1 /*
2 * Copyright (c) 2005, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "gc/shared/collectedHeap.inline.hpp"
28 #include "gc/shared/tlab_globals.hpp"
29 #include "libadt/vectset.hpp"
30 #include "memory/universe.hpp"
31 #include "opto/addnode.hpp"
32 #include "opto/arraycopynode.hpp"
33 #include "opto/callnode.hpp"
34 #include "opto/castnode.hpp"
35 #include "opto/cfgnode.hpp"
36 #include "opto/compile.hpp"
37 #include "opto/convertnode.hpp"
38 #include "opto/graphKit.hpp"
39 #include "opto/intrinsicnode.hpp"
40 #include "opto/locknode.hpp"
41 #include "opto/loopnode.hpp"
42 #include "opto/macro.hpp"
43 #include "opto/memnode.hpp"
44 #include "opto/narrowptrnode.hpp"
45 #include "opto/node.hpp"
46 #include "opto/opaquenode.hpp"
47 #include "opto/phaseX.hpp"
48 #include "opto/rootnode.hpp"
49 #include "opto/runtime.hpp"
50 #include "opto/subnode.hpp"
51 #include "opto/subtypenode.hpp"
52 #include "opto/type.hpp"
53 #include "prims/jvmtiExport.hpp"
54 #include "runtime/continuation.hpp"
55 #include "runtime/sharedRuntime.hpp"
56 #include "utilities/macros.hpp"
57 #include "utilities/powerOfTwo.hpp"
58 #if INCLUDE_G1GC
59 #include "gc/g1/g1ThreadLocalData.hpp"
60 #endif // INCLUDE_G1GC
61
62
63 //
64 // Replace any references to "oldref" in inputs to "use" with "newref".
65 // Returns the number of replacements made.
66 //
67 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
68 int nreplacements = 0;
69 uint req = use->req();
70 for (uint j = 0; j < use->len(); j++) {
71 Node *uin = use->in(j);
72 if (uin == oldref) {
73 if (j < req)
74 use->set_req(j, newref);
75 else
76 use->set_prec(j, newref);
77 nreplacements++;
78 } else if (j >= req && uin == nullptr) {
79 break;
80 }
81 }
82 return nreplacements;
83 }
84
85 void PhaseMacroExpand::migrate_outs(Node *old, Node *target) {
86 assert(old != nullptr, "sanity");
87 for (DUIterator_Fast imax, i = old->fast_outs(imax); i < imax; i++) {
88 Node* use = old->fast_out(i);
89 _igvn.rehash_node_delayed(use);
90 imax -= replace_input(use, old, target);
91 // back up iterator
92 --i;
93 }
94 assert(old->outcnt() == 0, "all uses must be deleted");
95 }
96
97 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
98 Node* cmp;
99 if (mask != 0) {
100 Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
101 cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
102 } else {
103 cmp = word;
104 }
105 Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
106 IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
107 transform_later(iff);
108
109 // Fast path taken.
110 Node *fast_taken = transform_later(new IfFalseNode(iff));
111
112 // Fast path not-taken, i.e. slow path
113 Node *slow_taken = transform_later(new IfTrueNode(iff));
114
115 if (return_fast_path) {
116 region->init_req(edge, slow_taken); // Capture slow-control
117 return fast_taken;
118 } else {
119 region->init_req(edge, fast_taken); // Capture fast-control
120 return slow_taken;
121 }
122 }
123
124 //--------------------copy_predefined_input_for_runtime_call--------------------
125 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
126 // Set fixed predefined input arguments
127 call->init_req( TypeFunc::Control, ctrl );
128 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) );
129 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
130 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
131 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
132 }
133
134 //------------------------------make_slow_call---------------------------------
135 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type,
136 address slow_call, const char* leaf_name, Node* slow_path,
137 Node* parm0, Node* parm1, Node* parm2) {
138
139 // Slow-path call
140 CallNode *call = leaf_name
141 ? (CallNode*)new CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
142 : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), TypeRawPtr::BOTTOM );
143
144 // Slow path call has no side-effects, uses few values
145 copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
146 if (parm0 != nullptr) call->init_req(TypeFunc::Parms+0, parm0);
147 if (parm1 != nullptr) call->init_req(TypeFunc::Parms+1, parm1);
148 if (parm2 != nullptr) call->init_req(TypeFunc::Parms+2, parm2);
149 call->copy_call_debug_info(&_igvn, oldcall);
150 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
151 _igvn.replace_node(oldcall, call);
152 transform_later(call);
153
154 return call;
155 }
156
157 void PhaseMacroExpand::eliminate_gc_barrier(Node* p2x) {
158 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
159 bs->eliminate_gc_barrier(this, p2x);
160 #ifndef PRODUCT
161 if (PrintOptoStatistics) {
162 Atomic::inc(&PhaseMacroExpand::_GC_barriers_removed_counter);
163 }
164 #endif
165 }
166
167 // Search for a memory operation for the specified memory slice.
168 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
169 Node *orig_mem = mem;
170 Node *alloc_mem = alloc->in(TypeFunc::Memory);
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->in(TypeFunc::Memory);
375
376 uint length = mem->req();
377 GrowableArray <Node *> values(length, length, nullptr);
378
379 // create a new Phi for the value
380 PhiNode *phi = new PhiNode(mem->in(0), phi_type, nullptr, mem->_idx, instance_id, alias_idx, offset);
381 transform_later(phi);
382 value_phis->push(phi, mem->_idx);
383
384 for (uint j = 1; j < length; j++) {
385 Node *in = mem->in(j);
386 if (in == nullptr || in->is_top()) {
387 values.at_put(j, in);
388 } else {
389 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
390 if (val == start_mem || val == alloc_mem) {
391 // hit a sentinel, return appropriate 0 value
392 values.at_put(j, _igvn.zerocon(ft));
393 continue;
394 }
395 if (val->is_Initialize()) {
396 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
397 }
398 if (val == nullptr) {
399 return nullptr; // can't find a value on this path
400 }
401 if (val == mem) {
402 values.at_put(j, mem);
403 } else if (val->is_Store()) {
404 Node* n = val->in(MemNode::ValueIn);
405 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
406 n = bs->step_over_gc_barrier(n);
407 if (is_subword_type(ft)) {
408 n = Compile::narrow_value(ft, n, phi_type, &_igvn, true);
409 }
410 values.at_put(j, n);
411 } else if(val->is_Proj() && val->in(0) == alloc) {
412 values.at_put(j, _igvn.zerocon(ft));
413 } else if (val->is_Phi()) {
414 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
415 if (val == nullptr) {
416 return nullptr;
417 }
418 values.at_put(j, val);
419 } else if (val->Opcode() == Op_SCMemProj) {
420 assert(val->in(0)->is_LoadStore() ||
421 val->in(0)->Opcode() == Op_EncodeISOArray ||
422 val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity");
423 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
424 return nullptr;
425 } else if (val->is_ArrayCopy()) {
426 Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc);
427 if (res == nullptr) {
428 return nullptr;
429 }
430 values.at_put(j, res);
431 } else {
432 DEBUG_ONLY( val->dump(); )
433 assert(false, "unknown node on this path");
434 return nullptr; // unknown node on this path
435 }
436 }
437 }
438 // Set Phi's inputs
439 for (uint j = 1; j < length; j++) {
440 if (values.at(j) == mem) {
441 phi->init_req(j, phi);
442 } else {
443 phi->init_req(j, values.at(j));
444 }
445 }
446 return phi;
447 }
448
449 // Search the last value stored into the object's field.
450 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) {
451 assert(adr_t->is_known_instance_field(), "instance required");
452 int instance_id = adr_t->instance_id();
453 assert((uint)instance_id == alloc->_idx, "wrong allocation");
454
455 int alias_idx = C->get_alias_index(adr_t);
456 int offset = adr_t->offset();
457 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
458 Node *alloc_ctrl = alloc->in(TypeFunc::Control);
459 Node *alloc_mem = alloc->in(TypeFunc::Memory);
460 VectorSet visited;
461
462 bool done = sfpt_mem == alloc_mem;
463 Node *mem = sfpt_mem;
464 while (!done) {
465 if (visited.test_set(mem->_idx)) {
466 return nullptr; // found a loop, give up
467 }
468 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
469 if (mem == start_mem || mem == alloc_mem) {
470 done = true; // hit a sentinel, return appropriate 0 value
471 } else if (mem->is_Initialize()) {
472 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
473 if (mem == nullptr) {
474 done = true; // Something go wrong.
475 } else if (mem->is_Store()) {
476 const TypePtr* atype = mem->as_Store()->adr_type();
477 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
478 done = true;
479 }
480 } else if (mem->is_Store()) {
481 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
482 assert(atype != nullptr, "address type must be oopptr");
483 assert(C->get_alias_index(atype) == alias_idx &&
484 atype->is_known_instance_field() && atype->offset() == offset &&
485 atype->instance_id() == instance_id, "store is correct memory slice");
486 done = true;
487 } else if (mem->is_Phi()) {
488 // try to find a phi's unique input
489 Node *unique_input = nullptr;
490 Node *top = C->top();
491 for (uint i = 1; i < mem->req(); i++) {
492 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
493 if (n == nullptr || n == top || n == mem) {
494 continue;
495 } else if (unique_input == nullptr) {
496 unique_input = n;
497 } else if (unique_input != n) {
498 unique_input = top;
499 break;
500 }
501 }
502 if (unique_input != nullptr && unique_input != top) {
503 mem = unique_input;
504 } else {
505 done = true;
506 }
507 } else if (mem->is_ArrayCopy()) {
508 done = true;
509 } else {
510 DEBUG_ONLY( mem->dump(); )
511 assert(false, "unexpected node");
512 }
513 }
514 if (mem != nullptr) {
515 if (mem == start_mem || mem == alloc_mem) {
516 // hit a sentinel, return appropriate 0 value
517 return _igvn.zerocon(ft);
518 } else if (mem->is_Store()) {
519 Node* n = mem->in(MemNode::ValueIn);
520 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
521 n = bs->step_over_gc_barrier(n);
522 return n;
523 } else if (mem->is_Phi()) {
524 // attempt to produce a Phi reflecting the values on the input paths of the Phi
525 Node_Stack value_phis(8);
526 Node* phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
527 if (phi != nullptr) {
528 return phi;
529 } else {
530 // Kill all new Phis
531 while(value_phis.is_nonempty()) {
532 Node* n = value_phis.node();
533 _igvn.replace_node(n, C->top());
534 value_phis.pop();
535 }
536 }
537 } else if (mem->is_ArrayCopy()) {
538 Node* ctl = mem->in(0);
539 Node* m = mem->in(TypeFunc::Memory);
540 if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj()) {
541 // pin the loads in the uncommon trap path
542 ctl = sfpt_ctl;
543 m = sfpt_mem;
544 }
545 return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc);
546 }
547 }
548 // Something go wrong.
549 return nullptr;
550 }
551
552 // Check the possibility of scalar replacement.
553 bool PhaseMacroExpand::can_eliminate_allocation(PhaseIterGVN* igvn, AllocateNode *alloc, GrowableArray <SafePointNode *>* safepoints) {
554 // Scan the uses of the allocation to check for anything that would
555 // prevent us from eliminating it.
556 NOT_PRODUCT( const char* fail_eliminate = nullptr; )
557 DEBUG_ONLY( Node* disq_node = nullptr; )
558 bool can_eliminate = true;
559 bool reduce_merge_precheck = (safepoints == nullptr);
560
561 Node* res = alloc->result_cast();
562 const TypeOopPtr* res_type = nullptr;
563 if (res == nullptr) {
564 // All users were eliminated.
