set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2440 }
2441
2442 if (has_io) {
2443 set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2444 }
2445 return call;
2446
2447 }
2448
2449 //------------------------------merge_memory-----------------------------------
2450 // Merge memory from one path into the current memory state.
2451 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2452 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2453 Node* old_slice = mms.force_memory();
2454 Node* new_slice = mms.memory2();
2455 if (old_slice != new_slice) {
2456 PhiNode* phi;
2457 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2458 if (mms.is_empty()) {
2459 // clone base memory Phi's inputs for this memory slice
2460 assert(old_slice == mms.base_memory(), "sanity");
2461 phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2462 _gvn.set_type(phi, Type::MEMORY);
2463 for (uint i = 1; i < phi->req(); i++) {
2464 phi->init_req(i, old_slice->in(i));
2465 }
2466 } else {
2467 phi = old_slice->as_Phi(); // Phi was generated already
2468 }
2469 } else {
2470 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2471 _gvn.set_type(phi, Type::MEMORY);
2472 }
2473 phi->set_req(new_path, new_slice);
2474 mms.set_memory(phi);
2475 }
2476 }
2477 }
2478
2479 //------------------------------make_slow_call_ex------------------------------
2480 // Make the exception handler hookups for the slow call
2481 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2482 if (stopped()) return;
2483
2484 // Make a catch node with just two handlers: fall-through and catch-all
2485 Node* i_o = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2486 Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2487 Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2488 Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) );
2489
2490 { PreserveJVMState pjvms(this);
2491 set_control(excp);
2492 set_i_o(i_o);
2493
2494 if (excp != top()) {
2495 if (deoptimize) {
2496 // Deoptimize if an exception is caught. Don't construct exception state in this case.
2497 uncommon_trap(Deoptimization::Reason_unhandled,
2498 Deoptimization::Action_none);
2499 } else {
2500 // Create an exception state also.
2501 // Use an exact type if the caller has specified a specific exception.
2502 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2503 Node* ex_oop = new CreateExNode(ex_type, control(), i_o);
2504 add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2505 }
2506 }
2507 }
2508
2509 // Get the no-exception control from the CatchNode.
2510 set_control(norm);
2511 }
2512
2513 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2514 Node* cmp = NULL;
2515 switch(bt) {
2516 case T_INT: cmp = new CmpINode(in1, in2); break;
2517 case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2518 default: fatal("unexpected comparison type %s", type2name(bt));
2519 }
2520 gvn->transform(cmp);
2521 Node* bol = gvn->transform(new BoolNode(cmp, test));
2522 IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2523 gvn->transform(iff);
2524 if (!bol->is_Con()) gvn->record_for_igvn(iff);
2525 return iff;
2526 }
2527
2528
2529 //-------------------------------gen_subtype_check-----------------------------
2530 // Generate a subtyping check. Takes as input the subtype and supertype.
2531 // Returns 2 values: sets the default control() to the true path and returns
2532 // the false path. Only reads invariant memory; sets no (visible) memory.
2533 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2534 // but that's not exposed to the optimizer. This call also doesn't take in an
2535 // Object; if you wish to check an Object you need to load the Object's class
2536 // prior to coming here.
2537 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2538 Compile* C = gvn->C;
2539
2540 if ((*ctrl)->is_top()) {
2541 return C->top();
2542 }
2543
2544 // Fast check for identical types, perhaps identical constants.
2545 // The types can even be identical non-constants, in cases
2546 // involving Array.newInstance, Object.clone, etc.
2547 if (subklass == superklass)
2548 return C->top(); // false path is dead; no test needed.
2549
2550 if (gvn->type(superklass)->singleton()) {
2551 ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2552 ciKlass* subk = gvn->type(subklass)->is_klassptr()->klass();
2553
2554 // In the common case of an exact superklass, try to fold up the
2555 // test before generating code. You may ask, why not just generate
2556 // the code and then let it fold up? The answer is that the generated
2557 // code will necessarily include null checks, which do not always
2558 // completely fold away. If they are also needless, then they turn
2559 // into a performance loss. Example:
2560 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2561 // Here, the type of 'fa' is often exact, so the store check
2562 // of fa[1]=x will fold up, without testing the nullness of x.
2563 switch (C->static_subtype_check(superk, subk)) {
2564 case Compile::SSC_always_false:
2565 {
2566 Node* always_fail = *ctrl;
2567 *ctrl = gvn->C->top();
2568 return always_fail;
2569 }
2570 case Compile::SSC_always_true:
2571 return C->top();
2572 case Compile::SSC_easy_test:
2573 {
2574 // Just do a direct pointer compare and be done.
2575 IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2576 *ctrl = gvn->transform(new IfTrueNode(iff));
2577 return gvn->transform(new IfFalseNode(iff));
2578 }
2579 case Compile::SSC_full_test:
2580 break;
2581 default:
2582 ShouldNotReachHere();
2583 }
2584 }
2585
2586 // %%% Possible further optimization: Even if the superklass is not exact,
2587 // if the subklass is the unique subtype of the superklass, the check
2588 // will always succeed. We could leave a dependency behind to ensure this.
2589
2590 // First load the super-klass's check-offset
2591 Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2592 Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2593 Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2594 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2595 bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2596
2597 // Load from the sub-klass's super-class display list, or a 1-word cache of
2598 // the secondary superclass list, or a failing value with a sentinel offset
2599 // if the super-klass is an interface or exceptionally deep in the Java
2600 // hierarchy and we have to scan the secondary superclass list the hard way.
2601 // Worst-case type is a little odd: NULL is allowed as a result (usually
2602 // klass loads can never produce a NULL).
2603 Node *chk_off_X = chk_off;
2604 #ifdef _LP64
2605 chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2606 #endif
2607 Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2608 // For some types like interfaces the following loadKlass is from a 1-word
2609 // cache which is mutable so can't use immutable memory. Other
2610 // types load from the super-class display table which is immutable.
2611 m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2612 Node *kmem = might_be_cache ? m : C->immutable_memory();
2613 Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::BOTTOM));
2614
2615 // Compile speed common case: ARE a subtype and we canNOT fail
2616 if( superklass == nkls )
2617 return C->top(); // false path is dead; no test needed.
2618
2619 // See if we get an immediate positive hit. Happens roughly 83% of the
2620 // time. Test to see if the value loaded just previously from the subklass
2621 // is exactly the superklass.
2622 IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2623 Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2624 *ctrl = gvn->transform(new IfFalseNode(iff1));
2625
2626 // Compile speed common case: Check for being deterministic right now. If
2627 // chk_off is a constant and not equal to cacheoff then we are NOT a
2628 // subklass. In this case we need exactly the 1 test above and we can
2629 // return those results immediately.
2630 if (!might_be_cache) {
2631 Node* not_subtype_ctrl = *ctrl;
2632 *ctrl = iftrue1; // We need exactly the 1 test above
2633 return not_subtype_ctrl;
2634 }
2635
2636 // Gather the various success & failures here
2637 RegionNode *r_ok_subtype = new RegionNode(4);
2638 gvn->record_for_igvn(r_ok_subtype);
2639 RegionNode *r_not_subtype = new RegionNode(3);
2640 gvn->record_for_igvn(r_not_subtype);
2641
2642 r_ok_subtype->init_req(1, iftrue1);
2643
2644 // Check for immediate negative hit. Happens roughly 11% of the time (which
2645 // is roughly 63% of the remaining cases). Test to see if the loaded
2646 // check-offset points into the subklass display list or the 1-element
2647 // cache. If it points to the display (and NOT the cache) and the display
2648 // missed then it's not a subtype.
2649 Node *cacheoff = gvn->intcon(cacheoff_con);
2650 IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2651 r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2652 *ctrl = gvn->transform(new IfFalseNode(iff2));
2653
2654 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2655 // No performance impact (too rare) but allows sharing of secondary arrays
2656 // which has some footprint reduction.
2657 IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2658 r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2659 *ctrl = gvn->transform(new IfFalseNode(iff3));
2660
2661 // -- Roads not taken here: --
2662 // We could also have chosen to perform the self-check at the beginning
2663 // of this code sequence, as the assembler does. This would not pay off
2664 // the same way, since the optimizer, unlike the assembler, can perform
2665 // static type analysis to fold away many successful self-checks.
2666 // Non-foldable self checks work better here in second position, because
2667 // the initial primary superclass check subsumes a self-check for most
2668 // types. An exception would be a secondary type like array-of-interface,
2669 // which does not appear in its own primary supertype display.
2670 // Finally, we could have chosen to move the self-check into the
2671 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2672 // dependent manner. But it is worthwhile to have the check here,
2673 // where it can be perhaps be optimized. The cost in code space is
2674 // small (register compare, branch).
2675
2676 // Now do a linear scan of the secondary super-klass array. Again, no real
2677 // performance impact (too rare) but it's gotta be done.
2678 // Since the code is rarely used, there is no penalty for moving it
2679 // out of line, and it can only improve I-cache density.
2680 // The decision to inline or out-of-line this final check is platform
2681 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2682 Node* psc = gvn->transform(
2683 new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2684
2685 IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2686 r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2687 r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2688
2689 // Return false path; set default control to true path.
