1 /*
2 * Copyright (c) 2001, 2018, 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 "ci/ciUtilities.hpp"
27 #include "compiler/compileLog.hpp"
28 #include "gc/g1/heapRegion.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/c2/barrierSetC2.hpp"
31 #include "interpreter/interpreter.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "opto/addnode.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/convertnode.hpp"
36 #include "opto/graphKit.hpp"
37 #include "opto/idealKit.hpp"
38 #include "opto/intrinsicnode.hpp"
39 #include "opto/locknode.hpp"
40 #include "opto/machnode.hpp"
41 #include "opto/opaquenode.hpp"
42 #include "opto/parse.hpp"
43 #include "opto/rootnode.hpp"
44 #include "opto/runtime.hpp"
45 #include "runtime/deoptimization.hpp"
46 #include "runtime/sharedRuntime.hpp"
47
48 //----------------------------GraphKit-----------------------------------------
49 // Main utility constructor.
50 GraphKit::GraphKit(JVMState* jvms)
51 : Phase(Phase::Parser),
52 _env(C->env()),
53 _gvn(*C->initial_gvn()),
54 _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
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 _barrier_set(BarrierSet::barrier_set()->barrier_set_c2())
67 {
68 _exceptions = NULL;
69 set_map(NULL);
70 debug_only(_sp = -99);
71 debug_only(set_bci(-99));
72 }
73
74
75
76 //---------------------------clean_stack---------------------------------------
77 // Clear away rubbish from the stack area of the JVM state.
78 // This destroys any arguments that may be waiting on the stack.
79 void GraphKit::clean_stack(int from_sp) {
80 SafePointNode* map = this->map();
81 JVMState* jvms = this->jvms();
82 int stk_size = jvms->stk_size();
83 int stkoff = jvms->stkoff();
84 Node* top = this->top();
85 for (int i = from_sp; i < stk_size; i++) {
86 if (map->in(stkoff + i) != top) {
87 map->set_req(stkoff + i, top);
88 }
89 }
90 }
91
92
93 //--------------------------------sync_jvms-----------------------------------
94 // Make sure our current jvms agrees with our parse state.
95 JVMState* GraphKit::sync_jvms() const {
96 JVMState* jvms = this->jvms();
97 jvms->set_bci(bci()); // Record the new bci in the JVMState
98 jvms->set_sp(sp()); // Record the new sp in the JVMState
99 assert(jvms_in_sync(), "jvms is now in sync");
100 return jvms;
101 }
102
103 //--------------------------------sync_jvms_for_reexecute---------------------
104 // Make sure our current jvms agrees with our parse state. This version
105 // uses the reexecute_sp for reexecuting bytecodes.
106 JVMState* GraphKit::sync_jvms_for_reexecute() {
107 JVMState* jvms = this->jvms();
108 jvms->set_bci(bci()); // Record the new bci in the JVMState
109 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState
110 return jvms;
111 }
112
113 #ifdef ASSERT
114 bool GraphKit::jvms_in_sync() const {
115 Parse* parse = is_Parse();
116 if (parse == NULL) {
117 if (bci() != jvms()->bci()) return false;
118 if (sp() != (int)jvms()->sp()) return false;
119 return true;
120 }
121 if (jvms()->method() != parse->method()) return false;
122 if (jvms()->bci() != parse->bci()) return false;
123 int jvms_sp = jvms()->sp();
124 if (jvms_sp != parse->sp()) return false;
125 int jvms_depth = jvms()->depth();
126 if (jvms_depth != parse->depth()) return false;
127 return true;
128 }
129
130 // Local helper checks for special internal merge points
131 // used to accumulate and merge exception states.
132 // They are marked by the region's in(0) edge being the map itself.
133 // Such merge points must never "escape" into the parser at large,
134 // until they have been handed to gvn.transform.
135 static bool is_hidden_merge(Node* reg) {
136 if (reg == NULL) return false;
137 if (reg->is_Phi()) {
138 reg = reg->in(0);
139 if (reg == NULL) return false;
140 }
141 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
142 }
143
144 void GraphKit::verify_map() const {
145 if (map() == NULL) return; // null map is OK
146 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
147 assert(!map()->has_exceptions(), "call add_exception_states_from 1st");
148 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
149 }
150
151 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
152 assert(ex_map->next_exception() == NULL, "not already part of a chain");
153 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
154 }
155 #endif
156
157 //---------------------------stop_and_kill_map---------------------------------
158 // Set _map to NULL, signalling a stop to further bytecode execution.
159 // First smash the current map's control to a constant, to mark it dead.
160 void GraphKit::stop_and_kill_map() {
161 SafePointNode* dead_map = stop();
162 if (dead_map != NULL) {
163 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
164 assert(dead_map->is_killed(), "must be so marked");
165 }
166 }
167
168
169 //--------------------------------stopped--------------------------------------
170 // Tell if _map is NULL, or control is top.
171 bool GraphKit::stopped() {
172 if (map() == NULL) return true;
173 else if (control() == top()) return true;
174 else return false;
175 }
176
177
178 //-----------------------------has_ex_handler----------------------------------
179 // Tell if this method or any caller method has exception handlers.
180 bool GraphKit::has_ex_handler() {
181 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
182 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
183 return true;
184 }
185 }
186 return false;
187 }
188
189 //------------------------------save_ex_oop------------------------------------
190 // Save an exception without blowing stack contents or other JVM state.
191 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
192 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
193 ex_map->add_req(ex_oop);
194 debug_only(verify_exception_state(ex_map));
195 }
196
197 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
198 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
199 Node* ex_oop = ex_map->in(ex_map->req()-1);
200 if (clear_it) ex_map->del_req(ex_map->req()-1);
201 return ex_oop;
202 }
203
204 //-----------------------------saved_ex_oop------------------------------------
205 // Recover a saved exception from its map.
206 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
207 return common_saved_ex_oop(ex_map, false);
208 }
209
210 //--------------------------clear_saved_ex_oop---------------------------------
211 // Erase a previously saved exception from its map.
212 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
213 return common_saved_ex_oop(ex_map, true);
214 }
215
216 #ifdef ASSERT
217 //---------------------------has_saved_ex_oop----------------------------------
218 // Erase a previously saved exception from its map.
219 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
220 return ex_map->req() == ex_map->jvms()->endoff()+1;
221 }
222 #endif
223
224 //-------------------------make_exception_state--------------------------------
225 // Turn the current JVM state into an exception state, appending the ex_oop.
226 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
227 sync_jvms();
228 SafePointNode* ex_map = stop(); // do not manipulate this map any more
229 set_saved_ex_oop(ex_map, ex_oop);
230 return ex_map;
231 }
232
233
234 //--------------------------add_exception_state--------------------------------
235 // Add an exception to my list of exceptions.
236 void GraphKit::add_exception_state(SafePointNode* ex_map) {
237 if (ex_map == NULL || ex_map->control() == top()) {
238 return;
239 }
240 #ifdef ASSERT
241 verify_exception_state(ex_map);
242 if (has_exceptions()) {
243 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
244 }
245 #endif
246
247 // If there is already an exception of exactly this type, merge with it.
248 // In particular, null-checks and other low-level exceptions common up here.
249 Node* ex_oop = saved_ex_oop(ex_map);
250 const Type* ex_type = _gvn.type(ex_oop);
251 if (ex_oop == top()) {
252 // No action needed.
253 return;
254 }
255 assert(ex_type->isa_instptr(), "exception must be an instance");
256 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
257 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
258 // We check sp also because call bytecodes can generate exceptions
259 // both before and after arguments are popped!
260 if (ex_type2 == ex_type
261 && e2->_jvms->sp() == ex_map->_jvms->sp()) {
262 combine_exception_states(ex_map, e2);
263 return;
264 }
265 }
266
267 // No pre-existing exception of the same type. Chain it on the list.
268 push_exception_state(ex_map);
269 }
270
271 //-----------------------add_exception_states_from-----------------------------
272 void GraphKit::add_exception_states_from(JVMState* jvms) {
273 SafePointNode* ex_map = jvms->map()->next_exception();
274 if (ex_map != NULL) {
275 jvms->map()->set_next_exception(NULL);
276 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
277 next_map = ex_map->next_exception();
278 ex_map->set_next_exception(NULL);
279 add_exception_state(ex_map);
280 }
281 }
282 }
283
284 //-----------------------transfer_exceptions_into_jvms-------------------------
285 JVMState* GraphKit::transfer_exceptions_into_jvms() {
286 if (map() == NULL) {
287 // We need a JVMS to carry the exceptions, but the map has gone away.
288 // Create a scratch JVMS, cloned from any of the exception states...
289 if (has_exceptions()) {
290 _map = _exceptions;
291 _map = clone_map();
292 _map->set_next_exception(NULL);
293 clear_saved_ex_oop(_map);
294 debug_only(verify_map());
295 } else {
296 // ...or created from scratch
297 JVMState* jvms = new (C) JVMState(_method, NULL);
298 jvms->set_bci(_bci);
299 jvms->set_sp(_sp);
300 jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
301 set_jvms(jvms);
302 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top());
303 set_all_memory(top());
304 while (map()->req() < jvms->endoff()) map()->add_req(top());
305 }
306 // (This is a kludge, in case you didn't notice.)
307 set_control(top());
308 }
309 JVMState* jvms = sync_jvms();
310 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
311 jvms->map()->set_next_exception(_exceptions);
312 _exceptions = NULL; // done with this set of exceptions
313 return jvms;
314 }
315
316 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
317 assert(is_hidden_merge(dstphi), "must be a special merge node");
318 assert(is_hidden_merge(srcphi), "must be a special merge node");
319 uint limit = srcphi->req();
320 for (uint i = PhiNode::Input; i < limit; i++) {
321 dstphi->add_req(srcphi->in(i));
322 }
323 }
324 static inline void add_one_req(Node* dstphi, Node* src) {
325 assert(is_hidden_merge(dstphi), "must be a special merge node");
326 assert(!is_hidden_merge(src), "must not be a special merge node");
327 dstphi->add_req(src);
328 }
329
330 //-----------------------combine_exception_states------------------------------
331 // This helper function combines exception states by building phis on a
332 // specially marked state-merging region. These regions and phis are
333 // untransformed, and can build up gradually. The region is marked by
334 // having a control input of its exception map, rather than NULL. Such
335 // regions do not appear except in this function, and in use_exception_state.
336 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
337 if (failing()) return; // dying anyway...
338 JVMState* ex_jvms = ex_map->_jvms;
339 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
340 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
341 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
342 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
343 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
344 assert(ex_map->req() == phi_map->req(), "matching maps");
345 uint tos = ex_jvms->stkoff() + ex_jvms->sp();
346 Node* hidden_merge_mark = root();
347 Node* region = phi_map->control();
348 MergeMemNode* phi_mem = phi_map->merged_memory();
349 MergeMemNode* ex_mem = ex_map->merged_memory();
350 if (region->in(0) != hidden_merge_mark) {
351 // The control input is not (yet) a specially-marked region in phi_map.
352 // Make it so, and build some phis.
353 region = new RegionNode(2);
354 _gvn.set_type(region, Type::CONTROL);
355 region->set_req(0, hidden_merge_mark); // marks an internal ex-state
356 region->init_req(1, phi_map->control());
357 phi_map->set_control(region);
358 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
359 record_for_igvn(io_phi);
360 _gvn.set_type(io_phi, Type::ABIO);
361 phi_map->set_i_o(io_phi);
362 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
363 Node* m = mms.memory();
364 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
365 record_for_igvn(m_phi);
366 _gvn.set_type(m_phi, Type::MEMORY);
367 mms.set_memory(m_phi);
368 }
369 }
370
371 // Either or both of phi_map and ex_map might already be converted into phis.
372 Node* ex_control = ex_map->control();
373 // if there is special marking on ex_map also, we add multiple edges from src
374 bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
375 // how wide was the destination phi_map, originally?
376 uint orig_width = region->req();
377
378 if (add_multiple) {
379 add_n_reqs(region, ex_control);
380 add_n_reqs(phi_map->i_o(), ex_map->i_o());
381 } else {
382 // ex_map has no merges, so we just add single edges everywhere
383 add_one_req(region, ex_control);
384 add_one_req(phi_map->i_o(), ex_map->i_o());
385 }
386 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
387 if (mms.is_empty()) {
388 // get a copy of the base memory, and patch some inputs into it
389 const TypePtr* adr_type = mms.adr_type(C);
390 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
391 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
392 mms.set_memory(phi);
393 // Prepare to append interesting stuff onto the newly sliced phi:
394 while (phi->req() > orig_width) phi->del_req(phi->req()-1);
395 }
396 // Append stuff from ex_map:
397 if (add_multiple) {
398 add_n_reqs(mms.memory(), mms.memory2());
399 } else {
400 add_one_req(mms.memory(), mms.memory2());
401 }
402 }
403 uint limit = ex_map->req();
404 for (uint i = TypeFunc::Parms; i < limit; i++) {
405 // Skip everything in the JVMS after tos. (The ex_oop follows.)
406 if (i == tos) i = ex_jvms->monoff();
407 Node* src = ex_map->in(i);
408 Node* dst = phi_map->in(i);
409 if (src != dst) {
410 PhiNode* phi;
411 if (dst->in(0) != region) {
412 dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
413 record_for_igvn(phi);
414 _gvn.set_type(phi, phi->type());
415 phi_map->set_req(i, dst);
416 // Prepare to append interesting stuff onto the new phi:
417 while (dst->req() > orig_width) dst->del_req(dst->req()-1);
418 } else {
419 assert(dst->is_Phi(), "nobody else uses a hidden region");
420 phi = dst->as_Phi();
421 }
422 if (add_multiple && src->in(0) == ex_control) {
423 // Both are phis.
424 add_n_reqs(dst, src);
425 } else {
426 while (dst->req() < region->req()) add_one_req(dst, src);
427 }
428 const Type* srctype = _gvn.type(src);
429 if (phi->type() != srctype) {
430 const Type* dsttype = phi->type()->meet_speculative(srctype);
431 if (phi->type() != dsttype) {
432 phi->set_type(dsttype);
433 _gvn.set_type(phi, dsttype);
434 }
435 }
436 }
437 }
438 phi_map->merge_replaced_nodes_with(ex_map);
439 }
440
441 //--------------------------use_exception_state--------------------------------
442 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
443 if (failing()) { stop(); return top(); }
444 Node* region = phi_map->control();
445 Node* hidden_merge_mark = root();
446 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
447 Node* ex_oop = clear_saved_ex_oop(phi_map);
448 if (region->in(0) == hidden_merge_mark) {
449 // Special marking for internal ex-states. Process the phis now.
450 region->set_req(0, region); // now it's an ordinary region
451 set_jvms(phi_map->jvms()); // ...so now we can use it as a map
452 // Note: Setting the jvms also sets the bci and sp.
453 set_control(_gvn.transform(region));
454 uint tos = jvms()->stkoff() + sp();
455 for (uint i = 1; i < tos; i++) {
456 Node* x = phi_map->in(i);
457 if (x->in(0) == region) {
458 assert(x->is_Phi(), "expected a special phi");
459 phi_map->set_req(i, _gvn.transform(x));
460 }
461 }
462 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
463 Node* x = mms.memory();
464 if (x->in(0) == region) {
465 assert(x->is_Phi(), "nobody else uses a hidden region");
466 mms.set_memory(_gvn.transform(x));
467 }
468 }
469 if (ex_oop->in(0) == region) {
470 assert(ex_oop->is_Phi(), "expected a special phi");
471 ex_oop = _gvn.transform(ex_oop);
472 }
473 } else {
474 set_jvms(phi_map->jvms());
475 }
476
477 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
478 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
479 return ex_oop;
480 }
481
482 //---------------------------------java_bc-------------------------------------
483 Bytecodes::Code GraphKit::java_bc() const {
484 ciMethod* method = this->method();
485 int bci = this->bci();
486 if (method != NULL && bci != InvocationEntryBci)
487 return method->java_code_at_bci(bci);
488 else
489 return Bytecodes::_illegal;
490 }
491
492 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
493 bool must_throw) {
494 // if the exception capability is set, then we will generate code
495 // to check the JavaThread.should_post_on_exceptions flag to see
496 // if we actually need to report exception events (for this
497 // thread). If we don't need to report exception events, we will
498 // take the normal fast path provided by add_exception_events. If
499 // exception event reporting is enabled for this thread, we will
500 // take the uncommon_trap in the BuildCutout below.
501
502 // first must access the should_post_on_exceptions_flag in this thread's JavaThread
503 Node* jthread = _gvn.transform(new ThreadLocalNode());
504 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
505 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
506
507 // Test the should_post_on_exceptions_flag vs. 0
508 Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
509 Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
510
511 // Branch to slow_path if should_post_on_exceptions_flag was true
512 { BuildCutout unless(this, tst, PROB_MAX);
513 // Do not try anything fancy if we're notifying the VM on every throw.
514 // Cf. case Bytecodes::_athrow in parse2.cpp.
515 uncommon_trap(reason, Deoptimization::Action_none,
516 (ciKlass*)NULL, (char*)NULL, must_throw);
517 }
518
519 }
520
521 //------------------------------builtin_throw----------------------------------
522 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
523 bool must_throw = true;
524
525 if (env()->jvmti_can_post_on_exceptions()) {
526 // check if we must post exception events, take uncommon trap if so
527 uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
528 // here if should_post_on_exceptions is false
529 // continue on with the normal codegen
530 }
531
532 // If this particular condition has not yet happened at this
533 // bytecode, then use the uncommon trap mechanism, and allow for
534 // a future recompilation if several traps occur here.
535 // If the throw is hot, try to use a more complicated inline mechanism
536 // which keeps execution inside the compiled code.
537 bool treat_throw_as_hot = false;
538 ciMethodData* md = method()->method_data();
539
540 if (ProfileTraps) {
541 if (too_many_traps(reason)) {
542 treat_throw_as_hot = true;
543 }
544 // (If there is no MDO at all, assume it is early in
545 // execution, and that any deopts are part of the
546 // startup transient, and don't need to be remembered.)
547
548 // Also, if there is a local exception handler, treat all throws
549 // as hot if there has been at least one in this method.
