1 /*
2 * Copyright (c) 2005, 2014, 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 "libadt/vectset.hpp"
28 #include "opto/addnode.hpp"
29 #include "opto/callnode.hpp"
30 #include "opto/castnode.hpp"
31 #include "opto/cfgnode.hpp"
32 #include "opto/compile.hpp"
33 #include "opto/convertnode.hpp"
34 #include "opto/locknode.hpp"
35 #include "opto/loopnode.hpp"
36 #include "opto/macro.hpp"
37 #include "opto/memnode.hpp"
38 #include "opto/narrowptrnode.hpp"
39 #include "opto/node.hpp"
40 #include "opto/opaquenode.hpp"
41 #include "opto/phaseX.hpp"
42 #include "opto/rootnode.hpp"
43 #include "opto/runtime.hpp"
44 #include "opto/subnode.hpp"
45 #include "opto/type.hpp"
46 #include "runtime/sharedRuntime.hpp"
47
48
49 //
50 // Replace any references to "oldref" in inputs to "use" with "newref".
51 // Returns the number of replacements made.
52 //
53 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
54 int nreplacements = 0;
55 uint req = use->req();
56 for (uint j = 0; j < use->len(); j++) {
57 Node *uin = use->in(j);
58 if (uin == oldref) {
59 if (j < req)
60 use->set_req(j, newref);
61 else
62 use->set_prec(j, newref);
63 nreplacements++;
64 } else if (j >= req && uin == NULL) {
65 break;
66 }
67 }
68 return nreplacements;
69 }
70
71 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
72 // Copy debug information and adjust JVMState information
73 uint old_dbg_start = oldcall->tf()->domain()->cnt();
74 uint new_dbg_start = newcall->tf()->domain()->cnt();
75 int jvms_adj = new_dbg_start - old_dbg_start;
76 assert (new_dbg_start == newcall->req(), "argument count mismatch");
77
78 // SafePointScalarObject node could be referenced several times in debug info.
79 // Use Dict to record cloned nodes.
80 Dict* sosn_map = new Dict(cmpkey,hashkey);
81 for (uint i = old_dbg_start; i < oldcall->req(); i++) {
82 Node* old_in = oldcall->in(i);
83 // Clone old SafePointScalarObjectNodes, adjusting their field contents.
84 if (old_in != NULL && old_in->is_SafePointScalarObject()) {
85 SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
86 uint old_unique = C->unique();
87 Node* new_in = old_sosn->clone(sosn_map);
88 if (old_unique != C->unique()) { // New node?
89 new_in->set_req(0, C->root()); // reset control edge
90 new_in = transform_later(new_in); // Register new node.
91 }
92 old_in = new_in;
93 }
94 newcall->add_req(old_in);
95 }
96
97 // JVMS may be shared so clone it before we modify it
98 newcall->set_jvms(oldcall->jvms() != NULL ? oldcall->jvms()->clone_deep(C) : NULL);
99 for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
100 jvms->set_map(newcall);
101 jvms->set_locoff(jvms->locoff()+jvms_adj);
102 jvms->set_stkoff(jvms->stkoff()+jvms_adj);
103 jvms->set_monoff(jvms->monoff()+jvms_adj);
104 jvms->set_scloff(jvms->scloff()+jvms_adj);
105 jvms->set_endoff(jvms->endoff()+jvms_adj);
106 }
107 }
108
109 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
110 Node* cmp;
111 if (mask != 0) {
112 Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
113 cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
114 } else {
115 cmp = word;
116 }
117 Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
118 IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
119 transform_later(iff);
120
121 // Fast path taken.
122 Node *fast_taken = transform_later(new IfFalseNode(iff));
123
124 // Fast path not-taken, i.e. slow path
125 Node *slow_taken = transform_later(new IfTrueNode(iff));
126
127 if (return_fast_path) {
128 region->init_req(edge, slow_taken); // Capture slow-control
129 return fast_taken;
130 } else {
131 region->init_req(edge, fast_taken); // Capture fast-control
132 return slow_taken;
133 }
134 }
135
136 //--------------------copy_predefined_input_for_runtime_call--------------------
137 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
138 // Set fixed predefined input arguments
139 call->init_req( TypeFunc::Control, ctrl );
140 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) );
141 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
142 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
143 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
144 }
145
146 //------------------------------make_slow_call---------------------------------
147 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, address slow_call, const char* leaf_name, Node* slow_path, Node* parm0, Node* parm1) {
148
149 // Slow-path call
150 CallNode *call = leaf_name
151 ? (CallNode*)new CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
152 : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
153
154 // Slow path call has no side-effects, uses few values
155 copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
156 if (parm0 != NULL) call->init_req(TypeFunc::Parms+0, parm0);
157 if (parm1 != NULL) call->init_req(TypeFunc::Parms+1, parm1);
158 copy_call_debug_info(oldcall, call);
159 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
160 _igvn.replace_node(oldcall, call);
161 transform_later(call);
162
163 return call;
164 }
165
166 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
167 _fallthroughproj = NULL;
168 _fallthroughcatchproj = NULL;
169 _ioproj_fallthrough = NULL;
170 _ioproj_catchall = NULL;
171 _catchallcatchproj = NULL;
172 _memproj_fallthrough = NULL;
173 _memproj_catchall = NULL;
174 _resproj = NULL;
175 for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
176 ProjNode *pn = call->fast_out(i)->as_Proj();
177 switch (pn->_con) {
178 case TypeFunc::Control:
179 {
180 // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
181 _fallthroughproj = pn;
182 DUIterator_Fast jmax, j = pn->fast_outs(jmax);
183 const Node *cn = pn->fast_out(j);
184 if (cn->is_Catch()) {
185 ProjNode *cpn = NULL;
186 for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
187 cpn = cn->fast_out(k)->as_Proj();
188 assert(cpn->is_CatchProj(), "must be a CatchProjNode");
189 if (cpn->_con == CatchProjNode::fall_through_index)
190 _fallthroughcatchproj = cpn;
191 else {
192 assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
193 _catchallcatchproj = cpn;
194 }
195 }
196 }
197 break;
198 }
199 case TypeFunc::I_O:
200 if (pn->_is_io_use)
201 _ioproj_catchall = pn;
202 else
203 _ioproj_fallthrough = pn;
204 break;
205 case TypeFunc::Memory:
206 if (pn->_is_io_use)
207 _memproj_catchall = pn;
208 else
209 _memproj_fallthrough = pn;
210 break;
211 case TypeFunc::Parms:
212 _resproj = pn;
213 break;
214 default:
215 assert(false, "unexpected projection from allocation node.");
216 }
217 }
218
219 }
220
221 // Eliminate a card mark sequence. p2x is a ConvP2XNode
222 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
223 assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
224 if (!UseG1GC) {
225 // vanilla/CMS post barrier
226 Node *shift = p2x->unique_out();
227 Node *addp = shift->unique_out();
228 for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
229 Node *mem = addp->last_out(j);
230 if (UseCondCardMark && mem->is_Load()) {
231 assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
232 // The load is checking if the card has been written so
233 // replace it with zero to fold the test.
234 _igvn.replace_node(mem, intcon(0));
235 continue;
236 }
237 assert(mem->is_Store(), "store required");
238 _igvn.replace_node(mem, mem->in(MemNode::Memory));
239 }
240 } else {
241 // G1 pre/post barriers
242 assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
243 // It could be only one user, URShift node, in Object.clone() instrinsic
244 // but the new allocation is passed to arraycopy stub and it could not
245 // be scalar replaced. So we don't check the case.
246
247 // An other case of only one user (Xor) is when the value check for NULL
248 // in G1 post barrier is folded after CCP so the code which used URShift
249 // is removed.
250
251 // Take Region node before eliminating post barrier since it also
252 // eliminates CastP2X node when it has only one user.
253 Node* this_region = p2x->in(0);
254 assert(this_region != NULL, "");
255
256 // Remove G1 post barrier.
257
258 // Search for CastP2X->Xor->URShift->Cmp path which
259 // checks if the store done to a different from the value's region.
260 // And replace Cmp with #0 (false) to collapse G1 post barrier.
261 Node* xorx = NULL;
262 for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
263 Node* u = p2x->fast_out(i);
264 if (u->Opcode() == Op_XorX) {
265 xorx = u;
266 break;
267 }
268 }
269 assert(xorx != NULL, "missing G1 post barrier");
270 Node* shift = xorx->unique_out();
271 Node* cmpx = shift->unique_out();
272 assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
273 cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
274 "missing region check in G1 post barrier");
275 _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
276
277 // Remove G1 pre barrier.
278
279 // Search "if (marking != 0)" check and set it to "false".
280 // There is no G1 pre barrier if previous stored value is NULL
281 // (for example, after initialization).
282 if (this_region->is_Region() && this_region->req() == 3) {
283 int ind = 1;
284 if (!this_region->in(ind)->is_IfFalse()) {
285 ind = 2;
286 }
287 if (this_region->in(ind)->is_IfFalse()) {
288 Node* bol = this_region->in(ind)->in(0)->in(1);
289 assert(bol->is_Bool(), "");
290 cmpx = bol->in(1);
291 if (bol->as_Bool()->_test._test == BoolTest::ne &&
292 cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
293 cmpx->in(1)->is_Load()) {
294 Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
295 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
296 PtrQueue::byte_offset_of_active());
297 if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
298 adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
299 adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
300 _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
301 }
302 }
303 }
304 }
305 // Now CastP2X can be removed since it is used only on dead path
306 // which currently still alive until igvn optimize it.
307 assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
308 _igvn.replace_node(p2x, top());
309 }
310 }
311
312 // Search for a memory operation for the specified memory slice.
313 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
314 Node *orig_mem = mem;
315 Node *alloc_mem = alloc->in(TypeFunc::Memory);
316 const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
317 while (true) {
318 if (mem == alloc_mem || mem == start_mem ) {
319 return mem; // hit one of our sentinels
320 } else if (mem->is_MergeMem()) {
321 mem = mem->as_MergeMem()->memory_at(alias_idx);
322 } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
323 Node *in = mem->in(0);
324 // we can safely skip over safepoints, calls, locks and membars because we
325 // already know that the object is safe to eliminate.
326 if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
327 return in;
328 } else if (in->is_Call()) {
329 CallNode *call = in->as_Call();
330 if (!call->may_modify(tinst, phase)) {
331 mem = call->in(TypeFunc::Memory);
332 }
333 mem = in->in(TypeFunc::Memory);
334 } else if (in->is_MemBar()) {
335 mem = in->in(TypeFunc::Memory);
336 } else {
337 assert(false, "unexpected projection");
338 }
339 } else if (mem->is_Store()) {
340 const TypePtr* atype = mem->as_Store()->adr_type();
341 int adr_idx = Compile::current()->get_alias_index(atype);
342 if (adr_idx == alias_idx) {
343 assert(atype->isa_oopptr(), "address type must be oopptr");
344 int adr_offset = atype->offset();
345 uint adr_iid = atype->is_oopptr()->instance_id();
346 // Array elements references have the same alias_idx
347 // but different offset and different instance_id.
348 if (adr_offset == offset && adr_iid == alloc->_idx)
349 return mem;
350 } else {
351 assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
352 }
353 mem = mem->in(MemNode::Memory);
354 } else if (mem->is_ClearArray()) {
355 if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
356 // Can not bypass initialization of the instance
357 // we are looking.