565 } else if (!res->is_CheckCastPP()) {
566 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
567 can_eliminate = false;
568 } else {
569 res_type = igvn->type(res)->isa_oopptr();
570 if (res_type == nullptr) {
571 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
572 can_eliminate = false;
573 } else if (res_type->isa_aryptr()) {
574 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
575 if (length < 0) {
576 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
577 can_eliminate = false;
578 }
579 }
580 }
581
582 if (can_eliminate && res != nullptr) {
583 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
584 for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
585 j < jmax && can_eliminate; j++) {
586 Node* use = res->fast_out(j);
587
588 if (use->is_AddP()) {
589 const TypePtr* addp_type = igvn->type(use)->is_ptr();
590 int offset = addp_type->offset();
591
592 if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
593 NOT_PRODUCT(fail_eliminate = "Undefined field reference";)
594 can_eliminate = false;
595 break;
596 }
597 for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
598 k < kmax && can_eliminate; k++) {
599 Node* n = use->fast_out(k);
600 if (!n->is_Store() && n->Opcode() != Op_CastP2X && !bs->is_gc_pre_barrier_node(n) && !reduce_merge_precheck) {
601 DEBUG_ONLY(disq_node = n;)
602 if (n->is_Load() || n->is_LoadStore()) {
603 NOT_PRODUCT(fail_eliminate = "Field load";)
604 } else {
605 NOT_PRODUCT(fail_eliminate = "Not store field reference";)
606 }
607 can_eliminate = false;
608 }
609 }
610 } else if (use->is_ArrayCopy() &&
611 (use->as_ArrayCopy()->is_clonebasic() ||
612 use->as_ArrayCopy()->is_arraycopy_validated() ||
613 use->as_ArrayCopy()->is_copyof_validated() ||
614 use->as_ArrayCopy()->is_copyofrange_validated()) &&
615 use->in(ArrayCopyNode::Dest) == res) {
616 // ok to eliminate
617 } else if (use->is_SafePoint()) {
618 SafePointNode* sfpt = use->as_SafePoint();
619 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
620 // Object is passed as argument.
621 DEBUG_ONLY(disq_node = use;)
622 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
623 can_eliminate = false;
624 }
625 Node* sfptMem = sfpt->memory();
626 if (sfptMem == nullptr || sfptMem->is_top()) {
627 DEBUG_ONLY(disq_node = use;)
628 NOT_PRODUCT(fail_eliminate = "null or TOP memory";)
629 can_eliminate = false;
630 } else if (!reduce_merge_precheck) {
631 safepoints->append_if_missing(sfpt);
632 }
633 } else if (reduce_merge_precheck && (use->is_Phi() || use->is_EncodeP() || use->Opcode() == Op_MemBarRelease)) {
634 // Nothing to do
635 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
636 if (use->is_Phi()) {
637 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
638 NOT_PRODUCT(fail_eliminate = "Object is return value";)
639 } else {
640 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
641 }
642 DEBUG_ONLY(disq_node = use;)
643 } else {
644 if (use->Opcode() == Op_Return) {
645 NOT_PRODUCT(fail_eliminate = "Object is return value";)
646 } else {
647 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
648 }
649 DEBUG_ONLY(disq_node = use;)
650 }
651 can_eliminate = false;
652 }
653 }
654 }
655
656 #ifndef PRODUCT
657 if (PrintEliminateAllocations && safepoints != nullptr) {
658 if (can_eliminate) {
659 tty->print("Scalar ");
660 if (res == nullptr)
661 alloc->dump();
662 else
663 res->dump();
664 } else if (alloc->_is_scalar_replaceable) {
665 tty->print("NotScalar (%s)", fail_eliminate);
666 if (res == nullptr)
667 alloc->dump();
668 else
669 res->dump();
670 #ifdef ASSERT
671 if (disq_node != nullptr) {
672 tty->print(" >>>> ");
673 disq_node->dump();
674 }
675 #endif /*ASSERT*/
676 }
677 }
678
679 if (TraceReduceAllocationMerges && !can_eliminate && reduce_merge_precheck) {
680 tty->print_cr("\tCan't eliminate allocation because '%s': ", fail_eliminate != nullptr ? fail_eliminate : "");
681 DEBUG_ONLY(if (disq_node != nullptr) disq_node->dump();)
682 }
683 #endif
684 return can_eliminate;
685 }
686
687 void PhaseMacroExpand::undo_previous_scalarizations(GrowableArray <SafePointNode *> safepoints_done, AllocateNode* alloc) {
688 Node* res = alloc->result_cast();
689 int nfields = 0;
690 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
691
692 if (res != nullptr) {
693 const TypeOopPtr* res_type = _igvn.type(res)->isa_oopptr();
694
695 if (res_type->isa_instptr()) {
696 // find the fields of the class which will be needed for safepoint debug information
697 ciInstanceKlass* iklass = res_type->is_instptr()->instance_klass();
698 nfields = iklass->nof_nonstatic_fields();
699 } else {
700 // find the array's elements which will be needed for safepoint debug information
701 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
702 assert(nfields >= 0, "must be an array klass.");
703 }
704 }
705
706 // rollback processed safepoints
707 while (safepoints_done.length() > 0) {
708 SafePointNode* sfpt_done = safepoints_done.pop();
709 // remove any extra entries we added to the safepoint
710 uint last = sfpt_done->req() - 1;
711 for (int k = 0; k < nfields; k++) {
712 sfpt_done->del_req(last--);
713 }
714 JVMState *jvms = sfpt_done->jvms();
715 jvms->set_endoff(sfpt_done->req());
716 // Now make a pass over the debug information replacing any references
717 // to SafePointScalarObjectNode with the allocated object.
718 int start = jvms->debug_start();
719 int end = jvms->debug_end();
720 for (int i = start; i < end; i++) {
721 if (sfpt_done->in(i)->is_SafePointScalarObject()) {
722 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
723 if (scobj->first_index(jvms) == sfpt_done->req() &&
724 scobj->n_fields() == (uint)nfields) {
725 assert(scobj->alloc() == alloc, "sanity");
726 sfpt_done->set_req(i, res);
727 }
728 }
729 }
730 _igvn._worklist.push(sfpt_done);
731 }
732 }
733
734 SafePointScalarObjectNode* PhaseMacroExpand::create_scalarized_object_description(AllocateNode *alloc, SafePointNode* sfpt) {
735 // Fields of scalar objs are referenced only at the end
736 // of regular debuginfo at the last (youngest) JVMS.
737 // Record relative start index.
738 ciInstanceKlass* iklass = nullptr;
739 BasicType basic_elem_type = T_ILLEGAL;
740 const Type* field_type = nullptr;
741 const TypeOopPtr* res_type = nullptr;
742 int nfields = 0;
743 int array_base = 0;
744 int element_size = 0;
745 uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
746 Node* res = alloc->result_cast();
747
748 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
749 assert(sfpt->jvms() != nullptr, "missed JVMS");
750
751 if (res != nullptr) { // Could be null when there are no users
752 res_type = _igvn.type(res)->isa_oopptr();
753
754 if (res_type->isa_instptr()) {
755 // find the fields of the class which will be needed for safepoint debug information
756 iklass = res_type->is_instptr()->instance_klass();
757 nfields = iklass->nof_nonstatic_fields();
758 } else {
759 // find the array's elements which will be needed for safepoint debug information
760 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
761 assert(nfields >= 0, "must be an array klass.");
762 basic_elem_type = res_type->is_aryptr()->elem()->array_element_basic_type();
763 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
764 element_size = type2aelembytes(basic_elem_type);
765 field_type = res_type->is_aryptr()->elem();
766 }
767 }
768
769 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type, alloc, first_ind, nfields);
770 sobj->init_req(0, C->root());
771 transform_later(sobj);
772
773 // Scan object's fields adding an input to the safepoint for each field.
774 for (int j = 0; j < nfields; j++) {
775 intptr_t offset;
776 ciField* field = nullptr;
777 if (iklass != nullptr) {
778 field = iklass->nonstatic_field_at(j);
779 offset = field->offset_in_bytes();
780 ciType* elem_type = field->type();
781 basic_elem_type = field->layout_type();
782
783 // The next code is taken from Parse::do_get_xxx().
784 if (is_reference_type(basic_elem_type)) {
785 if (!elem_type->is_loaded()) {
786 field_type = TypeInstPtr::BOTTOM;
787 } else if (field != nullptr && field->is_static_constant()) {
788 ciObject* con = field->constant_value().as_object();
789 // Do not "join" in the previous type; it doesn't add value,
790 // and may yield a vacuous result if the field is of interface type.
791 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
792 assert(field_type != nullptr, "field singleton type must be consistent");
793 } else {
794 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
795 }
796 if (UseCompressedOops) {
797 field_type = field_type->make_narrowoop();
798 basic_elem_type = T_NARROWOOP;
799 }
800 } else {
801 field_type = Type::get_const_basic_type(basic_elem_type);
802 }
803 } else {
804 offset = array_base + j * (intptr_t)element_size;
805 }
806
807 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
808
809 Node *field_val = value_from_mem(sfpt->memory(), sfpt->control(), basic_elem_type, field_type, field_addr_type, alloc);
810
811 // We weren't able to find a value for this field,
812 // give up on eliminating this allocation.
813 if (field_val == nullptr) {
814 uint last = sfpt->req() - 1;
815 for (int k = 0; k < j; k++) {
816 sfpt->del_req(last--);
817 }
818 _igvn._worklist.push(sfpt);
819
820 #ifndef PRODUCT
821 if (PrintEliminateAllocations) {
822 if (field != nullptr) {
823 tty->print("=== At SafePoint node %d can't find value of field: ", sfpt->_idx);
824 field->print();
825 int field_idx = C->get_alias_index(field_addr_type);
826 tty->print(" (alias_idx=%d)", field_idx);
827 } else { // Array's element
828 tty->print("=== At SafePoint node %d can't find value of array element [%d]", sfpt->_idx, j);
829 }
830 tty->print(", which prevents elimination of: ");
831 if (res == nullptr)
832 alloc->dump();
833 else
834 res->dump();
835 }
836 #endif
837
838 return nullptr;
839 }
840
841 if (UseCompressedOops && field_type->isa_narrowoop()) {
842 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
843 // to be able scalar replace the allocation.
844 if (field_val->is_EncodeP()) {
845 field_val = field_val->in(1);
846 } else {
847 field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
848 }
849 }
850 sfpt->add_req(field_val);
851 }
852
853 sfpt->jvms()->set_endoff(sfpt->req());
854
855 return sobj;
856 }
857
858 // Do scalar replacement.
859 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
860 GrowableArray <SafePointNode *> safepoints_done;
861 Node* res = alloc->result_cast();
862 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result");
863
864 // Process the safepoint uses
865 while (safepoints.length() > 0) {
866 SafePointNode* sfpt = safepoints.pop();
867 SafePointScalarObjectNode* sobj = create_scalarized_object_description(alloc, sfpt);
868
869 if (sobj == nullptr) {
870 undo_previous_scalarizations(safepoints_done, alloc);
871 return false;
872 }
873
874 // Now make a pass over the debug information replacing any references
875 // to the allocated object with "sobj"
876 JVMState *jvms = sfpt->jvms();
877 sfpt->replace_edges_in_range(res, sobj, jvms->debug_start(), jvms->debug_end(), &_igvn);
878 _igvn._worklist.push(sfpt);
879
880 // keep it for rollback
881 safepoints_done.append_if_missing(sfpt);
882 }
883
884 return true;
885 }
886
887 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) {
888 Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control);
889 Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory);
890 if (ctl_proj != nullptr) {
891 igvn.replace_node(ctl_proj, n->in(0));
892 }
893 if (mem_proj != nullptr) {
894 igvn.replace_node(mem_proj, n->in(TypeFunc::Memory));
895 }
896 }
897
898 // Process users of eliminated allocation.
