1 /*
2 * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "ci/ciValueKlass.hpp"
28 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
29 #include "gc/g1/heapRegion.hpp"
30 #include "gc/shared/barrierSet.hpp"
31 #include "gc/shared/cardTableModRefBS.hpp"
32 #include "gc/shared/collectedHeap.hpp"
33 #include "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 "opto/valuetypenode.hpp"
46 #include "runtime/deoptimization.hpp"
47 #include "runtime/sharedRuntime.hpp"
48
49 //----------------------------GraphKit-----------------------------------------
50 // Main utility constructor.
51 GraphKit::GraphKit(JVMState* jvms)
52 : Phase(Phase::Parser),
53 _env(C->env()),
54 _gvn(*C->initial_gvn())
55 {
56 _exceptions = jvms->map()->next_exception();
57 if (_exceptions != NULL) jvms->map()->set_next_exception(NULL);
58 set_jvms(jvms);
59 }
60
61 // Private constructor for parser.
62 GraphKit::GraphKit()
63 : Phase(Phase::Parser),
64 _env(C->env()),
65 _gvn(*C->initial_gvn())
66 {
67 _exceptions = NULL;
68 set_map(NULL);
69 debug_only(_sp = -99);
70 debug_only(set_bci(-99));
71 }
72
73
74
75 //---------------------------clean_stack---------------------------------------
76 // Clear away rubbish from the stack area of the JVM state.
77 // This destroys any arguments that may be waiting on the stack.
78 void GraphKit::clean_stack(int from_sp) {
79 SafePointNode* map = this->map();
80 JVMState* jvms = this->jvms();
81 int stk_size = jvms->stk_size();
82 int stkoff = jvms->stkoff();
83 Node* top = this->top();
84 for (int i = from_sp; i < stk_size; i++) {
85 if (map->in(stkoff + i) != top) {
86 map->set_req(stkoff + i, top);
87 }
88 }
89 }
90
91
92 //--------------------------------sync_jvms-----------------------------------
93 // Make sure our current jvms agrees with our parse state.
94 JVMState* GraphKit::sync_jvms() const {
95 JVMState* jvms = this->jvms();
96 jvms->set_bci(bci()); // Record the new bci in the JVMState
97 jvms->set_sp(sp()); // Record the new sp in the JVMState
98 assert(jvms_in_sync(), "jvms is now in sync");
99 return jvms;
100 }
101
102 //--------------------------------sync_jvms_for_reexecute---------------------
103 // Make sure our current jvms agrees with our parse state. This version
104 // uses the reexecute_sp for reexecuting bytecodes.
105 JVMState* GraphKit::sync_jvms_for_reexecute() {
106 JVMState* jvms = this->jvms();
107 jvms->set_bci(bci()); // Record the new bci in the JVMState
108 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState
109 return jvms;
110 }
111
112 #ifdef ASSERT
113 bool GraphKit::jvms_in_sync() const {
114 Parse* parse = is_Parse();
115 if (parse == NULL) {
116 if (bci() != jvms()->bci()) return false;
117 if (sp() != (int)jvms()->sp()) return false;
118 return true;
119 }
120 if (jvms()->method() != parse->method()) return false;
121 if (jvms()->bci() != parse->bci()) return false;
122 int jvms_sp = jvms()->sp();
123 if (jvms_sp != parse->sp()) return false;
124 int jvms_depth = jvms()->depth();
125 if (jvms_depth != parse->depth()) return false;
126 return true;
127 }
128
129 // Local helper checks for special internal merge points
130 // used to accumulate and merge exception states.
131 // They are marked by the region's in(0) edge being the map itself.
132 // Such merge points must never "escape" into the parser at large,
133 // until they have been handed to gvn.transform.
134 static bool is_hidden_merge(Node* reg) {
135 if (reg == NULL) return false;
136 if (reg->is_Phi()) {
137 reg = reg->in(0);
138 if (reg == NULL) return false;
139 }
140 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
141 }
142
143 void GraphKit::verify_map() const {
144 if (map() == NULL) return; // null map is OK
145 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
146 assert(!map()->has_exceptions(), "call add_exception_states_from 1st");
147 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
148 }
149
150 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
151 assert(ex_map->next_exception() == NULL, "not already part of a chain");
152 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
153 }
154 #endif
155
156 //---------------------------stop_and_kill_map---------------------------------
157 // Set _map to NULL, signalling a stop to further bytecode execution.
158 // First smash the current map's control to a constant, to mark it dead.
159 void GraphKit::stop_and_kill_map() {
160 SafePointNode* dead_map = stop();
161 if (dead_map != NULL) {
162 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
163 assert(dead_map->is_killed(), "must be so marked");
164 }
165 }
166
167
168 //--------------------------------stopped--------------------------------------
169 // Tell if _map is NULL, or control is top.
170 bool GraphKit::stopped() {
171 if (map() == NULL) return true;
172 else if (control() == top()) return true;
173 else return false;
174 }
175
176
177 //-----------------------------has_ex_handler----------------------------------
178 // Tell if this method or any caller method has exception handlers.
179 bool GraphKit::has_ex_handler() {
180 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
181 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
182 return true;
183 }
184 }
185 return false;
186 }
187
188 //------------------------------save_ex_oop------------------------------------
189 // Save an exception without blowing stack contents or other JVM state.
190 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
191 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
192 ex_map->add_req(ex_oop);
193 debug_only(verify_exception_state(ex_map));
194 }
195
196 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
197 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
198 Node* ex_oop = ex_map->in(ex_map->req()-1);
199 if (clear_it) ex_map->del_req(ex_map->req()-1);
200 return ex_oop;
201 }
202
203 //-----------------------------saved_ex_oop------------------------------------
204 // Recover a saved exception from its map.
205 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
206 return common_saved_ex_oop(ex_map, false);
207 }
208
209 //--------------------------clear_saved_ex_oop---------------------------------
210 // Erase a previously saved exception from its map.
211 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
212 return common_saved_ex_oop(ex_map, true);
213 }
214
215 #ifdef ASSERT
216 //---------------------------has_saved_ex_oop----------------------------------
217 // Erase a previously saved exception from its map.
218 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
219 return ex_map->req() == ex_map->jvms()->endoff()+1;
220 }
221 #endif
222
223 //-------------------------make_exception_state--------------------------------
224 // Turn the current JVM state into an exception state, appending the ex_oop.
225 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
226 sync_jvms();
227 SafePointNode* ex_map = stop(); // do not manipulate this map any more
228 set_saved_ex_oop(ex_map, ex_oop);
229 return ex_map;
230 }
231
232
233 //--------------------------add_exception_state--------------------------------
234 // Add an exception to my list of exceptions.
235 void GraphKit::add_exception_state(SafePointNode* ex_map) {
236 if (ex_map == NULL || ex_map->control() == top()) {
237 return;
238 }
239 #ifdef ASSERT
240 verify_exception_state(ex_map);
241 if (has_exceptions()) {
242 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
243 }
244 #endif
245
246 // If there is already an exception of exactly this type, merge with it.
247 // In particular, null-checks and other low-level exceptions common up here.
248 Node* ex_oop = saved_ex_oop(ex_map);
249 const Type* ex_type = _gvn.type(ex_oop);
250 if (ex_oop == top()) {
251 // No action needed.
252 return;
253 }
254 assert(ex_type->isa_instptr(), "exception must be an instance");
255 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
256 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
257 // We check sp also because call bytecodes can generate exceptions
258 // both before and after arguments are popped!
259 if (ex_type2 == ex_type
260 && e2->_jvms->sp() == ex_map->_jvms->sp()) {
261 combine_exception_states(ex_map, e2);
262 return;
263 }
264 }
265
266 // No pre-existing exception of the same type. Chain it on the list.
267 push_exception_state(ex_map);
268 }
269
270 //-----------------------add_exception_states_from-----------------------------
271 void GraphKit::add_exception_states_from(JVMState* jvms) {
272 SafePointNode* ex_map = jvms->map()->next_exception();
273 if (ex_map != NULL) {
274 jvms->map()->set_next_exception(NULL);
275 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
276 next_map = ex_map->next_exception();
277 ex_map->set_next_exception(NULL);
278 add_exception_state(ex_map);
279 }
280 }
281 }
282
283 //-----------------------transfer_exceptions_into_jvms-------------------------
284 JVMState* GraphKit::transfer_exceptions_into_jvms() {
285 if (map() == NULL) {
286 // We need a JVMS to carry the exceptions, but the map has gone away.
287 // Create a scratch JVMS, cloned from any of the exception states...
288 if (has_exceptions()) {
289 _map = _exceptions;
290 _map = clone_map();
291 _map->set_next_exception(NULL);
292 clear_saved_ex_oop(_map);
293 debug_only(verify_map());
294 } else {
295 // ...or created from scratch
296 JVMState* jvms = new (C) JVMState(_method, NULL);
297 jvms->set_bci(_bci);
298 jvms->set_sp(_sp);
299 jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
300 set_jvms(jvms);
301 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top());
302 set_all_memory(top());
303 while (map()->req() < jvms->endoff()) map()->add_req(top());
304 }
305 // (This is a kludge, in case you didn't notice.)
306 set_control(top());
307 }
308 JVMState* jvms = sync_jvms();
309 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
310 jvms->map()->set_next_exception(_exceptions);
311 _exceptions = NULL; // done with this set of exceptions
312 return jvms;
313 }
314
315 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
316 assert(is_hidden_merge(dstphi), "must be a special merge node");
317 assert(is_hidden_merge(srcphi), "must be a special merge node");
318 uint limit = srcphi->req();
319 for (uint i = PhiNode::Input; i < limit; i++) {
320 dstphi->add_req(srcphi->in(i));
321 }
322 }
323 static inline void add_one_req(Node* dstphi, Node* src) {
324 assert(is_hidden_merge(dstphi), "must be a special merge node");
325 assert(!is_hidden_merge(src), "must not be a special merge node");
326 dstphi->add_req(src);
327 }
328
329 //-----------------------combine_exception_states------------------------------
330 // This helper function combines exception states by building phis on a
331 // specially marked state-merging region. These regions and phis are
332 // untransformed, and can build up gradually. The region is marked by
333 // having a control input of its exception map, rather than NULL. Such
334 // regions do not appear except in this function, and in use_exception_state.
335 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
336 if (failing()) return; // dying anyway...
337 JVMState* ex_jvms = ex_map->_jvms;
338 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
339 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
340 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
341 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
342 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
343 assert(ex_map->req() == phi_map->req(), "matching maps");
344 uint tos = ex_jvms->stkoff() + ex_jvms->sp();
345 Node* hidden_merge_mark = root();
346 Node* region = phi_map->control();
347 MergeMemNode* phi_mem = phi_map->merged_memory();
348 MergeMemNode* ex_mem = ex_map->merged_memory();
349 if (region->in(0) != hidden_merge_mark) {
350 // The control input is not (yet) a specially-marked region in phi_map.
351 // Make it so, and build some phis.
352 region = new RegionNode(2);
353 _gvn.set_type(region, Type::CONTROL);
354 region->set_req(0, hidden_merge_mark); // marks an internal ex-state
355 region->init_req(1, phi_map->control());
356 phi_map->set_control(region);
357 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
358 record_for_igvn(io_phi);
359 _gvn.set_type(io_phi, Type::ABIO);
360 phi_map->set_i_o(io_phi);
361 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
362 Node* m = mms.memory();
363 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
364 record_for_igvn(m_phi);
365 _gvn.set_type(m_phi, Type::MEMORY);
366 mms.set_memory(m_phi);
367 }
368 }
369
370 // Either or both of phi_map and ex_map might already be converted into phis.
371 Node* ex_control = ex_map->control();
372 // if there is special marking on ex_map also, we add multiple edges from src
373 bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
374 // how wide was the destination phi_map, originally?
375 uint orig_width = region->req();
376
377 if (add_multiple) {
378 add_n_reqs(region, ex_control);
379 add_n_reqs(phi_map->i_o(), ex_map->i_o());
380 } else {
381 // ex_map has no merges, so we just add single edges everywhere
382 add_one_req(region, ex_control);
383 add_one_req(phi_map->i_o(), ex_map->i_o());
384 }
385 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
386 if (mms.is_empty()) {
387 // get a copy of the base memory, and patch some inputs into it
388 const TypePtr* adr_type = mms.adr_type(C);
389 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
390 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
391 mms.set_memory(phi);
392 // Prepare to append interesting stuff onto the newly sliced phi:
393 while (phi->req() > orig_width) phi->del_req(phi->req()-1);
394 }
395 // Append stuff from ex_map:
396 if (add_multiple) {
397 add_n_reqs(mms.memory(), mms.memory2());
398 } else {
399 add_one_req(mms.memory(), mms.memory2());
400 }
401 }
402 uint limit = ex_map->req();
403 for (uint i = TypeFunc::Parms; i < limit; i++) {
404 // Skip everything in the JVMS after tos. (The ex_oop follows.)
405 if (i == tos) i = ex_jvms->monoff();
406 Node* src = ex_map->in(i);
407 Node* dst = phi_map->in(i);
408 if (src != dst) {
409 PhiNode* phi;
410 if (dst->in(0) != region) {
411 dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
412 record_for_igvn(phi);
413 _gvn.set_type(phi, phi->type());
414 phi_map->set_req(i, dst);
415 // Prepare to append interesting stuff onto the new phi:
416 while (dst->req() > orig_width) dst->del_req(dst->req()-1);
417 } else {
418 assert(dst->is_Phi(), "nobody else uses a hidden region");
419 phi = dst->as_Phi();
420 }
421 if (add_multiple && src->in(0) == ex_control) {
422 // Both are phis.
423 add_n_reqs(dst, src);
424 } else {
425 while (dst->req() < region->req()) add_one_req(dst, src);
426 }
427 const Type* srctype = _gvn.type(src);
428 if (phi->type() != srctype) {
429 const Type* dsttype = phi->type()->meet_speculative(srctype);
430 if (phi->type() != dsttype) {
431 phi->set_type(dsttype);
432 _gvn.set_type(phi, dsttype);
433 }
434 }
435 }
436 }
437 phi_map->merge_replaced_nodes_with(ex_map);
438 }
439
440 //--------------------------use_exception_state--------------------------------
441 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
442 if (failing()) { stop(); return top(); }
443 Node* region = phi_map->control();
444 Node* hidden_merge_mark = root();
445 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
446 Node* ex_oop = clear_saved_ex_oop(phi_map);
447 if (region->in(0) == hidden_merge_mark) {
448 // Special marking for internal ex-states. Process the phis now.
449 region->set_req(0, region); // now it's an ordinary region
450 set_jvms(phi_map->jvms()); // ...so now we can use it as a map
451 // Note: Setting the jvms also sets the bci and sp.
452 set_control(_gvn.transform(region));
453 uint tos = jvms()->stkoff() + sp();
454 for (uint i = 1; i < tos; i++) {
455 Node* x = phi_map->in(i);
456 if (x->in(0) == region) {
457 assert(x->is_Phi(), "expected a special phi");
458 phi_map->set_req(i, _gvn.transform(x));
459 }
460 }
461 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
462 Node* x = mms.memory();
463 if (x->in(0) == region) {
464 assert(x->is_Phi(), "nobody else uses a hidden region");
465 mms.set_memory(_gvn.transform(x));
466 }
467 }
468 if (ex_oop->in(0) == region) {
469 assert(ex_oop->is_Phi(), "expected a special phi");
470 ex_oop = _gvn.transform(ex_oop);
471 }
472 } else {
473 set_jvms(phi_map->jvms());
474 }
475
476 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
477 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
478 return ex_oop;
479 }
480
481 //---------------------------------java_bc-------------------------------------
482 Bytecodes::Code GraphKit::java_bc() const {
483 ciMethod* method = this->method();
484 int bci = this->bci();
485 if (method != NULL && bci != InvocationEntryBci)
486 return method->java_code_at_bci(bci);
487 else
488 return Bytecodes::_illegal;
489 }
490
491 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
492 bool must_throw) {
493 // if the exception capability is set, then we will generate code
494 // to check the JavaThread.should_post_on_exceptions flag to see
495 // if we actually need to report exception events (for this
496 // thread). If we don't need to report exception events, we will
497 // take the normal fast path provided by add_exception_events. If
498 // exception event reporting is enabled for this thread, we will
499 // take the uncommon_trap in the BuildCutout below.
500
501 // first must access the should_post_on_exceptions_flag in this thread's JavaThread
502 Node* jthread = _gvn.transform(new ThreadLocalNode());
503 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
504 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
505
506 // Test the should_post_on_exceptions_flag vs. 0
507 Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
508 Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
509
510 // Branch to slow_path if should_post_on_exceptions_flag was true
511 { BuildCutout unless(this, tst, PROB_MAX);
512 // Do not try anything fancy if we're notifying the VM on every throw.
513 // Cf. case Bytecodes::_athrow in parse2.cpp.
514 uncommon_trap(reason, Deoptimization::Action_none,
515 (ciKlass*)NULL, (char*)NULL, must_throw);
516 }
517
518 }
519
520 //------------------------------builtin_throw----------------------------------
521 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
522 bool must_throw = true;
523
524 if (env()->jvmti_can_post_on_exceptions()) {
525 // check if we must post exception events, take uncommon trap if so
526 uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
527 // here if should_post_on_exceptions is false
528 // continue on with the normal codegen
529 }
530
531 // If this particular condition has not yet happened at this
532 // bytecode, then use the uncommon trap mechanism, and allow for
533 // a future recompilation if several traps occur here.
534 // If the throw is hot, try to use a more complicated inline mechanism
535 // which keeps execution inside the compiled code.
536 bool treat_throw_as_hot = false;
537 ciMethodData* md = method()->method_data();
538
539 if (ProfileTraps) {
540 if (too_many_traps(reason)) {
541 treat_throw_as_hot = true;
542 }
543 // (If there is no MDO at all, assume it is early in
544 // execution, and that any deopts are part of the
545 // startup transient, and don't need to be remembered.)
546
547 // Also, if there is a local exception handler, treat all throws
548 // as hot if there has been at least one in this method.
549 if (C->trap_count(reason) != 0
550 && method()->method_data()->trap_count(reason) != 0
551 && has_ex_handler()) {
552 treat_throw_as_hot = true;
553 }
554 }
555
556 // If this throw happens frequently, an uncommon trap might cause
557 // a performance pothole. If there is a local exception handler,
558 // and if this particular bytecode appears to be deoptimizing often,
559 // let us handle the throw inline, with a preconstructed instance.
560 // Note: If the deopt count has blown up, the uncommon trap
561 // runtime is going to flush this nmethod, not matter what.
562 if (treat_throw_as_hot
563 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
564 // If the throw is local, we use a pre-existing instance and
565 // punt on the backtrace. This would lead to a missing backtrace
566 // (a repeat of 4292742) if the backtrace object is ever asked
567 // for its backtrace.
568 // Fixing this remaining case of 4292742 requires some flavor of
569 // escape analysis. Leave that for the future.
570 ciInstance* ex_obj = NULL;
571 switch (reason) {
572 case Deoptimization::Reason_null_check:
573 ex_obj = env()->NullPointerException_instance();
574 break;
575 case Deoptimization::Reason_div0_check:
576 ex_obj = env()->ArithmeticException_instance();
577 break;
578 case Deoptimization::Reason_range_check:
579 ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
580 break;
581 case Deoptimization::Reason_class_check:
582 if (java_bc() == Bytecodes::_aastore) {
583 ex_obj = env()->ArrayStoreException_instance();
584 } else {
585 ex_obj = env()->ClassCastException_instance();
586 }
587 break;
588 }
589 if (failing()) { stop(); return; } // exception allocation might fail
590 if (ex_obj != NULL) {
591 // Cheat with a preallocated exception object.
