1 /*
2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "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)
53 : Phase(Phase::Parser),
54 _env(C->env()),
55 _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 }
61
62 // Private constructor for parser.
63 GraphKit::GraphKit()
64 : Phase(Phase::Parser),
65 _env(C->env()),
66 _gvn(*C->initial_gvn())
67 {
68 _exceptions = NULL;
69 set_map(NULL);
70 debug_only(_sp = -99);
71 debug_only(set_bci(-99));
72 }
73
74
75
76 //---------------------------clean_stack---------------------------------------
77 // Clear away rubbish from the stack area of the JVM state.
78 // This destroys any arguments that may be waiting on the stack.
79 void GraphKit::clean_stack(int from_sp) {
80 SafePointNode* map = this->map();
81 JVMState* jvms = this->jvms();
82 int stk_size = jvms->stk_size();
83 int stkoff = jvms->stkoff();
84 Node* top = this->top();
85 for (int i = from_sp; i < stk_size; i++) {
86 if (map->in(stkoff + i) != top) {
87 map->set_req(stkoff + i, top);
88 }
89 }
90 }
91
92
93 //--------------------------------sync_jvms-----------------------------------
94 // Make sure our current jvms agrees with our parse state.
95 JVMState* GraphKit::sync_jvms() const {
96 JVMState* jvms = this->jvms();
97 jvms->set_bci(bci()); // Record the new bci in the JVMState
98 jvms->set_sp(sp()); // Record the new sp in the JVMState
99 assert(jvms_in_sync(), "jvms is now in sync");
100 return jvms;
101 }
102
103 //--------------------------------sync_jvms_for_reexecute---------------------
104 // Make sure our current jvms agrees with our parse state. This version
105 // uses the reexecute_sp for reexecuting bytecodes.
106 JVMState* GraphKit::sync_jvms_for_reexecute() {
107 JVMState* jvms = this->jvms();
108 jvms->set_bci(bci()); // Record the new bci in the JVMState
109 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState
110 return jvms;
111 }
112
113 #ifdef ASSERT
114 bool GraphKit::jvms_in_sync() const {
115 Parse* parse = is_Parse();
116 if (parse == NULL) {
117 if (bci() != jvms()->bci()) return false;
118 if (sp() != (int)jvms()->sp()) return false;
119 return true;
120 }
121 if (jvms()->method() != parse->method()) return false;
122 if (jvms()->bci() != parse->bci()) return false;
123 int jvms_sp = jvms()->sp();
124 if (jvms_sp != parse->sp()) return false;
125 int jvms_depth = jvms()->depth();
126 if (jvms_depth != parse->depth()) return false;
127 return true;
128 }
129
130 // Local helper checks for special internal merge points
131 // used to accumulate and merge exception states.
132 // They are marked by the region's in(0) edge being the map itself.
133 // Such merge points must never "escape" into the parser at large,
134 // until they have been handed to gvn.transform.
135 static bool is_hidden_merge(Node* reg) {
136 if (reg == NULL) return false;
137 if (reg->is_Phi()) {
138 reg = reg->in(0);
139 if (reg == NULL) return false;
140 }
141 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
142 }
143
144 void GraphKit::verify_map() const {
145 if (map() == NULL) return; // null map is OK
146 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
147 assert(!map()->has_exceptions(), "call add_exception_states_from 1st");
148 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
149 }
150
151 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
152 assert(ex_map->next_exception() == NULL, "not already part of a chain");
153 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
154 }
155 #endif
156
157 //---------------------------stop_and_kill_map---------------------------------
158 // Set _map to NULL, signalling a stop to further bytecode execution.
159 // First smash the current map's control to a constant, to mark it dead.
160 void GraphKit::stop_and_kill_map() {
161 SafePointNode* dead_map = stop();
162 if (dead_map != NULL) {
163 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
164 assert(dead_map->is_killed(), "must be so marked");
165 }
166 }
167
168
169 //--------------------------------stopped--------------------------------------
170 // Tell if _map is NULL, or control is top.
171 bool GraphKit::stopped() {
172 if (map() == NULL) return true;
173 else if (control() == top()) return true;
174 else return false;
175 }
176
177
178 //-----------------------------has_ex_handler----------------------------------
179 // Tell if this method or any caller method has exception handlers.
180 bool GraphKit::has_ex_handler() {
181 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
182 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
183 return true;
184 }
185 }
186 return false;
187 }
188
189 //------------------------------save_ex_oop------------------------------------
190 // Save an exception without blowing stack contents or other JVM state.
191 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
192 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
193 ex_map->add_req(ex_oop);
194 debug_only(verify_exception_state(ex_map));
195 }
196
197 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
198 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
199 Node* ex_oop = ex_map->in(ex_map->req()-1);
200 if (clear_it) ex_map->del_req(ex_map->req()-1);
201 return ex_oop;
202 }
203
204 //-----------------------------saved_ex_oop------------------------------------
205 // Recover a saved exception from its map.
206 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
207 return common_saved_ex_oop(ex_map, false);
208 }
209
210 //--------------------------clear_saved_ex_oop---------------------------------
211 // Erase a previously saved exception from its map.
212 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
213 return common_saved_ex_oop(ex_map, true);
214 }
215
216 #ifdef ASSERT
217 //---------------------------has_saved_ex_oop----------------------------------
218 // Erase a previously saved exception from its map.
219 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
220 return ex_map->req() == ex_map->jvms()->endoff()+1;
221 }
222 #endif
223
224 //-------------------------make_exception_state--------------------------------
225 // Turn the current JVM state into an exception state, appending the ex_oop.
226 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
227 sync_jvms();
228 SafePointNode* ex_map = stop(); // do not manipulate this map any more
229 set_saved_ex_oop(ex_map, ex_oop);
230 return ex_map;
231 }
232
233
234 //--------------------------add_exception_state--------------------------------
235 // Add an exception to my list of exceptions.
236 void GraphKit::add_exception_state(SafePointNode* ex_map) {
237 if (ex_map == NULL || ex_map->control() == top()) {
238 return;
239 }
240 #ifdef ASSERT
241 verify_exception_state(ex_map);
242 if (has_exceptions()) {
243 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
244 }
245 #endif
246
247 // If there is already an exception of exactly this type, merge with it.
248 // In particular, null-checks and other low-level exceptions common up here.
249 Node* ex_oop = saved_ex_oop(ex_map);
250 const Type* ex_type = _gvn.type(ex_oop);
251 if (ex_oop == top()) {
252 // No action needed.
253 return;
254 }
255 assert(ex_type->isa_instptr(), "exception must be an instance");
256 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
257 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
258 // We check sp also because call bytecodes can generate exceptions
259 // both before and after arguments are popped!
260 if (ex_type2 == ex_type
261 && e2->_jvms->sp() == ex_map->_jvms->sp()) {
262 combine_exception_states(ex_map, e2);
263 return;
264 }
265 }
266
267 // No pre-existing exception of the same type. Chain it on the list.
268 push_exception_state(ex_map);
269 }
270
271 //-----------------------add_exception_states_from-----------------------------
272 void GraphKit::add_exception_states_from(JVMState* jvms) {
273 SafePointNode* ex_map = jvms->map()->next_exception();
274 if (ex_map != NULL) {
275 jvms->map()->set_next_exception(NULL);
276 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
277 next_map = ex_map->next_exception();
278 ex_map->set_next_exception(NULL);
279 add_exception_state(ex_map);
280 }
281 }
282 }
283
284 //-----------------------transfer_exceptions_into_jvms-------------------------
285 JVMState* GraphKit::transfer_exceptions_into_jvms() {
286 if (map() == NULL) {
287 // We need a JVMS to carry the exceptions, but the map has gone away.
288 // Create a scratch JVMS, cloned from any of the exception states...
289 if (has_exceptions()) {
290 _map = _exceptions;
291 _map = clone_map();
292 _map->set_next_exception(NULL);
293 clear_saved_ex_oop(_map);
294 debug_only(verify_map());
295 } else {
296 // ...or created from scratch
297 JVMState* jvms = new (C) JVMState(_method, NULL);
298 jvms->set_bci(_bci);
299 jvms->set_sp(_sp);
300 jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
301 set_jvms(jvms);
302 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top());
303 set_all_memory(top());
304 while (map()->req() < jvms->endoff()) map()->add_req(top());
305 }
306 // (This is a kludge, in case you didn't notice.)
307 set_control(top());
308 }
309 JVMState* jvms = sync_jvms();
310 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
311 jvms->map()->set_next_exception(_exceptions);
312 _exceptions = NULL; // done with this set of exceptions
313 return jvms;
314 }
315
316 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
317 assert(is_hidden_merge(dstphi), "must be a special merge node");
318 assert(is_hidden_merge(srcphi), "must be a special merge node");
319 uint limit = srcphi->req();
320 for (uint i = PhiNode::Input; i < limit; i++) {
321 dstphi->add_req(srcphi->in(i));
322 }
323 }
324 static inline void add_one_req(Node* dstphi, Node* src) {
325 assert(is_hidden_merge(dstphi), "must be a special merge node");
326 assert(!is_hidden_merge(src), "must not be a special merge node");
327 dstphi->add_req(src);
328 }
329
330 //-----------------------combine_exception_states------------------------------
331 // This helper function combines exception states by building phis on a
332 // specially marked state-merging region. These regions and phis are
333 // untransformed, and can build up gradually. The region is marked by
334 // having a control input of its exception map, rather than NULL. Such
335 // regions do not appear except in this function, and in use_exception_state.
336 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
337 if (failing()) return; // dying anyway...
338 JVMState* ex_jvms = ex_map->_jvms;
339 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
340 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
341 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
342 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
343 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
344 assert(ex_map->req() == phi_map->req(), "matching maps");
345 uint tos = ex_jvms->stkoff() + ex_jvms->sp();
346 Node* hidden_merge_mark = root();
347 Node* region = phi_map->control();
348 MergeMemNode* phi_mem = phi_map->merged_memory();
349 MergeMemNode* ex_mem = ex_map->merged_memory();
350 if (region->in(0) != hidden_merge_mark) {
351 // The control input is not (yet) a specially-marked region in phi_map.
352 // Make it so, and build some phis.
353 region = new RegionNode(2);
354 _gvn.set_type(region, Type::CONTROL);
355 region->set_req(0, hidden_merge_mark); // marks an internal ex-state
356 region->init_req(1, phi_map->control());
357 phi_map->set_control(region);
358 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
359 record_for_igvn(io_phi);
360 _gvn.set_type(io_phi, Type::ABIO);
361 phi_map->set_i_o(io_phi);
362 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
363 Node* m = mms.memory();
364 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
365 record_for_igvn(m_phi);
366 _gvn.set_type(m_phi, Type::MEMORY);
367 mms.set_memory(m_phi);
368 }
369 }
370
371 // Either or both of phi_map and ex_map might already be converted into phis.
372 Node* ex_control = ex_map->control();
373 // if there is special marking on ex_map also, we add multiple edges from src
374 bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
375 // how wide was the destination phi_map, originally?
376 uint orig_width = region->req();
377
378 if (add_multiple) {
379 add_n_reqs(region, ex_control);
380 add_n_reqs(phi_map->i_o(), ex_map->i_o());
381 } else {
382 // ex_map has no merges, so we just add single edges everywhere
383 add_one_req(region, ex_control);
384 add_one_req(phi_map->i_o(), ex_map->i_o());
385 }
386 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
387 if (mms.is_empty()) {
388 // get a copy of the base memory, and patch some inputs into it
389 const TypePtr* adr_type = mms.adr_type(C);
390 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
391 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
392 mms.set_memory(phi);
393 // Prepare to append interesting stuff onto the newly sliced phi:
394 while (phi->req() > orig_width) phi->del_req(phi->req()-1);
395 }
396 // Append stuff from ex_map:
397 if (add_multiple) {
398 add_n_reqs(mms.memory(), mms.memory2());
399 } else {
400 add_one_req(mms.memory(), mms.memory2());
401 }
402 }
403 uint limit = ex_map->req();
404 for (uint i = TypeFunc::Parms; i < limit; i++) {
405 // Skip everything in the JVMS after tos. (The ex_oop follows.)
406 if (i == tos) i = ex_jvms->monoff();
407 Node* src = ex_map->in(i);
408 Node* dst = phi_map->in(i);
409 if (src != dst) {
410 PhiNode* phi;
411 if (dst->in(0) != region) {
412 dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
413 record_for_igvn(phi);
414 _gvn.set_type(phi, phi->type());
415 phi_map->set_req(i, dst);
416 // Prepare to append interesting stuff onto the new phi:
417 while (dst->req() > orig_width) dst->del_req(dst->req()-1);
418 } else {
419 assert(dst->is_Phi(), "nobody else uses a hidden region");
420 phi = dst->as_Phi();
421 }
422 if (add_multiple && src->in(0) == ex_control) {
423 // Both are phis.
424 add_n_reqs(dst, src);
425 } else {
426 while (dst->req() < region->req()) add_one_req(dst, src);
427 }
428 const Type* srctype = _gvn.type(src);
429 if (phi->type() != srctype) {
430 const Type* dsttype = phi->type()->meet_speculative(srctype);
431 if (phi->type() != dsttype) {
432 phi->set_type(dsttype);
433 _gvn.set_type(phi, dsttype);
434 }
435 }
436 }
437 }
438 phi_map->merge_replaced_nodes_with(ex_map);
439 }
440
441 //--------------------------use_exception_state--------------------------------
442 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
443 if (failing()) { stop(); return top(); }
444 Node* region = phi_map->control();
445 Node* hidden_merge_mark = root();
446 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
447 Node* ex_oop = clear_saved_ex_oop(phi_map);
448 if (region->in(0) == hidden_merge_mark) {
449 // Special marking for internal ex-states. Process the phis now.
450 region->set_req(0, region); // now it's an ordinary region
451 set_jvms(phi_map->jvms()); // ...so now we can use it as a map
452 // Note: Setting the jvms also sets the bci and sp.
453 set_control(_gvn.transform(region));
454 uint tos = jvms()->stkoff() + sp();
455 for (uint i = 1; i < tos; i++) {
456 Node* x = phi_map->in(i);
457 if (x->in(0) == region) {
458 assert(x->is_Phi(), "expected a special phi");
459 phi_map->set_req(i, _gvn.transform(x));
460 }
461 }
462 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
463 Node* x = mms.memory();
464 if (x->in(0) == region) {
465 assert(x->is_Phi(), "nobody else uses a hidden region");
466 mms.set_memory(_gvn.transform(x));
467 }
468 }
469 if (ex_oop->in(0) == region) {
470 assert(ex_oop->is_Phi(), "expected a special phi");
471 ex_oop = _gvn.transform(ex_oop);
472 }
473 } else {
474 set_jvms(phi_map->jvms());
475 }
476
477 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
478 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
479 return ex_oop;
480 }
481
482 //---------------------------------java_bc-------------------------------------
483 Bytecodes::Code GraphKit::java_bc() const {
484 ciMethod* method = this->method();
485 int bci = this->bci();
486 if (method != NULL && bci != InvocationEntryBci)
487 return method->java_code_at_bci(bci);
488 else
489 return Bytecodes::_illegal;
490 }
491
492 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
493 bool must_throw) {
494 // if the exception capability is set, then we will generate code
495 // to check the JavaThread.should_post_on_exceptions flag to see
496 // if we actually need to report exception events (for this
497 // thread). If we don't need to report exception events, we will
498 // take the normal fast path provided by add_exception_events. If
499 // exception event reporting is enabled for this thread, we will
500 // take the uncommon_trap in the BuildCutout below.
501
502 // first must access the should_post_on_exceptions_flag in this thread's JavaThread
503 Node* jthread = _gvn.transform(new ThreadLocalNode());
504 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
505 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
506
507 // Test the should_post_on_exceptions_flag vs. 0
508 Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
509 Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
510
511 // Branch to slow_path if should_post_on_exceptions_flag was true
512 { BuildCutout unless(this, tst, PROB_MAX);
513 // Do not try anything fancy if we're notifying the VM on every throw.
514 // Cf. case Bytecodes::_athrow in parse2.cpp.
515 uncommon_trap(reason, Deoptimization::Action_none,
516 (ciKlass*)NULL, (char*)NULL, must_throw);
517 }
518
519 }
520
521 //------------------------------builtin_throw----------------------------------
522 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
523 bool must_throw = true;
524
525 if (env()->jvmti_can_post_on_exceptions()) {
526 // check if we must post exception events, take uncommon trap if so
527 uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
528 // here if should_post_on_exceptions is false
529 // continue on with the normal codegen
530 }
531
532 // If this particular condition has not yet happened at this
533 // bytecode, then use the uncommon trap mechanism, and allow for
534 // a future recompilation if several traps occur here.
535 // If the throw is hot, try to use a more complicated inline mechanism
536 // which keeps execution inside the compiled code.
537 bool treat_throw_as_hot = false;
538 ciMethodData* md = method()->method_data();
539
540 if (ProfileTraps) {
541 if (too_many_traps(reason)) {
542 treat_throw_as_hot = true;
543 }
544 // (If there is no MDO at all, assume it is early in
545 // execution, and that any deopts are part of the
546 // startup transient, and don't need to be remembered.)
547
548 // Also, if there is a local exception handler, treat all throws
549 // as hot if there has been at least one in this method.
550 if (C->trap_count(reason) != 0
551 && method()->method_data()->trap_count(reason) != 0
552 && has_ex_handler()) {
553 treat_throw_as_hot = true;
554 }
555 }
556
557 // If this throw happens frequently, an uncommon trap might cause
558 // a performance pothole. If there is a local exception handler,
559 // and if this particular bytecode appears to be deoptimizing often,
560 // let us handle the throw inline, with a preconstructed instance.
561 // Note: If the deopt count has blown up, the uncommon trap
562 // runtime is going to flush this nmethod, not matter what.
563 if (treat_throw_as_hot
564 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
565 // If the throw is local, we use a pre-existing instance and
566 // punt on the backtrace. This would lead to a missing backtrace
567 // (a repeat of 4292742) if the backtrace object is ever asked
568 // for its backtrace.
569 // Fixing this remaining case of 4292742 requires some flavor of
570 // escape analysis. Leave that for the future.
571 ciInstance* ex_obj = NULL;
572 switch (reason) {
573 case Deoptimization::Reason_null_check:
574 ex_obj = env()->NullPointerException_instance();
575 break;
576 case Deoptimization::Reason_div0_check:
577 ex_obj = env()->ArithmeticException_instance();
578 break;
579 case Deoptimization::Reason_range_check:
580 ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
581 break;
582 case Deoptimization::Reason_class_check:
583 if (java_bc() == Bytecodes::_aastore || java_bc() == Bytecodes::_vastore) {
584 ex_obj = env()->ArrayStoreException_instance();
585 } else {
586 ex_obj = env()->ClassCastException_instance();
587 }
588 break;
589 }
590 if (failing()) { stop(); return; } // exception allocation might fail
591 if (ex_obj != NULL) {
592 // Cheat with a preallocated exception object.
593 if (C->log() != NULL)
594 C->log()->elem("hot_throw preallocated='1' reason='%s'",
595 Deoptimization::trap_reason_name(reason));
596 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj);
597 Node* ex_node = _gvn.transform(ConNode::make(ex_con));
598
599 // Clear the detail message of the preallocated exception object.
600 // Weblogic sometimes mutates the detail message of exceptions
601 // using reflection.