899 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
900 Node* res = alloc->result_cast();
901 if (res != nullptr) {
902 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
903 Node *use = res->last_out(j);
904 uint oc1 = res->outcnt();
905
906 if (use->is_AddP()) {
907 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
908 Node *n = use->last_out(k);
909 uint oc2 = use->outcnt();
910 if (n->is_Store()) {
911 #ifdef ASSERT
912 // Verify that there is no dependent MemBarVolatile nodes,
913 // they should be removed during IGVN, see MemBarNode::Ideal().
914 for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
915 p < pmax; p++) {
916 Node* mb = n->fast_out(p);
917 assert(mb->is_Initialize() || !mb->is_MemBar() ||
918 mb->req() <= MemBarNode::Precedent ||
919 mb->in(MemBarNode::Precedent) != n,
920 "MemBarVolatile should be eliminated for non-escaping object");
921 }
922 #endif
923 _igvn.replace_node(n, n->in(MemNode::Memory));
924 } else {
925 eliminate_gc_barrier(n);
926 }
927 k -= (oc2 - use->outcnt());
928 }
929 _igvn.remove_dead_node(use);
930 } else if (use->is_ArrayCopy()) {
931 // Disconnect ArrayCopy node
932 ArrayCopyNode* ac = use->as_ArrayCopy();
933 if (ac->is_clonebasic()) {
934 Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out();
935 disconnect_projections(ac, _igvn);
936 assert(alloc->in(TypeFunc::Memory)->is_Proj() && alloc->in(TypeFunc::Memory)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation");
937 Node* membar_before = alloc->in(TypeFunc::Memory)->in(0);
938 disconnect_projections(membar_before->as_MemBar(), _igvn);
939 if (membar_after->is_MemBar()) {
940 disconnect_projections(membar_after->as_MemBar(), _igvn);
941 }
942 } else {
943 assert(ac->is_arraycopy_validated() ||
944 ac->is_copyof_validated() ||
945 ac->is_copyofrange_validated(), "unsupported");
946 CallProjections callprojs;
947 ac->extract_projections(&callprojs, true);
948
949 _igvn.replace_node(callprojs.fallthrough_ioproj, ac->in(TypeFunc::I_O));
950 _igvn.replace_node(callprojs.fallthrough_memproj, ac->in(TypeFunc::Memory));
951 _igvn.replace_node(callprojs.fallthrough_catchproj, ac->in(TypeFunc::Control));
952
953 // Set control to top. IGVN will remove the remaining projections
954 ac->set_req(0, top());
955 ac->replace_edge(res, top(), &_igvn);
956
957 // Disconnect src right away: it can help find new
958 // opportunities for allocation elimination
959 Node* src = ac->in(ArrayCopyNode::Src);
960 ac->replace_edge(src, top(), &_igvn);
961 // src can be top at this point if src and dest of the
962 // arraycopy were the same
963 if (src->outcnt() == 0 && !src->is_top()) {
964 _igvn.remove_dead_node(src);
965 }
966 }
967 _igvn._worklist.push(ac);
968 } else {
969 eliminate_gc_barrier(use);
970 }
971 j -= (oc1 - res->outcnt());
972 }
973 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
974 _igvn.remove_dead_node(res);
975 }
976
977 //
978 // Process other users of allocation's projections
979 //
980 if (_callprojs.resproj != nullptr && _callprojs.resproj->outcnt() != 0) {
981 // First disconnect stores captured by Initialize node.
982 // If Initialize node is eliminated first in the following code,
983 // it will kill such stores and DUIterator_Last will assert.
984 for (DUIterator_Fast jmax, j = _callprojs.resproj->fast_outs(jmax); j < jmax; j++) {
985 Node* use = _callprojs.resproj->fast_out(j);
986 if (use->is_AddP()) {
987 // raw memory addresses used only by the initialization
988 _igvn.replace_node(use, C->top());
989 --j; --jmax;
990 }
991 }
992 for (DUIterator_Last jmin, j = _callprojs.resproj->last_outs(jmin); j >= jmin; ) {
993 Node* use = _callprojs.resproj->last_out(j);
994 uint oc1 = _callprojs.resproj->outcnt();
995 if (use->is_Initialize()) {
996 // Eliminate Initialize node.
997 InitializeNode *init = use->as_Initialize();
998 assert(init->outcnt() <= 2, "only a control and memory projection expected");
999 Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
1000 if (ctrl_proj != nullptr) {
1001 _igvn.replace_node(ctrl_proj, init->in(TypeFunc::Control));
1002 #ifdef ASSERT
1003 // If the InitializeNode has no memory out, it will die, and tmp will become null
1004 Node* tmp = init->in(TypeFunc::Control);
1005 assert(tmp == nullptr || tmp == _callprojs.fallthrough_catchproj, "allocation control projection");
1006 #endif
1007 }
1008 Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
1009 if (mem_proj != nullptr) {
1010 Node *mem = init->in(TypeFunc::Memory);
1011 #ifdef ASSERT
1012 if (mem->is_MergeMem()) {
1013 assert(mem->in(TypeFunc::Memory) == _callprojs.fallthrough_memproj, "allocation memory projection");
1014 } else {
1015 assert(mem == _callprojs.fallthrough_memproj, "allocation memory projection");
1016 }
1017 #endif
1018 _igvn.replace_node(mem_proj, mem);
1019 }
1020 } else {
1021 assert(false, "only Initialize or AddP expected");
1022 }
1023 j -= (oc1 - _callprojs.resproj->outcnt());
1024 }
1025 }
1026 if (_callprojs.fallthrough_catchproj != nullptr) {
1027 _igvn.replace_node(_callprojs.fallthrough_catchproj, alloc->in(TypeFunc::Control));
1028 }
1029 if (_callprojs.fallthrough_memproj != nullptr) {
1030 _igvn.replace_node(_callprojs.fallthrough_memproj, alloc->in(TypeFunc::Memory));
1031 }
1032 if (_callprojs.catchall_memproj != nullptr) {
1033 _igvn.replace_node(_callprojs.catchall_memproj, C->top());
1034 }
1035 if (_callprojs.fallthrough_ioproj != nullptr) {
1036 _igvn.replace_node(_callprojs.fallthrough_ioproj, alloc->in(TypeFunc::I_O));
1037 }
1038 if (_callprojs.catchall_ioproj != nullptr) {
1039 _igvn.replace_node(_callprojs.catchall_ioproj, C->top());
1040 }
1041 if (_callprojs.catchall_catchproj != nullptr) {
1042 _igvn.replace_node(_callprojs.catchall_catchproj, C->top());
1043 }
1044 }
1045
1046 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
1047 // If reallocation fails during deoptimization we'll pop all
1048 // interpreter frames for this compiled frame and that won't play
1049 // nice with JVMTI popframe.
1050 // We avoid this issue by eager reallocation when the popframe request
1051 // is received.
1052 if (!EliminateAllocations || !alloc->_is_non_escaping) {
1053 return false;
1054 }
1055 Node* klass = alloc->in(AllocateNode::KlassNode);
1056 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
1057 Node* res = alloc->result_cast();
1058 // Eliminate boxing allocations which are not used
1059 // regardless scalar replaceable status.
1060 bool boxing_alloc = C->eliminate_boxing() &&
1061 tklass->isa_instklassptr() &&
1062 tklass->is_instklassptr()->instance_klass()->is_box_klass();
1063 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != nullptr))) {
1064 return false;
1065 }
1066
1067 alloc->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1068
1069 GrowableArray <SafePointNode *> safepoints;
1070 if (!can_eliminate_allocation(&_igvn, alloc, &safepoints)) {
1071 return false;
1072 }
1073
1074 if (!alloc->_is_scalar_replaceable) {
1075 assert(res == nullptr, "sanity");
1076 // We can only eliminate allocation if all debug info references
1077 // are already replaced with SafePointScalarObject because
1078 // we can't search for a fields value without instance_id.
1079 if (safepoints.length() > 0) {
1080 return false;
1081 }
1082 }
1083
1084 if (!scalar_replacement(alloc, safepoints)) {
1085 return false;
1086 }
1087
1088 CompileLog* log = C->log();
1089 if (log != nullptr) {
1090 log->head("eliminate_allocation type='%d'",
1091 log->identify(tklass->exact_klass()));
1092 JVMState* p = alloc->jvms();
1093 while (p != nullptr) {
1094 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1095 p = p->caller();
1096 }
1097 log->tail("eliminate_allocation");
1098 }
1099
1100 process_users_of_allocation(alloc);
1101
1102 #ifndef PRODUCT
1103 if (PrintEliminateAllocations) {
1104 if (alloc->is_AllocateArray())
1105 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1106 else
1107 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1108 }
1109 #endif
1110
1111 return true;
1112 }
1113
1114 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1115 // EA should remove all uses of non-escaping boxing node.
1116 if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != nullptr) {
1117 return false;
1118 }
1119
1120 assert(boxing->result_cast() == nullptr, "unexpected boxing node result");
1121
1122 boxing->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1123
1124 const TypeTuple* r = boxing->tf()->range();
1125 assert(r->cnt() > TypeFunc::Parms, "sanity");
1126 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1127 assert(t != nullptr, "sanity");
1128
1129 CompileLog* log = C->log();
1130 if (log != nullptr) {
1131 log->head("eliminate_boxing type='%d'",
1132 log->identify(t->instance_klass()));
1133 JVMState* p = boxing->jvms();
1134 while (p != nullptr) {
1135 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1136 p = p->caller();
1137 }
1138 log->tail("eliminate_boxing");
1139 }
1140
1141 process_users_of_allocation(boxing);
1142
1143 #ifndef PRODUCT
1144 if (PrintEliminateAllocations) {
1145 tty->print("++++ Eliminated: %d ", boxing->_idx);
1146 boxing->method()->print_short_name(tty);
1147 tty->cr();
1148 }
1149 #endif
1150
1151 return true;
1152 }
1153
1154
1155 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1156 Node* adr = basic_plus_adr(base, offset);
1157 const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1158 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1159 transform_later(value);
1160 return value;
1161 }
1162
1163
1164 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1165 Node* adr = basic_plus_adr(base, offset);
1166 mem = StoreNode::make(_igvn, ctl, mem, adr, nullptr, value, bt, MemNode::unordered);
1167 transform_later(mem);
1168 return mem;
1169 }
1170
1171 //=============================================================================
1172 //
1173 // A L L O C A T I O N
1174 //
1175 // Allocation attempts to be fast in the case of frequent small objects.
1176 // It breaks down like this:
1177 //
1178 // 1) Size in doublewords is computed. This is a constant for objects and
1179 // variable for most arrays. Doubleword units are used to avoid size
1180 // overflow of huge doubleword arrays. We need doublewords in the end for
1181 // rounding.
1182 //
1183 // 2) Size is checked for being 'too large'. Too-large allocations will go
1184 // the slow path into the VM. The slow path can throw any required
1185 // exceptions, and does all the special checks for very large arrays. The
1186 // size test can constant-fold away for objects. For objects with
1187 // finalizers it constant-folds the otherway: you always go slow with
1188 // finalizers.
1189 //
1190 // 3) If NOT using TLABs, this is the contended loop-back point.
1191 // Load-Locked the heap top. If using TLABs normal-load the heap top.
1192 //
1193 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
1194 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
1195 // "size*8" we always enter the VM, where "largish" is a constant picked small
1196 // enough that there's always space between the eden max and 4Gig (old space is
1197 // there so it's quite large) and large enough that the cost of entering the VM
1198 // is dwarfed by the cost to initialize the space.
1199 //
1200 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1201 // down. If contended, repeat at step 3. If using TLABs normal-store
1202 // adjusted heap top back down; there is no contention.
1203 //
1204 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
1205 // fields.
1206 //
1207 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1208 // oop flavor.
1209 //
1210 //=============================================================================
1211 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1212 // Allocations bigger than this always go the slow route.
1213 // This value must be small enough that allocation attempts that need to
1214 // trigger exceptions go the slow route. Also, it must be small enough so
1215 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1216 //=============================================================================j//
1217 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1218 // The allocator will coalesce int->oop copies away. See comment in
1219 // coalesce.cpp about how this works. It depends critically on the exact
1220 // code shape produced here, so if you are changing this code shape
1221 // make sure the GC info for the heap-top is correct in and around the
1222 // slow-path call.