592 if (C->log() != NULL)
593 C->log()->elem("hot_throw preallocated='1' reason='%s'",
594 Deoptimization::trap_reason_name(reason));
595 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj);
596 Node* ex_node = _gvn.transform(ConNode::make(ex_con));
597
598 // Clear the detail message of the preallocated exception object.
599 // Weblogic sometimes mutates the detail message of exceptions
600 // using reflection.
601 int offset = java_lang_Throwable::get_detailMessage_offset();
602 const TypePtr* adr_typ = ex_con->add_offset(offset);
603
604 Node *adr = basic_plus_adr(ex_node, ex_node, offset);
605 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
606 // Conservatively release stores of object references.
607 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
608
609 add_exception_state(make_exception_state(ex_node));
610 return;
611 }
612 }
613
614 // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
615 // It won't be much cheaper than bailing to the interp., since we'll
616 // have to pass up all the debug-info, and the runtime will have to
617 // create the stack trace.
618
619 // Usual case: Bail to interpreter.
620 // Reserve the right to recompile if we haven't seen anything yet.
621
622 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
623 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
624 if (treat_throw_as_hot
625 && (method()->method_data()->trap_recompiled_at(bci(), m)
626 || C->too_many_traps(reason))) {
627 // We cannot afford to take more traps here. Suffer in the interpreter.
628 if (C->log() != NULL)
629 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
630 Deoptimization::trap_reason_name(reason),
631 C->trap_count(reason));
632 action = Deoptimization::Action_none;
633 }
634
635 // "must_throw" prunes the JVM state to include only the stack, if there
636 // are no local exception handlers. This should cut down on register
637 // allocation time and code size, by drastically reducing the number
638 // of in-edges on the call to the uncommon trap.
639
640 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
641 }
642
643
644 //----------------------------PreserveJVMState---------------------------------
645 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
646 debug_only(kit->verify_map());
647 _kit = kit;
648 _map = kit->map(); // preserve the map
649 _sp = kit->sp();
650 kit->set_map(clone_map ? kit->clone_map() : NULL);
651 #ifdef ASSERT
652 _bci = kit->bci();
653 Parse* parser = kit->is_Parse();
654 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
655 _block = block;
656 #endif
657 }
658 PreserveJVMState::~PreserveJVMState() {
659 GraphKit* kit = _kit;
660 #ifdef ASSERT
661 assert(kit->bci() == _bci, "bci must not shift");
662 Parse* parser = kit->is_Parse();
663 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
664 assert(block == _block, "block must not shift");
665 #endif
666 kit->set_map(_map);
667 kit->set_sp(_sp);
668 }
669
670
671 //-----------------------------BuildCutout-------------------------------------
672 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
673 : PreserveJVMState(kit)
674 {
675 assert(p->is_Con() || p->is_Bool(), "test must be a bool");
676 SafePointNode* outer_map = _map; // preserved map is caller's
677 SafePointNode* inner_map = kit->map();
678 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
679 outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
680 inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
681 }
682 BuildCutout::~BuildCutout() {
683 GraphKit* kit = _kit;
684 assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
685 }
686
687 //---------------------------PreserveReexecuteState----------------------------
688 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
689 assert(!kit->stopped(), "must call stopped() before");
690 _kit = kit;
691 _sp = kit->sp();
692 _reexecute = kit->jvms()->_reexecute;
693 }
694 PreserveReexecuteState::~PreserveReexecuteState() {
695 if (_kit->stopped()) return;
696 _kit->jvms()->_reexecute = _reexecute;
697 _kit->set_sp(_sp);
698 }
699
700 //------------------------------clone_map--------------------------------------
701 // Implementation of PreserveJVMState
702 //
703 // Only clone_map(...) here. If this function is only used in the
704 // PreserveJVMState class we may want to get rid of this extra
705 // function eventually and do it all there.
706
707 SafePointNode* GraphKit::clone_map() {
708 if (map() == NULL) return NULL;
709
710 // Clone the memory edge first
711 Node* mem = MergeMemNode::make(map()->memory());
712 gvn().set_type_bottom(mem);
713
714 SafePointNode *clonemap = (SafePointNode*)map()->clone();
715 JVMState* jvms = this->jvms();
716 JVMState* clonejvms = jvms->clone_shallow(C);
717 clonemap->set_memory(mem);
718 clonemap->set_jvms(clonejvms);
719 clonejvms->set_map(clonemap);
720 record_for_igvn(clonemap);
721 gvn().set_type_bottom(clonemap);
722 return clonemap;
723 }
724
725
726 //-----------------------------set_map_clone-----------------------------------
727 void GraphKit::set_map_clone(SafePointNode* m) {
728 _map = m;
729 _map = clone_map();
730 _map->set_next_exception(NULL);
731 debug_only(verify_map());
732 }
733
734
735 //----------------------------kill_dead_locals---------------------------------
736 // Detect any locals which are known to be dead, and force them to top.
737 void GraphKit::kill_dead_locals() {
738 // Consult the liveness information for the locals. If any
739 // of them are unused, then they can be replaced by top(). This
740 // should help register allocation time and cut down on the size
741 // of the deoptimization information.
742
743 // This call is made from many of the bytecode handling
744 // subroutines called from the Big Switch in do_one_bytecode.
745 // Every bytecode which might include a slow path is responsible
746 // for killing its dead locals. The more consistent we
747 // are about killing deads, the fewer useless phis will be
748 // constructed for them at various merge points.
749
750 // bci can be -1 (InvocationEntryBci). We return the entry
751 // liveness for the method.
752
753 if (method() == NULL || method()->code_size() == 0) {
754 // We are building a graph for a call to a native method.
755 // All locals are live.
756 return;
757 }
758
759 ResourceMark rm;
760
761 // Consult the liveness information for the locals. If any
762 // of them are unused, then they can be replaced by top(). This
763 // should help register allocation time and cut down on the size
764 // of the deoptimization information.
765 MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
766
767 int len = (int)live_locals.size();
768 assert(len <= jvms()->loc_size(), "too many live locals");
769 for (int local = 0; local < len; local++) {
770 if (!live_locals.at(local)) {
771 set_local(local, top());
772 }
773 }
774 }
775
776 #ifdef ASSERT
777 //-------------------------dead_locals_are_killed------------------------------
778 // Return true if all dead locals are set to top in the map.
779 // Used to assert "clean" debug info at various points.
780 bool GraphKit::dead_locals_are_killed() {
781 if (method() == NULL || method()->code_size() == 0) {
782 // No locals need to be dead, so all is as it should be.
783 return true;
784 }
785
786 // Make sure somebody called kill_dead_locals upstream.
787 ResourceMark rm;
788 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
789 if (jvms->loc_size() == 0) continue; // no locals to consult
790 SafePointNode* map = jvms->map();
791 ciMethod* method = jvms->method();
792 int bci = jvms->bci();
793 if (jvms == this->jvms()) {
794 bci = this->bci(); // it might not yet be synched
795 }
796 MethodLivenessResult live_locals = method->liveness_at_bci(bci);
797 int len = (int)live_locals.size();
798 if (!live_locals.is_valid() || len == 0)
799 // This method is trivial, or is poisoned by a breakpoint.
800 return true;
801 assert(len == jvms->loc_size(), "live map consistent with locals map");
802 for (int local = 0; local < len; local++) {
803 if (!live_locals.at(local) && map->local(jvms, local) != top()) {
804 if (PrintMiscellaneous && (Verbose || WizardMode)) {
805 tty->print_cr("Zombie local %d: ", local);
806 jvms->dump();
807 }
808 return false;
809 }
810 }
811 }
812 return true;
813 }
814
815 #endif //ASSERT
816
817 // Helper function for enforcing certain bytecodes to reexecute if
818 // deoptimization happens
819 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
820 ciMethod* cur_method = jvms->method();
821 int cur_bci = jvms->bci();
822 if (cur_method != NULL && cur_bci != InvocationEntryBci) {
823 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
824 return Interpreter::bytecode_should_reexecute(code) ||
825 is_anewarray && code == Bytecodes::_multianewarray;
826 // Reexecute _multianewarray bytecode which was replaced with
827 // sequence of [a]newarray. See Parse::do_multianewarray().
828 //
829 // Note: interpreter should not have it set since this optimization
830 // is limited by dimensions and guarded by flag so in some cases
831 // multianewarray() runtime calls will be generated and
832 // the bytecode should not be reexecutes (stack will not be reset).
833 } else
834 return false;
835 }
836
837 // Helper function for adding JVMState and debug information to node
838 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
839 // Add the safepoint edges to the call (or other safepoint).
840
841 // Make sure dead locals are set to top. This
842 // should help register allocation time and cut down on the size
843 // of the deoptimization information.
844 assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
845
846 // Walk the inline list to fill in the correct set of JVMState's
847 // Also fill in the associated edges for each JVMState.
848
849 // If the bytecode needs to be reexecuted we need to put
850 // the arguments back on the stack.
851 const bool should_reexecute = jvms()->should_reexecute();
852 JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
853
854 // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
855 // undefined if the bci is different. This is normal for Parse but it
856 // should not happen for LibraryCallKit because only one bci is processed.
857 assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
858 "in LibraryCallKit the reexecute bit should not change");
859
860 // If we are guaranteed to throw, we can prune everything but the
861 // input to the current bytecode.
862 bool can_prune_locals = false;
863 uint stack_slots_not_pruned = 0;
864 int inputs = 0, depth = 0;
865 if (must_throw) {
866 assert(method() == youngest_jvms->method(), "sanity");
867 if (compute_stack_effects(inputs, depth)) {
868 can_prune_locals = true;
869 stack_slots_not_pruned = inputs;
870 }
871 }
872
873 if (env()->should_retain_local_variables()) {
874 // At any safepoint, this method can get breakpointed, which would
875 // then require an immediate deoptimization.
876 can_prune_locals = false; // do not prune locals
877 stack_slots_not_pruned = 0;
878 }
879
880 // do not scribble on the input jvms
881 JVMState* out_jvms = youngest_jvms->clone_deep(C);
882 call->set_jvms(out_jvms); // Start jvms list for call node
883
884 // For a known set of bytecodes, the interpreter should reexecute them if
885 // deoptimization happens. We set the reexecute state for them here
886 if (out_jvms->is_reexecute_undefined() && //don't change if already specified
887 should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
888 out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
889 }
890
891 // Presize the call:
892 DEBUG_ONLY(uint non_debug_edges = call->req());
893 call->add_req_batch(top(), youngest_jvms->debug_depth());
894 assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
895
896 // Set up edges so that the call looks like this:
897 // Call [state:] ctl io mem fptr retadr
898 // [parms:] parm0 ... parmN
899 // [root:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
900 // [...mid:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
901 // [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
902 // Note that caller debug info precedes callee debug info.
903
904 // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
905 uint debug_ptr = call->req();
906
907 // Loop over the map input edges associated with jvms, add them
908 // to the call node, & reset all offsets to match call node array.
909 for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
910 uint debug_end = debug_ptr;
911 uint debug_start = debug_ptr - in_jvms->debug_size();
912 debug_ptr = debug_start; // back up the ptr
913
914 uint p = debug_start; // walks forward in [debug_start, debug_end)
915 uint j, k, l;
916 SafePointNode* in_map = in_jvms->map();
917 out_jvms->set_map(call);
918
919 if (can_prune_locals) {
920 assert(in_jvms->method() == out_jvms->method(), "sanity");
921 // If the current throw can reach an exception handler in this JVMS,
922 // then we must keep everything live that can reach that handler.
923 // As a quick and dirty approximation, we look for any handlers at all.
924 if (in_jvms->method()->has_exception_handlers()) {
925 can_prune_locals = false;
926 }
927 }
928
929 // Add the Locals
930 k = in_jvms->locoff();
931 l = in_jvms->loc_size();
932 out_jvms->set_locoff(p);
933 if (!can_prune_locals) {
934 for (j = 0; j < l; j++)
935 call->set_req(p++, in_map->in(k+j));
936 } else {
937 p += l; // already set to top above by add_req_batch
938 }
939
940 // Add the Expression Stack
941 k = in_jvms->stkoff();
942 l = in_jvms->sp();
943 out_jvms->set_stkoff(p);
944 if (!can_prune_locals) {
945 for (j = 0; j < l; j++)
946 call->set_req(p++, in_map->in(k+j));
947 } else if (can_prune_locals && stack_slots_not_pruned != 0) {
948 // Divide stack into {S0,...,S1}, where S0 is set to top.
949 uint s1 = stack_slots_not_pruned;
950 stack_slots_not_pruned = 0; // for next iteration
951 if (s1 > l) s1 = l;
952 uint s0 = l - s1;
953 p += s0; // skip the tops preinstalled by add_req_batch
954 for (j = s0; j < l; j++)
955 call->set_req(p++, in_map->in(k+j));
956 } else {
957 p += l; // already set to top above by add_req_batch
958 }
959
960 // Add the Monitors
961 k = in_jvms->monoff();
962 l = in_jvms->mon_size();
963 out_jvms->set_monoff(p);
964 for (j = 0; j < l; j++)
965 call->set_req(p++, in_map->in(k+j));
966
967 // Copy any scalar object fields.
968 k = in_jvms->scloff();
969 l = in_jvms->scl_size();
970 out_jvms->set_scloff(p);
971 for (j = 0; j < l; j++)
972 call->set_req(p++, in_map->in(k+j));
973
974 // Finish the new jvms.
975 out_jvms->set_endoff(p);
976
977 assert(out_jvms->endoff() == debug_end, "fill ptr must match");
978 assert(out_jvms->depth() == in_jvms->depth(), "depth must match");
979 assert(out_jvms->loc_size() == in_jvms->loc_size(), "size must match");
980 assert(out_jvms->mon_size() == in_jvms->mon_size(), "size must match");
981 assert(out_jvms->scl_size() == in_jvms->scl_size(), "size must match");
982 assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
983
984 // Update the two tail pointers in parallel.
985 out_jvms = out_jvms->caller();
986 in_jvms = in_jvms->caller();
987 }
988
989 assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
990
991 // Test the correctness of JVMState::debug_xxx accessors:
992 assert(call->jvms()->debug_start() == non_debug_edges, "");
993 assert(call->jvms()->debug_end() == call->req(), "");
994 assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
995 }
996
997 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
998 Bytecodes::Code code = java_bc();
999 if (code == Bytecodes::_wide) {
1000 code = method()->java_code_at_bci(bci() + 1);
1001 }
1002
1003 BasicType rtype = T_ILLEGAL;
1004 int rsize = 0;
1005
1006 if (code != Bytecodes::_illegal) {
1007 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1008 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1009 if (rtype < T_CONFLICT)
1010 rsize = type2size[rtype];
1011 }
1012
1013 switch (code) {
1014 case Bytecodes::_illegal:
1015 return false;
1016
1017 case Bytecodes::_ldc:
1018 case Bytecodes::_ldc_w:
1019 case Bytecodes::_ldc2_w:
1020 inputs = 0;
1021 break;
1022
1023 case Bytecodes::_dup: inputs = 1; break;
1024 case Bytecodes::_dup_x1: inputs = 2; break;
1025 case Bytecodes::_dup_x2: inputs = 3; break;
1026 case Bytecodes::_dup2: inputs = 2; break;
1027 case Bytecodes::_dup2_x1: inputs = 3; break;
1028 case Bytecodes::_dup2_x2: inputs = 4; break;
1029 case Bytecodes::_swap: inputs = 2; break;
1030 case Bytecodes::_arraylength: inputs = 1; break;
1031
1032 case Bytecodes::_getstatic:
1033 case Bytecodes::_putstatic:
1034 case Bytecodes::_getfield:
1035 case Bytecodes::_vgetfield:
1036 case Bytecodes::_putfield:
1037 {
1038 bool ignored_will_link;
1039 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1040 int size = field->type()->size();
1041 bool is_get = (depth >= 0), is_static = (depth & 1);
1042 inputs = (is_static ? 0 : 1);
1043 if (is_get) {
1044 depth = size - inputs;
1045 } else {
1046 inputs += size; // putxxx pops the value from the stack
1047 depth = - inputs;
1048 }
1049 }
1050 break;
1051
1052 case Bytecodes::_invokevirtual:
1053 case Bytecodes::_invokedirect:
1054 case Bytecodes::_invokespecial:
1055 case Bytecodes::_invokestatic:
1056 case Bytecodes::_invokedynamic:
1057 case Bytecodes::_invokeinterface:
1058 {
1059 bool ignored_will_link;
1060 ciSignature* declared_signature = NULL;
1061 ciMethod* ignored_callee = method()->get_method_at_bci(bci(), ignored_will_link, &declared_signature);
1062 assert(declared_signature != NULL, "cannot be null");
1063 inputs = declared_signature->arg_size_for_bc(code);
1064 int size = declared_signature->return_type()->size();
1065 depth = size - inputs;
1066 }
1067 break;
1068
1069 case Bytecodes::_multianewarray:
1070 {
1071 ciBytecodeStream iter(method());
1072 iter.reset_to_bci(bci());
1073 iter.next();
1074 inputs = iter.get_dimensions();
1075 assert(rsize == 1, "");
1076 depth = rsize - inputs;
1077 }
1078 break;
1079
1080 case Bytecodes::_vnew: {
1081 // vnew pops the values from the stack
1082 ciValueKlass* vk = method()->holder()->as_value_klass();
1083 inputs = vk->field_size();
1084 depth = rsize - inputs;
1085 break;
1086 }
1087
1088 case Bytecodes::_ireturn:
1089 case Bytecodes::_lreturn:
1090 case Bytecodes::_freturn:
1091 case Bytecodes::_dreturn:
1092 case Bytecodes::_areturn:
1093 case Bytecodes::_vreturn:
1094 assert(rsize = -depth, "");
1095 inputs = rsize;
1096 break;
1097
1098 case Bytecodes::_jsr:
1099 case Bytecodes::_jsr_w:
1100 inputs = 0;
1101 depth = 1; // S.B. depth=1, not zero
1102 break;
1103
1104 default:
1105 // bytecode produces a typed result
1106 inputs = rsize - depth;
1107 assert(inputs >= 0, "");
1108 break;
1109 }
1110
1111 #ifdef ASSERT
1112 // spot check
1113 int outputs = depth + inputs;
1114 assert(outputs >= 0, "sanity");
1115 switch (code) {
1116 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1117 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break;
1118 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break;
1119 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break;
1120 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break;
1121 }
1122 #endif //ASSERT
1123
1124 return true;
1125 }
1126
1127
1128
1129 //------------------------------basic_plus_adr---------------------------------
1130 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1131 // short-circuit a common case
1132 if (offset == intcon(0)) return ptr;
1133 return _gvn.transform( new AddPNode(base, ptr, offset) );
1134 }
1135
1136 Node* GraphKit::ConvI2L(Node* offset) {
1137 // short-circuit a common case
1138 jint offset_con = find_int_con(offset, Type::OffsetBot);
1139 if (offset_con != Type::OffsetBot) {
1140 return longcon((jlong) offset_con);
1141 }
1142 return _gvn.transform( new ConvI2LNode(offset));
1143 }
1144
1145 Node* GraphKit::ConvI2UL(Node* offset) {
1146 juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1147 if (offset_con != (juint) Type::OffsetBot) {
1148 return longcon((julong) offset_con);
1149 }
1150 Node* conv = _gvn.transform( new ConvI2LNode(offset));
1151 Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1152 return _gvn.transform( new AndLNode(conv, mask) );
1153 }
1154
1155 Node* GraphKit::ConvL2I(Node* offset) {
1156 // short-circuit a common case
1157 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1158 if (offset_con != (jlong)Type::OffsetBot) {
1159 return intcon((int) offset_con);
1160 }
1161 return _gvn.transform( new ConvL2INode(offset));
1162 }
1163
1164 //-------------------------load_object_klass-----------------------------------
1165 Node* GraphKit::load_object_klass(Node* obj) {
1166 // Special-case a fresh allocation to avoid building nodes:
1167 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1168 if (akls != NULL) return akls;
1169 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1170 return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1171 }
1172
1173 //-------------------------load_array_length-----------------------------------
1174 Node* GraphKit::load_array_length(Node* array) {
1175 // Special-case a fresh allocation to avoid building nodes:
1176 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1177 Node *alen;
1178 if (alloc == NULL) {
1179 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1180 alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1181 } else {
1182 alen = alloc->Ideal_length();
1183 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1184 if (ccast != alen) {
1185 alen = _gvn.transform(ccast);
1186 }
1187 }
1188 return alen;
1189 }
1190
1191 //------------------------------do_null_check----------------------------------
1192 // Helper function to do a NULL pointer check. Returned value is
1193 // the incoming address with NULL casted away. You are allowed to use the
1194 // not-null value only if you are control dependent on the test.
