1 /*
2 * Copyright (c) 2005, 2019, 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 "libadt/vectset.hpp"
29 #include "memory/universe.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/arraycopynode.hpp"
32 #include "opto/callnode.hpp"
33 #include "opto/castnode.hpp"
34 #include "opto/cfgnode.hpp"
35 #include "opto/compile.hpp"
36 #include "opto/convertnode.hpp"
37 #include "opto/graphKit.hpp"
38 #include "opto/intrinsicnode.hpp"
39 #include "opto/locknode.hpp"
40 #include "opto/loopnode.hpp"
41 #include "opto/macro.hpp"
42 #include "opto/memnode.hpp"
43 #include "opto/narrowptrnode.hpp"
44 #include "opto/node.hpp"
45 #include "opto/opaquenode.hpp"
46 #include "opto/phaseX.hpp"
47 #include "opto/rootnode.hpp"
48 #include "opto/runtime.hpp"
49 #include "opto/subnode.hpp"
50 #include "opto/subtypenode.hpp"
51 #include "opto/type.hpp"
52 #include "runtime/sharedRuntime.hpp"
53 #include "utilities/macros.hpp"
54 #include "utilities/powerOfTwo.hpp"
55 #if INCLUDE_G1GC
56 #include "gc/g1/g1ThreadLocalData.hpp"
57 #endif // INCLUDE_G1GC
58 #if INCLUDE_SHENANDOAHGC
59 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
60 #endif
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 == NULL) {
79 break;
80 }
81 }
82 return nreplacements;
83 }
84
85 void PhaseMacroExpand::migrate_outs(Node *old, Node *target) {
86 assert(old != NULL, "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 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
98 // Copy debug information and adjust JVMState information
99 uint old_dbg_start = oldcall->tf()->domain()->cnt();
100 uint new_dbg_start = newcall->tf()->domain()->cnt();
101 int jvms_adj = new_dbg_start - old_dbg_start;
102 assert (new_dbg_start == newcall->req(), "argument count mismatch");
103
104 // SafePointScalarObject node could be referenced several times in debug info.
105 // Use Dict to record cloned nodes.
106 Dict* sosn_map = new Dict(cmpkey,hashkey);
107 for (uint i = old_dbg_start; i < oldcall->req(); i++) {
108 Node* old_in = oldcall->in(i);
109 // Clone old SafePointScalarObjectNodes, adjusting their field contents.
110 if (old_in != NULL && old_in->is_SafePointScalarObject()) {
111 SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
112 uint old_unique = C->unique();
113 Node* new_in = old_sosn->clone(sosn_map);
114 if (old_unique != C->unique()) { // New node?
115 new_in->set_req(0, C->root()); // reset control edge
116 new_in = transform_later(new_in); // Register new node.
117 }
118 old_in = new_in;
119 }
120 newcall->add_req(old_in);
121 }
122
123 // JVMS may be shared so clone it before we modify it
124 newcall->set_jvms(oldcall->jvms() != NULL ? oldcall->jvms()->clone_deep(C) : NULL);
125 for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
126 jvms->set_map(newcall);
127 jvms->set_locoff(jvms->locoff()+jvms_adj);
128 jvms->set_stkoff(jvms->stkoff()+jvms_adj);
129 jvms->set_monoff(jvms->monoff()+jvms_adj);
130 jvms->set_scloff(jvms->scloff()+jvms_adj);
131 jvms->set_endoff(jvms->endoff()+jvms_adj);
132 }
133 }
134
135 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
136 Node* cmp;
137 if (mask != 0) {
138 Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
139 cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
140 } else {
141 cmp = word;
142 }
143 Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
144 IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
145 transform_later(iff);
146
147 // Fast path taken.
148 Node *fast_taken = transform_later(new IfFalseNode(iff));
149
150 // Fast path not-taken, i.e. slow path
151 Node *slow_taken = transform_later(new IfTrueNode(iff));
152
153 if (return_fast_path) {
154 region->init_req(edge, slow_taken); // Capture slow-control
155 return fast_taken;
156 } else {
157 region->init_req(edge, fast_taken); // Capture fast-control
158 return slow_taken;
159 }
160 }
161
162 //--------------------copy_predefined_input_for_runtime_call--------------------
163 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
164 // Set fixed predefined input arguments
165 call->init_req( TypeFunc::Control, ctrl );
166 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) );
167 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
168 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
169 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
170 }
171
172 //------------------------------make_slow_call---------------------------------
173 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type,
174 address slow_call, const char* leaf_name, Node* slow_path,
175 Node* parm0, Node* parm1, Node* parm2) {
176
177 // Slow-path call
178 CallNode *call = leaf_name
179 ? (CallNode*)new CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
180 : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
181
182 // Slow path call has no side-effects, uses few values
183 copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
184 if (parm0 != NULL) call->init_req(TypeFunc::Parms+0, parm0);
185 if (parm1 != NULL) call->init_req(TypeFunc::Parms+1, parm1);
186 if (parm2 != NULL) call->init_req(TypeFunc::Parms+2, parm2);
187 copy_call_debug_info(oldcall, call);
188 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
189 _igvn.replace_node(oldcall, call);
190 transform_later(call);
191
192 return call;
193 }
194
195 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
196 _fallthroughproj = NULL;
197 _fallthroughcatchproj = NULL;
198 _ioproj_fallthrough = NULL;
199 _ioproj_catchall = NULL;
200 _catchallcatchproj = NULL;
201 _memproj_fallthrough = NULL;
202 _memproj_catchall = NULL;
203 _resproj = NULL;
204 for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
205 ProjNode *pn = call->fast_out(i)->as_Proj();
206 switch (pn->_con) {
207 case TypeFunc::Control:
208 {
209 // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
210 _fallthroughproj = pn;
211 DUIterator_Fast jmax, j = pn->fast_outs(jmax);
212 const Node *cn = pn->fast_out(j);
213 if (cn->is_Catch()) {
214 ProjNode *cpn = NULL;
215 for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
216 cpn = cn->fast_out(k)->as_Proj();
217 assert(cpn->is_CatchProj(), "must be a CatchProjNode");
218 if (cpn->_con == CatchProjNode::fall_through_index)
219 _fallthroughcatchproj = cpn;
220 else {
221 assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
222 _catchallcatchproj = cpn;
223 }
224 }
225 }
226 break;
227 }
228 case TypeFunc::I_O:
229 if (pn->_is_io_use)
230 _ioproj_catchall = pn;
231 else
232 _ioproj_fallthrough = pn;
233 break;
234 case TypeFunc::Memory:
235 if (pn->_is_io_use)
236 _memproj_catchall = pn;
237 else
238 _memproj_fallthrough = pn;
239 break;
240 case TypeFunc::Parms:
241 _resproj = pn;
242 break;
243 default:
244 assert(false, "unexpected projection from allocation node.");
245 }
246 }
247
248 }
249
250 void PhaseMacroExpand::eliminate_gc_barrier(Node* p2x) {
251 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
252 bs->eliminate_gc_barrier(this, p2x);
253 }
254
255 // Search for a memory operation for the specified memory slice.
256 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
257 Node *orig_mem = mem;
258 Node *alloc_mem = alloc->in(TypeFunc::Memory);
259 const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
260 while (true) {
261 if (mem == alloc_mem || mem == start_mem ) {
262 return mem; // hit one of our sentinels
263 } else if (mem->is_MergeMem()) {
264 mem = mem->as_MergeMem()->memory_at(alias_idx);
265 } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
266 Node *in = mem->in(0);
267 // we can safely skip over safepoints, calls, locks and membars because we
268 // already know that the object is safe to eliminate.
269 if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
270 return in;
271 } else if (in->is_Call()) {
272 CallNode *call = in->as_Call();
273 if (call->may_modify(tinst, phase)) {
274 assert(call->is_ArrayCopy(), "ArrayCopy is the only call node that doesn't make allocation escape");
275 if (call->as_ArrayCopy()->modifies(offset, offset, phase, false)) {
276 return in;
277 }
278 }
279 mem = in->in(TypeFunc::Memory);
280 } else if (in->is_MemBar()) {
281 ArrayCopyNode* ac = NULL;
282 if (ArrayCopyNode::may_modify(tinst, in->as_MemBar(), phase, ac)) {
283 assert(ac != NULL && ac->is_clonebasic(), "Only basic clone is a non escaping clone");
284 return ac;
285 }
286 mem = in->in(TypeFunc::Memory);
287 } else {
288 assert(false, "unexpected projection");
289 }
290 } else if (mem->is_Store()) {
291 const TypePtr* atype = mem->as_Store()->adr_type();
292 int adr_idx = phase->C->get_alias_index(atype);
293 if (adr_idx == alias_idx) {
294 assert(atype->isa_oopptr(), "address type must be oopptr");
295 int adr_offset = atype->offset();
296 uint adr_iid = atype->is_oopptr()->instance_id();
297 // Array elements references have the same alias_idx
298 // but different offset and different instance_id.
299 if (adr_offset == offset && adr_iid == alloc->_idx)
300 return mem;
301 } else {
302 assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
303 }
304 mem = mem->in(MemNode::Memory);
305 } else if (mem->is_ClearArray()) {
306 if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
307 // Can not bypass initialization of the instance
308 // we are looking.
309 debug_only(intptr_t offset;)
310 assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
311 InitializeNode* init = alloc->as_Allocate()->initialization();
312 // We are looking for stored value, return Initialize node
313 // or memory edge from Allocate node.
314 if (init != NULL)
315 return init;
316 else
317 return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
318 }
319 // Otherwise skip it (the call updated 'mem' value).
320 } else if (mem->Opcode() == Op_SCMemProj) {
321 mem = mem->in(0);
322 Node* adr = NULL;
323 if (mem->is_LoadStore()) {
324 adr = mem->in(MemNode::Address);
325 } else {
326 assert(mem->Opcode() == Op_EncodeISOArray ||
327 mem->Opcode() == Op_StrCompressedCopy, "sanity");
328 adr = mem->in(3); // Destination array
329 }
330 const TypePtr* atype = adr->bottom_type()->is_ptr();
331 int adr_idx = phase->C->get_alias_index(atype);
332 if (adr_idx == alias_idx) {
333 DEBUG_ONLY(mem->dump();)
334 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
335 return NULL;
336 }
337 mem = mem->in(MemNode::Memory);
338 } else if (mem->Opcode() == Op_StrInflatedCopy) {
339 Node* adr = mem->in(3); // Destination array
340 const TypePtr* atype = adr->bottom_type()->is_ptr();
341 int adr_idx = phase->C->get_alias_index(atype);
342 if (adr_idx == alias_idx) {
343 DEBUG_ONLY(mem->dump();)
344 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
345 return NULL;
346 }
347 mem = mem->in(MemNode::Memory);
348 } else {
349 return mem;
350 }
351 assert(mem != orig_mem, "dead memory loop");
352 }
353 }
354
355 // Generate loads from source of the arraycopy for fields of
356 // destination needed at a deoptimization point
357 Node* PhaseMacroExpand::make_arraycopy_load(ArrayCopyNode* ac, intptr_t offset, Node* ctl, Node* mem, BasicType ft, const Type *ftype, AllocateNode *alloc) {
358 BasicType bt = ft;
359 const Type *type = ftype;
360 if (ft == T_NARROWOOP) {
361 bt = T_OBJECT;
362 type = ftype->make_oopptr();
363 }
364 Node* res = NULL;
365 if (ac->is_clonebasic()) {
366 assert(ac->in(ArrayCopyNode::Src) != ac->in(ArrayCopyNode::Dest), "clone source equals destination");
367 Node* base = ac->in(ArrayCopyNode::Src);
368 Node* adr = _igvn.transform(new AddPNode(base, base, MakeConX(offset)));
369 const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset);
370 MergeMemNode* mergemen = MergeMemNode::make(mem);
371 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
372 res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt);
373 } else {
374 if (ac->modifies(offset, offset, &_igvn, true)) {
375 assert(ac->in(ArrayCopyNode::Dest) == alloc->result_cast(), "arraycopy destination should be allocation's result");
376 uint shift = exact_log2(type2aelembytes(bt));
377 Node* src_pos = ac->in(ArrayCopyNode::SrcPos);
378 Node* dest_pos = ac->in(ArrayCopyNode::DestPos);
379 const TypeInt* src_pos_t = _igvn.type(src_pos)->is_int();
380 const TypeInt* dest_pos_t = _igvn.type(dest_pos)->is_int();
381
382 Node* adr = NULL;
383 const TypePtr* adr_type = NULL;
384 if (src_pos_t->is_con() && dest_pos_t->is_con()) {
385 intptr_t off = ((src_pos_t->get_con() - dest_pos_t->get_con()) << shift) + offset;
386 Node* base = ac->in(ArrayCopyNode::Src);
387 adr = _igvn.transform(new AddPNode(base, base, MakeConX(off)));
388 adr_type = _igvn.type(base)->is_ptr()->add_offset(off);
389 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) {
390 // Don't emit a new load from src if src == dst but try to get the value from memory instead
391 return value_from_mem(ac->in(TypeFunc::Memory), ctl, ft, ftype, adr_type->isa_oopptr(), alloc);
392 }
393 } else {
394 Node* diff = _igvn.transform(new SubINode(ac->in(ArrayCopyNode::SrcPos), ac->in(ArrayCopyNode::DestPos)));
395 #ifdef _LP64
396 diff = _igvn.transform(new ConvI2LNode(diff));
397 #endif
398 diff = _igvn.transform(new LShiftXNode(diff, intcon(shift)));
399
400 Node* off = _igvn.transform(new AddXNode(MakeConX(offset), diff));
401 Node* base = ac->in(ArrayCopyNode::Src);
402 adr = _igvn.transform(new AddPNode(base, base, off));
403 adr_type = _igvn.type(base)->is_ptr()->add_offset(Type::OffsetBot);
404 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) {
405 // Non constant offset in the array: we can't statically
406 // determine the value
407 return NULL;
408 }
409 }
410 MergeMemNode* mergemen = MergeMemNode::make(mem);
411 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
412 res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt);
413 }
414 }
415 if (res != NULL) {
416 if (ftype->isa_narrowoop()) {
417 // PhaseMacroExpand::scalar_replacement adds DecodeN nodes
418 res = _igvn.transform(new EncodePNode(res, ftype));
419 }
420 return res;
421 }
422 return NULL;
423 }
424
425 //
426 // Given a Memory Phi, compute a value Phi containing the values from stores
427 // on the input paths.