2690 *ctrl = gvn->transform(r_ok_subtype);
2691 return gvn->transform(r_not_subtype);
2692 }
2693
2694 // Profile-driven exact type check:
2695 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2696 float prob,
2697 Node* *casted_receiver) {
2698 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2699 Node* recv_klass = load_object_klass(receiver);
2700 Node* fail = type_check(recv_klass, tklass, prob);
2701 const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2702 assert(recv_xtype->klass_is_exact(), "");
2703
2704 // Subsume downstream occurrences of receiver with a cast to
2705 // recv_xtype, since now we know what the type will be.
2706 Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2707 (*casted_receiver) = _gvn.transform(cast);
2708 // (User must make the replace_in_map call.)
2709
2710 return fail;
2711 }
2712
2713 Node* GraphKit::type_check(Node* recv_klass, const TypeKlassPtr* tklass,
2714 float prob) {
2715 //const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2716 Node* want_klass = makecon(tklass);
2717 Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass));
2718 Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2719 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2720 set_control( _gvn.transform( new IfTrueNode (iff)));
2721 Node* fail = _gvn.transform( new IfFalseNode(iff));
2722 return fail;
2723 }
2724
2725
2726 //------------------------------seems_never_null-------------------------------
2727 // Use null_seen information if it is available from the profile.
2728 // If we see an unexpected null at a type check we record it and force a
2729 // recompile; the offending check will be recompiled to handle NULLs.
2730 // If we see several offending BCIs, then all checks in the
2731 // method will be recompiled.
2732 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2733 speculating = !_gvn.type(obj)->speculative_maybe_null();
2734 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2735 if (UncommonNullCast // Cutout for this technique
2736 && obj != null() // And not the -Xcomp stupid case?
2737 && !too_many_traps(reason)
2738 ) {
2739 if (speculating) {
2740 return true;
2741 }
2742 if (data == NULL)
2743 // Edge case: no mature data. Be optimistic here.
2744 return true;
2745 // If the profile has not seen a null, assume it won't happen.
2746 assert(java_bc() == Bytecodes::_checkcast ||
2747 java_bc() == Bytecodes::_instanceof ||
2748 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2749 return !data->as_BitData()->null_seen();
2750 }
2751 speculating = false;
2752 return false;
2753 }
2754
2755 //------------------------maybe_cast_profiled_receiver-------------------------
2756 // If the profile has seen exactly one type, narrow to exactly that type.
2757 // Subsequent type checks will always fold up.
2758 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2759 ciKlass* require_klass,
2760 ciKlass* spec_klass,
2761 bool safe_for_replace) {
2762 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2763
2764 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2765
2766 // Make sure we haven't already deoptimized from this tactic.
2767 if (too_many_traps(reason) || too_many_recompiles(reason))
2768 return NULL;
2769
2770 // (No, this isn't a call, but it's enough like a virtual call
2771 // to use the same ciMethod accessor to get the profile info...)
2772 // If we have a speculative type use it instead of profiling (which
2773 // may not help us)
2774 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2775 if (exact_kls != NULL) {// no cast failures here
2776 if (require_klass == NULL ||
2777 C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2778 // If we narrow the type to match what the type profile sees or
2779 // the speculative type, we can then remove the rest of the
2780 // cast.
2781 // This is a win, even if the exact_kls is very specific,
2782 // because downstream operations, such as method calls,
2783 // will often benefit from the sharper type.
2784 Node* exact_obj = not_null_obj; // will get updated in place...
2785 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2786 &exact_obj);
2787 { PreserveJVMState pjvms(this);
2788 set_control(slow_ctl);
2789 uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2790 }
2791 if (safe_for_replace) {
2792 replace_in_map(not_null_obj, exact_obj);
2793 }
2794 return exact_obj;
2795 }
2796 // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2797 }
2798
2799 return NULL;
2800 }
2801
2802 /**
2803 * Cast obj to type and emit guard unless we had too many traps here
2804 * already
2805 *
2806 * @param obj node being casted
2807 * @param type type to cast the node to
2808 * @param not_null true if we know node cannot be null
2809 */
2810 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2811 ciKlass* type,
2812 bool not_null) {
2813 if (stopped()) {
2814 return obj;
2815 }
2816
2817 // type == NULL if profiling tells us this object is always null
2818 if (type != NULL) {
2819 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2820 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2821
2822 if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2823 !too_many_traps(class_reason) &&
2824 !too_many_recompiles(class_reason)) {
2825 Node* not_null_obj = NULL;
2826 // not_null is true if we know the object is not null and
2827 // there's no need for a null check
2828 if (!not_null) {
2829 Node* null_ctl = top();
2830 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2831 assert(null_ctl->is_top(), "no null control here");
2832 } else {
2833 not_null_obj = obj;
2834 }
2835
2836 Node* exact_obj = not_null_obj;
2837 ciKlass* exact_kls = type;
2838 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2839 &exact_obj);
2840 {
2841 PreserveJVMState pjvms(this);
2842 set_control(slow_ctl);
2843 uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2844 }
2845 replace_in_map(not_null_obj, exact_obj);
2846 obj = exact_obj;
2847 }
2848 } else {
2849 if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2850 !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2851 Node* exact_obj = null_assert(obj);
2852 replace_in_map(obj, exact_obj);
2853 obj = exact_obj;
2854 }
2855 }
2856 return obj;
2857 }
2858
2859 //-------------------------------gen_instanceof--------------------------------
2860 // Generate an instance-of idiom. Used by both the instance-of bytecode
2861 // and the reflective instance-of call.
2862 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2863 kill_dead_locals(); // Benefit all the uncommon traps
2864 assert( !stopped(), "dead parse path should be checked in callers" );
2865 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2866 "must check for not-null not-dead klass in callers");
2867
2868 // Make the merge point
2869 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2870 RegionNode* region = new RegionNode(PATH_LIMIT);
2871 Node* phi = new PhiNode(region, TypeInt::BOOL);
2872 C->set_has_split_ifs(true); // Has chance for split-if optimization
2873
2874 ciProfileData* data = NULL;
2875 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode
2876 data = method()->method_data()->bci_to_data(bci());
2877 }
2878 bool speculative_not_null = false;
2879 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile
2880 && seems_never_null(obj, data, speculative_not_null));
2881
2882 // Null check; get casted pointer; set region slot 3
2883 Node* null_ctl = top();
2884 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2885
2886 // If not_null_obj is dead, only null-path is taken
2887 if (stopped()) { // Doing instance-of on a NULL?
2888 set_control(null_ctl);
2889 return intcon(0);
2890 }
2891 region->init_req(_null_path, null_ctl);
2892 phi ->init_req(_null_path, intcon(0)); // Set null path value
2893 if (null_ctl == top()) {
2894 // Do this eagerly, so that pattern matches like is_diamond_phi
2895 // will work even during parsing.
2896 assert(_null_path == PATH_LIMIT-1, "delete last");
2897 region->del_req(_null_path);
2898 phi ->del_req(_null_path);
2899 }
2900
2901 // Do we know the type check always succeed?
2902 bool known_statically = false;
2903 if (_gvn.type(superklass)->singleton()) {
2904 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2905 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2906 if (subk != NULL && subk->is_loaded()) {
2907 int static_res = C->static_subtype_check(superk, subk);
2908 known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2909 }
2910 }
2911
2912 if (!known_statically) {
2913 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2914 // We may not have profiling here or it may not help us. If we
2915 // have a speculative type use it to perform an exact cast.
2916 ciKlass* spec_obj_type = obj_type->speculative_type();
2917 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2918 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2919 if (stopped()) { // Profile disagrees with this path.
2920 set_control(null_ctl); // Null is the only remaining possibility.
2921 return intcon(0);
2922 }
2923 if (cast_obj != NULL) {
2924 not_null_obj = cast_obj;
2925 }
2926 }
2927 }
2928
2929 // Load the object's klass
2930 Node* obj_klass = load_object_klass(not_null_obj);
2931
2932 // Generate the subtype check
2933 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2934
2935 // Plug in the success path to the general merge in slot 1.
2936 region->init_req(_obj_path, control());
2937 phi ->init_req(_obj_path, intcon(1));
2938
2939 // Plug in the failing path to the general merge in slot 2.
2940 region->init_req(_fail_path, not_subtype_ctrl);
2941 phi ->init_req(_fail_path, intcon(0));
2942
2943 // Return final merged results
2944 set_control( _gvn.transform(region) );
2945 record_for_igvn(region);
2946
2947 // If we know the type check always succeeds then we don't use the
2948 // profiling data at this bytecode. Don't lose it, feed it to the
2949 // type system as a speculative type.
2950 if (safe_for_replace) {
2951 Node* casted_obj = record_profiled_receiver_for_speculation(obj);
2952 replace_in_map(obj, casted_obj);
2953 }
2954
2955 return _gvn.transform(phi);
2956 }
2957
2958 //-------------------------------gen_checkcast---------------------------------
2959 // Generate a checkcast idiom. Used by both the checkcast bytecode and the
2960 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the
2961 // uncommon-trap paths work. Adjust stack after this call.
2962 // If failure_control is supplied and not null, it is filled in with
2963 // the control edge for the cast failure. Otherwise, an appropriate
2964 // uncommon trap or exception is thrown.
2965 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2966 Node* *failure_control) {
2967 kill_dead_locals(); // Benefit all the uncommon traps
2968 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2969 assert(tk->is_loaded(), "must be loaded");
2970 const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2971
2972 // Fast cutout: Check the case that the cast is vacuously true.