1195 #ifndef PRODUCT
1196 extern int explicit_null_checks_inserted,
1197 explicit_null_checks_elided;
1198 #endif
1199 Node* GraphKit::null_check_common(Node* value, BasicType type,
1200 // optional arguments for variations:
1201 bool assert_null,
1202 Node* *null_control,
1203 bool speculative) {
1204 assert(!assert_null || null_control == NULL, "not both at once");
1205 if (stopped()) return top();
1206 if (!GenerateCompilerNullChecks && !assert_null && null_control == NULL) {
1207 // For some performance testing, we may wish to suppress null checking.
1208 value = cast_not_null(value); // Make it appear to be non-null (4962416).
1209 return value;
1210 }
1211 NOT_PRODUCT(explicit_null_checks_inserted++);
1212
1213 // Construct NULL check
1214 Node *chk = NULL;
1215 switch(type) {
1216 case T_LONG : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1217 case T_INT : chk = new CmpINode(value, _gvn.intcon(0)); break;
1218 case T_ARRAY : // fall through
1219 type = T_OBJECT; // simplify further tests
1220 case T_OBJECT : {
1221 const Type *t = _gvn.type( value );
1222
1223 const TypeOopPtr* tp = t->isa_oopptr();
1224 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1225 // Only for do_null_check, not any of its siblings:
1226 && !assert_null && null_control == NULL) {
1227 // Usually, any field access or invocation on an unloaded oop type
1228 // will simply fail to link, since the statically linked class is
1229 // likely also to be unloaded. However, in -Xcomp mode, sometimes
1230 // the static class is loaded but the sharper oop type is not.
1231 // Rather than checking for this obscure case in lots of places,
1232 // we simply observe that a null check on an unloaded class
1233 // will always be followed by a nonsense operation, so we
1234 // can just issue the uncommon trap here.
1235 // Our access to the unloaded class will only be correct
1236 // after it has been loaded and initialized, which requires
1237 // a trip through the interpreter.
1238 #ifndef PRODUCT
1239 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1240 #endif
1241 uncommon_trap(Deoptimization::Reason_unloaded,
1242 Deoptimization::Action_reinterpret,
1243 tp->klass(), "!loaded");
1244 return top();
1245 }
1246
1247 if (assert_null) {
1248 // See if the type is contained in NULL_PTR.
1249 // If so, then the value is already null.
1250 if (t->higher_equal(TypePtr::NULL_PTR)) {
1251 NOT_PRODUCT(explicit_null_checks_elided++);
1252 return value; // Elided null assert quickly!
1253 }
1254 } else {
1255 // See if mixing in the NULL pointer changes type.
1256 // If so, then the NULL pointer was not allowed in the original
1257 // type. In other words, "value" was not-null.
1258 if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1259 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1260 NOT_PRODUCT(explicit_null_checks_elided++);
1261 return value; // Elided null check quickly!
1262 }
1263 }
1264 chk = new CmpPNode( value, null() );
1265 break;
1266 }
1267
1268 default:
1269 fatal("unexpected type: %s", type2name(type));
1270 }
1271 assert(chk != NULL, "sanity check");
1272 chk = _gvn.transform(chk);
1273
1274 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1275 BoolNode *btst = new BoolNode( chk, btest);
1276 Node *tst = _gvn.transform( btst );
1277
1278 //-----------
1279 // if peephole optimizations occurred, a prior test existed.
1280 // If a prior test existed, maybe it dominates as we can avoid this test.
1281 if (tst != btst && type == T_OBJECT) {
1282 // At this point we want to scan up the CFG to see if we can
1283 // find an identical test (and so avoid this test altogether).
1284 Node *cfg = control();
1285 int depth = 0;
1286 while( depth < 16 ) { // Limit search depth for speed
1287 if( cfg->Opcode() == Op_IfTrue &&
1288 cfg->in(0)->in(1) == tst ) {
1289 // Found prior test. Use "cast_not_null" to construct an identical
1290 // CastPP (and hence hash to) as already exists for the prior test.
1291 // Return that casted value.
1292 if (assert_null) {
1293 replace_in_map(value, null());
1294 return null(); // do not issue the redundant test
1295 }
1296 Node *oldcontrol = control();
1297 set_control(cfg);
1298 Node *res = cast_not_null(value);
1299 set_control(oldcontrol);
1300 NOT_PRODUCT(explicit_null_checks_elided++);
1301 return res;
1302 }
1303 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1304 if (cfg == NULL) break; // Quit at region nodes
1305 depth++;
1306 }
1307 }
1308
1309 //-----------
1310 // Branch to failure if null
1311 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen
1312 Deoptimization::DeoptReason reason;
1313 if (assert_null) {
1314 reason = Deoptimization::Reason_null_assert;
1315 } else if (type == T_OBJECT) {
1316 reason = Deoptimization::reason_null_check(speculative);
1317 } else {
1318 reason = Deoptimization::Reason_div0_check;
1319 }
1320 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1321 // ciMethodData::has_trap_at will return a conservative -1 if any
1322 // must-be-null assertion has failed. This could cause performance
1323 // problems for a method after its first do_null_assert failure.
1324 // Consider using 'Reason_class_check' instead?
1325
1326 // To cause an implicit null check, we set the not-null probability
1327 // to the maximum (PROB_MAX). For an explicit check the probability
1328 // is set to a smaller value.
1329 if (null_control != NULL || too_many_traps(reason)) {
1330 // probability is less likely
1331 ok_prob = PROB_LIKELY_MAG(3);
1332 } else if (!assert_null &&
1333 (ImplicitNullCheckThreshold > 0) &&
1334 method() != NULL &&
1335 (method()->method_data()->trap_count(reason)
1336 >= (uint)ImplicitNullCheckThreshold)) {
1337 ok_prob = PROB_LIKELY_MAG(3);
1338 }
1339
1340 if (null_control != NULL) {
1341 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1342 Node* null_true = _gvn.transform( new IfFalseNode(iff));
1343 set_control( _gvn.transform( new IfTrueNode(iff)));
1344 #ifndef PRODUCT
1345 if (null_true == top()) {
1346 explicit_null_checks_elided++;
1347 }
1348 #endif
1349 (*null_control) = null_true;
1350 } else {
1351 BuildCutout unless(this, tst, ok_prob);
1352 // Check for optimizer eliding test at parse time
1353 if (stopped()) {
1354 // Failure not possible; do not bother making uncommon trap.
1355 NOT_PRODUCT(explicit_null_checks_elided++);
1356 } else if (assert_null) {
1357 uncommon_trap(reason,
1358 Deoptimization::Action_make_not_entrant,
1359 NULL, "assert_null");
1360 } else {
1361 replace_in_map(value, zerocon(type));
1362 builtin_throw(reason);
1363 }
1364 }
1365
1366 // Must throw exception, fall-thru not possible?
1367 if (stopped()) {
1368 return top(); // No result
1369 }
1370
1371 if (assert_null) {
1372 // Cast obj to null on this path.
1373 replace_in_map(value, zerocon(type));
1374 return zerocon(type);
1375 }
1376
1377 // Cast obj to not-null on this path, if there is no null_control.
1378 // (If there is a null_control, a non-null value may come back to haunt us.)
1379 if (type == T_OBJECT) {
1380 Node* cast = cast_not_null(value, false);
1381 if (null_control == NULL || (*null_control) == top())
1382 replace_in_map(value, cast);
1383 value = cast;
1384 }
1385
1386 return value;
1387 }
1388
1389
1390 //------------------------------cast_not_null----------------------------------
1391 // Cast obj to not-null on this path
1392 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1393 const Type *t = _gvn.type(obj);
1394 const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1395 // Object is already not-null?
1396 if( t == t_not_null ) return obj;
1397
1398 Node *cast = new CastPPNode(obj,t_not_null);
1399 cast->init_req(0, control());
1400 cast = _gvn.transform( cast );
1401
1402 // Scan for instances of 'obj' in the current JVM mapping.
1403 // These instances are known to be not-null after the test.
1404 if (do_replace_in_map)
1405 replace_in_map(obj, cast);
1406
1407 return cast; // Return casted value
1408 }
1409
1410
1411 //--------------------------replace_in_map-------------------------------------
1412 void GraphKit::replace_in_map(Node* old, Node* neww) {
1413 if (old == neww) {
1414 return;
1415 }
1416
1417 map()->replace_edge(old, neww);
1418
1419 // Note: This operation potentially replaces any edge
1420 // on the map. This includes locals, stack, and monitors
1421 // of the current (innermost) JVM state.
1422
1423 // don't let inconsistent types from profiling escape this
1424 // method
1425
1426 const Type* told = _gvn.type(old);
1427 const Type* tnew = _gvn.type(neww);
1428
1429 if (!tnew->higher_equal(told)) {
1430 return;
1431 }
1432
1433 map()->record_replaced_node(old, neww);
1434 }
1435
1436
1437 //=============================================================================
1438 //--------------------------------memory---------------------------------------
1439 Node* GraphKit::memory(uint alias_idx) {
1440 MergeMemNode* mem = merged_memory();
1441 Node* p = mem->memory_at(alias_idx);
1442 _gvn.set_type(p, Type::MEMORY); // must be mapped
1443 return p;
1444 }
1445
1446 //-----------------------------reset_memory------------------------------------
1447 Node* GraphKit::reset_memory() {
1448 Node* mem = map()->memory();
1449 // do not use this node for any more parsing!
1450 debug_only( map()->set_memory((Node*)NULL) );
1451 return _gvn.transform( mem );
1452 }
1453
1454 //------------------------------set_all_memory---------------------------------
1455 void GraphKit::set_all_memory(Node* newmem) {
1456 Node* mergemem = MergeMemNode::make(newmem);
1457 gvn().set_type_bottom(mergemem);
1458 map()->set_memory(mergemem);
1459 }
1460
1461 //------------------------------set_all_memory_call----------------------------
1462 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1463 Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1464 set_all_memory(newmem);
1465 }
1466
1467 //=============================================================================
1468 //
1469 // parser factory methods for MemNodes
1470 //
1471 // These are layered on top of the factory methods in LoadNode and StoreNode,
1472 // and integrate with the parser's memory state and _gvn engine.
1473 //
1474
1475 // factory methods in "int adr_idx"
1476 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1477 int adr_idx,
1478 MemNode::MemOrd mo,
1479 LoadNode::ControlDependency control_dependency,
1480 bool require_atomic_access,
1481 bool unaligned,
1482 bool mismatched) {
1483 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1484 const TypePtr* adr_type = NULL; // debug-mode-only argument
1485 debug_only(adr_type = C->get_adr_type(adr_idx));
1486 Node* mem = memory(adr_idx);
1487 Node* ld;
1488 if (require_atomic_access && bt == T_LONG) {
1489 ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1490 } else if (require_atomic_access && bt == T_DOUBLE) {
1491 ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1492 } else {
1493 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1494 }
1495 ld = _gvn.transform(ld);
1496
1497 if (bt == T_VALUETYPE) {
1498 // Load value type from oop
1499 ld = ValueTypeNode::make(gvn(), map()->memory(), ld);
1500 } else if ((bt == T_OBJECT) && C->do_escape_analysis() || C->eliminate_boxing()) {
1501 // Improve graph before escape analysis and boxing elimination.
1502 record_for_igvn(ld);
1503 }
1504 return ld;
1505 }
1506
1507 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1508 int adr_idx,
1509 MemNode::MemOrd mo,
1510 bool require_atomic_access,
1511 bool unaligned,
1512 bool mismatched) {
1513 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1514 const TypePtr* adr_type = NULL;
1515 debug_only(adr_type = C->get_adr_type(adr_idx));
1516 Node *mem = memory(adr_idx);
1517 Node* st;
1518 if (require_atomic_access && bt == T_LONG) {
1519 st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1520 } else if (require_atomic_access && bt == T_DOUBLE) {
1521 st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1522 } else {
1523 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1524 }
1525 if (unaligned) {
1526 st->as_Store()->set_unaligned_access();
1527 }
1528 if (mismatched) {
1529 st->as_Store()->set_mismatched_access();
1530 }
1531 st = _gvn.transform(st);
1532 set_memory(st, adr_idx);
1533 // Back-to-back stores can only remove intermediate store with DU info
1534 // so push on worklist for optimizer.
1535 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1536 record_for_igvn(st);
1537
1538 return st;
1539 }
1540
1541
1542 void GraphKit::pre_barrier(bool do_load,
1543 Node* ctl,
1544 Node* obj,
1545 Node* adr,
1546 uint adr_idx,
1547 Node* val,
1548 const TypeOopPtr* val_type,
1549 Node* pre_val,
1550 BasicType bt) {
1551
1552 BarrierSet* bs = Universe::heap()->barrier_set();
1553 set_control(ctl);
1554 switch (bs->kind()) {
1555 case BarrierSet::G1SATBCTLogging:
1556 g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1557 break;
1558
1559 case BarrierSet::CardTableForRS:
1560 case BarrierSet::CardTableExtension:
1561 case BarrierSet::ModRef:
1562 break;
1563
1564 default :
1565 ShouldNotReachHere();
1566
1567 }
1568 }
1569
1570 bool GraphKit::can_move_pre_barrier() const {
1571 BarrierSet* bs = Universe::heap()->barrier_set();
1572 switch (bs->kind()) {
1573 case BarrierSet::G1SATBCTLogging:
1574 return true; // Can move it if no safepoint
1575
1576 case BarrierSet::CardTableForRS:
1577 case BarrierSet::CardTableExtension:
1578 case BarrierSet::ModRef:
1579 return true; // There is no pre-barrier
1580
1581 default :
1582 ShouldNotReachHere();
1583 }
1584 return false;
1585 }
1586
1587 void GraphKit::post_barrier(Node* ctl,
1588 Node* store,
1589 Node* obj,
1590 Node* adr,
1591 uint adr_idx,
1592 Node* val,
1593 BasicType bt,
1594 bool use_precise) {
1595 BarrierSet* bs = Universe::heap()->barrier_set();
1596 set_control(ctl);
1597 switch (bs->kind()) {
1598 case BarrierSet::G1SATBCTLogging:
1599 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1600 break;
1601
1602 case BarrierSet::CardTableForRS:
1603 case BarrierSet::CardTableExtension:
1604 write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1605 break;
1606
1607 case BarrierSet::ModRef:
1608 break;
1609
1610 default :
1611 ShouldNotReachHere();
1612
1613 }
1614 }
1615
1616 Node* GraphKit::store_oop(Node* ctl,
1617 Node* obj,
1618 Node* adr,
1619 const TypePtr* adr_type,
1620 Node* val,
1621 const TypeOopPtr* val_type,
1622 BasicType bt,
1623 bool use_precise,
1624 MemNode::MemOrd mo,
1625 bool mismatched) {
1626 // Transformation of a value which could be NULL pointer (CastPP #NULL)
1627 // could be delayed during Parse (for example, in adjust_map_after_if()).
1628 // Execute transformation here to avoid barrier generation in such case.
1629 if (_gvn.type(val) == TypePtr::NULL_PTR)
1630 val = _gvn.makecon(TypePtr::NULL_PTR);
1631
1632 set_control(ctl);
1633 if (stopped()) return top(); // Dead path ?
1634
1635 assert(bt == T_OBJECT || bt == T_VALUETYPE, "sanity");
1636 assert(val != NULL, "not dead path");
1637 uint adr_idx = C->get_alias_index(adr_type);
1638 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1639
1640 if (bt == T_VALUETYPE) {
1641 // Allocate value type and store oop
1642 val = val->as_ValueType()->store_to_memory(this);
1643 }
1644
1645 pre_barrier(true /* do_load */,
1646 control(), obj, adr, adr_idx, val, val_type,
1647 NULL /* pre_val */,
1648 bt);
1649
1650 Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1651 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1652 return store;
1653 }
1654
1655 // Could be an array or object we don't know at compile time (unsafe ref.)
1656 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1657 Node* obj, // containing obj
1658 Node* adr, // actual adress to store val at
1659 const TypePtr* adr_type,
1660 Node* val,
1661 BasicType bt,
1662 MemNode::MemOrd mo,
1663 bool mismatched) {
1664 Compile::AliasType* at = C->alias_type(adr_type);
1665 const TypeOopPtr* val_type = NULL;
1666 if (adr_type->isa_instptr()) {
1667 if (at->field() != NULL) {
1668 // known field. This code is a copy of the do_put_xxx logic.
1669 ciField* field = at->field();
1670 if (!field->type()->is_loaded()) {
1671 val_type = TypeInstPtr::BOTTOM;
1672 } else {
1673 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1674 }
1675 }
1676 } else if (adr_type->isa_aryptr()) {
1677 val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1678 }
1679 if (val_type == NULL) {
1680 val_type = TypeInstPtr::BOTTOM;
1681 }
1682 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1683 }
1684
1685
1686 //-------------------------array_element_address-------------------------
1687 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1688 const TypeInt* sizetype, Node* ctrl) {
1689 uint shift = exact_log2(type2aelembytes(elembt));
1690 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1691
1692 // short-circuit a common case (saves lots of confusing waste motion)
1693 jint idx_con = find_int_con(idx, -1);
1694 if (idx_con >= 0) {
1695 intptr_t offset = header + ((intptr_t)idx_con << shift);
1696 return basic_plus_adr(ary, offset);
1697 }
1698
1699 // must be correct type for alignment purposes
1700 Node* base = basic_plus_adr(ary, header);
1701 idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1702 Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1703 return basic_plus_adr(ary, base, scale);
1704 }
1705
1706 //-------------------------load_array_element-------------------------
1707 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1708 const Type* elemtype = arytype->elem();
1709 BasicType elembt = elemtype->array_element_basic_type();
1710 Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1711 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1712 return ld;
1713 }
1714
1715 //-------------------------set_arguments_for_java_call-------------------------
1716 // Arguments (pre-popped from the stack) are taken from the JVMS.