550 if (C->trap_count(reason) != 0
551 && method()->method_data()->trap_count(reason) != 0
552 && has_ex_handler()) {
553 treat_throw_as_hot = true;
554 }
555 }
556
557 // If this throw happens frequently, an uncommon trap might cause
558 // a performance pothole. If there is a local exception handler,
559 // and if this particular bytecode appears to be deoptimizing often,
560 // let us handle the throw inline, with a preconstructed instance.
561 // Note: If the deopt count has blown up, the uncommon trap
562 // runtime is going to flush this nmethod, not matter what.
563 if (treat_throw_as_hot
564 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
565 // If the throw is local, we use a pre-existing instance and
566 // punt on the backtrace. This would lead to a missing backtrace
567 // (a repeat of 4292742) if the backtrace object is ever asked
568 // for its backtrace.
569 // Fixing this remaining case of 4292742 requires some flavor of
570 // escape analysis. Leave that for the future.
571 ciInstance* ex_obj = NULL;
572 switch (reason) {
573 case Deoptimization::Reason_null_check:
574 ex_obj = env()->NullPointerException_instance();
575 break;
576 case Deoptimization::Reason_div0_check:
577 ex_obj = env()->ArithmeticException_instance();
578 break;
579 case Deoptimization::Reason_range_check:
580 ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
581 break;
582 case Deoptimization::Reason_class_check:
583 if (java_bc() == Bytecodes::_aastore) {
584 ex_obj = env()->ArrayStoreException_instance();
585 } else {
586 ex_obj = env()->ClassCastException_instance();
587 }
588 break;
589 default:
590 break;
591 }
592 if (failing()) { stop(); return; } // exception allocation might fail
593 if (ex_obj != NULL) {
594 // Cheat with a preallocated exception object.
595 if (C->log() != NULL)
596 C->log()->elem("hot_throw preallocated='1' reason='%s'",
597 Deoptimization::trap_reason_name(reason));
598 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj);
599 Node* ex_node = _gvn.transform(ConNode::make(ex_con));
600
601 // Clear the detail message of the preallocated exception object.
602 // Weblogic sometimes mutates the detail message of exceptions
603 // using reflection.
604 int offset = java_lang_Throwable::get_detailMessage_offset();
605 const TypePtr* adr_typ = ex_con->add_offset(offset);
606
607 Node *adr = basic_plus_adr(ex_node, ex_node, offset);
608 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
609 Node *store = access_store_at(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, IN_HEAP);
610
611 add_exception_state(make_exception_state(ex_node));
612 return;
613 }
614 }
615
616 // %%% Maybe add entry to OptoRuntime which directly throws the exc.?
617 // It won't be much cheaper than bailing to the interp., since we'll
618 // have to pass up all the debug-info, and the runtime will have to
619 // create the stack trace.
620
621 // Usual case: Bail to interpreter.
622 // Reserve the right to recompile if we haven't seen anything yet.
623
624 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? C->method() : NULL;
625 Deoptimization::DeoptAction action = Deoptimization::Action_maybe_recompile;
626 if (treat_throw_as_hot
627 && (method()->method_data()->trap_recompiled_at(bci(), m)
628 || C->too_many_traps(reason))) {
629 // We cannot afford to take more traps here. Suffer in the interpreter.
630 if (C->log() != NULL)
631 C->log()->elem("hot_throw preallocated='0' reason='%s' mcount='%d'",
632 Deoptimization::trap_reason_name(reason),
633 C->trap_count(reason));
634 action = Deoptimization::Action_none;
635 }
636
637 // "must_throw" prunes the JVM state to include only the stack, if there
638 // are no local exception handlers. This should cut down on register
639 // allocation time and code size, by drastically reducing the number
640 // of in-edges on the call to the uncommon trap.
641
642 uncommon_trap(reason, action, (ciKlass*)NULL, (char*)NULL, must_throw);
643 }
644
645
646 //----------------------------PreserveJVMState---------------------------------
647 PreserveJVMState::PreserveJVMState(GraphKit* kit, bool clone_map) {
648 debug_only(kit->verify_map());
649 _kit = kit;
650 _map = kit->map(); // preserve the map
651 _sp = kit->sp();
652 kit->set_map(clone_map ? kit->clone_map() : NULL);
653 #ifdef ASSERT
654 _bci = kit->bci();
655 Parse* parser = kit->is_Parse();
656 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
657 _block = block;
658 #endif
659 }
660 PreserveJVMState::~PreserveJVMState() {
661 GraphKit* kit = _kit;
662 #ifdef ASSERT
663 assert(kit->bci() == _bci, "bci must not shift");
664 Parse* parser = kit->is_Parse();
665 int block = (parser == NULL || parser->block() == NULL) ? -1 : parser->block()->rpo();
666 assert(block == _block, "block must not shift");
667 #endif
668 kit->set_map(_map);
669 kit->set_sp(_sp);
670 }
671
672
673 //-----------------------------BuildCutout-------------------------------------
674 BuildCutout::BuildCutout(GraphKit* kit, Node* p, float prob, float cnt)
675 : PreserveJVMState(kit)
676 {
677 assert(p->is_Con() || p->is_Bool(), "test must be a bool");
678 SafePointNode* outer_map = _map; // preserved map is caller's
679 SafePointNode* inner_map = kit->map();
680 IfNode* iff = kit->create_and_map_if(outer_map->control(), p, prob, cnt);
681 outer_map->set_control(kit->gvn().transform( new IfTrueNode(iff) ));
682 inner_map->set_control(kit->gvn().transform( new IfFalseNode(iff) ));
683 }
684 BuildCutout::~BuildCutout() {
685 GraphKit* kit = _kit;
686 assert(kit->stopped(), "cutout code must stop, throw, return, etc.");
687 }
688
689 //---------------------------PreserveReexecuteState----------------------------
690 PreserveReexecuteState::PreserveReexecuteState(GraphKit* kit) {
691 assert(!kit->stopped(), "must call stopped() before");
692 _kit = kit;
693 _sp = kit->sp();
694 _reexecute = kit->jvms()->_reexecute;
695 }
696 PreserveReexecuteState::~PreserveReexecuteState() {
697 if (_kit->stopped()) return;
698 _kit->jvms()->_reexecute = _reexecute;
699 _kit->set_sp(_sp);
700 }
701
702 //------------------------------clone_map--------------------------------------
703 // Implementation of PreserveJVMState
704 //
705 // Only clone_map(...) here. If this function is only used in the
706 // PreserveJVMState class we may want to get rid of this extra
707 // function eventually and do it all there.
708
709 SafePointNode* GraphKit::clone_map() {
710 if (map() == NULL) return NULL;
711
712 // Clone the memory edge first
713 Node* mem = MergeMemNode::make(map()->memory());
714 gvn().set_type_bottom(mem);
715
716 SafePointNode *clonemap = (SafePointNode*)map()->clone();
717 JVMState* jvms = this->jvms();
718 JVMState* clonejvms = jvms->clone_shallow(C);
719 clonemap->set_memory(mem);
720 clonemap->set_jvms(clonejvms);
721 clonejvms->set_map(clonemap);
722 record_for_igvn(clonemap);
723 gvn().set_type_bottom(clonemap);
724 return clonemap;
725 }
726
727
728 //-----------------------------set_map_clone-----------------------------------
729 void GraphKit::set_map_clone(SafePointNode* m) {
730 _map = m;
731 _map = clone_map();
732 _map->set_next_exception(NULL);
733 debug_only(verify_map());
734 }
735
736
737 //----------------------------kill_dead_locals---------------------------------
738 // Detect any locals which are known to be dead, and force them to top.
739 void GraphKit::kill_dead_locals() {
740 // Consult the liveness information for the locals. If any
741 // of them are unused, then they can be replaced by top(). This
742 // should help register allocation time and cut down on the size
743 // of the deoptimization information.
744
745 // This call is made from many of the bytecode handling
746 // subroutines called from the Big Switch in do_one_bytecode.
747 // Every bytecode which might include a slow path is responsible
748 // for killing its dead locals. The more consistent we
749 // are about killing deads, the fewer useless phis will be
750 // constructed for them at various merge points.
751
752 // bci can be -1 (InvocationEntryBci). We return the entry
753 // liveness for the method.
754
755 if (method() == NULL || method()->code_size() == 0) {
756 // We are building a graph for a call to a native method.
757 // All locals are live.
758 return;
759 }
760
761 ResourceMark rm;
762
763 // Consult the liveness information for the locals. If any
764 // of them are unused, then they can be replaced by top(). This
765 // should help register allocation time and cut down on the size
766 // of the deoptimization information.
767 MethodLivenessResult live_locals = method()->liveness_at_bci(bci());
768
769 int len = (int)live_locals.size();
770 assert(len <= jvms()->loc_size(), "too many live locals");
771 for (int local = 0; local < len; local++) {
772 if (!live_locals.at(local)) {
773 set_local(local, top());
774 }
775 }
776 }
777
778 #ifdef ASSERT
779 //-------------------------dead_locals_are_killed------------------------------
780 // Return true if all dead locals are set to top in the map.
781 // Used to assert "clean" debug info at various points.
782 bool GraphKit::dead_locals_are_killed() {
783 if (method() == NULL || method()->code_size() == 0) {
784 // No locals need to be dead, so all is as it should be.
785 return true;
786 }
787
788 // Make sure somebody called kill_dead_locals upstream.
789 ResourceMark rm;
790 for (JVMState* jvms = this->jvms(); jvms != NULL; jvms = jvms->caller()) {
791 if (jvms->loc_size() == 0) continue; // no locals to consult
792 SafePointNode* map = jvms->map();
793 ciMethod* method = jvms->method();
794 int bci = jvms->bci();
795 if (jvms == this->jvms()) {
796 bci = this->bci(); // it might not yet be synched
797 }
798 MethodLivenessResult live_locals = method->liveness_at_bci(bci);
799 int len = (int)live_locals.size();
800 if (!live_locals.is_valid() || len == 0)
801 // This method is trivial, or is poisoned by a breakpoint.
802 return true;
803 assert(len == jvms->loc_size(), "live map consistent with locals map");
804 for (int local = 0; local < len; local++) {
805 if (!live_locals.at(local) && map->local(jvms, local) != top()) {
806 if (PrintMiscellaneous && (Verbose || WizardMode)) {
807 tty->print_cr("Zombie local %d: ", local);
808 jvms->dump();
809 }
810 return false;
811 }
812 }
813 }
814 return true;
815 }
816
817 #endif //ASSERT
818
819 // Helper function for enforcing certain bytecodes to reexecute if
820 // deoptimization happens
821 static bool should_reexecute_implied_by_bytecode(JVMState *jvms, bool is_anewarray) {
822 ciMethod* cur_method = jvms->method();
823 int cur_bci = jvms->bci();
824 if (cur_method != NULL && cur_bci != InvocationEntryBci) {
825 Bytecodes::Code code = cur_method->java_code_at_bci(cur_bci);
826 return Interpreter::bytecode_should_reexecute(code) ||
827 (is_anewarray && code == Bytecodes::_multianewarray);
828 // Reexecute _multianewarray bytecode which was replaced with
829 // sequence of [a]newarray. See Parse::do_multianewarray().
830 //
831 // Note: interpreter should not have it set since this optimization
832 // is limited by dimensions and guarded by flag so in some cases
833 // multianewarray() runtime calls will be generated and
834 // the bytecode should not be reexecutes (stack will not be reset).
835 } else
836 return false;
837 }
838
839 // Helper function for adding JVMState and debug information to node
840 void GraphKit::add_safepoint_edges(SafePointNode* call, bool must_throw) {
841 // Add the safepoint edges to the call (or other safepoint).
842
843 // Make sure dead locals are set to top. This
844 // should help register allocation time and cut down on the size
845 // of the deoptimization information.
846 assert(dead_locals_are_killed(), "garbage in debug info before safepoint");
847
848 // Walk the inline list to fill in the correct set of JVMState's
849 // Also fill in the associated edges for each JVMState.
850
851 // If the bytecode needs to be reexecuted we need to put
852 // the arguments back on the stack.
853 const bool should_reexecute = jvms()->should_reexecute();
854 JVMState* youngest_jvms = should_reexecute ? sync_jvms_for_reexecute() : sync_jvms();
855
856 // NOTE: set_bci (called from sync_jvms) might reset the reexecute bit to
857 // undefined if the bci is different. This is normal for Parse but it
858 // should not happen for LibraryCallKit because only one bci is processed.
859 assert(!is_LibraryCallKit() || (jvms()->should_reexecute() == should_reexecute),
860 "in LibraryCallKit the reexecute bit should not change");
861
862 // If we are guaranteed to throw, we can prune everything but the
863 // input to the current bytecode.
864 bool can_prune_locals = false;
865 uint stack_slots_not_pruned = 0;
866 int inputs = 0, depth = 0;
867 if (must_throw) {
868 assert(method() == youngest_jvms->method(), "sanity");
869 if (compute_stack_effects(inputs, depth)) {
870 can_prune_locals = true;
871 stack_slots_not_pruned = inputs;
872 }
873 }
874
875 if (env()->should_retain_local_variables()) {
876 // At any safepoint, this method can get breakpointed, which would
877 // then require an immediate deoptimization.
878 can_prune_locals = false; // do not prune locals
879 stack_slots_not_pruned = 0;
880 }
881
882 // do not scribble on the input jvms
883 JVMState* out_jvms = youngest_jvms->clone_deep(C);
884 call->set_jvms(out_jvms); // Start jvms list for call node
885
886 // For a known set of bytecodes, the interpreter should reexecute them if
887 // deoptimization happens. We set the reexecute state for them here
888 if (out_jvms->is_reexecute_undefined() && //don't change if already specified
889 should_reexecute_implied_by_bytecode(out_jvms, call->is_AllocateArray())) {
890 out_jvms->set_should_reexecute(true); //NOTE: youngest_jvms not changed
891 }
892
893 // Presize the call:
894 DEBUG_ONLY(uint non_debug_edges = call->req());
895 call->add_req_batch(top(), youngest_jvms->debug_depth());
896 assert(call->req() == non_debug_edges + youngest_jvms->debug_depth(), "");
897
898 // Set up edges so that the call looks like this:
899 // Call [state:] ctl io mem fptr retadr
900 // [parms:] parm0 ... parmN
901 // [root:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
902 // [...mid:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN [...]
903 // [young:] loc0 ... locN stk0 ... stkSP mon0 obj0 ... monN objN
904 // Note that caller debug info precedes callee debug info.
905
906 // Fill pointer walks backwards from "young:" to "root:" in the diagram above:
907 uint debug_ptr = call->req();
908
909 // Loop over the map input edges associated with jvms, add them
910 // to the call node, & reset all offsets to match call node array.
911 for (JVMState* in_jvms = youngest_jvms; in_jvms != NULL; ) {
912 uint debug_end = debug_ptr;
913 uint debug_start = debug_ptr - in_jvms->debug_size();
914 debug_ptr = debug_start; // back up the ptr
915
916 uint p = debug_start; // walks forward in [debug_start, debug_end)
917 uint j, k, l;
918 SafePointNode* in_map = in_jvms->map();
919 out_jvms->set_map(call);
920
921 if (can_prune_locals) {
922 assert(in_jvms->method() == out_jvms->method(), "sanity");
923 // If the current throw can reach an exception handler in this JVMS,
924 // then we must keep everything live that can reach that handler.
925 // As a quick and dirty approximation, we look for any handlers at all.
926 if (in_jvms->method()->has_exception_handlers()) {
927 can_prune_locals = false;
928 }
929 }
930
931 // Add the Locals
932 k = in_jvms->locoff();
933 l = in_jvms->loc_size();
934 out_jvms->set_locoff(p);
935 if (!can_prune_locals) {
936 for (j = 0; j < l; j++)
937 call->set_req(p++, in_map->in(k+j));
938 } else {
939 p += l; // already set to top above by add_req_batch
940 }
941
942 // Add the Expression Stack
943 k = in_jvms->stkoff();
944 l = in_jvms->sp();
945 out_jvms->set_stkoff(p);
946 if (!can_prune_locals) {
947 for (j = 0; j < l; j++)
948 call->set_req(p++, in_map->in(k+j));
949 } else if (can_prune_locals && stack_slots_not_pruned != 0) {
950 // Divide stack into {S0,...,S1}, where S0 is set to top.
951 uint s1 = stack_slots_not_pruned;
952 stack_slots_not_pruned = 0; // for next iteration
953 if (s1 > l) s1 = l;
954 uint s0 = l - s1;
955 p += s0; // skip the tops preinstalled by add_req_batch
956 for (j = s0; j < l; j++)
957 call->set_req(p++, in_map->in(k+j));
958 } else {
959 p += l; // already set to top above by add_req_batch
960 }
961
962 // Add the Monitors
963 k = in_jvms->monoff();
964 l = in_jvms->mon_size();
965 out_jvms->set_monoff(p);
966 for (j = 0; j < l; j++)
967 call->set_req(p++, in_map->in(k+j));
968
969 // Copy any scalar object fields.
970 k = in_jvms->scloff();
971 l = in_jvms->scl_size();
972 out_jvms->set_scloff(p);
973 for (j = 0; j < l; j++)
974 call->set_req(p++, in_map->in(k+j));
975
976 // Finish the new jvms.
977 out_jvms->set_endoff(p);
978
979 assert(out_jvms->endoff() == debug_end, "fill ptr must match");
980 assert(out_jvms->depth() == in_jvms->depth(), "depth must match");
981 assert(out_jvms->loc_size() == in_jvms->loc_size(), "size must match");
982 assert(out_jvms->mon_size() == in_jvms->mon_size(), "size must match");
983 assert(out_jvms->scl_size() == in_jvms->scl_size(), "size must match");
984 assert(out_jvms->debug_size() == in_jvms->debug_size(), "size must match");
985
986 // Update the two tail pointers in parallel.