358 debug_only(intptr_t offset;)
359 assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
360 InitializeNode* init = alloc->as_Allocate()->initialization();
361 // We are looking for stored value, return Initialize node
362 // or memory edge from Allocate node.
363 if (init != NULL)
364 return init;
365 else
366 return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
367 }
368 // Otherwise skip it (the call updated 'mem' value).
369 } else if (mem->Opcode() == Op_SCMemProj) {
370 mem = mem->in(0);
371 Node* adr = NULL;
372 if (mem->is_LoadStore()) {
373 adr = mem->in(MemNode::Address);
374 } else {
375 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
376 adr = mem->in(3); // Destination array
377 }
378 const TypePtr* atype = adr->bottom_type()->is_ptr();
379 int adr_idx = Compile::current()->get_alias_index(atype);
380 if (adr_idx == alias_idx) {
381 assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
382 return NULL;
383 }
384 mem = mem->in(MemNode::Memory);
385 } else {
386 return mem;
387 }
388 assert(mem != orig_mem, "dead memory loop");
389 }
390 }
391
392 //
393 // Given a Memory Phi, compute a value Phi containing the values from stores
394 // on the input paths.
395 // Note: this function is recursive, its depth is limied by the "level" argument
396 // Returns the computed Phi, or NULL if it cannot compute it.
397 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, Node *alloc, Node_Stack *value_phis, int level) {
398 assert(mem->is_Phi(), "sanity");
399 int alias_idx = C->get_alias_index(adr_t);
400 int offset = adr_t->offset();
401 int instance_id = adr_t->instance_id();
402
403 // Check if an appropriate value phi already exists.
404 Node* region = mem->in(0);
405 for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
406 Node* phi = region->fast_out(k);
407 if (phi->is_Phi() && phi != mem &&
408 phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
409 return phi;
410 }
411 }
412 // Check if an appropriate new value phi already exists.
413 Node* new_phi = value_phis->find(mem->_idx);
414 if (new_phi != NULL)
415 return new_phi;
416
417 if (level <= 0) {
418 return NULL; // Give up: phi tree too deep
419 }
420 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
421 Node *alloc_mem = alloc->in(TypeFunc::Memory);
422
423 uint length = mem->req();
424 GrowableArray <Node *> values(length, length, NULL, false);
425
426 // create a new Phi for the value
427 PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
428 transform_later(phi);
429 value_phis->push(phi, mem->_idx);
430
431 for (uint j = 1; j < length; j++) {
432 Node *in = mem->in(j);
433 if (in == NULL || in->is_top()) {
434 values.at_put(j, in);
435 } else {
436 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
437 if (val == start_mem || val == alloc_mem) {
438 // hit a sentinel, return appropriate 0 value
439 values.at_put(j, _igvn.zerocon(ft));
440 continue;
441 }
442 if (val->is_Initialize()) {
443 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
444 }
445 if (val == NULL) {
446 return NULL; // can't find a value on this path
447 }
448 if (val == mem) {
449 values.at_put(j, mem);
450 } else if (val->is_Store()) {
451 values.at_put(j, val->in(MemNode::ValueIn));
452 } else if(val->is_Proj() && val->in(0) == alloc) {
453 values.at_put(j, _igvn.zerocon(ft));
454 } else if (val->is_Phi()) {
455 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
456 if (val == NULL) {
457 return NULL;
458 }
459 values.at_put(j, val);
460 } else if (val->Opcode() == Op_SCMemProj) {
461 assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
462 assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
463 return NULL;
464 } else {
465 #ifdef ASSERT
466 val->dump();
467 assert(false, "unknown node on this path");
468 #endif
469 return NULL; // unknown node on this path
470 }
471 }
472 }
473 // Set Phi's inputs
474 for (uint j = 1; j < length; j++) {
475 if (values.at(j) == mem) {
476 phi->init_req(j, phi);
477 } else {
478 phi->init_req(j, values.at(j));
479 }
480 }
481 return phi;
482 }
483
484 // Search the last value stored into the object's field.
485 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
486 assert(adr_t->is_known_instance_field(), "instance required");
487 int instance_id = adr_t->instance_id();
488 assert((uint)instance_id == alloc->_idx, "wrong allocation");
489
490 int alias_idx = C->get_alias_index(adr_t);
491 int offset = adr_t->offset();
492 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
493 Node *alloc_ctrl = alloc->in(TypeFunc::Control);
494 Node *alloc_mem = alloc->in(TypeFunc::Memory);
495 Arena *a = Thread::current()->resource_area();
496 VectorSet visited(a);
497
498
499 bool done = sfpt_mem == alloc_mem;
500 Node *mem = sfpt_mem;
501 while (!done) {
502 if (visited.test_set(mem->_idx)) {
503 return NULL; // found a loop, give up
504 }
505 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
506 if (mem == start_mem || mem == alloc_mem) {
507 done = true; // hit a sentinel, return appropriate 0 value
508 } else if (mem->is_Initialize()) {
509 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
510 if (mem == NULL) {
511 done = true; // Something go wrong.
512 } else if (mem->is_Store()) {
513 const TypePtr* atype = mem->as_Store()->adr_type();
514 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
515 done = true;
516 }
517 } else if (mem->is_Store()) {
518 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
519 assert(atype != NULL, "address type must be oopptr");
520 assert(C->get_alias_index(atype) == alias_idx &&
521 atype->is_known_instance_field() && atype->offset() == offset &&
522 atype->instance_id() == instance_id, "store is correct memory slice");
523 done = true;
524 } else if (mem->is_Phi()) {
525 // try to find a phi's unique input
526 Node *unique_input = NULL;
527 Node *top = C->top();
528 for (uint i = 1; i < mem->req(); i++) {
529 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
530 if (n == NULL || n == top || n == mem) {
531 continue;
532 } else if (unique_input == NULL) {
533 unique_input = n;
534 } else if (unique_input != n) {
535 unique_input = top;
536 break;
537 }
538 }
539 if (unique_input != NULL && unique_input != top) {
540 mem = unique_input;
541 } else {
542 done = true;
543 }
544 } else {
545 assert(false, "unexpected node");
546 }
547 }
548 if (mem != NULL) {
549 if (mem == start_mem || mem == alloc_mem) {
550 // hit a sentinel, return appropriate 0 value
551 return _igvn.zerocon(ft);
552 } else if (mem->is_Store()) {
553 return mem->in(MemNode::ValueIn);
554 } else if (mem->is_Phi()) {
555 // attempt to produce a Phi reflecting the values on the input paths of the Phi
556 Node_Stack value_phis(a, 8);
557 Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
558 if (phi != NULL) {
559 return phi;
560 } else {
561 // Kill all new Phis
562 while(value_phis.is_nonempty()) {
563 Node* n = value_phis.node();
564 _igvn.replace_node(n, C->top());
565 value_phis.pop();
566 }
567 }
568 }
569 }
570 // Something go wrong.
571 return NULL;
572 }
573
574 // Check the possibility of scalar replacement.
575 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
576 // Scan the uses of the allocation to check for anything that would
577 // prevent us from eliminating it.
578 NOT_PRODUCT( const char* fail_eliminate = NULL; )
579 DEBUG_ONLY( Node* disq_node = NULL; )
580 bool can_eliminate = true;
581
582 Node* res = alloc->result_cast();
583 const TypeOopPtr* res_type = NULL;
584 if (res == NULL) {
585 // All users were eliminated.
586 } else if (!res->is_CheckCastPP()) {
587 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
588 can_eliminate = false;
589 } else {
590 res_type = _igvn.type(res)->isa_oopptr();
591 if (res_type == NULL) {
592 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
593 can_eliminate = false;
594 } else if (res_type->isa_aryptr()) {
595 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
596 if (length < 0) {
597 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
598 can_eliminate = false;
599 }
600 }
601 }
602
603 if (can_eliminate && res != NULL) {
604 for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
605 j < jmax && can_eliminate; j++) {
606 Node* use = res->fast_out(j);
607
608 if (use->is_AddP()) {
609 const TypePtr* addp_type = _igvn.type(use)->is_ptr();
610 int offset = addp_type->offset();
611
612 if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
613 NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
614 can_eliminate = false;
615 break;
616 }
617 for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
618 k < kmax && can_eliminate; k++) {
619 Node* n = use->fast_out(k);
620 if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
621 DEBUG_ONLY(disq_node = n;)
622 if (n->is_Load() || n->is_LoadStore()) {
623 NOT_PRODUCT(fail_eliminate = "Field load";)
624 } else {
625 NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
626 }
627 can_eliminate = false;
628 }
629 }
630 } else if (use->is_SafePoint()) {
631 SafePointNode* sfpt = use->as_SafePoint();
632 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
633 // Object is passed as argument.
634 DEBUG_ONLY(disq_node = use;)
635 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
636 can_eliminate = false;
637 }
638 Node* sfptMem = sfpt->memory();
639 if (sfptMem == NULL || sfptMem->is_top()) {
640 DEBUG_ONLY(disq_node = use;)
641 NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
642 can_eliminate = false;
643 } else {
644 safepoints.append_if_missing(sfpt);
645 }
646 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
647 if (use->is_Phi()) {
648 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
649 NOT_PRODUCT(fail_eliminate = "Object is return value";)
650 } else {
651 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
652 }
653 DEBUG_ONLY(disq_node = use;)
654 } else {
655 if (use->Opcode() == Op_Return) {
656 NOT_PRODUCT(fail_eliminate = "Object is return value";)
657 }else {
658 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
659 }
660 DEBUG_ONLY(disq_node = use;)
661 }
662 can_eliminate = false;
663 }
664 }
665 }
666
667 #ifndef PRODUCT
668 if (PrintEliminateAllocations) {
669 if (can_eliminate) {
670 tty->print("Scalar ");
671 if (res == NULL)
672 alloc->dump();
673 else
674 res->dump();
675 } else if (alloc->_is_scalar_replaceable) {
676 tty->print("NotScalar (%s)", fail_eliminate);
677 if (res == NULL)
678 alloc->dump();
679 else
680 res->dump();
681 #ifdef ASSERT
682 if (disq_node != NULL) {
683 tty->print(" >>>> ");
684 disq_node->dump();
685 }
686 #endif /*ASSERT*/
687 }
688 }
689 #endif
690 return can_eliminate;
691 }
692
693 // Do scalar replacement.
694 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
695 GrowableArray <SafePointNode *> safepoints_done;
696
697 ciKlass* klass = NULL;
698 ciInstanceKlass* iklass = NULL;
699 int nfields = 0;
700 int array_base;
701 int element_size;
702 BasicType basic_elem_type;
703 ciType* elem_type;
704
705 Node* res = alloc->result_cast();
706 assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result");
707 const TypeOopPtr* res_type = NULL;
708 if (res != NULL) { // Could be NULL when there are no users
709 res_type = _igvn.type(res)->isa_oopptr();
710 }
711
712 if (res != NULL) {
713 klass = res_type->klass();
714 if (res_type->isa_instptr()) {
715 // find the fields of the class which will be needed for safepoint debug information
716 assert(klass->is_instance_klass(), "must be an instance klass.");
717 iklass = klass->as_instance_klass();
718 nfields = iklass->nof_nonstatic_fields();
719 } else {
720 // find the array's elements which will be needed for safepoint debug information
721 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
722 assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
723 elem_type = klass->as_array_klass()->element_type();
724 basic_elem_type = elem_type->basic_type();
725 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
726 element_size = type2aelembytes(basic_elem_type);
727 }
728 }
729 //
730 // Process the safepoint uses
731 //
732 while (safepoints.length() > 0) {
733 SafePointNode* sfpt = safepoints.pop();
734 Node* mem = sfpt->memory();
735 assert(sfpt->jvms() != NULL, "missed JVMS");
736 // Fields of scalar objs are referenced only at the end
737 // of regular debuginfo at the last (youngest) JVMS.