1717 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1718 // Add the call arguments:
1719 uint nargs = call->method()->arg_size();
1720 for (uint i = 0, idx = 0; i < nargs; i++) {
1721 Node* arg = argument(i);
1722 if (ValueTypePassFieldsAsArgs) {
1723 if (arg->is_ValueType()) {
1724 ValueTypeNode* vt = arg->as_ValueType();
1725 // We don't pass value type arguments by reference but instead
1726 // pass each field of the value type
1727 idx += vt->set_arguments_for_java_call(call, idx + TypeFunc::Parms, *this);
1728 } else {
1729 call->init_req(idx + TypeFunc::Parms, arg);
1730 idx++;
1731 }
1732 } else {
1733 if (arg->is_ValueType()) {
1734 // Pass value type argument via oop to callee
1735 arg = arg->as_ValueType()->store_to_memory(this);
1736 }
1737 call->init_req(i + TypeFunc::Parms, arg);
1738 }
1739 }
1740 }
1741
1742 //---------------------------set_edges_for_java_call---------------------------
1743 // Connect a newly created call into the current JVMS.
1744 // A return value node (if any) is returned from set_edges_for_java_call.
1745 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1746
1747 // Add the predefined inputs:
1748 call->init_req( TypeFunc::Control, control() );
1749 call->init_req( TypeFunc::I_O , i_o() );
1750 call->init_req( TypeFunc::Memory , reset_memory() );
1751 call->init_req( TypeFunc::FramePtr, frameptr() );
1752 call->init_req( TypeFunc::ReturnAdr, top() );
1753
1754 add_safepoint_edges(call, must_throw);
1755
1756 Node* xcall = _gvn.transform(call);
1757
1758 if (xcall == top()) {
1759 set_control(top());
1760 return;
1761 }
1762 assert(xcall == call, "call identity is stable");
1763
1764 // Re-use the current map to produce the result.
1765
1766 set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1767 set_i_o( _gvn.transform(new ProjNode(call, TypeFunc::I_O , separate_io_proj)));
1768 set_all_memory_call(xcall, separate_io_proj);
1769
1770 //return xcall; // no need, caller already has it
1771 }
1772
1773 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1774 if (stopped()) return top(); // maybe the call folded up?
1775
1776 // Capture the return value, if any.
1777 Node* ret;
1778 if (call->method() == NULL ||
1779 call->method()->return_type()->basic_type() == T_VOID)
1780 ret = top();
1781 else ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1782
1783 // Note: Since any out-of-line call can produce an exception,
1784 // we always insert an I_O projection from the call into the result.
1785
1786 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1787
1788 if (separate_io_proj) {
1789 // The caller requested separate projections be used by the fall
1790 // through and exceptional paths, so replace the projections for
1791 // the fall through path.
1792 set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1793 set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1794 }
1795 return ret;
1796 }
1797
1798 //--------------------set_predefined_input_for_runtime_call--------------------
1799 // Reading and setting the memory state is way conservative here.
1800 // The real problem is that I am not doing real Type analysis on memory,
1801 // so I cannot distinguish card mark stores from other stores. Across a GC
1802 // point the Store Barrier and the card mark memory has to agree. I cannot
1803 // have a card mark store and its barrier split across the GC point from
1804 // either above or below. Here I get that to happen by reading ALL of memory.
1805 // A better answer would be to separate out card marks from other memory.
1806 // For now, return the input memory state, so that it can be reused
1807 // after the call, if this call has restricted memory effects.
1808 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1809 // Set fixed predefined input arguments
1810 Node* memory = reset_memory();
1811 call->init_req( TypeFunc::Control, control() );
1812 call->init_req( TypeFunc::I_O, top() ); // does no i/o
1813 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs
1814 call->init_req( TypeFunc::FramePtr, frameptr() );
1815 call->init_req( TypeFunc::ReturnAdr, top() );
1816 return memory;
1817 }
1818
1819 //-------------------set_predefined_output_for_runtime_call--------------------
1820 // Set control and memory (not i_o) from the call.
1821 // If keep_mem is not NULL, use it for the output state,
1822 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1823 // If hook_mem is NULL, this call produces no memory effects at all.
1824 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1825 // then only that memory slice is taken from the call.
1826 // In the last case, we must put an appropriate memory barrier before
1827 // the call, so as to create the correct anti-dependencies on loads
1828 // preceding the call.
1829 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1830 Node* keep_mem,
1831 const TypePtr* hook_mem) {
1832 // no i/o
1833 set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1834 if (keep_mem) {
1835 // First clone the existing memory state
1836 set_all_memory(keep_mem);
1837 if (hook_mem != NULL) {
1838 // Make memory for the call
1839 Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1840 // Set the RawPtr memory state only. This covers all the heap top/GC stuff
1841 // We also use hook_mem to extract specific effects from arraycopy stubs.
1842 set_memory(mem, hook_mem);
1843 }
1844 // ...else the call has NO memory effects.
1845
1846 // Make sure the call advertises its memory effects precisely.
1847 // This lets us build accurate anti-dependences in gcm.cpp.
1848 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1849 "call node must be constructed correctly");
1850 } else {
1851 assert(hook_mem == NULL, "");
1852 // This is not a "slow path" call; all memory comes from the call.
1853 set_all_memory_call(call);
1854 }
1855 }
1856
1857
1858 // Replace the call with the current state of the kit.
1859 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1860 JVMState* ejvms = NULL;
1861 if (has_exceptions()) {
1862 ejvms = transfer_exceptions_into_jvms();
1863 }
1864
1865 ReplacedNodes replaced_nodes = map()->replaced_nodes();
1866 ReplacedNodes replaced_nodes_exception;
1867 Node* ex_ctl = top();
1868
1869 SafePointNode* final_state = stop();
1870
1871 // Find all the needed outputs of this call
1872 CallProjections callprojs;
1873 call->extract_projections(&callprojs, true);
1874
1875 Node* init_mem = call->in(TypeFunc::Memory);
1876 Node* final_mem = final_state->in(TypeFunc::Memory);
1877 Node* final_ctl = final_state->in(TypeFunc::Control);
1878 Node* final_io = final_state->in(TypeFunc::I_O);
1879
1880 // Replace all the old call edges with the edges from the inlining result
1881 if (callprojs.fallthrough_catchproj != NULL) {
1882 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1883 }
1884 if (callprojs.fallthrough_memproj != NULL) {
1885 if (final_mem->is_MergeMem()) {
1886 // Parser's exits MergeMem was not transformed but may be optimized
1887 final_mem = _gvn.transform(final_mem);
1888 }
1889 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem);
1890 }
1891 if (callprojs.fallthrough_ioproj != NULL) {
1892 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io);
1893 }
1894
1895 // Replace the result with the new result if it exists and is used
1896 if (callprojs.resproj != NULL && result != NULL) {
1897 C->gvn_replace_by(callprojs.resproj, result);
1898 }
1899
1900 if (ejvms == NULL) {
1901 // No exception edges to simply kill off those paths
1902 if (callprojs.catchall_catchproj != NULL) {
1903 C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1904 }
1905 if (callprojs.catchall_memproj != NULL) {
1906 C->gvn_replace_by(callprojs.catchall_memproj, C->top());
1907 }
1908 if (callprojs.catchall_ioproj != NULL) {
1909 C->gvn_replace_by(callprojs.catchall_ioproj, C->top());
1910 }
1911 // Replace the old exception object with top
1912 if (callprojs.exobj != NULL) {
1913 C->gvn_replace_by(callprojs.exobj, C->top());
1914 }
1915 } else {
1916 GraphKit ekit(ejvms);
1917
1918 // Load my combined exception state into the kit, with all phis transformed:
1919 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1920 replaced_nodes_exception = ex_map->replaced_nodes();
1921
1922 Node* ex_oop = ekit.use_exception_state(ex_map);
1923
1924 if (callprojs.catchall_catchproj != NULL) {
1925 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1926 ex_ctl = ekit.control();
1927 }
1928 if (callprojs.catchall_memproj != NULL) {
1929 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory());
1930 }
1931 if (callprojs.catchall_ioproj != NULL) {
1932 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o());
1933 }
1934
1935 // Replace the old exception object with the newly created one
1936 if (callprojs.exobj != NULL) {
1937 C->gvn_replace_by(callprojs.exobj, ex_oop);
1938 }
1939 }
1940
1941 // Disconnect the call from the graph
1942 call->disconnect_inputs(NULL, C);
1943 C->gvn_replace_by(call, C->top());
1944
1945 // Clean up any MergeMems that feed other MergeMems since the
1946 // optimizer doesn't like that.
1947 if (final_mem->is_MergeMem()) {
1948 Node_List wl;
1949 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1950 Node* m = i.get();
1951 if (m->is_MergeMem() && !wl.contains(m)) {
1952 wl.push(m);
1953 }
1954 }
1955 while (wl.size() > 0) {
1956 _gvn.transform(wl.pop());
1957 }
1958 }
1959
1960 if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1961 replaced_nodes.apply(C, final_ctl);
1962 }
1963 if (!ex_ctl->is_top() && do_replaced_nodes) {
1964 replaced_nodes_exception.apply(C, ex_ctl);
1965 }
1966 }
1967
1968
1969 //------------------------------increment_counter------------------------------
1970 // for statistics: increment a VM counter by 1
1971
1972 void GraphKit::increment_counter(address counter_addr) {
1973 Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1974 increment_counter(adr1);
1975 }
1976
1977 void GraphKit::increment_counter(Node* counter_addr) {
1978 int adr_type = Compile::AliasIdxRaw;
1979 Node* ctrl = control();
1980 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1981 Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1982 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1983 }
1984
1985
1986 //------------------------------uncommon_trap----------------------------------
1987 // Bail out to the interpreter in mid-method. Implemented by calling the
1988 // uncommon_trap blob. This helper function inserts a runtime call with the
1989 // right debug info.
1990 void GraphKit::uncommon_trap(int trap_request,
1991 ciKlass* klass, const char* comment,
1992 bool must_throw,
1993 bool keep_exact_action) {
1994 if (failing()) stop();
1995 if (stopped()) return; // trap reachable?
1996
1997 // Note: If ProfileTraps is true, and if a deopt. actually
1998 // occurs here, the runtime will make sure an MDO exists. There is
1999 // no need to call method()->ensure_method_data() at this point.
2000
2001 // Set the stack pointer to the right value for reexecution:
2002 set_sp(reexecute_sp());
2003
2004 #ifdef ASSERT
2005 if (!must_throw) {
2006 // Make sure the stack has at least enough depth to execute
2007 // the current bytecode.
2008 int inputs, ignored_depth;
2009 if (compute_stack_effects(inputs, ignored_depth)) {
2010 assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2011 Bytecodes::name(java_bc()), sp(), inputs);
2012 }
2013 }
2014 #endif
2015
2016 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2017 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2018
2019 switch (action) {
2020 case Deoptimization::Action_maybe_recompile:
2021 case Deoptimization::Action_reinterpret:
2022 // Temporary fix for 6529811 to allow virtual calls to be sure they
2023 // get the chance to go from mono->bi->mega
2024 if (!keep_exact_action &&
2025 Deoptimization::trap_request_index(trap_request) < 0 &&
2026 too_many_recompiles(reason)) {
2027 // This BCI is causing too many recompilations.
2028 if (C->log() != NULL) {
2029 C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2030 Deoptimization::trap_reason_name(reason),
2031 Deoptimization::trap_action_name(action));
2032 }
2033 action = Deoptimization::Action_none;
2034 trap_request = Deoptimization::make_trap_request(reason, action);
2035 } else {
2036 C->set_trap_can_recompile(true);
2037 }
2038 break;
2039 case Deoptimization::Action_make_not_entrant:
2040 C->set_trap_can_recompile(true);
2041 break;
2042 #ifdef ASSERT
2043 case Deoptimization::Action_none:
2044 case Deoptimization::Action_make_not_compilable:
2045 break;
2046 default:
2047 fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2048 break;
2049 #endif
2050 }
2051
2052 if (TraceOptoParse) {
2053 char buf[100];
2054 tty->print_cr("Uncommon trap %s at bci:%d",
2055 Deoptimization::format_trap_request(buf, sizeof(buf),
2056 trap_request), bci());
2057 }
2058
2059 CompileLog* log = C->log();
2060 if (log != NULL) {
2061 int kid = (klass == NULL)? -1: log->identify(klass);
2062 log->begin_elem("uncommon_trap bci='%d'", bci());
2063 char buf[100];
2064 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2065 trap_request));
2066 if (kid >= 0) log->print(" klass='%d'", kid);
2067 if (comment != NULL) log->print(" comment='%s'", comment);
2068 log->end_elem();
2069 }
2070
2071 // Make sure any guarding test views this path as very unlikely
2072 Node *i0 = control()->in(0);
2073 if (i0 != NULL && i0->is_If()) { // Found a guarding if test?
2074 IfNode *iff = i0->as_If();
2075 float f = iff->_prob; // Get prob
2076 if (control()->Opcode() == Op_IfTrue) {
2077 if (f > PROB_UNLIKELY_MAG(4))
2078 iff->_prob = PROB_MIN;
2079 } else {
2080 if (f < PROB_LIKELY_MAG(4))
2081 iff->_prob = PROB_MAX;
2082 }
2083 }
2084
2085 // Clear out dead values from the debug info.
2086 kill_dead_locals();
2087
2088 // Now insert the uncommon trap subroutine call
2089 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2090 const TypePtr* no_memory_effects = NULL;
2091 // Pass the index of the class to be loaded
2092 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2093 (must_throw ? RC_MUST_THROW : 0),
2094 OptoRuntime::uncommon_trap_Type(),
2095 call_addr, "uncommon_trap", no_memory_effects,
2096 intcon(trap_request));
2097 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2098 "must extract request correctly from the graph");
2099 assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2100
2101 call->set_req(TypeFunc::ReturnAdr, returnadr());
2102 // The debug info is the only real input to this call.
2103
2104 // Halt-and-catch fire here. The above call should never return!
2105 HaltNode* halt = new HaltNode(control(), frameptr());
2106 _gvn.set_type_bottom(halt);
2107 root()->add_req(halt);
2108
2109 stop_and_kill_map();
2110 }
2111
2112
2113 //--------------------------just_allocated_object------------------------------
2114 // Report the object that was just allocated.
2115 // It must be the case that there are no intervening safepoints.
2116 // We use this to determine if an object is so "fresh" that
2117 // it does not require card marks.
2118 Node* GraphKit::just_allocated_object(Node* current_control) {
2119 if (C->recent_alloc_ctl() == current_control)
2120 return C->recent_alloc_obj();
2121 return NULL;
2122 }
2123
2124
2125 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2126 // (Note: TypeFunc::make has a cache that makes this fast.)
2127 const TypeFunc* tf = TypeFunc::make(dest_method);
2128 int nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2129 for (int j = 0; j < nargs; j++) {
2130 const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2131 if( targ->basic_type() == T_DOUBLE ) {
2132 // If any parameters are doubles, they must be rounded before
2133 // the call, dstore_rounding does gvn.transform
2134 Node *arg = argument(j);
2135 arg = dstore_rounding(arg);
2136 set_argument(j, arg);
2137 }
2138 }
2139 }
2140
2141 /**
2142 * Record profiling data exact_kls for Node n with the type system so
2143 * that it can propagate it (speculation)
2144 *
2145 * @param n node that the type applies to
2146 * @param exact_kls type from profiling
2147 * @param maybe_null did profiling see null?
2148 *
2149 * @return node with improved type
2150 */
2151 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, bool maybe_null) {
2152 const Type* current_type = _gvn.type(n);
2153 assert(UseTypeSpeculation, "type speculation must be on");
2154
2155 const TypePtr* speculative = current_type->speculative();
2156
2157 // Should the klass from the profile be recorded in the speculative type?
2158 if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2159 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2160 const TypeOopPtr* xtype = tklass->as_instance_type();
2161 assert(xtype->klass_is_exact(), "Should be exact");
2162 // Any reason to believe n is not null (from this profiling or a previous one)?
2163 const TypePtr* ptr = (maybe_null && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2164 // record the new speculative type's depth
2165 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2166 speculative = speculative->with_inline_depth(jvms()->depth());
2167 } else if (current_type->would_improve_ptr(maybe_null)) {
2168 // Profiling report that null was never seen so we can change the
2169 // speculative type to non null ptr.
2170 assert(!maybe_null, "nothing to improve");
2171 if (speculative == NULL) {
2172 speculative = TypePtr::NOTNULL;
2173 } else {
2174 const TypePtr* ptr = TypePtr::NOTNULL;
2175 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2176 }
2177 }
2178
2179 if (speculative != current_type->speculative()) {
2180 // Build a type with a speculative type (what we think we know
2181 // about the type but will need a guard when we use it)
2182 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2183 // We're changing the type, we need a new CheckCast node to carry
2184 // the new type. The new type depends on the control: what
2185 // profiling tells us is only valid from here as far as we can
2186 // tell.
2187 Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2188 cast = _gvn.transform(cast);
2189 replace_in_map(n, cast);
2190 n = cast;
2191 }
2192
2193 return n;
2194 }
2195
2196 /**
2197 * Record profiling data from receiver profiling at an invoke with the
2198 * type system so that it can propagate it (speculation)
2199 *
2200 * @param n receiver node
2201 *
2202 * @return node with improved type
2203 */
2204 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2205 if (!UseTypeSpeculation) {
2206 return n;
2207 }
2208 ciKlass* exact_kls = profile_has_unique_klass();
2209 bool maybe_null = true;
2210 if (java_bc() == Bytecodes::_checkcast ||
2211 java_bc() == Bytecodes::_instanceof ||
2212 java_bc() == Bytecodes::_aastore) {
2213 ciProfileData* data = method()->method_data()->bci_to_data(bci());
2214 bool maybe_null = data == NULL ? true : data->as_BitData()->null_seen();
2215 }
2216 return record_profile_for_speculation(n, exact_kls, maybe_null);
2217 return n;
2218 }
2219
2220 /**
2221 * Record profiling data from argument profiling at an invoke with the
2222 * type system so that it can propagate it (speculation)
2223 *
2224 * @param dest_method target method for the call
2225 * @param bc what invoke bytecode is this?
