1 /*
2 * Copyright (c) 2005, 2025, 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 "compiler/compileLog.hpp"
26 #include "gc/shared/collectedHeap.inline.hpp"
27 #include "gc/shared/tlab_globals.hpp"
28 #include "libadt/vectset.hpp"
29 #include "memory/universe.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/arraycopynode.hpp"
32 #include "opto/callnode.hpp"
33 #include "opto/castnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/compile.hpp"
36 #include "opto/convertnode.hpp"
37 #include "opto/graphKit.hpp"
38 #include "opto/intrinsicnode.hpp"
39 #include "opto/locknode.hpp"
40 #include "opto/loopnode.hpp"
41 #include "opto/macro.hpp"
42 #include "opto/memnode.hpp"
43 #include "opto/narrowptrnode.hpp"
44 #include "opto/node.hpp"
45 #include "opto/opaquenode.hpp"
46 #include "opto/phaseX.hpp"
47 #include "opto/rootnode.hpp"
48 #include "opto/runtime.hpp"
49 #include "opto/subnode.hpp"
50 #include "opto/subtypenode.hpp"
51 #include "opto/type.hpp"
52 #include "prims/jvmtiExport.hpp"
53 #include "runtime/continuation.hpp"
54 #include "runtime/sharedRuntime.hpp"
55 #include "utilities/macros.hpp"
56 #include "utilities/powerOfTwo.hpp"
57 #if INCLUDE_G1GC
58 #include "gc/g1/g1ThreadLocalData.hpp"
59 #endif // INCLUDE_G1GC
60
61
62 //
63 // Replace any references to "oldref" in inputs to "use" with "newref".
64 // Returns the number of replacements made.
65 //
66 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
67 int nreplacements = 0;
68 uint req = use->req();
69 for (uint j = 0; j < use->len(); j++) {
70 Node *uin = use->in(j);
71 if (uin == oldref) {
72 if (j < req)
73 use->set_req(j, newref);
74 else
75 use->set_prec(j, newref);
76 nreplacements++;
77 } else if (j >= req && uin == nullptr) {
78 break;
79 }
80 }
81 return nreplacements;
82 }
83
84 void PhaseMacroExpand::migrate_outs(Node *old, Node *target) {
85 assert(old != nullptr, "sanity");
86 for (DUIterator_Fast imax, i = old->fast_outs(imax); i < imax; i++) {
87 Node* use = old->fast_out(i);
88 _igvn.rehash_node_delayed(use);
89 imax -= replace_input(use, old, target);
90 // back up iterator
91 --i;
92 }
93 assert(old->outcnt() == 0, "all uses must be deleted");
94 }
95
96 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
97 Node* cmp;
98 if (mask != 0) {
99 Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
100 cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
101 } else {
102 cmp = word;
103 }
104 Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
105 IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
106 transform_later(iff);
107
108 // Fast path taken.
109 Node *fast_taken = transform_later(new IfFalseNode(iff));
110
111 // Fast path not-taken, i.e. slow path
112 Node *slow_taken = transform_later(new IfTrueNode(iff));
113
114 if (return_fast_path) {
115 region->init_req(edge, slow_taken); // Capture slow-control
116 return fast_taken;
117 } else {
118 region->init_req(edge, fast_taken); // Capture fast-control
119 return slow_taken;
120 }
121 }
122
123 //--------------------copy_predefined_input_for_runtime_call--------------------
124 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
125 // Set fixed predefined input arguments
126 call->init_req( TypeFunc::Control, ctrl );
127 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) );
128 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
129 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
130 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
131 }
132
133 //------------------------------make_slow_call---------------------------------
134 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type,
135 address slow_call, const char* leaf_name, Node* slow_path,
136 Node* parm0, Node* parm1, Node* parm2) {
137
138 // Slow-path call
139 CallNode *call = leaf_name
140 ? (CallNode*)new CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
141 : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), TypeRawPtr::BOTTOM );
142
143 // Slow path call has no side-effects, uses few values
144 copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
145 if (parm0 != nullptr) call->init_req(TypeFunc::Parms+0, parm0);
146 if (parm1 != nullptr) call->init_req(TypeFunc::Parms+1, parm1);
147 if (parm2 != nullptr) call->init_req(TypeFunc::Parms+2, parm2);
148 call->copy_call_debug_info(&_igvn, oldcall);
149 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
150 _igvn.replace_node(oldcall, call);
151 transform_later(call);
152
153 return call;
154 }
155
156 void PhaseMacroExpand::eliminate_gc_barrier(Node* p2x) {
157 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
158 bs->eliminate_gc_barrier(this, p2x);
159 #ifndef PRODUCT
160 if (PrintOptoStatistics) {
161 Atomic::inc(&PhaseMacroExpand::_GC_barriers_removed_counter);
162 }
163 #endif
164 }
165
166 // Search for a memory operation for the specified memory slice.
167 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
168 Node *orig_mem = mem;
169 Node *alloc_mem = alloc->as_Allocate()->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false);
170 assert(alloc_mem != nullptr, "Allocation without a memory projection.");
171 const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
172 while (true) {
173 if (mem == alloc_mem || mem == start_mem ) {
174 return mem; // hit one of our sentinels
175 } else if (mem->is_MergeMem()) {
176 mem = mem->as_MergeMem()->memory_at(alias_idx);
177 } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
178 Node *in = mem->in(0);
179 // we can safely skip over safepoints, calls, locks and membars because we
180 // already know that the object is safe to eliminate.
181 if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
182 return in;
183 } else if (in->is_Call()) {
184 CallNode *call = in->as_Call();
185 if (call->may_modify(tinst, phase)) {
186 assert(call->is_ArrayCopy(), "ArrayCopy is the only call node that doesn't make allocation escape");
187 if (call->as_ArrayCopy()->modifies(offset, offset, phase, false)) {
188 return in;
189 }
190 }
191 mem = in->in(TypeFunc::Memory);
192 } else if (in->is_MemBar()) {
193 ArrayCopyNode* ac = nullptr;
194 if (ArrayCopyNode::may_modify(tinst, in->as_MemBar(), phase, ac)) {
195 if (ac != nullptr) {
196 assert(ac->is_clonebasic(), "Only basic clone is a non escaping clone");
197 return ac;
198 }
199 }
200 mem = in->in(TypeFunc::Memory);
201 } else {
202 #ifdef ASSERT
203 in->dump();
204 mem->dump();
205 assert(false, "unexpected projection");
206 #endif
207 }
208 } else if (mem->is_Store()) {
209 const TypePtr* atype = mem->as_Store()->adr_type();
210 int adr_idx = phase->C->get_alias_index(atype);
211 if (adr_idx == alias_idx) {
212 assert(atype->isa_oopptr(), "address type must be oopptr");
213 int adr_offset = atype->offset();
214 uint adr_iid = atype->is_oopptr()->instance_id();
215 // Array elements references have the same alias_idx
216 // but different offset and different instance_id.
217 if (adr_offset == offset && adr_iid == alloc->_idx) {
218 return mem;
219 }
220 } else {
221 assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
222 }
223 mem = mem->in(MemNode::Memory);
224 } else if (mem->is_ClearArray()) {
225 if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
226 // Can not bypass initialization of the instance
227 // we are looking.
228 debug_only(intptr_t offset;)
229 assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
230 InitializeNode* init = alloc->as_Allocate()->initialization();
231 // We are looking for stored value, return Initialize node
232 // or memory edge from Allocate node.
233 if (init != nullptr) {
234 return init;
235 } else {
236 return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
237 }
238 }
239 // Otherwise skip it (the call updated 'mem' value).
240 } else if (mem->Opcode() == Op_SCMemProj) {
241 mem = mem->in(0);
242 Node* adr = nullptr;
243 if (mem->is_LoadStore()) {
244 adr = mem->in(MemNode::Address);
245 } else {
246 assert(mem->Opcode() == Op_EncodeISOArray ||
247 mem->Opcode() == Op_StrCompressedCopy, "sanity");
248 adr = mem->in(3); // Destination array
249 }
250 const TypePtr* atype = adr->bottom_type()->is_ptr();
251 int adr_idx = phase->C->get_alias_index(atype);
252 if (adr_idx == alias_idx) {
253 DEBUG_ONLY(mem->dump();)
254 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
255 return nullptr;
256 }
257 mem = mem->in(MemNode::Memory);
258 } else if (mem->Opcode() == Op_StrInflatedCopy) {
259 Node* adr = mem->in(3); // Destination array
260 const TypePtr* atype = adr->bottom_type()->is_ptr();
261 int adr_idx = phase->C->get_alias_index(atype);
262 if (adr_idx == alias_idx) {
263 DEBUG_ONLY(mem->dump();)
264 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
265 return nullptr;
266 }
267 mem = mem->in(MemNode::Memory);
268 } else {
269 return mem;
270 }
271 assert(mem != orig_mem, "dead memory loop");
272 }
273 }
274
275 // Generate loads from source of the arraycopy for fields of
276 // destination needed at a deoptimization point
277 Node* PhaseMacroExpand::make_arraycopy_load(ArrayCopyNode* ac, intptr_t offset, Node* ctl, Node* mem, BasicType ft, const Type *ftype, AllocateNode *alloc) {
278 BasicType bt = ft;
279 const Type *type = ftype;
280 if (ft == T_NARROWOOP) {
281 bt = T_OBJECT;
282 type = ftype->make_oopptr();
283 }
284 Node* res = nullptr;
285 if (ac->is_clonebasic()) {
286 assert(ac->in(ArrayCopyNode::Src) != ac->in(ArrayCopyNode::Dest), "clone source equals destination");
287 Node* base = ac->in(ArrayCopyNode::Src);
288 Node* adr = _igvn.transform(new AddPNode(base, base, _igvn.MakeConX(offset)));
289 const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset);
290 MergeMemNode* mergemen = _igvn.transform(MergeMemNode::make(mem))->as_MergeMem();
291 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
292 res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt);
293 } else {
294 if (ac->modifies(offset, offset, &_igvn, true)) {
295 assert(ac->in(ArrayCopyNode::Dest) == alloc->result_cast(), "arraycopy destination should be allocation's result");
296 uint shift = exact_log2(type2aelembytes(bt));
297 Node* src_pos = ac->in(ArrayCopyNode::SrcPos);
298 Node* dest_pos = ac->in(ArrayCopyNode::DestPos);
299 const TypeInt* src_pos_t = _igvn.type(src_pos)->is_int();
300 const TypeInt* dest_pos_t = _igvn.type(dest_pos)->is_int();
301
302 Node* adr = nullptr;
303 const TypePtr* adr_type = nullptr;
304 if (src_pos_t->is_con() && dest_pos_t->is_con()) {
305 intptr_t off = ((src_pos_t->get_con() - dest_pos_t->get_con()) << shift) + offset;
306 Node* base = ac->in(ArrayCopyNode::Src);
307 adr = _igvn.transform(new AddPNode(base, base, _igvn.MakeConX(off)));
308 adr_type = _igvn.type(base)->is_ptr()->add_offset(off);
309 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) {
310 // Don't emit a new load from src if src == dst but try to get the value from memory instead
311 return value_from_mem(ac->in(TypeFunc::Memory), ctl, ft, ftype, adr_type->isa_oopptr(), alloc);
312 }
313 } else {
314 Node* diff = _igvn.transform(new SubINode(ac->in(ArrayCopyNode::SrcPos), ac->in(ArrayCopyNode::DestPos)));
315 #ifdef _LP64
316 diff = _igvn.transform(new ConvI2LNode(diff));
317 #endif
318 diff = _igvn.transform(new LShiftXNode(diff, _igvn.intcon(shift)));
319
320 Node* off = _igvn.transform(new AddXNode(_igvn.MakeConX(offset), diff));
321 Node* base = ac->in(ArrayCopyNode::Src);
322 adr = _igvn.transform(new AddPNode(base, base, off));
323 adr_type = _igvn.type(base)->is_ptr()->add_offset(Type::OffsetBot);
324 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) {
325 // Non constant offset in the array: we can't statically
326 // determine the value
327 return nullptr;
328 }
329 }
330 MergeMemNode* mergemen = _igvn.transform(MergeMemNode::make(mem))->as_MergeMem();
331 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
332 res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt);
333 }
334 }
335 if (res != nullptr) {
336 if (ftype->isa_narrowoop()) {
337 // PhaseMacroExpand::scalar_replacement adds DecodeN nodes
338 res = _igvn.transform(new EncodePNode(res, ftype));
339 }
340 return res;
341 }
342 return nullptr;
343 }
344
345 //
346 // Given a Memory Phi, compute a value Phi containing the values from stores
347 // on the input paths.
348 // Note: this function is recursive, its depth is limited by the "level" argument
349 // Returns the computed Phi, or null if it cannot compute it.
350 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, AllocateNode *alloc, Node_Stack *value_phis, int level) {
351 assert(mem->is_Phi(), "sanity");
352 int alias_idx = C->get_alias_index(adr_t);
353 int offset = adr_t->offset();
354 int instance_id = adr_t->instance_id();
355
356 // Check if an appropriate value phi already exists.
357 Node* region = mem->in(0);
358 for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
359 Node* phi = region->fast_out(k);
360 if (phi->is_Phi() && phi != mem &&
361 phi->as_Phi()->is_same_inst_field(phi_type, (int)mem->_idx, instance_id, alias_idx, offset)) {
362 return phi;
363 }
364 }
365 // Check if an appropriate new value phi already exists.
