1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/bcEscapeAnalyzer.hpp"
27 #include "compiler/oopMap.hpp"
28 #include "opto/callnode.hpp"
29 #include "opto/escape.hpp"
30 #include "opto/locknode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/matcher.hpp"
33 #include "opto/parse.hpp"
34 #include "opto/regalloc.hpp"
35 #include "opto/regmask.hpp"
36 #include "opto/rootnode.hpp"
37 #include "opto/runtime.hpp"
38
39 // Portions of code courtesy of Clifford Click
40
41 // Optimization - Graph Style
42
43 //=============================================================================
44 uint StartNode::size_of() const { return sizeof(*this); }
45 uint StartNode::cmp( const Node &n ) const
46 { return _domain == ((StartNode&)n)._domain; }
47 const Type *StartNode::bottom_type() const { return _domain; }
48 const Type *StartNode::Value(PhaseTransform *phase) const { return _domain; }
49 #ifndef PRODUCT
50 void StartNode::dump_spec(outputStream *st) const { st->print(" #"); _domain->dump_on(st);}
51 #endif
52
53 //------------------------------Ideal------------------------------------------
54 Node *StartNode::Ideal(PhaseGVN *phase, bool can_reshape){
55 return remove_dead_region(phase, can_reshape) ? this : NULL;
56 }
57
58 //------------------------------calling_convention-----------------------------
59 void StartNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
60 Matcher::calling_convention( sig_bt, parm_regs, argcnt, false );
61 }
62
63 //------------------------------Registers--------------------------------------
64 const RegMask &StartNode::in_RegMask(uint) const {
65 return RegMask::Empty;
66 }
67
68 //------------------------------match------------------------------------------
69 // Construct projections for incoming parameters, and their RegMask info
70 Node *StartNode::match( const ProjNode *proj, const Matcher *match ) {
71 switch (proj->_con) {
72 case TypeFunc::Control:
73 case TypeFunc::I_O:
74 case TypeFunc::Memory:
75 return new (match->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
76 case TypeFunc::FramePtr:
77 return new (match->C, 1) MachProjNode(this,proj->_con,Matcher::c_frame_ptr_mask, Op_RegP);
78 case TypeFunc::ReturnAdr:
79 return new (match->C, 1) MachProjNode(this,proj->_con,match->_return_addr_mask,Op_RegP);
80 case TypeFunc::Parms:
81 default: {
82 uint parm_num = proj->_con - TypeFunc::Parms;
83 const Type *t = _domain->field_at(proj->_con);
84 if (t->base() == Type::Half) // 2nd half of Longs and Doubles
85 return new (match->C, 1) ConNode(Type::TOP);
86 uint ideal_reg = Matcher::base2reg[t->base()];
87 RegMask &rm = match->_calling_convention_mask[parm_num];
88 return new (match->C, 1) MachProjNode(this,proj->_con,rm,ideal_reg);
89 }
90 }
91 return NULL;
92 }
93
94 //------------------------------StartOSRNode----------------------------------
95 // The method start node for an on stack replacement adapter
96
97 //------------------------------osr_domain-----------------------------
98 const TypeTuple *StartOSRNode::osr_domain() {
99 const Type **fields = TypeTuple::fields(2);
100 fields[TypeFunc::Parms+0] = TypeRawPtr::BOTTOM; // address of osr buffer
101
102 return TypeTuple::make(TypeFunc::Parms+1, fields);
103 }
104
105 //=============================================================================
106 const char * const ParmNode::names[TypeFunc::Parms+1] = {
107 "Control", "I_O", "Memory", "FramePtr", "ReturnAdr", "Parms"
108 };
109
110 #ifndef PRODUCT
111 void ParmNode::dump_spec(outputStream *st) const {
112 if( _con < TypeFunc::Parms ) {
113 st->print(names[_con]);
114 } else {
115 st->print("Parm%d: ",_con-TypeFunc::Parms);
116 // Verbose and WizardMode dump bottom_type for all nodes
117 if( !Verbose && !WizardMode ) bottom_type()->dump_on(st);
118 }
119 }
120 #endif
121
122 uint ParmNode::ideal_reg() const {
123 switch( _con ) {
124 case TypeFunc::Control : // fall through
125 case TypeFunc::I_O : // fall through
126 case TypeFunc::Memory : return 0;
127 case TypeFunc::FramePtr : // fall through
128 case TypeFunc::ReturnAdr: return Op_RegP;
129 default : assert( _con > TypeFunc::Parms, "" );
130 // fall through
131 case TypeFunc::Parms : {
132 // Type of argument being passed
133 const Type *t = in(0)->as_Start()->_domain->field_at(_con);
134 return Matcher::base2reg[t->base()];
135 }
136 }
137 ShouldNotReachHere();
138 return 0;
139 }
140
141 //=============================================================================
142 ReturnNode::ReturnNode(uint edges, Node *cntrl, Node *i_o, Node *memory, Node *frameptr, Node *retadr ) : Node(edges) {
143 init_req(TypeFunc::Control,cntrl);
144 init_req(TypeFunc::I_O,i_o);
145 init_req(TypeFunc::Memory,memory);
146 init_req(TypeFunc::FramePtr,frameptr);
147 init_req(TypeFunc::ReturnAdr,retadr);
148 }
149
150 Node *ReturnNode::Ideal(PhaseGVN *phase, bool can_reshape){
151 return remove_dead_region(phase, can_reshape) ? this : NULL;
152 }
153
154 const Type *ReturnNode::Value( PhaseTransform *phase ) const {
155 return ( phase->type(in(TypeFunc::Control)) == Type::TOP)
156 ? Type::TOP
157 : Type::BOTTOM;
158 }
159
160 // Do we Match on this edge index or not? No edges on return nodes
161 uint ReturnNode::match_edge(uint idx) const {
162 return 0;
163 }
164
165
166 #ifndef PRODUCT
167 void ReturnNode::dump_req() const {
168 // Dump the required inputs, enclosed in '(' and ')'
169 uint i; // Exit value of loop
170 for( i=0; i<req(); i++ ) { // For all required inputs
171 if( i == TypeFunc::Parms ) tty->print("returns");
172 if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
173 else tty->print("_ ");
174 }
175 }
176 #endif
177
178 //=============================================================================
179 RethrowNode::RethrowNode(
180 Node* cntrl,
181 Node* i_o,
182 Node* memory,
183 Node* frameptr,
184 Node* ret_adr,
185 Node* exception
186 ) : Node(TypeFunc::Parms + 1) {
187 init_req(TypeFunc::Control , cntrl );
188 init_req(TypeFunc::I_O , i_o );
189 init_req(TypeFunc::Memory , memory );
190 init_req(TypeFunc::FramePtr , frameptr );
191 init_req(TypeFunc::ReturnAdr, ret_adr);
192 init_req(TypeFunc::Parms , exception);
193 }
194
195 Node *RethrowNode::Ideal(PhaseGVN *phase, bool can_reshape){
196 return remove_dead_region(phase, can_reshape) ? this : NULL;
197 }
198
199 const Type *RethrowNode::Value( PhaseTransform *phase ) const {
200 return (phase->type(in(TypeFunc::Control)) == Type::TOP)
201 ? Type::TOP
202 : Type::BOTTOM;
203 }
204
205 uint RethrowNode::match_edge(uint idx) const {
206 return 0;
207 }
208
209 #ifndef PRODUCT
210 void RethrowNode::dump_req() const {
211 // Dump the required inputs, enclosed in '(' and ')'
212 uint i; // Exit value of loop
213 for( i=0; i<req(); i++ ) { // For all required inputs
214 if( i == TypeFunc::Parms ) tty->print("exception");
215 if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
216 else tty->print("_ ");
217 }
218 }
219 #endif
220
221 //=============================================================================
222 // Do we Match on this edge index or not? Match only target address & method
223 uint TailCallNode::match_edge(uint idx) const {