428 // Note: this function is recursive, its depth is limited by the "level" argument
429 // Returns the computed Phi, or NULL if it cannot compute it.
430 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) {
431 assert(mem->is_Phi(), "sanity");
432 int alias_idx = C->get_alias_index(adr_t);
433 int offset = adr_t->offset();
434 int instance_id = adr_t->instance_id();
435
436 // Check if an appropriate value phi already exists.
437 Node* region = mem->in(0);
438 for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
439 Node* phi = region->fast_out(k);
440 if (phi->is_Phi() && phi != mem &&
441 phi->as_Phi()->is_same_inst_field(phi_type, (int)mem->_idx, instance_id, alias_idx, offset)) {
442 return phi;
443 }
444 }
445 // Check if an appropriate new value phi already exists.
446 Node* new_phi = value_phis->find(mem->_idx);
447 if (new_phi != NULL)
448 return new_phi;
449
450 if (level <= 0) {
451 return NULL; // Give up: phi tree too deep
452 }
453 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
454 Node *alloc_mem = alloc->in(TypeFunc::Memory);
455
456 uint length = mem->req();
457 GrowableArray <Node *> values(length, length, NULL);
458
459 // create a new Phi for the value
460 PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, mem->_idx, instance_id, alias_idx, offset);
461 transform_later(phi);
462 value_phis->push(phi, mem->_idx);
463
464 for (uint j = 1; j < length; j++) {
465 Node *in = mem->in(j);
466 if (in == NULL || in->is_top()) {
467 values.at_put(j, in);
468 } else {
469 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
470 if (val == start_mem || val == alloc_mem) {
471 // hit a sentinel, return appropriate 0 value
472 values.at_put(j, _igvn.zerocon(ft));
473 continue;
474 }
475 if (val->is_Initialize()) {
476 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
477 }
478 if (val == NULL) {
479 return NULL; // can't find a value on this path
480 }
481 if (val == mem) {
482 values.at_put(j, mem);
483 } else if (val->is_Store()) {
484 Node* n = val->in(MemNode::ValueIn);
485 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
486 n = bs->step_over_gc_barrier(n);
487 values.at_put(j, n);
488 } else if(val->is_Proj() && val->in(0) == alloc) {
489 values.at_put(j, _igvn.zerocon(ft));
490 } else if (val->is_Phi()) {
491 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
492 if (val == NULL) {
493 return NULL;
494 }
495 values.at_put(j, val);
496 } else if (val->Opcode() == Op_SCMemProj) {
497 assert(val->in(0)->is_LoadStore() ||
498 val->in(0)->Opcode() == Op_EncodeISOArray ||
499 val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity");
500 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
501 return NULL;
502 } else if (val->is_ArrayCopy()) {
503 Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc);
504 if (res == NULL) {
505 return NULL;
506 }
507 values.at_put(j, res);
508 } else {
509 #ifdef ASSERT
510 val->dump();
511 assert(false, "unknown node on this path");
512 #endif
513 return NULL; // unknown node on this path
514 }
515 }
516 }
517 // Set Phi's inputs
518 for (uint j = 1; j < length; j++) {
519 if (values.at(j) == mem) {
520 phi->init_req(j, phi);
521 } else {
522 phi->init_req(j, values.at(j));
523 }
524 }
525 return phi;
526 }
527
528 // Search the last value stored into the object's field.
529 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) {
530 assert(adr_t->is_known_instance_field(), "instance required");
531 int instance_id = adr_t->instance_id();
532 assert((uint)instance_id == alloc->_idx, "wrong allocation");
533
534 int alias_idx = C->get_alias_index(adr_t);
535 int offset = adr_t->offset();
536 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
537 Node *alloc_ctrl = alloc->in(TypeFunc::Control);
538 Node *alloc_mem = alloc->in(TypeFunc::Memory);
539 VectorSet visited;
540
541 bool done = sfpt_mem == alloc_mem;
542 Node *mem = sfpt_mem;
543 while (!done) {
544 if (visited.test_set(mem->_idx)) {
545 return NULL; // found a loop, give up
546 }
547 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
548 if (mem == start_mem || mem == alloc_mem) {
549 done = true; // hit a sentinel, return appropriate 0 value
550 } else if (mem->is_Initialize()) {
551 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
552 if (mem == NULL) {
553 done = true; // Something go wrong.
554 } else if (mem->is_Store()) {
555 const TypePtr* atype = mem->as_Store()->adr_type();
556 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
557 done = true;
558 }
559 } else if (mem->is_Store()) {
560 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
561 assert(atype != NULL, "address type must be oopptr");
562 assert(C->get_alias_index(atype) == alias_idx &&
563 atype->is_known_instance_field() && atype->offset() == offset &&
564 atype->instance_id() == instance_id, "store is correct memory slice");
565 done = true;
566 } else if (mem->is_Phi()) {
567 // try to find a phi's unique input
568 Node *unique_input = NULL;
569 Node *top = C->top();
570 for (uint i = 1; i < mem->req(); i++) {
571 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
572 if (n == NULL || n == top || n == mem) {
573 continue;
574 } else if (unique_input == NULL) {
575 unique_input = n;
576 } else if (unique_input != n) {
577 unique_input = top;
578 break;
579 }
580 }
581 if (unique_input != NULL && unique_input != top) {
582 mem = unique_input;
583 } else {
584 done = true;
585 }
586 } else if (mem->is_ArrayCopy()) {
587 done = true;
588 } else {
589 assert(false, "unexpected node");
590 }
591 }
592 if (mem != NULL) {
593 if (mem == start_mem || mem == alloc_mem) {
594 // hit a sentinel, return appropriate 0 value
595 return _igvn.zerocon(ft);
596 } else if (mem->is_Store()) {
597 Node* n = mem->in(MemNode::ValueIn);
598 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
599 n = bs->step_over_gc_barrier(n);
600 return n;
601 } else if (mem->is_Phi()) {
602 // attempt to produce a Phi reflecting the values on the input paths of the Phi
603 Node_Stack value_phis(8);
604 Node* phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
605 if (phi != NULL) {
606 return phi;
607 } else {
608 // Kill all new Phis
609 while(value_phis.is_nonempty()) {
610 Node* n = value_phis.node();
611 _igvn.replace_node(n, C->top());
612 value_phis.pop();
613 }
614 }
615 } else if (mem->is_ArrayCopy()) {
616 Node* ctl = mem->in(0);
617 Node* m = mem->in(TypeFunc::Memory);
618 if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj(Deoptimization::Reason_none)) {
619 // pin the loads in the uncommon trap path
620 ctl = sfpt_ctl;
621 m = sfpt_mem;
622 }
623 return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc);
624 }
625 }
626 // Something go wrong.
627 return NULL;
628 }
629
630 // Check the possibility of scalar replacement.
631 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
632 // Scan the uses of the allocation to check for anything that would
633 // prevent us from eliminating it.
634 NOT_PRODUCT( const char* fail_eliminate = NULL; )
635 DEBUG_ONLY( Node* disq_node = NULL; )
636 bool can_eliminate = true;
637
638 Node* res = alloc->result_cast();
639 const TypeOopPtr* res_type = NULL;
640 if (res == NULL) {
641 // All users were eliminated.
642 } else if (!res->is_CheckCastPP()) {
643 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
644 can_eliminate = false;
645 } else {
646 res_type = _igvn.type(res)->isa_oopptr();
647 if (res_type == NULL) {
648 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
649 can_eliminate = false;
650 } else if (res_type->isa_aryptr()) {
651 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
652 if (length < 0) {
653 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
654 can_eliminate = false;
655 }
656 }
657 }
658
659 if (can_eliminate && res != NULL) {
660 for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
661 j < jmax && can_eliminate; j++) {
662 Node* use = res->fast_out(j);
663
664 if (use->is_AddP()) {
665 const TypePtr* addp_type = _igvn.type(use)->is_ptr();
666 int offset = addp_type->offset();
667
668 if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
669 NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
670 can_eliminate = false;
671 break;
672 }
673 for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
674 k < kmax && can_eliminate; k++) {
675 Node* n = use->fast_out(k);
676 if (!n->is_Store() && n->Opcode() != Op_CastP2X
677 SHENANDOAHGC_ONLY(&& (!UseShenandoahGC || !ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(n))) ) {
678 DEBUG_ONLY(disq_node = n;)
679 if (n->is_Load() || n->is_LoadStore()) {
680 NOT_PRODUCT(fail_eliminate = "Field load";)
681 } else {
682 NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
683 }
684 can_eliminate = false;
685 }
686 }
687 } else if (use->is_ArrayCopy() &&
688 (use->as_ArrayCopy()->is_clonebasic() ||
689 use->as_ArrayCopy()->is_arraycopy_validated() ||
690 use->as_ArrayCopy()->is_copyof_validated() ||
691 use->as_ArrayCopy()->is_copyofrange_validated()) &&
692 use->in(ArrayCopyNode::Dest) == res) {
693 // ok to eliminate
694 } else if (use->is_SafePoint()) {
695 SafePointNode* sfpt = use->as_SafePoint();
696 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
697 // Object is passed as argument.
698 DEBUG_ONLY(disq_node = use;)
699 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
700 can_eliminate = false;
701 }
702 Node* sfptMem = sfpt->memory();
703 if (sfptMem == NULL || sfptMem->is_top()) {
704 DEBUG_ONLY(disq_node = use;)
705 NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
706 can_eliminate = false;
707 } else {
708 safepoints.append_if_missing(sfpt);
709 }
710 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
711 if (use->is_Phi()) {
712 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
713 NOT_PRODUCT(fail_eliminate = "Object is return value";)
714 } else {
715 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
716 }
717 DEBUG_ONLY(disq_node = use;)
718 } else {
719 if (use->Opcode() == Op_Return) {
720 NOT_PRODUCT(fail_eliminate = "Object is return value";)
721 }else {
722 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
723 }
724 DEBUG_ONLY(disq_node = use;)
725 }
726 can_eliminate = false;
727 }
728 }
729 }
730
731 #ifndef PRODUCT
732 if (PrintEliminateAllocations) {
733 if (can_eliminate) {
734 tty->print("Scalar ");
735 if (res == NULL)
736 alloc->dump();
737 else
738 res->dump();
739 } else if (alloc->_is_scalar_replaceable) {
740 tty->print("NotScalar (%s)", fail_eliminate);
741 if (res == NULL)
742 alloc->dump();
743 else
744 res->dump();
745 #ifdef ASSERT
746 if (disq_node != NULL) {
747 tty->print(" >>>> ");
748 disq_node->dump();
749 }
750 #endif /*ASSERT*/
751 }
752 }
753 #endif
754 return can_eliminate;
755 }
756
757 // Do scalar replacement.