987 out_jvms = out_jvms->caller();
988 in_jvms = in_jvms->caller();
989 }
990
991 assert(debug_ptr == non_debug_edges, "debug info must fit exactly");
992
993 // Test the correctness of JVMState::debug_xxx accessors:
994 assert(call->jvms()->debug_start() == non_debug_edges, "");
995 assert(call->jvms()->debug_end() == call->req(), "");
996 assert(call->jvms()->debug_depth() == call->req() - non_debug_edges, "");
997 }
998
999 bool GraphKit::compute_stack_effects(int& inputs, int& depth) {
1000 Bytecodes::Code code = java_bc();
1001 if (code == Bytecodes::_wide) {
1002 code = method()->java_code_at_bci(bci() + 1);
1003 }
1004
1005 BasicType rtype = T_ILLEGAL;
1006 int rsize = 0;
1007
1008 if (code != Bytecodes::_illegal) {
1009 depth = Bytecodes::depth(code); // checkcast=0, athrow=-1
1010 rtype = Bytecodes::result_type(code); // checkcast=P, athrow=V
1011 if (rtype < T_CONFLICT)
1012 rsize = type2size[rtype];
1013 }
1014
1015 switch (code) {
1016 case Bytecodes::_illegal:
1017 return false;
1018
1019 case Bytecodes::_ldc:
1020 case Bytecodes::_ldc_w:
1021 case Bytecodes::_ldc2_w:
1022 inputs = 0;
1023 break;
1024
1025 case Bytecodes::_dup: inputs = 1; break;
1026 case Bytecodes::_dup_x1: inputs = 2; break;
1027 case Bytecodes::_dup_x2: inputs = 3; break;
1028 case Bytecodes::_dup2: inputs = 2; break;
1029 case Bytecodes::_dup2_x1: inputs = 3; break;
1030 case Bytecodes::_dup2_x2: inputs = 4; break;
1031 case Bytecodes::_swap: inputs = 2; break;
1032 case Bytecodes::_arraylength: inputs = 1; break;
1033
1034 case Bytecodes::_getstatic:
1035 case Bytecodes::_putstatic:
1036 case Bytecodes::_getfield:
1037 case Bytecodes::_putfield:
1038 {
1039 bool ignored_will_link;
1040 ciField* field = method()->get_field_at_bci(bci(), ignored_will_link);
1041 int size = field->type()->size();
1042 bool is_get = (depth >= 0), is_static = (depth & 1);
1043 inputs = (is_static ? 0 : 1);
1044 if (is_get) {
1045 depth = size - inputs;
1046 } else {
1047 inputs += size; // putxxx pops the value from the stack
1048 depth = - inputs;
1049 }
1050 }
1051 break;
1052
1053 case Bytecodes::_invokevirtual:
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::_ireturn:
1081 case Bytecodes::_lreturn:
1082 case Bytecodes::_freturn:
1083 case Bytecodes::_dreturn:
1084 case Bytecodes::_areturn:
1085 assert(rsize == -depth, "");
1086 inputs = rsize;
1087 break;
1088
1089 case Bytecodes::_jsr:
1090 case Bytecodes::_jsr_w:
1091 inputs = 0;
1092 depth = 1; // S.B. depth=1, not zero
1093 break;
1094
1095 default:
1096 // bytecode produces a typed result
1097 inputs = rsize - depth;
1098 assert(inputs >= 0, "");
1099 break;
1100 }
1101
1102 #ifdef ASSERT
1103 // spot check
1104 int outputs = depth + inputs;
1105 assert(outputs >= 0, "sanity");
1106 switch (code) {
1107 case Bytecodes::_checkcast: assert(inputs == 1 && outputs == 1, ""); break;
1108 case Bytecodes::_athrow: assert(inputs == 1 && outputs == 0, ""); break;
1109 case Bytecodes::_aload_0: assert(inputs == 0 && outputs == 1, ""); break;
1110 case Bytecodes::_return: assert(inputs == 0 && outputs == 0, ""); break;
1111 case Bytecodes::_drem: assert(inputs == 4 && outputs == 2, ""); break;
1112 default: break;
1113 }
1114 #endif //ASSERT
1115
1116 return true;
1117 }
1118
1119
1120
1121 //------------------------------basic_plus_adr---------------------------------
1122 Node* GraphKit::basic_plus_adr(Node* base, Node* ptr, Node* offset) {
1123 // short-circuit a common case
1124 if (offset == intcon(0)) return ptr;
1125 return _gvn.transform( new AddPNode(base, ptr, offset) );
1126 }
1127
1128 Node* GraphKit::ConvI2L(Node* offset) {
1129 // short-circuit a common case
1130 jint offset_con = find_int_con(offset, Type::OffsetBot);
1131 if (offset_con != Type::OffsetBot) {
1132 return longcon((jlong) offset_con);
1133 }
1134 return _gvn.transform( new ConvI2LNode(offset));
1135 }
1136
1137 Node* GraphKit::ConvI2UL(Node* offset) {
1138 juint offset_con = (juint) find_int_con(offset, Type::OffsetBot);
1139 if (offset_con != (juint) Type::OffsetBot) {
1140 return longcon((julong) offset_con);
1141 }
1142 Node* conv = _gvn.transform( new ConvI2LNode(offset));
1143 Node* mask = _gvn.transform(ConLNode::make((julong) max_juint));
1144 return _gvn.transform( new AndLNode(conv, mask) );
1145 }
1146
1147 Node* GraphKit::ConvL2I(Node* offset) {
1148 // short-circuit a common case
1149 jlong offset_con = find_long_con(offset, (jlong)Type::OffsetBot);
1150 if (offset_con != (jlong)Type::OffsetBot) {
1151 return intcon((int) offset_con);
1152 }
1153 return _gvn.transform( new ConvL2INode(offset));
1154 }
1155
1156 //-------------------------load_object_klass-----------------------------------
1157 Node* GraphKit::load_object_klass(Node* obj) {
1158 // Special-case a fresh allocation to avoid building nodes:
1159 Node* akls = AllocateNode::Ideal_klass(obj, &_gvn);
1160 if (akls != NULL) return akls;
1161 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1162 return _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), k_adr, TypeInstPtr::KLASS));
1163 }
1164
1165 //-------------------------load_array_length-----------------------------------
1166 Node* GraphKit::load_array_length(Node* array) {
1167 // Special-case a fresh allocation to avoid building nodes:
1168 AllocateArrayNode* alloc = AllocateArrayNode::Ideal_array_allocation(array, &_gvn);
1169 Node *alen;
1170 if (alloc == NULL) {
1171 Node *r_adr = basic_plus_adr(array, arrayOopDesc::length_offset_in_bytes());
1172 alen = _gvn.transform( new LoadRangeNode(0, immutable_memory(), r_adr, TypeInt::POS));
1173 } else {
1174 alen = alloc->Ideal_length();
1175 Node* ccast = alloc->make_ideal_length(_gvn.type(array)->is_oopptr(), &_gvn);
1176 if (ccast != alen) {
1177 alen = _gvn.transform(ccast);
1178 }
1179 }
1180 return alen;
1181 }
1182
1183 //------------------------------do_null_check----------------------------------
1184 // Helper function to do a NULL pointer check. Returned value is
1185 // the incoming address with NULL casted away. You are allowed to use the
1186 // not-null value only if you are control dependent on the test.
1187 #ifndef PRODUCT
1188 extern int explicit_null_checks_inserted,
1189 explicit_null_checks_elided;
1190 #endif
1191 Node* GraphKit::null_check_common(Node* value, BasicType type,
1192 // optional arguments for variations:
1193 bool assert_null,
1194 Node* *null_control,
1195 bool speculative) {
1196 assert(!assert_null || null_control == NULL, "not both at once");
1197 if (stopped()) return top();
1198 NOT_PRODUCT(explicit_null_checks_inserted++);
1199
1200 // Construct NULL check
1201 Node *chk = NULL;
1202 switch(type) {
1203 case T_LONG : chk = new CmpLNode(value, _gvn.zerocon(T_LONG)); break;
1204 case T_INT : chk = new CmpINode(value, _gvn.intcon(0)); break;
1205 case T_ARRAY : // fall through
1206 type = T_OBJECT; // simplify further tests
1207 case T_OBJECT : {
1208 const Type *t = _gvn.type( value );
1209
1210 const TypeOopPtr* tp = t->isa_oopptr();
1211 if (tp != NULL && tp->klass() != NULL && !tp->klass()->is_loaded()
1212 // Only for do_null_check, not any of its siblings:
1213 && !assert_null && null_control == NULL) {
1214 // Usually, any field access or invocation on an unloaded oop type
1215 // will simply fail to link, since the statically linked class is
1216 // likely also to be unloaded. However, in -Xcomp mode, sometimes
1217 // the static class is loaded but the sharper oop type is not.
1218 // Rather than checking for this obscure case in lots of places,
1219 // we simply observe that a null check on an unloaded class
1220 // will always be followed by a nonsense operation, so we
1221 // can just issue the uncommon trap here.
1222 // Our access to the unloaded class will only be correct
1223 // after it has been loaded and initialized, which requires
1224 // a trip through the interpreter.
1225 #ifndef PRODUCT
1226 if (WizardMode) { tty->print("Null check of unloaded "); tp->klass()->print(); tty->cr(); }
1227 #endif
1228 uncommon_trap(Deoptimization::Reason_unloaded,
1229 Deoptimization::Action_reinterpret,
1230 tp->klass(), "!loaded");
1231 return top();
1232 }
1233
1234 if (assert_null) {
1235 // See if the type is contained in NULL_PTR.
1236 // If so, then the value is already null.
1237 if (t->higher_equal(TypePtr::NULL_PTR)) {
1238 NOT_PRODUCT(explicit_null_checks_elided++);
1239 return value; // Elided null assert quickly!
1240 }
1241 } else {
1242 // See if mixing in the NULL pointer changes type.
1243 // If so, then the NULL pointer was not allowed in the original
1244 // type. In other words, "value" was not-null.
1245 if (t->meet(TypePtr::NULL_PTR) != t->remove_speculative()) {
1246 // same as: if (!TypePtr::NULL_PTR->higher_equal(t)) ...
1247 NOT_PRODUCT(explicit_null_checks_elided++);
1248 return value; // Elided null check quickly!
1249 }
1250 }
1251 chk = new CmpPNode( value, null() );
1252 break;
1253 }
1254
1255 default:
1256 fatal("unexpected type: %s", type2name(type));
1257 }
1258 assert(chk != NULL, "sanity check");
1259 chk = _gvn.transform(chk);
1260
1261 BoolTest::mask btest = assert_null ? BoolTest::eq : BoolTest::ne;
1262 BoolNode *btst = new BoolNode( chk, btest);
1263 Node *tst = _gvn.transform( btst );
1264
1265 //-----------
1266 // if peephole optimizations occurred, a prior test existed.
1267 // If a prior test existed, maybe it dominates as we can avoid this test.
1268 if (tst != btst && type == T_OBJECT) {
1269 // At this point we want to scan up the CFG to see if we can
1270 // find an identical test (and so avoid this test altogether).
1271 Node *cfg = control();
1272 int depth = 0;
1273 while( depth < 16 ) { // Limit search depth for speed
1274 if( cfg->Opcode() == Op_IfTrue &&
1275 cfg->in(0)->in(1) == tst ) {
1276 // Found prior test. Use "cast_not_null" to construct an identical
1277 // CastPP (and hence hash to) as already exists for the prior test.
1278 // Return that casted value.
1279 if (assert_null) {
1280 replace_in_map(value, null());
1281 return null(); // do not issue the redundant test
1282 }
1283 Node *oldcontrol = control();
1284 set_control(cfg);
1285 Node *res = cast_not_null(value);
1286 set_control(oldcontrol);
1287 NOT_PRODUCT(explicit_null_checks_elided++);
1288 return res;
1289 }
1290 cfg = IfNode::up_one_dom(cfg, /*linear_only=*/ true);
1291 if (cfg == NULL) break; // Quit at region nodes
1292 depth++;
1293 }
1294 }
1295
1296 //-----------
1297 // Branch to failure if null
1298 float ok_prob = PROB_MAX; // a priori estimate: nulls never happen
1299 Deoptimization::DeoptReason reason;
1300 if (assert_null) {
1301 reason = Deoptimization::reason_null_assert(speculative);
1302 } else if (type == T_OBJECT) {
1303 reason = Deoptimization::reason_null_check(speculative);
1304 } else {
1305 reason = Deoptimization::Reason_div0_check;
1306 }
1307 // %%% Since Reason_unhandled is not recorded on a per-bytecode basis,
1308 // ciMethodData::has_trap_at will return a conservative -1 if any
1309 // must-be-null assertion has failed. This could cause performance
1310 // problems for a method after its first do_null_assert failure.
1311 // Consider using 'Reason_class_check' instead?
1312
1313 // To cause an implicit null check, we set the not-null probability
1314 // to the maximum (PROB_MAX). For an explicit check the probability
1315 // is set to a smaller value.
1316 if (null_control != NULL || too_many_traps(reason)) {
1317 // probability is less likely
1318 ok_prob = PROB_LIKELY_MAG(3);
1319 } else if (!assert_null &&
1320 (ImplicitNullCheckThreshold > 0) &&
1321 method() != NULL &&
1322 (method()->method_data()->trap_count(reason)
1323 >= (uint)ImplicitNullCheckThreshold)) {
1324 ok_prob = PROB_LIKELY_MAG(3);
1325 }
1326
1327 if (null_control != NULL) {
1328 IfNode* iff = create_and_map_if(control(), tst, ok_prob, COUNT_UNKNOWN);
1329 Node* null_true = _gvn.transform( new IfFalseNode(iff));
1330 set_control( _gvn.transform( new IfTrueNode(iff)));
1331 #ifndef PRODUCT
1332 if (null_true == top()) {
1333 explicit_null_checks_elided++;
1334 }
1335 #endif
1336 (*null_control) = null_true;
1337 } else {
1338 BuildCutout unless(this, tst, ok_prob);
1339 // Check for optimizer eliding test at parse time
1340 if (stopped()) {
1341 // Failure not possible; do not bother making uncommon trap.
1342 NOT_PRODUCT(explicit_null_checks_elided++);
1343 } else if (assert_null) {
1344 uncommon_trap(reason,
1345 Deoptimization::Action_make_not_entrant,
1346 NULL, "assert_null");
1347 } else {
1348 replace_in_map(value, zerocon(type));
1349 builtin_throw(reason);
1350 }
1351 }
1352
1353 // Must throw exception, fall-thru not possible?
1354 if (stopped()) {
1355 return top(); // No result
1356 }
1357
1358 if (assert_null) {
1359 // Cast obj to null on this path.
1360 replace_in_map(value, zerocon(type));
1361 return zerocon(type);
1362 }
1363
1364 // Cast obj to not-null on this path, if there is no null_control.
1365 // (If there is a null_control, a non-null value may come back to haunt us.)
1366 if (type == T_OBJECT) {
1367 Node* cast = cast_not_null(value, false);
1368 if (null_control == NULL || (*null_control) == top())
1369 replace_in_map(value, cast);
1370 value = cast;
1371 }
1372
1373 return value;
1374 }
1375
1376
1377 //------------------------------cast_not_null----------------------------------
1378 // Cast obj to not-null on this path
1379 Node* GraphKit::cast_not_null(Node* obj, bool do_replace_in_map) {
1380 const Type *t = _gvn.type(obj);
1381 const Type *t_not_null = t->join_speculative(TypePtr::NOTNULL);
1382 // Object is already not-null?
1383 if( t == t_not_null ) return obj;
1384
1385 Node *cast = new CastPPNode(obj,t_not_null);
1386 cast->init_req(0, control());
1387 cast = _gvn.transform( cast );
1388
1389 // Scan for instances of 'obj' in the current JVM mapping.
1390 // These instances are known to be not-null after the test.
1391 if (do_replace_in_map)
1392 replace_in_map(obj, cast);
1393
1394 return cast; // Return casted value
1395 }
1396
1397 // Sometimes in intrinsics, we implicitly know an object is not null
1398 // (there's no actual null check) so we can cast it to not null. In
1399 // the course of optimizations, the input to the cast can become null.
1400 // In that case that data path will die and we need the control path
1401 // to become dead as well to keep the graph consistent. So we have to
1402 // add a check for null for which one branch can't be taken. It uses
1403 // an Opaque4 node that will cause the check to be removed after loop
1404 // opts so the test goes away and the compiled code doesn't execute a
1405 // useless check.
1406 Node* GraphKit::must_be_not_null(Node* value, bool do_replace_in_map) {
1407 Node* chk = _gvn.transform(new CmpPNode(value, null()));
1408 Node *tst = _gvn.transform(new BoolNode(chk, BoolTest::ne));
1409 Node* opaq = _gvn.transform(new Opaque4Node(C, tst, intcon(1)));
1410 IfNode *iff = new IfNode(control(), opaq, PROB_MAX, COUNT_UNKNOWN);
1411 _gvn.set_type(iff, iff->Value(&_gvn));
1412 Node *if_f = _gvn.transform(new IfFalseNode(iff));
1413 Node *frame = _gvn.transform(new ParmNode(C->start(), TypeFunc::FramePtr));
1414 Node *halt = _gvn.transform(new HaltNode(if_f, frame));
1415 C->root()->add_req(halt);
1416 Node *if_t = _gvn.transform(new IfTrueNode(iff));
1417 set_control(if_t);
1418 return cast_not_null(value, do_replace_in_map);
1419 }
1420
1421
1422 //--------------------------replace_in_map-------------------------------------
1423 void GraphKit::replace_in_map(Node* old, Node* neww) {
1424 if (old == neww) {
1425 return;
1426 }
1427
1428 map()->replace_edge(old, neww);
1429
1430 // Note: This operation potentially replaces any edge
1431 // on the map. This includes locals, stack, and monitors
1432 // of the current (innermost) JVM state.
1433
1434 // don't let inconsistent types from profiling escape this
1435 // method
1436
1437 const Type* told = _gvn.type(old);
1438 const Type* tnew = _gvn.type(neww);
1439
1440 if (!tnew->higher_equal(told)) {
1441 return;
1442 }
1443
1444 map()->record_replaced_node(old, neww);
1445 }
1446
1447
1448 //=============================================================================
1449 //--------------------------------memory---------------------------------------
1450 Node* GraphKit::memory(uint alias_idx) {
1451 MergeMemNode* mem = merged_memory();
1452 Node* p = mem->memory_at(alias_idx);
1453 _gvn.set_type(p, Type::MEMORY); // must be mapped
1454 return p;
1455 }
1456
1457 //-----------------------------reset_memory------------------------------------
1458 Node* GraphKit::reset_memory() {
1459 Node* mem = map()->memory();
1460 // do not use this node for any more parsing!
