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 "compiler/compileLog.hpp"
27 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
28 #include "gc/g1/heapRegion.hpp"
29 #include "gc/shared/barrierSet.hpp"
30 #include "gc/shared/cardTableModRefBS.hpp"
31 #include "gc/shared/collectedHeap.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "opto/addnode.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/convertnode.hpp"
36 #include "opto/graphKit.hpp"
37 #include "opto/idealKit.hpp"
38 #include "opto/intrinsicnode.hpp"
39 #include "opto/locknode.hpp"
40 #include "opto/machnode.hpp"
41 #include "opto/narrowptrnode.hpp"
42 #include "opto/opaquenode.hpp"
43 #include "opto/parse.hpp"
44 #include "opto/rootnode.hpp"
45 #include "opto/runtime.hpp"
46 #include "runtime/deoptimization.hpp"
47 #include "runtime/sharedRuntime.hpp"
48
49 //----------------------------GraphKit-----------------------------------------
50 // Main utility constructor.
51 GraphKit::GraphKit(JVMState* jvms)
52 : Phase(Phase::Parser),
53 _env(C->env()),
54 _gvn(*C->initial_gvn())
55 {
56 _exceptions = jvms->map()->next_exception();
57 if (_exceptions != NULL) jvms->map()->set_next_exception(NULL);
58 set_jvms(jvms);
59 }
60
61 // Private constructor for parser.
62 GraphKit::GraphKit()
63 : Phase(Phase::Parser),
64 _env(C->env()),
65 _gvn(*C->initial_gvn())
66 {
67 _exceptions = NULL;
68 set_map(NULL);
69 debug_only(_sp = -99);
70 debug_only(set_bci(-99));
71 }
72
73
74
75 //---------------------------clean_stack---------------------------------------
76 // Clear away rubbish from the stack area of the JVM state.
77 // This destroys any arguments that may be waiting on the stack.
78 void GraphKit::clean_stack(int from_sp) {
79 SafePointNode* map = this->map();
80 JVMState* jvms = this->jvms();
81 int stk_size = jvms->stk_size();
82 int stkoff = jvms->stkoff();
83 Node* top = this->top();
84 for (int i = from_sp; i < stk_size; i++) {
85 if (map->in(stkoff + i) != top) {
86 map->set_req(stkoff + i, top);
87 }
88 }
89 }
90
91
92 //--------------------------------sync_jvms-----------------------------------
93 // Make sure our current jvms agrees with our parse state.
94 JVMState* GraphKit::sync_jvms() const {
95 JVMState* jvms = this->jvms();
96 jvms->set_bci(bci()); // Record the new bci in the JVMState
97 jvms->set_sp(sp()); // Record the new sp in the JVMState
98 assert(jvms_in_sync(), "jvms is now in sync");
99 return jvms;
100 }
101
102 //--------------------------------sync_jvms_for_reexecute---------------------
103 // Make sure our current jvms agrees with our parse state. This version
104 // uses the reexecute_sp for reexecuting bytecodes.
105 JVMState* GraphKit::sync_jvms_for_reexecute() {
106 JVMState* jvms = this->jvms();
107 jvms->set_bci(bci()); // Record the new bci in the JVMState
108 jvms->set_sp(reexecute_sp()); // Record the new sp in the JVMState
109 return jvms;
110 }
111
112 #ifdef ASSERT
113 bool GraphKit::jvms_in_sync() const {
114 Parse* parse = is_Parse();
115 if (parse == NULL) {
116 if (bci() != jvms()->bci()) return false;
117 if (sp() != (int)jvms()->sp()) return false;
118 return true;
119 }
120 if (jvms()->method() != parse->method()) return false;
121 if (jvms()->bci() != parse->bci()) return false;
122 int jvms_sp = jvms()->sp();
123 if (jvms_sp != parse->sp()) return false;
124 int jvms_depth = jvms()->depth();
125 if (jvms_depth != parse->depth()) return false;
126 return true;
127 }
128
129 // Local helper checks for special internal merge points
130 // used to accumulate and merge exception states.
131 // They are marked by the region's in(0) edge being the map itself.
132 // Such merge points must never "escape" into the parser at large,
133 // until they have been handed to gvn.transform.
134 static bool is_hidden_merge(Node* reg) {
135 if (reg == NULL) return false;
136 if (reg->is_Phi()) {
137 reg = reg->in(0);
138 if (reg == NULL) return false;
139 }
140 return reg->is_Region() && reg->in(0) != NULL && reg->in(0)->is_Root();
141 }
142
143 void GraphKit::verify_map() const {
144 if (map() == NULL) return; // null map is OK
145 assert(map()->req() <= jvms()->endoff(), "no extra garbage on map");
146 assert(!map()->has_exceptions(), "call add_exception_states_from 1st");
147 assert(!is_hidden_merge(control()), "call use_exception_state, not set_map");
148 }
149
150 void GraphKit::verify_exception_state(SafePointNode* ex_map) {
151 assert(ex_map->next_exception() == NULL, "not already part of a chain");
152 assert(has_saved_ex_oop(ex_map), "every exception state has an ex_oop");
153 }
154 #endif
155
156 //---------------------------stop_and_kill_map---------------------------------
157 // Set _map to NULL, signalling a stop to further bytecode execution.
158 // First smash the current map's control to a constant, to mark it dead.
159 void GraphKit::stop_and_kill_map() {
160 SafePointNode* dead_map = stop();
161 if (dead_map != NULL) {
162 dead_map->disconnect_inputs(NULL, C); // Mark the map as killed.
163 assert(dead_map->is_killed(), "must be so marked");
164 }
165 }
166
167
168 //--------------------------------stopped--------------------------------------
169 // Tell if _map is NULL, or control is top.
170 bool GraphKit::stopped() {
171 if (map() == NULL) return true;
172 else if (control() == top()) return true;
173 else return false;
174 }
175
176
177 //-----------------------------has_ex_handler----------------------------------
178 // Tell if this method or any caller method has exception handlers.
179 bool GraphKit::has_ex_handler() {
180 for (JVMState* jvmsp = jvms(); jvmsp != NULL; jvmsp = jvmsp->caller()) {
181 if (jvmsp->has_method() && jvmsp->method()->has_exception_handlers()) {
182 return true;
183 }
184 }
185 return false;
186 }
187
188 //------------------------------save_ex_oop------------------------------------
189 // Save an exception without blowing stack contents or other JVM state.
190 void GraphKit::set_saved_ex_oop(SafePointNode* ex_map, Node* ex_oop) {
191 assert(!has_saved_ex_oop(ex_map), "clear ex-oop before setting again");
192 ex_map->add_req(ex_oop);
193 debug_only(verify_exception_state(ex_map));
194 }
195
196 inline static Node* common_saved_ex_oop(SafePointNode* ex_map, bool clear_it) {
197 assert(GraphKit::has_saved_ex_oop(ex_map), "ex_oop must be there");
198 Node* ex_oop = ex_map->in(ex_map->req()-1);
199 if (clear_it) ex_map->del_req(ex_map->req()-1);
200 return ex_oop;
201 }
202
203 //-----------------------------saved_ex_oop------------------------------------
204 // Recover a saved exception from its map.
205 Node* GraphKit::saved_ex_oop(SafePointNode* ex_map) {
206 return common_saved_ex_oop(ex_map, false);
207 }
208
209 //--------------------------clear_saved_ex_oop---------------------------------
210 // Erase a previously saved exception from its map.
211 Node* GraphKit::clear_saved_ex_oop(SafePointNode* ex_map) {
212 return common_saved_ex_oop(ex_map, true);
213 }
214
215 #ifdef ASSERT
216 //---------------------------has_saved_ex_oop----------------------------------
217 // Erase a previously saved exception from its map.
218 bool GraphKit::has_saved_ex_oop(SafePointNode* ex_map) {
219 return ex_map->req() == ex_map->jvms()->endoff()+1;
220 }
221 #endif
222
223 //-------------------------make_exception_state--------------------------------
224 // Turn the current JVM state into an exception state, appending the ex_oop.
225 SafePointNode* GraphKit::make_exception_state(Node* ex_oop) {
226 sync_jvms();
227 SafePointNode* ex_map = stop(); // do not manipulate this map any more
228 set_saved_ex_oop(ex_map, ex_oop);
229 return ex_map;
230 }
231
232
233 //--------------------------add_exception_state--------------------------------
234 // Add an exception to my list of exceptions.
235 void GraphKit::add_exception_state(SafePointNode* ex_map) {
236 if (ex_map == NULL || ex_map->control() == top()) {
237 return;
238 }
239 #ifdef ASSERT
240 verify_exception_state(ex_map);
241 if (has_exceptions()) {
242 assert(ex_map->jvms()->same_calls_as(_exceptions->jvms()), "all collected exceptions must come from the same place");
243 }
244 #endif
245
246 // If there is already an exception of exactly this type, merge with it.
247 // In particular, null-checks and other low-level exceptions common up here.
248 Node* ex_oop = saved_ex_oop(ex_map);
249 const Type* ex_type = _gvn.type(ex_oop);
250 if (ex_oop == top()) {
251 // No action needed.
252 return;
253 }
254 assert(ex_type->isa_instptr(), "exception must be an instance");
255 for (SafePointNode* e2 = _exceptions; e2 != NULL; e2 = e2->next_exception()) {
256 const Type* ex_type2 = _gvn.type(saved_ex_oop(e2));
257 // We check sp also because call bytecodes can generate exceptions
258 // both before and after arguments are popped!
259 if (ex_type2 == ex_type
260 && e2->_jvms->sp() == ex_map->_jvms->sp()) {
261 combine_exception_states(ex_map, e2);
262 return;
263 }
264 }
265
266 // No pre-existing exception of the same type. Chain it on the list.
267 push_exception_state(ex_map);
268 }
269
270 //-----------------------add_exception_states_from-----------------------------
271 void GraphKit::add_exception_states_from(JVMState* jvms) {
272 SafePointNode* ex_map = jvms->map()->next_exception();
273 if (ex_map != NULL) {
274 jvms->map()->set_next_exception(NULL);
275 for (SafePointNode* next_map; ex_map != NULL; ex_map = next_map) {
276 next_map = ex_map->next_exception();
277 ex_map->set_next_exception(NULL);
278 add_exception_state(ex_map);
279 }
280 }
281 }
282
283 //-----------------------transfer_exceptions_into_jvms-------------------------
284 JVMState* GraphKit::transfer_exceptions_into_jvms() {
285 if (map() == NULL) {
286 // We need a JVMS to carry the exceptions, but the map has gone away.
287 // Create a scratch JVMS, cloned from any of the exception states...
288 if (has_exceptions()) {
289 _map = _exceptions;
290 _map = clone_map();
291 _map->set_next_exception(NULL);
292 clear_saved_ex_oop(_map);
293 debug_only(verify_map());
294 } else {
295 // ...or created from scratch
296 JVMState* jvms = new (C) JVMState(_method, NULL);
297 jvms->set_bci(_bci);
298 jvms->set_sp(_sp);
299 jvms->set_map(new SafePointNode(TypeFunc::Parms, jvms));
300 set_jvms(jvms);
301 for (uint i = 0; i < map()->req(); i++) map()->init_req(i, top());
302 set_all_memory(top());
303 while (map()->req() < jvms->endoff()) map()->add_req(top());
304 }
305 // (This is a kludge, in case you didn't notice.)
306 set_control(top());
307 }
308 JVMState* jvms = sync_jvms();
309 assert(!jvms->map()->has_exceptions(), "no exceptions on this map yet");
310 jvms->map()->set_next_exception(_exceptions);
311 _exceptions = NULL; // done with this set of exceptions
312 return jvms;
313 }
314
315 static inline void add_n_reqs(Node* dstphi, Node* srcphi) {
316 assert(is_hidden_merge(dstphi), "must be a special merge node");
317 assert(is_hidden_merge(srcphi), "must be a special merge node");
318 uint limit = srcphi->req();
319 for (uint i = PhiNode::Input; i < limit; i++) {
320 dstphi->add_req(srcphi->in(i));
321 }
322 }
323 static inline void add_one_req(Node* dstphi, Node* src) {
324 assert(is_hidden_merge(dstphi), "must be a special merge node");
325 assert(!is_hidden_merge(src), "must not be a special merge node");
326 dstphi->add_req(src);
327 }
328
329 //-----------------------combine_exception_states------------------------------
330 // This helper function combines exception states by building phis on a
331 // specially marked state-merging region. These regions and phis are
332 // untransformed, and can build up gradually. The region is marked by
333 // having a control input of its exception map, rather than NULL. Such
334 // regions do not appear except in this function, and in use_exception_state.
335 void GraphKit::combine_exception_states(SafePointNode* ex_map, SafePointNode* phi_map) {
336 if (failing()) return; // dying anyway...
337 JVMState* ex_jvms = ex_map->_jvms;
338 assert(ex_jvms->same_calls_as(phi_map->_jvms), "consistent call chains");
339 assert(ex_jvms->stkoff() == phi_map->_jvms->stkoff(), "matching locals");
340 assert(ex_jvms->sp() == phi_map->_jvms->sp(), "matching stack sizes");
341 assert(ex_jvms->monoff() == phi_map->_jvms->monoff(), "matching JVMS");
342 assert(ex_jvms->scloff() == phi_map->_jvms->scloff(), "matching scalar replaced objects");
343 assert(ex_map->req() == phi_map->req(), "matching maps");
344 uint tos = ex_jvms->stkoff() + ex_jvms->sp();
345 Node* hidden_merge_mark = root();
346 Node* region = phi_map->control();
347 MergeMemNode* phi_mem = phi_map->merged_memory();
348 MergeMemNode* ex_mem = ex_map->merged_memory();
349 if (region->in(0) != hidden_merge_mark) {
350 // The control input is not (yet) a specially-marked region in phi_map.
351 // Make it so, and build some phis.
352 region = new RegionNode(2);
353 _gvn.set_type(region, Type::CONTROL);
354 region->set_req(0, hidden_merge_mark); // marks an internal ex-state
355 region->init_req(1, phi_map->control());
356 phi_map->set_control(region);
357 Node* io_phi = PhiNode::make(region, phi_map->i_o(), Type::ABIO);
358 record_for_igvn(io_phi);
359 _gvn.set_type(io_phi, Type::ABIO);
360 phi_map->set_i_o(io_phi);
361 for (MergeMemStream mms(phi_mem); mms.next_non_empty(); ) {
362 Node* m = mms.memory();
363 Node* m_phi = PhiNode::make(region, m, Type::MEMORY, mms.adr_type(C));
364 record_for_igvn(m_phi);
365 _gvn.set_type(m_phi, Type::MEMORY);
366 mms.set_memory(m_phi);
367 }
368 }
369
370 // Either or both of phi_map and ex_map might already be converted into phis.
371 Node* ex_control = ex_map->control();
372 // if there is special marking on ex_map also, we add multiple edges from src
373 bool add_multiple = (ex_control->in(0) == hidden_merge_mark);
374 // how wide was the destination phi_map, originally?
375 uint orig_width = region->req();
376
377 if (add_multiple) {
378 add_n_reqs(region, ex_control);
379 add_n_reqs(phi_map->i_o(), ex_map->i_o());
380 } else {
381 // ex_map has no merges, so we just add single edges everywhere
382 add_one_req(region, ex_control);
383 add_one_req(phi_map->i_o(), ex_map->i_o());
384 }
385 for (MergeMemStream mms(phi_mem, ex_mem); mms.next_non_empty2(); ) {
386 if (mms.is_empty()) {
387 // get a copy of the base memory, and patch some inputs into it
388 const TypePtr* adr_type = mms.adr_type(C);
389 Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
390 assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
391 mms.set_memory(phi);
392 // Prepare to append interesting stuff onto the newly sliced phi:
393 while (phi->req() > orig_width) phi->del_req(phi->req()-1);
394 }
395 // Append stuff from ex_map:
396 if (add_multiple) {
397 add_n_reqs(mms.memory(), mms.memory2());
398 } else {
399 add_one_req(mms.memory(), mms.memory2());
400 }
401 }
402 uint limit = ex_map->req();
403 for (uint i = TypeFunc::Parms; i < limit; i++) {
404 // Skip everything in the JVMS after tos. (The ex_oop follows.)
405 if (i == tos) i = ex_jvms->monoff();
406 Node* src = ex_map->in(i);
407 Node* dst = phi_map->in(i);
408 if (src != dst) {
409 PhiNode* phi;
410 if (dst->in(0) != region) {
411 dst = phi = PhiNode::make(region, dst, _gvn.type(dst));
412 record_for_igvn(phi);
413 _gvn.set_type(phi, phi->type());
414 phi_map->set_req(i, dst);
415 // Prepare to append interesting stuff onto the new phi:
416 while (dst->req() > orig_width) dst->del_req(dst->req()-1);
417 } else {
418 assert(dst->is_Phi(), "nobody else uses a hidden region");
419 phi = dst->as_Phi();
420 }
421 if (add_multiple && src->in(0) == ex_control) {
422 // Both are phis.
423 add_n_reqs(dst, src);
424 } else {
425 while (dst->req() < region->req()) add_one_req(dst, src);
426 }
427 const Type* srctype = _gvn.type(src);
428 if (phi->type() != srctype) {
429 const Type* dsttype = phi->type()->meet_speculative(srctype);
430 if (phi->type() != dsttype) {
431 phi->set_type(dsttype);
432 _gvn.set_type(phi, dsttype);
433 }
434 }
435 }
436 }
437 phi_map->merge_replaced_nodes_with(ex_map);
438 }
439
440 //--------------------------use_exception_state--------------------------------
441 Node* GraphKit::use_exception_state(SafePointNode* phi_map) {
442 if (failing()) { stop(); return top(); }
443 Node* region = phi_map->control();
444 Node* hidden_merge_mark = root();
445 assert(phi_map->jvms()->map() == phi_map, "sanity: 1-1 relation");
446 Node* ex_oop = clear_saved_ex_oop(phi_map);
447 if (region->in(0) == hidden_merge_mark) {
448 // Special marking for internal ex-states. Process the phis now.
449 region->set_req(0, region); // now it's an ordinary region
450 set_jvms(phi_map->jvms()); // ...so now we can use it as a map
451 // Note: Setting the jvms also sets the bci and sp.
452 set_control(_gvn.transform(region));
453 uint tos = jvms()->stkoff() + sp();
454 for (uint i = 1; i < tos; i++) {
455 Node* x = phi_map->in(i);
456 if (x->in(0) == region) {
457 assert(x->is_Phi(), "expected a special phi");
458 phi_map->set_req(i, _gvn.transform(x));
459 }
460 }
461 for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
462 Node* x = mms.memory();
463 if (x->in(0) == region) {
464 assert(x->is_Phi(), "nobody else uses a hidden region");
465 mms.set_memory(_gvn.transform(x));
466 }
467 }
468 if (ex_oop->in(0) == region) {
469 assert(ex_oop->is_Phi(), "expected a special phi");
470 ex_oop = _gvn.transform(ex_oop);
471 }
472 } else {
473 set_jvms(phi_map->jvms());
474 }
475
476 assert(!is_hidden_merge(phi_map->control()), "hidden ex. states cleared");
477 assert(!is_hidden_merge(phi_map->i_o()), "hidden ex. states cleared");
478 return ex_oop;
479 }
480
481 //---------------------------------java_bc-------------------------------------
482 Bytecodes::Code GraphKit::java_bc() const {
483 ciMethod* method = this->method();
484 int bci = this->bci();
485 if (method != NULL && bci != InvocationEntryBci)
486 return method->java_code_at_bci(bci);
487 else
488 return Bytecodes::_illegal;
489 }
490
491 void GraphKit::uncommon_trap_if_should_post_on_exceptions(Deoptimization::DeoptReason reason,
492 bool must_throw) {
493 // if the exception capability is set, then we will generate code
494 // to check the JavaThread.should_post_on_exceptions flag to see
495 // if we actually need to report exception events (for this
496 // thread). If we don't need to report exception events, we will
497 // take the normal fast path provided by add_exception_events. If
498 // exception event reporting is enabled for this thread, we will
499 // take the uncommon_trap in the BuildCutout below.
