Wed, 16 Nov 2011 09:13:57 -0800
6890673: Eliminate allocations immediately after EA
Summary: Try to eliminate allocations and related locks immediately after escape analysis.
Reviewed-by: never
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 */
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"
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 }
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");
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, C->root()); // 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 }
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 }
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);
115 // Fast path taken.
116 Node *fast_taken = transform_later( new (C, 1) IfFalseNode(iff) );
118 // Fast path not-taken, i.e. slow path
119 Node *slow_taken = transform_later( new (C, 1) IfTrueNode(iff) );
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 }
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 }
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) {
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 );
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);
158 return call;
159 }
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 }
214 }
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.
242 // Remove G1 post barrier.
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));
263 // Remove G1 pre barrier.
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 }
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 }
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();
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 = value_phis->find(mem->_idx);
395 if (new_phi != NULL)
396 return new_phi;
398 if (level <= 0) {
399 return NULL; // Give up: phi tree too deep
400 }
401 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
402 Node *alloc_mem = alloc->in(TypeFunc::Memory);
404 uint length = mem->req();
405 GrowableArray <Node *> values(length, length, NULL);
407 // create a new Phi for the value
408 PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
409 transform_later(phi);
410 value_phis->push(phi, mem->_idx);
412 for (uint j = 1; j < length; j++) {
413 Node *in = mem->in(j);
414 if (in == NULL || in->is_top()) {
415 values.at_put(j, in);
416 } else {
417 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
418 if (val == start_mem || val == alloc_mem) {
419 // hit a sentinel, return appropriate 0 value
420 values.at_put(j, _igvn.zerocon(ft));
421 continue;
422 }
423 if (val->is_Initialize()) {
424 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
425 }
426 if (val == NULL) {
427 return NULL; // can't find a value on this path
428 }
429 if (val == mem) {
430 values.at_put(j, mem);
431 } else if (val->is_Store()) {
432 values.at_put(j, val->in(MemNode::ValueIn));
433 } else if(val->is_Proj() && val->in(0) == alloc) {
434 values.at_put(j, _igvn.zerocon(ft));
435 } else if (val->is_Phi()) {
436 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
437 if (val == NULL) {
438 return NULL;
439 }
440 values.at_put(j, val);
441 } else if (val->Opcode() == Op_SCMemProj) {
442 assert(val->in(0)->is_LoadStore(), "sanity");
443 assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
444 return NULL;
445 } else {
446 #ifdef ASSERT
447 val->dump();
448 assert(false, "unknown node on this path");
449 #endif
450 return NULL; // unknown node on this path
451 }
452 }
453 }
454 // Set Phi's inputs
455 for (uint j = 1; j < length; j++) {
456 if (values.at(j) == mem) {
457 phi->init_req(j, phi);
458 } else {
459 phi->init_req(j, values.at(j));
460 }
461 }
462 return phi;
463 }
465 // Search the last value stored into the object's field.
466 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
467 assert(adr_t->is_known_instance_field(), "instance required");
468 int instance_id = adr_t->instance_id();
469 assert((uint)instance_id == alloc->_idx, "wrong allocation");
471 int alias_idx = C->get_alias_index(adr_t);
472 int offset = adr_t->offset();
473 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
474 Node *alloc_ctrl = alloc->in(TypeFunc::Control);
475 Node *alloc_mem = alloc->in(TypeFunc::Memory);
476 Arena *a = Thread::current()->resource_area();
477 VectorSet visited(a);
480 bool done = sfpt_mem == alloc_mem;
481 Node *mem = sfpt_mem;
482 while (!done) {
483 if (visited.test_set(mem->_idx)) {
484 return NULL; // found a loop, give up
485 }
486 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
487 if (mem == start_mem || mem == alloc_mem) {
488 done = true; // hit a sentinel, return appropriate 0 value
489 } else if (mem->is_Initialize()) {
490 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
491 if (mem == NULL) {
492 done = true; // Something go wrong.
493 } else if (mem->is_Store()) {
494 const TypePtr* atype = mem->as_Store()->adr_type();
495 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
496 done = true;
497 }
498 } else if (mem->is_Store()) {
499 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
500 assert(atype != NULL, "address type must be oopptr");
501 assert(C->get_alias_index(atype) == alias_idx &&
502 atype->is_known_instance_field() && atype->offset() == offset &&
503 atype->instance_id() == instance_id, "store is correct memory slice");
504 done = true;
505 } else if (mem->is_Phi()) {
506 // try to find a phi's unique input
507 Node *unique_input = NULL;
508 Node *top = C->top();
509 for (uint i = 1; i < mem->req(); i++) {
510 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
511 if (n == NULL || n == top || n == mem) {
512 continue;
513 } else if (unique_input == NULL) {
514 unique_input = n;
515 } else if (unique_input != n) {
516 unique_input = top;
517 break;
518 }
519 }
520 if (unique_input != NULL && unique_input != top) {
521 mem = unique_input;
522 } else {
523 done = true;
524 }
525 } else {
526 assert(false, "unexpected node");
527 }
528 }
529 if (mem != NULL) {
530 if (mem == start_mem || mem == alloc_mem) {
531 // hit a sentinel, return appropriate 0 value
532 return _igvn.zerocon(ft);
533 } else if (mem->is_Store()) {
534 return mem->in(MemNode::ValueIn);
535 } else if (mem->is_Phi()) {
536 // attempt to produce a Phi reflecting the values on the input paths of the Phi
537 Node_Stack value_phis(a, 8);
538 Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
539 if (phi != NULL) {
540 return phi;
541 } else {
542 // Kill all new Phis
543 while(value_phis.is_nonempty()) {
544 Node* n = value_phis.node();
545 _igvn.replace_node(n, C->top());
546 value_phis.pop();
547 }
548 }
549 }
550 }
551 // Something go wrong.
552 return NULL;
553 }
555 // Check the possibility of scalar replacement.
556 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
557 // Scan the uses of the allocation to check for anything that would
558 // prevent us from eliminating it.
559 NOT_PRODUCT( const char* fail_eliminate = NULL; )
560 DEBUG_ONLY( Node* disq_node = NULL; )
561 bool can_eliminate = true;
563 Node* res = alloc->result_cast();
564 const TypeOopPtr* res_type = NULL;
565 if (res == NULL) {
566 // All users were eliminated.
567 } else if (!res->is_CheckCastPP()) {
568 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
569 can_eliminate = false;
570 } else {
571 res_type = _igvn.type(res)->isa_oopptr();
572 if (res_type == NULL) {
573 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
574 can_eliminate = false;
575 } else if (res_type->isa_aryptr()) {
576 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
577 if (length < 0) {
578 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
579 can_eliminate = false;
580 }
581 }
582 }
584 if (can_eliminate && res != NULL) {
585 for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
586 j < jmax && can_eliminate; j++) {
587 Node* use = res->fast_out(j);
589 if (use->is_AddP()) {
590 const TypePtr* addp_type = _igvn.type(use)->is_ptr();
591 int offset = addp_type->offset();
593 if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
594 NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
595 can_eliminate = false;
596 break;
597 }
598 for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
599 k < kmax && can_eliminate; k++) {
600 Node* n = use->fast_out(k);
601 if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
602 DEBUG_ONLY(disq_node = n;)
603 if (n->is_Load() || n->is_LoadStore()) {
604 NOT_PRODUCT(fail_eliminate = "Field load";)
605 } else {
606 NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
607 }
608 can_eliminate = false;
609 }
610 }
611 } else if (use->is_SafePoint()) {
612 SafePointNode* sfpt = use->as_SafePoint();
613 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
614 // Object is passed as argument.
615 DEBUG_ONLY(disq_node = use;)
616 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
617 can_eliminate = false;
618 }
619 Node* sfptMem = sfpt->memory();
620 if (sfptMem == NULL || sfptMem->is_top()) {
621 DEBUG_ONLY(disq_node = use;)
622 NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
623 can_eliminate = false;
624 } else {
625 safepoints.append_if_missing(sfpt);
626 }
627 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
628 if (use->is_Phi()) {
629 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
630 NOT_PRODUCT(fail_eliminate = "Object is return value";)
631 } else {
632 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
633 }
634 DEBUG_ONLY(disq_node = use;)
635 } else {
636 if (use->Opcode() == Op_Return) {
637 NOT_PRODUCT(fail_eliminate = "Object is return value";)
638 }else {
639 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
640 }
641 DEBUG_ONLY(disq_node = use;)
642 }
643 can_eliminate = false;
644 }
645 }
646 }
648 #ifndef PRODUCT
649 if (PrintEliminateAllocations) {
650 if (can_eliminate) {
651 tty->print("Scalar ");
652 if (res == NULL)
653 alloc->dump();
654 else
655 res->dump();
656 } else {
657 tty->print("NotScalar (%s)", fail_eliminate);
658 if (res == NULL)
659 alloc->dump();
660 else
661 res->dump();
662 #ifdef ASSERT
663 if (disq_node != NULL) {
664 tty->print(" >>>> ");
665 disq_node->dump();
666 }
667 #endif /*ASSERT*/
668 }
669 }
670 #endif
671 return can_eliminate;
672 }
674 // Do scalar replacement.
