1 /*
2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
28 #include "gc/g1/heapRegion.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/cardTableModRefBS.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "opto/addnode.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/convertnode.hpp"
36 #include "opto/graphKit.hpp"
37 #include "opto/idealKit.hpp"
38 #include "opto/intrinsicnode.hpp"
39 #include "opto/locknode.hpp"
40 #include "opto/machnode.hpp"
41 #include "opto/opaquenode.hpp"
42 #include "opto/parse.hpp"
43 #include "opto/rootnode.hpp"
44 #include "opto/runtime.hpp"
45 #include "runtime/deoptimization.hpp"
46 #include "runtime/sharedRuntime.hpp"
47
48 //----------------------------GraphKit-----------------------------------------
49 // Main utility constructor.
50 GraphKit::GraphKit(JVMState* jvms)
51 : Phase(Phase::Parser),
52 _env(C->env()),
53 _gvn(*C->initial_gvn())
54 {
55 _exceptions = jvms->map()->next_exception();
56 if (_exceptions != NULL) jvms->map()->set_next_exception(NULL);
57 set_jvms(jvms);
58 }
59
60 // Private constructor for parser.
61 GraphKit::GraphKit()
62 : Phase(Phase::Parser),
63 _env(C->env()),
64 _gvn(*C->initial_gvn())
65 {
66 _exceptions = NULL;
67 set_map(NULL);
68 debug_only(_sp = -99);
69 debug_only(set_bci(-99));
70 }
71
72
73
74 //---------------------------clean_stack---------------------------------------
75 // Clear away rubbish from the stack area of the JVM state.
76 // This destroys any arguments that may be waiting on the stack.
77 void GraphKit::clean_stack(int from_sp) {
78 SafePointNode* map = this->map();
79 JVMState* jvms = this->jvms();
80 int stk_size = jvms->stk_size();
81 int stkoff = jvms->stkoff();
82 Node* top = this->top();
83 for (int i = from_sp; i < stk_size; i++) {
84 if (map->in(stkoff + i) != top) {
85 map->set_req(stkoff + i, top);
86 }
87 }
88 }
89
90
91 //--------------------------------sync_jvms-----------------------------------
92 // Make sure our current jvms agrees with our parse state.
93 JVMState* GraphKit::sync_jvms() const {
94 JVMState* jvms = this->jvms();
95 jvms->set_bci(bci()); // Record the new bci in the JVMState
96 jvms->set_sp(sp()); // Record the new sp in the JVMState
97 assert(jvms_in_sync(), "jvms is now in sync");
98 return jvms;
99 }
100
101 //--------------------------------sync_jvms_for_reexecute---------------------
102 // Make sure our current jvms agrees with our parse state. This version
103 // uses the reexecute_sp for reexecuting bytecodes.
104 JVMState* GraphKit::sync_jvms_for_reexecute() {
105 JVMState* jvms = this->jvms();
106 jvms->set_bci(bci()); // Record the new bci in the JVMState
107 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState
108 return jvms;
109 }
110
111 #ifdef ASSERT
112 bool GraphKit::jvms_in_sync() const {
113 Parse* parse = is_Parse();
114 if (parse == NULL) {
115 if (bci() != jvms()->bci()) return false;
116 if (sp() != (int)jvms()->sp()) return false;
117 return true;
118 }
119 if (jvms()->method() != parse->method()) return false;
120 if (jvms()->bci() != parse->bci()) return false;
121 int jvms_sp = jvms()->sp();
122 if (jvms_sp != parse->sp()) return false;
123 int jvms_depth = jvms()->depth();
124 if (jvms_depth != parse->depth()) return false;
125 return true;
126 }
127
128 // Local helper checks for special internal merge points
129 // used to accumulate and merge exception states.
130 // They are marked by the region's in(0) edge being the map itself.
131 // Such merge points must never "escape" into the parser at large,
132 // until they have been handed to gvn.transform.
133 static bool is_hidden_merge(Node* reg) {
134 if (reg == NULL) return false;
135 if (reg->is_Phi()) {
136 reg = reg->in(0);
137 if (reg == NULL) return false;
138 }
139 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
140 }
141
142 void GraphKit::verify_map() const {
143 if (map() == NULL) return; // null map is OK
144 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
145 assert(!map()->has_exceptions(), "call add_exception_states_from 1st");
146 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
147 }
148
149 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
150 assert(ex_map->next_exception() == NULL, "not already part of a chain");
151 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
152 }
153 #endif
154
155 //---------------------------stop_and_kill_map---------------------------------
156 // Set _map to NULL, signalling a stop to further bytecode execution.
157 // First smash the current map's control to a constant, to mark it dead.
158 void GraphKit::stop_and_kill_map() {
159 SafePointNode* dead_map = stop();
160 if (dead_map != NULL) {
161 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
162 assert(dead_map->is_killed(), "must be so marked");
163 }
164 }
165
166
167 //--------------------------------stopped--------------------------------------
168 // Tell if _map is NULL, or control is top.
169 bool GraphKit::stopped() {
170 if (map() == NULL) return true;
171 else if (control() == top()) return true;
172 else return false;
173 }
174
175
176 //-----------------------------has_ex_handler----------------------------------
177 // Tell if this method or any caller method has exception handlers.
178 bool GraphKit::has_ex_handler() {
179 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
180 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
181 return true;
182 }
183 }
184 return false;
185 }
186
187 //------------------------------save_ex_oop------------------------------------
188 // Save an exception without blowing stack contents or other JVM state.
189 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
190 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
191 ex_map->add_req(ex_oop);
192 debug_only(verify_exception_state(ex_map));
193 }
194
195 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
196 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
197 Node* ex_oop = ex_map->in(ex_map->req()-1);
198 if (clear_it) ex_map->del_req(ex_map->req()-1);
199 return ex_oop;
200 }
201
202 //-----------------------------saved_ex_oop------------------------------------
203 // Recover a saved exception from its map.
204 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
205 return common_saved_ex_oop(ex_map, false);
206 }
207
208 //--------------------------clear_saved_ex_oop---------------------------------
209 // Erase a previously saved exception from its map.
210 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
211 return common_saved_ex_oop(ex_map, true);
212 }
213
214 #ifdef ASSERT
215 //---------------------------has_saved_ex_oop----------------------------------
216 // Erase a previously saved exception from its map.
217 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
218 return ex_map->req() == ex_map->jvms()->endoff()+1;
219 }
220 #endif
221
222 //-------------------------make_exception_state--------------------------------
223 // Turn the current JVM state into an exception state, appending the ex_oop.
224 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
225 sync_jvms();
226 SafePointNode* ex_map = stop(); // do not manipulate this map any more
227 set_saved_ex_oop(ex_map, ex_oop);
228 return ex_map;
229 }
230
231
232 //--------------------------add_exception_state--------------------------------
233 // Add an exception to my list of exceptions.
234 void GraphKit::add_exception_state(SafePointNode* ex_map) {
235 if (ex_map == NULL || ex_map->control() == top()) {
236 return;
237 }
238 #ifdef ASSERT
239 verify_exception_state(ex_map);
240 if (has_exceptions()) {
241 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
242 }
243 #endif
244
245 // If there is already an exception of exactly this type, merge with it.
246 // In particular, null-checks and other low-level exceptions common up here.
247 Node* ex_oop = saved_ex_oop(ex_map);
248 const Type* ex_type = _gvn.type(ex_oop);
249 if (ex_oop == top()) {
250 // No action needed.
251 return;
252 }
253 assert(ex_type->isa_instptr(), "exception must be an instance");
254 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
255 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
256 // We check sp also because call bytecodes can generate exceptions
257 // both before and after arguments are popped!
258 if (ex_type2 == ex_type
259 && e2->_jvms->sp() == ex_map->_jvms->sp()) {
260 combine_exception_states(ex_map, e2);
261 return;
262 }
263 }
264
265 // No pre-existing exception of the same type. Chain it on the list.
266 push_exception_state(ex_map);
267 }
268
269 //-----------------------add_exception_states_from-----------------------------
270 void GraphKit::add_exception_states_from(JVMState* jvms) {
271 SafePointNode* ex_map = jvms->map()->next_exception();
272 if (ex_map != NULL) {
273 jvms->map()->set_next_exception(NULL);
274 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
275 next_map = ex_map->next_exception();
276 ex_map->set_next_exception(NULL);
277 add_exception_state(ex_map);
278 }
279 }
280 }
281
282 //-----------------------transfer_exceptions_into_jvms-------------------------
283 JVMState* GraphKit::transfer_exceptions_into_jvms() {
284 if (map() == NULL) {
285 // We need a JVMS to carry the exceptions, but the map has gone away.
286 // Create a scratch JVMS, cloned from any of the exception states...
287 if (has_exceptions()) {
288 _map = _exceptions;
289 _map = clone_map();
290 _map->set_next_exception(NULL);
291 clear_saved_ex_oop(_map);
292 debug_only(verify_map());
293 } else {
294 // ...or created from scratch
295 JVMState* jvms = new (C) JVMState(_method, NULL);
296 jvms->set_bci(_bci);
297 jvms->set_sp(_sp);
298 jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
299 set_jvms(jvms);
300 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top());
301 set_all_memory(top());
302 while (map()->req() < jvms->endoff()) map()->add_req(top());
303 }
304 // (This is a kludge, in case you didn't notice.)
305 set_control(top());
306 }
307 JVMState* jvms = sync_jvms();
308 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
309 jvms->map()->set_next_exception(_exceptions);
310 _exceptions = NULL; // done with this set of exceptions
311 return jvms;
312 }
313
314 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
315 assert(is_hidden_merge(dstphi), "must be a special merge node");
316 assert(is_hidden_merge(srcphi), "must be a special merge node");
317 uint limit = srcphi->req();
318 for (uint i = PhiNode::Input; i < limit; i++) {
319 dstphi->add_req(srcphi->in(i));
320 }
321 }
322 static inline void add_one_req(Node* dstphi, Node* src) {
323 assert(is_hidden_merge(dstphi), "must be a special merge node");
324 assert(!is_hidden_merge(src), "must not be a special merge node");
325 dstphi->add_req(src);
326 }
327
328 //-----------------------combine_exception_states------------------------------
329 // This helper function combines exception states by building phis on a
330 // specially marked state-merging region. These regions and phis are
331 // untransformed, and can build up gradually. The region is marked by
332 // having a control input of its exception map, rather than NULL. Such
333 // regions do not appear except in this function, and in use_exception_state.
334 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
335 if (failing()) return; // dying anyway...
336 JVMState* ex_jvms = ex_map->_jvms;
337 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
338 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
339 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
340 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
341 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
342 assert(ex_map->req() == phi_map->req(), "matching maps");
343 uint tos = ex_jvms->stkoff() + ex_jvms->sp();
344 Node* hidden_merge_mark = root();
345 Node* region = phi_map->control();
346 MergeMemNode* phi_mem = phi_map->merged_memory();
347 MergeMemNode* ex_mem = ex_map->merged_memory();
348 if (region->in(0) != hidden_merge_mark) {
349 // The control input is not (yet) a specially-marked region in phi_map.
350 // Make it so, and build some phis.
351 region = new RegionNode(2);
352 _gvn.set_type(region, Type::CONTROL);
353 region->set_req(0, hidden_merge_mark); // marks an internal ex-state
354 region->init_req(1, phi_map->control());
355 phi_map->set_control(region);
356 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
357 record_for_igvn(io_phi);
358 _gvn.set_type(io_phi, Type::ABIO);
359 phi_map->set_i_o(io_phi);
360 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
361 Node* m = mms.memory();
362 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
363 record_for_igvn(m_phi);
364 _gvn.set_type(m_phi, Type::MEMORY);
365 mms.set_memory(m_phi);
366 }
367 }
368
369 // Either or both of phi_map and ex_map might already be converted into phis.
370 Node* ex_control = ex_map->control();
371 // if there is special marking on ex_map also, we add multiple edges from src
372 bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
373 // how wide was the destination phi_map, originally?
374 uint orig_width = region->req();
375
376 if (add_multiple) {
377 add_n_reqs(region, ex_control);
378 add_n_reqs(phi_map->i_o(), ex_map->i_o());
379 } else {
380 // ex_map has no merges, so we just add single edges everywhere
381 add_one_req(region, ex_control);
382 add_one_req(phi_map->i_o(), ex_map->i_o());
383 }
384 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
385 if (mms.is_empty()) {
386 // get a copy of the base memory, and patch some inputs into it
387 const TypePtr* adr_type = mms.adr_type(C);
388 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
389 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
390 mms.set_memory(phi);
391 // Prepare to append interesting stuff onto the newly sliced phi:
392 while (phi->req() > orig_width) phi->del_req(phi->req()-1);
393 }
394 // Append stuff from ex_map:
395 if (add_multiple) {
396 add_n_reqs(mms.memory(), mms.memory2());
397 } else {
398 add_one_req(mms.memory(), mms.memory2());
399 }
400 }
401 uint limit = ex_map->req();
402 for (uint i = TypeFunc::Parms; i < limit; i++) {
403 // Skip everything in the JVMS after tos. (The ex_oop follows.)
404 if (i == tos) i = ex_jvms->monoff();
405 Node* src = ex_map->in(i);
406 Node* dst = phi_map->in(i);
407 if (src != dst) {
408 PhiNode* phi;
409 if (dst->in(0) != region) {
410 dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
411 record_for_igvn(phi);
412 _gvn.set_type(phi, phi->type());
413 phi_map->set_req(i, dst);
414 // Prepare to append interesting stuff onto the new phi:
415 while (dst->req() > orig_width) dst->del_req(dst->req()-1);
416 } else {
417 assert(dst->is_Phi(), "nobody else uses a hidden region");
418 phi = dst->as_Phi();
419 }
420 if (add_multiple && src->in(0) == ex_control) {
421 // Both are phis.
422 add_n_reqs(dst, src);
423 } else {
424 while (dst->req() < region->req()) add_one_req(dst, src);
425 }
426 const Type* srctype = _gvn.type(src);
427 if (phi->type() != srctype) {
428 const Type* dsttype = phi->type()->meet_speculative(srctype);
429 if (phi->type() != dsttype) {
430 phi->set_type(dsttype);
431 _gvn.set_type(phi, dsttype);
432 }
433 }
434 }
435 }
436 phi_map->merge_replaced_nodes_with(ex_map);
437 }
438
439 //--------------------------use_exception_state--------------------------------
440 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
441 if (failing()) { stop(); return top(); }
442 Node* region = phi_map->control();
443 Node* hidden_merge_mark = root();
444 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
445 Node* ex_oop = clear_saved_ex_oop(phi_map);
446 if (region->in(0) == hidden_merge_mark) {
447 // Special marking for internal ex-states. Process the phis now.
448 region->set_req(0, region); // now it's an ordinary region
449 set_jvms(phi_map->jvms()); // ...so now we can use it as a map
450 // Note: Setting the jvms also sets the bci and sp.
451 set_control(_gvn.transform(region));
452 uint tos = jvms()->stkoff() + sp();
453 for (uint i = 1; i < tos; i++) {
454 Node* x = phi_map->in(i);
455 if (x->in(0) == region) {
456 assert(x->is_Phi(), "expected a special phi");
457 phi_map->set_req(i, _gvn.transform(x));
458 }
459 }
460 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
461 Node* x = mms.memory();
462 if (x->in(0) == region) {
463 assert(x->is_Phi(), "nobody else uses a hidden region");
464 mms.set_memory(_gvn.transform(x));
465 }
466 }
467 if (ex_oop->in(0) == region) {
468 assert(ex_oop->is_Phi(), "expected a special phi");
469 ex_oop = _gvn.transform(ex_oop);
470 }
471 } else {
472 set_jvms(phi_map->jvms());
473 }
474
475 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
476 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
477 return ex_oop;
478 }
479
480 //---------------------------------java_bc-------------------------------------
481 Bytecodes::Code GraphKit::java_bc() const {
482 ciMethod* method = this->method();
483 int bci = this->bci();
484 if (method != NULL && bci != InvocationEntryBci)
485 return method->java_code_at_bci(bci);
486 else
487 return Bytecodes::_illegal;
488 }
489
490 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
491 bool must_throw) {
492 // if the exception capability is set, then we will generate code
493 // to check the JavaThread.should_post_on_exceptions flag to see
494 // if we actually need to report exception events (for this
495 // thread). If we don't need to report exception events, we will
496 // take the normal fast path provided by add_exception_events. If
497 // exception event reporting is enabled for this thread, we will
498 // take the uncommon_trap in the BuildCutout below.
499
500 // first must access the should_post_on_exceptions_flag in this thread's JavaThread
501 Node* jthread = _gvn.transform(new ThreadLocalNode());
502 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
503 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
504
505 // Test the should_post_on_exceptions_flag vs. 0
506 Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
507 Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
508
509 // Branch to slow_path if should_post_on_exceptions_flag was true
510 { BuildCutout unless(this, tst, PROB_MAX);
511 // Do not try anything fancy if we're notifying the VM on every throw.
512 // Cf. case Bytecodes::_athrow in parse2.cpp.
513 uncommon_trap(reason, Deoptimization::Action_none,
514 (ciKlass*)NULL, (char*)NULL, must_throw);
515 }
516
517 }
518
519 //------------------------------builtin_throw----------------------------------
520 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
521 bool must_throw = true;
522
523 if (env()->jvmti_can_post_on_exceptions()) {
524 // check if we must post exception events, take uncommon trap if so
525 uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
526 // here if should_post_on_exceptions is false
527 // continue on with the normal codegen
528 }
529
530 // If this particular condition has not yet happened at this
531 // bytecode, then use the uncommon trap mechanism, and allow for
532 // a future recompilation if several traps occur here.
533 // If the throw is hot, try to use a more complicated inline mechanism
534 // which keeps execution inside the compiled code.
535 bool treat_throw_as_hot = false;
536 ciMethodData* md = method()->method_data();
537
538 if (ProfileTraps) {
539 if (too_many_traps(reason)) {
540 treat_throw_as_hot = true;
541 }
542 // (If there is no MDO at all, assume it is early in
543 // execution, and that any deopts are part of the
544 // startup transient, and don't need to be remembered.)
545
546 // Also, if there is a local exception handler, treat all throws
547 // as hot if there has been at least one in this method.
548 if (C->trap_count(reason) != 0
549 && method()->method_data()->trap_count(reason) != 0
550 && has_ex_handler()) {
551 treat_throw_as_hot = true;
552 }
553 }
554
555 // If this throw happens frequently, an uncommon trap might cause
556 // a performance pothole. If there is a local exception handler,
557 // and if this particular bytecode appears to be deoptimizing often,
558 // let us handle the throw inline, with a preconstructed instance.
559 // Note: If the deopt count has blown up, the uncommon trap
560 // runtime is going to flush this nmethod, not matter what.
561 if (treat_throw_as_hot
562 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
563 // If the throw is local, we use a pre-existing instance and
564 // punt on the backtrace. This would lead to a missing backtrace
565 // (a repeat of 4292742) if the backtrace object is ever asked
566 // for its backtrace.
567 // Fixing this remaining case of 4292742 requires some flavor of
568 // escape analysis. Leave that for the future.