758 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
759 GrowableArray <SafePointNode *> safepoints_done;
760
761 ciKlass* klass = NULL;
762 ciInstanceKlass* iklass = NULL;
763 int nfields = 0;
764 int array_base = 0;
765 int element_size = 0;
766 BasicType basic_elem_type = T_ILLEGAL;
767 ciType* elem_type = NULL;
768
769 Node* res = alloc->result_cast();
770 assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result");
771 const TypeOopPtr* res_type = NULL;
772 if (res != NULL) { // Could be NULL when there are no users
773 res_type = _igvn.type(res)->isa_oopptr();
774 }
775
776 if (res != NULL) {
777 klass = res_type->klass();
778 if (res_type->isa_instptr()) {
779 // find the fields of the class which will be needed for safepoint debug information
780 assert(klass->is_instance_klass(), "must be an instance klass.");
781 iklass = klass->as_instance_klass();
782 nfields = iklass->nof_nonstatic_fields();
783 } else {
784 // find the array's elements which will be needed for safepoint debug information
785 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
786 assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
787 elem_type = klass->as_array_klass()->element_type();
788 basic_elem_type = elem_type->basic_type();
789 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
790 element_size = type2aelembytes(basic_elem_type);
791 }
792 }
793 //
794 // Process the safepoint uses
795 //
796 while (safepoints.length() > 0) {
797 SafePointNode* sfpt = safepoints.pop();
798 Node* mem = sfpt->memory();
799 Node* ctl = sfpt->control();
800 assert(sfpt->jvms() != NULL, "missed JVMS");
801 // Fields of scalar objs are referenced only at the end
802 // of regular debuginfo at the last (youngest) JVMS.
803 // Record relative start index.
804 uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
805 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
806 #ifdef ASSERT
807 alloc,
808 #endif
809 first_ind, nfields);
810 sobj->init_req(0, C->root());
811 transform_later(sobj);
812
813 // Scan object's fields adding an input to the safepoint for each field.
814 for (int j = 0; j < nfields; j++) {
815 intptr_t offset;
816 ciField* field = NULL;
817 if (iklass != NULL) {
818 field = iklass->nonstatic_field_at(j);
819 offset = field->offset();
820 elem_type = field->type();
821 basic_elem_type = field->layout_type();
822 } else {
823 offset = array_base + j * (intptr_t)element_size;
824 }
825
826 const Type *field_type;
827 // The next code is taken from Parse::do_get_xxx().
828 if (is_reference_type(basic_elem_type)) {
829 if (!elem_type->is_loaded()) {
830 field_type = TypeInstPtr::BOTTOM;
831 } else if (field != NULL && field->is_static_constant()) {
832 // This can happen if the constant oop is non-perm.
833 ciObject* con = field->constant_value().as_object();
834 // Do not "join" in the previous type; it doesn't add value,
835 // and may yield a vacuous result if the field is of interface type.
836 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
837 assert(field_type != NULL, "field singleton type must be consistent");
838 } else {
839 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
840 }
841 if (UseCompressedOops) {
842 field_type = field_type->make_narrowoop();
843 basic_elem_type = T_NARROWOOP;
844 }
845 } else {
846 field_type = Type::get_const_basic_type(basic_elem_type);
847 }
848
849 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
850
851 Node *field_val = value_from_mem(mem, ctl, basic_elem_type, field_type, field_addr_type, alloc);
852 if (field_val == NULL) {
853 // We weren't able to find a value for this field,
854 // give up on eliminating this allocation.
855
856 // Remove any extra entries we added to the safepoint.
857 uint last = sfpt->req() - 1;
858 for (int k = 0; k < j; k++) {
859 sfpt->del_req(last--);
860 }
861 _igvn._worklist.push(sfpt);
862 // rollback processed safepoints
863 while (safepoints_done.length() > 0) {
864 SafePointNode* sfpt_done = safepoints_done.pop();
865 // remove any extra entries we added to the safepoint
866 last = sfpt_done->req() - 1;
867 for (int k = 0; k < nfields; k++) {
868 sfpt_done->del_req(last--);
869 }
870 JVMState *jvms = sfpt_done->jvms();
871 jvms->set_endoff(sfpt_done->req());
872 // Now make a pass over the debug information replacing any references
873 // to SafePointScalarObjectNode with the allocated object.
874 int start = jvms->debug_start();
875 int end = jvms->debug_end();
876 for (int i = start; i < end; i++) {
877 if (sfpt_done->in(i)->is_SafePointScalarObject()) {
878 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
879 if (scobj->first_index(jvms) == sfpt_done->req() &&
880 scobj->n_fields() == (uint)nfields) {
881 assert(scobj->alloc() == alloc, "sanity");
882 sfpt_done->set_req(i, res);
883 }
884 }
885 }
886 _igvn._worklist.push(sfpt_done);
887 }
888 #ifndef PRODUCT
889 if (PrintEliminateAllocations) {
890 if (field != NULL) {
891 tty->print("=== At SafePoint node %d can't find value of Field: ",
892 sfpt->_idx);
893 field->print();
894 int field_idx = C->get_alias_index(field_addr_type);
895 tty->print(" (alias_idx=%d)", field_idx);
896 } else { // Array's element
897 tty->print("=== At SafePoint node %d can't find value of array element [%d]",
898 sfpt->_idx, j);
899 }
900 tty->print(", which prevents elimination of: ");
901 if (res == NULL)
902 alloc->dump();
903 else
904 res->dump();
905 }
906 #endif
907 return false;
908 }
909 if (UseCompressedOops && field_type->isa_narrowoop()) {
910 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
911 // to be able scalar replace the allocation.
912 if (field_val->is_EncodeP()) {
913 field_val = field_val->in(1);
914 } else {
915 field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
916 }
917 }
918 sfpt->add_req(field_val);
919 }
920 JVMState *jvms = sfpt->jvms();
921 jvms->set_endoff(sfpt->req());
922 // Now make a pass over the debug information replacing any references
923 // to the allocated object with "sobj"
924 int start = jvms->debug_start();
925 int end = jvms->debug_end();
926 sfpt->replace_edges_in_range(res, sobj, start, end);
927 _igvn._worklist.push(sfpt);
928 safepoints_done.append_if_missing(sfpt); // keep it for rollback
929 }
930 return true;
931 }
932
933 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) {
934 Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control);
935 Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory);
936 if (ctl_proj != NULL) {
937 igvn.replace_node(ctl_proj, n->in(0));
938 }
939 if (mem_proj != NULL) {
940 igvn.replace_node(mem_proj, n->in(TypeFunc::Memory));
941 }
942 }
943
944 // Process users of eliminated allocation.
945 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
946 Node* res = alloc->result_cast();
947 if (res != NULL) {
948 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
949 Node *use = res->last_out(j);
950 uint oc1 = res->outcnt();
951
952 if (use->is_AddP()) {
953 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
954 Node *n = use->last_out(k);
955 uint oc2 = use->outcnt();
956 if (n->is_Store()) {
957 #ifdef ASSERT
958 // Verify that there is no dependent MemBarVolatile nodes,
959 // they should be removed during IGVN, see MemBarNode::Ideal().
960 for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
961 p < pmax; p++) {
962 Node* mb = n->fast_out(p);
963 assert(mb->is_Initialize() || !mb->is_MemBar() ||
964 mb->req() <= MemBarNode::Precedent ||
965 mb->in(MemBarNode::Precedent) != n,
966 "MemBarVolatile should be eliminated for non-escaping object");
967 }
968 #endif
969 _igvn.replace_node(n, n->in(MemNode::Memory));
970 } else {
971 eliminate_gc_barrier(n);
972 }
973 k -= (oc2 - use->outcnt());
974 }
975 _igvn.remove_dead_node(use);
976 } else if (use->is_ArrayCopy()) {
977 // Disconnect ArrayCopy node
978 ArrayCopyNode* ac = use->as_ArrayCopy();
979 if (ac->is_clonebasic()) {
980 Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out();
981 disconnect_projections(ac, _igvn);
982 assert(alloc->in(TypeFunc::Memory)->is_Proj() && alloc->in(TypeFunc::Memory)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation");
983 Node* membar_before = alloc->in(TypeFunc::Memory)->in(0);
984 disconnect_projections(membar_before->as_MemBar(), _igvn);
985 if (membar_after->is_MemBar()) {
986 disconnect_projections(membar_after->as_MemBar(), _igvn);
987 }
988 } else {
989 assert(ac->is_arraycopy_validated() ||
990 ac->is_copyof_validated() ||
991 ac->is_copyofrange_validated(), "unsupported");
992 CallProjections callprojs;
993 ac->extract_projections(&callprojs, true);
994
995 _igvn.replace_node(callprojs.fallthrough_ioproj, ac->in(TypeFunc::I_O));
996 _igvn.replace_node(callprojs.fallthrough_memproj, ac->in(TypeFunc::Memory));
997 _igvn.replace_node(callprojs.fallthrough_catchproj, ac->in(TypeFunc::Control));
998
999 // Set control to top. IGVN will remove the remaining projections
1000 ac->set_req(0, top());
1001 ac->replace_edge(res, top());
1002
1003 // Disconnect src right away: it can help find new
1004 // opportunities for allocation elimination
1005 Node* src = ac->in(ArrayCopyNode::Src);
1006 ac->replace_edge(src, top());
1007 // src can be top at this point if src and dest of the
1008 // arraycopy were the same
1009 if (src->outcnt() == 0 && !src->is_top()) {
1010 _igvn.remove_dead_node(src);
1011 }
1012 }
1013 _igvn._worklist.push(ac);
1014 } else {
1015 eliminate_gc_barrier(use);
1016 }
1017 j -= (oc1 - res->outcnt());
1018 }
1019 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
1020 _igvn.remove_dead_node(res);
1021 }
1022
1023 //
1024 // Process other users of allocation's projections
1025 //
1026 if (_resproj != NULL && _resproj->outcnt() != 0) {
1027 // First disconnect stores captured by Initialize node.
1028 // If Initialize node is eliminated first in the following code,
1029 // it will kill such stores and DUIterator_Last will assert.
1030 for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax); j < jmax; j++) {
1031 Node *use = _resproj->fast_out(j);
1032 if (use->is_AddP()) {
1033 // raw memory addresses used only by the initialization
1034 _igvn.replace_node(use, C->top());
1035 --j; --jmax;
1036 }
1037 }
1038 for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
1039 Node *use = _resproj->last_out(j);
1040 uint oc1 = _resproj->outcnt();
1041 if (use->is_Initialize()) {
1042 // Eliminate Initialize node.
1043 InitializeNode *init = use->as_Initialize();
1044 assert(init->outcnt() <= 2, "only a control and memory projection expected");
1045 Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
1046 if (ctrl_proj != NULL) {
1047 _igvn.replace_node(ctrl_proj, init->in(TypeFunc::Control));
1048 #ifdef ASSERT
1049 Node* tmp = init->in(TypeFunc::Control);
1050 assert(tmp == _fallthroughcatchproj, "allocation control projection");
1051 #endif
1052 }
1053 Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
1054 if (mem_proj != NULL) {
1055 Node *mem = init->in(TypeFunc::Memory);
1056 #ifdef ASSERT
1057 if (mem->is_MergeMem()) {
1058 assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
1059 } else {
1060 assert(mem == _memproj_fallthrough, "allocation memory projection");
1061 }
1062 #endif
1063 _igvn.replace_node(mem_proj, mem);
1064 }
1065 } else {
1066 assert(false, "only Initialize or AddP expected");
1067 }
1068 j -= (oc1 - _resproj->outcnt());
1069 }
1070 }
1071 if (_fallthroughcatchproj != NULL) {
1072 _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
1073 }
1074 if (_memproj_fallthrough != NULL) {
1075 _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
1076 }
1077 if (_memproj_catchall != NULL) {
1078 _igvn.replace_node(_memproj_catchall, C->top());
1079 }
1080 if (_ioproj_fallthrough != NULL) {
1081 _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
1082 }
1083 if (_ioproj_catchall != NULL) {
1084 _igvn.replace_node(_ioproj_catchall, C->top());
1085 }
1086 if (_catchallcatchproj != NULL) {
1087 _igvn.replace_node(_catchallcatchproj, C->top());
1088 }
1089 }
1090
1091 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
1092 // Don't do scalar replacement if the frame can be popped by JVMTI:
1093 // if reallocation fails during deoptimization we'll pop all
1094 // interpreter frames for this compiled frame and that won't play
1095 // nice with JVMTI popframe.
1096 if (!EliminateAllocations || JvmtiExport::can_pop_frame() || !alloc->_is_non_escaping) {
1097 return false;
1098 }
1099 Node* klass = alloc->in(AllocateNode::KlassNode);
1100 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
1101 Node* res = alloc->result_cast();
1102 // Eliminate boxing allocations which are not used
1103 // regardless scalar replacable status.
1104 bool boxing_alloc = C->eliminate_boxing() &&
1105 tklass->klass()->is_instance_klass() &&
1106 tklass->klass()->as_instance_klass()->is_box_klass();
1107 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
1108 return false;
1109 }
1110
1111 extract_call_projections(alloc);
1112
1113 GrowableArray <SafePointNode *> safepoints;
1114 if (!can_eliminate_allocation(alloc, safepoints)) {
1115 return false;
1116 }
1117
1118 if (!alloc->_is_scalar_replaceable) {
1119 assert(res == NULL, "sanity");
1120 // We can only eliminate allocation if all debug info references
1121 // are already replaced with SafePointScalarObject because
1122 // we can't search for a fields value without instance_id.