675 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
676 GrowableArray <SafePointNode *> safepoints_done;
678 ciKlass* klass = NULL;
679 ciInstanceKlass* iklass = NULL;
680 int nfields = 0;
681 int array_base;
682 int element_size;
683 BasicType basic_elem_type;
684 ciType* elem_type;
686 Node* res = alloc->result_cast();
687 const TypeOopPtr* res_type = NULL;
688 if (res != NULL) { // Could be NULL when there are no users
689 res_type = _igvn.type(res)->isa_oopptr();
690 }
692 if (res != NULL) {
693 klass = res_type->klass();
694 if (res_type->isa_instptr()) {
695 // find the fields of the class which will be needed for safepoint debug information
696 assert(klass->is_instance_klass(), "must be an instance klass.");
697 iklass = klass->as_instance_klass();
698 nfields = iklass->nof_nonstatic_fields();
699 } else {
700 // find the array's elements which will be needed for safepoint debug information
701 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
702 assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
703 elem_type = klass->as_array_klass()->element_type();
704 basic_elem_type = elem_type->basic_type();
705 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
706 element_size = type2aelembytes(basic_elem_type);
707 }
708 }
709 //
710 // Process the safepoint uses
711 //
712 while (safepoints.length() > 0) {
713 SafePointNode* sfpt = safepoints.pop();
714 Node* mem = sfpt->memory();
715 uint first_ind = sfpt->req();
716 SafePointScalarObjectNode* sobj = new (C, 1) SafePointScalarObjectNode(res_type,
717 #ifdef ASSERT
718 alloc,
719 #endif
720 first_ind, nfields);
721 sobj->init_req(0, C->root());
722 transform_later(sobj);
724 // Scan object's fields adding an input to the safepoint for each field.
725 for (int j = 0; j < nfields; j++) {
726 intptr_t offset;
727 ciField* field = NULL;
728 if (iklass != NULL) {
729 field = iklass->nonstatic_field_at(j);
730 offset = field->offset();
731 elem_type = field->type();
732 basic_elem_type = field->layout_type();
733 } else {
734 offset = array_base + j * (intptr_t)element_size;
735 }
737 const Type *field_type;
738 // The next code is taken from Parse::do_get_xxx().
739 if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
740 if (!elem_type->is_loaded()) {
741 field_type = TypeInstPtr::BOTTOM;
742 } else if (field != NULL && field->is_constant() && field->is_static()) {
743 // This can happen if the constant oop is non-perm.
744 ciObject* con = field->constant_value().as_object();
745 // Do not "join" in the previous type; it doesn't add value,
746 // and may yield a vacuous result if the field is of interface type.
747 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
748 assert(field_type != NULL, "field singleton type must be consistent");
749 } else {
750 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
751 }
752 if (UseCompressedOops) {
753 field_type = field_type->make_narrowoop();
754 basic_elem_type = T_NARROWOOP;
755 }
756 } else {
757 field_type = Type::get_const_basic_type(basic_elem_type);
758 }
760 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
762 Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
763 if (field_val == NULL) {
764 // We weren't able to find a value for this field,
765 // give up on eliminating this allocation.
767 // Remove any extra entries we added to the safepoint.
768 uint last = sfpt->req() - 1;
769 for (int k = 0; k < j; k++) {
770 sfpt->del_req(last--);
771 }
772 // rollback processed safepoints
773 while (safepoints_done.length() > 0) {
774 SafePointNode* sfpt_done = safepoints_done.pop();
775 // remove any extra entries we added to the safepoint
776 last = sfpt_done->req() - 1;
777 for (int k = 0; k < nfields; k++) {
778 sfpt_done->del_req(last--);
779 }
780 JVMState *jvms = sfpt_done->jvms();
781 jvms->set_endoff(sfpt_done->req());
782 // Now make a pass over the debug information replacing any references
783 // to SafePointScalarObjectNode with the allocated object.
784 int start = jvms->debug_start();
785 int end = jvms->debug_end();
786 for (int i = start; i < end; i++) {
787 if (sfpt_done->in(i)->is_SafePointScalarObject()) {
788 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
789 if (scobj->first_index() == sfpt_done->req() &&
790 scobj->n_fields() == (uint)nfields) {
791 assert(scobj->alloc() == alloc, "sanity");
792 sfpt_done->set_req(i, res);
793 }
794 }
795 }
796 }
797 #ifndef PRODUCT
798 if (PrintEliminateAllocations) {
799 if (field != NULL) {
800 tty->print("=== At SafePoint node %d can't find value of Field: ",
801 sfpt->_idx);
802 field->print();
803 int field_idx = C->get_alias_index(field_addr_type);
804 tty->print(" (alias_idx=%d)", field_idx);
805 } else { // Array's element
806 tty->print("=== At SafePoint node %d can't find value of array element [%d]",
807 sfpt->_idx, j);
808 }
809 tty->print(", which prevents elimination of: ");
810 if (res == NULL)
811 alloc->dump();
812 else
813 res->dump();
814 }
815 #endif
816 return false;
817 }
818 if (UseCompressedOops && field_type->isa_narrowoop()) {
819 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
820 // to be able scalar replace the allocation.
821 if (field_val->is_EncodeP()) {
822 field_val = field_val->in(1);
823 } else {
824 field_val = transform_later(new (C, 2) DecodeNNode(field_val, field_val->bottom_type()->make_ptr()));
825 }
826 }
827 sfpt->add_req(field_val);
828 }
829 JVMState *jvms = sfpt->jvms();
830 jvms->set_endoff(sfpt->req());
831 // Now make a pass over the debug information replacing any references
832 // to the allocated object with "sobj"
833 int start = jvms->debug_start();
834 int end = jvms->debug_end();
835 for (int i = start; i < end; i++) {
836 if (sfpt->in(i) == res) {
837 sfpt->set_req(i, sobj);
838 }
839 }
840 safepoints_done.append_if_missing(sfpt); // keep it for rollback
841 }
842 return true;
843 }
845 // Process users of eliminated allocation.
846 void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
847 Node* res = alloc->result_cast();
848 if (res != NULL) {
849 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
850 Node *use = res->last_out(j);
851 uint oc1 = res->outcnt();
853 if (use->is_AddP()) {
854 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
855 Node *n = use->last_out(k);
856 uint oc2 = use->outcnt();
857 if (n->is_Store()) {
858 #ifdef ASSERT
859 // Verify that there is no dependent MemBarVolatile nodes,
860 // they should be removed during IGVN, see MemBarNode::Ideal().
861 for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
862 p < pmax; p++) {
863 Node* mb = n->fast_out(p);
864 assert(mb->is_Initialize() || !mb->is_MemBar() ||
865 mb->req() <= MemBarNode::Precedent ||
866 mb->in(MemBarNode::Precedent) != n,
867 "MemBarVolatile should be eliminated for non-escaping object");
868 }
869 #endif
870 _igvn.replace_node(n, n->in(MemNode::Memory));
871 } else {
872 eliminate_card_mark(n);
873 }
874 k -= (oc2 - use->outcnt());
875 }
876 } else {
877 eliminate_card_mark(use);
878 }
879 j -= (oc1 - res->outcnt());
880 }
881 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
882 _igvn.remove_dead_node(res);
883 }
885 //
886 // Process other users of allocation's projections
887 //
888 if (_resproj != NULL && _resproj->outcnt() != 0) {
889 for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
890 Node *use = _resproj->last_out(j);
891 uint oc1 = _resproj->outcnt();
892 if (use->is_Initialize()) {
893 // Eliminate Initialize node.
