1 /*
2 * Copyright (c) 2005, 2018, 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/locknode.hpp"
39 #include "opto/loopnode.hpp"
40 #include "opto/macro.hpp"
41 #include "opto/memnode.hpp"
42 #include "opto/narrowptrnode.hpp"
43 #include "opto/node.hpp"
44 #include "opto/opaquenode.hpp"
45 #include "opto/phaseX.hpp"
46 #include "opto/rootnode.hpp"
47 #include "opto/runtime.hpp"
48 #include "opto/subnode.hpp"
49 #include "opto/type.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "utilities/macros.hpp"
52 #if INCLUDE_G1GC
53 #include "gc/g1/g1ThreadLocalData.hpp"
54 #endif // INCLUDE_G1GC
55 #if INCLUDE_SHENANDOAHGC
56 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
57 #endif
58
59
60 //
61 // Replace any references to "oldref" in inputs to "use" with "newref".
62 // Returns the number of replacements made.
63 //
64 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
65 int nreplacements = 0;
66 uint req = use->req();
67 for (uint j = 0; j < use->len(); j++) {
68 Node *uin = use->in(j);
69 if (uin == oldref) {
70 if (j < req)
71 use->set_req(j, newref);
72 else
73 use->set_prec(j, newref);
74 nreplacements++;
75 } else if (j >= req && uin == NULL) {
76 break;
77 }
78 }
79 return nreplacements;
80 }
81
82 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
83 // Copy debug information and adjust JVMState information
84 uint old_dbg_start = oldcall->tf()->domain()->cnt();
85 uint new_dbg_start = newcall->tf()->domain()->cnt();
86 int jvms_adj = new_dbg_start - old_dbg_start;
87 assert (new_dbg_start == newcall->req(), "argument count mismatch");
88
89 // SafePointScalarObject node could be referenced several times in debug info.
90 // Use Dict to record cloned nodes.
91 Dict* sosn_map = new Dict(cmpkey,hashkey);
92 for (uint i = old_dbg_start; i < oldcall->req(); i++) {
93 Node* old_in = oldcall->in(i);
94 // Clone old SafePointScalarObjectNodes, adjusting their field contents.
95 if (old_in != NULL && old_in->is_SafePointScalarObject()) {
96 SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
97 uint old_unique = C->unique();
98 Node* new_in = old_sosn->clone(sosn_map);
99 if (old_unique != C->unique()) { // New node?
100 new_in->set_req(0, C->root()); // reset control edge
101 new_in = transform_later(new_in); // Register new node.
102 }
103 old_in = new_in;
104 }
105 newcall->add_req(old_in);
106 }
107
108 // JVMS may be shared so clone it before we modify it
109 newcall->set_jvms(oldcall->jvms() != NULL ? oldcall->jvms()->clone_deep(C) : NULL);
110 for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
111 jvms->set_map(newcall);
112 jvms->set_locoff(jvms->locoff()+jvms_adj);
113 jvms->set_stkoff(jvms->stkoff()+jvms_adj);
114 jvms->set_monoff(jvms->monoff()+jvms_adj);
115 jvms->set_scloff(jvms->scloff()+jvms_adj);
116 jvms->set_endoff(jvms->endoff()+jvms_adj);
117 }
118 }
119
120 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
121 Node* cmp;
122 if (mask != 0) {
123 Node* and_node = transform_later(new AndXNode(word, MakeConX(mask)));
124 cmp = transform_later(new CmpXNode(and_node, MakeConX(bits)));
125 } else {
126 cmp = word;
127 }
128 Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne));
129 IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
130 transform_later(iff);
131
132 // Fast path taken.
133 Node *fast_taken = transform_later(new IfFalseNode(iff));
134
135 // Fast path not-taken, i.e. slow path
136 Node *slow_taken = transform_later(new IfTrueNode(iff));
137
138 if (return_fast_path) {
139 region->init_req(edge, slow_taken); // Capture slow-control
140 return fast_taken;
141 } else {
142 region->init_req(edge, fast_taken); // Capture fast-control
143 return slow_taken;
144 }
145 }
146
147 //--------------------copy_predefined_input_for_runtime_call--------------------
148 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
149 // Set fixed predefined input arguments
150 call->init_req( TypeFunc::Control, ctrl );
151 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) );
152 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
153 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
154 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
155 }
156
157 //------------------------------make_slow_call---------------------------------
158 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type,
159 address slow_call, const char* leaf_name, Node* slow_path,
160 Node* parm0, Node* parm1, Node* parm2) {
161
162 // Slow-path call
163 CallNode *call = leaf_name
164 ? (CallNode*)new CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
165 : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
166
167 // Slow path call has no side-effects, uses few values
168 copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
169 if (parm0 != NULL) call->init_req(TypeFunc::Parms+0, parm0);
170 if (parm1 != NULL) call->init_req(TypeFunc::Parms+1, parm1);
171 if (parm2 != NULL) call->init_req(TypeFunc::Parms+2, parm2);
172 copy_call_debug_info(oldcall, call);
173 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
174 _igvn.replace_node(oldcall, call);
175 transform_later(call);
176
177 return call;
178 }
179
180 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
181 _fallthroughproj = NULL;
182 _fallthroughcatchproj = NULL;
183 _ioproj_fallthrough = NULL;
184 _ioproj_catchall = NULL;
185 _catchallcatchproj = NULL;
186 _memproj_fallthrough = NULL;
187 _memproj_catchall = NULL;
188 _resproj = NULL;
189 for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
190 ProjNode *pn = call->fast_out(i)->as_Proj();
191 switch (pn->_con) {
192 case TypeFunc::Control:
193 {
194 // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
195 _fallthroughproj = pn;
196 DUIterator_Fast jmax, j = pn->fast_outs(jmax);
197 const Node *cn = pn->fast_out(j);
198 if (cn->is_Catch()) {
199 ProjNode *cpn = NULL;
200 for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
201 cpn = cn->fast_out(k)->as_Proj();
202 assert(cpn->is_CatchProj(), "must be a CatchProjNode");
203 if (cpn->_con == CatchProjNode::fall_through_index)
204 _fallthroughcatchproj = cpn;
205 else {
206 assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
207 _catchallcatchproj = cpn;
208 }
209 }
210 }
211 break;
212 }
213 case TypeFunc::I_O:
214 if (pn->_is_io_use)
215 _ioproj_catchall = pn;
216 else
217 _ioproj_fallthrough = pn;
218 break;
219 case TypeFunc::Memory:
220 if (pn->_is_io_use)
221 _memproj_catchall = pn;
222 else
223 _memproj_fallthrough = pn;
224 break;
225 case TypeFunc::Parms:
226 _resproj = pn;
227 break;
228 default:
229 assert(false, "unexpected projection from allocation node.");
230 }
231 }
232
233 }
234
235 void PhaseMacroExpand::eliminate_gc_barrier(Node* p2x) {
236 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2();
237 bs->eliminate_gc_barrier(this, p2x);
238 }
239
240 // Search for a memory operation for the specified memory slice.
241 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
242 Node *orig_mem = mem;
243 Node *alloc_mem = alloc->in(TypeFunc::Memory);
244 const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
245 while (true) {
246 if (mem == alloc_mem || mem == start_mem ) {
247 return mem; // hit one of our sentinels
248 } else if (mem->is_MergeMem()) {
249 mem = mem->as_MergeMem()->memory_at(alias_idx);
250 } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
251 Node *in = mem->in(0);
252 // we can safely skip over safepoints, calls, locks and membars because we
253 // already know that the object is safe to eliminate.
254 if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
255 return in;
256 } else if (in->is_Call()) {
257 CallNode *call = in->as_Call();
258 if (call->may_modify(tinst, phase)) {
259 assert(call->is_ArrayCopy(), "ArrayCopy is the only call node that doesn't make allocation escape");
260 if (call->as_ArrayCopy()->modifies(offset, offset, phase, false)) {
261 return in;
262 }
263 }
264 mem = in->in(TypeFunc::Memory);
265 } else if (in->is_MemBar()) {
266 ArrayCopyNode* ac = NULL;
267 if (ArrayCopyNode::may_modify(tinst, in->as_MemBar(), phase, ac)) {
268 assert(ac != NULL && ac->is_clonebasic(), "Only basic clone is a non escaping clone");
269 return ac;
270 }
271 mem = in->in(TypeFunc::Memory);
272 } else {
273 assert(false, "unexpected projection");
274 }
275 } else if (mem->is_Store()) {
276 const TypePtr* atype = mem->as_Store()->adr_type();
277 int adr_idx = phase->C->get_alias_index(atype);
278 if (adr_idx == alias_idx) {
279 assert(atype->isa_oopptr(), "address type must be oopptr");
280 int adr_offset = atype->offset();
281 uint adr_iid = atype->is_oopptr()->instance_id();
282 // Array elements references have the same alias_idx
283 // but different offset and different instance_id.
284 if (adr_offset == offset && adr_iid == alloc->_idx)
285 return mem;
286 } else {
287 assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
288 }
289 mem = mem->in(MemNode::Memory);
290 } else if (mem->is_ClearArray()) {
291 if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
292 // Can not bypass initialization of the instance
293 // we are looking.
294 debug_only(intptr_t offset;)
295 assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
296 InitializeNode* init = alloc->as_Allocate()->initialization();
297 // We are looking for stored value, return Initialize node
298 // or memory edge from Allocate node.
299 if (init != NULL)
300 return init;
301 else
302 return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
303 }
304 // Otherwise skip it (the call updated 'mem' value).