224 return TypeFunc::Parms <= idx && idx <= TypeFunc::Parms+1;
225 }
226
227 //=============================================================================
228 // Do we Match on this edge index or not? Match only target address & oop
229 uint TailJumpNode::match_edge(uint idx) const {
230 return TypeFunc::Parms <= idx && idx <= TypeFunc::Parms+1;
231 }
232
233 //=============================================================================
234 JVMState::JVMState(ciMethod* method, JVMState* caller) {
235 assert(method != NULL, "must be valid call site");
236 _method = method;
237 _reexecute = Reexecute_Undefined;
238 debug_only(_bci = -99); // random garbage value
239 debug_only(_map = (SafePointNode*)-1);
240 _caller = caller;
241 _depth = 1 + (caller == NULL ? 0 : caller->depth());
242 _locoff = TypeFunc::Parms;
243 _stkoff = _locoff + _method->max_locals();
244 _monoff = _stkoff + _method->max_stack();
245 _scloff = _monoff;
246 _endoff = _monoff;
247 _sp = 0;
248 }
249 JVMState::JVMState(int stack_size) {
250 _method = NULL;
251 _bci = InvocationEntryBci;
252 _reexecute = Reexecute_Undefined;
253 debug_only(_map = (SafePointNode*)-1);
254 _caller = NULL;
255 _depth = 1;
256 _locoff = TypeFunc::Parms;
257 _stkoff = _locoff;
258 _monoff = _stkoff + stack_size;
259 _scloff = _monoff;
260 _endoff = _monoff;
261 _sp = 0;
262 }
263
264 //--------------------------------of_depth-------------------------------------
265 JVMState* JVMState::of_depth(int d) const {
266 const JVMState* jvmp = this;
267 assert(0 < d && (uint)d <= depth(), "oob");
268 for (int skip = depth() - d; skip > 0; skip--) {
269 jvmp = jvmp->caller();
270 }
271 assert(jvmp->depth() == (uint)d, "found the right one");
272 return (JVMState*)jvmp;
273 }
274
275 //-----------------------------same_calls_as-----------------------------------
276 bool JVMState::same_calls_as(const JVMState* that) const {
277 if (this == that) return true;
278 if (this->depth() != that->depth()) return false;
279 const JVMState* p = this;
280 const JVMState* q = that;
281 for (;;) {
282 if (p->_method != q->_method) return false;
283 if (p->_method == NULL) return true; // bci is irrelevant
284 if (p->_bci != q->_bci) return false;
285 if (p->_reexecute != q->_reexecute) return false;
286 p = p->caller();
287 q = q->caller();
288 if (p == q) return true;
289 assert(p != NULL && q != NULL, "depth check ensures we don't run off end");
290 }
291 }
292
293 //------------------------------debug_start------------------------------------
294 uint JVMState::debug_start() const {
295 debug_only(JVMState* jvmroot = of_depth(1));
296 assert(jvmroot->locoff() <= this->locoff(), "youngest JVMState must be last");
297 return of_depth(1)->locoff();
298 }
299
300 //-------------------------------debug_end-------------------------------------
301 uint JVMState::debug_end() const {
302 debug_only(JVMState* jvmroot = of_depth(1));
303 assert(jvmroot->endoff() <= this->endoff(), "youngest JVMState must be last");
304 return endoff();
305 }
306
307 //------------------------------debug_depth------------------------------------
308 uint JVMState::debug_depth() const {
309 uint total = 0;
310 for (const JVMState* jvmp = this; jvmp != NULL; jvmp = jvmp->caller()) {
311 total += jvmp->debug_size();
312 }
313 return total;
314 }
315
316 #ifndef PRODUCT
317
318 //------------------------------format_helper----------------------------------
319 // Given an allocation (a Chaitin object) and a Node decide if the Node carries
320 // any defined value or not. If it does, print out the register or constant.
321 static void format_helper( PhaseRegAlloc *regalloc, outputStream* st, Node *n, const char *msg, uint i, GrowableArray<SafePointScalarObjectNode*> *scobjs ) {
322 if (n == NULL) { st->print(" NULL"); return; }
323 if (n->is_SafePointScalarObject()) {
324 // Scalar replacement.
325 SafePointScalarObjectNode* spobj = n->as_SafePointScalarObject();
326 scobjs->append_if_missing(spobj);
327 int sco_n = scobjs->find(spobj);
328 assert(sco_n >= 0, "");
329 st->print(" %s%d]=#ScObj" INT32_FORMAT, msg, i, sco_n);
330 return;
331 }
332 if( OptoReg::is_valid(regalloc->get_reg_first(n))) { // Check for undefined
333 char buf[50];
334 regalloc->dump_register(n,buf);
335 st->print(" %s%d]=%s",msg,i,buf);
336 } else { // No register, but might be constant
337 const Type *t = n->bottom_type();
338 switch (t->base()) {
339 case Type::Int:
340 st->print(" %s%d]=#"INT32_FORMAT,msg,i,t->is_int()->get_con());
341 break;
342 case Type::AnyPtr:
343 assert( t == TypePtr::NULL_PTR, "" );
344 st->print(" %s%d]=#NULL",msg,i);
345 break;
346 case Type::AryPtr:
347 case Type::KlassPtr:
348 case Type::InstPtr:
349 st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,t->isa_oopptr()->const_oop());
350 break;
351 case Type::NarrowOop:
352 st->print(" %s%d]=#Ptr" INTPTR_FORMAT,msg,i,t->make_ptr()->isa_oopptr()->const_oop());
353 break;
354 case Type::RawPtr:
355 st->print(" %s%d]=#Raw" INTPTR_FORMAT,msg,i,t->is_rawptr());
356 break;
357 case Type::DoubleCon:
358 st->print(" %s%d]=#%fD",msg,i,t->is_double_constant()->_d);
359 break;
360 case Type::FloatCon:
361 st->print(" %s%d]=#%fF",msg,i,t->is_float_constant()->_f);
362 break;
363 case Type::Long:
364 st->print(" %s%d]=#"INT64_FORMAT,msg,i,t->is_long()->get_con());
365 break;
366 case Type::Half:
367 case Type::Top:
368 st->print(" %s%d]=_",msg,i);
369 break;
370 default: ShouldNotReachHere();
371 }
372 }
373 }
374
375 //------------------------------format-----------------------------------------
376 void JVMState::format(PhaseRegAlloc *regalloc, const Node *n, outputStream* st) const {
377 st->print(" #");
378 if( _method ) {
379 _method->print_short_name(st);
380 st->print(" @ bci:%d ",_bci);
381 } else {
382 st->print_cr(" runtime stub ");
383 return;
384 }
385 if (n->is_MachSafePoint()) {
386 GrowableArray<SafePointScalarObjectNode*> scobjs;
387 MachSafePointNode *mcall = n->as_MachSafePoint();
388 uint i;
389 // Print locals
390 for( i = 0; i < (uint)loc_size(); i++ )
391 format_helper( regalloc, st, mcall->local(this, i), "L[", i, &scobjs );
392 // Print stack
393 for (i = 0; i < (uint)stk_size(); i++) {
394 if ((uint)(_stkoff + i) >= mcall->len())
395 st->print(" oob ");
396 else
397 format_helper( regalloc, st, mcall->stack(this, i), "STK[", i, &scobjs );
398 }
399 for (i = 0; (int)i < nof_monitors(); i++) {
400 Node *box = mcall->monitor_box(this, i);
401 Node *obj = mcall->monitor_obj(this, i);
402 if ( OptoReg::is_valid(regalloc->get_reg_first(box)) ) {
403 while( !box->is_BoxLock() ) box = box->in(1);
404 format_helper( regalloc, st, box, "MON-BOX[", i, &scobjs );
405 } else {
406 OptoReg::Name box_reg = BoxLockNode::stack_slot(box);
407 st->print(" MON-BOX%d=%s+%d",
408 i,
409 OptoReg::regname(OptoReg::c_frame_pointer),
410 regalloc->reg2offset(box_reg));
411 }
412 const char* obj_msg = "MON-OBJ[";
413 if (EliminateLocks) {
414 while( !box->is_BoxLock() ) box = box->in(1);
415 if (box->as_BoxLock()->is_eliminated())
416 obj_msg = "MON-OBJ(LOCK ELIMINATED)[";
417 }
418 format_helper( regalloc, st, obj, obj_msg, i, &scobjs );
419 }
420
421 for (i = 0; i < (uint)scobjs.length(); i++) {
422 // Scalar replaced objects.