366 Node* new_phi = value_phis->find(mem->_idx);
367 if (new_phi != nullptr)
368 return new_phi;
369
370 if (level <= 0) {
371 return nullptr; // Give up: phi tree too deep
372 }
373 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
374 Node *alloc_mem = alloc->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false);
375 assert(alloc_mem != nullptr, "Allocation without a memory projection.");
376
377 uint length = mem->req();
378 GrowableArray <Node *> values(length, length, nullptr);
379
380 // create a new Phi for the value
381 PhiNode *phi = new PhiNode(mem->in(0), phi_type, nullptr, mem->_idx, instance_id, alias_idx, offset);
382 transform_later(phi);
383 value_phis->push(phi, mem->_idx);
384
385 for (uint j = 1; j < length; j++) {
386 Node *in = mem->in(j);
387 if (in == nullptr || in->is_top()) {
388 values.at_put(j, in);
389 } else {
390 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
391 if (val == start_mem || val == alloc_mem) {
392 // hit a sentinel, return appropriate 0 value
393 values.at_put(j, _igvn.zerocon(ft));
394 continue;
395 }
396 if (val->is_Initialize()) {
397 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
398 }
399 if (val == nullptr) {
400 return nullptr; // can't find a value on this path
401 }
402 if (val == mem) {
403 values.at_put(j, mem);
404 } else if (val->is_Store()) {
405 Node* n = val->in(MemNode::ValueIn);
406 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
407 n = bs->step_over_gc_barrier(n);
408 if (is_subword_type(ft)) {
409 n = Compile::narrow_value(ft, n, phi_type, &_igvn, true);
410 }
411 values.at_put(j, n);
412 } else if(val->is_Proj() && val->in(0) == alloc) {
413 values.at_put(j, _igvn.zerocon(ft));
414 } else if (val->is_Phi()) {
415 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
416 if (val == nullptr) {
417 return nullptr;
418 }
419 values.at_put(j, val);
420 } else if (val->Opcode() == Op_SCMemProj) {
421 assert(val->in(0)->is_LoadStore() ||
422 val->in(0)->Opcode() == Op_EncodeISOArray ||
423 val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity");
424 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
425 return nullptr;
426 } else if (val->is_ArrayCopy()) {
427 Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc);
428 if (res == nullptr) {
429 return nullptr;
430 }
431 values.at_put(j, res);
432 } else if (val->is_top()) {
433 // This indicates that this path into the phi is dead. Top will eventually also propagate into the Region.
434 // IGVN will clean this up later.
435 values.at_put(j, val);
436 } else {
437 DEBUG_ONLY( val->dump(); )
438 assert(false, "unknown node on this path");
439 return nullptr; // unknown node on this path
440 }
441 }
442 }
443 // Set Phi's inputs
444 for (uint j = 1; j < length; j++) {
445 if (values.at(j) == mem) {
446 phi->init_req(j, phi);
447 } else {
448 phi->init_req(j, values.at(j));
449 }
450 }
451 return phi;
452 }
453
454 // Search the last value stored into the object's field.
455 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) {
456 assert(adr_t->is_known_instance_field(), "instance required");
457 int instance_id = adr_t->instance_id();
458 assert((uint)instance_id == alloc->_idx, "wrong allocation");
459
460 int alias_idx = C->get_alias_index(adr_t);
461 int offset = adr_t->offset();
462 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
463 Node *alloc_ctrl = alloc->in(TypeFunc::Control);
464 Node *alloc_mem = alloc->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false);
465 assert(alloc_mem != nullptr, "Allocation without a memory projection.");
466 VectorSet visited;
467
468 bool done = sfpt_mem == alloc_mem;
469 Node *mem = sfpt_mem;
470 while (!done) {
471 if (visited.test_set(mem->_idx)) {
472 return nullptr; // found a loop, give up
473 }
474 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
475 if (mem == start_mem || mem == alloc_mem) {
476 done = true; // hit a sentinel, return appropriate 0 value
477 } else if (mem->is_Initialize()) {
478 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
479 if (mem == nullptr) {
480 done = true; // Something go wrong.
481 } else if (mem->is_Store()) {
482 const TypePtr* atype = mem->as_Store()->adr_type();
483 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
484 done = true;
485 }
486 } else if (mem->is_Store()) {
487 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
488 assert(atype != nullptr, "address type must be oopptr");
489 assert(C->get_alias_index(atype) == alias_idx &&
490 atype->is_known_instance_field() && atype->offset() == offset &&
491 atype->instance_id() == instance_id, "store is correct memory slice");
492 done = true;
493 } else if (mem->is_Phi()) {
494 // try to find a phi's unique input
495 Node *unique_input = nullptr;
496 Node *top = C->top();
497 for (uint i = 1; i < mem->req(); i++) {
498 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
499 if (n == nullptr || n == top || n == mem) {
500 continue;
501 } else if (unique_input == nullptr) {
502 unique_input = n;
503 } else if (unique_input != n) {
504 unique_input = top;
505 break;
506 }
507 }
508 if (unique_input != nullptr && unique_input != top) {
509 mem = unique_input;
510 } else {
511 done = true;
512 }
513 } else if (mem->is_ArrayCopy()) {
514 done = true;
515 } else {
516 DEBUG_ONLY( mem->dump(); )
517 assert(false, "unexpected node");
518 }
519 }
520 if (mem != nullptr) {
521 if (mem == start_mem || mem == alloc_mem) {
522 // hit a sentinel, return appropriate 0 value
523 return _igvn.zerocon(ft);
524 } else if (mem->is_Store()) {
525 Node* n = mem->in(MemNode::ValueIn);
526 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
527 n = bs->step_over_gc_barrier(n);
528 return n;
529 } else if (mem->is_Phi()) {
530 // attempt to produce a Phi reflecting the values on the input paths of the Phi
531 Node_Stack value_phis(8);
532 Node* phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
533 if (phi != nullptr) {
534 return phi;
535 } else {
536 // Kill all new Phis
537 while(value_phis.is_nonempty()) {
538 Node* n = value_phis.node();
539 _igvn.replace_node(n, C->top());
540 value_phis.pop();
541 }
542 }
543 } else if (mem->is_ArrayCopy()) {
544 Node* ctl = mem->in(0);
545 Node* m = mem->in(TypeFunc::Memory);
546 if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj()) {
547 // pin the loads in the uncommon trap path
548 ctl = sfpt_ctl;
549 m = sfpt_mem;
550 }
551 return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc);
552 }
553 }
554 // Something go wrong.
555 return nullptr;
556 }
557
558 // Check the possibility of scalar replacement.
559 bool PhaseMacroExpand::can_eliminate_allocation(PhaseIterGVN* igvn, AllocateNode *alloc, GrowableArray <SafePointNode *>* safepoints) {
560 // Scan the uses of the allocation to check for anything that would
561 // prevent us from eliminating it.
562 NOT_PRODUCT( const char* fail_eliminate = nullptr; )
563 DEBUG_ONLY( Node* disq_node = nullptr; )
564 bool can_eliminate = true;
565 bool reduce_merge_precheck = (safepoints == nullptr);
566
567 Node* res = alloc->result_cast();
568 const TypeOopPtr* res_type = nullptr;
569 if (res == nullptr) {
570 // All users were eliminated.
571 } else if (!res->is_CheckCastPP()) {
572 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
573 can_eliminate = false;
574 } else {
575 res_type = igvn->type(res)->isa_oopptr();
576 if (res_type == nullptr) {
577 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
578 can_eliminate = false;
579 } else if (!res_type->klass_is_exact()) {
580 NOT_PRODUCT(fail_eliminate = "Not an exact type.";)
581 can_eliminate = false;
582 } else if (res_type->isa_aryptr()) {
583 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
584 if (length < 0) {
585 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
586 can_eliminate = false;
587 }
588 }
589 }
590
591 if (can_eliminate && res != nullptr) {
592 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
593 for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
594 j < jmax && can_eliminate; j++) {
595 Node* use = res->fast_out(j);
596
597 if (use->is_AddP()) {
598 const TypePtr* addp_type = igvn->type(use)->is_ptr();
599 int offset = addp_type->offset();
600
601 if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
602 NOT_PRODUCT(fail_eliminate = "Undefined field reference";)
603 can_eliminate = false;
604 break;
605 }
606 for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
607 k < kmax && can_eliminate; k++) {
608 Node* n = use->fast_out(k);
609 if (!n->is_Store() && n->Opcode() != Op_CastP2X && !bs->is_gc_pre_barrier_node(n) && !reduce_merge_precheck) {
610 DEBUG_ONLY(disq_node = n;)
611 if (n->is_Load() || n->is_LoadStore()) {
612 NOT_PRODUCT(fail_eliminate = "Field load";)
613 } else {
614 NOT_PRODUCT(fail_eliminate = "Not store field reference";)
615 }
616 can_eliminate = false;
617 }
618 }
619 } else if (use->is_ArrayCopy() &&
620 (use->as_ArrayCopy()->is_clonebasic() ||
621 use->as_ArrayCopy()->is_arraycopy_validated() ||
622 use->as_ArrayCopy()->is_copyof_validated() ||
623 use->as_ArrayCopy()->is_copyofrange_validated()) &&
624 use->in(ArrayCopyNode::Dest) == res) {
625 // ok to eliminate
626 } else if (use->is_SafePoint()) {
627 SafePointNode* sfpt = use->as_SafePoint();
628 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
629 // Object is passed as argument.
630 DEBUG_ONLY(disq_node = use;)
631 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
632 can_eliminate = false;
633 }
634 Node* sfptMem = sfpt->memory();
635 if (sfptMem == nullptr || sfptMem->is_top()) {
636 DEBUG_ONLY(disq_node = use;)
637 NOT_PRODUCT(fail_eliminate = "null or TOP memory";)
638 can_eliminate = false;
639 } else if (!reduce_merge_precheck) {
640 safepoints->append_if_missing(sfpt);
641 }
642 } else if (reduce_merge_precheck &&
643 (use->is_Phi() || use->is_EncodeP() ||
644 use->Opcode() == Op_MemBarRelease ||
645 (UseStoreStoreForCtor && use->Opcode() == Op_MemBarStoreStore))) {
646 // Nothing to do
647 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
648 if (use->is_Phi()) {
649 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
650 NOT_PRODUCT(fail_eliminate = "Object is return value";)
651 } else {
652 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
653 }
654 DEBUG_ONLY(disq_node = use;)
655 } else {
656 if (use->Opcode() == Op_Return) {
657 NOT_PRODUCT(fail_eliminate = "Object is return value";)
658 } else {
659 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
660 }
661 DEBUG_ONLY(disq_node = use;)
662 }
663 can_eliminate = false;
664 }
665 }
666 }
667
668 #ifndef PRODUCT
669 if (PrintEliminateAllocations && safepoints != nullptr) {
670 if (can_eliminate) {
671 tty->print("Scalar ");
672 if (res == nullptr)
673 alloc->dump();
674 else
675 res->dump();
676 } else if (alloc->_is_scalar_replaceable) {
677 tty->print("NotScalar (%s)", fail_eliminate);
678 if (res == nullptr)
679 alloc->dump();
680 else
681 res->dump();
682 #ifdef ASSERT
683 if (disq_node != nullptr) {
684 tty->print(" >>>> ");
685 disq_node->dump();
686 }
687 #endif /*ASSERT*/
688 }
689 }
690
691 if (TraceReduceAllocationMerges && !can_eliminate && reduce_merge_precheck) {
692 tty->print_cr("\tCan't eliminate allocation because '%s': ", fail_eliminate != nullptr ? fail_eliminate : "");
693 DEBUG_ONLY(if (disq_node != nullptr) disq_node->dump();)
694 }
695 #endif
696 return can_eliminate;
697 }
698
699 void PhaseMacroExpand::undo_previous_scalarizations(GrowableArray <SafePointNode *> safepoints_done, AllocateNode* alloc) {
700 Node* res = alloc->result_cast();
701 int nfields = 0;
702 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
703
704 if (res != nullptr) {
705 const TypeOopPtr* res_type = _igvn.type(res)->isa_oopptr();
706
707 if (res_type->isa_instptr()) {
708 // find the fields of the class which will be needed for safepoint debug information
709 ciInstanceKlass* iklass = res_type->is_instptr()->instance_klass();
710 nfields = iklass->nof_nonstatic_fields();
711 } else {
712 // find the array's elements which will be needed for safepoint debug information
713 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
714 assert(nfields >= 0, "must be an array klass.");
715 }
716 }
717
718 // rollback processed safepoints
719 while (safepoints_done.length() > 0) {
720 SafePointNode* sfpt_done = safepoints_done.pop();
721 // remove any extra entries we added to the safepoint
722 uint last = sfpt_done->req() - 1;
723 for (int k = 0; k < nfields; k++) {
724 sfpt_done->del_req(last--);
725 }
726 JVMState *jvms = sfpt_done->jvms();
727 jvms->set_endoff(sfpt_done->req());
728 // Now make a pass over the debug information replacing any references
729 // to SafePointScalarObjectNode with the allocated object.