1223 //
1224
1225 void PhaseMacroExpand::expand_allocate_common(
1226 AllocateNode* alloc, // allocation node to be expanded
1227 Node* length, // array length for an array allocation
1228 const TypeFunc* slow_call_type, // Type of slow call
1229 address slow_call_address, // Address of slow call
1230 Node* valid_length_test // whether length is valid or not
1231 )
1232 {
1233 Node* ctrl = alloc->in(TypeFunc::Control);
1234 Node* mem = alloc->in(TypeFunc::Memory);
1235 Node* i_o = alloc->in(TypeFunc::I_O);
1236 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
1237 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1238 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1239 assert(ctrl != nullptr, "must have control");
1240
1241 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1242 // they will not be used if "always_slow" is set
1243 enum { slow_result_path = 1, fast_result_path = 2 };
1244 Node *result_region = nullptr;
1245 Node *result_phi_rawmem = nullptr;
1246 Node *result_phi_rawoop = nullptr;
1247 Node *result_phi_i_o = nullptr;
1248
1249 // The initial slow comparison is a size check, the comparison
1250 // we want to do is a BoolTest::gt
1251 bool expand_fast_path = true;
1252 int tv = _igvn.find_int_con(initial_slow_test, -1);
1253 if (tv >= 0) {
1254 // InitialTest has constant result
1255 // 0 - can fit in TLAB
1256 // 1 - always too big or negative
1257 assert(tv <= 1, "0 or 1 if a constant");
1258 expand_fast_path = (tv == 0);
1259 initial_slow_test = nullptr;
1260 } else {
1261 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1262 }
1263
1264 if (!UseTLAB) {
1265 // Force slow-path allocation
1266 expand_fast_path = false;
1267 initial_slow_test = nullptr;
1268 }
1269
1270 bool allocation_has_use = (alloc->result_cast() != nullptr);
1271 if (!allocation_has_use) {
1272 InitializeNode* init = alloc->initialization();
1273 if (init != nullptr) {
1274 init->remove(&_igvn);
1275 }
1276 if (expand_fast_path && (initial_slow_test == nullptr)) {
1277 // Remove allocation node and return.
1278 // Size is a non-negative constant -> no initial check needed -> directly to fast path.
1279 // Also, no usages -> empty fast path -> no fall out to slow path -> nothing left.
1280 #ifndef PRODUCT
1281 if (PrintEliminateAllocations) {
1282 tty->print("NotUsed ");
1283 Node* res = alloc->proj_out_or_null(TypeFunc::Parms);
1284 if (res != nullptr) {
1285 res->dump();
1286 } else {
1287 alloc->dump();
1288 }
1289 }
1290 #endif
1291 yank_alloc_node(alloc);
1292 return;
1293 }
1294 }
1295
1296 enum { too_big_or_final_path = 1, need_gc_path = 2 };
1297 Node *slow_region = nullptr;
1298 Node *toobig_false = ctrl;
1299
1300 // generate the initial test if necessary
1301 if (initial_slow_test != nullptr ) {
1302 assert (expand_fast_path, "Only need test if there is a fast path");
1303 slow_region = new RegionNode(3);
1304
1305 // Now make the initial failure test. Usually a too-big test but
1306 // might be a TRUE for finalizers or a fancy class check for
1307 // newInstance0.
1308 IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1309 transform_later(toobig_iff);
1310 // Plug the failing-too-big test into the slow-path region
1311 Node *toobig_true = new IfTrueNode( toobig_iff );
1312 transform_later(toobig_true);
1313 slow_region ->init_req( too_big_or_final_path, toobig_true );
1314 toobig_false = new IfFalseNode( toobig_iff );
1315 transform_later(toobig_false);
1316 } else {
1317 // No initial test, just fall into next case
1318 assert(allocation_has_use || !expand_fast_path, "Should already have been handled");
1319 toobig_false = ctrl;
1320 debug_only(slow_region = NodeSentinel);
1321 }
1322
1323 // If we are here there are several possibilities
1324 // - expand_fast_path is false - then only a slow path is expanded. That's it.
1325 // no_initial_check means a constant allocation.
1326 // - If check always evaluates to false -> expand_fast_path is false (see above)
1327 // - If check always evaluates to true -> directly into fast path (but may bailout to slowpath)
1328 // if !allocation_has_use the fast path is empty
1329 // if !allocation_has_use && no_initial_check
1330 // - Then there are no fastpath that can fall out to slowpath -> no allocation code at all.
1331 // removed by yank_alloc_node above.
1332
1333 Node *slow_mem = mem; // save the current memory state for slow path
1334 // generate the fast allocation code unless we know that the initial test will always go slow
1335 if (expand_fast_path) {
1336 // Fast path modifies only raw memory.
1337 if (mem->is_MergeMem()) {
1338 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1339 }
1340
1341 // allocate the Region and Phi nodes for the result
1342 result_region = new RegionNode(3);
1343 result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1344 result_phi_i_o = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1345
1346 // Grab regular I/O before optional prefetch may change it.
1347 // Slow-path does no I/O so just set it to the original I/O.
1348 result_phi_i_o->init_req(slow_result_path, i_o);
1349
1350 // Name successful fast-path variables
1351 Node* fast_oop_ctrl;
1352 Node* fast_oop_rawmem;
1353 if (allocation_has_use) {
1354 Node* needgc_ctrl = nullptr;
1355 result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1356
1357 intx prefetch_lines = length != nullptr ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1358 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1359 Node* fast_oop = bs->obj_allocate(this, mem, toobig_false, size_in_bytes, i_o, needgc_ctrl,
1360 fast_oop_ctrl, fast_oop_rawmem,
1361 prefetch_lines);
1362
1363 if (initial_slow_test != nullptr) {
1364 // This completes all paths into the slow merge point
1365 slow_region->init_req(need_gc_path, needgc_ctrl);
1366 transform_later(slow_region);
1367 } else {
1368 // No initial slow path needed!
1369 // Just fall from the need-GC path straight into the VM call.
1370 slow_region = needgc_ctrl;
1371 }
1372
1373 InitializeNode* init = alloc->initialization();
1374 fast_oop_rawmem = initialize_object(alloc,
1375 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1376 klass_node, length, size_in_bytes);
1377 expand_initialize_membar(alloc, init, fast_oop_ctrl, fast_oop_rawmem);
1378 expand_dtrace_alloc_probe(alloc, fast_oop, fast_oop_ctrl, fast_oop_rawmem);
1379
1380 result_phi_rawoop->init_req(fast_result_path, fast_oop);
1381 } else {
1382 assert (initial_slow_test != nullptr, "sanity");
1383 fast_oop_ctrl = toobig_false;
1384 fast_oop_rawmem = mem;
1385 transform_later(slow_region);
1386 }
1387
1388 // Plug in the successful fast-path into the result merge point
1389 result_region ->init_req(fast_result_path, fast_oop_ctrl);
1390 result_phi_i_o ->init_req(fast_result_path, i_o);
1391 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1392 } else {
1393 slow_region = ctrl;
1394 result_phi_i_o = i_o; // Rename it to use in the following code.
1395 }
1396
1397 // Generate slow-path call
1398 CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1399 OptoRuntime::stub_name(slow_call_address),
1400 TypePtr::BOTTOM);
1401 call->init_req(TypeFunc::Control, slow_region);
1402 call->init_req(TypeFunc::I_O, top()); // does no i/o
1403 call->init_req(TypeFunc::Memory, slow_mem); // may gc ptrs
1404 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1405 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1406
1407 call->init_req(TypeFunc::Parms+0, klass_node);
1408 if (length != nullptr) {
1409 call->init_req(TypeFunc::Parms+1, length);
1410 }
1411
1412 // Copy debug information and adjust JVMState information, then replace
1413 // allocate node with the call
1414 call->copy_call_debug_info(&_igvn, alloc);
1415 // For array allocations, copy the valid length check to the call node so Compile::final_graph_reshaping() can verify
1416 // that the call has the expected number of CatchProj nodes (in case the allocation always fails and the fallthrough
1417 // path dies).
1418 if (valid_length_test != nullptr) {
1419 call->add_req(valid_length_test);
1420 }
1421 if (expand_fast_path) {
1422 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1423 } else {
1424 // Hook i_o projection to avoid its elimination during allocation
1425 // replacement (when only a slow call is generated).
1426 call->set_req(TypeFunc::I_O, result_phi_i_o);
1427 }
1428 _igvn.replace_node(alloc, call);
1429 transform_later(call);
1430
1431 // Identify the output projections from the allocate node and
1432 // adjust any references to them.
1433 // The control and io projections look like:
1434 //
1435 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
1436 // Allocate Catch
1437 // ^---Proj(io) <-------+ ^---CatchProj(io)
1438 //
1439 // We are interested in the CatchProj nodes.
1440 //
1441 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1442
1443 // An allocate node has separate memory projections for the uses on
1444 // the control and i_o paths. Replace the control memory projection with
1445 // result_phi_rawmem (unless we are only generating a slow call when
1446 // both memory projections are combined)
1447 if (expand_fast_path && _callprojs.fallthrough_memproj != nullptr) {
1448 migrate_outs(_callprojs.fallthrough_memproj, result_phi_rawmem);
1449 }
1450 // Now change uses of catchall_memproj to use fallthrough_memproj and delete
1451 // catchall_memproj so we end up with a call that has only 1 memory projection.
1452 if (_callprojs.catchall_memproj != nullptr ) {
1453 if (_callprojs.fallthrough_memproj == nullptr) {
1454 _callprojs.fallthrough_memproj = new ProjNode(call, TypeFunc::Memory);
1455 transform_later(_callprojs.fallthrough_memproj);
1456 }
1457 migrate_outs(_callprojs.catchall_memproj, _callprojs.fallthrough_memproj);
1458 _igvn.remove_dead_node(_callprojs.catchall_memproj);
1459 }
1460
1461 // An allocate node has separate i_o projections for the uses on the control
1462 // and i_o paths. Always replace the control i_o projection with result i_o
1463 // otherwise incoming i_o become dead when only a slow call is generated
1464 // (it is different from memory projections where both projections are
1465 // combined in such case).
1466 if (_callprojs.fallthrough_ioproj != nullptr) {
1467 migrate_outs(_callprojs.fallthrough_ioproj, result_phi_i_o);
1468 }
1469 // Now change uses of catchall_ioproj to use fallthrough_ioproj and delete
1470 // catchall_ioproj so we end up with a call that has only 1 i_o projection.
1471 if (_callprojs.catchall_ioproj != nullptr ) {
1472 if (_callprojs.fallthrough_ioproj == nullptr) {
1473 _callprojs.fallthrough_ioproj = new ProjNode(call, TypeFunc::I_O);
1474 transform_later(_callprojs.fallthrough_ioproj);
1475 }
1476 migrate_outs(_callprojs.catchall_ioproj, _callprojs.fallthrough_ioproj);
1477 _igvn.remove_dead_node(_callprojs.catchall_ioproj);
1478 }
1479
1480 // if we generated only a slow call, we are done
1481 if (!expand_fast_path) {
1482 // Now we can unhook i_o.
1483 if (result_phi_i_o->outcnt() > 1) {
1484 call->set_req(TypeFunc::I_O, top());
1485 } else {
1486 assert(result_phi_i_o->unique_ctrl_out() == call, "sanity");
1487 // Case of new array with negative size known during compilation.
1488 // AllocateArrayNode::Ideal() optimization disconnect unreachable
1489 // following code since call to runtime will throw exception.
1490 // As result there will be no users of i_o after the call.
1491 // Leave i_o attached to this call to avoid problems in preceding graph.