738 // Record relative start index.
739 uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
740 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
741 #ifdef ASSERT
742 alloc,
743 #endif
744 first_ind, nfields);
745 sobj->init_req(0, C->root());
746 transform_later(sobj);
747
748 // Scan object's fields adding an input to the safepoint for each field.
749 for (int j = 0; j < nfields; j++) {
750 intptr_t offset;
751 ciField* field = NULL;
752 if (iklass != NULL) {
753 field = iklass->nonstatic_field_at(j);
754 offset = field->offset();
755 elem_type = field->type();
756 basic_elem_type = field->layout_type();
757 } else {
758 offset = array_base + j * (intptr_t)element_size;
759 }
760
761 const Type *field_type;
762 // The next code is taken from Parse::do_get_xxx().
763 if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
764 if (!elem_type->is_loaded()) {
765 field_type = TypeInstPtr::BOTTOM;
766 } else if (field != NULL && field->is_constant() && field->is_static()) {
767 // This can happen if the constant oop is non-perm.
768 ciObject* con = field->constant_value().as_object();
769 // Do not "join" in the previous type; it doesn't add value,
770 // and may yield a vacuous result if the field is of interface type.
771 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
772 assert(field_type != NULL, "field singleton type must be consistent");
773 } else {
774 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
775 }
776 if (UseCompressedOops) {
777 field_type = field_type->make_narrowoop();
778 basic_elem_type = T_NARROWOOP;
779 }
780 } else {
781 field_type = Type::get_const_basic_type(basic_elem_type);
782 }
783
784 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
785
786 Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
787 if (field_val == NULL) {
788 // We weren't able to find a value for this field,
789 // give up on eliminating this allocation.
790
791 // Remove any extra entries we added to the safepoint.
792 uint last = sfpt->req() - 1;
793 for (int k = 0; k < j; k++) {
794 sfpt->del_req(last--);
795 }
796 _igvn._worklist.push(sfpt);
797 // rollback processed safepoints
798 while (safepoints_done.length() > 0) {
799 SafePointNode* sfpt_done = safepoints_done.pop();
800 // remove any extra entries we added to the safepoint
801 last = sfpt_done->req() - 1;
802 for (int k = 0; k < nfields; k++) {
803 sfpt_done->del_req(last--);
804 }
805 JVMState *jvms = sfpt_done->jvms();
806 jvms->set_endoff(sfpt_done->req());
807 // Now make a pass over the debug information replacing any references
808 // to SafePointScalarObjectNode with the allocated object.
809 int start = jvms->debug_start();
810 int end = jvms->debug_end();
811 for (int i = start; i < end; i++) {
812 if (sfpt_done->in(i)->is_SafePointScalarObject()) {
813 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
814 if (scobj->first_index(jvms) == sfpt_done->req() &&
815 scobj->n_fields() == (uint)nfields) {
816 assert(scobj->alloc() == alloc, "sanity");
817 sfpt_done->set_req(i, res);
818 }
819 }
820 }
821 _igvn._worklist.push(sfpt_done);
822 }
823 #ifndef PRODUCT
824 if (PrintEliminateAllocations) {
825 if (field != NULL) {
826 tty->print("=== At SafePoint node %d can't find value of Field: ",
827 sfpt->_idx);
828 field->print();
829 int field_idx = C->get_alias_index(field_addr_type);
830 tty->print(" (alias_idx=%d)", field_idx);
831 } else { // Array's element
832 tty->print("=== At SafePoint node %d can't find value of array element [%d]",
833 sfpt->_idx, j);
834 }
835 tty->print(", which prevents elimination of: ");
836 if (res == NULL)
837 alloc->dump();
838 else
839 res->dump();
840 }
841 #endif
842 return false;
843 }
844 if (UseCompressedOops && field_type->isa_narrowoop()) {
845 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
846 // to be able scalar replace the allocation.
847 if (field_val->is_EncodeP()) {
848 field_val = field_val->in(1);
849 } else {
850 field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
851 }
852 }
853 sfpt->add_req(field_val);
854 }
855 JVMState *jvms = sfpt->jvms();
856 jvms->set_endoff(sfpt->req());
857 // Now make a pass over the debug information replacing any references
858 // to the allocated object with "sobj"
859 int start = jvms->debug_start();
860 int end = jvms->debug_end();
861 sfpt->replace_edges_in_range(res, sobj, start, end);
862 _igvn._worklist.push(sfpt);
863 safepoints_done.append_if_missing(sfpt); // keep it for rollback
864 }
865 return true;
866 }
867
868 // Process users of eliminated allocation.
869 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
870 Node* res = alloc->result_cast();
871 if (res != NULL) {
872 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
873 Node *use = res->last_out(j);
874 uint oc1 = res->outcnt();
875
876 if (use->is_AddP()) {
877 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
878 Node *n = use->last_out(k);
879 uint oc2 = use->outcnt();
880 if (n->is_Store()) {
881 #ifdef ASSERT
882 // Verify that there is no dependent MemBarVolatile nodes,
883 // they should be removed during IGVN, see MemBarNode::Ideal().
884 for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
885 p < pmax; p++) {
886 Node* mb = n->fast_out(p);
887 assert(mb->is_Initialize() || !mb->is_MemBar() ||
888 mb->req() <= MemBarNode::Precedent ||
889 mb->in(MemBarNode::Precedent) != n,
890 "MemBarVolatile should be eliminated for non-escaping object");
891 }
892 #endif
893 _igvn.replace_node(n, n->in(MemNode::Memory));
894 } else {
895 eliminate_card_mark(n);
896 }
897 k -= (oc2 - use->outcnt());
898 }
899 } else {
900 eliminate_card_mark(use);
901 }
902 j -= (oc1 - res->outcnt());
903 }
904 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
905 _igvn.remove_dead_node(res);
906 }
907
908 //
909 // Process other users of allocation's projections
910 //
911 if (_resproj != NULL && _resproj->outcnt() != 0) {
912 // First disconnect stores captured by Initialize node.
913 // If Initialize node is eliminated first in the following code,
914 // it will kill such stores and DUIterator_Last will assert.
915 for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax); j < jmax; j++) {
916 Node *use = _resproj->fast_out(j);
917 if (use->is_AddP()) {
918 // raw memory addresses used only by the initialization
919 _igvn.replace_node(use, C->top());
920 --j; --jmax;
921 }
922 }
923 for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
924 Node *use = _resproj->last_out(j);
925 uint oc1 = _resproj->outcnt();
926 if (use->is_Initialize()) {
927 // Eliminate Initialize node.
928 InitializeNode *init = use->as_Initialize();
929 assert(init->outcnt() <= 2, "only a control and memory projection expected");
930 Node *ctrl_proj = init->proj_out(TypeFunc::Control);
931 if (ctrl_proj != NULL) {
932 assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
933 _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
934 }
935 Node *mem_proj = init->proj_out(TypeFunc::Memory);
936 if (mem_proj != NULL) {
937 Node *mem = init->in(TypeFunc::Memory);
938 #ifdef ASSERT
939 if (mem->is_MergeMem()) {
940 assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
941 } else {
942 assert(mem == _memproj_fallthrough, "allocation memory projection");
943 }
944 #endif
945 _igvn.replace_node(mem_proj, mem);
946 }
947 } else {
948 assert(false, "only Initialize or AddP expected");
949 }
950 j -= (oc1 - _resproj->outcnt());
951 }
952 }
953 if (_fallthroughcatchproj != NULL) {
954 _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
955 }
956 if (_memproj_fallthrough != NULL) {
957 _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
958 }
959 if (_memproj_catchall != NULL) {
960 _igvn.replace_node(_memproj_catchall, C->top());
961 }
962 if (_ioproj_fallthrough != NULL) {
963 _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
964 }
965 if (_ioproj_catchall != NULL) {
966 _igvn.replace_node(_ioproj_catchall, C->top());
967 }
968 if (_catchallcatchproj != NULL) {
969 _igvn.replace_node(_catchallcatchproj, C->top());
970 }
971 }
972
973 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
974 if (!EliminateAllocations || !alloc->_is_non_escaping) {
975 return false;
976 }
977 Node* klass = alloc->in(AllocateNode::KlassNode);
978 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
979 Node* res = alloc->result_cast();
980 // Eliminate boxing allocations which are not used
981 // regardless scalar replacable status.
982 bool boxing_alloc = C->eliminate_boxing() &&
983 tklass->klass()->is_instance_klass() &&
984 tklass->klass()->as_instance_klass()->is_box_klass();
985 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
986 return false;
987 }
988
989 extract_call_projections(alloc);
990
991 GrowableArray <SafePointNode *> safepoints;
992 if (!can_eliminate_allocation(alloc, safepoints)) {
993 return false;
994 }
995
996 if (!alloc->_is_scalar_replaceable) {
997 assert(res == NULL, "sanity");
998 // We can only eliminate allocation if all debug info references
999 // are already replaced with SafePointScalarObject because
1000 // we can't search for a fields value without instance_id.
1001 if (safepoints.length() > 0) {
1002 return false;
1003 }
1004 }
1005
1006 if (!scalar_replacement(alloc, safepoints)) {
1007 return false;
1008 }
1009
1010 CompileLog* log = C->log();
1011 if (log != NULL) {
1012 log->head("eliminate_allocation type='%d'",
1013 log->identify(tklass->klass()));
1014 JVMState* p = alloc->jvms();
1015 while (p != NULL) {
1016 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1017 p = p->caller();
1018 }
1019 log->tail("eliminate_allocation");
1020 }
1021
1022 process_users_of_allocation(alloc);
1023
1024 #ifndef PRODUCT
1025 if (PrintEliminateAllocations) {
1026 if (alloc->is_AllocateArray())
1027 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1028 else
1029 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1030 }
1031 #endif
1032
1033 return true;
1034 }
1035
1036 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1037 // EA should remove all uses of non-escaping boxing node.