1123 if (safepoints.length() > 0) {
1124 return false;
1125 }
1126 }
1127
1128 if (!scalar_replacement(alloc, safepoints)) {
1129 return false;
1130 }
1131
1132 CompileLog* log = C->log();
1133 if (log != NULL) {
1134 log->head("eliminate_allocation type='%d'",
1135 log->identify(tklass->klass()));
1136 JVMState* p = alloc->jvms();
1137 while (p != NULL) {
1138 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1139 p = p->caller();
1140 }
1141 log->tail("eliminate_allocation");
1142 }
1143
1144 process_users_of_allocation(alloc);
1145
1146 #ifndef PRODUCT
1147 if (PrintEliminateAllocations) {
1148 if (alloc->is_AllocateArray())
1149 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1150 else
1151 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1152 }
1153 #endif
1154
1155 return true;
1156 }
1157
1158 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1159 // EA should remove all uses of non-escaping boxing node.
1160 if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != NULL) {
1161 return false;
1162 }
1163
1164 assert(boxing->result_cast() == NULL, "unexpected boxing node result");
1165
1166 extract_call_projections(boxing);
1167
1168 const TypeTuple* r = boxing->tf()->range();
1169 assert(r->cnt() > TypeFunc::Parms, "sanity");
1170 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1171 assert(t != NULL, "sanity");
1172
1173 CompileLog* log = C->log();
1174 if (log != NULL) {
1175 log->head("eliminate_boxing type='%d'",
1176 log->identify(t->klass()));
1177 JVMState* p = boxing->jvms();
1178 while (p != NULL) {
1179 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1180 p = p->caller();
1181 }
1182 log->tail("eliminate_boxing");
1183 }
1184
1185 process_users_of_allocation(boxing);
1186
1187 #ifndef PRODUCT
1188 if (PrintEliminateAllocations) {
1189 tty->print("++++ Eliminated: %d ", boxing->_idx);
1190 boxing->method()->print_short_name(tty);
1191 tty->cr();
1192 }
1193 #endif
1194
1195 return true;
1196 }
1197
1198 //---------------------------set_eden_pointers-------------------------
1199 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1200 if (UseTLAB) { // Private allocation: load from TLS
1201 Node* thread = transform_later(new ThreadLocalNode());
1202 int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1203 int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1204 eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1205 eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1206 } else { // Shared allocation: load from globals
1207 CollectedHeap* ch = Universe::heap();
1208 address top_adr = (address)ch->top_addr();
1209 address end_adr = (address)ch->end_addr();
1210 eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1211 eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1212 }
1213 }
1214
1215
1216 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1217 Node* adr = basic_plus_adr(base, offset);
1218 const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1219 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1220 transform_later(value);
1221 return value;
1222 }
1223
1224
1225 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1226 Node* adr = basic_plus_adr(base, offset);
1227 mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
1228 transform_later(mem);
1229 return mem;
1230 }
1231
1232 //=============================================================================
1233 //
1234 // A L L O C A T I O N
1235 //
1236 // Allocation attempts to be fast in the case of frequent small objects.
1237 // It breaks down like this:
1238 //
1239 // 1) Size in doublewords is computed. This is a constant for objects and
1240 // variable for most arrays. Doubleword units are used to avoid size
1241 // overflow of huge doubleword arrays. We need doublewords in the end for
1242 // rounding.
1243 //
1244 // 2) Size is checked for being 'too large'. Too-large allocations will go
1245 // the slow path into the VM. The slow path can throw any required
1246 // exceptions, and does all the special checks for very large arrays. The
1247 // size test can constant-fold away for objects. For objects with
1248 // finalizers it constant-folds the otherway: you always go slow with
1249 // finalizers.
1250 //
1251 // 3) If NOT using TLABs, this is the contended loop-back point.
1252 // Load-Locked the heap top. If using TLABs normal-load the heap top.
1253 //
1254 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
1255 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
1256 // "size*8" we always enter the VM, where "largish" is a constant picked small
1257 // enough that there's always space between the eden max and 4Gig (old space is
1258 // there so it's quite large) and large enough that the cost of entering the VM
1259 // is dwarfed by the cost to initialize the space.
1260 //
1261 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1262 // down. If contended, repeat at step 3. If using TLABs normal-store
1263 // adjusted heap top back down; there is no contention.
1264 //
1265 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
1266 // fields.
1267 //
1268 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1269 // oop flavor.
1270 //
1271 //=============================================================================
1272 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1273 // Allocations bigger than this always go the slow route.
1274 // This value must be small enough that allocation attempts that need to
1275 // trigger exceptions go the slow route. Also, it must be small enough so
1276 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1277 //=============================================================================j//
1278 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1279 // The allocator will coalesce int->oop copies away. See comment in
1280 // coalesce.cpp about how this works. It depends critically on the exact
1281 // code shape produced here, so if you are changing this code shape
1282 // make sure the GC info for the heap-top is correct in and around the
1283 // slow-path call.
1284 //
1285
1286 void PhaseMacroExpand::expand_allocate_common(
1287 AllocateNode* alloc, // allocation node to be expanded
1288 Node* length, // array length for an array allocation
1289 const TypeFunc* slow_call_type, // Type of slow call
1290 address slow_call_address // Address of slow call
1291 )
1292 {
1293 Node* ctrl = alloc->in(TypeFunc::Control);
1294 Node* mem = alloc->in(TypeFunc::Memory);
1295 Node* i_o = alloc->in(TypeFunc::I_O);
1296 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
1297 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1298 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1299 assert(ctrl != NULL, "must have control");
1300
1301 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1302 // they will not be used if "always_slow" is set
1303 enum { slow_result_path = 1, fast_result_path = 2 };
1304 Node *result_region = NULL;
1305 Node *result_phi_rawmem = NULL;
1306 Node *result_phi_rawoop = NULL;
1307 Node *result_phi_i_o = NULL;
1308
1309 // The initial slow comparison is a size check, the comparison
1310 // we want to do is a BoolTest::gt
1311 bool expand_fast_path = true;
1312 int tv = _igvn.find_int_con(initial_slow_test, -1);
1313 if (tv >= 0) {
1314 // InitialTest has constant result
1315 // 0 - can fit in TLAB
1316 // 1 - always too big or negative
1317 assert(tv <= 1, "0 or 1 if a constant");
1318 expand_fast_path = (tv == 0);
1319 initial_slow_test = NULL;
1320 } else {
1321 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1322 }
1323
1324 if (C->env()->dtrace_alloc_probes() ||
1325 (!UseTLAB && !Universe::heap()->supports_inline_contig_alloc())) {
1326 // Force slow-path allocation
1327 expand_fast_path = false;
1328 initial_slow_test = NULL;
1329 }
1330
1331 bool allocation_has_use = (alloc->result_cast() != NULL);
1332 if (!allocation_has_use) {
1333 InitializeNode* init = alloc->initialization();
1334 if (init != NULL) {
1335 init->remove(&_igvn);
1336 }
1337 if (expand_fast_path && (initial_slow_test == NULL)) {
1338 // Remove allocation node and return.
1339 // Size is a non-negative constant -> no initial check needed -> directly to fast path.
1340 // Also, no usages -> empty fast path -> no fall out to slow path -> nothing left.
1341 #ifndef PRODUCT
1342 if (PrintEliminateAllocations) {
1343 tty->print("NotUsed ");
1344 Node* res = alloc->proj_out_or_null(TypeFunc::Parms);
1345 if (res != NULL) {
1346 res->dump();
1347 } else {
1348 alloc->dump();
1349 }
1350 }
1351 #endif
1352 yank_alloc_node(alloc);
1353 return;
1354 }
1355 }
1356
1357 enum { too_big_or_final_path = 1, need_gc_path = 2 };
1358 Node *slow_region = NULL;
1359 Node *toobig_false = ctrl;
1360
1361 // generate the initial test if necessary
1362 if (initial_slow_test != NULL ) {
1363 assert (expand_fast_path, "Only need test if there is a fast path");
1364 slow_region = new RegionNode(3);
1365
1366 // Now make the initial failure test. Usually a too-big test but
1367 // might be a TRUE for finalizers or a fancy class check for
1368 // newInstance0.
1369 IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1370 transform_later(toobig_iff);
1371 // Plug the failing-too-big test into the slow-path region
1372 Node *toobig_true = new IfTrueNode( toobig_iff );
1373 transform_later(toobig_true);
1374 slow_region ->init_req( too_big_or_final_path, toobig_true );
1375 toobig_false = new IfFalseNode( toobig_iff );
1376 transform_later(toobig_false);
1377 } else {
1378 // No initial test, just fall into next case
1379 assert(allocation_has_use || !expand_fast_path, "Should already have been handled");
1380 toobig_false = ctrl;
1381 debug_only(slow_region = NodeSentinel);
1382 }
1383
1384 // If we are here there are several possibilities
1385 // - expand_fast_path is false - then only a slow path is expanded. That's it.
1386 // no_initial_check means a constant allocation.
1387 // - If check always evaluates to false -> expand_fast_path is false (see above)
1388 // - If check always evaluates to true -> directly into fast path (but may bailout to slowpath)
1389 // if !allocation_has_use the fast path is empty
1390 // if !allocation_has_use && no_initial_check
1391 // - Then there are no fastpath that can fall out to slowpath -> no allocation code at all.
1392 // removed by yank_alloc_node above.
1393
1394 Node *slow_mem = mem; // save the current memory state for slow path
1395 // generate the fast allocation code unless we know that the initial test will always go slow
1396 if (expand_fast_path) {
1397 // Fast path modifies only raw memory.
1398 if (mem->is_MergeMem()) {
1399 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1400 }
1401
1402 // allocate the Region and Phi nodes for the result
1403 result_region = new RegionNode(3);
1404 result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1405 result_phi_i_o = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1406
1407 // Grab regular I/O before optional prefetch may change it.
1408 // Slow-path does no I/O so just set it to the original I/O.
1409 result_phi_i_o->init_req(slow_result_path, i_o);
1410
1411 // Name successful fast-path variables
1412 Node* fast_oop_ctrl;
1413 Node* fast_oop_rawmem;
1414 if (allocation_has_use) {
1415 Node* needgc_ctrl = NULL;
1416 result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1417
1418 intx prefetch_lines = length != NULL ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1419 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1420 Node* fast_oop = bs->obj_allocate(this, ctrl, mem, toobig_false, size_in_bytes, i_o, needgc_ctrl,
1421 fast_oop_ctrl, fast_oop_rawmem,
1422 prefetch_lines);
1423
1424 if (initial_slow_test != NULL) {
1425 // This completes all paths into the slow merge point
1426 slow_region->init_req(need_gc_path, needgc_ctrl);
1427 transform_later(slow_region);
1428 } else {
1429 // No initial slow path needed!
1430 // Just fall from the need-GC path straight into the VM call.
1431 slow_region = needgc_ctrl;
1432 }
1433
1434 InitializeNode* init = alloc->initialization();
1435 fast_oop_rawmem = initialize_object(alloc,
1436 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1437 klass_node, length, size_in_bytes);
1438 expand_initialize_membar(alloc, init, fast_oop_ctrl, fast_oop_rawmem);
1439 expand_dtrace_alloc_probe(alloc, fast_oop, fast_oop_ctrl, fast_oop_rawmem);
1440
1441 result_phi_rawoop->init_req(fast_result_path, fast_oop);
1442 } else {
1443 assert (initial_slow_test != NULL, "sanity");
1444 fast_oop_ctrl = toobig_false;
1445 fast_oop_rawmem = mem;
1446 transform_later(slow_region);
1447 }
1448
1449 // Plug in the successful fast-path into the result merge point
1450 result_region ->init_req(fast_result_path, fast_oop_ctrl);
1451 result_phi_i_o ->init_req(fast_result_path, i_o);
1452 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1453 } else {
1454 slow_region = ctrl;
1455 result_phi_i_o = i_o; // Rename it to use in the following code.
1456 }
1457
1458 // Generate slow-path call
1459 CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1460 OptoRuntime::stub_name(slow_call_address),
1461 alloc->jvms()->bci(),
1462 TypePtr::BOTTOM);
1463 call->init_req(TypeFunc::Control, slow_region);
1464 call->init_req(TypeFunc::I_O, top()); // does no i/o
1465 call->init_req(TypeFunc::Memory, slow_mem); // may gc ptrs
1466 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1467 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1468
1469 call->init_req(TypeFunc::Parms+0, klass_node);
1470 if (length != NULL) {
1471 call->init_req(TypeFunc::Parms+1, length);
1472 }
1473
1474 // Copy debug information and adjust JVMState information, then replace
1475 // allocate node with the call
1476 copy_call_debug_info((CallNode *) alloc, call);
1477 if (expand_fast_path) {
1478 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1479 } else {
1480 // Hook i_o projection to avoid its elimination during allocation
1481 // replacement (when only a slow call is generated).