500
501 // first must access the should_post_on_exceptions_flag in this thread's JavaThread
502 Node* jthread = _gvn.transform(new ThreadLocalNode());
503 Node* adr = basic_plus_adr(top(), jthread, in_bytes(JavaThread::should_post_on_exceptions_flag_offset()));
504 Node* should_post_flag = make_load(control(), adr, TypeInt::INT, T_INT, Compile::AliasIdxRaw, MemNode::unordered);
505
506 // Test the should_post_on_exceptions_flag vs. 0
507 Node* chk = _gvn.transform( new CmpINode(should_post_flag, intcon(0)) );
508 Node* tst = _gvn.transform( new BoolNode(chk, BoolTest::eq) );
509
510 // Branch to slow_path if should_post_on_exceptions_flag was true
511 { BuildCutout unless(this, tst, PROB_MAX);
512 // Do not try anything fancy if we're notifying the VM on every throw.
513 // Cf. case Bytecodes::_athrow in parse2.cpp.
514 uncommon_trap(reason, Deoptimization::Action_none,
515 (ciKlass*)NULL, (char*)NULL, must_throw);
516 }
517
518 }
519
520 //------------------------------builtin_throw----------------------------------
521 void GraphKit::builtin_throw(Deoptimization::DeoptReason reason, Node* arg) {
522 bool must_throw = true;
523
524 if (env()->jvmti_can_post_on_exceptions()) {
525 // check if we must post exception events, take uncommon trap if so
526 uncommon_trap_if_should_post_on_exceptions(reason, must_throw);
527 // here if should_post_on_exceptions is false
528 // continue on with the normal codegen
529 }
530
531 // If this particular condition has not yet happened at this
532 // bytecode, then use the uncommon trap mechanism, and allow for
533 // a future recompilation if several traps occur here.
534 // If the throw is hot, try to use a more complicated inline mechanism
535 // which keeps execution inside the compiled code.
536 bool treat_throw_as_hot = false;
537 ciMethodData* md = method()->method_data();
538
539 if (ProfileTraps) {
540 if (too_many_traps(reason)) {
541 treat_throw_as_hot = true;
542 }
543 // (If there is no MDO at all, assume it is early in
544 // execution, and that any deopts are part of the
545 // startup transient, and don't need to be remembered.)
546
547 // Also, if there is a local exception handler, treat all throws
548 // as hot if there has been at least one in this method.
549 if (C->trap_count(reason) != 0
550 && method()->method_data()->trap_count(reason) != 0
551 && has_ex_handler()) {
552 treat_throw_as_hot = true;
553 }
554 }
555
556 // If this throw happens frequently, an uncommon trap might cause
557 // a performance pothole. If there is a local exception handler,
558 // and if this particular bytecode appears to be deoptimizing often,
559 // let us handle the throw inline, with a preconstructed instance.
560 // Note: If the deopt count has blown up, the uncommon trap
561 // runtime is going to flush this nmethod, not matter what.
562 if (treat_throw_as_hot
563 && (!StackTraceInThrowable || OmitStackTraceInFastThrow)) {
564 // If the throw is local, we use a pre-existing instance and
565 // punt on the backtrace. This would lead to a missing backtrace
566 // (a repeat of 4292742) if the backtrace object is ever asked
567 // for its backtrace.
568 // Fixing this remaining case of 4292742 requires some flavor of
569 // escape analysis. Leave that for the future.
570 ciInstance* ex_obj = NULL;
571 switch (reason) {
572 case Deoptimization::Reason_null_check:
573 ex_obj = env()->NullPointerException_instance();
574 break;
575 case Deoptimization::Reason_div0_check:
576 ex_obj = env()->ArithmeticException_instance();
577 break;
578 case Deoptimization::Reason_range_check:
579 ex_obj = env()->ArrayIndexOutOfBoundsException_instance();
580 break;
581 case Deoptimization::Reason_class_check:
582 if (java_bc() == Bytecodes::_aastore) {
583 ex_obj = env()->ArrayStoreException_instance();
584 } else {
585 ex_obj = env()->ClassCastException_instance();
586 }
587 break;
588 default:
589 break;
590 }
591 if (failing()) { stop(); return; } // exception allocation might fail
592 if (ex_obj != NULL) {
593 // Cheat with a preallocated exception object.
594 if (C->log() != NULL)
595 C->log()->elem("hot_throw preallocated='1' reason='%s'",
596 Deoptimization::trap_reason_name(reason));
597 const TypeInstPtr* ex_con = TypeInstPtr::make(ex_obj);
598 Node* ex_node = _gvn.transform(ConNode::make(ex_con));
599
600 // Clear the detail message of the preallocated exception object.
601 // Weblogic sometimes mutates the detail message of exceptions
602 // using reflection.
603 int offset = java_lang_Throwable::get_detailMessage_offset();
604 const TypePtr* adr_typ = ex_con->add_offset(offset);
605
606 Node *adr = basic_plus_adr(ex_node, ex_node, offset);
607 const TypeOopPtr* val_type = TypeOopPtr::make_from_klass(env()->String_klass());
608 // Conservatively release stores of object references.
609 Node *store = store_oop_to_object(control(), ex_node, adr, adr_typ, null(), val_type, T_OBJECT, MemNode::release);
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
1549 void GraphKit::pre_barrier(bool do_load,
1550 Node* ctl,
1551 Node* obj,
1552 Node* adr,
1553 uint adr_idx,
1554 Node* val,
1555 const TypeOopPtr* val_type,
1556 Node* pre_val,
1557 BasicType bt) {
1558
1559 BarrierSet* bs = Universe::heap()->barrier_set();
1560 set_control(ctl);
1561 switch (bs->kind()) {
1562 case BarrierSet::G1SATBCTLogging:
1563 g1_write_barrier_pre(do_load, obj, adr, adr_idx, val, val_type, pre_val, bt);
1564 break;
1565
1566 case BarrierSet::CardTableForRS:
1567 case BarrierSet::CardTableExtension:
1568 case BarrierSet::ModRef:
1569 break;
1570
1571 default :
1572 ShouldNotReachHere();
1573
1574 }
1575 }
1576
1577 bool GraphKit::can_move_pre_barrier() const {
1578 BarrierSet* bs = Universe::heap()->barrier_set();
1579 switch (bs->kind()) {
1580 case BarrierSet::G1SATBCTLogging:
1581 return true; // Can move it if no safepoint
1582
1583 case BarrierSet::CardTableForRS:
1584 case BarrierSet::CardTableExtension:
1585 case BarrierSet::ModRef:
1586 return true; // There is no pre-barrier
1587
1588 default :
1589 ShouldNotReachHere();
1590 }
1591 return false;
1592 }
1593
1594 void GraphKit::post_barrier(Node* ctl,
1595 Node* store,
1596 Node* obj,
1597 Node* adr,
1598 uint adr_idx,
1599 Node* val,
1600 BasicType bt,
1601 bool use_precise) {
1602 BarrierSet* bs = Universe::heap()->barrier_set();
1603 set_control(ctl);
1604 switch (bs->kind()) {
1605 case BarrierSet::G1SATBCTLogging:
1606 g1_write_barrier_post(store, obj, adr, adr_idx, val, bt, use_precise);
1607 break;
1608
1609 case BarrierSet::CardTableForRS:
1610 case BarrierSet::CardTableExtension:
1611 write_barrier_post(store, obj, adr, adr_idx, val, use_precise);
1612 break;
1613
1614 case BarrierSet::ModRef:
1615 break;
1616
1617 default :
1618 ShouldNotReachHere();
1619
1620 }
1621 }
1622
1623 Node* GraphKit::store_oop(Node* ctl,
1624 Node* obj,
1625 Node* adr,
1626 const TypePtr* adr_type,
1627 Node* val,
1628 const TypeOopPtr* val_type,
1629 BasicType bt,
1630 bool use_precise,
1631 MemNode::MemOrd mo,
1632 bool mismatched) {
1633 // Transformation of a value which could be NULL pointer (CastPP #NULL)
1634 // could be delayed during Parse (for example, in adjust_map_after_if()).
1635 // Execute transformation here to avoid barrier generation in such case.
1636 if (_gvn.type(val) == TypePtr::NULL_PTR)
1637 val = _gvn.makecon(TypePtr::NULL_PTR);
1638
1639 set_control(ctl);
1640 if (stopped()) return top(); // Dead path ?
1641
1642 assert(bt == T_OBJECT, "sanity");
1643 assert(val != NULL, "not dead path");
1644 uint adr_idx = C->get_alias_index(adr_type);
1645 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
1646
1647 pre_barrier(true /* do_load */,
1648 control(), obj, adr, adr_idx, val, val_type,
1649 NULL /* pre_val */,
1650 bt);
1651
1652 Node* store = store_to_memory(control(), adr, val, bt, adr_idx, mo, mismatched);
1653 post_barrier(control(), store, obj, adr, adr_idx, val, bt, use_precise);
1654 return store;
1655 }
1656
1657 // Could be an array or object we don't know at compile time (unsafe ref.)
1658 Node* GraphKit::store_oop_to_unknown(Node* ctl,
1659 Node* obj, // containing obj
1660 Node* adr, // actual adress to store val at
1661 const TypePtr* adr_type,
1662 Node* val,
1663 BasicType bt,
1664 MemNode::MemOrd mo,
1665 bool mismatched) {
1666 Compile::AliasType* at = C->alias_type(adr_type);
1667 const TypeOopPtr* val_type = NULL;
1668 if (adr_type->isa_instptr()) {
1669 if (at->field() != NULL) {
1670 // known field. This code is a copy of the do_put_xxx logic.
1671 ciField* field = at->field();
1672 if (!field->type()->is_loaded()) {
1673 val_type = TypeInstPtr::BOTTOM;
1674 } else {
1675 val_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
1676 }
1677 }
1678 } else if (adr_type->isa_aryptr()) {
1679 val_type = adr_type->is_aryptr()->elem()->make_oopptr();
1680 }
1681 if (val_type == NULL) {
1682 val_type = TypeInstPtr::BOTTOM;
1683 }
1684 return store_oop(ctl, obj, adr, adr_type, val, val_type, bt, true, mo, mismatched);
1685 }
1686
1687
1688 //-------------------------array_element_address-------------------------
1689 Node* GraphKit::array_element_address(Node* ary, Node* idx, BasicType elembt,
1690 const TypeInt* sizetype, Node* ctrl) {
1691 uint shift = exact_log2(type2aelembytes(elembt));
1692 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
1693
1694 // short-circuit a common case (saves lots of confusing waste motion)
1695 jint idx_con = find_int_con(idx, -1);
1696 if (idx_con >= 0) {
1697 intptr_t offset = header + ((intptr_t)idx_con << shift);
1698 return basic_plus_adr(ary, offset);
1699 }
1700
1701 // must be correct type for alignment purposes
1702 Node* base = basic_plus_adr(ary, header);
1703 idx = Compile::conv_I2X_index(&_gvn, idx, sizetype, ctrl);
1704 Node* scale = _gvn.transform( new LShiftXNode(idx, intcon(shift)) );
1705 return basic_plus_adr(ary, base, scale);
1706 }
1707
1708 //-------------------------load_array_element-------------------------
1709 Node* GraphKit::load_array_element(Node* ctl, Node* ary, Node* idx, const TypeAryPtr* arytype) {
1710 const Type* elemtype = arytype->elem();
1711 BasicType elembt = elemtype->array_element_basic_type();
1712 Node* adr = array_element_address(ary, idx, elembt, arytype->size());
1713 if (elembt == T_NARROWOOP) {
1714 elembt = T_OBJECT; // To satisfy switch in LoadNode::make()
1715 }
1716 Node* ld = make_load(ctl, adr, elemtype, elembt, arytype, MemNode::unordered);
1717 return ld;
1718 }
1719
1720 //-------------------------set_arguments_for_java_call-------------------------
1721 // Arguments (pre-popped from the stack) are taken from the JVMS.
1722 void GraphKit::set_arguments_for_java_call(CallJavaNode* call) {
1723 // Add the call arguments:
1724 uint nargs = call->method()->arg_size();
1725 for (uint i = 0; i < nargs; i++) {
1726 Node* arg = argument(i);
1727 call->init_req(i + TypeFunc::Parms, arg);
1728 }
1729 }
1730
1731 //---------------------------set_edges_for_java_call---------------------------
1732 // Connect a newly created call into the current JVMS.
1733 // A return value node (if any) is returned from set_edges_for_java_call.
1734 void GraphKit::set_edges_for_java_call(CallJavaNode* call, bool must_throw, bool separate_io_proj) {
1735
1736 // Add the predefined inputs:
1737 call->init_req( TypeFunc::Control, control() );
1738 call->init_req( TypeFunc::I_O , i_o() );
1739 call->init_req( TypeFunc::Memory , reset_memory() );
1740 call->init_req( TypeFunc::FramePtr, frameptr() );
1741 call->init_req( TypeFunc::ReturnAdr, top() );
1742
1743 add_safepoint_edges(call, must_throw);
1744
1745 Node* xcall = _gvn.transform(call);
1746
1747 if (xcall == top()) {
1748 set_control(top());
1749 return;
1750 }
1751 assert(xcall == call, "call identity is stable");
1752
1753 // Re-use the current map to produce the result.
1754
1755 set_control(_gvn.transform(new ProjNode(call, TypeFunc::Control)));
1756 set_i_o( _gvn.transform(new ProjNode(call, TypeFunc::I_O , separate_io_proj)));
1757 set_all_memory_call(xcall, separate_io_proj);
1758
1759 //return xcall; // no need, caller already has it
1760 }
1761
1762 Node* GraphKit::set_results_for_java_call(CallJavaNode* call, bool separate_io_proj) {
1763 if (stopped()) return top(); // maybe the call folded up?
1764
1765 // Capture the return value, if any.
1766 Node* ret;
1767 if (call->method() == NULL ||
1768 call->method()->return_type()->basic_type() == T_VOID)
1769 ret = top();
1770 else ret = _gvn.transform(new ProjNode(call, TypeFunc::Parms));
1771
1772 // Note: Since any out-of-line call can produce an exception,
1773 // we always insert an I_O projection from the call into the result.
1774
1775 make_slow_call_ex(call, env()->Throwable_klass(), separate_io_proj);
1776
1777 if (separate_io_proj) {
1778 // The caller requested separate projections be used by the fall
1779 // through and exceptional paths, so replace the projections for
1780 // the fall through path.
1781 set_i_o(_gvn.transform( new ProjNode(call, TypeFunc::I_O) ));
1782 set_all_memory(_gvn.transform( new ProjNode(call, TypeFunc::Memory) ));
1783 }
1784 return ret;
1785 }
1786
1787 //--------------------set_predefined_input_for_runtime_call--------------------
1788 // Reading and setting the memory state is way conservative here.
1789 // The real problem is that I am not doing real Type analysis on memory,
1790 // so I cannot distinguish card mark stores from other stores. Across a GC
1791 // point the Store Barrier and the card mark memory has to agree. I cannot
1792 // have a card mark store and its barrier split across the GC point from
1793 // either above or below. Here I get that to happen by reading ALL of memory.
1794 // A better answer would be to separate out card marks from other memory.
1795 // For now, return the input memory state, so that it can be reused
1796 // after the call, if this call has restricted memory effects.
1797 Node* GraphKit::set_predefined_input_for_runtime_call(SafePointNode* call) {
1798 // Set fixed predefined input arguments
1799 Node* memory = reset_memory();
1800 call->init_req( TypeFunc::Control, control() );
1801 call->init_req( TypeFunc::I_O, top() ); // does no i/o
1802 call->init_req( TypeFunc::Memory, memory ); // may gc ptrs
1803 call->init_req( TypeFunc::FramePtr, frameptr() );
1804 call->init_req( TypeFunc::ReturnAdr, top() );
1805 return memory;
1806 }
1807
1808 //-------------------set_predefined_output_for_runtime_call--------------------
1809 // Set control and memory (not i_o) from the call.
1810 // If keep_mem is not NULL, use it for the output state,
1811 // except for the RawPtr output of the call, if hook_mem is TypeRawPtr::BOTTOM.
1812 // If hook_mem is NULL, this call produces no memory effects at all.
1813 // If hook_mem is a Java-visible memory slice (such as arraycopy operands),
1814 // then only that memory slice is taken from the call.
1815 // In the last case, we must put an appropriate memory barrier before
1816 // the call, so as to create the correct anti-dependencies on loads
1817 // preceding the call.
1818 void GraphKit::set_predefined_output_for_runtime_call(Node* call,
1819 Node* keep_mem,
1820 const TypePtr* hook_mem) {
1821 // no i/o
1822 set_control(_gvn.transform( new ProjNode(call,TypeFunc::Control) ));
1823 if (keep_mem) {
1824 // First clone the existing memory state
1825 set_all_memory(keep_mem);
1826 if (hook_mem != NULL) {
1827 // Make memory for the call
1828 Node* mem = _gvn.transform( new ProjNode(call, TypeFunc::Memory) );
1829 // Set the RawPtr memory state only. This covers all the heap top/GC stuff
1830 // We also use hook_mem to extract specific effects from arraycopy stubs.
1831 set_memory(mem, hook_mem);
1832 }
1833 // ...else the call has NO memory effects.
1834
1835 // Make sure the call advertises its memory effects precisely.
1836 // This lets us build accurate anti-dependences in gcm.cpp.
1837 assert(C->alias_type(call->adr_type()) == C->alias_type(hook_mem),
1838 "call node must be constructed correctly");
1839 } else {
1840 assert(hook_mem == NULL, "");
1841 // This is not a "slow path" call; all memory comes from the call.
1842 set_all_memory_call(call);
1843 }
1844 }
1845
1846
1847 // Replace the call with the current state of the kit.
1848 void GraphKit::replace_call(CallNode* call, Node* result, bool do_replaced_nodes) {
1849 JVMState* ejvms = NULL;
1850 if (has_exceptions()) {
1851 ejvms = transfer_exceptions_into_jvms();
1852 }
1853
1854 ReplacedNodes replaced_nodes = map()->replaced_nodes();
1855 ReplacedNodes replaced_nodes_exception;
1856 Node* ex_ctl = top();
1857
1858 SafePointNode* final_state = stop();
1859
1860 // Find all the needed outputs of this call
1861 CallProjections callprojs;
1862 call->extract_projections(&callprojs, true);
1863
1864 Node* init_mem = call->in(TypeFunc::Memory);
1865 Node* final_mem = final_state->in(TypeFunc::Memory);
1866 Node* final_ctl = final_state->in(TypeFunc::Control);
1867 Node* final_io = final_state->in(TypeFunc::I_O);
1868
1869 // Replace all the old call edges with the edges from the inlining result
1870 if (callprojs.fallthrough_catchproj != NULL) {
1871 C->gvn_replace_by(callprojs.fallthrough_catchproj, final_ctl);
1872 }
1873 if (callprojs.fallthrough_memproj != NULL) {
1874 if (final_mem->is_MergeMem()) {
1875 // Parser's exits MergeMem was not transformed but may be optimized
1876 final_mem = _gvn.transform(final_mem);
1877 }
1878 C->gvn_replace_by(callprojs.fallthrough_memproj, final_mem);
1879 }
1880 if (callprojs.fallthrough_ioproj != NULL) {
1881 C->gvn_replace_by(callprojs.fallthrough_ioproj, final_io);
1882 }
1883
1884 // Replace the result with the new result if it exists and is used
1885 if (callprojs.resproj != NULL && result != NULL) {
1886 C->gvn_replace_by(callprojs.resproj, result);
1887 }
1888
1889 if (ejvms == NULL) {
1890 // No exception edges to simply kill off those paths
1891 if (callprojs.catchall_catchproj != NULL) {
1892 C->gvn_replace_by(callprojs.catchall_catchproj, C->top());
1893 }
1894 if (callprojs.catchall_memproj != NULL) {
1895 C->gvn_replace_by(callprojs.catchall_memproj, C->top());
1896 }
1897 if (callprojs.catchall_ioproj != NULL) {
1898 C->gvn_replace_by(callprojs.catchall_ioproj, C->top());
1899 }
1900 // Replace the old exception object with top
1901 if (callprojs.exobj != NULL) {
1902 C->gvn_replace_by(callprojs.exobj, C->top());
1903 }
1904 } else {
1905 GraphKit ekit(ejvms);
1906
1907 // Load my combined exception state into the kit, with all phis transformed:
1908 SafePointNode* ex_map = ekit.combine_and_pop_all_exception_states();
1909 replaced_nodes_exception = ex_map->replaced_nodes();
1910
1911 Node* ex_oop = ekit.use_exception_state(ex_map);
1912
1913 if (callprojs.catchall_catchproj != NULL) {
1914 C->gvn_replace_by(callprojs.catchall_catchproj, ekit.control());
1915 ex_ctl = ekit.control();
1916 }
1917 if (callprojs.catchall_memproj != NULL) {
1918 C->gvn_replace_by(callprojs.catchall_memproj, ekit.reset_memory());
1919 }
1920 if (callprojs.catchall_ioproj != NULL) {
1921 C->gvn_replace_by(callprojs.catchall_ioproj, ekit.i_o());
1922 }
1923
1924 // Replace the old exception object with the newly created one
1925 if (callprojs.exobj != NULL) {
1926 C->gvn_replace_by(callprojs.exobj, ex_oop);
1927 }
1928 }
1929
1930 // Disconnect the call from the graph
1931 call->disconnect_inputs(NULL, C);
1932 C->gvn_replace_by(call, C->top());
1933
1934 // Clean up any MergeMems that feed other MergeMems since the
1935 // optimizer doesn't like that.