1461 debug_only( map()->set_memory((Node*)NULL) );
1462 return _gvn.transform( mem );
1463 }
1464
1465 //------------------------------set_all_memory---------------------------------
1466 void GraphKit::set_all_memory(Node* newmem) {
1467 Node* mergemem = MergeMemNode::make(newmem);
1468 gvn().set_type_bottom(mergemem);
1469 map()->set_memory(mergemem);
1470 }
1471
1472 //------------------------------set_all_memory_call----------------------------
1473 void GraphKit::set_all_memory_call(Node* call, bool separate_io_proj) {
1474 Node* newmem = _gvn.transform( new ProjNode(call, TypeFunc::Memory, separate_io_proj) );
1475 set_all_memory(newmem);
1476 }
1477
1478 //=============================================================================
1479 //
1480 // parser factory methods for MemNodes
1481 //
1482 // These are layered on top of the factory methods in LoadNode and StoreNode,
1483 // and integrate with the parser's memory state and _gvn engine.
1484 //
1485
1486 // factory methods in "int adr_idx"
1487 Node* GraphKit::make_load(Node* ctl, Node* adr, const Type* t, BasicType bt,
1488 int adr_idx,
1489 MemNode::MemOrd mo,
1490 LoadNode::ControlDependency control_dependency,
1491 bool require_atomic_access,
1492 bool unaligned,
1493 bool mismatched) {
1494 assert(adr_idx != Compile::AliasIdxTop, "use other make_load factory" );
1495 const TypePtr* adr_type = NULL; // debug-mode-only argument
1496 debug_only(adr_type = C->get_adr_type(adr_idx));
1497 Node* mem = memory(adr_idx);
1498 Node* ld;
1499 if (require_atomic_access && bt == T_LONG) {
1500 ld = LoadLNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1501 } else if (require_atomic_access && bt == T_DOUBLE) {
1502 ld = LoadDNode::make_atomic(ctl, mem, adr, adr_type, t, mo, control_dependency, unaligned, mismatched);
1503 } else {
1504 ld = LoadNode::make(_gvn, ctl, mem, adr, adr_type, t, bt, mo, control_dependency, unaligned, mismatched);
1505 }
1506 ld = _gvn.transform(ld);
1507 if (((bt == T_OBJECT) && C->do_escape_analysis()) || C->eliminate_boxing()) {
1508 // Improve graph before escape analysis and boxing elimination.
1509 record_for_igvn(ld);
1510 }
1511 return ld;
1512 }
1513
1514 Node* GraphKit::store_to_memory(Node* ctl, Node* adr, Node *val, BasicType bt,
1515 int adr_idx,
1516 MemNode::MemOrd mo,
1517 bool require_atomic_access,
1518 bool unaligned,
1519 bool mismatched) {
1520 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1521 const TypePtr* adr_type = NULL;
1522 debug_only(adr_type = C->get_adr_type(adr_idx));
1523 Node *mem = memory(adr_idx);
1524 Node* st;
1525 if (require_atomic_access && bt == T_LONG) {
1526 st = StoreLNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1527 } else if (require_atomic_access && bt == T_DOUBLE) {
1528 st = StoreDNode::make_atomic(ctl, mem, adr, adr_type, val, mo);
1529 } else {
1530 st = StoreNode::make(_gvn, ctl, mem, adr, adr_type, val, bt, mo);
1531 }
1532 if (unaligned) {
1533 st->as_Store()->set_unaligned_access();
1534 }
1535 if (mismatched) {
1536 st->as_Store()->set_mismatched_access();
1537 }
1538 st = _gvn.transform(st);
1539 set_memory(st, adr_idx);
1540 // Back-to-back stores can only remove intermediate store with DU info
1541 // so push on worklist for optimizer.
1542 if (mem->req() > MemNode::Address && adr == mem->in(MemNode::Address))
1543 record_for_igvn(st);
1544
1545 return st;
1546 }
1547
1548 Node* GraphKit::access_store_at(Node* ctl,
1549 Node* obj,
1550 Node* adr,
1551 const TypePtr* adr_type,
1552 Node* val,
1553 const Type* val_type,
1554 BasicType bt,
1555 DecoratorSet decorators) {
1556 // Transformation of a value which could be NULL pointer (CastPP #NULL)
1557 // could be delayed during Parse (for example, in adjust_map_after_if()).
1558 // Execute transformation here to avoid barrier generation in such case.
1559 if (_gvn.type(val) == TypePtr::NULL_PTR) {
1560 val = _gvn.makecon(TypePtr::NULL_PTR);
1561 }
1562
1563 set_control(ctl);
1564 if (stopped()) {
1565 return top(); // Dead path ?
1566 }
1567
1568 assert(val != NULL, "not dead path");
1569
1570 C2AccessValuePtr addr(adr, adr_type);
1571 C2AccessValue value(val, val_type);
1572 C2Access access(this, decorators | C2_WRITE_ACCESS, bt, obj, addr);
1573 if (access.is_raw()) {
1574 return _barrier_set->BarrierSetC2::store_at(access, value);
1575 } else {
1576 return _barrier_set->store_at(access, value);
1577 }
1578 }
1579
1580 Node* GraphKit::access_load_at(Node* obj, // containing obj
1581 Node* adr, // actual adress to store val at
1582 const TypePtr* adr_type,
1583 const Type* val_type,
1584 BasicType bt,
1585 DecoratorSet decorators) {
1586 if (stopped()) {
1587 return top(); // Dead path ?
1588 }
1589
1590 C2AccessValuePtr addr(adr, adr_type);
1591 C2Access access(this, decorators | C2_READ_ACCESS, bt, obj, addr);
1592 if (access.is_raw()) {
1593 return _barrier_set->BarrierSetC2::load_at(access, val_type);
1594 } else {
1595 return _barrier_set->load_at(access, val_type);
1596 }
1597 }
1598
1599 Node* GraphKit::access_atomic_cmpxchg_val_at(Node* ctl,
1600 Node* obj,
1601 Node* adr,
1602 const TypePtr* adr_type,
1603 int alias_idx,
1604 Node* expected_val,
1605 Node* new_val,
1606 const Type* value_type,
1607 BasicType bt,
1608 DecoratorSet decorators) {
1609 set_control(ctl);
1610 C2AccessValuePtr addr(adr, adr_type);
1611 C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1612 bt, obj, addr, alias_idx);
1613 if (access.is_raw()) {
1614 return _barrier_set->BarrierSetC2::atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1615 } else {
1616 return _barrier_set->atomic_cmpxchg_val_at(access, expected_val, new_val, value_type);
1617 }
1618 }
1619
1620 Node* GraphKit::access_atomic_cmpxchg_bool_at(Node* ctl,
1621 Node* obj,
1622 Node* adr,
1623 const TypePtr* adr_type,
1624 int alias_idx,
1625 Node* expected_val,
1626 Node* new_val,
1627 const Type* value_type,
1628 BasicType bt,
1629 DecoratorSet decorators) {
1630 set_control(ctl);
1631 C2AccessValuePtr addr(adr, adr_type);
1632 C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1633 bt, obj, addr, alias_idx);
1634 if (access.is_raw()) {
1635 return _barrier_set->BarrierSetC2::atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1636 } else {
1637 return _barrier_set->atomic_cmpxchg_bool_at(access, expected_val, new_val, value_type);
1638 }
1639 }
1640
1641 Node* GraphKit::access_atomic_xchg_at(Node* ctl,
1642 Node* obj,
1643 Node* adr,
1644 const TypePtr* adr_type,
1645 int alias_idx,
1646 Node* new_val,
1647 const Type* value_type,
1648 BasicType bt,
1649 DecoratorSet decorators) {
1650 set_control(ctl);
1651 C2AccessValuePtr addr(adr, adr_type);
1652 C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS,
1653 bt, obj, addr, alias_idx);
1654 if (access.is_raw()) {
1655 return _barrier_set->BarrierSetC2::atomic_xchg_at(access, new_val, value_type);
1656 } else {
1657 return _barrier_set->atomic_xchg_at(access, new_val, value_type);
1658 }
1659 }
1660
1661 Node* GraphKit::access_atomic_add_at(Node* ctl,
1662 Node* obj,
1663 Node* adr,
1664 const TypePtr* adr_type,
1665 int alias_idx,
1666 Node* new_val,
1667 const Type* value_type,
1668 BasicType bt,
1669 DecoratorSet decorators) {
1670 set_control(ctl);
1671 C2AccessValuePtr addr(adr, adr_type);
1672 C2AtomicAccess access(this, decorators | C2_READ_ACCESS | C2_WRITE_ACCESS, bt, obj, addr, alias_idx);
1673 if (access.is_raw()) {
1674 return _barrier_set->BarrierSetC2::atomic_add_at(access, new_val, value_type);
1675 } else {
1676 return _barrier_set->atomic_add_at(access, new_val, value_type);
1677 }
1678 }
1679
1680 void GraphKit::access_clone(Node* ctl, Node* src, Node* dst, Node* size, bool is_array) {
1681 set_control(ctl);
1682 return _barrier_set->clone(this, src, dst, size, is_array);
1683 }
1684
1685 //-------------------------array_element_address-------------------------
1686 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1687 const TypeInt* sizetype, Node* ctrl) {
1688 uint shift = exact_log2(type2aelembytes(elembt));
1689 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1690
1691 // short-circuit a common case (saves lots of confusing waste motion)
1692 jint idx_con = find_int_con(idx, -1);
1693 if (idx_con >= 0) {
1694 intptr_t offset = header + ((intptr_t)idx_con << shift);
1695 return basic_plus_adr(ary, offset);
1696 }
1697
1698 // must be correct type for alignment purposes
1699 Node* base = basic_plus_adr(ary, header);
1700 idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1701 Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1702 return basic_plus_adr(ary, base, scale);
1703 }
1704
1705 //-------------------------load_array_element-------------------------
1706 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1707 const Type* elemtype = arytype->elem();
1708 BasicType elembt = elemtype->array_element_basic_type();
1709 Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1710 if (elembt == T_NARROWOOP) {
1711 elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1712 }
1713 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1714 return ld;
1715 }
1716
1717 //-------------------------set_arguments_for_java_call-------------------------
1718 // Arguments (pre-popped from the stack) are taken from the JVMS.
1719 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1720 // Add the call arguments:
1721 uint nargs = call->method()->arg_size();
1722 for (uint i = 0; i < nargs; i++) {
1723 Node* arg = argument(i);
1724 call->init_req(i + TypeFunc::Parms, arg);
1725 }
1726 }
1727
1728 //---------------------------set_edges_for_java_call---------------------------
1729 // Connect a newly created call into the current JVMS.
1730 // A return value node (if any) is returned from set_edges_for_java_call.
1731 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1732
1733 // Add the predefined inputs:
1734 call->init_req( TypeFunc::Control, control() );
1735 call->init_req( TypeFunc::I_O , i_o() );
1736 call->init_req( TypeFunc::Memory , reset_memory() );
1737 call->init_req( TypeFunc::FramePtr, frameptr() );
1738 call->init_req( TypeFunc::ReturnAdr, top() );
1739
1740 add_safepoint_edges(call, must_throw);
1741
1742 Node* xcall = _gvn.transform(call);
1743
1744 if (xcall == top()) {
1745 set_control(top());
1746 return;
1747 }
1748 assert(xcall == call, "call identity is stable");
1749
1750 // Re-use the current map to produce the result.
1751
1752 set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1753 set_i_o( _gvn.transform(new ProjNode(call, TypeFunc::I_O , separate_io_proj)));
1754 set_all_memory_call(xcall, separate_io_proj);
1755
1756 //return xcall; // no need, caller already has it
1757 }
1758
1759 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1760 if (stopped()) return top(); // maybe the call folded up?
1761
1762 // Capture the return value, if any.
1763 Node* ret;
1764 if (call->method() == NULL ||
1765 call->method()->return_type()->basic_type() == T_VOID)
1766 ret = top();
1767 else ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1768
1769 // Note: Since any out-of-line call can produce an exception,
1770 // we always insert an I_O projection from the call into the result.
1771
1772 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1773
1774 if (separate_io_proj) {
1775 // The caller requested separate projections be used by the fall
1776 // through and exceptional paths, so replace the projections for
1777 // the fall through path.
1778 set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1779 set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1780 }
1781 return ret;
1782 }
1783
1784 //--------------------set_predefined_input_for_runtime_call--------------------
1785 // Reading and setting the memory state is way conservative here.
1786 // The real problem is that I am not doing real Type analysis on memory,
1787 // so I cannot distinguish card mark stores from other stores. Across a GC
1788 // point the Store Barrier and the card mark memory has to agree. I cannot
1789 // have a card mark store and its barrier split across the GC point from
1790 // either above or below. Here I get that to happen by reading ALL of memory.
1791 // A better answer would be to separate out card marks from other memory.
1792 // For now, return the input memory state, so that it can be reused
1793 // after the call, if this call has restricted memory effects.
1794 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1795 // Set fixed predefined input arguments
1796 Node* memory = reset_memory();
1797 call->init_req( TypeFunc::Control, control() );
1798 call->init_req( TypeFunc::I_O, top() ); // does no i/o
1799 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs
1800 call->init_req( TypeFunc::FramePtr, frameptr() );
1801 call->init_req( TypeFunc::ReturnAdr, top() );
1802 return memory;
1803 }
1804
1805 //-------------------set_predefined_output_for_runtime_call--------------------
1806 // Set control and memory (not i_o) from the call.
1807 // If keep_mem is not NULL, use it for the output state,
1808 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1809 // If hook_mem is NULL, this call produces no memory effects at all.
1810 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1811 // then only that memory slice is taken from the call.
1812 // In the last case, we must put an appropriate memory barrier before
1813 // the call, so as to create the correct anti-dependencies on loads
1814 // preceding the call.
1815 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1816 Node* keep_mem,
1817 const TypePtr* hook_mem) {
1818 // no i/o
1819 set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1820 if (keep_mem) {
1821 // First clone the existing memory state
1822 set_all_memory(keep_mem);
1823 if (hook_mem != NULL) {
1824 // Make memory for the call
1825 Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1826 // Set the RawPtr memory state only. This covers all the heap top/GC stuff
1827 // We also use hook_mem to extract specific effects from arraycopy stubs.
1828 set_memory(mem, hook_mem);
1829 }
1830 // ...else the call has NO memory effects.
1831
1832 // Make sure the call advertises its memory effects precisely.
1833 // This lets us build accurate anti-dependences in gcm.cpp.
1834 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1835 "call node must be constructed correctly");
1836 } else {
1837 assert(hook_mem == NULL, "");
1838 // This is not a "slow path" call; all memory comes from the call.
1839 set_all_memory_call(call);
1840 }
1841 }
1842
1843
1844 // Replace the call with the current state of the kit.
1845 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1846 JVMState* ejvms = NULL;
1847 if (has_exceptions()) {
1848 ejvms = transfer_exceptions_into_jvms();
1849 }
1850
1851 ReplacedNodes replaced_nodes = map()->replaced_nodes();
1852 ReplacedNodes replaced_nodes_exception;
1853 Node* ex_ctl = top();
1854
1855 SafePointNode* final_state = stop();
1856
1857 // Find all the needed outputs of this call
1858 CallProjections callprojs;
1859 call->extract_projections(&callprojs, true);
1860
1861 Node* init_mem = call->in(TypeFunc::Memory);
1862 Node* final_mem = final_state->in(TypeFunc::Memory);
1863 Node* final_ctl = final_state->in(TypeFunc::Control);
1864 Node* final_io = final_state->in(TypeFunc::I_O);
1865
1866 // Replace all the old call edges with the edges from the inlining result
1867 if (callprojs.fallthrough_catchproj != NULL) {
1868 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1869 }
1870 if (callprojs.fallthrough_memproj != NULL) {
1871 if (final_mem->is_MergeMem()) {
1872 // Parser's exits MergeMem was not transformed but may be optimized
1873 final_mem = _gvn.transform(final_mem);
1874 }
1875 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem);
1876 }
1877 if (callprojs.fallthrough_ioproj != NULL) {
1878 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io);
1879 }
1880
1881 // Replace the result with the new result if it exists and is used
1882 if (callprojs.resproj != NULL && result != NULL) {
1883 C->gvn_replace_by(callprojs.resproj, result);
1884 }
1885
1886 if (ejvms == NULL) {
1887 // No exception edges to simply kill off those paths
1888 if (callprojs.catchall_catchproj != NULL) {
1889 C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1890 }
1891 if (callprojs.catchall_memproj != NULL) {
1892 C->gvn_replace_by(callprojs.catchall_memproj, C->top());
1893 }
1894 if (callprojs.catchall_ioproj != NULL) {
1895 C->gvn_replace_by(callprojs.catchall_ioproj, C->top());
1896 }
1897 // Replace the old exception object with top
1898 if (callprojs.exobj != NULL) {
1899 C->gvn_replace_by(callprojs.exobj, C->top());
1900 }
1901 } else {
1902 GraphKit ekit(ejvms);
1903
1904 // Load my combined exception state into the kit, with all phis transformed:
1905 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1906 replaced_nodes_exception = ex_map->replaced_nodes();
1907
1908 Node* ex_oop = ekit.use_exception_state(ex_map);
1909
1910 if (callprojs.catchall_catchproj != NULL) {
1911 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1912 ex_ctl = ekit.control();
1913 }
1914 if (callprojs.catchall_memproj != NULL) {
1915 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory());
1916 }
1917 if (callprojs.catchall_ioproj != NULL) {
1918 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o());
1919 }
1920
1921 // Replace the old exception object with the newly created one
1922 if (callprojs.exobj != NULL) {
1923 C->gvn_replace_by(callprojs.exobj, ex_oop);
1924 }
1925 }
1926
1927 // Disconnect the call from the graph
1928 call->disconnect_inputs(NULL, C);
1929 C->gvn_replace_by(call, C->top());
1930
1931 // Clean up any MergeMems that feed other MergeMems since the
1932 // optimizer doesn't like that.