1482 call->set_req(TypeFunc::I_O, result_phi_i_o);
1483 }
1484 _igvn.replace_node(alloc, call);
1485 transform_later(call);
1486
1487 // Identify the output projections from the allocate node and
1488 // adjust any references to them.
1489 // The control and io projections look like:
1490 //
1491 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
1492 // Allocate Catch
1493 // ^---Proj(io) <-------+ ^---CatchProj(io)
1494 //
1495 // We are interested in the CatchProj nodes.
1496 //
1497 extract_call_projections(call);
1498
1499 // An allocate node has separate memory projections for the uses on
1500 // the control and i_o paths. Replace the control memory projection with
1501 // result_phi_rawmem (unless we are only generating a slow call when
1502 // both memory projections are combined)
1503 if (expand_fast_path && _memproj_fallthrough != NULL) {
1504 migrate_outs(_memproj_fallthrough, result_phi_rawmem);
1505 }
1506 // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1507 // _memproj_catchall so we end up with a call that has only 1 memory projection.
1508 if (_memproj_catchall != NULL ) {
1509 if (_memproj_fallthrough == NULL) {
1510 _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory);
1511 transform_later(_memproj_fallthrough);
1512 }
1513 migrate_outs(_memproj_catchall, _memproj_fallthrough);
1514 _igvn.remove_dead_node(_memproj_catchall);
1515 }
1516
1517 // An allocate node has separate i_o projections for the uses on the control
1518 // and i_o paths. Always replace the control i_o projection with result i_o
1519 // otherwise incoming i_o become dead when only a slow call is generated
1520 // (it is different from memory projections where both projections are
1521 // combined in such case).
1522 if (_ioproj_fallthrough != NULL) {
1523 migrate_outs(_ioproj_fallthrough, result_phi_i_o);
1524 }
1525 // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1526 // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1527 if (_ioproj_catchall != NULL ) {
1528 if (_ioproj_fallthrough == NULL) {
1529 _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O);
1530 transform_later(_ioproj_fallthrough);
1531 }
1532 migrate_outs(_ioproj_catchall, _ioproj_fallthrough);
1533 _igvn.remove_dead_node(_ioproj_catchall);
1534 }
1535
1536 // if we generated only a slow call, we are done
1537 if (!expand_fast_path) {
1538 // Now we can unhook i_o.
1539 if (result_phi_i_o->outcnt() > 1) {
1540 call->set_req(TypeFunc::I_O, top());
1541 } else {
1542 assert(result_phi_i_o->unique_ctrl_out() == call, "sanity");
1543 // Case of new array with negative size known during compilation.
1544 // AllocateArrayNode::Ideal() optimization disconnect unreachable
1545 // following code since call to runtime will throw exception.
1546 // As result there will be no users of i_o after the call.
1547 // Leave i_o attached to this call to avoid problems in preceding graph.
1548 }
1549 return;
1550 }
1551
1552 if (_fallthroughcatchproj != NULL) {
1553 ctrl = _fallthroughcatchproj->clone();
1554 transform_later(ctrl);
1555 _igvn.replace_node(_fallthroughcatchproj, result_region);
1556 } else {
1557 ctrl = top();
1558 }
1559 Node *slow_result;
1560 if (_resproj == NULL) {
1561 // no uses of the allocation result
1562 slow_result = top();
1563 } else {
1564 slow_result = _resproj->clone();
1565 transform_later(slow_result);
1566 _igvn.replace_node(_resproj, result_phi_rawoop);
1567 }
1568
1569 // Plug slow-path into result merge point
1570 result_region->init_req( slow_result_path, ctrl);
1571 transform_later(result_region);
1572 if (allocation_has_use) {
1573 result_phi_rawoop->init_req(slow_result_path, slow_result);
1574 transform_later(result_phi_rawoop);
1575 }
1576 result_phi_rawmem->init_req(slow_result_path, _memproj_fallthrough);
1577 transform_later(result_phi_rawmem);
1578 transform_later(result_phi_i_o);
1579 // This completes all paths into the result merge point
1580 }
1581
1582 // Remove alloc node that has no uses.
1583 void PhaseMacroExpand::yank_alloc_node(AllocateNode* alloc) {
1584 Node* ctrl = alloc->in(TypeFunc::Control);
1585 Node* mem = alloc->in(TypeFunc::Memory);
1586 Node* i_o = alloc->in(TypeFunc::I_O);
1587
1588 extract_call_projections(alloc);
1589 if (_resproj != NULL) {
1590 for (DUIterator_Fast imax, i = _resproj->fast_outs(imax); i < imax; i++) {
1591 Node* use = _resproj->fast_out(i);
1592 use->isa_MemBar()->remove(&_igvn);
1593 --imax;
1594 --i; // back up iterator
1595 }
1596 assert(_resproj->outcnt() == 0, "all uses must be deleted");
1597 _igvn.remove_dead_node(_resproj);
1598 }
1599 if (_fallthroughcatchproj != NULL) {
1600 migrate_outs(_fallthroughcatchproj, ctrl);
1601 _igvn.remove_dead_node(_fallthroughcatchproj);
1602 }
1603 if (_catchallcatchproj != NULL) {
1604 _igvn.rehash_node_delayed(_catchallcatchproj);
1605 _catchallcatchproj->set_req(0, top());
1606 }
1607 if (_fallthroughproj != NULL) {
1608 Node* catchnode = _fallthroughproj->unique_ctrl_out();
1609 _igvn.remove_dead_node(catchnode);
1610 _igvn.remove_dead_node(_fallthroughproj);
1611 }
1612 if (_memproj_fallthrough != NULL) {
1613 migrate_outs(_memproj_fallthrough, mem);
1614 _igvn.remove_dead_node(_memproj_fallthrough);
1615 }
1616 if (_ioproj_fallthrough != NULL) {
1617 migrate_outs(_ioproj_fallthrough, i_o);
1618 _igvn.remove_dead_node(_ioproj_fallthrough);
1619 }
1620 if (_memproj_catchall != NULL) {
1621 _igvn.rehash_node_delayed(_memproj_catchall);
1622 _memproj_catchall->set_req(0, top());
1623 }
1624 if (_ioproj_catchall != NULL) {
1625 _igvn.rehash_node_delayed(_ioproj_catchall);
1626 _ioproj_catchall->set_req(0, top());
1627 }
1628 #ifndef PRODUCT
1629 if (PrintEliminateAllocations) {
1630 if (alloc->is_AllocateArray()) {
1631 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1632 } else {
1633 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1634 }
1635 }
1636 #endif
1637 _igvn.remove_dead_node(alloc);
1638 }
1639
1640 void PhaseMacroExpand::expand_initialize_membar(AllocateNode* alloc, InitializeNode* init,
1641 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem) {
1642 // If initialization is performed by an array copy, any required
1643 // MemBarStoreStore was already added. If the object does not
1644 // escape no need for a MemBarStoreStore. If the object does not
1645 // escape in its initializer and memory barrier (MemBarStoreStore or
1646 // stronger) is already added at exit of initializer, also no need
1647 // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore
1648 // so that stores that initialize this object can't be reordered
1649 // with a subsequent store that makes this object accessible by
1650 // other threads.
1651 // Other threads include java threads and JVM internal threads
1652 // (for example concurrent GC threads). Current concurrent GC
1653 // implementation: G1 will not scan newly created object,
1654 // so it's safe to skip storestore barrier when allocation does
1655 // not escape.
1656 if (!alloc->does_not_escape_thread() &&
1657 !alloc->is_allocation_MemBar_redundant() &&
1658 (init == NULL || !init->is_complete_with_arraycopy())) {
1659 if (init == NULL || init->req() < InitializeNode::RawStores) {
1660 // No InitializeNode or no stores captured by zeroing
1661 // elimination. Simply add the MemBarStoreStore after object
1662 // initialization.
1663 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1664 transform_later(mb);
1665
1666 mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1667 mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1668 fast_oop_ctrl = new ProjNode(mb, TypeFunc::Control);
1669 transform_later(fast_oop_ctrl);
1670 fast_oop_rawmem = new ProjNode(mb, TypeFunc::Memory);
1671 transform_later(fast_oop_rawmem);
1672 } else {
1673 // Add the MemBarStoreStore after the InitializeNode so that
1674 // all stores performing the initialization that were moved
1675 // before the InitializeNode happen before the storestore
1676 // barrier.
1677
1678 Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control);
1679 Node* init_mem = init->proj_out_or_null(TypeFunc::Memory);
1680
1681 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1682 transform_later(mb);
1683
1684 Node* ctrl = new ProjNode(init, TypeFunc::Control);
1685 transform_later(ctrl);
1686 Node* mem = new ProjNode(init, TypeFunc::Memory);
1687 transform_later(mem);
1688
1689 // The MemBarStoreStore depends on control and memory coming
1690 // from the InitializeNode
1691 mb->init_req(TypeFunc::Memory, mem);
1692 mb->init_req(TypeFunc::Control, ctrl);
1693
1694 ctrl = new ProjNode(mb, TypeFunc::Control);
1695 transform_later(ctrl);
1696 mem = new ProjNode(mb, TypeFunc::Memory);
1697 transform_later(mem);
1698
1699 // All nodes that depended on the InitializeNode for control
1700 // and memory must now depend on the MemBarNode that itself
1701 // depends on the InitializeNode
1702 if (init_ctrl != NULL) {
1703 _igvn.replace_node(init_ctrl, ctrl);
1704 }
1705 if (init_mem != NULL) {
1706 _igvn.replace_node(init_mem, mem);
1707 }
1708 }
1709 }
1710 }
1711
1712 void PhaseMacroExpand::expand_dtrace_alloc_probe(AllocateNode* alloc, Node* oop,
1713 Node*& ctrl, Node*& rawmem) {
1714 if (C->env()->dtrace_extended_probes()) {
1715 // Slow-path call
1716 int size = TypeFunc::Parms + 2;
1717 CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1718 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1719 "dtrace_object_alloc",
1720 TypeRawPtr::BOTTOM);
1721
1722 // Get base of thread-local storage area
1723 Node* thread = new ThreadLocalNode();
1724 transform_later(thread);
1725
1726 call->init_req(TypeFunc::Parms + 0, thread);
1727 call->init_req(TypeFunc::Parms + 1, oop);
1728 call->init_req(TypeFunc::Control, ctrl);
1729 call->init_req(TypeFunc::I_O , top()); // does no i/o
1730 call->init_req(TypeFunc::Memory , ctrl);
1731 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1732 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1733 transform_later(call);
1734 ctrl = new ProjNode(call, TypeFunc::Control);
1735 transform_later(ctrl);
1736 rawmem = new ProjNode(call, TypeFunc::Memory);
1737 transform_later(rawmem);
1738 }
1739 }
1740
1741 // Helper for PhaseMacroExpand::expand_allocate_common.
1742 // Initializes the newly-allocated storage.
1743 Node*
1744 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1745 Node* control, Node* rawmem, Node* object,
1746 Node* klass_node, Node* length,
1747 Node* size_in_bytes) {
1748 InitializeNode* init = alloc->initialization();
1749 // Store the klass & mark bits
1750 Node* mark_node = alloc->make_ideal_mark(&_igvn, object, control, rawmem);
1751 if (!mark_node->is_Con()) {
1752 transform_later(mark_node);
1753 }
1754 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, TypeX_X->basic_type());
1755
1756 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1757 int header_size = alloc->minimum_header_size(); // conservatively small
1758
1759 // Array length
1760 if (length != NULL) { // Arrays need length field
1761 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1762 // conservatively small header size:
1763 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1764 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1765 if (k->is_array_klass()) // we know the exact header size in most cases:
1766 header_size = Klass::layout_helper_header_size(k->layout_helper());
1767 }
1768
1769 // Clear the object body, if necessary.
1770 if (init == NULL) {
1771 // The init has somehow disappeared; be cautious and clear everything.
1772 //
1773 // This can happen if a node is allocated but an uncommon trap occurs
1774 // immediately. In this case, the Initialize gets associated with the
1775 // trap, and may be placed in a different (outer) loop, if the Allocate
1776 // is in a loop. If (this is rare) the inner loop gets unrolled, then
1777 // there can be two Allocates to one Initialize. The answer in all these
1778 // edge cases is safety first. It is always safe to clear immediately
1779 // within an Allocate, and then (maybe or maybe not) clear some more later.
1780 if (!(UseTLAB && ZeroTLAB)) {
1781 rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1782 header_size, size_in_bytes,
1783 &_igvn);
1784 }
1785 } else {
1786 if (!init->is_complete()) {
1787 // Try to win by zeroing only what the init does not store.