1936 if (final_mem->is_MergeMem()) {
1937 Node_List wl;
1938 for (SimpleDUIterator i(final_mem); i.has_next(); i.next()) {
1939 Node* m = i.get();
1940 if (m->is_MergeMem() && !wl.contains(m)) {
1941 wl.push(m);
1942 }
1943 }
1944 while (wl.size() > 0) {
1945 _gvn.transform(wl.pop());
1946 }
1947 }
1948
1949 if (callprojs.fallthrough_catchproj != NULL && !final_ctl->is_top() && do_replaced_nodes) {
1950 replaced_nodes.apply(C, final_ctl);
1951 }
1952 if (!ex_ctl->is_top() && do_replaced_nodes) {
1953 replaced_nodes_exception.apply(C, ex_ctl);
1954 }
1955 }
1956
1957
1958 //------------------------------increment_counter------------------------------
1959 // for statistics: increment a VM counter by 1
1960
1961 void GraphKit::increment_counter(address counter_addr) {
1962 Node* adr1 = makecon(TypeRawPtr::make(counter_addr));
1963 increment_counter(adr1);
1964 }
1965
1966 void GraphKit::increment_counter(Node* counter_addr) {
1967 int adr_type = Compile::AliasIdxRaw;
1968 Node* ctrl = control();
1969 Node* cnt = make_load(ctrl, counter_addr, TypeInt::INT, T_INT, adr_type, MemNode::unordered);
1970 Node* incr = _gvn.transform(new AddINode(cnt, _gvn.intcon(1)));
1971 store_to_memory(ctrl, counter_addr, incr, T_INT, adr_type, MemNode::unordered);
1972 }
1973
1974
1975 //------------------------------uncommon_trap----------------------------------
1976 // Bail out to the interpreter in mid-method. Implemented by calling the
1977 // uncommon_trap blob. This helper function inserts a runtime call with the
1978 // right debug info.
1979 void GraphKit::uncommon_trap(int trap_request,
1980 ciKlass* klass, const char* comment,
1981 bool must_throw,
1982 bool keep_exact_action) {
1983 if (failing()) stop();
1984 if (stopped()) return; // trap reachable?
1985
1986 // Note: If ProfileTraps is true, and if a deopt. actually
1987 // occurs here, the runtime will make sure an MDO exists. There is
1988 // no need to call method()->ensure_method_data() at this point.
1989
1990 // Set the stack pointer to the right value for reexecution:
1991 set_sp(reexecute_sp());
1992
1993 #ifdef ASSERT
1994 if (!must_throw) {
1995 // Make sure the stack has at least enough depth to execute
1996 // the current bytecode.
1997 int inputs, ignored_depth;
1998 if (compute_stack_effects(inputs, ignored_depth)) {
1999 assert(sp() >= inputs, "must have enough JVMS stack to execute %s: sp=%d, inputs=%d",
2000 Bytecodes::name(java_bc()), sp(), inputs);
2001 }
2002 }
2003 #endif
2004
2005 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request);
2006 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request);
2007
2008 switch (action) {
2009 case Deoptimization::Action_maybe_recompile:
2010 case Deoptimization::Action_reinterpret:
2011 // Temporary fix for 6529811 to allow virtual calls to be sure they
2012 // get the chance to go from mono->bi->mega
2013 if (!keep_exact_action &&
2014 Deoptimization::trap_request_index(trap_request) < 0 &&
2015 too_many_recompiles(reason)) {
2016 // This BCI is causing too many recompilations.
2017 if (C->log() != NULL) {
2018 C->log()->elem("observe that='trap_action_change' reason='%s' from='%s' to='none'",
2019 Deoptimization::trap_reason_name(reason),
2020 Deoptimization::trap_action_name(action));
2021 }
2022 action = Deoptimization::Action_none;
2023 trap_request = Deoptimization::make_trap_request(reason, action);
2024 } else {
2025 C->set_trap_can_recompile(true);
2026 }
2027 break;
2028 case Deoptimization::Action_make_not_entrant:
2029 C->set_trap_can_recompile(true);
2030 break;
2031 case Deoptimization::Action_none:
2032 case Deoptimization::Action_make_not_compilable:
2033 break;
2034 default:
2035 #ifdef ASSERT
2036 fatal("unknown action %d: %s", action, Deoptimization::trap_action_name(action));
2037 #endif
2038 break;
2039 }
2040
2041 if (TraceOptoParse) {
2042 char buf[100];
2043 tty->print_cr("Uncommon trap %s at bci:%d",
2044 Deoptimization::format_trap_request(buf, sizeof(buf),
2045 trap_request), bci());
2046 }
2047
2048 CompileLog* log = C->log();
2049 if (log != NULL) {
2050 int kid = (klass == NULL)? -1: log->identify(klass);
2051 log->begin_elem("uncommon_trap bci='%d'", bci());
2052 char buf[100];
2053 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
2054 trap_request));
2055 if (kid >= 0) log->print(" klass='%d'", kid);
2056 if (comment != NULL) log->print(" comment='%s'", comment);
2057 log->end_elem();
2058 }
2059
2060 // Make sure any guarding test views this path as very unlikely
2061 Node *i0 = control()->in(0);
2062 if (i0 != NULL && i0->is_If()) { // Found a guarding if test?
2063 IfNode *iff = i0->as_If();
2064 float f = iff->_prob; // Get prob
2065 if (control()->Opcode() == Op_IfTrue) {
2066 if (f > PROB_UNLIKELY_MAG(4))
2067 iff->_prob = PROB_MIN;
2068 } else {
2069 if (f < PROB_LIKELY_MAG(4))
2070 iff->_prob = PROB_MAX;
2071 }
2072 }
2073
2074 // Clear out dead values from the debug info.
2075 kill_dead_locals();
2076
2077 // Now insert the uncommon trap subroutine call
2078 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
2079 const TypePtr* no_memory_effects = NULL;
2080 // Pass the index of the class to be loaded
2081 Node* call = make_runtime_call(RC_NO_LEAF | RC_UNCOMMON |
2082 (must_throw ? RC_MUST_THROW : 0),
2083 OptoRuntime::uncommon_trap_Type(),
2084 call_addr, "uncommon_trap", no_memory_effects,
2085 intcon(trap_request));
2086 assert(call->as_CallStaticJava()->uncommon_trap_request() == trap_request,
2087 "must extract request correctly from the graph");
2088 assert(trap_request != 0, "zero value reserved by uncommon_trap_request");
2089
2090 call->set_req(TypeFunc::ReturnAdr, returnadr());
2091 // The debug info is the only real input to this call.
2092
2093 // Halt-and-catch fire here. The above call should never return!
2094 HaltNode* halt = new HaltNode(control(), frameptr());
2095 _gvn.set_type_bottom(halt);
2096 root()->add_req(halt);
2097
2098 stop_and_kill_map();
2099 }
2100
2101
2102 //--------------------------just_allocated_object------------------------------
2103 // Report the object that was just allocated.
2104 // It must be the case that there are no intervening safepoints.
2105 // We use this to determine if an object is so "fresh" that
2106 // it does not require card marks.
2107 Node* GraphKit::just_allocated_object(Node* current_control) {
2108 if (C->recent_alloc_ctl() == current_control)
2109 return C->recent_alloc_obj();
2110 return NULL;
2111 }
2112
2113
2114 void GraphKit::round_double_arguments(ciMethod* dest_method) {
2115 // (Note: TypeFunc::make has a cache that makes this fast.)
2116 const TypeFunc* tf = TypeFunc::make(dest_method);
2117 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2118 for (int j = 0; j < nargs; j++) {
2119 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2120 if( targ->basic_type() == T_DOUBLE ) {
2121 // If any parameters are doubles, they must be rounded before
2122 // the call, dstore_rounding does gvn.transform
2123 Node *arg = argument(j);
2124 arg = dstore_rounding(arg);
2125 set_argument(j, arg);
2126 }
2127 }
2128 }
2129
2130 /**
2131 * Record profiling data exact_kls for Node n with the type system so
2132 * that it can propagate it (speculation)
2133 *
2134 * @param n node that the type applies to
2135 * @param exact_kls type from profiling
2136 * @param maybe_null did profiling see null?
2137 *
2138 * @return node with improved type
2139 */
2140 Node* GraphKit::record_profile_for_speculation(Node* n, ciKlass* exact_kls, ProfilePtrKind ptr_kind) {
2141 const Type* current_type = _gvn.type(n);
2142 assert(UseTypeSpeculation, "type speculation must be on");
2143
2144 const TypePtr* speculative = current_type->speculative();
2145
2146 // Should the klass from the profile be recorded in the speculative type?
2147 if (current_type->would_improve_type(exact_kls, jvms()->depth())) {
2148 const TypeKlassPtr* tklass = TypeKlassPtr::make(exact_kls);
2149 const TypeOopPtr* xtype = tklass->as_instance_type();
2150 assert(xtype->klass_is_exact(), "Should be exact");
2151 // Any reason to believe n is not null (from this profiling or a previous one)?
2152 assert(ptr_kind != ProfileAlwaysNull, "impossible here");
2153 const TypePtr* ptr = (ptr_kind == ProfileMaybeNull && current_type->speculative_maybe_null()) ? TypePtr::BOTTOM : TypePtr::NOTNULL;
2154 // record the new speculative type's depth
2155 speculative = xtype->cast_to_ptr_type(ptr->ptr())->is_ptr();
2156 speculative = speculative->with_inline_depth(jvms()->depth());
2157 } else if (current_type->would_improve_ptr(ptr_kind)) {
2158 // Profiling report that null was never seen so we can change the
2159 // speculative type to non null ptr.
2160 if (ptr_kind == ProfileAlwaysNull) {
2161 speculative = TypePtr::NULL_PTR;
2162 } else {
2163 assert(ptr_kind == ProfileNeverNull, "nothing else is an improvement");
2164 const TypePtr* ptr = TypePtr::NOTNULL;
2165 if (speculative != NULL) {
2166 speculative = speculative->cast_to_ptr_type(ptr->ptr())->is_ptr();
2167 } else {
2168 speculative = ptr;
2169 }
2170 }
2171 }
2172
2173 if (speculative != current_type->speculative()) {
2174 // Build a type with a speculative type (what we think we know
2175 // about the type but will need a guard when we use it)
2176 const TypeOopPtr* spec_type = TypeOopPtr::make(TypePtr::BotPTR, Type::OffsetBot, TypeOopPtr::InstanceBot, speculative);
2177 // We're changing the type, we need a new CheckCast node to carry
2178 // the new type. The new type depends on the control: what
2179 // profiling tells us is only valid from here as far as we can
2180 // tell.
2181 Node* cast = new CheckCastPPNode(control(), n, current_type->remove_speculative()->join_speculative(spec_type));
2182 cast = _gvn.transform(cast);
2183 replace_in_map(n, cast);
2184 n = cast;
2185 }
2186
2187 return n;
2188 }
2189
2190 /**
2191 * Record profiling data from receiver profiling at an invoke with the
2192 * type system so that it can propagate it (speculation)
2193 *
2194 * @param n receiver node
2195 *
2196 * @return node with improved type
2197 */
2198 Node* GraphKit::record_profiled_receiver_for_speculation(Node* n) {
2199 if (!UseTypeSpeculation) {
2200 return n;
2201 }
2202 ciKlass* exact_kls = profile_has_unique_klass();
2203 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2204 if ((java_bc() == Bytecodes::_checkcast ||
2205 java_bc() == Bytecodes::_instanceof ||
2206 java_bc() == Bytecodes::_aastore) &&
2207 method()->method_data()->is_mature()) {
2208 ciProfileData* data = method()->method_data()->bci_to_data(bci());
2209 if (data != NULL) {
2210 if (!data->as_BitData()->null_seen()) {
2211 ptr_kind = ProfileNeverNull;
2212 } else {
2213 assert(data->is_ReceiverTypeData(), "bad profile data type");
2214 ciReceiverTypeData* call = (ciReceiverTypeData*)data->as_ReceiverTypeData();
2215 uint i = 0;
2216 for (; i < call->row_limit(); i++) {
2217 ciKlass* receiver = call->receiver(i);
2218 if (receiver != NULL) {
2219 break;
2220 }
2221 }
2222 ptr_kind = (i == call->row_limit()) ? ProfileAlwaysNull : ProfileMaybeNull;
2223 }
2224 }
2225 }
2226 return record_profile_for_speculation(n, exact_kls, ptr_kind);
2227 }
2228
2229 /**
2230 * Record profiling data from argument profiling at an invoke with the
2231 * type system so that it can propagate it (speculation)
2232 *
2233 * @param dest_method target method for the call
2234 * @param bc what invoke bytecode is this?
2235 */
2236 void GraphKit::record_profiled_arguments_for_speculation(ciMethod* dest_method, Bytecodes::Code bc) {
2237 if (!UseTypeSpeculation) {
2238 return;
2239 }
2240 const TypeFunc* tf = TypeFunc::make(dest_method);
2241 int nargs = tf->domain()->cnt() - TypeFunc::Parms;
2242 int skip = Bytecodes::has_receiver(bc) ? 1 : 0;
2243 for (int j = skip, i = 0; j < nargs && i < TypeProfileArgsLimit; j++) {
2244 const Type *targ = tf->domain()->field_at(j + TypeFunc::Parms);
2245 if (targ->basic_type() == T_OBJECT || targ->basic_type() == T_ARRAY) {
2246 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2247 ciKlass* better_type = NULL;
2248 if (method()->argument_profiled_type(bci(), i, better_type, ptr_kind)) {
2249 record_profile_for_speculation(argument(j), better_type, ptr_kind);
2250 }
2251 i++;
2252 }
2253 }
2254 }
2255
2256 /**
2257 * Record profiling data from parameter profiling at an invoke with
2258 * the type system so that it can propagate it (speculation)
2259 */
2260 void GraphKit::record_profiled_parameters_for_speculation() {
2261 if (!UseTypeSpeculation) {
2262 return;
2263 }
2264 for (int i = 0, j = 0; i < method()->arg_size() ; i++) {
2265 if (_gvn.type(local(i))->isa_oopptr()) {
2266 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2267 ciKlass* better_type = NULL;
2268 if (method()->parameter_profiled_type(j, better_type, ptr_kind)) {
2269 record_profile_for_speculation(local(i), better_type, ptr_kind);
2270 }
2271 j++;
2272 }
2273 }
2274 }
2275
2276 /**
2277 * Record profiling data from return value profiling at an invoke with
2278 * the type system so that it can propagate it (speculation)
2279 */
2280 void GraphKit::record_profiled_return_for_speculation() {
2281 if (!UseTypeSpeculation) {
2282 return;
2283 }
2284 ProfilePtrKind ptr_kind = ProfileMaybeNull;
2285 ciKlass* better_type = NULL;
2286 if (method()->return_profiled_type(bci(), better_type, ptr_kind)) {
2287 // If profiling reports a single type for the return value,
2288 // feed it to the type system so it can propagate it as a
2289 // speculative type
2290 record_profile_for_speculation(stack(sp()-1), better_type, ptr_kind);
2291 }
2292 }
2293
2294 void GraphKit::round_double_result(ciMethod* dest_method) {
2295 // A non-strict method may return a double value which has an extended
2296 // exponent, but this must not be visible in a caller which is 'strict'
2297 // If a strict caller invokes a non-strict callee, round a double result
2298
2299 BasicType result_type = dest_method->return_type()->basic_type();
2300 assert( method() != NULL, "must have caller context");
2301 if( result_type == T_DOUBLE && method()->is_strict() && !dest_method->is_strict() ) {
2302 // Destination method's return value is on top of stack
2303 // dstore_rounding() does gvn.transform
2304 Node *result = pop_pair();
2305 result = dstore_rounding(result);
2306 push_pair(result);
2307 }
2308 }
2309
2310 // rounding for strict float precision conformance
2311 Node* GraphKit::precision_rounding(Node* n) {
2312 return UseStrictFP && _method->flags().is_strict()
2313 && UseSSE == 0 && Matcher::strict_fp_requires_explicit_rounding
2314 ? _gvn.transform( new RoundFloatNode(0, n) )
2315 : n;
2316 }
2317
2318 // rounding for strict double precision conformance
2319 Node* GraphKit::dprecision_rounding(Node *n) {
2320 return UseStrictFP && _method->flags().is_strict()
2321 && UseSSE <= 1 && Matcher::strict_fp_requires_explicit_rounding
2322 ? _gvn.transform( new RoundDoubleNode(0, n) )
2323 : n;
2324 }
2325
2326 // rounding for non-strict double stores
2327 Node* GraphKit::dstore_rounding(Node* n) {
2328 return Matcher::strict_fp_requires_explicit_rounding
2329 && UseSSE <= 1
2330 ? _gvn.transform( new RoundDoubleNode(0, n) )
2331 : n;
2332 }
2333
2334 //=============================================================================
2335 // Generate a fast path/slow path idiom. Graph looks like:
2336 // [foo] indicates that 'foo' is a parameter
2337 //
2338 // [in] NULL
2339 // \ /
2340 // CmpP
2341 // Bool ne
2342 // If
2343 // / \
2344 // True False-<2>
2345 // / |
2346 // / cast_not_null
2347 // Load | | ^
2348 // [fast_test] | |
2349 // gvn to opt_test | |
2350 // / \ | <1>
2351 // True False |
2352 // | \\ |
2353 // [slow_call] \[fast_result]
2354 // Ctl Val \ \
2355 // | \ \
2356 // Catch <1> \ \
2357 // / \ ^ \ \
2358 // Ex No_Ex | \ \
2359 // | \ \ | \ <2> \
2360 // ... \ [slow_res] | | \ [null_result]
2361 // \ \--+--+--- | |
2362 // \ | / \ | /
2363 // --------Region Phi
2364 //
2365 //=============================================================================
2366 // Code is structured as a series of driver functions all called 'do_XXX' that
2367 // call a set of helper functions. Helper functions first, then drivers.
2368
2369 //------------------------------null_check_oop---------------------------------
2370 // Null check oop. Set null-path control into Region in slot 3.
2371 // Make a cast-not-nullness use the other not-null control. Return cast.
2372 Node* GraphKit::null_check_oop(Node* value, Node* *null_control,
2373 bool never_see_null,
2374 bool safe_for_replace,
2375 bool speculative) {
2376 // Initial NULL check taken path
2377 (*null_control) = top();
2378 Node* cast = null_check_common(value, T_OBJECT, false, null_control, speculative);
2379
2380 // Generate uncommon_trap:
2381 if (never_see_null && (*null_control) != top()) {
2382 // If we see an unexpected null at a check-cast we record it and force a
2383 // recompile; the offending check-cast will be compiled to handle NULLs.