894 InitializeNode *init = use->as_Initialize();
895 assert(init->outcnt() <= 2, "only a control and memory projection expected");
896 Node *ctrl_proj = init->proj_out(TypeFunc::Control);
897 if (ctrl_proj != NULL) {
898 assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
899 _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
900 }
901 Node *mem_proj = init->proj_out(TypeFunc::Memory);
902 if (mem_proj != NULL) {
903 Node *mem = init->in(TypeFunc::Memory);
904 #ifdef ASSERT
905 if (mem->is_MergeMem()) {
906 assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
907 } else {
908 assert(mem == _memproj_fallthrough, "allocation memory projection");
909 }
910 #endif
911 _igvn.replace_node(mem_proj, mem);
912 }
913 } else if (use->is_AddP()) {
914 // raw memory addresses used only by the initialization
915 _igvn.replace_node(use, C->top());
916 } else {
917 assert(false, "only Initialize or AddP expected");
918 }
919 j -= (oc1 - _resproj->outcnt());
920 }
921 }
922 if (_fallthroughcatchproj != NULL) {
923 _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
924 }
925 if (_memproj_fallthrough != NULL) {
926 _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
927 }
928 if (_memproj_catchall != NULL) {
929 _igvn.replace_node(_memproj_catchall, C->top());
930 }
931 if (_ioproj_fallthrough != NULL) {
932 _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
933 }
934 if (_ioproj_catchall != NULL) {
935 _igvn.replace_node(_ioproj_catchall, C->top());
936 }
937 if (_catchallcatchproj != NULL) {
938 _igvn.replace_node(_catchallcatchproj, C->top());
939 }
940 }
942 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
944 if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {
945 return false;
946 }
948 extract_call_projections(alloc);
950 GrowableArray <SafePointNode *> safepoints;
951 if (!can_eliminate_allocation(alloc, safepoints)) {
952 return false;
953 }
955 if (!scalar_replacement(alloc, safepoints)) {
956 return false;
957 }
959 CompileLog* log = C->log();
960 if (log != NULL) {
961 Node* klass = alloc->in(AllocateNode::KlassNode);
962 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
963 log->head("eliminate_allocation type='%d'",
964 log->identify(tklass->klass()));
965 JVMState* p = alloc->jvms();
966 while (p != NULL) {
967 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
968 p = p->caller();
969 }
970 log->tail("eliminate_allocation");
971 }
973 process_users_of_allocation(alloc);
975 #ifndef PRODUCT
976 if (PrintEliminateAllocations) {
977 if (alloc->is_AllocateArray())
978 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
979 else
980 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
981 }
982 #endif
984 return true;
985 }
988 //---------------------------set_eden_pointers-------------------------
989 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
990 if (UseTLAB) { // Private allocation: load from TLS
991 Node* thread = transform_later(new (C, 1) ThreadLocalNode());
992 int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
993 int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
994 eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
995 eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
996 } else { // Shared allocation: load from globals
997 CollectedHeap* ch = Universe::heap();
998 address top_adr = (address)ch->top_addr();
999 address end_adr = (address)ch->end_addr();
1000 eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1001 eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1002 }
1003 }
1006 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1007 Node* adr = basic_plus_adr(base, offset);
1008 const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1009 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
1010 transform_later(value);
1011 return value;
1012 }
1015 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1016 Node* adr = basic_plus_adr(base, offset);
1017 mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
1018 transform_later(mem);
1019 return mem;
1020 }
1022 //=============================================================================
1023 //
1024 // A L L O C A T I O N
1025 //
1026 // Allocation attempts to be fast in the case of frequent small objects.
1027 // It breaks down like this:
1028 //
1029 // 1) Size in doublewords is computed. This is a constant for objects and
1030 // variable for most arrays. Doubleword units are used to avoid size
1031 // overflow of huge doubleword arrays. We need doublewords in the end for
1032 // rounding.
1033 //
1034 // 2) Size is checked for being 'too large'. Too-large allocations will go
1035 // the slow path into the VM. The slow path can throw any required
1036 // exceptions, and does all the special checks for very large arrays. The
1037 // size test can constant-fold away for objects. For objects with
1038 // finalizers it constant-folds the otherway: you always go slow with
1039 // finalizers.
1040 //
1041 // 3) If NOT using TLABs, this is the contended loop-back point.
1042 // Load-Locked the heap top. If using TLABs normal-load the heap top.
1043 //
1044 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
1045 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
1046 // "size*8" we always enter the VM, where "largish" is a constant picked small
1047 // enough that there's always space between the eden max and 4Gig (old space is
1048 // there so it's quite large) and large enough that the cost of entering the VM
1049 // is dwarfed by the cost to initialize the space.
1050 //
1051 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1052 // down. If contended, repeat at step 3. If using TLABs normal-store
1053 // adjusted heap top back down; there is no contention.
1054 //
1055 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
1056 // fields.
1057 //
1058 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1059 // oop flavor.
1060 //
1061 //=============================================================================
1062 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1063 // Allocations bigger than this always go the slow route.
1064 // This value must be small enough that allocation attempts that need to
1065 // trigger exceptions go the slow route. Also, it must be small enough so
1066 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1067 //=============================================================================j//
1068 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1069 // The allocator will coalesce int->oop copies away. See comment in
1070 // coalesce.cpp about how this works. It depends critically on the exact
1071 // code shape produced here, so if you are changing this code shape
1072 // make sure the GC info for the heap-top is correct in and around the
1073 // slow-path call.
1074 //
1076 void PhaseMacroExpand::expand_allocate_common(
1077 AllocateNode* alloc, // allocation node to be expanded
1078 Node* length, // array length for an array allocation
1079 const TypeFunc* slow_call_type, // Type of slow call
1080 address slow_call_address // Address of slow call
1081 )
1082 {
1084 Node* ctrl = alloc->in(TypeFunc::Control);
1085 Node* mem = alloc->in(TypeFunc::Memory);
1086 Node* i_o = alloc->in(TypeFunc::I_O);
1087 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
1088 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1089 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1091 assert(ctrl != NULL, "must have control");
1092 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1093 // they will not be used if "always_slow" is set
1094 enum { slow_result_path = 1, fast_result_path = 2 };
1095 Node *result_region;
1096 Node *result_phi_rawmem;
1097 Node *result_phi_rawoop;
1098 Node *result_phi_i_o;
1100 // The initial slow comparison is a size check, the comparison
1101 // we want to do is a BoolTest::gt
1102 bool always_slow = false;
1103 int tv = _igvn.find_int_con(initial_slow_test, -1);
1104 if (tv >= 0) {
1105 always_slow = (tv == 1);
1106 initial_slow_test = NULL;
1107 } else {
1108 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1109 }
1111 if (C->env()->dtrace_alloc_probes() ||
1112 !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
1113 (UseConcMarkSweepGC && CMSIncrementalMode))) {
1114 // Force slow-path allocation
1115 always_slow = true;
1116 initial_slow_test = NULL;
1117 }
1120 enum { too_big_or_final_path = 1, need_gc_path = 2 };
1121 Node *slow_region = NULL;
1122 Node *toobig_false = ctrl;
1124 assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1125 // generate the initial test if necessary
1126 if (initial_slow_test != NULL ) {
1127 slow_region = new (C, 3) RegionNode(3);
1129 // Now make the initial failure test. Usually a too-big test but
1130 // might be a TRUE for finalizers or a fancy class check for
1131 // newInstance0.
1132 IfNode *toobig_iff = new (C, 2) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1133 transform_later(toobig_iff);
1134 // Plug the failing-too-big test into the slow-path region
1135 Node *toobig_true = new (C, 1) IfTrueNode( toobig_iff );
1136 transform_later(toobig_true);
1137 slow_region ->init_req( too_big_or_final_path, toobig_true );
1138 toobig_false = new (C, 1) IfFalseNode( toobig_iff );
1139 transform_later(toobig_false);
1140 } else { // No initial test, just fall into next case
1141 toobig_false = ctrl;
1142 debug_only(slow_region = NodeSentinel);
1143 }
1145 Node *slow_mem = mem; // save the current memory state for slow path
1146 // generate the fast allocation code unless we know that the initial test will always go slow
1147 if (!always_slow) {
1148 // Fast path modifies only raw memory.
1149 if (mem->is_MergeMem()) {
1150 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1151 }
1153 Node* eden_top_adr;
1154 Node* eden_end_adr;
1156 set_eden_pointers(eden_top_adr, eden_end_adr);
1158 // Load Eden::end. Loop invariant and hoisted.
1159 //
1160 // Note: We set the control input on "eden_end" and "old_eden_top" when using
1161 // a TLAB to work around a bug where these values were being moved across
1162 // a safepoint. These are not oops, so they cannot be include in the oop
1163 // map, but they can be changed by a GC. The proper way to fix this would
1164 // be to set the raw memory state when generating a SafepointNode. However
1165 // this will require extensive changes to the loop optimization in order to
1166 // prevent a degradation of the optimization.
1167 // See comment in memnode.hpp, around line 227 in class LoadPNode.