602 int offset = java_lang_Throwable::get_detailMessage_offset();
603 const TypePtr* adr_typ = ex_con->add_offset(offset);
604
605 Node *adr = basic_plus_adr(ex_node, ex_node, offset);
606 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
607 // Conservatively release stores of object references.
608 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
609
610 add_exception_state(make_exception_state(ex_node));
611 return;
612 }
613 }
614
615 // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
616 // It won't be much cheaper than bailing to the interp., since we'll
617 // have to pass up all the debug-info, and the runtime will have to
618 // create the stack trace.
619
620 // Usual case: Bail to interpreter.
621 // Reserve the right to recompile if we haven't seen anything yet.
622
623 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
624 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
625 if (treat_throw_as_hot
626 && (method()->method_data()->trap_recompiled_at(bci(), m)
627 || C->too_many_traps(reason))) {
628 // We cannot afford to take more traps here. Suffer in the interpreter.
629 if (C->log() != NULL)
630 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
631 Deoptimization::trap_reason_name(reason),
632 C->trap_count(reason));
633 action = Deoptimization::Action_none;
634 }
635
636 // "must_throw" prunes the JVM state to include only the stack, if there
637 // are no local exception handlers. This should cut down on register
638 // allocation time and code size, by drastically reducing the number
639 // of in-edges on the call to the uncommon trap.
640
641 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
642 }
643
644
645 //----------------------------PreserveJVMState---------------------------------
646 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
647 debug_only(kit->verify_map());
648 _kit = kit;
649 _map = kit->map(); // preserve the map
650 _sp = kit->sp();
651 kit->set_map(clone_map ? kit->clone_map() : NULL);
652 #ifdef ASSERT
653 _bci = kit->bci();
654 Parse* parser = kit->is_Parse();
655 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
656 _block = block;
657 #endif
658 }
659 PreserveJVMState::~PreserveJVMState() {
660 GraphKit* kit = _kit;
661 #ifdef ASSERT
662 assert(kit->bci() == _bci, "bci must not shift");
663 Parse* parser = kit->is_Parse();
664 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
665 assert(block == _block, "block must not shift");
666 #endif
667 kit->set_map(_map);
668 kit->set_sp(_sp);
669 }
670
671
672 //-----------------------------BuildCutout-------------------------------------
673 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
674 : PreserveJVMState(kit)
675 {
676 assert(p->is_Con() || p->is_Bool(), "test must be a bool");
677 SafePointNode* outer_map = _map; // preserved map is caller's
678 SafePointNode* inner_map = kit->map();
679 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
680 outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
681 inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
682 }
683 BuildCutout::~BuildCutout() {
684 GraphKit* kit = _kit;
685 assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
686 }
687
688 //---------------------------PreserveReexecuteState----------------------------
689 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
690 assert(!kit->stopped(), "must call stopped() before");
691 _kit = kit;
692 _sp = kit->sp();
693 _reexecute = kit->jvms()->_reexecute;
694 }
695 PreserveReexecuteState::~PreserveReexecuteState() {
696 if (_kit->stopped()) return;
697 _kit->jvms()->_reexecute = _reexecute;
698 _kit->set_sp(_sp);
699 }
700
701 //------------------------------clone_map--------------------------------------
702 // Implementation of PreserveJVMState
703 //
704 // Only clone_map(...) here. If this function is only used in the
705 // PreserveJVMState class we may want to get rid of this extra
706 // function eventually and do it all there.
707
708 SafePointNode* GraphKit::clone_map() {
709 if (map() == NULL) return NULL;
710
711 // Clone the memory edge first
712 Node* mem = MergeMemNode::make(map()->memory());
713 gvn().set_type_bottom(mem);
714
715 SafePointNode *clonemap = (SafePointNode*)map()->clone();
716 JVMState* jvms = this->jvms();
717 JVMState* clonejvms = jvms->clone_shallow(C);
718 clonemap->set_memory(mem);
719 clonemap->set_jvms(clonejvms);
720 clonejvms->set_map(clonemap);
721 record_for_igvn(clonemap);
722 gvn().set_type_bottom(clonemap);
723 return clonemap;
724 }
725
726
727 //-----------------------------set_map_clone-----------------------------------
728 void GraphKit::set_map_clone(SafePointNode* m) {
729 _map = m;
730 _map = clone_map();
731 _map->set_next_exception(NULL);
732 debug_only(verify_map());
733 }
734
735
736 //----------------------------kill_dead_locals---------------------------------
737 // Detect any locals which are known to be dead, and force them to top.
738 void GraphKit::kill_dead_locals() {
739 // Consult the liveness information for the locals. If any
740 // of them are unused, then they can be replaced by top(). This
741 // should help register allocation time and cut down on the size
742 // of the deoptimization information.
743
744 // This call is made from many of the bytecode handling
745 // subroutines called from the Big Switch in do_one_bytecode.
746 // Every bytecode which might include a slow path is responsible
747 // for killing its dead locals. The more consistent we
748 // are about killing deads, the fewer useless phis will be
749 // constructed for them at various merge points.
750
751 // bci can be -1 (InvocationEntryBci). We return the entry
752 // liveness for the method.
753
754 if (method() == NULL || method()->code_size() == 0) {
755 // We are building a graph for a call to a native method.
756 // All locals are live.
757 return;
758 }
759
760 ResourceMark rm;
761
762 // Consult the liveness information for the locals. If any
763 // of them are unused, then they can be replaced by top(). This
764 // should help register allocation time and cut down on the size
765 // of the deoptimization information.
766 MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
767
768 int len = (int)live_locals.size();
769 assert(len <= jvms()->loc_size(), "too many live locals");
770 for (int local = 0; local < len; local++) {
771 if (!live_locals.at(local)) {
772 set_local(local, top());
773 }
774 }
775 }
776
777 #ifdef ASSERT
778 //-------------------------dead_locals_are_killed------------------------------
779 // Return true if all dead locals are set to top in the map.
780 // Used to assert "clean" debug info at various points.
781 bool GraphKit::dead_locals_are_killed() {
782 if (method() == NULL || method()->code_size() == 0) {
783 // No locals need to be dead, so all is as it should be.
784 return true;
785 }
786
787 // Make sure somebody called kill_dead_locals upstream.
788 ResourceMark rm;
789 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
790 if (jvms->loc_size() == 0) continue; // no locals to consult
791 SafePointNode* map = jvms->map();
792 ciMethod* method = jvms->method();
793 int bci = jvms->bci();
794 if (jvms == this->jvms()) {
795 bci = this->bci(); // it might not yet be synched
796 }
797 MethodLivenessResult live_locals = method->liveness_at_bci(bci);
798 int len = (int)live_locals.size();
799 if (!live_locals.is_valid() || len == 0)
800 // This method is trivial, or is poisoned by a breakpoint.
801 return true;
802 assert(len == jvms->loc_size(), "live map consistent with locals map");
803 for (int local = 0; local < len; local++) {
804 if (!live_locals.at(local) && map->local(jvms, local) != top()) {
805 if (PrintMiscellaneous && (Verbose || WizardMode)) {
806 tty->print_cr("Zombie local %d: ", local);
807 jvms->dump();
808 }
809 return false;
810 }
811 }
812 }
813 return true;
814 }
815
816 #endif //ASSERT
817
818 // Helper function for adding JVMState and debug information to node
819 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
820 // Add the safepoint edges to the call (or other safepoint).
821
822 // Make sure dead locals are set to top. This
823 // should help register allocation time and cut down on the size
824 // of the deoptimization information.
825 assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
826
827 // Walk the inline list to fill in the correct set of JVMState's
828 // Also fill in the associated edges for each JVMState.
829
830 // If the bytecode needs to be reexecuted we need to put
831 // the arguments back on the stack.
832 const bool should_reexecute = jvms()->should_reexecute();
833 JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
834
835 // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
836 // undefined if the bci is different. This is normal for Parse but it
837 // should not happen for LibraryCallKit because only one bci is processed.
838 assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
839 "in LibraryCallKit the reexecute bit should not change");
840
841 // If we are guaranteed to throw, we can prune everything but the
842 // input to the current bytecode.
843 bool can_prune_locals = false;
844 uint stack_slots_not_pruned = 0;
845 int inputs = 0, depth = 0;
846 if (must_throw) {
847 assert(method() == youngest_jvms->method(), "sanity");
848 if (compute_stack_effects(inputs, depth)) {
849 can_prune_locals = true;
850 stack_slots_not_pruned = inputs;
851 }
852 }
853
854 if (env()->should_retain_local_variables()) {
855 // At any safepoint, this method can get breakpointed, which would
856 // then require an immediate deoptimization.
857 can_prune_locals = false; // do not prune locals
858 stack_slots_not_pruned = 0;
859 }
860
861 C->add_safepoint_edges(call, youngest_jvms, can_prune_locals, stack_slots_not_pruned);
862 }
863
864 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
865 Bytecodes::Code code = java_bc();
866 if (code == Bytecodes::_wide) {
867 code = method()->java_code_at_bci(bci() + 1);
868 }
869
870 BasicType rtype = T_ILLEGAL;
871 int rsize = 0;
872
873 if (code != Bytecodes::_illegal) {
874 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
875 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
876 if (rtype < T_CONFLICT)
877 rsize = type2size[rtype];
878 }
879
880 switch (code) {
881 case Bytecodes::_illegal:
882 return false;
883
884 case Bytecodes::_ldc:
885 case Bytecodes::_ldc_w:
886 case Bytecodes::_ldc2_w:
887 inputs = 0;
888 break;
889
890 case Bytecodes::_dup: inputs = 1; break;
891 case Bytecodes::_dup_x1: inputs = 2; break;
892 case Bytecodes::_dup_x2: inputs = 3; break;
893 case Bytecodes::_dup2: inputs = 2; break;
894 case Bytecodes::_dup2_x1: inputs = 3; break;
895 case Bytecodes::_dup2_x2: inputs = 4; break;
896 case Bytecodes::_swap: inputs = 2; break;
897 case Bytecodes::_arraylength: inputs = 1; break;
898
899 case Bytecodes::_getstatic:
900 case Bytecodes::_putstatic:
901 case Bytecodes::_getfield:
902 case Bytecodes::_putfield:
903 {
904 bool ignored_will_link;
905 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
906 int size = field->type()->size();
907 bool is_get = (depth >= 0), is_static = (depth & 1);
908 inputs = (is_static ? 0 : 1);
909 if (is_get) {
910 depth = size - inputs;
911 } else {
912 inputs += size; // putxxx pops the value from the stack
913 depth = - inputs;
914 }
915 }
916 break;
917
918 case Bytecodes::_invokevirtual:
919 case Bytecodes::_invokespecial:
920 case Bytecodes::_invokestatic:
921 case Bytecodes::_invokedynamic:
922 case Bytecodes::_invokeinterface:
923 {
924 bool ignored_will_link;
925 ciSignature* declared_signature = NULL;
926 ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
927 assert(declared_signature != NULL, "cannot be null");
928 inputs = declared_signature->arg_size_for_bc(code);
929 int size = declared_signature->return_type()->size();
930 depth = size - inputs;
931 }
932 break;
933
934 case Bytecodes::_multianewarray:
935 {
936 ciBytecodeStream iter(method());
937 iter.reset_to_bci(bci());
938 iter.next();
939 inputs = iter.get_dimensions();
940 assert(rsize == 1, "");
941 depth = rsize - inputs;
942 }
943 break;
944
945 case Bytecodes::_vwithfield: {
946 bool ignored_will_link;
947 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
948 int size = field->type()->size();
949 inputs = size+1;
950 depth = rsize - inputs;
951 break;
952 }
953
954 case Bytecodes::_ireturn:
955 case Bytecodes::_lreturn:
956 case Bytecodes::_freturn:
957 case Bytecodes::_dreturn:
958 case Bytecodes::_areturn:
959 case Bytecodes::_vreturn:
960 assert(rsize == -depth, "");
961 inputs = rsize;
962 break;
963
964 case Bytecodes::_jsr:
965 case Bytecodes::_jsr_w:
966 inputs = 0;
967 depth = 1; // S.B. depth=1, not zero
968 break;
969
970 default:
971 // bytecode produces a typed result
972 inputs = rsize - depth;
973 assert(inputs >= 0, "");
974 break;
975 }
976
977 #ifdef ASSERT
978 // spot check
979 int outputs = depth + inputs;
980 assert(outputs >= 0, "sanity");
981 switch (code) {
982 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
983 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break;
984 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break;
985 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break;
986 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break;
987 }
988 #endif //ASSERT
989
990 return true;
991 }
992
993
994
995 //------------------------------basic_plus_adr---------------------------------
996 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
997 // short-circuit a common case
998 if (offset == intcon(0)) return ptr;
999 return _gvn.transform( new AddPNode(base, ptr, offset) );
1000 }
1001
1002 Node* GraphKit::ConvI2L(Node* offset) {
1003 // short-circuit a common case
1004 jint offset_con = find_int_con(offset, Type::OffsetBot);
1005 if (offset_con != Type::OffsetBot) {
1006 return longcon((jlong) offset_con);
1007 }
1008 return _gvn.transform( new ConvI2LNode(offset));
1009 }
1010
1011 Node* GraphKit::ConvI2UL(Node* offset) {
1012 juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1013 if (offset_con != (juint) Type::OffsetBot) {
1014 return longcon((julong) offset_con);
1015 }
1016 Node* conv = _gvn.transform( new ConvI2LNode(offset));
1017 Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1018 return _gvn.transform( new AndLNode(conv, mask) );
1019 }
1020
1021 Node* GraphKit::ConvL2I(Node* offset) {
1022 // short-circuit a common case
1023 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1024 if (offset_con != (jlong)Type::OffsetBot) {
1025 return intcon((int) offset_con);
1026 }
1027 return _gvn.transform( new ConvL2INode(offset));
1028 }
1029
1030 //-------------------------load_object_klass-----------------------------------
1031 Node* GraphKit::load_object_klass(Node* obj) {
1032 // Special-case a fresh allocation to avoid building nodes:
1033 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1034 if (akls != NULL) return akls;
1035 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1036 return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1037 }
1038
1039 //-------------------------load_array_length-----------------------------------
1040 Node* GraphKit::load_array_length(Node* array) {
1041 // Special-case a fresh allocation to avoid building nodes:
1042 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1043 Node *alen;
1044 if (alloc == NULL) {
1045 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1046 alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1047 } else {
1048 alen = alloc->Ideal_length();
1049 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1050 if (ccast != alen) {
1051 alen = _gvn.transform(ccast);
1052 }
1053 }
1054 return alen;
1055 }
1056
1057 //------------------------------do_null_check----------------------------------
1058 // Helper function to do a NULL pointer check. Returned value is
1059 // the incoming address with NULL casted away. You are allowed to use the
1060 // not-null value only if you are control dependent on the test.
1061 #ifndef PRODUCT
1062 extern int explicit_null_checks_inserted,
1063 explicit_null_checks_elided;
1064 #endif
1065 Node* GraphKit::null_check_common(Node* value, BasicType type,
1066 // optional arguments for variations:
1067 bool assert_null,
1068 Node* *null_control,
1069 bool speculative) {
1070 assert(!assert_null || null_control == NULL, "not both at once");
1071 if (stopped()) return top();
1072 NOT_PRODUCT(explicit_null_checks_inserted++);
1073
1074 // Construct NULL check
1075 Node *chk = NULL;
1076 switch(type) {
1077 case T_LONG : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1078 case T_INT : chk = new CmpINode(value, _gvn.intcon(0)); break;
1079 case T_VALUETYPE : // fall through
1080 case T_ARRAY : // fall through
1081 type = T_OBJECT; // simplify further tests
1082 case T_OBJECT : {
1083 const Type *t = _gvn.type( value );
1084
1085 const TypeOopPtr* tp = t->isa_oopptr();
1086 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1087 // Only for do_null_check, not any of its siblings:
1088 && !assert_null && null_control == NULL) {
1089 // Usually, any field access or invocation on an unloaded oop type
1090 // will simply fail to link, since the statically linked class is
1091 // likely also to be unloaded. However, in -Xcomp mode, sometimes
1092 // the static class is loaded but the sharper oop type is not.
1093 // Rather than checking for this obscure case in lots of places,
1094 // we simply observe that a null check on an unloaded class
1095 // will always be followed by a nonsense operation, so we
1096 // can just issue the uncommon trap here.
1097 // Our access to the unloaded class will only be correct
1098 // after it has been loaded and initialized, which requires
1099 // a trip through the interpreter.
1100 #ifndef PRODUCT
1101 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1102 #endif
1103 uncommon_trap(Deoptimization::Reason_unloaded,
1104 Deoptimization::Action_reinterpret,
1105 tp->klass(), "!loaded");
1106 return top();
1107 }
1108
1109 if (assert_null) {
1110 // See if the type is contained in NULL_PTR.
1111 // If so, then the value is already null.
1112 if (t->higher_equal(TypePtr::NULL_PTR)) {
1113 NOT_PRODUCT(explicit_null_checks_elided++);
1114 return value; // Elided null assert quickly!
1115 }
1116 } else {
1117 // See if mixing in the NULL pointer changes type.
1118 // If so, then the NULL pointer was not allowed in the original
1119 // type. In other words, "value" was not-null.
1120 if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1121 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1122 NOT_PRODUCT(explicit_null_checks_elided++);
1123 return value; // Elided null check quickly!
1124 }
1125 }
1126 chk = new CmpPNode( value, null() );
1127 break;
1128 }
1129
1130 default:
1131 fatal("unexpected type: %s", type2name(type));
1132 }
1133 assert(chk != NULL, "sanity check");
1134 chk = _gvn.transform(chk);
1135
1136 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1137 BoolNode *btst = new BoolNode( chk, btest);
1138 Node *tst = _gvn.transform( btst );
1139
1140 //-----------
1141 // if peephole optimizations occurred, a prior test existed.
1142 // If a prior test existed, maybe it dominates as we can avoid this test.
1143 if (tst != btst && type == T_OBJECT) {
1144 // At this point we want to scan up the CFG to see if we can
1145 // find an identical test (and so avoid this test altogether).
1146 Node *cfg = control();
1147 int depth = 0;
1148 while( depth < 16 ) { // Limit search depth for speed
1149 if( cfg->Opcode() == Op_IfTrue &&
1150 cfg->in(0)->in(1) == tst ) {
1151 // Found prior test. Use "cast_not_null" to construct an identical
1152 // CastPP (and hence hash to) as already exists for the prior test.
1153 // Return that casted value.
1154 if (assert_null) {
1155 replace_in_map(value, null());
1156 return null(); // do not issue the redundant test
1157 }
1158 Node *oldcontrol = control();
1159 set_control(cfg);
1160 Node *res = cast_not_null(value);
1161 set_control(oldcontrol);
1162 NOT_PRODUCT(explicit_null_checks_elided++);
1163 return res;
1164 }
1165 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1166 if (cfg == NULL) break; // Quit at region nodes
1167 depth++;
1168 }
1169 }
1170
1171 //-----------
1172 // Branch to failure if null
1173 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen
1174 Deoptimization::DeoptReason reason;
1175 if (assert_null) {
1176 reason = Deoptimization::Reason_null_assert;
1177 } else if (type == T_OBJECT) {
1178 reason = Deoptimization::reason_null_check(speculative);
1179 } else {
1180 reason = Deoptimization::Reason_div0_check;
1181 }
1182 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1183 // ciMethodData::has_trap_at will return a conservative -1 if any
1184 // must-be-null assertion has failed. This could cause performance
1185 // problems for a method after its first do_null_assert failure.