2384 // If we see more than one offending BCI, then all checkcasts in the
2385 // method will be compiled to handle NULLs.
2386 PreserveJVMState pjvms(this);
2387 set_control(*null_control);
2388 replace_in_map(value, null());
2389 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculative);
2390 uncommon_trap(reason,
2391 Deoptimization::Action_make_not_entrant);
2392 (*null_control) = top(); // NULL path is dead
2393 }
2394 if ((*null_control) == top() && safe_for_replace) {
2395 replace_in_map(value, cast);
2396 }
2397
2398 // Cast away null-ness on the result
2399 return cast;
2400 }
2401
2402 //------------------------------opt_iff----------------------------------------
2403 // Optimize the fast-check IfNode. Set the fast-path region slot 2.
2404 // Return slow-path control.
2405 Node* GraphKit::opt_iff(Node* region, Node* iff) {
2406 IfNode *opt_iff = _gvn.transform(iff)->as_If();
2407
2408 // Fast path taken; set region slot 2
2409 Node *fast_taken = _gvn.transform( new IfFalseNode(opt_iff) );
2410 region->init_req(2,fast_taken); // Capture fast-control
2411
2412 // Fast path not-taken, i.e. slow path
2413 Node *slow_taken = _gvn.transform( new IfTrueNode(opt_iff) );
2414 return slow_taken;
2415 }
2416
2417 //-----------------------------make_runtime_call-------------------------------
2418 Node* GraphKit::make_runtime_call(int flags,
2419 const TypeFunc* call_type, address call_addr,
2420 const char* call_name,
2421 const TypePtr* adr_type,
2422 // The following parms are all optional.
2423 // The first NULL ends the list.
2424 Node* parm0, Node* parm1,
2425 Node* parm2, Node* parm3,
2426 Node* parm4, Node* parm5,
2427 Node* parm6, Node* parm7) {
2428 // Slow-path call
2429 bool is_leaf = !(flags & RC_NO_LEAF);
2430 bool has_io = (!is_leaf && !(flags & RC_NO_IO));
2431 if (call_name == NULL) {
2432 assert(!is_leaf, "must supply name for leaf");
2433 call_name = OptoRuntime::stub_name(call_addr);
2434 }
2435 CallNode* call;
2436 if (!is_leaf) {
2437 call = new CallStaticJavaNode(call_type, call_addr, call_name,
2438 bci(), adr_type);
2439 } else if (flags & RC_NO_FP) {
2440 call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
2441 } else {
2442 call = new CallLeafNode(call_type, call_addr, call_name, adr_type);
2443 }
2444
2445 // The following is similar to set_edges_for_java_call,
2446 // except that the memory effects of the call are restricted to AliasIdxRaw.
2447
2448 // Slow path call has no side-effects, uses few values
2449 bool wide_in = !(flags & RC_NARROW_MEM);
2450 bool wide_out = (C->get_alias_index(adr_type) == Compile::AliasIdxBot);
2451
2452 Node* prev_mem = NULL;
2453 if (wide_in) {
2454 prev_mem = set_predefined_input_for_runtime_call(call);
2455 } else {
2456 assert(!wide_out, "narrow in => narrow out");
2457 Node* narrow_mem = memory(adr_type);
2458 prev_mem = reset_memory();
2459 map()->set_memory(narrow_mem);
2460 set_predefined_input_for_runtime_call(call);
2461 }
2462
2463 // Hook each parm in order. Stop looking at the first NULL.
2464 if (parm0 != NULL) { call->init_req(TypeFunc::Parms+0, parm0);
2465 if (parm1 != NULL) { call->init_req(TypeFunc::Parms+1, parm1);
2466 if (parm2 != NULL) { call->init_req(TypeFunc::Parms+2, parm2);
2467 if (parm3 != NULL) { call->init_req(TypeFunc::Parms+3, parm3);
2468 if (parm4 != NULL) { call->init_req(TypeFunc::Parms+4, parm4);
2469 if (parm5 != NULL) { call->init_req(TypeFunc::Parms+5, parm5);
2470 if (parm6 != NULL) { call->init_req(TypeFunc::Parms+6, parm6);
2471 if (parm7 != NULL) { call->init_req(TypeFunc::Parms+7, parm7);
2472 /* close each nested if ===> */ } } } } } } } }
2473 assert(call->in(call->req()-1) != NULL, "must initialize all parms");
2474
2475 if (!is_leaf) {
2476 // Non-leaves can block and take safepoints:
2477 add_safepoint_edges(call, ((flags & RC_MUST_THROW) != 0));
2478 }
2479 // Non-leaves can throw exceptions:
2480 if (has_io) {
2481 call->set_req(TypeFunc::I_O, i_o());
2482 }
2483
2484 if (flags & RC_UNCOMMON) {
2485 // Set the count to a tiny probability. Cf. Estimate_Block_Frequency.
2486 // (An "if" probability corresponds roughly to an unconditional count.
2487 // Sort of.)
2488 call->set_cnt(PROB_UNLIKELY_MAG(4));
2489 }
2490
2491 Node* c = _gvn.transform(call);
2492 assert(c == call, "cannot disappear");
2493
2494 if (wide_out) {
2495 // Slow path call has full side-effects.
2496 set_predefined_output_for_runtime_call(call);
2497 } else {
2498 // Slow path call has few side-effects, and/or sets few values.
2499 set_predefined_output_for_runtime_call(call, prev_mem, adr_type);
2500 }
2501
2502 if (has_io) {
2503 set_i_o(_gvn.transform(new ProjNode(call, TypeFunc::I_O)));
2504 }
2505 return call;
2506
2507 }
2508
2509 //------------------------------merge_memory-----------------------------------
2510 // Merge memory from one path into the current memory state.
2511 void GraphKit::merge_memory(Node* new_mem, Node* region, int new_path) {
2512 for (MergeMemStream mms(merged_memory(), new_mem->as_MergeMem()); mms.next_non_empty2(); ) {
2513 Node* old_slice = mms.force_memory();
2514 Node* new_slice = mms.memory2();
2515 if (old_slice != new_slice) {
2516 PhiNode* phi;
2517 if (old_slice->is_Phi() && old_slice->as_Phi()->region() == region) {
2518 if (mms.is_empty()) {
2519 // clone base memory Phi's inputs for this memory slice
2520 assert(old_slice == mms.base_memory(), "sanity");
2521 phi = PhiNode::make(region, NULL, Type::MEMORY, mms.adr_type(C));
2522 _gvn.set_type(phi, Type::MEMORY);
2523 for (uint i = 1; i < phi->req(); i++) {
2524 phi->init_req(i, old_slice->in(i));
2525 }
2526 } else {
2527 phi = old_slice->as_Phi(); // Phi was generated already
2528 }
2529 } else {
2530 phi = PhiNode::make(region, old_slice, Type::MEMORY, mms.adr_type(C));
2531 _gvn.set_type(phi, Type::MEMORY);
2532 }
2533 phi->set_req(new_path, new_slice);
2534 mms.set_memory(phi);
2535 }
2536 }
2537 }
2538
2539 //------------------------------make_slow_call_ex------------------------------
2540 // Make the exception handler hookups for the slow call
2541 void GraphKit::make_slow_call_ex(Node* call, ciInstanceKlass* ex_klass, bool separate_io_proj, bool deoptimize) {
2542 if (stopped()) return;
2543
2544 // Make a catch node with just two handlers: fall-through and catch-all
2545 Node* i_o = _gvn.transform( new ProjNode(call, TypeFunc::I_O, separate_io_proj) );
2546 Node* catc = _gvn.transform( new CatchNode(control(), i_o, 2) );
2547 Node* norm = _gvn.transform( new CatchProjNode(catc, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci) );
2548 Node* excp = _gvn.transform( new CatchProjNode(catc, CatchProjNode::catch_all_index, CatchProjNode::no_handler_bci) );
2549
2550 { PreserveJVMState pjvms(this);
2551 set_control(excp);
2552 set_i_o(i_o);
2553
2554 if (excp != top()) {
2555 if (deoptimize) {
2556 // Deoptimize if an exception is caught. Don't construct exception state in this case.
2557 uncommon_trap(Deoptimization::Reason_unhandled,
2558 Deoptimization::Action_none);
2559 } else {
2560 // Create an exception state also.
2561 // Use an exact type if the caller has specified a specific exception.
2562 const Type* ex_type = TypeOopPtr::make_from_klass_unique(ex_klass)->cast_to_ptr_type(TypePtr::NotNull);
2563 Node* ex_oop = new CreateExNode(ex_type, control(), i_o);
2564 add_exception_state(make_exception_state(_gvn.transform(ex_oop)));
2565 }
2566 }
2567 }
2568
2569 // Get the no-exception control from the CatchNode.
2570 set_control(norm);
2571 }
2572
2573 static IfNode* gen_subtype_check_compare(Node* ctrl, Node* in1, Node* in2, BoolTest::mask test, float p, PhaseGVN* gvn, BasicType bt) {
2574 Node* cmp = NULL;
2575 switch(bt) {
2576 case T_INT: cmp = new CmpINode(in1, in2); break;
2577 case T_ADDRESS: cmp = new CmpPNode(in1, in2); break;
2578 default: fatal("unexpected comparison type %s", type2name(bt));
2579 }
2580 gvn->transform(cmp);
2581 Node* bol = gvn->transform(new BoolNode(cmp, test));
2582 IfNode* iff = new IfNode(ctrl, bol, p, COUNT_UNKNOWN);
2583 gvn->transform(iff);
2584 if (!bol->is_Con()) gvn->record_for_igvn(iff);
2585 return iff;
2586 }
2587
2588
2589 //-------------------------------gen_subtype_check-----------------------------
2590 // Generate a subtyping check. Takes as input the subtype and supertype.
2591 // Returns 2 values: sets the default control() to the true path and returns
2592 // the false path. Only reads invariant memory; sets no (visible) memory.
2593 // The PartialSubtypeCheckNode sets the hidden 1-word cache in the encoding
2594 // but that's not exposed to the optimizer. This call also doesn't take in an
2595 // Object; if you wish to check an Object you need to load the Object's class
2596 // prior to coming here.
2597 Node* Phase::gen_subtype_check(Node* subklass, Node* superklass, Node** ctrl, MergeMemNode* mem, PhaseGVN* gvn) {
2598 Compile* C = gvn->C;
2599
2600 if ((*ctrl)->is_top()) {
2601 return C->top();
2602 }
2603
2604 // Fast check for identical types, perhaps identical constants.
2605 // The types can even be identical non-constants, in cases
2606 // involving Array.newInstance, Object.clone, etc.
2607 if (subklass == superklass)
2608 return C->top(); // false path is dead; no test needed.
2609
2610 if (gvn->type(superklass)->singleton()) {
2611 ciKlass* superk = gvn->type(superklass)->is_klassptr()->klass();
2612 ciKlass* subk = gvn->type(subklass)->is_klassptr()->klass();
2613
2614 // In the common case of an exact superklass, try to fold up the
2615 // test before generating code. You may ask, why not just generate
2616 // the code and then let it fold up? The answer is that the generated
2617 // code will necessarily include null checks, which do not always
2618 // completely fold away. If they are also needless, then they turn
2619 // into a performance loss. Example:
2620 // Foo[] fa = blah(); Foo x = fa[0]; fa[1] = x;
2621 // Here, the type of 'fa' is often exact, so the store check
2622 // of fa[1]=x will fold up, without testing the nullness of x.
2623 switch (C->static_subtype_check(superk, subk)) {
2624 case Compile::SSC_always_false:
2625 {
2626 Node* always_fail = *ctrl;
2627 *ctrl = gvn->C->top();
2628 return always_fail;
2629 }
2630 case Compile::SSC_always_true:
2631 return C->top();
2632 case Compile::SSC_easy_test:
2633 {
2634 // Just do a direct pointer compare and be done.
2635 IfNode* iff = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_STATIC_FREQUENT, gvn, T_ADDRESS);
2636 *ctrl = gvn->transform(new IfTrueNode(iff));
2637 return gvn->transform(new IfFalseNode(iff));
2638 }
2639 case Compile::SSC_full_test:
2640 break;
2641 default:
2642 ShouldNotReachHere();
2643 }
2644 }
2645
2646 // %%% Possible further optimization: Even if the superklass is not exact,
2647 // if the subklass is the unique subtype of the superklass, the check
2648 // will always succeed. We could leave a dependency behind to ensure this.
2649
2650 // First load the super-klass's check-offset
2651 Node *p1 = gvn->transform(new AddPNode(superklass, superklass, gvn->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
2652 Node* m = mem->memory_at(C->get_alias_index(gvn->type(p1)->is_ptr()));
2653 Node *chk_off = gvn->transform(new LoadINode(NULL, m, p1, gvn->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
2654 int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
2655 bool might_be_cache = (gvn->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
2656
2657 // Load from the sub-klass's super-class display list, or a 1-word cache of
2658 // the secondary superclass list, or a failing value with a sentinel offset
2659 // if the super-klass is an interface or exceptionally deep in the Java
2660 // hierarchy and we have to scan the secondary superclass list the hard way.
2661 // Worst-case type is a little odd: NULL is allowed as a result (usually
2662 // klass loads can never produce a NULL).
2663 Node *chk_off_X = chk_off;
2664 #ifdef _LP64
2665 chk_off_X = gvn->transform(new ConvI2LNode(chk_off_X));
2666 #endif
2667 Node *p2 = gvn->transform(new AddPNode(subklass,subklass,chk_off_X));
2668 // For some types like interfaces the following loadKlass is from a 1-word
2669 // cache which is mutable so can't use immutable memory. Other
2670 // types load from the super-class display table which is immutable.
2671 m = mem->memory_at(C->get_alias_index(gvn->type(p2)->is_ptr()));
2672 Node *kmem = might_be_cache ? m : C->immutable_memory();
2673 Node *nkls = gvn->transform(LoadKlassNode::make(*gvn, NULL, kmem, p2, gvn->type(p2)->is_ptr(), TypeKlassPtr::OBJECT_OR_NULL));
2674
2675 // Compile speed common case: ARE a subtype and we canNOT fail
2676 if( superklass == nkls )
2677 return C->top(); // false path is dead; no test needed.
2678
2679 // See if we get an immediate positive hit. Happens roughly 83% of the
2680 // time. Test to see if the value loaded just previously from the subklass
2681 // is exactly the superklass.
2682 IfNode *iff1 = gen_subtype_check_compare(*ctrl, superklass, nkls, BoolTest::eq, PROB_LIKELY(0.83f), gvn, T_ADDRESS);
2683 Node *iftrue1 = gvn->transform( new IfTrueNode (iff1));
2684 *ctrl = gvn->transform(new IfFalseNode(iff1));
2685
2686 // Compile speed common case: Check for being deterministic right now. If
2687 // chk_off is a constant and not equal to cacheoff then we are NOT a
2688 // subklass. In this case we need exactly the 1 test above and we can
2689 // return those results immediately.
2690 if (!might_be_cache) {
2691 Node* not_subtype_ctrl = *ctrl;
2692 *ctrl = iftrue1; // We need exactly the 1 test above
2693 return not_subtype_ctrl;
2694 }
2695
2696 // Gather the various success & failures here
2697 RegionNode *r_ok_subtype = new RegionNode(4);
2698 gvn->record_for_igvn(r_ok_subtype);
2699 RegionNode *r_not_subtype = new RegionNode(3);
2700 gvn->record_for_igvn(r_not_subtype);
2701
2702 r_ok_subtype->init_req(1, iftrue1);
2703
2704 // Check for immediate negative hit. Happens roughly 11% of the time (which
2705 // is roughly 63% of the remaining cases). Test to see if the loaded
2706 // check-offset points into the subklass display list or the 1-element
2707 // cache. If it points to the display (and NOT the cache) and the display
2708 // missed then it's not a subtype.
2709 Node *cacheoff = gvn->intcon(cacheoff_con);
2710 IfNode *iff2 = gen_subtype_check_compare(*ctrl, chk_off, cacheoff, BoolTest::ne, PROB_LIKELY(0.63f), gvn, T_INT);
2711 r_not_subtype->init_req(1, gvn->transform(new IfTrueNode (iff2)));
2712 *ctrl = gvn->transform(new IfFalseNode(iff2));
2713
2714 // Check for self. Very rare to get here, but it is taken 1/3 the time.
2715 // No performance impact (too rare) but allows sharing of secondary arrays
2716 // which has some footprint reduction.
2717 IfNode *iff3 = gen_subtype_check_compare(*ctrl, subklass, superklass, BoolTest::eq, PROB_LIKELY(0.36f), gvn, T_ADDRESS);
2718 r_ok_subtype->init_req(2, gvn->transform(new IfTrueNode(iff3)));
2719 *ctrl = gvn->transform(new IfFalseNode(iff3));
2720
2721 // -- Roads not taken here: --
2722 // We could also have chosen to perform the self-check at the beginning
2723 // of this code sequence, as the assembler does. This would not pay off
2724 // the same way, since the optimizer, unlike the assembler, can perform
2725 // static type analysis to fold away many successful self-checks.
2726 // Non-foldable self checks work better here in second position, because
2727 // the initial primary superclass check subsumes a self-check for most
2728 // types. An exception would be a secondary type like array-of-interface,
2729 // which does not appear in its own primary supertype display.
2730 // Finally, we could have chosen to move the self-check into the
2731 // PartialSubtypeCheckNode, and from there out-of-line in a platform
2732 // dependent manner. But it is worthwhile to have the check here,
2733 // where it can be perhaps be optimized. The cost in code space is
2734 // small (register compare, branch).
2735
2736 // Now do a linear scan of the secondary super-klass array. Again, no real
2737 // performance impact (too rare) but it's gotta be done.
2738 // Since the code is rarely used, there is no penalty for moving it
2739 // out of line, and it can only improve I-cache density.
2740 // The decision to inline or out-of-line this final check is platform
2741 // dependent, and is found in the AD file definition of PartialSubtypeCheck.
2742 Node* psc = gvn->transform(
2743 new PartialSubtypeCheckNode(*ctrl, subklass, superklass));
2744
2745 IfNode *iff4 = gen_subtype_check_compare(*ctrl, psc, gvn->zerocon(T_OBJECT), BoolTest::ne, PROB_FAIR, gvn, T_ADDRESS);
2746 r_not_subtype->init_req(2, gvn->transform(new IfTrueNode (iff4)));
2747 r_ok_subtype ->init_req(3, gvn->transform(new IfFalseNode(iff4)));
2748
2749 // Return false path; set default control to true path.
2750 *ctrl = gvn->transform(r_ok_subtype);
2751 return gvn->transform(r_not_subtype);
2752 }
2753
2754 // Profile-driven exact type check:
2755 Node* GraphKit::type_check_receiver(Node* receiver, ciKlass* klass,
2756 float prob,
2757 Node* *casted_receiver) {
2758 const TypeKlassPtr* tklass = TypeKlassPtr::make(klass);
2759 Node* recv_klass = load_object_klass(receiver);
2760 Node* want_klass = makecon(tklass);
2761 Node* cmp = _gvn.transform( new CmpPNode(recv_klass, want_klass) );
2762 Node* bol = _gvn.transform( new BoolNode(cmp, BoolTest::eq) );
2763 IfNode* iff = create_and_xform_if(control(), bol, prob, COUNT_UNKNOWN);
2764 set_control( _gvn.transform( new IfTrueNode (iff) ));
2765 Node* fail = _gvn.transform( new IfFalseNode(iff) );
2766
2767 const TypeOopPtr* recv_xtype = tklass->as_instance_type();
2768 assert(recv_xtype->klass_is_exact(), "");
2769
2770 // Subsume downstream occurrences of receiver with a cast to
2771 // recv_xtype, since now we know what the type will be.
2772 Node* cast = new CheckCastPPNode(control(), receiver, recv_xtype);
2773 (*casted_receiver) = _gvn.transform(cast);
2774 // (User must make the replace_in_map call.)
2775
2776 return fail;
2777 }
2778
2779
2780 //------------------------------seems_never_null-------------------------------
2781 // Use null_seen information if it is available from the profile.