1038 if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
1039 return false;
1040 }
1041
1042 assert(boxing->result_cast() == NULL, "unexpected boxing node result");
1043
1044 extract_call_projections(boxing);
1045
1046 const TypeTuple* r = boxing->tf()->range();
1047 assert(r->cnt() > TypeFunc::Parms, "sanity");
1048 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1049 assert(t != NULL, "sanity");
1050
1051 CompileLog* log = C->log();
1052 if (log != NULL) {
1053 log->head("eliminate_boxing type='%d'",
1054 log->identify(t->klass()));
1055 JVMState* p = boxing->jvms();
1056 while (p != NULL) {
1057 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1058 p = p->caller();
1059 }
1060 log->tail("eliminate_boxing");
1061 }
1062
1063 process_users_of_allocation(boxing);
1064
1065 #ifndef PRODUCT
1066 if (PrintEliminateAllocations) {
1067 tty->print("++++ Eliminated: %d ", boxing->_idx);
1068 boxing->method()->print_short_name(tty);
1069 tty->cr();
1070 }
1071 #endif
1072
1073 return true;
1074 }
1075
1076 //---------------------------set_eden_pointers-------------------------
1077 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1078 if (UseTLAB) { // Private allocation: load from TLS
1079 Node* thread = transform_later(new ThreadLocalNode());
1080 int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1081 int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1082 eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1083 eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1084 } else { // Shared allocation: load from globals
1085 CollectedHeap* ch = Universe::heap();
1086 address top_adr = (address)ch->top_addr();
1087 address end_adr = (address)ch->end_addr();
1088 eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1089 eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1090 }
1091 }
1092
1093
1094 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1095 Node* adr = basic_plus_adr(base, offset);
1096 const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1097 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1098 transform_later(value);
1099 return value;
1100 }
1101
1102
1103 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1104 Node* adr = basic_plus_adr(base, offset);
1105 mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
1106 transform_later(mem);
1107 return mem;
1108 }
1109
1110 //=============================================================================
1111 //
1112 // A L L O C A T I O N
1113 //
1114 // Allocation attempts to be fast in the case of frequent small objects.
1115 // It breaks down like this:
1116 //
1117 // 1) Size in doublewords is computed. This is a constant for objects and
1118 // variable for most arrays. Doubleword units are used to avoid size
1119 // overflow of huge doubleword arrays. We need doublewords in the end for
1120 // rounding.
1121 //
1122 // 2) Size is checked for being 'too large'. Too-large allocations will go
1123 // the slow path into the VM. The slow path can throw any required
1124 // exceptions, and does all the special checks for very large arrays. The
1125 // size test can constant-fold away for objects. For objects with
1126 // finalizers it constant-folds the otherway: you always go slow with
1127 // finalizers.
1128 //
1129 // 3) If NOT using TLABs, this is the contended loop-back point.
1130 // Load-Locked the heap top. If using TLABs normal-load the heap top.
1131 //
1132 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
1133 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
1134 // "size*8" we always enter the VM, where "largish" is a constant picked small
1135 // enough that there's always space between the eden max and 4Gig (old space is
1136 // there so it's quite large) and large enough that the cost of entering the VM
1137 // is dwarfed by the cost to initialize the space.
1138 //
1139 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1140 // down. If contended, repeat at step 3. If using TLABs normal-store
1141 // adjusted heap top back down; there is no contention.
1142 //
1143 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
1144 // fields.
1145 //
1146 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1147 // oop flavor.
1148 //
1149 //=============================================================================
1150 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1151 // Allocations bigger than this always go the slow route.
1152 // This value must be small enough that allocation attempts that need to
1153 // trigger exceptions go the slow route. Also, it must be small enough so
1154 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1155 //=============================================================================j//
1156 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1157 // The allocator will coalesce int->oop copies away. See comment in
1158 // coalesce.cpp about how this works. It depends critically on the exact
1159 // code shape produced here, so if you are changing this code shape
1160 // make sure the GC info for the heap-top is correct in and around the
1161 // slow-path call.
1162 //
1163
1164 void PhaseMacroExpand::expand_allocate_common(
1165 AllocateNode* alloc, // allocation node to be expanded
1166 Node* length, // array length for an array allocation
1167 const TypeFunc* slow_call_type, // Type of slow call
1168 address slow_call_address // Address of slow call
1169 )
1170 {
1171
1172 Node* ctrl = alloc->in(TypeFunc::Control);
1173 Node* mem = alloc->in(TypeFunc::Memory);
1174 Node* i_o = alloc->in(TypeFunc::I_O);
1175 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
1176 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1177 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1178
1179 assert(ctrl != NULL, "must have control");
1180 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1181 // they will not be used if "always_slow" is set
1182 enum { slow_result_path = 1, fast_result_path = 2 };
1183 Node *result_region;
1184 Node *result_phi_rawmem;
1185 Node *result_phi_rawoop;
1186 Node *result_phi_i_o;
1187
1188 // The initial slow comparison is a size check, the comparison
1189 // we want to do is a BoolTest::gt
1190 bool always_slow = false;
1191 int tv = _igvn.find_int_con(initial_slow_test, -1);
1192 if (tv >= 0) {
1193 always_slow = (tv == 1);
1194 initial_slow_test = NULL;
1195 } else {
1196 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1197 }
1198
1199 if (C->env()->dtrace_alloc_probes() ||
1200 !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc())) {
1201 // Force slow-path allocation
1202 always_slow = true;
1203 initial_slow_test = NULL;
1204 }
1205
1206
1207 enum { too_big_or_final_path = 1, need_gc_path = 2 };
1208 Node *slow_region = NULL;
1209 Node *toobig_false = ctrl;
1210
1211 assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1212 // generate the initial test if necessary
1213 if (initial_slow_test != NULL ) {
1214 slow_region = new RegionNode(3);
1215
1216 // Now make the initial failure test. Usually a too-big test but
1217 // might be a TRUE for finalizers or a fancy class check for
1218 // newInstance0.
1219 IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1220 transform_later(toobig_iff);
1221 // Plug the failing-too-big test into the slow-path region
1222 Node *toobig_true = new IfTrueNode( toobig_iff );
1223 transform_later(toobig_true);
1224 slow_region ->init_req( too_big_or_final_path, toobig_true );
1225 toobig_false = new IfFalseNode( toobig_iff );
1226 transform_later(toobig_false);
1227 } else { // No initial test, just fall into next case
1228 toobig_false = ctrl;
1229 debug_only(slow_region = NodeSentinel);
1230 }
1231
1232 Node *slow_mem = mem; // save the current memory state for slow path
1233 // generate the fast allocation code unless we know that the initial test will always go slow
1234 if (!always_slow) {
1235 // Fast path modifies only raw memory.
1236 if (mem->is_MergeMem()) {
1237 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1238 }
1239
1240 Node* eden_top_adr;
1241 Node* eden_end_adr;
1242
1243 set_eden_pointers(eden_top_adr, eden_end_adr);
1244
1245 // Load Eden::end. Loop invariant and hoisted.
1246 //
1247 // Note: We set the control input on "eden_end" and "old_eden_top" when using
1248 // a TLAB to work around a bug where these values were being moved across
1249 // a safepoint. These are not oops, so they cannot be include in the oop
1250 // map, but they can be changed by a GC. The proper way to fix this would
1251 // be to set the raw memory state when generating a SafepointNode. However
1252 // this will require extensive changes to the loop optimization in order to
1253 // prevent a degradation of the optimization.
1254 // See comment in memnode.hpp, around line 227 in class LoadPNode.
1255 Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1256
1257 // allocate the Region and Phi nodes for the result
1258 result_region = new RegionNode(3);
1259 result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1260 result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1261 result_phi_i_o = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1262
1263 // We need a Region for the loop-back contended case.
1264 enum { fall_in_path = 1, contended_loopback_path = 2 };
1265 Node *contended_region;
1266 Node *contended_phi_rawmem;
1267 if (UseTLAB) {
1268 contended_region = toobig_false;
1269 contended_phi_rawmem = mem;
1270 } else {
1271 contended_region = new RegionNode(3);
1272 contended_phi_rawmem = new PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1273 // Now handle the passing-too-big test. We fall into the contended
1274 // loop-back merge point.
1275 contended_region ->init_req(fall_in_path, toobig_false);
1276 contended_phi_rawmem->init_req(fall_in_path, mem);
1277 transform_later(contended_region);
1278 transform_later(contended_phi_rawmem);
1279 }
1280
1281 // Load(-locked) the heap top.
1282 // See note above concerning the control input when using a TLAB
1283 Node *old_eden_top = UseTLAB
1284 ? new LoadPNode (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered)
1285 : new LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr, MemNode::acquire);
1286
1287 transform_later(old_eden_top);
1288 // Add to heap top to get a new heap top
1289 Node *new_eden_top = new AddPNode(top(), old_eden_top, size_in_bytes);
1290 transform_later(new_eden_top);
1291 // Check for needing a GC; compare against heap end
1292 Node *needgc_cmp = new CmpPNode(new_eden_top, eden_end);
1293 transform_later(needgc_cmp);
1294 Node *needgc_bol = new BoolNode(needgc_cmp, BoolTest::ge);
1295 transform_later(needgc_bol);
1296 IfNode *needgc_iff = new IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1297 transform_later(needgc_iff);
1298
1299 // Plug the failing-heap-space-need-gc test into the slow-path region
1300 Node *needgc_true = new IfTrueNode(needgc_iff);
1301 transform_later(needgc_true);
1302 if (initial_slow_test) {
1303 slow_region->init_req(need_gc_path, needgc_true);
1304 // This completes all paths into the slow merge point
1305 transform_later(slow_region);
1306 } else { // No initial slow path needed!
1307 // Just fall from the need-GC path straight into the VM call.
1308 slow_region = needgc_true;
1309 }
1310 // No need for a GC. Setup for the Store-Conditional
1311 Node *needgc_false = new IfFalseNode(needgc_iff);
1312 transform_later(needgc_false);
1313
1314 // Grab regular I/O before optional prefetch may change it.
1315 // Slow-path does no I/O so just set it to the original I/O.
1316 result_phi_i_o->init_req(slow_result_path, i_o);
1317
1318 i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1319 old_eden_top, new_eden_top, length);
1320
1321 // Name successful fast-path variables
1322 Node* fast_oop = old_eden_top;
1323 Node* fast_oop_ctrl;
1324 Node* fast_oop_rawmem;
1325
1326 // Store (-conditional) the modified eden top back down.
1327 // StorePConditional produces flags for a test PLUS a modified raw
1328 // memory state.
1329 if (UseTLAB) {
1330 Node* store_eden_top =
1331 new StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1332 TypeRawPtr::BOTTOM, new_eden_top, MemNode::unordered);
1333 transform_later(store_eden_top);
1334 fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1335 fast_oop_rawmem = store_eden_top;
1336 } else {
1337 Node* store_eden_top =
1338 new StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1339 new_eden_top, fast_oop/*old_eden_top*/);
1340 transform_later(store_eden_top);
1341 Node *contention_check = new BoolNode(store_eden_top, BoolTest::ne);
1342 transform_later(contention_check);
1343 store_eden_top = new SCMemProjNode(store_eden_top);
1344 transform_later(store_eden_top);
1345
1346 // If not using TLABs, check to see if there was contention.
1347 IfNode *contention_iff = new IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1348 transform_later(contention_iff);
1349 Node *contention_true = new IfTrueNode(contention_iff);
1350 transform_later(contention_true);
1351 // If contention, loopback and try again.
1352 contended_region->init_req(contended_loopback_path, contention_true);
1353 contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1354
1355 // Fast-path succeeded with no contention!