1186 // Consider using 'Reason_class_check' instead?
1187
1188 // To cause an implicit null check, we set the not-null probability
1189 // to the maximum (PROB_MAX). For an explicit check the probability
1190 // is set to a smaller value.
1191 if (null_control != NULL || too_many_traps(reason)) {
1192 // probability is less likely
1193 ok_prob = PROB_LIKELY_MAG(3);
1194 } else if (!assert_null &&
1195 (ImplicitNullCheckThreshold > 0) &&
1196 method() != NULL &&
1197 (method()->method_data()->trap_count(reason)
1198 >= (uint)ImplicitNullCheckThreshold)) {
1199 ok_prob = PROB_LIKELY_MAG(3);
1200 }
1201
1202 if (null_control != NULL) {
1203 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1204 Node* null_true = _gvn.transform( new IfFalseNode(iff));
1205 set_control( _gvn.transform( new IfTrueNode(iff)));
1206 #ifndef PRODUCT
1207 if (null_true == top()) {
1208 explicit_null_checks_elided++;
1209 }
1210 #endif
1211 (*null_control) = null_true;
1212 } else {
1213 BuildCutout unless(this, tst, ok_prob);
1214 // Check for optimizer eliding test at parse time
1215 if (stopped()) {
1216 // Failure not possible; do not bother making uncommon trap.
1217 NOT_PRODUCT(explicit_null_checks_elided++);
1218 } else if (assert_null) {
1219 uncommon_trap(reason,
1220 Deoptimization::Action_make_not_entrant,
1221 NULL, "assert_null");
1222 } else {
1223 replace_in_map(value, zerocon(type));
1224 builtin_throw(reason);
1225 }
1226 }
1227
1228 // Must throw exception, fall-thru not possible?
1229 if (stopped()) {
1230 return top(); // No result
1231 }
1232
1233 if (assert_null) {
1234 // Cast obj to null on this path.
1235 replace_in_map(value, zerocon(type));
1236 return zerocon(type);
1237 }
1238
1239 // Cast obj to not-null on this path, if there is no null_control.
1240 // (If there is a null_control, a non-null value may come back to haunt us.)
1241 if (type == T_OBJECT) {
1242 Node* cast = cast_not_null(value, false);
1243 if (null_control == NULL || (*null_control) == top())
1244 replace_in_map(value, cast);
1245 value = cast;
1246 }
1247
1248 return value;
1249 }
1250
1251
1252 //------------------------------cast_not_null----------------------------------
1253 // Cast obj to not-null on this path
1254 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1255 const Type *t = _gvn.type(obj);
1256 const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1257 // Object is already not-null?
1258 if( t == t_not_null ) return obj;
1259
1260 Node *cast = new CastPPNode(obj,t_not_null);
1261 cast->init_req(0, control());
1262 cast = _gvn.transform( cast );
1263
1264 // Scan for instances of 'obj' in the current JVM mapping.
1265 // These instances are known to be not-null after the test.
1266 if (do_replace_in_map)
1267 replace_in_map(obj, cast);
1268
1269 return cast; // Return casted value
1270 }
1271
1272
1273 //--------------------------replace_in_map-------------------------------------
1274 void GraphKit::replace_in_map(Node* old, Node* neww) {
1275 if (old == neww) {
1276 return;
1277 }
1278
1279 map()->replace_edge(old, neww);
1280
1281 // Note: This operation potentially replaces any edge
1282 // on the map. This includes locals, stack, and monitors
1283 // of the current (innermost) JVM state.
1284
1285 // don't let inconsistent types from profiling escape this
1286 // method
1287
1288 const Type* told = _gvn.type(old);
1289 const Type* tnew = _gvn.type(neww);
1290
1291 if (!tnew->higher_equal(told)) {
1292 return;
1293 }
1294
1295 map()->record_replaced_node(old, neww);
1296 }
1297
1298
1299 //=============================================================================
1300 //--------------------------------memory---------------------------------------
1301 Node* GraphKit::memory(uint alias_idx) {
1302 MergeMemNode* mem = merged_memory();
1303 Node* p = mem->memory_at(alias_idx);
1304 _gvn.set_type(p, Type::MEMORY); // must be mapped
1305 return p;
1306 }
1307
1308 //-----------------------------reset_memory------------------------------------
1309 Node* GraphKit::reset_memory() {
1310 Node* mem = map()->memory();
1311 // do not use this node for any more parsing!
1312 debug_only( map()->set_memory((Node*)NULL) );
1313 return _gvn.transform( mem );
1314 }
1315
1316 //------------------------------set_all_memory---------------------------------
1317 void GraphKit::set_all_memory(Node* newmem) {
1318 Node* mergemem = MergeMemNode::make(newmem);
1319 gvn().set_type_bottom(mergemem);
1320 map()->set_memory(mergemem);
1321 }
1322
1323 //------------------------------set_all_memory_call----------------------------
1324 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1325 Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1326 set_all_memory(newmem);
1327 }
1328
1329 //=============================================================================
1330 //
1331 // parser factory methods for MemNodes
1332 //
1333 // These are layered on top of the factory methods in LoadNode and StoreNode,
1334 // and integrate with the parser's memory state and _gvn engine.
1335 //
1336
1337 // factory methods in "int adr_idx"
1338 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1339 int adr_idx,
1340 MemNode::MemOrd mo,
1341 LoadNode::ControlDependency control_dependency,
1342 bool require_atomic_access,
1343 bool unaligned,
1344 bool mismatched) {
1345 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1346 const TypePtr* adr_type = NULL; // debug-mode-only argument
1347 debug_only(adr_type = C->get_adr_type(adr_idx));
1348 Node* mem = memory(adr_idx);
1349 Node* ld;
1350 if (require_atomic_access && bt == T_LONG) {
1351 ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1352 } else if (require_atomic_access && bt == T_DOUBLE) {
1353 ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1354 } else {
1355 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1356 }
1357 ld = _gvn.transform(ld);
1358
1359 if (bt == T_VALUETYPE) {
1360 // Load non-flattened value type from memory. Add a null check and let the
1361 // interpreter take care of initializing the field to the default value type.
1362 Node* null_ctl = top();
1363 ld = null_check_common(ld, bt, false, &null_ctl, false);
1364 if (null_ctl != top()) {
1365 assert(!adr_type->isa_aryptr(), "value type array must be initialized");
1366 PreserveJVMState pjvms(this);
1367 set_control(null_ctl);
1368 uncommon_trap(Deoptimization::reason_null_check(false), Deoptimization::Action_maybe_recompile,
1369 t->is_valuetypeptr()->value_type()->value_klass(), "uninitialized non-flattened value type");
1370 }
1371 ld = ValueTypeNode::make(gvn(), map()->memory(), ld);
1372 } else if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1373 // Improve graph before escape analysis and boxing elimination.
1374 record_for_igvn(ld);
1375 }
1376 return ld;
1377 }
1378
1379 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1380 int adr_idx,
1381 MemNode::MemOrd mo,
1382 bool require_atomic_access,
1383 bool unaligned,
1384 bool mismatched) {
1385 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1386 const TypePtr* adr_type = NULL;
1387 debug_only(adr_type = C->get_adr_type(adr_idx));
1388 Node *mem = memory(adr_idx);
1389 Node* st;
1390 if (require_atomic_access && bt == T_LONG) {
1391 st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1392 } else if (require_atomic_access && bt == T_DOUBLE) {
1393 st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1394 } else {
1395 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1396 }
1397 if (unaligned) {
1398 st->as_Store()->set_unaligned_access();
1399 }
1400 if (mismatched) {
1401 st->as_Store()->set_mismatched_access();
1402 }
1403 st = _gvn.transform(st);
1404 set_memory(st, adr_idx);
1405 // Back-to-back stores can only remove intermediate store with DU info
1406 // so push on worklist for optimizer.
1407 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1408 record_for_igvn(st);
1409
1410 return st;
1411 }
1412
1413
1414 void GraphKit::pre_barrier(bool do_load,
1415 Node* ctl,
1416 Node* obj,
1417 Node* adr,
1418 uint adr_idx,
1419 Node* val,
1420 const TypeOopPtr* val_type,
1421 Node* pre_val,
1422 BasicType bt) {
1423
1424 BarrierSet* bs = Universe::heap()->barrier_set();
1425 set_control(ctl);
1426 switch (bs->kind()) {
1427 case BarrierSet::G1SATBCTLogging:
1428 g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1429 break;
1430
1431 case BarrierSet::CardTableForRS:
1432 case BarrierSet::CardTableExtension:
1433 case BarrierSet::ModRef:
1434 break;
1435
1436 default :
1437 ShouldNotReachHere();
1438
1439 }
1440 }
1441
1442 bool GraphKit::can_move_pre_barrier() const {
1443 BarrierSet* bs = Universe::heap()->barrier_set();
1444 switch (bs->kind()) {
1445 case BarrierSet::G1SATBCTLogging:
1446 return true; // Can move it if no safepoint
1447
1448 case BarrierSet::CardTableForRS:
1449 case BarrierSet::CardTableExtension:
1450 case BarrierSet::ModRef:
1451 return true; // There is no pre-barrier
1452
1453 default :
1454 ShouldNotReachHere();
1455 }
1456 return false;
1457 }
1458
1459 void GraphKit::post_barrier(Node* ctl,
1460 Node* store,
1461 Node* obj,
1462 Node* adr,
1463 uint adr_idx,
1464 Node* val,
1465 BasicType bt,
1466 bool use_precise) {
1467 BarrierSet* bs = Universe::heap()->barrier_set();
1468 set_control(ctl);
1469 switch (bs->kind()) {
1470 case BarrierSet::G1SATBCTLogging:
1471 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1472 break;
1473
1474 case BarrierSet::CardTableForRS:
1475 case BarrierSet::CardTableExtension:
1476 write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1477 break;
1478
1479 case BarrierSet::ModRef:
1480 break;
1481
1482 default :
1483 ShouldNotReachHere();
1484
1485 }
1486 }
1487
1488 Node* GraphKit::store_oop(Node* ctl,
1489 Node* obj,
1490 Node* adr,
1491 const TypePtr* adr_type,
1492 Node* val,
1493 const TypeOopPtr* val_type,
1494 BasicType bt,
1495 bool use_precise,
1496 MemNode::MemOrd mo,
1497 bool mismatched) {
1498 // Transformation of a value which could be NULL pointer (CastPP #NULL)
1499 // could be delayed during Parse (for example, in adjust_map_after_if()).
1500 // Execute transformation here to avoid barrier generation in such case.
1501 if (_gvn.type(val) == TypePtr::NULL_PTR)
1502 val = _gvn.makecon(TypePtr::NULL_PTR);
1503
1504 set_control(ctl);
1505 if (stopped()) return top(); // Dead path ?
1506
1507 assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1508 assert(val != NULL, "not dead path");
1509 uint adr_idx = C->get_alias_index(adr_type);
1510 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1511
1512 if (bt == T_VALUETYPE) {
1513 // Allocate value type and store oop
1514 val = val->as_ValueType()->allocate(this);
1515 }
1516
1517 pre_barrier(true /* do_load */,
1518 control(), obj, adr, adr_idx, val, val_type,
1519 NULL /* pre_val */,
1520 bt);
1521
1522 Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1523 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1524 return store;
1525 }
1526
1527 // Could be an array or object we don't know at compile time (unsafe ref.)
1528 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1529 Node* obj, // containing obj
1530 Node* adr, // actual adress to store val at
1531 const TypePtr* adr_type,
1532 Node* val,
1533 BasicType bt,
1534 MemNode::MemOrd mo,
1535 bool mismatched) {
1536 Compile::AliasType* at = C->alias_type(adr_type);
1537 const TypeOopPtr* val_type = NULL;
1538 if (adr_type->isa_instptr()) {
1539 if (at->field() != NULL) {
1540 // known field. This code is a copy of the do_put_xxx logic.
1541 ciField* field = at->field();
1542 if (!field->type()->is_loaded()) {
1543 val_type = TypeInstPtr::BOTTOM;
1544 } else {
1545 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1546 }
1547 }
1548 } else if (adr_type->isa_aryptr()) {
1549 val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1550 }
1551 if (val_type == NULL) {
1552 val_type = TypeInstPtr::BOTTOM;
1553 }
1554 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1555 }
1556
1557
1558 //-------------------------array_element_address-------------------------
1559 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1560 const TypeInt* sizetype, Node* ctrl) {
1561 uint shift = exact_log2(type2aelembytes(elembt));
1562 ciKlass* arytype_klass = _gvn.type(ary)->is_aryptr()->klass();
1563 if (arytype_klass->is_value_array_klass()) {
1564 ciValueArrayKlass* vak = arytype_klass->as_value_array_klass();
1565 shift = vak->log2_element_size();
1566 }
1567 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1568
1569 // short-circuit a common case (saves lots of confusing waste motion)
1570 jint idx_con = find_int_con(idx, -1);
1571 if (idx_con >= 0) {
1572 intptr_t offset = header + ((intptr_t)idx_con << shift);
1573 return basic_plus_adr(ary, offset);
1574 }
1575
1576 // must be correct type for alignment purposes
1577 Node* base = basic_plus_adr(ary, header);
1578 idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1579 Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1580 return basic_plus_adr(ary, base, scale);
1581 }
1582
1583 //-------------------------load_array_element-------------------------
1584 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1585 const Type* elemtype = arytype->elem();
1586 BasicType elembt = elemtype->array_element_basic_type();
1587 assert(elembt != T_VALUETYPE, "value types are not supported by this method");
1588 Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1589 if (elembt == T_NARROWOOP) {
1590 elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1591 }
1592 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1593 return ld;
1594 }
1595
1596 //-------------------------set_arguments_for_java_call-------------------------
1597 // Arguments (pre-popped from the stack) are taken from the JVMS.
1598 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1599 // Add the call arguments:
1600 const TypeTuple* domain = call->tf()->domain_sig();
1601 uint nargs = domain->cnt();
1602 for (uint i = TypeFunc::Parms, idx = TypeFunc::Parms; i < nargs; i++) {
1603 Node* arg = argument(i-TypeFunc::Parms);
1604 if (ValueTypePassFieldsAsArgs) {
1605 if (arg->is_ValueType()) {
1606 ValueTypeNode* vt = arg->as_ValueType();
1607 if (domain->field_at(i)->is_valuetypeptr()->klass() != C->env()->___Value_klass()) {
1608 // We don't pass value type arguments by reference but instead
1609 // pass each field of the value type
1610 idx += vt->pass_fields(call, idx, *this);
1611 // If a value type argument is passed as fields, attach the Method* to the call site
1612 // to be able to access the extended signature later via attached_method_before_pc().
1613 // For example, see CompiledMethod::preserve_callee_argument_oops().
1614 call->set_override_symbolic_info(true);
1615 } else {
1616 arg = arg->as_ValueType()->allocate(this);
1617 call->init_req(idx, arg);
1618 idx++;
1619 }
1620 } else {
1621 call->init_req(idx, arg);
1622 idx++;
1623 }
1624 } else {
1625 if (arg->is_ValueType()) {
1626 // Pass value type argument via oop to callee
1627 arg = arg->as_ValueType()->allocate(this);
1628 }
1629 call->init_req(i, arg);
1630 }
1631 }
1632 }
1633
1634 //---------------------------set_edges_for_java_call---------------------------
1635 // Connect a newly created call into the current JVMS.
1636 // A return value node (if any) is returned from set_edges_for_java_call.
1637 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1638
1639 // Add the predefined inputs:
1640 call->init_req( TypeFunc::Control, control() );
1641 call->init_req( TypeFunc::I_O , i_o() );
1642 call->init_req( TypeFunc::Memory , reset_memory() );
1643 call->init_req( TypeFunc::FramePtr, frameptr() );
1644 call->init_req( TypeFunc::ReturnAdr, top() );
1645
1646 add_safepoint_edges(call, must_throw);
1647
1648 Node* xcall = _gvn.transform(call);
1649
1650 if (xcall == top()) {
1651 set_control(top());
1652 return;
1653 }
1654 assert(xcall == call, "call identity is stable");
1655
1656 // Re-use the current map to produce the result.
1657
1658 set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1659 set_i_o( _gvn.transform(new ProjNode(call, TypeFunc::I_O , separate_io_proj)));
1660 set_all_memory_call(xcall, separate_io_proj);
1661
1662 //return xcall; // no need, caller already has it
1663 }
1664
1665 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1666 if (stopped()) return top(); // maybe the call folded up?
1667
1668 // Capture the return value, if any.
1669 Node* ret;
1670 if (call->method() == NULL ||
1671 call->method()->return_type()->basic_type() == T_VOID)
1672 ret = top();
1673 else {
1674 if (!call->tf()->returns_value_type_as_fields()) {
1675 ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1676 } else {
1677 // Return of multiple values (value type fields): we create a
1678 // ValueType node, each field is a projection from the call.
1679 const TypeTuple *range_sig = call->tf()->range_sig();
1680 const Type* t = range_sig->field_at(TypeFunc::Parms);
1681 assert(t->isa_valuetypeptr(), "only value types for multiple return values");
1682 ciValueKlass* vk = t->is_valuetypeptr()->value_type()->value_klass();
1683 ret = ValueTypeNode::make(_gvn, call, vk, TypeFunc::Parms+1, false);
1684 }
1685 }
1686
1687 // Note: Since any out-of-line call can produce an exception,
1688 // we always insert an I_O projection from the call into the result.
1689
1690 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1691
1692 if (separate_io_proj) {
1693 // The caller requested separate projections be used by the fall
1694 // through and exceptional paths, so replace the projections for
1695 // the fall through path.
1696 set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1697 set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1698 }
1699 return ret;
1700 }
1701
1702 //--------------------set_predefined_input_for_runtime_call--------------------
1703 // Reading and setting the memory state is way conservative here.
1704 // The real problem is that I am not doing real Type analysis on memory,
1705 // so I cannot distinguish card mark stores from other stores. Across a GC
1706 // point the Store Barrier and the card mark memory has to agree. I cannot
1707 // have a card mark store and its barrier split across the GC point from
1708 // either above or below. Here I get that to happen by reading ALL of memory.
1709 // A better answer would be to separate out card marks from other memory.
1710 // For now, return the input memory state, so that it can be reused
1711 // after the call, if this call has restricted memory effects.
1712 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1713 // Set fixed predefined input arguments
1714 Node* memory = reset_memory();
1715 call->init_req( TypeFunc::Control, control() );
1716 call->init_req( TypeFunc::I_O, top() ); // does no i/o
1717 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs
1718 call->init_req( TypeFunc::FramePtr, frameptr() );
1719 call->init_req( TypeFunc::ReturnAdr, top() );
1720 return memory;
1721 }
1722
1723 //-------------------set_predefined_output_for_runtime_call--------------------
1724 // Set control and memory (not i_o) from the call.
1725 // If keep_mem is not NULL, use it for the output state,
1726 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1727 // If hook_mem is NULL, this call produces no memory effects at all.
1728 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1729 // then only that memory slice is taken from the call.
1730 // In the last case, we must put an appropriate memory barrier before
1731 // the call, so as to create the correct anti-dependencies on loads
1732 // preceding the call.