305 } else if (mem->Opcode() == Op_SCMemProj) {
306 mem = mem->in(0);
307 Node* adr = NULL;
308 if (mem->is_LoadStore()) {
309 adr = mem->in(MemNode::Address);
310 } else {
311 assert(mem->Opcode() == Op_EncodeISOArray ||
312 mem->Opcode() == Op_StrCompressedCopy, "sanity");
313 adr = mem->in(3); // Destination array
314 }
315 const TypePtr* atype = adr->bottom_type()->is_ptr();
316 int adr_idx = phase->C->get_alias_index(atype);
317 if (adr_idx == alias_idx) {
318 DEBUG_ONLY(mem->dump();)
319 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
320 return NULL;
321 }
322 mem = mem->in(MemNode::Memory);
323 } else if (mem->Opcode() == Op_StrInflatedCopy) {
324 Node* adr = mem->in(3); // Destination array
325 const TypePtr* atype = adr->bottom_type()->is_ptr();
326 int adr_idx = phase->C->get_alias_index(atype);
327 if (adr_idx == alias_idx) {
328 DEBUG_ONLY(mem->dump();)
329 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field");
330 return NULL;
331 }
332 mem = mem->in(MemNode::Memory);
333 } else {
334 return mem;
335 }
336 assert(mem != orig_mem, "dead memory loop");
337 }
338 }
339
340 // Generate loads from source of the arraycopy for fields of
341 // destination needed at a deoptimization point
342 Node* PhaseMacroExpand::make_arraycopy_load(ArrayCopyNode* ac, intptr_t offset, Node* ctl, Node* mem, BasicType ft, const Type *ftype, AllocateNode *alloc) {
343 BasicType bt = ft;
344 const Type *type = ftype;
345 if (ft == T_NARROWOOP) {
346 bt = T_OBJECT;
347 type = ftype->make_oopptr();
348 }
349 Node* res = NULL;
350 if (ac->is_clonebasic()) {
351 assert(ac->in(ArrayCopyNode::Src) != ac->in(ArrayCopyNode::Dest), "clone source equals destination");
352 Node* base = ac->in(ArrayCopyNode::Src)->in(AddPNode::Base);
353 Node* adr = _igvn.transform(new AddPNode(base, base, MakeConX(offset)));
354 const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset);
355 res = LoadNode::make(_igvn, ctl, mem, adr, adr_type, type, bt, MemNode::unordered, LoadNode::UnknownControl);
356 } else {
357 if (ac->modifies(offset, offset, &_igvn, true)) {
358 assert(ac->in(ArrayCopyNode::Dest) == alloc->result_cast(), "arraycopy destination should be allocation's result");
359 uint shift = exact_log2(type2aelembytes(bt));
360 Node* diff = _igvn.transform(new SubINode(ac->in(ArrayCopyNode::SrcPos), ac->in(ArrayCopyNode::DestPos)));
361 #ifdef _LP64
362 diff = _igvn.transform(new ConvI2LNode(diff));
363 #endif
364 diff = _igvn.transform(new LShiftXNode(diff, intcon(shift)));
365
366 Node* off = _igvn.transform(new AddXNode(MakeConX(offset), diff));
367 Node* base = ac->in(ArrayCopyNode::Src);
368 Node* adr = _igvn.transform(new AddPNode(base, base, off));
369 const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset);
370 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) {
371 // Don't emit a new load from src if src == dst but try to get the value from memory instead
372 return value_from_mem(ac->in(TypeFunc::Memory), ctl, ft, ftype, adr_type->isa_oopptr(), alloc);
373 }
374 res = LoadNode::make(_igvn, ctl, mem, adr, adr_type, type, bt, MemNode::unordered, LoadNode::UnknownControl);
375 }
376 }
377 if (res != NULL) {
378 res = _igvn.transform(res);
379 if (ftype->isa_narrowoop()) {
380 // PhaseMacroExpand::scalar_replacement adds DecodeN nodes
381 res = _igvn.transform(new EncodePNode(res, ftype));
382 }
383 return res;
384 }
385 return NULL;
386 }
387
388 //
389 // Given a Memory Phi, compute a value Phi containing the values from stores
390 // on the input paths.
391 // Note: this function is recursive, its depth is limited by the "level" argument
392 // Returns the computed Phi, or NULL if it cannot compute it.
393 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) {
394 assert(mem->is_Phi(), "sanity");
395 int alias_idx = C->get_alias_index(adr_t);
396 int offset = adr_t->offset();
397 int instance_id = adr_t->instance_id();
398
399 // Check if an appropriate value phi already exists.
400 Node* region = mem->in(0);
401 for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
402 Node* phi = region->fast_out(k);
403 if (phi->is_Phi() && phi != mem &&
404 phi->as_Phi()->is_same_inst_field(phi_type, (int)mem->_idx, instance_id, alias_idx, offset)) {
405 return phi;
406 }
407 }
408 // Check if an appropriate new value phi already exists.
409 Node* new_phi = value_phis->find(mem->_idx);
410 if (new_phi != NULL)
411 return new_phi;
412
413 if (level <= 0) {
414 return NULL; // Give up: phi tree too deep
415 }
416 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
417 Node *alloc_mem = alloc->in(TypeFunc::Memory);
418
419 uint length = mem->req();
420 GrowableArray <Node *> values(length, length, NULL, false);
421
422 // create a new Phi for the value
423 PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, mem->_idx, instance_id, alias_idx, offset);
424 transform_later(phi);
425 value_phis->push(phi, mem->_idx);
426
427 for (uint j = 1; j < length; j++) {
428 Node *in = mem->in(j);
429 if (in == NULL || in->is_top()) {
430 values.at_put(j, in);
431 } else {
432 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
433 if (val == start_mem || val == alloc_mem) {
434 // hit a sentinel, return appropriate 0 value
435 values.at_put(j, _igvn.zerocon(ft));
436 continue;
437 }
438 if (val->is_Initialize()) {
439 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
440 }
441 if (val == NULL) {
442 return NULL; // can't find a value on this path
443 }
444 if (val == mem) {
445 values.at_put(j, mem);
446 } else if (val->is_Store()) {
447 Node* n = val->in(MemNode::ValueIn);
448 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
449 n = bs->step_over_gc_barrier(n);
450 values.at_put(j, n);
451 } else if(val->is_Proj() && val->in(0) == alloc) {
452 values.at_put(j, _igvn.zerocon(ft));
453 } else if (val->is_Phi()) {
454 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
455 if (val == NULL) {
456 return NULL;
457 }
458 values.at_put(j, val);
459 } else if (val->Opcode() == Op_SCMemProj) {
460 assert(val->in(0)->is_LoadStore() ||
461 val->in(0)->Opcode() == Op_EncodeISOArray ||
462 val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity");
463 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field");
464 return NULL;
465 } else if (val->is_ArrayCopy()) {
466 Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc);
467 if (res == NULL) {
468 return NULL;
469 }
470 values.at_put(j, res);
471 } else {
472 #ifdef ASSERT
473 val->dump();
474 assert(false, "unknown node on this path");
475 #endif
476 return NULL; // unknown node on this path
477 }
478 }
479 }
480 // Set Phi's inputs
481 for (uint j = 1; j < length; j++) {
482 if (values.at(j) == mem) {
483 phi->init_req(j, phi);
484 } else {
485 phi->init_req(j, values.at(j));
486 }
487 }
488 return phi;
489 }
490
491 // Search the last value stored into the object's field.
492 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) {
493 assert(adr_t->is_known_instance_field(), "instance required");
494 int instance_id = adr_t->instance_id();
495 assert((uint)instance_id == alloc->_idx, "wrong allocation");
496
497 int alias_idx = C->get_alias_index(adr_t);
498 int offset = adr_t->offset();
499 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory);
500 Node *alloc_ctrl = alloc->in(TypeFunc::Control);
501 Node *alloc_mem = alloc->in(TypeFunc::Memory);
502 Arena *a = Thread::current()->resource_area();
503 VectorSet visited(a);
504
505 bool done = sfpt_mem == alloc_mem;
506 Node *mem = sfpt_mem;
507 while (!done) {
508 if (visited.test_set(mem->_idx)) {
509 return NULL; // found a loop, give up
510 }
511 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
512 if (mem == start_mem || mem == alloc_mem) {
513 done = true; // hit a sentinel, return appropriate 0 value
514 } else if (mem->is_Initialize()) {
515 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
516 if (mem == NULL) {
517 done = true; // Something go wrong.
518 } else if (mem->is_Store()) {
519 const TypePtr* atype = mem->as_Store()->adr_type();
520 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
521 done = true;
522 }
523 } else if (mem->is_Store()) {
524 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
525 assert(atype != NULL, "address type must be oopptr");
526 assert(C->get_alias_index(atype) == alias_idx &&
527 atype->is_known_instance_field() && atype->offset() == offset &&
528 atype->instance_id() == instance_id, "store is correct memory slice");
529 done = true;
530 } else if (mem->is_Phi()) {
531 // try to find a phi's unique input
532 Node *unique_input = NULL;
533 Node *top = C->top();
534 for (uint i = 1; i < mem->req(); i++) {
535 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
536 if (n == NULL || n == top || n == mem) {
537 continue;
538 } else if (unique_input == NULL) {
539 unique_input = n;
540 } else if (unique_input != n) {
541 unique_input = top;
542 break;
543 }
544 }
545 if (unique_input != NULL && unique_input != top) {
546 mem = unique_input;
547 } else {
548 done = true;
549 }
550 } else if (mem->is_ArrayCopy()) {
551 done = true;
552 } else {
553 assert(false, "unexpected node");
554 }
555 }
556 if (mem != NULL) {
557 if (mem == start_mem || mem == alloc_mem) {
558 // hit a sentinel, return appropriate 0 value
559 return _igvn.zerocon(ft);
560 } else if (mem->is_Store()) {
561 Node* n = mem->in(MemNode::ValueIn);
562 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
563 n = bs->step_over_gc_barrier(n);
564 return n;
565 } else if (mem->is_Phi()) {
566 // attempt to produce a Phi reflecting the values on the input paths of the Phi
567 Node_Stack value_phis(a, 8);
568 Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
569 if (phi != NULL) {
570 return phi;
571 } else {
572 // Kill all new Phis
573 while(value_phis.is_nonempty()) {
574 Node* n = value_phis.node();
575 _igvn.replace_node(n, C->top());
576 value_phis.pop();
577 }
578 }
579 } else if (mem->is_ArrayCopy()) {
580 Node* ctl = mem->in(0);
581 Node* m = mem->in(TypeFunc::Memory);
582 if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj(Deoptimization::Reason_none)) {
583 // pin the loads in the uncommon trap path
584 ctl = sfpt_ctl;
585 m = sfpt_mem;
586 }
587 return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc);
588 }
589 }
590 // Something go wrong.