1356 Node *contention_false = new IfFalseNode(contention_iff);
1357 transform_later(contention_false);
1358 fast_oop_ctrl = contention_false;
1359
1360 // Bump total allocated bytes for this thread
1361 Node* thread = new ThreadLocalNode();
1362 transform_later(thread);
1363 Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1364 in_bytes(JavaThread::allocated_bytes_offset()));
1365 Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1366 0, TypeLong::LONG, T_LONG);
1367 #ifdef _LP64
1368 Node* alloc_size = size_in_bytes;
1369 #else
1370 Node* alloc_size = new ConvI2LNode(size_in_bytes);
1371 transform_later(alloc_size);
1372 #endif
1373 Node* new_alloc_bytes = new AddLNode(alloc_bytes, alloc_size);
1374 transform_later(new_alloc_bytes);
1375 fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1376 0, new_alloc_bytes, T_LONG);
1377 }
1378
1379 InitializeNode* init = alloc->initialization();
1380 fast_oop_rawmem = initialize_object(alloc,
1381 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1382 klass_node, length, size_in_bytes);
1383
1384 // If initialization is performed by an array copy, any required
1385 // MemBarStoreStore was already added. If the object does not
1386 // escape no need for a MemBarStoreStore. Otherwise we need a
1387 // MemBarStoreStore so that stores that initialize this object
1388 // can't be reordered with a subsequent store that makes this
1389 // object accessible by other threads.
1390 if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
1391 if (init == NULL || init->req() < InitializeNode::RawStores) {
1392 // No InitializeNode or no stores captured by zeroing
1393 // elimination. Simply add the MemBarStoreStore after object
1394 // initialization.
1395 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1396 transform_later(mb);
1397
1398 mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1399 mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1400 fast_oop_ctrl = new ProjNode(mb,TypeFunc::Control);
1401 transform_later(fast_oop_ctrl);
1402 fast_oop_rawmem = new ProjNode(mb,TypeFunc::Memory);
1403 transform_later(fast_oop_rawmem);
1404 } else {
1405 // Add the MemBarStoreStore after the InitializeNode so that
1406 // all stores performing the initialization that were moved
1407 // before the InitializeNode happen before the storestore
1408 // barrier.
1409
1410 Node* init_ctrl = init->proj_out(TypeFunc::Control);
1411 Node* init_mem = init->proj_out(TypeFunc::Memory);
1412
1413 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1414 transform_later(mb);
1415
1416 Node* ctrl = new ProjNode(init,TypeFunc::Control);
1417 transform_later(ctrl);
1418 Node* mem = new ProjNode(init,TypeFunc::Memory);
1419 transform_later(mem);
1420
1421 // The MemBarStoreStore depends on control and memory coming
1422 // from the InitializeNode
1423 mb->init_req(TypeFunc::Memory, mem);
1424 mb->init_req(TypeFunc::Control, ctrl);
1425
1426 ctrl = new ProjNode(mb,TypeFunc::Control);
1427 transform_later(ctrl);
1428 mem = new ProjNode(mb,TypeFunc::Memory);
1429 transform_later(mem);
1430
1431 // All nodes that depended on the InitializeNode for control
1432 // and memory must now depend on the MemBarNode that itself
1433 // depends on the InitializeNode
1434 _igvn.replace_node(init_ctrl, ctrl);
1435 _igvn.replace_node(init_mem, mem);
1436 }
1437 }
1438
1439 if (C->env()->dtrace_extended_probes()) {
1440 // Slow-path call
1441 int size = TypeFunc::Parms + 2;
1442 CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1443 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1444 "dtrace_object_alloc",
1445 TypeRawPtr::BOTTOM);
1446
1447 // Get base of thread-local storage area
1448 Node* thread = new ThreadLocalNode();
1449 transform_later(thread);
1450
1451 call->init_req(TypeFunc::Parms+0, thread);
1452 call->init_req(TypeFunc::Parms+1, fast_oop);
1453 call->init_req(TypeFunc::Control, fast_oop_ctrl);
1454 call->init_req(TypeFunc::I_O , top()); // does no i/o
1455 call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1456 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1457 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1458 transform_later(call);
1459 fast_oop_ctrl = new ProjNode(call,TypeFunc::Control);
1460 transform_later(fast_oop_ctrl);
1461 fast_oop_rawmem = new ProjNode(call,TypeFunc::Memory);
1462 transform_later(fast_oop_rawmem);
1463 }
1464
1465 // Plug in the successful fast-path into the result merge point
1466 result_region ->init_req(fast_result_path, fast_oop_ctrl);
1467 result_phi_rawoop->init_req(fast_result_path, fast_oop);
1468 result_phi_i_o ->init_req(fast_result_path, i_o);
1469 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1470 } else {
1471 slow_region = ctrl;
1472 result_phi_i_o = i_o; // Rename it to use in the following code.
1473 }
1474
1475 // Generate slow-path call
1476 CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1477 OptoRuntime::stub_name(slow_call_address),
1478 alloc->jvms()->bci(),
1479 TypePtr::BOTTOM);
1480 call->init_req( TypeFunc::Control, slow_region );
1481 call->init_req( TypeFunc::I_O , top() ) ; // does no i/o
1482 call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1483 call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1484 call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1485
1486 call->init_req(TypeFunc::Parms+0, klass_node);
1487 if (length != NULL) {
1488 call->init_req(TypeFunc::Parms+1, length);
1489 }
1490
1491 // Copy debug information and adjust JVMState information, then replace
1492 // allocate node with the call
1493 copy_call_debug_info((CallNode *) alloc, call);
1494 if (!always_slow) {
1495 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1496 } else {
1497 // Hook i_o projection to avoid its elimination during allocation
1498 // replacement (when only a slow call is generated).
1499 call->set_req(TypeFunc::I_O, result_phi_i_o);
1500 }
1501 _igvn.replace_node(alloc, call);
1502 transform_later(call);
1503
1504 // Identify the output projections from the allocate node and
1505 // adjust any references to them.
1506 // The control and io projections look like:
1507 //
1508 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
1509 // Allocate Catch
1510 // ^---Proj(io) <-------+ ^---CatchProj(io)
1511 //
1512 // We are interested in the CatchProj nodes.
1513 //
1514 extract_call_projections(call);
1515
1516 // An allocate node has separate memory projections for the uses on
1517 // the control and i_o paths. Replace the control memory projection with
1518 // result_phi_rawmem (unless we are only generating a slow call when
1519 // both memory projections are combined)
1520 if (!always_slow && _memproj_fallthrough != NULL) {
1521 for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1522 Node *use = _memproj_fallthrough->fast_out(i);
1523 _igvn.rehash_node_delayed(use);
1524 imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1525 // back up iterator
1526 --i;
1527 }
1528 }
1529 // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1530 // _memproj_catchall so we end up with a call that has only 1 memory projection.
1531 if (_memproj_catchall != NULL ) {
1532 if (_memproj_fallthrough == NULL) {
1533 _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory);
1534 transform_later(_memproj_fallthrough);
1535 }
1536 for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1537 Node *use = _memproj_catchall->fast_out(i);
1538 _igvn.rehash_node_delayed(use);
1539 imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1540 // back up iterator
1541 --i;
1542 }
1543 assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1544 _igvn.remove_dead_node(_memproj_catchall);
1545 }
1546
1547 // An allocate node has separate i_o projections for the uses on the control
1548 // and i_o paths. Always replace the control i_o projection with result i_o
1549 // otherwise incoming i_o become dead when only a slow call is generated
1550 // (it is different from memory projections where both projections are
1551 // combined in such case).
1552 if (_ioproj_fallthrough != NULL) {
1553 for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1554 Node *use = _ioproj_fallthrough->fast_out(i);
1555 _igvn.rehash_node_delayed(use);
1556 imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1557 // back up iterator
1558 --i;
1559 }
1560 }
1561 // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1562 // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1563 if (_ioproj_catchall != NULL ) {
1564 if (_ioproj_fallthrough == NULL) {
1565 _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O);
1566 transform_later(_ioproj_fallthrough);
1567 }
1568 for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1569 Node *use = _ioproj_catchall->fast_out(i);
1570 _igvn.rehash_node_delayed(use);
1571 imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1572 // back up iterator
1573 --i;
1574 }
1575 assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1576 _igvn.remove_dead_node(_ioproj_catchall);
1577 }
1578
1579 // if we generated only a slow call, we are done
1580 if (always_slow) {
1581 // Now we can unhook i_o.
1582 if (result_phi_i_o->outcnt() > 1) {
1583 call->set_req(TypeFunc::I_O, top());
1584 } else {
1585 assert(result_phi_i_o->unique_ctrl_out() == call, "");
1586 // Case of new array with negative size known during compilation.
1587 // AllocateArrayNode::Ideal() optimization disconnect unreachable
1588 // following code since call to runtime will throw exception.
1589 // As result there will be no users of i_o after the call.
1590 // Leave i_o attached to this call to avoid problems in preceding graph.
1591 }
1592 return;
1593 }
1594
1595
1596 if (_fallthroughcatchproj != NULL) {
1597 ctrl = _fallthroughcatchproj->clone();
1598 transform_later(ctrl);
1599 _igvn.replace_node(_fallthroughcatchproj, result_region);
1600 } else {
1601 ctrl = top();
1602 }
1603 Node *slow_result;
1604 if (_resproj == NULL) {
1605 // no uses of the allocation result
1606 slow_result = top();
1607 } else {
1608 slow_result = _resproj->clone();
1609 transform_later(slow_result);
1610 _igvn.replace_node(_resproj, result_phi_rawoop);
1611 }
1612
1613 // Plug slow-path into result merge point
1614 result_region ->init_req( slow_result_path, ctrl );
1615 result_phi_rawoop->init_req( slow_result_path, slow_result);
1616 result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1617 transform_later(result_region);
1618 transform_later(result_phi_rawoop);
1619 transform_later(result_phi_rawmem);
1620 transform_later(result_phi_i_o);
1621 // This completes all paths into the result merge point
1622 }
1623
1624
1625 // Helper for PhaseMacroExpand::expand_allocate_common.
1626 // Initializes the newly-allocated storage.
1627 Node*
1628 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1629 Node* control, Node* rawmem, Node* object,
1630 Node* klass_node, Node* length,
1631 Node* size_in_bytes) {
1632 InitializeNode* init = alloc->initialization();
1633 // Store the klass & mark bits
1634 Node* mark_node = NULL;
1635 // For now only enable fast locking for non-array types
1636 if (UseBiasedLocking && (length == NULL)) {
1637 mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1638 } else {
1639 mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1640 }
1641 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1642
1643 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1644 int header_size = alloc->minimum_header_size(); // conservatively small
1645
1646 // Array length
1647 if (length != NULL) { // Arrays need length field
1648 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1649 // conservatively small header size:
1650 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1651 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1652 if (k->is_array_klass()) // we know the exact header size in most cases:
1653 header_size = Klass::layout_helper_header_size(k->layout_helper());
1654 }
1655
1656 // Clear the object body, if necessary.
1657 if (init == NULL) {
1658 // The init has somehow disappeared; be cautious and clear everything.
1659 //
1660 // This can happen if a node is allocated but an uncommon trap occurs
1661 // immediately. In this case, the Initialize gets associated with the
1662 // trap, and may be placed in a different (outer) loop, if the Allocate
1663 // is in a loop. If (this is rare) the inner loop gets unrolled, then
1664 // there can be two Allocates to one Initialize. The answer in all these
1665 // edge cases is safety first. It is always safe to clear immediately
1666 // within an Allocate, and then (maybe or maybe not) clear some more later.