1733 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1734 Node* keep_mem,
1735 const TypePtr* hook_mem) {
1736 // no i/o
1737 set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1738 if (keep_mem) {
1739 // First clone the existing memory state
1740 set_all_memory(keep_mem);
1741 if (hook_mem != NULL) {
1742 // Make memory for the call
1743 Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1744 // Set the RawPtr memory state only. This covers all the heap top/GC stuff
1745 // We also use hook_mem to extract specific effects from arraycopy stubs.
1746 set_memory(mem, hook_mem);
1747 }
1748 // ...else the call has NO memory effects.
1749
1750 // Make sure the call advertises its memory effects precisely.
1751 // This lets us build accurate anti-dependences in gcm.cpp.
1752 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1753 "call node must be constructed correctly");
1754 } else {
1755 assert(hook_mem == NULL, "");
1756 // This is not a "slow path" call; all memory comes from the call.
1757 set_all_memory_call(call);
1758 }
1759 }
1760
1761
1762 // Replace the call with the current state of the kit.
1763 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1764 JVMState* ejvms = NULL;
1765 if (has_exceptions()) {
1766 ejvms = transfer_exceptions_into_jvms();
1767 }
1768
1769 ReplacedNodes replaced_nodes = map()->replaced_nodes();
1770 ReplacedNodes replaced_nodes_exception;
1771 Node* ex_ctl = top();
1772
1773 SafePointNode* final_state = stop();
1774
1775 // Find all the needed outputs of this call
1776 CallProjections callprojs;
1777 call->extract_projections(&callprojs, true);
1778
1779 Node* init_mem = call->in(TypeFunc::Memory);
1780 Node* final_mem = final_state->in(TypeFunc::Memory);
1781 Node* final_ctl = final_state->in(TypeFunc::Control);
1782 Node* final_io = final_state->in(TypeFunc::I_O);
1783
1784 // Replace all the old call edges with the edges from the inlining result
1785 if (callprojs.fallthrough_catchproj != NULL) {
1786 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1787 }
1788 if (callprojs.fallthrough_memproj != NULL) {
1789 if (final_mem->is_MergeMem()) {
1790 // Parser's exits MergeMem was not transformed but may be optimized
1791 final_mem = _gvn.transform(final_mem);
1792 }
1793 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem);
1794 }
1795 if (callprojs.fallthrough_ioproj != NULL) {
1796 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io);
1797 }
1798
1799 // Replace the result with the new result if it exists and is used
1800 if (callprojs.resproj != NULL && result != NULL) {
1801 C->gvn_replace_by(callprojs.resproj, result);
1802 }
1803
1804 if (ejvms == NULL) {
1805 // No exception edges to simply kill off those paths
1806 if (callprojs.catchall_catchproj != NULL) {
1807 C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1808 }
1809 if (callprojs.catchall_memproj != NULL) {
1810 C->gvn_replace_by(callprojs.catchall_memproj, C->top());
1811 }
1812 if (callprojs.catchall_ioproj != NULL) {
1813 C->gvn_replace_by(callprojs.catchall_ioproj, C->top());
1814 }
1815 // Replace the old exception object with top
1816 if (callprojs.exobj != NULL) {
1817 C->gvn_replace_by(callprojs.exobj, C->top());
1818 }
1819 } else {
1820 GraphKit ekit(ejvms);
1821
1822 // Load my combined exception state into the kit, with all phis transformed:
1823 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1824 replaced_nodes_exception = ex_map->replaced_nodes();
1825
1826 Node* ex_oop = ekit.use_exception_state(ex_map);
1827
1828 if (callprojs.catchall_catchproj != NULL) {
1829 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1830 ex_ctl = ekit.control();
1831 }
1832 if (callprojs.catchall_memproj != NULL) {
1833 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory());
1834 }
1835 if (callprojs.catchall_ioproj != NULL) {
1836 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o());
1837 }
1838
1839 // Replace the old exception object with the newly created one
1840 if (callprojs.exobj != NULL) {
1841 C->gvn_replace_by(callprojs.exobj, ex_oop);
1842 }
1843 }
1844
1845 // Disconnect the call from the graph
1846 call->disconnect_inputs(NULL, C);
1847 C->gvn_replace_by(call, C->top());
1848
1849 // Clean up any MergeMems that feed other MergeMems since the
1850 // optimizer doesn't like that.
1851 if (final_mem->is_MergeMem()) {
1852 Node_List wl;
1853 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1854 Node* m = i.get();
1855 if (m->is_MergeMem() && !wl.contains(m)) {
1856 wl.push(m);
1857 }
1858 }
1859 while (wl.size() > 0) {
1860 _gvn.transform(wl.pop());
1861 }
1862 }
1863
1864 if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1865 replaced_nodes.apply(C, final_ctl);
1866 }
1867 if (!ex_ctl->is_top() && do_replaced_nodes) {
1868 replaced_nodes_exception.apply(C, ex_ctl);
1869 }
1870 }
1871
1872
1873 //------------------------------increment_counter------------------------------
1874 // for statistics: increment a VM counter by 1
1875
1876 void GraphKit::increment_counter(address counter_addr) {
1877 Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1878 increment_counter(adr1);
1879 }
1880
1881 void GraphKit::increment_counter(Node* counter_addr) {
1882 int adr_type = Compile::AliasIdxRaw;
1883 Node* ctrl = control();
1884 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1885 Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1886 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1887 }
1888
1889
1890 //------------------------------uncommon_trap----------------------------------
1891 // Bail out to the interpreter in mid-method. Implemented by calling the
1892 // uncommon_trap blob. This helper function inserts a runtime call with the
1893 // right debug info.
1894 void GraphKit::uncommon_trap(int trap_request,
1895 ciKlass* klass, const char* comment,
1896 bool must_throw,
1897 bool keep_exact_action) {
1898 if (failing()) stop();
1899 if (stopped()) return; // trap reachable?
1900
1901 // Note: If ProfileTraps is true, and if a deopt. actually
1902 // occurs here, the runtime will make sure an MDO exists. There is
1903 // no need to call method()->ensure_method_data() at this point.
1904
1905 // Set the stack pointer to the right value for reexecution:
1906 set_sp(reexecute_sp());
1907
1908 #ifdef ASSERT
1909 if (!must_throw) {
1910 // Make sure the stack has at least enough depth to execute
1911 // the current bytecode.
1912 int inputs, ignored_depth;
1913 if (compute_stack_effects(inputs, ignored_depth)) {
1914 assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1915 Bytecodes::name(java_bc()), sp(), inputs);
1916 }
1917 }
1918 #endif
1919
1920 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
1921 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
1922
1923 switch (action) {
1924 case Deoptimization::Action_maybe_recompile:
1925 case Deoptimization::Action_reinterpret:
1926 // Temporary fix for 6529811 to allow virtual calls to be sure they
1927 // get the chance to go from mono->bi->mega
1928 if (!keep_exact_action &&
1929 Deoptimization::trap_request_index(trap_request) < 0 &&
1930 too_many_recompiles(reason)) {
1931 // This BCI is causing too many recompilations.
1932 if (C->log() != NULL) {
1933 C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
1934 Deoptimization::trap_reason_name(reason),
1935 Deoptimization::trap_action_name(action));
1936 }
1937 action = Deoptimization::Action_none;
1938 trap_request = Deoptimization::make_trap_request(reason, action);
1939 } else {
1940 C->set_trap_can_recompile(true);
1941 }
1942 break;
1943 case Deoptimization::Action_make_not_entrant:
1944 C->set_trap_can_recompile(true);
1945 break;
1946 #ifdef ASSERT
1947 case Deoptimization::Action_none:
1948 case Deoptimization::Action_make_not_compilable:
1949 break;
1950 default:
1951 fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
1952 break;
1953 #endif
1954 }
1955
1956 if (TraceOptoParse) {
1957 char buf[100];
1958 tty->print_cr("Uncommon trap %s at bci:%d",
1959 Deoptimization::format_trap_request(buf, sizeof(buf),
1960 trap_request), bci());
1961 }
1962
1963 CompileLog* log = C->log();
1964 if (log != NULL) {
1965 int kid = (klass == NULL)? -1: log->identify(klass);
1966 log->begin_elem("uncommon_trap bci='%d'", bci());
1967 char buf[100];
1968 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
1969 trap_request));
1970 if (kid >= 0) log->print(" klass='%d'", kid);
1971 if (comment != NULL) log->print(" comment='%s'", comment);
1972 log->end_elem();
1973 }
1974
1975 // Make sure any guarding test views this path as very unlikely
1976 Node *i0 = control()->in(0);
1977 if (i0 != NULL && i0->is_If()) { // Found a guarding if test?
1978 IfNode *iff = i0->as_If();
1979 float f = iff->_prob; // Get prob
1980 if (control()->Opcode() == Op_IfTrue) {
1981 if (f > PROB_UNLIKELY_MAG(4))
1982 iff->_prob = PROB_MIN;
1983 } else {
1984 if (f < PROB_LIKELY_MAG(4))
1985 iff->_prob = PROB_MAX;
1986 }
1987 }
1988
1989 // Clear out dead values from the debug info.
1990 kill_dead_locals();
1991
1992 // Now insert the uncommon trap subroutine call
1993 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
1994 const TypePtr* no_memory_effects = NULL;
1995 // Pass the index of the class to be loaded
1996 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
1997 (must_throw ? RC_MUST_THROW : 0),
1998 OptoRuntime::uncommon_trap_Type(),
1999 call_addr, "uncommon_trap", no_memory_effects,
2000 intcon(trap_request));
2001 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2002 "must extract request correctly from the graph");
2003 assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2004
2005 call->set_req(TypeFunc::ReturnAdr, returnadr());
2006 // The debug info is the only real input to this call.
2007
2008 // Halt-and-catch fire here. The above call should never return!
2009 HaltNode* halt = new HaltNode(control(), frameptr());
2010 _gvn.set_type_bottom(halt);
2011 root()->add_req(halt);
2012
2013 stop_and_kill_map();
2014 }
2015
2016
2017 //--------------------------just_allocated_object------------------------------
2018 // Report the object that was just allocated.
2019 // It must be the case that there are no intervening safepoints.
2020 // We use this to determine if an object is so "fresh" that
2021 // it does not require card marks.
2022 Node* GraphKit::just_allocated_object(Node* current_control) {
2023 if (C->recent_alloc_ctl() == current_control)
2024 return C->recent_alloc_obj();
2025 return NULL;
2026 }
2027
2028
2029 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2030 // (Note: TypeFunc::make has a cache that makes this fast.)
2031 const TypeFunc* tf = TypeFunc::make(dest_method);
2032 int nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2033 for (int j = 0; j < nargs; j++) {
2034 const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2035 if( targ->basic_type() == T_DOUBLE ) {
2036 // If any parameters are doubles, they must be rounded before
2037 // the call, dstore_rounding does gvn.transform
2038 Node *arg = argument(j);
2039 arg = dstore_rounding(arg);
2040 set_argument(j, arg);
2041 }
2042 }
2043 }
2044
2045 /**
2046 * Record profiling data exact_kls for Node n with the type system so
2047 * that it can propagate it (speculation)
2048 *
2049 * @param n node that the type applies to
2050 * @param exact_kls type from profiling
2051 * @param maybe_null did profiling see null?
2052 *
2053 * @return node with improved type
2054 */
2055 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2056 const Type* current_type = _gvn.type(n);
2057 assert(UseTypeSpeculation, "type speculation must be on");
2058
2059 const TypePtr* speculative = current_type->speculative();
2060
2061 // Should the klass from the profile be recorded in the speculative type?
2062 if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2063 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2064 const TypeOopPtr* xtype = tklass->as_instance_type();
2065 assert(xtype->klass_is_exact(), "Should be exact");
2066 // Any reason to believe n is not null (from this profiling or a previous one)?
2067 const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2068 // record the new speculative type's depth
2069 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2070 speculative = speculative->with_inline_depth(jvms()->depth());
2071 } else if (current_type->would_improve_ptr(maybe_null)) {
2072 // Profiling report that null was never seen so we can change the
2073 // speculative type to non null ptr.
2074 assert(!maybe_null, "nothing to improve");
2075 if (speculative == NULL) {
2076 speculative = TypePtr::NOTNULL;
2077 } else {
2078 const TypePtr* ptr = TypePtr::NOTNULL;
2079 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2080 }
2081 }
2082
2083 if (speculative != current_type->speculative()) {
2084 // Build a type with a speculative type (what we think we know
2085 // about the type but will need a guard when we use it)
2086 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::Offset::bottom, TypeOopPtr::InstanceBot, speculative);
2087 // We're changing the type, we need a new CheckCast node to carry
2088 // the new type. The new type depends on the control: what
2089 // profiling tells us is only valid from here as far as we can
2090 // tell.
2091 Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2092 cast = _gvn.transform(cast);
2093 replace_in_map(n, cast);
2094 n = cast;
2095 }
2096
2097 return n;
2098 }
2099
2100 /**
2101 * Record profiling data from receiver profiling at an invoke with the
2102 * type system so that it can propagate it (speculation)
2103 *
2104 * @param n receiver node
2105 *
2106 * @return node with improved type
2107 */
2108 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2109 if (!UseTypeSpeculation) {
2110 return n;
2111 }
2112 ciKlass* exact_kls = profile_has_unique_klass();
2113 bool maybe_null = true;
2114 if (java_bc() == Bytecodes::_checkcast ||
2115 java_bc() == Bytecodes::_instanceof ||
2116 java_bc() == Bytecodes::_aastore) {
2117 ciProfileData* data = method()->method_data()->bci_to_data(bci());
2118 maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2119 }
2120 return record_profile_for_speculation(n, exact_kls, maybe_null);
2121 }
2122
2123 /**
2124 * Record profiling data from argument profiling at an invoke with the
2125 * type system so that it can propagate it (speculation)
2126 *
2127 * @param dest_method target method for the call
2128 * @param bc what invoke bytecode is this?
2129 */
2130 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2131 if (!UseTypeSpeculation) {
2132 return;
2133 }
2134 const TypeFunc* tf = TypeFunc::make(dest_method);
2135 int nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2136 int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2137 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2138 const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2139 if (targ->isa_oopptr() && !targ->isa_valuetypeptr()) {
2140 bool maybe_null = true;
2141 ciKlass* better_type = NULL;
2142 if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2143 record_profile_for_speculation(argument(j), better_type, maybe_null);
2144 }
2145 i++;
2146 }
2147 }
2148 }
2149
2150 /**
2151 * Record profiling data from parameter profiling at an invoke with
2152 * the type system so that it can propagate it (speculation)
2153 */
2154 void GraphKit::record_profiled_parameters_for_speculation() {
2155 if (!UseTypeSpeculation) {
2156 return;
2157 }
2158 for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2159 if (_gvn.type(local(i))->isa_oopptr()) {
2160 bool maybe_null = true;
2161 ciKlass* better_type = NULL;
2162 if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2163 record_profile_for_speculation(local(i), better_type, maybe_null);
2164 }
2165 j++;
2166 }
2167 }
2168 }
2169
2170 /**
2171 * Record profiling data from return value profiling at an invoke with
2172 * the type system so that it can propagate it (speculation)
2173 */
2174 void GraphKit::record_profiled_return_for_speculation() {
2175 if (!UseTypeSpeculation) {
2176 return;
2177 }
2178 bool maybe_null = true;
2179 ciKlass* better_type = NULL;
2180 if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2181 // If profiling reports a single type for the return value,
2182 // feed it to the type system so it can propagate it as a
2183 // speculative type
2184 record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2185 }
2186 }
2187
2188 void GraphKit::round_double_result(ciMethod* dest_method) {
2189 // A non-strict method may return a double value which has an extended
2190 // exponent, but this must not be visible in a caller which is 'strict'
2191 // If a strict caller invokes a non-strict callee, round a double result
2192
2193 BasicType result_type = dest_method->return_type()->basic_type();
2194 assert( method() != NULL, "must have caller context");
2195 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2196 // Destination method's return value is on top of stack
2197 // dstore_rounding() does gvn.transform
2198 Node *result = pop_pair();
2199 result = dstore_rounding(result);
2200 push_pair(result);
2201 }
2202 }
2203
2204 // rounding for strict float precision conformance
2205 Node* GraphKit::precision_rounding(Node* n) {
2206 return UseStrictFP && _method->flags().is_strict()
2207 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2208 ? _gvn.transform( new RoundFloatNode(0, n) )
2209 : n;
2210 }
2211
2212 // rounding for strict double precision conformance
2213 Node* GraphKit::dprecision_rounding(Node *n) {
2214 return UseStrictFP && _method->flags().is_strict()
2215 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2216 ? _gvn.transform( new RoundDoubleNode(0, n) )
2217 : n;
2218 }
2219
2220 // rounding for non-strict double stores
2221 Node* GraphKit::dstore_rounding(Node* n) {
2222 return Matcher::strict_fp_requires_explicit_rounding
2223 && UseSSE <= 1
2224 ? _gvn.transform( new RoundDoubleNode(0, n) )
2225 : n;
2226 }
2227
2228 //=============================================================================
2229 // Generate a fast path/slow path idiom. Graph looks like:
2230 // [foo] indicates that 'foo' is a parameter
2231 //
2232 // [in] NULL
2233 // \ /
2234 // CmpP
2235 // Bool ne
2236 // If
2237 // / \
2238 // True False-<2>
2239 // / |
2240 // / cast_not_null
2241 // Load | | ^
2242 // [fast_test] | |
2243 // gvn to opt_test | |
2244 // / \ | <1>
2245 // True False |
2246 // | \\ |
2247 // [slow_call] \[fast_result]
2248 // Ctl Val \ \
2249 // | \ \
2250 // Catch <1> \ \
2251 // / \ ^ \ \
2252 // Ex No_Ex | \ \
2253 // | \ \ | \ <2> \
2254 // ... \ [slow_res] | | \ [null_result]
2255 // \ \--+--+--- | |
2256 // \ | / \ | /
2257 // --------Region Phi
2258 //
2259 //=============================================================================
2260 // Code is structured as a series of driver functions all called 'do_XXX' that
2261 // call a set of helper functions. Helper functions first, then drivers.
2262
2263 //------------------------------null_check_oop---------------------------------
2264 // Null check oop. Set null-path control into Region in slot 3.
2265 // Make a cast-not-nullness use the other not-null control. Return cast.
2266 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2267 bool never_see_null,
2268 bool safe_for_replace,
2269 bool speculative) {
2270 // Initial NULL check taken path
2271 (*null_control) = top();
2272 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2273
2274 // Generate uncommon_trap:
2275 if (never_see_null && (*null_control) != top()) {
2276 // If we see an unexpected null at a check-cast we record it and force a
2277 // recompile; the offending check-cast will be compiled to handle NULLs.
2278 // If we see more than one offending BCI, then all checkcasts in the
2279 // method will be compiled to handle NULLs.
2280 PreserveJVMState pjvms(this);
2281 set_control(*null_control);
2282 replace_in_map(value, null());
2283 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2284 uncommon_trap(reason,
2285 Deoptimization::Action_make_not_entrant);
2286 (*null_control) = top(); // NULL path is dead
2287 }
2288 if ((*null_control) == top() && safe_for_replace) {
2289 replace_in_map(value, cast);
2290 }
2291
2292 // Cast away null-ness on the result
2293 return cast;
2294 }
2295
2296 //------------------------------opt_iff----------------------------------------
2297 // Optimize the fast-check IfNode. Set the fast-path region slot 2.