1933 if (final_mem->is_MergeMem()) {
1934 Node_List wl;
1935 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1936 Node* m = i.get();
1937 if (m->is_MergeMem() && !wl.contains(m)) {
1938 wl.push(m);
1939 }
1940 }
1941 while (wl.size() > 0) {
1942 _gvn.transform(wl.pop());
1943 }
1944 }
1945
1946 if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1947 replaced_nodes.apply(C, final_ctl);
1948 }
1949 if (!ex_ctl->is_top() && do_replaced_nodes) {
1950 replaced_nodes_exception.apply(C, ex_ctl);
1951 }
1952 }
1953
1954
1955 //------------------------------increment_counter------------------------------
1956 // for statistics: increment a VM counter by 1
1957
1958 void GraphKit::increment_counter(address counter_addr) {
1959 Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1960 increment_counter(adr1);
1961 }
1962
1963 void GraphKit::increment_counter(Node* counter_addr) {
1964 int adr_type = Compile::AliasIdxRaw;
1965 Node* ctrl = control();
1966 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1967 Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1968 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1969 }
1970
1971
1972 //------------------------------uncommon_trap----------------------------------
1973 // Bail out to the interpreter in mid-method. Implemented by calling the
1974 // uncommon_trap blob. This helper function inserts a runtime call with the
1975 // right debug info.
1976 void GraphKit::uncommon_trap(int trap_request,
1977 ciKlass* klass, const char* comment,
1978 bool must_throw,
1979 bool keep_exact_action) {
1980 if (failing()) stop();
1981 if (stopped()) return; // trap reachable?
1982
1983 // Note: If ProfileTraps is true, and if a deopt. actually
1984 // occurs here, the runtime will make sure an MDO exists. There is
1985 // no need to call method()->ensure_method_data() at this point.
1986
1987 // Set the stack pointer to the right value for reexecution:
1988 set_sp(reexecute_sp());
1989
1990 #ifdef ASSERT
1991 if (!must_throw) {
1992 // Make sure the stack has at least enough depth to execute
1993 // the current bytecode.
1994 int inputs, ignored_depth;
1995 if (compute_stack_effects(inputs, ignored_depth)) {
1996 assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
1997 Bytecodes::name(java_bc()), sp(), inputs);
1998 }
1999 }
2000 #endif
2001
2002 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2003 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2004
2005 switch (action) {
2006 case Deoptimization::Action_maybe_recompile:
2007 case Deoptimization::Action_reinterpret:
2008 // Temporary fix for 6529811 to allow virtual calls to be sure they
2009 // get the chance to go from mono->bi->mega
2010 if (!keep_exact_action &&
2011 Deoptimization::trap_request_index(trap_request) < 0 &&
2012 too_many_recompiles(reason)) {
2013 // This BCI is causing too many recompilations.
2014 if (C->log() != NULL) {
2015 C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2016 Deoptimization::trap_reason_name(reason),
2017 Deoptimization::trap_action_name(action));
2018 }
2019 action = Deoptimization::Action_none;
2020 trap_request = Deoptimization::make_trap_request(reason, action);
2021 } else {
2022 C->set_trap_can_recompile(true);
2023 }
2024 break;
2025 case Deoptimization::Action_make_not_entrant:
2026 C->set_trap_can_recompile(true);
2027 break;
2028 case Deoptimization::Action_none:
2029 case Deoptimization::Action_make_not_compilable:
2030 break;
2031 default:
2032 #ifdef ASSERT
2033 fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2034 #endif
2035 break;
2036 }
2037
2038 if (TraceOptoParse) {
2039 char buf[100];
2040 tty->print_cr("Uncommon trap %s at bci:%d",
2041 Deoptimization::format_trap_request(buf, sizeof(buf),
2042 trap_request), bci());
2043 }
2044
2045 CompileLog* log = C->log();
2046 if (log != NULL) {
2047 int kid = (klass == NULL)? -1: log->identify(klass);
2048 log->begin_elem("uncommon_trap bci='%d'", bci());
2049 char buf[100];
2050 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2051 trap_request));
2052 if (kid >= 0) log->print(" klass='%d'", kid);
2053 if (comment != NULL) log->print(" comment='%s'", comment);
2054 log->end_elem();
2055 }
2056
2057 // Make sure any guarding test views this path as very unlikely
2058 Node *i0 = control()->in(0);
2059 if (i0 != NULL && i0->is_If()) { // Found a guarding if test?
2060 IfNode *iff = i0->as_If();
2061 float f = iff->_prob; // Get prob
2062 if (control()->Opcode() == Op_IfTrue) {
2063 if (f > PROB_UNLIKELY_MAG(4))
2064 iff->_prob = PROB_MIN;
2065 } else {
2066 if (f < PROB_LIKELY_MAG(4))
2067 iff->_prob = PROB_MAX;
2068 }
2069 }
2070
2071 // Clear out dead values from the debug info.
2072 kill_dead_locals();
2073
2074 // Now insert the uncommon trap subroutine call
2075 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2076 const TypePtr* no_memory_effects = NULL;
2077 // Pass the index of the class to be loaded
2078 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2079 (must_throw ? RC_MUST_THROW : 0),
2080 OptoRuntime::uncommon_trap_Type(),
2081 call_addr, "uncommon_trap", no_memory_effects,
2082 intcon(trap_request));
2083 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2084 "must extract request correctly from the graph");
2085 assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2086
2087 call->set_req(TypeFunc::ReturnAdr, returnadr());
2088 // The debug info is the only real input to this call.
2089
2090 // Halt-and-catch fire here. The above call should never return!
2091 HaltNode* halt = new HaltNode(control(), frameptr());
2092 _gvn.set_type_bottom(halt);
2093 root()->add_req(halt);
2094
2095 stop_and_kill_map();
2096 }
2097
2098
2099 //--------------------------just_allocated_object------------------------------
2100 // Report the object that was just allocated.
2101 // It must be the case that there are no intervening safepoints.
2102 // We use this to determine if an object is so "fresh" that
2103 // it does not require card marks.
2104 Node* GraphKit::just_allocated_object(Node* current_control) {
2105 if (C->recent_alloc_ctl() == current_control)
2106 return C->recent_alloc_obj();
2107 return NULL;
2108 }
2109
2110
2111 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2112 // (Note: TypeFunc::make has a cache that makes this fast.)
2113 const TypeFunc* tf = TypeFunc::make(dest_method);
2114 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2115 for (int j = 0; j < nargs; j++) {
2116 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2117 if( targ->basic_type() == T_DOUBLE ) {
2118 // If any parameters are doubles, they must be rounded before
2119 // the call, dstore_rounding does gvn.transform
2120 Node *arg = argument(j);
2121 arg = dstore_rounding(arg);
2122 set_argument(j, arg);
2123 }
2124 }
2125 }
2126
2127 /**
2128 * Record profiling data exact_kls for Node n with the type system so
2129 * that it can propagate it (speculation)
2130 *
2131 * @param n node that the type applies to
2132 * @param exact_kls type from profiling
2133 * @param maybe_null did profiling see null?
2134 *
2135 * @return node with improved type
2136 */
2137 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2138 const Type* current_type = _gvn.type(n);
2139 assert(UseTypeSpeculation, "type speculation must be on");
2140
2141 const TypePtr* speculative = current_type->speculative();
2142
2143 // Should the klass from the profile be recorded in the speculative type?
2144 if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2145 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2146 const TypeOopPtr* xtype = tklass->as_instance_type();
2147 assert(xtype->klass_is_exact(), "Should be exact");
2148 // Any reason to believe n is not null (from this profiling or a previous one)?
2149 assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2150 const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2151 // record the new speculative type's depth
2152 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2153 speculative = speculative->with_inline_depth(jvms()->depth());
2154 } else if (current_type->would_improve_ptr(ptr_kind)) {
2155 // Profiling report that null was never seen so we can change the
2156 // speculative type to non null ptr.
2157 if (ptr_kind == ProfileAlwaysNull) {
2158 speculative = TypePtr::NULL_PTR;
2159 } else {
2160 assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2161 const TypePtr* ptr = TypePtr::NOTNULL;
2162 if (speculative != NULL) {
2163 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2164 } else {
2165 speculative = ptr;
2166 }
2167 }
2168 }
2169
2170 if (speculative != current_type->speculative()) {
2171 // Build a type with a speculative type (what we think we know
2172 // about the type but will need a guard when we use it)
2173 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2174 // We're changing the type, we need a new CheckCast node to carry
2175 // the new type. The new type depends on the control: what
2176 // profiling tells us is only valid from here as far as we can
2177 // tell.
2178 Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2179 cast = _gvn.transform(cast);
2180 replace_in_map(n, cast);
2181 n = cast;
2182 }
2183
2184 return n;
2185 }
2186
2187 /**
2188 * Record profiling data from receiver profiling at an invoke with the
2189 * type system so that it can propagate it (speculation)
2190 *
2191 * @param n receiver node
2192 *
2193 * @return node with improved type
2194 */
2195 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2196 if (!UseTypeSpeculation) {
2197 return n;
2198 }
2199 ciKlass* exact_kls = profile_has_unique_klass();
2200 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2201 if ((java_bc() == Bytecodes::_checkcast ||
2202 java_bc() == Bytecodes::_instanceof ||
2203 java_bc() == Bytecodes::_aastore) &&
2204 method()->method_data()->is_mature()) {
2205 ciProfileData* data = method()->method_data()->bci_to_data(bci());
2206 if (data != NULL) {
2207 if (!data->as_BitData()->null_seen()) {
2208 ptr_kind = ProfileNeverNull;
2209 } else {
2210 assert(data->is_ReceiverTypeData(), "bad profile data type");
2211 ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2212 uint i = 0;
2213 for (; i < call->row_limit(); i++) {
2214 ciKlass* receiver = call->receiver(i);
2215 if (receiver != NULL) {
2216 break;
2217 }
2218 }
2219 ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2220 }
2221 }
2222 }
2223 return record_profile_for_speculation(n, exact_kls, ptr_kind);
2224 }
2225
2226 /**
2227 * Record profiling data from argument profiling at an invoke with the
2228 * type system so that it can propagate it (speculation)
2229 *
2230 * @param dest_method target method for the call
2231 * @param bc what invoke bytecode is this?
2232 */
2233 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2234 if (!UseTypeSpeculation) {
2235 return;
2236 }
2237 const TypeFunc* tf = TypeFunc::make(dest_method);
2238 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2239 int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2240 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2241 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2242 if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2243 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2244 ciKlass* better_type = NULL;
2245 if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2246 record_profile_for_speculation(argument(j), better_type, ptr_kind);
2247 }
2248 i++;
2249 }
2250 }
2251 }
2252
2253 /**
2254 * Record profiling data from parameter profiling at an invoke with
2255 * the type system so that it can propagate it (speculation)
2256 */
2257 void GraphKit::record_profiled_parameters_for_speculation() {
2258 if (!UseTypeSpeculation) {
2259 return;
2260 }
2261 for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2262 if (_gvn.type(local(i))->isa_oopptr()) {
2263 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2264 ciKlass* better_type = NULL;
2265 if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2266 record_profile_for_speculation(local(i), better_type, ptr_kind);
2267 }
2268 j++;
2269 }
2270 }
2271 }
2272
2273 /**
2274 * Record profiling data from return value profiling at an invoke with
2275 * the type system so that it can propagate it (speculation)
2276 */
2277 void GraphKit::record_profiled_return_for_speculation() {
2278 if (!UseTypeSpeculation) {
2279 return;
2280 }
2281 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2282 ciKlass* better_type = NULL;
2283 if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2284 // If profiling reports a single type for the return value,
2285 // feed it to the type system so it can propagate it as a
2286 // speculative type
2287 record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2288 }
2289 }
2290
2291 void GraphKit::round_double_result(ciMethod* dest_method) {
2292 // A non-strict method may return a double value which has an extended
2293 // exponent, but this must not be visible in a caller which is 'strict'
2294 // If a strict caller invokes a non-strict callee, round a double result
2295
2296 BasicType result_type = dest_method->return_type()->basic_type();
2297 assert( method() != NULL, "must have caller context");
2298 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2299 // Destination method's return value is on top of stack
2300 // dstore_rounding() does gvn.transform
2301 Node *result = pop_pair();
2302 result = dstore_rounding(result);
2303 push_pair(result);
2304 }
2305 }
2306
2307 // rounding for strict float precision conformance
2308 Node* GraphKit::precision_rounding(Node* n) {
2309 return UseStrictFP && _method->flags().is_strict()
2310 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2311 ? _gvn.transform( new RoundFloatNode(0, n) )
2312 : n;
2313 }
2314
2315 // rounding for strict double precision conformance
2316 Node* GraphKit::dprecision_rounding(Node *n) {
2317 return UseStrictFP && _method->flags().is_strict()
2318 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2319 ? _gvn.transform( new RoundDoubleNode(0, n) )
2320 : n;
2321 }
2322
2323 // rounding for non-strict double stores
2324 Node* GraphKit::dstore_rounding(Node* n) {
2325 return Matcher::strict_fp_requires_explicit_rounding
2326 && UseSSE <= 1
2327 ? _gvn.transform( new RoundDoubleNode(0, n) )
2328 : n;
2329 }
2330
2331 //=============================================================================
2332 // Generate a fast path/slow path idiom. Graph looks like:
2333 // [foo] indicates that 'foo' is a parameter
2334 //
2335 // [in] NULL
2336 // \ /
2337 // CmpP
2338 // Bool ne
2339 // If
2340 // / \
2341 // True False-<2>
2342 // / |
2343 // / cast_not_null
2344 // Load | | ^
2345 // [fast_test] | |
2346 // gvn to opt_test | |
2347 // / \ | <1>
2348 // True False |
2349 // | \\ |
2350 // [slow_call] \[fast_result]
2351 // Ctl Val \ \
2352 // | \ \
2353 // Catch <1> \ \
2354 // / \ ^ \ \
2355 // Ex No_Ex | \ \
2356 // | \ \ | \ <2> \
2357 // ... \ [slow_res] | | \ [null_result]
2358 // \ \--+--+--- | |
2359 // \ | / \ | /
2360 // --------Region Phi
2361 //
2362 //=============================================================================
2363 // Code is structured as a series of driver functions all called 'do_XXX' that
2364 // call a set of helper functions. Helper functions first, then drivers.
2365
2366 //------------------------------null_check_oop---------------------------------
2367 // Null check oop. Set null-path control into Region in slot 3.
2368 // Make a cast-not-nullness use the other not-null control. Return cast.
2369 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2370 bool never_see_null,
2371 bool safe_for_replace,
2372 bool speculative) {
2373 // Initial NULL check taken path
2374 (*null_control) = top();
2375 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2376
2377 // Generate uncommon_trap:
2378 if (never_see_null && (*null_control) != top()) {
2379 // If we see an unexpected null at a check-cast we record it and force a
2380 // recompile; the offending check-cast will be compiled to handle NULLs.
2381 // If we see more than one offending BCI, then all checkcasts in the
2382 // method will be compiled to handle NULLs.
2383 PreserveJVMState pjvms(this);
2384 set_control(*null_control);
2385 replace_in_map(value, null());
2386 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2387 uncommon_trap(reason,
2388 Deoptimization::Action_make_not_entrant);
2389 (*null_control) = top(); // NULL path is dead
2390 }
2391 if ((*null_control) == top() && safe_for_replace) {
2392 replace_in_map(value, cast);
2393 }
2394
2395 // Cast away null-ness on the result
2396 return cast;
2397 }
2398
2399 //------------------------------opt_iff----------------------------------------
2400 // Optimize the fast-check IfNode. Set the fast-path region slot 2.
2401 // Return slow-path control.
2402 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2403 IfNode *opt_iff = _gvn.transform(iff)->as_If();
2404
2405 // Fast path taken; set region slot 2
2406 Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2407 region->init_req(2,fast_taken); // Capture fast-control
2408
2409 // Fast path not-taken, i.e. slow path
2410 Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2411 return slow_taken;
2412 }
2413
2414 //-----------------------------make_runtime_call-------------------------------
2415 Node* GraphKit::make_runtime_call(int flags,
2416 const TypeFunc* call_type, address call_addr,
2417 const char* call_name,
2418 const TypePtr* adr_type,
2419 // The following parms are all optional.
2420 // The first NULL ends the list.
2421 Node* parm0, Node* parm1,
2422 Node* parm2, Node* parm3,
2423 Node* parm4, Node* parm5,
2424 Node* parm6, Node* parm7) {
2425 // Slow-path call
2426 bool is_leaf = !(flags & RC_NO_LEAF);
2427 bool has_io = (!is_leaf && !(flags & RC_NO_IO));
2428 if (call_name == NULL) {
2429 assert(!is_leaf, "must supply name for leaf");
2430 call_name = OptoRuntime::stub_name(call_addr);
2431 }
2432 CallNode* call;
2433 if (!is_leaf) {
2434 call = new CallStaticJavaNode(call_type, call_addr, call_name,
2435 bci(), adr_type);
2436 } else if (flags & RC_NO_FP) {
2437 call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2438 } else {
2439 call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2440 }
2441
2442 // The following is similar to set_edges_for_java_call,
2443 // except that the memory effects of the call are restricted to AliasIdxRaw.
2444
2445 // Slow path call has no side-effects, uses few values
2446 bool wide_in = !(flags & RC_NARROW_MEM);
2447 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2448
2449 Node* prev_mem = NULL;
2450 if (wide_in) {
2451 prev_mem = set_predefined_input_for_runtime_call(call);
2452 } else {
2453 assert(!wide_out, "narrow in => narrow out");
2454 Node* narrow_mem = memory(adr_type);
2455 prev_mem = reset_memory();
2456 map()->set_memory(narrow_mem);
2457 set_predefined_input_for_runtime_call(call);
2458 }
2459
2460 // Hook each parm in order. Stop looking at the first NULL.