569 ciInstance* ex_obj = NULL;
570 switch (reason) {
571 case Deoptimization::Reason_null_check:
572 ex_obj = env()->NullPointerException_instance();
573 break;
574 case Deoptimization::Reason_div0_check:
575 ex_obj = env()->ArithmeticException_instance();
576 break;
577 case Deoptimization::Reason_range_check:
578 ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
579 break;
580 case Deoptimization::Reason_class_check:
581 if (java_bc() == Bytecodes::_aastore) {
582 ex_obj = env()->ArrayStoreException_instance();
583 } else {
584 ex_obj = env()->ClassCastException_instance();
585 }
586 break;
587 }
588 if (failing()) { stop(); return; } // exception allocation might fail
589 if (ex_obj != NULL) {
590 // Cheat with a preallocated exception object.
591 if (C->log() != NULL)
592 C->log()->elem("hot_throw preallocated='1' reason='%s'",
593 Deoptimization::trap_reason_name(reason));
594 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj);
595 Node* ex_node = _gvn.transform(ConNode::make(ex_con));
596
597 // Clear the detail message of the preallocated exception object.
598 // Weblogic sometimes mutates the detail message of exceptions
599 // using reflection.
600 int offset = java_lang_Throwable::get_detailMessage_offset();
601 const TypePtr* adr_typ = ex_con->add_offset(offset);
602
603 Node *adr = basic_plus_adr(ex_node, ex_node, offset);
604 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
605 // Conservatively release stores of object references.
606 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
607
608 add_exception_state(make_exception_state(ex_node));
609 return;
610 }
611 }
612
613 // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
614 // It won't be much cheaper than bailing to the interp., since we'll
615 // have to pass up all the debug-info, and the runtime will have to
616 // create the stack trace.
617
618 // Usual case: Bail to interpreter.
619 // Reserve the right to recompile if we haven't seen anything yet.
620
621 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
622 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
623 if (treat_throw_as_hot
624 && (method()->method_data()->trap_recompiled_at(bci(), m)
625 || C->too_many_traps(reason))) {
626 // We cannot afford to take more traps here. Suffer in the interpreter.
627 if (C->log() != NULL)
628 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
629 Deoptimization::trap_reason_name(reason),
630 C->trap_count(reason));
631 action = Deoptimization::Action_none;
632 }
633
634 // "must_throw" prunes the JVM state to include only the stack, if there
635 // are no local exception handlers. This should cut down on register
636 // allocation time and code size, by drastically reducing the number
637 // of in-edges on the call to the uncommon trap.
638
639 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
640 }
641
642
643 //----------------------------PreserveJVMState---------------------------------
644 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
645 debug_only(kit->verify_map());
646 _kit = kit;
647 _map = kit->map(); // preserve the map
648 _sp = kit->sp();
649 kit->set_map(clone_map ? kit->clone_map() : NULL);
650 #ifdef ASSERT
651 _bci = kit->bci();
652 Parse* parser = kit->is_Parse();
653 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
654 _block = block;
655 #endif
656 }
657 PreserveJVMState::~PreserveJVMState() {
658 GraphKit* kit = _kit;
659 #ifdef ASSERT
660 assert(kit->bci() == _bci, "bci must not shift");
661 Parse* parser = kit->is_Parse();
662 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
663 assert(block == _block, "block must not shift");
664 #endif
665 kit->set_map(_map);
666 kit->set_sp(_sp);
667 }
668
669
670 //-----------------------------BuildCutout-------------------------------------
671 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
672 : PreserveJVMState(kit)
673 {
674 assert(p->is_Con() || p->is_Bool(), "test must be a bool");
675 SafePointNode* outer_map = _map; // preserved map is caller's
676 SafePointNode* inner_map = kit->map();
677 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
678 outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
679 inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
680 }
681 BuildCutout::~BuildCutout() {
682 GraphKit* kit = _kit;
683 assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
684 }
685
686 //---------------------------PreserveReexecuteState----------------------------
687 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
688 assert(!kit->stopped(), "must call stopped() before");
689 _kit = kit;
690 _sp = kit->sp();
691 _reexecute = kit->jvms()->_reexecute;
692 }
693 PreserveReexecuteState::~PreserveReexecuteState() {
694 if (_kit->stopped()) return;
695 _kit->jvms()->_reexecute = _reexecute;
696 _kit->set_sp(_sp);
697 }
698
699 //------------------------------clone_map--------------------------------------
700 // Implementation of PreserveJVMState
701 //
702 // Only clone_map(...) here. If this function is only used in the
703 // PreserveJVMState class we may want to get rid of this extra
704 // function eventually and do it all there.
705
706 SafePointNode* GraphKit::clone_map() {
707 if (map() == NULL) return NULL;
708
709 // Clone the memory edge first
710 Node* mem = MergeMemNode::make(map()->memory());
711 gvn().set_type_bottom(mem);
712
713 SafePointNode *clonemap = (SafePointNode*)map()->clone();
714 JVMState* jvms = this->jvms();
715 JVMState* clonejvms = jvms->clone_shallow(C);
716 clonemap->set_memory(mem);
717 clonemap->set_jvms(clonejvms);
718 clonejvms->set_map(clonemap);
719 record_for_igvn(clonemap);
720 gvn().set_type_bottom(clonemap);
721 return clonemap;
722 }
723
724
725 //-----------------------------set_map_clone-----------------------------------
726 void GraphKit::set_map_clone(SafePointNode* m) {
727 _map = m;
728 _map = clone_map();
729 _map->set_next_exception(NULL);
730 debug_only(verify_map());
731 }
732
733
734 //----------------------------kill_dead_locals---------------------------------
735 // Detect any locals which are known to be dead, and force them to top.
736 void GraphKit::kill_dead_locals() {
737 // Consult the liveness information for the locals. If any
738 // of them are unused, then they can be replaced by top(). This
739 // should help register allocation time and cut down on the size
740 // of the deoptimization information.
741
742 // This call is made from many of the bytecode handling
743 // subroutines called from the Big Switch in do_one_bytecode.
744 // Every bytecode which might include a slow path is responsible
745 // for killing its dead locals. The more consistent we
746 // are about killing deads, the fewer useless phis will be
747 // constructed for them at various merge points.
748
749 // bci can be -1 (InvocationEntryBci). We return the entry
750 // liveness for the method.
751
752 if (method() == NULL || method()->code_size() == 0) {
753 // We are building a graph for a call to a native method.
754 // All locals are live.
755 return;
756 }
757
758 ResourceMark rm;
759
760 // Consult the liveness information for the locals. If any
761 // of them are unused, then they can be replaced by top(). This
762 // should help register allocation time and cut down on the size
763 // of the deoptimization information.
764 MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
765
766 int len = (int)live_locals.size();
767 assert(len <= jvms()->loc_size(), "too many live locals");
768 for (int local = 0; local < len; local++) {
769 if (!live_locals.at(local)) {
770 set_local(local, top());
771 }
772 }
773 }
774
775 #ifdef ASSERT
776 //-------------------------dead_locals_are_killed------------------------------
777 // Return true if all dead locals are set to top in the map.
778 // Used to assert "clean" debug info at various points.
779 bool GraphKit::dead_locals_are_killed() {
780 if (method() == NULL || method()->code_size() == 0) {
781 // No locals need to be dead, so all is as it should be.
782 return true;
783 }
784
785 // Make sure somebody called kill_dead_locals upstream.
786 ResourceMark rm;
787 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
788 if (jvms->loc_size() == 0) continue; // no locals to consult
789 SafePointNode* map = jvms->map();
790 ciMethod* method = jvms->method();
791 int bci = jvms->bci();
792 if (jvms == this->jvms()) {
793 bci = this->bci(); // it might not yet be synched
794 }
795 MethodLivenessResult live_locals = method->liveness_at_bci(bci);
796 int len = (int)live_locals.size();
797 if (!live_locals.is_valid() || len == 0)
798 // This method is trivial, or is poisoned by a breakpoint.
799 return true;
800 assert(len == jvms->loc_size(), "live map consistent with locals map");
801 for (int local = 0; local < len; local++) {
802 if (!live_locals.at(local) && map->local(jvms, local) != top()) {
803 if (PrintMiscellaneous && (Verbose || WizardMode)) {
804 tty->print_cr("Zombie local %d: ", local);
805 jvms->dump();
806 }
807 return false;
808 }
809 }
810 }
811 return true;
812 }
813
814 #endif //ASSERT
815
816 // Helper function for enforcing certain bytecodes to reexecute if
817 // deoptimization happens
818 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
819 ciMethod* cur_method = jvms->method();
820 int cur_bci = jvms->bci();
821 if (cur_method != NULL && cur_bci != InvocationEntryBci) {
822 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
823 return Interpreter::bytecode_should_reexecute(code) ||
824 is_anewarray && code == Bytecodes::_multianewarray;
825 // Reexecute _multianewarray bytecode which was replaced with
826 // sequence of [a]newarray. See Parse::do_multianewarray().
827 //
828 // Note: interpreter should not have it set since this optimization
829 // is limited by dimensions and guarded by flag so in some cases
830 // multianewarray() runtime calls will be generated and
831 // the bytecode should not be reexecutes (stack will not be reset).
832 } else
833 return false;
834 }
835
836 // Helper function for adding JVMState and debug information to node
837 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
838 // Add the safepoint edges to the call (or other safepoint).
839
840 // Make sure dead locals are set to top. This
841 // should help register allocation time and cut down on the size
842 // of the deoptimization information.
843 assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
844
845 // Walk the inline list to fill in the correct set of JVMState's
846 // Also fill in the associated edges for each JVMState.
847
848 // If the bytecode needs to be reexecuted we need to put
849 // the arguments back on the stack.
850 const bool should_reexecute = jvms()->should_reexecute();
851 JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
852
853 // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
854 // undefined if the bci is different. This is normal for Parse but it
855 // should not happen for LibraryCallKit because only one bci is processed.
856 assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
857 "in LibraryCallKit the reexecute bit should not change");
858
859 // If we are guaranteed to throw, we can prune everything but the
860 // input to the current bytecode.
861 bool can_prune_locals = false;
862 uint stack_slots_not_pruned = 0;
863 int inputs = 0, depth = 0;
864 if (must_throw) {
865 assert(method() == youngest_jvms->method(), "sanity");
866 if (compute_stack_effects(inputs, depth)) {
867 can_prune_locals = true;
868 stack_slots_not_pruned = inputs;
869 }
870 }
871
872 if (env()->should_retain_local_variables()) {
873 // At any safepoint, this method can get breakpointed, which would
874 // then require an immediate deoptimization.
875 can_prune_locals = false; // do not prune locals
876 stack_slots_not_pruned = 0;
877 }
878
879 // do not scribble on the input jvms
880 JVMState* out_jvms = youngest_jvms->clone_deep(C);
881 call->set_jvms(out_jvms); // Start jvms list for call node
882
883 // For a known set of bytecodes, the interpreter should reexecute them if
884 // deoptimization happens. We set the reexecute state for them here
885 if (out_jvms->is_reexecute_undefined() && //don't change if already specified
886 should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
887 out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
888 }
889
890 // Presize the call:
891 DEBUG_ONLY(uint non_debug_edges = call->req());
892 call->add_req_batch(top(), youngest_jvms->debug_depth());
893 assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
894
895 // Set up edges so that the call looks like this:
896 // Call [state:] ctl io mem fptr retadr
897 // [parms:] parm0 ... parmN
898 // [root:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
899 // [...mid:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
900 // [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
901 // Note that caller debug info precedes callee debug info.
902
903 // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
904 uint debug_ptr = call->req();
905
906 // Loop over the map input edges associated with jvms, add them
907 // to the call node, & reset all offsets to match call node array.
908 for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
909 uint debug_end = debug_ptr;
910 uint debug_start = debug_ptr - in_jvms->debug_size();
911 debug_ptr = debug_start; // back up the ptr
912
913 uint p = debug_start; // walks forward in [debug_start, debug_end)
914 uint j, k, l;
915 SafePointNode* in_map = in_jvms->map();
916 out_jvms->set_map(call);
917
918 if (can_prune_locals) {
919 assert(in_jvms->method() == out_jvms->method(), "sanity");
920 // If the current throw can reach an exception handler in this JVMS,
921 // then we must keep everything live that can reach that handler.
922 // As a quick and dirty approximation, we look for any handlers at all.
923 if (in_jvms->method()->has_exception_handlers()) {
924 can_prune_locals = false;
925 }
926 }
927
928 // Add the Locals
929 k = in_jvms->locoff();
930 l = in_jvms->loc_size();
931 out_jvms->set_locoff(p);
932 if (!can_prune_locals) {
933 for (j = 0; j < l; j++)
934 call->set_req(p++, in_map->in(k+j));
935 } else {
936 p += l; // already set to top above by add_req_batch
937 }
938
939 // Add the Expression Stack
940 k = in_jvms->stkoff();
941 l = in_jvms->sp();
942 out_jvms->set_stkoff(p);
943 if (!can_prune_locals) {
944 for (j = 0; j < l; j++)
945 call->set_req(p++, in_map->in(k+j));
946 } else if (can_prune_locals && stack_slots_not_pruned != 0) {
947 // Divide stack into {S0,...,S1}, where S0 is set to top.
948 uint s1 = stack_slots_not_pruned;
949 stack_slots_not_pruned = 0; // for next iteration
950 if (s1 > l) s1 = l;
951 uint s0 = l - s1;
952 p += s0; // skip the tops preinstalled by add_req_batch
953 for (j = s0; j < l; j++)
954 call->set_req(p++, in_map->in(k+j));
955 } else {
956 p += l; // already set to top above by add_req_batch
957 }
958
959 // Add the Monitors
960 k = in_jvms->monoff();
961 l = in_jvms->mon_size();
962 out_jvms->set_monoff(p);
963 for (j = 0; j < l; j++)
964 call->set_req(p++, in_map->in(k+j));
965
966 // Copy any scalar object fields.
967 k = in_jvms->scloff();
968 l = in_jvms->scl_size();
969 out_jvms->set_scloff(p);
970 for (j = 0; j < l; j++)
971 call->set_req(p++, in_map->in(k+j));
972
973 // Finish the new jvms.
974 out_jvms->set_endoff(p);
975
976 assert(out_jvms->endoff() == debug_end, "fill ptr must match");
977 assert(out_jvms->depth() == in_jvms->depth(), "depth must match");
978 assert(out_jvms->loc_size() == in_jvms->loc_size(), "size must match");
979 assert(out_jvms->mon_size() == in_jvms->mon_size(), "size must match");
980 assert(out_jvms->scl_size() == in_jvms->scl_size(), "size must match");
981 assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
982
983 // Update the two tail pointers in parallel.
984 out_jvms = out_jvms->caller();
985 in_jvms = in_jvms->caller();
986 }
987
988 assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
989
990 // Test the correctness of JVMState::debug_xxx accessors:
991 assert(call->jvms()->debug_start() == non_debug_edges, "");
992 assert(call->jvms()->debug_end() == call->req(), "");
993 assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
994 }
995
996 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
997 Bytecodes::Code code = java_bc();
998 if (code == Bytecodes::_wide) {
999 code = method()->java_code_at_bci(bci() + 1);
1000 }
1001
1002 BasicType rtype = T_ILLEGAL;
1003 int rsize = 0;
1004
1005 if (code != Bytecodes::_illegal) {
1006 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1007 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1008 if (rtype < T_CONFLICT)
1009 rsize = type2size[rtype];
1010 }
1011
1012 switch (code) {
1013 case Bytecodes::_illegal:
1014 return false;
1015
1016 case Bytecodes::_ldc:
1017 case Bytecodes::_ldc_w:
1018 case Bytecodes::_ldc2_w:
1019 inputs = 0;
1020 break;
1021
1022 case Bytecodes::_dup: inputs = 1; break;
1023 case Bytecodes::_dup_x1: inputs = 2; break;
1024 case Bytecodes::_dup_x2: inputs = 3; break;
1025 case Bytecodes::_dup2: inputs = 2; break;
1026 case Bytecodes::_dup2_x1: inputs = 3; break;
1027 case Bytecodes::_dup2_x2: inputs = 4; break;
1028 case Bytecodes::_swap: inputs = 2; break;
1029 case Bytecodes::_arraylength: inputs = 1; break;
1030
1031 case Bytecodes::_getstatic:
1032 case Bytecodes::_putstatic:
1033 case Bytecodes::_getfield:
1034 case Bytecodes::_putfield:
1035 {
1036 bool ignored_will_link;
1037 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1038 int size = field->type()->size();
1039 bool is_get = (depth >= 0), is_static = (depth & 1);
1040 inputs = (is_static ? 0 : 1);
1041 if (is_get) {
1042 depth = size - inputs;
1043 } else {
1044 inputs += size; // putxxx pops the value from the stack
1045 depth = - inputs;
1046 }
1047 }
1048 break;
1049
1050 case Bytecodes::_invokevirtual:
1051 case Bytecodes::_invokespecial:
1052 case Bytecodes::_invokestatic:
1053 case Bytecodes::_invokedynamic:
1054 case Bytecodes::_invokeinterface:
1055 {
1056 bool ignored_will_link;
1057 ciSignature* declared_signature = NULL;
1058 ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1059 assert(declared_signature != NULL, "cannot be null");
1060 inputs = declared_signature->arg_size_for_bc(code);
1061 int size = declared_signature->return_type()->size();
1062 depth = size - inputs;
1063 }
1064 break;
1065
1066 case Bytecodes::_multianewarray:
1067 {
1068 ciBytecodeStream iter(method());
1069 iter.reset_to_bci(bci());
1070 iter.next();
1071 inputs = iter.get_dimensions();
1072 assert(rsize == 1, "");
1073 depth = rsize - inputs;
1074 }
1075 break;
1076
1077 case Bytecodes::_ireturn:
1078 case Bytecodes::_lreturn:
1079 case Bytecodes::_freturn:
1080 case Bytecodes::_dreturn:
1081 case Bytecodes::_areturn:
1082 assert(rsize == -depth, "");
1083 inputs = rsize;
1084 break;
1085
1086 case Bytecodes::_jsr:
1087 case Bytecodes::_jsr_w:
1088 inputs = 0;
1089 depth = 1; // S.B. depth=1, not zero
1090 break;
1091
1092 default:
1093 // bytecode produces a typed result
1094 inputs = rsize - depth;
1095 assert(inputs >= 0, "");
1096 break;
1097 }
1098
1099 #ifdef ASSERT
1100 // spot check
1101 int outputs = depth + inputs;
1102 assert(outputs >= 0, "sanity");
1103 switch (code) {
1104 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1105 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break;
1106 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break;
1107 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break;
1108 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break;
1109 }
1110 #endif //ASSERT
1111
1112 return true;
1113 }
1114
1115
1116
1117 //------------------------------basic_plus_adr---------------------------------
1118 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1119 // short-circuit a common case
1120 if (offset == intcon(0)) return ptr;
1121 return _gvn.transform( new AddPNode(base, ptr, offset) );
1122 }
1123
1124 Node* GraphKit::ConvI2L(Node* offset) {
1125 // short-circuit a common case
1126 jint offset_con = find_int_con(offset, Type::OffsetBot);
1127 if (offset_con != Type::OffsetBot) {
1128 return longcon((jlong) offset_con);
1129 }
1130 return _gvn.transform( new ConvI2LNode(offset));
1131 }
1132
1133 Node* GraphKit::ConvI2UL(Node* offset) {
1134 juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1135 if (offset_con != (juint) Type::OffsetBot) {
1136 return longcon((julong) offset_con);
1137 }
1138 Node* conv = _gvn.transform( new ConvI2LNode(offset));
1139 Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1140 return _gvn.transform( new AndLNode(conv, mask) );
1141 }
1142
1143 Node* GraphKit::ConvL2I(Node* offset) {
1144 // short-circuit a common case
1145 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1146 if (offset_con != (jlong)Type::OffsetBot) {
1147 return intcon((int) offset_con);
1148 }
1149 return _gvn.transform( new ConvL2INode(offset));
1150 }
1151
1152 //-------------------------load_object_klass-----------------------------------
1153 Node* GraphKit::load_object_klass(Node* obj) {
1154 // Special-case a fresh allocation to avoid building nodes:
1155 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1156 if (akls != NULL) return akls;
1157 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1158 return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1159 }
1160
1161 //-------------------------load_array_length-----------------------------------
1162 Node* GraphKit::load_array_length(Node* array) {
1163 // Special-case a fresh allocation to avoid building nodes:
1164 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1165 Node *alen;
1166 if (alloc == NULL) {
1167 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1168 alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1169 } else {
1170 alen = alloc->Ideal_length();
1171 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1172 if (ccast != alen) {
1173 alen = _gvn.transform(ccast);
1174 }
1175 }
1176 return alen;
1177 }
1178
1179 //------------------------------do_null_check----------------------------------
1180 // Helper function to do a NULL pointer check. Returned value is
1181 // the incoming address with NULL casted away. You are allowed to use the
1182 // not-null value only if you are control dependent on the test.