1168 Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1170 // allocate the Region and Phi nodes for the result
1171 result_region = new (C, 3) RegionNode(3);
1172 result_phi_rawmem = new (C, 3) PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1173 result_phi_rawoop = new (C, 3) PhiNode(result_region, TypeRawPtr::BOTTOM);
1174 result_phi_i_o = new (C, 3) PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1176 // We need a Region for the loop-back contended case.
1177 enum { fall_in_path = 1, contended_loopback_path = 2 };
1178 Node *contended_region;
1179 Node *contended_phi_rawmem;
1180 if (UseTLAB) {
1181 contended_region = toobig_false;
1182 contended_phi_rawmem = mem;
1183 } else {
1184 contended_region = new (C, 3) RegionNode(3);
1185 contended_phi_rawmem = new (C, 3) PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1186 // Now handle the passing-too-big test. We fall into the contended
1187 // loop-back merge point.
1188 contended_region ->init_req(fall_in_path, toobig_false);
1189 contended_phi_rawmem->init_req(fall_in_path, mem);
1190 transform_later(contended_region);
1191 transform_later(contended_phi_rawmem);
1192 }
1194 // Load(-locked) the heap top.
1195 // See note above concerning the control input when using a TLAB
1196 Node *old_eden_top = UseTLAB
1197 ? new (C, 3) LoadPNode (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM)
1198 : new (C, 3) LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr);
1200 transform_later(old_eden_top);
1201 // Add to heap top to get a new heap top
1202 Node *new_eden_top = new (C, 4) AddPNode(top(), old_eden_top, size_in_bytes);
1203 transform_later(new_eden_top);
1204 // Check for needing a GC; compare against heap end
1205 Node *needgc_cmp = new (C, 3) CmpPNode(new_eden_top, eden_end);
1206 transform_later(needgc_cmp);
1207 Node *needgc_bol = new (C, 2) BoolNode(needgc_cmp, BoolTest::ge);
1208 transform_later(needgc_bol);
1209 IfNode *needgc_iff = new (C, 2) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1210 transform_later(needgc_iff);
1212 // Plug the failing-heap-space-need-gc test into the slow-path region
1213 Node *needgc_true = new (C, 1) IfTrueNode(needgc_iff);
1214 transform_later(needgc_true);
1215 if (initial_slow_test) {
1216 slow_region->init_req(need_gc_path, needgc_true);
1217 // This completes all paths into the slow merge point
1218 transform_later(slow_region);
1219 } else { // No initial slow path needed!
1220 // Just fall from the need-GC path straight into the VM call.
1221 slow_region = needgc_true;
1222 }
1223 // No need for a GC. Setup for the Store-Conditional
1224 Node *needgc_false = new (C, 1) IfFalseNode(needgc_iff);
1225 transform_later(needgc_false);
1227 // Grab regular I/O before optional prefetch may change it.
1228 // Slow-path does no I/O so just set it to the original I/O.
1229 result_phi_i_o->init_req(slow_result_path, i_o);
1231 i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1232 old_eden_top, new_eden_top, length);
1234 // Name successful fast-path variables
1235 Node* fast_oop = old_eden_top;
1236 Node* fast_oop_ctrl;
1237 Node* fast_oop_rawmem;
1239 // Store (-conditional) the modified eden top back down.
1240 // StorePConditional produces flags for a test PLUS a modified raw
1241 // memory state.
1242 if (UseTLAB) {
1243 Node* store_eden_top =
1244 new (C, 4) StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1245 TypeRawPtr::BOTTOM, new_eden_top);
1246 transform_later(store_eden_top);
1247 fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1248 fast_oop_rawmem = store_eden_top;
1249 } else {
1250 Node* store_eden_top =
1251 new (C, 5) StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1252 new_eden_top, fast_oop/*old_eden_top*/);
1253 transform_later(store_eden_top);
1254 Node *contention_check = new (C, 2) BoolNode(store_eden_top, BoolTest::ne);
1255 transform_later(contention_check);
1256 store_eden_top = new (C, 1) SCMemProjNode(store_eden_top);
1257 transform_later(store_eden_top);
1259 // If not using TLABs, check to see if there was contention.
1260 IfNode *contention_iff = new (C, 2) IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1261 transform_later(contention_iff);
1262 Node *contention_true = new (C, 1) IfTrueNode(contention_iff);
1263 transform_later(contention_true);
1264 // If contention, loopback and try again.
1265 contended_region->init_req(contended_loopback_path, contention_true);
1266 contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1268 // Fast-path succeeded with no contention!
1269 Node *contention_false = new (C, 1) IfFalseNode(contention_iff);
1270 transform_later(contention_false);
1271 fast_oop_ctrl = contention_false;
1273 // Bump total allocated bytes for this thread
1274 Node* thread = new (C, 1) ThreadLocalNode();
1275 transform_later(thread);
1276 Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1277 in_bytes(JavaThread::allocated_bytes_offset()));
1278 Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1279 0, TypeLong::LONG, T_LONG);
1280 #ifdef _LP64
1281 Node* alloc_size = size_in_bytes;
1282 #else
1283 Node* alloc_size = new (C, 2) ConvI2LNode(size_in_bytes);
1284 transform_later(alloc_size);
1285 #endif
1286 Node* new_alloc_bytes = new (C, 3) AddLNode(alloc_bytes, alloc_size);
1287 transform_later(new_alloc_bytes);
1288 fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1289 0, new_alloc_bytes, T_LONG);
1290 }
1292 fast_oop_rawmem = initialize_object(alloc,
1293 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1294 klass_node, length, size_in_bytes);
1296 if (C->env()->dtrace_extended_probes()) {
1297 // Slow-path call
1298 int size = TypeFunc::Parms + 2;
1299 CallLeafNode *call = new (C, size) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1300 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1301 "dtrace_object_alloc",
1302 TypeRawPtr::BOTTOM);
1304 // Get base of thread-local storage area
1305 Node* thread = new (C, 1) ThreadLocalNode();
1306 transform_later(thread);
1308 call->init_req(TypeFunc::Parms+0, thread);
1309 call->init_req(TypeFunc::Parms+1, fast_oop);
1310 call->init_req(TypeFunc::Control, fast_oop_ctrl);
1311 call->init_req(TypeFunc::I_O , top()); // does no i/o
1312 call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1313 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1314 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1315 transform_later(call);
1316 fast_oop_ctrl = new (C, 1) ProjNode(call,TypeFunc::Control);
1317 transform_later(fast_oop_ctrl);
1318 fast_oop_rawmem = new (C, 1) ProjNode(call,TypeFunc::Memory);
1319 transform_later(fast_oop_rawmem);
1320 }
1322 // Plug in the successful fast-path into the result merge point
1323 result_region ->init_req(fast_result_path, fast_oop_ctrl);
1324 result_phi_rawoop->init_req(fast_result_path, fast_oop);
1325 result_phi_i_o ->init_req(fast_result_path, i_o);
1326 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1327 } else {
1328 slow_region = ctrl;
1329 }
1331 // Generate slow-path call
1332 CallNode *call = new (C, slow_call_type->domain()->cnt())
1333 CallStaticJavaNode(slow_call_type, slow_call_address,
1334 OptoRuntime::stub_name(slow_call_address),
1335 alloc->jvms()->bci(),
1336 TypePtr::BOTTOM);
1337 call->init_req( TypeFunc::Control, slow_region );
1338 call->init_req( TypeFunc::I_O , top() ) ; // does no i/o
1339 call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1340 call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1341 call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1343 call->init_req(TypeFunc::Parms+0, klass_node);
1344 if (length != NULL) {
1345 call->init_req(TypeFunc::Parms+1, length);
1346 }
1348 // Copy debug information and adjust JVMState information, then replace
1349 // allocate node with the call
1350 copy_call_debug_info((CallNode *) alloc, call);
1351 if (!always_slow) {
1352 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1353 }
1354 _igvn.replace_node(alloc, call);
1355 transform_later(call);
1357 // Identify the output projections from the allocate node and
1358 // adjust any references to them.
1359 // The control and io projections look like:
1360 //
1361 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
1362 // Allocate Catch
1363 // ^---Proj(io) <-------+ ^---CatchProj(io)
1364 //
1365 // We are interested in the CatchProj nodes.