730 int start = jvms->debug_start();
731 int end = jvms->debug_end();
732 for (int i = start; i < end; i++) {
733 if (sfpt_done->in(i)->is_SafePointScalarObject()) {
734 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
735 if (scobj->first_index(jvms) == sfpt_done->req() &&
736 scobj->n_fields() == (uint)nfields) {
737 assert(scobj->alloc() == alloc, "sanity");
738 sfpt_done->set_req(i, res);
739 }
740 }
741 }
742 _igvn._worklist.push(sfpt_done);
743 }
744 }
745
746 SafePointScalarObjectNode* PhaseMacroExpand::create_scalarized_object_description(AllocateNode *alloc, SafePointNode* sfpt) {
747 // Fields of scalar objs are referenced only at the end
748 // of regular debuginfo at the last (youngest) JVMS.
749 // Record relative start index.
750 ciInstanceKlass* iklass = nullptr;
751 BasicType basic_elem_type = T_ILLEGAL;
752 const Type* field_type = nullptr;
753 const TypeOopPtr* res_type = nullptr;
754 int nfields = 0;
755 int array_base = 0;
756 int element_size = 0;
757 uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
758 Node* res = alloc->result_cast();
759
760 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
761 assert(sfpt->jvms() != nullptr, "missed JVMS");
762
763 if (res != nullptr) { // Could be null when there are no users
764 res_type = _igvn.type(res)->isa_oopptr();
765
766 if (res_type->isa_instptr()) {
767 // find the fields of the class which will be needed for safepoint debug information
768 iklass = res_type->is_instptr()->instance_klass();
769 nfields = iklass->nof_nonstatic_fields();
770 } else {
771 // find the array's elements which will be needed for safepoint debug information
772 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
773 assert(nfields >= 0, "must be an array klass.");
774 basic_elem_type = res_type->is_aryptr()->elem()->array_element_basic_type();
775 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
776 element_size = type2aelembytes(basic_elem_type);
777 field_type = res_type->is_aryptr()->elem();
778 }
779 }
780
781 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type, alloc, first_ind, sfpt->jvms()->depth(), nfields);
782 sobj->init_req(0, C->root());
783 transform_later(sobj);
784
785 // Scan object's fields adding an input to the safepoint for each field.
786 for (int j = 0; j < nfields; j++) {
787 intptr_t offset;
788 ciField* field = nullptr;
789 if (iklass != nullptr) {
790 field = iklass->nonstatic_field_at(j);
791 offset = field->offset_in_bytes();
792 ciType* elem_type = field->type();
793 basic_elem_type = field->layout_type();
794
795 // The next code is taken from Parse::do_get_xxx().
796 if (is_reference_type(basic_elem_type)) {
797 if (!elem_type->is_loaded()) {
798 field_type = TypeInstPtr::BOTTOM;
799 } else if (field != nullptr && field->is_static_constant()) {
800 ciObject* con = field->constant_value().as_object();
801 // Do not "join" in the previous type; it doesn't add value,
802 // and may yield a vacuous result if the field is of interface type.
803 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
804 assert(field_type != nullptr, "field singleton type must be consistent");
805 } else {
806 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
807 }
808 if (UseCompressedOops) {
809 field_type = field_type->make_narrowoop();
810 basic_elem_type = T_NARROWOOP;
811 }
812 } else {
813 field_type = Type::get_const_basic_type(basic_elem_type);
814 }
815 } else {
816 offset = array_base + j * (intptr_t)element_size;
817 }
818
819 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
820
821 Node *field_val = value_from_mem(sfpt->memory(), sfpt->control(), basic_elem_type, field_type, field_addr_type, alloc);
822
823 // We weren't able to find a value for this field,
824 // give up on eliminating this allocation.
825 if (field_val == nullptr) {
826 uint last = sfpt->req() - 1;
827 for (int k = 0; k < j; k++) {
828 sfpt->del_req(last--);
829 }
830 _igvn._worklist.push(sfpt);
831
832 #ifndef PRODUCT
833 if (PrintEliminateAllocations) {
834 if (field != nullptr) {
835 tty->print("=== At SafePoint node %d can't find value of field: ", sfpt->_idx);
836 field->print();
837 int field_idx = C->get_alias_index(field_addr_type);
838 tty->print(" (alias_idx=%d)", field_idx);
839 } else { // Array's element
840 tty->print("=== At SafePoint node %d can't find value of array element [%d]", sfpt->_idx, j);
841 }
842 tty->print(", which prevents elimination of: ");
843 if (res == nullptr)
844 alloc->dump();
845 else
846 res->dump();
847 }
848 #endif
849
850 return nullptr;
851 }
852
853 if (UseCompressedOops && field_type->isa_narrowoop()) {
854 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
855 // to be able scalar replace the allocation.
856 if (field_val->is_EncodeP()) {
857 field_val = field_val->in(1);
858 } else {
859 field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
860 }
861 }
862 sfpt->add_req(field_val);
863 }
864
865 sfpt->jvms()->set_endoff(sfpt->req());
866
867 return sobj;
868 }
869
870 // Do scalar replacement.
871 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
872 GrowableArray <SafePointNode *> safepoints_done;
873 Node* res = alloc->result_cast();
874 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
875
876 // Process the safepoint uses
877 while (safepoints.length() > 0) {
878 SafePointNode* sfpt = safepoints.pop();
879 SafePointScalarObjectNode* sobj = create_scalarized_object_description(alloc, sfpt);
880
881 if (sobj == nullptr) {
882 undo_previous_scalarizations(safepoints_done, alloc);
883 return false;
884 }
885
886 // Now make a pass over the debug information replacing any references
887 // to the allocated object with "sobj"
888 JVMState *jvms = sfpt->jvms();
889 sfpt->replace_edges_in_range(res, sobj, jvms->debug_start(), jvms->debug_end(), &_igvn);
890 _igvn._worklist.push(sfpt);
891
892 // keep it for rollback
893 safepoints_done.append_if_missing(sfpt);
894 }
895
896 return true;
897 }
898
899 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) {
900 Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control);
901 Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory);
902 if (ctl_proj != nullptr) {
903 igvn.replace_node(ctl_proj, n->in(0));
904 }
905 if (mem_proj != nullptr) {
906 igvn.replace_node(mem_proj, n->in(TypeFunc::Memory));
907 }
908 }
909
910 // Process users of eliminated allocation.
911 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
912 Node* res = alloc->result_cast();
913 if (res != nullptr) {
914 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
915 Node *use = res->last_out(j);
916 uint oc1 = res->outcnt();
917
918 if (use->is_AddP()) {
919 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
920 Node *n = use->last_out(k);
921 uint oc2 = use->outcnt();
922 if (n->is_Store()) {
923 #ifdef ASSERT
924 // Verify that there is no dependent MemBarVolatile nodes,
925 // they should be removed during IGVN, see MemBarNode::Ideal().
926 for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
927 p < pmax; p++) {
928 Node* mb = n->fast_out(p);
929 assert(mb->is_Initialize() || !mb->is_MemBar() ||
930 mb->req() <= MemBarNode::Precedent ||
931 mb->in(MemBarNode::Precedent) != n,
932 "MemBarVolatile should be eliminated for non-escaping object");
933 }
934 #endif
935 _igvn.replace_node(n, n->in(MemNode::Memory));
936 } else {
937 eliminate_gc_barrier(n);
938 }
939 k -= (oc2 - use->outcnt());
940 }
941 _igvn.remove_dead_node(use);
942 } else if (use->is_ArrayCopy()) {
943 // Disconnect ArrayCopy node
944 ArrayCopyNode* ac = use->as_ArrayCopy();
945 if (ac->is_clonebasic()) {
946 Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out();
947 disconnect_projections(ac, _igvn);
948 assert(alloc->in(TypeFunc::Memory)->is_Proj() && alloc->in(TypeFunc::Memory)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation");
949 Node* membar_before = alloc->in(TypeFunc::Memory)->in(0);
950 disconnect_projections(membar_before->as_MemBar(), _igvn);
951 if (membar_after->is_MemBar()) {
952 disconnect_projections(membar_after->as_MemBar(), _igvn);
953 }
954 } else {
955 assert(ac->is_arraycopy_validated() ||
956 ac->is_copyof_validated() ||
957 ac->is_copyofrange_validated(), "unsupported");
958 CallProjections callprojs;
959 ac->extract_projections(&callprojs, true);
960
961 _igvn.replace_node(callprojs.fallthrough_ioproj, ac->in(TypeFunc::I_O));
962 _igvn.replace_node(callprojs.fallthrough_memproj, ac->in(TypeFunc::Memory));
963 _igvn.replace_node(callprojs.fallthrough_catchproj, ac->in(TypeFunc::Control));
964
965 // Set control to top. IGVN will remove the remaining projections
966 ac->set_req(0, top());
967 ac->replace_edge(res, top(), &_igvn);
968
969 // Disconnect src right away: it can help find new
970 // opportunities for allocation elimination
971 Node* src = ac->in(ArrayCopyNode::Src);
972 ac->replace_edge(src, top(), &_igvn);
973 // src can be top at this point if src and dest of the
974 // arraycopy were the same
975 if (src->outcnt() == 0 && !src->is_top()) {
976 _igvn.remove_dead_node(src);
977 }
978 }
979 _igvn._worklist.push(ac);
980 } else {
981 eliminate_gc_barrier(use);
982 }
983 j -= (oc1 - res->outcnt());
984 }
985 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
986 _igvn.remove_dead_node(res);
987 }
988
989 //
990 // Process other users of allocation's projections
991 //
992 if (_callprojs.resproj != nullptr && _callprojs.resproj->outcnt() != 0) {
993 // First disconnect stores captured by Initialize node.
994 // If Initialize node is eliminated first in the following code,
995 // it will kill such stores and DUIterator_Last will assert.
996 for (DUIterator_Fast jmax, j = _callprojs.resproj->fast_outs(jmax); j < jmax; j++) {
997 Node* use = _callprojs.resproj->fast_out(j);
998 if (use->is_AddP()) {
999 // raw memory addresses used only by the initialization
1000 _igvn.replace_node(use, C->top());
1001 --j; --jmax;
1002 }
1003 }
1004 for (DUIterator_Last jmin, j = _callprojs.resproj->last_outs(jmin); j >= jmin; ) {
1005 Node* use = _callprojs.resproj->last_out(j);
1006 uint oc1 = _callprojs.resproj->outcnt();
1007 if (use->is_Initialize()) {
1008 // Eliminate Initialize node.
1009 InitializeNode *init = use->as_Initialize();
1010 assert(init->outcnt() <= 2, "only a control and memory projection expected");
1011 Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
1012 if (ctrl_proj != nullptr) {
1013 _igvn.replace_node(ctrl_proj, init->in(TypeFunc::Control));
1014 #ifdef ASSERT
1015 // If the InitializeNode has no memory out, it will die, and tmp will become null
1016 Node* tmp = init->in(TypeFunc::Control);
1017 assert(tmp == nullptr || tmp == _callprojs.fallthrough_catchproj, "allocation control projection");
1018 #endif
1019 }
1020 Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
1021 if (mem_proj != nullptr) {
1022 Node *mem = init->in(TypeFunc::Memory);
1023 #ifdef ASSERT
1024 if (mem->is_MergeMem()) {
1025 assert(mem->in(TypeFunc::Memory) == _callprojs.fallthrough_memproj, "allocation memory projection");
1026 } else {
1027 assert(mem == _callprojs.fallthrough_memproj, "allocation memory projection");
1028 }
1029 #endif
1030 _igvn.replace_node(mem_proj, mem);
1031 }
1032 } else {
1033 assert(false, "only Initialize or AddP expected");
1034 }
1035 j -= (oc1 - _callprojs.resproj->outcnt());
1036 }
1037 }
1038 if (_callprojs.fallthrough_catchproj != nullptr) {
1039 _igvn.replace_node(_callprojs.fallthrough_catchproj, alloc->in(TypeFunc::Control));
1040 }
1041 if (_callprojs.fallthrough_memproj != nullptr) {
1042 _igvn.replace_node(_callprojs.fallthrough_memproj, alloc->in(TypeFunc::Memory));
1043 }
1044 if (_callprojs.catchall_memproj != nullptr) {
1045 _igvn.replace_node(_callprojs.catchall_memproj, C->top());
1046 }
1047 if (_callprojs.fallthrough_ioproj != nullptr) {
1048 _igvn.replace_node(_callprojs.fallthrough_ioproj, alloc->in(TypeFunc::I_O));
1049 }
1050 if (_callprojs.catchall_ioproj != nullptr) {
1051 _igvn.replace_node(_callprojs.catchall_ioproj, C->top());
1052 }
1053 if (_callprojs.catchall_catchproj != nullptr) {
1054 _igvn.replace_node(_callprojs.catchall_catchproj, C->top());
1055 }
1056 }
1057
1058 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
1059 // If reallocation fails during deoptimization we'll pop all
1060 // interpreter frames for this compiled frame and that won't play
1061 // nice with JVMTI popframe.
1062 // We avoid this issue by eager reallocation when the popframe request
1063 // is received.
1064 if (!EliminateAllocations || !alloc->_is_non_escaping) {
1065 return false;
1066 }
1067 Node* klass = alloc->in(AllocateNode::KlassNode);
1068 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
1069 Node* res = alloc->result_cast();
1070 // Eliminate boxing allocations which are not used
1071 // regardless scalar replaceable status.