2782 // If we see an unexpected null at a type check we record it and force a
2783 // recompile; the offending check will be recompiled to handle NULLs.
2784 // If we see several offending BCIs, then all checks in the
2785 // method will be recompiled.
2786 bool GraphKit::seems_never_null(Node* obj, ciProfileData* data, bool& speculating) {
2787 speculating = !_gvn.type(obj)->speculative_maybe_null();
2788 Deoptimization::DeoptReason reason = Deoptimization::reason_null_check(speculating);
2789 if (UncommonNullCast // Cutout for this technique
2790 && obj != null() // And not the -Xcomp stupid case?
2791 && !too_many_traps(reason)
2792 ) {
2793 if (speculating) {
2794 return true;
2795 }
2796 if (data == NULL)
2797 // Edge case: no mature data. Be optimistic here.
2798 return true;
2799 // If the profile has not seen a null, assume it won't happen.
2800 assert(java_bc() == Bytecodes::_checkcast ||
2801 java_bc() == Bytecodes::_instanceof ||
2802 java_bc() == Bytecodes::_aastore, "MDO must collect null_seen bit here");
2803 return !data->as_BitData()->null_seen();
2804 }
2805 speculating = false;
2806 return false;
2807 }
2808
2809 //------------------------maybe_cast_profiled_receiver-------------------------
2810 // If the profile has seen exactly one type, narrow to exactly that type.
2811 // Subsequent type checks will always fold up.
2812 Node* GraphKit::maybe_cast_profiled_receiver(Node* not_null_obj,
2813 ciKlass* require_klass,
2814 ciKlass* spec_klass,
2815 bool safe_for_replace) {
2816 if (!UseTypeProfile || !TypeProfileCasts) return NULL;
2817
2818 Deoptimization::DeoptReason reason = Deoptimization::reason_class_check(spec_klass != NULL);
2819
2820 // Make sure we haven't already deoptimized from this tactic.
2821 if (too_many_traps(reason) || too_many_recompiles(reason))
2822 return NULL;
2823
2824 // (No, this isn't a call, but it's enough like a virtual call
2825 // to use the same ciMethod accessor to get the profile info...)
2826 // If we have a speculative type use it instead of profiling (which
2827 // may not help us)
2828 ciKlass* exact_kls = spec_klass == NULL ? profile_has_unique_klass() : spec_klass;
2829 if (exact_kls != NULL) {// no cast failures here
2830 if (require_klass == NULL ||
2831 C->static_subtype_check(require_klass, exact_kls) == Compile::SSC_always_true) {
2832 // If we narrow the type to match what the type profile sees or
2833 // the speculative type, we can then remove the rest of the
2834 // cast.
2835 // This is a win, even if the exact_kls is very specific,
2836 // because downstream operations, such as method calls,
2837 // will often benefit from the sharper type.
2838 Node* exact_obj = not_null_obj; // will get updated in place...
2839 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2840 &exact_obj);
2841 { PreserveJVMState pjvms(this);
2842 set_control(slow_ctl);
2843 uncommon_trap_exact(reason, Deoptimization::Action_maybe_recompile);
2844 }
2845 if (safe_for_replace) {
2846 replace_in_map(not_null_obj, exact_obj);
2847 }
2848 return exact_obj;
2849 }
2850 // assert(ssc == Compile::SSC_always_true)... except maybe the profile lied to us.
2851 }
2852
2853 return NULL;
2854 }
2855
2856 /**
2857 * Cast obj to type and emit guard unless we had too many traps here
2858 * already
2859 *
2860 * @param obj node being casted
2861 * @param type type to cast the node to
2862 * @param not_null true if we know node cannot be null
2863 */
2864 Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
2865 ciKlass* type,
2866 bool not_null) {
2867 if (stopped()) {
2868 return obj;
2869 }
2870
2871 // type == NULL if profiling tells us this object is always null
2872 if (type != NULL) {
2873 Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
2874 Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
2875
2876 if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
2877 !too_many_traps(class_reason) &&
2878 !too_many_recompiles(class_reason)) {
2879 Node* not_null_obj = NULL;
2880 // not_null is true if we know the object is not null and
2881 // there's no need for a null check
2882 if (!not_null) {
2883 Node* null_ctl = top();
2884 not_null_obj = null_check_oop(obj, &null_ctl, true, true, true);
2885 assert(null_ctl->is_top(), "no null control here");
2886 } else {
2887 not_null_obj = obj;
2888 }
2889
2890 Node* exact_obj = not_null_obj;
2891 ciKlass* exact_kls = type;
2892 Node* slow_ctl = type_check_receiver(exact_obj, exact_kls, 1.0,
2893 &exact_obj);
2894 {
2895 PreserveJVMState pjvms(this);
2896 set_control(slow_ctl);
2897 uncommon_trap_exact(class_reason, Deoptimization::Action_maybe_recompile);
2898 }
2899 replace_in_map(not_null_obj, exact_obj);
2900 obj = exact_obj;
2901 }
2902 } else {
2903 if (!too_many_traps(Deoptimization::Reason_null_assert) &&
2904 !too_many_recompiles(Deoptimization::Reason_null_assert)) {
2905 Node* exact_obj = null_assert(obj);
2906 replace_in_map(obj, exact_obj);
2907 obj = exact_obj;
2908 }
2909 }
2910 return obj;
2911 }
2912
2913 //-------------------------------gen_instanceof--------------------------------
2914 // Generate an instance-of idiom. Used by both the instance-of bytecode
2915 // and the reflective instance-of call.
2916 Node* GraphKit::gen_instanceof(Node* obj, Node* superklass, bool safe_for_replace) {
2917 kill_dead_locals(); // Benefit all the uncommon traps
2918 assert( !stopped(), "dead parse path should be checked in callers" );
2919 assert(!TypePtr::NULL_PTR->higher_equal(_gvn.type(superklass)->is_klassptr()),
2920 "must check for not-null not-dead klass in callers");
2921
2922 // Make the merge point
2923 enum { _obj_path = 1, _fail_path, _null_path, PATH_LIMIT };
2924 RegionNode* region = new RegionNode(PATH_LIMIT);
2925 Node* phi = new PhiNode(region, TypeInt::BOOL);
2926 C->set_has_split_ifs(true); // Has chance for split-if optimization
2927
2928 ciProfileData* data = NULL;
2929 if (java_bc() == Bytecodes::_instanceof) { // Only for the bytecode
2930 data = method()->method_data()->bci_to_data(bci());
2931 }
2932 bool speculative_not_null = false;
2933 bool never_see_null = (ProfileDynamicTypes // aggressive use of profile
2934 && seems_never_null(obj, data, speculative_not_null));
2935
2936 // Null check; get casted pointer; set region slot 3
2937 Node* null_ctl = top();
2938 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
2939
2940 // If not_null_obj is dead, only null-path is taken
2941 if (stopped()) { // Doing instance-of on a NULL?
2942 set_control(null_ctl);
2943 return intcon(0);
2944 }
2945 region->init_req(_null_path, null_ctl);
2946 phi ->init_req(_null_path, intcon(0)); // Set null path value
2947 if (null_ctl == top()) {
2948 // Do this eagerly, so that pattern matches like is_diamond_phi
2949 // will work even during parsing.
2950 assert(_null_path == PATH_LIMIT-1, "delete last");
2951 region->del_req(_null_path);
2952 phi ->del_req(_null_path);
2953 }
2954
2955 // Do we know the type check always succeed?
2956 bool known_statically = false;
2957 if (_gvn.type(superklass)->singleton()) {
2958 ciKlass* superk = _gvn.type(superklass)->is_klassptr()->klass();
2959 ciKlass* subk = _gvn.type(obj)->is_oopptr()->klass();
2960 if (subk != NULL && subk->is_loaded()) {
2961 int static_res = C->static_subtype_check(superk, subk);
2962 known_statically = (static_res == Compile::SSC_always_true || static_res == Compile::SSC_always_false);
2963 }
2964 }
2965
2966 if (!known_statically) {
2967 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
2968 // We may not have profiling here or it may not help us. If we
2969 // have a speculative type use it to perform an exact cast.
2970 ciKlass* spec_obj_type = obj_type->speculative_type();
2971 if (spec_obj_type != NULL || (ProfileDynamicTypes && data != NULL)) {
2972 Node* cast_obj = maybe_cast_profiled_receiver(not_null_obj, NULL, spec_obj_type, safe_for_replace);
2973 if (stopped()) { // Profile disagrees with this path.
2974 set_control(null_ctl); // Null is the only remaining possibility.
2975 return intcon(0);
2976 }
2977 if (cast_obj != NULL) {
2978 not_null_obj = cast_obj;
2979 }
2980 }
2981 }
2982
2983 // Load the object's klass
2984 Node* obj_klass = load_object_klass(not_null_obj);
2985
2986 // Generate the subtype check
2987 Node* not_subtype_ctrl = gen_subtype_check(obj_klass, superklass);
2988
2989 // Plug in the success path to the general merge in slot 1.
2990 region->init_req(_obj_path, control());
2991 phi ->init_req(_obj_path, intcon(1));
2992
2993 // Plug in the failing path to the general merge in slot 2.
2994 region->init_req(_fail_path, not_subtype_ctrl);
2995 phi ->init_req(_fail_path, intcon(0));
2996
2997 // Return final merged results
2998 set_control( _gvn.transform(region) );
2999 record_for_igvn(region);
3000
3001 // If we know the type check always succeeds then we don't use the
3002 // profiling data at this bytecode. Don't lose it, feed it to the
3003 // type system as a speculative type.
3004 if (safe_for_replace) {
3005 Node* casted_obj = record_profiled_receiver_for_speculation(obj);
3006 replace_in_map(obj, casted_obj);
3007 }
3008
3009 return _gvn.transform(phi);
3010 }
3011
3012 //-------------------------------gen_checkcast---------------------------------
3013 // Generate a checkcast idiom. Used by both the checkcast bytecode and the
3014 // array store bytecode. Stack must be as-if BEFORE doing the bytecode so the
3015 // uncommon-trap paths work. Adjust stack after this call.
3016 // If failure_control is supplied and not null, it is filled in with
3017 // the control edge for the cast failure. Otherwise, an appropriate
3018 // uncommon trap or exception is thrown.
3019 Node* GraphKit::gen_checkcast(Node *obj, Node* superklass,
3020 Node* *failure_control) {
3021 kill_dead_locals(); // Benefit all the uncommon traps
3022 const TypeKlassPtr *tk = _gvn.type(superklass)->is_klassptr();
3023 const Type *toop = TypeOopPtr::make_from_klass(tk->klass());
3024
3025 // Fast cutout: Check the case that the cast is vacuously true.
3026 // This detects the common cases where the test will short-circuit
3027 // away completely. We do this before we perform the null check,
3028 // because if the test is going to turn into zero code, we don't
3029 // want a residual null check left around. (Causes a slowdown,
3030 // for example, in some objArray manipulations, such as a[i]=a[j].)
3031 if (tk->singleton()) {
3032 const TypeOopPtr* objtp = _gvn.type(obj)->isa_oopptr();
3033 if (objtp != NULL && objtp->klass() != NULL) {
3034 switch (C->static_subtype_check(tk->klass(), objtp->klass())) {
3035 case Compile::SSC_always_true:
3036 // If we know the type check always succeed then we don't use
3037 // the profiling data at this bytecode. Don't lose it, feed it
3038 // to the type system as a speculative type.
3039 return record_profiled_receiver_for_speculation(obj);
3040 case Compile::SSC_always_false:
3041 // It needs a null check because a null will *pass* the cast check.
3042 // A non-null value will always produce an exception.
3043 return null_assert(obj);
3044 }
3045 }
3046 }
3047
3048 ciProfileData* data = NULL;
3049 bool safe_for_replace = false;
3050 if (failure_control == NULL) { // use MDO in regular case only
3051 assert(java_bc() == Bytecodes::_aastore ||
3052 java_bc() == Bytecodes::_checkcast,
3053 "interpreter profiles type checks only for these BCs");
3054 data = method()->method_data()->bci_to_data(bci());
3055 safe_for_replace = true;
3056 }
3057
3058 // Make the merge point
3059 enum { _obj_path = 1, _null_path, PATH_LIMIT };
3060 RegionNode* region = new RegionNode(PATH_LIMIT);
3061 Node* phi = new PhiNode(region, toop);
3062 C->set_has_split_ifs(true); // Has chance for split-if optimization
3063
3064 // Use null-cast information if it is available
3065 bool speculative_not_null = false;
3066 bool never_see_null = ((failure_control == NULL) // regular case only
3067 && seems_never_null(obj, data, speculative_not_null));
3068
3069 // Null check; get casted pointer; set region slot 3
3070 Node* null_ctl = top();
3071 Node* not_null_obj = null_check_oop(obj, &null_ctl, never_see_null, safe_for_replace, speculative_not_null);
3072
3073 // If not_null_obj is dead, only null-path is taken
3074 if (stopped()) { // Doing instance-of on a NULL?
3075 set_control(null_ctl);
3076 return null();
3077 }
3078 region->init_req(_null_path, null_ctl);
3079 phi ->init_req(_null_path, null()); // Set null path value
3080 if (null_ctl == top()) {
3081 // Do this eagerly, so that pattern matches like is_diamond_phi
3082 // will work even during parsing.
3083 assert(_null_path == PATH_LIMIT-1, "delete last");
3084 region->del_req(_null_path);
3085 phi ->del_req(_null_path);
3086 }
3087
3088 Node* cast_obj = NULL;
3089 if (tk->klass_is_exact()) {
3090 // The following optimization tries to statically cast the speculative type of the object
3091 // (for example obtained during profiling) to the type of the superklass and then do a
3092 // dynamic check that the type of the object is what we expect. To work correctly
3093 // for checkcast and aastore the type of superklass should be exact.
3094 const TypeOopPtr* obj_type = _gvn.type(obj)->is_oopptr();
3095 // We may not have profiling here or it may not help us. If we have
3096 // a speculative type use it to perform an exact cast.
3097 ciKlass* spec_obj_type = obj_type->speculative_type();
3098 if (spec_obj_type != NULL || data != NULL) {
3099 cast_obj = maybe_cast_profiled_receiver(not_null_obj, tk->klass(), spec_obj_type, safe_for_replace);
3100 if (cast_obj != NULL) {
3101 if (failure_control != NULL) // failure is now impossible
3102 (*failure_control) = top();
3103 // adjust the type of the phi to the exact klass:
3104 phi->raise_bottom_type(_gvn.type(cast_obj)->meet_speculative(TypePtr::NULL_PTR));
3105 }
3106 }
3107 }
3108
3109 if (cast_obj == NULL) {
3110 // Load the object's klass
3111 Node* obj_klass = load_object_klass(not_null_obj);
3112
3113 // Generate the subtype check
3114 Node* not_subtype_ctrl = gen_subtype_check( obj_klass, superklass );
3115
3116 // Plug in success path into the merge
3117 cast_obj = _gvn.transform(new CheckCastPPNode(control(), not_null_obj, toop));
3118 // Failure path ends in uncommon trap (or may be dead - failure impossible)
3119 if (failure_control == NULL) {
3120 if (not_subtype_ctrl != top()) { // If failure is possible
3121 PreserveJVMState pjvms(this);
3122 set_control(not_subtype_ctrl);
3123 builtin_throw(Deoptimization::Reason_class_check, obj_klass);
3124 }
3125 } else {
3126 (*failure_control) = not_subtype_ctrl;
3127 }
3128 }
3129
3130 region->init_req(_obj_path, control());
3131 phi ->init_req(_obj_path, cast_obj);
3132
3133 // A merge of NULL or Casted-NotNull obj
3134 Node* res = _gvn.transform(phi);
3135
3136 // Note I do NOT always 'replace_in_map(obj,result)' here.
3137 // if( tk->klass()->can_be_primary_super() )
3138 // This means that if I successfully store an Object into an array-of-String
3139 // I 'forget' that the Object is really now known to be a String. I have to
3140 // do this because we don't have true union types for interfaces - if I store
3141 // a Baz into an array-of-Interface and then tell the optimizer it's an
3142 // Interface, I forget that it's also a Baz and cannot do Baz-like field
3143 // references to it. FIX THIS WHEN UNION TYPES APPEAR!
3144 // replace_in_map( obj, res );
3145
3146 // Return final merged results
3147 set_control( _gvn.transform(region) );
3148 record_for_igvn(region);
3149
3150 return record_profiled_receiver_for_speculation(res);
3151 }
3152
3153 //------------------------------next_monitor-----------------------------------
3154 // What number should be given to the next monitor?
3155 int GraphKit::next_monitor() {
3156 int current = jvms()->monitor_depth()* C->sync_stack_slots();
3157 int next = current + C->sync_stack_slots();
3158 // Keep the toplevel high water mark current:
3159 if (C->fixed_slots() < next) C->set_fixed_slots(next);
3160 return current;
3161 }
3162
3163 //------------------------------insert_mem_bar---------------------------------
3164 // Memory barrier to avoid floating things around
3165 // The membar serves as a pinch point between both control and all memory slices.
3166 Node* GraphKit::insert_mem_bar(int opcode, Node* precedent) {
3167 MemBarNode* mb = MemBarNode::make(C, opcode, Compile::AliasIdxBot, precedent);
3168 mb->init_req(TypeFunc::Control, control());
3169 mb->init_req(TypeFunc::Memory, reset_memory());
3170 Node* membar = _gvn.transform(mb);
3171 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3172 set_all_memory_call(membar);
3173 return membar;
3174 }
3175
3176 //-------------------------insert_mem_bar_volatile----------------------------
3177 // Memory barrier to avoid floating things around
3178 // The membar serves as a pinch point between both control and memory(alias_idx).
3179 // If you want to make a pinch point on all memory slices, do not use this
3180 // function (even with AliasIdxBot); use insert_mem_bar() instead.
3181 Node* GraphKit::insert_mem_bar_volatile(int opcode, int alias_idx, Node* precedent) {
3182 // When Parse::do_put_xxx updates a volatile field, it appends a series
3183 // of MemBarVolatile nodes, one for *each* volatile field alias category.
3184 // The first membar is on the same memory slice as the field store opcode.
3185 // This forces the membar to follow the store. (Bug 6500685 broke this.)
3186 // All the other membars (for other volatile slices, including AliasIdxBot,
3187 // which stands for all unknown volatile slices) are control-dependent
3188 // on the first membar. This prevents later volatile loads or stores
3189 // from sliding up past the just-emitted store.
3190
3191 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
3192 mb->set_req(TypeFunc::Control,control());
3193 if (alias_idx == Compile::AliasIdxBot) {
3194 mb->set_req(TypeFunc::Memory, merged_memory()->base_memory());
3195 } else {
3196 assert(!(opcode == Op_Initialize && alias_idx != Compile::AliasIdxRaw), "fix caller");
3197 mb->set_req(TypeFunc::Memory, memory(alias_idx));
3198 }
3199 Node* membar = _gvn.transform(mb);
3200 set_control(_gvn.transform(new ProjNode(membar, TypeFunc::Control)));
3201 if (alias_idx == Compile::AliasIdxBot) {
3202 merged_memory()->set_base_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)));
3203 } else {
3204 set_memory(_gvn.transform(new ProjNode(membar, TypeFunc::Memory)),alias_idx);
3205 }
3206 return membar;
3207 }
3208
3209 //------------------------------shared_lock------------------------------------
3210 // Emit locking code.
3211 FastLockNode* GraphKit::shared_lock(Node* obj) {
3212 // bci is either a monitorenter bc or InvocationEntryBci
3213 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3214 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3215
3216 if( !GenerateSynchronizationCode )
3217 return NULL; // Not locking things?
3218 if (stopped()) // Dead monitor?
3219 return NULL;
3220
3221 assert(dead_locals_are_killed(), "should kill locals before sync. point");
3222
3223 // Box the stack location
3224 Node* box = _gvn.transform(new BoxLockNode(next_monitor()));
3225 Node* mem = reset_memory();
3226
3227 FastLockNode * flock = _gvn.transform(new FastLockNode(0, obj, box) )->as_FastLock();
3228 if (UseBiasedLocking && PrintPreciseBiasedLockingStatistics) {
3229 // Create the counters for this fast lock.