1492 }
1493 return;
1494 }
1495
1496 if (_callprojs.fallthrough_catchproj != nullptr) {
1497 ctrl = _callprojs.fallthrough_catchproj->clone();
1498 transform_later(ctrl);
1499 _igvn.replace_node(_callprojs.fallthrough_catchproj, result_region);
1500 } else {
1501 ctrl = top();
1502 }
1503 Node *slow_result;
1504 if (_callprojs.resproj == nullptr) {
1505 // no uses of the allocation result
1506 slow_result = top();
1507 } else {
1508 slow_result = _callprojs.resproj->clone();
1509 transform_later(slow_result);
1510 _igvn.replace_node(_callprojs.resproj, result_phi_rawoop);
1511 }
1512
1513 // Plug slow-path into result merge point
1514 result_region->init_req( slow_result_path, ctrl);
1515 transform_later(result_region);
1516 if (allocation_has_use) {
1517 result_phi_rawoop->init_req(slow_result_path, slow_result);
1518 transform_later(result_phi_rawoop);
1519 }
1520 result_phi_rawmem->init_req(slow_result_path, _callprojs.fallthrough_memproj);
1521 transform_later(result_phi_rawmem);
1522 transform_later(result_phi_i_o);
1523 // This completes all paths into the result merge point
1524 }
1525
1526 // Remove alloc node that has no uses.
1527 void PhaseMacroExpand::yank_alloc_node(AllocateNode* alloc) {
1528 Node* ctrl = alloc->in(TypeFunc::Control);
1529 Node* mem = alloc->in(TypeFunc::Memory);
1530 Node* i_o = alloc->in(TypeFunc::I_O);
1531
1532 alloc->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
1533 if (_callprojs.resproj != nullptr) {
1534 for (DUIterator_Fast imax, i = _callprojs.resproj->fast_outs(imax); i < imax; i++) {
1535 Node* use = _callprojs.resproj->fast_out(i);
1536 use->isa_MemBar()->remove(&_igvn);
1537 --imax;
1538 --i; // back up iterator
1539 }
1540 assert(_callprojs.resproj->outcnt() == 0, "all uses must be deleted");
1541 _igvn.remove_dead_node(_callprojs.resproj);
1542 }
1543 if (_callprojs.fallthrough_catchproj != nullptr) {
1544 migrate_outs(_callprojs.fallthrough_catchproj, ctrl);
1545 _igvn.remove_dead_node(_callprojs.fallthrough_catchproj);
1546 }
1547 if (_callprojs.catchall_catchproj != nullptr) {
1548 _igvn.rehash_node_delayed(_callprojs.catchall_catchproj);
1549 _callprojs.catchall_catchproj->set_req(0, top());
1550 }
1551 if (_callprojs.fallthrough_proj != nullptr) {
1552 Node* catchnode = _callprojs.fallthrough_proj->unique_ctrl_out();
1553 _igvn.remove_dead_node(catchnode);
1554 _igvn.remove_dead_node(_callprojs.fallthrough_proj);
1555 }
1556 if (_callprojs.fallthrough_memproj != nullptr) {
1557 migrate_outs(_callprojs.fallthrough_memproj, mem);
1558 _igvn.remove_dead_node(_callprojs.fallthrough_memproj);
1559 }
1560 if (_callprojs.fallthrough_ioproj != nullptr) {
1561 migrate_outs(_callprojs.fallthrough_ioproj, i_o);
1562 _igvn.remove_dead_node(_callprojs.fallthrough_ioproj);
1563 }
1564 if (_callprojs.catchall_memproj != nullptr) {
1565 _igvn.rehash_node_delayed(_callprojs.catchall_memproj);
1566 _callprojs.catchall_memproj->set_req(0, top());
1567 }
1568 if (_callprojs.catchall_ioproj != nullptr) {
1569 _igvn.rehash_node_delayed(_callprojs.catchall_ioproj);
1570 _callprojs.catchall_ioproj->set_req(0, top());
1571 }
1572 #ifndef PRODUCT
1573 if (PrintEliminateAllocations) {
1574 if (alloc->is_AllocateArray()) {
1575 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1576 } else {
1577 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1578 }
1579 }
1580 #endif
1581 _igvn.remove_dead_node(alloc);
1582 }
1583
1584 void PhaseMacroExpand::expand_initialize_membar(AllocateNode* alloc, InitializeNode* init,
1585 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem) {
1586 // If initialization is performed by an array copy, any required
1587 // MemBarStoreStore was already added. If the object does not
1588 // escape no need for a MemBarStoreStore. If the object does not
1589 // escape in its initializer and memory barrier (MemBarStoreStore or
1590 // stronger) is already added at exit of initializer, also no need
1591 // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore
1592 // so that stores that initialize this object can't be reordered
1593 // with a subsequent store that makes this object accessible by
1594 // other threads.
1595 // Other threads include java threads and JVM internal threads
1596 // (for example concurrent GC threads). Current concurrent GC
1597 // implementation: G1 will not scan newly created object,
1598 // so it's safe to skip storestore barrier when allocation does
1599 // not escape.
1600 if (!alloc->does_not_escape_thread() &&
1601 !alloc->is_allocation_MemBar_redundant() &&
1602 (init == nullptr || !init->is_complete_with_arraycopy())) {
1603 if (init == nullptr || init->req() < InitializeNode::RawStores) {
1604 // No InitializeNode or no stores captured by zeroing
1605 // elimination. Simply add the MemBarStoreStore after object
1606 // initialization.
1607 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1608 transform_later(mb);
1609
1610 mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1611 mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1612 fast_oop_ctrl = new ProjNode(mb, TypeFunc::Control);
1613 transform_later(fast_oop_ctrl);
1614 fast_oop_rawmem = new ProjNode(mb, TypeFunc::Memory);
1615 transform_later(fast_oop_rawmem);
1616 } else {
1617 // Add the MemBarStoreStore after the InitializeNode so that
1618 // all stores performing the initialization that were moved
1619 // before the InitializeNode happen before the storestore
1620 // barrier.
1621
1622 Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control);
1623 Node* init_mem = init->proj_out_or_null(TypeFunc::Memory);
1624
1625 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1626 transform_later(mb);
1627
1628 Node* ctrl = new ProjNode(init, TypeFunc::Control);
1629 transform_later(ctrl);
1630 Node* mem = new ProjNode(init, TypeFunc::Memory);
1631 transform_later(mem);
1632
1633 // The MemBarStoreStore depends on control and memory coming
1634 // from the InitializeNode
1635 mb->init_req(TypeFunc::Memory, mem);
1636 mb->init_req(TypeFunc::Control, ctrl);
1637
1638 ctrl = new ProjNode(mb, TypeFunc::Control);
1639 transform_later(ctrl);
1640 mem = new ProjNode(mb, TypeFunc::Memory);
1641 transform_later(mem);
1642
1643 // All nodes that depended on the InitializeNode for control
1644 // and memory must now depend on the MemBarNode that itself
1645 // depends on the InitializeNode
1646 if (init_ctrl != nullptr) {
1647 _igvn.replace_node(init_ctrl, ctrl);
1648 }
1649 if (init_mem != nullptr) {
1650 _igvn.replace_node(init_mem, mem);
1651 }
1652 }
1653 }
1654 }
1655
1656 void PhaseMacroExpand::expand_dtrace_alloc_probe(AllocateNode* alloc, Node* oop,
1657 Node*& ctrl, Node*& rawmem) {
1658 if (C->env()->dtrace_alloc_probes()) {
1659 // Slow-path call
1660 int size = TypeFunc::Parms + 2;
1661 CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1662 CAST_FROM_FN_PTR(address,
1663 static_cast<int (*)(JavaThread*, oopDesc*)>(SharedRuntime::dtrace_object_alloc)),
1664 "dtrace_object_alloc",
1665 TypeRawPtr::BOTTOM);
1666
1667 // Get base of thread-local storage area
1668 Node* thread = new ThreadLocalNode();
1669 transform_later(thread);
1670
1671 call->init_req(TypeFunc::Parms + 0, thread);
1672 call->init_req(TypeFunc::Parms + 1, oop);
1673 call->init_req(TypeFunc::Control, ctrl);
1674 call->init_req(TypeFunc::I_O , top()); // does no i/o
1675 call->init_req(TypeFunc::Memory , rawmem);
1676 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1677 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1678 transform_later(call);
1679 ctrl = new ProjNode(call, TypeFunc::Control);
1680 transform_later(ctrl);
1681 rawmem = new ProjNode(call, TypeFunc::Memory);
1682 transform_later(rawmem);
1683 }
1684 }
1685
1686 // Helper for PhaseMacroExpand::expand_allocate_common.
1687 // Initializes the newly-allocated storage.
1688 Node*
1689 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1690 Node* control, Node* rawmem, Node* object,
1691 Node* klass_node, Node* length,
1692 Node* size_in_bytes) {
1693 InitializeNode* init = alloc->initialization();
1694 // Store the klass & mark bits
1695 Node* mark_node = alloc->make_ideal_mark(&_igvn, object, control, rawmem);
1696 if (!mark_node->is_Con()) {
1697 transform_later(mark_node);
1698 }
1699 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, TypeX_X->basic_type());
1700
1701 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1702 int header_size = alloc->minimum_header_size(); // conservatively small
1703
1704 // Array length
1705 if (length != nullptr) { // Arrays need length field
1706 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1707 // conservatively small header size:
1708 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1709 if (_igvn.type(klass_node)->isa_aryklassptr()) { // we know the exact header size in most cases:
1710 BasicType elem = _igvn.type(klass_node)->is_klassptr()->as_instance_type()->isa_aryptr()->elem()->array_element_basic_type();
1711 if (is_reference_type(elem, true)) {
1712 elem = T_OBJECT;
1713 }
1714 header_size = Klass::layout_helper_header_size(Klass::array_layout_helper(elem));
1715 }
1716 }
1717
1718 // Clear the object body, if necessary.
1719 if (init == nullptr) {
1720 // The init has somehow disappeared; be cautious and clear everything.
1721 //
1722 // This can happen if a node is allocated but an uncommon trap occurs
1723 // immediately. In this case, the Initialize gets associated with the
1724 // trap, and may be placed in a different (outer) loop, if the Allocate
1725 // is in a loop. If (this is rare) the inner loop gets unrolled, then
1726 // there can be two Allocates to one Initialize. The answer in all these
1727 // edge cases is safety first. It is always safe to clear immediately
1728 // within an Allocate, and then (maybe or maybe not) clear some more later.
1729 if (!(UseTLAB && ZeroTLAB)) {
1730 rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1731 header_size, size_in_bytes,
1732 &_igvn);
1733 }
1734 } else {
1735 if (!init->is_complete()) {
1736 // Try to win by zeroing only what the init does not store.
1737 // We can also try to do some peephole optimizations,
1738 // such as combining some adjacent subword stores.
1739 rawmem = init->complete_stores(control, rawmem, object,
1740 header_size, size_in_bytes, &_igvn);
1741 }
1742 // We have no more use for this link, since the AllocateNode goes away:
1743 init->set_req(InitializeNode::RawAddress, top());
1744 // (If we keep the link, it just confuses the register allocator,
1745 // who thinks he sees a real use of the address by the membar.)
1746 }
1747
1748 return rawmem;
1749 }
1750
1751 // Generate prefetch instructions for next allocations.
1752 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1753 Node*& contended_phi_rawmem,
1754 Node* old_eden_top, Node* new_eden_top,
1755 intx lines) {
1756 enum { fall_in_path = 1, pf_path = 2 };
1757 if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1758 // Generate prefetch allocation with watermark check.
1759 // As an allocation hits the watermark, we will prefetch starting
1760 // at a "distance" away from watermark.