423 st->print_cr("");
424 st->print(" # ScObj" INT32_FORMAT " ", i);
425 SafePointScalarObjectNode* spobj = scobjs.at(i);
426 ciKlass* cik = spobj->bottom_type()->is_oopptr()->klass();
427 assert(cik->is_instance_klass() ||
428 cik->is_array_klass(), "Not supported allocation.");
429 ciInstanceKlass *iklass = NULL;
430 if (cik->is_instance_klass()) {
431 cik->print_name_on(st);
432 iklass = cik->as_instance_klass();
433 } else if (cik->is_type_array_klass()) {
434 cik->as_array_klass()->base_element_type()->print_name_on(st);
435 st->print("[%d]", spobj->n_fields());
436 } else if (cik->is_obj_array_klass()) {
437 ciKlass* cie = cik->as_obj_array_klass()->base_element_klass();
438 if (cie->is_instance_klass()) {
439 cie->print_name_on(st);
440 } else if (cie->is_type_array_klass()) {
441 cie->as_array_klass()->base_element_type()->print_name_on(st);
442 } else {
443 ShouldNotReachHere();
444 }
445 st->print("[%d]", spobj->n_fields());
446 int ndim = cik->as_array_klass()->dimension() - 1;
447 while (ndim-- > 0) {
448 st->print("[]");
449 }
450 }
451 st->print("={");
452 uint nf = spobj->n_fields();
453 if (nf > 0) {
454 uint first_ind = spobj->first_index();
455 Node* fld_node = mcall->in(first_ind);
456 ciField* cifield;
457 if (iklass != NULL) {
458 st->print(" [");
459 cifield = iklass->nonstatic_field_at(0);
460 cifield->print_name_on(st);
461 format_helper( regalloc, st, fld_node, ":", 0, &scobjs );
462 } else {
463 format_helper( regalloc, st, fld_node, "[", 0, &scobjs );
464 }
465 for (uint j = 1; j < nf; j++) {
466 fld_node = mcall->in(first_ind+j);
467 if (iklass != NULL) {
468 st->print(", [");
469 cifield = iklass->nonstatic_field_at(j);
470 cifield->print_name_on(st);
471 format_helper( regalloc, st, fld_node, ":", j, &scobjs );
472 } else {
473 format_helper( regalloc, st, fld_node, ", [", j, &scobjs );
474 }
475 }
476 }
477 st->print(" }");
478 }
479 }
480 st->print_cr("");
481 if (caller() != NULL) caller()->format(regalloc, n, st);
482 }
483
484
485 void JVMState::dump_spec(outputStream *st) const {
486 if (_method != NULL) {
487 bool printed = false;
488 if (!Verbose) {
489 // The JVMS dumps make really, really long lines.
490 // Take out the most boring parts, which are the package prefixes.
491 char buf[500];
492 stringStream namest(buf, sizeof(buf));
493 _method->print_short_name(&namest);
494 if (namest.count() < sizeof(buf)) {
495 const char* name = namest.base();
496 if (name[0] == ' ') ++name;
497 const char* endcn = strchr(name, ':'); // end of class name
498 if (endcn == NULL) endcn = strchr(name, '(');
499 if (endcn == NULL) endcn = name + strlen(name);
500 while (endcn > name && endcn[-1] != '.' && endcn[-1] != '/')
501 --endcn;
502 st->print(" %s", endcn);
503 printed = true;
504 }
505 }
506 if (!printed)
507 _method->print_short_name(st);
508 st->print(" @ bci:%d",_bci);
509 if(_reexecute == Reexecute_True)
510 st->print(" reexecute");
511 } else {
512 st->print(" runtime stub");
513 }
514 if (caller() != NULL) caller()->dump_spec(st);
515 }
516
517
518 void JVMState::dump_on(outputStream* st) const {
519 if (_map && !((uintptr_t)_map & 1)) {
520 if (_map->len() > _map->req()) { // _map->has_exceptions()
521 Node* ex = _map->in(_map->req()); // _map->next_exception()
522 // skip the first one; it's already being printed
523 while (ex != NULL && ex->len() > ex->req()) {
524 ex = ex->in(ex->req()); // ex->next_exception()
525 ex->dump(1);
526 }
527 }
528 _map->dump(2);
529 }
530 st->print("JVMS depth=%d loc=%d stk=%d mon=%d scalar=%d end=%d mondepth=%d sp=%d bci=%d reexecute=%s method=",
531 depth(), locoff(), stkoff(), monoff(), scloff(), endoff(), monitor_depth(), sp(), bci(), should_reexecute()?"true":"false");
532 if (_method == NULL) {
533 st->print_cr("(none)");
534 } else {
535 _method->print_name(st);
536 st->cr();
537 if (bci() >= 0 && bci() < _method->code_size()) {
538 st->print(" bc: ");
539 _method->print_codes_on(bci(), bci()+1, st);
540 }
541 }
542 if (caller() != NULL) {
543 caller()->dump_on(st);
544 }
545 }
546
547 // Extra way to dump a jvms from the debugger,
548 // to avoid a bug with C++ member function calls.
549 void dump_jvms(JVMState* jvms) {
550 jvms->dump();
551 }
552 #endif
553
554 //--------------------------clone_shallow--------------------------------------
555 JVMState* JVMState::clone_shallow(Compile* C) const {
556 JVMState* n = has_method() ? new (C) JVMState(_method, _caller) : new (C) JVMState(0);
557 n->set_bci(_bci);
558 n->_reexecute = _reexecute;
559 n->set_locoff(_locoff);
560 n->set_stkoff(_stkoff);
561 n->set_monoff(_monoff);
562 n->set_scloff(_scloff);
563 n->set_endoff(_endoff);
564 n->set_sp(_sp);
565 n->set_map(_map);
566 return n;
567 }
568
569 //---------------------------clone_deep----------------------------------------
570 JVMState* JVMState::clone_deep(Compile* C) const {
571 JVMState* n = clone_shallow(C);
572 for (JVMState* p = n; p->_caller != NULL; p = p->_caller) {
573 p->_caller = p->_caller->clone_shallow(C);
574 }
575 assert(n->depth() == depth(), "sanity");
576 assert(n->debug_depth() == debug_depth(), "sanity");
577 return n;
578 }
579
580 //=============================================================================
581 uint CallNode::cmp( const Node &n ) const
582 { return _tf == ((CallNode&)n)._tf && _jvms == ((CallNode&)n)._jvms; }
583 #ifndef PRODUCT
584 void CallNode::dump_req() const {
585 // Dump the required inputs, enclosed in '(' and ')'
586 uint i; // Exit value of loop
587 for( i=0; i<req(); i++ ) { // For all required inputs
588 if( i == TypeFunc::Parms ) tty->print("(");
589 if( in(i) ) tty->print("%c%d ", Compile::current()->node_arena()->contains(in(i)) ? ' ' : 'o', in(i)->_idx);
590 else tty->print("_ ");
591 }
592 tty->print(")");
593 }
594
595 void CallNode::dump_spec(outputStream *st) const {
596 st->print(" ");
597 tf()->dump_on(st);
598 if (_cnt != COUNT_UNKNOWN) st->print(" C=%f",_cnt);
599 if (jvms() != NULL) jvms()->dump_spec(st);
600 }
601 #endif
602
603 const Type *CallNode::bottom_type() const { return tf()->range(); }
604 const Type *CallNode::Value(PhaseTransform *phase) const {
605 if (phase->type(in(0)) == Type::TOP) return Type::TOP;
606 return tf()->range();
607 }
608
609 //------------------------------calling_convention-----------------------------
610 void CallNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
611 // Use the standard compiler calling convention
612 Matcher::calling_convention( sig_bt, parm_regs, argcnt, true );
613 }
614
615
616 //------------------------------match------------------------------------------
617 // Construct projections for control, I/O, memory-fields, ..., and
618 // return result(s) along with their RegMask info
619 Node *CallNode::match( const ProjNode *proj, const Matcher *match ) {
620 switch (proj->_con) {
621 case TypeFunc::Control:
622 case TypeFunc::I_O:
623 case TypeFunc::Memory:
624 return new (match->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj);
625
626 case TypeFunc::Parms+1: // For LONG & DOUBLE returns
627 assert(tf()->_range->field_at(TypeFunc::Parms+1) == Type::HALF, "");
628 // 2nd half of doubles and longs
629 return new (match->C, 1) MachProjNode(this,proj->_con, RegMask::Empty, (uint)OptoReg::Bad);
630
631 case TypeFunc::Parms: { // Normal returns
632 uint ideal_reg = Matcher::base2reg[tf()->range()->field_at(TypeFunc::Parms)->base()];
633 OptoRegPair regs = is_CallRuntime()
634 ? match->c_return_value(ideal_reg,true) // Calls into C runtime
635 : match-> return_value(ideal_reg,true); // Calls into compiled Java code
636 RegMask rm = RegMask(regs.first());
637 if( OptoReg::is_valid(regs.second()) )
638 rm.Insert( regs.second() );
639 return new (match->C, 1) MachProjNode(this,proj->_con,rm,ideal_reg);
640 }
641
642 case TypeFunc::ReturnAdr:
643 case TypeFunc::FramePtr:
644 default:
645 ShouldNotReachHere();
646 }
647 return NULL;
648 }
649
650 // Do we Match on this edge index or not? Match no edges
651 uint CallNode::match_edge(uint idx) const {
652 return 0;
653 }
654
655 //
656 // Determine whether the call could modify the field of the specified
657 // instance at the specified offset.