2973 // This detects the common cases where the test will short-circuit
2974 // away completely. We do this before we perform the null check,
2975 // because if the test is going to turn into zero code, we don't
2976 // want a residual null check left around. (Causes a slowdown,
2977 // for example, in some objArray manipulations, such as a[i]=a[j].)
2978 if (tk->singleton()) {
2979 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2980 if (objtp != NULL && objtp->klass() != NULL) {
2981 switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
2982 case Compile::SSC_always_true:
2983 // If we know the type check always succeed then we don't use
2984 // the profiling data at this bytecode. Don't lose it, feed it
2985 // to the type system as a speculative type.
2986 return record_profiled_receiver_for_speculation(obj);
2987 case Compile::SSC_always_false:
2988 // It needs a null check because a null will *pass* the cast check.
2989 // A non-null value will always produce an exception.
2990 return null_assert(obj);
2991 }
2992 }
2993 }
2994
2995 ciProfileData* data = NULL;
2996 bool safe_for_replace = false;
2997 if (failure_control == NULL) { // use MDO in regular case only
2998 assert(java_bc() == Bytecodes::_aastore ||
2999 java_bc() == Bytecodes::_checkcast,
3000 "interpreter profiles type checks only for these BCs");
3001 data = method()->method_data()->bci_to_data(bci());
3002 safe_for_replace = true;
3003 }
3004
3005 // Make the merge point
3006 enum { _obj_path = 1, _null_path, PATH_LIMIT };
3007 RegionNode* region = new RegionNode(PATH_LIMIT);
3008 Node* phi = new PhiNode(region, toop);
3009 C->set_has_split_ifs(true); // Has chance for split-if optimization
3010
3011 // Use null-cast information if it is available
3012 bool speculative_not_null = false;
3013 bool never_see_null = ((failure_control == NULL) // regular case only
3014 && seems_never_null(obj, data, speculative_not_null));
3015
3016 // Null check; get casted pointer; set region slot 3
3017 Node* null_ctl = top();
3018 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3019
3020 // If not_null_obj is dead, only null-path is taken
3021 if (stopped()) { // Doing instance-of on a NULL?
3022 set_control(null_ctl);
3023 return null();
3024 }
3025 region->init_req(_null_path, null_ctl);
3026 phi ->init_req(_null_path, null()); // Set null path value
3027 if (null_ctl == top()) {
3028 // Do this eagerly, so that pattern matches like is_diamond_phi
3029 // will work even during parsing.
3030 assert(_null_path == PATH_LIMIT-1, "delete last");
3031 region->del_req(_null_path);
3032 phi ->del_req(_null_path);
3033 }
3034
3035 Node* cast_obj = NULL;
3036 if (tk->klass_is_exact()) {
3037 // The following optimization tries to statically cast the speculative type of the object
3038 // (for example obtained during profiling) to the type of the superklass and then do a
3039 // dynamic check that the type of the object is what we expect. To work correctly
3040 // for checkcast and aastore the type of superklass should be exact.
3041 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3042 // We may not have profiling here or it may not help us. If we have
3043 // a speculative type use it to perform an exact cast.
3044 ciKlass* spec_obj_type = obj_type->speculative_type();
3045 if (spec_obj_type != NULL || data != NULL) {
3046 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3047 if (cast_obj != NULL) {
3048 if (failure_control != NULL) // failure is now impossible
3049 (*failure_control) = top();
3050 // adjust the type of the phi to the exact klass:
3051 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3052 }
3053 }
3054 }
3055
3056 if (cast_obj == NULL) {
3057 // Load the object's klass
3058 Node* obj_klass = load_object_klass(not_null_obj);
3059
3060 // Generate the subtype check
3061 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3062
3063 // Plug in success path into the merge
3064 cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3065 // Failure path ends in uncommon trap (or may be dead - failure impossible)
3066 if (failure_control == NULL) {
3067 if (not_subtype_ctrl != top()) { // If failure is possible
3068 PreserveJVMState pjvms(this);
3069 set_control(not_subtype_ctrl);
3070 builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3071 }
3072 } else {
3073 (*failure_control) = not_subtype_ctrl;
3074 }
3075 }
3076
3077 region->init_req(_obj_path, control());
3078 phi ->init_req(_obj_path, cast_obj);
3079
3080 // A merge of NULL or Casted-NotNull obj
3081 Node* res = _gvn.transform(phi);
3082
3083 // Note I do NOT always 'replace_in_map(obj,result)' here.
3084 // if( tk->klass()->can_be_primary_super() )
3085 // This means that if I successfully store an Object into an array-of-String
3086 // I 'forget' that the Object is really now known to be a String. I have to
3087 // do this because we don't have true union types for interfaces - if I store
3088 // a Baz into an array-of-Interface and then tell the optimizer it's an
3089 // Interface, I forget that it's also a Baz and cannot do Baz-like field
3090 // references to it. FIX THIS WHEN UNION TYPES APPEAR!
3091 // replace_in_map( obj, res );
3092
3093 // Return final merged results
3094 set_control( _gvn.transform(region) );
3095 record_for_igvn(region);
3096
3097 return record_profiled_receiver_for_speculation(res);
3098 }
3099
3100 //------------------------------next_monitor-----------------------------------
3101 // What number should be given to the next monitor?
3102 int GraphKit::next_monitor() {
3103 int current = jvms()->monitor_depth()* C->sync_stack_slots();
3104 int next = current + C->sync_stack_slots();
3105 // Keep the toplevel high water mark current:
3106 if (C->fixed_slots() < next) C->set_fixed_slots(next);
3107 return current;
3108 }
3109
3110 //------------------------------insert_mem_bar---------------------------------
3111 // Memory barrier to avoid floating things around
3112 // The membar serves as a pinch point between both control and all memory slices.
3113 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3114 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3115 mb->init_req(TypeFunc::Control, control());
3116 mb->init_req(TypeFunc::Memory, reset_memory());
3117 Node* membar = _gvn.transform(mb);
3118 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3119 set_all_memory_call(membar);
3120 return membar;
3121 }
3122
3123 //-------------------------insert_mem_bar_volatile----------------------------
3124 // Memory barrier to avoid floating things around
3125 // The membar serves as a pinch point between both control and memory(alias_idx).
3126 // If you want to make a pinch point on all memory slices, do not use this
3127 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3128 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3129 // When Parse::do_put_xxx updates a volatile field, it appends a series
3130 // of MemBarVolatile nodes, one for *each* volatile field alias category.
3131 // The first membar is on the same memory slice as the field store opcode.
3132 // This forces the membar to follow the store. (Bug 6500685 broke this.)
3133 // All the other membars (for other volatile slices, including AliasIdxBot,
3134 // which stands for all unknown volatile slices) are control-dependent
3135 // on the first membar. This prevents later volatile loads or stores
3136 // from sliding up past the just-emitted store.
3137
3138 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3139 mb->set_req(TypeFunc::Control,control());
3140 if (alias_idx == Compile::AliasIdxBot) {
3141 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3142 } else {
3143 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3144 mb->set_req(TypeFunc::Memory, memory(alias_idx));
3145 }
3146 Node* membar = _gvn.transform(mb);
3147 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3148 if (alias_idx == Compile::AliasIdxBot) {
3149 merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3150 } else {
3151 set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3152 }
3153 return membar;
3154 }
3155
3156 //------------------------------shared_lock------------------------------------
3157 // Emit locking code.
3158 FastLockNode* GraphKit::shared_lock(Node* obj) {
3159 // bci is either a monitorenter bc or InvocationEntryBci
3160 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3161 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3162
3163 if( !GenerateSynchronizationCode )
3164 return NULL; // Not locking things?
3165 if (stopped()) // Dead monitor?
3166 return NULL;
3167
3168 assert(dead_locals_are_killed(), "should kill locals before sync. point");
3169
3170 // Box the stack location
3171 Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3172 Node* mem = reset_memory();
3173
3174 FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3175 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3176 // Create the counters for this fast lock.
3177 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3178 }
3179
3180 // Create the rtm counters for this fast lock if needed.
3181 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3182
3183 // Add monitor to debug info for the slow path. If we block inside the
3184 // slow path and de-opt, we need the monitor hanging around
3185 map()->push_monitor( flock );
3186
3187 const TypeFunc *tf = LockNode::lock_type();
3188 LockNode *lock = new LockNode(C, tf);
3189
3190 lock->init_req( TypeFunc::Control, control() );
3191 lock->init_req( TypeFunc::Memory , mem );
3192 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3193 lock->init_req( TypeFunc::FramePtr, frameptr() );
3194 lock->init_req( TypeFunc::ReturnAdr, top() );
3195
3196 lock->init_req(TypeFunc::Parms + 0, obj);
3197 lock->init_req(TypeFunc::Parms + 1, box);
3198 lock->init_req(TypeFunc::Parms + 2, flock);
3199 add_safepoint_edges(lock);
3200
3201 lock = _gvn.transform( lock )->as_Lock();
3202
3203 // lock has no side-effects, sets few values
3204 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3205
3206 insert_mem_bar(Op_MemBarAcquireLock);
3207
3208 // Add this to the worklist so that the lock can be eliminated
3209 record_for_igvn(lock);
3210
3211 #ifndef PRODUCT
3212 if (PrintLockStatistics) {
3213 // Update the counter for this lock. Don't bother using an atomic
3214 // operation since we don't require absolute accuracy.