2461 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2462 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2463 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2464 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2465 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2466 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2467 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2468 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2469 /* close each nested if ===> */ } } } } } } } }
2470 assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2471
2472 if (!is_leaf) {
2473 // Non-leaves can block and take safepoints:
2474 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2475 }
2476 // Non-leaves can throw exceptions:
2477 if (has_io) {
2478 call->set_req(TypeFunc::I_O, i_o());
2479 }
2480
2481 if (flags & RC_UNCOMMON) {
2482 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency.
2483 // (An "if" probability corresponds roughly to an unconditional count.
2484 // Sort of.)
2485 call->set_cnt(PROB_UNLIKELY_MAG(4));
2486 }
2487
2488 Node* c = _gvn.transform(call);
2489 assert(c == call, "cannot disappear");
2490
2491 if (wide_out) {
2492 // Slow path call has full side-effects.
2493 set_predefined_output_for_runtime_call(call);
2494 } else {
2495 // Slow path call has few side-effects, and/or sets few values.
2496 set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2497 }
2498
2499 if (has_io) {
2500 set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2501 }
2502 return call;
2503
2504 }
2505
2506 //------------------------------merge_memory-----------------------------------
2507 // Merge memory from one path into the current memory state.
2508 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2509 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2510 Node* old_slice = mms.force_memory();
2511 Node* new_slice = mms.memory2();
2512 if (old_slice != new_slice) {
2513 PhiNode* phi;
2514 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2515 if (mms.is_empty()) {
2516 // clone base memory Phi's inputs for this memory slice
2517 assert(old_slice == mms.base_memory(), "sanity");
2518 phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2519 _gvn.set_type(phi, Type::MEMORY);
2520 for (uint i = 1; i < phi->req(); i++) {
2521 phi->init_req(i, old_slice->in(i));
2522 }
2523 } else {
2524 phi = old_slice->as_Phi(); // Phi was generated already
2525 }
2526 } else {
2527 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2528 _gvn.set_type(phi, Type::MEMORY);
2529 }
2530 phi->set_req(new_path, new_slice);
2531 mms.set_memory(phi);
2532 }
2533 }
2534 }
2535
2536 //------------------------------make_slow_call_ex------------------------------
2537 // Make the exception handler hookups for the slow call
2538 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2539 if (stopped()) return;
2540
2541 // Make a catch node with just two handlers: fall-through and catch-all
2542 Node* i_o = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2543 Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2544 Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2545 Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) );
2546
2547 { PreserveJVMState pjvms(this);
2548 set_control(excp);
2549 set_i_o(i_o);
2550
2551 if (excp != top()) {
2552 if (deoptimize) {
2553 // Deoptimize if an exception is caught. Don't construct exception state in this case.
2554 uncommon_trap(Deoptimization::Reason_unhandled,
2555 Deoptimization::Action_none);
2556 } else {
2557 // Create an exception state also.
2558 // Use an exact type if the caller has specified a specific exception.
2559 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2560 Node* ex_oop = new CreateExNode(ex_type, control(), i_o);
2561 add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2562 }
2563 }
2564 }
2565
2566 // Get the no-exception control from the CatchNode.
2567 set_control(norm);
2568 }
2569
2570 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2571 Node* cmp = NULL;
2572 switch(bt) {
2573 case T_INT: cmp = new CmpINode(in1, in2); break;
2574 case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2575 default: fatal("unexpected comparison type %s", type2name(bt));
2576 }
2577 gvn->transform(cmp);
2578 Node* bol = gvn->transform(new BoolNode(cmp, test));
2579 IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2580 gvn->transform(iff);
2581 if (!bol->is_Con()) gvn->record_for_igvn(iff);
2582 return iff;
2583 }
2584
2585
2586 //-------------------------------gen_subtype_check-----------------------------
2587 // Generate a subtyping check. Takes as input the subtype and supertype.
2588 // Returns 2 values: sets the default control() to the true path and returns
2589 // the false path. Only reads invariant memory; sets no (visible) memory.
2590 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2591 // but that's not exposed to the optimizer. This call also doesn't take in an
2592 // Object; if you wish to check an Object you need to load the Object's class
2593 // prior to coming here.
2594 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2595 Compile* C = gvn->C;
2596
2597 if ((*ctrl)->is_top()) {
2598 return C->top();
2599 }
2600
2601 // Fast check for identical types, perhaps identical constants.
2602 // The types can even be identical non-constants, in cases
2603 // involving Array.newInstance, Object.clone, etc.
2604 if (subklass == superklass)
2605 return C->top(); // false path is dead; no test needed.
2606
2607 if (gvn->type(superklass)->singleton()) {
2608 ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2609 ciKlass* subk = gvn->type(subklass)->is_klassptr()->klass();
2610
2611 // In the common case of an exact superklass, try to fold up the
2612 // test before generating code. You may ask, why not just generate
2613 // the code and then let it fold up? The answer is that the generated
2614 // code will necessarily include null checks, which do not always
2615 // completely fold away. If they are also needless, then they turn
2616 // into a performance loss. Example:
2617 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2618 // Here, the type of 'fa' is often exact, so the store check
2619 // of fa[1]=x will fold up, without testing the nullness of x.
2620 switch (C->static_subtype_check(superk, subk)) {
2621 case Compile::SSC_always_false:
2622 {
2623 Node* always_fail = *ctrl;
2624 *ctrl = gvn->C->top();
2625 return always_fail;
2626 }
2627 case Compile::SSC_always_true:
2628 return C->top();
2629 case Compile::SSC_easy_test:
2630 {
2631 // Just do a direct pointer compare and be done.
2632 IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2633 *ctrl = gvn->transform(new IfTrueNode(iff));
2634 return gvn->transform(new IfFalseNode(iff));
2635 }
2636 case Compile::SSC_full_test:
2637 break;
2638 default:
2639 ShouldNotReachHere();
2640 }
2641 }
2642
2643 // %%% Possible further optimization: Even if the superklass is not exact,
2644 // if the subklass is the unique subtype of the superklass, the check
2645 // will always succeed. We could leave a dependency behind to ensure this.
2646
2647 // First load the super-klass's check-offset
2648 Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2649 Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2650 Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2651 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2652 bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2653
2654 // Load from the sub-klass's super-class display list, or a 1-word cache of
2655 // the secondary superclass list, or a failing value with a sentinel offset
2656 // if the super-klass is an interface or exceptionally deep in the Java
2657 // hierarchy and we have to scan the secondary superclass list the hard way.
2658 // Worst-case type is a little odd: NULL is allowed as a result (usually
2659 // klass loads can never produce a NULL).
2660 Node *chk_off_X = chk_off;
2661 #ifdef _LP64
2662 chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2663 #endif
2664 Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2665 // For some types like interfaces the following loadKlass is from a 1-word
2666 // cache which is mutable so can't use immutable memory. Other
2667 // types load from the super-class display table which is immutable.
2668 m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2669 Node *kmem = might_be_cache ? m : C->immutable_memory();
2670 Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2671
2672 // Compile speed common case: ARE a subtype and we canNOT fail
2673 if( superklass == nkls )
2674 return C->top(); // false path is dead; no test needed.
2675
2676 // See if we get an immediate positive hit. Happens roughly 83% of the
2677 // time. Test to see if the value loaded just previously from the subklass
2678 // is exactly the superklass.
2679 IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2680 Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2681 *ctrl = gvn->transform(new IfFalseNode(iff1));
2682
2683 // Compile speed common case: Check for being deterministic right now. If
2684 // chk_off is a constant and not equal to cacheoff then we are NOT a
2685 // subklass. In this case we need exactly the 1 test above and we can
2686 // return those results immediately.
2687 if (!might_be_cache) {
2688 Node* not_subtype_ctrl = *ctrl;
2689 *ctrl = iftrue1; // We need exactly the 1 test above
2690 return not_subtype_ctrl;
2691 }
2692
2693 // Gather the various success & failures here
2694 RegionNode *r_ok_subtype = new RegionNode(4);
2695 gvn->record_for_igvn(r_ok_subtype);
2696 RegionNode *r_not_subtype = new RegionNode(3);
2697 gvn->record_for_igvn(r_not_subtype);
2698
2699 r_ok_subtype->init_req(1, iftrue1);
2700
2701 // Check for immediate negative hit. Happens roughly 11% of the time (which
2702 // is roughly 63% of the remaining cases). Test to see if the loaded
2703 // check-offset points into the subklass display list or the 1-element
2704 // cache. If it points to the display (and NOT the cache) and the display
2705 // missed then it's not a subtype.
2706 Node *cacheoff = gvn->intcon(cacheoff_con);
2707 IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2708 r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2709 *ctrl = gvn->transform(new IfFalseNode(iff2));
2710
2711 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2712 // No performance impact (too rare) but allows sharing of secondary arrays
2713 // which has some footprint reduction.
2714 IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2715 r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2716 *ctrl = gvn->transform(new IfFalseNode(iff3));
2717
2718 // -- Roads not taken here: --
2719 // We could also have chosen to perform the self-check at the beginning
2720 // of this code sequence, as the assembler does. This would not pay off
2721 // the same way, since the optimizer, unlike the assembler, can perform
2722 // static type analysis to fold away many successful self-checks.
2723 // Non-foldable self checks work better here in second position, because
2724 // the initial primary superclass check subsumes a self-check for most
2725 // types. An exception would be a secondary type like array-of-interface,
2726 // which does not appear in its own primary supertype display.
2727 // Finally, we could have chosen to move the self-check into the
2728 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2729 // dependent manner. But it is worthwhile to have the check here,
2730 // where it can be perhaps be optimized. The cost in code space is
2731 // small (register compare, branch).
2732
2733 // Now do a linear scan of the secondary super-klass array. Again, no real
2734 // performance impact (too rare) but it's gotta be done.
2735 // Since the code is rarely used, there is no penalty for moving it
2736 // out of line, and it can only improve I-cache density.
2737 // The decision to inline or out-of-line this final check is platform
2738 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2739 Node* psc = gvn->transform(
2740 new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2741
2742 IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2743 r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2744 r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2745
2746 // Return false path; set default control to true path.
2747 *ctrl = gvn->transform(r_ok_subtype);
2748 return gvn->transform(r_not_subtype);
2749 }
2750
2751 // Profile-driven exact type check:
2752 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2753 float prob,
2754 Node* *casted_receiver) {
2755 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2756 Node* recv_klass = load_object_klass(receiver);
2757 Node* want_klass = makecon(tklass);
2758 Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2759 Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2760 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2761 set_control( _gvn.transform( new IfTrueNode (iff) ));
2762 Node* fail = _gvn.transform( new IfFalseNode(iff) );
2763
2764 const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2765 assert(recv_xtype->klass_is_exact(), "");
2766
2767 // Subsume downstream occurrences of receiver with a cast to
2768 // recv_xtype, since now we know what the type will be.
2769 Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2770 (*casted_receiver) = _gvn.transform(cast);
2771 // (User must make the replace_in_map call.)
2772
2773 return fail;
2774 }
2775
2776
2777 //------------------------------seems_never_null-------------------------------
2778 // Use null_seen information if it is available from the profile.
2779 // If we see an unexpected null at a type check we record it and force a
2780 // recompile; the offending check will be recompiled to handle NULLs.
2781 // If we see several offending BCIs, then all checks in the
2782 // method will be recompiled.
2783 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2784 speculating = !_gvn.type(obj)->speculative_maybe_null();
2785 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2786 if (UncommonNullCast // Cutout for this technique
2787 && obj != null() // And not the -Xcomp stupid case?
2788 && !too_many_traps(reason)
2789 ) {
2790 if (speculating) {
2791 return true;
2792 }
2793 if (data == NULL)
2794 // Edge case: no mature data. Be optimistic here.
2795 return true;
2796 // If the profile has not seen a null, assume it won't happen.
2797 assert(java_bc() == Bytecodes::_checkcast ||
2798 java_bc() == Bytecodes::_instanceof ||
2799 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2800 return !data->as_BitData()->null_seen();
2801 }
2802 speculating = false;
2803 return false;
2804 }
2805
2806 //------------------------maybe_cast_profiled_receiver-------------------------
2807 // If the profile has seen exactly one type, narrow to exactly that type.
2808 // Subsequent type checks will always fold up.
2809 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2810 ciKlass* require_klass,
2811 ciKlass* spec_klass,
2812 bool safe_for_replace) {
2813 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2814
2815 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2816
2817 // Make sure we haven't already deoptimized from this tactic.
2818 if (too_many_traps(reason) || too_many_recompiles(reason))
2819 return NULL;
2820
2821 // (No, this isn't a call, but it's enough like a virtual call
2822 // to use the same ciMethod accessor to get the profile info...)
2823 // If we have a speculative type use it instead of profiling (which
2824 // may not help us)
2825 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2826 if (exact_kls != NULL) {// no cast failures here
2827 if (require_klass == NULL ||
2828 C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2829 // If we narrow the type to match what the type profile sees or
2830 // the speculative type, we can then remove the rest of the
2831 // cast.
2832 // This is a win, even if the exact_kls is very specific,
2833 // because downstream operations, such as method calls,
2834 // will often benefit from the sharper type.
2835 Node* exact_obj = not_null_obj; // will get updated in place...
2836 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2837 &exact_obj);
2838 { PreserveJVMState pjvms(this);
2839 set_control(slow_ctl);
2840 uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2841 }
2842 if (safe_for_replace) {
2843 replace_in_map(not_null_obj, exact_obj);
2844 }
2845 return exact_obj;
2846 }
2847 // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2848 }
2849
2850 return NULL;
2851 }
2852
2853 /**
2854 * Cast obj to type and emit guard unless we had too many traps here
2855 * already
2856 *
2857 * @param obj node being casted
2858 * @param type type to cast the node to
2859 * @param not_null true if we know node cannot be null
2860 */
2861 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2862 ciKlass* type,
2863 bool not_null) {
2864 if (stopped()) {
2865 return obj;
2866 }
2867
2868 // type == NULL if profiling tells us this object is always null
2869 if (type != NULL) {
2870 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2871 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2872
2873 if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2874 !too_many_traps(class_reason) &&
2875 !too_many_recompiles(class_reason)) {
2876 Node* not_null_obj = NULL;
2877 // not_null is true if we know the object is not null and
2878 // there's no need for a null check
2879 if (!not_null) {
2880 Node* null_ctl = top();
2881 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2882 assert(null_ctl->is_top(), "no null control here");
2883 } else {
2884 not_null_obj = obj;
2885 }
2886
2887 Node* exact_obj = not_null_obj;
2888 ciKlass* exact_kls = type;
2889 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2890 &exact_obj);
2891 {
2892 PreserveJVMState pjvms(this);
2893 set_control(slow_ctl);
2894 uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2895 }
2896 replace_in_map(not_null_obj, exact_obj);
2897 obj = exact_obj;
2898 }
2899 } else {
2900 if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2901 !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2902 Node* exact_obj = null_assert(obj);
2903 replace_in_map(obj, exact_obj);
2904 obj = exact_obj;
2905 }
2906 }
2907 return obj;
2908 }
2909
2910 //-------------------------------gen_instanceof--------------------------------
2911 // Generate an instance-of idiom. Used by both the instance-of bytecode
2912 // and the reflective instance-of call.
2913 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2914 kill_dead_locals(); // Benefit all the uncommon traps
2915 assert( !stopped(), "dead parse path should be checked in callers" );
2916 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2917 "must check for not-null not-dead klass in callers");
2918
2919 // Make the merge point
2920 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2921 RegionNode* region = new RegionNode(PATH_LIMIT);
2922 Node* phi = new PhiNode(region, TypeInt::BOOL);
2923 C->set_has_split_ifs(true); // Has chance for split-if optimization
2924
2925 ciProfileData* data = NULL;
2926 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode
2927 data = method()->method_data()->bci_to_data(bci());
2928 }
2929 bool speculative_not_null = false;
2930 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile
2931 && seems_never_null(obj, data, speculative_not_null));
2932
2933 // Null check; get casted pointer; set region slot 3
2934 Node* null_ctl = top();
2935 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2936
2937 // If not_null_obj is dead, only null-path is taken
2938 if (stopped()) { // Doing instance-of on a NULL?
2939 set_control(null_ctl);
2940 return intcon(0);
2941 }
2942 region->init_req(_null_path, null_ctl);
2943 phi ->init_req(_null_path, intcon(0)); // Set null path value
2944 if (null_ctl == top()) {
2945 // Do this eagerly, so that pattern matches like is_diamond_phi
2946 // will work even during parsing.
2947 assert(_null_path == PATH_LIMIT-1, "delete last");
2948 region->del_req(_null_path);
2949 phi ->del_req(_null_path);
2950 }
2951
2952 // Do we know the type check always succeed?
2953 bool known_statically = false;
2954 if (_gvn.type(superklass)->singleton()) {
2955 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2956 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2957 if (subk != NULL && subk->is_loaded()) {
2958 int static_res = C->static_subtype_check(superk, subk);
2959 known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2960 }
2961 }
2962
2963 if (!known_statically) {
2964 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2965 // We may not have profiling here or it may not help us. If we
2966 // have a speculative type use it to perform an exact cast.
2967 ciKlass* spec_obj_type = obj_type->speculative_type();
2968 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2969 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2970 if (stopped()) { // Profile disagrees with this path.
2971 set_control(null_ctl); // Null is the only remaining possibility.
2972 return intcon(0);
2973 }
2974 if (cast_obj != NULL) {
2975 not_null_obj = cast_obj;
2976 }
2977 }
2978 }
2979
2980 // Load the object's klass
2981 Node* obj_klass = load_object_klass(not_null_obj);
2982
2983 // Generate the subtype check
2984 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2985
2986 // Plug in the success path to the general merge in slot 1.
2987 region->init_req(_obj_path, control());
2988 phi ->init_req(_obj_path, intcon(1));
2989
2990 // Plug in the failing path to the general merge in slot 2.
2991 region->init_req(_fail_path, not_subtype_ctrl);
2992 phi ->init_req(_fail_path, intcon(0));
2993
2994 // Return final merged results
2995 set_control( _gvn.transform(region) );
2996 record_for_igvn(region);
2997
2998 // If we know the type check always succeeds then we don't use the
2999 // profiling data at this bytecode. Don't lose it, feed it to the
3000 // type system as a speculative type.