1183 #ifndef PRODUCT
1184 extern int explicit_null_checks_inserted,
1185 explicit_null_checks_elided;
1186 #endif
1187 Node* GraphKit::null_check_common(Node* value, BasicType type,
1188 // optional arguments for variations:
1189 bool assert_null,
1190 Node* *null_control,
1191 bool speculative) {
1192 assert(!assert_null || null_control == NULL, "not both at once");
1193 if (stopped()) return top();
1194 NOT_PRODUCT(explicit_null_checks_inserted++);
1195
1196 // Construct NULL check
1197 Node *chk = NULL;
1198 switch(type) {
1199 case T_LONG : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1200 case T_INT : chk = new CmpINode(value, _gvn.intcon(0)); break;
1201 case T_ARRAY : // fall through
1202 type = T_OBJECT; // simplify further tests
1203 case T_OBJECT : {
1204 const Type *t = _gvn.type( value );
1205
1206 const TypeOopPtr* tp = t->isa_oopptr();
1207 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1208 // Only for do_null_check, not any of its siblings:
1209 && !assert_null && null_control == NULL) {
1210 // Usually, any field access or invocation on an unloaded oop type
1211 // will simply fail to link, since the statically linked class is
1212 // likely also to be unloaded. However, in -Xcomp mode, sometimes
1213 // the static class is loaded but the sharper oop type is not.
1214 // Rather than checking for this obscure case in lots of places,
1215 // we simply observe that a null check on an unloaded class
1216 // will always be followed by a nonsense operation, so we
1217 // can just issue the uncommon trap here.
1218 // Our access to the unloaded class will only be correct
1219 // after it has been loaded and initialized, which requires
1220 // a trip through the interpreter.
1221 #ifndef PRODUCT
1222 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1223 #endif
1224 uncommon_trap(Deoptimization::Reason_unloaded,
1225 Deoptimization::Action_reinterpret,
1226 tp->klass(), "!loaded");
1227 return top();
1228 }
1229
1230 if (assert_null) {
1231 // See if the type is contained in NULL_PTR.
1232 // If so, then the value is already null.
1233 if (t->higher_equal(TypePtr::NULL_PTR)) {
1234 NOT_PRODUCT(explicit_null_checks_elided++);
1235 return value; // Elided null assert quickly!
1236 }
1237 } else {
1238 // See if mixing in the NULL pointer changes type.
1239 // If so, then the NULL pointer was not allowed in the original
1240 // type. In other words, "value" was not-null.
1241 if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1242 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1243 NOT_PRODUCT(explicit_null_checks_elided++);
1244 return value; // Elided null check quickly!
1245 }
1246 }
1247 chk = new CmpPNode( value, null() );
1248 break;
1249 }
1250
1251 default:
1252 fatal("unexpected type: %s", type2name(type));
1253 }
1254 assert(chk != NULL, "sanity check");
1255 chk = _gvn.transform(chk);
1256
1257 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1258 BoolNode *btst = new BoolNode( chk, btest);
1259 Node *tst = _gvn.transform( btst );
1260
1261 //-----------
1262 // if peephole optimizations occurred, a prior test existed.
1263 // If a prior test existed, maybe it dominates as we can avoid this test.
1264 if (tst != btst && type == T_OBJECT) {
1265 // At this point we want to scan up the CFG to see if we can
1266 // find an identical test (and so avoid this test altogether).
1267 Node *cfg = control();
1268 int depth = 0;
1269 while( depth < 16 ) { // Limit search depth for speed
1270 if( cfg->Opcode() == Op_IfTrue &&
1271 cfg->in(0)->in(1) == tst ) {
1272 // Found prior test. Use "cast_not_null" to construct an identical
1273 // CastPP (and hence hash to) as already exists for the prior test.
1274 // Return that casted value.
1275 if (assert_null) {
1276 replace_in_map(value, null());
1277 return null(); // do not issue the redundant test
1278 }
1279 Node *oldcontrol = control();
1280 set_control(cfg);
1281 Node *res = cast_not_null(value);
1282 set_control(oldcontrol);
1283 NOT_PRODUCT(explicit_null_checks_elided++);
1284 return res;
1285 }
1286 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1287 if (cfg == NULL) break; // Quit at region nodes
1288 depth++;
1289 }
1290 }
1291
1292 //-----------
1293 // Branch to failure if null
1294 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen
1295 Deoptimization::DeoptReason reason;
1296 if (assert_null) {
1297 reason = Deoptimization::Reason_null_assert;
1298 } else if (type == T_OBJECT) {
1299 reason = Deoptimization::reason_null_check(speculative);
1300 } else {
1301 reason = Deoptimization::Reason_div0_check;
1302 }
1303 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1304 // ciMethodData::has_trap_at will return a conservative -1 if any
1305 // must-be-null assertion has failed. This could cause performance
1306 // problems for a method after its first do_null_assert failure.
1307 // Consider using 'Reason_class_check' instead?
1308
1309 // To cause an implicit null check, we set the not-null probability
1310 // to the maximum (PROB_MAX). For an explicit check the probability
1311 // is set to a smaller value.
1312 if (null_control != NULL || too_many_traps(reason)) {
1313 // probability is less likely
1314 ok_prob = PROB_LIKELY_MAG(3);
1315 } else if (!assert_null &&
1316 (ImplicitNullCheckThreshold > 0) &&
1317 method() != NULL &&
1318 (method()->method_data()->trap_count(reason)
1319 >= (uint)ImplicitNullCheckThreshold)) {
1320 ok_prob = PROB_LIKELY_MAG(3);
1321 }
1322
1323 if (null_control != NULL) {
1324 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1325 Node* null_true = _gvn.transform( new IfFalseNode(iff));
1326 set_control( _gvn.transform( new IfTrueNode(iff)));
1327 #ifndef PRODUCT
1328 if (null_true == top()) {
1329 explicit_null_checks_elided++;
1330 }
1331 #endif
1332 (*null_control) = null_true;
1333 } else {
1334 BuildCutout unless(this, tst, ok_prob);
1335 // Check for optimizer eliding test at parse time
1336 if (stopped()) {
1337 // Failure not possible; do not bother making uncommon trap.
1338 NOT_PRODUCT(explicit_null_checks_elided++);
1339 } else if (assert_null) {
1340 uncommon_trap(reason,
1341 Deoptimization::Action_make_not_entrant,
1342 NULL, "assert_null");
1343 } else {
1344 replace_in_map(value, zerocon(type));
1345 builtin_throw(reason);
1346 }
1347 }
1348
1349 // Must throw exception, fall-thru not possible?
1350 if (stopped()) {
1351 return top(); // No result
1352 }
1353
1354 if (assert_null) {
1355 // Cast obj to null on this path.
1356 replace_in_map(value, zerocon(type));
1357 return zerocon(type);
1358 }
1359
1360 // Cast obj to not-null on this path, if there is no null_control.
1361 // (If there is a null_control, a non-null value may come back to haunt us.)
1362 if (type == T_OBJECT) {
1363 Node* cast = cast_not_null(value, false);
1364 if (null_control == NULL || (*null_control) == top())
1365 replace_in_map(value, cast);
1366 value = cast;
1367 }
1368
1369 return value;
1370 }
1371
1372
1373 //------------------------------cast_not_null----------------------------------
1374 // Cast obj to not-null on this path
1375 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1376 const Type *t = _gvn.type(obj);
1377 const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1378 // Object is already not-null?
1379 if( t == t_not_null ) return obj;
1380
1381 Node *cast = new CastPPNode(obj,t_not_null);
1382 cast->init_req(0, control());
1383 cast = _gvn.transform( cast );
1384
1385 // Scan for instances of 'obj' in the current JVM mapping.
1386 // These instances are known to be not-null after the test.
1387 if (do_replace_in_map)
1388 replace_in_map(obj, cast);
1389
1390 return cast; // Return casted value
1391 }
1392
1393 // Sometimes in intrinsics, we implicitly know an object is not null
1394 // (there's no actual null check) so we can cast it to not null. In
1395 // the course of optimizations, the input to the cast can become null.
1396 // In that case that data path will die and we need the control path
1397 // to become dead as well to keep the graph consistent. So we have to
1398 // add a check for null for which one branch can't be taken. It uses
1399 // an Opaque4 node that will cause the check to be removed after loop
1400 // opts so the test goes away and the compiled code doesn't execute a
1401 // useless check.
1402 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1403 Node* chk = _gvn.transform(new CmpPNode(value, null()));
1404 Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1405 Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1406 IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1407 _gvn.set_type(iff, iff->Value(&_gvn));
1408 Node *if_f = _gvn.transform(new IfFalseNode(iff));
1409 Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1410 Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1411 C->root()->add_req(halt);
1412 Node *if_t = _gvn.transform(new IfTrueNode(iff));
1413 set_control(if_t);
1414 return cast_not_null(value, do_replace_in_map);
1415 }
1416
1417
1418 //--------------------------replace_in_map-------------------------------------
1419 void GraphKit::replace_in_map(Node* old, Node* neww) {
1420 if (old == neww) {
1421 return;
1422 }
1423
1424 map()->replace_edge(old, neww);
1425
1426 // Note: This operation potentially replaces any edge
1427 // on the map. This includes locals, stack, and monitors
1428 // of the current (innermost) JVM state.
1429
1430 // don't let inconsistent types from profiling escape this
1431 // method
1432
1433 const Type* told = _gvn.type(old);
1434 const Type* tnew = _gvn.type(neww);
1435
1436 if (!tnew->higher_equal(told)) {
1437 return;
1438 }
1439
1440 map()->record_replaced_node(old, neww);
1441 }
1442
1443
1444 //=============================================================================
1445 //--------------------------------memory---------------------------------------
1446 Node* GraphKit::memory(uint alias_idx) {
1447 MergeMemNode* mem = merged_memory();
1448 Node* p = mem->memory_at(alias_idx);
1449 _gvn.set_type(p, Type::MEMORY); // must be mapped
1450 return p;
1451 }
1452
1453 //-----------------------------reset_memory------------------------------------
1454 Node* GraphKit::reset_memory() {
1455 Node* mem = map()->memory();
1456 // do not use this node for any more parsing!
1457 debug_only( map()->set_memory((Node*)NULL) );
1458 return _gvn.transform( mem );
1459 }
1460
1461 //------------------------------set_all_memory---------------------------------
1462 void GraphKit::set_all_memory(Node* newmem) {
1463 Node* mergemem = MergeMemNode::make(newmem);
1464 gvn().set_type_bottom(mergemem);
1465 map()->set_memory(mergemem);
1466 }
1467
1468 //------------------------------set_all_memory_call----------------------------
1469 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1470 Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1471 set_all_memory(newmem);
1472 }
1473
1474 //=============================================================================
1475 //
1476 // parser factory methods for MemNodes
1477 //
1478 // These are layered on top of the factory methods in LoadNode and StoreNode,
1479 // and integrate with the parser's memory state and _gvn engine.
1480 //
1481
1482 // factory methods in "int adr_idx"
1483 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1484 int adr_idx,
1485 MemNode::MemOrd mo,
1486 LoadNode::ControlDependency control_dependency,
1487 bool require_atomic_access,
1488 bool unaligned,
1489 bool mismatched) {
1490 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1491 const TypePtr* adr_type = NULL; // debug-mode-only argument
1492 debug_only(adr_type = C->get_adr_type(adr_idx));
1493 Node* mem = memory(adr_idx);
1494 Node* ld;
1495 if (require_atomic_access && bt == T_LONG) {
1496 ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1497 } else if (require_atomic_access && bt == T_DOUBLE) {
1498 ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1499 } else {
1500 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1501 }
1502 ld = _gvn.transform(ld);
1503 if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1504 // Improve graph before escape analysis and boxing elimination.
1505 record_for_igvn(ld);
1506 }
1507 return ld;
1508 }
1509
1510 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1511 int adr_idx,
1512 MemNode::MemOrd mo,
1513 bool require_atomic_access,
1514 bool unaligned,
1515 bool mismatched) {
1516 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1517 const TypePtr* adr_type = NULL;
1518 debug_only(adr_type = C->get_adr_type(adr_idx));
1519 Node *mem = memory(adr_idx);
1520 Node* st;
1521 if (require_atomic_access && bt == T_LONG) {
1522 st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1523 } else if (require_atomic_access && bt == T_DOUBLE) {
1524 st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1525 } else {
1526 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1527 }
1528 if (unaligned) {
1529 st->as_Store()->set_unaligned_access();
1530 }
1531 if (mismatched) {
1532 st->as_Store()->set_mismatched_access();
1533 }
1534 st = _gvn.transform(st);
1535 set_memory(st, adr_idx);
1536 // Back-to-back stores can only remove intermediate store with DU info
1537 // so push on worklist for optimizer.
1538 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1539 record_for_igvn(st);
1540
1541 return st;
1542 }
1543
1544
1545 void GraphKit::pre_barrier(bool do_load,
1546 Node* ctl,
1547 Node* obj,
1548 Node* adr,
1549 uint adr_idx,
1550 Node* val,
1551 const TypeOopPtr* val_type,
1552 Node* pre_val,
1553 BasicType bt) {
1554
1555 BarrierSet* bs = Universe::heap()->barrier_set();
1556 set_control(ctl);
1557 switch (bs->kind()) {
1558 case BarrierSet::G1SATBCTLogging:
1559 g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1560 break;
1561
1562 case BarrierSet::CardTableForRS:
1563 case BarrierSet::CardTableExtension:
1564 case BarrierSet::ModRef:
1565 break;
1566
1567 default :
1568 ShouldNotReachHere();
1569
1570 }
1571 }
1572
1573 bool GraphKit::can_move_pre_barrier() const {
1574 BarrierSet* bs = Universe::heap()->barrier_set();
1575 switch (bs->kind()) {
1576 case BarrierSet::G1SATBCTLogging:
1577 return true; // Can move it if no safepoint
1578
1579 case BarrierSet::CardTableForRS:
1580 case BarrierSet::CardTableExtension:
1581 case BarrierSet::ModRef:
1582 return true; // There is no pre-barrier
1583
1584 default :
1585 ShouldNotReachHere();
1586 }
1587 return false;
1588 }
1589
1590 void GraphKit::post_barrier(Node* ctl,
1591 Node* store,
1592 Node* obj,
1593 Node* adr,
1594 uint adr_idx,
1595 Node* val,
1596 BasicType bt,
1597 bool use_precise) {
1598 BarrierSet* bs = Universe::heap()->barrier_set();
1599 set_control(ctl);
1600 switch (bs->kind()) {
1601 case BarrierSet::G1SATBCTLogging:
1602 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1603 break;
1604
1605 case BarrierSet::CardTableForRS:
1606 case BarrierSet::CardTableExtension:
1607 write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1608 break;
1609
1610 case BarrierSet::ModRef:
1611 break;
1612
1613 default :
1614 ShouldNotReachHere();
1615
1616 }
1617 }
1618
1619 Node* GraphKit::store_oop(Node* ctl,
1620 Node* obj,
1621 Node* adr,
1622 const TypePtr* adr_type,
1623 Node* val,
1624 const TypeOopPtr* val_type,
1625 BasicType bt,
1626 bool use_precise,
1627 MemNode::MemOrd mo,
1628 bool mismatched) {
1629 // Transformation of a value which could be NULL pointer (CastPP #NULL)
1630 // could be delayed during Parse (for example, in adjust_map_after_if()).
1631 // Execute transformation here to avoid barrier generation in such case.
1632 if (_gvn.type(val) == TypePtr::NULL_PTR)
1633 val = _gvn.makecon(TypePtr::NULL_PTR);
1634
1635 set_control(ctl);
1636 if (stopped()) return top(); // Dead path ?
1637
1638 assert(bt == T_OBJECT, "sanity");
1639 assert(val != NULL, "not dead path");
1640 uint adr_idx = C->get_alias_index(adr_type);
1641 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1642
1643 pre_barrier(true /* do_load */,
1644 control(), obj, adr, adr_idx, val, val_type,
1645 NULL /* pre_val */,
1646 bt);
1647
1648 Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1649 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1650 return store;
1651 }
1652
1653 // Could be an array or object we don't know at compile time (unsafe ref.)
1654 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1655 Node* obj, // containing obj
1656 Node* adr, // actual adress to store val at
1657 const TypePtr* adr_type,
1658 Node* val,
1659 BasicType bt,
1660 MemNode::MemOrd mo,
1661 bool mismatched) {
1662 Compile::AliasType* at = C->alias_type(adr_type);
1663 const TypeOopPtr* val_type = NULL;
1664 if (adr_type->isa_instptr()) {
1665 if (at->field() != NULL) {
1666 // known field. This code is a copy of the do_put_xxx logic.
1667 ciField* field = at->field();
1668 if (!field->type()->is_loaded()) {
1669 val_type = TypeInstPtr::BOTTOM;
1670 } else {
1671 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1672 }
1673 }
1674 } else if (adr_type->isa_aryptr()) {
1675 val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1676 }
1677 if (val_type == NULL) {
1678 val_type = TypeInstPtr::BOTTOM;
1679 }
1680 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1681 }
1682
1683
1684 //-------------------------array_element_address-------------------------
1685 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1686 const TypeInt* sizetype, Node* ctrl) {
1687 uint shift = exact_log2(type2aelembytes(elembt));
1688 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1689
1690 // short-circuit a common case (saves lots of confusing waste motion)
1691 jint idx_con = find_int_con(idx, -1);
1692 if (idx_con >= 0) {
1693 intptr_t offset = header + ((intptr_t)idx_con << shift);
1694 return basic_plus_adr(ary, offset);
1695 }
1696
1697 // must be correct type for alignment purposes
1698 Node* base = basic_plus_adr(ary, header);
1699 idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1700 Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1701 return basic_plus_adr(ary, base, scale);
1702 }
1703
1704 //-------------------------load_array_element-------------------------
1705 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1706 const Type* elemtype = arytype->elem();
1707 BasicType elembt = elemtype->array_element_basic_type();
1708 Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1709 if (elembt == T_NARROWOOP) {
1710 elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1711 }
1712 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1713 return ld;
1714 }
1715
1716 //-------------------------set_arguments_for_java_call-------------------------
1717 // Arguments (pre-popped from the stack) are taken from the JVMS.