3230 flock->create_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3231 }
3232
3233 // Create the rtm counters for this fast lock if needed.
3234 flock->create_rtm_lock_counter(sync_jvms()); // sync_jvms used to get current bci
3235
3236 // Add monitor to debug info for the slow path. If we block inside the
3237 // slow path and de-opt, we need the monitor hanging around
3238 map()->push_monitor( flock );
3239
3240 const TypeFunc *tf = LockNode::lock_type();
3241 LockNode *lock = new LockNode(C, tf);
3242
3243 lock->init_req( TypeFunc::Control, control() );
3244 lock->init_req( TypeFunc::Memory , mem );
3245 lock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3246 lock->init_req( TypeFunc::FramePtr, frameptr() );
3247 lock->init_req( TypeFunc::ReturnAdr, top() );
3248
3249 lock->init_req(TypeFunc::Parms + 0, obj);
3250 lock->init_req(TypeFunc::Parms + 1, box);
3251 lock->init_req(TypeFunc::Parms + 2, flock);
3252 add_safepoint_edges(lock);
3253
3254 lock = _gvn.transform( lock )->as_Lock();
3255
3256 // lock has no side-effects, sets few values
3257 set_predefined_output_for_runtime_call(lock, mem, TypeRawPtr::BOTTOM);
3258
3259 insert_mem_bar(Op_MemBarAcquireLock);
3260
3261 // Add this to the worklist so that the lock can be eliminated
3262 record_for_igvn(lock);
3263
3264 #ifndef PRODUCT
3265 if (PrintLockStatistics) {
3266 // Update the counter for this lock. Don't bother using an atomic
3267 // operation since we don't require absolute accuracy.
3268 lock->create_lock_counter(map()->jvms());
3269 increment_counter(lock->counter()->addr());
3270 }
3271 #endif
3272
3273 return flock;
3274 }
3275
3276
3277 //------------------------------shared_unlock----------------------------------
3278 // Emit unlocking code.
3279 void GraphKit::shared_unlock(Node* box, Node* obj) {
3280 // bci is either a monitorenter bc or InvocationEntryBci
3281 // %%% SynchronizationEntryBCI is redundant; use InvocationEntryBci in interfaces
3282 assert(SynchronizationEntryBCI == InvocationEntryBci, "");
3283
3284 if( !GenerateSynchronizationCode )
3285 return;
3286 if (stopped()) { // Dead monitor?
3287 map()->pop_monitor(); // Kill monitor from debug info
3288 return;
3289 }
3290
3291 // Memory barrier to avoid floating things down past the locked region
3292 insert_mem_bar(Op_MemBarReleaseLock);
3293
3294 const TypeFunc *tf = OptoRuntime::complete_monitor_exit_Type();
3295 UnlockNode *unlock = new UnlockNode(C, tf);
3296 #ifdef ASSERT
3297 unlock->set_dbg_jvms(sync_jvms());
3298 #endif
3299 uint raw_idx = Compile::AliasIdxRaw;
3300 unlock->init_req( TypeFunc::Control, control() );
3301 unlock->init_req( TypeFunc::Memory , memory(raw_idx) );
3302 unlock->init_req( TypeFunc::I_O , top() ) ; // does no i/o
3303 unlock->init_req( TypeFunc::FramePtr, frameptr() );
3304 unlock->init_req( TypeFunc::ReturnAdr, top() );
3305
3306 unlock->init_req(TypeFunc::Parms + 0, obj);
3307 unlock->init_req(TypeFunc::Parms + 1, box);
3308 unlock = _gvn.transform(unlock)->as_Unlock();
3309
3310 Node* mem = reset_memory();
3311
3312 // unlock has no side-effects, sets few values
3313 set_predefined_output_for_runtime_call(unlock, mem, TypeRawPtr::BOTTOM);
3314
3315 // Kill monitor from debug info
3316 map()->pop_monitor( );
3317 }
3318
3319 //-------------------------------get_layout_helper-----------------------------
3320 // If the given klass is a constant or known to be an array,
3321 // fetch the constant layout helper value into constant_value
3322 // and return (Node*)NULL. Otherwise, load the non-constant
3323 // layout helper value, and return the node which represents it.
3324 // This two-faced routine is useful because allocation sites
3325 // almost always feature constant types.
3326 Node* GraphKit::get_layout_helper(Node* klass_node, jint& constant_value) {
3327 const TypeKlassPtr* inst_klass = _gvn.type(klass_node)->isa_klassptr();
3328 if (!StressReflectiveCode && inst_klass != NULL) {
3329 ciKlass* klass = inst_klass->klass();
3330 bool xklass = inst_klass->klass_is_exact();
3331 if (xklass || klass->is_array_klass()) {
3332 jint lhelper = klass->layout_helper();
3333 if (lhelper != Klass::_lh_neutral_value) {
3334 constant_value = lhelper;
3335 return (Node*) NULL;
3336 }
3337 }
3338 }
3339 constant_value = Klass::_lh_neutral_value; // put in a known value
3340 Node* lhp = basic_plus_adr(klass_node, klass_node, in_bytes(Klass::layout_helper_offset()));
3341 return make_load(NULL, lhp, TypeInt::INT, T_INT, MemNode::unordered);
3342 }
3343
3344 // We just put in an allocate/initialize with a big raw-memory effect.
3345 // Hook selected additional alias categories on the initialization.
3346 static void hook_memory_on_init(GraphKit& kit, int alias_idx,
3347 MergeMemNode* init_in_merge,
3348 Node* init_out_raw) {
3349 DEBUG_ONLY(Node* init_in_raw = init_in_merge->base_memory());
3350 assert(init_in_merge->memory_at(alias_idx) == init_in_raw, "");
3351
3352 Node* prevmem = kit.memory(alias_idx);
3353 init_in_merge->set_memory_at(alias_idx, prevmem);
3354 kit.set_memory(init_out_raw, alias_idx);
3355 }
3356
3357 //---------------------------set_output_for_allocation-------------------------
3358 Node* GraphKit::set_output_for_allocation(AllocateNode* alloc,
3359 const TypeOopPtr* oop_type,
3360 bool deoptimize_on_exception) {
3361 int rawidx = Compile::AliasIdxRaw;
3362 alloc->set_req( TypeFunc::FramePtr, frameptr() );
3363 add_safepoint_edges(alloc);
3364 Node* allocx = _gvn.transform(alloc);
3365 set_control( _gvn.transform(new ProjNode(allocx, TypeFunc::Control) ) );
3366 // create memory projection for i_o
3367 set_memory ( _gvn.transform( new ProjNode(allocx, TypeFunc::Memory, true) ), rawidx );
3368 make_slow_call_ex(allocx, env()->Throwable_klass(), true, deoptimize_on_exception);
3369
3370 // create a memory projection as for the normal control path
3371 Node* malloc = _gvn.transform(new ProjNode(allocx, TypeFunc::Memory));
3372 set_memory(malloc, rawidx);
3373
3374 // a normal slow-call doesn't change i_o, but an allocation does
3375 // we create a separate i_o projection for the normal control path
3376 set_i_o(_gvn.transform( new ProjNode(allocx, TypeFunc::I_O, false) ) );
3377 Node* rawoop = _gvn.transform( new ProjNode(allocx, TypeFunc::Parms) );
3378
3379 // put in an initialization barrier
3380 InitializeNode* init = insert_mem_bar_volatile(Op_Initialize, rawidx,
3381 rawoop)->as_Initialize();
3382 assert(alloc->initialization() == init, "2-way macro link must work");
3383 assert(init ->allocation() == alloc, "2-way macro link must work");
3384 {
3385 // Extract memory strands which may participate in the new object's
3386 // initialization, and source them from the new InitializeNode.
3387 // This will allow us to observe initializations when they occur,
3388 // and link them properly (as a group) to the InitializeNode.
3389 assert(init->in(InitializeNode::Memory) == malloc, "");
3390 MergeMemNode* minit_in = MergeMemNode::make(malloc);
3391 init->set_req(InitializeNode::Memory, minit_in);
3392 record_for_igvn(minit_in); // fold it up later, if possible
3393 Node* minit_out = memory(rawidx);
3394 assert(minit_out->is_Proj() && minit_out->in(0) == init, "");
3395 if (oop_type->isa_aryptr()) {
3396 const TypePtr* telemref = oop_type->add_offset(Type::OffsetBot);
3397 int elemidx = C->get_alias_index(telemref);
3398 hook_memory_on_init(*this, elemidx, minit_in, minit_out);
3399 } else if (oop_type->isa_instptr()) {
3400 ciInstanceKlass* ik = oop_type->klass()->as_instance_klass();
3401 for (int i = 0, len = ik->nof_nonstatic_fields(); i < len; i++) {
3402 ciField* field = ik->nonstatic_field_at(i);
3403 if (field->offset() >= TrackedInitializationLimit * HeapWordSize)
3404 continue; // do not bother to track really large numbers of fields
3405 // Find (or create) the alias category for this field:
3406 int fieldidx = C->alias_type(field)->index();
3407 hook_memory_on_init(*this, fieldidx, minit_in, minit_out);
3408 }
3409 }
3410 }
3411
3412 // Cast raw oop to the real thing...
3413 Node* javaoop = new CheckCastPPNode(control(), rawoop, oop_type);
3414 javaoop = _gvn.transform(javaoop);
3415 C->set_recent_alloc(control(), javaoop);
3416 assert(just_allocated_object(control()) == javaoop, "just allocated");
3417
3418 #ifdef ASSERT
3419 { // Verify that the AllocateNode::Ideal_allocation recognizers work:
3420 assert(AllocateNode::Ideal_allocation(rawoop, &_gvn) == alloc,
3421 "Ideal_allocation works");
3422 assert(AllocateNode::Ideal_allocation(javaoop, &_gvn) == alloc,
3423 "Ideal_allocation works");
3424 if (alloc->is_AllocateArray()) {
3425 assert(AllocateArrayNode::Ideal_array_allocation(rawoop, &_gvn) == alloc->as_AllocateArray(),
3426 "Ideal_allocation works");
3427 assert(AllocateArrayNode::Ideal_array_allocation(javaoop, &_gvn) == alloc->as_AllocateArray(),
3428 "Ideal_allocation works");
3429 } else {
3430 assert(alloc->in(AllocateNode::ALength)->is_top(), "no length, please");
3431 }
3432 }
3433 #endif //ASSERT
3434
3435 return javaoop;
3436 }
3437
3438 //---------------------------new_instance--------------------------------------
3439 // This routine takes a klass_node which may be constant (for a static type)
3440 // or may be non-constant (for reflective code). It will work equally well
3441 // for either, and the graph will fold nicely if the optimizer later reduces
3442 // the type to a constant.
3443 // The optional arguments are for specialized use by intrinsics:
3444 // - If 'extra_slow_test' if not null is an extra condition for the slow-path.
3445 // - If 'return_size_val', report the the total object size to the caller.
3446 // - deoptimize_on_exception controls how Java exceptions are handled (rethrow vs deoptimize)
3447 Node* GraphKit::new_instance(Node* klass_node,
3448 Node* extra_slow_test,
3449 Node* *return_size_val,
3450 bool deoptimize_on_exception) {
3451 // Compute size in doublewords
3452 // The size is always an integral number of doublewords, represented
3453 // as a positive bytewise size stored in the klass's layout_helper.
3454 // The layout_helper also encodes (in a low bit) the need for a slow path.
3455 jint layout_con = Klass::_lh_neutral_value;
3456 Node* layout_val = get_layout_helper(klass_node, layout_con);
3457 int layout_is_con = (layout_val == NULL);
3458
3459 if (extra_slow_test == NULL) extra_slow_test = intcon(0);
3460 // Generate the initial go-slow test. It's either ALWAYS (return a
3461 // Node for 1) or NEVER (return a NULL) or perhaps (in the reflective
3462 // case) a computed value derived from the layout_helper.
3463 Node* initial_slow_test = NULL;
3464 if (layout_is_con) {
3465 assert(!StressReflectiveCode, "stress mode does not use these paths");
3466 bool must_go_slow = Klass::layout_helper_needs_slow_path(layout_con);
3467 initial_slow_test = must_go_slow ? intcon(1) : extra_slow_test;
3468 } else { // reflective case
3469 // This reflective path is used by Unsafe.allocateInstance.
3470 // (It may be stress-tested by specifying StressReflectiveCode.)
3471 // Basically, we want to get into the VM is there's an illegal argument.
3472 Node* bit = intcon(Klass::_lh_instance_slow_path_bit);
3473 initial_slow_test = _gvn.transform( new AndINode(layout_val, bit) );
3474 if (extra_slow_test != intcon(0)) {
3475 initial_slow_test = _gvn.transform( new OrINode(initial_slow_test, extra_slow_test) );
3476 }
3477 // (Macro-expander will further convert this to a Bool, if necessary.)
3478 }
3479
3480 // Find the size in bytes. This is easy; it's the layout_helper.
3481 // The size value must be valid even if the slow path is taken.
3482 Node* size = NULL;
3483 if (layout_is_con) {
3484 size = MakeConX(Klass::layout_helper_size_in_bytes(layout_con));
3485 } else { // reflective case
3486 // This reflective path is used by clone and Unsafe.allocateInstance.
3487 size = ConvI2X(layout_val);
3488
3489 // Clear the low bits to extract layout_helper_size_in_bytes:
3490 assert((int)Klass::_lh_instance_slow_path_bit < BytesPerLong, "clear bit");
3491 Node* mask = MakeConX(~ (intptr_t)right_n_bits(LogBytesPerLong));
3492 size = _gvn.transform( new AndXNode(size, mask) );
3493 }
3494 if (return_size_val != NULL) {
3495 (*return_size_val) = size;
3496 }
3497
3498 // This is a precise notnull oop of the klass.
3499 // (Actually, it need not be precise if this is a reflective allocation.)
3500 // It's what we cast the result to.
3501 const TypeKlassPtr* tklass = _gvn.type(klass_node)->isa_klassptr();
3502 if (!tklass) tklass = TypeKlassPtr::OBJECT;
3503 const TypeOopPtr* oop_type = tklass->as_instance_type();
3504
3505 // Now generate allocation code
3506
3507 // The entire memory state is needed for slow path of the allocation
3508 // since GC and deoptimization can happened.
3509 Node *mem = reset_memory();
3510 set_all_memory(mem); // Create new memory state
3511
3512 AllocateNode* alloc = new AllocateNode(C, AllocateNode::alloc_type(Type::TOP),
3513 control(), mem, i_o(),
3514 size, klass_node,
3515 initial_slow_test);
3516
3517 return set_output_for_allocation(alloc, oop_type, deoptimize_on_exception);
3518 }
3519
3520 //-------------------------------new_array-------------------------------------
3521 // helper for both newarray and anewarray
3522 // The 'length' parameter is (obviously) the length of the array.
3523 // See comments on new_instance for the meaning of the other arguments.
3524 Node* GraphKit::new_array(Node* klass_node, // array klass (maybe variable)
3525 Node* length, // number of array elements
3526 int nargs, // number of arguments to push back for uncommon trap
3527 Node* *return_size_val,
3528 bool deoptimize_on_exception) {
3529 jint layout_con = Klass::_lh_neutral_value;
3530 Node* layout_val = get_layout_helper(klass_node, layout_con);
3531 int layout_is_con = (layout_val == NULL);
3532
3533 if (!layout_is_con && !StressReflectiveCode &&
3534 !too_many_traps(Deoptimization::Reason_class_check)) {
3535 // This is a reflective array creation site.
3536 // Optimistically assume that it is a subtype of Object[],
3537 // so that we can fold up all the address arithmetic.
3538 layout_con = Klass::array_layout_helper(T_OBJECT);
3539 Node* cmp_lh = _gvn.transform( new CmpINode(layout_val, intcon(layout_con)) );
3540 Node* bol_lh = _gvn.transform( new BoolNode(cmp_lh, BoolTest::eq) );
3541 { BuildCutout unless(this, bol_lh, PROB_MAX);
3542 inc_sp(nargs);
3543 uncommon_trap(Deoptimization::Reason_class_check,
3544 Deoptimization::Action_maybe_recompile);
3545 }
3546 layout_val = NULL;
3547 layout_is_con = true;
3548 }
3549
3550 // Generate the initial go-slow test. Make sure we do not overflow
3551 // if length is huge (near 2Gig) or negative! We do not need
3552 // exact double-words here, just a close approximation of needed
3553 // double-words. We can't add any offset or rounding bits, lest we
3554 // take a size -1 of bytes and make it positive. Use an unsigned
3555 // compare, so negative sizes look hugely positive.
3556 int fast_size_limit = FastAllocateSizeLimit;
3557 if (layout_is_con) {
3558 assert(!StressReflectiveCode, "stress mode does not use these paths");
3559 // Increase the size limit if we have exact knowledge of array type.
3560 int log2_esize = Klass::layout_helper_log2_element_size(layout_con);
3561 fast_size_limit <<= (LogBytesPerLong - log2_esize);
3562 }
3563
3564 Node* initial_slow_cmp = _gvn.transform( new CmpUNode( length, intcon( fast_size_limit ) ) );
3565 Node* initial_slow_test = _gvn.transform( new BoolNode( initial_slow_cmp, BoolTest::gt ) );
3566
3567 // --- Size Computation ---
3568 // array_size = round_to_heap(array_header + (length << elem_shift));
3569 // where round_to_heap(x) == align_to(x, MinObjAlignmentInBytes)
3570 // and align_to(x, y) == ((x + y-1) & ~(y-1))
3571 // The rounding mask is strength-reduced, if possible.
3572 int round_mask = MinObjAlignmentInBytes - 1;
3573 Node* header_size = NULL;
3574 int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
3575 // (T_BYTE has the weakest alignment and size restrictions...)
3576 if (layout_is_con) {
3577 int hsize = Klass::layout_helper_header_size(layout_con);
3578 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3579 BasicType etype = Klass::layout_helper_element_type(layout_con);
3580 if ((round_mask & ~right_n_bits(eshift)) == 0)
3581 round_mask = 0; // strength-reduce it if it goes away completely
3582 assert((hsize & right_n_bits(eshift)) == 0, "hsize is pre-rounded");
3583 assert(header_size_min <= hsize, "generic minimum is smallest");
3584 header_size_min = hsize;
3585 header_size = intcon(hsize + round_mask);
3586 } else {
3587 Node* hss = intcon(Klass::_lh_header_size_shift);
3588 Node* hsm = intcon(Klass::_lh_header_size_mask);
3589 Node* hsize = _gvn.transform( new URShiftINode(layout_val, hss) );
3590 hsize = _gvn.transform( new AndINode(hsize, hsm) );
3591 Node* mask = intcon(round_mask);
3592 header_size = _gvn.transform( new AddINode(hsize, mask) );
3593 }
3594
3595 Node* elem_shift = NULL;
3596 if (layout_is_con) {
3597 int eshift = Klass::layout_helper_log2_element_size(layout_con);
3598 if (eshift != 0)
3599 elem_shift = intcon(eshift);
3600 } else {
3601 // There is no need to mask or shift this value.
3602 // The semantics of LShiftINode include an implicit mask to 0x1F.
3603 assert(Klass::_lh_log2_element_size_shift == 0, "use shift in place");
3604 elem_shift = layout_val;
3605 }
3606
3607 // Transition to native address size for all offset calculations:
3608 Node* lengthx = ConvI2X(length);
3609 Node* headerx = ConvI2X(header_size);
3610 #ifdef _LP64
3611 { const TypeInt* tilen = _gvn.find_int_type(length);
3612 if (tilen != NULL && tilen->_lo < 0) {
3613 // Add a manual constraint to a positive range. Cf. array_element_address.
3614 jint size_max = fast_size_limit;
3615 if (size_max > tilen->_hi) size_max = tilen->_hi;
3616 const TypeInt* tlcon = TypeInt::make(0, size_max, Type::WidenMin);
3617
3618 // Only do a narrow I2L conversion if the range check passed.