658 //
659 bool CallNode::may_modify(const TypePtr *addr_t, PhaseTransform *phase) {
660 const TypeOopPtr *adrInst_t = addr_t->isa_oopptr();
661
662 // If not an OopPtr or not an instance type, assume the worst.
663 // Note: currently this method is called only for instance types.
664 if (adrInst_t == NULL || !adrInst_t->is_known_instance()) {
665 return true;
666 }
667 // The instance_id is set only for scalar-replaceable allocations which
668 // are not passed as arguments according to Escape Analysis.
669 return false;
670 }
671
672 // Does this call have a direct reference to n other than debug information?
673 bool CallNode::has_non_debug_use(Node *n) {
674 const TypeTuple * d = tf()->domain();
675 for (uint i = TypeFunc::Parms; i < d->cnt(); i++) {
676 Node *arg = in(i);
677 if (arg == n) {
678 return true;
679 }
680 }
681 return false;
682 }
683
684 // Returns the unique CheckCastPP of a call
685 // or 'this' if there are several CheckCastPP
686 // or returns NULL if there is no one.
687 Node *CallNode::result_cast() {
688 Node *cast = NULL;
689
690 Node *p = proj_out(TypeFunc::Parms);
691 if (p == NULL)
692 return NULL;
693
694 for (DUIterator_Fast imax, i = p->fast_outs(imax); i < imax; i++) {
695 Node *use = p->fast_out(i);
696 if (use->is_CheckCastPP()) {
697 if (cast != NULL) {
698 return this; // more than 1 CheckCastPP
699 }
700 cast = use;
701 }
702 }
703 return cast;
704 }
705
706
707 void CallNode::extract_projections(CallProjections* projs, bool separate_io_proj) {
708 projs->fallthrough_proj = NULL;
709 projs->fallthrough_catchproj = NULL;
710 projs->fallthrough_ioproj = NULL;
711 projs->catchall_ioproj = NULL;
712 projs->catchall_catchproj = NULL;
713 projs->fallthrough_memproj = NULL;
714 projs->catchall_memproj = NULL;
715 projs->resproj = NULL;
716 projs->exobj = NULL;
717
718 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
719 ProjNode *pn = fast_out(i)->as_Proj();
720 if (pn->outcnt() == 0) continue;
721 switch (pn->_con) {
722 case TypeFunc::Control:
723 {
724 // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
725 projs->fallthrough_proj = pn;
726 DUIterator_Fast jmax, j = pn->fast_outs(jmax);
727 const Node *cn = pn->fast_out(j);
728 if (cn->is_Catch()) {
729 ProjNode *cpn = NULL;
730 for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
731 cpn = cn->fast_out(k)->as_Proj();
732 assert(cpn->is_CatchProj(), "must be a CatchProjNode");
733 if (cpn->_con == CatchProjNode::fall_through_index)
734 projs->fallthrough_catchproj = cpn;
735 else {
736 assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
737 projs->catchall_catchproj = cpn;
738 }
739 }
740 }
741 break;
742 }
743 case TypeFunc::I_O:
744 if (pn->_is_io_use)
745 projs->catchall_ioproj = pn;
746 else
747 projs->fallthrough_ioproj = pn;
748 for (DUIterator j = pn->outs(); pn->has_out(j); j++) {
749 Node* e = pn->out(j);
750 if (e->Opcode() == Op_CreateEx && e->in(0)->is_CatchProj()) {
751 assert(projs->exobj == NULL, "only one");
752 projs->exobj = e;
753 }
754 }
755 break;
756 case TypeFunc::Memory:
757 if (pn->_is_io_use)
758 projs->catchall_memproj = pn;
759 else
760 projs->fallthrough_memproj = pn;
761 break;
762 case TypeFunc::Parms:
763 projs->resproj = pn;
764 break;
765 default:
766 assert(false, "unexpected projection from allocation node.");
767 }
768 }
769
770 // The resproj may not exist because the result couuld be ignored
771 // and the exception object may not exist if an exception handler
772 // swallows the exception but all the other must exist and be found.
773 assert(projs->fallthrough_proj != NULL, "must be found");
774 assert(projs->fallthrough_catchproj != NULL, "must be found");
775 assert(projs->fallthrough_memproj != NULL, "must be found");
776 assert(projs->fallthrough_ioproj != NULL, "must be found");
777 assert(projs->catchall_catchproj != NULL, "must be found");
778 if (separate_io_proj) {
779 assert(projs->catchall_memproj != NULL, "must be found");
780 assert(projs->catchall_ioproj != NULL, "must be found");
781 }
782 }
783
784
785 //=============================================================================
786 uint CallJavaNode::size_of() const { return sizeof(*this); }
787 uint CallJavaNode::cmp( const Node &n ) const {
788 CallJavaNode &call = (CallJavaNode&)n;
789 return CallNode::cmp(call) && _method == call._method;
790 }
791 #ifndef PRODUCT
792 void CallJavaNode::dump_spec(outputStream *st) const {
793 if( _method ) _method->print_short_name(st);
794 CallNode::dump_spec(st);
795 }
796 #endif
797
798 //=============================================================================
799 uint CallStaticJavaNode::size_of() const { return sizeof(*this); }
800 uint CallStaticJavaNode::cmp( const Node &n ) const {
801 CallStaticJavaNode &call = (CallStaticJavaNode&)n;
802 return CallJavaNode::cmp(call);
803 }
804
805 //----------------------------uncommon_trap_request----------------------------
806 // If this is an uncommon trap, return the request code, else zero.