1788 // We can also try to do some peephole optimizations,
1789 // such as combining some adjacent subword stores.
1790 rawmem = init->complete_stores(control, rawmem, object,
1791 header_size, size_in_bytes, &_igvn);
1792 }
1793 // We have no more use for this link, since the AllocateNode goes away:
1794 init->set_req(InitializeNode::RawAddress, top());
1795 // (If we keep the link, it just confuses the register allocator,
1796 // who thinks he sees a real use of the address by the membar.)
1797 }
1798
1799 return rawmem;
1800 }
1801
1802 // Generate prefetch instructions for next allocations.
1803 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1804 Node*& contended_phi_rawmem,
1805 Node* old_eden_top, Node* new_eden_top,
1806 intx lines) {
1807 enum { fall_in_path = 1, pf_path = 2 };
1808 if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1809 // Generate prefetch allocation with watermark check.
1810 // As an allocation hits the watermark, we will prefetch starting
1811 // at a "distance" away from watermark.
1812
1813 Node *pf_region = new RegionNode(3);
1814 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1815 TypeRawPtr::BOTTOM );
1816 // I/O is used for Prefetch
1817 Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1818
1819 Node *thread = new ThreadLocalNode();
1820 transform_later(thread);
1821
1822 Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1823 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1824 transform_later(eden_pf_adr);
1825
1826 Node *old_pf_wm = new LoadPNode(needgc_false,
1827 contended_phi_rawmem, eden_pf_adr,
1828 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1829 MemNode::unordered);
1830 transform_later(old_pf_wm);
1831
1832 // check against new_eden_top
1833 Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1834 transform_later(need_pf_cmp);
1835 Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1836 transform_later(need_pf_bol);
1837 IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1838 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1839 transform_later(need_pf_iff);
1840
1841 // true node, add prefetchdistance
1842 Node *need_pf_true = new IfTrueNode( need_pf_iff );
1843 transform_later(need_pf_true);
1844
1845 Node *need_pf_false = new IfFalseNode( need_pf_iff );
1846 transform_later(need_pf_false);
1847
1848 Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1849 _igvn.MakeConX(AllocatePrefetchDistance) );
1850 transform_later(new_pf_wmt );
1851 new_pf_wmt->set_req(0, need_pf_true);
1852
1853 Node *store_new_wmt = new StorePNode(need_pf_true,
1854 contended_phi_rawmem, eden_pf_adr,
1855 TypeRawPtr::BOTTOM, new_pf_wmt,
1856 MemNode::unordered);
1857 transform_later(store_new_wmt);
1858
1859 // adding prefetches
1860 pf_phi_abio->init_req( fall_in_path, i_o );
1861
1862 Node *prefetch_adr;
1863 Node *prefetch;
1864 uint step_size = AllocatePrefetchStepSize;
1865 uint distance = 0;
1866
1867 for ( intx i = 0; i < lines; i++ ) {
1868 prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1869 _igvn.MakeConX(distance) );
1870 transform_later(prefetch_adr);
1871 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1872 transform_later(prefetch);
1873 distance += step_size;
1874 i_o = prefetch;
1875 }
1876 pf_phi_abio->set_req( pf_path, i_o );
1877
1878 pf_region->init_req( fall_in_path, need_pf_false );
1879 pf_region->init_req( pf_path, need_pf_true );
1880
1881 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1882 pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1883
1884 transform_later(pf_region);
1885 transform_later(pf_phi_rawmem);
1886 transform_later(pf_phi_abio);
1887
1888 needgc_false = pf_region;
1889 contended_phi_rawmem = pf_phi_rawmem;
1890 i_o = pf_phi_abio;
1891 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1892 // Insert a prefetch instruction for each allocation.
1893 // This code is used to generate 1 prefetch instruction per cache line.
1894
1895 // Generate several prefetch instructions.
1896 uint step_size = AllocatePrefetchStepSize;
1897 uint distance = AllocatePrefetchDistance;
1898
1899 // Next cache address.
1900 Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1901 _igvn.MakeConX(step_size + distance));
1902 transform_later(cache_adr);
1903 cache_adr = new CastP2XNode(needgc_false, cache_adr);
1904 transform_later(cache_adr);
1905 // Address is aligned to execute prefetch to the beginning of cache line size
1906 // (it is important when BIS instruction is used on SPARC as prefetch).
1907 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1908 cache_adr = new AndXNode(cache_adr, mask);
1909 transform_later(cache_adr);
1910 cache_adr = new CastX2PNode(cache_adr);
1911 transform_later(cache_adr);
1912
1913 // Prefetch
1914 Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1915 prefetch->set_req(0, needgc_false);
1916 transform_later(prefetch);
1917 contended_phi_rawmem = prefetch;
1918 Node *prefetch_adr;
1919 distance = step_size;
1920 for ( intx i = 1; i < lines; i++ ) {
1921 prefetch_adr = new AddPNode( cache_adr, cache_adr,
1922 _igvn.MakeConX(distance) );
1923 transform_later(prefetch_adr);
1924 prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1925 transform_later(prefetch);
1926 distance += step_size;
1927 contended_phi_rawmem = prefetch;
1928 }
1929 } else if( AllocatePrefetchStyle > 0 ) {
1930 // Insert a prefetch for each allocation only on the fast-path
1931 Node *prefetch_adr;
1932 Node *prefetch;
1933 // Generate several prefetch instructions.
1934 uint step_size = AllocatePrefetchStepSize;
1935 uint distance = AllocatePrefetchDistance;
1936 for ( intx i = 0; i < lines; i++ ) {
1937 prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1938 _igvn.MakeConX(distance) );
1939 transform_later(prefetch_adr);
1940 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1941 // Do not let it float too high, since if eden_top == eden_end,
1942 // both might be null.
1943 if( i == 0 ) { // Set control for first prefetch, next follows it
1944 prefetch->init_req(0, needgc_false);
1945 }
1946 transform_later(prefetch);
1947 distance += step_size;
1948 i_o = prefetch;
1949 }
1950 }
1951 return i_o;
1952 }
1953
1954
1955 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1956 expand_allocate_common(alloc, NULL,
1957 OptoRuntime::new_instance_Type(),
1958 OptoRuntime::new_instance_Java());
1959 }
1960
1961 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1962 Node* length = alloc->in(AllocateNode::ALength);
1963 InitializeNode* init = alloc->initialization();
1964 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1965 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1966 address slow_call_address; // Address of slow call
1967 if (init != NULL && init->is_complete_with_arraycopy() &&
1968 k->is_type_array_klass()) {
1969 // Don't zero type array during slow allocation in VM since
1970 // it will be initialized later by arraycopy in compiled code.
1971 slow_call_address = OptoRuntime::new_array_nozero_Java();
1972 } else {
1973 slow_call_address = OptoRuntime::new_array_Java();
1974 }
1975 expand_allocate_common(alloc, length,
1976 OptoRuntime::new_array_Type(),
1977 slow_call_address);
1978 }
1979
1980 //-------------------mark_eliminated_box----------------------------------
1981 //
1982 // During EA obj may point to several objects but after few ideal graph
1983 // transformations (CCP) it may point to only one non escaping object
1984 // (but still using phi), corresponding locks and unlocks will be marked
1985 // for elimination. Later obj could be replaced with a new node (new phi)
1986 // and which does not have escape information. And later after some graph
1987 // reshape other locks and unlocks (which were not marked for elimination
1988 // before) are connected to this new obj (phi) but they still will not be
1989 // marked for elimination since new obj has no escape information.
1990 // Mark all associated (same box and obj) lock and unlock nodes for
1991 // elimination if some of them marked already.
1992 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1993 if (oldbox->as_BoxLock()->is_eliminated())
1994 return; // This BoxLock node was processed already.
1995
1996 // New implementation (EliminateNestedLocks) has separate BoxLock
1997 // node for each locked region so mark all associated locks/unlocks as
1998 // eliminated even if different objects are referenced in one locked region
1999 // (for example, OSR compilation of nested loop inside locked scope).
2000 if (EliminateNestedLocks ||
2001 oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
2002 // Box is used only in one lock region. Mark this box as eliminated.
2003 _igvn.hash_delete(oldbox);
2004 oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
2005 _igvn.hash_insert(oldbox);
2006
2007 for (uint i = 0; i < oldbox->outcnt(); i++) {
2008 Node* u = oldbox->raw_out(i);
2009 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
2010 AbstractLockNode* alock = u->as_AbstractLock();
2011 // Check lock's box since box could be referenced by Lock's debug info.
2012 if (alock->box_node() == oldbox) {
2013 // Mark eliminated all related locks and unlocks.
2014 #ifdef ASSERT
2015 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4");
2016 #endif
2017 alock->set_non_esc_obj();
2018 }
2019 }
2020 }
2021 return;
2022 }
2023
2024 // Create new "eliminated" BoxLock node and use it in monitor debug info
2025 // instead of oldbox for the same object.
2026 BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
2027
2028 // Note: BoxLock node is marked eliminated only here and it is used
2029 // to indicate that all associated lock and unlock nodes are marked
2030 // for elimination.
2031 newbox->set_eliminated();
2032 transform_later(newbox);
2033
2034 // Replace old box node with new box for all users of the same object.
2035 for (uint i = 0; i < oldbox->outcnt();) {
2036 bool next_edge = true;
2037
2038 Node* u = oldbox->raw_out(i);
2039 if (u->is_AbstractLock()) {
2040 AbstractLockNode* alock = u->as_AbstractLock();
2041 if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
2042 // Replace Box and mark eliminated all related locks and unlocks.
2043 #ifdef ASSERT
2044 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5");
2045 #endif
2046 alock->set_non_esc_obj();
2047 _igvn.rehash_node_delayed(alock);
2048 alock->set_box_node(newbox);
2049 next_edge = false;
2050 }
2051 }
2052 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
2053 FastLockNode* flock = u->as_FastLock();
2054 assert(flock->box_node() == oldbox, "sanity");
2055 _igvn.rehash_node_delayed(flock);
2056 flock->set_box_node(newbox);
2057 next_edge = false;
2058 }
2059
2060 // Replace old box in monitor debug info.
2061 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
2062 SafePointNode* sfn = u->as_SafePoint();
2063 JVMState* youngest_jvms = sfn->jvms();
2064 int max_depth = youngest_jvms->depth();
2065 for (int depth = 1; depth <= max_depth; depth++) {
2066 JVMState* jvms = youngest_jvms->of_depth(depth);
2067 int num_mon = jvms->nof_monitors();
2068 // Loop over monitors
2069 for (int idx = 0; idx < num_mon; idx++) {
2070 Node* obj_node = sfn->monitor_obj(jvms, idx);
2071 Node* box_node = sfn->monitor_box(jvms, idx);
2072 if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
2073 int j = jvms->monitor_box_offset(idx);
2074 _igvn.replace_input_of(u, j, newbox);
2075 next_edge = false;
2076 }
2077 }
2078 }
2079 }
2080 if (next_edge) i++;
2081 }
2082 }
2083
2084 //-----------------------mark_eliminated_locking_nodes-----------------------
2085 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
2086 if (EliminateNestedLocks) {
2087 if (alock->is_nested()) {
2088 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
2089 return;
2090 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
2091 // Only Lock node has JVMState needed here.
2092 // Not that preceding claim is documented anywhere else.
2093 if (alock->jvms() != NULL) {
2094 if (alock->as_Lock()->is_nested_lock_region()) {
2095 // Mark eliminated related nested locks and unlocks.
2096 Node* obj = alock->obj_node();
2097 BoxLockNode* box_node = alock->box_node()->as_BoxLock();
2098 assert(!box_node->is_eliminated(), "should not be marked yet");
2099 // Note: BoxLock node is marked eliminated only here
2100 // and it is used to indicate that all associated lock
2101 // and unlock nodes are marked for elimination.
2102 box_node->set_eliminated(); // Box's hash is always NO_HASH here
2103 for (uint i = 0; i < box_node->outcnt(); i++) {
2104 Node* u = box_node->raw_out(i);
2105 if (u->is_AbstractLock()) {
2106 alock = u->as_AbstractLock();
2107 if (alock->box_node() == box_node) {
2108 // Verify that this Box is referenced only by related locks.
2109 assert(alock->obj_node()->eqv_uncast(obj), "");
2110 // Mark all related locks and unlocks.
2111 #ifdef ASSERT
2112 alock->log_lock_optimization(C, "eliminate_lock_set_nested");
2113 #endif
2114 alock->set_nested();
2115 }
2116 }
2117 }
2118 } else {
2119 #ifdef ASSERT
2120 alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region");
2121 if (C->log() != NULL)
2122 alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output
2123 #endif
2124 }
2125 }
2126 return;
2127 }
2128 // Process locks for non escaping object
2129 assert(alock->is_non_esc_obj(), "");
2130 } // EliminateNestedLocks
2131
2132 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2133 // Look for all locks of this object and mark them and
2134 // corresponding BoxLock nodes as eliminated.