1072 bool boxing_alloc = C->eliminate_boxing() &&
1073 tklass->isa_instklassptr() &&
1074 tklass->is_instklassptr()->instance_klass()->is_box_klass();
1075 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != nullptr))) {
1076 return false;
1077 }
1078
1079 alloc->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1080
1081 GrowableArray <SafePointNode *> safepoints;
1082 if (!can_eliminate_allocation(&_igvn, alloc, &safepoints)) {
1083 return false;
1084 }
1085
1086 if (!alloc->_is_scalar_replaceable) {
1087 assert(res == nullptr, "sanity");
1088 // We can only eliminate allocation if all debug info references
1089 // are already replaced with SafePointScalarObject because
1090 // we can't search for a fields value without instance_id.
1091 if (safepoints.length() > 0) {
1092 return false;
1093 }
1094 }
1095
1096 if (!scalar_replacement(alloc, safepoints)) {
1097 return false;
1098 }
1099
1100 CompileLog* log = C->log();
1101 if (log != nullptr) {
1102 log->head("eliminate_allocation type='%d'",
1103 log->identify(tklass->exact_klass()));
1104 JVMState* p = alloc->jvms();
1105 while (p != nullptr) {
1106 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1107 p = p->caller();
1108 }
1109 log->tail("eliminate_allocation");
1110 }
1111
1112 process_users_of_allocation(alloc);
1113
1114 #ifndef PRODUCT
1115 if (PrintEliminateAllocations) {
1116 if (alloc->is_AllocateArray())
1117 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1118 else
1119 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1120 }
1121 #endif
1122
1123 return true;
1124 }
1125
1126 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1127 // EA should remove all uses of non-escaping boxing node.
1128 if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != nullptr) {
1129 return false;
1130 }
1131
1132 assert(boxing->result_cast() == nullptr, "unexpected boxing node result");
1133
1134 boxing->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1135
1136 const TypeTuple* r = boxing->tf()->range();
1137 assert(r->cnt() > TypeFunc::Parms, "sanity");
1138 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1139 assert(t != nullptr, "sanity");
1140
1141 CompileLog* log = C->log();
1142 if (log != nullptr) {
1143 log->head("eliminate_boxing type='%d'",
1144 log->identify(t->instance_klass()));
1145 JVMState* p = boxing->jvms();
1146 while (p != nullptr) {
1147 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1148 p = p->caller();
1149 }
1150 log->tail("eliminate_boxing");
1151 }
1152
1153 process_users_of_allocation(boxing);
1154
1155 #ifndef PRODUCT
1156 if (PrintEliminateAllocations) {
1157 tty->print("++++ Eliminated: %d ", boxing->_idx);
1158 boxing->method()->print_short_name(tty);
1159 tty->cr();
1160 }
1161 #endif
1162
1163 return true;
1164 }
1165
1166
1167 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1168 Node* adr = basic_plus_adr(base, offset);
1169 const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1170 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1171 transform_later(value);
1172 return value;
1173 }
1174
1175
1176 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1177 Node* adr = basic_plus_adr(base, offset);
1178 mem = StoreNode::make(_igvn, ctl, mem, adr, nullptr, value, bt, MemNode::unordered);
1179 transform_later(mem);
1180 return mem;
1181 }
1182
1183 //=============================================================================
1184 //
1185 // A L L O C A T I O N
1186 //
1187 // Allocation attempts to be fast in the case of frequent small objects.
1188 // It breaks down like this:
1189 //
1190 // 1) Size in doublewords is computed. This is a constant for objects and
1191 // variable for most arrays. Doubleword units are used to avoid size
1192 // overflow of huge doubleword arrays. We need doublewords in the end for
1193 // rounding.
1194 //
1195 // 2) Size is checked for being 'too large'. Too-large allocations will go
1196 // the slow path into the VM. The slow path can throw any required
1197 // exceptions, and does all the special checks for very large arrays. The
1198 // size test can constant-fold away for objects. For objects with
1199 // finalizers it constant-folds the otherway: you always go slow with
1200 // finalizers.
1201 //
1202 // 3) If NOT using TLABs, this is the contended loop-back point.
1203 // Load-Locked the heap top. If using TLABs normal-load the heap top.
1204 //
1205 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
1206 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
1207 // "size*8" we always enter the VM, where "largish" is a constant picked small
1208 // enough that there's always space between the eden max and 4Gig (old space is
1209 // there so it's quite large) and large enough that the cost of entering the VM
1210 // is dwarfed by the cost to initialize the space.
1211 //
1212 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1213 // down. If contended, repeat at step 3. If using TLABs normal-store
1214 // adjusted heap top back down; there is no contention.
1215 //
1216 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
1217 // fields.
1218 //
1219 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1220 // oop flavor.
1221 //
1222 //=============================================================================
1223 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1224 // Allocations bigger than this always go the slow route.
1225 // This value must be small enough that allocation attempts that need to
1226 // trigger exceptions go the slow route. Also, it must be small enough so
1227 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1228 //=============================================================================j//
1229 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1230 // The allocator will coalesce int->oop copies away. See comment in
1231 // coalesce.cpp about how this works. It depends critically on the exact
1232 // code shape produced here, so if you are changing this code shape
1233 // make sure the GC info for the heap-top is correct in and around the
1234 // slow-path call.
1235 //
1236
1237 void PhaseMacroExpand::expand_allocate_common(
1238 AllocateNode* alloc, // allocation node to be expanded
1239 Node* length, // array length for an array allocation
1240 const TypeFunc* slow_call_type, // Type of slow call
1241 address slow_call_address, // Address of slow call
1242 Node* valid_length_test // whether length is valid or not
1243 )
1244 {
1245 Node* ctrl = alloc->in(TypeFunc::Control);
1246 Node* mem = alloc->in(TypeFunc::Memory);
1247 Node* i_o = alloc->in(TypeFunc::I_O);
1248 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
1249 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1250 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1251 assert(ctrl != nullptr, "must have control");
1252
1253 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1254 // they will not be used if "always_slow" is set
1255 enum { slow_result_path = 1, fast_result_path = 2 };
1256 Node *result_region = nullptr;
1257 Node *result_phi_rawmem = nullptr;
1258 Node *result_phi_rawoop = nullptr;
1259 Node *result_phi_i_o = nullptr;
1260
1261 // The initial slow comparison is a size check, the comparison
1262 // we want to do is a BoolTest::gt
1263 bool expand_fast_path = true;
1264 int tv = _igvn.find_int_con(initial_slow_test, -1);
1265 if (tv >= 0) {
1266 // InitialTest has constant result
1267 // 0 - can fit in TLAB
1268 // 1 - always too big or negative
1269 assert(tv <= 1, "0 or 1 if a constant");
1270 expand_fast_path = (tv == 0);
1271 initial_slow_test = nullptr;
1272 } else {
1273 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1274 }
1275
1276 if (!UseTLAB) {
1277 // Force slow-path allocation
1278 expand_fast_path = false;
1279 initial_slow_test = nullptr;
1280 }
1281
1282 bool allocation_has_use = (alloc->result_cast() != nullptr);
1283 if (!allocation_has_use) {
1284 InitializeNode* init = alloc->initialization();
1285 if (init != nullptr) {
1286 init->remove(&_igvn);
1287 }
1288 if (expand_fast_path && (initial_slow_test == nullptr)) {
1289 // Remove allocation node and return.
1290 // Size is a non-negative constant -> no initial check needed -> directly to fast path.
1291 // Also, no usages -> empty fast path -> no fall out to slow path -> nothing left.
1292 #ifndef PRODUCT
1293 if (PrintEliminateAllocations) {
1294 tty->print("NotUsed ");
1295 Node* res = alloc->proj_out_or_null(TypeFunc::Parms);
1296 if (res != nullptr) {
1297 res->dump();
1298 } else {
1299 alloc->dump();
1300 }
1301 }
1302 #endif
1303 yank_alloc_node(alloc);
1304 return;
1305 }
1306 }
1307
1308 enum { too_big_or_final_path = 1, need_gc_path = 2 };
1309 Node *slow_region = nullptr;
1310 Node *toobig_false = ctrl;
1311
1312 // generate the initial test if necessary
1313 if (initial_slow_test != nullptr ) {
1314 assert (expand_fast_path, "Only need test if there is a fast path");
1315 slow_region = new RegionNode(3);
1316
1317 // Now make the initial failure test. Usually a too-big test but
1318 // might be a TRUE for finalizers.
1319 IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1320 transform_later(toobig_iff);
1321 // Plug the failing-too-big test into the slow-path region
1322 Node *toobig_true = new IfTrueNode( toobig_iff );
1323 transform_later(toobig_true);
1324 slow_region ->init_req( too_big_or_final_path, toobig_true );
1325 toobig_false = new IfFalseNode( toobig_iff );
1326 transform_later(toobig_false);
1327 } else {
1328 // No initial test, just fall into next case
1329 assert(allocation_has_use || !expand_fast_path, "Should already have been handled");
1330 toobig_false = ctrl;
1331 debug_only(slow_region = NodeSentinel);
1332 }
1333
1334 // If we are here there are several possibilities
1335 // - expand_fast_path is false - then only a slow path is expanded. That's it.
1336 // no_initial_check means a constant allocation.
1337 // - If check always evaluates to false -> expand_fast_path is false (see above)
1338 // - If check always evaluates to true -> directly into fast path (but may bailout to slowpath)
1339 // if !allocation_has_use the fast path is empty
1340 // if !allocation_has_use && no_initial_check
1341 // - Then there are no fastpath that can fall out to slowpath -> no allocation code at all.
1342 // removed by yank_alloc_node above.
1343
1344 Node *slow_mem = mem; // save the current memory state for slow path
1345 // generate the fast allocation code unless we know that the initial test will always go slow
1346 if (expand_fast_path) {
1347 // Fast path modifies only raw memory.
1348 if (mem->is_MergeMem()) {
1349 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1350 }
1351
1352 // allocate the Region and Phi nodes for the result
1353 result_region = new RegionNode(3);
1354 result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1355 result_phi_i_o = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1356
1357 // Grab regular I/O before optional prefetch may change it.
1358 // Slow-path does no I/O so just set it to the original I/O.
1359 result_phi_i_o->init_req(slow_result_path, i_o);
1360
1361 // Name successful fast-path variables
1362 Node* fast_oop_ctrl;
1363 Node* fast_oop_rawmem;
1364 if (allocation_has_use) {
1365 Node* needgc_ctrl = nullptr;
1366 result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1367
1368 intx prefetch_lines = length != nullptr ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1369 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1370 Node* fast_oop = bs->obj_allocate(this, mem, toobig_false, size_in_bytes, i_o, needgc_ctrl,
1371 fast_oop_ctrl, fast_oop_rawmem,
1372 prefetch_lines);
1373
1374 if (initial_slow_test != nullptr) {
1375 // This completes all paths into the slow merge point
1376 slow_region->init_req(need_gc_path, needgc_ctrl);
1377 transform_later(slow_region);
1378 } else {
1379 // No initial slow path needed!
1380 // Just fall from the need-GC path straight into the VM call.
1381 slow_region = needgc_ctrl;
1382 }
1383
1384 InitializeNode* init = alloc->initialization();
1385 fast_oop_rawmem = initialize_object(alloc,
1386 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1387 klass_node, length, size_in_bytes);
1388 expand_initialize_membar(alloc, init, fast_oop_ctrl, fast_oop_rawmem);
1389 expand_dtrace_alloc_probe(alloc, fast_oop, fast_oop_ctrl, fast_oop_rawmem);
1390
1391 result_phi_rawoop->init_req(fast_result_path, fast_oop);
1392 } else {
1393 assert (initial_slow_test != nullptr, "sanity");
1394 fast_oop_ctrl = toobig_false;
1395 fast_oop_rawmem = mem;
1396 transform_later(slow_region);
1397 }
1398
1399 // Plug in the successful fast-path into the result merge point
1400 result_region ->init_req(fast_result_path, fast_oop_ctrl);
1401 result_phi_i_o ->init_req(fast_result_path, i_o);
1402 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1403 } else {
1404 slow_region = ctrl;
1405 result_phi_i_o = i_o; // Rename it to use in the following code.
1406 }
1407
1408 // Generate slow-path call
1409 CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1410 OptoRuntime::stub_name(slow_call_address),
1411 TypePtr::BOTTOM);
1412 call->init_req(TypeFunc::Control, slow_region);
1413 call->init_req(TypeFunc::I_O, top()); // does no i/o
1414 call->init_req(TypeFunc::Memory, slow_mem); // may gc ptrs
1415 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1416 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1417
1418 call->init_req(TypeFunc::Parms+0, klass_node);
1419 if (length != nullptr) {
1420 call->init_req(TypeFunc::Parms+1, length);
1421 }
1422
1423 // Copy debug information and adjust JVMState information, then replace
1424 // allocate node with the call
1425 call->copy_call_debug_info(&_igvn, alloc);
1426 // For array allocations, copy the valid length check to the call node so Compile::final_graph_reshaping() can verify
1427 // that the call has the expected number of CatchProj nodes (in case the allocation always fails and the fallthrough
1428 // path dies).
1429 if (valid_length_test != nullptr) {
1430 call->add_req(valid_length_test);
1431 }
1432 if (expand_fast_path) {
1433 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1434 } else {
1435 // Hook i_o projection to avoid its elimination during allocation
1436 // replacement (when only a slow call is generated).