807 int CallStaticJavaNode::uncommon_trap_request() const {
808 if (_name != NULL && !strcmp(_name, "uncommon_trap")) {
809 return extract_uncommon_trap_request(this);
810 }
811 return 0;
812 }
813 int CallStaticJavaNode::extract_uncommon_trap_request(const Node* call) {
814 #ifndef PRODUCT
815 if (!(call->req() > TypeFunc::Parms &&
816 call->in(TypeFunc::Parms) != NULL &&
817 call->in(TypeFunc::Parms)->is_Con())) {
818 assert(_in_dump_cnt != 0, "OK if dumping");
819 tty->print("[bad uncommon trap]");
820 return 0;
821 }
822 #endif
823 return call->in(TypeFunc::Parms)->bottom_type()->is_int()->get_con();
824 }
825
826 #ifndef PRODUCT
827 void CallStaticJavaNode::dump_spec(outputStream *st) const {
828 st->print("# Static ");
829 if (_name != NULL) {
830 st->print("%s", _name);
831 int trap_req = uncommon_trap_request();
832 if (trap_req != 0) {
833 char buf[100];
834 st->print("(%s)",
835 Deoptimization::format_trap_request(buf, sizeof(buf),
836 trap_req));
837 }
838 st->print(" ");
839 }
840 CallJavaNode::dump_spec(st);
841 }
842 #endif
843
844 //=============================================================================
845 uint CallDynamicJavaNode::size_of() const { return sizeof(*this); }
846 uint CallDynamicJavaNode::cmp( const Node &n ) const {
847 CallDynamicJavaNode &call = (CallDynamicJavaNode&)n;
848 return CallJavaNode::cmp(call);
849 }
850 #ifndef PRODUCT
851 void CallDynamicJavaNode::dump_spec(outputStream *st) const {
852 st->print("# Dynamic ");
853 CallJavaNode::dump_spec(st);
854 }
855 #endif
856
857 //=============================================================================
858 uint CallRuntimeNode::size_of() const { return sizeof(*this); }
859 uint CallRuntimeNode::cmp( const Node &n ) const {
860 CallRuntimeNode &call = (CallRuntimeNode&)n;
861 return CallNode::cmp(call) && !strcmp(_name,call._name);
862 }
863 #ifndef PRODUCT
864 void CallRuntimeNode::dump_spec(outputStream *st) const {
865 st->print("# ");
866 st->print(_name);
867 CallNode::dump_spec(st);
868 }
869 #endif
870
871 //------------------------------calling_convention-----------------------------
872 void CallRuntimeNode::calling_convention( BasicType* sig_bt, VMRegPair *parm_regs, uint argcnt ) const {
873 Matcher::c_calling_convention( sig_bt, parm_regs, argcnt );
874 }
875
876 //=============================================================================
877 //------------------------------calling_convention-----------------------------
878
879
880 //=============================================================================
881 #ifndef PRODUCT
882 void CallLeafNode::dump_spec(outputStream *st) const {
883 st->print("# ");
884 st->print(_name);
885 CallNode::dump_spec(st);
886 }
887 #endif
888
889 //=============================================================================
890
891 void SafePointNode::set_local(JVMState* jvms, uint idx, Node *c) {
892 assert(verify_jvms(jvms), "jvms must match");
893 int loc = jvms->locoff() + idx;
894 if (in(loc)->is_top() && idx > 0 && !c->is_top() ) {
895 // If current local idx is top then local idx - 1 could
896 // be a long/double that needs to be killed since top could
897 // represent the 2nd half ofthe long/double.
898 uint ideal = in(loc -1)->ideal_reg();
899 if (ideal == Op_RegD || ideal == Op_RegL) {
900 // set other (low index) half to top
901 set_req(loc - 1, in(loc));
902 }
903 }
904 set_req(loc, c);
905 }
906
907 uint SafePointNode::size_of() const { return sizeof(*this); }
908 uint SafePointNode::cmp( const Node &n ) const {
909 return (&n == this); // Always fail except on self
910 }
911
912 //-------------------------set_next_exception----------------------------------
913 void SafePointNode::set_next_exception(SafePointNode* n) {
914 assert(n == NULL || n->Opcode() == Op_SafePoint, "correct value for next_exception");
915 if (len() == req()) {
916 if (n != NULL) add_prec(n);
917 } else {
918 set_prec(req(), n);
919 }
920 }
921
922
923 //----------------------------next_exception-----------------------------------
924 SafePointNode* SafePointNode::next_exception() const {
925 if (len() == req()) {
926 return NULL;
927 } else {
928 Node* n = in(req());
929 assert(n == NULL || n->Opcode() == Op_SafePoint, "no other uses of prec edges");
930 return (SafePointNode*) n;
931 }
932 }
933
934
935 //------------------------------Ideal------------------------------------------
936 // Skip over any collapsed Regions
937 Node *SafePointNode::Ideal(PhaseGVN *phase, bool can_reshape) {
938 return remove_dead_region(phase, can_reshape) ? this : NULL;
939 }
940
941 //------------------------------Identity---------------------------------------
942 // Remove obviously duplicate safepoints
943 Node *SafePointNode::Identity( PhaseTransform *phase ) {
944
945 // If you have back to back safepoints, remove one
946 if( in(TypeFunc::Control)->is_SafePoint() )
947 return in(TypeFunc::Control);
948
949 if( in(0)->is_Proj() ) {
950 Node *n0 = in(0)->in(0);
951 // Check if he is a call projection (except Leaf Call)
952 if( n0->is_Catch() ) {
953 n0 = n0->in(0)->in(0);
954 assert( n0->is_Call(), "expect a call here" );
955 }
956 if( n0->is_Call() && n0->as_Call()->guaranteed_safepoint() ) {
957 // Useless Safepoint, so remove it
958 return in(TypeFunc::Control);
959 }
960 }
961
962 return this;
963 }
964
965 //------------------------------Value------------------------------------------
966 const Type *SafePointNode::Value( PhaseTransform *phase ) const {
967 if( phase->type(in(0)) == Type::TOP ) return Type::TOP;
968 if( phase->eqv( in(0), this ) ) return Type::TOP; // Dead infinite loop
969 return Type::CONTROL;
970 }
971
972 #ifndef PRODUCT
973 void SafePointNode::dump_spec(outputStream *st) const {
974 st->print(" SafePoint ");
975 }
976 #endif
977
978 const RegMask &SafePointNode::in_RegMask(uint idx) const {
979 if( idx < TypeFunc::Parms ) return RegMask::Empty;
980 // Values outside the domain represent debug info
981 return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
982 }
983 const RegMask &SafePointNode::out_RegMask() const {
984 return RegMask::Empty;
985 }
986
987
988 void SafePointNode::grow_stack(JVMState* jvms, uint grow_by) {
989 assert((int)grow_by > 0, "sanity");
990 int monoff = jvms->monoff();
991 int scloff = jvms->scloff();
992 int endoff = jvms->endoff();
993 assert(endoff == (int)req(), "no other states or debug info after me");
994 Node* top = Compile::current()->top();
995 for (uint i = 0; i < grow_by; i++) {
996 ins_req(monoff, top);
997 }
998 jvms->set_monoff(monoff + grow_by);
999 jvms->set_scloff(scloff + grow_by);
1000 jvms->set_endoff(endoff + grow_by);
1001 }
1002
1003 void SafePointNode::push_monitor(const FastLockNode *lock) {
1004 // Add a LockNode, which points to both the original BoxLockNode (the
1005 // stack space for the monitor) and the Object being locked.
1006 const int MonitorEdges = 2;
1007 assert(JVMState::logMonitorEdges == exact_log2(MonitorEdges), "correct MonitorEdges");
1008 assert(req() == jvms()->endoff(), "correct sizing");
1009 int nextmon = jvms()->scloff();
1010 if (GenerateSynchronizationCode) {
1011 add_req(lock->box_node());
1012 add_req(lock->obj_node());
1013 } else {
1014 Node* top = Compile::current()->top();
1015 add_req(top);
1016 add_req(top);
1017 }
1018 jvms()->set_scloff(nextmon+MonitorEdges);
1019 jvms()->set_endoff(req());
1020 }
1021
1022 void SafePointNode::pop_monitor() {
1023 // Delete last monitor from debug info
1024 debug_only(int num_before_pop = jvms()->nof_monitors());
1025 const int MonitorEdges = (1<<JVMState::logMonitorEdges);
1026 int scloff = jvms()->scloff();
1027 int endoff = jvms()->endoff();
1028 int new_scloff = scloff - MonitorEdges;
1029 int new_endoff = endoff - MonitorEdges;
1030 jvms()->set_scloff(new_scloff);
1031 jvms()->set_endoff(new_endoff);
1032 while (scloff > new_scloff) del_req(--scloff);
1033 assert(jvms()->nof_monitors() == num_before_pop-1, "");
1034 }
1035
1036 Node *SafePointNode::peek_monitor_box() const {
1037 int mon = jvms()->nof_monitors() - 1;
1038 assert(mon >= 0, "most have a monitor");
1039 return monitor_box(jvms(), mon);
1040 }
1041
1042 Node *SafePointNode::peek_monitor_obj() const {
1043 int mon = jvms()->nof_monitors() - 1;
1044 assert(mon >= 0, "most have a monitor");
1045 return monitor_obj(jvms(), mon);
1046 }
1047
1048 // Do we Match on this edge index or not? Match no edges
1049 uint SafePointNode::match_edge(uint idx) const {
1050 if( !needs_polling_address_input() )
1051 return 0;
1052
1053 return (TypeFunc::Parms == idx);
1054 }
1055
1056 //============== SafePointScalarObjectNode ==============
1057
1058 SafePointScalarObjectNode::SafePointScalarObjectNode(const TypeOopPtr* tp,
1059 #ifdef ASSERT
1060 AllocateNode* alloc,
1061 #endif
1062 uint first_index,
1063 uint n_fields) :