1718 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1719 // Add the call arguments:
1720 uint nargs = call->method()->arg_size();
1721 for (uint i = 0; i < nargs; i++) {
1722 Node* arg = argument(i);
1723 call->init_req(i + TypeFunc::Parms, arg);
1724 }
1725 }
1726
1727 //---------------------------set_edges_for_java_call---------------------------
1728 // Connect a newly created call into the current JVMS.
1729 // A return value node (if any) is returned from set_edges_for_java_call.
1730 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1731
1732 // Add the predefined inputs:
1733 call->init_req( TypeFunc::Control, control() );
1734 call->init_req( TypeFunc::I_O , i_o() );
1735 call->init_req( TypeFunc::Memory , reset_memory() );
1736 call->init_req( TypeFunc::FramePtr, frameptr() );
1737 call->init_req( TypeFunc::ReturnAdr, top() );
1738
1739 add_safepoint_edges(call, must_throw);
1740
1741 Node* xcall = _gvn.transform(call);
1742
1743 if (xcall == top()) {
1744 set_control(top());
1745 return;
1746 }
1747 assert(xcall == call, "call identity is stable");
1748
1749 // Re-use the current map to produce the result.
1750
1751 set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1752 set_i_o( _gvn.transform(new ProjNode(call, TypeFunc::I_O , separate_io_proj)));
1753 set_all_memory_call(xcall, separate_io_proj);
1754
1755 //return xcall; // no need, caller already has it
1756 }
1757
1758 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1759 if (stopped()) return top(); // maybe the call folded up?
1760
1761 // Capture the return value, if any.
1762 Node* ret;
1763 if (call->method() == NULL ||
1764 call->method()->return_type()->basic_type() == T_VOID)
1765 ret = top();
1766 else ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1767
1768 // Note: Since any out-of-line call can produce an exception,
1769 // we always insert an I_O projection from the call into the result.
1770
1771 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1772
1773 if (separate_io_proj) {
1774 // The caller requested separate projections be used by the fall
1775 // through and exceptional paths, so replace the projections for
1776 // the fall through path.
1777 set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1778 set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1779 }
1780 return ret;
1781 }
1782
1783 //--------------------set_predefined_input_for_runtime_call--------------------
1784 // Reading and setting the memory state is way conservative here.
1785 // The real problem is that I am not doing real Type analysis on memory,
1786 // so I cannot distinguish card mark stores from other stores. Across a GC
1787 // point the Store Barrier and the card mark memory has to agree. I cannot
1788 // have a card mark store and its barrier split across the GC point from
1789 // either above or below. Here I get that to happen by reading ALL of memory.
1790 // A better answer would be to separate out card marks from other memory.
1791 // For now, return the input memory state, so that it can be reused
1792 // after the call, if this call has restricted memory effects.
1793 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1794 // Set fixed predefined input arguments
1795 Node* memory = reset_memory();
1796 call->init_req( TypeFunc::Control, control() );
1797 call->init_req( TypeFunc::I_O, top() ); // does no i/o
1798 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs
1799 call->init_req( TypeFunc::FramePtr, frameptr() );
1800 call->init_req( TypeFunc::ReturnAdr, top() );
1801 return memory;
1802 }
1803
1804 //-------------------set_predefined_output_for_runtime_call--------------------
1805 // Set control and memory (not i_o) from the call.
1806 // If keep_mem is not NULL, use it for the output state,
1807 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1808 // If hook_mem is NULL, this call produces no memory effects at all.
1809 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1810 // then only that memory slice is taken from the call.
1811 // In the last case, we must put an appropriate memory barrier before
1812 // the call, so as to create the correct anti-dependencies on loads
1813 // preceding the call.
1814 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1815 Node* keep_mem,
1816 const TypePtr* hook_mem) {
1817 // no i/o
1818 set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1819 if (keep_mem) {
1820 // First clone the existing memory state
1821 set_all_memory(keep_mem);
1822 if (hook_mem != NULL) {
1823 // Make memory for the call
1824 Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1825 // Set the RawPtr memory state only. This covers all the heap top/GC stuff
1826 // We also use hook_mem to extract specific effects from arraycopy stubs.
1827 set_memory(mem, hook_mem);
1828 }
1829 // ...else the call has NO memory effects.
1830
1831 // Make sure the call advertises its memory effects precisely.
1832 // This lets us build accurate anti-dependences in gcm.cpp.
1833 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1834 "call node must be constructed correctly");
1835 } else {
1836 assert(hook_mem == NULL, "");
1837 // This is not a "slow path" call; all memory comes from the call.
1838 set_all_memory_call(call);
1839 }
1840 }
1841
1842
1843 // Replace the call with the current state of the kit.
1844 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1845 JVMState* ejvms = NULL;
1846 if (has_exceptions()) {
1847 ejvms = transfer_exceptions_into_jvms();
1848 }
1849
1850 ReplacedNodes replaced_nodes = map()->replaced_nodes();
1851 ReplacedNodes replaced_nodes_exception;
1852 Node* ex_ctl = top();
1853
1854 SafePointNode* final_state = stop();
1855
1856 // Find all the needed outputs of this call
1857 CallProjections callprojs;
1858 call->extract_projections(&callprojs, true);
1859
1860 Node* init_mem = call->in(TypeFunc::Memory);
1861 Node* final_mem = final_state->in(TypeFunc::Memory);
1862 Node* final_ctl = final_state->in(TypeFunc::Control);
1863 Node* final_io = final_state->in(TypeFunc::I_O);
1864
1865 // Replace all the old call edges with the edges from the inlining result
1866 if (callprojs.fallthrough_catchproj != NULL) {
1867 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1868 }
1869 if (callprojs.fallthrough_memproj != NULL) {
1870 if (final_mem->is_MergeMem()) {
1871 // Parser's exits MergeMem was not transformed but may be optimized
1872 final_mem = _gvn.transform(final_mem);
1873 }
1874 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem);
1875 }
1876 if (callprojs.fallthrough_ioproj != NULL) {
1877 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io);
1878 }
1879
1880 // Replace the result with the new result if it exists and is used
1881 if (callprojs.resproj != NULL && result != NULL) {
1882 C->gvn_replace_by(callprojs.resproj, result);
1883 }
1884
1885 if (ejvms == NULL) {
1886 // No exception edges to simply kill off those paths
1887 if (callprojs.catchall_catchproj != NULL) {
1888 C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1889 }
1890 if (callprojs.catchall_memproj != NULL) {
1891 C->gvn_replace_by(callprojs.catchall_memproj, C->top());
1892 }
1893 if (callprojs.catchall_ioproj != NULL) {
1894 C->gvn_replace_by(callprojs.catchall_ioproj, C->top());
1895 }
1896 // Replace the old exception object with top
1897 if (callprojs.exobj != NULL) {
1898 C->gvn_replace_by(callprojs.exobj, C->top());
1899 }
1900 } else {
1901 GraphKit ekit(ejvms);
1902
1903 // Load my combined exception state into the kit, with all phis transformed:
1904 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1905 replaced_nodes_exception = ex_map->replaced_nodes();
1906
1907 Node* ex_oop = ekit.use_exception_state(ex_map);
1908
1909 if (callprojs.catchall_catchproj != NULL) {
1910 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1911 ex_ctl = ekit.control();
1912 }
1913 if (callprojs.catchall_memproj != NULL) {
1914 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory());
1915 }
1916 if (callprojs.catchall_ioproj != NULL) {
1917 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o());
1918 }
1919
1920 // Replace the old exception object with the newly created one
1921 if (callprojs.exobj != NULL) {
1922 C->gvn_replace_by(callprojs.exobj, ex_oop);
1923 }
1924 }
1925
1926 // Disconnect the call from the graph
1927 call->disconnect_inputs(NULL, C);
1928 C->gvn_replace_by(call, C->top());
1929
1930 // Clean up any MergeMems that feed other MergeMems since the
1931 // optimizer doesn't like that.
1932 if (final_mem->is_MergeMem()) {
1933 Node_List wl;
1934 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1935 Node* m = i.get();
1936 if (m->is_MergeMem() && !wl.contains(m)) {
1937 wl.push(m);
1938 }
1939 }
1940 while (wl.size() > 0) {
1941 _gvn.transform(wl.pop());
1942 }
1943 }
1944
1945 if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1946 replaced_nodes.apply(C, final_ctl);
1947 }
1948 if (!ex_ctl->is_top() && do_replaced_nodes) {
1949 replaced_nodes_exception.apply(C, ex_ctl);
1950 }
1951 }
1952
1953
1954 //------------------------------increment_counter------------------------------
1955 // for statistics: increment a VM counter by 1
1956
1957 void GraphKit::increment_counter(address counter_addr) {
1958 Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1959 increment_counter(adr1);
1960 }
1961
1962 void GraphKit::increment_counter(Node* counter_addr) {
1963 int adr_type = Compile::AliasIdxRaw;
1964 Node* ctrl = control();
1965 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1966 Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1967 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1968 }
1969
1970
1971 //------------------------------uncommon_trap----------------------------------
1972 // Bail out to the interpreter in mid-method. Implemented by calling the
1973 // uncommon_trap blob. This helper function inserts a runtime call with the
1974 // right debug info.
1975 void GraphKit::uncommon_trap(int trap_request,
1976 ciKlass* klass, const char* comment,
1977 bool must_throw,
1978 bool keep_exact_action) {
1979 if (failing()) stop();
1980 if (stopped()) return; // trap reachable?
1981
1982 // Note: If ProfileTraps is true, and if a deopt. actually
1983 // occurs here, the runtime will make sure an MDO exists. There is
1984 // no need to call method()->ensure_method_data() at this point.
1985
1986 // Set the stack pointer to the right value for reexecution:
1987 set_sp(reexecute_sp());
1988
1989 #ifdef ASSERT
1990 if (!must_throw) {
1991 // Make sure the stack has at least enough depth to execute
1992 // the current bytecode.
1993 int inputs, ignored_depth;
1994 if (compute_stack_effects(inputs, ignored_depth)) {
1995 assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1996 Bytecodes::name(java_bc()), sp(), inputs);
1997 }
1998 }
1999 #endif
2000
2001 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2002 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2003
2004 switch (action) {
2005 case Deoptimization::Action_maybe_recompile:
2006 case Deoptimization::Action_reinterpret:
2007 // Temporary fix for 6529811 to allow virtual calls to be sure they
2008 // get the chance to go from mono->bi->mega
2009 if (!keep_exact_action &&
2010 Deoptimization::trap_request_index(trap_request) < 0 &&
2011 too_many_recompiles(reason)) {
2012 // This BCI is causing too many recompilations.
2013 if (C->log() != NULL) {
2014 C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2015 Deoptimization::trap_reason_name(reason),
2016 Deoptimization::trap_action_name(action));
2017 }
2018 action = Deoptimization::Action_none;
2019 trap_request = Deoptimization::make_trap_request(reason, action);
2020 } else {
2021 C->set_trap_can_recompile(true);
2022 }
2023 break;
2024 case Deoptimization::Action_make_not_entrant:
2025 C->set_trap_can_recompile(true);
2026 break;
2027 #ifdef ASSERT
2028 case Deoptimization::Action_none:
2029 case Deoptimization::Action_make_not_compilable:
2030 break;
2031 default:
2032 fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2033 break;
2034 #endif
2035 }
2036
2037 if (TraceOptoParse) {
2038 char buf[100];
2039 tty->print_cr("Uncommon trap %s at bci:%d",
2040 Deoptimization::format_trap_request(buf, sizeof(buf),
2041 trap_request), bci());
2042 }
2043
2044 CompileLog* log = C->log();
2045 if (log != NULL) {
2046 int kid = (klass == NULL)? -1: log->identify(klass);
2047 log->begin_elem("uncommon_trap bci='%d'", bci());
2048 char buf[100];
2049 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2050 trap_request));
2051 if (kid >= 0) log->print(" klass='%d'", kid);
2052 if (comment != NULL) log->print(" comment='%s'", comment);
2053 log->end_elem();
2054 }
2055
2056 // Make sure any guarding test views this path as very unlikely
2057 Node *i0 = control()->in(0);
2058 if (i0 != NULL && i0->is_If()) { // Found a guarding if test?
2059 IfNode *iff = i0->as_If();
2060 float f = iff->_prob; // Get prob
2061 if (control()->Opcode() == Op_IfTrue) {
2062 if (f > PROB_UNLIKELY_MAG(4))
2063 iff->_prob = PROB_MIN;
2064 } else {
2065 if (f < PROB_LIKELY_MAG(4))
2066 iff->_prob = PROB_MAX;
2067 }
2068 }
2069
2070 // Clear out dead values from the debug info.
2071 kill_dead_locals();
2072
2073 // Now insert the uncommon trap subroutine call
2074 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2075 const TypePtr* no_memory_effects = NULL;
2076 // Pass the index of the class to be loaded
2077 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2078 (must_throw ? RC_MUST_THROW : 0),
2079 OptoRuntime::uncommon_trap_Type(),
2080 call_addr, "uncommon_trap", no_memory_effects,
2081 intcon(trap_request));
2082 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2083 "must extract request correctly from the graph");
2084 assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2085
2086 call->set_req(TypeFunc::ReturnAdr, returnadr());
2087 // The debug info is the only real input to this call.
2088
2089 // Halt-and-catch fire here. The above call should never return!
2090 HaltNode* halt = new HaltNode(control(), frameptr());
2091 _gvn.set_type_bottom(halt);
2092 root()->add_req(halt);
2093
2094 stop_and_kill_map();
2095 }
2096
2097
2098 //--------------------------just_allocated_object------------------------------
2099 // Report the object that was just allocated.
2100 // It must be the case that there are no intervening safepoints.
2101 // We use this to determine if an object is so "fresh" that
2102 // it does not require card marks.
2103 Node* GraphKit::just_allocated_object(Node* current_control) {
2104 if (C->recent_alloc_ctl() == current_control)
2105 return C->recent_alloc_obj();
2106 return NULL;
2107 }
2108
2109
2110 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2111 // (Note: TypeFunc::make has a cache that makes this fast.)
2112 const TypeFunc* tf = TypeFunc::make(dest_method);
2113 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2114 for (int j = 0; j < nargs; j++) {
2115 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2116 if( targ->basic_type() == T_DOUBLE ) {
2117 // If any parameters are doubles, they must be rounded before
2118 // the call, dstore_rounding does gvn.transform
2119 Node *arg = argument(j);
2120 arg = dstore_rounding(arg);
2121 set_argument(j, arg);
2122 }
2123 }
2124 }
2125
2126 /**
2127 * Record profiling data exact_kls for Node n with the type system so
2128 * that it can propagate it (speculation)
2129 *
2130 * @param n node that the type applies to
2131 * @param exact_kls type from profiling
2132 * @param maybe_null did profiling see null?
2133 *
2134 * @return node with improved type
2135 */
2136 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2137 const Type* current_type = _gvn.type(n);
2138 assert(UseTypeSpeculation, "type speculation must be on");
2139
2140 const TypePtr* speculative = current_type->speculative();
2141
2142 // Should the klass from the profile be recorded in the speculative type?
2143 if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2144 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2145 const TypeOopPtr* xtype = tklass->as_instance_type();
2146 assert(xtype->klass_is_exact(), "Should be exact");
2147 // Any reason to believe n is not null (from this profiling or a previous one)?
2148 const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2149 // record the new speculative type's depth
2150 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2151 speculative = speculative->with_inline_depth(jvms()->depth());
2152 } else if (current_type->would_improve_ptr(maybe_null)) {
2153 // Profiling report that null was never seen so we can change the
2154 // speculative type to non null ptr.
2155 assert(!maybe_null, "nothing to improve");
2156 if (speculative == NULL) {
2157 speculative = TypePtr::NOTNULL;
2158 } else {
2159 const TypePtr* ptr = TypePtr::NOTNULL;
2160 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2161 }
2162 }
2163
2164 if (speculative != current_type->speculative()) {
2165 // Build a type with a speculative type (what we think we know
2166 // about the type but will need a guard when we use it)
2167 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2168 // We're changing the type, we need a new CheckCast node to carry
2169 // the new type. The new type depends on the control: what
2170 // profiling tells us is only valid from here as far as we can
2171 // tell.
2172 Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2173 cast = _gvn.transform(cast);
2174 replace_in_map(n, cast);
2175 n = cast;
2176 }
2177
2178 return n;
2179 }
2180
2181 /**
2182 * Record profiling data from receiver profiling at an invoke with the
2183 * type system so that it can propagate it (speculation)
2184 *
2185 * @param n receiver node
2186 *
2187 * @return node with improved type
2188 */
2189 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2190 if (!UseTypeSpeculation) {
2191 return n;
2192 }
2193 ciKlass* exact_kls = profile_has_unique_klass();
2194 bool maybe_null = true;
2195 if (java_bc() == Bytecodes::_checkcast ||
2196 java_bc() == Bytecodes::_instanceof ||
2197 java_bc() == Bytecodes::_aastore) {
2198 ciProfileData* data = method()->method_data()->bci_to_data(bci());
2199 maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2200 }
2201 return record_profile_for_speculation(n, exact_kls, maybe_null);
2202 }
2203
2204 /**
2205 * Record profiling data from argument profiling at an invoke with the
2206 * type system so that it can propagate it (speculation)
2207 *
2208 * @param dest_method target method for the call
2209 * @param bc what invoke bytecode is this?