3215 lock->create_lock_counter(map()->jvms());
3216 increment_counter(lock->counter()->addr());
3217 }
3218 #endif
3219
3220 return flock;
3221 }
3222
3223
3224 //------------------------------shared_unlock----------------------------------
3225 // Emit unlocking code.
3226 void GraphKit::shared_unlock(Node* box, Node* obj) {
3227 // bci is either a monitorenter bc or InvocationEntryBci
3228 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3229 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3230
3231 if( !GenerateSynchronizationCode )
3232 return;
3233 if (stopped()) { // Dead monitor?
3234 map()->pop_monitor(); // Kill monitor from debug info
3235 return;
3236 }
3237
3238 // Memory barrier to avoid floating things down past the locked region
3239 insert_mem_bar(Op_MemBarReleaseLock);
3240
3241 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3242 UnlockNode *unlock = new UnlockNode(C, tf);
3243 #ifdef ASSERT
3244 unlock->set_dbg_jvms(sync_jvms());
3245 #endif
3246 uint raw_idx = Compile::AliasIdxRaw;
3247 unlock->init_req( TypeFunc::Control, control() );
3248 unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3249 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3250 unlock->init_req( TypeFunc::FramePtr, frameptr() );
3251 unlock->init_req( TypeFunc::ReturnAdr, top() );
3252
3253 unlock->init_req(TypeFunc::Parms + 0, obj);
3254 unlock->init_req(TypeFunc::Parms + 1, box);
3255 unlock = _gvn.transform(unlock)->as_Unlock();
3256
3257 Node* mem = reset_memory();
3258
3259 // unlock has no side-effects, sets few values
3260 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3261
3262 // Kill monitor from debug info
3263 map()->pop_monitor( );
3264 }
3265
3266 //-------------------------------get_layout_helper-----------------------------
3267 // If the given klass is a constant or known to be an array,
3268 // fetch the constant layout helper value into constant_value
3269 // and return (Node*)NULL. Otherwise, load the non-constant
3270 // layout helper value, and return the node which represents it.
3271 // This two-faced routine is useful because allocation sites
3272 // almost always feature constant types.
3273 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3274 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3275 if (!StressReflectiveCode && inst_klass != NULL) {
3276 ciKlass* klass = inst_klass->klass();
3277 assert(klass != NULL, "klass should not be NULL");
3278 bool xklass = inst_klass->klass_is_exact();
3279 if (xklass || klass->is_array_klass()) {
3280 jint lhelper = klass->layout_helper();
3281 if (lhelper != Klass::_lh_neutral_value) {
3282 constant_value = lhelper;
3283 return (Node*) NULL;
3284 }
3285 }
3286 }
3287 constant_value = Klass::_lh_neutral_value; // put in a known value
3288 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3289 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3290 }
3291
3292 // We just put in an allocate/initialize with a big raw-memory effect.
3293 // Hook selected additional alias categories on the initialization.
3294 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3295 MergeMemNode* init_in_merge,
3296 Node* init_out_raw) {
3297 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3298 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3299
3300 Node* prevmem = kit.memory(alias_idx);
3301 init_in_merge->set_memory_at(alias_idx, prevmem);
3302 kit.set_memory(init_out_raw, alias_idx);
3303 }
3304
3305 //---------------------------set_output_for_allocation-------------------------
3306 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3307 const TypeOopPtr* oop_type,
3308 bool deoptimize_on_exception) {
3309 int rawidx = Compile::AliasIdxRaw;
3310 alloc->set_req( TypeFunc::FramePtr, frameptr() );
3311 add_safepoint_edges(alloc);
3312 Node* allocx = _gvn.transform(alloc);
3313 set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3314 // create memory projection for i_o
3315 set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3316 make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3317
3318 // create a memory projection as for the normal control path
3319 Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3320 set_memory(malloc, rawidx);
3321
3322 // a normal slow-call doesn't change i_o, but an allocation does
3323 // we create a separate i_o projection for the normal control path
3324 set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3325 Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3326
3327 // put in an initialization barrier
3328 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3329 rawoop)->as_Initialize();
3330 assert(alloc->initialization() == init, "2-way macro link must work");
3331 assert(init ->allocation() == alloc, "2-way macro link must work");
3332 {
3333 // Extract memory strands which may participate in the new object's
3334 // initialization, and source them from the new InitializeNode.
3335 // This will allow us to observe initializations when they occur,
3336 // and link them properly (as a group) to the InitializeNode.
3337 assert(init->in(InitializeNode::Memory) == malloc, "");
3338 MergeMemNode* minit_in = MergeMemNode::make(malloc);
3339 init->set_req(InitializeNode::Memory, minit_in);
3340 record_for_igvn(minit_in); // fold it up later, if possible
3341 Node* minit_out = memory(rawidx);
3342 assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3343 if (oop_type->isa_aryptr()) {
3344 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3345 int elemidx = C->get_alias_index(telemref);
3346 hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3347 } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3348 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3349 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3350 ciField* field = ik->nonstatic_field_at(i);
3351 if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3352 continue; // do not bother to track really large numbers of fields
3353 // Find (or create) the alias category for this field:
3354 int fieldidx = C->alias_type(field)->index();
3355 hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3356 }
3357 }
3358 }
3359
3360 // Cast raw oop to the real thing...
3361 Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3362 javaoop = _gvn.transform(javaoop);
3363 C->set_recent_alloc(control(), javaoop);
3364 assert(just_allocated_object(control()) == javaoop, "just allocated");
3365
3366 #ifdef ASSERT
3367 { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3368 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3369 "Ideal_allocation works");
3370 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3371 "Ideal_allocation works");
3372 if (alloc->is_AllocateArray()) {
3373 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3374 "Ideal_allocation works");
3375 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3376 "Ideal_allocation works");
3377 } else {
3378 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3379 }
3380 }
3381 #endif //ASSERT
3382
3383 return javaoop;
3384 }
3385
3386 //---------------------------new_instance--------------------------------------
3387 // This routine takes a klass_node which may be constant (for a static type)
3388 // or may be non-constant (for reflective code). It will work equally well
3389 // for either, and the graph will fold nicely if the optimizer later reduces
3390 // the type to a constant.
3391 // The optional arguments are for specialized use by intrinsics:
3392 // - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3393 // - If 'return_size_val', report the the total object size to the caller.
3394 // - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3395 Node* GraphKit::new_instance(Node* klass_node,
3396 Node* extra_slow_test,
3397 Node* *return_size_val,
3398 bool deoptimize_on_exception,
3399 ValueTypeBaseNode* value_node) {
3400 // Compute size in doublewords
3401 // The size is always an integral number of doublewords, represented
3402 // as a positive bytewise size stored in the klass's layout_helper.
3403 // The layout_helper also encodes (in a low bit) the need for a slow path.
3404 jint layout_con = Klass::_lh_neutral_value;
3405 Node* layout_val = get_layout_helper(klass_node, layout_con);
3406 bool layout_is_con = (layout_val == NULL);
3407
3408 if (extra_slow_test == NULL) extra_slow_test = intcon(0);
3409 // Generate the initial go-slow test. It's either ALWAYS (return a
3410 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3411 // case) a computed value derived from the layout_helper.
3412 Node* initial_slow_test = NULL;
3413 if (layout_is_con) {
3414 assert(!StressReflectiveCode, "stress mode does not use these paths");
3415 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3416 initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3417 } else { // reflective case
3418 // This reflective path is used by Unsafe.allocateInstance.
3419 // (It may be stress-tested by specifying StressReflectiveCode.)
3420 // Basically, we want to get into the VM is there's an illegal argument.
3421 Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3422 initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3423 if (extra_slow_test != intcon(0)) {
3424 initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3425 }
3426 // (Macro-expander will further convert this to a Bool, if necessary.)
3427 }
3428
3429 // Find the size in bytes. This is easy; it's the layout_helper.
3430 // The size value must be valid even if the slow path is taken.
3431 Node* size = NULL;
3432 if (layout_is_con) {
3433 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3434 } else { // reflective case
3435 // This reflective path is used by clone and Unsafe.allocateInstance.
3436 size = ConvI2X(layout_val);
3437
3438 // Clear the low bits to extract layout_helper_size_in_bytes:
3439 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3440 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3441 size = _gvn.transform( new AndXNode(size, mask) );
3442 }
3443 if (return_size_val != NULL) {
3444 (*return_size_val) = size;
3445 }
3446
3447 // This is a precise notnull oop of the klass.
3448 // (Actually, it need not be precise if this is a reflective allocation.)
3449 // It's what we cast the result to.
3450 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3451 if (!tklass) tklass = TypeKlassPtr::OBJECT;
3452 const TypeOopPtr* oop_type = tklass->as_instance_type();
3453
3454 // Now generate allocation code
3455
3456 // The entire memory state is needed for slow path of the allocation
3457 // since GC and deoptimization can happen.
3458 Node *mem = reset_memory();
3459 set_all_memory(mem); // Create new memory state
3460
3461 AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3462 control(), mem, i_o(),
3463 size, klass_node,
3464 initial_slow_test, value_node);
3465
3466 return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3467 }
3468
3469 //-------------------------------new_array-------------------------------------
3470 // helper for newarray and anewarray
3471 // The 'length' parameter is (obviously) the length of the array.
3472 // See comments on new_instance for the meaning of the other arguments.