1437 call->set_req(TypeFunc::I_O, result_phi_i_o);
1438 }
1439 _igvn.replace_node(alloc, call);
1440 transform_later(call);
1441
1442 // Identify the output projections from the allocate node and
1443 // adjust any references to them.
1444 // The control and io projections look like:
1445 //
1446 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
1447 // Allocate Catch
1448 // ^---Proj(io) <-------+ ^---CatchProj(io)
1449 //
1450 // We are interested in the CatchProj nodes.
1451 //
1452 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1453
1454 // An allocate node has separate memory projections for the uses on
1455 // the control and i_o paths. Replace the control memory projection with
1456 // result_phi_rawmem (unless we are only generating a slow call when
1457 // both memory projections are combined)
1458 if (expand_fast_path && _callprojs.fallthrough_memproj != nullptr) {
1459 migrate_outs(_callprojs.fallthrough_memproj, result_phi_rawmem);
1460 }
1461 // Now change uses of catchall_memproj to use fallthrough_memproj and delete
1462 // catchall_memproj so we end up with a call that has only 1 memory projection.
1463 if (_callprojs.catchall_memproj != nullptr ) {
1464 if (_callprojs.fallthrough_memproj == nullptr) {
1465 _callprojs.fallthrough_memproj = new ProjNode(call, TypeFunc::Memory);
1466 transform_later(_callprojs.fallthrough_memproj);
1467 }
1468 migrate_outs(_callprojs.catchall_memproj, _callprojs.fallthrough_memproj);
1469 _igvn.remove_dead_node(_callprojs.catchall_memproj);
1470 }
1471
1472 // An allocate node has separate i_o projections for the uses on the control
1473 // and i_o paths. Always replace the control i_o projection with result i_o
1474 // otherwise incoming i_o become dead when only a slow call is generated
1475 // (it is different from memory projections where both projections are
1476 // combined in such case).
1477 if (_callprojs.fallthrough_ioproj != nullptr) {
1478 migrate_outs(_callprojs.fallthrough_ioproj, result_phi_i_o);
1479 }
1480 // Now change uses of catchall_ioproj to use fallthrough_ioproj and delete
1481 // catchall_ioproj so we end up with a call that has only 1 i_o projection.
1482 if (_callprojs.catchall_ioproj != nullptr ) {
1483 if (_callprojs.fallthrough_ioproj == nullptr) {
1484 _callprojs.fallthrough_ioproj = new ProjNode(call, TypeFunc::I_O);
1485 transform_later(_callprojs.fallthrough_ioproj);
1486 }
1487 migrate_outs(_callprojs.catchall_ioproj, _callprojs.fallthrough_ioproj);
1488 _igvn.remove_dead_node(_callprojs.catchall_ioproj);
1489 }
1490
1491 // if we generated only a slow call, we are done
1492 if (!expand_fast_path) {
1493 // Now we can unhook i_o.
1494 if (result_phi_i_o->outcnt() > 1) {
1495 call->set_req(TypeFunc::I_O, top());
1496 } else {
1497 assert(result_phi_i_o->unique_ctrl_out() == call, "sanity");
1498 // Case of new array with negative size known during compilation.
1499 // AllocateArrayNode::Ideal() optimization disconnect unreachable
1500 // following code since call to runtime will throw exception.
1501 // As result there will be no users of i_o after the call.
1502 // Leave i_o attached to this call to avoid problems in preceding graph.
1503 }
1504 return;
1505 }
1506
1507 if (_callprojs.fallthrough_catchproj != nullptr) {
1508 ctrl = _callprojs.fallthrough_catchproj->clone();
1509 transform_later(ctrl);
1510 _igvn.replace_node(_callprojs.fallthrough_catchproj, result_region);
1511 } else {
1512 ctrl = top();
1513 }
1514 Node *slow_result;
1515 if (_callprojs.resproj == nullptr) {
1516 // no uses of the allocation result
1517 slow_result = top();
1518 } else {
1519 slow_result = _callprojs.resproj->clone();
1520 transform_later(slow_result);
1521 _igvn.replace_node(_callprojs.resproj, result_phi_rawoop);
1522 }
1523
1524 // Plug slow-path into result merge point
1525 result_region->init_req( slow_result_path, ctrl);
1526 transform_later(result_region);
1527 if (allocation_has_use) {
1528 result_phi_rawoop->init_req(slow_result_path, slow_result);
1529 transform_later(result_phi_rawoop);
1530 }
1531 result_phi_rawmem->init_req(slow_result_path, _callprojs.fallthrough_memproj);
1532 transform_later(result_phi_rawmem);
1533 transform_later(result_phi_i_o);
1534 // This completes all paths into the result merge point
1535 }
1536
1537 // Remove alloc node that has no uses.
1538 void PhaseMacroExpand::yank_alloc_node(AllocateNode* alloc) {
1539 Node* ctrl = alloc->in(TypeFunc::Control);
1540 Node* mem = alloc->in(TypeFunc::Memory);
1541 Node* i_o = alloc->in(TypeFunc::I_O);
1542
1543 alloc->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1544 if (_callprojs.resproj != nullptr) {
1545 for (DUIterator_Fast imax, i = _callprojs.resproj->fast_outs(imax); i < imax; i++) {
1546 Node* use = _callprojs.resproj->fast_out(i);
1547 use->isa_MemBar()->remove(&_igvn);
1548 --imax;
1549 --i; // back up iterator
1550 }
1551 assert(_callprojs.resproj->outcnt() == 0, "all uses must be deleted");
1552 _igvn.remove_dead_node(_callprojs.resproj);
1553 }
1554 if (_callprojs.fallthrough_catchproj != nullptr) {
1555 migrate_outs(_callprojs.fallthrough_catchproj, ctrl);
1556 _igvn.remove_dead_node(_callprojs.fallthrough_catchproj);
1557 }
1558 if (_callprojs.catchall_catchproj != nullptr) {
1559 _igvn.rehash_node_delayed(_callprojs.catchall_catchproj);
1560 _callprojs.catchall_catchproj->set_req(0, top());
1561 }
1562 if (_callprojs.fallthrough_proj != nullptr) {
1563 Node* catchnode = _callprojs.fallthrough_proj->unique_ctrl_out();
1564 _igvn.remove_dead_node(catchnode);
1565 _igvn.remove_dead_node(_callprojs.fallthrough_proj);
1566 }
1567 if (_callprojs.fallthrough_memproj != nullptr) {
1568 migrate_outs(_callprojs.fallthrough_memproj, mem);
1569 _igvn.remove_dead_node(_callprojs.fallthrough_memproj);
1570 }
1571 if (_callprojs.fallthrough_ioproj != nullptr) {
1572 migrate_outs(_callprojs.fallthrough_ioproj, i_o);
1573 _igvn.remove_dead_node(_callprojs.fallthrough_ioproj);
1574 }
1575 if (_callprojs.catchall_memproj != nullptr) {
1576 _igvn.rehash_node_delayed(_callprojs.catchall_memproj);
1577 _callprojs.catchall_memproj->set_req(0, top());
1578 }
1579 if (_callprojs.catchall_ioproj != nullptr) {
1580 _igvn.rehash_node_delayed(_callprojs.catchall_ioproj);
1581 _callprojs.catchall_ioproj->set_req(0, top());
1582 }
1583 #ifndef PRODUCT
1584 if (PrintEliminateAllocations) {
1585 if (alloc->is_AllocateArray()) {
1586 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1587 } else {
1588 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1589 }
1590 }
1591 #endif
1592 _igvn.remove_dead_node(alloc);
1593 }
1594
1595 void PhaseMacroExpand::expand_initialize_membar(AllocateNode* alloc, InitializeNode* init,
1596 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem) {
1597 // If initialization is performed by an array copy, any required
1598 // MemBarStoreStore was already added. If the object does not
1599 // escape no need for a MemBarStoreStore. If the object does not
1600 // escape in its initializer and memory barrier (MemBarStoreStore or
1601 // stronger) is already added at exit of initializer, also no need
1602 // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore
1603 // so that stores that initialize this object can't be reordered
1604 // with a subsequent store that makes this object accessible by
1605 // other threads.
1606 // Other threads include java threads and JVM internal threads
1607 // (for example concurrent GC threads). Current concurrent GC
1608 // implementation: G1 will not scan newly created object,
1609 // so it's safe to skip storestore barrier when allocation does
1610 // not escape.
1611 if (!alloc->does_not_escape_thread() &&
1612 !alloc->is_allocation_MemBar_redundant() &&
1613 (init == nullptr || !init->is_complete_with_arraycopy())) {
1614 if (init == nullptr || init->req() < InitializeNode::RawStores) {
1615 // No InitializeNode or no stores captured by zeroing
1616 // elimination. Simply add the MemBarStoreStore after object
1617 // initialization.
1618 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1619 transform_later(mb);
1620
1621 mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1622 mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1623 fast_oop_ctrl = new ProjNode(mb, TypeFunc::Control);
1624 transform_later(fast_oop_ctrl);
1625 fast_oop_rawmem = new ProjNode(mb, TypeFunc::Memory);
1626 transform_later(fast_oop_rawmem);
1627 } else {
1628 // Add the MemBarStoreStore after the InitializeNode so that
1629 // all stores performing the initialization that were moved
1630 // before the InitializeNode happen before the storestore
1631 // barrier.
1632
1633 Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control);
1634 Node* init_mem = init->proj_out_or_null(TypeFunc::Memory);
1635
1636 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1637 transform_later(mb);
1638
1639 Node* ctrl = new ProjNode(init, TypeFunc::Control);
1640 transform_later(ctrl);
1641 Node* mem = new ProjNode(init, TypeFunc::Memory);
1642 transform_later(mem);
1643
1644 // The MemBarStoreStore depends on control and memory coming
1645 // from the InitializeNode
1646 mb->init_req(TypeFunc::Memory, mem);
1647 mb->init_req(TypeFunc::Control, ctrl);
1648
1649 ctrl = new ProjNode(mb, TypeFunc::Control);
1650 transform_later(ctrl);
1651 mem = new ProjNode(mb, TypeFunc::Memory);
1652 transform_later(mem);
1653
1654 // All nodes that depended on the InitializeNode for control
1655 // and memory must now depend on the MemBarNode that itself
1656 // depends on the InitializeNode
1657 if (init_ctrl != nullptr) {
1658 _igvn.replace_node(init_ctrl, ctrl);
1659 }
1660 if (init_mem != nullptr) {
1661 _igvn.replace_node(init_mem, mem);
1662 }
1663 }
1664 }
1665 }
1666
1667 void PhaseMacroExpand::expand_dtrace_alloc_probe(AllocateNode* alloc, Node* oop,
1668 Node*& ctrl, Node*& rawmem) {
1669 if (C->env()->dtrace_alloc_probes()) {
1670 // Slow-path call
1671 int size = TypeFunc::Parms + 2;
1672 CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1673 CAST_FROM_FN_PTR(address,
1674 static_cast<int (*)(JavaThread*, oopDesc*)>(SharedRuntime::dtrace_object_alloc)),
1675 "dtrace_object_alloc",
1676 TypeRawPtr::BOTTOM);
1677
1678 // Get base of thread-local storage area
1679 Node* thread = new ThreadLocalNode();
1680 transform_later(thread);
1681
1682 call->init_req(TypeFunc::Parms + 0, thread);
1683 call->init_req(TypeFunc::Parms + 1, oop);
1684 call->init_req(TypeFunc::Control, ctrl);
1685 call->init_req(TypeFunc::I_O , top()); // does no i/o
1686 call->init_req(TypeFunc::Memory , rawmem);
1687 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1688 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1689 transform_later(call);
1690 ctrl = new ProjNode(call, TypeFunc::Control);
1691 transform_later(ctrl);
1692 rawmem = new ProjNode(call, TypeFunc::Memory);
1693 transform_later(rawmem);
1694 }
1695 }
1696
1697 // Helper for PhaseMacroExpand::expand_allocate_common.
1698 // Initializes the newly-allocated storage.
1699 Node*
1700 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1701 Node* control, Node* rawmem, Node* object,
1702 Node* klass_node, Node* length,
1703 Node* size_in_bytes) {
1704 InitializeNode* init = alloc->initialization();
1705 // Store the klass & mark bits
1706 Node* mark_node = alloc->make_ideal_mark(&_igvn, object, control, rawmem);
1707 if (!mark_node->is_Con()) {
1708 transform_later(mark_node);
1709 }
1710 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, TypeX_X->basic_type());
1711
1712 if (!UseCompactObjectHeaders) {
1713 rawmem = make_store(control, rawmem, object, Type::klass_offset(), klass_node, T_METADATA);
1714 }
1715 int header_size = alloc->minimum_header_size(); // conservatively small
1716
1717 // Array length
1718 if (length != nullptr) { // Arrays need length field
1719 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1720 // conservatively small header size:
1721 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1722 if (_igvn.type(klass_node)->isa_aryklassptr()) { // we know the exact header size in most cases:
1723 BasicType elem = _igvn.type(klass_node)->is_klassptr()->as_instance_type()->isa_aryptr()->elem()->array_element_basic_type();
1724 if (is_reference_type(elem, true)) {
1725 elem = T_OBJECT;
1726 }
1727 header_size = Klass::layout_helper_header_size(Klass::array_layout_helper(elem));
1728 }
1729 }
1730
1731 // Clear the object body, if necessary.