591 return NULL;
592 }
593
594 // Check the possibility of scalar replacement.
595 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
596 // Scan the uses of the allocation to check for anything that would
597 // prevent us from eliminating it.
598 NOT_PRODUCT( const char* fail_eliminate = NULL; )
599 DEBUG_ONLY( Node* disq_node = NULL; )
600 bool can_eliminate = true;
601
602 Node* res = alloc->result_cast();
603 const TypeOopPtr* res_type = NULL;
604 if (res == NULL) {
605 // All users were eliminated.
606 } else if (!res->is_CheckCastPP()) {
607 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
608 can_eliminate = false;
609 } else {
610 res_type = _igvn.type(res)->isa_oopptr();
611 if (res_type == NULL) {
612 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
613 can_eliminate = false;
614 } else if (res_type->isa_aryptr()) {
615 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
616 if (length < 0) {
617 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
618 can_eliminate = false;
619 }
620 }
621 }
622
623 if (can_eliminate && res != NULL) {
624 for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
625 j < jmax && can_eliminate; j++) {
626 Node* use = res->fast_out(j);
627
628 if (use->is_AddP()) {
629 const TypePtr* addp_type = _igvn.type(use)->is_ptr();
630 int offset = addp_type->offset();
631
632 if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
633 NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
634 can_eliminate = false;
635 break;
636 }
637 for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
638 k < kmax && can_eliminate; k++) {
639 Node* n = use->fast_out(k);
640 if (!n->is_Store() && n->Opcode() != Op_CastP2X &&
641 SHENANDOAHGC_ONLY((!UseShenandoahGC || !ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(n)) &&)
642 !(n->is_ArrayCopy() &&
643 n->as_ArrayCopy()->is_clonebasic() &&
644 n->in(ArrayCopyNode::Dest) == use)) {
645 DEBUG_ONLY(disq_node = n;)
646 if (n->is_Load() || n->is_LoadStore()) {
647 NOT_PRODUCT(fail_eliminate = "Field load";)
648 } else {
649 NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
650 }
651 can_eliminate = false;
652 }
653 }
654 } else if (use->is_ArrayCopy() &&
655 (use->as_ArrayCopy()->is_arraycopy_validated() ||
656 use->as_ArrayCopy()->is_copyof_validated() ||
657 use->as_ArrayCopy()->is_copyofrange_validated()) &&
658 use->in(ArrayCopyNode::Dest) == res) {
659 // ok to eliminate
660 } else if (use->is_SafePoint()) {
661 SafePointNode* sfpt = use->as_SafePoint();
662 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
663 // Object is passed as argument.
664 DEBUG_ONLY(disq_node = use;)
665 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
666 can_eliminate = false;
667 }
668 Node* sfptMem = sfpt->memory();
669 if (sfptMem == NULL || sfptMem->is_top()) {
670 DEBUG_ONLY(disq_node = use;)
671 NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
672 can_eliminate = false;
673 } else {
674 safepoints.append_if_missing(sfpt);
675 }
676 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
677 if (use->is_Phi()) {
678 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
679 NOT_PRODUCT(fail_eliminate = "Object is return value";)
680 } else {
681 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
682 }
683 DEBUG_ONLY(disq_node = use;)
684 } else {
685 if (use->Opcode() == Op_Return) {
686 NOT_PRODUCT(fail_eliminate = "Object is return value";)
687 }else {
688 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
689 }
690 DEBUG_ONLY(disq_node = use;)
691 }
692 can_eliminate = false;
693 }
694 }
695 }
696
697 #ifndef PRODUCT
698 if (PrintEliminateAllocations) {
699 if (can_eliminate) {
700 tty->print("Scalar ");
701 if (res == NULL)
702 alloc->dump();
703 else
704 res->dump();
705 } else if (alloc->_is_scalar_replaceable) {
706 tty->print("NotScalar (%s)", fail_eliminate);
707 if (res == NULL)
708 alloc->dump();
709 else
710 res->dump();
711 #ifdef ASSERT
712 if (disq_node != NULL) {
713 tty->print(" >>>> ");
714 disq_node->dump();
715 }
716 #endif /*ASSERT*/
717 }
718 }
719 #endif
720 return can_eliminate;
721 }
722
723 // Do scalar replacement.
724 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
725 GrowableArray <SafePointNode *> safepoints_done;
726
727 ciKlass* klass = NULL;
728 ciInstanceKlass* iklass = NULL;
729 int nfields = 0;
730 int array_base = 0;
731 int element_size = 0;
732 BasicType basic_elem_type = T_ILLEGAL;
733 ciType* elem_type = NULL;
734
735 Node* res = alloc->result_cast();
736 assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result");
737 const TypeOopPtr* res_type = NULL;
738 if (res != NULL) { // Could be NULL when there are no users
739 res_type = _igvn.type(res)->isa_oopptr();
740 }
741
742 if (res != NULL) {
743 klass = res_type->klass();
744 if (res_type->isa_instptr()) {
745 // find the fields of the class which will be needed for safepoint debug information
746 assert(klass->is_instance_klass(), "must be an instance klass.");
747 iklass = klass->as_instance_klass();
748 nfields = iklass->nof_nonstatic_fields();
749 } else {
750 // find the array's elements which will be needed for safepoint debug information
751 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
752 assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
753 elem_type = klass->as_array_klass()->element_type();
754 basic_elem_type = elem_type->basic_type();
755 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
756 element_size = type2aelembytes(basic_elem_type);
757 }
758 }
759 //
760 // Process the safepoint uses
761 //
762 while (safepoints.length() > 0) {
763 SafePointNode* sfpt = safepoints.pop();
764 Node* mem = sfpt->memory();
765 Node* ctl = sfpt->control();
766 assert(sfpt->jvms() != NULL, "missed JVMS");
767 // Fields of scalar objs are referenced only at the end
768 // of regular debuginfo at the last (youngest) JVMS.
769 // Record relative start index.
770 uint first_ind = (sfpt->req() - sfpt->jvms()->scloff());
771 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type,
772 #ifdef ASSERT
773 alloc,
774 #endif
775 first_ind, nfields);
776 sobj->init_req(0, C->root());
777 transform_later(sobj);
778
779 // Scan object's fields adding an input to the safepoint for each field.
780 for (int j = 0; j < nfields; j++) {
781 intptr_t offset;
782 ciField* field = NULL;
783 if (iklass != NULL) {
784 field = iklass->nonstatic_field_at(j);
785 offset = field->offset();
786 elem_type = field->type();
787 basic_elem_type = field->layout_type();
788 } else {
789 offset = array_base + j * (intptr_t)element_size;
790 }
791
792 const Type *field_type;
793 // The next code is taken from Parse::do_get_xxx().
794 if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
795 if (!elem_type->is_loaded()) {
796 field_type = TypeInstPtr::BOTTOM;
797 } else if (field != NULL && field->is_static_constant()) {
798 // This can happen if the constant oop is non-perm.
799 ciObject* con = field->constant_value().as_object();
800 // Do not "join" in the previous type; it doesn't add value,
801 // and may yield a vacuous result if the field is of interface type.
802 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
803 assert(field_type != NULL, "field singleton type must be consistent");
804 } else {
805 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
806 }
807 if (UseCompressedOops) {
808 field_type = field_type->make_narrowoop();
809 basic_elem_type = T_NARROWOOP;
810 }
811 } else {
812 field_type = Type::get_const_basic_type(basic_elem_type);
813 }
814
815 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
816
817 Node *field_val = value_from_mem(mem, ctl, basic_elem_type, field_type, field_addr_type, alloc);
818 if (field_val == NULL) {
819 // We weren't able to find a value for this field,
820 // give up on eliminating this allocation.
821
822 // Remove any extra entries we added to the safepoint.
823 uint last = sfpt->req() - 1;
824 for (int k = 0; k < j; k++) {
825 sfpt->del_req(last--);
826 }
827 _igvn._worklist.push(sfpt);
828 // rollback processed safepoints
829 while (safepoints_done.length() > 0) {
830 SafePointNode* sfpt_done = safepoints_done.pop();
831 // remove any extra entries we added to the safepoint
832 last = sfpt_done->req() - 1;
833 for (int k = 0; k < nfields; k++) {
834 sfpt_done->del_req(last--);
835 }
836 JVMState *jvms = sfpt_done->jvms();
837 jvms->set_endoff(sfpt_done->req());
838 // Now make a pass over the debug information replacing any references
839 // to SafePointScalarObjectNode with the allocated object.
840 int start = jvms->debug_start();
841 int end = jvms->debug_end();
842 for (int i = start; i < end; i++) {
843 if (sfpt_done->in(i)->is_SafePointScalarObject()) {
844 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
845 if (scobj->first_index(jvms) == sfpt_done->req() &&
846 scobj->n_fields() == (uint)nfields) {
847 assert(scobj->alloc() == alloc, "sanity");
848 sfpt_done->set_req(i, res);
849 }
850 }
851 }
852 _igvn._worklist.push(sfpt_done);
853 }
854 #ifndef PRODUCT
855 if (PrintEliminateAllocations) {
856 if (field != NULL) {
857 tty->print("=== At SafePoint node %d can't find value of Field: ",
858 sfpt->_idx);
859 field->print();
860 int field_idx = C->get_alias_index(field_addr_type);
861 tty->print(" (alias_idx=%d)", field_idx);
862 } else { // Array's element
863 tty->print("=== At SafePoint node %d can't find value of array element [%d]",
864 sfpt->_idx, j);
865 }
866 tty->print(", which prevents elimination of: ");
867 if (res == NULL)
868 alloc->dump();
869 else
870 res->dump();
871 }
872 #endif
873 return false;
874 }
875 if (UseCompressedOops && field_type->isa_narrowoop()) {
876 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
877 // to be able scalar replace the allocation.