1761
1762 Node *pf_region = new RegionNode(3);
1763 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1764 TypeRawPtr::BOTTOM );
1765 // I/O is used for Prefetch
1766 Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1767
1768 Node *thread = new ThreadLocalNode();
1769 transform_later(thread);
1770
1771 Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1772 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1773 transform_later(eden_pf_adr);
1774
1775 Node *old_pf_wm = new LoadPNode(needgc_false,
1776 contended_phi_rawmem, eden_pf_adr,
1777 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1778 MemNode::unordered);
1779 transform_later(old_pf_wm);
1780
1781 // check against new_eden_top
1782 Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1783 transform_later(need_pf_cmp);
1784 Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1785 transform_later(need_pf_bol);
1786 IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1787 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1788 transform_later(need_pf_iff);
1789
1790 // true node, add prefetchdistance
1791 Node *need_pf_true = new IfTrueNode( need_pf_iff );
1792 transform_later(need_pf_true);
1793
1794 Node *need_pf_false = new IfFalseNode( need_pf_iff );
1795 transform_later(need_pf_false);
1796
1797 Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1798 _igvn.MakeConX(AllocatePrefetchDistance) );
1799 transform_later(new_pf_wmt );
1800 new_pf_wmt->set_req(0, need_pf_true);
1801
1802 Node *store_new_wmt = new StorePNode(need_pf_true,
1803 contended_phi_rawmem, eden_pf_adr,
1804 TypeRawPtr::BOTTOM, new_pf_wmt,
1805 MemNode::unordered);
1806 transform_later(store_new_wmt);
1807
1808 // adding prefetches
1809 pf_phi_abio->init_req( fall_in_path, i_o );
1810
1811 Node *prefetch_adr;
1812 Node *prefetch;
1813 uint step_size = AllocatePrefetchStepSize;
1814 uint distance = 0;
1815
1816 for ( intx i = 0; i < lines; i++ ) {
1817 prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1818 _igvn.MakeConX(distance) );
1819 transform_later(prefetch_adr);
1820 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1821 transform_later(prefetch);
1822 distance += step_size;
1823 i_o = prefetch;
1824 }
1825 pf_phi_abio->set_req( pf_path, i_o );
1826
1827 pf_region->init_req( fall_in_path, need_pf_false );
1828 pf_region->init_req( pf_path, need_pf_true );
1829
1830 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1831 pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1832
1833 transform_later(pf_region);
1834 transform_later(pf_phi_rawmem);
1835 transform_later(pf_phi_abio);
1836
1837 needgc_false = pf_region;
1838 contended_phi_rawmem = pf_phi_rawmem;
1839 i_o = pf_phi_abio;
1840 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1841 // Insert a prefetch instruction for each allocation.
1842 // This code is used to generate 1 prefetch instruction per cache line.
1843
1844 // Generate several prefetch instructions.
1845 uint step_size = AllocatePrefetchStepSize;
1846 uint distance = AllocatePrefetchDistance;
1847
1848 // Next cache address.
1849 Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1850 _igvn.MakeConX(step_size + distance));
1851 transform_later(cache_adr);
1852 cache_adr = new CastP2XNode(needgc_false, cache_adr);
1853 transform_later(cache_adr);
1854 // Address is aligned to execute prefetch to the beginning of cache line size
1855 // (it is important when BIS instruction is used on SPARC as prefetch).
1856 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1857 cache_adr = new AndXNode(cache_adr, mask);
1858 transform_later(cache_adr);
1859 cache_adr = new CastX2PNode(cache_adr);
1860 transform_later(cache_adr);
1861
1862 // Prefetch
1863 Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1864 prefetch->set_req(0, needgc_false);
1865 transform_later(prefetch);
1866 contended_phi_rawmem = prefetch;
1867 Node *prefetch_adr;
1868 distance = step_size;
1869 for ( intx i = 1; i < lines; i++ ) {
1870 prefetch_adr = new AddPNode( cache_adr, cache_adr,
1871 _igvn.MakeConX(distance) );
1872 transform_later(prefetch_adr);
1873 prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1874 transform_later(prefetch);
1875 distance += step_size;
1876 contended_phi_rawmem = prefetch;
1877 }
1878 } else if( AllocatePrefetchStyle > 0 ) {
1879 // Insert a prefetch for each allocation only on the fast-path
1880 Node *prefetch_adr;
1881 Node *prefetch;
1882 // Generate several prefetch instructions.
1883 uint step_size = AllocatePrefetchStepSize;
1884 uint distance = AllocatePrefetchDistance;
1885 for ( intx i = 0; i < lines; i++ ) {
1886 prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1887 _igvn.MakeConX(distance) );
1888 transform_later(prefetch_adr);
1889 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1890 // Do not let it float too high, since if eden_top == eden_end,
1891 // both might be null.
1892 if( i == 0 ) { // Set control for first prefetch, next follows it
1893 prefetch->init_req(0, needgc_false);
1894 }
1895 transform_later(prefetch);
1896 distance += step_size;
1897 i_o = prefetch;
1898 }
1899 }
1900 return i_o;
1901 }
1902
1903
1904 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1905 expand_allocate_common(alloc, nullptr,
1906 OptoRuntime::new_instance_Type(),
1907 OptoRuntime::new_instance_Java(), nullptr);
1908 }
1909
1910 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1911 Node* length = alloc->in(AllocateNode::ALength);
1912 Node* valid_length_test = alloc->in(AllocateNode::ValidLengthTest);
1913 InitializeNode* init = alloc->initialization();
1914 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1915 const TypeAryKlassPtr* ary_klass_t = _igvn.type(klass_node)->isa_aryklassptr();
1916 address slow_call_address; // Address of slow call
1917 if (init != nullptr && init->is_complete_with_arraycopy() &&
1918 ary_klass_t && ary_klass_t->elem()->isa_klassptr() == nullptr) {
1919 // Don't zero type array during slow allocation in VM since
1920 // it will be initialized later by arraycopy in compiled code.
1921 slow_call_address = OptoRuntime::new_array_nozero_Java();
1922 } else {
1923 slow_call_address = OptoRuntime::new_array_Java();
1924 }
1925 expand_allocate_common(alloc, length,
1926 OptoRuntime::new_array_Type(),
1927 slow_call_address, valid_length_test);
1928 }
1929
1930 //-------------------mark_eliminated_box----------------------------------
1931 //
1932 // During EA obj may point to several objects but after few ideal graph
1933 // transformations (CCP) it may point to only one non escaping object
1934 // (but still using phi), corresponding locks and unlocks will be marked
1935 // for elimination. Later obj could be replaced with a new node (new phi)
1936 // and which does not have escape information. And later after some graph
1937 // reshape other locks and unlocks (which were not marked for elimination
1938 // before) are connected to this new obj (phi) but they still will not be
1939 // marked for elimination since new obj has no escape information.
1940 // Mark all associated (same box and obj) lock and unlock nodes for
1941 // elimination if some of them marked already.
1942 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1943 if (oldbox->as_BoxLock()->is_eliminated()) {
1944 return; // This BoxLock node was processed already.
1945 }
1946 // New implementation (EliminateNestedLocks) has separate BoxLock
1947 // node for each locked region so mark all associated locks/unlocks as
1948 // eliminated even if different objects are referenced in one locked region
1949 // (for example, OSR compilation of nested loop inside locked scope).
1950 if (EliminateNestedLocks ||
1951 oldbox->as_BoxLock()->is_simple_lock_region(nullptr, obj, nullptr)) {
1952 // Box is used only in one lock region. Mark this box as eliminated.
1953 _igvn.hash_delete(oldbox);
1954 oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1955 _igvn.hash_insert(oldbox);
1956
1957 for (uint i = 0; i < oldbox->outcnt(); i++) {
1958 Node* u = oldbox->raw_out(i);
1959 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1960 AbstractLockNode* alock = u->as_AbstractLock();
1961 // Check lock's box since box could be referenced by Lock's debug info.
1962 if (alock->box_node() == oldbox) {
1963 // Mark eliminated all related locks and unlocks.
1964 #ifdef ASSERT
1965 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4");
1966 #endif
1967 alock->set_non_esc_obj();
1968 }
1969 }
1970 }
1971 return;
1972 }
1973
1974 // Create new "eliminated" BoxLock node and use it in monitor debug info
1975 // instead of oldbox for the same object.
1976 BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1977
1978 // Note: BoxLock node is marked eliminated only here and it is used
1979 // to indicate that all associated lock and unlock nodes are marked
1980 // for elimination.
1981 newbox->set_eliminated();
1982 transform_later(newbox);
1983
1984 // Replace old box node with new box for all users of the same object.
1985 for (uint i = 0; i < oldbox->outcnt();) {
1986 bool next_edge = true;
1987
1988 Node* u = oldbox->raw_out(i);
1989 if (u->is_AbstractLock()) {
1990 AbstractLockNode* alock = u->as_AbstractLock();
1991 if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
1992 // Replace Box and mark eliminated all related locks and unlocks.
1993 #ifdef ASSERT
1994 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5");
1995 #endif
1996 alock->set_non_esc_obj();
1997 _igvn.rehash_node_delayed(alock);
1998 alock->set_box_node(newbox);
1999 next_edge = false;
2000 }
2001 }
2002 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
2003 FastLockNode* flock = u->as_FastLock();
2004 assert(flock->box_node() == oldbox, "sanity");
2005 _igvn.rehash_node_delayed(flock);
2006 flock->set_box_node(newbox);
2007 next_edge = false;
2008 }
2009
2010 // Replace old box in monitor debug info.
2011 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
2012 SafePointNode* sfn = u->as_SafePoint();
2013 JVMState* youngest_jvms = sfn->jvms();
2014 int max_depth = youngest_jvms->depth();
2015 for (int depth = 1; depth <= max_depth; depth++) {
2016 JVMState* jvms = youngest_jvms->of_depth(depth);
2017 int num_mon = jvms->nof_monitors();
2018 // Loop over monitors
2019 for (int idx = 0; idx < num_mon; idx++) {
2020 Node* obj_node = sfn->monitor_obj(jvms, idx);
2021 Node* box_node = sfn->monitor_box(jvms, idx);
2022 if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
2023 int j = jvms->monitor_box_offset(idx);
2024 _igvn.replace_input_of(u, j, newbox);
2025 next_edge = false;
2026 }
2027 }
2028 }
2029 }
2030 if (next_edge) i++;
2031 }
2032 }
2033
2034 //-----------------------mark_eliminated_locking_nodes-----------------------
2035 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
2036 if (EliminateNestedLocks) {
2037 if (alock->is_nested()) {
2038 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
2039 return;
2040 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
2041 // Only Lock node has JVMState needed here.
2042 // Not that preceding claim is documented anywhere else.
2043 if (alock->jvms() != nullptr) {
2044 if (alock->as_Lock()->is_nested_lock_region()) {
2045 // Mark eliminated related nested locks and unlocks.
2046 Node* obj = alock->obj_node();
2047 BoxLockNode* box_node = alock->box_node()->as_BoxLock();
2048 assert(!box_node->is_eliminated(), "should not be marked yet");
2049 // Note: BoxLock node is marked eliminated only here
2050 // and it is used to indicate that all associated lock
2051 // and unlock nodes are marked for elimination.
2052 box_node->set_eliminated(); // Box's hash is always NO_HASH here
2053 for (uint i = 0; i < box_node->outcnt(); i++) {
2054 Node* u = box_node->raw_out(i);
2055 if (u->is_AbstractLock()) {
2056 alock = u->as_AbstractLock();
2057 if (alock->box_node() == box_node) {
2058 // Verify that this Box is referenced only by related locks.
2059 assert(alock->obj_node()->eqv_uncast(obj), "");
2060 // Mark all related locks and unlocks.
2061 #ifdef ASSERT
2062 alock->log_lock_optimization(C, "eliminate_lock_set_nested");
2063 #endif
2064 alock->set_nested();
2065 }
2066 }
2067 }
2068 } else {
2069 #ifdef ASSERT
2070 alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region");
2071 if (C->log() != nullptr)
2072 alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output
2073 #endif
2074 }
2075 }
2076 return;
2077 }
2078 // Process locks for non escaping object
2079 assert(alock->is_non_esc_obj(), "");
2080 } // EliminateNestedLocks
2081
2082 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2083 // Look for all locks of this object and mark them and
2084 // corresponding BoxLock nodes as eliminated.