1732 if (init == nullptr) {
1733 // The init has somehow disappeared; be cautious and clear everything.
1734 //
1735 // This can happen if a node is allocated but an uncommon trap occurs
1736 // immediately. In this case, the Initialize gets associated with the
1737 // trap, and may be placed in a different (outer) loop, if the Allocate
1738 // is in a loop. If (this is rare) the inner loop gets unrolled, then
1739 // there can be two Allocates to one Initialize. The answer in all these
1740 // edge cases is safety first. It is always safe to clear immediately
1741 // within an Allocate, and then (maybe or maybe not) clear some more later.
1742 if (!(UseTLAB && ZeroTLAB)) {
1743 rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1744 header_size, size_in_bytes,
1745 &_igvn);
1746 }
1747 } else {
1748 if (!init->is_complete()) {
1749 // Try to win by zeroing only what the init does not store.
1750 // We can also try to do some peephole optimizations,
1751 // such as combining some adjacent subword stores.
1752 rawmem = init->complete_stores(control, rawmem, object,
1753 header_size, size_in_bytes, &_igvn);
1754 }
1755 // We have no more use for this link, since the AllocateNode goes away:
1756 init->set_req(InitializeNode::RawAddress, top());
1757 // (If we keep the link, it just confuses the register allocator,
1758 // who thinks he sees a real use of the address by the membar.)
1759 }
1760
1761 return rawmem;
1762 }
1763
1764 // Generate prefetch instructions for next allocations.
1765 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1766 Node*& contended_phi_rawmem,
1767 Node* old_eden_top, Node* new_eden_top,
1768 intx lines) {
1769 enum { fall_in_path = 1, pf_path = 2 };
1770 if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1771 // Generate prefetch allocation with watermark check.
1772 // As an allocation hits the watermark, we will prefetch starting
1773 // at a "distance" away from watermark.
1774
1775 Node *pf_region = new RegionNode(3);
1776 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1777 TypeRawPtr::BOTTOM );
1778 // I/O is used for Prefetch
1779 Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1780
1781 Node *thread = new ThreadLocalNode();
1782 transform_later(thread);
1783
1784 Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1785 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1786 transform_later(eden_pf_adr);
1787
1788 Node *old_pf_wm = new LoadPNode(needgc_false,
1789 contended_phi_rawmem, eden_pf_adr,
1790 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1791 MemNode::unordered);
1792 transform_later(old_pf_wm);
1793
1794 // check against new_eden_top
1795 Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1796 transform_later(need_pf_cmp);
1797 Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1798 transform_later(need_pf_bol);
1799 IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1800 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1801 transform_later(need_pf_iff);
1802
1803 // true node, add prefetchdistance
1804 Node *need_pf_true = new IfTrueNode( need_pf_iff );
1805 transform_later(need_pf_true);
1806
1807 Node *need_pf_false = new IfFalseNode( need_pf_iff );
1808 transform_later(need_pf_false);
1809
1810 Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1811 _igvn.MakeConX(AllocatePrefetchDistance) );
1812 transform_later(new_pf_wmt );
1813 new_pf_wmt->set_req(0, need_pf_true);
1814
1815 Node *store_new_wmt = new StorePNode(need_pf_true,
1816 contended_phi_rawmem, eden_pf_adr,
1817 TypeRawPtr::BOTTOM, new_pf_wmt,
1818 MemNode::unordered);
1819 transform_later(store_new_wmt);
1820
1821 // adding prefetches
1822 pf_phi_abio->init_req( fall_in_path, i_o );
1823
1824 Node *prefetch_adr;
1825 Node *prefetch;
1826 uint step_size = AllocatePrefetchStepSize;
1827 uint distance = 0;
1828
1829 for ( intx i = 0; i < lines; i++ ) {
1830 prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1831 _igvn.MakeConX(distance) );
1832 transform_later(prefetch_adr);
1833 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1834 transform_later(prefetch);
1835 distance += step_size;
1836 i_o = prefetch;
1837 }
1838 pf_phi_abio->set_req( pf_path, i_o );
1839
1840 pf_region->init_req( fall_in_path, need_pf_false );
1841 pf_region->init_req( pf_path, need_pf_true );
1842
1843 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1844 pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1845
1846 transform_later(pf_region);
1847 transform_later(pf_phi_rawmem);
1848 transform_later(pf_phi_abio);
1849
1850 needgc_false = pf_region;
1851 contended_phi_rawmem = pf_phi_rawmem;
1852 i_o = pf_phi_abio;
1853 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1854 // Insert a prefetch instruction for each allocation.
1855 // This code is used to generate 1 prefetch instruction per cache line.
1856
1857 // Generate several prefetch instructions.
1858 uint step_size = AllocatePrefetchStepSize;
1859 uint distance = AllocatePrefetchDistance;
1860
1861 // Next cache address.
1862 Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1863 _igvn.MakeConX(step_size + distance));
1864 transform_later(cache_adr);
1865 cache_adr = new CastP2XNode(needgc_false, cache_adr);
1866 transform_later(cache_adr);
1867 // Address is aligned to execute prefetch to the beginning of cache line size
1868 // (it is important when BIS instruction is used on SPARC as prefetch).
1869 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1870 cache_adr = new AndXNode(cache_adr, mask);
1871 transform_later(cache_adr);
1872 cache_adr = new CastX2PNode(cache_adr);
1873 transform_later(cache_adr);
1874
1875 // Prefetch
1876 Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1877 prefetch->set_req(0, needgc_false);
1878 transform_later(prefetch);
1879 contended_phi_rawmem = prefetch;
1880 Node *prefetch_adr;
1881 distance = step_size;
1882 for ( intx i = 1; i < lines; i++ ) {
1883 prefetch_adr = new AddPNode( cache_adr, cache_adr,
1884 _igvn.MakeConX(distance) );
1885 transform_later(prefetch_adr);
1886 prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1887 transform_later(prefetch);
1888 distance += step_size;
1889 contended_phi_rawmem = prefetch;
1890 }
1891 } else if( AllocatePrefetchStyle > 0 ) {
1892 // Insert a prefetch for each allocation only on the fast-path
1893 Node *prefetch_adr;
1894 Node *prefetch;
1895 // Generate several prefetch instructions.
1896 uint step_size = AllocatePrefetchStepSize;
1897 uint distance = AllocatePrefetchDistance;
1898 for ( intx i = 0; i < lines; i++ ) {
1899 prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1900 _igvn.MakeConX(distance) );
1901 transform_later(prefetch_adr);
1902 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1903 // Do not let it float too high, since if eden_top == eden_end,
1904 // both might be null.
1905 if( i == 0 ) { // Set control for first prefetch, next follows it
1906 prefetch->init_req(0, needgc_false);
1907 }
1908 transform_later(prefetch);
1909 distance += step_size;
1910 i_o = prefetch;
1911 }
1912 }
1913 return i_o;
1914 }
1915
1916
1917 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1918 expand_allocate_common(alloc, nullptr,
1919 OptoRuntime::new_instance_Type(),
1920 OptoRuntime::new_instance_Java(), nullptr);
1921 }
1922
1923 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1924 Node* length = alloc->in(AllocateNode::ALength);
1925 Node* valid_length_test = alloc->in(AllocateNode::ValidLengthTest);
1926 InitializeNode* init = alloc->initialization();
1927 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1928 const TypeAryKlassPtr* ary_klass_t = _igvn.type(klass_node)->isa_aryklassptr();
1929 address slow_call_address; // Address of slow call
1930 if (init != nullptr && init->is_complete_with_arraycopy() &&
1931 ary_klass_t && ary_klass_t->elem()->isa_klassptr() == nullptr) {
1932 // Don't zero type array during slow allocation in VM since
1933 // it will be initialized later by arraycopy in compiled code.
1934 slow_call_address = OptoRuntime::new_array_nozero_Java();
1935 } else {
1936 slow_call_address = OptoRuntime::new_array_Java();
1937 }
1938 expand_allocate_common(alloc, length,
1939 OptoRuntime::new_array_Type(),
1940 slow_call_address, valid_length_test);
1941 }
1942
1943 //-------------------mark_eliminated_box----------------------------------
1944 //
1945 // During EA obj may point to several objects but after few ideal graph
1946 // transformations (CCP) it may point to only one non escaping object
1947 // (but still using phi), corresponding locks and unlocks will be marked
1948 // for elimination. Later obj could be replaced with a new node (new phi)
1949 // and which does not have escape information. And later after some graph
1950 // reshape other locks and unlocks (which were not marked for elimination
1951 // before) are connected to this new obj (phi) but they still will not be
1952 // marked for elimination since new obj has no escape information.
1953 // Mark all associated (same box and obj) lock and unlock nodes for
1954 // elimination if some of them marked already.
1955 void PhaseMacroExpand::mark_eliminated_box(Node* box, Node* obj) {
1956 BoxLockNode* oldbox = box->as_BoxLock();
1957 if (oldbox->is_eliminated()) {
1958 return; // This BoxLock node was processed already.
1959 }
1960 assert(!oldbox->is_unbalanced(), "this should not be called for unbalanced region");
1961 // New implementation (EliminateNestedLocks) has separate BoxLock
1962 // node for each locked region so mark all associated locks/unlocks as
1963 // eliminated even if different objects are referenced in one locked region
1964 // (for example, OSR compilation of nested loop inside locked scope).
1965 if (EliminateNestedLocks ||
1966 oldbox->as_BoxLock()->is_simple_lock_region(nullptr, obj, nullptr)) {
1967 // Box is used only in one lock region. Mark this box as eliminated.
1968 oldbox->set_local(); // This verifies correct state of BoxLock
1969 _igvn.hash_delete(oldbox);
1970 oldbox->set_eliminated(); // This changes box's hash value
1971 _igvn.hash_insert(oldbox);
1972
1973 for (uint i = 0; i < oldbox->outcnt(); i++) {
1974 Node* u = oldbox->raw_out(i);
1975 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1976 AbstractLockNode* alock = u->as_AbstractLock();
1977 // Check lock's box since box could be referenced by Lock's debug info.
1978 if (alock->box_node() == oldbox) {
1979 // Mark eliminated all related locks and unlocks.
1980 #ifdef ASSERT
1981 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4");
1982 #endif
1983 alock->set_non_esc_obj();
1984 }
1985 }
1986 }
1987 return;
1988 }
1989
1990 // Create new "eliminated" BoxLock node and use it in monitor debug info
1991 // instead of oldbox for the same object.
1992 BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1993
1994 // Note: BoxLock node is marked eliminated only here and it is used
1995 // to indicate that all associated lock and unlock nodes are marked
1996 // for elimination.
1997 newbox->set_local(); // This verifies correct state of BoxLock
1998 newbox->set_eliminated();
1999 transform_later(newbox);
2000
2001 // Replace old box node with new box for all users of the same object.
2002 for (uint i = 0; i < oldbox->outcnt();) {
2003 bool next_edge = true;
2004
2005 Node* u = oldbox->raw_out(i);
2006 if (u->is_AbstractLock()) {
2007 AbstractLockNode* alock = u->as_AbstractLock();
2008 if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
2009 // Replace Box and mark eliminated all related locks and unlocks.
2010 #ifdef ASSERT
2011 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5");
2012 #endif
2013 alock->set_non_esc_obj();
2014 _igvn.rehash_node_delayed(alock);
2015 alock->set_box_node(newbox);
2016 next_edge = false;
2017 }
2018 }
2019 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
2020 FastLockNode* flock = u->as_FastLock();
2021 assert(flock->box_node() == oldbox, "sanity");
2022 _igvn.rehash_node_delayed(flock);
2023 flock->set_box_node(newbox);
2024 next_edge = false;
2025 }
2026
2027 // Replace old box in monitor debug info.
2028 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
2029 SafePointNode* sfn = u->as_SafePoint();
2030 JVMState* youngest_jvms = sfn->jvms();
2031 int max_depth = youngest_jvms->depth();
2032 for (int depth = 1; depth <= max_depth; depth++) {
2033 JVMState* jvms = youngest_jvms->of_depth(depth);
2034 int num_mon = jvms->nof_monitors();
2035 // Loop over monitors
2036 for (int idx = 0; idx < num_mon; idx++) {
2037 Node* obj_node = sfn->monitor_obj(jvms, idx);
2038 Node* box_node = sfn->monitor_box(jvms, idx);
2039 if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
2040 int j = jvms->monitor_box_offset(idx);
2041 _igvn.replace_input_of(u, j, newbox);
2042 next_edge = false;
2043 }
2044 }
2045 }
2046 }
2047 if (next_edge) i++;
2048 }
2049 }
2050
2051 //-----------------------mark_eliminated_locking_nodes-----------------------
2052 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
2053 if (!alock->is_balanced()) {
2054 return; // Can't do any more elimination for this locking region
2055 }
2056 if (EliminateNestedLocks) {
2057 if (alock->is_nested()) {
2058 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
2059 return;
2060 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
2061 // Only Lock node has JVMState needed here.
2062 // Not that preceding claim is documented anywhere else.
2063 if (alock->jvms() != nullptr) {
2064 if (alock->as_Lock()->is_nested_lock_region()) {
2065 // Mark eliminated related nested locks and unlocks.
