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