2210 */
2211 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2212 if (!UseTypeSpeculation) {
2213 return;
2214 }
2215 const TypeFunc* tf = TypeFunc::make(dest_method);
2216 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2217 int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2218 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2219 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2220 if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2221 bool maybe_null = true;
2222 ciKlass* better_type = NULL;
2223 if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2224 record_profile_for_speculation(argument(j), better_type, maybe_null);
2225 }
2226 i++;
2227 }
2228 }
2229 }
2230
2231 /**
2232 * Record profiling data from parameter profiling at an invoke with
2233 * the type system so that it can propagate it (speculation)
2234 */
2235 void GraphKit::record_profiled_parameters_for_speculation() {
2236 if (!UseTypeSpeculation) {
2237 return;
2238 }
2239 for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2240 if (_gvn.type(local(i))->isa_oopptr()) {
2241 bool maybe_null = true;
2242 ciKlass* better_type = NULL;
2243 if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2244 record_profile_for_speculation(local(i), better_type, maybe_null);
2245 }
2246 j++;
2247 }
2248 }
2249 }
2250
2251 /**
2252 * Record profiling data from return value profiling at an invoke with
2253 * the type system so that it can propagate it (speculation)
2254 */
2255 void GraphKit::record_profiled_return_for_speculation() {
2256 if (!UseTypeSpeculation) {
2257 return;
2258 }
2259 bool maybe_null = true;
2260 ciKlass* better_type = NULL;
2261 if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2262 // If profiling reports a single type for the return value,
2263 // feed it to the type system so it can propagate it as a
2264 // speculative type
2265 record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2266 }
2267 }
2268
2269 void GraphKit::round_double_result(ciMethod* dest_method) {
2270 // A non-strict method may return a double value which has an extended
2271 // exponent, but this must not be visible in a caller which is 'strict'
2272 // If a strict caller invokes a non-strict callee, round a double result
2273
2274 BasicType result_type = dest_method->return_type()->basic_type();
2275 assert( method() != NULL, "must have caller context");
2276 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2277 // Destination method's return value is on top of stack
2278 // dstore_rounding() does gvn.transform
2279 Node *result = pop_pair();
2280 result = dstore_rounding(result);
2281 push_pair(result);
2282 }
2283 }
2284
2285 // rounding for strict float precision conformance
2286 Node* GraphKit::precision_rounding(Node* n) {
2287 return UseStrictFP && _method->flags().is_strict()
2288 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2289 ? _gvn.transform( new RoundFloatNode(0, n) )
2290 : n;
2291 }
2292
2293 // rounding for strict double precision conformance
2294 Node* GraphKit::dprecision_rounding(Node *n) {
2295 return UseStrictFP && _method->flags().is_strict()
2296 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2297 ? _gvn.transform( new RoundDoubleNode(0, n) )
2298 : n;
2299 }
2300
2301 // rounding for non-strict double stores
2302 Node* GraphKit::dstore_rounding(Node* n) {
2303 return Matcher::strict_fp_requires_explicit_rounding
2304 && UseSSE <= 1
2305 ? _gvn.transform( new RoundDoubleNode(0, n) )
2306 : n;
2307 }
2308
2309 //=============================================================================
2310 // Generate a fast path/slow path idiom. Graph looks like:
2311 // [foo] indicates that 'foo' is a parameter
2312 //
2313 // [in] NULL
2314 // \ /
2315 // CmpP
2316 // Bool ne
2317 // If
2318 // / \
2319 // True False-<2>
2320 // / |
2321 // / cast_not_null
2322 // Load | | ^
2323 // [fast_test] | |
2324 // gvn to opt_test | |
2325 // / \ | <1>
2326 // True False |
2327 // | \\ |
2328 // [slow_call] \[fast_result]
2329 // Ctl Val \ \
2330 // | \ \
2331 // Catch <1> \ \
2332 // / \ ^ \ \
2333 // Ex No_Ex | \ \
2334 // | \ \ | \ <2> \
2335 // ... \ [slow_res] | | \ [null_result]
2336 // \ \--+--+--- | |
2337 // \ | / \ | /
2338 // --------Region Phi
2339 //
2340 //=============================================================================
2341 // Code is structured as a series of driver functions all called 'do_XXX' that
2342 // call a set of helper functions. Helper functions first, then drivers.
2343
2344 //------------------------------null_check_oop---------------------------------
2345 // Null check oop. Set null-path control into Region in slot 3.
2346 // Make a cast-not-nullness use the other not-null control. Return cast.
2347 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2348 bool never_see_null,
2349 bool safe_for_replace,
2350 bool speculative) {
2351 // Initial NULL check taken path
2352 (*null_control) = top();
2353 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2354
2355 // Generate uncommon_trap:
2356 if (never_see_null && (*null_control) != top()) {
2357 // If we see an unexpected null at a check-cast we record it and force a
2358 // recompile; the offending check-cast will be compiled to handle NULLs.
2359 // If we see more than one offending BCI, then all checkcasts in the
2360 // method will be compiled to handle NULLs.
2361 PreserveJVMState pjvms(this);
2362 set_control(*null_control);
2363 replace_in_map(value, null());
2364 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2365 uncommon_trap(reason,
2366 Deoptimization::Action_make_not_entrant);
2367 (*null_control) = top(); // NULL path is dead
2368 }
2369 if ((*null_control) == top() && safe_for_replace) {
2370 replace_in_map(value, cast);
2371 }
2372
2373 // Cast away null-ness on the result
2374 return cast;
2375 }
2376
2377 //------------------------------opt_iff----------------------------------------
2378 // Optimize the fast-check IfNode. Set the fast-path region slot 2.
2379 // Return slow-path control.
2380 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2381 IfNode *opt_iff = _gvn.transform(iff)->as_If();
2382
2383 // Fast path taken; set region slot 2
2384 Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2385 region->init_req(2,fast_taken); // Capture fast-control
2386
2387 // Fast path not-taken, i.e. slow path
2388 Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2389 return slow_taken;
2390 }
2391
2392 //-----------------------------make_runtime_call-------------------------------
2393 Node* GraphKit::make_runtime_call(int flags,
2394 const TypeFunc* call_type, address call_addr,
2395 const char* call_name,
2396 const TypePtr* adr_type,
2397 // The following parms are all optional.
2398 // The first NULL ends the list.
2399 Node* parm0, Node* parm1,
2400 Node* parm2, Node* parm3,
2401 Node* parm4, Node* parm5,
2402 Node* parm6, Node* parm7) {
2403 // Slow-path call
2404 bool is_leaf = !(flags & RC_NO_LEAF);
2405 bool has_io = (!is_leaf && !(flags & RC_NO_IO));
2406 if (call_name == NULL) {
2407 assert(!is_leaf, "must supply name for leaf");
2408 call_name = OptoRuntime::stub_name(call_addr);
2409 }
2410 CallNode* call;
2411 if (!is_leaf) {
2412 call = new CallStaticJavaNode(call_type, call_addr, call_name,
2413 bci(), adr_type);
2414 } else if (flags & RC_NO_FP) {
2415 call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2416 } else {
2417 call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2418 }
2419
2420 // The following is similar to set_edges_for_java_call,
2421 // except that the memory effects of the call are restricted to AliasIdxRaw.
2422
2423 // Slow path call has no side-effects, uses few values
2424 bool wide_in = !(flags & RC_NARROW_MEM);
2425 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2426
2427 Node* prev_mem = NULL;
2428 if (wide_in) {
2429 prev_mem = set_predefined_input_for_runtime_call(call);
2430 } else {
2431 assert(!wide_out, "narrow in => narrow out");
2432 Node* narrow_mem = memory(adr_type);
2433 prev_mem = reset_memory();
2434 map()->set_memory(narrow_mem);
2435 set_predefined_input_for_runtime_call(call);
2436 }
2437
2438 // Hook each parm in order. Stop looking at the first NULL.
2439 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2440 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2441 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2442 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2443 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2444 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2445 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2446 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2447 /* close each nested if ===> */ } } } } } } } }
2448 assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2449
2450 if (!is_leaf) {
2451 // Non-leaves can block and take safepoints:
2452 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2453 }
2454 // Non-leaves can throw exceptions:
2455 if (has_io) {
2456 call->set_req(TypeFunc::I_O, i_o());
2457 }
2458
2459 if (flags & RC_UNCOMMON) {
2460 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency.
2461 // (An "if" probability corresponds roughly to an unconditional count.
2462 // Sort of.)
2463 call->set_cnt(PROB_UNLIKELY_MAG(4));
2464 }
2465
2466 Node* c = _gvn.transform(call);
2467 assert(c == call, "cannot disappear");
2468
2469 if (wide_out) {
2470 // Slow path call has full side-effects.
2471 set_predefined_output_for_runtime_call(call);
2472 } else {
2473 // Slow path call has few side-effects, and/or sets few values.
2474 set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2475 }
2476
2477 if (has_io) {
2478 set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2479 }
2480 return call;
2481
2482 }
2483
2484 //------------------------------merge_memory-----------------------------------
2485 // Merge memory from one path into the current memory state.
2486 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2487 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2488 Node* old_slice = mms.force_memory();
2489 Node* new_slice = mms.memory2();
2490 if (old_slice != new_slice) {
2491 PhiNode* phi;
2492 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2493 if (mms.is_empty()) {
2494 // clone base memory Phi's inputs for this memory slice
2495 assert(old_slice == mms.base_memory(), "sanity");
2496 phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2497 _gvn.set_type(phi, Type::MEMORY);
2498 for (uint i = 1; i < phi->req(); i++) {
2499 phi->init_req(i, old_slice->in(i));
2500 }
2501 } else {
2502 phi = old_slice->as_Phi(); // Phi was generated already
2503 }
2504 } else {
2505 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2506 _gvn.set_type(phi, Type::MEMORY);
2507 }
2508 phi->set_req(new_path, new_slice);
2509 mms.set_memory(phi);
2510 }
2511 }
2512 }
2513
2514 //------------------------------make_slow_call_ex------------------------------
2515 // Make the exception handler hookups for the slow call
2516 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2517 if (stopped()) return;
2518
2519 // Make a catch node with just two handlers: fall-through and catch-all
2520 Node* i_o = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2521 Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2522 Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2523 Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) );
2524
2525 { PreserveJVMState pjvms(this);
2526 set_control(excp);
2527 set_i_o(i_o);
2528
2529 if (excp != top()) {
2530 if (deoptimize) {
2531 // Deoptimize if an exception is caught. Don't construct exception state in this case.
2532 uncommon_trap(Deoptimization::Reason_unhandled,
2533 Deoptimization::Action_none);
2534 } else {
2535 // Create an exception state also.
2536 // Use an exact type if the caller has specified a specific exception.
2537 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2538 Node* ex_oop = new CreateExNode(ex_type, control(), i_o);
2539 add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2540 }
2541 }
2542 }
2543
2544 // Get the no-exception control from the CatchNode.
2545 set_control(norm);
2546 }
2547
2548 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2549 Node* cmp = NULL;
2550 switch(bt) {
2551 case T_INT: cmp = new CmpINode(in1, in2); break;
2552 case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2553 default: fatal("unexpected comparison type %s", type2name(bt));
2554 }
2555 gvn->transform(cmp);
2556 Node* bol = gvn->transform(new BoolNode(cmp, test));
2557 IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2558 gvn->transform(iff);
2559 if (!bol->is_Con()) gvn->record_for_igvn(iff);
2560 return iff;
2561 }
2562
2563
2564 //-------------------------------gen_subtype_check-----------------------------
2565 // Generate a subtyping check. Takes as input the subtype and supertype.
2566 // Returns 2 values: sets the default control() to the true path and returns
2567 // the false path. Only reads invariant memory; sets no (visible) memory.
2568 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2569 // but that's not exposed to the optimizer. This call also doesn't take in an
2570 // Object; if you wish to check an Object you need to load the Object's class
2571 // prior to coming here.
2572 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2573 Compile* C = gvn->C;
2574
2575 if ((*ctrl)->is_top()) {
2576 return C->top();
2577 }
2578
2579 // Fast check for identical types, perhaps identical constants.
2580 // The types can even be identical non-constants, in cases
2581 // involving Array.newInstance, Object.clone, etc.
2582 if (subklass == superklass)
2583 return C->top(); // false path is dead; no test needed.
2584
2585 if (gvn->type(superklass)->singleton()) {
2586 ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2587 ciKlass* subk = gvn->type(subklass)->is_klassptr()->klass();
2588
2589 // In the common case of an exact superklass, try to fold up the
2590 // test before generating code. You may ask, why not just generate
2591 // the code and then let it fold up? The answer is that the generated
2592 // code will necessarily include null checks, which do not always
2593 // completely fold away. If they are also needless, then they turn
2594 // into a performance loss. Example:
2595 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2596 // Here, the type of 'fa' is often exact, so the store check
2597 // of fa[1]=x will fold up, without testing the nullness of x.
2598 switch (C->static_subtype_check(superk, subk)) {
2599 case Compile::SSC_always_false:
2600 {
2601 Node* always_fail = *ctrl;
2602 *ctrl = gvn->C->top();
2603 return always_fail;
2604 }
2605 case Compile::SSC_always_true:
2606 return C->top();
2607 case Compile::SSC_easy_test:
2608 {
2609 // Just do a direct pointer compare and be done.
2610 IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2611 *ctrl = gvn->transform(new IfTrueNode(iff));
2612 return gvn->transform(new IfFalseNode(iff));
2613 }
2614 case Compile::SSC_full_test:
2615 break;
2616 default:
2617 ShouldNotReachHere();
2618 }
2619 }
2620
2621 // %%% Possible further optimization: Even if the superklass is not exact,
2622 // if the subklass is the unique subtype of the superklass, the check
2623 // will always succeed. We could leave a dependency behind to ensure this.
2624
2625 // First load the super-klass's check-offset
2626 Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2627 Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2628 Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2629 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2630 bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2631
2632 // Load from the sub-klass's super-class display list, or a 1-word cache of
2633 // the secondary superclass list, or a failing value with a sentinel offset
2634 // if the super-klass is an interface or exceptionally deep in the Java
2635 // hierarchy and we have to scan the secondary superclass list the hard way.
2636 // Worst-case type is a little odd: NULL is allowed as a result (usually
2637 // klass loads can never produce a NULL).
2638 Node *chk_off_X = chk_off;
2639 #ifdef _LP64
2640 chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2641 #endif
2642 Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2643 // For some types like interfaces the following loadKlass is from a 1-word
2644 // cache which is mutable so can't use immutable memory. Other
2645 // types load from the super-class display table which is immutable.
2646 m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2647 Node *kmem = might_be_cache ? m : C->immutable_memory();
2648 Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2649
2650 // Compile speed common case: ARE a subtype and we canNOT fail
2651 if( superklass == nkls )
2652 return C->top(); // false path is dead; no test needed.
2653
2654 // See if we get an immediate positive hit. Happens roughly 83% of the
2655 // time. Test to see if the value loaded just previously from the subklass
2656 // is exactly the superklass.
2657 IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2658 Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2659 *ctrl = gvn->transform(new IfFalseNode(iff1));
2660
2661 // Compile speed common case: Check for being deterministic right now. If
2662 // chk_off is a constant and not equal to cacheoff then we are NOT a
2663 // subklass. In this case we need exactly the 1 test above and we can
2664 // return those results immediately.
2665 if (!might_be_cache) {
2666 Node* not_subtype_ctrl = *ctrl;
2667 *ctrl = iftrue1; // We need exactly the 1 test above
2668 return not_subtype_ctrl;
2669 }
2670
2671 // Gather the various success & failures here
2672 RegionNode *r_ok_subtype = new RegionNode(4);
2673 gvn->record_for_igvn(r_ok_subtype);
2674 RegionNode *r_not_subtype = new RegionNode(3);
2675 gvn->record_for_igvn(r_not_subtype);
2676
2677 r_ok_subtype->init_req(1, iftrue1);
2678
2679 // Check for immediate negative hit. Happens roughly 11% of the time (which
2680 // is roughly 63% of the remaining cases). Test to see if the loaded
2681 // check-offset points into the subklass display list or the 1-element
2682 // cache. If it points to the display (and NOT the cache) and the display
2683 // missed then it's not a subtype.
2684 Node *cacheoff = gvn->intcon(cacheoff_con);
2685 IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2686 r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2687 *ctrl = gvn->transform(new IfFalseNode(iff2));
2688
2689 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2690 // No performance impact (too rare) but allows sharing of secondary arrays
2691 // which has some footprint reduction.
2692 IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2693 r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2694 *ctrl = gvn->transform(new IfFalseNode(iff3));
2695
2696 // -- Roads not taken here: --
2697 // We could also have chosen to perform the self-check at the beginning
2698 // of this code sequence, as the assembler does. This would not pay off
2699 // the same way, since the optimizer, unlike the assembler, can perform
2700 // static type analysis to fold away many successful self-checks.
2701 // Non-foldable self checks work better here in second position, because
2702 // the initial primary superclass check subsumes a self-check for most
2703 // types. An exception would be a secondary type like array-of-interface,
2704 // which does not appear in its own primary supertype display.
2705 // Finally, we could have chosen to move the self-check into the
2706 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2707 // dependent manner. But it is worthwhile to have the check here,
2708 // where it can be perhaps be optimized. The cost in code space is
2709 // small (register compare, branch).
2710
2711 // Now do a linear scan of the secondary super-klass array. Again, no real
2712 // performance impact (too rare) but it's gotta be done.
2713 // Since the code is rarely used, there is no penalty for moving it
2714 // out of line, and it can only improve I-cache density.
2715 // The decision to inline or out-of-line this final check is platform
2716 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2717 Node* psc = gvn->transform(
2718 new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2719
2720 IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2721 r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2722 r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2723
2724 // Return false path; set default control to true path.
2725 *ctrl = gvn->transform(r_ok_subtype);
2726 return gvn->transform(r_not_subtype);
2727 }
2728
2729 // Profile-driven exact type check:
2730 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2731 float prob,
2732 Node* *casted_receiver) {
2733 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2734 Node* recv_klass = load_object_klass(receiver);
2735 Node* want_klass = makecon(tklass);
2736 Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2737 Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2738 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2739 set_control( _gvn.transform( new IfTrueNode (iff) ));
2740 Node* fail = _gvn.transform( new IfFalseNode(iff) );
2741
2742 const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2743 assert(recv_xtype->klass_is_exact(), "");
2744
2745 // Subsume downstream occurrences of receiver with a cast to
2746 // recv_xtype, since now we know what the type will be.
2747 Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2748 (*casted_receiver) = _gvn.transform(cast);
2749 // (User must make the replace_in_map call.)
2750
2751 return fail;
2752 }
2753
2754
2755 //------------------------------seems_never_null-------------------------------
2756 // Use null_seen information if it is available from the profile.
2757 // If we see an unexpected null at a type check we record it and force a
2758 // recompile; the offending check will be recompiled to handle NULLs.
2759 // If we see several offending BCIs, then all checks in the
2760 // method will be recompiled.
2761 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2762 speculating = !_gvn.type(obj)->speculative_maybe_null();
2763 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2764 if (UncommonNullCast // Cutout for this technique
2765 && obj != null() // And not the -Xcomp stupid case?
2766 && !too_many_traps(reason)
2767 ) {
2768 if (speculating) {
2769 return true;
2770 }
2771 if (data == NULL)
2772 // Edge case: no mature data. Be optimistic here.
2773 return true;
2774 // If the profile has not seen a null, assume it won't happen.
2775 assert(java_bc() == Bytecodes::_checkcast ||
2776 java_bc() == Bytecodes::_instanceof ||
2777 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2778 return !data->as_BitData()->null_seen();
2779 }
2780 speculating = false;
2781 return false;
2782 }
2783
2784 //------------------------maybe_cast_profiled_receiver-------------------------
2785 // If the profile has seen exactly one type, narrow to exactly that type.
2786 // Subsequent type checks will always fold up.
2787 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2788 ciKlass* require_klass,
2789 ciKlass* spec_klass,
2790 bool safe_for_replace) {
2791 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2792
2793 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2794
2795 // Make sure we haven't already deoptimized from this tactic.
2796 if (too_many_traps(reason) || too_many_recompiles(reason))
2797 return NULL;
2798
2799 // (No, this isn't a call, but it's enough like a virtual call
2800 // to use the same ciMethod accessor to get the profile info...)