878 if (field_val->is_EncodeP()) {
879 field_val = field_val->in(1);
880 } else {
881 field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type()));
882 }
883 }
884 sfpt->add_req(field_val);
885 }
886 JVMState *jvms = sfpt->jvms();
887 jvms->set_endoff(sfpt->req());
888 // Now make a pass over the debug information replacing any references
889 // to the allocated object with "sobj"
890 int start = jvms->debug_start();
891 int end = jvms->debug_end();
892 sfpt->replace_edges_in_range(res, sobj, start, end);
893 _igvn._worklist.push(sfpt);
894 safepoints_done.append_if_missing(sfpt); // keep it for rollback
895 }
896 return true;
897 }
898
899 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) {
900 Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control);
901 Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory);
902 if (ctl_proj != NULL) {
903 igvn.replace_node(ctl_proj, n->in(0));
904 }
905 if (mem_proj != NULL) {
906 igvn.replace_node(mem_proj, n->in(TypeFunc::Memory));
907 }
908 }
909
910 // Process users of eliminated allocation.
911 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
912 Node* res = alloc->result_cast();
913 if (res != NULL) {
914 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
915 Node *use = res->last_out(j);
916 uint oc1 = res->outcnt();
917
918 if (use->is_AddP()) {
919 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
920 Node *n = use->last_out(k);
921 uint oc2 = use->outcnt();
922 if (n->is_Store()) {
923 #ifdef ASSERT
924 // Verify that there is no dependent MemBarVolatile nodes,
925 // they should be removed during IGVN, see MemBarNode::Ideal().
926 for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
927 p < pmax; p++) {
928 Node* mb = n->fast_out(p);
929 assert(mb->is_Initialize() || !mb->is_MemBar() ||
930 mb->req() <= MemBarNode::Precedent ||
931 mb->in(MemBarNode::Precedent) != n,
932 "MemBarVolatile should be eliminated for non-escaping object");
933 }
934 #endif
935 _igvn.replace_node(n, n->in(MemNode::Memory));
936 } else if (n->is_ArrayCopy()) {
937 // Disconnect ArrayCopy node
938 ArrayCopyNode* ac = n->as_ArrayCopy();
939 assert(ac->is_clonebasic(), "unexpected array copy kind");
940 Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out();
941 disconnect_projections(ac, _igvn);
942 assert(alloc->in(0)->is_Proj() && alloc->in(0)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation");
943 Node* membar_before = alloc->in(0)->in(0);
944 disconnect_projections(membar_before->as_MemBar(), _igvn);
945 if (membar_after->is_MemBar()) {
946 disconnect_projections(membar_after->as_MemBar(), _igvn);
947 }
948 } else {
949 eliminate_gc_barrier(n);
950 }
951 k -= (oc2 - use->outcnt());
952 }
953 _igvn.remove_dead_node(use);
954 } else if (use->is_ArrayCopy()) {
955 // Disconnect ArrayCopy node
956 ArrayCopyNode* ac = use->as_ArrayCopy();
957 assert(ac->is_arraycopy_validated() ||
958 ac->is_copyof_validated() ||
959 ac->is_copyofrange_validated(), "unsupported");
960 CallProjections callprojs;
961 ac->extract_projections(&callprojs, true);
962
963 _igvn.replace_node(callprojs.fallthrough_ioproj, ac->in(TypeFunc::I_O));
964 _igvn.replace_node(callprojs.fallthrough_memproj, ac->in(TypeFunc::Memory));
965 _igvn.replace_node(callprojs.fallthrough_catchproj, ac->in(TypeFunc::Control));
966
967 // Set control to top. IGVN will remove the remaining projections
968 ac->set_req(0, top());
969 ac->replace_edge(res, top());
970
971 // Disconnect src right away: it can help find new
972 // opportunities for allocation elimination
973 Node* src = ac->in(ArrayCopyNode::Src);
974 ac->replace_edge(src, top());
975 // src can be top at this point if src and dest of the
976 // arraycopy were the same
977 if (src->outcnt() == 0 && !src->is_top()) {
978 _igvn.remove_dead_node(src);
979 }
980
981 _igvn._worklist.push(ac);
982 } else {
983 eliminate_gc_barrier(use);
984 }
985 j -= (oc1 - res->outcnt());
986 }
987 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
988 _igvn.remove_dead_node(res);
989 }
990
991 //
992 // Process other users of allocation's projections
993 //
994 if (_resproj != NULL && _resproj->outcnt() != 0) {
995 // First disconnect stores captured by Initialize node.
996 // If Initialize node is eliminated first in the following code,
997 // it will kill such stores and DUIterator_Last will assert.
998 for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax); j < jmax; j++) {
999 Node *use = _resproj->fast_out(j);
1000 if (use->is_AddP()) {
1001 // raw memory addresses used only by the initialization
1002 _igvn.replace_node(use, C->top());
1003 --j; --jmax;
1004 }
1005 }
1006 for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
1007 Node *use = _resproj->last_out(j);
1008 uint oc1 = _resproj->outcnt();
1009 if (use->is_Initialize()) {
1010 // Eliminate Initialize node.
1011 InitializeNode *init = use->as_Initialize();
1012 assert(init->outcnt() <= 2, "only a control and memory projection expected");
1013 Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
1014 if (ctrl_proj != NULL) {
1015 _igvn.replace_node(ctrl_proj, init->in(TypeFunc::Control));
1016 #ifdef ASSERT
1017 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1018 Node* tmp = init->in(TypeFunc::Control);
1019 while (bs->is_gc_barrier_node(tmp)) {
1020 Node* tmp2 = bs->step_over_gc_barrier_ctrl(tmp);
1021 assert(tmp != tmp2, "Must make progress");
1022 tmp = tmp2;
1023 }
1024 assert(tmp == _fallthroughcatchproj, "allocation control projection");
1025 #endif
1026 }
1027 Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
1028 if (mem_proj != NULL) {
1029 Node *mem = init->in(TypeFunc::Memory);
1030 #ifdef ASSERT
1031 if (mem->is_MergeMem()) {
1032 assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
1033 } else {
1034 assert(mem == _memproj_fallthrough, "allocation memory projection");
1035 }
1036 #endif
1037 _igvn.replace_node(mem_proj, mem);
1038 }
1039 } else {
1040 assert(false, "only Initialize or AddP expected");
1041 }
1042 j -= (oc1 - _resproj->outcnt());
1043 }
1044 }
1045 if (_fallthroughcatchproj != NULL) {
1046 _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
1047 }
1048 if (_memproj_fallthrough != NULL) {
1049 _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
1050 }
1051 if (_memproj_catchall != NULL) {
1052 _igvn.replace_node(_memproj_catchall, C->top());
1053 }
1054 if (_ioproj_fallthrough != NULL) {
1055 _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
1056 }
1057 if (_ioproj_catchall != NULL) {
1058 _igvn.replace_node(_ioproj_catchall, C->top());
1059 }
1060 if (_catchallcatchproj != NULL) {
1061 _igvn.replace_node(_catchallcatchproj, C->top());
1062 }
1063 }
1064
1065 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
1066 // Don't do scalar replacement if the frame can be popped by JVMTI:
1067 // if reallocation fails during deoptimization we'll pop all
1068 // interpreter frames for this compiled frame and that won't play
1069 // nice with JVMTI popframe.
1070 if (!EliminateAllocations || JvmtiExport::can_pop_frame() || !alloc->_is_non_escaping) {
1071 return false;
1072 }
1073 Node* klass = alloc->in(AllocateNode::KlassNode);
1074 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
1075 Node* res = alloc->result_cast();
1076 // Eliminate boxing allocations which are not used
1077 // regardless scalar replacable status.
1078 bool boxing_alloc = C->eliminate_boxing() &&
1079 tklass->klass()->is_instance_klass() &&
1080 tklass->klass()->as_instance_klass()->is_box_klass();
1081 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
1082 return false;
1083 }
1084
1085 extract_call_projections(alloc);
1086
1087 GrowableArray <SafePointNode *> safepoints;
1088 if (!can_eliminate_allocation(alloc, safepoints)) {
1089 return false;
1090 }
1091
1092 if (!alloc->_is_scalar_replaceable) {
1093 assert(res == NULL, "sanity");
1094 // We can only eliminate allocation if all debug info references
1095 // are already replaced with SafePointScalarObject because
1096 // we can't search for a fields value without instance_id.
1097 if (safepoints.length() > 0) {
1098 return false;
1099 }
1100 }
1101
1102 if (!scalar_replacement(alloc, safepoints)) {
1103 return false;
1104 }
1105
1106 CompileLog* log = C->log();
1107 if (log != NULL) {
1108 log->head("eliminate_allocation type='%d'",
1109 log->identify(tklass->klass()));
1110 JVMState* p = alloc->jvms();
1111 while (p != NULL) {
1112 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1113 p = p->caller();
1114 }
1115 log->tail("eliminate_allocation");
1116 }
1117
1118 process_users_of_allocation(alloc);
1119
1120 #ifndef PRODUCT
1121 if (PrintEliminateAllocations) {
1122 if (alloc->is_AllocateArray())
1123 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1124 else
1125 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1126 }
1127 #endif
1128
1129 return true;
1130 }
1131
1132 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1133 // EA should remove all uses of non-escaping boxing node.