1667 if (!ZeroTLAB)
1668 rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1669 header_size, size_in_bytes,
1670 &_igvn);
1671 } else {
1672 if (!init->is_complete()) {
1673 // Try to win by zeroing only what the init does not store.
1674 // We can also try to do some peephole optimizations,
1675 // such as combining some adjacent subword stores.
1676 rawmem = init->complete_stores(control, rawmem, object,
1677 header_size, size_in_bytes, &_igvn);
1678 }
1679 // We have no more use for this link, since the AllocateNode goes away:
1680 init->set_req(InitializeNode::RawAddress, top());
1681 // (If we keep the link, it just confuses the register allocator,
1682 // who thinks he sees a real use of the address by the membar.)
1683 }
1684
1685 return rawmem;
1686 }
1687
1688 // Generate prefetch instructions for next allocations.
1689 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1690 Node*& contended_phi_rawmem,
1691 Node* old_eden_top, Node* new_eden_top,
1692 Node* length) {
1693 enum { fall_in_path = 1, pf_path = 2 };
1694 if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1695 // Generate prefetch allocation with watermark check.
1696 // As an allocation hits the watermark, we will prefetch starting
1697 // at a "distance" away from watermark.
1698
1699 Node *pf_region = new RegionNode(3);
1700 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1701 TypeRawPtr::BOTTOM );
1702 // I/O is used for Prefetch
1703 Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1704
1705 Node *thread = new ThreadLocalNode();
1706 transform_later(thread);
1707
1708 Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1709 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1710 transform_later(eden_pf_adr);
1711
1712 Node *old_pf_wm = new LoadPNode(needgc_false,
1713 contended_phi_rawmem, eden_pf_adr,
1714 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1715 MemNode::unordered);
1716 transform_later(old_pf_wm);
1717
1718 // check against new_eden_top
1719 Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1720 transform_later(need_pf_cmp);
1721 Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1722 transform_later(need_pf_bol);
1723 IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1724 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1725 transform_later(need_pf_iff);
1726
1727 // true node, add prefetchdistance
1728 Node *need_pf_true = new IfTrueNode( need_pf_iff );
1729 transform_later(need_pf_true);
1730
1731 Node *need_pf_false = new IfFalseNode( need_pf_iff );
1732 transform_later(need_pf_false);
1733
1734 Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1735 _igvn.MakeConX(AllocatePrefetchDistance) );
1736 transform_later(new_pf_wmt );
1737 new_pf_wmt->set_req(0, need_pf_true);
1738
1739 Node *store_new_wmt = new StorePNode(need_pf_true,
1740 contended_phi_rawmem, eden_pf_adr,
1741 TypeRawPtr::BOTTOM, new_pf_wmt,
1742 MemNode::unordered);
1743 transform_later(store_new_wmt);
1744
1745 // adding prefetches
1746 pf_phi_abio->init_req( fall_in_path, i_o );
1747
1748 Node *prefetch_adr;
1749 Node *prefetch;
1750 uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1751 uint step_size = AllocatePrefetchStepSize;
1752 uint distance = 0;
1753
1754 for ( uint i = 0; i < lines; i++ ) {
1755 prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1756 _igvn.MakeConX(distance) );
1757 transform_later(prefetch_adr);
1758 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1759 transform_later(prefetch);
1760 distance += step_size;
1761 i_o = prefetch;
1762 }
1763 pf_phi_abio->set_req( pf_path, i_o );
1764
1765 pf_region->init_req( fall_in_path, need_pf_false );
1766 pf_region->init_req( pf_path, need_pf_true );
1767
1768 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1769 pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1770
1771 transform_later(pf_region);
1772 transform_later(pf_phi_rawmem);
1773 transform_later(pf_phi_abio);
1774
1775 needgc_false = pf_region;
1776 contended_phi_rawmem = pf_phi_rawmem;
1777 i_o = pf_phi_abio;
1778 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1779 // Insert a prefetch for each allocation.
1780 // This code is used for Sparc with BIS.
1781 Node *pf_region = new RegionNode(3);
1782 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1783 TypeRawPtr::BOTTOM );
1784 transform_later(pf_region);
1785
1786 // Generate several prefetch instructions.
1787 uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1788 uint step_size = AllocatePrefetchStepSize;
1789 uint distance = AllocatePrefetchDistance;
1790
1791 // Next cache address.
1792 Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1793 _igvn.MakeConX(distance));
1794 transform_later(cache_adr);
1795 cache_adr = new CastP2XNode(needgc_false, cache_adr);
1796 transform_later(cache_adr);
1797 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1798 cache_adr = new AndXNode(cache_adr, mask);
1799 transform_later(cache_adr);
1800 cache_adr = new CastX2PNode(cache_adr);
1801 transform_later(cache_adr);
1802
1803 // Prefetch
1804 Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1805 prefetch->set_req(0, needgc_false);
1806 transform_later(prefetch);
1807 contended_phi_rawmem = prefetch;
1808 Node *prefetch_adr;
1809 distance = step_size;
1810 for ( uint i = 1; i < lines; i++ ) {
1811 prefetch_adr = new AddPNode( cache_adr, cache_adr,
1812 _igvn.MakeConX(distance) );
1813 transform_later(prefetch_adr);
1814 prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1815 transform_later(prefetch);
1816 distance += step_size;
1817 contended_phi_rawmem = prefetch;
1818 }
1819 } else if( AllocatePrefetchStyle > 0 ) {
1820 // Insert a prefetch for each allocation only on the fast-path
1821 Node *prefetch_adr;
1822 Node *prefetch;
1823 // Generate several prefetch instructions.
1824 uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1825 uint step_size = AllocatePrefetchStepSize;
1826 uint distance = AllocatePrefetchDistance;
1827 for ( uint i = 0; i < lines; i++ ) {
1828 prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1829 _igvn.MakeConX(distance) );
1830 transform_later(prefetch_adr);
1831 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1832 // Do not let it float too high, since if eden_top == eden_end,
1833 // both might be null.
1834 if( i == 0 ) { // Set control for first prefetch, next follows it
1835 prefetch->init_req(0, needgc_false);
1836 }
1837 transform_later(prefetch);
1838 distance += step_size;
1839 i_o = prefetch;
1840 }
1841 }
1842 return i_o;
1843 }
1844
1845
1846 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1847 expand_allocate_common(alloc, NULL,
1848 OptoRuntime::new_instance_Type(),
1849 OptoRuntime::new_instance_Java());
1850 }
1851
1852 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1853 Node* length = alloc->in(AllocateNode::ALength);
1854 InitializeNode* init = alloc->initialization();
1855 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1856 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1857 address slow_call_address; // Address of slow call
1858 if (init != NULL && init->is_complete_with_arraycopy() &&
1859 k->is_type_array_klass()) {
1860 // Don't zero type array during slow allocation in VM since
1861 // it will be initialized later by arraycopy in compiled code.
1862 slow_call_address = OptoRuntime::new_array_nozero_Java();
1863 } else {
1864 slow_call_address = OptoRuntime::new_array_Java();
1865 }
1866 expand_allocate_common(alloc, length,
1867 OptoRuntime::new_array_Type(),
1868 slow_call_address);
1869 }
1870
1871 //-------------------mark_eliminated_box----------------------------------
1872 //
1873 // During EA obj may point to several objects but after few ideal graph
1874 // transformations (CCP) it may point to only one non escaping object
1875 // (but still using phi), corresponding locks and unlocks will be marked
1876 // for elimination. Later obj could be replaced with a new node (new phi)
1877 // and which does not have escape information. And later after some graph
1878 // reshape other locks and unlocks (which were not marked for elimination
1879 // before) are connected to this new obj (phi) but they still will not be
1880 // marked for elimination since new obj has no escape information.
1881 // Mark all associated (same box and obj) lock and unlock nodes for
1882 // elimination if some of them marked already.
1883 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1884 if (oldbox->as_BoxLock()->is_eliminated())
1885 return; // This BoxLock node was processed already.
1886
1887 // New implementation (EliminateNestedLocks) has separate BoxLock
1888 // node for each locked region so mark all associated locks/unlocks as
1889 // eliminated even if different objects are referenced in one locked region
1890 // (for example, OSR compilation of nested loop inside locked scope).
1891 if (EliminateNestedLocks ||
1892 oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
1893 // Box is used only in one lock region. Mark this box as eliminated.
1894 _igvn.hash_delete(oldbox);
1895 oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1896 _igvn.hash_insert(oldbox);
1897
1898 for (uint i = 0; i < oldbox->outcnt(); i++) {
1899 Node* u = oldbox->raw_out(i);
1900 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1901 AbstractLockNode* alock = u->as_AbstractLock();
1902 // Check lock's box since box could be referenced by Lock's debug info.
1903 if (alock->box_node() == oldbox) {
1904 // Mark eliminated all related locks and unlocks.
1905 alock->set_non_esc_obj();
1906 }
1907 }
1908 }
1909 return;
1910 }
1911
1912 // Create new "eliminated" BoxLock node and use it in monitor debug info
1913 // instead of oldbox for the same object.
1914 BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1915
1916 // Note: BoxLock node is marked eliminated only here and it is used
1917 // to indicate that all associated lock and unlock nodes are marked
1918 // for elimination.
1919 newbox->set_eliminated();
1920 transform_later(newbox);
1921
1922 // Replace old box node with new box for all users of the same object.
1923 for (uint i = 0; i < oldbox->outcnt();) {
1924 bool next_edge = true;
1925
1926 Node* u = oldbox->raw_out(i);
1927 if (u->is_AbstractLock()) {
1928 AbstractLockNode* alock = u->as_AbstractLock();
1929 if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
1930 // Replace Box and mark eliminated all related locks and unlocks.
1931 alock->set_non_esc_obj();
1932 _igvn.rehash_node_delayed(alock);
1933 alock->set_box_node(newbox);
1934 next_edge = false;
1935 }
1936 }
1937 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
1938 FastLockNode* flock = u->as_FastLock();
1939 assert(flock->box_node() == oldbox, "sanity");
1940 _igvn.rehash_node_delayed(flock);
1941 flock->set_box_node(newbox);
1942 next_edge = false;
1943 }
1944
1945 // Replace old box in monitor debug info.
1946 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1947 SafePointNode* sfn = u->as_SafePoint();
1948 JVMState* youngest_jvms = sfn->jvms();
1949 int max_depth = youngest_jvms->depth();
1950 for (int depth = 1; depth <= max_depth; depth++) {
1951 JVMState* jvms = youngest_jvms->of_depth(depth);
1952 int num_mon = jvms->nof_monitors();
1953 // Loop over monitors
1954 for (int idx = 0; idx < num_mon; idx++) {
1955 Node* obj_node = sfn->monitor_obj(jvms, idx);
1956 Node* box_node = sfn->monitor_box(jvms, idx);
1957 if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
1958 int j = jvms->monitor_box_offset(idx);
1959 _igvn.replace_input_of(u, j, newbox);
1960 next_edge = false;
1961 }
1962 }
1963 }
1964 }
1965 if (next_edge) i++;
1966 }
1967 }
1968
1969 //-----------------------mark_eliminated_locking_nodes-----------------------
1970 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1971 if (EliminateNestedLocks) {
1972 if (alock->is_nested()) {
1973 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
1974 return;
1975 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
1976 // Only Lock node has JVMState needed here.