3619 IfNode* iff = new IfNode(control(), initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
3620 _gvn.transform(iff);
3621 RegionNode* region = new RegionNode(3);
3622 _gvn.set_type(region, Type::CONTROL);
3623 lengthx = new PhiNode(region, TypeLong::LONG);
3624 _gvn.set_type(lengthx, TypeLong::LONG);
3625
3626 // Range check passed. Use ConvI2L node with narrow type.
3627 Node* passed = IfFalse(iff);
3628 region->init_req(1, passed);
3629 // Make I2L conversion control dependent to prevent it from
3630 // floating above the range check during loop optimizations.
3631 lengthx->init_req(1, C->constrained_convI2L(&_gvn, length, tlcon, passed));
3632
3633 // Range check failed. Use ConvI2L with wide type because length may be invalid.
3634 region->init_req(2, IfTrue(iff));
3635 lengthx->init_req(2, ConvI2X(length));
3636
3637 set_control(region);
3638 record_for_igvn(region);
3639 record_for_igvn(lengthx);
3640 }
3641 }
3642 #endif
3643
3644 // Combine header size (plus rounding) and body size. Then round down.
3645 // This computation cannot overflow, because it is used only in two
3646 // places, one where the length is sharply limited, and the other
3647 // after a successful allocation.
3648 Node* abody = lengthx;
3649 if (elem_shift != NULL)
3650 abody = _gvn.transform( new LShiftXNode(lengthx, elem_shift) );
3651 Node* size = _gvn.transform( new AddXNode(headerx, abody) );
3652 if (round_mask != 0) {
3653 Node* mask = MakeConX(~round_mask);
3654 size = _gvn.transform( new AndXNode(size, mask) );
3655 }
3656 // else if round_mask == 0, the size computation is self-rounding
3657
3658 if (return_size_val != NULL) {
3659 // This is the size
3660 (*return_size_val) = size;
3661 }
3662
3663 // Now generate allocation code
3664
3665 // The entire memory state is needed for slow path of the allocation
3666 // since GC and deoptimization can happened.
3667 Node *mem = reset_memory();
3668 set_all_memory(mem); // Create new memory state
3669
3670 if (initial_slow_test->is_Bool()) {
3671 // Hide it behind a CMoveI, or else PhaseIdealLoop::split_up will get sick.
3672 initial_slow_test = initial_slow_test->as_Bool()->as_int_value(&_gvn);
3673 }
3674
3675 // Create the AllocateArrayNode and its result projections
3676 AllocateArrayNode* alloc
3677 = new AllocateArrayNode(C, AllocateArrayNode::alloc_type(TypeInt::INT),
3678 control(), mem, i_o(),
3679 size, klass_node,
3680 initial_slow_test,
3681 length);
3682
3683 // Cast to correct type. Note that the klass_node may be constant or not,
3684 // and in the latter case the actual array type will be inexact also.
3685 // (This happens via a non-constant argument to inline_native_newArray.)
3686 // In any case, the value of klass_node provides the desired array type.
3687 const TypeInt* length_type = _gvn.find_int_type(length);
3688 const TypeOopPtr* ary_type = _gvn.type(klass_node)->is_klassptr()->as_instance_type();
3689 if (ary_type->isa_aryptr() && length_type != NULL) {
3690 // Try to get a better type than POS for the size
3691 ary_type = ary_type->is_aryptr()->cast_to_size(length_type);
3692 }
3693
3694 Node* javaoop = set_output_for_allocation(alloc, ary_type, deoptimize_on_exception);
3695
3696 // Cast length on remaining path to be as narrow as possible
3697 if (map()->find_edge(length) >= 0) {
3698 Node* ccast = alloc->make_ideal_length(ary_type, &_gvn);
3699 if (ccast != length) {
3700 _gvn.set_type_bottom(ccast);
3701 record_for_igvn(ccast);
3702 replace_in_map(length, ccast);
3703 }
3704 }
3705
3706 return javaoop;
3707 }
3708
3709 // The following "Ideal_foo" functions are placed here because they recognize
3710 // the graph shapes created by the functions immediately above.
3711
3712 //---------------------------Ideal_allocation----------------------------------
3713 // Given an oop pointer or raw pointer, see if it feeds from an AllocateNode.
3714 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase) {
3715 if (ptr == NULL) { // reduce dumb test in callers
3716 return NULL;
3717 }
3718 if (ptr->is_CheckCastPP()) { // strip only one raw-to-oop cast
3719 ptr = ptr->in(1);
3720 if (ptr == NULL) return NULL;
3721 }
3722 // Return NULL for allocations with several casts:
3723 // j.l.reflect.Array.newInstance(jobject, jint)
3724 // Object.clone()
3725 // to keep more precise type from last cast.
3726 if (ptr->is_Proj()) {
3727 Node* allo = ptr->in(0);
3728 if (allo != NULL && allo->is_Allocate()) {
3729 return allo->as_Allocate();
3730 }
3731 }
3732 // Report failure to match.
3733 return NULL;
3734 }
3735
3736 // Fancy version which also strips off an offset (and reports it to caller).
3737 AllocateNode* AllocateNode::Ideal_allocation(Node* ptr, PhaseTransform* phase,
3738 intptr_t& offset) {
3739 Node* base = AddPNode::Ideal_base_and_offset(ptr, phase, offset);
3740 if (base == NULL) return NULL;
3741 return Ideal_allocation(base, phase);
3742 }
3743
3744 // Trace Initialize <- Proj[Parm] <- Allocate
3745 AllocateNode* InitializeNode::allocation() {
3746 Node* rawoop = in(InitializeNode::RawAddress);
3747 if (rawoop->is_Proj()) {
3748 Node* alloc = rawoop->in(0);
3749 if (alloc->is_Allocate()) {
3750 return alloc->as_Allocate();
3751 }
3752 }
3753 return NULL;
3754 }
3755
3756 // Trace Allocate -> Proj[Parm] -> Initialize
3757 InitializeNode* AllocateNode::initialization() {
3758 ProjNode* rawoop = proj_out_or_null(AllocateNode::RawAddress);
3759 if (rawoop == NULL) return NULL;
3760 for (DUIterator_Fast imax, i = rawoop->fast_outs(imax); i < imax; i++) {
3761 Node* init = rawoop->fast_out(i);
3762 if (init->is_Initialize()) {
3763 assert(init->as_Initialize()->allocation() == this, "2-way link");
3764 return init->as_Initialize();
3765 }
3766 }
3767 return NULL;
3768 }
3769
3770 //----------------------------- loop predicates ---------------------------
3771
3772 //------------------------------add_predicate_impl----------------------------
3773 void GraphKit::add_predicate_impl(Deoptimization::DeoptReason reason, int nargs) {
3774 // Too many traps seen?
3775 if (too_many_traps(reason)) {
3776 #ifdef ASSERT
3777 if (TraceLoopPredicate) {
3778 int tc = C->trap_count(reason);
3779 tty->print("too many traps=%s tcount=%d in ",
3780 Deoptimization::trap_reason_name(reason), tc);
3781 method()->print(); // which method has too many predicate traps
3782 tty->cr();
3783 }
3784 #endif
3785 // We cannot afford to take more traps here,
3786 // do not generate predicate.
3787 return;
3788 }
3789
3790 Node *cont = _gvn.intcon(1);
3791 Node* opq = _gvn.transform(new Opaque1Node(C, cont));
3792 Node *bol = _gvn.transform(new Conv2BNode(opq));
3793 IfNode* iff = create_and_map_if(control(), bol, PROB_MAX, COUNT_UNKNOWN);
3794 Node* iffalse = _gvn.transform(new IfFalseNode(iff));
3795 C->add_predicate_opaq(opq);
3796 {
3797 PreserveJVMState pjvms(this);
3798 set_control(iffalse);
3799 inc_sp(nargs);
3800 uncommon_trap(reason, Deoptimization::Action_maybe_recompile);
3801 }
3802 Node* iftrue = _gvn.transform(new IfTrueNode(iff));
3803 set_control(iftrue);
3804 }
3805
3806 //------------------------------add_predicate---------------------------------
3807 void GraphKit::add_predicate(int nargs) {
3808 if (UseLoopPredicate) {
3809 add_predicate_impl(Deoptimization::Reason_predicate, nargs);
3810 }
3811 // loop's limit check predicate should be near the loop.
3812 add_predicate_impl(Deoptimization::Reason_loop_limit_check, nargs);
3813 }
3814
3815 //----------------------------- store barriers ----------------------------
3816 #define __ ideal.
3817
3818 void GraphKit::sync_kit(IdealKit& ideal) {
3819 set_all_memory(__ merged_memory());
3820 set_i_o(__ i_o());
3821 set_control(__ ctrl());
3822 }
3823
3824 void GraphKit::final_sync(IdealKit& ideal) {
3825 // Final sync IdealKit and graphKit.
3826 sync_kit(ideal);
3827 }
3828
3829 Node* GraphKit::byte_map_base_node() {
3830 // Get base of card map
3831 CardTableModRefBS* ct =
3832 barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set());
3833 assert(sizeof(*ct->byte_map_base) == sizeof(jbyte), "adjust users of this code");
3834 if (ct->byte_map_base != NULL) {
3835 return makecon(TypeRawPtr::make((address)ct->byte_map_base));
3836 } else {
3837 return null();
3838 }
3839 }
3840
3841 // vanilla/CMS post barrier
3842 // Insert a write-barrier store. This is to let generational GC work; we have
3843 // to flag all oop-stores before the next GC point.
3844 void GraphKit::write_barrier_post(Node* oop_store,
3845 Node* obj,
3846 Node* adr,
3847 uint adr_idx,
3848 Node* val,
3849 bool use_precise) {
3850 // No store check needed if we're storing a NULL or an old object
3851 // (latter case is probably a string constant). The concurrent
3852 // mark sweep garbage collector, however, needs to have all nonNull
3853 // oop updates flagged via card-marks.
3854 if (val != NULL && val->is_Con()) {
3855 // must be either an oop or NULL
3856 const Type* t = val->bottom_type();
3857 if (t == TypePtr::NULL_PTR || t == Type::TOP)
3858 // stores of null never (?) need barriers
3859 return;
3860 }
3861
3862 if (use_ReduceInitialCardMarks()
3863 && obj == just_allocated_object(control())) {
3864 // We can skip marks on a freshly-allocated object in Eden.
3865 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
3866 // That routine informs GC to take appropriate compensating steps,
3867 // upon a slow-path allocation, so as to make this card-mark
3868 // elision safe.
3869 return;
3870 }
3871
3872 if (!use_precise) {
3873 // All card marks for a (non-array) instance are in one place:
3874 adr = obj;
3875 }
3876 // (Else it's an array (or unknown), and we want more precise card marks.)
3877 assert(adr != NULL, "");
3878
3879 IdealKit ideal(this, true);
3880
3881 // Convert the pointer to an int prior to doing math on it
3882 Node* cast = __ CastPX(__ ctrl(), adr);
3883
3884 // Divide by card size
3885 assert(Universe::heap()->barrier_set()->is_a(BarrierSet::CardTableModRef),
3886 "Only one we handle so far.");
3887 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
3888
3889 // Combine card table base and card offset
3890 Node* card_adr = __ AddP(__ top(), byte_map_base_node(), card_offset );
3891
3892 // Get the alias_index for raw card-mark memory
3893 int adr_type = Compile::AliasIdxRaw;
3894 Node* zero = __ ConI(0); // Dirty card value
3895 BasicType bt = T_BYTE;
3896
3897 if (UseConcMarkSweepGC && UseCondCardMark) {
3898 insert_mem_bar(Op_MemBarVolatile); // StoreLoad barrier
3899 __ sync_kit(this);
3900 }
3901
3902 if (UseCondCardMark) {
3903 // The classic GC reference write barrier is typically implemented
3904 // as a store into the global card mark table. Unfortunately
3905 // unconditional stores can result in false sharing and excessive
3906 // coherence traffic as well as false transactional aborts.
3907 // UseCondCardMark enables MP "polite" conditional card mark
3908 // stores. In theory we could relax the load from ctrl() to
3909 // no_ctrl, but that doesn't buy much latitude.
3910 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, bt, adr_type);
3911 __ if_then(card_val, BoolTest::ne, zero);
3912 }
3913
3914 // Smash zero into card
3915 if( !UseConcMarkSweepGC ) {
3916 __ store(__ ctrl(), card_adr, zero, bt, adr_type, MemNode::unordered);
3917 } else {
3918 // Specialized path for CM store barrier
3919 __ storeCM(__ ctrl(), card_adr, zero, oop_store, adr_idx, bt, adr_type);
3920 }
3921
3922 if (UseCondCardMark) {
3923 __ end_if();
3924 }
3925
3926 // Final sync IdealKit and GraphKit.
3927 final_sync(ideal);
3928 }
3929 /*
3930 * Determine if the G1 pre-barrier can be removed. The pre-barrier is
3931 * required by SATB to make sure all objects live at the start of the
3932 * marking are kept alive, all reference updates need to any previous
3933 * reference stored before writing.
3934 *
3935 * If the previous value is NULL there is no need to save the old value.
3936 * References that are NULL are filtered during runtime by the barrier
3937 * code to avoid unnecessary queuing.
3938 *
3939 * However in the case of newly allocated objects it might be possible to
3940 * prove that the reference about to be overwritten is NULL during compile
3941 * time and avoid adding the barrier code completely.
3942 *
3943 * The compiler needs to determine that the object in which a field is about
3944 * to be written is newly allocated, and that no prior store to the same field
3945 * has happened since the allocation.
3946 *
3947 * Returns true if the pre-barrier can be removed
3948 */
3949 bool GraphKit::g1_can_remove_pre_barrier(PhaseTransform* phase, Node* adr,
3950 BasicType bt, uint adr_idx) {
3951 intptr_t offset = 0;
3952 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
3953 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
3954
3955 if (offset == Type::OffsetBot) {
3956 return false; // cannot unalias unless there are precise offsets
3957 }
3958
3959 if (alloc == NULL) {
3960 return false; // No allocation found
3961 }
3962
3963 intptr_t size_in_bytes = type2aelembytes(bt);
3964
3965 Node* mem = memory(adr_idx); // start searching here...
3966
3967 for (int cnt = 0; cnt < 50; cnt++) {
3968
3969 if (mem->is_Store()) {
3970
3971 Node* st_adr = mem->in(MemNode::Address);
3972 intptr_t st_offset = 0;
3973 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
3974
3975 if (st_base == NULL) {
3976 break; // inscrutable pointer
3977 }
3978
3979 // Break we have found a store with same base and offset as ours so break
3980 if (st_base == base && st_offset == offset) {
3981 break;
3982 }
3983
3984 if (st_offset != offset && st_offset != Type::OffsetBot) {
3985 const int MAX_STORE = BytesPerLong;
3986 if (st_offset >= offset + size_in_bytes ||
3987 st_offset <= offset - MAX_STORE ||
3988 st_offset <= offset - mem->as_Store()->memory_size()) {
3989 // Success: The offsets are provably independent.
3990 // (You may ask, why not just test st_offset != offset and be done?
3991 // The answer is that stores of different sizes can co-exist
3992 // in the same sequence of RawMem effects. We sometimes initialize
3993 // a whole 'tile' of array elements with a single jint or jlong.)
3994 mem = mem->in(MemNode::Memory);
3995 continue; // advance through independent store memory
3996 }
3997 }
3998
3999 if (st_base != base
4000 && MemNode::detect_ptr_independence(base, alloc, st_base,
4001 AllocateNode::Ideal_allocation(st_base, phase),
4002 phase)) {
4003 // Success: The bases are provably independent.
4004 mem = mem->in(MemNode::Memory);
4005 continue; // advance through independent store memory
4006 }
4007 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4008
4009 InitializeNode* st_init = mem->in(0)->as_Initialize();
4010 AllocateNode* st_alloc = st_init->allocation();
4011
4012 // Make sure that we are looking at the same allocation site.
4013 // The alloc variable is guaranteed to not be null here from earlier check.
4014 if (alloc == st_alloc) {
4015 // Check that the initialization is storing NULL so that no previous store
4016 // has been moved up and directly write a reference
4017 Node* captured_store = st_init->find_captured_store(offset,
4018 type2aelembytes(T_OBJECT),
4019 phase);
4020 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
4021 return true;
4022 }
4023 }
4024 }
4025
4026 // Unless there is an explicit 'continue', we must bail out here,
4027 // because 'mem' is an inscrutable memory state (e.g., a call).
4028 break;
4029 }
4030
4031 return false;
4032 }
4033
4034 // G1 pre/post barriers
4035 void GraphKit::g1_write_barrier_pre(bool do_load,
4036 Node* obj,
4037 Node* adr,
4038 uint alias_idx,
4039 Node* val,
4040 const TypeOopPtr* val_type,
4041 Node* pre_val,
4042 BasicType bt) {
4043
4044 // Some sanity checks
4045 // Note: val is unused in this routine.
4046
4047 if (do_load) {
4048 // We need to generate the load of the previous value
4049 assert(obj != NULL, "must have a base");
4050 assert(adr != NULL, "where are loading from?");
4051 assert(pre_val == NULL, "loaded already?");
4052 assert(val_type != NULL, "need a type");
4053
4054 if (use_ReduceInitialCardMarks()
4055 && g1_can_remove_pre_barrier(&_gvn, adr, bt, alias_idx)) {
4056 return;
4057 }
4058
4059 } else {
4060 // In this case both val_type and alias_idx are unused.
4061 assert(pre_val != NULL, "must be loaded already");
4062 // Nothing to be done if pre_val is null.
4063 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
4064 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
4065 }
4066 assert(bt == T_OBJECT, "or we shouldn't be here");
4067
4068 IdealKit ideal(this, true);
4069
4070 Node* tls = __ thread(); // ThreadLocalStorage
4071
4072 Node* no_ctrl = NULL;
4073 Node* no_base = __ top();
4074 Node* zero = __ ConI(0);
4075 Node* zeroX = __ ConX(0);
4076
4077 float likely = PROB_LIKELY(0.999);
4078 float unlikely = PROB_UNLIKELY(0.999);
4079
4080 BasicType active_type = in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 ? T_INT : T_BYTE;
4081 assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 4 || in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "flag width");
4082
4083 // Offsets into the thread
4084 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 648
4085 SATBMarkQueue::byte_offset_of_active());
4086 const int index_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 656
4087 SATBMarkQueue::byte_offset_of_index());
4088 const int buffer_offset = in_bytes(JavaThread::satb_mark_queue_offset() + // 652
4089 SATBMarkQueue::byte_offset_of_buf());
4090
4091 // Now the actual pointers into the thread
4092 Node* marking_adr = __ AddP(no_base, tls, __ ConX(marking_offset));
4093 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4094 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4095
4096 // Now some of the values
4097 Node* marking = __ load(__ ctrl(), marking_adr, TypeInt::INT, active_type, Compile::AliasIdxRaw);
4098
4099 // if (!marking)
4100 __ if_then(marking, BoolTest::ne, zero, unlikely); {
4101 BasicType index_bt = TypeX_X->basic_type();
4102 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
4103 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
4104
4105 if (do_load) {
4106 // load original value
4107 // alias_idx correct??
4108 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
4109 }
4110
4111 // if (pre_val != NULL)
4112 __ if_then(pre_val, BoolTest::ne, null()); {
4113 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4114
4115 // is the queue for this thread full?
4116 __ if_then(index, BoolTest::ne, zeroX, likely); {
4117
4118 // decrement the index
4119 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4120
4121 // Now get the buffer location we will log the previous value into and store it
4122 Node *log_addr = __ AddP(no_base, buffer, next_index);
4123 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
4124 // update the index
4125 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
4126
4127 } __ else_(); {
4128
4129 // logging buffer is full, call the runtime
4130 const TypeFunc *tf = OptoRuntime::g1_wb_pre_Type();
4131 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_pre), "g1_wb_pre", pre_val, tls);
4132 } __ end_if(); // (!index)
4133 } __ end_if(); // (pre_val != NULL)
4134 } __ end_if(); // (!marking)
4135
4136 // Final sync IdealKit and GraphKit.
