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