1366 //
1367 extract_call_projections(call);
1369 // An allocate node has separate memory projections for the uses on the control and i_o paths
1370 // Replace uses of the control memory projection with result_phi_rawmem (unless we are only generating a slow call)
1371 if (!always_slow && _memproj_fallthrough != NULL) {
1372 for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1373 Node *use = _memproj_fallthrough->fast_out(i);
1374 _igvn.hash_delete(use);
1375 imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1376 _igvn._worklist.push(use);
1377 // back up iterator
1378 --i;
1379 }
1380 }
1381 // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete _memproj_catchall so
1382 // we end up with a call that has only 1 memory projection
1383 if (_memproj_catchall != NULL ) {
1384 if (_memproj_fallthrough == NULL) {
1385 _memproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::Memory);
1386 transform_later(_memproj_fallthrough);
1387 }
1388 for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1389 Node *use = _memproj_catchall->fast_out(i);
1390 _igvn.hash_delete(use);
1391 imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1392 _igvn._worklist.push(use);
1393 // back up iterator
1394 --i;
1395 }
1396 }
1398 // An allocate node has separate i_o projections for the uses on the control and i_o paths
1399 // Replace uses of the control i_o projection with result_phi_i_o (unless we are only generating a slow call)
1400 if (_ioproj_fallthrough == NULL) {
1401 _ioproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::I_O);
1402 transform_later(_ioproj_fallthrough);
1403 } else if (!always_slow) {
1404 for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1405 Node *use = _ioproj_fallthrough->fast_out(i);
1407 _igvn.hash_delete(use);
1408 imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1409 _igvn._worklist.push(use);
1410 // back up iterator
1411 --i;
1412 }
1413 }
1414 // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete _ioproj_catchall so
1415 // we end up with a call that has only 1 control projection
1416 if (_ioproj_catchall != NULL ) {
1417 for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1418 Node *use = _ioproj_catchall->fast_out(i);
1419 _igvn.hash_delete(use);
1420 imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1421 _igvn._worklist.push(use);
1422 // back up iterator
1423 --i;
1424 }
1425 }
1427 // if we generated only a slow call, we are done
1428 if (always_slow)
1429 return;
1432 if (_fallthroughcatchproj != NULL) {
1433 ctrl = _fallthroughcatchproj->clone();
1434 transform_later(ctrl);
1435 _igvn.replace_node(_fallthroughcatchproj, result_region);
1436 } else {
1437 ctrl = top();
1438 }
1439 Node *slow_result;
1440 if (_resproj == NULL) {
1441 // no uses of the allocation result
1442 slow_result = top();
1443 } else {
1444 slow_result = _resproj->clone();
1445 transform_later(slow_result);
1446 _igvn.replace_node(_resproj, result_phi_rawoop);
1447 }
1449 // Plug slow-path into result merge point
1450 result_region ->init_req( slow_result_path, ctrl );
1451 result_phi_rawoop->init_req( slow_result_path, slow_result);
1452 result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1453 transform_later(result_region);
1454 transform_later(result_phi_rawoop);
1455 transform_later(result_phi_rawmem);
1456 transform_later(result_phi_i_o);
1457 // This completes all paths into the result merge point
1458 }
1461 // Helper for PhaseMacroExpand::expand_allocate_common.
1462 // Initializes the newly-allocated storage.
1463 Node*
1464 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1465 Node* control, Node* rawmem, Node* object,
1466 Node* klass_node, Node* length,
1467 Node* size_in_bytes) {
1468 InitializeNode* init = alloc->initialization();
1469 // Store the klass & mark bits
1470 Node* mark_node = NULL;
1471 // For now only enable fast locking for non-array types
1472 if (UseBiasedLocking && (length == NULL)) {
1473 mark_node = make_load(control, rawmem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeRawPtr::BOTTOM, T_ADDRESS);
1474 } else {
1475 mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1476 }
1477 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1479 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_OBJECT);
1480 int header_size = alloc->minimum_header_size(); // conservatively small
1482 // Array length
1483 if (length != NULL) { // Arrays need length field
1484 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1485 // conservatively small header size:
1486 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1487 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1488 if (k->is_array_klass()) // we know the exact header size in most cases:
1489 header_size = Klass::layout_helper_header_size(k->layout_helper());
1490 }
1492 // Clear the object body, if necessary.
1493 if (init == NULL) {
1494 // The init has somehow disappeared; be cautious and clear everything.
1495 //
1496 // This can happen if a node is allocated but an uncommon trap occurs
1497 // immediately. In this case, the Initialize gets associated with the
1498 // trap, and may be placed in a different (outer) loop, if the Allocate
1499 // is in a loop. If (this is rare) the inner loop gets unrolled, then
1500 // there can be two Allocates to one Initialize. The answer in all these
1501 // edge cases is safety first. It is always safe to clear immediately
1502 // within an Allocate, and then (maybe or maybe not) clear some more later.
1503 if (!ZeroTLAB)
1504 rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1505 header_size, size_in_bytes,
1506 &_igvn);
1507 } else {
1508 if (!init->is_complete()) {
1509 // Try to win by zeroing only what the init does not store.
1510 // We can also try to do some peephole optimizations,
1511 // such as combining some adjacent subword stores.
1512 rawmem = init->complete_stores(control, rawmem, object,
1513 header_size, size_in_bytes, &_igvn);
1514 }
1515 // We have no more use for this link, since the AllocateNode goes away:
1516 init->set_req(InitializeNode::RawAddress, top());
1517 // (If we keep the link, it just confuses the register allocator,
1518 // who thinks he sees a real use of the address by the membar.)
1519 }
1521 return rawmem;
1522 }
1524 // Generate prefetch instructions for next allocations.
1525 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1526 Node*& contended_phi_rawmem,
1527 Node* old_eden_top, Node* new_eden_top,
1528 Node* length) {
1529 enum { fall_in_path = 1, pf_path = 2 };
1530 if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1531 // Generate prefetch allocation with watermark check.
1532 // As an allocation hits the watermark, we will prefetch starting
1533 // at a "distance" away from watermark.
1535 Node *pf_region = new (C, 3) RegionNode(3);
1536 Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
1537 TypeRawPtr::BOTTOM );
1538 // I/O is used for Prefetch
1539 Node *pf_phi_abio = new (C, 3) PhiNode( pf_region, Type::ABIO );
1541 Node *thread = new (C, 1) ThreadLocalNode();
1542 transform_later(thread);
1544 Node *eden_pf_adr = new (C, 4) AddPNode( top()/*not oop*/, thread,
1545 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1546 transform_later(eden_pf_adr);
1548 Node *old_pf_wm = new (C, 3) LoadPNode( needgc_false,
1549 contended_phi_rawmem, eden_pf_adr,
1550 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
1551 transform_later(old_pf_wm);
1553 // check against new_eden_top
1554 Node *need_pf_cmp = new (C, 3) CmpPNode( new_eden_top, old_pf_wm );
1555 transform_later(need_pf_cmp);
1556 Node *need_pf_bol = new (C, 2) BoolNode( need_pf_cmp, BoolTest::ge );
1557 transform_later(need_pf_bol);
1558 IfNode *need_pf_iff = new (C, 2) IfNode( needgc_false, need_pf_bol,
1559 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1560 transform_later(need_pf_iff);
1562 // true node, add prefetchdistance
1563 Node *need_pf_true = new (C, 1) IfTrueNode( need_pf_iff );
1564 transform_later(need_pf_true);
1566 Node *need_pf_false = new (C, 1) IfFalseNode( need_pf_iff );
1567 transform_later(need_pf_false);
1569 Node *new_pf_wmt = new (C, 4) AddPNode( top(), old_pf_wm,
1570 _igvn.MakeConX(AllocatePrefetchDistance) );
1571 transform_later(new_pf_wmt );
1572 new_pf_wmt->set_req(0, need_pf_true);
1574 Node *store_new_wmt = new (C, 4) StorePNode( need_pf_true,
1575 contended_phi_rawmem, eden_pf_adr,
1576 TypeRawPtr::BOTTOM, new_pf_wmt );
1577 transform_later(store_new_wmt);
1579 // adding prefetches
1580 pf_phi_abio->init_req( fall_in_path, i_o );
1582 Node *prefetch_adr;
1583 Node *prefetch;
1584 uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1585 uint step_size = AllocatePrefetchStepSize;
1586 uint distance = 0;
1588 for ( uint i = 0; i < lines; i++ ) {
1589 prefetch_adr = new (C, 4) AddPNode( old_pf_wm, new_pf_wmt,
1590 _igvn.MakeConX(distance) );
1591 transform_later(prefetch_adr);
1592 prefetch = new (C, 3) PrefetchAllocationNode( i_o, prefetch_adr );
1593 transform_later(prefetch);
1594 distance += step_size;
1595 i_o = prefetch;
1596 }
1597 pf_phi_abio->set_req( pf_path, i_o );
1599 pf_region->init_req( fall_in_path, need_pf_false );
1600 pf_region->init_req( pf_path, need_pf_true );
1602 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1603 pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1605 transform_later(pf_region);
1606 transform_later(pf_phi_rawmem);
1607 transform_later(pf_phi_abio);
1609 needgc_false = pf_region;
1610 contended_phi_rawmem = pf_phi_rawmem;
1611 i_o = pf_phi_abio;
1612 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1613 // Insert a prefetch for each allocation.