3473 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable)
3474 Node* length, // number of array elements
3475 int nargs, // number of arguments to push back for uncommon trap
3476 Node* *return_size_val,
3477 bool deoptimize_on_exception) {
3478 jint layout_con = Klass::_lh_neutral_value;
3479 Node* layout_val = get_layout_helper(klass_node, layout_con);
3480 bool layout_is_con = (layout_val == NULL);
3481
3482 if (!layout_is_con && !StressReflectiveCode &&
3483 !too_many_traps(Deoptimization::Reason_class_check)) {
3484 // This is a reflective array creation site.
3485 // Optimistically assume that it is a subtype of Object[],
3486 // so that we can fold up all the address arithmetic.
3487 layout_con = Klass::array_layout_helper(T_OBJECT);
3488 Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3489 Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3490 { BuildCutout unless(this, bol_lh, PROB_MAX);
3491 inc_sp(nargs);
3492 uncommon_trap(Deoptimization::Reason_class_check,
3493 Deoptimization::Action_maybe_recompile);
3494 }
3495 layout_val = NULL;
3496 layout_is_con = true;
3497 }
3498
3499 // Generate the initial go-slow test. Make sure we do not overflow
3500 // if length is huge (near 2Gig) or negative! We do not need
3501 // exact double-words here, just a close approximation of needed
3502 // double-words. We can't add any offset or rounding bits, lest we
3503 // take a size -1 of bytes and make it positive. Use an unsigned
3504 // compare, so negative sizes look hugely positive.
3505 int fast_size_limit = FastAllocateSizeLimit;
3506 if (layout_is_con) {
3507 assert(!StressReflectiveCode, "stress mode does not use these paths");
3508 // Increase the size limit if we have exact knowledge of array type.
3509 int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3510 fast_size_limit <<= (LogBytesPerLong - log2_esize);
3511 }
3512
3513 Node* initial_slow_cmp = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3514 Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3515
3516 // --- Size Computation ---
3517 // array_size = round_to_heap(array_header + (length << elem_shift));
3518 // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3519 // and align_to(x, y) == ((x + y-1) & ~(y-1))
3520 // The rounding mask is strength-reduced, if possible.
3521 int round_mask = MinObjAlignmentInBytes - 1;
3522 Node* header_size = NULL;
3523 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3524 // (T_BYTE has the weakest alignment and size restrictions...)
3525 if (layout_is_con) {
3526 int hsize = Klass::layout_helper_header_size(layout_con);
3527 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3528 BasicType etype = Klass::layout_helper_element_type(layout_con);
3529 bool is_value_array = Klass::layout_helper_is_valueArray(layout_con);
3530 if ((round_mask & ~right_n_bits(eshift)) == 0)
3531 round_mask = 0; // strength-reduce it if it goes away completely
3532 assert(is_value_array || (hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3533 assert(header_size_min <= hsize, "generic minimum is smallest");
3534 header_size_min = hsize;
3535 header_size = intcon(hsize + round_mask);
3536 } else {
3537 Node* hss = intcon(Klass::_lh_header_size_shift);
3538 Node* hsm = intcon(Klass::_lh_header_size_mask);
3539 Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3540 hsize = _gvn.transform( new AndINode(hsize, hsm) );
3541 Node* mask = intcon(round_mask);
3542 header_size = _gvn.transform( new AddINode(hsize, mask) );
3543 }
3544
3545 Node* elem_shift = NULL;
3546 if (layout_is_con) {
3547 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3548 if (eshift != 0)
3549 elem_shift = intcon(eshift);
3550 } else {
3551 // There is no need to mask or shift this value.
3552 // The semantics of LShiftINode include an implicit mask to 0x1F.
3553 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3554 elem_shift = layout_val;
3555 }
3556
3557 // Transition to native address size for all offset calculations:
3558 Node* lengthx = ConvI2X(length);
3559 Node* headerx = ConvI2X(header_size);
3560 #ifdef _LP64
3561 { const TypeInt* tilen = _gvn.find_int_type(length);
3562 if (tilen != NULL && tilen->_lo < 0) {
3563 // Add a manual constraint to a positive range. Cf. array_element_address.
3564 jint size_max = fast_size_limit;
3565 if (size_max > tilen->_hi) size_max = tilen->_hi;
3566 const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3567
3568 // Only do a narrow I2L conversion if the range check passed.
3569 IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3570 _gvn.transform(iff);
3571 RegionNode* region = new RegionNode(3);
3572 _gvn.set_type(region, Type::CONTROL);
3573 lengthx = new PhiNode(region, TypeLong::LONG);
3574 _gvn.set_type(lengthx, TypeLong::LONG);
3575
3576 // Range check passed. Use ConvI2L node with narrow type.
3577 Node* passed = IfFalse(iff);
3578 region->init_req(1, passed);
3579 // Make I2L conversion control dependent to prevent it from
3580 // floating above the range check during loop optimizations.
3581 lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3582
3583 // Range check failed. Use ConvI2L with wide type because length may be invalid.
3584 region->init_req(2, IfTrue(iff));
3585 lengthx->init_req(2, ConvI2X(length));
3586
3587 set_control(region);
3588 record_for_igvn(region);
3589 record_for_igvn(lengthx);
3590 }
3591 }
3592 #endif
3593
3594 // Combine header size (plus rounding) and body size. Then round down.
3595 // This computation cannot overflow, because it is used only in two
3596 // places, one where the length is sharply limited, and the other
3597 // after a successful allocation.
3598 Node* abody = lengthx;
3599 if (elem_shift != NULL)
3600 abody = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3601 Node* size = _gvn.transform( new AddXNode(headerx, abody) );
3602 if (round_mask != 0) {
3603 Node* mask = MakeConX(~round_mask);
3604 size = _gvn.transform( new AndXNode(size, mask) );
3605 }
3606 // else if round_mask == 0, the size computation is self-rounding
3607
3608 if (return_size_val != NULL) {
3609 // This is the size
3610 (*return_size_val) = size;
3611 }
3612
3613 // Now generate allocation code
3614
3615 // The entire memory state is needed for slow path of the allocation
3616 // since GC and deoptimization can happen.
3617 Node *mem = reset_memory();
3618 set_all_memory(mem); // Create new memory state
3619
3620 if (initial_slow_test->is_Bool()) {
3621 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3622 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3623 }
3624
3625 // Create the AllocateArrayNode and its result projections
3626 AllocateArrayNode* alloc
3627 = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3628 control(), mem, i_o(),
3629 size, klass_node,
3630 initial_slow_test,
3631 length);
3632
3633 // Cast to correct type. Note that the klass_node may be constant or not,
3634 // and in the latter case the actual array type will be inexact also.
3635 // (This happens via a non-constant argument to inline_native_newArray.)
3636 // In any case, the value of klass_node provides the desired array type.
3637 const TypeInt* length_type = _gvn.find_int_type(length);
3638 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3639 if (ary_type->isa_aryptr() && length_type != NULL) {
3640 // Try to get a better type than POS for the size
3641 ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3642 }
3643
3644 Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3645
3646 // Cast length on remaining path to be as narrow as possible
3647 if (map()->find_edge(length) >= 0) {
3648 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3649 if (ccast != length) {
3650 _gvn.set_type_bottom(ccast);
3651 record_for_igvn(ccast);
3652 replace_in_map(length, ccast);
3653 }
3654 }
3655
3656 const TypeAryPtr* ary_ptr = ary_type->isa_aryptr();
3657 ciKlass* elem_klass = ary_ptr != NULL ? ary_ptr->klass()->as_array_klass()->element_klass() : NULL;
3658 if (elem_klass != NULL && elem_klass->is_valuetype()) {
3659 ciValueKlass* vk = elem_klass->as_value_klass();
3660 if (!vk->flatten_array()) {
3661 // Non-flattened value type arrays need to be initialized with default value type oops
3662 initialize_value_type_array(javaoop, length, elem_klass->as_value_klass(), nargs);
3663 InitializeNode* init = alloc->initialization();
3664 init->set_complete_with_arraycopy();
3665 }
3666 }
3667
3668 return javaoop;
3669 }
3670
3671 void GraphKit::initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs) {
3672 // Check for zero length
3673 Node* null_ctl = top();
3674 null_check_common(length, T_INT, false, &null_ctl, false);
3675 if (stopped()) {
3676 set_control(null_ctl); // Always zero
3677 return;
3678 }
3679
3680 // Prepare for merging control and IO
3681 RegionNode* res_ctl = new RegionNode(3);
3682 res_ctl->init_req(1, null_ctl);
3683 gvn().set_type(res_ctl, Type::CONTROL);
3684 record_for_igvn(res_ctl);
3685 Node* res_io = PhiNode::make(res_ctl, i_o(), Type::ABIO);
3686 gvn().set_type(res_io, Type::ABIO);
3687 record_for_igvn(res_io);
3688
3689 // TODO comment
3690 SafePointNode* loop_map = NULL;
3691 {
3692 PreserveJVMState pjvms(this);
3693 // Create default value type and store it to memory
3694 Node* oop = ValueTypeNode::make_default(gvn(), vk);
3695 oop = oop->as_ValueType()->allocate(this)->get_oop();
3696
3697 length = SubI(length, intcon(1));
3698 add_predicate(nargs);
3699 RegionNode* loop = new RegionNode(3);
3700 loop->init_req(1, control());
3701 gvn().set_type(loop, Type::CONTROL);
3702 record_for_igvn(loop);
3703
3704 Node* index = new PhiNode(loop, TypeInt::INT);
3705 index->init_req(1, intcon(0));
3706 gvn().set_type(index, TypeInt::INT);
3707 record_for_igvn(index);
3708
3709 // TODO explain why we need to capture all memory
3710 PhiNode* mem = new PhiNode(loop, Type::MEMORY, TypePtr::BOTTOM);
3711 mem->init_req(1, reset_memory());
3712 gvn().set_type(mem, Type::MEMORY);
3713 record_for_igvn(mem);
3714 set_control(loop);
3715 set_all_memory(mem);
3716 // Initialize array element
3717 Node* adr = array_element_address(array, index, T_OBJECT);
3718 const TypeOopPtr* elemtype = TypeValueTypePtr::make(TypePtr::NotNull, vk);
3719 Node* store = store_oop_to_array(control(), array, adr, TypeAryPtr::OOPS, oop, elemtype, T_OBJECT, MemNode::release);
3720
3721 IfNode* iff = create_and_map_if(control(), Bool(CmpI(index, length), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3722 loop->init_req(2, IfTrue(iff));
3723 mem->init_req(2, merged_memory());
3724 index->init_req(2, AddI(index, intcon(1)));
3725
3726 res_ctl->init_req(2, IfFalse(iff));
3727 res_io->set_req(2, i_o());
3728 loop_map = stop();
3729 }
3730 // Set merged control, IO and memory
3731 set_control(res_ctl);
3732 set_i_o(res_io);
3733 merge_memory(loop_map->merged_memory(), res_ctl, 2);
3734
3735 // Transform new memory Phis.