1977 if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
1978 // Mark eliminated related nested locks and unlocks.
1979 Node* obj = alock->obj_node();
1980 BoxLockNode* box_node = alock->box_node()->as_BoxLock();
1981 assert(!box_node->is_eliminated(), "should not be marked yet");
1982 // Note: BoxLock node is marked eliminated only here
1983 // and it is used to indicate that all associated lock
1984 // and unlock nodes are marked for elimination.
1985 box_node->set_eliminated(); // Box's hash is always NO_HASH here
1986 for (uint i = 0; i < box_node->outcnt(); i++) {
1987 Node* u = box_node->raw_out(i);
1988 if (u->is_AbstractLock()) {
1989 alock = u->as_AbstractLock();
1990 if (alock->box_node() == box_node) {
1991 // Verify that this Box is referenced only by related locks.
1992 assert(alock->obj_node()->eqv_uncast(obj), "");
1993 // Mark all related locks and unlocks.
1994 alock->set_nested();
1995 }
1996 }
1997 }
1998 }
1999 return;
2000 }
2001 // Process locks for non escaping object
2002 assert(alock->is_non_esc_obj(), "");
2003 } // EliminateNestedLocks
2004
2005 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2006 // Look for all locks of this object and mark them and
2007 // corresponding BoxLock nodes as eliminated.
2008 Node* obj = alock->obj_node();
2009 for (uint j = 0; j < obj->outcnt(); j++) {
2010 Node* o = obj->raw_out(j);
2011 if (o->is_AbstractLock() &&
2012 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2013 alock = o->as_AbstractLock();
2014 Node* box = alock->box_node();
2015 // Replace old box node with new eliminated box for all users
2016 // of the same object and mark related locks as eliminated.
2017 mark_eliminated_box(box, obj);
2018 }
2019 }
2020 }
2021 }
2022
2023 // we have determined that this lock/unlock can be eliminated, we simply
2024 // eliminate the node without expanding it.
2025 //
2026 // Note: The membar's associated with the lock/unlock are currently not
2027 // eliminated. This should be investigated as a future enhancement.
2028 //
2029 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2030
2031 if (!alock->is_eliminated()) {
2032 return false;
2033 }
2034 #ifdef ASSERT
2035 if (!alock->is_coarsened()) {
2036 // Check that new "eliminated" BoxLock node is created.
2037 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2038 assert(oldbox->is_eliminated(), "should be done already");
2039 }
2040 #endif
2041 CompileLog* log = C->log();
2042 if (log != NULL) {
2043 log->head("eliminate_lock lock='%d'",
2044 alock->is_Lock());
2045 JVMState* p = alock->jvms();
2046 while (p != NULL) {
2047 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
2048 p = p->caller();
2049 }
2050 log->tail("eliminate_lock");
2051 }
2052
2053 #ifndef PRODUCT
2054 if (PrintEliminateLocks) {
2055 if (alock->is_Lock()) {
2056 tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2057 } else {
2058 tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2059 }
2060 }
2061 #endif
2062
2063 Node* mem = alock->in(TypeFunc::Memory);
2064 Node* ctrl = alock->in(TypeFunc::Control);
2065
2066 extract_call_projections(alock);
2067 // There are 2 projections from the lock. The lock node will
2068 // be deleted when its last use is subsumed below.
2069 assert(alock->outcnt() == 2 &&
2070 _fallthroughproj != NULL &&
2071 _memproj_fallthrough != NULL,
2072 "Unexpected projections from Lock/Unlock");
2073
2074 Node* fallthroughproj = _fallthroughproj;
2075 Node* memproj_fallthrough = _memproj_fallthrough;
2076
2077 // The memory projection from a lock/unlock is RawMem
2078 // The input to a Lock is merged memory, so extract its RawMem input
2079 // (unless the MergeMem has been optimized away.)
2080 if (alock->is_Lock()) {
2081 // Seach for MemBarAcquireLock node and delete it also.
2082 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2083 assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2084 Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2085 Node* memproj = membar->proj_out(TypeFunc::Memory);
2086 _igvn.replace_node(ctrlproj, fallthroughproj);
2087 _igvn.replace_node(memproj, memproj_fallthrough);
2088
2089 // Delete FastLock node also if this Lock node is unique user
2090 // (a loop peeling may clone a Lock node).
2091 Node* flock = alock->as_Lock()->fastlock_node();
2092 if (flock->outcnt() == 1) {
2093 assert(flock->unique_out() == alock, "sanity");
2094 _igvn.replace_node(flock, top());
2095 }
2096 }
2097
2098 // Seach for MemBarReleaseLock node and delete it also.
2099 if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
2100 ctrl->in(0)->is_MemBar()) {
2101 MemBarNode* membar = ctrl->in(0)->as_MemBar();
2102 assert(membar->Opcode() == Op_MemBarReleaseLock &&
2103 mem->is_Proj() && membar == mem->in(0), "");
2104 _igvn.replace_node(fallthroughproj, ctrl);
2105 _igvn.replace_node(memproj_fallthrough, mem);
2106 fallthroughproj = ctrl;
2107 memproj_fallthrough = mem;
2108 ctrl = membar->in(TypeFunc::Control);
2109 mem = membar->in(TypeFunc::Memory);
2110 }
2111
2112 _igvn.replace_node(fallthroughproj, ctrl);
2113 _igvn.replace_node(memproj_fallthrough, mem);
2114 return true;
2115 }
2116
2117
2118 //------------------------------expand_lock_node----------------------
2119 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2120
2121 Node* ctrl = lock->in(TypeFunc::Control);
2122 Node* mem = lock->in(TypeFunc::Memory);
2123 Node* obj = lock->obj_node();
2124 Node* box = lock->box_node();
2125 Node* flock = lock->fastlock_node();
2126
2127 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2128
2129 // Make the merge point
2130 Node *region;
2131 Node *mem_phi;
2132 Node *slow_path;
2133
2134 if (UseOptoBiasInlining) {
2135 /*
2136 * See the full description in MacroAssembler::biased_locking_enter().
2137 *
2138 * if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2139 * // The object is biased.
2140 * proto_node = klass->prototype_header;
2141 * o_node = thread | proto_node;
2142 * x_node = o_node ^ mark_word;
2143 * if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2144 * // Done.
2145 * } else {
2146 * if( (x_node & biased_lock_mask) != 0 ) {
2147 * // The klass's prototype header is no longer biased.
2148 * cas(&mark_word, mark_word, proto_node)
2149 * goto cas_lock;
2150 * } else {
2151 * // The klass's prototype header is still biased.
2152 * if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2153 * old = mark_word;
2154 * new = o_node;
2155 * } else {
2156 * // Different thread or anonymous biased.
2157 * old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2158 * new = thread | old;
2159 * }
2160 * // Try to rebias.
2161 * if( cas(&mark_word, old, new) == 0 ) {
2162 * // Done.
2163 * } else {
2164 * goto slow_path; // Failed.
2165 * }
2166 * }
2167 * }
2168 * } else {
2169 * // The object is not biased.
2170 * cas_lock:
2171 * if( FastLock(obj) == 0 ) {
2172 * // Done.
2173 * } else {
2174 * slow_path:
2175 * OptoRuntime::complete_monitor_locking_Java(obj);
2176 * }
2177 * }
2178 */
2179
2180 region = new RegionNode(5);
2181 // create a Phi for the memory state
2182 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2183
2184 Node* fast_lock_region = new RegionNode(3);
2185 Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2186
2187 // First, check mark word for the biased lock pattern.
2188 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2189
2190 // Get fast path - mark word has the biased lock pattern.
2191 ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2192 markOopDesc::biased_lock_mask_in_place,
2193 markOopDesc::biased_lock_pattern, true);
2194 // fast_lock_region->in(1) is set to slow path.
2195 fast_lock_mem_phi->init_req(1, mem);
2196
2197 // Now check that the lock is biased to the current thread and has
2198 // the same epoch and bias as Klass::_prototype_header.
2199
2200 // Special-case a fresh allocation to avoid building nodes:
2201 Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2202 if (klass_node == NULL) {
2203 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2204 klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
2205 #ifdef _LP64
2206 if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2207 assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2208 klass_node->in(1)->init_req(0, ctrl);
2209 } else
2210 #endif
2211 klass_node->init_req(0, ctrl);
2212 }
2213 Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2214
2215 Node* thread = transform_later(new ThreadLocalNode());
2216 Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2217 Node* o_node = transform_later(new OrXNode(cast_thread, proto_node));
2218 Node* x_node = transform_later(new XorXNode(o_node, mark_node));
2219
2220 // Get slow path - mark word does NOT match the value.
2221 Node* not_biased_ctrl = opt_bits_test(ctrl, region, 3, x_node,
2222 (~markOopDesc::age_mask_in_place), 0);
2223 // region->in(3) is set to fast path - the object is biased to the current thread.
2224 mem_phi->init_req(3, mem);
2225
2226
2227 // Mark word does NOT match the value (thread | Klass::_prototype_header).
2228
2229
2230 // First, check biased pattern.
2231 // Get fast path - _prototype_header has the same biased lock pattern.
2232 ctrl = opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2233 markOopDesc::biased_lock_mask_in_place, 0, true);
2234
2235 not_biased_ctrl = fast_lock_region->in(2); // Slow path
2236 // fast_lock_region->in(2) - the prototype header is no longer biased
2237 // and we have to revoke the bias on this object.
2238 // We are going to try to reset the mark of this object to the prototype
2239 // value and fall through to the CAS-based locking scheme.
2240 Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2241 Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr,
2242 proto_node, mark_node);
2243 transform_later(cas);
2244 Node* proj = transform_later(new SCMemProjNode(cas));
2245 fast_lock_mem_phi->init_req(2, proj);
2246
2247
2248 // Second, check epoch bits.
2249 Node* rebiased_region = new RegionNode(3);
2250 Node* old_phi = new PhiNode( rebiased_region, TypeX_X);
2251 Node* new_phi = new PhiNode( rebiased_region, TypeX_X);
2252
2253 // Get slow path - mark word does NOT match epoch bits.
2254 Node* epoch_ctrl = opt_bits_test(ctrl, rebiased_region, 1, x_node,
2255 markOopDesc::epoch_mask_in_place, 0);
2256 // The epoch of the current bias is not valid, attempt to rebias the object
2257 // toward the current thread.
2258 rebiased_region->init_req(2, epoch_ctrl);
2259 old_phi->init_req(2, mark_node);
2260 new_phi->init_req(2, o_node);
2261
2262 // rebiased_region->in(1) is set to fast path.
2263 // The epoch of the current bias is still valid but we know
2264 // nothing about the owner; it might be set or it might be clear.
2265 Node* cmask = MakeConX(markOopDesc::biased_lock_mask_in_place |
2266 markOopDesc::age_mask_in_place |
2267 markOopDesc::epoch_mask_in_place);
2268 Node* old = transform_later(new AndXNode(mark_node, cmask));
2269 cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2270 Node* new_mark = transform_later(new OrXNode(cast_thread, old));
2271 old_phi->init_req(1, old);
2272 new_phi->init_req(1, new_mark);
2273
2274 transform_later(rebiased_region);
2275 transform_later(old_phi);
2276 transform_later(new_phi);
2277
2278 // Try to acquire the bias of the object using an atomic operation.