2298 // Return slow-path control.
2299 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2300 IfNode *opt_iff = _gvn.transform(iff)->as_If();
2301
2302 // Fast path taken; set region slot 2
2303 Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2304 region->init_req(2,fast_taken); // Capture fast-control
2305
2306 // Fast path not-taken, i.e. slow path
2307 Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2308 return slow_taken;
2309 }
2310
2311 //-----------------------------make_runtime_call-------------------------------
2312 Node* GraphKit::make_runtime_call(int flags,
2313 const TypeFunc* call_type, address call_addr,
2314 const char* call_name,
2315 const TypePtr* adr_type,
2316 // The following parms are all optional.
2317 // The first NULL ends the list.
2318 Node* parm0, Node* parm1,
2319 Node* parm2, Node* parm3,
2320 Node* parm4, Node* parm5,
2321 Node* parm6, Node* parm7) {
2322 // Slow-path call
2323 bool is_leaf = !(flags & RC_NO_LEAF);
2324 bool has_io = (!is_leaf && !(flags & RC_NO_IO));
2325 if (call_name == NULL) {
2326 assert(!is_leaf, "must supply name for leaf");
2327 call_name = OptoRuntime::stub_name(call_addr);
2328 }
2329 CallNode* call;
2330 if (!is_leaf) {
2331 call = new CallStaticJavaNode(call_type, call_addr, call_name,
2332 bci(), adr_type);
2333 } else if (flags & RC_NO_FP) {
2334 call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2335 } else {
2336 call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2337 }
2338
2339 // The following is similar to set_edges_for_java_call,
2340 // except that the memory effects of the call are restricted to AliasIdxRaw.
2341
2342 // Slow path call has no side-effects, uses few values
2343 bool wide_in = !(flags & RC_NARROW_MEM);
2344 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2345
2346 Node* prev_mem = NULL;
2347 if (wide_in) {
2348 prev_mem = set_predefined_input_for_runtime_call(call);
2349 } else {
2350 assert(!wide_out, "narrow in => narrow out");
2351 Node* narrow_mem = memory(adr_type);
2352 prev_mem = reset_memory();
2353 map()->set_memory(narrow_mem);
2354 set_predefined_input_for_runtime_call(call);
2355 }
2356
2357 // Hook each parm in order. Stop looking at the first NULL.
2358 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2359 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2360 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2361 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2362 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2363 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2364 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2365 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2366 /* close each nested if ===> */ } } } } } } } }
2367 assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2368
2369 if (!is_leaf) {
2370 // Non-leaves can block and take safepoints:
2371 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2372 }
2373 // Non-leaves can throw exceptions:
2374 if (has_io) {
2375 call->set_req(TypeFunc::I_O, i_o());
2376 }
2377
2378 if (flags & RC_UNCOMMON) {
2379 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency.
2380 // (An "if" probability corresponds roughly to an unconditional count.
2381 // Sort of.)
2382 call->set_cnt(PROB_UNLIKELY_MAG(4));
2383 }
2384
2385 Node* c = _gvn.transform(call);
2386 assert(c == call, "cannot disappear");
2387
2388 if (wide_out) {
2389 // Slow path call has full side-effects.
2390 set_predefined_output_for_runtime_call(call);
2391 } else {
2392 // Slow path call has few side-effects, and/or sets few values.
2393 set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2394 }
2395
2396 if (has_io) {
2397 set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2398 }
2399 return call;
2400
2401 }
2402
2403 //------------------------------merge_memory-----------------------------------
2404 // Merge memory from one path into the current memory state.
2405 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2406 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2407 Node* old_slice = mms.force_memory();
2408 Node* new_slice = mms.memory2();
2409 if (old_slice != new_slice) {
2410 PhiNode* phi;
2411 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2412 if (mms.is_empty()) {
2413 // clone base memory Phi's inputs for this memory slice
2414 assert(old_slice == mms.base_memory(), "sanity");
2415 phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2416 _gvn.set_type(phi, Type::MEMORY);
2417 for (uint i = 1; i < phi->req(); i++) {
2418 phi->init_req(i, old_slice->in(i));
2419 }
2420 } else {
2421 phi = old_slice->as_Phi(); // Phi was generated already
2422 }
2423 } else {
2424 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2425 _gvn.set_type(phi, Type::MEMORY);
2426 }
2427 phi->set_req(new_path, new_slice);
2428 mms.set_memory(phi);
2429 }
2430 }
2431 }
2432
2433 //------------------------------make_slow_call_ex------------------------------
2434 // Make the exception handler hookups for the slow call
2435 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2436 if (stopped()) return;
2437
2438 // Make a catch node with just two handlers: fall-through and catch-all
2439 Node* i_o = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2440 Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2441 Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2442 Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) );
2443
2444 { PreserveJVMState pjvms(this);
2445 set_control(excp);
2446 set_i_o(i_o);
2447
2448 if (excp != top()) {
2449 if (deoptimize) {
2450 // Deoptimize if an exception is caught. Don't construct exception state in this case.
2451 uncommon_trap(Deoptimization::Reason_unhandled,
2452 Deoptimization::Action_none);
2453 } else {
2454 // Create an exception state also.
2455 // Use an exact type if the caller has specified a specific exception.
2456 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2457 Node* ex_oop = new CreateExNode(ex_type, control(), i_o);
2458 add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2459 }
2460 }
2461 }
2462
2463 // Get the no-exception control from the CatchNode.
2464 set_control(norm);
2465 }
2466
2467 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2468 Node* cmp = NULL;
2469 switch(bt) {
2470 case T_INT: cmp = new CmpINode(in1, in2); break;
2471 case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2472 default: fatal("unexpected comparison type %s", type2name(bt));
2473 }
2474 gvn->transform(cmp);
2475 Node* bol = gvn->transform(new BoolNode(cmp, test));
2476 IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2477 gvn->transform(iff);
2478 if (!bol->is_Con()) gvn->record_for_igvn(iff);
2479 return iff;
2480 }
2481
2482
2483 //-------------------------------gen_subtype_check-----------------------------
2484 // Generate a subtyping check. Takes as input the subtype and supertype.
2485 // Returns 2 values: sets the default control() to the true path and returns
2486 // the false path. Only reads invariant memory; sets no (visible) memory.
2487 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2488 // but that's not exposed to the optimizer. This call also doesn't take in an
2489 // Object; if you wish to check an Object you need to load the Object's class
2490 // prior to coming here.
2491 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2492 Compile* C = gvn->C;
2493
2494 if ((*ctrl)->is_top()) {
2495 return C->top();
2496 }
2497
2498 // Fast check for identical types, perhaps identical constants.
2499 // The types can even be identical non-constants, in cases
2500 // involving Array.newInstance, Object.clone, etc.
2501 if (subklass == superklass)
2502 return C->top(); // false path is dead; no test needed.
2503
2504 if (gvn->type(superklass)->singleton()) {
2505 ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2506 ciKlass* subk = gvn->type(subklass)->is_klassptr()->klass();
2507
2508 // In the common case of an exact superklass, try to fold up the
2509 // test before generating code. You may ask, why not just generate
2510 // the code and then let it fold up? The answer is that the generated
2511 // code will necessarily include null checks, which do not always
2512 // completely fold away. If they are also needless, then they turn
2513 // into a performance loss. Example:
2514 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2515 // Here, the type of 'fa' is often exact, so the store check
2516 // of fa[1]=x will fold up, without testing the nullness of x.
2517 switch (C->static_subtype_check(superk, subk)) {
2518 case Compile::SSC_always_false:
2519 {
2520 Node* always_fail = *ctrl;
2521 *ctrl = gvn->C->top();
2522 return always_fail;
2523 }
2524 case Compile::SSC_always_true:
2525 return C->top();
2526 case Compile::SSC_easy_test:
2527 {
2528 // Just do a direct pointer compare and be done.
2529 IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2530 *ctrl = gvn->transform(new IfTrueNode(iff));
2531 return gvn->transform(new IfFalseNode(iff));
2532 }
2533 case Compile::SSC_full_test:
2534 break;
2535 default:
2536 ShouldNotReachHere();
2537 }
2538 }
2539
2540 // %%% Possible further optimization: Even if the superklass is not exact,
2541 // if the subklass is the unique subtype of the superklass, the check
2542 // will always succeed. We could leave a dependency behind to ensure this.
2543
2544 // First load the super-klass's check-offset
2545 Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2546 Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2547 Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2548 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2549 bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2550
2551 // Load from the sub-klass's super-class display list, or a 1-word cache of
2552 // the secondary superclass list, or a failing value with a sentinel offset
2553 // if the super-klass is an interface or exceptionally deep in the Java
2554 // hierarchy and we have to scan the secondary superclass list the hard way.
2555 // Worst-case type is a little odd: NULL is allowed as a result (usually
2556 // klass loads can never produce a NULL).
2557 Node *chk_off_X = chk_off;
2558 #ifdef _LP64
2559 chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2560 #endif
2561 Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2562 // For some types like interfaces the following loadKlass is from a 1-word
2563 // cache which is mutable so can't use immutable memory. Other
2564 // types load from the super-class display table which is immutable.
2565 m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2566 Node *kmem = might_be_cache ? m : C->immutable_memory();
2567 Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::BOTTOM));
2568
2569 // Compile speed common case: ARE a subtype and we canNOT fail
2570 if( superklass == nkls )
2571 return C->top(); // false path is dead; no test needed.
2572
2573 // See if we get an immediate positive hit. Happens roughly 83% of the
2574 // time. Test to see if the value loaded just previously from the subklass
2575 // is exactly the superklass.
2576 IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2577 Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2578 *ctrl = gvn->transform(new IfFalseNode(iff1));
2579
2580 // Compile speed common case: Check for being deterministic right now. If
2581 // chk_off is a constant and not equal to cacheoff then we are NOT a
2582 // subklass. In this case we need exactly the 1 test above and we can
2583 // return those results immediately.
2584 if (!might_be_cache) {
2585 Node* not_subtype_ctrl = *ctrl;
2586 *ctrl = iftrue1; // We need exactly the 1 test above
2587 return not_subtype_ctrl;
2588 }
2589
2590 // Gather the various success & failures here
2591 RegionNode *r_ok_subtype = new RegionNode(4);
2592 gvn->record_for_igvn(r_ok_subtype);
2593 RegionNode *r_not_subtype = new RegionNode(3);
2594 gvn->record_for_igvn(r_not_subtype);
2595
2596 r_ok_subtype->init_req(1, iftrue1);
2597
2598 // Check for immediate negative hit. Happens roughly 11% of the time (which
2599 // is roughly 63% of the remaining cases). Test to see if the loaded
2600 // check-offset points into the subklass display list or the 1-element
2601 // cache. If it points to the display (and NOT the cache) and the display
2602 // missed then it's not a subtype.
2603 Node *cacheoff = gvn->intcon(cacheoff_con);
2604 IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2605 r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2606 *ctrl = gvn->transform(new IfFalseNode(iff2));
2607
2608 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2609 // No performance impact (too rare) but allows sharing of secondary arrays
2610 // which has some footprint reduction.
2611 IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2612 r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2613 *ctrl = gvn->transform(new IfFalseNode(iff3));
2614
2615 // -- Roads not taken here: --
2616 // We could also have chosen to perform the self-check at the beginning
2617 // of this code sequence, as the assembler does. This would not pay off
2618 // the same way, since the optimizer, unlike the assembler, can perform
2619 // static type analysis to fold away many successful self-checks.
2620 // Non-foldable self checks work better here in second position, because
2621 // the initial primary superclass check subsumes a self-check for most
2622 // types. An exception would be a secondary type like array-of-interface,
2623 // which does not appear in its own primary supertype display.
2624 // Finally, we could have chosen to move the self-check into the
2625 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2626 // dependent manner. But it is worthwhile to have the check here,
2627 // where it can be perhaps be optimized. The cost in code space is
2628 // small (register compare, branch).
2629
2630 // Now do a linear scan of the secondary super-klass array. Again, no real
2631 // performance impact (too rare) but it's gotta be done.
2632 // Since the code is rarely used, there is no penalty for moving it
2633 // out of line, and it can only improve I-cache density.
2634 // The decision to inline or out-of-line this final check is platform
2635 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2636 Node* psc = gvn->transform(
2637 new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2638
2639 IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2640 r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2641 r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2642
2643 // Return false path; set default control to true path.
2644 *ctrl = gvn->transform(r_ok_subtype);
2645 return gvn->transform(r_not_subtype);
2646 }
2647
2648 // Profile-driven exact type check:
2649 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2650 float prob,
2651 Node* *casted_receiver) {
2652 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2653 Node* recv_klass = load_object_klass(receiver);
2654 Node* fail = type_check(recv_klass, tklass, prob);
2655 const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2656 assert(recv_xtype->klass_is_exact(), "");
2657
2658 // Subsume downstream occurrences of receiver with a cast to
2659 // recv_xtype, since now we know what the type will be.
2660 Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2661 (*casted_receiver) = _gvn.transform(cast);
2662 // (User must make the replace_in_map call.)
2663
2664 return fail;
2665 }
2666
2667 Node* GraphKit::type_check(Node* recv_klass, const TypeKlassPtr* tklass,
2668 float prob) {
2669 //const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2670 Node* want_klass = makecon(tklass);
2671 Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass));
2672 Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2673 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2674 set_control( _gvn.transform( new IfTrueNode (iff)));
2675 Node* fail = _gvn.transform( new IfFalseNode(iff));
2676 return fail;
2677 }
2678
2679
2680 //------------------------------seems_never_null-------------------------------
2681 // Use null_seen information if it is available from the profile.
2682 // If we see an unexpected null at a type check we record it and force a
2683 // recompile; the offending check will be recompiled to handle NULLs.
2684 // If we see several offending BCIs, then all checks in the
2685 // method will be recompiled.
2686 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2687 speculating = !_gvn.type(obj)->speculative_maybe_null();
2688 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2689 if (UncommonNullCast // Cutout for this technique
2690 && obj != null() // And not the -Xcomp stupid case?
2691 && !too_many_traps(reason)
2692 ) {
2693 if (speculating) {
2694 return true;
2695 }
2696 if (data == NULL)
2697 // Edge case: no mature data. Be optimistic here.
2698 return true;
2699 // If the profile has not seen a null, assume it won't happen.
2700 assert(java_bc() == Bytecodes::_checkcast ||
2701 java_bc() == Bytecodes::_instanceof ||
2702 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2703 return !data->as_BitData()->null_seen();
2704 }
2705 speculating = false;
2706 return false;
2707 }
2708
2709 //------------------------maybe_cast_profiled_receiver-------------------------
2710 // If the profile has seen exactly one type, narrow to exactly that type.
2711 // Subsequent type checks will always fold up.
2712 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2713 ciKlass* require_klass,
2714 ciKlass* spec_klass,
2715 bool safe_for_replace) {
2716 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2717
2718 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2719
2720 // Make sure we haven't already deoptimized from this tactic.
2721 if (too_many_traps(reason) || too_many_recompiles(reason))
2722 return NULL;
2723
2724 // (No, this isn't a call, but it's enough like a virtual call
2725 // to use the same ciMethod accessor to get the profile info...)
2726 // If we have a speculative type use it instead of profiling (which
2727 // may not help us)
2728 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2729 if (exact_kls != NULL) {// no cast failures here
2730 if (require_klass == NULL ||
2731 C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2732 // If we narrow the type to match what the type profile sees or
2733 // the speculative type, we can then remove the rest of the
2734 // cast.
2735 // This is a win, even if the exact_kls is very specific,
2736 // because downstream operations, such as method calls,
2737 // will often benefit from the sharper type.
2738 Node* exact_obj = not_null_obj; // will get updated in place...
2739 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2740 &exact_obj);
2741 { PreserveJVMState pjvms(this);
2742 set_control(slow_ctl);
2743 uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2744 }
2745 if (safe_for_replace) {
2746 replace_in_map(not_null_obj, exact_obj);
2747 }
2748 return exact_obj;
2749 }
2750 // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2751 }
2752
2753 return NULL;
2754 }
2755
2756 /**
2757 * Cast obj to type and emit guard unless we had too many traps here
2758 * already
2759 *
2760 * @param obj node being casted
2761 * @param type type to cast the node to
2762 * @param not_null true if we know node cannot be null
2763 */
2764 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2765 ciKlass* type,
2766 bool not_null) {
2767 if (stopped()) {
2768 return obj;
2769 }
2770
2771 // type == NULL if profiling tells us this object is always null
2772 if (type != NULL) {
2773 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2774 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2775
2776 if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2777 !too_many_traps(class_reason) &&
2778 !too_many_recompiles(class_reason)) {
2779 Node* not_null_obj = NULL;
2780 // not_null is true if we know the object is not null and
2781 // there's no need for a null check
2782 if (!not_null) {
2783 Node* null_ctl = top();
2784 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2785 assert(null_ctl->is_top(), "no null control here");
2786 } else {
2787 not_null_obj = obj;
2788 }
2789
2790 Node* exact_obj = not_null_obj;
2791 ciKlass* exact_kls = type;
2792 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2793 &exact_obj);
2794 {
2795 PreserveJVMState pjvms(this);
2796 set_control(slow_ctl);
2797 uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2798 }
2799 replace_in_map(not_null_obj, exact_obj);
2800 obj = exact_obj;
2801 }
2802 } else {
2803 if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2804 !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2805 Node* exact_obj = null_assert(obj);
2806 replace_in_map(obj, exact_obj);
2807 obj = exact_obj;
2808 }
2809 }
2810 return obj;
2811 }
2812
2813 //-------------------------------gen_instanceof--------------------------------
2814 // Generate an instance-of idiom. Used by both the instance-of bytecode
2815 // and the reflective instance-of call.
2816 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2817 kill_dead_locals(); // Benefit all the uncommon traps
2818 assert( !stopped(), "dead parse path should be checked in callers" );
2819 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2820 "must check for not-null not-dead klass in callers");
2821
2822 // Make the merge point
2823 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2824 RegionNode* region = new RegionNode(PATH_LIMIT);
2825 Node* phi = new PhiNode(region, TypeInt::BOOL);
2826 C->set_has_split_ifs(true); // Has chance for split-if optimization
2827
2828 ciProfileData* data = NULL;
2829 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode
2830 data = method()->method_data()->bci_to_data(bci());
2831 }
2832 bool speculative_not_null = false;
2833 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile
2834 && seems_never_null(obj, data, speculative_not_null));
2835
2836 // Null check; get casted pointer; set region slot 3
2837 Node* null_ctl = top();
2838 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2839
2840 // If not_null_obj is dead, only null-path is taken
2841 if (stopped()) { // Doing instance-of on a NULL?
2842 set_control(null_ctl);
2843 return intcon(0);
2844 }
2845 region->init_req(_null_path, null_ctl);
2846 phi ->init_req(_null_path, intcon(0)); // Set null path value
2847 if (null_ctl == top()) {
2848 // Do this eagerly, so that pattern matches like is_diamond_phi
2849 // will work even during parsing.
2850 assert(_null_path == PATH_LIMIT-1, "delete last");
2851 region->del_req(_null_path);
2852 phi ->del_req(_null_path);
2853 }
2854
2855 // Do we know the type check always succeed?