1134 if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != NULL) {
1135 return false;
1136 }
1137
1138 assert(boxing->result_cast() == NULL, "unexpected boxing node result");
1139
1140 extract_call_projections(boxing);
1141
1142 const TypeTuple* r = boxing->tf()->range();
1143 assert(r->cnt() > TypeFunc::Parms, "sanity");
1144 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1145 assert(t != NULL, "sanity");
1146
1147 CompileLog* log = C->log();
1148 if (log != NULL) {
1149 log->head("eliminate_boxing type='%d'",
1150 log->identify(t->klass()));
1151 JVMState* p = boxing->jvms();
1152 while (p != NULL) {
1153 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1154 p = p->caller();
1155 }
1156 log->tail("eliminate_boxing");
1157 }
1158
1159 process_users_of_allocation(boxing);
1160
1161 #ifndef PRODUCT
1162 if (PrintEliminateAllocations) {
1163 tty->print("++++ Eliminated: %d ", boxing->_idx);
1164 boxing->method()->print_short_name(tty);
1165 tty->cr();
1166 }
1167 #endif
1168
1169 return true;
1170 }
1171
1172 //---------------------------set_eden_pointers-------------------------
1173 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1174 if (UseTLAB) { // Private allocation: load from TLS
1175 Node* thread = transform_later(new ThreadLocalNode());
1176 int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1177 int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1178 eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1179 eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1180 } else { // Shared allocation: load from globals
1181 CollectedHeap* ch = Universe::heap();
1182 address top_adr = (address)ch->top_addr();
1183 address end_adr = (address)ch->end_addr();
1184 eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1185 eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1186 }
1187 }
1188
1189
1190 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1191 Node* adr = basic_plus_adr(base, offset);
1192 const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1193 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered);
1194 transform_later(value);
1195 return value;
1196 }
1197
1198
1199 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1200 Node* adr = basic_plus_adr(base, offset);
1201 mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered);
1202 transform_later(mem);
1203 return mem;
1204 }
1205
1206 //=============================================================================
1207 //
1208 // A L L O C A T I O N
1209 //
1210 // Allocation attempts to be fast in the case of frequent small objects.
1211 // It breaks down like this:
1212 //
1213 // 1) Size in doublewords is computed. This is a constant for objects and
1214 // variable for most arrays. Doubleword units are used to avoid size
1215 // overflow of huge doubleword arrays. We need doublewords in the end for
1216 // rounding.
1217 //
1218 // 2) Size is checked for being 'too large'. Too-large allocations will go
1219 // the slow path into the VM. The slow path can throw any required
1220 // exceptions, and does all the special checks for very large arrays. The
1221 // size test can constant-fold away for objects. For objects with
1222 // finalizers it constant-folds the otherway: you always go slow with
1223 // finalizers.
1224 //
1225 // 3) If NOT using TLABs, this is the contended loop-back point.
1226 // Load-Locked the heap top. If using TLABs normal-load the heap top.
1227 //
1228 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
1229 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
1230 // "size*8" we always enter the VM, where "largish" is a constant picked small
1231 // enough that there's always space between the eden max and 4Gig (old space is
1232 // there so it's quite large) and large enough that the cost of entering the VM
1233 // is dwarfed by the cost to initialize the space.
1234 //
1235 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1236 // down. If contended, repeat at step 3. If using TLABs normal-store
1237 // adjusted heap top back down; there is no contention.
1238 //
1239 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
1240 // fields.
1241 //
1242 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1243 // oop flavor.
1244 //
1245 //=============================================================================
1246 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1247 // Allocations bigger than this always go the slow route.
1248 // This value must be small enough that allocation attempts that need to
1249 // trigger exceptions go the slow route. Also, it must be small enough so
1250 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1251 //=============================================================================j//
1252 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1253 // The allocator will coalesce int->oop copies away. See comment in
1254 // coalesce.cpp about how this works. It depends critically on the exact
1255 // code shape produced here, so if you are changing this code shape
1256 // make sure the GC info for the heap-top is correct in and around the
1257 // slow-path call.
1258 //
1259
1260 void PhaseMacroExpand::expand_allocate_common(
1261 AllocateNode* alloc, // allocation node to be expanded
1262 Node* length, // array length for an array allocation
1263 const TypeFunc* slow_call_type, // Type of slow call
1264 address slow_call_address // Address of slow call
1265 )
1266 {
1267
1268 Node* ctrl = alloc->in(TypeFunc::Control);
1269 Node* mem = alloc->in(TypeFunc::Memory);
1270 Node* i_o = alloc->in(TypeFunc::I_O);
1271 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
1272 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1273 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1274
1275 assert(ctrl != NULL, "must have control");
1276 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1277 // they will not be used if "always_slow" is set
1278 enum { slow_result_path = 1, fast_result_path = 2 };
1279 Node *result_region = NULL;
1280 Node *result_phi_rawmem = NULL;
1281 Node *result_phi_rawoop = NULL;
1282 Node *result_phi_i_o = NULL;
1283
1284 // The initial slow comparison is a size check, the comparison
1285 // we want to do is a BoolTest::gt
1286 bool always_slow = false;
1287 int tv = _igvn.find_int_con(initial_slow_test, -1);
1288 if (tv >= 0) {
1289 always_slow = (tv == 1);
1290 initial_slow_test = NULL;
1291 } else {
1292 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1293 }
1294
1295 if (C->env()->dtrace_alloc_probes() ||
1296 (!UseTLAB && !Universe::heap()->supports_inline_contig_alloc())) {
1297 // Force slow-path allocation
1298 always_slow = true;
1299 initial_slow_test = NULL;
1300 }
1301
1302
1303 enum { too_big_or_final_path = 1, need_gc_path = 2 };
1304 Node *slow_region = NULL;
1305 Node *toobig_false = ctrl;
1306
1307 assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1308 // generate the initial test if necessary
1309 if (initial_slow_test != NULL ) {
1310 slow_region = new RegionNode(3);
1311
1312 // Now make the initial failure test. Usually a too-big test but
1313 // might be a TRUE for finalizers or a fancy class check for
1314 // newInstance0.
1315 IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1316 transform_later(toobig_iff);
1317 // Plug the failing-too-big test into the slow-path region
1318 Node *toobig_true = new IfTrueNode( toobig_iff );
1319 transform_later(toobig_true);
1320 slow_region ->init_req( too_big_or_final_path, toobig_true );
1321 toobig_false = new IfFalseNode( toobig_iff );
1322 transform_later(toobig_false);
1323 } else { // No initial test, just fall into next case
1324 toobig_false = ctrl;
1325 debug_only(slow_region = NodeSentinel);
1326 }
1327
1328 Node *slow_mem = mem; // save the current memory state for slow path
1329 // generate the fast allocation code unless we know that the initial test will always go slow
1330 if (!always_slow) {
1331 // Fast path modifies only raw memory.
1332 if (mem->is_MergeMem()) {
1333 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1334 }
1335
1336 // allocate the Region and Phi nodes for the result
1337 result_region = new RegionNode(3);
1338 result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1339 result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM);
1340 result_phi_i_o = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1341
1342 // Grab regular I/O before optional prefetch may change it.
1343 // Slow-path does no I/O so just set it to the original I/O.
1344 result_phi_i_o->init_req(slow_result_path, i_o);
1345
1346 Node* needgc_ctrl = NULL;
1347 // Name successful fast-path variables
1348 Node* fast_oop_ctrl;
1349 Node* fast_oop_rawmem;
1350
1351 intx prefetch_lines = length != NULL ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1352
1353 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1354 Node* fast_oop = bs->obj_allocate(this, ctrl, mem, toobig_false, size_in_bytes, i_o, needgc_ctrl,
1355 fast_oop_ctrl, fast_oop_rawmem,
1356 prefetch_lines);
1357
1358 if (initial_slow_test) {
1359 slow_region->init_req(need_gc_path, needgc_ctrl);
1360 // This completes all paths into the slow merge point
1361 transform_later(slow_region);
1362 } else { // No initial slow path needed!
1363 // Just fall from the need-GC path straight into the VM call.
1364 slow_region = needgc_ctrl;
1365 }
1366
1367 InitializeNode* init = alloc->initialization();
1368 fast_oop_rawmem = initialize_object(alloc,
1369 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1370 klass_node, length, size_in_bytes);
1371
1372 // If initialization is performed by an array copy, any required
1373 // MemBarStoreStore was already added. If the object does not
1374 // escape no need for a MemBarStoreStore. If the object does not
1375 // escape in its initializer and memory barrier (MemBarStoreStore or
1376 // stronger) is already added at exit of initializer, also no need
1377 // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore
1378 // so that stores that initialize this object can't be reordered
1379 // with a subsequent store that makes this object accessible by
1380 // other threads.
1381 // Other threads include java threads and JVM internal threads
1382 // (for example concurrent GC threads). Current concurrent GC
1383 // implementation: CMS and G1 will not scan newly created object,
1384 // so it's safe to skip storestore barrier when allocation does
1385 // not escape.
1386 if (!alloc->does_not_escape_thread() &&
1387 !alloc->is_allocation_MemBar_redundant() &&
1388 (init == NULL || !init->is_complete_with_arraycopy())) {
1389 if (init == NULL || init->req() < InitializeNode::RawStores) {
1390 // No InitializeNode or no stores captured by zeroing
1391 // elimination. Simply add the MemBarStoreStore after object
1392 // initialization.
1393 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1394 transform_later(mb);
1395
1396 mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1397 mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1398 fast_oop_ctrl = new ProjNode(mb,TypeFunc::Control);
1399 transform_later(fast_oop_ctrl);
1400 fast_oop_rawmem = new ProjNode(mb,TypeFunc::Memory);
1401 transform_later(fast_oop_rawmem);
1402 } else {
1403 // Add the MemBarStoreStore after the InitializeNode so that
1404 // all stores performing the initialization that were moved
1405 // before the InitializeNode happen before the storestore
1406 // barrier.