1614 // This code is used for Sparc with BIS.
1615 Node *pf_region = new (C, 3) RegionNode(3);
1616 Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
1617 TypeRawPtr::BOTTOM );
1619 // Generate several prefetch instructions.
1620 uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1621 uint step_size = AllocatePrefetchStepSize;
1622 uint distance = AllocatePrefetchDistance;
1624 // Next cache address.
1625 Node *cache_adr = new (C, 4) AddPNode(old_eden_top, old_eden_top,
1626 _igvn.MakeConX(distance));
1627 transform_later(cache_adr);
1628 cache_adr = new (C, 2) CastP2XNode(needgc_false, cache_adr);
1629 transform_later(cache_adr);
1630 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1631 cache_adr = new (C, 3) AndXNode(cache_adr, mask);
1632 transform_later(cache_adr);
1633 cache_adr = new (C, 2) CastX2PNode(cache_adr);
1634 transform_later(cache_adr);
1636 // Prefetch
1637 Node *prefetch = new (C, 3) PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1638 prefetch->set_req(0, needgc_false);
1639 transform_later(prefetch);
1640 contended_phi_rawmem = prefetch;
1641 Node *prefetch_adr;
1642 distance = step_size;
1643 for ( uint i = 1; i < lines; i++ ) {
1644 prefetch_adr = new (C, 4) AddPNode( cache_adr, cache_adr,
1645 _igvn.MakeConX(distance) );
1646 transform_later(prefetch_adr);
1647 prefetch = new (C, 3) PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1648 transform_later(prefetch);
1649 distance += step_size;
1650 contended_phi_rawmem = prefetch;
1651 }
1652 } else if( AllocatePrefetchStyle > 0 ) {
1653 // Insert a prefetch for each allocation only on the fast-path
1654 Node *prefetch_adr;
1655 Node *prefetch;
1656 // Generate several prefetch instructions.
1657 uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1658 uint step_size = AllocatePrefetchStepSize;
1659 uint distance = AllocatePrefetchDistance;
1660 for ( uint i = 0; i < lines; i++ ) {
1661 prefetch_adr = new (C, 4) AddPNode( old_eden_top, new_eden_top,
1662 _igvn.MakeConX(distance) );
1663 transform_later(prefetch_adr);
1664 prefetch = new (C, 3) PrefetchAllocationNode( i_o, prefetch_adr );
1665 // Do not let it float too high, since if eden_top == eden_end,
1666 // both might be null.
1667 if( i == 0 ) { // Set control for first prefetch, next follows it
1668 prefetch->init_req(0, needgc_false);
1669 }
1670 transform_later(prefetch);
1671 distance += step_size;
1672 i_o = prefetch;
1673 }
1674 }
1675 return i_o;
1676 }
1679 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1680 expand_allocate_common(alloc, NULL,
1681 OptoRuntime::new_instance_Type(),
1682 OptoRuntime::new_instance_Java());
1683 }
1685 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1686 Node* length = alloc->in(AllocateNode::ALength);
1687 InitializeNode* init = alloc->initialization();
1688 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1689 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1690 address slow_call_address; // Address of slow call
1691 if (init != NULL && init->is_complete_with_arraycopy() &&
1692 k->is_type_array_klass()) {
1693 // Don't zero type array during slow allocation in VM since
1694 // it will be initialized later by arraycopy in compiled code.
1695 slow_call_address = OptoRuntime::new_array_nozero_Java();
1696 } else {
1697 slow_call_address = OptoRuntime::new_array_Java();
1698 }
1699 expand_allocate_common(alloc, length,
1700 OptoRuntime::new_array_Type(),
1701 slow_call_address);
1702 }
1704 //-----------------------mark_eliminated_locking_nodes-----------------------
1705 // During EA obj may point to several objects but after few ideal graph
1706 // transformations (CCP) it may point to only one non escaping object
1707 // (but still using phi), corresponding locks and unlocks will be marked
1708 // for elimination. Later obj could be replaced with a new node (new phi)
1709 // and which does not have escape information. And later after some graph
1710 // reshape other locks and unlocks (which were not marked for elimination
1711 // before) are connected to this new obj (phi) but they still will not be
1712 // marked for elimination since new obj has no escape information.
1713 // Mark all associated (same box and obj) lock and unlock nodes for
1714 // elimination if some of them marked already.
1715 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1716 if (!alock->is_eliminated()) {
1717 return;
1718 }
1719 if (!alock->is_coarsened()) { // Eliminated by EA
1720 // Create new "eliminated" BoxLock node and use it
1721 // in monitor debug info for the same object.
1722 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
1723 Node* obj = alock->obj_node();
1724 if (!oldbox->is_eliminated()) {
1725 BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1726 // Note: BoxLock node is marked eliminated only here
1727 // and it is used to indicate that all associated lock
1728 // and unlock nodes are marked for elimination.
1729 newbox->set_eliminated();
1730 transform_later(newbox);
1731 // Replace old box node with new box for all users
1732 // of the same object.
1733 for (uint i = 0; i < oldbox->outcnt();) {
1735 bool next_edge = true;
1736 Node* u = oldbox->raw_out(i);
1737 if (u->is_AbstractLock() &&
1738 u->as_AbstractLock()->obj_node() == obj &&
1739 u->as_AbstractLock()->box_node() == oldbox) {
1740 // Mark all associated locks and unlocks.
1741 u->as_AbstractLock()->set_eliminated();
1742 _igvn.hash_delete(u);
1743 u->set_req(TypeFunc::Parms + 1, newbox);
1744 next_edge = false;
1745 }
1746 // Replace old box in monitor debug info.
1747 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1748 SafePointNode* sfn = u->as_SafePoint();
1749 JVMState* youngest_jvms = sfn->jvms();
1750 int max_depth = youngest_jvms->depth();
1751 for (int depth = 1; depth <= max_depth; depth++) {
1752 JVMState* jvms = youngest_jvms->of_depth(depth);
1753 int num_mon = jvms->nof_monitors();
1754 // Loop over monitors
1755 for (int idx = 0; idx < num_mon; idx++) {
1756 Node* obj_node = sfn->monitor_obj(jvms, idx);
1757 Node* box_node = sfn->monitor_box(jvms, idx);
1758 if (box_node == oldbox && obj_node == obj) {
1759 int j = jvms->monitor_box_offset(idx);
1760 _igvn.hash_delete(u);
1761 u->set_req(j, newbox);
1762 next_edge = false;
1763 }
1764 } // for (int idx = 0;
1765 } // for (int depth = 1;
1766 } // if (u->is_SafePoint()
1767 if (next_edge) i++;
1768 } // for (uint i = 0; i < oldbox->outcnt();)
1769 } // if (!oldbox->is_eliminated())
1770 } // if (!alock->is_coarsened())
1771 }
1773 // we have determined that this lock/unlock can be eliminated, we simply
1774 // eliminate the node without expanding it.
1775 //
1776 // Note: The membar's associated with the lock/unlock are currently not
1777 // eliminated. This should be investigated as a future enhancement.
1778 //
1779 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
1781 if (!alock->is_eliminated()) {
1782 return false;
1783 }
1784 #ifdef ASSERT
1785 if (alock->is_Lock() && !alock->is_coarsened()) {
1786 // Check that new "eliminated" BoxLock node is created.
1787 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
1788 assert(oldbox->is_eliminated(), "should be done already");
1789 }
1790 #endif
1791 CompileLog* log = C->log();
1792 if (log != NULL) {
1793 log->head("eliminate_lock lock='%d'",
1794 alock->is_Lock());
1795 JVMState* p = alock->jvms();
1796 while (p != NULL) {
1797 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1798 p = p->caller();
1799 }
1800 log->tail("eliminate_lock");
1801 }
1803 #ifndef PRODUCT
1804 if (PrintEliminateLocks) {
1805 if (alock->is_Lock()) {
1806 tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
1807 } else {
1808 tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
1809 }
1810 }
1811 #endif
1813 Node* mem = alock->in(TypeFunc::Memory);
1814 Node* ctrl = alock->in(TypeFunc::Control);
1816 extract_call_projections(alock);
1817 // There are 2 projections from the lock. The lock node will
1818 // be deleted when its last use is subsumed below.