2135 Node* obj = alock->obj_node();
2136 for (uint j = 0; j < obj->outcnt(); j++) {
2137 Node* o = obj->raw_out(j);
2138 if (o->is_AbstractLock() &&
2139 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2140 alock = o->as_AbstractLock();
2141 Node* box = alock->box_node();
2142 // Replace old box node with new eliminated box for all users
2143 // of the same object and mark related locks as eliminated.
2144 mark_eliminated_box(box, obj);
2145 }
2146 }
2147 }
2148 }
2149
2150 // we have determined that this lock/unlock can be eliminated, we simply
2151 // eliminate the node without expanding it.
2152 //
2153 // Note: The membar's associated with the lock/unlock are currently not
2154 // eliminated. This should be investigated as a future enhancement.
2155 //
2156 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2157
2158 if (!alock->is_eliminated()) {
2159 return false;
2160 }
2161 #ifdef ASSERT
2162 if (!alock->is_coarsened()) {
2163 // Check that new "eliminated" BoxLock node is created.
2164 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2165 assert(oldbox->is_eliminated(), "should be done already");
2166 }
2167 #endif
2168
2169 alock->log_lock_optimization(C, "eliminate_lock");
2170
2171 #ifndef PRODUCT
2172 if (PrintEliminateLocks) {
2173 if (alock->is_Lock()) {
2174 tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2175 } else {
2176 tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2177 }
2178 }
2179 #endif
2180
2181 Node* mem = alock->in(TypeFunc::Memory);
2182 Node* ctrl = alock->in(TypeFunc::Control);
2183 guarantee(ctrl != NULL, "missing control projection, cannot replace_node() with NULL");
2184
2185 extract_call_projections(alock);
2186 // There are 2 projections from the lock. The lock node will
2187 // be deleted when its last use is subsumed below.
2188 assert(alock->outcnt() == 2 &&
2189 _fallthroughproj != NULL &&
2190 _memproj_fallthrough != NULL,
2191 "Unexpected projections from Lock/Unlock");
2192
2193 Node* fallthroughproj = _fallthroughproj;
2194 Node* memproj_fallthrough = _memproj_fallthrough;
2195
2196 // The memory projection from a lock/unlock is RawMem
2197 // The input to a Lock is merged memory, so extract its RawMem input
2198 // (unless the MergeMem has been optimized away.)
2199 if (alock->is_Lock()) {
2200 // Seach for MemBarAcquireLock node and delete it also.
2201 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2202 assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2203 Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2204 Node* memproj = membar->proj_out(TypeFunc::Memory);
2205 _igvn.replace_node(ctrlproj, fallthroughproj);
2206 _igvn.replace_node(memproj, memproj_fallthrough);
2207
2208 // Delete FastLock node also if this Lock node is unique user
2209 // (a loop peeling may clone a Lock node).
2210 Node* flock = alock->as_Lock()->fastlock_node();
2211 if (flock->outcnt() == 1) {
2212 assert(flock->unique_out() == alock, "sanity");
2213 _igvn.replace_node(flock, top());
2214 }
2215 }
2216
2217 // Seach for MemBarReleaseLock node and delete it also.
2218 if (alock->is_Unlock() && ctrl->is_Proj() && ctrl->in(0)->is_MemBar()) {
2219 MemBarNode* membar = ctrl->in(0)->as_MemBar();
2220 assert(membar->Opcode() == Op_MemBarReleaseLock &&
2221 mem->is_Proj() && membar == mem->in(0), "");
2222 _igvn.replace_node(fallthroughproj, ctrl);
2223 _igvn.replace_node(memproj_fallthrough, mem);
2224 fallthroughproj = ctrl;
2225 memproj_fallthrough = mem;
2226 ctrl = membar->in(TypeFunc::Control);
2227 mem = membar->in(TypeFunc::Memory);
2228 }
2229
2230 _igvn.replace_node(fallthroughproj, ctrl);
2231 _igvn.replace_node(memproj_fallthrough, mem);
2232 return true;
2233 }
2234
2235
2236 //------------------------------expand_lock_node----------------------
2237 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2238
2239 Node* ctrl = lock->in(TypeFunc::Control);
2240 Node* mem = lock->in(TypeFunc::Memory);
2241 Node* obj = lock->obj_node();
2242 Node* box = lock->box_node();
2243 Node* flock = lock->fastlock_node();
2244
2245 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2246
2247 // Make the merge point
2248 Node *region;
2249 Node *mem_phi;
2250 Node *slow_path;
2251
2252 if (UseOptoBiasInlining) {
2253 /*
2254 * See the full description in MacroAssembler::biased_locking_enter().
2255 *
2256 * if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2257 * // The object is biased.
2258 * proto_node = klass->prototype_header;
2259 * o_node = thread | proto_node;
2260 * x_node = o_node ^ mark_word;
2261 * if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2262 * // Done.
2263 * } else {
2264 * if( (x_node & biased_lock_mask) != 0 ) {
2265 * // The klass's prototype header is no longer biased.
2266 * cas(&mark_word, mark_word, proto_node)
2267 * goto cas_lock;
2268 * } else {
2269 * // The klass's prototype header is still biased.
2270 * if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2271 * old = mark_word;
2272 * new = o_node;
2273 * } else {
2274 * // Different thread or anonymous biased.
2275 * old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2276 * new = thread | old;
2277 * }
2278 * // Try to rebias.
2279 * if( cas(&mark_word, old, new) == 0 ) {
2280 * // Done.
2281 * } else {
2282 * goto slow_path; // Failed.
2283 * }
2284 * }
2285 * }
2286 * } else {
2287 * // The object is not biased.
2288 * cas_lock:
2289 * if( FastLock(obj) == 0 ) {
2290 * // Done.
2291 * } else {
2292 * slow_path:
2293 * OptoRuntime::complete_monitor_locking_Java(obj);
2294 * }
2295 * }
2296 */
2297
2298 region = new RegionNode(5);
2299 // create a Phi for the memory state
2300 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2301
2302 Node* fast_lock_region = new RegionNode(3);
2303 Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2304
2305 // First, check mark word for the biased lock pattern.
2306 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2307
2308 // Get fast path - mark word has the biased lock pattern.
2309 ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2310 markWord::biased_lock_mask_in_place,
2311 markWord::biased_lock_pattern, true);
2312 // fast_lock_region->in(1) is set to slow path.
2313 fast_lock_mem_phi->init_req(1, mem);
2314
2315 // Now check that the lock is biased to the current thread and has
2316 // the same epoch and bias as Klass::_prototype_header.
2317
2318 // Special-case a fresh allocation to avoid building nodes:
2319 Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2320 if (klass_node == NULL) {
2321 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2322 klass_node = transform_later(LoadKlassNode::make(_igvn, NULL, mem, k_adr, _igvn.type(k_adr)->is_ptr()));
2323 #ifdef _LP64
2324 if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2325 assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2326 klass_node->in(1)->init_req(0, ctrl);
2327 } else
2328 #endif
2329 klass_node->init_req(0, ctrl);
2330 }
2331 Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2332
2333 Node* thread = transform_later(new ThreadLocalNode());
2334 Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2335 Node* o_node = transform_later(new OrXNode(cast_thread, proto_node));
2336 Node* x_node = transform_later(new XorXNode(o_node, mark_node));
2337
2338 // Get slow path - mark word does NOT match the value.
2339 STATIC_ASSERT(markWord::age_mask_in_place <= INT_MAX);
2340 Node* not_biased_ctrl = opt_bits_test(ctrl, region, 3, x_node,
2341 (~(int)markWord::age_mask_in_place), 0);
2342 // region->in(3) is set to fast path - the object is biased to the current thread.
2343 mem_phi->init_req(3, mem);
2344
2345
2346 // Mark word does NOT match the value (thread | Klass::_prototype_header).
2347
2348
2349 // First, check biased pattern.
2350 // Get fast path - _prototype_header has the same biased lock pattern.
2351 ctrl = opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2352 markWord::biased_lock_mask_in_place, 0, true);
2353
2354 not_biased_ctrl = fast_lock_region->in(2); // Slow path
2355 // fast_lock_region->in(2) - the prototype header is no longer biased
2356 // and we have to revoke the bias on this object.
2357 // We are going to try to reset the mark of this object to the prototype
2358 // value and fall through to the CAS-based locking scheme.
2359 Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2360 Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr,
2361 proto_node, mark_node);
2362 transform_later(cas);
2363 Node* proj = transform_later(new SCMemProjNode(cas));
2364 fast_lock_mem_phi->init_req(2, proj);
2365
2366
2367 // Second, check epoch bits.
2368 Node* rebiased_region = new RegionNode(3);
2369 Node* old_phi = new PhiNode( rebiased_region, TypeX_X);
2370 Node* new_phi = new PhiNode( rebiased_region, TypeX_X);
2371
2372 // Get slow path - mark word does NOT match epoch bits.
2373 Node* epoch_ctrl = opt_bits_test(ctrl, rebiased_region, 1, x_node,
2374 markWord::epoch_mask_in_place, 0);
2375 // The epoch of the current bias is not valid, attempt to rebias the object
2376 // toward the current thread.
2377 rebiased_region->init_req(2, epoch_ctrl);
2378 old_phi->init_req(2, mark_node);
2379 new_phi->init_req(2, o_node);
2380
2381 // rebiased_region->in(1) is set to fast path.
2382 // The epoch of the current bias is still valid but we know
2383 // nothing about the owner; it might be set or it might be clear.
2384 Node* cmask = MakeConX(markWord::biased_lock_mask_in_place |
2385 markWord::age_mask_in_place |
2386 markWord::epoch_mask_in_place);
2387 Node* old = transform_later(new AndXNode(mark_node, cmask));
2388 cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2389 Node* new_mark = transform_later(new OrXNode(cast_thread, old));
2390 old_phi->init_req(1, old);
2391 new_phi->init_req(1, new_mark);
2392
2393 transform_later(rebiased_region);
2394 transform_later(old_phi);
2395 transform_later(new_phi);
2396
2397 // Try to acquire the bias of the object using an atomic operation.
2398 // If this fails we will go in to the runtime to revoke the object's bias.
2399 cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi);
2400 transform_later(cas);
2401 proj = transform_later(new SCMemProjNode(cas));
2402
2403 // Get slow path - Failed to CAS.
2404 not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2405 mem_phi->init_req(4, proj);
2406 // region->in(4) is set to fast path - the object is rebiased to the current thread.
2407
2408 // Failed to CAS.
2409 slow_path = new RegionNode(3);
2410 Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2411
2412 slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2413 slow_mem->init_req(1, proj);
2414
2415 // Call CAS-based locking scheme (FastLock node).
2416
2417 transform_later(fast_lock_region);
2418 transform_later(fast_lock_mem_phi);
2419
2420 // Get slow path - FastLock failed to lock the object.
2421 ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2422 mem_phi->init_req(2, fast_lock_mem_phi);
2423 // region->in(2) is set to fast path - the object is locked to the current thread.
2424
2425 slow_path->init_req(2, ctrl); // Capture slow-control
2426 slow_mem->init_req(2, fast_lock_mem_phi);
2427
2428 transform_later(slow_path);
2429 transform_later(slow_mem);
2430 // Reset lock's memory edge.
2431 lock->set_req(TypeFunc::Memory, slow_mem);
2432
2433 } else {
2434 region = new RegionNode(3);
2435 // create a Phi for the memory state
2436 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2437
2438 // Optimize test; set region slot 2
2439 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2440 mem_phi->init_req(2, mem);
2441 }
2442
2443 // Make slow path call
2444 CallNode *call = make_slow_call((CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(),
2445 OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path,
2446 obj, box, NULL);
2447
2448 extract_call_projections(call);
2449
2450 // Slow path can only throw asynchronous exceptions, which are always
2451 // de-opted. So the compiler thinks the slow-call can never throw an
2452 // exception. If it DOES throw an exception we would need the debug
2453 // info removed first (since if it throws there is no monitor).
2454 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2455 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2456
2457 // Capture slow path
2458 // disconnect fall-through projection from call and create a new one
2459 // hook up users of fall-through projection to region
2460 Node *slow_ctrl = _fallthroughproj->clone();
2461 transform_later(slow_ctrl);
2462 _igvn.hash_delete(_fallthroughproj);
2463 _fallthroughproj->disconnect_inputs(NULL, C);
2464 region->init_req(1, slow_ctrl);
2465 // region inputs are now complete
2466 transform_later(region);
2467 _igvn.replace_node(_fallthroughproj, region);
2468
2469 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2470 mem_phi->init_req(1, memproj );
2471 transform_later(mem_phi);
2472 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2473 }
2474
2475 //------------------------------expand_unlock_node----------------------
2476 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2477
2478 Node* ctrl = unlock->in(TypeFunc::Control);
2479 Node* mem = unlock->in(TypeFunc::Memory);
2480 Node* obj = unlock->obj_node();
2481 Node* box = unlock->box_node();
2482
2483 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2484
2485 // No need for a null check on unlock
2486
2487 // Make the merge point
2488 Node *region;
2489 Node *mem_phi;
2490
2491 if (UseOptoBiasInlining) {
2492 // Check for biased locking unlock case, which is a no-op.