2801 // If we have a speculative type use it instead of profiling (which
2802 // may not help us)
2803 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2804 if (exact_kls != NULL) {// no cast failures here
2805 if (require_klass == NULL ||
2806 C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2807 // If we narrow the type to match what the type profile sees or
2808 // the speculative type, we can then remove the rest of the
2809 // cast.
2810 // This is a win, even if the exact_kls is very specific,
2811 // because downstream operations, such as method calls,
2812 // will often benefit from the sharper type.
2813 Node* exact_obj = not_null_obj; // will get updated in place...
2814 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2815 &exact_obj);
2816 { PreserveJVMState pjvms(this);
2817 set_control(slow_ctl);
2818 uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2819 }
2820 if (safe_for_replace) {
2821 replace_in_map(not_null_obj, exact_obj);
2822 }
2823 return exact_obj;
2824 }
2825 // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2826 }
2827
2828 return NULL;
2829 }
2830
2831 /**
2832 * Cast obj to type and emit guard unless we had too many traps here
2833 * already
2834 *
2835 * @param obj node being casted
2836 * @param type type to cast the node to
2837 * @param not_null true if we know node cannot be null
2838 */
2839 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2840 ciKlass* type,
2841 bool not_null) {
2842 if (stopped()) {
2843 return obj;
2844 }
2845
2846 // type == NULL if profiling tells us this object is always null
2847 if (type != NULL) {
2848 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2849 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2850
2851 if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2852 !too_many_traps(class_reason) &&
2853 !too_many_recompiles(class_reason)) {
2854 Node* not_null_obj = NULL;
2855 // not_null is true if we know the object is not null and
2856 // there's no need for a null check
2857 if (!not_null) {
2858 Node* null_ctl = top();
2859 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2860 assert(null_ctl->is_top(), "no null control here");
2861 } else {
2862 not_null_obj = obj;
2863 }
2864
2865 Node* exact_obj = not_null_obj;
2866 ciKlass* exact_kls = type;
2867 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2868 &exact_obj);
2869 {
2870 PreserveJVMState pjvms(this);
2871 set_control(slow_ctl);
2872 uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2873 }
2874 replace_in_map(not_null_obj, exact_obj);
2875 obj = exact_obj;
2876 }
2877 } else {
2878 if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2879 !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2880 Node* exact_obj = null_assert(obj);
2881 replace_in_map(obj, exact_obj);
2882 obj = exact_obj;
2883 }
2884 }
2885 return obj;
2886 }
2887
2888 //-------------------------------gen_instanceof--------------------------------
2889 // Generate an instance-of idiom. Used by both the instance-of bytecode
2890 // and the reflective instance-of call.
2891 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2892 kill_dead_locals(); // Benefit all the uncommon traps
2893 assert( !stopped(), "dead parse path should be checked in callers" );
2894 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2895 "must check for not-null not-dead klass in callers");
2896
2897 // Make the merge point
2898 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2899 RegionNode* region = new RegionNode(PATH_LIMIT);
2900 Node* phi = new PhiNode(region, TypeInt::BOOL);
2901 C->set_has_split_ifs(true); // Has chance for split-if optimization
2902
2903 ciProfileData* data = NULL;
2904 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode
2905 data = method()->method_data()->bci_to_data(bci());
2906 }
2907 bool speculative_not_null = false;
2908 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile
2909 && seems_never_null(obj, data, speculative_not_null));
2910
2911 // Null check; get casted pointer; set region slot 3
2912 Node* null_ctl = top();
2913 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2914
2915 // If not_null_obj is dead, only null-path is taken
2916 if (stopped()) { // Doing instance-of on a NULL?
2917 set_control(null_ctl);
2918 return intcon(0);
2919 }
2920 region->init_req(_null_path, null_ctl);
2921 phi ->init_req(_null_path, intcon(0)); // Set null path value
2922 if (null_ctl == top()) {
2923 // Do this eagerly, so that pattern matches like is_diamond_phi
2924 // will work even during parsing.
2925 assert(_null_path == PATH_LIMIT-1, "delete last");
2926 region->del_req(_null_path);
2927 phi ->del_req(_null_path);
2928 }
2929
2930 // Do we know the type check always succeed?
2931 bool known_statically = false;
2932 if (_gvn.type(superklass)->singleton()) {
2933 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2934 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2935 if (subk != NULL && subk->is_loaded()) {
2936 int static_res = C->static_subtype_check(superk, subk);
2937 known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2938 }
2939 }
2940
2941 if (known_statically && UseTypeSpeculation) {
2942 // If we know the type check always succeeds then we don't use the
2943 // profiling data at this bytecode. Don't lose it, feed it to the
2944 // type system as a speculative type.
2945 not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2946 } else {
2947 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2948 // We may not have profiling here or it may not help us. If we
2949 // have a speculative type use it to perform an exact cast.
2950 ciKlass* spec_obj_type = obj_type->speculative_type();
2951 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2952 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2953 if (stopped()) { // Profile disagrees with this path.
2954 set_control(null_ctl); // Null is the only remaining possibility.
2955 return intcon(0);
2956 }
2957 if (cast_obj != NULL) {
2958 not_null_obj = cast_obj;
2959 }
2960 }
2961 }
2962
2963 // Load the object's klass
2964 Node* obj_klass = load_object_klass(not_null_obj);
2965
2966 // Generate the subtype check
2967 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2968
2969 // Plug in the success path to the general merge in slot 1.
2970 region->init_req(_obj_path, control());
2971 phi ->init_req(_obj_path, intcon(1));
2972
2973 // Plug in the failing path to the general merge in slot 2.
2974 region->init_req(_fail_path, not_subtype_ctrl);
2975 phi ->init_req(_fail_path, intcon(0));
2976
2977 // Return final merged results
2978 set_control( _gvn.transform(region) );
2979 record_for_igvn(region);
2980 return _gvn.transform(phi);
2981 }
2982
2983 //-------------------------------gen_checkcast---------------------------------
2984 // Generate a checkcast idiom. Used by both the checkcast bytecode and the
2985 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the
2986 // uncommon-trap paths work. Adjust stack after this call.
2987 // If failure_control is supplied and not null, it is filled in with
2988 // the control edge for the cast failure. Otherwise, an appropriate
2989 // uncommon trap or exception is thrown.
2990 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
2991 Node* *failure_control) {
2992 kill_dead_locals(); // Benefit all the uncommon traps
2993 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
2994 const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
2995
2996 // Fast cutout: Check the case that the cast is vacuously true.
2997 // This detects the common cases where the test will short-circuit
2998 // away completely. We do this before we perform the null check,
2999 // because if the test is going to turn into zero code, we don't
3000 // want a residual null check left around. (Causes a slowdown,
3001 // for example, in some objArray manipulations, such as a[i]=a[j].)
3002 if (tk->singleton()) {
3003 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3004 if (objtp != NULL && objtp->klass() != NULL) {
3005 switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3006 case Compile::SSC_always_true:
3007 // If we know the type check always succeed then we don't use
3008 // the profiling data at this bytecode. Don't lose it, feed it
3009 // to the type system as a speculative type.
3010 return record_profiled_receiver_for_speculation(obj);
3011 case Compile::SSC_always_false:
3012 // It needs a null check because a null will *pass* the cast check.
3013 // A non-null value will always produce an exception.
3014 return null_assert(obj);
3015 }
3016 }
3017 }
3018
3019 ciProfileData* data = NULL;
3020 bool safe_for_replace = false;
3021 if (failure_control == NULL) { // use MDO in regular case only
3022 assert(java_bc() == Bytecodes::_aastore ||
3023 java_bc() == Bytecodes::_checkcast,
3024 "interpreter profiles type checks only for these BCs");
3025 data = method()->method_data()->bci_to_data(bci());
3026 safe_for_replace = true;
3027 }
3028
3029 // Make the merge point
3030 enum { _obj_path = 1, _null_path, PATH_LIMIT };
3031 RegionNode* region = new RegionNode(PATH_LIMIT);
3032 Node* phi = new PhiNode(region, toop);
3033 C->set_has_split_ifs(true); // Has chance for split-if optimization
3034
3035 // Use null-cast information if it is available
3036 bool speculative_not_null = false;
3037 bool never_see_null = ((failure_control == NULL) // regular case only
3038 && seems_never_null(obj, data, speculative_not_null));
3039
3040 // Null check; get casted pointer; set region slot 3
3041 Node* null_ctl = top();
3042 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3043
3044 // If not_null_obj is dead, only null-path is taken
3045 if (stopped()) { // Doing instance-of on a NULL?
3046 set_control(null_ctl);
3047 return null();
3048 }
3049 region->init_req(_null_path, null_ctl);
3050 phi ->init_req(_null_path, null()); // Set null path value
3051 if (null_ctl == top()) {
3052 // Do this eagerly, so that pattern matches like is_diamond_phi
3053 // will work even during parsing.
3054 assert(_null_path == PATH_LIMIT-1, "delete last");
3055 region->del_req(_null_path);
3056 phi ->del_req(_null_path);
3057 }
3058
3059 Node* cast_obj = NULL;
3060 if (tk->klass_is_exact()) {
3061 // The following optimization tries to statically cast the speculative type of the object
3062 // (for example obtained during profiling) to the type of the superklass and then do a
3063 // dynamic check that the type of the object is what we expect. To work correctly
3064 // for checkcast and aastore the type of superklass should be exact.
3065 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3066 // We may not have profiling here or it may not help us. If we have
3067 // a speculative type use it to perform an exact cast.
3068 ciKlass* spec_obj_type = obj_type->speculative_type();
3069 if (spec_obj_type != NULL || data != NULL) {
3070 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3071 if (cast_obj != NULL) {
3072 if (failure_control != NULL) // failure is now impossible
3073 (*failure_control) = top();
3074 // adjust the type of the phi to the exact klass:
3075 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3076 }
3077 }
3078 }
3079
3080 if (cast_obj == NULL) {
3081 // Load the object's klass
3082 Node* obj_klass = load_object_klass(not_null_obj);
3083
3084 // Generate the subtype check
3085 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3086
3087 // Plug in success path into the merge
3088 cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3089 // Failure path ends in uncommon trap (or may be dead - failure impossible)
3090 if (failure_control == NULL) {
3091 if (not_subtype_ctrl != top()) { // If failure is possible
3092 PreserveJVMState pjvms(this);
3093 set_control(not_subtype_ctrl);
3094 builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3095 }
3096 } else {
3097 (*failure_control) = not_subtype_ctrl;
3098 }
3099 }
3100
3101 region->init_req(_obj_path, control());
3102 phi ->init_req(_obj_path, cast_obj);
3103
3104 // A merge of NULL or Casted-NotNull obj
3105 Node* res = _gvn.transform(phi);
3106
3107 // Note I do NOT always 'replace_in_map(obj,result)' here.
3108 // if( tk->klass()->can_be_primary_super() )
3109 // This means that if I successfully store an Object into an array-of-String
3110 // I 'forget' that the Object is really now known to be a String. I have to
3111 // do this because we don't have true union types for interfaces - if I store
3112 // a Baz into an array-of-Interface and then tell the optimizer it's an
3113 // Interface, I forget that it's also a Baz and cannot do Baz-like field
3114 // references to it. FIX THIS WHEN UNION TYPES APPEAR!
3115 // replace_in_map( obj, res );
3116
3117 // Return final merged results
3118 set_control( _gvn.transform(region) );
3119 record_for_igvn(region);
3120 return res;
3121 }
3122
3123 //------------------------------next_monitor-----------------------------------
3124 // What number should be given to the next monitor?
3125 int GraphKit::next_monitor() {
3126 int current = jvms()->monitor_depth()* C->sync_stack_slots();
3127 int next = current + C->sync_stack_slots();
3128 // Keep the toplevel high water mark current:
3129 if (C->fixed_slots() < next) C->set_fixed_slots(next);
3130 return current;
3131 }
3132
3133 //------------------------------insert_mem_bar---------------------------------
3134 // Memory barrier to avoid floating things around
3135 // The membar serves as a pinch point between both control and all memory slices.
3136 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3137 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3138 mb->init_req(TypeFunc::Control, control());
3139 mb->init_req(TypeFunc::Memory, reset_memory());
3140 Node* membar = _gvn.transform(mb);
3141 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3142 set_all_memory_call(membar);
3143 return membar;
3144 }
3145
3146 //-------------------------insert_mem_bar_volatile----------------------------
3147 // Memory barrier to avoid floating things around
3148 // The membar serves as a pinch point between both control and memory(alias_idx).
3149 // If you want to make a pinch point on all memory slices, do not use this
3150 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3151 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3152 // When Parse::do_put_xxx updates a volatile field, it appends a series
3153 // of MemBarVolatile nodes, one for *each* volatile field alias category.
3154 // The first membar is on the same memory slice as the field store opcode.
3155 // This forces the membar to follow the store. (Bug 6500685 broke this.)
3156 // All the other membars (for other volatile slices, including AliasIdxBot,
3157 // which stands for all unknown volatile slices) are control-dependent
3158 // on the first membar. This prevents later volatile loads or stores
3159 // from sliding up past the just-emitted store.
3160
3161 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3162 mb->set_req(TypeFunc::Control,control());
3163 if (alias_idx == Compile::AliasIdxBot) {
3164 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3165 } else {
3166 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3167 mb->set_req(TypeFunc::Memory, memory(alias_idx));
3168 }
3169 Node* membar = _gvn.transform(mb);
3170 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3171 if (alias_idx == Compile::AliasIdxBot) {
3172 merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3173 } else {
3174 set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3175 }
3176 return membar;
3177 }
3178
3179 //------------------------------shared_lock------------------------------------
3180 // Emit locking code.
3181 FastLockNode* GraphKit::shared_lock(Node* obj) {
3182 // bci is either a monitorenter bc or InvocationEntryBci
3183 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3184 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3185
3186 if( !GenerateSynchronizationCode )
3187 return NULL; // Not locking things?
3188 if (stopped()) // Dead monitor?
3189 return NULL;
3190
3191 assert(dead_locals_are_killed(), "should kill locals before sync. point");
3192
3193 // Box the stack location
3194 Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3195 Node* mem = reset_memory();
3196
3197 FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3198 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3199 // Create the counters for this fast lock.
3200 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3201 }
3202
3203 // Create the rtm counters for this fast lock if needed.
3204 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3205
3206 // Add monitor to debug info for the slow path. If we block inside the
3207 // slow path and de-opt, we need the monitor hanging around
3208 map()->push_monitor( flock );
3209
3210 const TypeFunc *tf = LockNode::lock_type();
3211 LockNode *lock = new LockNode(C, tf);
3212
3213 lock->init_req( TypeFunc::Control, control() );
3214 lock->init_req( TypeFunc::Memory , mem );
3215 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3216 lock->init_req( TypeFunc::FramePtr, frameptr() );
3217 lock->init_req( TypeFunc::ReturnAdr, top() );
3218
3219 lock->init_req(TypeFunc::Parms + 0, obj);
3220 lock->init_req(TypeFunc::Parms + 1, box);
3221 lock->init_req(TypeFunc::Parms + 2, flock);
3222 add_safepoint_edges(lock);
3223
3224 lock = _gvn.transform( lock )->as_Lock();
3225
3226 // lock has no side-effects, sets few values
3227 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3228
3229 insert_mem_bar(Op_MemBarAcquireLock);
3230
3231 // Add this to the worklist so that the lock can be eliminated
3232 record_for_igvn(lock);
3233
3234 #ifndef PRODUCT
3235 if (PrintLockStatistics) {
3236 // Update the counter for this lock. Don't bother using an atomic
3237 // operation since we don't require absolute accuracy.
3238 lock->create_lock_counter(map()->jvms());
3239 increment_counter(lock->counter()->addr());
3240 }
3241 #endif
3242
3243 return flock;
3244 }
3245
3246
3247 //------------------------------shared_unlock----------------------------------
3248 // Emit unlocking code.
3249 void GraphKit::shared_unlock(Node* box, Node* obj) {
3250 // bci is either a monitorenter bc or InvocationEntryBci
3251 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3252 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3253
3254 if( !GenerateSynchronizationCode )
3255 return;
3256 if (stopped()) { // Dead monitor?
3257 map()->pop_monitor(); // Kill monitor from debug info
3258 return;
3259 }
3260
3261 // Memory barrier to avoid floating things down past the locked region
3262 insert_mem_bar(Op_MemBarReleaseLock);
3263
3264 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3265 UnlockNode *unlock = new UnlockNode(C, tf);
3266 #ifdef ASSERT
3267 unlock->set_dbg_jvms(sync_jvms());
3268 #endif
3269 uint raw_idx = Compile::AliasIdxRaw;
3270 unlock->init_req( TypeFunc::Control, control() );
3271 unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3272 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3273 unlock->init_req( TypeFunc::FramePtr, frameptr() );
3274 unlock->init_req( TypeFunc::ReturnAdr, top() );
3275
3276 unlock->init_req(TypeFunc::Parms + 0, obj);
3277 unlock->init_req(TypeFunc::Parms + 1, box);
3278 unlock = _gvn.transform(unlock)->as_Unlock();
3279
3280 Node* mem = reset_memory();
3281
3282 // unlock has no side-effects, sets few values
3283 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3284
3285 // Kill monitor from debug info
3286 map()->pop_monitor( );
3287 }
3288
3289 //-------------------------------get_layout_helper-----------------------------
3290 // If the given klass is a constant or known to be an array,
3291 // fetch the constant layout helper value into constant_value
3292 // and return (Node*)NULL. Otherwise, load the non-constant
3293 // layout helper value, and return the node which represents it.
3294 // This two-faced routine is useful because allocation sites
3295 // almost always feature constant types.
3296 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3297 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3298 if (!StressReflectiveCode && inst_klass != NULL) {
3299 ciKlass* klass = inst_klass->klass();
3300 bool xklass = inst_klass->klass_is_exact();
3301 if (xklass || klass->is_array_klass()) {
3302 jint lhelper = klass->layout_helper();
3303 if (lhelper != Klass::_lh_neutral_value) {
3304 constant_value = lhelper;
3305 return (Node*) NULL;
3306 }
3307 }
3308 }
3309 constant_value = Klass::_lh_neutral_value; // put in a known value
3310 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3311 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3312 }
3313
3314 // We just put in an allocate/initialize with a big raw-memory effect.
3315 // Hook selected additional alias categories on the initialization.
3316 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3317 MergeMemNode* init_in_merge,
3318 Node* init_out_raw) {
3319 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3320 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3321
3322 Node* prevmem = kit.memory(alias_idx);
3323 init_in_merge->set_memory_at(alias_idx, prevmem);
3324 kit.set_memory(init_out_raw, alias_idx);
3325 }
3326
3327 //---------------------------set_output_for_allocation-------------------------
3328 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3329 const TypeOopPtr* oop_type,
3330 bool deoptimize_on_exception) {
3331 int rawidx = Compile::AliasIdxRaw;
3332 alloc->set_req( TypeFunc::FramePtr, frameptr() );
3333 add_safepoint_edges(alloc);
3334 Node* allocx = _gvn.transform(alloc);
3335 set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3336 // create memory projection for i_o
3337 set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3338 make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3339
3340 // create a memory projection as for the normal control path
3341 Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3342 set_memory(malloc, rawidx);
3343
3344 // a normal slow-call doesn't change i_o, but an allocation does
3345 // we create a separate i_o projection for the normal control path
3346 set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3347 Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3348
3349 // put in an initialization barrier
3350 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3351 rawoop)->as_Initialize();
3352 assert(alloc->initialization() == init, "2-way macro link must work");
3353 assert(init ->allocation() == alloc, "2-way macro link must work");
3354 {
3355 // Extract memory strands which may participate in the new object's
3356 // initialization, and source them from the new InitializeNode.