2856 bool known_statically = false;
2857 if (_gvn.type(superklass)->singleton()) {
2858 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2859 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2860 if (subk != NULL && subk->is_loaded()) {
2861 int static_res = C->static_subtype_check(superk, subk);
2862 known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2863 }
2864 }
2865
2866 if (known_statically && UseTypeSpeculation) {
2867 // If we know the type check always succeeds then we don't use the
2868 // profiling data at this bytecode. Don't lose it, feed it to the
2869 // type system as a speculative type.
2870 not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2871 } else {
2872 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2873 // We may not have profiling here or it may not help us. If we
2874 // have a speculative type use it to perform an exact cast.
2875 ciKlass* spec_obj_type = obj_type->speculative_type();
2876 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2877 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2878 if (stopped()) { // Profile disagrees with this path.
2879 set_control(null_ctl); // Null is the only remaining possibility.
2880 return intcon(0);
2881 }
2882 if (cast_obj != NULL) {
2883 not_null_obj = cast_obj;
2884 }
2885 }
2886 }
2887
2888 // Load the object's klass
2889 Node* obj_klass = load_object_klass(not_null_obj);
2890
2891 // Generate the subtype check
2892 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2893
2894 // Plug in the success path to the general merge in slot 1.
2895 region->init_req(_obj_path, control());
2896 phi ->init_req(_obj_path, intcon(1));
2897
2898 // Plug in the failing path to the general merge in slot 2.
2899 region->init_req(_fail_path, not_subtype_ctrl);
2900 phi ->init_req(_fail_path, intcon(0));
2901
2902 // Return final merged results
2903 set_control( _gvn.transform(region) );
2904 record_for_igvn(region);
2905 return _gvn.transform(phi);
2906 }
2907
2908 //-------------------------------gen_checkcast---------------------------------
2909 // Generate a checkcast idiom. Used by both the checkcast bytecode and the
2910 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the
2911 // uncommon-trap paths work. Adjust stack after this call.
2912 // If failure_control is supplied and not null, it is filled in with
2913 // the control edge for the cast failure. Otherwise, an appropriate
2914 // uncommon trap or exception is thrown.
2915 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2916 Node* *failure_control) {
2917 kill_dead_locals(); // Benefit all the uncommon traps
2918 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2919 assert(tk->is_loaded(), "must be loaded");
2920 const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2921
2922 // Fast cutout: Check the case that the cast is vacuously true.
2923 // This detects the common cases where the test will short-circuit
2924 // away completely. We do this before we perform the null check,
2925 // because if the test is going to turn into zero code, we don't
2926 // want a residual null check left around. (Causes a slowdown,
2927 // for example, in some objArray manipulations, such as a[i]=a[j].)
2928 if (tk->singleton()) {
2929 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
2930 if (objtp != NULL && objtp->klass() != NULL) {
2931 switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
2932 case Compile::SSC_always_true:
2933 // If we know the type check always succeed then we don't use
2934 // the profiling data at this bytecode. Don't lose it, feed it
2935 // to the type system as a speculative type.
2936 return record_profiled_receiver_for_speculation(obj);
2937 case Compile::SSC_always_false:
2938 // It needs a null check because a null will *pass* the cast check.
2939 // A non-null value will always produce an exception.
2940 return null_assert(obj);
2941 }
2942 }
2943 }
2944
2945 ciProfileData* data = NULL;
2946 bool safe_for_replace = false;
2947 if (failure_control == NULL) { // use MDO in regular case only
2948 assert(java_bc() == Bytecodes::_aastore ||
2949 java_bc() == Bytecodes::_checkcast,
2950 "interpreter profiles type checks only for these BCs");
2951 data = method()->method_data()->bci_to_data(bci());
2952 safe_for_replace = true;
2953 }
2954
2955 // Make the merge point
2956 enum { _obj_path = 1, _null_path, PATH_LIMIT };
2957 RegionNode* region = new RegionNode(PATH_LIMIT);
2958 Node* phi = new PhiNode(region, toop);
2959 C->set_has_split_ifs(true); // Has chance for split-if optimization
2960
2961 // Use null-cast information if it is available
2962 bool speculative_not_null = false;
2963 bool never_see_null = ((failure_control == NULL) // regular case only
2964 && seems_never_null(obj, data, speculative_not_null));
2965
2966 // Null check; get casted pointer; set region slot 3
2967 Node* null_ctl = top();
2968 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2969
2970 // If not_null_obj is dead, only null-path is taken
2971 if (stopped()) { // Doing instance-of on a NULL?
2972 set_control(null_ctl);
2973 return null();
2974 }
2975 region->init_req(_null_path, null_ctl);
2976 phi ->init_req(_null_path, null()); // Set null path value
2977 if (null_ctl == top()) {
2978 // Do this eagerly, so that pattern matches like is_diamond_phi
2979 // will work even during parsing.
2980 assert(_null_path == PATH_LIMIT-1, "delete last");
2981 region->del_req(_null_path);
2982 phi ->del_req(_null_path);
2983 }
2984
2985 Node* cast_obj = NULL;
2986 if (tk->klass_is_exact()) {
2987 // The following optimization tries to statically cast the speculative type of the object
2988 // (for example obtained during profiling) to the type of the superklass and then do a
2989 // dynamic check that the type of the object is what we expect. To work correctly
2990 // for checkcast and aastore the type of superklass should be exact.
2991 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2992 // We may not have profiling here or it may not help us. If we have
2993 // a speculative type use it to perform an exact cast.
2994 ciKlass* spec_obj_type = obj_type->speculative_type();
2995 if (spec_obj_type != NULL || data != NULL) {
2996 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
2997 if (cast_obj != NULL) {
2998 if (failure_control != NULL) // failure is now impossible
2999 (*failure_control) = top();
3000 // adjust the type of the phi to the exact klass:
3001 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3002 }
3003 }
3004 }
3005
3006 if (cast_obj == NULL) {
3007 // Load the object's klass
3008 Node* obj_klass = load_object_klass(not_null_obj);
3009
3010 // Generate the subtype check
3011 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3012
3013 // Plug in success path into the merge
3014 cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3015 // Failure path ends in uncommon trap (or may be dead - failure impossible)
3016 if (failure_control == NULL) {
3017 if (not_subtype_ctrl != top()) { // If failure is possible
3018 PreserveJVMState pjvms(this);
3019 set_control(not_subtype_ctrl);
3020 builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3021 }
3022 } else {
3023 (*failure_control) = not_subtype_ctrl;
3024 }
3025 }
3026
3027 region->init_req(_obj_path, control());
3028 phi ->init_req(_obj_path, cast_obj);
3029
3030 // A merge of NULL or Casted-NotNull obj
3031 Node* res = _gvn.transform(phi);
3032
3033 // Note I do NOT always 'replace_in_map(obj,result)' here.
3034 // if( tk->klass()->can_be_primary_super() )
3035 // This means that if I successfully store an Object into an array-of-String
3036 // I 'forget' that the Object is really now known to be a String. I have to
3037 // do this because we don't have true union types for interfaces - if I store
3038 // a Baz into an array-of-Interface and then tell the optimizer it's an
3039 // Interface, I forget that it's also a Baz and cannot do Baz-like field
3040 // references to it. FIX THIS WHEN UNION TYPES APPEAR!
3041 // replace_in_map( obj, res );
3042
3043 // Return final merged results
3044 set_control( _gvn.transform(region) );
3045 record_for_igvn(region);
3046 return res;
3047 }
3048
3049 //------------------------------next_monitor-----------------------------------
3050 // What number should be given to the next monitor?
3051 int GraphKit::next_monitor() {
3052 int current = jvms()->monitor_depth()* C->sync_stack_slots();
3053 int next = current + C->sync_stack_slots();
3054 // Keep the toplevel high water mark current:
3055 if (C->fixed_slots() < next) C->set_fixed_slots(next);
3056 return current;
3057 }
3058
3059 //------------------------------insert_mem_bar---------------------------------
3060 // Memory barrier to avoid floating things around
3061 // The membar serves as a pinch point between both control and all memory slices.
3062 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3063 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3064 mb->init_req(TypeFunc::Control, control());
3065 mb->init_req(TypeFunc::Memory, reset_memory());
3066 Node* membar = _gvn.transform(mb);
3067 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3068 set_all_memory_call(membar);
3069 return membar;
3070 }
3071
3072 //-------------------------insert_mem_bar_volatile----------------------------
3073 // Memory barrier to avoid floating things around
3074 // The membar serves as a pinch point between both control and memory(alias_idx).
3075 // If you want to make a pinch point on all memory slices, do not use this
3076 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3077 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3078 // When Parse::do_put_xxx updates a volatile field, it appends a series
3079 // of MemBarVolatile nodes, one for *each* volatile field alias category.
3080 // The first membar is on the same memory slice as the field store opcode.
3081 // This forces the membar to follow the store. (Bug 6500685 broke this.)
3082 // All the other membars (for other volatile slices, including AliasIdxBot,
3083 // which stands for all unknown volatile slices) are control-dependent
3084 // on the first membar. This prevents later volatile loads or stores
3085 // from sliding up past the just-emitted store.
3086
3087 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3088 mb->set_req(TypeFunc::Control,control());
3089 if (alias_idx == Compile::AliasIdxBot) {
3090 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3091 } else {
3092 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3093 mb->set_req(TypeFunc::Memory, memory(alias_idx));
3094 }
3095 Node* membar = _gvn.transform(mb);
3096 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3097 if (alias_idx == Compile::AliasIdxBot) {
3098 merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3099 } else {
3100 set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3101 }
3102 return membar;
3103 }
3104
3105 //------------------------------shared_lock------------------------------------
3106 // Emit locking code.
3107 FastLockNode* GraphKit::shared_lock(Node* obj) {
3108 // bci is either a monitorenter bc or InvocationEntryBci
3109 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3110 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3111
3112 if( !GenerateSynchronizationCode )
3113 return NULL; // Not locking things?
3114 if (stopped()) // Dead monitor?
3115 return NULL;
3116
3117 assert(dead_locals_are_killed(), "should kill locals before sync. point");
3118
3119 // Box the stack location
3120 Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3121 Node* mem = reset_memory();
3122
3123 FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3124 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3125 // Create the counters for this fast lock.
3126 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3127 }
3128
3129 // Create the rtm counters for this fast lock if needed.
3130 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3131
3132 // Add monitor to debug info for the slow path. If we block inside the
3133 // slow path and de-opt, we need the monitor hanging around
3134 map()->push_monitor( flock );
3135
3136 const TypeFunc *tf = LockNode::lock_type();
3137 LockNode *lock = new LockNode(C, tf);
3138
3139 lock->init_req( TypeFunc::Control, control() );
3140 lock->init_req( TypeFunc::Memory , mem );
3141 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3142 lock->init_req( TypeFunc::FramePtr, frameptr() );
3143 lock->init_req( TypeFunc::ReturnAdr, top() );
3144
3145 lock->init_req(TypeFunc::Parms + 0, obj);
3146 lock->init_req(TypeFunc::Parms + 1, box);
3147 lock->init_req(TypeFunc::Parms + 2, flock);
3148 add_safepoint_edges(lock);
3149
3150 lock = _gvn.transform( lock )->as_Lock();
3151
3152 // lock has no side-effects, sets few values
3153 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3154
3155 insert_mem_bar(Op_MemBarAcquireLock);
3156
3157 // Add this to the worklist so that the lock can be eliminated
3158 record_for_igvn(lock);
3159
3160 #ifndef PRODUCT
3161 if (PrintLockStatistics) {
3162 // Update the counter for this lock. Don't bother using an atomic
3163 // operation since we don't require absolute accuracy.
3164 lock->create_lock_counter(map()->jvms());
3165 increment_counter(lock->counter()->addr());
3166 }
3167 #endif
3168
3169 return flock;
3170 }
3171
3172
3173 //------------------------------shared_unlock----------------------------------
3174 // Emit unlocking code.
3175 void GraphKit::shared_unlock(Node* box, Node* obj) {
3176 // bci is either a monitorenter bc or InvocationEntryBci
3177 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3178 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3179
3180 if( !GenerateSynchronizationCode )
3181 return;
3182 if (stopped()) { // Dead monitor?
3183 map()->pop_monitor(); // Kill monitor from debug info
3184 return;
3185 }
3186
3187 // Memory barrier to avoid floating things down past the locked region
3188 insert_mem_bar(Op_MemBarReleaseLock);
3189
3190 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3191 UnlockNode *unlock = new UnlockNode(C, tf);
3192 #ifdef ASSERT
3193 unlock->set_dbg_jvms(sync_jvms());
3194 #endif
3195 uint raw_idx = Compile::AliasIdxRaw;
3196 unlock->init_req( TypeFunc::Control, control() );
3197 unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3198 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3199 unlock->init_req( TypeFunc::FramePtr, frameptr() );
3200 unlock->init_req( TypeFunc::ReturnAdr, top() );
3201
3202 unlock->init_req(TypeFunc::Parms + 0, obj);
3203 unlock->init_req(TypeFunc::Parms + 1, box);
3204 unlock = _gvn.transform(unlock)->as_Unlock();
3205
3206 Node* mem = reset_memory();
3207
3208 // unlock has no side-effects, sets few values
3209 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3210
3211 // Kill monitor from debug info
3212 map()->pop_monitor( );
3213 }
3214
3215 //-------------------------------get_layout_helper-----------------------------
3216 // If the given klass is a constant or known to be an array,
3217 // fetch the constant layout helper value into constant_value
3218 // and return (Node*)NULL. Otherwise, load the non-constant
3219 // layout helper value, and return the node which represents it.
3220 // This two-faced routine is useful because allocation sites
3221 // almost always feature constant types.
3222 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3223 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3224 if (!StressReflectiveCode && inst_klass != NULL) {
3225 ciKlass* klass = inst_klass->klass();
3226 assert(klass != NULL, "klass should not be NULL");
3227 bool xklass = inst_klass->klass_is_exact();
3228 if (xklass || klass->is_array_klass()) {
3229 jint lhelper = klass->layout_helper();
3230 if (lhelper != Klass::_lh_neutral_value) {
3231 constant_value = lhelper;
3232 return (Node*) NULL;
3233 }
3234 }
3235 }
3236 constant_value = Klass::_lh_neutral_value; // put in a known value
3237 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3238 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3239 }
3240
3241 // We just put in an allocate/initialize with a big raw-memory effect.
3242 // Hook selected additional alias categories on the initialization.
3243 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3244 MergeMemNode* init_in_merge,
3245 Node* init_out_raw) {
3246 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3247 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3248
3249 Node* prevmem = kit.memory(alias_idx);
3250 init_in_merge->set_memory_at(alias_idx, prevmem);
3251 kit.set_memory(init_out_raw, alias_idx);
3252 }
3253
3254 //---------------------------set_output_for_allocation-------------------------
3255 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3256 const TypeOopPtr* oop_type,
3257 bool deoptimize_on_exception) {
3258 int rawidx = Compile::AliasIdxRaw;
3259 alloc->set_req( TypeFunc::FramePtr, frameptr() );
3260 add_safepoint_edges(alloc);
3261 Node* allocx = _gvn.transform(alloc);
3262 set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3263 // create memory projection for i_o
3264 set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3265 make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3266
3267 // create a memory projection as for the normal control path
3268 Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3269 set_memory(malloc, rawidx);
3270
3271 // a normal slow-call doesn't change i_o, but an allocation does
3272 // we create a separate i_o projection for the normal control path
3273 set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3274 Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3275
3276 // put in an initialization barrier
3277 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3278 rawoop)->as_Initialize();
3279 assert(alloc->initialization() == init, "2-way macro link must work");
3280 assert(init ->allocation() == alloc, "2-way macro link must work");
3281 {
3282 // Extract memory strands which may participate in the new object's
3283 // initialization, and source them from the new InitializeNode.
3284 // This will allow us to observe initializations when they occur,
3285 // and link them properly (as a group) to the InitializeNode.
3286 assert(init->in(InitializeNode::Memory) == malloc, "");
3287 MergeMemNode* minit_in = MergeMemNode::make(malloc);
3288 init->set_req(InitializeNode::Memory, minit_in);
3289 record_for_igvn(minit_in); // fold it up later, if possible
3290 Node* minit_out = memory(rawidx);
3291 assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3292 if (oop_type->isa_aryptr()) {
3293 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3294 int elemidx = C->get_alias_index(telemref);
3295 hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3296 } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3297 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3298 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3299 ciField* field = ik->nonstatic_field_at(i);
3300 if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3301 continue; // do not bother to track really large numbers of fields
3302 // Find (or create) the alias category for this field:
3303 int fieldidx = C->alias_type(field)->index();
3304 hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3305 }
3306 }
3307 }
3308
3309 // Cast raw oop to the real thing...
3310 Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3311 javaoop = _gvn.transform(javaoop);
3312 C->set_recent_alloc(control(), javaoop);
3313 assert(just_allocated_object(control()) == javaoop, "just allocated");
3314
3315 #ifdef ASSERT
3316 { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3317 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3318 "Ideal_allocation works");
3319 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3320 "Ideal_allocation works");
3321 if (alloc->is_AllocateArray()) {
3322 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3323 "Ideal_allocation works");
3324 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3325 "Ideal_allocation works");
3326 } else {
3327 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3328 }
3329 }
3330 #endif //ASSERT
3331
3332 return javaoop;
3333 }
3334
3335 //---------------------------new_instance--------------------------------------
3336 // This routine takes a klass_node which may be constant (for a static type)
3337 // or may be non-constant (for reflective code). It will work equally well
3338 // for either, and the graph will fold nicely if the optimizer later reduces
3339 // the type to a constant.
3340 // The optional arguments are for specialized use by intrinsics:
3341 // - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3342 // - If 'return_size_val', report the the total object size to the caller.
3343 // - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3344 Node* GraphKit::new_instance(Node* klass_node,
3345 Node* extra_slow_test,
3346 Node* *return_size_val,
3347 bool deoptimize_on_exception,
3348 ValueTypeNode* value_node) {
3349 // Compute size in doublewords
3350 // The size is always an integral number of doublewords, represented
3351 // as a positive bytewise size stored in the klass's layout_helper.
3352 // The layout_helper also encodes (in a low bit) the need for a slow path.
3353 jint layout_con = Klass::_lh_neutral_value;
3354 Node* layout_val = get_layout_helper(klass_node, layout_con);
3355 bool layout_is_con = (layout_val == NULL);
3356
3357 if (extra_slow_test == NULL) extra_slow_test = intcon(0);
3358 // Generate the initial go-slow test. It's either ALWAYS (return a
3359 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3360 // case) a computed value derived from the layout_helper.
3361 Node* initial_slow_test = NULL;
3362 if (layout_is_con) {
3363 assert(!StressReflectiveCode, "stress mode does not use these paths");
3364 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3365 initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3366 } else { // reflective case
3367 // This reflective path is used by Unsafe.allocateInstance.
3368 // (It may be stress-tested by specifying StressReflectiveCode.)
3369 // Basically, we want to get into the VM is there's an illegal argument.
3370 Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3371 initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3372 if (extra_slow_test != intcon(0)) {
3373 initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3374 }
3375 // (Macro-expander will further convert this to a Bool, if necessary.)
3376 }
3377
3378 // Find the size in bytes. This is easy; it's the layout_helper.
3379 // The size value must be valid even if the slow path is taken.
3380 Node* size = NULL;
3381 if (layout_is_con) {
3382 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3383 } else { // reflective case
3384 // This reflective path is used by clone and Unsafe.allocateInstance.