1819 assert(alock->outcnt() == 2 &&
1820 _fallthroughproj != NULL &&
1821 _memproj_fallthrough != NULL,
1822 "Unexpected projections from Lock/Unlock");
1824 Node* fallthroughproj = _fallthroughproj;
1825 Node* memproj_fallthrough = _memproj_fallthrough;
1827 // The memory projection from a lock/unlock is RawMem
1828 // The input to a Lock is merged memory, so extract its RawMem input
1829 // (unless the MergeMem has been optimized away.)
1830 if (alock->is_Lock()) {
1831 // Seach for MemBarAcquireLock node and delete it also.
1832 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
1833 assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
1834 Node* ctrlproj = membar->proj_out(TypeFunc::Control);
1835 Node* memproj = membar->proj_out(TypeFunc::Memory);
1836 _igvn.replace_node(ctrlproj, fallthroughproj);
1837 _igvn.replace_node(memproj, memproj_fallthrough);
1839 // Delete FastLock node also if this Lock node is unique user
1840 // (a loop peeling may clone a Lock node).
1841 Node* flock = alock->as_Lock()->fastlock_node();
1842 if (flock->outcnt() == 1) {
1843 assert(flock->unique_out() == alock, "sanity");
1844 _igvn.replace_node(flock, top());
1845 }
1846 }
1848 // Seach for MemBarReleaseLock node and delete it also.
1849 if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
1850 ctrl->in(0)->is_MemBar()) {
1851 MemBarNode* membar = ctrl->in(0)->as_MemBar();
1852 assert(membar->Opcode() == Op_MemBarReleaseLock &&
1853 mem->is_Proj() && membar == mem->in(0), "");
1854 _igvn.replace_node(fallthroughproj, ctrl);
1855 _igvn.replace_node(memproj_fallthrough, mem);
1856 fallthroughproj = ctrl;
1857 memproj_fallthrough = mem;
1858 ctrl = membar->in(TypeFunc::Control);
1859 mem = membar->in(TypeFunc::Memory);
1860 }
1862 _igvn.replace_node(fallthroughproj, ctrl);
1863 _igvn.replace_node(memproj_fallthrough, mem);
1864 return true;
1865 }
1868 //------------------------------expand_lock_node----------------------
1869 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
1871 Node* ctrl = lock->in(TypeFunc::Control);
1872 Node* mem = lock->in(TypeFunc::Memory);
1873 Node* obj = lock->obj_node();
1874 Node* box = lock->box_node();
1875 Node* flock = lock->fastlock_node();
1877 // Make the merge point
1878 Node *region;
1879 Node *mem_phi;
1880 Node *slow_path;
1882 if (UseOptoBiasInlining) {
1883 /*
1884 * See the full description in MacroAssembler::biased_locking_enter().
1885 *
1886 * if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
1887 * // The object is biased.
1888 * proto_node = klass->prototype_header;
1889 * o_node = thread | proto_node;
1890 * x_node = o_node ^ mark_word;
1891 * if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
1892 * // Done.
1893 * } else {
1894 * if( (x_node & biased_lock_mask) != 0 ) {
1895 * // The klass's prototype header is no longer biased.
1896 * cas(&mark_word, mark_word, proto_node)
1897 * goto cas_lock;
1898 * } else {
1899 * // The klass's prototype header is still biased.
1900 * if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
1901 * old = mark_word;
1902 * new = o_node;
1903 * } else {
1904 * // Different thread or anonymous biased.
1905 * old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
1906 * new = thread | old;
1907 * }
1908 * // Try to rebias.
1909 * if( cas(&mark_word, old, new) == 0 ) {
1910 * // Done.
1911 * } else {
1912 * goto slow_path; // Failed.
1913 * }
1914 * }
1915 * }
1916 * } else {
1917 * // The object is not biased.
1918 * cas_lock:
1919 * if( FastLock(obj) == 0 ) {
1920 * // Done.
1921 * } else {
1922 * slow_path:
1923 * OptoRuntime::complete_monitor_locking_Java(obj);
1924 * }
1925 * }
1926 */
1928 region = new (C, 5) RegionNode(5);
1929 // create a Phi for the memory state
1930 mem_phi = new (C, 5) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
1932 Node* fast_lock_region = new (C, 3) RegionNode(3);
1933 Node* fast_lock_mem_phi = new (C, 3) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1935 // First, check mark word for the biased lock pattern.
1936 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
1938 // Get fast path - mark word has the biased lock pattern.
1939 ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
1940 markOopDesc::biased_lock_mask_in_place,
1941 markOopDesc::biased_lock_pattern, true);
1942 // fast_lock_region->in(1) is set to slow path.
1943 fast_lock_mem_phi->init_req(1, mem);
1945 // Now check that the lock is biased to the current thread and has
1946 // the same epoch and bias as Klass::_prototype_header.
1948 // Special-case a fresh allocation to avoid building nodes:
1949 Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
1950 if (klass_node == NULL) {
1951 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
1952 klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
1953 #ifdef _LP64
1954 if (UseCompressedOops && klass_node->is_DecodeN()) {
1955 assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
1956 klass_node->in(1)->init_req(0, ctrl);
1957 } else
1958 #endif
1959 klass_node->init_req(0, ctrl);
1960 }
1961 Node *proto_node = make_load(ctrl, mem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeX_X, TypeX_X->basic_type());
1963 Node* thread = transform_later(new (C, 1) ThreadLocalNode());
1964 Node* cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
1965 Node* o_node = transform_later(new (C, 3) OrXNode(cast_thread, proto_node));
1966 Node* x_node = transform_later(new (C, 3) XorXNode(o_node, mark_node));
1968 // Get slow path - mark word does NOT match the value.
1969 Node* not_biased_ctrl = opt_bits_test(ctrl, region, 3, x_node,
1970 (~markOopDesc::age_mask_in_place), 0);
1971 // region->in(3) is set to fast path - the object is biased to the current thread.
1972 mem_phi->init_req(3, mem);
1975 // Mark word does NOT match the value (thread | Klass::_prototype_header).
1978 // First, check biased pattern.
1979 // Get fast path - _prototype_header has the same biased lock pattern.
1980 ctrl = opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
1981 markOopDesc::biased_lock_mask_in_place, 0, true);
1983 not_biased_ctrl = fast_lock_region->in(2); // Slow path
1984 // fast_lock_region->in(2) - the prototype header is no longer biased
1985 // and we have to revoke the bias on this object.
1986 // We are going to try to reset the mark of this object to the prototype
1987 // value and fall through to the CAS-based locking scheme.
1988 Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
1989 Node* cas = new (C, 5) StoreXConditionalNode(not_biased_ctrl, mem, adr,
1990 proto_node, mark_node);
1991 transform_later(cas);
1992 Node* proj = transform_later( new (C, 1) SCMemProjNode(cas));
1993 fast_lock_mem_phi->init_req(2, proj);
1996 // Second, check epoch bits.
1997 Node* rebiased_region = new (C, 3) RegionNode(3);
1998 Node* old_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
1999 Node* new_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X);
2001 // Get slow path - mark word does NOT match epoch bits.
2002 Node* epoch_ctrl = opt_bits_test(ctrl, rebiased_region, 1, x_node,
2003 markOopDesc::epoch_mask_in_place, 0);
2004 // The epoch of the current bias is not valid, attempt to rebias the object
2005 // toward the current thread.
2006 rebiased_region->init_req(2, epoch_ctrl);
2007 old_phi->init_req(2, mark_node);
2008 new_phi->init_req(2, o_node);
2010 // rebiased_region->in(1) is set to fast path.
2011 // The epoch of the current bias is still valid but we know
2012 // nothing about the owner; it might be set or it might be clear.
2013 Node* cmask = MakeConX(markOopDesc::biased_lock_mask_in_place |
2014 markOopDesc::age_mask_in_place |
2015 markOopDesc::epoch_mask_in_place);
2016 Node* old = transform_later(new (C, 3) AndXNode(mark_node, cmask));
2017 cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread));
2018 Node* new_mark = transform_later(new (C, 3) OrXNode(cast_thread, old));
2019 old_phi->init_req(1, old);
2020 new_phi->init_req(1, new_mark);
2022 transform_later(rebiased_region);
2023 transform_later(old_phi);
2024 transform_later(new_phi);
2026 // Try to acquire the bias of the object using an atomic operation.
2027 // If this fails we will go in to the runtime to revoke the object's bias.
2028 cas = new (C, 5) StoreXConditionalNode(rebiased_region, mem, adr,
2029 new_phi, old_phi);
2030 transform_later(cas);
2031 proj = transform_later( new (C, 1) SCMemProjNode(cas));
2033 // Get slow path - Failed to CAS.