2226 */
2227 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2228 if (!UseTypeSpeculation) {
2229 return;
2230 }
2231 const TypeFunc* tf = TypeFunc::make(dest_method);
2232 int nargs = tf->domain_sig()->cnt() - TypeFunc::Parms;
2233 int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2234 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2235 const Type *targ = tf->domain_sig()->field_at(j + TypeFunc::Parms);
2236 if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2237 bool maybe_null = true;
2238 ciKlass* better_type = NULL;
2239 if (method()->argument_profiled_type(bci(), i, better_type, maybe_null)) {
2240 record_profile_for_speculation(argument(j), better_type, maybe_null);
2241 }
2242 i++;
2243 }
2244 }
2245 }
2246
2247 /**
2248 * Record profiling data from parameter profiling at an invoke with
2249 * the type system so that it can propagate it (speculation)
2250 */
2251 void GraphKit::record_profiled_parameters_for_speculation() {
2252 if (!UseTypeSpeculation) {
2253 return;
2254 }
2255 for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2256 if (_gvn.type(local(i))->isa_oopptr()) {
2257 bool maybe_null = true;
2258 ciKlass* better_type = NULL;
2259 if (method()->parameter_profiled_type(j, better_type, maybe_null)) {
2260 record_profile_for_speculation(local(i), better_type, maybe_null);
2261 }
2262 j++;
2263 }
2264 }
2265 }
2266
2267 /**
2268 * Record profiling data from return value profiling at an invoke with
2269 * the type system so that it can propagate it (speculation)
2270 */
2271 void GraphKit::record_profiled_return_for_speculation() {
2272 if (!UseTypeSpeculation) {
2273 return;
2274 }
2275 bool maybe_null = true;
2276 ciKlass* better_type = NULL;
2277 if (method()->return_profiled_type(bci(), better_type, maybe_null)) {
2278 // If profiling reports a single type for the return value,
2279 // feed it to the type system so it can propagate it as a
2280 // speculative type
2281 record_profile_for_speculation(stack(sp()-1), better_type, maybe_null);
2282 }
2283 }
2284
2285 void GraphKit::round_double_result(ciMethod* dest_method) {
2286 // A non-strict method may return a double value which has an extended
2287 // exponent, but this must not be visible in a caller which is 'strict'
2288 // If a strict caller invokes a non-strict callee, round a double result
2289
2290 BasicType result_type = dest_method->return_type()->basic_type();
2291 assert( method() != NULL, "must have caller context");
2292 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2293 // Destination method's return value is on top of stack
2294 // dstore_rounding() does gvn.transform
2295 Node *result = pop_pair();
2296 result = dstore_rounding(result);
2297 push_pair(result);
2298 }
2299 }
2300
2301 // rounding for strict float precision conformance
2302 Node* GraphKit::precision_rounding(Node* n) {
2303 return UseStrictFP && _method->flags().is_strict()
2304 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2305 ? _gvn.transform( new RoundFloatNode(0, n) )
2306 : n;
2307 }
2308
2309 // rounding for strict double precision conformance
2310 Node* GraphKit::dprecision_rounding(Node *n) {
2311 return UseStrictFP && _method->flags().is_strict()
2312 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2313 ? _gvn.transform( new RoundDoubleNode(0, n) )
2314 : n;
2315 }
2316
2317 // rounding for non-strict double stores
2318 Node* GraphKit::dstore_rounding(Node* n) {
2319 return Matcher::strict_fp_requires_explicit_rounding
2320 && UseSSE <= 1
2321 ? _gvn.transform( new RoundDoubleNode(0, n) )
2322 : n;
2323 }
2324
2325 //=============================================================================
2326 // Generate a fast path/slow path idiom. Graph looks like:
2327 // [foo] indicates that 'foo' is a parameter
2328 //
2329 // [in] NULL
2330 // \ /
2331 // CmpP
2332 // Bool ne
2333 // If
2334 // / \
2335 // True False-<2>
2336 // / |
2337 // / cast_not_null
2338 // Load | | ^
2339 // [fast_test] | |
2340 // gvn to opt_test | |
2341 // / \ | <1>
2342 // True False |
2343 // | \\ |
2344 // [slow_call] \[fast_result]
2345 // Ctl Val \ \
2346 // | \ \
2347 // Catch <1> \ \
2348 // / \ ^ \ \
2349 // Ex No_Ex | \ \
2350 // | \ \ | \ <2> \
2351 // ... \ [slow_res] | | \ [null_result]
2352 // \ \--+--+--- | |
2353 // \ | / \ | /
2354 // --------Region Phi
2355 //
2356 //=============================================================================
2357 // Code is structured as a series of driver functions all called 'do_XXX' that
2358 // call a set of helper functions. Helper functions first, then drivers.
2359
2360 //------------------------------null_check_oop---------------------------------
2361 // Null check oop. Set null-path control into Region in slot 3.
2362 // Make a cast-not-nullness use the other not-null control. Return cast.
2363 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2364 bool never_see_null,
2365 bool safe_for_replace,
2366 bool speculative) {
2367 // Initial NULL check taken path
2368 (*null_control) = top();
2369 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2370
2371 // Generate uncommon_trap:
2372 if (never_see_null && (*null_control) != top()) {
2373 // If we see an unexpected null at a check-cast we record it and force a
2374 // recompile; the offending check-cast will be compiled to handle NULLs.
2375 // If we see more than one offending BCI, then all checkcasts in the
2376 // method will be compiled to handle NULLs.
2377 PreserveJVMState pjvms(this);
2378 set_control(*null_control);
2379 replace_in_map(value, null());
2380 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2381 uncommon_trap(reason,
2382 Deoptimization::Action_make_not_entrant);
2383 (*null_control) = top(); // NULL path is dead
2384 }
2385 if ((*null_control) == top() && safe_for_replace) {
2386 replace_in_map(value, cast);
2387 }
2388
2389 // Cast away null-ness on the result
2390 return cast;
2391 }
2392
2393 //------------------------------opt_iff----------------------------------------
2394 // Optimize the fast-check IfNode. Set the fast-path region slot 2.
2395 // Return slow-path control.
2396 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2397 IfNode *opt_iff = _gvn.transform(iff)->as_If();
2398
2399 // Fast path taken; set region slot 2
2400 Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2401 region->init_req(2,fast_taken); // Capture fast-control
2402
2403 // Fast path not-taken, i.e. slow path
2404 Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2405 return slow_taken;
2406 }
2407
2408 //-----------------------------make_runtime_call-------------------------------
2409 Node* GraphKit::make_runtime_call(int flags,
2410 const TypeFunc* call_type, address call_addr,
2411 const char* call_name,
2412 const TypePtr* adr_type,
2413 // The following parms are all optional.
2414 // The first NULL ends the list.
2415 Node* parm0, Node* parm1,
2416 Node* parm2, Node* parm3,
2417 Node* parm4, Node* parm5,
2418 Node* parm6, Node* parm7) {
2419 // Slow-path call
2420 bool is_leaf = !(flags & RC_NO_LEAF);
2421 bool has_io = (!is_leaf && !(flags & RC_NO_IO));
2422 if (call_name == NULL) {
2423 assert(!is_leaf, "must supply name for leaf");
2424 call_name = OptoRuntime::stub_name(call_addr);
2425 }
2426 CallNode* call;
2427 if (!is_leaf) {
2428 call = new CallStaticJavaNode(call_type, call_addr, call_name,
2429 bci(), adr_type);
2430 } else if (flags & RC_NO_FP) {
2431 call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2432 } else {
2433 call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2434 }
2435
2436 // The following is similar to set_edges_for_java_call,
2437 // except that the memory effects of the call are restricted to AliasIdxRaw.
2438
2439 // Slow path call has no side-effects, uses few values
2440 bool wide_in = !(flags & RC_NARROW_MEM);
2441 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2442
2443 Node* prev_mem = NULL;
2444 if (wide_in) {
2445 prev_mem = set_predefined_input_for_runtime_call(call);
2446 } else {
2447 assert(!wide_out, "narrow in => narrow out");
2448 Node* narrow_mem = memory(adr_type);
2449 prev_mem = reset_memory();
2450 map()->set_memory(narrow_mem);
2451 set_predefined_input_for_runtime_call(call);
2452 }
2453
2454 // Hook each parm in order. Stop looking at the first NULL.
2455 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2456 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2457 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2458 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2459 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2460 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2461 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2462 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2463 /* close each nested if ===> */ } } } } } } } }
2464 assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2465
2466 if (!is_leaf) {
2467 // Non-leaves can block and take safepoints:
2468 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2469 }
2470 // Non-leaves can throw exceptions:
2471 if (has_io) {
2472 call->set_req(TypeFunc::I_O, i_o());
2473 }
2474
2475 if (flags & RC_UNCOMMON) {
2476 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency.
2477 // (An "if" probability corresponds roughly to an unconditional count.
2478 // Sort of.)
2479 call->set_cnt(PROB_UNLIKELY_MAG(4));
2480 }
2481
2482 Node* c = _gvn.transform(call);
2483 assert(c == call, "cannot disappear");
2484
2485 if (wide_out) {
2486 // Slow path call has full side-effects.
2487 set_predefined_output_for_runtime_call(call);
2488 } else {
2489 // Slow path call has few side-effects, and/or sets few values.
2490 set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2491 }
2492
2493 if (has_io) {
2494 set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2495 }
2496 return call;
2497
2498 }
2499
2500 //------------------------------merge_memory-----------------------------------
2501 // Merge memory from one path into the current memory state.
2502 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2503 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2504 Node* old_slice = mms.force_memory();
2505 Node* new_slice = mms.memory2();
2506 if (old_slice != new_slice) {
2507 PhiNode* phi;
2508 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2509 if (mms.is_empty()) {
2510 // clone base memory Phi's inputs for this memory slice
2511 assert(old_slice == mms.base_memory(), "sanity");
2512 phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2513 _gvn.set_type(phi, Type::MEMORY);
2514 for (uint i = 1; i < phi->req(); i++) {
2515 phi->init_req(i, old_slice->in(i));
2516 }
2517 } else {
2518 phi = old_slice->as_Phi(); // Phi was generated already
2519 }
2520 } else {
2521 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2522 _gvn.set_type(phi, Type::MEMORY);
2523 }
2524 phi->set_req(new_path, new_slice);
2525 mms.set_memory(phi);
2526 }
2527 }
2528 }
2529
2530 //------------------------------make_slow_call_ex------------------------------
2531 // Make the exception handler hookups for the slow call
2532 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2533 if (stopped()) return;
2534
2535 // Make a catch node with just two handlers: fall-through and catch-all
2536 Node* i_o = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2537 Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2538 Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2539 Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) );
2540
2541 { PreserveJVMState pjvms(this);
2542 set_control(excp);
2543 set_i_o(i_o);
2544
2545 if (excp != top()) {
2546 if (deoptimize) {
2547 // Deoptimize if an exception is caught. Don't construct exception state in this case.
2548 uncommon_trap(Deoptimization::Reason_unhandled,
2549 Deoptimization::Action_none);
2550 } else {
2551 // Create an exception state also.
2552 // Use an exact type if the caller has specified a specific exception.
2553 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2554 Node* ex_oop = new CreateExNode(ex_type, control(), i_o);
2555 add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2556 }
2557 }
2558 }
2559
2560 // Get the no-exception control from the CatchNode.
2561 set_control(norm);
2562 }
2563
2564 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2565 Node* cmp = NULL;
2566 switch(bt) {
2567 case T_INT: cmp = new CmpINode(in1, in2); break;
2568 case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2569 default: fatal("unexpected comparison type %s", type2name(bt));
2570 }
2571 gvn->transform(cmp);
2572 Node* bol = gvn->transform(new BoolNode(cmp, test));
2573 IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2574 gvn->transform(iff);
2575 if (!bol->is_Con()) gvn->record_for_igvn(iff);
2576 return iff;
2577 }
2578
2579
2580 //-------------------------------gen_subtype_check-----------------------------
2581 // Generate a subtyping check. Takes as input the subtype and supertype.
2582 // Returns 2 values: sets the default control() to the true path and returns
2583 // the false path. Only reads invariant memory; sets no (visible) memory.
2584 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2585 // but that's not exposed to the optimizer. This call also doesn't take in an
2586 // Object; if you wish to check an Object you need to load the Object's class
2587 // prior to coming here.
2588 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2589 Compile* C = gvn->C;
2590
2591 if ((*ctrl)->is_top()) {
2592 return C->top();
2593 }
2594
2595 // Fast check for identical types, perhaps identical constants.
2596 // The types can even be identical non-constants, in cases
2597 // involving Array.newInstance, Object.clone, etc.
2598 if (subklass == superklass)
2599 return C->top(); // false path is dead; no test needed.
2600
2601 if (gvn->type(superklass)->singleton()) {
2602 ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2603 ciKlass* subk = gvn->type(subklass)->is_klassptr()->klass();
2604
2605 // In the common case of an exact superklass, try to fold up the
2606 // test before generating code. You may ask, why not just generate
2607 // the code and then let it fold up? The answer is that the generated
2608 // code will necessarily include null checks, which do not always
2609 // completely fold away. If they are also needless, then they turn
2610 // into a performance loss. Example:
2611 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2612 // Here, the type of 'fa' is often exact, so the store check
2613 // of fa[1]=x will fold up, without testing the nullness of x.
2614 switch (C->static_subtype_check(superk, subk)) {
2615 case Compile::SSC_always_false:
2616 {
2617 Node* always_fail = *ctrl;
2618 *ctrl = gvn->C->top();
2619 return always_fail;
2620 }
2621 case Compile::SSC_always_true:
2622 return C->top();
2623 case Compile::SSC_easy_test:
2624 {
2625 // Just do a direct pointer compare and be done.
2626 IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2627 *ctrl = gvn->transform(new IfTrueNode(iff));
2628 return gvn->transform(new IfFalseNode(iff));
2629 }
2630 case Compile::SSC_full_test:
2631 break;
2632 default:
2633 ShouldNotReachHere();
2634 }
2635 }
2636
2637 // %%% Possible further optimization: Even if the superklass is not exact,
2638 // if the subklass is the unique subtype of the superklass, the check
2639 // will always succeed. We could leave a dependency behind to ensure this.
2640
2641 // First load the super-klass's check-offset
2642 Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2643 Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2644 Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2645 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2646 bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2647
2648 // Load from the sub-klass's super-class display list, or a 1-word cache of
2649 // the secondary superclass list, or a failing value with a sentinel offset
2650 // if the super-klass is an interface or exceptionally deep in the Java
2651 // hierarchy and we have to scan the secondary superclass list the hard way.
2652 // Worst-case type is a little odd: NULL is allowed as a result (usually
2653 // klass loads can never produce a NULL).
2654 Node *chk_off_X = chk_off;
2655 #ifdef _LP64
2656 chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2657 #endif
2658 Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2659 // For some types like interfaces the following loadKlass is from a 1-word
2660 // cache which is mutable so can't use immutable memory. Other
2661 // types load from the super-class display table which is immutable.
2662 m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2663 Node *kmem = might_be_cache ? m : C->immutable_memory();
2664 Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2665
2666 // Compile speed common case: ARE a subtype and we canNOT fail
2667 if( superklass == nkls )
2668 return C->top(); // false path is dead; no test needed.
2669
2670 // See if we get an immediate positive hit. Happens roughly 83% of the
2671 // time. Test to see if the value loaded just previously from the subklass
2672 // is exactly the superklass.
2673 IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2674 Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2675 *ctrl = gvn->transform(new IfFalseNode(iff1));
2676
2677 // Compile speed common case: Check for being deterministic right now. If
2678 // chk_off is a constant and not equal to cacheoff then we are NOT a
2679 // subklass. In this case we need exactly the 1 test above and we can
2680 // return those results immediately.
2681 if (!might_be_cache) {
2682 Node* not_subtype_ctrl = *ctrl;
2683 *ctrl = iftrue1; // We need exactly the 1 test above
2684 return not_subtype_ctrl;
2685 }
2686
2687 // Gather the various success & failures here
2688 RegionNode *r_ok_subtype = new RegionNode(4);
2689 gvn->record_for_igvn(r_ok_subtype);
2690 RegionNode *r_not_subtype = new RegionNode(3);
2691 gvn->record_for_igvn(r_not_subtype);
2692
2693 r_ok_subtype->init_req(1, iftrue1);
2694
2695 // Check for immediate negative hit. Happens roughly 11% of the time (which
2696 // is roughly 63% of the remaining cases). Test to see if the loaded
2697 // check-offset points into the subklass display list or the 1-element
2698 // cache. If it points to the display (and NOT the cache) and the display
2699 // missed then it's not a subtype.
2700 Node *cacheoff = gvn->intcon(cacheoff_con);
2701 IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2702 r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2703 *ctrl = gvn->transform(new IfFalseNode(iff2));
2704
2705 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2706 // No performance impact (too rare) but allows sharing of secondary arrays
2707 // which has some footprint reduction.
2708 IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2709 r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2710 *ctrl = gvn->transform(new IfFalseNode(iff3));
2711
2712 // -- Roads not taken here: --
2713 // We could also have chosen to perform the self-check at the beginning
2714 // of this code sequence, as the assembler does. This would not pay off
2715 // the same way, since the optimizer, unlike the assembler, can perform
2716 // static type analysis to fold away many successful self-checks.
2717 // Non-foldable self checks work better here in second position, because
2718 // the initial primary superclass check subsumes a self-check for most
2719 // types. An exception would be a secondary type like array-of-interface,
2720 // which does not appear in its own primary supertype display.
2721 // Finally, we could have chosen to move the self-check into the
2722 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2723 // dependent manner. But it is worthwhile to have the check here,
2724 // where it can be perhaps be optimized. The cost in code space is
2725 // small (register compare, branch).
2726
2727 // Now do a linear scan of the secondary super-klass array. Again, no real
2728 // performance impact (too rare) but it's gotta be done.
2729 // Since the code is rarely used, there is no penalty for moving it
2730 // out of line, and it can only improve I-cache density.
2731 // The decision to inline or out-of-line this final check is platform
2732 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2733 Node* psc = gvn->transform(
2734 new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2735
2736 IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2737 r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2738 r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2739
2740 // Return false path; set default control to true path.
2741 *ctrl = gvn->transform(r_ok_subtype);
2742 return gvn->transform(r_not_subtype);
2743 }
2744
2745 // Profile-driven exact type check:
2746 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2747 float prob,
2748 Node* *casted_receiver) {
2749 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2750 Node* recv_klass = load_object_klass(receiver);
2751 Node* want_klass = makecon(tklass);
2752 Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2753 Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2754 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2755 set_control( _gvn.transform( new IfTrueNode (iff) ));
2756 Node* fail = _gvn.transform( new IfFalseNode(iff) );
2757
2758 const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2759 assert(recv_xtype->klass_is_exact(), "");
2760
2761 // Subsume downstream occurrences of receiver with a cast to
2762 // recv_xtype, since now we know what the type will be.
2763 Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2764 (*casted_receiver) = _gvn.transform(cast);
2765 // (User must make the replace_in_map call.)
2766
2767 return fail;
2768 }
2769
2770
2771 //------------------------------seems_never_null-------------------------------
2772 // Use null_seen information if it is available from the profile.
2773 // If we see an unexpected null at a type check we record it and force a
2774 // recompile; the offending check will be recompiled to handle NULLs.
2775 // If we see several offending BCIs, then all checks in the
2776 // method will be recompiled.
2777 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2778 speculating = !_gvn.type(obj)->speculative_maybe_null();
2779 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2780 if (UncommonNullCast // Cutout for this technique
2781 && obj != null() // And not the -Xcomp stupid case?
2782 && !too_many_traps(reason)
2783 ) {
2784 if (speculating) {
2785 return true;
2786 }
2787 if (data == NULL)
2788 // Edge case: no mature data. Be optimistic here.
2789 return true;
2790 // If the profile has not seen a null, assume it won't happen.
2791 assert(java_bc() == Bytecodes::_checkcast ||
2792 java_bc() == Bytecodes::_instanceof ||
2793 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2794 return !data->as_BitData()->null_seen();
2795 }
2796 speculating = false;
2797 return false;
2798 }
2799
2800 //------------------------maybe_cast_profiled_receiver-------------------------
2801 // If the profile has seen exactly one type, narrow to exactly that type.
2802 // Subsequent type checks will always fold up.
2803 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2804 ciKlass* require_klass,
2805 ciKlass* spec_klass,
2806 bool safe_for_replace) {
2807 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2808
2809 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2810
2811 // Make sure we haven't already deoptimized from this tactic.