3385 size = ConvI2X(layout_val);
3386
3387 // Clear the low bits to extract layout_helper_size_in_bytes:
3388 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3389 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3390 size = _gvn.transform( new AndXNode(size, mask) );
3391 }
3392 if (return_size_val != NULL) {
3393 (*return_size_val) = size;
3394 }
3395
3396 // This is a precise notnull oop of the klass.
3397 // (Actually, it need not be precise if this is a reflective allocation.)
3398 // It's what we cast the result to.
3399 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3400 if (!tklass) tklass = TypeKlassPtr::OBJECT;
3401 const TypeOopPtr* oop_type = tklass->as_instance_type();
3402
3403 // Now generate allocation code
3404
3405 // The entire memory state is needed for slow path of the allocation
3406 // since GC and deoptimization can happen.
3407 Node *mem = reset_memory();
3408 set_all_memory(mem); // Create new memory state
3409
3410 AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3411 control(), mem, i_o(),
3412 size, klass_node,
3413 initial_slow_test, value_node);
3414
3415 return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3416 }
3417
3418 //-------------------------------new_array-------------------------------------
3419 // helper for newarray and anewarray
3420 // The 'length' parameter is (obviously) the length of the array.
3421 // See comments on new_instance for the meaning of the other arguments.
3422 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable)
3423 Node* length, // number of array elements
3424 int nargs, // number of arguments to push back for uncommon trap
3425 Node* *return_size_val,
3426 bool deoptimize_on_exception) {
3427 jint layout_con = Klass::_lh_neutral_value;
3428 Node* layout_val = get_layout_helper(klass_node, layout_con);
3429 bool layout_is_con = (layout_val == NULL);
3430
3431 if (!layout_is_con && !StressReflectiveCode &&
3432 !too_many_traps(Deoptimization::Reason_class_check)) {
3433 // This is a reflective array creation site.
3434 // Optimistically assume that it is a subtype of Object[],
3435 // so that we can fold up all the address arithmetic.
3436 layout_con = Klass::array_layout_helper(T_OBJECT);
3437 Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3438 Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3439 { BuildCutout unless(this, bol_lh, PROB_MAX);
3440 inc_sp(nargs);
3441 uncommon_trap(Deoptimization::Reason_class_check,
3442 Deoptimization::Action_maybe_recompile);
3443 }
3444 layout_val = NULL;
3445 layout_is_con = true;
3446 }
3447
3448 // Generate the initial go-slow test. Make sure we do not overflow
3449 // if length is huge (near 2Gig) or negative! We do not need
3450 // exact double-words here, just a close approximation of needed
3451 // double-words. We can't add any offset or rounding bits, lest we
3452 // take a size -1 of bytes and make it positive. Use an unsigned
3453 // compare, so negative sizes look hugely positive.
3454 int fast_size_limit = FastAllocateSizeLimit;
3455 if (layout_is_con) {
3456 assert(!StressReflectiveCode, "stress mode does not use these paths");
3457 // Increase the size limit if we have exact knowledge of array type.
3458 int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3459 fast_size_limit <<= (LogBytesPerLong - log2_esize);
3460 }
3461
3462 Node* initial_slow_cmp = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3463 Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3464
3465 // --- Size Computation ---
3466 // array_size = round_to_heap(array_header + (length << elem_shift));
3467 // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3468 // and round_to(x, y) == ((x + y-1) & ~(y-1))
3469 // The rounding mask is strength-reduced, if possible.
3470 int round_mask = MinObjAlignmentInBytes - 1;
3471 Node* header_size = NULL;
3472 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3473 // (T_BYTE has the weakest alignment and size restrictions...)
3474 if (layout_is_con) {
3475 int hsize = Klass::layout_helper_header_size(layout_con);
3476 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3477 BasicType etype = Klass::layout_helper_element_type(layout_con);
3478 bool is_value_array = Klass::layout_helper_is_valueArray(layout_con);
3479 if ((round_mask & ~right_n_bits(eshift)) == 0)
3480 round_mask = 0; // strength-reduce it if it goes away completely
3481 assert(is_value_array || (hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3482 assert(header_size_min <= hsize, "generic minimum is smallest");
3483 header_size_min = hsize;
3484 header_size = intcon(hsize + round_mask);
3485 } else {
3486 Node* hss = intcon(Klass::_lh_header_size_shift);
3487 Node* hsm = intcon(Klass::_lh_header_size_mask);
3488 Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3489 hsize = _gvn.transform( new AndINode(hsize, hsm) );
3490 Node* mask = intcon(round_mask);
3491 header_size = _gvn.transform( new AddINode(hsize, mask) );
3492 }
3493
3494 Node* elem_shift = NULL;
3495 if (layout_is_con) {
3496 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3497 if (eshift != 0)
3498 elem_shift = intcon(eshift);
3499 } else {
3500 // There is no need to mask or shift this value.
3501 // The semantics of LShiftINode include an implicit mask to 0x1F.
3502 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3503 elem_shift = layout_val;
3504 }
3505
3506 // Transition to native address size for all offset calculations:
3507 Node* lengthx = ConvI2X(length);
3508 Node* headerx = ConvI2X(header_size);
3509 #ifdef _LP64
3510 { const TypeInt* tilen = _gvn.find_int_type(length);
3511 if (tilen != NULL && tilen->_lo < 0) {
3512 // Add a manual constraint to a positive range. Cf. array_element_address.
3513 jint size_max = fast_size_limit;
3514 if (size_max > tilen->_hi) size_max = tilen->_hi;
3515 const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3516
3517 // Only do a narrow I2L conversion if the range check passed.
3518 IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3519 _gvn.transform(iff);
3520 RegionNode* region = new RegionNode(3);
3521 _gvn.set_type(region, Type::CONTROL);
3522 lengthx = new PhiNode(region, TypeLong::LONG);
3523 _gvn.set_type(lengthx, TypeLong::LONG);
3524
3525 // Range check passed. Use ConvI2L node with narrow type.
3526 Node* passed = IfFalse(iff);
3527 region->init_req(1, passed);
3528 // Make I2L conversion control dependent to prevent it from
3529 // floating above the range check during loop optimizations.
3530 lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3531
3532 // Range check failed. Use ConvI2L with wide type because length may be invalid.
3533 region->init_req(2, IfTrue(iff));
3534 lengthx->init_req(2, ConvI2X(length));
3535
3536 set_control(region);
3537 record_for_igvn(region);
3538 record_for_igvn(lengthx);
3539 }
3540 }
3541 #endif
3542
3543 // Combine header size (plus rounding) and body size. Then round down.
3544 // This computation cannot overflow, because it is used only in two
3545 // places, one where the length is sharply limited, and the other
3546 // after a successful allocation.
3547 Node* abody = lengthx;
3548 if (elem_shift != NULL)
3549 abody = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3550 Node* size = _gvn.transform( new AddXNode(headerx, abody) );
3551 if (round_mask != 0) {
3552 Node* mask = MakeConX(~round_mask);
3553 size = _gvn.transform( new AndXNode(size, mask) );
3554 }
3555 // else if round_mask == 0, the size computation is self-rounding
3556
3557 if (return_size_val != NULL) {
3558 // This is the size
3559 (*return_size_val) = size;
3560 }
3561
3562 // Now generate allocation code
3563
3564 // The entire memory state is needed for slow path of the allocation
3565 // since GC and deoptimization can happen.
3566 Node *mem = reset_memory();
3567 set_all_memory(mem); // Create new memory state
3568
3569 if (initial_slow_test->is_Bool()) {
3570 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3571 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3572 }
3573
3574 // Create the AllocateArrayNode and its result projections
3575 AllocateArrayNode* alloc
3576 = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3577 control(), mem, i_o(),
3578 size, klass_node,
3579 initial_slow_test,
3580 length);
3581
3582 // Cast to correct type. Note that the klass_node may be constant or not,
3583 // and in the latter case the actual array type will be inexact also.
3584 // (This happens via a non-constant argument to inline_native_newArray.)
3585 // In any case, the value of klass_node provides the desired array type.
3586 const TypeInt* length_type = _gvn.find_int_type(length);
3587 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3588 if (ary_type->isa_aryptr() && length_type != NULL) {
3589 // Try to get a better type than POS for the size
3590 ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3591 }
3592
3593 Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3594
3595 // Cast length on remaining path to be as narrow as possible
3596 if (map()->find_edge(length) >= 0) {
3597 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3598 if (ccast != length) {
3599 _gvn.set_type_bottom(ccast);
3600 record_for_igvn(ccast);
3601 replace_in_map(length, ccast);
3602 }
3603 }
3604
3605 const TypeAryPtr* ary_ptr = ary_type->isa_aryptr();
3606 ciKlass* elem_klass = ary_ptr != NULL ? ary_ptr->klass()->as_array_klass()->element_klass() : NULL;
3607 if (elem_klass != NULL && elem_klass->is_valuetype()) {
3608 ciValueKlass* vk = elem_klass->as_value_klass();
3609 if (!vk->flatten_array()) {
3610 // Non-flattened value type arrays need to be initialized with default value type oops
3611 initialize_value_type_array(javaoop, length, elem_klass->as_value_klass(), nargs);
3612 InitializeNode* init = alloc->initialization();
3613 init->set_complete_with_arraycopy();
3614 }
3615 }
3616
3617 return javaoop;
3618 }
3619
3620 void GraphKit::initialize_value_type_array(Node* array, Node* length, ciValueKlass* vk, int nargs) {
3621 // Check for zero length
3622 Node* null_ctl = top();
3623 null_check_common(length, T_INT, false, &null_ctl, false);
3624 if (stopped()) {
3625 set_control(null_ctl); // Always zero
3626 return;
3627 }
3628
3629 // Prepare for merging control and IO
3630 RegionNode* res_ctl = new RegionNode(3);
3631 res_ctl->init_req(1, null_ctl);
3632 gvn().set_type(res_ctl, Type::CONTROL);
3633 record_for_igvn(res_ctl);
3634 Node* res_io = PhiNode::make(res_ctl, i_o(), Type::ABIO);
3635 gvn().set_type(res_io, Type::ABIO);
3636 record_for_igvn(res_io);
3637
3638 // TODO comment
3639 SafePointNode* loop_map = NULL;
3640 {
3641 PreserveJVMState pjvms(this);
3642 // Create default value type and store it to memory
3643 Node* oop = ValueTypeNode::make_default(gvn(), vk);
3644 oop = oop->as_ValueType()->allocate(this);
3645
3646 length = SubI(length, intcon(1));
3647 add_predicate(nargs);
3648 RegionNode* loop = new RegionNode(3);
3649 loop->init_req(1, control());
3650 gvn().set_type(loop, Type::CONTROL);
3651 record_for_igvn(loop);
3652
3653 Node* index = new PhiNode(loop, TypeInt::INT);
3654 index->init_req(1, intcon(0));
3655 gvn().set_type(index, TypeInt::INT);
3656 record_for_igvn(index);
3657
3658 // TODO explain why we need to capture all memory
3659 PhiNode* mem = new PhiNode(loop, Type::MEMORY, TypePtr::BOTTOM);
3660 mem->init_req(1, reset_memory());
3661 gvn().set_type(mem, Type::MEMORY);
3662 record_for_igvn(mem);
3663 set_control(loop);
3664 set_all_memory(mem);
3665 // Initialize array element
3666 Node* adr = array_element_address(array, index, T_OBJECT);
3667 const TypeOopPtr* elemtype = TypeValueTypePtr::make(TypePtr::NotNull, vk);
3668 Node* store = store_oop_to_array(control(), array, adr, TypeAryPtr::OOPS, oop, elemtype, T_OBJECT, MemNode::release);
3669
3670 IfNode* iff = create_and_map_if(control(), Bool(CmpI(index, length), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3671 loop->init_req(2, IfTrue(iff));
3672 mem->init_req(2, merged_memory());
3673 index->init_req(2, AddI(index, intcon(1)));
3674
3675 res_ctl->init_req(2, IfFalse(iff));
3676 res_io->set_req(2, i_o());
3677 loop_map = stop();
3678 }
3679 // Set merged control, IO and memory
3680 set_control(res_ctl);
3681 set_i_o(res_io);
3682 merge_memory(loop_map->merged_memory(), res_ctl, 2);
3683
3684 // Transform new memory Phis.
3685 for (MergeMemStream mms(merged_memory()); mms.next_non_empty();) {
3686 Node* phi = mms.memory();
3687 if (phi->is_Phi() && phi->in(0) == res_ctl) {
3688 mms.set_memory(gvn().transform(phi));
3689 }
3690 }
3691 }
3692
3693 // The following "Ideal_foo" functions are placed here because they recognize
3694 // the graph shapes created by the functions immediately above.
3695
3696 //---------------------------Ideal_allocation----------------------------------
3697 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3698 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3699 if (ptr == NULL) { // reduce dumb test in callers
3700 return NULL;
3701 }
3702 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3703 ptr = ptr->in(1);
3704 if (ptr == NULL) return NULL;
3705 }
3706 // Return NULL for allocations with several casts:
3707 // j.l.reflect.Array.newInstance(jobject, jint)
3708 // Object.clone()
3709 // to keep more precise type from last cast.
3710 if (ptr->is_Proj()) {
3711 Node* allo = ptr->in(0);
3712 if (allo != NULL && allo->is_Allocate()) {
3713 return allo->as_Allocate();
3714 }
3715 }
3716 // Report failure to match.
3717 return NULL;
3718 }
3719
3720 // Fancy version which also strips off an offset (and reports it to caller).
3721 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3722 intptr_t& offset) {
3723 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3724 if (base == NULL) return NULL;
3725 return Ideal_allocation(base, phase);
3726 }
3727
3728 // Trace Initialize <- Proj[Parm] <- Allocate
3729 AllocateNode* InitializeNode::allocation() {
3730 Node* rawoop = in(InitializeNode::RawAddress);
3731 if (rawoop->is_Proj()) {
3732 Node* alloc = rawoop->in(0);
3733 if (alloc->is_Allocate()) {
3734 return alloc->as_Allocate();
3735 }
3736 }
3737 return NULL;
3738 }
3739
3740 // Trace Allocate -> Proj[Parm] -> Initialize
3741 InitializeNode* AllocateNode::initialization() {
3742 ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3743 if (rawoop == NULL) return NULL;
3744 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3745 Node* init = rawoop->fast_out(i);
3746 if (init->is_Initialize()) {
3747 assert(init->as_Initialize()->allocation() == this, "2-way link");
3748 return init->as_Initialize();
3749 }
3750 }
3751 return NULL;
3752 }
3753
3754 //----------------------------- loop predicates ---------------------------
3755
3756 //------------------------------add_predicate_impl----------------------------
3757 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3758 // Too many traps seen?
3759 if (too_many_traps(reason)) {
3760 #ifdef ASSERT
3761 if (TraceLoopPredicate) {
3762 int tc = C->trap_count(reason);
3763 tty->print("too many traps=%s tcount=%d in ",
3764 Deoptimization::trap_reason_name(reason), tc);
3765 method()->print(); // which method has too many predicate traps
3766 tty->cr();
3767 }
3768 #endif
3769 // We cannot afford to take more traps here,
3770 // do not generate predicate.
3771 return;
3772 }
3773
3774 Node *cont = _gvn.intcon(1);
3775 Node* opq = _gvn.transform(new Opaque1Node(C, cont));
3776 Node *bol = _gvn.transform(new Conv2BNode(opq));
3777 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3778 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3779 C->add_predicate_opaq(opq);
3780 {
3781 PreserveJVMState pjvms(this);
3782 set_control(iffalse);
3783 inc_sp(nargs);
3784 uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3785 }
3786 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3787 set_control(iftrue);
3788 }
3789
3790 //------------------------------add_predicate---------------------------------
3791 void GraphKit::add_predicate(int nargs) {
3792 if (UseLoopPredicate) {
3793 add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3794 }
3795 // loop's limit check predicate should be near the loop.
3796 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3797 }
3798
3799 //----------------------------- store barriers ----------------------------
3800 #define __ ideal.
3801
3802 void GraphKit::sync_kit(IdealKit& ideal) {
3803 set_all_memory(__ merged_memory());
3804 set_i_o(__ i_o());
3805 set_control(__ ctrl());
3806 }
3807
3808 void GraphKit::final_sync(IdealKit& ideal) {
3809 // Final sync IdealKit and graphKit.
3810 sync_kit(ideal);
3811 }
3812
3813 Node* GraphKit::byte_map_base_node() {
3814 // Get base of card map
3815 CardTableModRefBS* ct =
3816 barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3817 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3818 if (ct->byte_map_base != NULL) {
3819 return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3820 } else {
3821 return null();
3822 }
3823 }
3824
3825 // vanilla/CMS post barrier
3826 // Insert a write-barrier store. This is to let generational GC work; we have
3827 // to flag all oop-stores before the next GC point.
3828 void GraphKit::write_barrier_post(Node* oop_store,
3829 Node* obj,
3830 Node* adr,
3831 uint adr_idx,
3832 Node* val,
3833 bool use_precise) {
3834 // No store check needed if we're storing a NULL or an old object
3835 // (latter case is probably a string constant). The concurrent
3836 // mark sweep garbage collector, however, needs to have all nonNull
3837 // oop updates flagged via card-marks.
3838 if (val != NULL && val->is_Con()) {
3839 // must be either an oop or NULL
3840 const Type* t = val->bottom_type();
3841 if (t == TypePtr::NULL_PTR || t == Type::TOP)
3842 // stores of null never (?) need barriers
3843 return;
3844 }
3845
3846 if (use_ReduceInitialCardMarks()
3847 && obj == just_allocated_object(control())) {
3848 // We can skip marks on a freshly-allocated object in Eden.
3849 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3850 // That routine informs GC to take appropriate compensating steps,
3851 // upon a slow-path allocation, so as to make this card-mark
3852 // elision safe.
3853 return;
3854 }
3855
3856 if (!use_precise) {
3857 // All card marks for a (non-array) instance are in one place:
3858 adr = obj;
3859 }
3860 // (Else it's an array (or unknown), and we want more precise card marks.)
3861 assert(adr != NULL, "");
3862
3863 IdealKit ideal(this, true);
3864
3865 // Convert the pointer to an int prior to doing math on it
3866 Node* cast = __ CastPX(__ ctrl(), adr);
3867
3868 // Divide by card size
3869 assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3870 "Only one we handle so far.");
3871 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3872
3873 // Combine card table base and card offset
3874 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3875
3876 // Get the alias_index for raw card-mark memory
3877 int adr_type = Compile::AliasIdxRaw;
3878 Node* zero = __ ConI(0); // Dirty card value
3879 BasicType bt = T_BYTE;
3880
3881 if (UseConcMarkSweepGC && UseCondCardMark) {
3882 insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
3883 __ sync_kit(this);
3884 }
3885
3886 if (UseCondCardMark) {
3887 // The classic GC reference write barrier is typically implemented
3888 // as a store into the global card mark table. Unfortunately
3889 // unconditional stores can result in false sharing and excessive
3890 // coherence traffic as well as false transactional aborts.
3891 // UseCondCardMark enables MP "polite" conditional card mark
3892 // stores. In theory we could relax the load from ctrl() to
3893 // no_ctrl, but that doesn't buy much latitude.