2085 Node* obj = alock->obj_node();
2086 for (uint j = 0; j < obj->outcnt(); j++) {
2087 Node* o = obj->raw_out(j);
2088 if (o->is_AbstractLock() &&
2089 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2090 alock = o->as_AbstractLock();
2091 Node* box = alock->box_node();
2092 // Replace old box node with new eliminated box for all users
2093 // of the same object and mark related locks as eliminated.
2094 mark_eliminated_box(box, obj);
2095 }
2096 }
2097 }
2098 }
2099
2100 // we have determined that this lock/unlock can be eliminated, we simply
2101 // eliminate the node without expanding it.
2102 //
2103 // Note: The membar's associated with the lock/unlock are currently not
2104 // eliminated. This should be investigated as a future enhancement.
2105 //
2106 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2107
2108 if (!alock->is_eliminated()) {
2109 return false;
2110 }
2111 #ifdef ASSERT
2112 if (!alock->is_coarsened()) {
2113 // Check that new "eliminated" BoxLock node is created.
2114 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2115 assert(oldbox->is_eliminated(), "should be done already");
2116 }
2117 #endif
2118
2119 alock->log_lock_optimization(C, "eliminate_lock");
2120
2121 #ifndef PRODUCT
2122 if (PrintEliminateLocks) {
2123 tty->print_cr("++++ Eliminated: %d %s '%s'", alock->_idx, (alock->is_Lock() ? "Lock" : "Unlock"), alock->kind_as_string());
2124 }
2125 #endif
2126
2127 Node* mem = alock->in(TypeFunc::Memory);
2128 Node* ctrl = alock->in(TypeFunc::Control);
2129 guarantee(ctrl != nullptr, "missing control projection, cannot replace_node() with null");
2130
2131 alock->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
2132 // There are 2 projections from the lock. The lock node will
2133 // be deleted when its last use is subsumed below.
2134 assert(alock->outcnt() == 2 &&
2135 _callprojs.fallthrough_proj != nullptr &&
2136 _callprojs.fallthrough_memproj != nullptr,
2137 "Unexpected projections from Lock/Unlock");
2138
2139 Node* fallthroughproj = _callprojs.fallthrough_proj;
2140 Node* memproj_fallthrough = _callprojs.fallthrough_memproj;
2141
2142 // The memory projection from a lock/unlock is RawMem
2143 // The input to a Lock is merged memory, so extract its RawMem input
2144 // (unless the MergeMem has been optimized away.)
2145 if (alock->is_Lock()) {
2146 // Search for MemBarAcquireLock node and delete it also.
2147 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2148 assert(membar != nullptr && membar->Opcode() == Op_MemBarAcquireLock, "");
2149 Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2150 Node* memproj = membar->proj_out(TypeFunc::Memory);
2151 _igvn.replace_node(ctrlproj, fallthroughproj);
2152 _igvn.replace_node(memproj, memproj_fallthrough);
2153
2154 // Delete FastLock node also if this Lock node is unique user
2155 // (a loop peeling may clone a Lock node).
2156 Node* flock = alock->as_Lock()->fastlock_node();
2157 if (flock->outcnt() == 1) {
2158 assert(flock->unique_out() == alock, "sanity");
2159 _igvn.replace_node(flock, top());
2160 }
2161 }
2162
2163 // Search for MemBarReleaseLock node and delete it also.
2164 if (alock->is_Unlock() && ctrl->is_Proj() && ctrl->in(0)->is_MemBar()) {
2165 MemBarNode* membar = ctrl->in(0)->as_MemBar();
2166 assert(membar->Opcode() == Op_MemBarReleaseLock &&
2167 mem->is_Proj() && membar == mem->in(0), "");
2168 _igvn.replace_node(fallthroughproj, ctrl);
2169 _igvn.replace_node(memproj_fallthrough, mem);
2170 fallthroughproj = ctrl;
2171 memproj_fallthrough = mem;
2172 ctrl = membar->in(TypeFunc::Control);
2173 mem = membar->in(TypeFunc::Memory);
2174 }
2175
2176 _igvn.replace_node(fallthroughproj, ctrl);
2177 _igvn.replace_node(memproj_fallthrough, mem);
2178 return true;
2179 }
2180
2181
2182 //------------------------------expand_lock_node----------------------
2183 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2184
2185 Node* ctrl = lock->in(TypeFunc::Control);
2186 Node* mem = lock->in(TypeFunc::Memory);
2187 Node* obj = lock->obj_node();
2188 Node* box = lock->box_node();
2189 Node* flock = lock->fastlock_node();
2190
2191 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2192
2193 // Make the merge point
2194 Node *region;
2195 Node *mem_phi;
2196 Node *slow_path;
2197
2198 region = new RegionNode(3);
2199 // create a Phi for the memory state
2200 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2201
2202 // Optimize test; set region slot 2
2203 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2204 mem_phi->init_req(2, mem);
2205
2206 // Make slow path call
2207 CallNode *call = make_slow_call((CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(),
2208 OptoRuntime::complete_monitor_locking_Java(), nullptr, slow_path,
2209 obj, box, nullptr);
2210
2211 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
2212
2213 // Slow path can only throw asynchronous exceptions, which are always
2214 // de-opted. So the compiler thinks the slow-call can never throw an
2215 // exception. If it DOES throw an exception we would need the debug
2216 // info removed first (since if it throws there is no monitor).
2217 assert(_callprojs.fallthrough_ioproj == nullptr && _callprojs.catchall_ioproj == nullptr &&
2218 _callprojs.catchall_memproj == nullptr && _callprojs.catchall_catchproj == nullptr, "Unexpected projection from Lock");
2219
2220 // Capture slow path
2221 // disconnect fall-through projection from call and create a new one
2222 // hook up users of fall-through projection to region
2223 Node *slow_ctrl = _callprojs.fallthrough_proj->clone();
2224 transform_later(slow_ctrl);
2225 _igvn.hash_delete(_callprojs.fallthrough_proj);
2226 _callprojs.fallthrough_proj->disconnect_inputs(C);
2227 region->init_req(1, slow_ctrl);
2228 // region inputs are now complete
2229 transform_later(region);
2230 _igvn.replace_node(_callprojs.fallthrough_proj, region);
2231
2232 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2233
2234 mem_phi->init_req(1, memproj);
2235
2236 transform_later(mem_phi);
2237
2238 _igvn.replace_node(_callprojs.fallthrough_memproj, mem_phi);
2239 }
2240
2241 //------------------------------expand_unlock_node----------------------
2242 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2243
2244 Node* ctrl = unlock->in(TypeFunc::Control);
2245 Node* mem = unlock->in(TypeFunc::Memory);
2246 Node* obj = unlock->obj_node();
2247 Node* box = unlock->box_node();
2248
2249 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2250
2251 // No need for a null check on unlock
2252
2253 // Make the merge point
2254 Node *region;
2255 Node *mem_phi;
2256
2257 region = new RegionNode(3);
2258 // create a Phi for the memory state
2259 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2260
2261 FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2262 funlock = transform_later( funlock )->as_FastUnlock();
2263 // Optimize test; set region slot 2
2264 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2265 Node *thread = transform_later(new ThreadLocalNode());
2266
2267 CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(),
2268 CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C),
2269 "complete_monitor_unlocking_C", slow_path, obj, box, thread);
2270
2271 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/);
2272 assert(_callprojs.fallthrough_ioproj == nullptr && _callprojs.catchall_ioproj == nullptr &&
2273 _callprojs.catchall_memproj == nullptr && _callprojs.catchall_catchproj == nullptr, "Unexpected projection from Lock");
2274
2275 // No exceptions for unlocking
2276 // Capture slow path
2277 // disconnect fall-through projection from call and create a new one
2278 // hook up users of fall-through projection to region
2279 Node *slow_ctrl = _callprojs.fallthrough_proj->clone();
2280 transform_later(slow_ctrl);
2281 _igvn.hash_delete(_callprojs.fallthrough_proj);
2282 _callprojs.fallthrough_proj->disconnect_inputs(C);
2283 region->init_req(1, slow_ctrl);
2284 // region inputs are now complete
2285 transform_later(region);
2286 _igvn.replace_node(_callprojs.fallthrough_proj, region);
2287
2288 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2289 mem_phi->init_req(1, memproj );
2290 mem_phi->init_req(2, mem);
2291 transform_later(mem_phi);
2292
2293 _igvn.replace_node(_callprojs.fallthrough_memproj, mem_phi);
2294 }
2295
2296 void PhaseMacroExpand::expand_subtypecheck_node(SubTypeCheckNode *check) {
2297 assert(check->in(SubTypeCheckNode::Control) == nullptr, "should be pinned");
2298 Node* bol = check->unique_out();
2299 Node* obj_or_subklass = check->in(SubTypeCheckNode::ObjOrSubKlass);
2300 Node* superklass = check->in(SubTypeCheckNode::SuperKlass);
2301 assert(bol->is_Bool() && bol->as_Bool()->_test._test == BoolTest::ne, "unexpected bool node");
2302
2303 for (DUIterator_Last imin, i = bol->last_outs(imin); i >= imin; --i) {
2304 Node* iff = bol->last_out(i);
2305 assert(iff->is_If(), "where's the if?");
2306
2307 if (iff->in(0)->is_top()) {
2308 _igvn.replace_input_of(iff, 1, C->top());
2309 continue;
2310 }
2311
2312 Node* iftrue = iff->as_If()->proj_out(1);
2313 Node* iffalse = iff->as_If()->proj_out(0);
2314 Node* ctrl = iff->in(0);
2315
2316 Node* subklass = nullptr;
2317 if (_igvn.type(obj_or_subklass)->isa_klassptr()) {
2318 subklass = obj_or_subklass;
2319 } else {
2320 Node* k_adr = basic_plus_adr(obj_or_subklass, oopDesc::klass_offset_in_bytes());
2321 subklass = _igvn.transform(LoadKlassNode::make(_igvn, nullptr, C->immutable_memory(), k_adr, TypeInstPtr::KLASS));
2322 }
2323
2324 Node* not_subtype_ctrl = Phase::gen_subtype_check(subklass, superklass, &ctrl, nullptr, _igvn, check->method(), check->bci());
2325
2326 _igvn.replace_input_of(iff, 0, C->top());
2327 _igvn.replace_node(iftrue, not_subtype_ctrl);
2328 _igvn.replace_node(iffalse, ctrl);
2329 }
2330 _igvn.replace_node(check, C->top());
2331 }
2332
2333 //---------------------------eliminate_macro_nodes----------------------
2334 // Eliminate scalar replaced allocations and associated locks.
2335 void PhaseMacroExpand::eliminate_macro_nodes() {
2336 if (C->macro_count() == 0)
2337 return;
2338 NOT_PRODUCT(int membar_before = count_MemBar(C);)
2339
2340 // Before elimination may re-mark (change to Nested or NonEscObj)
2341 // all associated (same box and obj) lock and unlock nodes.
2342 int cnt = C->macro_count();
2343 for (int i=0; i < cnt; i++) {
2344 Node *n = C->macro_node(i);
2345 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2346 mark_eliminated_locking_nodes(n->as_AbstractLock());
2347 }
2348 }
2349 // Re-marking may break consistency of Coarsened locks.