1064 TypeNode(tp, 1), // 1 control input -- seems required. Get from root.
1065 #ifdef ASSERT
1066 _alloc(alloc),
1067 #endif
1068 _first_index(first_index),
1069 _n_fields(n_fields)
1070 {
1071 init_class_id(Class_SafePointScalarObject);
1072 }
1073
1074 bool SafePointScalarObjectNode::pinned() const { return true; }
1075 bool SafePointScalarObjectNode::depends_only_on_test() const { return false; }
1076
1077 uint SafePointScalarObjectNode::ideal_reg() const {
1078 return 0; // No matching to machine instruction
1079 }
1080
1081 const RegMask &SafePointScalarObjectNode::in_RegMask(uint idx) const {
1082 return *(Compile::current()->matcher()->idealreg2debugmask[in(idx)->ideal_reg()]);
1083 }
1084
1085 const RegMask &SafePointScalarObjectNode::out_RegMask() const {
1086 return RegMask::Empty;
1087 }
1088
1089 uint SafePointScalarObjectNode::match_edge(uint idx) const {
1090 return 0;
1091 }
1092
1093 SafePointScalarObjectNode*
1094 SafePointScalarObjectNode::clone(int jvms_adj, Dict* sosn_map) const {
1095 void* cached = (*sosn_map)[(void*)this];
1096 if (cached != NULL) {
1097 return (SafePointScalarObjectNode*)cached;
1098 }
1099 Compile* C = Compile::current();
1100 SafePointScalarObjectNode* res = (SafePointScalarObjectNode*)Node::clone();
1101 res->_first_index += jvms_adj;
1102 sosn_map->Insert((void*)this, (void*)res);
1103 return res;
1104 }
1105
1106
1107 #ifndef PRODUCT
1108 void SafePointScalarObjectNode::dump_spec(outputStream *st) const {
1109 st->print(" # fields@[%d..%d]", first_index(),
1110 first_index() + n_fields() - 1);
1111 }
1112
1113 #endif
1114
1115 //=============================================================================
1116 uint AllocateNode::size_of() const { return sizeof(*this); }
1117
1118 AllocateNode::AllocateNode(Compile* C, const TypeFunc *atype,
1119 Node *ctrl, Node *mem, Node *abio,
1120 Node *size, Node *klass_node, Node *initial_test)
1121 : CallNode(atype, NULL, TypeRawPtr::BOTTOM)
1122 {
1123 init_class_id(Class_Allocate);
1124 init_flags(Flag_is_macro);
1125 _is_scalar_replaceable = false;
1126 Node *topnode = C->top();
1127
1128 init_req( TypeFunc::Control , ctrl );
1129 init_req( TypeFunc::I_O , abio );
1130 init_req( TypeFunc::Memory , mem );
1131 init_req( TypeFunc::ReturnAdr, topnode );
1132 init_req( TypeFunc::FramePtr , topnode );
1133 init_req( AllocSize , size);
1134 init_req( KlassNode , klass_node);
1135 init_req( InitialTest , initial_test);
1136 init_req( ALength , topnode);
1137 C->add_macro_node(this);
1138 }
1139
1140 //=============================================================================
1141 uint AllocateArrayNode::size_of() const { return sizeof(*this); }
1142
1143 Node* AllocateArrayNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1144 if (remove_dead_region(phase, can_reshape)) return this;
1145
1146 const Type* type = phase->type(Ideal_length());
1147 if (type->isa_int() && type->is_int()->_hi < 0) {
1148 if (can_reshape) {
1149 PhaseIterGVN *igvn = phase->is_IterGVN();
1150 // Unreachable fall through path (negative array length),
1151 // the allocation can only throw so disconnect it.
1152 Node* proj = proj_out(TypeFunc::Control);
1153 Node* catchproj = NULL;
1154 if (proj != NULL) {
1155 for (DUIterator_Fast imax, i = proj->fast_outs(imax); i < imax; i++) {
1156 Node *cn = proj->fast_out(i);
1157 if (cn->is_Catch()) {
1158 catchproj = cn->as_Multi()->proj_out(CatchProjNode::fall_through_index);
1159 break;
1160 }
1161 }
1162 }
1163 if (catchproj != NULL && catchproj->outcnt() > 0 &&
1164 (catchproj->outcnt() > 1 ||
1165 catchproj->unique_out()->Opcode() != Op_Halt)) {
1166 assert(catchproj->is_CatchProj(), "must be a CatchProjNode");
1167 Node* nproj = catchproj->clone();
1168 igvn->register_new_node_with_optimizer(nproj);
1169
1170 Node *frame = new (phase->C, 1) ParmNode( phase->C->start(), TypeFunc::FramePtr );
1171 frame = phase->transform(frame);
1172 // Halt & Catch Fire
1173 Node *halt = new (phase->C, TypeFunc::Parms) HaltNode( nproj, frame );
1174 phase->C->root()->add_req(halt);
1175 phase->transform(halt);
1176
1177 igvn->replace_node(catchproj, phase->C->top());
1178 return this;
1179 }
1180 } else {
1181 // Can't correct it during regular GVN so register for IGVN
1182 phase->C->record_for_igvn(this);
1183 }
1184 }
1185 return NULL;
1186 }
1187
1188 // Retrieve the length from the AllocateArrayNode. Narrow the type with a
1189 // CastII, if appropriate. If we are not allowed to create new nodes, and
1190 // a CastII is appropriate, return NULL.
1191 Node *AllocateArrayNode::make_ideal_length(const TypeOopPtr* oop_type, PhaseTransform *phase, bool allow_new_nodes) {
1192 Node *length = in(AllocateNode::ALength);
1193 assert(length != NULL, "length is not null");
1194
1195 const TypeInt* length_type = phase->find_int_type(length);
1196 const TypeAryPtr* ary_type = oop_type->isa_aryptr();
1197
1198 if (ary_type != NULL && length_type != NULL) {
1199 const TypeInt* narrow_length_type = ary_type->narrow_size_type(length_type);
1200 if (narrow_length_type != length_type) {
1201 // Assert one of:
1202 // - the narrow_length is 0
1203 // - the narrow_length is not wider than length
1204 assert(narrow_length_type == TypeInt::ZERO ||
1205 (narrow_length_type->_hi <= length_type->_hi &&
1206 narrow_length_type->_lo >= length_type->_lo),
1207 "narrow type must be narrower than length type");
1208
1209 // Return NULL if new nodes are not allowed
1210 if (!allow_new_nodes) return NULL;
1211 // Create a cast which is control dependent on the initialization to
1212 // propagate the fact that the array length must be positive.
1213 length = new (phase->C, 2) CastIINode(length, narrow_length_type);
1214 length->set_req(0, initialization()->proj_out(0));
1215 }
1216 }
1217
1218 return length;
1219 }
1220
1221 //=============================================================================
1222 uint LockNode::size_of() const { return sizeof(*this); }
1223
1224 // Redundant lock elimination
1225 //
1226 // There are various patterns of locking where we release and
1227 // immediately reacquire a lock in a piece of code where no operations
1228 // occur in between that would be observable. In those cases we can
1229 // skip releasing and reacquiring the lock without violating any
1230 // fairness requirements. Doing this around a loop could cause a lock
1231 // to be held for a very long time so we concentrate on non-looping
1232 // control flow. We also require that the operations are fully
1233 // redundant meaning that we don't introduce new lock operations on
1234 // some paths so to be able to eliminate it on others ala PRE. This
1235 // would probably require some more extensive graph manipulation to
1236 // guarantee that the memory edges were all handled correctly.