2812 if (too_many_traps(reason) || too_many_recompiles(reason))
2813 return NULL;
2814
2815 // (No, this isn't a call, but it's enough like a virtual call
2816 // to use the same ciMethod accessor to get the profile info...)
2817 // If we have a speculative type use it instead of profiling (which
2818 // may not help us)
2819 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2820 if (exact_kls != NULL) {// no cast failures here
2821 if (require_klass == NULL ||
2822 C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2823 // If we narrow the type to match what the type profile sees or
2824 // the speculative type, we can then remove the rest of the
2825 // cast.
2826 // This is a win, even if the exact_kls is very specific,
2827 // because downstream operations, such as method calls,
2828 // will often benefit from the sharper type.
2829 Node* exact_obj = not_null_obj; // will get updated in place...
2830 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2831 &exact_obj);
2832 { PreserveJVMState pjvms(this);
2833 set_control(slow_ctl);
2834 uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2835 }
2836 if (safe_for_replace) {
2837 replace_in_map(not_null_obj, exact_obj);
2838 }
2839 return exact_obj;
2840 }
2841 // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2842 }
2843
2844 return NULL;
2845 }
2846
2847 /**
2848 * Cast obj to type and emit guard unless we had too many traps here
2849 * already
2850 *
2851 * @param obj node being casted
2852 * @param type type to cast the node to
2853 * @param not_null true if we know node cannot be null
2854 */
2855 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2856 ciKlass* type,
2857 bool not_null) {
2858 if (stopped()) {
2859 return obj;
2860 }
2861
2862 // type == NULL if profiling tells us this object is always null
2863 if (type != NULL) {
2864 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2865 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2866
2867 if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2868 !too_many_traps(class_reason) &&
2869 !too_many_recompiles(class_reason)) {
2870 Node* not_null_obj = NULL;
2871 // not_null is true if we know the object is not null and
2872 // there's no need for a null check
2873 if (!not_null) {
2874 Node* null_ctl = top();
2875 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2876 assert(null_ctl->is_top(), "no null control here");
2877 } else {
2878 not_null_obj = obj;
2879 }
2880
2881 Node* exact_obj = not_null_obj;
2882 ciKlass* exact_kls = type;
2883 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2884 &exact_obj);
2885 {
2886 PreserveJVMState pjvms(this);
2887 set_control(slow_ctl);
2888 uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2889 }
2890 replace_in_map(not_null_obj, exact_obj);
2891 obj = exact_obj;
2892 }
2893 } else {
2894 if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2895 !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2896 Node* exact_obj = null_assert(obj);
2897 replace_in_map(obj, exact_obj);
2898 obj = exact_obj;
2899 }
2900 }
2901 return obj;
2902 }
2903
2904 //-------------------------------gen_instanceof--------------------------------
2905 // Generate an instance-of idiom. Used by both the instance-of bytecode
2906 // and the reflective instance-of call.
2907 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2908 kill_dead_locals(); // Benefit all the uncommon traps
2909 assert( !stopped(), "dead parse path should be checked in callers" );
2910 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2911 "must check for not-null not-dead klass in callers");
2912
2913 // Make the merge point
2914 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2915 RegionNode* region = new RegionNode(PATH_LIMIT);
2916 Node* phi = new PhiNode(region, TypeInt::BOOL);
2917 C->set_has_split_ifs(true); // Has chance for split-if optimization
2918
2919 ciProfileData* data = NULL;
2920 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode
2921 data = method()->method_data()->bci_to_data(bci());
2922 }
2923 bool speculative_not_null = false;
2924 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile
2925 && seems_never_null(obj, data, speculative_not_null));
2926
2927 // Null check; get casted pointer; set region slot 3
2928 Node* null_ctl = top();
2929 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2930
2931 // If not_null_obj is dead, only null-path is taken
2932 if (stopped()) { // Doing instance-of on a NULL?
2933 set_control(null_ctl);
2934 return intcon(0);
2935 }
2936 region->init_req(_null_path, null_ctl);
2937 phi ->init_req(_null_path, intcon(0)); // Set null path value
2938 if (null_ctl == top()) {
2939 // Do this eagerly, so that pattern matches like is_diamond_phi
2940 // will work even during parsing.
2941 assert(_null_path == PATH_LIMIT-1, "delete last");
2942 region->del_req(_null_path);
2943 phi ->del_req(_null_path);
2944 }
2945
2946 // Do we know the type check always succeed?
2947 bool known_statically = false;
2948 if (_gvn.type(superklass)->singleton()) {
2949 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2950 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2951 if (subk != NULL && subk->is_loaded()) {
2952 int static_res = C->static_subtype_check(superk, subk);
2953 known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2954 }
2955 }
2956
2957 if (known_statically && UseTypeSpeculation) {
2958 // If we know the type check always succeeds then we don't use the
2959 // profiling data at this bytecode. Don't lose it, feed it to the
2960 // type system as a speculative type.
2961 not_null_obj = record_profiled_receiver_for_speculation(not_null_obj);
2962 } else {
2963 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2964 // We may not have profiling here or it may not help us. If we
2965 // have a speculative type use it to perform an exact cast.
2966 ciKlass* spec_obj_type = obj_type->speculative_type();
2967 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2968 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2969 if (stopped()) { // Profile disagrees with this path.
2970 set_control(null_ctl); // Null is the only remaining possibility.
2971 return intcon(0);
2972 }
2973 if (cast_obj != NULL) {
2974 not_null_obj = cast_obj;
2975 }
2976 }
2977 }
2978
2979 // Load the object's klass
2980 Node* obj_klass = load_object_klass(not_null_obj);
2981
2982 // Generate the subtype check
2983 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2984
2985 // Plug in the success path to the general merge in slot 1.
2986 region->init_req(_obj_path, control());
2987 phi ->init_req(_obj_path, intcon(1));
2988
2989 // Plug in the failing path to the general merge in slot 2.
2990 region->init_req(_fail_path, not_subtype_ctrl);
2991 phi ->init_req(_fail_path, intcon(0));
2992
2993 // Return final merged results
2994 set_control( _gvn.transform(region) );
2995 record_for_igvn(region);
2996 return _gvn.transform(phi);
2997 }
2998
2999 //-------------------------------gen_checkcast---------------------------------
3000 // Generate a checkcast idiom. Used by both the checkcast bytecode and the
3001 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the
3002 // uncommon-trap paths work. Adjust stack after this call.
3003 // If failure_control is supplied and not null, it is filled in with
3004 // the control edge for the cast failure. Otherwise, an appropriate
3005 // uncommon trap or exception is thrown.
3006 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3007 Node* *failure_control) {
3008 kill_dead_locals(); // Benefit all the uncommon traps
3009 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3010 const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3011
3012 // Fast cutout: Check the case that the cast is vacuously true.
3013 // This detects the common cases where the test will short-circuit
3014 // away completely. We do this before we perform the null check,
3015 // because if the test is going to turn into zero code, we don't
3016 // want a residual null check left around. (Causes a slowdown,
3017 // for example, in some objArray manipulations, such as a[i]=a[j].)
3018 if (tk->singleton()) {
3019 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3020 if (objtp != NULL && objtp->klass() != NULL) {
3021 switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3022 case Compile::SSC_always_true:
3023 // If we know the type check always succeed then we don't use
3024 // the profiling data at this bytecode. Don't lose it, feed it
3025 // to the type system as a speculative type.
3026 return record_profiled_receiver_for_speculation(obj);
3027 case Compile::SSC_always_false:
3028 // It needs a null check because a null will *pass* the cast check.
3029 // A non-null value will always produce an exception.
3030 return null_assert(obj);
3031 }
3032 }
3033 }
3034
3035 ciProfileData* data = NULL;
3036 bool safe_for_replace = false;
3037 if (failure_control == NULL) { // use MDO in regular case only
3038 assert(java_bc() == Bytecodes::_aastore ||
3039 java_bc() == Bytecodes::_checkcast,
3040 "interpreter profiles type checks only for these BCs");
3041 data = method()->method_data()->bci_to_data(bci());
3042 safe_for_replace = true;
3043 }
3044
3045 // Make the merge point
3046 enum { _obj_path = 1, _null_path, PATH_LIMIT };
3047 RegionNode* region = new RegionNode(PATH_LIMIT);
3048 Node* phi = new PhiNode(region, toop);
3049 C->set_has_split_ifs(true); // Has chance for split-if optimization
3050
3051 // Use null-cast information if it is available
3052 bool speculative_not_null = false;
3053 bool never_see_null = ((failure_control == NULL) // regular case only
3054 && seems_never_null(obj, data, speculative_not_null));
3055
3056 // Null check; get casted pointer; set region slot 3
3057 Node* null_ctl = top();
3058 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3059
3060 // If not_null_obj is dead, only null-path is taken
3061 if (stopped()) { // Doing instance-of on a NULL?
3062 set_control(null_ctl);
3063 return null();
3064 }
3065 region->init_req(_null_path, null_ctl);
3066 phi ->init_req(_null_path, null()); // Set null path value
3067 if (null_ctl == top()) {
3068 // Do this eagerly, so that pattern matches like is_diamond_phi
3069 // will work even during parsing.
3070 assert(_null_path == PATH_LIMIT-1, "delete last");
3071 region->del_req(_null_path);
3072 phi ->del_req(_null_path);
3073 }
3074
3075 Node* cast_obj = NULL;
3076 if (tk->klass_is_exact()) {
3077 // The following optimization tries to statically cast the speculative type of the object
3078 // (for example obtained during profiling) to the type of the superklass and then do a
3079 // dynamic check that the type of the object is what we expect. To work correctly
3080 // for checkcast and aastore the type of superklass should be exact.
3081 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3082 // We may not have profiling here or it may not help us. If we have
3083 // a speculative type use it to perform an exact cast.
3084 ciKlass* spec_obj_type = obj_type->speculative_type();
3085 if (spec_obj_type != NULL || data != NULL) {
3086 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3087 if (cast_obj != NULL) {
3088 if (failure_control != NULL) // failure is now impossible
3089 (*failure_control) = top();
3090 // adjust the type of the phi to the exact klass:
3091 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3092 }
3093 }
3094 }
3095
3096 if (cast_obj == NULL) {
3097 // Load the object's klass
3098 Node* obj_klass = load_object_klass(not_null_obj);
3099
3100 // Generate the subtype check
3101 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3102
3103 // Plug in success path into the merge
3104 cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3105 // Failure path ends in uncommon trap (or may be dead - failure impossible)
3106 if (failure_control == NULL) {
3107 if (not_subtype_ctrl != top()) { // If failure is possible
3108 PreserveJVMState pjvms(this);
3109 set_control(not_subtype_ctrl);
3110 builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3111 }
3112 } else {
3113 (*failure_control) = not_subtype_ctrl;
3114 }
3115 }
3116
3117 region->init_req(_obj_path, control());
3118 phi ->init_req(_obj_path, cast_obj);
3119
3120 // A merge of NULL or Casted-NotNull obj
3121 Node* res = _gvn.transform(phi);
3122
3123 // Note I do NOT always 'replace_in_map(obj,result)' here.
3124 // if( tk->klass()->can_be_primary_super() )
3125 // This means that if I successfully store an Object into an array-of-String
3126 // I 'forget' that the Object is really now known to be a String. I have to
3127 // do this because we don't have true union types for interfaces - if I store
3128 // a Baz into an array-of-Interface and then tell the optimizer it's an
3129 // Interface, I forget that it's also a Baz and cannot do Baz-like field
3130 // references to it. FIX THIS WHEN UNION TYPES APPEAR!
3131 // replace_in_map( obj, res );
3132
3133 // Return final merged results
3134 set_control( _gvn.transform(region) );
3135 record_for_igvn(region);
3136 return res;
3137 }
3138
3139 //------------------------------next_monitor-----------------------------------
3140 // What number should be given to the next monitor?
3141 int GraphKit::next_monitor() {
3142 int current = jvms()->monitor_depth()* C->sync_stack_slots();
3143 int next = current + C->sync_stack_slots();
3144 // Keep the toplevel high water mark current:
3145 if (C->fixed_slots() < next) C->set_fixed_slots(next);
3146 return current;
3147 }
3148
3149 //------------------------------insert_mem_bar---------------------------------
3150 // Memory barrier to avoid floating things around
3151 // The membar serves as a pinch point between both control and all memory slices.
3152 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3153 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3154 mb->init_req(TypeFunc::Control, control());
3155 mb->init_req(TypeFunc::Memory, reset_memory());
3156 Node* membar = _gvn.transform(mb);
3157 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3158 set_all_memory_call(membar);
3159 return membar;
3160 }
3161
3162 //-------------------------insert_mem_bar_volatile----------------------------
3163 // Memory barrier to avoid floating things around
3164 // The membar serves as a pinch point between both control and memory(alias_idx).
3165 // If you want to make a pinch point on all memory slices, do not use this
3166 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3167 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3168 // When Parse::do_put_xxx updates a volatile field, it appends a series
3169 // of MemBarVolatile nodes, one for *each* volatile field alias category.
3170 // The first membar is on the same memory slice as the field store opcode.
3171 // This forces the membar to follow the store. (Bug 6500685 broke this.)
3172 // All the other membars (for other volatile slices, including AliasIdxBot,
3173 // which stands for all unknown volatile slices) are control-dependent
3174 // on the first membar. This prevents later volatile loads or stores
3175 // from sliding up past the just-emitted store.
3176
3177 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3178 mb->set_req(TypeFunc::Control,control());
3179 if (alias_idx == Compile::AliasIdxBot) {
3180 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3181 } else {
3182 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3183 mb->set_req(TypeFunc::Memory, memory(alias_idx));
3184 }
3185 Node* membar = _gvn.transform(mb);
3186 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3187 if (alias_idx == Compile::AliasIdxBot) {
3188 merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3189 } else {
3190 set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3191 }
3192 return membar;
3193 }
3194
3195 void GraphKit::insert_store_load_for_barrier() {
3196 Node* mem = reset_memory();
3197 MemBarNode* mb = MemBarNode::make(C, Op_MemBarVolatile, Compile::AliasIdxBot);
3198 mb->init_req(TypeFunc::Control, control());
3199 mb->init_req(TypeFunc::Memory, mem);
3200 Node* membar = _gvn.transform(mb);
3201 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3202 Node* newmem = _gvn.transform(new ProjNode(membar, TypeFunc::Memory));
3203 set_all_memory(mem);
3204 set_memory(newmem, Compile::AliasIdxRaw);
3205 }
3206
3207
3208 //------------------------------shared_lock------------------------------------
3209 // Emit locking code.
3210 FastLockNode* GraphKit::shared_lock(Node* obj) {
3211 // bci is either a monitorenter bc or InvocationEntryBci
3212 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3213 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3214
3215 if( !GenerateSynchronizationCode )
3216 return NULL; // Not locking things?
3217 if (stopped()) // Dead monitor?
3218 return NULL;
3219
3220 assert(dead_locals_are_killed(), "should kill locals before sync. point");
3221
3222 // Box the stack location
3223 Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3224 Node* mem = reset_memory();
3225
3226 FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3227 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3228 // Create the counters for this fast lock.
3229 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3230 }
3231
3232 // Create the rtm counters for this fast lock if needed.
3233 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3234
3235 // Add monitor to debug info for the slow path. If we block inside the
3236 // slow path and de-opt, we need the monitor hanging around
3237 map()->push_monitor( flock );
3238
3239 const TypeFunc *tf = LockNode::lock_type();
3240 LockNode *lock = new LockNode(C, tf);
3241
3242 lock->init_req( TypeFunc::Control, control() );
3243 lock->init_req( TypeFunc::Memory , mem );
3244 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3245 lock->init_req( TypeFunc::FramePtr, frameptr() );
3246 lock->init_req( TypeFunc::ReturnAdr, top() );
3247
3248 lock->init_req(TypeFunc::Parms + 0, obj);
3249 lock->init_req(TypeFunc::Parms + 1, box);
3250 lock->init_req(TypeFunc::Parms + 2, flock);
3251 add_safepoint_edges(lock);
3252
3253 lock = _gvn.transform( lock )->as_Lock();
3254
3255 // lock has no side-effects, sets few values
3256 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3257
3258 insert_mem_bar(Op_MemBarAcquireLock);
3259
3260 // Add this to the worklist so that the lock can be eliminated
3261 record_for_igvn(lock);
3262
3263 #ifndef PRODUCT
3264 if (PrintLockStatistics) {
3265 // Update the counter for this lock. Don't bother using an atomic
3266 // operation since we don't require absolute accuracy.
3267 lock->create_lock_counter(map()->jvms());
3268 increment_counter(lock->counter()->addr());
3269 }
3270 #endif
3271
3272 return flock;
3273 }
3274
3275
3276 //------------------------------shared_unlock----------------------------------
3277 // Emit unlocking code.
3278 void GraphKit::shared_unlock(Node* box, Node* obj) {
3279 // bci is either a monitorenter bc or InvocationEntryBci
3280 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3281 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3282
3283 if( !GenerateSynchronizationCode )
3284 return;
3285 if (stopped()) { // Dead monitor?
3286 map()->pop_monitor(); // Kill monitor from debug info
3287 return;
3288 }
3289
3290 // Memory barrier to avoid floating things down past the locked region
3291 insert_mem_bar(Op_MemBarReleaseLock);
3292
3293 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3294 UnlockNode *unlock = new UnlockNode(C, tf);
3295 #ifdef ASSERT
3296 unlock->set_dbg_jvms(sync_jvms());
3297 #endif
3298 uint raw_idx = Compile::AliasIdxRaw;
3299 unlock->init_req( TypeFunc::Control, control() );
3300 unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3301 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3302 unlock->init_req( TypeFunc::FramePtr, frameptr() );
3303 unlock->init_req( TypeFunc::ReturnAdr, top() );
3304
3305 unlock->init_req(TypeFunc::Parms + 0, obj);
3306 unlock->init_req(TypeFunc::Parms + 1, box);
3307 unlock = _gvn.transform(unlock)->as_Unlock();
3308
3309 Node* mem = reset_memory();
3310
3311 // unlock has no side-effects, sets few values
3312 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3313
3314 // Kill monitor from debug info
3315 map()->pop_monitor( );
3316 }
3317
3318 //-------------------------------get_layout_helper-----------------------------
3319 // If the given klass is a constant or known to be an array,
3320 // fetch the constant layout helper value into constant_value
3321 // and return (Node*)NULL. Otherwise, load the non-constant
3322 // layout helper value, and return the node which represents it.
3323 // This two-faced routine is useful because allocation sites
3324 // almost always feature constant types.
3325 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3326 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3327 if (!StressReflectiveCode && inst_klass != NULL) {
3328 ciKlass* klass = inst_klass->klass();
3329 bool xklass = inst_klass->klass_is_exact();
3330 if (xklass || klass->is_array_klass()) {
3331 jint lhelper = klass->layout_helper();
3332 if (lhelper != Klass::_lh_neutral_value) {
3333 constant_value = lhelper;
3334 return (Node*) NULL;
3335 }
3336 }
3337 }
3338 constant_value = Klass::_lh_neutral_value; // put in a known value
3339 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3340 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3341 }
3342
3343 // We just put in an allocate/initialize with a big raw-memory effect.
3344 // Hook selected additional alias categories on the initialization.