2066 Node* obj = alock->obj_node();
2067 BoxLockNode* box_node = alock->box_node()->as_BoxLock();
2068 assert(!box_node->is_eliminated(), "should not be marked yet");
2069 // Note: BoxLock node is marked eliminated only here
2070 // and it is used to indicate that all associated lock
2071 // and unlock nodes are marked for elimination.
2072 box_node->set_eliminated(); // Box's hash is always NO_HASH here
2073 for (uint i = 0; i < box_node->outcnt(); i++) {
2074 Node* u = box_node->raw_out(i);
2075 if (u->is_AbstractLock()) {
2076 alock = u->as_AbstractLock();
2077 if (alock->box_node() == box_node) {
2078 // Verify that this Box is referenced only by related locks.
2079 assert(alock->obj_node()->eqv_uncast(obj), "");
2080 // Mark all related locks and unlocks.
2081 #ifdef ASSERT
2082 alock->log_lock_optimization(C, "eliminate_lock_set_nested");
2083 #endif
2084 alock->set_nested();
2085 }
2086 }
2087 }
2088 } else {
2089 #ifdef ASSERT
2090 alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region");
2091 if (C->log() != nullptr)
2092 alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output
2093 #endif
2094 }
2095 }
2096 return;
2097 }
2098 // Process locks for non escaping object
2099 assert(alock->is_non_esc_obj(), "");
2100 } // EliminateNestedLocks
2101
2102 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2103 // Look for all locks of this object and mark them and
2104 // corresponding BoxLock nodes as eliminated.
2105 Node* obj = alock->obj_node();
2106 for (uint j = 0; j < obj->outcnt(); j++) {
2107 Node* o = obj->raw_out(j);
2108 if (o->is_AbstractLock() &&
2109 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2110 alock = o->as_AbstractLock();
2111 Node* box = alock->box_node();
2112 // Replace old box node with new eliminated box for all users
2113 // of the same object and mark related locks as eliminated.
2114 mark_eliminated_box(box, obj);
2115 }
2116 }
2117 }
2118 }
2119
2120 // we have determined that this lock/unlock can be eliminated, we simply
2121 // eliminate the node without expanding it.
2122 //
2123 // Note: The membar's associated with the lock/unlock are currently not
2124 // eliminated. This should be investigated as a future enhancement.
2125 //
2126 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2127
2128 if (!alock->is_eliminated()) {
2129 return false;
2130 }
2131 #ifdef ASSERT
2132 if (!alock->is_coarsened()) {
2133 // Check that new "eliminated" BoxLock node is created.
2134 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2135 assert(oldbox->is_eliminated(), "should be done already");
2136 }
2137 #endif
2138
2139 alock->log_lock_optimization(C, "eliminate_lock");
2140
2141 #ifndef PRODUCT
2142 if (PrintEliminateLocks) {
2143 tty->print_cr("++++ Eliminated: %d %s '%s'", alock->_idx, (alock->is_Lock() ? "Lock" : "Unlock"), alock->kind_as_string());
2144 }
2145 #endif
2146
2147 Node* mem = alock->in(TypeFunc::Memory);
2148 Node* ctrl = alock->in(TypeFunc::Control);
2149 guarantee(ctrl != nullptr, "missing control projection, cannot replace_node() with null");
2150
2151 alock->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
2152 // There are 2 projections from the lock. The lock node will
2153 // be deleted when its last use is subsumed below.
2154 assert(alock->outcnt() == 2 &&
2155 _callprojs.fallthrough_proj != nullptr &&
2156 _callprojs.fallthrough_memproj != nullptr,
2157 "Unexpected projections from Lock/Unlock");
2158
2159 Node* fallthroughproj = _callprojs.fallthrough_proj;
2160 Node* memproj_fallthrough = _callprojs.fallthrough_memproj;
2161
2162 // The memory projection from a lock/unlock is RawMem
2163 // The input to a Lock is merged memory, so extract its RawMem input
2164 // (unless the MergeMem has been optimized away.)
2165 if (alock->is_Lock()) {
2166 // Search for MemBarAcquireLock node and delete it also.
2167 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2168 assert(membar != nullptr && membar->Opcode() == Op_MemBarAcquireLock, "");
2169 Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2170 Node* memproj = membar->proj_out(TypeFunc::Memory);
2171 _igvn.replace_node(ctrlproj, fallthroughproj);
2172 _igvn.replace_node(memproj, memproj_fallthrough);
2173
2174 // Delete FastLock node also if this Lock node is unique user
2175 // (a loop peeling may clone a Lock node).
2176 Node* flock = alock->as_Lock()->fastlock_node();
2177 if (flock->outcnt() == 1) {
2178 assert(flock->unique_out() == alock, "sanity");
2179 _igvn.replace_node(flock, top());
2180 }
2181 }
2182
2183 // Search for MemBarReleaseLock node and delete it also.
2184 if (alock->is_Unlock() && ctrl->is_Proj() && ctrl->in(0)->is_MemBar()) {
2185 MemBarNode* membar = ctrl->in(0)->as_MemBar();
2186 assert(membar->Opcode() == Op_MemBarReleaseLock &&
2187 mem->is_Proj() && membar == mem->in(0), "");
2188 _igvn.replace_node(fallthroughproj, ctrl);
2189 _igvn.replace_node(memproj_fallthrough, mem);
2190 fallthroughproj = ctrl;
2191 memproj_fallthrough = mem;
2192 ctrl = membar->in(TypeFunc::Control);
2193 mem = membar->in(TypeFunc::Memory);
2194 }
2195
2196 _igvn.replace_node(fallthroughproj, ctrl);
2197 _igvn.replace_node(memproj_fallthrough, mem);
2198 return true;
2199 }
2200
2201
2202 //------------------------------expand_lock_node----------------------
2203 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2204
2205 Node* ctrl = lock->in(TypeFunc::Control);
2206 Node* mem = lock->in(TypeFunc::Memory);
2207 Node* obj = lock->obj_node();
2208 Node* box = lock->box_node();
2209 Node* flock = lock->fastlock_node();
2210
2211 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2212
2213 // Make the merge point
2214 Node *region;
2215 Node *mem_phi;
2216 Node *slow_path;
2217
2218 region = new RegionNode(3);
2219 // create a Phi for the memory state
2220 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2221
2222 // Optimize test; set region slot 2
2223 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2224 mem_phi->init_req(2, mem);
2225
2226 // Make slow path call
2227 CallNode* call = make_slow_call(lock, OptoRuntime::complete_monitor_enter_Type(),
2228 OptoRuntime::complete_monitor_locking_Java(), nullptr, slow_path,
2229 obj, box, nullptr);
2230
2231 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
2232
2233 // Slow path can only throw asynchronous exceptions, which are always
2234 // de-opted. So the compiler thinks the slow-call can never throw an
2235 // exception. If it DOES throw an exception we would need the debug
2236 // info removed first (since if it throws there is no monitor).
2237 assert(_callprojs.fallthrough_ioproj == nullptr && _callprojs.catchall_ioproj == nullptr &&
2238 _callprojs.catchall_memproj == nullptr && _callprojs.catchall_catchproj == nullptr, "Unexpected projection from Lock");
2239
2240 // Capture slow path
2241 // disconnect fall-through projection from call and create a new one
2242 // hook up users of fall-through projection to region
2243 Node *slow_ctrl = _callprojs.fallthrough_proj->clone();
2244 transform_later(slow_ctrl);
2245 _igvn.hash_delete(_callprojs.fallthrough_proj);
2246 _callprojs.fallthrough_proj->disconnect_inputs(C);
2247 region->init_req(1, slow_ctrl);
2248 // region inputs are now complete
2249 transform_later(region);
2250 _igvn.replace_node(_callprojs.fallthrough_proj, region);
2251
2252 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2253
2254 mem_phi->init_req(1, memproj);
2255
2256 transform_later(mem_phi);
2257
2258 _igvn.replace_node(_callprojs.fallthrough_memproj, mem_phi);
2259 }
2260
2261 //------------------------------expand_unlock_node----------------------
2262 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2263
2264 Node* ctrl = unlock->in(TypeFunc::Control);
2265 Node* mem = unlock->in(TypeFunc::Memory);
2266 Node* obj = unlock->obj_node();
2267 Node* box = unlock->box_node();
2268
2269 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2270
2271 // No need for a null check on unlock
2272
2273 // Make the merge point
2274 Node *region;
2275 Node *mem_phi;
2276
2277 region = new RegionNode(3);
2278 // create a Phi for the memory state
2279 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2280
2281 FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2282 funlock = transform_later( funlock )->as_FastUnlock();
2283 // Optimize test; set region slot 2
2284 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2285 Node *thread = transform_later(new ThreadLocalNode());
2286
2287 CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(),
2288 CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C),
2289 "complete_monitor_unlocking_C", slow_path, obj, box, thread);
2290
2291 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
2292 assert(_callprojs.fallthrough_ioproj == nullptr && _callprojs.catchall_ioproj == nullptr &&
2293 _callprojs.catchall_memproj == nullptr && _callprojs.catchall_catchproj == nullptr, "Unexpected projection from Lock");
2294
2295 // No exceptions for unlocking
2296 // Capture slow path
2297 // disconnect fall-through projection from call and create a new one
2298 // hook up users of fall-through projection to region
2299 Node *slow_ctrl = _callprojs.fallthrough_proj->clone();
2300 transform_later(slow_ctrl);
2301 _igvn.hash_delete(_callprojs.fallthrough_proj);
2302 _callprojs.fallthrough_proj->disconnect_inputs(C);
2303 region->init_req(1, slow_ctrl);
2304 // region inputs are now complete
2305 transform_later(region);
2306 _igvn.replace_node(_callprojs.fallthrough_proj, region);
2307
2308 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2309 mem_phi->init_req(1, memproj );
2310 mem_phi->init_req(2, mem);
2311 transform_later(mem_phi);
2312
2313 _igvn.replace_node(_callprojs.fallthrough_memproj, mem_phi);
2314 }
2315
2316 void PhaseMacroExpand::expand_subtypecheck_node(SubTypeCheckNode *check) {
2317 assert(check->in(SubTypeCheckNode::Control) == nullptr, "should be pinned");
2318 Node* bol = check->unique_out();
2319 Node* obj_or_subklass = check->in(SubTypeCheckNode::ObjOrSubKlass);
2320 Node* superklass = check->in(SubTypeCheckNode::SuperKlass);
2321 assert(bol->is_Bool() && bol->as_Bool()->_test._test == BoolTest::ne, "unexpected bool node");
2322
2323 for (DUIterator_Last imin, i = bol->last_outs(imin); i >= imin; --i) {
2324 Node* iff = bol->last_out(i);
2325 assert(iff->is_If(), "where's the if?");
2326
2327 if (iff->in(0)->is_top()) {
2328 _igvn.replace_input_of(iff, 1, C->top());
2329 continue;
2330 }
2331
2332 Node* iftrue = iff->as_If()->proj_out(1);
2333 Node* iffalse = iff->as_If()->proj_out(0);
2334 Node* ctrl = iff->in(0);
2335
2336 Node* subklass = nullptr;
2337 if (_igvn.type(obj_or_subklass)->isa_klassptr()) {
2338 subklass = obj_or_subklass;
2339 } else {
2340 Node* k_adr = basic_plus_adr(obj_or_subklass, Type::klass_offset());
2341 subklass = _igvn.transform(LoadKlassNode::make(_igvn, nullptr, C->immutable_memory(), k_adr, TypeInstPtr::KLASS));
2342 }
2343
2344 Node* not_subtype_ctrl = Phase::gen_subtype_check(subklass, superklass, &ctrl, nullptr, _igvn, check->method(), check->bci());
2345
2346 _igvn.replace_input_of(iff, 0, C->top());
2347 _igvn.replace_node(iftrue, not_subtype_ctrl);
2348 _igvn.replace_node(iffalse, ctrl);
2349 }
2350 _igvn.replace_node(check, C->top());
2351 }
2352
2353 //---------------------------eliminate_macro_nodes----------------------
2354 // Eliminate scalar replaced allocations and associated locks.
2355 void PhaseMacroExpand::eliminate_macro_nodes() {
2356 if (C->macro_count() == 0)
2357 return;
2358 NOT_PRODUCT(int membar_before = count_MemBar(C);)
2359
2360 // Before elimination may re-mark (change to Nested or NonEscObj)
2361 // all associated (same box and obj) lock and unlock nodes.
2362 int cnt = C->macro_count();
2363 for (int i=0; i < cnt; i++) {
2364 Node *n = C->macro_node(i);
2365 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2366 mark_eliminated_locking_nodes(n->as_AbstractLock());
2367 }
2368 }
2369 // Re-marking may break consistency of Coarsened locks.
2370 if (!C->coarsened_locks_consistent()) {
2371 return; // recompile without Coarsened locks if broken
2372 } else {
2373 // After coarsened locks are eliminated locking regions
2374 // become unbalanced. We should not execute any more
2375 // locks elimination optimizations on them.