1407
1408 Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control);
1409 Node* init_mem = init->proj_out_or_null(TypeFunc::Memory);
1410
1411 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1412 transform_later(mb);
1413
1414 Node* ctrl = new ProjNode(init,TypeFunc::Control);
1415 transform_later(ctrl);
1416 Node* mem = new ProjNode(init,TypeFunc::Memory);
1417 transform_later(mem);
1418
1419 // The MemBarStoreStore depends on control and memory coming
1420 // from the InitializeNode
1421 mb->init_req(TypeFunc::Memory, mem);
1422 mb->init_req(TypeFunc::Control, ctrl);
1423
1424 ctrl = new ProjNode(mb,TypeFunc::Control);
1425 transform_later(ctrl);
1426 mem = new ProjNode(mb,TypeFunc::Memory);
1427 transform_later(mem);
1428
1429 // All nodes that depended on the InitializeNode for control
1430 // and memory must now depend on the MemBarNode that itself
1431 // depends on the InitializeNode
1432 if (init_ctrl != NULL) {
1433 _igvn.replace_node(init_ctrl, ctrl);
1434 }
1435 if (init_mem != NULL) {
1436 _igvn.replace_node(init_mem, mem);
1437 }
1438 }
1439 }
1440
1441 if (C->env()->dtrace_extended_probes()) {
1442 // Slow-path call
1443 int size = TypeFunc::Parms + 2;
1444 CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1445 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1446 "dtrace_object_alloc",
1447 TypeRawPtr::BOTTOM);
1448
1449 // Get base of thread-local storage area
1450 Node* thread = new ThreadLocalNode();
1451 transform_later(thread);
1452
1453 call->init_req(TypeFunc::Parms+0, thread);
1454 call->init_req(TypeFunc::Parms+1, fast_oop);
1455 call->init_req(TypeFunc::Control, fast_oop_ctrl);
1456 call->init_req(TypeFunc::I_O , top()); // does no i/o
1457 call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1458 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1459 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1460 transform_later(call);
1461 fast_oop_ctrl = new ProjNode(call,TypeFunc::Control);
1462 transform_later(fast_oop_ctrl);
1463 fast_oop_rawmem = new ProjNode(call,TypeFunc::Memory);
1464 transform_later(fast_oop_rawmem);
1465 }
1466
1467 // Plug in the successful fast-path into the result merge point
1468 result_region ->init_req(fast_result_path, fast_oop_ctrl);
1469 result_phi_rawoop->init_req(fast_result_path, fast_oop);
1470 result_phi_i_o ->init_req(fast_result_path, i_o);
1471 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1472 } else {
1473 slow_region = ctrl;
1474 result_phi_i_o = i_o; // Rename it to use in the following code.
1475 }
1476
1477 // Generate slow-path call
1478 CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address,
1479 OptoRuntime::stub_name(slow_call_address),
1480 alloc->jvms()->bci(),
1481 TypePtr::BOTTOM);
1482 call->init_req( TypeFunc::Control, slow_region );
1483 call->init_req( TypeFunc::I_O , top() ) ; // does no i/o
1484 call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1485 call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1486 call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1487
1488 call->init_req(TypeFunc::Parms+0, klass_node);
1489 if (length != NULL) {
1490 call->init_req(TypeFunc::Parms+1, length);
1491 }
1492
1493 // Copy debug information and adjust JVMState information, then replace
1494 // allocate node with the call
1495 copy_call_debug_info((CallNode *) alloc, call);
1496 if (!always_slow) {
1497 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1498 } else {
1499 // Hook i_o projection to avoid its elimination during allocation
1500 // replacement (when only a slow call is generated).
1501 call->set_req(TypeFunc::I_O, result_phi_i_o);
1502 }
1503 _igvn.replace_node(alloc, call);
1504 transform_later(call);
1505
1506 // Identify the output projections from the allocate node and
1507 // adjust any references to them.
1508 // The control and io projections look like:
1509 //
1510 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
1511 // Allocate Catch
1512 // ^---Proj(io) <-------+ ^---CatchProj(io)
1513 //
1514 // We are interested in the CatchProj nodes.
1515 //
1516 extract_call_projections(call);
1517
1518 // An allocate node has separate memory projections for the uses on
1519 // the control and i_o paths. Replace the control memory projection with
1520 // result_phi_rawmem (unless we are only generating a slow call when
1521 // both memory projections are combined)
1522 if (!always_slow && _memproj_fallthrough != NULL) {
1523 for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1524 Node *use = _memproj_fallthrough->fast_out(i);
1525 _igvn.rehash_node_delayed(use);
1526 imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1527 // back up iterator
1528 --i;
1529 }
1530 }
1531 // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1532 // _memproj_catchall so we end up with a call that has only 1 memory projection.
1533 if (_memproj_catchall != NULL ) {
1534 if (_memproj_fallthrough == NULL) {
1535 _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory);
1536 transform_later(_memproj_fallthrough);
1537 }
1538 for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1539 Node *use = _memproj_catchall->fast_out(i);
1540 _igvn.rehash_node_delayed(use);
1541 imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1542 // back up iterator
1543 --i;
1544 }
1545 assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1546 _igvn.remove_dead_node(_memproj_catchall);
1547 }
1548
1549 // An allocate node has separate i_o projections for the uses on the control
1550 // and i_o paths. Always replace the control i_o projection with result i_o
1551 // otherwise incoming i_o become dead when only a slow call is generated
1552 // (it is different from memory projections where both projections are
1553 // combined in such case).
1554 if (_ioproj_fallthrough != NULL) {
1555 for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1556 Node *use = _ioproj_fallthrough->fast_out(i);
1557 _igvn.rehash_node_delayed(use);
1558 imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1559 // back up iterator
1560 --i;
1561 }
1562 }
1563 // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1564 // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1565 if (_ioproj_catchall != NULL ) {
1566 if (_ioproj_fallthrough == NULL) {
1567 _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O);
1568 transform_later(_ioproj_fallthrough);
1569 }
1570 for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1571 Node *use = _ioproj_catchall->fast_out(i);
1572 _igvn.rehash_node_delayed(use);
1573 imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1574 // back up iterator
1575 --i;
1576 }
1577 assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1578 _igvn.remove_dead_node(_ioproj_catchall);
1579 }
1580
1581 // if we generated only a slow call, we are done
1582 if (always_slow) {
1583 // Now we can unhook i_o.
1584 if (result_phi_i_o->outcnt() > 1) {
1585 call->set_req(TypeFunc::I_O, top());
1586 } else {
1587 assert(result_phi_i_o->unique_ctrl_out() == call, "");
1588 // Case of new array with negative size known during compilation.
1589 // AllocateArrayNode::Ideal() optimization disconnect unreachable
1590 // following code since call to runtime will throw exception.
1591 // As result there will be no users of i_o after the call.
1592 // Leave i_o attached to this call to avoid problems in preceding graph.
1593 }
1594 return;
1595 }
1596
1597
1598 if (_fallthroughcatchproj != NULL) {
1599 ctrl = _fallthroughcatchproj->clone();
1600 transform_later(ctrl);
1601 _igvn.replace_node(_fallthroughcatchproj, result_region);
1602 } else {
1603 ctrl = top();
1604 }
1605 Node *slow_result;
1606 if (_resproj == NULL) {
1607 // no uses of the allocation result
1608 slow_result = top();
1609 } else {
1610 slow_result = _resproj->clone();
1611 transform_later(slow_result);
1612 _igvn.replace_node(_resproj, result_phi_rawoop);
1613 }
1614
1615 // Plug slow-path into result merge point
1616 result_region ->init_req( slow_result_path, ctrl );
1617 result_phi_rawoop->init_req( slow_result_path, slow_result);
1618 result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1619 transform_later(result_region);
1620 transform_later(result_phi_rawoop);
1621 transform_later(result_phi_rawmem);
1622 transform_later(result_phi_i_o);
1623 // This completes all paths into the result merge point
1624 }
1625
1626
1627 // Helper for PhaseMacroExpand::expand_allocate_common.
1628 // Initializes the newly-allocated storage.
1629 Node*
1630 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1631 Node* control, Node* rawmem, Node* object,
1632 Node* klass_node, Node* length,
1633 Node* size_in_bytes) {
1634 InitializeNode* init = alloc->initialization();
1635 // Store the klass & mark bits
1636 Node* mark_node = NULL;
1637 // For now only enable fast locking for non-array types
1638 if (UseBiasedLocking && (length == NULL)) {
1639 mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1640 } else {
1641 mark_node = makecon(TypeRawPtr::make((address)markWord::prototype().value()));
1642 }
1643 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1644
1645 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1646 int header_size = alloc->minimum_header_size(); // conservatively small
1647
1648 // Array length
1649 if (length != NULL) { // Arrays need length field
1650 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1651 // conservatively small header size:
1652 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1653 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1654 if (k->is_array_klass()) // we know the exact header size in most cases:
1655 header_size = Klass::layout_helper_header_size(k->layout_helper());
1656 }
1657
1658 // Clear the object body, if necessary.
1659 if (init == NULL) {
1660 // The init has somehow disappeared; be cautious and clear everything.
1661 //
1662 // This can happen if a node is allocated but an uncommon trap occurs
1663 // immediately. In this case, the Initialize gets associated with the
1664 // trap, and may be placed in a different (outer) loop, if the Allocate
1665 // is in a loop. If (this is rare) the inner loop gets unrolled, then
1666 // there can be two Allocates to one Initialize. The answer in all these
1667 // edge cases is safety first. It is always safe to clear immediately
1668 // within an Allocate, and then (maybe or maybe not) clear some more later.
1669 if (!(UseTLAB && ZeroTLAB)) {
1670 rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1671 header_size, size_in_bytes,
1672 &_igvn);
1673 }
1674 } else {
1675 if (!init->is_complete()) {
1676 // Try to win by zeroing only what the init does not store.