2350 if (!C->coarsened_locks_consistent()) {
2351 return; // recompile without Coarsened locks if broken
2352 }
2353
2354 // First, attempt to eliminate locks
2355 bool progress = true;
2356 while (progress) {
2357 progress = false;
2358 for (int i = C->macro_count(); i > 0; i = MIN2(i - 1, C->macro_count())) { // more than 1 element can be eliminated at once
2359 Node* n = C->macro_node(i - 1);
2360 bool success = false;
2361 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2362 if (n->is_AbstractLock()) {
2363 success = eliminate_locking_node(n->as_AbstractLock());
2364 #ifndef PRODUCT
2365 if (success && PrintOptoStatistics) {
2366 Atomic::inc(&PhaseMacroExpand::_monitor_objects_removed_counter);
2367 }
2368 #endif
2369 }
2370 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2371 progress = progress || success;
2372 }
2373 }
2374 // Next, attempt to eliminate allocations
2375 _has_locks = false;
2376 progress = true;
2377 while (progress) {
2378 progress = false;
2379 for (int i = C->macro_count(); i > 0; i = MIN2(i - 1, C->macro_count())) { // more than 1 element can be eliminated at once
2380 Node* n = C->macro_node(i - 1);
2381 bool success = false;
2382 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2383 switch (n->class_id()) {
2384 case Node::Class_Allocate:
2385 case Node::Class_AllocateArray:
2386 success = eliminate_allocate_node(n->as_Allocate());
2387 #ifndef PRODUCT
2388 if (success && PrintOptoStatistics) {
2389 Atomic::inc(&PhaseMacroExpand::_objs_scalar_replaced_counter);
2390 }
2391 #endif
2392 break;
2393 case Node::Class_CallStaticJava:
2394 success = eliminate_boxing_node(n->as_CallStaticJava());
2395 break;
2396 case Node::Class_Lock:
2397 case Node::Class_Unlock:
2398 assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2399 _has_locks = true;
2400 break;
2401 case Node::Class_ArrayCopy:
2402 break;
2403 case Node::Class_OuterStripMinedLoop:
2404 break;
2405 case Node::Class_SubTypeCheck:
2406 break;
2407 case Node::Class_Opaque1:
2408 break;
2409 default:
2410 assert(n->Opcode() == Op_LoopLimit ||
2411 n->Opcode() == Op_Opaque3 ||
2412 n->Opcode() == Op_Opaque4 ||
2413 n->Opcode() == Op_MaxL ||
2414 n->Opcode() == Op_MinL ||
2415 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(n),
2416 "unknown node type in macro list");
2417 }
2418 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2419 progress = progress || success;
2420 }
2421 }
2422 #ifndef PRODUCT
2423 if (PrintOptoStatistics) {
2424 int membar_after = count_MemBar(C);
2425 Atomic::add(&PhaseMacroExpand::_memory_barriers_removed_counter, membar_before - membar_after);
2426 }
2427 #endif
2428 }
2429
2430 //------------------------------expand_macro_nodes----------------------
2431 // Returns true if a failure occurred.
2432 bool PhaseMacroExpand::expand_macro_nodes() {
2433 // Last attempt to eliminate macro nodes.
2434 eliminate_macro_nodes();
2435 if (C->failing()) return true;
2436
2437 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2438 bool progress = true;
2439 while (progress) {
2440 progress = false;
2441 for (int i = C->macro_count(); i > 0; i--) {
2442 Node* n = C->macro_node(i-1);
2443 bool success = false;
2444 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2445 if (n->Opcode() == Op_LoopLimit) {
2446 // Remove it from macro list and put on IGVN worklist to optimize.
2447 C->remove_macro_node(n);
2448 _igvn._worklist.push(n);
2449 success = true;
2450 } else if (n->Opcode() == Op_CallStaticJava) {
2451 // Remove it from macro list and put on IGVN worklist to optimize.
2452 C->remove_macro_node(n);
2453 _igvn._worklist.push(n);
2454 success = true;
2455 } else if (n->is_Opaque1()) {
2456 _igvn.replace_node(n, n->in(1));
2457 success = true;
2458 #if INCLUDE_RTM_OPT
2459 } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2460 assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2461 assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2462 Node* cmp = n->unique_out();
2463 #ifdef ASSERT
2464 // Validate graph.
2465 assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2466 BoolNode* bol = cmp->unique_out()->as_Bool();
2467 assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2468 (bol->_test._test == BoolTest::ne), "");
2469 IfNode* ifn = bol->unique_out()->as_If();
2470 assert((ifn->outcnt() == 2) &&
2471 ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change) != nullptr, "");
2472 #endif
2473 Node* repl = n->in(1);
2474 if (!_has_locks) {
2475 // Remove RTM state check if there are no locks in the code.
2476 // Replace input to compare the same value.
2477 repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2478 }
2479 _igvn.replace_node(n, repl);
2480 success = true;
2481 #endif
2482 } else if (n->Opcode() == Op_Opaque4) {
2483 // With Opaque4 nodes, the expectation is that the test of input 1
2484 // is always equal to the constant value of input 2. So we can
2485 // remove the Opaque4 and replace it by input 2. In debug builds,
2486 // leave the non constant test in instead to sanity check that it
2487 // never fails (if it does, that subgraph was constructed so, at
2488 // runtime, a Halt node is executed).
2489 #ifdef ASSERT
2490 _igvn.replace_node(n, n->in(1));
2491 #else
2492 _igvn.replace_node(n, n->in(2));
2493 #endif
2494 success = true;
2495 } else if (n->Opcode() == Op_OuterStripMinedLoop) {
2496 n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn);
2497 C->remove_macro_node(n);
2498 success = true;
2499 } else if (n->Opcode() == Op_MaxL) {
2500 // Since MaxL and MinL are not implemented in the backend, we expand them to
2501 // a CMoveL construct now. At least until here, the type could be computed
2502 // precisely. CMoveL is not so smart, but we can give it at least the best
2503 // type we know abouot n now.
2504 Node* repl = MaxNode::signed_max(n->in(1), n->in(2), _igvn.type(n), _igvn);
2505 _igvn.replace_node(n, repl);
2506 success = true;
2507 } else if (n->Opcode() == Op_MinL) {
2508 Node* repl = MaxNode::signed_min(n->in(1), n->in(2), _igvn.type(n), _igvn);
2509 _igvn.replace_node(n, repl);
2510 success = true;
2511 }
2512 assert(!success || (C->macro_count() == (old_macro_count - 1)), "elimination must have deleted one node from macro list");
2513 progress = progress || success;
2514 }
2515 }
2516
2517 // Clean up the graph so we're less likely to hit the maximum node
2518 // limit
2519 _igvn.set_delay_transform(false);
2520 _igvn.optimize();
2521 if (C->failing()) return true;
2522 _igvn.set_delay_transform(true);
2523
2524
2525 // Because we run IGVN after each expansion, some macro nodes may go
2526 // dead and be removed from the list as we iterate over it. Move
2527 // Allocate nodes (processed in a second pass) at the beginning of
2528 // the list and then iterate from the last element of the list until
2529 // an Allocate node is seen. This is robust to random deletion in
2530 // the list due to nodes going dead.
2531 C->sort_macro_nodes();
2532
2533 // expand arraycopy "macro" nodes first
2534 // For ReduceBulkZeroing, we must first process all arraycopy nodes
2535 // before the allocate nodes are expanded.
2536 while (C->macro_count() > 0) {
2537 int macro_count = C->macro_count();
2538 Node * n = C->macro_node(macro_count-1);
2539 assert(n->is_macro(), "only macro nodes expected here");
2540 if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) {
2541 // node is unreachable, so don't try to expand it
2542 C->remove_macro_node(n);
2543 continue;
2544 }
2545 if (n->is_Allocate()) {
2546 break;
2547 }
2548 // Make sure expansion will not cause node limit to be exceeded.
2549 // Worst case is a macro node gets expanded into about 200 nodes.
2550 // Allow 50% more for optimization.
2551 if (C->check_node_count(300, "out of nodes before macro expansion")) {
2552 return true;
2553 }
2554
2555 DEBUG_ONLY(int old_macro_count = C->macro_count();)
2556 switch (n->class_id()) {
2557 case Node::Class_Lock:
2558 expand_lock_node(n->as_Lock());
2559 break;
2560 case Node::Class_Unlock:
2561 expand_unlock_node(n->as_Unlock());
2562 break;
2563 case Node::Class_ArrayCopy:
2564 expand_arraycopy_node(n->as_ArrayCopy());
2565 break;
2566 case Node::Class_SubTypeCheck:
2567 expand_subtypecheck_node(n->as_SubTypeCheck());
2568 break;
2569 default:
2570 assert(false, "unknown node type in macro list");
2571 }
2572 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
2573 if (C->failing()) return true;
2574
2575 // Clean up the graph so we're less likely to hit the maximum node
2576 // limit
2577 _igvn.set_delay_transform(false);
2578 _igvn.optimize();
2579 if (C->failing()) return true;
2580 _igvn.set_delay_transform(true);
2581 }
2582
2583 // All nodes except Allocate nodes are expanded now. There could be
2584 // new optimization opportunities (such as folding newly created
2585 // load from a just allocated object). Run IGVN.
2586
2587 // expand "macro" nodes
2588 // nodes are removed from the macro list as they are processed
2589 while (C->macro_count() > 0) {
2590 int macro_count = C->macro_count();
2591 Node * n = C->macro_node(macro_count-1);
2592 assert(n->is_macro(), "only macro nodes expected here");
2593 if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) {
2594 // node is unreachable, so don't try to expand it
2595 C->remove_macro_node(n);
2596 continue;
2597 }
2598 // Make sure expansion will not cause node limit to be exceeded.
2599 // Worst case is a macro node gets expanded into about 200 nodes.
2600 // Allow 50% more for optimization.
2601 if (C->check_node_count(300, "out of nodes before macro expansion")) {
2602 return true;
2603 }
2604 switch (n->class_id()) {
2605 case Node::Class_Allocate:
2606 expand_allocate(n->as_Allocate());
2607 break;
2608 case Node::Class_AllocateArray:
2609 expand_allocate_array(n->as_AllocateArray());
2610 break;
2611 default:
2612 assert(false, "unknown node type in macro list");
2613 }
2614 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2615 if (C->failing()) return true;
2616
2617 // Clean up the graph so we're less likely to hit the maximum node
2618 // limit
2619 _igvn.set_delay_transform(false);
2620 _igvn.optimize();
2621 if (C->failing()) return true;
2622 _igvn.set_delay_transform(true);
2623 }
2624
2625 _igvn.set_delay_transform(false);
2626 return false;
2627 }
2628
2629 #ifndef PRODUCT
2630 int PhaseMacroExpand::_objs_scalar_replaced_counter = 0;
2631 int PhaseMacroExpand::_monitor_objects_removed_counter = 0;
2632 int PhaseMacroExpand::_GC_barriers_removed_counter = 0;
2633 int PhaseMacroExpand::_memory_barriers_removed_counter = 0;
2634
2635 void PhaseMacroExpand::print_statistics() {
2636 tty->print("Objects scalar replaced = %d, ", Atomic::load(&_objs_scalar_replaced_counter));
2637 tty->print("Monitor objects removed = %d, ", Atomic::load(&_monitor_objects_removed_counter));
2638 tty->print("GC barriers removed = %d, ", Atomic::load(&_GC_barriers_removed_counter));
2639 tty->print_cr("Memory barriers removed = %d", Atomic::load(&_memory_barriers_removed_counter));
2640 }
2641
2642 int PhaseMacroExpand::count_MemBar(Compile *C) {
2643 if (!PrintOptoStatistics) {
2644 return 0;
2645 }
2646 Unique_Node_List ideal_nodes;
2647 int total = 0;
2648 ideal_nodes.map(C->live_nodes(), nullptr);
2649 ideal_nodes.push(C->root());
2650 for (uint next = 0; next < ideal_nodes.size(); ++next) {
2651 Node* n = ideal_nodes.at(next);
2652 if (n->is_MemBar()) {
2653 total++;
2654 }
2655 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2656 Node* m = n->fast_out(i);
2657 ideal_nodes.push(m);
2658 }
2659 }
2660 return total;
2661 }
2662 #endif