3736 for (MergeMemStream mms(merged_memory()); mms.next_non_empty();) {
3737 Node* phi = mms.memory();
3738 if (phi->is_Phi() && phi->in(0) == res_ctl) {
3739 mms.set_memory(gvn().transform(phi));
3740 }
3741 }
3742 }
3743
3744 // The following "Ideal_foo" functions are placed here because they recognize
3745 // the graph shapes created by the functions immediately above.
3746
3747 //---------------------------Ideal_allocation----------------------------------
3748 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3749 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3750 if (ptr == NULL) { // reduce dumb test in callers
3751 return NULL;
3752 }
3753 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3754 ptr = ptr->in(1);
3755 if (ptr == NULL) return NULL;
3756 }
3757 // Return NULL for allocations with several casts:
3758 // j.l.reflect.Array.newInstance(jobject, jint)
3759 // Object.clone()
3760 // to keep more precise type from last cast.
3761 if (ptr->is_Proj()) {
3762 Node* allo = ptr->in(0);
3763 if (allo != NULL && allo->is_Allocate()) {
3764 return allo->as_Allocate();
3765 }
3766 }
3767 // Report failure to match.
3768 return NULL;
3769 }
3770
3771 // Fancy version which also strips off an offset (and reports it to caller).
3772 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3773 intptr_t& offset) {
3774 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3775 if (base == NULL) return NULL;
3776 return Ideal_allocation(base, phase);
3777 }
3778
3779 // Trace Initialize <- Proj[Parm] <- Allocate
3780 AllocateNode* InitializeNode::allocation() {
3781 Node* rawoop = in(InitializeNode::RawAddress);
3782 if (rawoop->is_Proj()) {
3783 Node* alloc = rawoop->in(0);
3784 if (alloc->is_Allocate()) {
3785 return alloc->as_Allocate();
3786 }
3787 }
3788 return NULL;
3789 }
3790
3791 // Trace Allocate -> Proj[Parm] -> Initialize
3792 InitializeNode* AllocateNode::initialization() {
3793 ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3794 if (rawoop == NULL) return NULL;
3795 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3796 Node* init = rawoop->fast_out(i);
3797 if (init->is_Initialize()) {
3798 assert(init->as_Initialize()->allocation() == this, "2-way link");
3799 return init->as_Initialize();
3800 }
3801 }
3802 return NULL;
3803 }
3804
3805 //----------------------------- loop predicates ---------------------------
3806
3807 //------------------------------add_predicate_impl----------------------------
3808 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3809 // Too many traps seen?
3810 if (too_many_traps(reason)) {
3811 #ifdef ASSERT
3812 if (TraceLoopPredicate) {
3813 int tc = C->trap_count(reason);
3814 tty->print("too many traps=%s tcount=%d in ",
3815 Deoptimization::trap_reason_name(reason), tc);
3816 method()->print(); // which method has too many predicate traps
3817 tty->cr();
3818 }
3819 #endif
3820 // We cannot afford to take more traps here,
3821 // do not generate predicate.
3822 return;
3823 }
3824
3825 Node *cont = _gvn.intcon(1);
3826 Node* opq = _gvn.transform(new Opaque1Node(C, cont));
3827 Node *bol = _gvn.transform(new Conv2BNode(opq));
3828 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3829 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3830 C->add_predicate_opaq(opq);
3831 {
3832 PreserveJVMState pjvms(this);
3833 set_control(iffalse);
3834 inc_sp(nargs);
3835 uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3836 }
3837 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3838 set_control(iftrue);
3839 }
3840
3841 //------------------------------add_predicate---------------------------------
3842 void GraphKit::add_predicate(int nargs) {
3843 if (UseLoopPredicate) {
3844 add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3845 }
3846 // loop's limit check predicate should be near the loop.
3847 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3848 }
3849
3850 //----------------------------- store barriers ----------------------------
3851 #define __ ideal.
3852
3853 void GraphKit::sync_kit(IdealKit& ideal) {
3854 set_all_memory(__ merged_memory());
3855 set_i_o(__ i_o());
3856 set_control(__ ctrl());
3857 }
3858
3859 void GraphKit::final_sync(IdealKit& ideal) {
3860 // Final sync IdealKit and graphKit.
3861 sync_kit(ideal);
3862 }
3863
3864 Node* GraphKit::byte_map_base_node() {
3865 // Get base of card map
3866 CardTableModRefBS* ct =
3867 barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3868 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3869 if (ct->byte_map_base != NULL) {
3870 return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3871 } else {
3872 return null();
3873 }
3874 }
3875
3876 // vanilla/CMS post barrier
3877 // Insert a write-barrier store. This is to let generational GC work; we have
3878 // to flag all oop-stores before the next GC point.
3879 void GraphKit::write_barrier_post(Node* oop_store,
3880 Node* obj,
3881 Node* adr,
3882 uint adr_idx,
3883 Node* val,
3884 bool use_precise) {
3885 // No store check needed if we're storing a NULL or an old object
3886 // (latter case is probably a string constant). The concurrent
3887 // mark sweep garbage collector, however, needs to have all nonNull
3888 // oop updates flagged via card-marks.
3889 if (val != NULL && val->is_Con()) {
3890 // must be either an oop or NULL
3891 const Type* t = val->bottom_type();
3892 if (t == TypePtr::NULL_PTR || t == Type::TOP)
3893 // stores of null never (?) need barriers
3894 return;
3895 }
3896
3897 if (use_ReduceInitialCardMarks()
3898 && obj == just_allocated_object(control())) {
3899 // We can skip marks on a freshly-allocated object in Eden.
3900 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3901 // That routine informs GC to take appropriate compensating steps,
3902 // upon a slow-path allocation, so as to make this card-mark
3903 // elision safe.
3904 return;
3905 }
3906
3907 if (!use_precise) {
3908 // All card marks for a (non-array) instance are in one place:
3909 adr = obj;
3910 }
3911 // (Else it's an array (or unknown), and we want more precise card marks.)
3912 assert(adr != NULL, "");
3913
3914 IdealKit ideal(this, true);
3915
3916 // Convert the pointer to an int prior to doing math on it
3917 Node* cast = __ CastPX(__ ctrl(), adr);
3918
3919 // Divide by card size
3920 assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3921 "Only one we handle so far.");
3922 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3923
3924 // Combine card table base and card offset
3925 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3926
3927 // Get the alias_index for raw card-mark memory
3928 int adr_type = Compile::AliasIdxRaw;
3929 Node* zero = __ ConI(0); // Dirty card value
3930 BasicType bt = T_BYTE;
3931
3932 if (UseConcMarkSweepGC && UseCondCardMark) {
3933 insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
3934 __ sync_kit(this);
3935 }
3936
3937 if (UseCondCardMark) {
3938 // The classic GC reference write barrier is typically implemented
3939 // as a store into the global card mark table. Unfortunately
3940 // unconditional stores can result in false sharing and excessive
3941 // coherence traffic as well as false transactional aborts.
3942 // UseCondCardMark enables MP "polite" conditional card mark
3943 // stores. In theory we could relax the load from ctrl() to
3944 // no_ctrl, but that doesn't buy much latitude.
3945 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3946 __ if_then(card_val, BoolTest::ne, zero);
3947 }
3948
3949 // Smash zero into card
3950 if( !UseConcMarkSweepGC ) {
3951 __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3952 } else {
3953 // Specialized path for CM store barrier
3954 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3955 }
3956
3957 if (UseCondCardMark) {
3958 __ end_if();
3959 }
3960
3961 // Final sync IdealKit and GraphKit.
3962 final_sync(ideal);
3963 }
3964 /*
3965 * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3966 * required by SATB to make sure all objects live at the start of the
3967 * marking are kept alive, all reference updates need to any previous
3968 * reference stored before writing.
3969 *
3970 * If the previous value is NULL there is no need to save the old value.
3971 * References that are NULL are filtered during runtime by the barrier
3972 * code to avoid unnecessary queuing.