3345 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3346 MergeMemNode* init_in_merge,
3347 Node* init_out_raw) {
3348 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3349 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3350
3351 Node* prevmem = kit.memory(alias_idx);
3352 init_in_merge->set_memory_at(alias_idx, prevmem);
3353 kit.set_memory(init_out_raw, alias_idx);
3354 }
3355
3356 //---------------------------set_output_for_allocation-------------------------
3357 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3358 const TypeOopPtr* oop_type,
3359 bool deoptimize_on_exception) {
3360 int rawidx = Compile::AliasIdxRaw;
3361 alloc->set_req( TypeFunc::FramePtr, frameptr() );
3362 add_safepoint_edges(alloc);
3363 Node* allocx = _gvn.transform(alloc);
3364 set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3365 // create memory projection for i_o
3366 set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3367 make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3368
3369 // create a memory projection as for the normal control path
3370 Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3371 set_memory(malloc, rawidx);
3372
3373 // a normal slow-call doesn't change i_o, but an allocation does
3374 // we create a separate i_o projection for the normal control path
3375 set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3376 Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3377
3378 // put in an initialization barrier
3379 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3380 rawoop)->as_Initialize();
3381 assert(alloc->initialization() == init, "2-way macro link must work");
3382 assert(init ->allocation() == alloc, "2-way macro link must work");
3383 {
3384 // Extract memory strands which may participate in the new object's
3385 // initialization, and source them from the new InitializeNode.
3386 // This will allow us to observe initializations when they occur,
3387 // and link them properly (as a group) to the InitializeNode.
3388 assert(init->in(InitializeNode::Memory) == malloc, "");
3389 MergeMemNode* minit_in = MergeMemNode::make(malloc);
3390 init->set_req(InitializeNode::Memory, minit_in);
3391 record_for_igvn(minit_in); // fold it up later, if possible
3392 Node* minit_out = memory(rawidx);
3393 assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3394 if (oop_type->isa_aryptr()) {
3395 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3396 int elemidx = C->get_alias_index(telemref);
3397 hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3398 } else if (oop_type->isa_instptr() || oop_type->isa_valuetypeptr()) {
3399 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3400 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3401 ciField* field = ik->nonstatic_field_at(i);
3402 if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3403 continue; // do not bother to track really large numbers of fields
3404 // Find (or create) the alias category for this field:
3405 int fieldidx = C->alias_type(field)->index();
3406 hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3407 }
3408 }
3409 }
3410
3411 // Cast raw oop to the real thing...
3412 Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3413 javaoop = _gvn.transform(javaoop);
3414 C->set_recent_alloc(control(), javaoop);
3415 assert(just_allocated_object(control()) == javaoop, "just allocated");
3416
3417 #ifdef ASSERT
3418 { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3419 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3420 "Ideal_allocation works");
3421 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3422 "Ideal_allocation works");
3423 if (alloc->is_AllocateArray()) {
3424 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3425 "Ideal_allocation works");
3426 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3427 "Ideal_allocation works");
3428 } else {
3429 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3430 }
3431 }
3432 #endif //ASSERT
3433
3434 return javaoop;
3435 }
3436
3437 //---------------------------new_instance--------------------------------------
3438 // This routine takes a klass_node which may be constant (for a static type)
3439 // or may be non-constant (for reflective code). It will work equally well
3440 // for either, and the graph will fold nicely if the optimizer later reduces
3441 // the type to a constant.
3442 // The optional arguments are for specialized use by intrinsics:
3443 // - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3444 // - If 'return_size_val', report the the total object size to the caller.
3445 // - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3446 Node* GraphKit::new_instance(Node* klass_node,
3447 Node* extra_slow_test,
3448 Node* *return_size_val,
3449 bool deoptimize_on_exception) {
3450 // Compute size in doublewords
3451 // The size is always an integral number of doublewords, represented
3452 // as a positive bytewise size stored in the klass's layout_helper.
3453 // The layout_helper also encodes (in a low bit) the need for a slow path.
3454 jint layout_con = Klass::_lh_neutral_value;
3455 Node* layout_val = get_layout_helper(klass_node, layout_con);
3456 int layout_is_con = (layout_val == NULL);
3457
3458 if (extra_slow_test == NULL) extra_slow_test = intcon(0);
3459 // Generate the initial go-slow test. It's either ALWAYS (return a
3460 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3461 // case) a computed value derived from the layout_helper.
3462 Node* initial_slow_test = NULL;
3463 if (layout_is_con) {
3464 assert(!StressReflectiveCode, "stress mode does not use these paths");
3465 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3466 initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3467 } else { // reflective case
3468 // This reflective path is used by Unsafe.allocateInstance.
3469 // (It may be stress-tested by specifying StressReflectiveCode.)
3470 // Basically, we want to get into the VM is there's an illegal argument.
3471 Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3472 initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3473 if (extra_slow_test != intcon(0)) {
3474 initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3475 }
3476 // (Macro-expander will further convert this to a Bool, if necessary.)
3477 }
3478
3479 // Find the size in bytes. This is easy; it's the layout_helper.
3480 // The size value must be valid even if the slow path is taken.
3481 Node* size = NULL;
3482 if (layout_is_con) {
3483 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3484 } else { // reflective case
3485 // This reflective path is used by clone and Unsafe.allocateInstance.
3486 size = ConvI2X(layout_val);
3487
3488 // Clear the low bits to extract layout_helper_size_in_bytes:
3489 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3490 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3491 size = _gvn.transform( new AndXNode(size, mask) );
3492 }
3493 if (return_size_val != NULL) {
3494 (*return_size_val) = size;
3495 }
3496
3497 // This is a precise notnull oop of the klass.
3498 // (Actually, it need not be precise if this is a reflective allocation.)
3499 // It's what we cast the result to.
3500 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3501 if (!tklass) tklass = TypeKlassPtr::OBJECT;
3502 const TypeOopPtr* oop_type = tklass->as_instance_type();
3503
3504 // Now generate allocation code
3505
3506 // The entire memory state is needed for slow path of the allocation
3507 // since GC and deoptimization can happen.
3508 Node *mem = reset_memory();
3509 set_all_memory(mem); // Create new memory state
3510
3511 AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3512 control(), mem, i_o(),
3513 size, klass_node,
3514 initial_slow_test);
3515
3516 return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3517 }
3518
3519 //-------------------------------new_array-------------------------------------
3520 // helper for both newarray and anewarray
3521 // The 'length' parameter is (obviously) the length of the array.
3522 // See comments on new_instance for the meaning of the other arguments.
3523 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable)
3524 Node* length, // number of array elements
3525 int nargs, // number of arguments to push back for uncommon trap
3526 Node* *return_size_val,
3527 bool deoptimize_on_exception) {
3528 jint layout_con = Klass::_lh_neutral_value;
3529 Node* layout_val = get_layout_helper(klass_node, layout_con);
3530 int layout_is_con = (layout_val == NULL);
3531
3532 if (!layout_is_con && !StressReflectiveCode &&
3533 !too_many_traps(Deoptimization::Reason_class_check)) {
3534 // This is a reflective array creation site.
3535 // Optimistically assume that it is a subtype of Object[],
3536 // so that we can fold up all the address arithmetic.
3537 layout_con = Klass::array_layout_helper(T_OBJECT);
3538 Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3539 Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3540 { BuildCutout unless(this, bol_lh, PROB_MAX);
3541 inc_sp(nargs);
3542 uncommon_trap(Deoptimization::Reason_class_check,
3543 Deoptimization::Action_maybe_recompile);
3544 }
3545 layout_val = NULL;
3546 layout_is_con = true;
3547 }
3548
3549 // Generate the initial go-slow test. Make sure we do not overflow
3550 // if length is huge (near 2Gig) or negative! We do not need
3551 // exact double-words here, just a close approximation of needed
3552 // double-words. We can't add any offset or rounding bits, lest we
3553 // take a size -1 of bytes and make it positive. Use an unsigned
3554 // compare, so negative sizes look hugely positive.
3555 int fast_size_limit = FastAllocateSizeLimit;
3556 if (layout_is_con) {
3557 assert(!StressReflectiveCode, "stress mode does not use these paths");
3558 // Increase the size limit if we have exact knowledge of array type.
3559 int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3560 fast_size_limit <<= (LogBytesPerLong - log2_esize);
3561 }
3562
3563 Node* initial_slow_cmp = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3564 Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3565
3566 // --- Size Computation ---
3567 // array_size = round_to_heap(array_header + (length << elem_shift));
3568 // where round_to_heap(x) == round_to(x, MinObjAlignmentInBytes)
3569 // and round_to(x, y) == ((x + y-1) & ~(y-1))
3570 // The rounding mask is strength-reduced, if possible.
3571 int round_mask = MinObjAlignmentInBytes - 1;
3572 Node* header_size = NULL;
3573 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3574 // (T_BYTE has the weakest alignment and size restrictions...)
3575 if (layout_is_con) {
3576 int hsize = Klass::layout_helper_header_size(layout_con);
3577 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3578 BasicType etype = Klass::layout_helper_element_type(layout_con);
3579 if ((round_mask & ~right_n_bits(eshift)) == 0)
3580 round_mask = 0; // strength-reduce it if it goes away completely
3581 assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3582 assert(header_size_min <= hsize, "generic minimum is smallest");
3583 header_size_min = hsize;
3584 header_size = intcon(hsize + round_mask);
3585 } else {
3586 Node* hss = intcon(Klass::_lh_header_size_shift);
3587 Node* hsm = intcon(Klass::_lh_header_size_mask);
3588 Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3589 hsize = _gvn.transform( new AndINode(hsize, hsm) );
3590 Node* mask = intcon(round_mask);
3591 header_size = _gvn.transform( new AddINode(hsize, mask) );
3592 }
3593
3594 Node* elem_shift = NULL;
3595 if (layout_is_con) {
3596 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3597 if (eshift != 0)
3598 elem_shift = intcon(eshift);
3599 } else {
3600 // There is no need to mask or shift this value.
3601 // The semantics of LShiftINode include an implicit mask to 0x1F.
3602 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3603 elem_shift = layout_val;
3604 }
3605
3606 // Transition to native address size for all offset calculations:
3607 Node* lengthx = ConvI2X(length);
3608 Node* headerx = ConvI2X(header_size);
3609 #ifdef _LP64
3610 { const TypeInt* tilen = _gvn.find_int_type(length);
3611 if (tilen != NULL && tilen->_lo < 0) {
3612 // Add a manual constraint to a positive range. Cf. array_element_address.
3613 jint size_max = fast_size_limit;
3614 if (size_max > tilen->_hi) size_max = tilen->_hi;
3615 const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3616
3617 // Only do a narrow I2L conversion if the range check passed.
3618 IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3619 _gvn.transform(iff);
3620 RegionNode* region = new RegionNode(3);
3621 _gvn.set_type(region, Type::CONTROL);
3622 lengthx = new PhiNode(region, TypeLong::LONG);
3623 _gvn.set_type(lengthx, TypeLong::LONG);
3624
3625 // Range check passed. Use ConvI2L node with narrow type.
3626 Node* passed = IfFalse(iff);
3627 region->init_req(1, passed);
3628 // Make I2L conversion control dependent to prevent it from
3629 // floating above the range check during loop optimizations.
3630 lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3631
3632 // Range check failed. Use ConvI2L with wide type because length may be invalid.
3633 region->init_req(2, IfTrue(iff));
3634 lengthx->init_req(2, ConvI2X(length));
3635
3636 set_control(region);
3637 record_for_igvn(region);
3638 record_for_igvn(lengthx);
3639 }
3640 }
3641 #endif
3642
3643 // Combine header size (plus rounding) and body size. Then round down.
3644 // This computation cannot overflow, because it is used only in two
3645 // places, one where the length is sharply limited, and the other
3646 // after a successful allocation.
3647 Node* abody = lengthx;
3648 if (elem_shift != NULL)
3649 abody = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3650 Node* size = _gvn.transform( new AddXNode(headerx, abody) );
3651 if (round_mask != 0) {
3652 Node* mask = MakeConX(~round_mask);
3653 size = _gvn.transform( new AndXNode(size, mask) );
3654 }
3655 // else if round_mask == 0, the size computation is self-rounding
3656
3657 if (return_size_val != NULL) {
3658 // This is the size
3659 (*return_size_val) = size;
3660 }
3661
3662 // Now generate allocation code
3663
3664 // The entire memory state is needed for slow path of the allocation
3665 // since GC and deoptimization can happened.
3666 Node *mem = reset_memory();
3667 set_all_memory(mem); // Create new memory state
3668
3669 if (initial_slow_test->is_Bool()) {
3670 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3671 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3672 }
3673
3674 // Create the AllocateArrayNode and its result projections
3675 AllocateArrayNode* alloc
3676 = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3677 control(), mem, i_o(),
3678 size, klass_node,
3679 initial_slow_test,
3680 length);
3681
3682 // Cast to correct type. Note that the klass_node may be constant or not,
3683 // and in the latter case the actual array type will be inexact also.
3684 // (This happens via a non-constant argument to inline_native_newArray.)
3685 // In any case, the value of klass_node provides the desired array type.
3686 const TypeInt* length_type = _gvn.find_int_type(length);
3687 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3688 if (ary_type->isa_aryptr() && length_type != NULL) {
3689 // Try to get a better type than POS for the size
3690 ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3691 }
3692
3693 Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3694
3695 // Cast length on remaining path to be as narrow as possible
3696 if (map()->find_edge(length) >= 0) {
3697 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3698 if (ccast != length) {
3699 _gvn.set_type_bottom(ccast);
3700 record_for_igvn(ccast);
3701 replace_in_map(length, ccast);
3702 }
3703 }
3704
3705 return javaoop;
3706 }
3707
3708 // The following "Ideal_foo" functions are placed here because they recognize
3709 // the graph shapes created by the functions immediately above.
3710
3711 //---------------------------Ideal_allocation----------------------------------
3712 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3713 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3714 if (ptr == NULL) { // reduce dumb test in callers
3715 return NULL;
3716 }
3717 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3718 ptr = ptr->in(1);
3719 if (ptr == NULL) return NULL;
3720 }
3721 // Return NULL for allocations with several casts:
3722 // j.l.reflect.Array.newInstance(jobject, jint)
3723 // Object.clone()
3724 // to keep more precise type from last cast.
3725 if (ptr->is_Proj()) {
3726 Node* allo = ptr->in(0);
3727 if (allo != NULL && allo->is_Allocate()) {
3728 return allo->as_Allocate();
3729 }
3730 }
3731 // Report failure to match.
3732 return NULL;
3733 }
3734
3735 // Fancy version which also strips off an offset (and reports it to caller).
3736 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3737 intptr_t& offset) {
3738 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3739 if (base == NULL) return NULL;
3740 return Ideal_allocation(base, phase);
3741 }
3742
3743 // Trace Initialize <- Proj[Parm] <- Allocate
3744 AllocateNode* InitializeNode::allocation() {
3745 Node* rawoop = in(InitializeNode::RawAddress);
3746 if (rawoop->is_Proj()) {
3747 Node* alloc = rawoop->in(0);
3748 if (alloc->is_Allocate()) {
3749 return alloc->as_Allocate();
3750 }
3751 }
3752 return NULL;
3753 }
3754
3755 // Trace Allocate -> Proj[Parm] -> Initialize
3756 InitializeNode* AllocateNode::initialization() {
3757 ProjNode* rawoop = proj_out(AllocateNode::RawAddress);
3758 if (rawoop == NULL) return NULL;
3759 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3760 Node* init = rawoop->fast_out(i);
3761 if (init->is_Initialize()) {
3762 assert(init->as_Initialize()->allocation() == this, "2-way link");
3763 return init->as_Initialize();
3764 }
3765 }
3766 return NULL;
3767 }
3768
3769 //----------------------------- loop predicates ---------------------------
3770
3771 //------------------------------add_predicate_impl----------------------------
3772 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3773 // Too many traps seen?
3774 if (too_many_traps(reason)) {
3775 #ifdef ASSERT
3776 if (TraceLoopPredicate) {
3777 int tc = C->trap_count(reason);
3778 tty->print("too many traps=%s tcount=%d in ",
3779 Deoptimization::trap_reason_name(reason), tc);
3780 method()->print(); // which method has too many predicate traps
3781 tty->cr();
3782 }
3783 #endif
3784 // We cannot afford to take more traps here,
3785 // do not generate predicate.
3786 return;
3787 }
3788
3789 Node *cont = _gvn.intcon(1);
3790 Node* opq = _gvn.transform(new Opaque1Node(C, cont));
3791 Node *bol = _gvn.transform(new Conv2BNode(opq));
3792 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3793 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3794 C->add_predicate_opaq(opq);
3795 {
3796 PreserveJVMState pjvms(this);
3797 set_control(iffalse);
3798 inc_sp(nargs);
3799 uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3800 }
3801 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3802 set_control(iftrue);
3803 }
3804
3805 //------------------------------add_predicate---------------------------------
3806 void GraphKit::add_predicate(int nargs) {
3807 if (UseLoopPredicate) {
3808 add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3809 }
3810 // loop's limit check predicate should be near the loop.
3811 if (LoopLimitCheck) {
3812 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3813 }
3814 }
3815
3816 //----------------------------- store barriers ----------------------------
3817 #define __ ideal.
3818
3819 void GraphKit::sync_kit(IdealKit& ideal) {
3820 set_all_memory(__ merged_memory());
3821 set_i_o(__ i_o());
3822 set_control(__ ctrl());
3823 }
3824
3825 void GraphKit::final_sync(IdealKit& ideal) {
3826 // Final sync IdealKit and graphKit.
3827 sync_kit(ideal);
3828 }
3829
3830 Node* GraphKit::byte_map_base_node() {
3831 // Get base of card map
3832 CardTableModRefBS* ct =
3833 barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3834 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3835 if (ct->byte_map_base != NULL) {
3836 return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3837 } else {
3838 return null();
3839 }
3840 }
3841
3842 // vanilla/CMS post barrier
3843 // Insert a write-barrier store. This is to let generational GC work; we have
3844 // to flag all oop-stores before the next GC point.
3845 void GraphKit::write_barrier_post(Node* oop_store,
3846 Node* obj,
3847 Node* adr,
3848 uint adr_idx,
3849 Node* val,
3850 bool use_precise) {
3851 // No store check needed if we're storing a NULL or an old object
3852 // (latter case is probably a string constant). The concurrent
3853 // mark sweep garbage collector, however, needs to have all nonNull
3854 // oop updates flagged via card-marks.
3855 if (val != NULL && val->is_Con()) {
3856 // must be either an oop or NULL
3857 const Type* t = val->bottom_type();
3858 if (t == TypePtr::NULL_PTR || t == Type::TOP)
3859 // stores of null never (?) need barriers
3860 return;
3861 }
3862
3863 if (use_ReduceInitialCardMarks()
3864 && obj == just_allocated_object(control())) {
3865 // We can skip marks on a freshly-allocated object in Eden.
3866 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3867 // That routine informs GC to take appropriate compensating steps,
3868 // upon a slow-path allocation, so as to make this card-mark
3869 // elision safe.
3870 return;
3871 }
3872
3873 if (!use_precise) {
3874 // All card marks for a (non-array) instance are in one place:
3875 adr = obj;
3876 }
3877 // (Else it's an array (or unknown), and we want more precise card marks.)