1237 //
1238 // Assuming p is a simple predicate which can't trap in any way and s
1239 // is a synchronized method consider this code:
1240 //
1241 // s();
1242 // if (p)
1243 // s();
1244 // else
1245 // s();
1246 // s();
1247 //
1248 // 1. The unlocks of the first call to s can be eliminated if the
1249 // locks inside the then and else branches are eliminated.
1250 //
1251 // 2. The unlocks of the then and else branches can be eliminated if
1252 // the lock of the final call to s is eliminated.
1253 //
1254 // Either of these cases subsumes the simple case of sequential control flow
1255 //
1256 // Addtionally we can eliminate versions without the else case:
1257 //
1258 // s();
1259 // if (p)
1260 // s();
1261 // s();
1262 //
1263 // 3. In this case we eliminate the unlock of the first s, the lock
1264 // and unlock in the then case and the lock in the final s.
1265 //
1266 // Note also that in all these cases the then/else pieces don't have
1267 // to be trivial as long as they begin and end with synchronization
1268 // operations.
1269 //
1270 // s();
1271 // if (p)
1272 // s();
1273 // f();
1274 // s();
1275 // s();
1276 //
1277 // The code will work properly for this case, leaving in the unlock
1278 // before the call to f and the relock after it.
1279 //
1280 // A potentially interesting case which isn't handled here is when the
1281 // locking is partially redundant.
1282 //
1283 // s();
1284 // if (p)
1285 // s();
1286 //
1287 // This could be eliminated putting unlocking on the else case and
1288 // eliminating the first unlock and the lock in the then side.
1289 // Alternatively the unlock could be moved out of the then side so it
1290 // was after the merge and the first unlock and second lock
1291 // eliminated. This might require less manipulation of the memory
1292 // state to get correct.
1293 //
1294 // Additionally we might allow work between a unlock and lock before
1295 // giving up eliminating the locks. The current code disallows any
1296 // conditional control flow between these operations. A formulation
1297 // similar to partial redundancy elimination computing the
1298 // availability of unlocking and the anticipatability of locking at a
1299 // program point would allow detection of fully redundant locking with
1300 // some amount of work in between. I'm not sure how often I really
1301 // think that would occur though. Most of the cases I've seen
1302 // indicate it's likely non-trivial work would occur in between.
1303 // There may be other more complicated constructs where we could
1304 // eliminate locking but I haven't seen any others appear as hot or
1305 // interesting.
1306 //
1307 // Locking and unlocking have a canonical form in ideal that looks
1308 // roughly like this:
1309 //
1310 // <obj>
1311 // | \\------+
1312 // | \ \
1313 // | BoxLock \
1314 // | | | \
1315 // | | \ \
1316 // | | FastLock
1317 // | | /
1318 // | | /
1319 // | | |
1320 //
1321 // Lock
1322 // |
1323 // Proj #0
1324 // |
1325 // MembarAcquire
1326 // |
1327 // Proj #0
1328 //
1329 // MembarRelease
1330 // |
1331 // Proj #0
1332 // |
1333 // Unlock
1334 // |
1335 // Proj #0
1336 //
1337 //
1338 // This code proceeds by processing Lock nodes during PhaseIterGVN
1339 // and searching back through its control for the proper code
1340 // patterns. Once it finds a set of lock and unlock operations to
1341 // eliminate they are marked as eliminatable which causes the
1342 // expansion of the Lock and Unlock macro nodes to make the operation a NOP
1343 //
1344 //=============================================================================
1345
1346 //
1347 // Utility function to skip over uninteresting control nodes. Nodes skipped are:
1348 // - copy regions. (These may not have been optimized away yet.)
1349 // - eliminated locking nodes
1350 //
1351 static Node *next_control(Node *ctrl) {
1352 if (ctrl == NULL)
1353 return NULL;
1354 while (1) {
1355 if (ctrl->is_Region()) {
1356 RegionNode *r = ctrl->as_Region();
1357 Node *n = r->is_copy();
1358 if (n == NULL)
1359 break; // hit a region, return it
1360 else
1361 ctrl = n;
1362 } else if (ctrl->is_Proj()) {
1363 Node *in0 = ctrl->in(0);
1364 if (in0->is_AbstractLock() && in0->as_AbstractLock()->is_eliminated()) {
1365 ctrl = in0->in(0);
1366 } else {
1367 break;
1368 }
1369 } else {
1370 break; // found an interesting control
1371 }
1372 }
1373 return ctrl;
1374 }
1375 //
1376 // Given a control, see if it's the control projection of an Unlock which
1377 // operating on the same object as lock.
1378 //
1379 bool AbstractLockNode::find_matching_unlock(const Node* ctrl, LockNode* lock,
1380 GrowableArray<AbstractLockNode*> &lock_ops) {
1381 ProjNode *ctrl_proj = (ctrl->is_Proj()) ? ctrl->as_Proj() : NULL;
1382 if (ctrl_proj != NULL && ctrl_proj->_con == TypeFunc::Control) {
1383 Node *n = ctrl_proj->in(0);
1384 if (n != NULL && n->is_Unlock()) {
1385 UnlockNode *unlock = n->as_Unlock();
1386 if ((lock->obj_node() == unlock->obj_node()) &&
1387 (lock->box_node() == unlock->box_node()) && !unlock->is_eliminated()) {
1388 lock_ops.append(unlock);
1389 return true;
1390 }
1391 }
1392 }
1393 return false;
1394 }
1395
1396 //
1397 // Find the lock matching an unlock. Returns null if a safepoint
1398 // or complicated control is encountered first.
1399 LockNode *AbstractLockNode::find_matching_lock(UnlockNode* unlock) {
1400 LockNode *lock_result = NULL;
1401 // find the matching lock, or an intervening safepoint
1402 Node *ctrl = next_control(unlock->in(0));
1403 while (1) {
1404 assert(ctrl != NULL, "invalid control graph");
1405 assert(!ctrl->is_Start(), "missing lock for unlock");
1406 if (ctrl->is_top()) break; // dead control path
1407 if (ctrl->is_Proj()) ctrl = ctrl->in(0);
1408 if (ctrl->is_SafePoint()) {
1409 break; // found a safepoint (may be the lock we are searching for)
1410 } else if (ctrl->is_Region()) {
1411 // Check for a simple diamond pattern. Punt on anything more complicated
1412 if (ctrl->req() == 3 && ctrl->in(1) != NULL && ctrl->in(2) != NULL) {
1413 Node *in1 = next_control(ctrl->in(1));
1414 Node *in2 = next_control(ctrl->in(2));
1415 if (((in1->is_IfTrue() && in2->is_IfFalse()) ||
1416 (in2->is_IfTrue() && in1->is_IfFalse())) && (in1->in(0) == in2->in(0))) {
1417 ctrl = next_control(in1->in(0)->in(0));
1418 } else {
1419 break;
1420 }
1421 } else {
1422 break;
1423 }
1424 } else {
1425 ctrl = next_control(ctrl->in(0)); // keep searching
1426 }
1427 }
1428 if (ctrl->is_Lock()) {
1429 LockNode *lock = ctrl->as_Lock();
1430 if ((lock->obj_node() == unlock->obj_node()) &&
1431 (lock->box_node() == unlock->box_node())) {
1432 lock_result = lock;
1433 }
1434 }
1435 return lock_result;
1436 }
1437
1438 // This code corresponds to case 3 above.