3973 *
3974 * However in the case of newly allocated objects it might be possible to
3975 * prove that the reference about to be overwritten is NULL during compile
3976 * time and avoid adding the barrier code completely.
3977 *
3978 * The compiler needs to determine that the object in which a field is about
3979 * to be written is newly allocated, and that no prior store to the same field
3980 * has happened since the allocation.
3981 *
3982 * Returns true if the pre-barrier can be removed
3983 */
3984 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3985 BasicType bt, uint adr_idx) {
3986 intptr_t offset = 0;
3987 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3988 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3989
3990 if (offset == Type::OffsetBot) {
3991 return false; // cannot unalias unless there are precise offsets
3992 }
3993
3994 if (alloc == NULL) {
3995 return false; // No allocation found
3996 }
3997
3998 intptr_t size_in_bytes = type2aelembytes(bt);
3999
4000 Node* mem = memory(adr_idx); // start searching here...
4001
4002 for (int cnt = 0; cnt < 50; cnt++) {
4003
4004 if (mem->is_Store()) {
4005
4006 Node* st_adr = mem->in(MemNode::Address);
4007 intptr_t st_offset = 0;
4008 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
4009
4010 if (st_base == NULL) {
4011 break; // inscrutable pointer
4012 }
4013
4014 // Break we have found a store with same base and offset as ours so break
4015 if (st_base == base && st_offset == offset) {
4016 break;
4017 }
4018
4019 if (st_offset != offset && st_offset != Type::OffsetBot) {
4020 const int MAX_STORE = BytesPerLong;
4021 if (st_offset >= offset + size_in_bytes ||
4022 st_offset <= offset - MAX_STORE ||
4023 st_offset <= offset - mem->as_Store()->memory_size()) {
4024 // Success: The offsets are provably independent.
4025 // (You may ask, why not just test st_offset != offset and be done?
4026 // The answer is that stores of different sizes can co-exist
4027 // in the same sequence of RawMem effects. We sometimes initialize
4028 // a whole 'tile' of array elements with a single jint or jlong.)
4029 mem = mem->in(MemNode::Memory);
4030 continue; // advance through independent store memory
4031 }
4032 }
4033
4034 if (st_base != base
4035 && MemNode::detect_ptr_independence(base, alloc, st_base,
4036 AllocateNode::Ideal_allocation(st_base, phase),
4037 phase)) {
4038 // Success: The bases are provably independent.
4039 mem = mem->in(MemNode::Memory);
4040 continue; // advance through independent store memory
4041 }
4042 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4043
4044 InitializeNode* st_init = mem->in(0)->as_Initialize();
4045 AllocateNode* st_alloc = st_init->allocation();
4046
4047 // Make sure that we are looking at the same allocation site.
4048 // The alloc variable is guaranteed to not be null here from earlier check.
4049 if (alloc == st_alloc) {
4050 // Check that the initialization is storing NULL so that no previous store
4051 // has been moved up and directly write a reference
4052 Node* captured_store = st_init->find_captured_store(offset,
4053 type2aelembytes(T_OBJECT),
4054 phase);
4055 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4056 return true;
4057 }
4058 }
4059 }
4060
4061 // Unless there is an explicit 'continue', we must bail out here,
4062 // because 'mem' is an inscrutable memory state (e.g., a call).
4063 break;
4064 }
4065
4066 return false;
4067 }
4068
4069 // G1 pre/post barriers
4070 void GraphKit::g1_write_barrier_pre(bool do_load,
4071 Node* obj,
4072 Node* adr,
4073 uint alias_idx,
4074 Node* val,
4075 const TypeOopPtr* val_type,
4076 Node* pre_val,
4077 BasicType bt) {
4078
4079 // Some sanity checks
4080 // Note: val is unused in this routine.
4081
4082 if (do_load) {
4083 // We need to generate the load of the previous value
4084 assert(obj != NULL, "must have a base");
4085 assert(adr != NULL, "where are loading from?");
4086 assert(pre_val == NULL, "loaded already?");
4087 assert(val_type != NULL, "need a type");
4088
4089 if (use_ReduceInitialCardMarks()
4090 && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4091 return;
4092 }
4093
4094 } else {
4095 // In this case both val_type and alias_idx are unused.
4096 assert(pre_val != NULL, "must be loaded already");
4097 // Nothing to be done if pre_val is null.
4098 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4099 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4100 }
4101 assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4102
4103 IdealKit ideal(this, true);
4104
4105 Node* tls = __ thread(); // ThreadLocalStorage
4106
4107 Node* no_ctrl = NULL;
4108 Node* no_base = __ top();
4109 Node* zero = __ ConI(0);
4110 Node* zeroX = __ ConX(0);
4111
4112 float likely = PROB_LIKELY(0.999);
4113 float unlikely = PROB_UNLIKELY(0.999);
4114
4115 BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4116 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4117
4118 // Offsets into the thread
4119 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648
4120 SATBMarkQueue::byte_offset_of_active());
4121 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656
4122 SATBMarkQueue::byte_offset_of_index());
4123 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652
4124 SATBMarkQueue::byte_offset_of_buf());
4125
4126 // Now the actual pointers into the thread
4127 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4128 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4129 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4130
4131 // Now some of the values
4132 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4133
4134 // if (!marking)
4135 __ if_then(marking, BoolTest::ne, zero, unlikely); {
4136 BasicType index_bt = TypeX_X->basic_type();
4137 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4138 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4139
4140 if (do_load) {
4141 // load original value
4142 // alias_idx correct??
4143 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4144 }
4145
4146 // if (pre_val != NULL)
4147 __ if_then(pre_val, BoolTest::ne, null()); {
4148 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4149
4150 // is the queue for this thread full?
4151 __ if_then(index, BoolTest::ne, zeroX, likely); {
4152
4153 // decrement the index
4154 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4155
4156 // Now get the buffer location we will log the previous value into and store it
4157 Node *log_addr = __ AddP(no_base, buffer, next_index);
4158 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4159 // update the index
4160 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4161
4162 } __ else_(); {
4163
4164 // logging buffer is full, call the runtime
4165 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4166 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4167 } __ end_if(); // (!index)
4168 } __ end_if(); // (pre_val != NULL)
4169 } __ end_if(); // (!marking)
4170
4171 // Final sync IdealKit and GraphKit.
4172 final_sync(ideal);
4173 }
4174
4175 /*
4176 * G1 similar to any GC with a Young Generation requires a way to keep track of
4177 * references from Old Generation to Young Generation to make sure all live
4178 * objects are found. G1 also requires to keep track of object references
4179 * between different regions to enable evacuation of old regions, which is done
4180 * as part of mixed collections. References are tracked in remembered sets and
4181 * is continuously updated as reference are written to with the help of the
4182 * post-barrier.
4183 *
4184 * To reduce the number of updates to the remembered set the post-barrier
4185 * filters updates to fields in objects located in the Young Generation,
4186 * the same region as the reference, when the NULL is being written or
4187 * if the card is already marked as dirty by an earlier write.
4188 *
4189 * Under certain circumstances it is possible to avoid generating the
4190 * post-barrier completely if it is possible during compile time to prove
4191 * the object is newly allocated and that no safepoint exists between the
4192 * allocation and the store.
4193 *
4194 * In the case of slow allocation the allocation code must handle the barrier
4195 * as part of the allocation in the case the allocated object is not located
4196 * in the nursery, this would happen for humongous objects. This is similar to
4197 * how CMS is required to handle this case, see the comments for the method
4198 * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4199 * A deferred card mark is required for these objects and handled in the above
4200 * mentioned methods.
4201 *
4202 * Returns true if the post barrier can be removed
4203 */
4204 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4205 Node* adr) {
4206 intptr_t offset = 0;
4207 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4208 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4209
4210 if (offset == Type::OffsetBot) {
4211 return false; // cannot unalias unless there are precise offsets
4212 }
4213
4214 if (alloc == NULL) {
4215 return false; // No allocation found
4216 }
4217
4218 // Start search from Store node
4219 Node* mem = store->in(MemNode::Control);
4220 if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4221
4222 InitializeNode* st_init = mem->in(0)->as_Initialize();
4223 AllocateNode* st_alloc = st_init->allocation();
4224
4225 // Make sure we are looking at the same allocation
4226 if (alloc == st_alloc) {
4227 return true;
4228 }
4229 }
4230
4231 return false;
4232 }
4233
4234 //
4235 // Update the card table and add card address to the queue
4236 //
4237 void GraphKit::g1_mark_card(IdealKit& ideal,
4238 Node* card_adr,
4239 Node* oop_store,
4240 uint oop_alias_idx,
4241 Node* index,
4242 Node* index_adr,
4243 Node* buffer,
4244 const TypeFunc* tf) {
4245
4246 Node* zero = __ ConI(0);
4247 Node* zeroX = __ ConX(0);
4248 Node* no_base = __ top();
4249 BasicType card_bt = T_BYTE;
4250 // Smash zero into card. MUST BE ORDERED WRT TO STORE
4251 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4252
4253 // Now do the queue work
4254 __ if_then(index, BoolTest::ne, zeroX); {
4255
4256 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4257 Node* log_addr = __ AddP(no_base, buffer, next_index);
4258
4259 // Order, see storeCM.