3357 // This will allow us to observe initializations when they occur,
3358 // and link them properly (as a group) to the InitializeNode.
3359 assert(init->in(InitializeNode::Memory) == malloc, "");
3360 MergeMemNode* minit_in = MergeMemNode::make(malloc);
3361 init->set_req(InitializeNode::Memory, minit_in);
3362 record_for_igvn(minit_in); // fold it up later, if possible
3363 Node* minit_out = memory(rawidx);
3364 assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3365 if (oop_type->isa_aryptr()) {
3366 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3367 int elemidx = C->get_alias_index(telemref);
3368 hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3369 } else if (oop_type->isa_instptr()) {
3370 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3371 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3372 ciField* field = ik->nonstatic_field_at(i);
3373 if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3374 continue; // do not bother to track really large numbers of fields
3375 // Find (or create) the alias category for this field:
3376 int fieldidx = C->alias_type(field)->index();
3377 hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3378 }
3379 }
3380 }
3381
3382 // Cast raw oop to the real thing...
3383 Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3384 javaoop = _gvn.transform(javaoop);
3385 C->set_recent_alloc(control(), javaoop);
3386 assert(just_allocated_object(control()) == javaoop, "just allocated");
3387
3388 #ifdef ASSERT
3389 { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3390 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3391 "Ideal_allocation works");
3392 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3393 "Ideal_allocation works");
3394 if (alloc->is_AllocateArray()) {
3395 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3396 "Ideal_allocation works");
3397 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3398 "Ideal_allocation works");
3399 } else {
3400 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3401 }
3402 }
3403 #endif //ASSERT
3404
3405 return javaoop;
3406 }
3407
3408 //---------------------------new_instance--------------------------------------
3409 // This routine takes a klass_node which may be constant (for a static type)
3410 // or may be non-constant (for reflective code). It will work equally well
3411 // for either, and the graph will fold nicely if the optimizer later reduces
3412 // the type to a constant.
3413 // The optional arguments are for specialized use by intrinsics:
3414 // - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3415 // - If 'return_size_val', report the the total object size to the caller.
3416 // - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3417 Node* GraphKit::new_instance(Node* klass_node,
3418 Node* extra_slow_test,
3419 Node* *return_size_val,
3420 bool deoptimize_on_exception) {
3421 // Compute size in doublewords
3422 // The size is always an integral number of doublewords, represented
3423 // as a positive bytewise size stored in the klass's layout_helper.
3424 // The layout_helper also encodes (in a low bit) the need for a slow path.
3425 jint layout_con = Klass::_lh_neutral_value;
3426 Node* layout_val = get_layout_helper(klass_node, layout_con);
3427 int layout_is_con = (layout_val == NULL);
3428
3429 if (extra_slow_test == NULL) extra_slow_test = intcon(0);
3430 // Generate the initial go-slow test. It's either ALWAYS (return a
3431 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3432 // case) a computed value derived from the layout_helper.
3433 Node* initial_slow_test = NULL;
3434 if (layout_is_con) {
3435 assert(!StressReflectiveCode, "stress mode does not use these paths");
3436 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3437 initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3438 } else { // reflective case
3439 // This reflective path is used by Unsafe.allocateInstance.
3440 // (It may be stress-tested by specifying StressReflectiveCode.)
3441 // Basically, we want to get into the VM is there's an illegal argument.
3442 Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3443 initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3444 if (extra_slow_test != intcon(0)) {
3445 initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3446 }
3447 // (Macro-expander will further convert this to a Bool, if necessary.)
3448 }
3449
3450 // Find the size in bytes. This is easy; it's the layout_helper.
3451 // The size value must be valid even if the slow path is taken.
3452 Node* size = NULL;
3453 if (layout_is_con) {
3454 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3455 } else { // reflective case
3456 // This reflective path is used by clone and Unsafe.allocateInstance.
3457 size = ConvI2X(layout_val);
3458
3459 // Clear the low bits to extract layout_helper_size_in_bytes:
3460 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3461 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3462 size = _gvn.transform( new AndXNode(size, mask) );
3463 }
3464 if (return_size_val != NULL) {
3465 (*return_size_val) = size;
3466 }
3467
3468 // This is a precise notnull oop of the klass.
3469 // (Actually, it need not be precise if this is a reflective allocation.)
3470 // It's what we cast the result to.
3471 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3472 if (!tklass) tklass = TypeKlassPtr::OBJECT;
3473 const TypeOopPtr* oop_type = tklass->as_instance_type();
3474
3475 // Now generate allocation code
3476
3477 // The entire memory state is needed for slow path of the allocation
3478 // since GC and deoptimization can happened.
3479 Node *mem = reset_memory();
3480 set_all_memory(mem); // Create new memory state
3481
3482 AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3483 control(), mem, i_o(),
3484 size, klass_node,
3485 initial_slow_test);
3486
3487 return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3488 }
3489
3490 //-------------------------------new_array-------------------------------------
3491 // helper for both newarray and anewarray
3492 // The 'length' parameter is (obviously) the length of the array.
3493 // See comments on new_instance for the meaning of the other arguments.
3494 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable)
3495 Node* length, // number of array elements
3496 int nargs, // number of arguments to push back for uncommon trap
3497 Node* *return_size_val,
3498 bool deoptimize_on_exception) {
3499 jint layout_con = Klass::_lh_neutral_value;
3500 Node* layout_val = get_layout_helper(klass_node, layout_con);
3501 int layout_is_con = (layout_val == NULL);
3502
3503 if (!layout_is_con && !StressReflectiveCode &&
3504 !too_many_traps(Deoptimization::Reason_class_check)) {
3505 // This is a reflective array creation site.
3506 // Optimistically assume that it is a subtype of Object[],
3507 // so that we can fold up all the address arithmetic.
3508 layout_con = Klass::array_layout_helper(T_OBJECT);
3509 Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3510 Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3511 { BuildCutout unless(this, bol_lh, PROB_MAX);
3512 inc_sp(nargs);
3513 uncommon_trap(Deoptimization::Reason_class_check,
3514 Deoptimization::Action_maybe_recompile);
3515 }
3516 layout_val = NULL;
3517 layout_is_con = true;
3518 }
3519
3520 // Generate the initial go-slow test. Make sure we do not overflow
3521 // if length is huge (near 2Gig) or negative! We do not need
3522 // exact double-words here, just a close approximation of needed
3523 // double-words. We can't add any offset or rounding bits, lest we
3524 // take a size -1 of bytes and make it positive. Use an unsigned
3525 // compare, so negative sizes look hugely positive.
3526 int fast_size_limit = FastAllocateSizeLimit;
3527 if (layout_is_con) {
3528 assert(!StressReflectiveCode, "stress mode does not use these paths");
3529 // Increase the size limit if we have exact knowledge of array type.
3530 int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3531 fast_size_limit <<= (LogBytesPerLong - log2_esize);
3532 }
3533
3534 Node* initial_slow_cmp = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3535 Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3536
3537 // --- Size Computation ---
3538 // array_size = round_to_heap(array_header + (length << elem_shift));
3539 // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3540 // and round_to(x, y) == ((x + y-1) & ~(y-1))
3541 // The rounding mask is strength-reduced, if possible.
3542 int round_mask = MinObjAlignmentInBytes - 1;
3543 Node* header_size = NULL;
3544 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3545 // (T_BYTE has the weakest alignment and size restrictions...)
3546 if (layout_is_con) {
3547 int hsize = Klass::layout_helper_header_size(layout_con);
3548 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3549 BasicType etype = Klass::layout_helper_element_type(layout_con);
3550 if ((round_mask & ~right_n_bits(eshift)) == 0)
3551 round_mask = 0; // strength-reduce it if it goes away completely
3552 assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3553 assert(header_size_min <= hsize, "generic minimum is smallest");
3554 header_size_min = hsize;
3555 header_size = intcon(hsize + round_mask);
3556 } else {
3557 Node* hss = intcon(Klass::_lh_header_size_shift);
3558 Node* hsm = intcon(Klass::_lh_header_size_mask);
3559 Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3560 hsize = _gvn.transform( new AndINode(hsize, hsm) );
3561 Node* mask = intcon(round_mask);
3562 header_size = _gvn.transform( new AddINode(hsize, mask) );
3563 }
3564
3565 Node* elem_shift = NULL;
3566 if (layout_is_con) {
3567 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3568 if (eshift != 0)
3569 elem_shift = intcon(eshift);
3570 } else {
3571 // There is no need to mask or shift this value.
3572 // The semantics of LShiftINode include an implicit mask to 0x1F.
3573 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3574 elem_shift = layout_val;
3575 }
3576
3577 // Transition to native address size for all offset calculations:
3578 Node* lengthx = ConvI2X(length);
3579 Node* headerx = ConvI2X(header_size);
3580 #ifdef _LP64
3581 { const TypeInt* tilen = _gvn.find_int_type(length);
3582 if (tilen != NULL && tilen->_lo < 0) {
3583 // Add a manual constraint to a positive range. Cf. array_element_address.
3584 jint size_max = fast_size_limit;
3585 if (size_max > tilen->_hi) size_max = tilen->_hi;
3586 const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3587
3588 // Only do a narrow I2L conversion if the range check passed.
3589 IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3590 _gvn.transform(iff);
3591 RegionNode* region = new RegionNode(3);
3592 _gvn.set_type(region, Type::CONTROL);
3593 lengthx = new PhiNode(region, TypeLong::LONG);
3594 _gvn.set_type(lengthx, TypeLong::LONG);
3595
3596 // Range check passed. Use ConvI2L node with narrow type.
3597 Node* passed = IfFalse(iff);
3598 region->init_req(1, passed);
3599 // Make I2L conversion control dependent to prevent it from
3600 // floating above the range check during loop optimizations.
3601 lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3602
3603 // Range check failed. Use ConvI2L with wide type because length may be invalid.
3604 region->init_req(2, IfTrue(iff));
3605 lengthx->init_req(2, ConvI2X(length));
3606
3607 set_control(region);
3608 record_for_igvn(region);
3609 record_for_igvn(lengthx);
3610 }
3611 }
3612 #endif
3613
3614 // Combine header size (plus rounding) and body size. Then round down.
3615 // This computation cannot overflow, because it is used only in two
3616 // places, one where the length is sharply limited, and the other
3617 // after a successful allocation.
3618 Node* abody = lengthx;
3619 if (elem_shift != NULL)
3620 abody = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3621 Node* size = _gvn.transform( new AddXNode(headerx, abody) );
3622 if (round_mask != 0) {
3623 Node* mask = MakeConX(~round_mask);
3624 size = _gvn.transform( new AndXNode(size, mask) );
3625 }
3626 // else if round_mask == 0, the size computation is self-rounding
3627
3628 if (return_size_val != NULL) {
3629 // This is the size
3630 (*return_size_val) = size;
3631 }
3632
3633 // Now generate allocation code
3634
3635 // The entire memory state is needed for slow path of the allocation
3636 // since GC and deoptimization can happened.
3637 Node *mem = reset_memory();
3638 set_all_memory(mem); // Create new memory state
3639
3640 if (initial_slow_test->is_Bool()) {
3641 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3642 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3643 }
3644
3645 // Create the AllocateArrayNode and its result projections
3646 AllocateArrayNode* alloc
3647 = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3648 control(), mem, i_o(),
3649 size, klass_node,
3650 initial_slow_test,
3651 length);
3652
3653 // Cast to correct type. Note that the klass_node may be constant or not,
3654 // and in the latter case the actual array type will be inexact also.
3655 // (This happens via a non-constant argument to inline_native_newArray.)
3656 // In any case, the value of klass_node provides the desired array type.
3657 const TypeInt* length_type = _gvn.find_int_type(length);
3658 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3659 if (ary_type->isa_aryptr() && length_type != NULL) {
3660 // Try to get a better type than POS for the size
3661 ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3662 }
3663
3664 Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3665
3666 // Cast length on remaining path to be as narrow as possible
3667 if (map()->find_edge(length) >= 0) {
3668 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3669 if (ccast != length) {
3670 _gvn.set_type_bottom(ccast);
3671 record_for_igvn(ccast);
3672 replace_in_map(length, ccast);
3673 }
3674 }
3675
3676 return javaoop;
3677 }
3678
3679 // The following "Ideal_foo" functions are placed here because they recognize
3680 // the graph shapes created by the functions immediately above.
3681
3682 //---------------------------Ideal_allocation----------------------------------
3683 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3684 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3685 if (ptr == NULL) { // reduce dumb test in callers
3686 return NULL;
3687 }
3688 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3689 ptr = ptr->in(1);
3690 if (ptr == NULL) return NULL;
3691 }
3692 // Return NULL for allocations with several casts:
3693 // j.l.reflect.Array.newInstance(jobject, jint)
3694 // Object.clone()
3695 // to keep more precise type from last cast.
3696 if (ptr->is_Proj()) {
3697 Node* allo = ptr->in(0);
3698 if (allo != NULL && allo->is_Allocate()) {
3699 return allo->as_Allocate();
3700 }
3701 }
3702 // Report failure to match.
3703 return NULL;
3704 }
3705
3706 // Fancy version which also strips off an offset (and reports it to caller).
3707 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3708 intptr_t& offset) {
3709 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3710 if (base == NULL) return NULL;
3711 return Ideal_allocation(base, phase);
3712 }
3713
3714 // Trace Initialize <- Proj[Parm] <- Allocate
3715 AllocateNode* InitializeNode::allocation() {
3716 Node* rawoop = in(InitializeNode::RawAddress);
3717 if (rawoop->is_Proj()) {
3718 Node* alloc = rawoop->in(0);
3719 if (alloc->is_Allocate()) {
3720 return alloc->as_Allocate();
3721 }
3722 }
3723 return NULL;
3724 }
3725
3726 // Trace Allocate -> Proj[Parm] -> Initialize
3727 InitializeNode* AllocateNode::initialization() {
3728 ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3729 if (rawoop == NULL) return NULL;
3730 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3731 Node* init = rawoop->fast_out(i);
3732 if (init->is_Initialize()) {
3733 assert(init->as_Initialize()->allocation() == this, "2-way link");
3734 return init->as_Initialize();
3735 }
3736 }
3737 return NULL;
3738 }
3739
3740 //----------------------------- loop predicates ---------------------------
3741
3742 //------------------------------add_predicate_impl----------------------------
3743 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3744 // Too many traps seen?
3745 if (too_many_traps(reason)) {
3746 #ifdef ASSERT
3747 if (TraceLoopPredicate) {
3748 int tc = C->trap_count(reason);
3749 tty->print("too many traps=%s tcount=%d in ",
3750 Deoptimization::trap_reason_name(reason), tc);
3751 method()->print(); // which method has too many predicate traps
3752 tty->cr();
3753 }
3754 #endif
3755 // We cannot afford to take more traps here,
3756 // do not generate predicate.
3757 return;
3758 }
3759
3760 Node *cont = _gvn.intcon(1);
3761 Node* opq = _gvn.transform(new Opaque1Node(C, cont));
3762 Node *bol = _gvn.transform(new Conv2BNode(opq));
3763 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3764 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3765 C->add_predicate_opaq(opq);
3766 {
3767 PreserveJVMState pjvms(this);
3768 set_control(iffalse);
3769 inc_sp(nargs);
3770 uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3771 }
3772 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3773 set_control(iftrue);
3774 }
3775
3776 //------------------------------add_predicate---------------------------------
3777 void GraphKit::add_predicate(int nargs) {
3778 if (UseLoopPredicate) {
3779 add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3780 }
3781 // loop's limit check predicate should be near the loop.
3782 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3783 }
3784
3785 //----------------------------- store barriers ----------------------------
3786 #define __ ideal.
3787
3788 void GraphKit::sync_kit(IdealKit& ideal) {
3789 set_all_memory(__ merged_memory());
3790 set_i_o(__ i_o());
3791 set_control(__ ctrl());
3792 }
3793
3794 void GraphKit::final_sync(IdealKit& ideal) {
3795 // Final sync IdealKit and graphKit.
3796 sync_kit(ideal);
3797 }
3798
3799 Node* GraphKit::byte_map_base_node() {
3800 // Get base of card map
3801 CardTableModRefBS* ct =
3802 barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3803 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3804 if (ct->byte_map_base != NULL) {
3805 return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3806 } else {
3807 return null();
3808 }
3809 }
3810
3811 // vanilla/CMS post barrier
3812 // Insert a write-barrier store. This is to let generational GC work; we have
3813 // to flag all oop-stores before the next GC point.
3814 void GraphKit::write_barrier_post(Node* oop_store,
3815 Node* obj,
3816 Node* adr,
3817 uint adr_idx,
3818 Node* val,
3819 bool use_precise) {
3820 // No store check needed if we're storing a NULL or an old object
3821 // (latter case is probably a string constant). The concurrent
3822 // mark sweep garbage collector, however, needs to have all nonNull
3823 // oop updates flagged via card-marks.
3824 if (val != NULL && val->is_Con()) {
3825 // must be either an oop or NULL
3826 const Type* t = val->bottom_type();
3827 if (t == TypePtr::NULL_PTR || t == Type::TOP)
3828 // stores of null never (?) need barriers
3829 return;
3830 }
3831
3832 if (use_ReduceInitialCardMarks()
3833 && obj == just_allocated_object(control())) {
3834 // We can skip marks on a freshly-allocated object in Eden.
3835 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3836 // That routine informs GC to take appropriate compensating steps,
3837 // upon a slow-path allocation, so as to make this card-mark
3838 // elision safe.
3839 return;
3840 }
3841
3842 if (!use_precise) {
3843 // All card marks for a (non-array) instance are in one place:
3844 adr = obj;
3845 }
3846 // (Else it's an array (or unknown), and we want more precise card marks.)
3847 assert(adr != NULL, "");
3848
3849 IdealKit ideal(this, true);
3850
3851 // Convert the pointer to an int prior to doing math on it
3852 Node* cast = __ CastPX(__ ctrl(), adr);
3853
3854 // Divide by card size
3855 assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3856 "Only one we handle so far.");
3857 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3858
3859 // Combine card table base and card offset
3860 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3861
3862 // Get the alias_index for raw card-mark memory
3863 int adr_type = Compile::AliasIdxRaw;
3864 Node* zero = __ ConI(0); // Dirty card value
3865 BasicType bt = T_BYTE;
3866
3867 if (UseConcMarkSweepGC && UseCondCardMark) {
3868 insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
3869 __ sync_kit(this);
3870 }
3871
3872 if (UseCondCardMark) {
3873 // The classic GC reference write barrier is typically implemented
3874 // as a store into the global card mark table. Unfortunately
3875 // unconditional stores can result in false sharing and excessive
3876 // coherence traffic as well as false transactional aborts.
3877 // UseCondCardMark enables MP "polite" conditional card mark
3878 // stores. In theory we could relax the load from ctrl() to
3879 // no_ctrl, but that doesn't buy much latitude.