3894 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3895 __ if_then(card_val, BoolTest::ne, zero);
3896 }
3897
3898 // Smash zero into card
3899 if( !UseConcMarkSweepGC ) {
3900 __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3901 } else {
3902 // Specialized path for CM store barrier
3903 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3904 }
3905
3906 if (UseCondCardMark) {
3907 __ end_if();
3908 }
3909
3910 // Final sync IdealKit and GraphKit.
3911 final_sync(ideal);
3912 }
3913 /*
3914 * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3915 * required by SATB to make sure all objects live at the start of the
3916 * marking are kept alive, all reference updates need to any previous
3917 * reference stored before writing.
3918 *
3919 * If the previous value is NULL there is no need to save the old value.
3920 * References that are NULL are filtered during runtime by the barrier
3921 * code to avoid unnecessary queuing.
3922 *
3923 * However in the case of newly allocated objects it might be possible to
3924 * prove that the reference about to be overwritten is NULL during compile
3925 * time and avoid adding the barrier code completely.
3926 *
3927 * The compiler needs to determine that the object in which a field is about
3928 * to be written is newly allocated, and that no prior store to the same field
3929 * has happened since the allocation.
3930 *
3931 * Returns true if the pre-barrier can be removed
3932 */
3933 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3934 BasicType bt, uint adr_idx) {
3935 intptr_t offset = 0;
3936 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3937 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3938
3939 if (offset == Type::OffsetBot) {
3940 return false; // cannot unalias unless there are precise offsets
3941 }
3942
3943 if (alloc == NULL) {
3944 return false; // No allocation found
3945 }
3946
3947 intptr_t size_in_bytes = type2aelembytes(bt);
3948
3949 Node* mem = memory(adr_idx); // start searching here...
3950
3951 for (int cnt = 0; cnt < 50; cnt++) {
3952
3953 if (mem->is_Store()) {
3954
3955 Node* st_adr = mem->in(MemNode::Address);
3956 intptr_t st_offset = 0;
3957 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3958
3959 if (st_base == NULL) {
3960 break; // inscrutable pointer
3961 }
3962
3963 // Break we have found a store with same base and offset as ours so break
3964 if (st_base == base && st_offset == offset) {
3965 break;
3966 }
3967
3968 if (st_offset != offset && st_offset != Type::OffsetBot) {
3969 const int MAX_STORE = BytesPerLong;
3970 if (st_offset >= offset + size_in_bytes ||
3971 st_offset <= offset - MAX_STORE ||
3972 st_offset <= offset - mem->as_Store()->memory_size()) {
3973 // Success: The offsets are provably independent.
3974 // (You may ask, why not just test st_offset != offset and be done?
3975 // The answer is that stores of different sizes can co-exist
3976 // in the same sequence of RawMem effects. We sometimes initialize
3977 // a whole 'tile' of array elements with a single jint or jlong.)
3978 mem = mem->in(MemNode::Memory);
3979 continue; // advance through independent store memory
3980 }
3981 }
3982
3983 if (st_base != base
3984 && MemNode::detect_ptr_independence(base, alloc, st_base,
3985 AllocateNode::Ideal_allocation(st_base, phase),
3986 phase)) {
3987 // Success: The bases are provably independent.
3988 mem = mem->in(MemNode::Memory);
3989 continue; // advance through independent store memory
3990 }
3991 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
3992
3993 InitializeNode* st_init = mem->in(0)->as_Initialize();
3994 AllocateNode* st_alloc = st_init->allocation();
3995
3996 // Make sure that we are looking at the same allocation site.
3997 // The alloc variable is guaranteed to not be null here from earlier check.
3998 if (alloc == st_alloc) {
3999 // Check that the initialization is storing NULL so that no previous store
4000 // has been moved up and directly write a reference
4001 Node* captured_store = st_init->find_captured_store(offset,
4002 type2aelembytes(T_OBJECT),
4003 phase);
4004 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4005 return true;
4006 }
4007 }
4008 }
4009
4010 // Unless there is an explicit 'continue', we must bail out here,
4011 // because 'mem' is an inscrutable memory state (e.g., a call).
4012 break;
4013 }
4014
4015 return false;
4016 }
4017
4018 // G1 pre/post barriers
4019 void GraphKit::g1_write_barrier_pre(bool do_load,
4020 Node* obj,
4021 Node* adr,
4022 uint alias_idx,
4023 Node* val,
4024 const TypeOopPtr* val_type,
4025 Node* pre_val,
4026 BasicType bt) {
4027
4028 // Some sanity checks
4029 // Note: val is unused in this routine.
4030
4031 if (do_load) {
4032 // We need to generate the load of the previous value
4033 assert(obj != NULL, "must have a base");
4034 assert(adr != NULL, "where are loading from?");
4035 assert(pre_val == NULL, "loaded already?");
4036 assert(val_type != NULL, "need a type");
4037
4038 if (use_ReduceInitialCardMarks()
4039 && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4040 return;
4041 }
4042
4043 } else {
4044 // In this case both val_type and alias_idx are unused.
4045 assert(pre_val != NULL, "must be loaded already");
4046 // Nothing to be done if pre_val is null.
4047 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4048 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4049 }
4050 assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4051
4052 IdealKit ideal(this, true);
4053
4054 Node* tls = __ thread(); // ThreadLocalStorage
4055
4056 Node* no_ctrl = NULL;
4057 Node* no_base = __ top();
4058 Node* zero = __ ConI(0);
4059 Node* zeroX = __ ConX(0);
4060
4061 float likely = PROB_LIKELY(0.999);
4062 float unlikely = PROB_UNLIKELY(0.999);
4063
4064 BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4065 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4066
4067 // Offsets into the thread
4068 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648
4069 SATBMarkQueue::byte_offset_of_active());
4070 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656
4071 SATBMarkQueue::byte_offset_of_index());
4072 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652
4073 SATBMarkQueue::byte_offset_of_buf());
4074
4075 // Now the actual pointers into the thread
4076 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4077 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4078 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4079
4080 // Now some of the values
4081 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4082
4083 // if (!marking)
4084 __ if_then(marking, BoolTest::ne, zero, unlikely); {
4085 BasicType index_bt = TypeX_X->basic_type();
4086 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4087 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4088
4089 if (do_load) {
4090 // load original value
4091 // alias_idx correct??
4092 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4093 }
4094
4095 // if (pre_val != NULL)
4096 __ if_then(pre_val, BoolTest::ne, null()); {
4097 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4098
4099 // is the queue for this thread full?
4100 __ if_then(index, BoolTest::ne, zeroX, likely); {
4101
4102 // decrement the index
4103 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4104
4105 // Now get the buffer location we will log the previous value into and store it
4106 Node *log_addr = __ AddP(no_base, buffer, next_index);
4107 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4108 // update the index
4109 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4110
4111 } __ else_(); {
4112
4113 // logging buffer is full, call the runtime
4114 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4115 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4116 } __ end_if(); // (!index)
4117 } __ end_if(); // (pre_val != NULL)
4118 } __ end_if(); // (!marking)
4119
4120 // Final sync IdealKit and GraphKit.
4121 final_sync(ideal);
4122 }
4123
4124 /*
4125 * G1 similar to any GC with a Young Generation requires a way to keep track of
4126 * references from Old Generation to Young Generation to make sure all live
4127 * objects are found. G1 also requires to keep track of object references
4128 * between different regions to enable evacuation of old regions, which is done
4129 * as part of mixed collections. References are tracked in remembered sets and
4130 * is continuously updated as reference are written to with the help of the
4131 * post-barrier.
4132 *
4133 * To reduce the number of updates to the remembered set the post-barrier
4134 * filters updates to fields in objects located in the Young Generation,
4135 * the same region as the reference, when the NULL is being written or
4136 * if the card is already marked as dirty by an earlier write.
4137 *
4138 * Under certain circumstances it is possible to avoid generating the
4139 * post-barrier completely if it is possible during compile time to prove
4140 * the object is newly allocated and that no safepoint exists between the
4141 * allocation and the store.
4142 *
4143 * In the case of slow allocation the allocation code must handle the barrier
4144 * as part of the allocation in the case the allocated object is not located
4145 * in the nursery, this would happen for humongous objects. This is similar to
4146 * how CMS is required to handle this case, see the comments for the method
4147 * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4148 * A deferred card mark is required for these objects and handled in the above
4149 * mentioned methods.
4150 *
4151 * Returns true if the post barrier can be removed
4152 */
4153 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4154 Node* adr) {
4155 intptr_t offset = 0;
4156 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4157 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4158
4159 if (offset == Type::OffsetBot) {
4160 return false; // cannot unalias unless there are precise offsets
4161 }
4162
4163 if (alloc == NULL) {
4164 return false; // No allocation found
4165 }
4166
4167 // Start search from Store node
4168 Node* mem = store->in(MemNode::Control);
4169 if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4170
4171 InitializeNode* st_init = mem->in(0)->as_Initialize();
4172 AllocateNode* st_alloc = st_init->allocation();
4173
4174 // Make sure we are looking at the same allocation
4175 if (alloc == st_alloc) {
4176 return true;
4177 }
4178 }
4179
4180 return false;
4181 }
4182
4183 //
4184 // Update the card table and add card address to the queue
4185 //
4186 void GraphKit::g1_mark_card(IdealKit& ideal,
4187 Node* card_adr,
4188 Node* oop_store,
4189 uint oop_alias_idx,
4190 Node* index,
4191 Node* index_adr,
4192 Node* buffer,
4193 const TypeFunc* tf) {
4194
4195 Node* zero = __ ConI(0);
4196 Node* zeroX = __ ConX(0);
4197 Node* no_base = __ top();
4198 BasicType card_bt = T_BYTE;
4199 // Smash zero into card. MUST BE ORDERED WRT TO STORE
4200 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4201
4202 // Now do the queue work
4203 __ if_then(index, BoolTest::ne, zeroX); {
4204
4205 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4206 Node* log_addr = __ AddP(no_base, buffer, next_index);
4207
4208 // Order, see storeCM.
4209 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4210 __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4211
4212 } __ else_(); {
4213 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4214 } __ end_if();
4215
4216 }
4217
4218 void GraphKit::g1_write_barrier_post(Node* oop_store,
4219 Node* obj,
4220 Node* adr,
4221 uint alias_idx,
4222 Node* val,
4223 BasicType bt,
4224 bool use_precise) {
4225 // If we are writing a NULL then we need no post barrier
4226
4227 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4228 // Must be NULL
4229 const Type* t = val->bottom_type();
4230 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4231 // No post barrier if writing NULLx
4232 return;
4233 }
4234
4235 if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4236 // We can skip marks on a freshly-allocated object in Eden.
4237 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4238 // That routine informs GC to take appropriate compensating steps,
4239 // upon a slow-path allocation, so as to make this card-mark
4240 // elision safe.
4241 return;
4242 }
4243
4244 if (use_ReduceInitialCardMarks()
4245 && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4246 return;
4247 }
4248
4249 if (!use_precise) {
4250 // All card marks for a (non-array) instance are in one place:
4251 adr = obj;
4252 }
4253 // (Else it's an array (or unknown), and we want more precise card marks.)
4254 assert(adr != NULL, "");
4255
4256 IdealKit ideal(this, true);
4257
4258 Node* tls = __ thread(); // ThreadLocalStorage
4259
4260 Node* no_base = __ top();
4261 float likely = PROB_LIKELY(0.999);
4262 float unlikely = PROB_UNLIKELY(0.999);
4263 Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4264 Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4265 Node* zeroX = __ ConX(0);
4266
4267 // Get the alias_index for raw card-mark memory
4268 const TypePtr* card_type = TypeRawPtr::BOTTOM;
4269
4270 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4271
4272 // Offsets into the thread
4273 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4274 DirtyCardQueue::byte_offset_of_index());
4275 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4276 DirtyCardQueue::byte_offset_of_buf());
4277
4278 // Pointers into the thread
4279
4280 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4281 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4282
4283 // Now some values
4284 // Use ctrl to avoid hoisting these values past a safepoint, which could
4285 // potentially reset these fields in the JavaThread.
4286 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4287 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4288
4289 // Convert the store obj pointer to an int prior to doing math on it
4290 // Must use ctrl to prevent "integerized oop" existing across safepoint
4291 Node* cast = __ CastPX(__ ctrl(), adr);
4292
4293 // Divide pointer by card size
4294 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4295
4296 // Combine card table base and card offset
4297 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4298
4299 // If we know the value being stored does it cross regions?
4300
4301 if (val != NULL) {
4302 // Does the store cause us to cross regions?
4303
4304 // Should be able to do an unsigned compare of region_size instead of
4305 // and extra shift. Do we have an unsigned compare??
4306 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4307 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4308
4309 // if (xor_res == 0) same region so skip
4310 __ if_then(xor_res, BoolTest::ne, zeroX); {
4311
4312 // No barrier if we are storing a NULL
4313 __ if_then(val, BoolTest::ne, null(), unlikely); {
4314
4315 // Ok must mark the card if not already dirty
4316
4317 // load the original value of the card
4318 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4319
4320 __ if_then(card_val, BoolTest::ne, young_card); {
4321 sync_kit(ideal);
4322 // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4323 insert_mem_bar(Op_MemBarVolatile, oop_store);
4324 __ sync_kit(this);
4325
4326 Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4327 __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4328 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4329 } __ end_if();
4330 } __ end_if();
4331 } __ end_if();
4332 } __ end_if();
4333 } else {
4334 // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4335 // We don't need a barrier here if the destination is a newly allocated object
4336 // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4337 // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4338 assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4339 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4340 __ if_then(card_val, BoolTest::ne, young_card); {
4341 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4342 } __ end_if();
4343 }
4344
4345 // Final sync IdealKit and GraphKit.
4346 final_sync(ideal);
4347 }
4348 #undef __
4349
4350
4351 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4352 Node* len = load_array_length(load_String_value(ctrl, str));
4353 Node* coder = load_String_coder(ctrl, str);
4354 // Divide length by 2 if coder is UTF16
4355 return _gvn.transform(new RShiftINode(len, coder));
4356 }
4357
4358 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4359 int value_offset = java_lang_String::value_offset_in_bytes();
4360 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4361 false, NULL, Type::Offset(0));
4362 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4363 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4364 TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4365 ciTypeArrayKlass::make(T_BYTE), true, Type::Offset(0));
4366 int value_field_idx = C->get_alias_index(value_field_type);
4367 Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4368 value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4369 // String.value field is known to be @Stable.
4370 if (UseImplicitStableValues) {
4371 load = cast_array_to_stable(load, value_type);
4372 }
4373 return load;
4374 }
4375
4376 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4377 if (!CompactStrings) {
4378 return intcon(java_lang_String::CODER_UTF16);
4379 }
4380 int coder_offset = java_lang_String::coder_offset_in_bytes();
4381 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4382 false, NULL, Type::Offset(0));
4383 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4384 int coder_field_idx = C->get_alias_index(coder_field_type);
4385 return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4386 TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4387 }
4388
4389 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4390 int value_offset = java_lang_String::value_offset_in_bytes();
4391 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4392 false, NULL, Type::Offset(0));
4393 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4394 store_oop_to_object(ctrl, str, basic_plus_adr(str, value_offset), value_field_type,
4395 value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4396 }
4397
4398 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4399 int coder_offset = java_lang_String::coder_offset_in_bytes();
4400 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4401 false, NULL, Type::Offset(0));
4402 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4403 int coder_field_idx = C->get_alias_index(coder_field_type);
4404 store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4405 value, T_BYTE, coder_field_idx, MemNode::unordered);
4406 }
4407
4408 // Capture src and dst memory state with a MergeMemNode
4409 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4410 if (src_type == dst_type) {
4411 // Types are equal, we don't need a MergeMemNode
4412 return memory(src_type);
4413 }
4414 MergeMemNode* merge = MergeMemNode::make(map()->memory());
4415 record_for_igvn(merge); // fold it up later, if possible
4416 int src_idx = C->get_alias_index(src_type);
4417 int dst_idx = C->get_alias_index(dst_type);
4418 merge->set_memory_at(src_idx, memory(src_idx));
4419 merge->set_memory_at(dst_idx, memory(dst_idx));
4420 return merge;
4421 }
4422
4423 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4424 assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4425 assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4426 // If input and output memory types differ, capture both states to preserve
4427 // the dependency between preceding and subsequent loads/stores.
4428 // For example, the following program:
4429 // StoreB
4430 // compress_string
4431 // LoadB
4432 // has this memory graph (use->def):
4433 // LoadB -> compress_string -> CharMem
4434 // ... -> StoreB -> ByteMem
4435 // The intrinsic hides the dependency between LoadB and StoreB, causing
4436 // the load to read from memory not containing the result of the StoreB.
4437 // The correct memory graph should look like this:
4438 // LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4439 Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4440 StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4441 Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4442 set_memory(res_mem, TypeAryPtr::BYTES);
4443 return str;
4444 }
4445
4446 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4447 assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4448 assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4449 // Capture src and dst memory (see comment in 'compress_string').
4450 Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4451 StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4452 set_memory(_gvn.transform(str), dst_type);
4453 }
4454
4455 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4456 /**
4457 * int i_char = start;
4458 * for (int i_byte = 0; i_byte < count; i_byte++) {
4459 * dst[i_char++] = (char)(src[i_byte] & 0xff);
4460 * }
4461 */
4462 add_predicate();
4463 RegionNode* head = new RegionNode(3);
4464 head->init_req(1, control());
4465 gvn().set_type(head, Type::CONTROL);
4466 record_for_igvn(head);
4467
4468 Node* i_byte = new PhiNode(head, TypeInt::INT);
4469 i_byte->init_req(1, intcon(0));
4470 gvn().set_type(i_byte, TypeInt::INT);
4471 record_for_igvn(i_byte);
4472
4473 Node* i_char = new PhiNode(head, TypeInt::INT);
4474 i_char->init_req(1, start);
4475 gvn().set_type(i_char, TypeInt::INT);
4476 record_for_igvn(i_char);
4477
4478 Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4479 gvn().set_type(mem, Type::MEMORY);
4480 record_for_igvn(mem);
4481 set_control(head);
4482 set_memory(mem, TypeAryPtr::BYTES);
4483 Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4484 Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4485 AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4486 false, false, true /* mismatched */);
4487
4488 IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4489 head->init_req(2, IfTrue(iff));
4490 mem->init_req(2, st);
4491 i_byte->init_req(2, AddI(i_byte, intcon(1)));
4492 i_char->init_req(2, AddI(i_char, intcon(2)));
4493
4494 set_control(IfFalse(iff));
4495 set_memory(st, TypeAryPtr::BYTES);
4496 }
4497
4498 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4499 if (!field->is_constant()) {
4500 return NULL; // Field not marked as constant.
4501 }
4502 ciInstance* holder = NULL;
4503 if (!field->is_static()) {
4504 ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4505 if (const_oop != NULL && const_oop->is_instance()) {
4506 holder = const_oop->as_instance();
4507 }
4508 }
4509 const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4510 /*is_unsigned_load=*/false);
4511 if (con_type != NULL) {
4512 Node* con = makecon(con_type);
4513 if (field->layout_type() == T_VALUETYPE) {
4514 // Load value type from constant oop
4515 con = ValueTypeNode::make(gvn(), map()->memory(), con);
4516 }
4517 return con;
4518 }
4519 return NULL;
4520 }
4521
4522 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4523 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4524 // assumption of CCP analysis.
4525 return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4526 }