4260 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4261 __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4262
4263 } __ else_(); {
4264 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4265 } __ end_if();
4266
4267 }
4268
4269 void GraphKit::g1_write_barrier_post(Node* oop_store,
4270 Node* obj,
4271 Node* adr,
4272 uint alias_idx,
4273 Node* val,
4274 BasicType bt,
4275 bool use_precise) {
4276 // If we are writing a NULL then we need no post barrier
4277
4278 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4279 // Must be NULL
4280 const Type* t = val->bottom_type();
4281 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4282 // No post barrier if writing NULLx
4283 return;
4284 }
4285
4286 if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4287 // We can skip marks on a freshly-allocated object in Eden.
4288 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4289 // That routine informs GC to take appropriate compensating steps,
4290 // upon a slow-path allocation, so as to make this card-mark
4291 // elision safe.
4292 return;
4293 }
4294
4295 if (use_ReduceInitialCardMarks()
4296 && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4297 return;
4298 }
4299
4300 if (!use_precise) {
4301 // All card marks for a (non-array) instance are in one place:
4302 adr = obj;
4303 }
4304 // (Else it's an array (or unknown), and we want more precise card marks.)
4305 assert(adr != NULL, "");
4306
4307 IdealKit ideal(this, true);
4308
4309 Node* tls = __ thread(); // ThreadLocalStorage
4310
4311 Node* no_base = __ top();
4312 float likely = PROB_LIKELY(0.999);
4313 float unlikely = PROB_UNLIKELY(0.999);
4314 Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4315 Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4316 Node* zeroX = __ ConX(0);
4317
4318 // Get the alias_index for raw card-mark memory
4319 const TypePtr* card_type = TypeRawPtr::BOTTOM;
4320
4321 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4322
4323 // Offsets into the thread
4324 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4325 DirtyCardQueue::byte_offset_of_index());
4326 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4327 DirtyCardQueue::byte_offset_of_buf());
4328
4329 // Pointers into the thread
4330
4331 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4332 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4333
4334 // Now some values
4335 // Use ctrl to avoid hoisting these values past a safepoint, which could
4336 // potentially reset these fields in the JavaThread.
4337 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4338 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4339
4340 // Convert the store obj pointer to an int prior to doing math on it
4341 // Must use ctrl to prevent "integerized oop" existing across safepoint
4342 Node* cast = __ CastPX(__ ctrl(), adr);
4343
4344 // Divide pointer by card size
4345 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4346
4347 // Combine card table base and card offset
4348 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4349
4350 // If we know the value being stored does it cross regions?
4351
4352 if (val != NULL) {
4353 // Does the store cause us to cross regions?
4354
4355 // Should be able to do an unsigned compare of region_size instead of
4356 // and extra shift. Do we have an unsigned compare??
4357 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4358 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4359
4360 // if (xor_res == 0) same region so skip
4361 __ if_then(xor_res, BoolTest::ne, zeroX); {
4362
4363 // No barrier if we are storing a NULL
4364 __ if_then(val, BoolTest::ne, null(), unlikely); {
4365
4366 // Ok must mark the card if not already dirty
4367
4368 // load the original value of the card
4369 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4370
4371 __ if_then(card_val, BoolTest::ne, young_card); {
4372 sync_kit(ideal);
4373 // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4374 insert_mem_bar(Op_MemBarVolatile, oop_store);
4375 __ sync_kit(this);
4376
4377 Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4378 __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4379 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4380 } __ end_if();
4381 } __ end_if();
4382 } __ end_if();
4383 } __ end_if();
4384 } else {
4385 // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4386 // We don't need a barrier here if the destination is a newly allocated object
4387 // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4388 // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4389 assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4390 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4391 __ if_then(card_val, BoolTest::ne, young_card); {
4392 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4393 } __ end_if();
4394 }
4395
4396 // Final sync IdealKit and GraphKit.
4397 final_sync(ideal);
4398 }
4399 #undef __
4400
4401
4402 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4403 Node* len = load_array_length(load_String_value(ctrl, str));
4404 Node* coder = load_String_coder(ctrl, str);
4405 // Divide length by 2 if coder is UTF16
4406 return _gvn.transform(new RShiftINode(len, coder));
4407 }
4408
4409 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4410 int value_offset = java_lang_String::value_offset_in_bytes();
4411 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4412 false, NULL, Type::Offset(0));
4413 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4414 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4415 TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4416 ciTypeArrayKlass::make(T_BYTE), true, Type::Offset(0));
4417 int value_field_idx = C->get_alias_index(value_field_type);
4418 Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4419 value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4420 // String.value field is known to be @Stable.
4421 if (UseImplicitStableValues) {
4422 load = cast_array_to_stable(load, value_type);
4423 }
4424 return load;
4425 }
4426
4427 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4428 if (!CompactStrings) {
4429 return intcon(java_lang_String::CODER_UTF16);
4430 }
4431 int coder_offset = java_lang_String::coder_offset_in_bytes();
4432 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4433 false, NULL, Type::Offset(0));
4434 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4435 int coder_field_idx = C->get_alias_index(coder_field_type);
4436 return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4437 TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4438 }
4439
4440 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4441 int value_offset = java_lang_String::value_offset_in_bytes();
4442 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4443 false, NULL, Type::Offset(0));
4444 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4445 store_oop_to_object(ctrl, str, basic_plus_adr(str, value_offset), value_field_type,
4446 value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4447 }
4448
4449 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4450 int coder_offset = java_lang_String::coder_offset_in_bytes();
4451 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4452 false, NULL, Type::Offset(0));
4453 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4454 int coder_field_idx = C->get_alias_index(coder_field_type);
4455 store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4456 value, T_BYTE, coder_field_idx, MemNode::unordered);
4457 }
4458
4459 // Capture src and dst memory state with a MergeMemNode
4460 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4461 if (src_type == dst_type) {
4462 // Types are equal, we don't need a MergeMemNode
4463 return memory(src_type);
4464 }
4465 MergeMemNode* merge = MergeMemNode::make(map()->memory());
4466 record_for_igvn(merge); // fold it up later, if possible
4467 int src_idx = C->get_alias_index(src_type);
4468 int dst_idx = C->get_alias_index(dst_type);
4469 merge->set_memory_at(src_idx, memory(src_idx));
4470 merge->set_memory_at(dst_idx, memory(dst_idx));
4471 return merge;
4472 }
4473
4474 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4475 assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4476 assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4477 // If input and output memory types differ, capture both states to preserve
4478 // the dependency between preceding and subsequent loads/stores.
4479 // For example, the following program:
4480 // StoreB
4481 // compress_string
4482 // LoadB
4483 // has this memory graph (use->def):
4484 // LoadB -> compress_string -> CharMem
4485 // ... -> StoreB -> ByteMem
4486 // The intrinsic hides the dependency between LoadB and StoreB, causing
4487 // the load to read from memory not containing the result of the StoreB.
4488 // The correct memory graph should look like this:
4489 // LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4490 Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4491 StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4492 Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4493 set_memory(res_mem, TypeAryPtr::BYTES);
4494 return str;
4495 }
4496
4497 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4498 assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4499 assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4500 // Capture src and dst memory (see comment in 'compress_string').
4501 Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4502 StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4503 set_memory(_gvn.transform(str), dst_type);
4504 }
4505
4506 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4507 /**
4508 * int i_char = start;
4509 * for (int i_byte = 0; i_byte < count; i_byte++) {
4510 * dst[i_char++] = (char)(src[i_byte] & 0xff);
4511 * }
4512 */
4513 add_predicate();
4514 RegionNode* head = new RegionNode(3);
4515 head->init_req(1, control());
4516 gvn().set_type(head, Type::CONTROL);
4517 record_for_igvn(head);
4518
4519 Node* i_byte = new PhiNode(head, TypeInt::INT);
4520 i_byte->init_req(1, intcon(0));
4521 gvn().set_type(i_byte, TypeInt::INT);
4522 record_for_igvn(i_byte);
4523
4524 Node* i_char = new PhiNode(head, TypeInt::INT);
4525 i_char->init_req(1, start);
4526 gvn().set_type(i_char, TypeInt::INT);
4527 record_for_igvn(i_char);
4528
4529 Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4530 gvn().set_type(mem, Type::MEMORY);
4531 record_for_igvn(mem);
4532 set_control(head);
4533 set_memory(mem, TypeAryPtr::BYTES);
4534 Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4535 Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4536 AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4537 false, false, true /* mismatched */);
4538
4539 IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4540 head->init_req(2, IfTrue(iff));
4541 mem->init_req(2, st);
4542 i_byte->init_req(2, AddI(i_byte, intcon(1)));
4543 i_char->init_req(2, AddI(i_char, intcon(2)));
4544
4545 set_control(IfFalse(iff));
4546 set_memory(st, TypeAryPtr::BYTES);
4547 }
4548
4549 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4550 if (!field->is_constant()) {
4551 return NULL; // Field not marked as constant.
4552 }
4553 ciInstance* holder = NULL;
4554 if (!field->is_static()) {
4555 ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4556 if (const_oop != NULL && const_oop->is_instance()) {
4557 holder = const_oop->as_instance();
4558 }
4559 }
4560 const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4561 /*is_unsigned_load=*/false);
4562 if (con_type != NULL) {
4563 Node* con = makecon(con_type);
4564 if (field->layout_type() == T_VALUETYPE) {
4565 // Load value type from constant oop
4566 con = ValueTypeNode::make(this, con);
4567 }
4568 return con;
4569 }
4570 return NULL;
4571 }
4572
4573 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4574 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4575 // assumption of CCP analysis.
4576 return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4577 }