2034 not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2035 mem_phi->init_req(4, proj);
2036 // region->in(4) is set to fast path - the object is rebiased to the current thread.
2038 // Failed to CAS.
2039 slow_path = new (C, 3) RegionNode(3);
2040 Node *slow_mem = new (C, 3) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2042 slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2043 slow_mem->init_req(1, proj);
2045 // Call CAS-based locking scheme (FastLock node).
2047 transform_later(fast_lock_region);
2048 transform_later(fast_lock_mem_phi);
2050 // Get slow path - FastLock failed to lock the object.
2051 ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2052 mem_phi->init_req(2, fast_lock_mem_phi);
2053 // region->in(2) is set to fast path - the object is locked to the current thread.
2055 slow_path->init_req(2, ctrl); // Capture slow-control
2056 slow_mem->init_req(2, fast_lock_mem_phi);
2058 transform_later(slow_path);
2059 transform_later(slow_mem);
2060 // Reset lock's memory edge.
2061 lock->set_req(TypeFunc::Memory, slow_mem);
2063 } else {
2064 region = new (C, 3) RegionNode(3);
2065 // create a Phi for the memory state
2066 mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2068 // Optimize test; set region slot 2
2069 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2070 mem_phi->init_req(2, mem);
2071 }
2073 // Make slow path call
2074 CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2076 extract_call_projections(call);
2078 // Slow path can only throw asynchronous exceptions, which are always
2079 // de-opted. So the compiler thinks the slow-call can never throw an
2080 // exception. If it DOES throw an exception we would need the debug
2081 // info removed first (since if it throws there is no monitor).
2082 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2083 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2085 // Capture slow path
2086 // disconnect fall-through projection from call and create a new one
2087 // hook up users of fall-through projection to region
2088 Node *slow_ctrl = _fallthroughproj->clone();
2089 transform_later(slow_ctrl);
2090 _igvn.hash_delete(_fallthroughproj);
2091 _fallthroughproj->disconnect_inputs(NULL);
2092 region->init_req(1, slow_ctrl);
2093 // region inputs are now complete
2094 transform_later(region);
2095 _igvn.replace_node(_fallthroughproj, region);
2097 Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
2098 mem_phi->init_req(1, memproj );
2099 transform_later(mem_phi);
2100 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2101 }
2103 //------------------------------expand_unlock_node----------------------
2104 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2106 Node* ctrl = unlock->in(TypeFunc::Control);
2107 Node* mem = unlock->in(TypeFunc::Memory);
2108 Node* obj = unlock->obj_node();
2109 Node* box = unlock->box_node();
2111 // No need for a null check on unlock
2113 // Make the merge point
2114 Node *region;
2115 Node *mem_phi;
2117 if (UseOptoBiasInlining) {
2118 // Check for biased locking unlock case, which is a no-op.
2119 // See the full description in MacroAssembler::biased_locking_exit().
2120 region = new (C, 4) RegionNode(4);
2121 // create a Phi for the memory state
2122 mem_phi = new (C, 4) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2123 mem_phi->init_req(3, mem);
2125 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2126 ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2127 markOopDesc::biased_lock_mask_in_place,
2128 markOopDesc::biased_lock_pattern);
2129 } else {
2130 region = new (C, 3) RegionNode(3);
2131 // create a Phi for the memory state
2132 mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2133 }
2135 FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box );
2136 funlock = transform_later( funlock )->as_FastUnlock();
2137 // Optimize test; set region slot 2
2138 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2140 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 );
2142 extract_call_projections(call);
2144 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2145 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2147 // No exceptions for unlocking
2148 // Capture slow path
2149 // disconnect fall-through projection from call and create a new one
2150 // hook up users of fall-through projection to region
2151 Node *slow_ctrl = _fallthroughproj->clone();
2152 transform_later(slow_ctrl);
2153 _igvn.hash_delete(_fallthroughproj);
2154 _fallthroughproj->disconnect_inputs(NULL);
2155 region->init_req(1, slow_ctrl);
2156 // region inputs are now complete
2157 transform_later(region);
2158 _igvn.replace_node(_fallthroughproj, region);
2160 Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
2161 mem_phi->init_req(1, memproj );
2162 mem_phi->init_req(2, mem);
2163 transform_later(mem_phi);
2164 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2165 }
2167 //---------------------------eliminate_macro_nodes----------------------
2168 // Eliminate scalar replaced allocations and associated locks.
2169 void PhaseMacroExpand::eliminate_macro_nodes() {
2170 if (C->macro_count() == 0)
2171 return;
2173 // First, attempt to eliminate locks
2174 int cnt = C->macro_count();
2175 for (int i=0; i < cnt; i++) {
2176 Node *n = C->macro_node(i);
2177 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2178 // Before elimination mark all associated (same box and obj)
2179 // lock and unlock nodes.
2180 mark_eliminated_locking_nodes(n->as_AbstractLock());
2181 }
2182 }
2183 bool progress = true;
2184 while (progress) {
2185 progress = false;
2186 for (int i = C->macro_count(); i > 0; i--) {
2187 Node * n = C->macro_node(i-1);
2188 bool success = false;
2189 debug_only(int old_macro_count = C->macro_count(););
2190 if (n->is_AbstractLock()) {
2191 success = eliminate_locking_node(n->as_AbstractLock());
2192 }
2193 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2194 progress = progress || success;
2195 }
2196 }
2197 // Next, attempt to eliminate allocations
2198 progress = true;
2199 while (progress) {
2200 progress = false;
2201 for (int i = C->macro_count(); i > 0; i--) {
2202 Node * n = C->macro_node(i-1);
2203 bool success = false;
2204 debug_only(int old_macro_count = C->macro_count(););
2205 switch (n->class_id()) {
2206 case Node::Class_Allocate:
2207 case Node::Class_AllocateArray:
2208 success = eliminate_allocate_node(n->as_Allocate());
2209 break;
2210 case Node::Class_Lock:
2211 case Node::Class_Unlock:
2212 assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2213 break;
2214 default:
2215 assert(n->Opcode() == Op_LoopLimit ||
2216 n->Opcode() == Op_Opaque1 ||
2217 n->Opcode() == Op_Opaque2, "unknown node type in macro list");
2218 }
2219 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2220 progress = progress || success;
2221 }
2222 }
2223 }
2225 //------------------------------expand_macro_nodes----------------------
2226 // Returns true if a failure occurred.
2227 bool PhaseMacroExpand::expand_macro_nodes() {
2228 // Last attempt to eliminate macro nodes.
2229 eliminate_macro_nodes();
2231 // Make sure expansion will not cause node limit to be exceeded.
2232 // Worst case is a macro node gets expanded into about 50 nodes.
2233 // Allow 50% more for optimization.
2234 if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2235 return true;
2237 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2238 bool progress = true;
2239 while (progress) {
2240 progress = false;
2241 for (int i = C->macro_count(); i > 0; i--) {
2242 Node * n = C->macro_node(i-1);
2243 bool success = false;
2244 debug_only(int old_macro_count = C->macro_count(););
2245 if (n->Opcode() == Op_LoopLimit) {
2246 // Remove it from macro list and put on IGVN worklist to optimize.
2247 C->remove_macro_node(n);
2248 _igvn._worklist.push(n);
2249 success = true;
2250 } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2251 _igvn.replace_node(n, n->in(1));
2252 success = true;
2253 }
2254 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2255 progress = progress || success;
2256 }
2257 }
2259 // expand "macro" nodes
2260 // nodes are removed from the macro list as they are processed
2261 while (C->macro_count() > 0) {
2262 int macro_count = C->macro_count();
2263 Node * n = C->macro_node(macro_count-1);
2264 assert(n->is_macro(), "only macro nodes expected here");
2265 if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2266 // node is unreachable, so don't try to expand it
2267 C->remove_macro_node(n);
2268 continue;
2269 }
2270 switch (n->class_id()) {
2271 case Node::Class_Allocate:
2272 expand_allocate(n->as_Allocate());
2273 break;
2274 case Node::Class_AllocateArray:
2275 expand_allocate_array(n->as_AllocateArray());
2276 break;
2277 case Node::Class_Lock:
2278 expand_lock_node(n->as_Lock());
2279 break;
2280 case Node::Class_Unlock:
2281 expand_unlock_node(n->as_Unlock());
2282 break;
2283 default:
2284 assert(false, "unknown node type in macro list");
2285 }
2286 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2287 if (C->failing()) return true;
2288 }
2290 _igvn.set_delay_transform(false);
2291 _igvn.optimize();
2292 if (C->failing()) return true;
2293 return false;
2294 }