3001 if (safe_for_replace) {
3002 Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3003 replace_in_map(obj, casted_obj);
3004 }
3005
3006 return _gvn.transform(phi);
3007 }
3008
3009 //-------------------------------gen_checkcast---------------------------------
3010 // Generate a checkcast idiom. Used by both the checkcast bytecode and the
3011 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the
3012 // uncommon-trap paths work. Adjust stack after this call.
3013 // If failure_control is supplied and not null, it is filled in with
3014 // the control edge for the cast failure. Otherwise, an appropriate
3015 // uncommon trap or exception is thrown.
3016 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3017 Node* *failure_control) {
3018 kill_dead_locals(); // Benefit all the uncommon traps
3019 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3020 const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3021
3022 // Fast cutout: Check the case that the cast is vacuously true.
3023 // This detects the common cases where the test will short-circuit
3024 // away completely. We do this before we perform the null check,
3025 // because if the test is going to turn into zero code, we don't
3026 // want a residual null check left around. (Causes a slowdown,
3027 // for example, in some objArray manipulations, such as a[i]=a[j].)
3028 if (tk->singleton()) {
3029 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3030 if (objtp != NULL && objtp->klass() != NULL) {
3031 switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3032 case Compile::SSC_always_true:
3033 // If we know the type check always succeed then we don't use
3034 // the profiling data at this bytecode. Don't lose it, feed it
3035 // to the type system as a speculative type.
3036 return record_profiled_receiver_for_speculation(obj);
3037 case Compile::SSC_always_false:
3038 // It needs a null check because a null will *pass* the cast check.
3039 // A non-null value will always produce an exception.
3040 return null_assert(obj);
3041 }
3042 }
3043 }
3044
3045 ciProfileData* data = NULL;
3046 bool safe_for_replace = false;
3047 if (failure_control == NULL) { // use MDO in regular case only
3048 assert(java_bc() == Bytecodes::_aastore ||
3049 java_bc() == Bytecodes::_checkcast,
3050 "interpreter profiles type checks only for these BCs");
3051 data = method()->method_data()->bci_to_data(bci());
3052 safe_for_replace = true;
3053 }
3054
3055 // Make the merge point
3056 enum { _obj_path = 1, _null_path, PATH_LIMIT };
3057 RegionNode* region = new RegionNode(PATH_LIMIT);
3058 Node* phi = new PhiNode(region, toop);
3059 C->set_has_split_ifs(true); // Has chance for split-if optimization
3060
3061 // Use null-cast information if it is available
3062 bool speculative_not_null = false;
3063 bool never_see_null = ((failure_control == NULL) // regular case only
3064 && seems_never_null(obj, data, speculative_not_null));
3065
3066 // Null check; get casted pointer; set region slot 3
3067 Node* null_ctl = top();
3068 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3069
3070 // If not_null_obj is dead, only null-path is taken
3071 if (stopped()) { // Doing instance-of on a NULL?
3072 set_control(null_ctl);
3073 return null();
3074 }
3075 region->init_req(_null_path, null_ctl);
3076 phi ->init_req(_null_path, null()); // Set null path value
3077 if (null_ctl == top()) {
3078 // Do this eagerly, so that pattern matches like is_diamond_phi
3079 // will work even during parsing.
3080 assert(_null_path == PATH_LIMIT-1, "delete last");
3081 region->del_req(_null_path);
3082 phi ->del_req(_null_path);
3083 }
3084
3085 Node* cast_obj = NULL;
3086 if (tk->klass_is_exact()) {
3087 // The following optimization tries to statically cast the speculative type of the object
3088 // (for example obtained during profiling) to the type of the superklass and then do a
3089 // dynamic check that the type of the object is what we expect. To work correctly
3090 // for checkcast and aastore the type of superklass should be exact.
3091 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3092 // We may not have profiling here or it may not help us. If we have
3093 // a speculative type use it to perform an exact cast.
3094 ciKlass* spec_obj_type = obj_type->speculative_type();
3095 if (spec_obj_type != NULL || data != NULL) {
3096 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3097 if (cast_obj != NULL) {
3098 if (failure_control != NULL) // failure is now impossible
3099 (*failure_control) = top();
3100 // adjust the type of the phi to the exact klass:
3101 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3102 }
3103 }
3104 }
3105
3106 if (cast_obj == NULL) {
3107 // Load the object's klass
3108 Node* obj_klass = load_object_klass(not_null_obj);
3109
3110 // Generate the subtype check
3111 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3112
3113 // Plug in success path into the merge
3114 cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3115 // Failure path ends in uncommon trap (or may be dead - failure impossible)
3116 if (failure_control == NULL) {
3117 if (not_subtype_ctrl != top()) { // If failure is possible
3118 PreserveJVMState pjvms(this);
3119 set_control(not_subtype_ctrl);
3120 builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3121 }
3122 } else {
3123 (*failure_control) = not_subtype_ctrl;
3124 }
3125 }
3126
3127 region->init_req(_obj_path, control());
3128 phi ->init_req(_obj_path, cast_obj);
3129
3130 // A merge of NULL or Casted-NotNull obj
3131 Node* res = _gvn.transform(phi);
3132
3133 // Note I do NOT always 'replace_in_map(obj,result)' here.
3134 // if( tk->klass()->can_be_primary_super() )
3135 // This means that if I successfully store an Object into an array-of-String
3136 // I 'forget' that the Object is really now known to be a String. I have to
3137 // do this because we don't have true union types for interfaces - if I store
3138 // a Baz into an array-of-Interface and then tell the optimizer it's an
3139 // Interface, I forget that it's also a Baz and cannot do Baz-like field
3140 // references to it. FIX THIS WHEN UNION TYPES APPEAR!
3141 // replace_in_map( obj, res );
3142
3143 // Return final merged results
3144 set_control( _gvn.transform(region) );
3145 record_for_igvn(region);
3146
3147 return record_profiled_receiver_for_speculation(res);
3148 }
3149
3150 //------------------------------next_monitor-----------------------------------
3151 // What number should be given to the next monitor?
3152 int GraphKit::next_monitor() {
3153 int current = jvms()->monitor_depth()* C->sync_stack_slots();
3154 int next = current + C->sync_stack_slots();
3155 // Keep the toplevel high water mark current:
3156 if (C->fixed_slots() < next) C->set_fixed_slots(next);
3157 return current;
3158 }
3159
3160 //------------------------------insert_mem_bar---------------------------------
3161 // Memory barrier to avoid floating things around
3162 // The membar serves as a pinch point between both control and all memory slices.
3163 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3164 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3165 mb->init_req(TypeFunc::Control, control());
3166 mb->init_req(TypeFunc::Memory, reset_memory());
3167 Node* membar = _gvn.transform(mb);
3168 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3169 set_all_memory_call(membar);
3170 return membar;
3171 }
3172
3173 //-------------------------insert_mem_bar_volatile----------------------------
3174 // Memory barrier to avoid floating things around
3175 // The membar serves as a pinch point between both control and memory(alias_idx).
3176 // If you want to make a pinch point on all memory slices, do not use this
3177 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3178 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3179 // When Parse::do_put_xxx updates a volatile field, it appends a series
3180 // of MemBarVolatile nodes, one for *each* volatile field alias category.
3181 // The first membar is on the same memory slice as the field store opcode.
3182 // This forces the membar to follow the store. (Bug 6500685 broke this.)
3183 // All the other membars (for other volatile slices, including AliasIdxBot,
3184 // which stands for all unknown volatile slices) are control-dependent
3185 // on the first membar. This prevents later volatile loads or stores
3186 // from sliding up past the just-emitted store.
3187
3188 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3189 mb->set_req(TypeFunc::Control,control());
3190 if (alias_idx == Compile::AliasIdxBot) {
3191 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3192 } else {
3193 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3194 mb->set_req(TypeFunc::Memory, memory(alias_idx));
3195 }
3196 Node* membar = _gvn.transform(mb);
3197 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3198 if (alias_idx == Compile::AliasIdxBot) {
3199 merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3200 } else {
3201 set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3202 }
3203 return membar;
3204 }
3205
3206 //------------------------------shared_lock------------------------------------
3207 // Emit locking code.
3208 FastLockNode* GraphKit::shared_lock(Node* obj) {
3209 // bci is either a monitorenter bc or InvocationEntryBci
3210 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3211 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3212
3213 if( !GenerateSynchronizationCode )
3214 return NULL; // Not locking things?
3215 if (stopped()) // Dead monitor?
3216 return NULL;
3217
3218 assert(dead_locals_are_killed(), "should kill locals before sync. point");
3219
3220 // Box the stack location
3221 Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3222 Node* mem = reset_memory();
3223
3224 FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3225 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3226 // Create the counters for this fast lock.
3227 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3228 }
3229
3230 // Create the rtm counters for this fast lock if needed.
3231 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3232
3233 // Add monitor to debug info for the slow path. If we block inside the
3234 // slow path and de-opt, we need the monitor hanging around
3235 map()->push_monitor( flock );
3236
3237 const TypeFunc *tf = LockNode::lock_type();
3238 LockNode *lock = new LockNode(C, tf);
3239
3240 lock->init_req( TypeFunc::Control, control() );
3241 lock->init_req( TypeFunc::Memory , mem );
3242 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3243 lock->init_req( TypeFunc::FramePtr, frameptr() );
3244 lock->init_req( TypeFunc::ReturnAdr, top() );
3245
3246 lock->init_req(TypeFunc::Parms + 0, obj);
3247 lock->init_req(TypeFunc::Parms + 1, box);
3248 lock->init_req(TypeFunc::Parms + 2, flock);
3249 add_safepoint_edges(lock);
3250
3251 lock = _gvn.transform( lock )->as_Lock();
3252
3253 // lock has no side-effects, sets few values
3254 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3255
3256 insert_mem_bar(Op_MemBarAcquireLock);
3257
3258 // Add this to the worklist so that the lock can be eliminated
3259 record_for_igvn(lock);
3260
3261 #ifndef PRODUCT
3262 if (PrintLockStatistics) {
3263 // Update the counter for this lock. Don't bother using an atomic
3264 // operation since we don't require absolute accuracy.
3265 lock->create_lock_counter(map()->jvms());
3266 increment_counter(lock->counter()->addr());
3267 }
3268 #endif
3269
3270 return flock;
3271 }
3272
3273
3274 //------------------------------shared_unlock----------------------------------
3275 // Emit unlocking code.
3276 void GraphKit::shared_unlock(Node* box, Node* obj) {
3277 // bci is either a monitorenter bc or InvocationEntryBci
3278 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3279 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3280
3281 if( !GenerateSynchronizationCode )
3282 return;
3283 if (stopped()) { // Dead monitor?
3284 map()->pop_monitor(); // Kill monitor from debug info
3285 return;
3286 }
3287
3288 // Memory barrier to avoid floating things down past the locked region
3289 insert_mem_bar(Op_MemBarReleaseLock);
3290
3291 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3292 UnlockNode *unlock = new UnlockNode(C, tf);
3293 #ifdef ASSERT
3294 unlock->set_dbg_jvms(sync_jvms());
3295 #endif
3296 uint raw_idx = Compile::AliasIdxRaw;
3297 unlock->init_req( TypeFunc::Control, control() );
3298 unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3299 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3300 unlock->init_req( TypeFunc::FramePtr, frameptr() );
3301 unlock->init_req( TypeFunc::ReturnAdr, top() );
3302
3303 unlock->init_req(TypeFunc::Parms + 0, obj);
3304 unlock->init_req(TypeFunc::Parms + 1, box);
3305 unlock = _gvn.transform(unlock)->as_Unlock();
3306
3307 Node* mem = reset_memory();
3308
3309 // unlock has no side-effects, sets few values
3310 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3311
3312 // Kill monitor from debug info
3313 map()->pop_monitor( );
3314 }
3315
3316 //-------------------------------get_layout_helper-----------------------------
3317 // If the given klass is a constant or known to be an array,
3318 // fetch the constant layout helper value into constant_value
3319 // and return (Node*)NULL. Otherwise, load the non-constant
3320 // layout helper value, and return the node which represents it.
3321 // This two-faced routine is useful because allocation sites
3322 // almost always feature constant types.
3323 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3324 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3325 if (!StressReflectiveCode && inst_klass != NULL) {
3326 ciKlass* klass = inst_klass->klass();
3327 bool xklass = inst_klass->klass_is_exact();
3328 if (xklass || klass->is_array_klass()) {
3329 jint lhelper = klass->layout_helper();
3330 if (lhelper != Klass::_lh_neutral_value) {
3331 constant_value = lhelper;
3332 return (Node*) NULL;
3333 }
3334 }
3335 }
3336 constant_value = Klass::_lh_neutral_value; // put in a known value
3337 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3338 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3339 }
3340
3341 // We just put in an allocate/initialize with a big raw-memory effect.
3342 // Hook selected additional alias categories on the initialization.
3343 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3344 MergeMemNode* init_in_merge,
3345 Node* init_out_raw) {
3346 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3347 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3348
3349 Node* prevmem = kit.memory(alias_idx);
3350 init_in_merge->set_memory_at(alias_idx, prevmem);
3351 kit.set_memory(init_out_raw, alias_idx);
3352 }
3353
3354 //---------------------------set_output_for_allocation-------------------------
3355 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3356 const TypeOopPtr* oop_type,
3357 bool deoptimize_on_exception) {
3358 int rawidx = Compile::AliasIdxRaw;
3359 alloc->set_req( TypeFunc::FramePtr, frameptr() );
3360 add_safepoint_edges(alloc);
3361 Node* allocx = _gvn.transform(alloc);
3362 set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3363 // create memory projection for i_o
3364 set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3365 make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3366
3367 // create a memory projection as for the normal control path
3368 Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3369 set_memory(malloc, rawidx);
3370
3371 // a normal slow-call doesn't change i_o, but an allocation does
3372 // we create a separate i_o projection for the normal control path
3373 set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3374 Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3375
3376 // put in an initialization barrier
3377 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3378 rawoop)->as_Initialize();
3379 assert(alloc->initialization() == init, "2-way macro link must work");
3380 assert(init ->allocation() == alloc, "2-way macro link must work");
3381 {
3382 // Extract memory strands which may participate in the new object's
3383 // initialization, and source them from the new InitializeNode.
3384 // This will allow us to observe initializations when they occur,
3385 // and link them properly (as a group) to the InitializeNode.
3386 assert(init->in(InitializeNode::Memory) == malloc, "");
3387 MergeMemNode* minit_in = MergeMemNode::make(malloc);
3388 init->set_req(InitializeNode::Memory, minit_in);
3389 record_for_igvn(minit_in); // fold it up later, if possible
3390 Node* minit_out = memory(rawidx);
3391 assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3392 if (oop_type->isa_aryptr()) {
3393 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3394 int elemidx = C->get_alias_index(telemref);
3395 hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3396 } else if (oop_type->isa_instptr()) {
3397 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3398 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3399 ciField* field = ik->nonstatic_field_at(i);
3400 if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3401 continue; // do not bother to track really large numbers of fields
3402 // Find (or create) the alias category for this field:
3403 int fieldidx = C->alias_type(field)->index();
3404 hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3405 }
3406 }
3407 }
3408
3409 // Cast raw oop to the real thing...
3410 Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3411 javaoop = _gvn.transform(javaoop);
3412 C->set_recent_alloc(control(), javaoop);
3413 assert(just_allocated_object(control()) == javaoop, "just allocated");
3414
3415 #ifdef ASSERT
3416 { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3417 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3418 "Ideal_allocation works");
3419 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3420 "Ideal_allocation works");
3421 if (alloc->is_AllocateArray()) {
3422 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3423 "Ideal_allocation works");
3424 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3425 "Ideal_allocation works");
3426 } else {
3427 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3428 }
3429 }
3430 #endif //ASSERT
3431
3432 return javaoop;
3433 }
3434
3435 //---------------------------new_instance--------------------------------------
3436 // This routine takes a klass_node which may be constant (for a static type)
3437 // or may be non-constant (for reflective code). It will work equally well
3438 // for either, and the graph will fold nicely if the optimizer later reduces
3439 // the type to a constant.
3440 // The optional arguments are for specialized use by intrinsics:
3441 // - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3442 // - If 'return_size_val', report the the total object size to the caller.
3443 // - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3444 Node* GraphKit::new_instance(Node* klass_node,
3445 Node* extra_slow_test,
3446 Node* *return_size_val,
3447 bool deoptimize_on_exception) {
3448 // Compute size in doublewords
3449 // The size is always an integral number of doublewords, represented
3450 // as a positive bytewise size stored in the klass's layout_helper.
3451 // The layout_helper also encodes (in a low bit) the need for a slow path.
3452 jint layout_con = Klass::_lh_neutral_value;
3453 Node* layout_val = get_layout_helper(klass_node, layout_con);
3454 int layout_is_con = (layout_val == NULL);
3455
3456 if (extra_slow_test == NULL) extra_slow_test = intcon(0);
3457 // Generate the initial go-slow test. It's either ALWAYS (return a
3458 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3459 // case) a computed value derived from the layout_helper.
3460 Node* initial_slow_test = NULL;
3461 if (layout_is_con) {
3462 assert(!StressReflectiveCode, "stress mode does not use these paths");
3463 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3464 initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3465 } else { // reflective case
3466 // This reflective path is used by Unsafe.allocateInstance.
3467 // (It may be stress-tested by specifying StressReflectiveCode.)
3468 // Basically, we want to get into the VM is there's an illegal argument.
3469 Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3470 initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3471 if (extra_slow_test != intcon(0)) {
3472 initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3473 }
3474 // (Macro-expander will further convert this to a Bool, if necessary.)
3475 }
3476
3477 // Find the size in bytes. This is easy; it's the layout_helper.
3478 // The size value must be valid even if the slow path is taken.
3479 Node* size = NULL;
3480 if (layout_is_con) {
3481 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3482 } else { // reflective case
3483 // This reflective path is used by clone and Unsafe.allocateInstance.