1677 // We can also try to do some peephole optimizations,
1678 // such as combining some adjacent subword stores.
1679 rawmem = init->complete_stores(control, rawmem, object,
1680 header_size, size_in_bytes, &_igvn);
1681 }
1682 // We have no more use for this link, since the AllocateNode goes away:
1683 init->set_req(InitializeNode::RawAddress, top());
1684 // (If we keep the link, it just confuses the register allocator,
1685 // who thinks he sees a real use of the address by the membar.)
1686 }
1687
1688 return rawmem;
1689 }
1690
1691 // Generate prefetch instructions for next allocations.
1692 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1693 Node*& contended_phi_rawmem,
1694 Node* old_eden_top, Node* new_eden_top,
1695 intx lines) {
1696 enum { fall_in_path = 1, pf_path = 2 };
1697 if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1698 // Generate prefetch allocation with watermark check.
1699 // As an allocation hits the watermark, we will prefetch starting
1700 // at a "distance" away from watermark.
1701
1702 Node *pf_region = new RegionNode(3);
1703 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY,
1704 TypeRawPtr::BOTTOM );
1705 // I/O is used for Prefetch
1706 Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO );
1707
1708 Node *thread = new ThreadLocalNode();
1709 transform_later(thread);
1710
1711 Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread,
1712 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1713 transform_later(eden_pf_adr);
1714
1715 Node *old_pf_wm = new LoadPNode(needgc_false,
1716 contended_phi_rawmem, eden_pf_adr,
1717 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM,
1718 MemNode::unordered);
1719 transform_later(old_pf_wm);
1720
1721 // check against new_eden_top
1722 Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm );
1723 transform_later(need_pf_cmp);
1724 Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge );
1725 transform_later(need_pf_bol);
1726 IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol,
1727 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1728 transform_later(need_pf_iff);
1729
1730 // true node, add prefetchdistance
1731 Node *need_pf_true = new IfTrueNode( need_pf_iff );
1732 transform_later(need_pf_true);
1733
1734 Node *need_pf_false = new IfFalseNode( need_pf_iff );
1735 transform_later(need_pf_false);
1736
1737 Node *new_pf_wmt = new AddPNode( top(), old_pf_wm,
1738 _igvn.MakeConX(AllocatePrefetchDistance) );
1739 transform_later(new_pf_wmt );
1740 new_pf_wmt->set_req(0, need_pf_true);
1741
1742 Node *store_new_wmt = new StorePNode(need_pf_true,
1743 contended_phi_rawmem, eden_pf_adr,
1744 TypeRawPtr::BOTTOM, new_pf_wmt,
1745 MemNode::unordered);
1746 transform_later(store_new_wmt);
1747
1748 // adding prefetches
1749 pf_phi_abio->init_req( fall_in_path, i_o );
1750
1751 Node *prefetch_adr;
1752 Node *prefetch;
1753 uint step_size = AllocatePrefetchStepSize;
1754 uint distance = 0;
1755
1756 for ( intx i = 0; i < lines; i++ ) {
1757 prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt,
1758 _igvn.MakeConX(distance) );
1759 transform_later(prefetch_adr);
1760 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1761 transform_later(prefetch);
1762 distance += step_size;
1763 i_o = prefetch;
1764 }
1765 pf_phi_abio->set_req( pf_path, i_o );
1766
1767 pf_region->init_req( fall_in_path, need_pf_false );
1768 pf_region->init_req( pf_path, need_pf_true );
1769
1770 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1771 pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1772
1773 transform_later(pf_region);
1774 transform_later(pf_phi_rawmem);
1775 transform_later(pf_phi_abio);
1776
1777 needgc_false = pf_region;
1778 contended_phi_rawmem = pf_phi_rawmem;
1779 i_o = pf_phi_abio;
1780 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) {
1781 // Insert a prefetch instruction for each allocation.
1782 // This code is used to generate 1 prefetch instruction per cache line.
1783
1784 // Generate several prefetch instructions.
1785 uint step_size = AllocatePrefetchStepSize;
1786 uint distance = AllocatePrefetchDistance;
1787
1788 // Next cache address.
1789 Node *cache_adr = new AddPNode(old_eden_top, old_eden_top,
1790 _igvn.MakeConX(step_size + distance));
1791 transform_later(cache_adr);
1792 cache_adr = new CastP2XNode(needgc_false, cache_adr);
1793 transform_later(cache_adr);
1794 // Address is aligned to execute prefetch to the beginning of cache line size
1795 // (it is important when BIS instruction is used on SPARC as prefetch).
1796 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1797 cache_adr = new AndXNode(cache_adr, mask);
1798 transform_later(cache_adr);
1799 cache_adr = new CastX2PNode(cache_adr);
1800 transform_later(cache_adr);
1801
1802 // Prefetch
1803 Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1804 prefetch->set_req(0, needgc_false);
1805 transform_later(prefetch);
1806 contended_phi_rawmem = prefetch;
1807 Node *prefetch_adr;
1808 distance = step_size;
1809 for ( intx i = 1; i < lines; i++ ) {
1810 prefetch_adr = new AddPNode( cache_adr, cache_adr,
1811 _igvn.MakeConX(distance) );
1812 transform_later(prefetch_adr);
1813 prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1814 transform_later(prefetch);
1815 distance += step_size;
1816 contended_phi_rawmem = prefetch;
1817 }
1818 } else if( AllocatePrefetchStyle > 0 ) {
1819 // Insert a prefetch for each allocation only on the fast-path
1820 Node *prefetch_adr;
1821 Node *prefetch;
1822 // Generate several prefetch instructions.
1823 uint step_size = AllocatePrefetchStepSize;
1824 uint distance = AllocatePrefetchDistance;
1825 for ( intx i = 0; i < lines; i++ ) {
1826 prefetch_adr = new AddPNode( old_eden_top, new_eden_top,
1827 _igvn.MakeConX(distance) );
1828 transform_later(prefetch_adr);
1829 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr );
1830 // Do not let it float too high, since if eden_top == eden_end,
1831 // both might be null.
1832 if( i == 0 ) { // Set control for first prefetch, next follows it
1833 prefetch->init_req(0, needgc_false);
1834 }
1835 transform_later(prefetch);
1836 distance += step_size;
1837 i_o = prefetch;
1838 }
1839 }
1840 return i_o;
1841 }
1842
1843
1844 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1845 expand_allocate_common(alloc, NULL,
1846 OptoRuntime::new_instance_Type(),
1847 OptoRuntime::new_instance_Java());
1848 }
1849
1850 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1851 Node* length = alloc->in(AllocateNode::ALength);
1852 InitializeNode* init = alloc->initialization();
1853 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1854 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1855 address slow_call_address; // Address of slow call
1856 if (init != NULL && init->is_complete_with_arraycopy() &&
1857 k->is_type_array_klass()) {
1858 // Don't zero type array during slow allocation in VM since
1859 // it will be initialized later by arraycopy in compiled code.
1860 slow_call_address = OptoRuntime::new_array_nozero_Java();
1861 } else {
1862 slow_call_address = OptoRuntime::new_array_Java();
1863 }
1864 expand_allocate_common(alloc, length,
1865 OptoRuntime::new_array_Type(),
1866 slow_call_address);
1867 }
1868
1869 //-------------------mark_eliminated_box----------------------------------
1870 //
1871 // During EA obj may point to several objects but after few ideal graph
1872 // transformations (CCP) it may point to only one non escaping object
1873 // (but still using phi), corresponding locks and unlocks will be marked
1874 // for elimination. Later obj could be replaced with a new node (new phi)
1875 // and which does not have escape information. And later after some graph
1876 // reshape other locks and unlocks (which were not marked for elimination
1877 // before) are connected to this new obj (phi) but they still will not be
1878 // marked for elimination since new obj has no escape information.
1879 // Mark all associated (same box and obj) lock and unlock nodes for
1880 // elimination if some of them marked already.
1881 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1882 if (oldbox->as_BoxLock()->is_eliminated())
1883 return; // This BoxLock node was processed already.
1884
1885 // New implementation (EliminateNestedLocks) has separate BoxLock
1886 // node for each locked region so mark all associated locks/unlocks as
1887 // eliminated even if different objects are referenced in one locked region
1888 // (for example, OSR compilation of nested loop inside locked scope).
1889 if (EliminateNestedLocks ||
1890 oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
1891 // Box is used only in one lock region. Mark this box as eliminated.
1892 _igvn.hash_delete(oldbox);
1893 oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1894 _igvn.hash_insert(oldbox);
1895
1896 for (uint i = 0; i < oldbox->outcnt(); i++) {
1897 Node* u = oldbox->raw_out(i);
1898 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1899 AbstractLockNode* alock = u->as_AbstractLock();
1900 // Check lock's box since box could be referenced by Lock's debug info.
1901 if (alock->box_node() == oldbox) {
1902 // Mark eliminated all related locks and unlocks.
1903 #ifdef ASSERT
1904 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4");
1905 #endif
1906 alock->set_non_esc_obj();
1907 }
1908 }
1909 }
1910 return;
1911 }
1912
1913 // Create new "eliminated" BoxLock node and use it in monitor debug info
1914 // instead of oldbox for the same object.
1915 BoxLockNode* newbox = oldbox->clone()->as_BoxLock();
1916
1917 // Note: BoxLock node is marked eliminated only here and it is used
1918 // to indicate that all associated lock and unlock nodes are marked
1919 // for elimination.
1920 newbox->set_eliminated();
1921 transform_later(newbox);
1922
1923 // Replace old box node with new box for all users of the same object.
1924 for (uint i = 0; i < oldbox->outcnt();) {
1925 bool next_edge = true;
1926
1927 Node* u = oldbox->raw_out(i);
1928 if (u->is_AbstractLock()) {
1929 AbstractLockNode* alock = u->as_AbstractLock();
1930 if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) {
1931 // Replace Box and mark eliminated all related locks and unlocks.