1439
1440 bool AbstractLockNode::find_lock_and_unlock_through_if(Node* node, LockNode* lock,
1441 GrowableArray<AbstractLockNode*> &lock_ops) {
1442 Node* if_node = node->in(0);
1443 bool if_true = node->is_IfTrue();
1444
1445 if (if_node->is_If() && if_node->outcnt() == 2 && (if_true || node->is_IfFalse())) {
1446 Node *lock_ctrl = next_control(if_node->in(0));
1447 if (find_matching_unlock(lock_ctrl, lock, lock_ops)) {
1448 Node* lock1_node = NULL;
1449 ProjNode* proj = if_node->as_If()->proj_out(!if_true);
1450 if (if_true) {
1451 if (proj->is_IfFalse() && proj->outcnt() == 1) {
1452 lock1_node = proj->unique_out();
1453 }
1454 } else {
1455 if (proj->is_IfTrue() && proj->outcnt() == 1) {
1456 lock1_node = proj->unique_out();
1457 }
1458 }
1459 if (lock1_node != NULL && lock1_node->is_Lock()) {
1460 LockNode *lock1 = lock1_node->as_Lock();
1461 if ((lock->obj_node() == lock1->obj_node()) &&
1462 (lock->box_node() == lock1->box_node()) && !lock1->is_eliminated()) {
1463 lock_ops.append(lock1);
1464 return true;
1465 }
1466 }
1467 }
1468 }
1469
1470 lock_ops.trunc_to(0);
1471 return false;
1472 }
1473
1474 bool AbstractLockNode::find_unlocks_for_region(const RegionNode* region, LockNode* lock,
1475 GrowableArray<AbstractLockNode*> &lock_ops) {
1476 // check each control merging at this point for a matching unlock.
1477 // in(0) should be self edge so skip it.
1478 for (int i = 1; i < (int)region->req(); i++) {
1479 Node *in_node = next_control(region->in(i));
1480 if (in_node != NULL) {
1481 if (find_matching_unlock(in_node, lock, lock_ops)) {
1482 // found a match so keep on checking.
1483 continue;
1484 } else if (find_lock_and_unlock_through_if(in_node, lock, lock_ops)) {
1485 continue;
1486 }
1487
1488 // If we fall through to here then it was some kind of node we
1489 // don't understand or there wasn't a matching unlock, so give
1490 // up trying to merge locks.
1491 lock_ops.trunc_to(0);
1492 return false;
1493 }
1494 }
1495 return true;
1496
1497 }
1498
1499 #ifndef PRODUCT
1500 //
1501 // Create a counter which counts the number of times this lock is acquired
1502 //
1503 void AbstractLockNode::create_lock_counter(JVMState* state) {
1504 _counter = OptoRuntime::new_named_counter(state, NamedCounter::LockCounter);
1505 }
1506 #endif
1507
1508 void AbstractLockNode::set_eliminated() {
1509 _eliminate = true;
1510 #ifndef PRODUCT
1511 if (_counter) {
1512 // Update the counter to indicate that this lock was eliminated.
1513 // The counter update code will stay around even though the
1514 // optimizer will eliminate the lock operation itself.
1515 _counter->set_tag(NamedCounter::EliminatedLockCounter);
1516 }
1517 #endif
1518 }
1519
1520 //=============================================================================
1521 Node *LockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1522
1523 // perform any generic optimizations first (returns 'this' or NULL)
1524 Node *result = SafePointNode::Ideal(phase, can_reshape);
1525
1526 // Now see if we can optimize away this lock. We don't actually
1527 // remove the locking here, we simply set the _eliminate flag which
1528 // prevents macro expansion from expanding the lock. Since we don't
1529 // modify the graph, the value returned from this function is the
1530 // one computed above.
1531 if (result == NULL && can_reshape && EliminateLocks && !is_eliminated()) {
1532 //
1533 // If we are locking an unescaped object, the lock/unlock is unnecessary
1534 //
1535 ConnectionGraph *cgr = phase->C->congraph();
1536 PointsToNode::EscapeState es = PointsToNode::GlobalEscape;
1537 if (cgr != NULL)
1538 es = cgr->escape_state(obj_node());
1539 if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
1540 // Mark it eliminated to update any counters
1541 this->set_eliminated();
1542 return result;
1543 }
1544
1545 //
1546 // Try lock coarsening
1547 //
1548 PhaseIterGVN* iter = phase->is_IterGVN();
1549 if (iter != NULL) {
1550
1551 GrowableArray<AbstractLockNode*> lock_ops;
1552
1553 Node *ctrl = next_control(in(0));
1554
1555 // now search back for a matching Unlock
1556 if (find_matching_unlock(ctrl, this, lock_ops)) {
1557 // found an unlock directly preceding this lock. This is the
1558 // case of single unlock directly control dependent on a
1559 // single lock which is the trivial version of case 1 or 2.
1560 } else if (ctrl->is_Region() ) {
1561 if (find_unlocks_for_region(ctrl->as_Region(), this, lock_ops)) {
1562 // found lock preceded by multiple unlocks along all paths
1563 // joining at this point which is case 3 in description above.
1564 }
1565 } else {
1566 // see if this lock comes from either half of an if and the
1567 // predecessors merges unlocks and the other half of the if
1568 // performs a lock.
1569 if (find_lock_and_unlock_through_if(ctrl, this, lock_ops)) {
1570 // found unlock splitting to an if with locks on both branches.
1571 }
1572 }
1573
1574 if (lock_ops.length() > 0) {
1575 // add ourselves to the list of locks to be eliminated.
1576 lock_ops.append(this);
1577
1578 #ifndef PRODUCT
1579 if (PrintEliminateLocks) {
1580 int locks = 0;
1581 int unlocks = 0;
1582 for (int i = 0; i < lock_ops.length(); i++) {
1583 AbstractLockNode* lock = lock_ops.at(i);
1584 if (lock->Opcode() == Op_Lock)
1585 locks++;
1586 else
1587 unlocks++;
1588 if (Verbose) {
1589 lock->dump(1);
1590 }
1591 }
1592 tty->print_cr("***Eliminated %d unlocks and %d locks", unlocks, locks);
1593 }
1594 #endif
1595
1596 // for each of the identified locks, mark them
1597 // as eliminatable
1598 for (int i = 0; i < lock_ops.length(); i++) {
1599 AbstractLockNode* lock = lock_ops.at(i);
1600
1601 // Mark it eliminated to update any counters
1602 lock->set_eliminated();
1603 lock->set_coarsened();
1604 }
1605 } else if (result != NULL && ctrl->is_Region() &&
1606 iter->_worklist.member(ctrl)) {
1607 // We weren't able to find any opportunities but the region this
1608 // lock is control dependent on hasn't been processed yet so put
1609 // this lock back on the worklist so we can check again once any
1610 // region simplification has occurred.
1611 iter->_worklist.push(this);
1612 }
1613 }
1614 }
1615
1616 return result;
1617 }
1618
1619 //=============================================================================
1620 uint UnlockNode::size_of() const { return sizeof(*this); }
1621
1622 //=============================================================================
1623 Node *UnlockNode::Ideal(PhaseGVN *phase, bool can_reshape) {
1624
1625 // perform any generic optimizations first (returns 'this' or NULL)
1626 Node * result = SafePointNode::Ideal(phase, can_reshape);
1627
1628 // Now see if we can optimize away this unlock. We don't actually
1629 // remove the unlocking here, we simply set the _eliminate flag which
1630 // prevents macro expansion from expanding the unlock. Since we don't
1631 // modify the graph, the value returned from this function is the
1632 // one computed above.
1633 // Escape state is defined after Parse phase.
1634 if (result == NULL && can_reshape && EliminateLocks && !is_eliminated()) {
1635 //
1636 // If we are unlocking an unescaped object, the lock/unlock is unnecessary.
1637 //
1638 ConnectionGraph *cgr = phase->C->congraph();
1639 PointsToNode::EscapeState es = PointsToNode::GlobalEscape;
1640 if (cgr != NULL)
1641 es = cgr->escape_state(obj_node());
1642 if (es != PointsToNode::UnknownEscape && es != PointsToNode::GlobalEscape) {
1643 // Mark it eliminated to update any counters
1644 this->set_eliminated();
1645 }
1646 }
1647 return result;
1648 }