3484 size = ConvI2X(layout_val);
3485
3486 // Clear the low bits to extract layout_helper_size_in_bytes:
3487 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3488 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3489 size = _gvn.transform( new AndXNode(size, mask) );
3490 }
3491 if (return_size_val != NULL) {
3492 (*return_size_val) = size;
3493 }
3494
3495 // This is a precise notnull oop of the klass.
3496 // (Actually, it need not be precise if this is a reflective allocation.)
3497 // It's what we cast the result to.
3498 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3499 if (!tklass) tklass = TypeKlassPtr::OBJECT;
3500 const TypeOopPtr* oop_type = tklass->as_instance_type();
3501
3502 // Now generate allocation code
3503
3504 // The entire memory state is needed for slow path of the allocation
3505 // since GC and deoptimization can happened.
3506 Node *mem = reset_memory();
3507 set_all_memory(mem); // Create new memory state
3508
3509 AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3510 control(), mem, i_o(),
3511 size, klass_node,
3512 initial_slow_test);
3513
3514 return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3515 }
3516
3517 //-------------------------------new_array-------------------------------------
3518 // helper for both newarray and anewarray
3519 // The 'length' parameter is (obviously) the length of the array.
3520 // See comments on new_instance for the meaning of the other arguments.
3521 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable)
3522 Node* length, // number of array elements
3523 int nargs, // number of arguments to push back for uncommon trap
3524 Node* *return_size_val,
3525 bool deoptimize_on_exception) {
3526 jint layout_con = Klass::_lh_neutral_value;
3527 Node* layout_val = get_layout_helper(klass_node, layout_con);
3528 int layout_is_con = (layout_val == NULL);
3529
3530 if (!layout_is_con && !StressReflectiveCode &&
3531 !too_many_traps(Deoptimization::Reason_class_check)) {
3532 // This is a reflective array creation site.
3533 // Optimistically assume that it is a subtype of Object[],
3534 // so that we can fold up all the address arithmetic.
3535 layout_con = Klass::array_layout_helper(T_OBJECT);
3536 Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3537 Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3538 { BuildCutout unless(this, bol_lh, PROB_MAX);
3539 inc_sp(nargs);
3540 uncommon_trap(Deoptimization::Reason_class_check,
3541 Deoptimization::Action_maybe_recompile);
3542 }
3543 layout_val = NULL;
3544 layout_is_con = true;
3545 }
3546
3547 // Generate the initial go-slow test. Make sure we do not overflow
3548 // if length is huge (near 2Gig) or negative! We do not need
3549 // exact double-words here, just a close approximation of needed
3550 // double-words. We can't add any offset or rounding bits, lest we
3551 // take a size -1 of bytes and make it positive. Use an unsigned
3552 // compare, so negative sizes look hugely positive.
3553 int fast_size_limit = FastAllocateSizeLimit;
3554 if (layout_is_con) {
3555 assert(!StressReflectiveCode, "stress mode does not use these paths");
3556 // Increase the size limit if we have exact knowledge of array type.
3557 int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3558 fast_size_limit <<= (LogBytesPerLong - log2_esize);
3559 }
3560
3561 Node* initial_slow_cmp = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3562 Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3563
3564 // --- Size Computation ---
3565 // array_size = round_to_heap(array_header + (length << elem_shift));
3566 // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3567 // and align_to(x, y) == ((x + y-1) & ~(y-1))
3568 // The rounding mask is strength-reduced, if possible.
3569 int round_mask = MinObjAlignmentInBytes - 1;
3570 Node* header_size = NULL;
3571 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3572 // (T_BYTE has the weakest alignment and size restrictions...)
3573 if (layout_is_con) {
3574 int hsize = Klass::layout_helper_header_size(layout_con);
3575 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3576 BasicType etype = Klass::layout_helper_element_type(layout_con);
3577 if ((round_mask & ~right_n_bits(eshift)) == 0)
3578 round_mask = 0; // strength-reduce it if it goes away completely
3579 assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3580 assert(header_size_min <= hsize, "generic minimum is smallest");
3581 header_size_min = hsize;
3582 header_size = intcon(hsize + round_mask);
3583 } else {
3584 Node* hss = intcon(Klass::_lh_header_size_shift);
3585 Node* hsm = intcon(Klass::_lh_header_size_mask);
3586 Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3587 hsize = _gvn.transform( new AndINode(hsize, hsm) );
3588 Node* mask = intcon(round_mask);
3589 header_size = _gvn.transform( new AddINode(hsize, mask) );
3590 }
3591
3592 Node* elem_shift = NULL;
3593 if (layout_is_con) {
3594 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3595 if (eshift != 0)
3596 elem_shift = intcon(eshift);
3597 } else {
3598 // There is no need to mask or shift this value.
3599 // The semantics of LShiftINode include an implicit mask to 0x1F.
3600 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3601 elem_shift = layout_val;
3602 }
3603
3604 // Transition to native address size for all offset calculations:
3605 Node* lengthx = ConvI2X(length);
3606 Node* headerx = ConvI2X(header_size);
3607 #ifdef _LP64
3608 { const TypeInt* tilen = _gvn.find_int_type(length);
3609 if (tilen != NULL && tilen->_lo < 0) {
3610 // Add a manual constraint to a positive range. Cf. array_element_address.
3611 jint size_max = fast_size_limit;
3612 if (size_max > tilen->_hi) size_max = tilen->_hi;
3613 const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3614
3615 // Only do a narrow I2L conversion if the range check passed.
3616 IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3617 _gvn.transform(iff);
3618 RegionNode* region = new RegionNode(3);
3619 _gvn.set_type(region, Type::CONTROL);
3620 lengthx = new PhiNode(region, TypeLong::LONG);
3621 _gvn.set_type(lengthx, TypeLong::LONG);
3622
3623 // Range check passed. Use ConvI2L node with narrow type.
3624 Node* passed = IfFalse(iff);
3625 region->init_req(1, passed);
3626 // Make I2L conversion control dependent to prevent it from
3627 // floating above the range check during loop optimizations.
3628 lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3629
3630 // Range check failed. Use ConvI2L with wide type because length may be invalid.
3631 region->init_req(2, IfTrue(iff));
3632 lengthx->init_req(2, ConvI2X(length));
3633
3634 set_control(region);
3635 record_for_igvn(region);
3636 record_for_igvn(lengthx);
3637 }
3638 }
3639 #endif
3640
3641 // Combine header size (plus rounding) and body size. Then round down.
3642 // This computation cannot overflow, because it is used only in two
3643 // places, one where the length is sharply limited, and the other
3644 // after a successful allocation.
3645 Node* abody = lengthx;
3646 if (elem_shift != NULL)
3647 abody = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3648 Node* size = _gvn.transform( new AddXNode(headerx, abody) );
3649 if (round_mask != 0) {
3650 Node* mask = MakeConX(~round_mask);
3651 size = _gvn.transform( new AndXNode(size, mask) );
3652 }
3653 // else if round_mask == 0, the size computation is self-rounding
3654
3655 if (return_size_val != NULL) {
3656 // This is the size
3657 (*return_size_val) = size;
3658 }
3659
3660 // Now generate allocation code
3661
3662 // The entire memory state is needed for slow path of the allocation
3663 // since GC and deoptimization can happened.
3664 Node *mem = reset_memory();
3665 set_all_memory(mem); // Create new memory state
3666
3667 if (initial_slow_test->is_Bool()) {
3668 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3669 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3670 }
3671
3672 // Create the AllocateArrayNode and its result projections
3673 AllocateArrayNode* alloc
3674 = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3675 control(), mem, i_o(),
3676 size, klass_node,
3677 initial_slow_test,
3678 length);
3679
3680 // Cast to correct type. Note that the klass_node may be constant or not,
3681 // and in the latter case the actual array type will be inexact also.
3682 // (This happens via a non-constant argument to inline_native_newArray.)
3683 // In any case, the value of klass_node provides the desired array type.
3684 const TypeInt* length_type = _gvn.find_int_type(length);
3685 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3686 if (ary_type->isa_aryptr() && length_type != NULL) {
3687 // Try to get a better type than POS for the size
3688 ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3689 }
3690
3691 Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3692
3693 // Cast length on remaining path to be as narrow as possible
3694 if (map()->find_edge(length) >= 0) {
3695 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3696 if (ccast != length) {
3697 _gvn.set_type_bottom(ccast);
3698 record_for_igvn(ccast);
3699 replace_in_map(length, ccast);
3700 }
3701 }
3702
3703 return javaoop;
3704 }
3705
3706 // The following "Ideal_foo" functions are placed here because they recognize
3707 // the graph shapes created by the functions immediately above.
3708
3709 //---------------------------Ideal_allocation----------------------------------
3710 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3711 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3712 if (ptr == NULL) { // reduce dumb test in callers
3713 return NULL;
3714 }
3715 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3716 ptr = ptr->in(1);
3717 if (ptr == NULL) return NULL;
3718 }
3719 // Return NULL for allocations with several casts:
3720 // j.l.reflect.Array.newInstance(jobject, jint)
3721 // Object.clone()
3722 // to keep more precise type from last cast.
3723 if (ptr->is_Proj()) {
3724 Node* allo = ptr->in(0);
3725 if (allo != NULL && allo->is_Allocate()) {
3726 return allo->as_Allocate();
3727 }
3728 }
3729 // Report failure to match.
3730 return NULL;
3731 }
3732
3733 // Fancy version which also strips off an offset (and reports it to caller).
3734 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3735 intptr_t& offset) {
3736 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3737 if (base == NULL) return NULL;
3738 return Ideal_allocation(base, phase);
3739 }
3740
3741 // Trace Initialize <- Proj[Parm] <- Allocate
3742 AllocateNode* InitializeNode::allocation() {
3743 Node* rawoop = in(InitializeNode::RawAddress);
3744 if (rawoop->is_Proj()) {
3745 Node* alloc = rawoop->in(0);
3746 if (alloc->is_Allocate()) {
3747 return alloc->as_Allocate();
3748 }
3749 }
3750 return NULL;
3751 }
3752
3753 // Trace Allocate -> Proj[Parm] -> Initialize
3754 InitializeNode* AllocateNode::initialization() {
3755 ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
3756 if (rawoop == NULL) return NULL;
3757 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3758 Node* init = rawoop->fast_out(i);
3759 if (init->is_Initialize()) {
3760 assert(init->as_Initialize()->allocation() == this, "2-way link");
3761 return init->as_Initialize();
3762 }
3763 }
3764 return NULL;
3765 }
3766
3767 //----------------------------- loop predicates ---------------------------
3768
3769 //------------------------------add_predicate_impl----------------------------
3770 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3771 // Too many traps seen?
3772 if (too_many_traps(reason)) {
3773 #ifdef ASSERT
3774 if (TraceLoopPredicate) {
3775 int tc = C->trap_count(reason);
3776 tty->print("too many traps=%s tcount=%d in ",
3777 Deoptimization::trap_reason_name(reason), tc);
3778 method()->print(); // which method has too many predicate traps
3779 tty->cr();
3780 }
3781 #endif
3782 // We cannot afford to take more traps here,
3783 // do not generate predicate.
3784 return;
3785 }
3786
3787 Node *cont = _gvn.intcon(1);
3788 Node* opq = _gvn.transform(new Opaque1Node(C, cont));
3789 Node *bol = _gvn.transform(new Conv2BNode(opq));
3790 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3791 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3792 C->add_predicate_opaq(opq);
3793 {
3794 PreserveJVMState pjvms(this);
3795 set_control(iffalse);
3796 inc_sp(nargs);
3797 uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3798 }
3799 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3800 set_control(iftrue);
3801 }
3802
3803 //------------------------------add_predicate---------------------------------
3804 void GraphKit::add_predicate(int nargs) {
3805 if (UseLoopPredicate) {
3806 add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3807 }
3808 // loop's limit check predicate should be near the loop.
3809 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3810 }
3811
3812 void GraphKit::sync_kit(IdealKit& ideal) {
3813 set_all_memory(ideal.merged_memory());
3814 set_i_o(ideal.i_o());
3815 set_control(ideal.ctrl());
3816 }
3817
3818 void GraphKit::final_sync(IdealKit& ideal) {
3819 // Final sync IdealKit and graphKit.
3820 sync_kit(ideal);
3821 }
3822
3823 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
3824 Node* len = load_array_length(load_String_value(ctrl, str));
3825 Node* coder = load_String_coder(ctrl, str);
3826 // Divide length by 2 if coder is UTF16
3827 return _gvn.transform(new RShiftINode(len, coder));
3828 }
3829
3830 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
3831 int value_offset = java_lang_String::value_offset_in_bytes();
3832 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3833 false, NULL, 0);
3834 const TypePtr* value_field_type = string_type->add_offset(value_offset);
3835 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
3836 TypeAry::make(TypeInt::BYTE, TypeInt::POS),
3837 ciTypeArrayKlass::make(T_BYTE), true, 0);
3838 Node* p = basic_plus_adr(str, str, value_offset);
3839 Node* load = access_load_at(str, p, value_field_type, value_type, T_OBJECT,
3840 IN_HEAP | C2_CONTROL_DEPENDENT_LOAD);
3841 // String.value field is known to be @Stable.
3842 if (UseImplicitStableValues) {
3843 load = cast_array_to_stable(load, value_type);
3844 }
3845 return load;
3846 }
3847
3848 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
3849 if (!CompactStrings) {
3850 return intcon(java_lang_String::CODER_UTF16);
3851 }
3852 int coder_offset = java_lang_String::coder_offset_in_bytes();
3853 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3854 false, NULL, 0);
3855 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
3856 int coder_field_idx = C->get_alias_index(coder_field_type);
3857 return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
3858 TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
3859 }
3860
3861 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
3862 int value_offset = java_lang_String::value_offset_in_bytes();
3863 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3864 false, NULL, 0);
3865 const TypePtr* value_field_type = string_type->add_offset(value_offset);
3866 access_store_at(ctrl, str, basic_plus_adr(str, value_offset), value_field_type,
3867 value, TypeAryPtr::BYTES, T_OBJECT, IN_HEAP);
3868 }
3869
3870 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
3871 int coder_offset = java_lang_String::coder_offset_in_bytes();
3872 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
3873 false, NULL, 0);
3874 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
3875 int coder_field_idx = C->get_alias_index(coder_field_type);
3876 store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
3877 value, T_BYTE, coder_field_idx, MemNode::unordered);
3878 }
3879
3880 // Capture src and dst memory state with a MergeMemNode
3881 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
3882 if (src_type == dst_type) {
3883 // Types are equal, we don't need a MergeMemNode
3884 return memory(src_type);
3885 }
3886 MergeMemNode* merge = MergeMemNode::make(map()->memory());
3887 record_for_igvn(merge); // fold it up later, if possible
3888 int src_idx = C->get_alias_index(src_type);
3889 int dst_idx = C->get_alias_index(dst_type);
3890 merge->set_memory_at(src_idx, memory(src_idx));
3891 merge->set_memory_at(dst_idx, memory(dst_idx));
3892 return merge;
3893 }
3894
3895 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
3896 assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
3897 assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
3898 // If input and output memory types differ, capture both states to preserve
3899 // the dependency between preceding and subsequent loads/stores.
3900 // For example, the following program:
3901 // StoreB
3902 // compress_string
3903 // LoadB
3904 // has this memory graph (use->def):
3905 // LoadB -> compress_string -> CharMem
3906 // ... -> StoreB -> ByteMem
3907 // The intrinsic hides the dependency between LoadB and StoreB, causing
3908 // the load to read from memory not containing the result of the StoreB.
3909 // The correct memory graph should look like this:
3910 // LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
3911 Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
3912 StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
3913 Node* res_mem = _gvn.transform(new SCMemProjNode(str));
3914 set_memory(res_mem, TypeAryPtr::BYTES);
3915 return str;
3916 }
3917
3918 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
3919 assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
3920 assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
3921 // Capture src and dst memory (see comment in 'compress_string').
3922 Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
3923 StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
3924 set_memory(_gvn.transform(str), dst_type);
3925 }
3926
3927 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
3928 /**
3929 * int i_char = start;
3930 * for (int i_byte = 0; i_byte < count; i_byte++) {
3931 * dst[i_char++] = (char)(src[i_byte] & 0xff);
3932 * }
3933 */
3934 add_predicate();
3935 RegionNode* head = new RegionNode(3);
3936 head->init_req(1, control());
3937 gvn().set_type(head, Type::CONTROL);
3938 record_for_igvn(head);
3939
3940 Node* i_byte = new PhiNode(head, TypeInt::INT);
3941 i_byte->init_req(1, intcon(0));
3942 gvn().set_type(i_byte, TypeInt::INT);
3943 record_for_igvn(i_byte);
3944
3945 Node* i_char = new PhiNode(head, TypeInt::INT);
3946 i_char->init_req(1, start);
3947 gvn().set_type(i_char, TypeInt::INT);
3948 record_for_igvn(i_char);
3949
3950 Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
3951 gvn().set_type(mem, Type::MEMORY);
3952 record_for_igvn(mem);
3953 set_control(head);
3954 set_memory(mem, TypeAryPtr::BYTES);
3955 Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
3956 Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
3957 AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
3958 false, false, true /* mismatched */);
3959
3960 IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
3961 head->init_req(2, IfTrue(iff));
3962 mem->init_req(2, st);
3963 i_byte->init_req(2, AddI(i_byte, intcon(1)));
3964 i_char->init_req(2, AddI(i_char, intcon(2)));
3965
3966 set_control(IfFalse(iff));
3967 set_memory(st, TypeAryPtr::BYTES);
3968 }
3969
3970 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
3971 if (!field->is_constant()) {
3972 return NULL; // Field not marked as constant.
3973 }
3974 ciInstance* holder = NULL;
3975 if (!field->is_static()) {
3976 ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
3977 if (const_oop != NULL && const_oop->is_instance()) {
3978 holder = const_oop->as_instance();
3979 }
3980 }
3981 const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
3982 /*is_unsigned_load=*/false);
3983 if (con_type != NULL) {
3984 return makecon(con_type);
3985 }
3986 return NULL;
3987 }
3988
3989 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
3990 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
3991 // assumption of CCP analysis.
3992 return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
3993 }