2376 C->mark_unbalanced_boxes();
2377 }
2378
2379 // First, attempt to eliminate locks
2380 bool progress = true;
2381 while (progress) {
2382 progress = false;
2383 for (int i = C->macro_count(); i > 0; i = MIN2(i - 1, C->macro_count())) { // more than 1 element can be eliminated at once
2384 Node* n = C->macro_node(i - 1);
2385 bool success = false;
2386 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2387 if (n->is_AbstractLock()) {
2388 success = eliminate_locking_node(n->as_AbstractLock());
2389 #ifndef PRODUCT
2390 if (success && PrintOptoStatistics) {
2391 Atomic::inc(&PhaseMacroExpand::_monitor_objects_removed_counter);
2392 }
2393 #endif
2394 }
2395 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2396 progress = progress || success;
2397 }
2398 }
2399 // Next, attempt to eliminate allocations
2400 _has_locks = false;
2401 progress = true;
2402 while (progress) {
2403 progress = false;
2404 for (int i = C->macro_count(); i > 0; i = MIN2(i - 1, C->macro_count())) { // more than 1 element can be eliminated at once
2405 Node* n = C->macro_node(i - 1);
2406 bool success = false;
2407 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2408 switch (n->class_id()) {
2409 case Node::Class_Allocate:
2410 case Node::Class_AllocateArray:
2411 success = eliminate_allocate_node(n->as_Allocate());
2412 #ifndef PRODUCT
2413 if (success && PrintOptoStatistics) {
2414 Atomic::inc(&PhaseMacroExpand::_objs_scalar_replaced_counter);
2415 }
2416 #endif
2417 break;
2418 case Node::Class_CallStaticJava:
2419 success = eliminate_boxing_node(n->as_CallStaticJava());
2420 break;
2421 case Node::Class_Lock:
2422 case Node::Class_Unlock:
2423 assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2424 _has_locks = true;
2425 break;
2426 case Node::Class_ArrayCopy:
2427 break;
2428 case Node::Class_OuterStripMinedLoop:
2429 break;
2430 case Node::Class_SubTypeCheck:
2431 break;
2432 case Node::Class_Opaque1:
2433 break;
2434 default:
2435 assert(n->Opcode() == Op_LoopLimit ||
2436 n->Opcode() == Op_ModD ||
2437 n->Opcode() == Op_ModF ||
2438 n->is_OpaqueNotNull() ||
2439 n->is_OpaqueInitializedAssertionPredicate() ||
2440 n->Opcode() == Op_MaxL ||
2441 n->Opcode() == Op_MinL ||
2442 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(n),
2443 "unknown node type in macro list");
2444 }
2445 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2446 progress = progress || success;
2447 }
2448 }
2449 #ifndef PRODUCT
2450 if (PrintOptoStatistics) {
2451 int membar_after = count_MemBar(C);
2452 Atomic::add(&PhaseMacroExpand::_memory_barriers_removed_counter, membar_before - membar_after);
2453 }
2454 #endif
2455 }
2456
2457 //------------------------------expand_macro_nodes----------------------
2458 // Returns true if a failure occurred.
2459 bool PhaseMacroExpand::expand_macro_nodes() {
2460 // Do not allow new macro nodes once we started to expand
2461 C->reset_allow_macro_nodes();
2462 if (StressMacroExpansion) {
2463 C->shuffle_macro_nodes();
2464 }
2465 // Last attempt to eliminate macro nodes.
2466 eliminate_macro_nodes();
2467 if (C->failing()) return true;
2468
2469 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2470 bool progress = true;
2471 while (progress) {
2472 progress = false;
2473 for (int i = C->macro_count(); i > 0; i--) {
2474 Node* n = C->macro_node(i-1);
2475 bool success = false;
2476 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2477 if (n->Opcode() == Op_LoopLimit) {
2478 // Remove it from macro list and put on IGVN worklist to optimize.
2479 C->remove_macro_node(n);
2480 _igvn._worklist.push(n);
2481 success = true;
2482 } else if (n->Opcode() == Op_CallStaticJava) {
2483 // Remove it from macro list and put on IGVN worklist to optimize.
2484 C->remove_macro_node(n);
2485 _igvn._worklist.push(n);
2486 success = true;
2487 } else if (n->is_Opaque1()) {
2488 _igvn.replace_node(n, n->in(1));
2489 success = true;
2490 } else if (n->is_OpaqueNotNull()) {
2491 // Tests with OpaqueNotNull nodes are implicitly known to be true. Replace the node with true. In debug builds,
2492 // we leave the test in the graph to have an additional sanity check at runtime. If the test fails (i.e. a bug),
2493 // we will execute a Halt node.
2494 #ifdef ASSERT
2495 _igvn.replace_node(n, n->in(1));
2496 #else
2497 _igvn.replace_node(n, _igvn.intcon(1));
2498 #endif
2499 success = true;
2500 } else if (n->is_OpaqueInitializedAssertionPredicate()) {
2501 // Initialized Assertion Predicates must always evaluate to true. Therefore, we get rid of them in product
2502 // builds as they are useless. In debug builds we keep them as additional verification code. Even though
2503 // loop opts are already over, we want to keep Initialized Assertion Predicates alive as long as possible to
2504 // enable folding of dead control paths within which cast nodes become top after due to impossible types -
2505 // even after loop opts are over. Therefore, we delay the removal of these opaque nodes until now.
2506 #ifdef ASSERT
2507 _igvn.replace_node(n, n->in(1));
2508 #else
2509 _igvn.replace_node(n, _igvn.intcon(1));
2510 #endif // ASSERT
2511 } else if (n->Opcode() == Op_OuterStripMinedLoop) {
2512 n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn);
2513 C->remove_macro_node(n);
2514 success = true;
2515 } else if (n->Opcode() == Op_MaxL) {
2516 // Since MaxL and MinL are not implemented in the backend, we expand them to
2517 // a CMoveL construct now. At least until here, the type could be computed
2518 // precisely. CMoveL is not so smart, but we can give it at least the best
2519 // type we know abouot n now.
2520 Node* repl = MaxNode::signed_max(n->in(1), n->in(2), _igvn.type(n), _igvn);
2521 _igvn.replace_node(n, repl);
2522 success = true;
2523 } else if (n->Opcode() == Op_MinL) {
2524 Node* repl = MaxNode::signed_min(n->in(1), n->in(2), _igvn.type(n), _igvn);
2525 _igvn.replace_node(n, repl);
2526 success = true;
2527 }
2528 assert(!success || (C->macro_count() == (old_macro_count - 1)), "elimination must have deleted one node from macro list");
2529 progress = progress || success;
2530 if (success) {
2531 C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n);
2532 }
2533 }
2534 }
2535
2536 // Clean up the graph so we're less likely to hit the maximum node
2537 // limit
2538 _igvn.set_delay_transform(false);
2539 _igvn.optimize();
2540 if (C->failing()) return true;
2541 _igvn.set_delay_transform(true);
2542
2543
2544 // Because we run IGVN after each expansion, some macro nodes may go
2545 // dead and be removed from the list as we iterate over it. Move
2546 // Allocate nodes (processed in a second pass) at the beginning of
2547 // the list and then iterate from the last element of the list until
2548 // an Allocate node is seen. This is robust to random deletion in
2549 // the list due to nodes going dead.
2550 C->sort_macro_nodes();
2551
2552 // expand arraycopy "macro" nodes first
2553 // For ReduceBulkZeroing, we must first process all arraycopy nodes
2554 // before the allocate nodes are expanded.
2555 while (C->macro_count() > 0) {
2556 int macro_count = C->macro_count();
2557 Node * n = C->macro_node(macro_count-1);
2558 assert(n->is_macro(), "only macro nodes expected here");
2559 if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) {
2560 // node is unreachable, so don't try to expand it
2561 C->remove_macro_node(n);
2562 continue;
2563 }
2564 if (n->is_Allocate()) {
2565 break;
2566 }
2567 // Make sure expansion will not cause node limit to be exceeded.
2568 // Worst case is a macro node gets expanded into about 200 nodes.
2569 // Allow 50% more for optimization.
2570 if (C->check_node_count(300, "out of nodes before macro expansion")) {
2571 return true;
2572 }
2573
2574 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2575 switch (n->class_id()) {
2576 case Node::Class_Lock:
2577 expand_lock_node(n->as_Lock());
2578 break;
2579 case Node::Class_Unlock:
2580 expand_unlock_node(n->as_Unlock());
2581 break;
2582 case Node::Class_ArrayCopy:
2583 expand_arraycopy_node(n->as_ArrayCopy());
2584 break;
2585 case Node::Class_SubTypeCheck:
2586 expand_subtypecheck_node(n->as_SubTypeCheck());
2587 break;
2588 default:
2589 switch (n->Opcode()) {
2590 case Op_ModD:
2591 case Op_ModF: {
2592 bool is_drem = n->Opcode() == Op_ModD;
2593 CallNode* mod_macro = n->as_Call();
2594 CallNode* call = new CallLeafNode(mod_macro->tf(),
2595 is_drem ? CAST_FROM_FN_PTR(address, SharedRuntime::drem)
2596 : CAST_FROM_FN_PTR(address, SharedRuntime::frem),
2597 is_drem ? "drem" : "frem", TypeRawPtr::BOTTOM);
2598 call->init_req(TypeFunc::Control, mod_macro->in(TypeFunc::Control));
2599 call->init_req(TypeFunc::I_O, mod_macro->in(TypeFunc::I_O));
2600 call->init_req(TypeFunc::Memory, mod_macro->in(TypeFunc::Memory));
2601 call->init_req(TypeFunc::ReturnAdr, mod_macro->in(TypeFunc::ReturnAdr));
2602 call->init_req(TypeFunc::FramePtr, mod_macro->in(TypeFunc::FramePtr));
2603 for (unsigned int i = 0; i < mod_macro->tf()->domain()->cnt() - TypeFunc::Parms; i++) {
2604 call->init_req(TypeFunc::Parms + i, mod_macro->in(TypeFunc::Parms + i));
2605 }
2606 _igvn.replace_node(mod_macro, call);
2607 transform_later(call);
2608 break;
2609 }
2610 default:
2611 assert(false, "unknown node type in macro list");
2612 }
2613 }
2614 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
2615 if (C->failing()) return true;
2616 C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n);
2617
2618 // Clean up the graph so we're less likely to hit the maximum node
2619 // limit
2620 _igvn.set_delay_transform(false);
2621 _igvn.optimize();
2622 if (C->failing()) return true;
2623 _igvn.set_delay_transform(true);
2624 }
2625
2626 // All nodes except Allocate nodes are expanded now. There could be
2627 // new optimization opportunities (such as folding newly created
2628 // load from a just allocated object). Run IGVN.
2629
2630 // expand "macro" nodes
2631 // nodes are removed from the macro list as they are processed
2632 while (C->macro_count() > 0) {
2633 int macro_count = C->macro_count();
2634 Node * n = C->macro_node(macro_count-1);
2635 assert(n->is_macro(), "only macro nodes expected here");
2636 if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) {
2637 // node is unreachable, so don't try to expand it
2638 C->remove_macro_node(n);
2639 continue;
2640 }
2641 // Make sure expansion will not cause node limit to be exceeded.
2642 // Worst case is a macro node gets expanded into about 200 nodes.
2643 // Allow 50% more for optimization.
2644 if (C->check_node_count(300, "out of nodes before macro expansion")) {
2645 return true;
2646 }
2647 switch (n->class_id()) {
2648 case Node::Class_Allocate:
2649 expand_allocate(n->as_Allocate());
2650 break;
2651 case Node::Class_AllocateArray:
2652 expand_allocate_array(n->as_AllocateArray());
2653 break;
2654 default:
2655 assert(false, "unknown node type in macro list");
2656 }
2657 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2658 if (C->failing()) return true;
2659 C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n);
2660
2661 // Clean up the graph so we're less likely to hit the maximum node
2662 // limit
2663 _igvn.set_delay_transform(false);
2664 _igvn.optimize();
2665 if (C->failing()) return true;
2666 _igvn.set_delay_transform(true);
2667 }
2668
2669 _igvn.set_delay_transform(false);
2670 return false;
2671 }
2672
2673 #ifndef PRODUCT
2674 int PhaseMacroExpand::_objs_scalar_replaced_counter = 0;
2675 int PhaseMacroExpand::_monitor_objects_removed_counter = 0;
2676 int PhaseMacroExpand::_GC_barriers_removed_counter = 0;
2677 int PhaseMacroExpand::_memory_barriers_removed_counter = 0;
2678
2679 void PhaseMacroExpand::print_statistics() {
2680 tty->print("Objects scalar replaced = %d, ", Atomic::load(&_objs_scalar_replaced_counter));
2681 tty->print("Monitor objects removed = %d, ", Atomic::load(&_monitor_objects_removed_counter));
2682 tty->print("GC barriers removed = %d, ", Atomic::load(&_GC_barriers_removed_counter));
2683 tty->print_cr("Memory barriers removed = %d", Atomic::load(&_memory_barriers_removed_counter));
2684 }
2685
2686 int PhaseMacroExpand::count_MemBar(Compile *C) {
2687 if (!PrintOptoStatistics) {
2688 return 0;
2689 }
2690 Unique_Node_List ideal_nodes;
2691 int total = 0;
2692 ideal_nodes.map(C->live_nodes(), nullptr);
2693 ideal_nodes.push(C->root());
2694 for (uint next = 0; next < ideal_nodes.size(); ++next) {
2695 Node* n = ideal_nodes.at(next);
2696 if (n->is_MemBar()) {
2697 total++;
2698 }
2699 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2700 Node* m = n->fast_out(i);
2701 ideal_nodes.push(m);
2702 }
2703 }
2704 return total;
2705 }
2706 #endif