2279 // If this fails we will go in to the runtime to revoke the object's bias.
2280 cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi);
2281 transform_later(cas);
2282 proj = transform_later(new SCMemProjNode(cas));
2283
2284 // Get slow path - Failed to CAS.
2285 not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2286 mem_phi->init_req(4, proj);
2287 // region->in(4) is set to fast path - the object is rebiased to the current thread.
2288
2289 // Failed to CAS.
2290 slow_path = new RegionNode(3);
2291 Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2292
2293 slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2294 slow_mem->init_req(1, proj);
2295
2296 // Call CAS-based locking scheme (FastLock node).
2297
2298 transform_later(fast_lock_region);
2299 transform_later(fast_lock_mem_phi);
2300
2301 // Get slow path - FastLock failed to lock the object.
2302 ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2303 mem_phi->init_req(2, fast_lock_mem_phi);
2304 // region->in(2) is set to fast path - the object is locked to the current thread.
2305
2306 slow_path->init_req(2, ctrl); // Capture slow-control
2307 slow_mem->init_req(2, fast_lock_mem_phi);
2308
2309 transform_later(slow_path);
2310 transform_later(slow_mem);
2311 // Reset lock's memory edge.
2312 lock->set_req(TypeFunc::Memory, slow_mem);
2313
2314 } else {
2315 region = new RegionNode(3);
2316 // create a Phi for the memory state
2317 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2318
2319 // Optimize test; set region slot 2
2320 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2321 mem_phi->init_req(2, mem);
2322 }
2323
2324 // Make slow path call
2325 CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2326
2327 extract_call_projections(call);
2328
2329 // Slow path can only throw asynchronous exceptions, which are always
2330 // de-opted. So the compiler thinks the slow-call can never throw an
2331 // exception. If it DOES throw an exception we would need the debug
2332 // info removed first (since if it throws there is no monitor).
2333 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2334 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2335
2336 // Capture slow path
2337 // disconnect fall-through projection from call and create a new one
2338 // hook up users of fall-through projection to region
2339 Node *slow_ctrl = _fallthroughproj->clone();
2340 transform_later(slow_ctrl);
2341 _igvn.hash_delete(_fallthroughproj);
2342 _fallthroughproj->disconnect_inputs(NULL, C);
2343 region->init_req(1, slow_ctrl);
2344 // region inputs are now complete
2345 transform_later(region);
2346 _igvn.replace_node(_fallthroughproj, region);
2347
2348 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2349 mem_phi->init_req(1, memproj );
2350 transform_later(mem_phi);
2351 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2352 }
2353
2354 //------------------------------expand_unlock_node----------------------
2355 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2356
2357 Node* ctrl = unlock->in(TypeFunc::Control);
2358 Node* mem = unlock->in(TypeFunc::Memory);
2359 Node* obj = unlock->obj_node();
2360 Node* box = unlock->box_node();
2361
2362 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2363
2364 // No need for a null check on unlock
2365
2366 // Make the merge point
2367 Node *region;
2368 Node *mem_phi;
2369
2370 if (UseOptoBiasInlining) {
2371 // Check for biased locking unlock case, which is a no-op.
2372 // See the full description in MacroAssembler::biased_locking_exit().
2373 region = new RegionNode(4);
2374 // create a Phi for the memory state
2375 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2376 mem_phi->init_req(3, mem);
2377
2378 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2379 ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2380 markOopDesc::biased_lock_mask_in_place,
2381 markOopDesc::biased_lock_pattern);
2382 } else {
2383 region = new RegionNode(3);
2384 // create a Phi for the memory state
2385 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2386 }
2387
2388 FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2389 funlock = transform_later( funlock )->as_FastUnlock();
2390 // Optimize test; set region slot 2
2391 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2392
2393 CallNode *call = make_slow_call( (CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), "complete_monitor_unlocking_C", slow_path, obj, box );
2394
2395 extract_call_projections(call);
2396
2397 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2398 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2399
2400 // No exceptions for unlocking
2401 // Capture slow path
2402 // disconnect fall-through projection from call and create a new one
2403 // hook up users of fall-through projection to region
2404 Node *slow_ctrl = _fallthroughproj->clone();
2405 transform_later(slow_ctrl);
2406 _igvn.hash_delete(_fallthroughproj);
2407 _fallthroughproj->disconnect_inputs(NULL, C);
2408 region->init_req(1, slow_ctrl);
2409 // region inputs are now complete
2410 transform_later(region);
2411 _igvn.replace_node(_fallthroughproj, region);
2412
2413 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2414 mem_phi->init_req(1, memproj );
2415 mem_phi->init_req(2, mem);
2416 transform_later(mem_phi);
2417 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2418 }
2419
2420 //---------------------------eliminate_macro_nodes----------------------
2421 // Eliminate scalar replaced allocations and associated locks.
2422 void PhaseMacroExpand::eliminate_macro_nodes() {
2423 if (C->macro_count() == 0)
2424 return;
2425
2426 // First, attempt to eliminate locks
2427 int cnt = C->macro_count();
2428 for (int i=0; i < cnt; i++) {
2429 Node *n = C->macro_node(i);
2430 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2431 // Before elimination mark all associated (same box and obj)
2432 // lock and unlock nodes.
2433 mark_eliminated_locking_nodes(n->as_AbstractLock());
2434 }
2435 }
2436 bool progress = true;
2437 while (progress) {
2438 progress = false;
2439 for (int i = C->macro_count(); i > 0; i--) {
2440 Node * n = C->macro_node(i-1);
2441 bool success = false;
2442 debug_only(int old_macro_count = C->macro_count(););
2443 if (n->is_AbstractLock()) {
2444 success = eliminate_locking_node(n->as_AbstractLock());
2445 }
2446 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2447 progress = progress || success;
2448 }
2449 }
2450 // Next, attempt to eliminate allocations
2451 _has_locks = false;
2452 progress = true;
2453 while (progress) {
2454 progress = false;
2455 for (int i = C->macro_count(); i > 0; i--) {
2456 Node * n = C->macro_node(i-1);
2457 bool success = false;
2458 debug_only(int old_macro_count = C->macro_count(););
2459 switch (n->class_id()) {
2460 case Node::Class_Allocate:
2461 case Node::Class_AllocateArray:
2462 success = eliminate_allocate_node(n->as_Allocate());
2463 break;
2464 case Node::Class_CallStaticJava:
2465 success = eliminate_boxing_node(n->as_CallStaticJava());
2466 break;
2467 case Node::Class_Lock:
2468 case Node::Class_Unlock:
2469 assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2470 _has_locks = true;
2471 break;
2472 case Node::Class_ArrayCopy:
2473 break;
2474 default:
2475 assert(n->Opcode() == Op_LoopLimit ||
2476 n->Opcode() == Op_Opaque1 ||
2477 n->Opcode() == Op_Opaque2 ||
2478 n->Opcode() == Op_Opaque3, "unknown node type in macro list");
2479 }
2480 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2481 progress = progress || success;
2482 }
2483 }
2484 }
2485
2486 //------------------------------expand_macro_nodes----------------------
2487 // Returns true if a failure occurred.
2488 bool PhaseMacroExpand::expand_macro_nodes() {
2489 // Last attempt to eliminate macro nodes.
2490 eliminate_macro_nodes();
2491
2492 // Make sure expansion will not cause node limit to be exceeded.
2493 // Worst case is a macro node gets expanded into about 50 nodes.
2494 // Allow 50% more for optimization.
2495 if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2496 return true;
2497
2498 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2499 bool progress = true;
2500 while (progress) {
2501 progress = false;
2502 for (int i = C->macro_count(); i > 0; i--) {
2503 Node * n = C->macro_node(i-1);
2504 bool success = false;
2505 debug_only(int old_macro_count = C->macro_count(););
2506 if (n->Opcode() == Op_LoopLimit) {
2507 // Remove it from macro list and put on IGVN worklist to optimize.
2508 C->remove_macro_node(n);
2509 _igvn._worklist.push(n);
2510 success = true;
2511 } else if (n->Opcode() == Op_CallStaticJava) {
2512 // Remove it from macro list and put on IGVN worklist to optimize.
2513 C->remove_macro_node(n);
2514 _igvn._worklist.push(n);
2515 success = true;
2516 } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2517 _igvn.replace_node(n, n->in(1));
2518 success = true;
2519 #if INCLUDE_RTM_OPT
2520 } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2521 assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2522 assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2523 Node* cmp = n->unique_out();
2524 #ifdef ASSERT
2525 // Validate graph.
2526 assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2527 BoolNode* bol = cmp->unique_out()->as_Bool();
2528 assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2529 (bol->_test._test == BoolTest::ne), "");
2530 IfNode* ifn = bol->unique_out()->as_If();
2531 assert((ifn->outcnt() == 2) &&
2532 ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change), "");
2533 #endif
2534 Node* repl = n->in(1);
2535 if (!_has_locks) {
2536 // Remove RTM state check if there are no locks in the code.
2537 // Replace input to compare the same value.
2538 repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2539 }
2540 _igvn.replace_node(n, repl);
2541 success = true;
2542 #endif
2543 }
2544 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2545 progress = progress || success;
2546 }
2547 }
2548
2549 // expand arraycopy "macro" nodes first
2550 // For ReduceBulkZeroing, we must first process all arraycopy nodes
2551 // before the allocate nodes are expanded.
2552 int macro_idx = C->macro_count() - 1;
2553 while (macro_idx >= 0) {
2554 Node * n = C->macro_node(macro_idx);
2555 assert(n->is_macro(), "only macro nodes expected here");
2556 if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2557 // node is unreachable, so don't try to expand it
2558 C->remove_macro_node(n);
2559 } else if (n->is_ArrayCopy()){
2560 int macro_count = C->macro_count();
2561 expand_arraycopy_node(n->as_ArrayCopy());
2562 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2563 }
2564 if (C->failing()) return true;
2565 macro_idx --;
2566 }
2567
2568 // expand "macro" nodes
2569 // nodes are removed from the macro list as they are processed
2570 while (C->macro_count() > 0) {
2571 int macro_count = C->macro_count();
2572 Node * n = C->macro_node(macro_count-1);
2573 assert(n->is_macro(), "only macro nodes expected here");
2574 if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2575 // node is unreachable, so don't try to expand it
2576 C->remove_macro_node(n);
2577 continue;
2578 }
2579 switch (n->class_id()) {
2580 case Node::Class_Allocate:
2581 expand_allocate(n->as_Allocate());
2582 break;
2583 case Node::Class_AllocateArray:
2584 expand_allocate_array(n->as_AllocateArray());
2585 break;
2586 case Node::Class_Lock:
2587 expand_lock_node(n->as_Lock());
2588 break;
2589 case Node::Class_Unlock:
2590 expand_unlock_node(n->as_Unlock());
2591 break;
2592 default:
2593 assert(false, "unknown node type in macro list");
2594 }
2595 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2596 if (C->failing()) return true;
2597 }
2598
2599 _igvn.set_delay_transform(false);
2600 _igvn.optimize();
2601 if (C->failing()) return true;
2602 return false;
2603 }