3880 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3881 __ if_then(card_val, BoolTest::ne, zero);
3882 }
3883
3884 // Smash zero into card
3885 if( !UseConcMarkSweepGC ) {
3886 __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3887 } else {
3888 // Specialized path for CM store barrier
3889 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3890 }
3891
3892 if (UseCondCardMark) {
3893 __ end_if();
3894 }
3895
3896 // Final sync IdealKit and GraphKit.
3897 final_sync(ideal);
3898 }
3899 /*
3900 * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3901 * required by SATB to make sure all objects live at the start of the
3902 * marking are kept alive, all reference updates need to any previous
3903 * reference stored before writing.
3904 *
3905 * If the previous value is NULL there is no need to save the old value.
3906 * References that are NULL are filtered during runtime by the barrier
3907 * code to avoid unnecessary queuing.
3908 *
3909 * However in the case of newly allocated objects it might be possible to
3910 * prove that the reference about to be overwritten is NULL during compile
3911 * time and avoid adding the barrier code completely.
3912 *
3913 * The compiler needs to determine that the object in which a field is about
3914 * to be written is newly allocated, and that no prior store to the same field
3915 * has happened since the allocation.
3916 *
3917 * Returns true if the pre-barrier can be removed
3918 */
3919 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3920 BasicType bt, uint adr_idx) {
3921 intptr_t offset = 0;
3922 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3923 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3924
3925 if (offset == Type::OffsetBot) {
3926 return false; // cannot unalias unless there are precise offsets
3927 }
3928
3929 if (alloc == NULL) {
3930 return false; // No allocation found
3931 }
3932
3933 intptr_t size_in_bytes = type2aelembytes(bt);
3934
3935 Node* mem = memory(adr_idx); // start searching here...
3936
3937 for (int cnt = 0; cnt < 50; cnt++) {
3938
3939 if (mem->is_Store()) {
3940
3941 Node* st_adr = mem->in(MemNode::Address);
3942 intptr_t st_offset = 0;
3943 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3944
3945 if (st_base == NULL) {
3946 break; // inscrutable pointer
3947 }
3948
3949 // Break we have found a store with same base and offset as ours so break
3950 if (st_base == base && st_offset == offset) {
3951 break;
3952 }
3953
3954 if (st_offset != offset && st_offset != Type::OffsetBot) {
3955 const int MAX_STORE = BytesPerLong;
3956 if (st_offset >= offset + size_in_bytes ||
3957 st_offset <= offset - MAX_STORE ||
3958 st_offset <= offset - mem->as_Store()->memory_size()) {
3959 // Success: The offsets are provably independent.
3960 // (You may ask, why not just test st_offset != offset and be done?
3961 // The answer is that stores of different sizes can co-exist
3962 // in the same sequence of RawMem effects. We sometimes initialize
3963 // a whole 'tile' of array elements with a single jint or jlong.)
3964 mem = mem->in(MemNode::Memory);
3965 continue; // advance through independent store memory
3966 }
3967 }
3968
3969 if (st_base != base
3970 && MemNode::detect_ptr_independence(base, alloc, st_base,
3971 AllocateNode::Ideal_allocation(st_base, phase),
3972 phase)) {
3973 // Success: The bases are provably independent.
3974 mem = mem->in(MemNode::Memory);
3975 continue; // advance through independent store memory
3976 }
3977 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
3978
3979 InitializeNode* st_init = mem->in(0)->as_Initialize();
3980 AllocateNode* st_alloc = st_init->allocation();
3981
3982 // Make sure that we are looking at the same allocation site.
3983 // The alloc variable is guaranteed to not be null here from earlier check.
3984 if (alloc == st_alloc) {
3985 // Check that the initialization is storing NULL so that no previous store
3986 // has been moved up and directly write a reference
3987 Node* captured_store = st_init->find_captured_store(offset,
3988 type2aelembytes(T_OBJECT),
3989 phase);
3990 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
3991 return true;
3992 }
3993 }
3994 }
3995
3996 // Unless there is an explicit 'continue', we must bail out here,
3997 // because 'mem' is an inscrutable memory state (e.g., a call).
3998 break;
3999 }
4000
4001 return false;
4002 }
4003
4004 // G1 pre/post barriers
4005 void GraphKit::g1_write_barrier_pre(bool do_load,
4006 Node* obj,
4007 Node* adr,
4008 uint alias_idx,
4009 Node* val,
4010 const TypeOopPtr* val_type,
4011 Node* pre_val,
4012 BasicType bt) {
4013
4014 // Some sanity checks
4015 // Note: val is unused in this routine.
4016
4017 if (do_load) {
4018 // We need to generate the load of the previous value
4019 assert(obj != NULL, "must have a base");
4020 assert(adr != NULL, "where are loading from?");
4021 assert(pre_val == NULL, "loaded already?");
4022 assert(val_type != NULL, "need a type");
4023
4024 if (use_ReduceInitialCardMarks()
4025 && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4026 return;
4027 }
4028
4029 } else {
4030 // In this case both val_type and alias_idx are unused.
4031 assert(pre_val != NULL, "must be loaded already");
4032 // Nothing to be done if pre_val is null.
4033 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4034 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4035 }
4036 assert(bt == T_OBJECT, "or we shouldn't be here");
4037
4038 IdealKit ideal(this, true);
4039
4040 Node* tls = __ thread(); // ThreadLocalStorage
4041
4042 Node* no_ctrl = NULL;
4043 Node* no_base = __ top();
4044 Node* zero = __ ConI(0);
4045 Node* zeroX = __ ConX(0);
4046
4047 float likely = PROB_LIKELY(0.999);
4048 float unlikely = PROB_UNLIKELY(0.999);
4049
4050 BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4051 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4052
4053 // Offsets into the thread
4054 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648
4055 SATBMarkQueue::byte_offset_of_active());
4056 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656
4057 SATBMarkQueue::byte_offset_of_index());
4058 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652
4059 SATBMarkQueue::byte_offset_of_buf());
4060
4061 // Now the actual pointers into the thread
4062 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4063 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4064 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4065
4066 // Now some of the values
4067 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4068
4069 // if (!marking)
4070 __ if_then(marking, BoolTest::ne, zero, unlikely); {
4071 BasicType index_bt = TypeX_X->basic_type();
4072 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4073 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4074
4075 if (do_load) {
4076 // load original value
4077 // alias_idx correct??
4078 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4079 }
4080
4081 // if (pre_val != NULL)
4082 __ if_then(pre_val, BoolTest::ne, null()); {
4083 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4084
4085 // is the queue for this thread full?
4086 __ if_then(index, BoolTest::ne, zeroX, likely); {
4087
4088 // decrement the index
4089 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4090
4091 // Now get the buffer location we will log the previous value into and store it
4092 Node *log_addr = __ AddP(no_base, buffer, next_index);
4093 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4094 // update the index
4095 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4096
4097 } __ else_(); {
4098
4099 // logging buffer is full, call the runtime
4100 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4101 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4102 } __ end_if(); // (!index)
4103 } __ end_if(); // (pre_val != NULL)
4104 } __ end_if(); // (!marking)
4105
4106 // Final sync IdealKit and GraphKit.
4107 final_sync(ideal);
4108 }
4109
4110 /*
4111 * G1 similar to any GC with a Young Generation requires a way to keep track of
4112 * references from Old Generation to Young Generation to make sure all live
4113 * objects are found. G1 also requires to keep track of object references
4114 * between different regions to enable evacuation of old regions, which is done
4115 * as part of mixed collections. References are tracked in remembered sets and
4116 * is continuously updated as reference are written to with the help of the
4117 * post-barrier.
4118 *
4119 * To reduce the number of updates to the remembered set the post-barrier
4120 * filters updates to fields in objects located in the Young Generation,
4121 * the same region as the reference, when the NULL is being written or
4122 * if the card is already marked as dirty by an earlier write.
4123 *
4124 * Under certain circumstances it is possible to avoid generating the
4125 * post-barrier completely if it is possible during compile time to prove
4126 * the object is newly allocated and that no safepoint exists between the
4127 * allocation and the store.
4128 *
4129 * In the case of slow allocation the allocation code must handle the barrier
4130 * as part of the allocation in the case the allocated object is not located
4131 * in the nursery, this would happen for humongous objects. This is similar to
4132 * how CMS is required to handle this case, see the comments for the method
4133 * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4134 * A deferred card mark is required for these objects and handled in the above
4135 * mentioned methods.
4136 *
4137 * Returns true if the post barrier can be removed
4138 */
4139 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4140 Node* adr) {
4141 intptr_t offset = 0;
4142 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4143 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4144
4145 if (offset == Type::OffsetBot) {
4146 return false; // cannot unalias unless there are precise offsets
4147 }
4148
4149 if (alloc == NULL) {
4150 return false; // No allocation found
4151 }
4152
4153 // Start search from Store node
4154 Node* mem = store->in(MemNode::Control);
4155 if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4156
4157 InitializeNode* st_init = mem->in(0)->as_Initialize();
4158 AllocateNode* st_alloc = st_init->allocation();
4159
4160 // Make sure we are looking at the same allocation
4161 if (alloc == st_alloc) {
4162 return true;
4163 }
4164 }
4165
4166 return false;
4167 }
4168
4169 //
4170 // Update the card table and add card address to the queue
4171 //
4172 void GraphKit::g1_mark_card(IdealKit& ideal,
4173 Node* card_adr,
4174 Node* oop_store,
4175 uint oop_alias_idx,
4176 Node* index,
4177 Node* index_adr,
4178 Node* buffer,
4179 const TypeFunc* tf) {
4180
4181 Node* zero = __ ConI(0);
4182 Node* zeroX = __ ConX(0);
4183 Node* no_base = __ top();
4184 BasicType card_bt = T_BYTE;
4185 // Smash zero into card. MUST BE ORDERED WRT TO STORE
4186 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4187
4188 // Now do the queue work
4189 __ if_then(index, BoolTest::ne, zeroX); {
4190
4191 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4192 Node* log_addr = __ AddP(no_base, buffer, next_index);
4193
4194 // Order, see storeCM.
4195 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4196 __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4197
4198 } __ else_(); {
4199 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4200 } __ end_if();
4201
4202 }
4203
4204 void GraphKit::g1_write_barrier_post(Node* oop_store,
4205 Node* obj,
4206 Node* adr,
4207 uint alias_idx,
4208 Node* val,
4209 BasicType bt,
4210 bool use_precise) {
4211 // If we are writing a NULL then we need no post barrier
4212
4213 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4214 // Must be NULL
4215 const Type* t = val->bottom_type();
4216 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4217 // No post barrier if writing NULLx
4218 return;
4219 }
4220
4221 if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4222 // We can skip marks on a freshly-allocated object in Eden.
4223 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4224 // That routine informs GC to take appropriate compensating steps,
4225 // upon a slow-path allocation, so as to make this card-mark
4226 // elision safe.
4227 return;
4228 }
4229
4230 if (use_ReduceInitialCardMarks()
4231 && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4232 return;
4233 }
4234
4235 if (!use_precise) {
4236 // All card marks for a (non-array) instance are in one place:
4237 adr = obj;
4238 }
4239 // (Else it's an array (or unknown), and we want more precise card marks.)
4240 assert(adr != NULL, "");
4241
4242 IdealKit ideal(this, true);
4243
4244 Node* tls = __ thread(); // ThreadLocalStorage
4245
4246 Node* no_base = __ top();
4247 float likely = PROB_LIKELY(0.999);
4248 float unlikely = PROB_UNLIKELY(0.999);
4249 Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4250 Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4251 Node* zeroX = __ ConX(0);
4252
4253 // Get the alias_index for raw card-mark memory
4254 const TypePtr* card_type = TypeRawPtr::BOTTOM;
4255
4256 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4257
4258 // Offsets into the thread
4259 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4260 DirtyCardQueue::byte_offset_of_index());
4261 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4262 DirtyCardQueue::byte_offset_of_buf());
4263
4264 // Pointers into the thread
4265
4266 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4267 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4268
4269 // Now some values
4270 // Use ctrl to avoid hoisting these values past a safepoint, which could
4271 // potentially reset these fields in the JavaThread.
4272 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4273 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4274
4275 // Convert the store obj pointer to an int prior to doing math on it
4276 // Must use ctrl to prevent "integerized oop" existing across safepoint
4277 Node* cast = __ CastPX(__ ctrl(), adr);
4278
4279 // Divide pointer by card size
4280 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4281
4282 // Combine card table base and card offset
4283 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4284
4285 // If we know the value being stored does it cross regions?
4286
4287 if (val != NULL) {
4288 // Does the store cause us to cross regions?
4289
4290 // Should be able to do an unsigned compare of region_size instead of
4291 // and extra shift. Do we have an unsigned compare??
4292 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4293 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4294
4295 // if (xor_res == 0) same region so skip
4296 __ if_then(xor_res, BoolTest::ne, zeroX); {
4297
4298 // No barrier if we are storing a NULL
4299 __ if_then(val, BoolTest::ne, null(), unlikely); {
4300
4301 // Ok must mark the card if not already dirty
4302
4303 // load the original value of the card
4304 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4305
4306 __ if_then(card_val, BoolTest::ne, young_card); {
4307 sync_kit(ideal);
4308 // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4309 insert_mem_bar(Op_MemBarVolatile, oop_store);
4310 __ sync_kit(this);
4311
4312 Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4313 __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4314 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4315 } __ end_if();
4316 } __ end_if();
4317 } __ end_if();
4318 } __ end_if();
4319 } else {
4320 // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4321 // We don't need a barrier here if the destination is a newly allocated object
4322 // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4323 // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4324 assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4325 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4326 __ if_then(card_val, BoolTest::ne, young_card); {
4327 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4328 } __ end_if();
4329 }
4330
4331 // Final sync IdealKit and GraphKit.
4332 final_sync(ideal);
4333 }
4334 #undef __
4335
4336
4337 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4338 Node* len = load_array_length(load_String_value(ctrl, str));
4339 Node* coder = load_String_coder(ctrl, str);
4340 // Divide length by 2 if coder is UTF16
4341 return _gvn.transform(new RShiftINode(len, coder));
4342 }
4343
4344 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4345 int value_offset = java_lang_String::value_offset_in_bytes();
4346 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4347 false, NULL, 0);
4348 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4349 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4350 TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4351 ciTypeArrayKlass::make(T_BYTE), true, 0);
4352 int value_field_idx = C->get_alias_index(value_field_type);
4353 Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4354 value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4355 // String.value field is known to be @Stable.
4356 if (UseImplicitStableValues) {
4357 load = cast_array_to_stable(load, value_type);
4358 }
4359 return load;
4360 }
4361
4362 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4363 if (!CompactStrings) {
4364 return intcon(java_lang_String::CODER_UTF16);
4365 }
4366 int coder_offset = java_lang_String::coder_offset_in_bytes();
4367 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4368 false, NULL, 0);
4369 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4370 int coder_field_idx = C->get_alias_index(coder_field_type);
4371 return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4372 TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4373 }
4374
4375 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4376 int value_offset = java_lang_String::value_offset_in_bytes();
4377 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4378 false, NULL, 0);
4379 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4380 store_oop_to_object(ctrl, str, basic_plus_adr(str, value_offset), value_field_type,
4381 value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4382 }
4383
4384 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4385 int coder_offset = java_lang_String::coder_offset_in_bytes();
4386 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4387 false, NULL, 0);
4388 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4389 int coder_field_idx = C->get_alias_index(coder_field_type);
4390 store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4391 value, T_BYTE, coder_field_idx, MemNode::unordered);
4392 }
4393
4394 // Capture src and dst memory state with a MergeMemNode
4395 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4396 if (src_type == dst_type) {
4397 // Types are equal, we don't need a MergeMemNode
4398 return memory(src_type);
4399 }
4400 MergeMemNode* merge = MergeMemNode::make(map()->memory());
4401 record_for_igvn(merge); // fold it up later, if possible
4402 int src_idx = C->get_alias_index(src_type);
4403 int dst_idx = C->get_alias_index(dst_type);
4404 merge->set_memory_at(src_idx, memory(src_idx));
4405 merge->set_memory_at(dst_idx, memory(dst_idx));
4406 return merge;
4407 }
4408
4409 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4410 assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4411 assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4412 // If input and output memory types differ, capture both states to preserve
4413 // the dependency between preceding and subsequent loads/stores.
4414 // For example, the following program:
4415 // StoreB
4416 // compress_string
4417 // LoadB
4418 // has this memory graph (use->def):
4419 // LoadB -> compress_string -> CharMem
4420 // ... -> StoreB -> ByteMem
4421 // The intrinsic hides the dependency between LoadB and StoreB, causing
4422 // the load to read from memory not containing the result of the StoreB.
4423 // The correct memory graph should look like this:
4424 // LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4425 Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4426 StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4427 Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4428 set_memory(res_mem, TypeAryPtr::BYTES);
4429 return str;
4430 }
4431
4432 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4433 assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4434 assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4435 // Capture src and dst memory (see comment in 'compress_string').
4436 Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4437 StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4438 set_memory(_gvn.transform(str), dst_type);
4439 }
4440
4441 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4442 /**
4443 * int i_char = start;
4444 * for (int i_byte = 0; i_byte < count; i_byte++) {
4445 * dst[i_char++] = (char)(src[i_byte] & 0xff);
4446 * }
4447 */
4448 add_predicate();
4449 RegionNode* head = new RegionNode(3);
4450 head->init_req(1, control());
4451 gvn().set_type(head, Type::CONTROL);
4452 record_for_igvn(head);
4453
4454 Node* i_byte = new PhiNode(head, TypeInt::INT);
4455 i_byte->init_req(1, intcon(0));
4456 gvn().set_type(i_byte, TypeInt::INT);
4457 record_for_igvn(i_byte);
4458
4459 Node* i_char = new PhiNode(head, TypeInt::INT);
4460 i_char->init_req(1, start);
4461 gvn().set_type(i_char, TypeInt::INT);
4462 record_for_igvn(i_char);
4463
4464 Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4465 gvn().set_type(mem, Type::MEMORY);
4466 record_for_igvn(mem);
4467 set_control(head);
4468 set_memory(mem, TypeAryPtr::BYTES);
4469 Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4470 Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4471 AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4472 false, false, true /* mismatched */);
4473
4474 IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4475 head->init_req(2, IfTrue(iff));
4476 mem->init_req(2, st);
4477 i_byte->init_req(2, AddI(i_byte, intcon(1)));
4478 i_char->init_req(2, AddI(i_char, intcon(2)));
4479
4480 set_control(IfFalse(iff));
4481 set_memory(st, TypeAryPtr::BYTES);
4482 }
4483
4484 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4485 if (!field->is_constant()) {
4486 return NULL; // Field not marked as constant.
4487 }
4488 ciInstance* holder = NULL;
4489 if (!field->is_static()) {
4490 ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4491 if (const_oop != NULL && const_oop->is_instance()) {
4492 holder = const_oop->as_instance();
4493 }
4494 }
4495 const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4496 /*is_unsigned_load=*/false);
4497 if (con_type != NULL) {
4498 return makecon(con_type);
4499 }
4500 return NULL;
4501 }
4502
4503 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4504 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4505 // assumption of CCP analysis.
4506 return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4507 }