2493 // See the full description in MacroAssembler::biased_locking_exit().
2494 region = new RegionNode(4);
2495 // create a Phi for the memory state
2496 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2497 mem_phi->init_req(3, mem);
2498
2499 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2500 ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2501 markWord::biased_lock_mask_in_place,
2502 markWord::biased_lock_pattern);
2503 } else {
2504 region = new RegionNode(3);
2505 // create a Phi for the memory state
2506 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2507 }
2508
2509 FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2510 funlock = transform_later( funlock )->as_FastUnlock();
2511 // Optimize test; set region slot 2
2512 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2513 Node *thread = transform_later(new ThreadLocalNode());
2514
2515 CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(),
2516 CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C),
2517 "complete_monitor_unlocking_C", slow_path, obj, box, thread);
2518
2519 extract_call_projections(call);
2520
2521 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2522 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2523
2524 // No exceptions for unlocking
2525 // Capture slow path
2526 // disconnect fall-through projection from call and create a new one
2527 // hook up users of fall-through projection to region
2528 Node *slow_ctrl = _fallthroughproj->clone();
2529 transform_later(slow_ctrl);
2530 _igvn.hash_delete(_fallthroughproj);
2531 _fallthroughproj->disconnect_inputs(NULL, C);
2532 region->init_req(1, slow_ctrl);
2533 // region inputs are now complete
2534 transform_later(region);
2535 _igvn.replace_node(_fallthroughproj, region);
2536
2537 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2538 mem_phi->init_req(1, memproj );
2539 mem_phi->init_req(2, mem);
2540 transform_later(mem_phi);
2541 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2542 }
2543
2544 void PhaseMacroExpand::expand_subtypecheck_node(SubTypeCheckNode *check) {
2545 assert(check->in(SubTypeCheckNode::Control) == NULL, "should be pinned");
2546 Node* bol = check->unique_out();
2547 Node* obj_or_subklass = check->in(SubTypeCheckNode::ObjOrSubKlass);
2548 Node* superklass = check->in(SubTypeCheckNode::SuperKlass);
2549 assert(bol->is_Bool() && bol->as_Bool()->_test._test == BoolTest::ne, "unexpected bool node");
2550
2551 for (DUIterator_Last imin, i = bol->last_outs(imin); i >= imin; --i) {
2552 Node* iff = bol->last_out(i);
2553 assert(iff->is_If(), "where's the if?");
2554
2555 if (iff->in(0)->is_top()) {
2556 _igvn.replace_input_of(iff, 1, C->top());
2557 continue;
2558 }
2559
2560 Node* iftrue = iff->as_If()->proj_out(1);
2561 Node* iffalse = iff->as_If()->proj_out(0);
2562 Node* ctrl = iff->in(0);
2563
2564 Node* subklass = NULL;
2565 if (_igvn.type(obj_or_subklass)->isa_klassptr()) {
2566 subklass = obj_or_subklass;
2567 } else {
2568 Node* k_adr = basic_plus_adr(obj_or_subklass, oopDesc::klass_offset_in_bytes());
2569 subklass = _igvn.transform(LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), k_adr, TypeInstPtr::KLASS));
2570 }
2571
2572 Node* not_subtype_ctrl = Phase::gen_subtype_check(subklass, superklass, &ctrl, NULL, _igvn);
2573
2574 _igvn.replace_input_of(iff, 0, C->top());
2575 _igvn.replace_node(iftrue, not_subtype_ctrl);
2576 _igvn.replace_node(iffalse, ctrl);
2577 }
2578 _igvn.replace_node(check, C->top());
2579 }
2580
2581 //---------------------------eliminate_macro_nodes----------------------
2582 // Eliminate scalar replaced allocations and associated locks.
2583 void PhaseMacroExpand::eliminate_macro_nodes() {
2584 if (C->macro_count() == 0)
2585 return;
2586
2587 // First, attempt to eliminate locks
2588 int cnt = C->macro_count();
2589 for (int i=0; i < cnt; i++) {
2590 Node *n = C->macro_node(i);
2591 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2592 // Before elimination mark all associated (same box and obj)
2593 // lock and unlock nodes.
2594 mark_eliminated_locking_nodes(n->as_AbstractLock());
2595 }
2596 }
2597 bool progress = true;
2598 while (progress) {
2599 progress = false;
2600 for (int i = C->macro_count(); i > 0; i--) {
2601 Node * n = C->macro_node(i-1);
2602 bool success = false;
2603 debug_only(int old_macro_count = C->macro_count(););
2604 if (n->is_AbstractLock()) {
2605 success = eliminate_locking_node(n->as_AbstractLock());
2606 }
2607 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2608 progress = progress || success;
2609 }
2610 }
2611 // Next, attempt to eliminate allocations
2612 _has_locks = false;
2613 progress = true;
2614 while (progress) {
2615 progress = false;
2616 for (int i = C->macro_count(); i > 0; i--) {
2617 Node * n = C->macro_node(i-1);
2618 bool success = false;
2619 debug_only(int old_macro_count = C->macro_count(););
2620 switch (n->class_id()) {
2621 case Node::Class_Allocate:
2622 case Node::Class_AllocateArray:
2623 success = eliminate_allocate_node(n->as_Allocate());
2624 break;
2625 case Node::Class_CallStaticJava:
2626 success = eliminate_boxing_node(n->as_CallStaticJava());
2627 break;
2628 case Node::Class_Lock:
2629 case Node::Class_Unlock:
2630 assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2631 _has_locks = true;
2632 break;
2633 case Node::Class_ArrayCopy:
2634 break;
2635 case Node::Class_OuterStripMinedLoop:
2636 break;
2637 case Node::Class_SubTypeCheck:
2638 break;
2639 default:
2640 assert(n->Opcode() == Op_LoopLimit ||
2641 n->Opcode() == Op_Opaque1 ||
2642 n->Opcode() == Op_Opaque2 ||
2643 n->Opcode() == Op_Opaque3 ||
2644 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(n),
2645 "unknown node type in macro list");
2646 }
2647 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2648 progress = progress || success;
2649 }
2650 }
2651 }
2652
2653 //------------------------------expand_macro_nodes----------------------
2654 // Returns true if a failure occurred.
2655 bool PhaseMacroExpand::expand_macro_nodes() {
2656 // Last attempt to eliminate macro nodes.
2657 eliminate_macro_nodes();
2658
2659 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2660 bool progress = true;
2661 while (progress) {
2662 progress = false;
2663 for (int i = C->macro_count(); i > 0; i--) {
2664 Node* n = C->macro_node(i-1);
2665 bool success = false;
2666 debug_only(int old_macro_count = C->macro_count(););
2667 if (n->Opcode() == Op_LoopLimit) {
2668 // Remove it from macro list and put on IGVN worklist to optimize.
2669 C->remove_macro_node(n);
2670 _igvn._worklist.push(n);
2671 success = true;
2672 } else if (n->Opcode() == Op_CallStaticJava) {
2673 // Remove it from macro list and put on IGVN worklist to optimize.
2674 C->remove_macro_node(n);
2675 _igvn._worklist.push(n);
2676 success = true;
2677 } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2678 _igvn.replace_node(n, n->in(1));
2679 success = true;
2680 #if INCLUDE_RTM_OPT
2681 } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2682 assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2683 assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2684 Node* cmp = n->unique_out();
2685 #ifdef ASSERT
2686 // Validate graph.
2687 assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2688 BoolNode* bol = cmp->unique_out()->as_Bool();
2689 assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2690 (bol->_test._test == BoolTest::ne), "");
2691 IfNode* ifn = bol->unique_out()->as_If();
2692 assert((ifn->outcnt() == 2) &&
2693 ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change) != NULL, "");
2694 #endif
2695 Node* repl = n->in(1);
2696 if (!_has_locks) {
2697 // Remove RTM state check if there are no locks in the code.
2698 // Replace input to compare the same value.
2699 repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2700 }
2701 _igvn.replace_node(n, repl);
2702 success = true;
2703 #endif
2704 } else if (n->Opcode() == Op_OuterStripMinedLoop) {
2705 n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn);
2706 C->remove_macro_node(n);
2707 success = true;
2708 }
2709 assert(!success || (C->macro_count() == (old_macro_count - 1)), "elimination must have deleted one node from macro list");
2710 progress = progress || success;
2711 }
2712 }
2713
2714 // Clean up the graph so we're less likely to hit the maximum node
2715 // limit
2716 _igvn.set_delay_transform(false);
2717 _igvn.optimize();
2718 if (C->failing()) return true;
2719 _igvn.set_delay_transform(true);
2720
2721
2722 // Because we run IGVN after each expansion, some macro nodes may go
2723 // dead and be removed from the list as we iterate over it. Move
2724 // Allocate nodes (processed in a second pass) at the beginning of
2725 // the list and then iterate from the last element of the list until
2726 // an Allocate node is seen. This is robust to random deletion in
2727 // the list due to nodes going dead.
2728 C->sort_macro_nodes();
2729
2730 // expand arraycopy "macro" nodes first
2731 // For ReduceBulkZeroing, we must first process all arraycopy nodes
2732 // before the allocate nodes are expanded.
2733 while (C->macro_count() > 0) {
2734 int macro_count = C->macro_count();
2735 Node * n = C->macro_node(macro_count-1);
2736 assert(n->is_macro(), "only macro nodes expected here");
2737 if (_igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) {
2738 // node is unreachable, so don't try to expand it
2739 C->remove_macro_node(n);
2740 continue;
2741 }
2742 if (n->is_Allocate()) {
2743 break;
2744 }
2745 // Make sure expansion will not cause node limit to be exceeded.
2746 // Worst case is a macro node gets expanded into about 200 nodes.
2747 // Allow 50% more for optimization.
2748 if (C->check_node_count(300, "out of nodes before macro expansion")) {
2749 return true;
2750 }
2751
2752 debug_only(int old_macro_count = C->macro_count(););
2753 switch (n->class_id()) {
2754 case Node::Class_Lock:
2755 expand_lock_node(n->as_Lock());
2756 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
2757 break;
2758 case Node::Class_Unlock:
2759 expand_unlock_node(n->as_Unlock());
2760 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
2761 break;
2762 case Node::Class_ArrayCopy:
2763 expand_arraycopy_node(n->as_ArrayCopy());
2764 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
2765 break;
2766 case Node::Class_SubTypeCheck:
2767 expand_subtypecheck_node(n->as_SubTypeCheck());
2768 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list");
2769 break;
2770 default:
2771 assert(false, "unknown node type in macro list");
2772 }
2773 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2774 if (C->failing()) return true;
2775
2776 // Clean up the graph so we're less likely to hit the maximum node
2777 // limit
2778 _igvn.set_delay_transform(false);
2779 _igvn.optimize();
2780 if (C->failing()) return true;
2781 _igvn.set_delay_transform(true);
2782 }
2783
2784 // All nodes except Allocate nodes are expanded now. There could be
2785 // new optimization opportunities (such as folding newly created
2786 // load from a just allocated object). Run IGVN.
2787
2788 // expand "macro" nodes
2789 // nodes are removed from the macro list as they are processed
2790 while (C->macro_count() > 0) {
2791 int macro_count = C->macro_count();
2792 Node * n = C->macro_node(macro_count-1);
2793 assert(n->is_macro(), "only macro nodes expected here");
2794 if (_igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) {
2795 // node is unreachable, so don't try to expand it
2796 C->remove_macro_node(n);
2797 continue;
2798 }
2799 // Make sure expansion will not cause node limit to be exceeded.
2800 // Worst case is a macro node gets expanded into about 200 nodes.
2801 // Allow 50% more for optimization.
2802 if (C->check_node_count(300, "out of nodes before macro expansion")) {
2803 return true;
2804 }
2805 switch (n->class_id()) {
2806 case Node::Class_Allocate:
2807 expand_allocate(n->as_Allocate());
2808 break;
2809 case Node::Class_AllocateArray:
2810 expand_allocate_array(n->as_AllocateArray());
2811 break;
2812 default:
2813 assert(false, "unknown node type in macro list");
2814 }
2815 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2816 if (C->failing()) return true;
2817
2818 // Clean up the graph so we're less likely to hit the maximum node
2819 // limit
2820 _igvn.set_delay_transform(false);
2821 _igvn.optimize();
2822 if (C->failing()) return true;
2823 _igvn.set_delay_transform(true);
2824 }
2825
2826 _igvn.set_delay_transform(false);
2827 return false;
2828 }