3878 assert(adr != NULL, "");
3879
3880 IdealKit ideal(this, true);
3881
3882 // Convert the pointer to an int prior to doing math on it
3883 Node* cast = __ CastPX(__ ctrl(), adr);
3884
3885 // Divide by card size
3886 assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3887 "Only one we handle so far.");
3888 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3889
3890 // Combine card table base and card offset
3891 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3892
3893 // Get the alias_index for raw card-mark memory
3894 int adr_type = Compile::AliasIdxRaw;
3895 Node* zero = __ ConI(0); // Dirty card value
3896 BasicType bt = T_BYTE;
3897
3898 if (UseConcMarkSweepGC && UseCondCardMark) {
3899 insert_store_load_for_barrier();
3900 __ sync_kit(this);
3901 }
3902
3903 if (UseCondCardMark) {
3904 // The classic GC reference write barrier is typically implemented
3905 // as a store into the global card mark table. Unfortunately
3906 // unconditional stores can result in false sharing and excessive
3907 // coherence traffic as well as false transactional aborts.
3908 // UseCondCardMark enables MP "polite" conditional card mark
3909 // stores. In theory we could relax the load from ctrl() to
3910 // no_ctrl, but that doesn't buy much latitude.
3911 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3912 __ if_then(card_val, BoolTest::ne, zero);
3913 }
3914
3915 // Smash zero into card
3916 if( !UseConcMarkSweepGC ) {
3917 __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3918 } else {
3919 // Specialized path for CM store barrier
3920 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3921 }
3922
3923 if (UseCondCardMark) {
3924 __ end_if();
3925 }
3926
3927 // Final sync IdealKit and GraphKit.
3928 final_sync(ideal);
3929 }
3930 /*
3931 * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3932 * required by SATB to make sure all objects live at the start of the
3933 * marking are kept alive, all reference updates need to any previous
3934 * reference stored before writing.
3935 *
3936 * If the previous value is NULL there is no need to save the old value.
3937 * References that are NULL are filtered during runtime by the barrier
3938 * code to avoid unnecessary queuing.
3939 *
3940 * However in the case of newly allocated objects it might be possible to
3941 * prove that the reference about to be overwritten is NULL during compile
3942 * time and avoid adding the barrier code completely.
3943 *
3944 * The compiler needs to determine that the object in which a field is about
3945 * to be written is newly allocated, and that no prior store to the same field
3946 * has happened since the allocation.
3947 *
3948 * Returns true if the pre-barrier can be removed
3949 */
3950 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3951 BasicType bt, uint adr_idx) {
3952 intptr_t offset = 0;
3953 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3954 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3955
3956 if (offset == Type::OffsetBot) {
3957 return false; // cannot unalias unless there are precise offsets
3958 }
3959
3960 if (alloc == NULL) {
3961 return false; // No allocation found
3962 }
3963
3964 intptr_t size_in_bytes = type2aelembytes(bt);
3965
3966 Node* mem = memory(adr_idx); // start searching here...
3967
3968 for (int cnt = 0; cnt < 50; cnt++) {
3969
3970 if (mem->is_Store()) {
3971
3972 Node* st_adr = mem->in(MemNode::Address);
3973 intptr_t st_offset = 0;
3974 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3975
3976 if (st_base == NULL) {
3977 break; // inscrutable pointer
3978 }
3979
3980 // Break we have found a store with same base and offset as ours so break
3981 if (st_base == base && st_offset == offset) {
3982 break;
3983 }
3984
3985 if (st_offset != offset && st_offset != Type::OffsetBot) {
3986 const int MAX_STORE = BytesPerLong;
3987 if (st_offset >= offset + size_in_bytes ||
3988 st_offset <= offset - MAX_STORE ||
3989 st_offset <= offset - mem->as_Store()->memory_size()) {
3990 // Success: The offsets are provably independent.
3991 // (You may ask, why not just test st_offset != offset and be done?
3992 // The answer is that stores of different sizes can co-exist
3993 // in the same sequence of RawMem effects. We sometimes initialize
3994 // a whole 'tile' of array elements with a single jint or jlong.)
3995 mem = mem->in(MemNode::Memory);
3996 continue; // advance through independent store memory
3997 }
3998 }
3999
4000 if (st_base != base
4001 && MemNode::detect_ptr_independence(base, alloc, st_base,
4002 AllocateNode::Ideal_allocation(st_base, phase),
4003 phase)) {
4004 // Success: The bases are provably independent.
4005 mem = mem->in(MemNode::Memory);
4006 continue; // advance through independent store memory
4007 }
4008 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4009
4010 InitializeNode* st_init = mem->in(0)->as_Initialize();
4011 AllocateNode* st_alloc = st_init->allocation();
4012
4013 // Make sure that we are looking at the same allocation site.
4014 // The alloc variable is guaranteed to not be null here from earlier check.
4015 if (alloc == st_alloc) {
4016 // Check that the initialization is storing NULL so that no previous store
4017 // has been moved up and directly write a reference
4018 Node* captured_store = st_init->find_captured_store(offset,
4019 type2aelembytes(T_OBJECT),
4020 phase);
4021 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4022 return true;
4023 }
4024 }
4025 }
4026
4027 // Unless there is an explicit 'continue', we must bail out here,
4028 // because 'mem' is an inscrutable memory state (e.g., a call).
4029 break;
4030 }
4031
4032 return false;
4033 }
4034
4035 // G1 pre/post barriers
4036 void GraphKit::g1_write_barrier_pre(bool do_load,
4037 Node* obj,
4038 Node* adr,
4039 uint alias_idx,
4040 Node* val,
4041 const TypeOopPtr* val_type,
4042 Node* pre_val,
4043 BasicType bt) {
4044
4045 // Some sanity checks
4046 // Note: val is unused in this routine.
4047
4048 if (do_load) {
4049 // We need to generate the load of the previous value
4050 assert(obj != NULL, "must have a base");
4051 assert(adr != NULL, "where are loading from?");
4052 assert(pre_val == NULL, "loaded already?");
4053 assert(val_type != NULL, "need a type");
4054
4055 if (use_ReduceInitialCardMarks()
4056 && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4057 return;
4058 }
4059
4060 } else {
4061 // In this case both val_type and alias_idx are unused.
4062 assert(pre_val != NULL, "must be loaded already");
4063 // Nothing to be done if pre_val is null.
4064 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4065 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4066 }
4067 assert(bt == T_OBJECT || bt == T_VALUETYPE, "or we shouldn't be here");
4068
4069 IdealKit ideal(this, true);
4070
4071 Node* tls = __ thread(); // ThreadLocalStorage
4072
4073 Node* no_ctrl = NULL;
4074 Node* no_base = __ top();
4075 Node* zero = __ ConI(0);
4076 Node* zeroX = __ ConX(0);
4077
4078 float likely = PROB_LIKELY(0.999);
4079 float unlikely = PROB_UNLIKELY(0.999);
4080
4081 BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4082 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4083
4084 // Offsets into the thread
4085 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648
4086 SATBMarkQueue::byte_offset_of_active());
4087 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656
4088 SATBMarkQueue::byte_offset_of_index());
4089 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652
4090 SATBMarkQueue::byte_offset_of_buf());
4091
4092 // Now the actual pointers into the thread
4093 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4094 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4095 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4096
4097 // Now some of the values
4098 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4099
4100 // if (!marking)
4101 __ if_then(marking, BoolTest::ne, zero, unlikely); {
4102 BasicType index_bt = TypeX_X->basic_type();
4103 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4104 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4105
4106 if (do_load) {
4107 // load original value
4108 // alias_idx correct??
4109 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4110 }
4111
4112 // if (pre_val != NULL)
4113 __ if_then(pre_val, BoolTest::ne, null()); {
4114 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4115
4116 // is the queue for this thread full?
4117 __ if_then(index, BoolTest::ne, zeroX, likely); {
4118
4119 // decrement the index
4120 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4121
4122 // Now get the buffer location we will log the previous value into and store it
4123 Node *log_addr = __ AddP(no_base, buffer, next_index);
4124 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4125 // update the index
4126 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4127
4128 } __ else_(); {
4129
4130 // logging buffer is full, call the runtime
4131 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4132 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4133 } __ end_if(); // (!index)
4134 } __ end_if(); // (pre_val != NULL)
4135 } __ end_if(); // (!marking)
4136
4137 // Final sync IdealKit and GraphKit.
4138 final_sync(ideal);
4139 }
4140
4141 /*
4142 * G1 similar to any GC with a Young Generation requires a way to keep track of
4143 * references from Old Generation to Young Generation to make sure all live
4144 * objects are found. G1 also requires to keep track of object references
4145 * between different regions to enable evacuation of old regions, which is done
4146 * as part of mixed collections. References are tracked in remembered sets and
4147 * is continuously updated as reference are written to with the help of the
4148 * post-barrier.
4149 *
4150 * To reduce the number of updates to the remembered set the post-barrier
4151 * filters updates to fields in objects located in the Young Generation,
4152 * the same region as the reference, when the NULL is being written or
4153 * if the card is already marked as dirty by an earlier write.
4154 *
4155 * Under certain circumstances it is possible to avoid generating the
4156 * post-barrier completely if it is possible during compile time to prove
4157 * the object is newly allocated and that no safepoint exists between the
4158 * allocation and the store.
4159 *
4160 * In the case of slow allocation the allocation code must handle the barrier
4161 * as part of the allocation in the case the allocated object is not located
4162 * in the nursery, this would happen for humongous objects. This is similar to
4163 * how CMS is required to handle this case, see the comments for the method
4164 * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4165 * A deferred card mark is required for these objects and handled in the above
4166 * mentioned methods.
4167 *
4168 * Returns true if the post barrier can be removed
4169 */
4170 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4171 Node* adr) {
4172 intptr_t offset = 0;
4173 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4174 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4175
4176 if (offset == Type::OffsetBot) {
4177 return false; // cannot unalias unless there are precise offsets
4178 }
4179
4180 if (alloc == NULL) {
4181 return false; // No allocation found
4182 }
4183
4184 // Start search from Store node
4185 Node* mem = store->in(MemNode::Control);
4186 if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4187
4188 InitializeNode* st_init = mem->in(0)->as_Initialize();
4189 AllocateNode* st_alloc = st_init->allocation();
4190
4191 // Make sure we are looking at the same allocation
4192 if (alloc == st_alloc) {
4193 return true;
4194 }
4195 }
4196
4197 return false;
4198 }
4199
4200 //
4201 // Update the card table and add card address to the queue
4202 //
4203 void GraphKit::g1_mark_card(IdealKit& ideal,
4204 Node* card_adr,
4205 Node* oop_store,
4206 uint oop_alias_idx,
4207 Node* index,
4208 Node* index_adr,
4209 Node* buffer,
4210 const TypeFunc* tf) {
4211
4212 Node* zero = __ ConI(0);
4213 Node* zeroX = __ ConX(0);
4214 Node* no_base = __ top();
4215 BasicType card_bt = T_BYTE;
4216 // Smash zero into card. MUST BE ORDERED WRT TO STORE
4217 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4218
4219 // Now do the queue work
4220 __ if_then(index, BoolTest::ne, zeroX); {
4221
4222 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4223 Node* log_addr = __ AddP(no_base, buffer, next_index);
4224
4225 // Order, see storeCM.
4226 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4227 __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4228
4229 } __ else_(); {
4230 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4231 } __ end_if();
4232
4233 }
4234
4235 void GraphKit::g1_write_barrier_post(Node* oop_store,
4236 Node* obj,
4237 Node* adr,
4238 uint alias_idx,
4239 Node* val,
4240 BasicType bt,
4241 bool use_precise) {
4242 // If we are writing a NULL then we need no post barrier
4243
4244 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4245 // Must be NULL
4246 const Type* t = val->bottom_type();
4247 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4248 // No post barrier if writing NULLx
4249 return;
4250 }
4251
4252 if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4253 // We can skip marks on a freshly-allocated object in Eden.
4254 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4255 // That routine informs GC to take appropriate compensating steps,
4256 // upon a slow-path allocation, so as to make this card-mark
4257 // elision safe.
4258 return;
4259 }
4260
4261 if (use_ReduceInitialCardMarks()
4262 && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4263 return;
4264 }
4265
4266 if (!use_precise) {
4267 // All card marks for a (non-array) instance are in one place:
4268 adr = obj;
4269 }
4270 // (Else it's an array (or unknown), and we want more precise card marks.)
4271 assert(adr != NULL, "");
4272
4273 IdealKit ideal(this, true);
4274
4275 Node* tls = __ thread(); // ThreadLocalStorage
4276
4277 Node* no_base = __ top();
4278 float likely = PROB_LIKELY(0.999);
4279 float unlikely = PROB_UNLIKELY(0.999);
4280 Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4281 Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4282 Node* zeroX = __ ConX(0);
4283
4284 // Get the alias_index for raw card-mark memory
4285 const TypePtr* card_type = TypeRawPtr::BOTTOM;
4286
4287 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4288
4289 // Offsets into the thread
4290 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4291 DirtyCardQueue::byte_offset_of_index());
4292 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4293 DirtyCardQueue::byte_offset_of_buf());
4294
4295 // Pointers into the thread
4296
4297 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4298 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4299
4300 // Now some values
4301 // Use ctrl to avoid hoisting these values past a safepoint, which could
4302 // potentially reset these fields in the JavaThread.
4303 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4304 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4305
4306 // Convert the store obj pointer to an int prior to doing math on it
4307 // Must use ctrl to prevent "integerized oop" existing across safepoint
4308 Node* cast = __ CastPX(__ ctrl(), adr);
4309
4310 // Divide pointer by card size
4311 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4312
4313 // Combine card table base and card offset
4314 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4315
4316 // If we know the value being stored does it cross regions?
4317
4318 if (val != NULL) {
4319 // Does the store cause us to cross regions?
4320
4321 // Should be able to do an unsigned compare of region_size instead of
4322 // and extra shift. Do we have an unsigned compare??
4323 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4324 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4325
4326 // if (xor_res == 0) same region so skip
4327 __ if_then(xor_res, BoolTest::ne, zeroX); {
4328
4329 // No barrier if we are storing a NULL
4330 __ if_then(val, BoolTest::ne, null(), unlikely); {
4331
4332 // Ok must mark the card if not already dirty
4333
4334 // load the original value of the card
4335 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4336
4337 __ if_then(card_val, BoolTest::ne, young_card); {
4338 sync_kit(ideal);
4339 insert_store_load_for_barrier();
4340 __ sync_kit(this);
4341
4342 Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4343 __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4344 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4345 } __ end_if();
4346 } __ end_if();
4347 } __ end_if();
4348 } __ end_if();
4349 } else {
4350 // Object.clone() instrinsic uses this path.
4351 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4352 }
4353
4354 // Final sync IdealKit and GraphKit.
4355 final_sync(ideal);
4356 }
4357 #undef __
4358
4359
4360 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4361 Node* len = load_array_length(load_String_value(ctrl, str));
4362 Node* coder = load_String_coder(ctrl, str);
4363 // Divide length by 2 if coder is UTF16
4364 return _gvn.transform(new RShiftINode(len, coder));
4365 }
4366
4367 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4368 int value_offset = java_lang_String::value_offset_in_bytes();
4369 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4370 false, NULL, 0);
4371 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4372 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4373 TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4374 ciTypeArrayKlass::make(T_BYTE), true, 0);
4375 int value_field_idx = C->get_alias_index(value_field_type);
4376 Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4377 value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4378 // String.value field is known to be @Stable.
4379 if (UseImplicitStableValues) {
4380 load = cast_array_to_stable(load, value_type);
4381 }
4382 return load;
4383 }
4384
4385 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4386 if (java_lang_String::has_coder_field()) {
4387 if (!CompactStrings) {
4388 return intcon(java_lang_String::CODER_UTF16);
4389 }
4390 int coder_offset = java_lang_String::coder_offset_in_bytes();
4391 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4392 false, NULL, 0);
4393 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4394 int coder_field_idx = C->get_alias_index(coder_field_type);
4395 return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4396 TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4397 } else {
4398 return intcon(0); // false
4399 }
4400 }
4401
4402 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4403 int value_offset = java_lang_String::value_offset_in_bytes();
4404 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4405 false, NULL, 0);
4406 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4407 store_oop_to_object(ctrl, str, basic_plus_adr(str, value_offset), value_field_type,
4408 value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4409 }
4410
4411 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4412 int coder_offset = java_lang_String::coder_offset_in_bytes();
4413 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4414 false, NULL, 0);
4415 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4416 int coder_field_idx = C->get_alias_index(coder_field_type);
4417 store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4418 value, T_BYTE, coder_field_idx, MemNode::unordered);
4419 }
4420
4421 // Capture src and dst memory state with a MergeMemNode
4422 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4423 if (src_type == dst_type) {
4424 // Types are equal, we don't need a MergeMemNode
4425 return memory(src_type);
4426 }
4427 MergeMemNode* merge = MergeMemNode::make(map()->memory());
4428 record_for_igvn(merge); // fold it up later, if possible
4429 int src_idx = C->get_alias_index(src_type);
4430 int dst_idx = C->get_alias_index(dst_type);
4431 merge->set_memory_at(src_idx, memory(src_idx));
4432 merge->set_memory_at(dst_idx, memory(dst_idx));
4433 return merge;
4434 }
4435
4436 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4437 assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4438 assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4439 // If input and output memory types differ, capture both states to preserve
4440 // the dependency between preceding and subsequent loads/stores.
4441 // For example, the following program:
4442 // StoreB
4443 // compress_string
4444 // LoadB
4445 // has this memory graph (use->def):
4446 // LoadB -> compress_string -> CharMem
4447 // ... -> StoreB -> ByteMem
4448 // The intrinsic hides the dependency between LoadB and StoreB, causing
4449 // the load to read from memory not containing the result of the StoreB.
4450 // The correct memory graph should look like this:
4451 // LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4452 Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4453 StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4454 Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4455 set_memory(res_mem, TypeAryPtr::BYTES);
4456 return str;
4457 }
4458
4459 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4460 assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4461 assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4462 // Capture src and dst memory (see comment in 'compress_string').
4463 Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4464 StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4465 set_memory(_gvn.transform(str), dst_type);
4466 }
4467
4468 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4469 /**
4470 * int i_char = start;
4471 * for (int i_byte = 0; i_byte < count; i_byte++) {
4472 * dst[i_char++] = (char)(src[i_byte] & 0xff);
4473 * }
4474 */
4475 add_predicate();
4476 RegionNode* head = new RegionNode(3);
4477 head->init_req(1, control());
4478 gvn().set_type(head, Type::CONTROL);
4479 record_for_igvn(head);
4480
4481 Node* i_byte = new PhiNode(head, TypeInt::INT);
4482 i_byte->init_req(1, intcon(0));
4483 gvn().set_type(i_byte, TypeInt::INT);
4484 record_for_igvn(i_byte);
4485
4486 Node* i_char = new PhiNode(head, TypeInt::INT);
4487 i_char->init_req(1, start);
4488 gvn().set_type(i_char, TypeInt::INT);
4489 record_for_igvn(i_char);
4490
4491 Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4492 gvn().set_type(mem, Type::MEMORY);
4493 record_for_igvn(mem);
4494 set_control(head);
4495 set_memory(mem, TypeAryPtr::BYTES);
4496 Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4497 Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4498 AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4499 false, false, true /* mismatched */);
4500
4501 IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4502 head->init_req(2, IfTrue(iff));
4503 mem->init_req(2, st);
4504 i_byte->init_req(2, AddI(i_byte, intcon(1)));
4505 i_char->init_req(2, AddI(i_char, intcon(2)));
4506
4507 set_control(IfFalse(iff));
4508 set_memory(st, TypeAryPtr::BYTES);
4509 }
4510
4511 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4512 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4513 // assumption of CCP analysis.
4514 return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4515 }