4137 final_sync(ideal);
4138 }
4139
4140 /*
4141 * G1 similar to any GC with a Young Generation requires a way to keep track of
4142 * references from Old Generation to Young Generation to make sure all live
4143 * objects are found. G1 also requires to keep track of object references
4144 * between different regions to enable evacuation of old regions, which is done
4145 * as part of mixed collections. References are tracked in remembered sets and
4146 * is continuously updated as reference are written to with the help of the
4147 * post-barrier.
4148 *
4149 * To reduce the number of updates to the remembered set the post-barrier
4150 * filters updates to fields in objects located in the Young Generation,
4151 * the same region as the reference, when the NULL is being written or
4152 * if the card is already marked as dirty by an earlier write.
4153 *
4154 * Under certain circumstances it is possible to avoid generating the
4155 * post-barrier completely if it is possible during compile time to prove
4156 * the object is newly allocated and that no safepoint exists between the
4157 * allocation and the store.
4158 *
4159 * In the case of slow allocation the allocation code must handle the barrier
4160 * as part of the allocation in the case the allocated object is not located
4161 * in the nursery, this would happen for humongous objects. This is similar to
4162 * how CMS is required to handle this case, see the comments for the method
4163 * CollectedHeap::new_store_pre_barrier and OptoRuntime::new_store_pre_barrier.
4164 * A deferred card mark is required for these objects and handled in the above
4165 * mentioned methods.
4166 *
4167 * Returns true if the post barrier can be removed
4168 */
4169 bool GraphKit::g1_can_remove_post_barrier(PhaseTransform* phase, Node* store,
4170 Node* adr) {
4171 intptr_t offset = 0;
4172 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
4173 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
4174
4175 if (offset == Type::OffsetBot) {
4176 return false; // cannot unalias unless there are precise offsets
4177 }
4178
4179 if (alloc == NULL) {
4180 return false; // No allocation found
4181 }
4182
4183 // Start search from Store node
4184 Node* mem = store->in(MemNode::Control);
4185 if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
4186
4187 InitializeNode* st_init = mem->in(0)->as_Initialize();
4188 AllocateNode* st_alloc = st_init->allocation();
4189
4190 // Make sure we are looking at the same allocation
4191 if (alloc == st_alloc) {
4192 return true;
4193 }
4194 }
4195
4196 return false;
4197 }
4198
4199 //
4200 // Update the card table and add card address to the queue
4201 //
4202 void GraphKit::g1_mark_card(IdealKit& ideal,
4203 Node* card_adr,
4204 Node* oop_store,
4205 uint oop_alias_idx,
4206 Node* index,
4207 Node* index_adr,
4208 Node* buffer,
4209 const TypeFunc* tf) {
4210
4211 Node* zero = __ ConI(0);
4212 Node* zeroX = __ ConX(0);
4213 Node* no_base = __ top();
4214 BasicType card_bt = T_BYTE;
4215 // Smash zero into card. MUST BE ORDERED WRT TO STORE
4216 __ storeCM(__ ctrl(), card_adr, zero, oop_store, oop_alias_idx, card_bt, Compile::AliasIdxRaw);
4217
4218 // Now do the queue work
4219 __ if_then(index, BoolTest::ne, zeroX); {
4220
4221 Node* next_index = _gvn.transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
4222 Node* log_addr = __ AddP(no_base, buffer, next_index);
4223
4224 // Order, see storeCM.
4225 __ store(__ ctrl(), log_addr, card_adr, T_ADDRESS, Compile::AliasIdxRaw, MemNode::unordered);
4226 __ store(__ ctrl(), index_adr, next_index, TypeX_X->basic_type(), Compile::AliasIdxRaw, MemNode::unordered);
4227
4228 } __ else_(); {
4229 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, SharedRuntime::g1_wb_post), "g1_wb_post", card_adr, __ thread());
4230 } __ end_if();
4231
4232 }
4233
4234 void GraphKit::g1_write_barrier_post(Node* oop_store,
4235 Node* obj,
4236 Node* adr,
4237 uint alias_idx,
4238 Node* val,
4239 BasicType bt,
4240 bool use_precise) {
4241 // If we are writing a NULL then we need no post barrier
4242
4243 if (val != NULL && val->is_Con() && val->bottom_type() == TypePtr::NULL_PTR) {
4244 // Must be NULL
4245 const Type* t = val->bottom_type();
4246 assert(t == Type::TOP || t == TypePtr::NULL_PTR, "must be NULL");
4247 // No post barrier if writing NULLx
4248 return;
4249 }
4250
4251 if (use_ReduceInitialCardMarks() && obj == just_allocated_object(control())) {
4252 // We can skip marks on a freshly-allocated object in Eden.
4253 // Keep this code in sync with new_store_pre_barrier() in runtime.cpp.
4254 // That routine informs GC to take appropriate compensating steps,
4255 // upon a slow-path allocation, so as to make this card-mark
4256 // elision safe.
4257 return;
4258 }
4259
4260 if (use_ReduceInitialCardMarks()
4261 && g1_can_remove_post_barrier(&_gvn, oop_store, adr)) {
4262 return;
4263 }
4264
4265 if (!use_precise) {
4266 // All card marks for a (non-array) instance are in one place:
4267 adr = obj;
4268 }
4269 // (Else it's an array (or unknown), and we want more precise card marks.)
4270 assert(adr != NULL, "");
4271
4272 IdealKit ideal(this, true);
4273
4274 Node* tls = __ thread(); // ThreadLocalStorage
4275
4276 Node* no_base = __ top();
4277 float likely = PROB_LIKELY(0.999);
4278 float unlikely = PROB_UNLIKELY(0.999);
4279 Node* young_card = __ ConI((jint)G1SATBCardTableModRefBS::g1_young_card_val());
4280 Node* dirty_card = __ ConI((jint)CardTableModRefBS::dirty_card_val());
4281 Node* zeroX = __ ConX(0);
4282
4283 // Get the alias_index for raw card-mark memory
4284 const TypePtr* card_type = TypeRawPtr::BOTTOM;
4285
4286 const TypeFunc *tf = OptoRuntime::g1_wb_post_Type();
4287
4288 // Offsets into the thread
4289 const int index_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4290 DirtyCardQueue::byte_offset_of_index());
4291 const int buffer_offset = in_bytes(JavaThread::dirty_card_queue_offset() +
4292 DirtyCardQueue::byte_offset_of_buf());
4293
4294 // Pointers into the thread
4295
4296 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
4297 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
4298
4299 // Now some values
4300 // Use ctrl to avoid hoisting these values past a safepoint, which could
4301 // potentially reset these fields in the JavaThread.
4302 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, TypeX_X->basic_type(), Compile::AliasIdxRaw);
4303 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
4304
4305 // Convert the store obj pointer to an int prior to doing math on it
4306 // Must use ctrl to prevent "integerized oop" existing across safepoint
4307 Node* cast = __ CastPX(__ ctrl(), adr);
4308
4309 // Divide pointer by card size
4310 Node* card_offset = __ URShiftX( cast, __ ConI(CardTableModRefBS::card_shift) );
4311
4312 // Combine card table base and card offset
4313 Node* card_adr = __ AddP(no_base, byte_map_base_node(), card_offset );
4314
4315 // If we know the value being stored does it cross regions?
4316
4317 if (val != NULL) {
4318 // Does the store cause us to cross regions?
4319
4320 // Should be able to do an unsigned compare of region_size instead of
4321 // and extra shift. Do we have an unsigned compare??
4322 // Node* region_size = __ ConI(1 << HeapRegion::LogOfHRGrainBytes);
4323 Node* xor_res = __ URShiftX ( __ XorX( cast, __ CastPX(__ ctrl(), val)), __ ConI(HeapRegion::LogOfHRGrainBytes));
4324
4325 // if (xor_res == 0) same region so skip
4326 __ if_then(xor_res, BoolTest::ne, zeroX); {
4327
4328 // No barrier if we are storing a NULL
4329 __ if_then(val, BoolTest::ne, null(), unlikely); {
4330
4331 // Ok must mark the card if not already dirty
4332
4333 // load the original value of the card
4334 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4335
4336 __ if_then(card_val, BoolTest::ne, young_card); {
4337 sync_kit(ideal);
4338 // Use Op_MemBarVolatile to achieve the effect of a StoreLoad barrier.
4339 insert_mem_bar(Op_MemBarVolatile, oop_store);
4340 __ sync_kit(this);
4341
4342 Node* card_val_reload = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4343 __ if_then(card_val_reload, BoolTest::ne, dirty_card); {
4344 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4345 } __ end_if();
4346 } __ end_if();
4347 } __ end_if();
4348 } __ end_if();
4349 } else {
4350 // The Object.clone() intrinsic uses this path if !ReduceInitialCardMarks.
4351 // We don't need a barrier here if the destination is a newly allocated object
4352 // in Eden. Otherwise, GC verification breaks because we assume that cards in Eden
4353 // are set to 'g1_young_gen' (see G1SATBCardTableModRefBS::verify_g1_young_region()).
4354 assert(!use_ReduceInitialCardMarks(), "can only happen with card marking");
4355 Node* card_val = __ load(__ ctrl(), card_adr, TypeInt::INT, T_BYTE, Compile::AliasIdxRaw);
4356 __ if_then(card_val, BoolTest::ne, young_card); {
4357 g1_mark_card(ideal, card_adr, oop_store, alias_idx, index, index_adr, buffer, tf);
4358 } __ end_if();
4359 }
4360
4361 // Final sync IdealKit and GraphKit.
4362 final_sync(ideal);
4363 }
4364 #undef __
4365
4366
4367 Node* GraphKit::load_String_length(Node* ctrl, Node* str) {
4368 Node* len = load_array_length(load_String_value(ctrl, str));
4369 Node* coder = load_String_coder(ctrl, str);
4370 // Divide length by 2 if coder is UTF16
4371 return _gvn.transform(new RShiftINode(len, coder));
4372 }
4373
4374 Node* GraphKit::load_String_value(Node* ctrl, Node* str) {
4375 int value_offset = java_lang_String::value_offset_in_bytes();
4376 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4377 false, NULL, 0);
4378 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4379 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
4380 TypeAry::make(TypeInt::BYTE, TypeInt::POS),
4381 ciTypeArrayKlass::make(T_BYTE), true, 0);
4382 int value_field_idx = C->get_alias_index(value_field_type);
4383 Node* load = make_load(ctrl, basic_plus_adr(str, str, value_offset),
4384 value_type, T_OBJECT, value_field_idx, MemNode::unordered);
4385 // String.value field is known to be @Stable.
4386 if (UseImplicitStableValues) {
4387 load = cast_array_to_stable(load, value_type);
4388 }
4389 return load;
4390 }
4391
4392 Node* GraphKit::load_String_coder(Node* ctrl, Node* str) {
4393 if (!CompactStrings) {
4394 return intcon(java_lang_String::CODER_UTF16);
4395 }
4396 int coder_offset = java_lang_String::coder_offset_in_bytes();
4397 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4398 false, NULL, 0);
4399 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4400 int coder_field_idx = C->get_alias_index(coder_field_type);
4401 return make_load(ctrl, basic_plus_adr(str, str, coder_offset),
4402 TypeInt::BYTE, T_BYTE, coder_field_idx, MemNode::unordered);
4403 }
4404
4405 void GraphKit::store_String_value(Node* ctrl, Node* str, Node* value) {
4406 int value_offset = java_lang_String::value_offset_in_bytes();
4407 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4408 false, NULL, 0);
4409 const TypePtr* value_field_type = string_type->add_offset(value_offset);
4410 store_oop_to_object(ctrl, str, basic_plus_adr(str, value_offset), value_field_type,
4411 value, TypeAryPtr::BYTES, T_OBJECT, MemNode::unordered);
4412 }
4413
4414 void GraphKit::store_String_coder(Node* ctrl, Node* str, Node* value) {
4415 int coder_offset = java_lang_String::coder_offset_in_bytes();
4416 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
4417 false, NULL, 0);
4418 const TypePtr* coder_field_type = string_type->add_offset(coder_offset);
4419 int coder_field_idx = C->get_alias_index(coder_field_type);
4420 store_to_memory(ctrl, basic_plus_adr(str, coder_offset),
4421 value, T_BYTE, coder_field_idx, MemNode::unordered);
4422 }
4423
4424 // Capture src and dst memory state with a MergeMemNode
4425 Node* GraphKit::capture_memory(const TypePtr* src_type, const TypePtr* dst_type) {
4426 if (src_type == dst_type) {
4427 // Types are equal, we don't need a MergeMemNode
4428 return memory(src_type);
4429 }
4430 MergeMemNode* merge = MergeMemNode::make(map()->memory());
4431 record_for_igvn(merge); // fold it up later, if possible
4432 int src_idx = C->get_alias_index(src_type);
4433 int dst_idx = C->get_alias_index(dst_type);
4434 merge->set_memory_at(src_idx, memory(src_idx));
4435 merge->set_memory_at(dst_idx, memory(dst_idx));
4436 return merge;
4437 }
4438
4439 Node* GraphKit::compress_string(Node* src, const TypeAryPtr* src_type, Node* dst, Node* count) {
4440 assert(Matcher::match_rule_supported(Op_StrCompressedCopy), "Intrinsic not supported");
4441 assert(src_type == TypeAryPtr::BYTES || src_type == TypeAryPtr::CHARS, "invalid source type");
4442 // If input and output memory types differ, capture both states to preserve
4443 // the dependency between preceding and subsequent loads/stores.
4444 // For example, the following program:
4445 // StoreB
4446 // compress_string
4447 // LoadB
4448 // has this memory graph (use->def):
4449 // LoadB -> compress_string -> CharMem
4450 // ... -> StoreB -> ByteMem
4451 // The intrinsic hides the dependency between LoadB and StoreB, causing
4452 // the load to read from memory not containing the result of the StoreB.
4453 // The correct memory graph should look like this:
4454 // LoadB -> compress_string -> MergeMem(CharMem, StoreB(ByteMem))
4455 Node* mem = capture_memory(src_type, TypeAryPtr::BYTES);
4456 StrCompressedCopyNode* str = new StrCompressedCopyNode(control(), mem, src, dst, count);
4457 Node* res_mem = _gvn.transform(new SCMemProjNode(str));
4458 set_memory(res_mem, TypeAryPtr::BYTES);
4459 return str;
4460 }
4461
4462 void GraphKit::inflate_string(Node* src, Node* dst, const TypeAryPtr* dst_type, Node* count) {
4463 assert(Matcher::match_rule_supported(Op_StrInflatedCopy), "Intrinsic not supported");
4464 assert(dst_type == TypeAryPtr::BYTES || dst_type == TypeAryPtr::CHARS, "invalid dest type");
4465 // Capture src and dst memory (see comment in 'compress_string').
4466 Node* mem = capture_memory(TypeAryPtr::BYTES, dst_type);
4467 StrInflatedCopyNode* str = new StrInflatedCopyNode(control(), mem, src, dst, count);
4468 set_memory(_gvn.transform(str), dst_type);
4469 }
4470
4471 void GraphKit::inflate_string_slow(Node* src, Node* dst, Node* start, Node* count) {
4472 /**
4473 * int i_char = start;
4474 * for (int i_byte = 0; i_byte < count; i_byte++) {
4475 * dst[i_char++] = (char)(src[i_byte] & 0xff);
4476 * }
4477 */
4478 add_predicate();
4479 RegionNode* head = new RegionNode(3);
4480 head->init_req(1, control());
4481 gvn().set_type(head, Type::CONTROL);
4482 record_for_igvn(head);
4483
4484 Node* i_byte = new PhiNode(head, TypeInt::INT);
4485 i_byte->init_req(1, intcon(0));
4486 gvn().set_type(i_byte, TypeInt::INT);
4487 record_for_igvn(i_byte);
4488
4489 Node* i_char = new PhiNode(head, TypeInt::INT);
4490 i_char->init_req(1, start);
4491 gvn().set_type(i_char, TypeInt::INT);
4492 record_for_igvn(i_char);
4493
4494 Node* mem = PhiNode::make(head, memory(TypeAryPtr::BYTES), Type::MEMORY, TypeAryPtr::BYTES);
4495 gvn().set_type(mem, Type::MEMORY);
4496 record_for_igvn(mem);
4497 set_control(head);
4498 set_memory(mem, TypeAryPtr::BYTES);
4499 Node* ch = load_array_element(control(), src, i_byte, TypeAryPtr::BYTES);
4500 Node* st = store_to_memory(control(), array_element_address(dst, i_char, T_BYTE),
4501 AndI(ch, intcon(0xff)), T_CHAR, TypeAryPtr::BYTES, MemNode::unordered,
4502 false, false, true /* mismatched */);
4503
4504 IfNode* iff = create_and_map_if(head, Bool(CmpI(i_byte, count), BoolTest::lt), PROB_FAIR, COUNT_UNKNOWN);
4505 head->init_req(2, IfTrue(iff));
4506 mem->init_req(2, st);
4507 i_byte->init_req(2, AddI(i_byte, intcon(1)));
4508 i_char->init_req(2, AddI(i_char, intcon(2)));
4509
4510 set_control(IfFalse(iff));
4511 set_memory(st, TypeAryPtr::BYTES);
4512 }
4513
4514 Node* GraphKit::make_constant_from_field(ciField* field, Node* obj) {
4515 if (!field->is_constant()) {
4516 return NULL; // Field not marked as constant.
4517 }
4518 ciInstance* holder = NULL;
4519 if (!field->is_static()) {
4520 ciObject* const_oop = obj->bottom_type()->is_oopptr()->const_oop();
4521 if (const_oop != NULL && const_oop->is_instance()) {
4522 holder = const_oop->as_instance();
4523 }
4524 }
4525 const Type* con_type = Type::make_constant_from_field(field, holder, field->layout_type(),
4526 /*is_unsigned_load=*/false);
4527 if (con_type != NULL) {
4528 return makecon(con_type);
4529 }
4530 return NULL;
4531 }
4532
4533 Node* GraphKit::cast_array_to_stable(Node* ary, const TypeAryPtr* ary_type) {
4534 // Reify the property as a CastPP node in Ideal graph to comply with monotonicity
4535 // assumption of CCP analysis.
4536 return _gvn.transform(new CastPPNode(ary, ary_type->cast_to_stable(true)));
4537 }
4538
4539 Node* GraphKit::acmp(Node* a, Node* b) {
4540 // In the case were both operands might be value types, we need to
4541 // use the new acmp implementation. Otherwise, i.e. if one operand
4542 // is not a value type, we can use the old acmp implementation.
4543 Node* cmp = C->optimize_acmp(&_gvn, a, b);
4544 if (cmp != NULL) {
4545 return cmp; // Use optimized/old acmp
4546 }
4547
4548 Node* region = new RegionNode(2);
4549 Node* is_value = new PhiNode(region, TypeX_X);
4550
4551 // Null check operand before loading the is_value bit
4552 if (!TypePtr::NULL_PTR->higher_equal(_gvn.type(b))) {
4553 // Operand 'b' is never null, swap operands to avoid null check
4554 swap(a, b);
4555 }
4556 // TODO we need to speculate on 'a' being non-null / always null
4557 Node* null_ctl = top();
4558 Node* not_null_a = null_check_oop(a, &null_ctl);
4559 assert(!stopped(), "operand is always null");
4560 if (null_ctl != top()) {
4561 region->add_req(null_ctl);
4562 is_value->add_req(_gvn.MakeConX(0));
4563 if (Verbose) tty->print_cr("\n# NEW (parse time)");
4564 } else {
4565 if (Verbose) tty->print_cr("\n# NEW WITHOUT NULL (parse time)");
4566 }
4567
4568 Node* value_bit = C->load_is_value_bit(&_gvn, not_null_a);
4569 region->init_req(1, control());
4570 is_value->set_req(1, value_bit);
4571
4572 set_control(_gvn.transform(region));
4573 is_value = _gvn.transform(is_value);
4574
4575 // Perturbe oop if operand is a value type to make comparison fail
4576 Node* pert = _gvn.transform(new AddPNode(a, a, is_value));
4577 return new CmpPNode(pert, b);
4578 }