1932 #ifdef ASSERT
1933 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5");
1934 #endif
1935 alock->set_non_esc_obj();
1936 _igvn.rehash_node_delayed(alock);
1937 alock->set_box_node(newbox);
1938 next_edge = false;
1939 }
1940 }
1941 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
1942 FastLockNode* flock = u->as_FastLock();
1943 assert(flock->box_node() == oldbox, "sanity");
1944 _igvn.rehash_node_delayed(flock);
1945 flock->set_box_node(newbox);
1946 next_edge = false;
1947 }
1948
1949 // Replace old box in monitor debug info.
1950 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1951 SafePointNode* sfn = u->as_SafePoint();
1952 JVMState* youngest_jvms = sfn->jvms();
1953 int max_depth = youngest_jvms->depth();
1954 for (int depth = 1; depth <= max_depth; depth++) {
1955 JVMState* jvms = youngest_jvms->of_depth(depth);
1956 int num_mon = jvms->nof_monitors();
1957 // Loop over monitors
1958 for (int idx = 0; idx < num_mon; idx++) {
1959 Node* obj_node = sfn->monitor_obj(jvms, idx);
1960 Node* box_node = sfn->monitor_box(jvms, idx);
1961 if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
1962 int j = jvms->monitor_box_offset(idx);
1963 _igvn.replace_input_of(u, j, newbox);
1964 next_edge = false;
1965 }
1966 }
1967 }
1968 }
1969 if (next_edge) i++;
1970 }
1971 }
1972
1973 //-----------------------mark_eliminated_locking_nodes-----------------------
1974 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1975 if (EliminateNestedLocks) {
1976 if (alock->is_nested()) {
1977 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
1978 return;
1979 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
1980 // Only Lock node has JVMState needed here.
1981 // Not that preceding claim is documented anywhere else.
1982 if (alock->jvms() != NULL) {
1983 if (alock->as_Lock()->is_nested_lock_region()) {
1984 // Mark eliminated related nested locks and unlocks.
1985 Node* obj = alock->obj_node();
1986 BoxLockNode* box_node = alock->box_node()->as_BoxLock();
1987 assert(!box_node->is_eliminated(), "should not be marked yet");
1988 // Note: BoxLock node is marked eliminated only here
1989 // and it is used to indicate that all associated lock
1990 // and unlock nodes are marked for elimination.
1991 box_node->set_eliminated(); // Box's hash is always NO_HASH here
1992 for (uint i = 0; i < box_node->outcnt(); i++) {
1993 Node* u = box_node->raw_out(i);
1994 if (u->is_AbstractLock()) {
1995 alock = u->as_AbstractLock();
1996 if (alock->box_node() == box_node) {
1997 // Verify that this Box is referenced only by related locks.
1998 assert(alock->obj_node()->eqv_uncast(obj), "");
1999 // Mark all related locks and unlocks.
2000 #ifdef ASSERT
2001 alock->log_lock_optimization(C, "eliminate_lock_set_nested");
2002 #endif
2003 alock->set_nested();
2004 }
2005 }
2006 }
2007 } else {
2008 #ifdef ASSERT
2009 alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region");
2010 if (C->log() != NULL)
2011 alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output
2012 #endif
2013 }
2014 }
2015 return;
2016 }
2017 // Process locks for non escaping object
2018 assert(alock->is_non_esc_obj(), "");
2019 } // EliminateNestedLocks
2020
2021 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
2022 // Look for all locks of this object and mark them and
2023 // corresponding BoxLock nodes as eliminated.
2024 Node* obj = alock->obj_node();
2025 for (uint j = 0; j < obj->outcnt(); j++) {
2026 Node* o = obj->raw_out(j);
2027 if (o->is_AbstractLock() &&
2028 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
2029 alock = o->as_AbstractLock();
2030 Node* box = alock->box_node();
2031 // Replace old box node with new eliminated box for all users
2032 // of the same object and mark related locks as eliminated.
2033 mark_eliminated_box(box, obj);
2034 }
2035 }
2036 }
2037 }
2038
2039 // we have determined that this lock/unlock can be eliminated, we simply
2040 // eliminate the node without expanding it.
2041 //
2042 // Note: The membar's associated with the lock/unlock are currently not
2043 // eliminated. This should be investigated as a future enhancement.
2044 //
2045 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2046
2047 if (!alock->is_eliminated()) {
2048 return false;
2049 }
2050 #ifdef ASSERT
2051 if (!alock->is_coarsened()) {
2052 // Check that new "eliminated" BoxLock node is created.
2053 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2054 assert(oldbox->is_eliminated(), "should be done already");
2055 }
2056 #endif
2057
2058 alock->log_lock_optimization(C, "eliminate_lock");
2059
2060 #ifndef PRODUCT
2061 if (PrintEliminateLocks) {
2062 if (alock->is_Lock()) {
2063 tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2064 } else {
2065 tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2066 }
2067 }
2068 #endif
2069
2070 Node* mem = alock->in(TypeFunc::Memory);
2071 Node* ctrl = alock->in(TypeFunc::Control);
2072 guarantee(ctrl != NULL, "missing control projection, cannot replace_node() with NULL");
2073
2074 extract_call_projections(alock);
2075 // There are 2 projections from the lock. The lock node will
2076 // be deleted when its last use is subsumed below.
2077 assert(alock->outcnt() == 2 &&
2078 _fallthroughproj != NULL &&
2079 _memproj_fallthrough != NULL,
2080 "Unexpected projections from Lock/Unlock");
2081
2082 Node* fallthroughproj = _fallthroughproj;
2083 Node* memproj_fallthrough = _memproj_fallthrough;
2084
2085 // The memory projection from a lock/unlock is RawMem
2086 // The input to a Lock is merged memory, so extract its RawMem input
2087 // (unless the MergeMem has been optimized away.)
2088 if (alock->is_Lock()) {
2089 // Seach for MemBarAcquireLock node and delete it also.
2090 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2091 assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2092 Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2093 Node* memproj = membar->proj_out(TypeFunc::Memory);
2094 _igvn.replace_node(ctrlproj, fallthroughproj);
2095 _igvn.replace_node(memproj, memproj_fallthrough);
2096
2097 // Delete FastLock node also if this Lock node is unique user
2098 // (a loop peeling may clone a Lock node).
2099 Node* flock = alock->as_Lock()->fastlock_node();
2100 if (flock->outcnt() == 1) {
2101 assert(flock->unique_out() == alock, "sanity");
2102 _igvn.replace_node(flock, top());
2103 }
2104 }
2105
2106 // Seach for MemBarReleaseLock node and delete it also.
2107 if (alock->is_Unlock() && ctrl->is_Proj() && ctrl->in(0)->is_MemBar()) {
2108 MemBarNode* membar = ctrl->in(0)->as_MemBar();
2109 assert(membar->Opcode() == Op_MemBarReleaseLock &&
2110 mem->is_Proj() && membar == mem->in(0), "");
2111 _igvn.replace_node(fallthroughproj, ctrl);
2112 _igvn.replace_node(memproj_fallthrough, mem);
2113 fallthroughproj = ctrl;
2114 memproj_fallthrough = mem;
2115 ctrl = membar->in(TypeFunc::Control);
2116 mem = membar->in(TypeFunc::Memory);
2117 }
2118
2119 _igvn.replace_node(fallthroughproj, ctrl);
2120 _igvn.replace_node(memproj_fallthrough, mem);
2121 return true;
2122 }
2123
2124
2125 //------------------------------expand_lock_node----------------------
2126 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2127
2128 Node* ctrl = lock->in(TypeFunc::Control);
2129 Node* mem = lock->in(TypeFunc::Memory);
2130 Node* obj = lock->obj_node();
2131 Node* box = lock->box_node();
2132 Node* flock = lock->fastlock_node();
2133
2134 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2135
2136 // Make the merge point
2137 Node *region;
2138 Node *mem_phi;
2139 Node *slow_path;
2140
2141 if (UseOptoBiasInlining) {
2142 /*
2143 * See the full description in MacroAssembler::biased_locking_enter().
2144 *
2145 * if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2146 * // The object is biased.
2147 * proto_node = klass->prototype_header;
2148 * o_node = thread | proto_node;
2149 * x_node = o_node ^ mark_word;
2150 * if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2151 * // Done.
2152 * } else {
2153 * if( (x_node & biased_lock_mask) != 0 ) {
2154 * // The klass's prototype header is no longer biased.
2155 * cas(&mark_word, mark_word, proto_node)
2156 * goto cas_lock;
2157 * } else {
2158 * // The klass's prototype header is still biased.
2159 * if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2160 * old = mark_word;
2161 * new = o_node;
2162 * } else {
2163 * // Different thread or anonymous biased.
2164 * old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2165 * new = thread | old;
2166 * }
2167 * // Try to rebias.
2168 * if( cas(&mark_word, old, new) == 0 ) {
2169 * // Done.
2170 * } else {
2171 * goto slow_path; // Failed.
2172 * }
2173 * }
2174 * }
2175 * } else {
2176 * // The object is not biased.
2177 * cas_lock:
2178 * if( FastLock(obj) == 0 ) {
2179 * // Done.
2180 * } else {
2181 * slow_path:
2182 * OptoRuntime::complete_monitor_locking_Java(obj);
2183 * }
2184 * }
2185 */
2186
2187 region = new RegionNode(5);
2188 // create a Phi for the memory state
2189 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2190
2191 Node* fast_lock_region = new RegionNode(3);
2192 Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2193
2194 // First, check mark word for the biased lock pattern.
2195 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2196
2197 // Get fast path - mark word has the biased lock pattern.
2198 ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2199 markWord::biased_lock_mask_in_place,
2200 markWord::biased_lock_pattern, true);
2201 // fast_lock_region->in(1) is set to slow path.
2202 fast_lock_mem_phi->init_req(1, mem);
2203
2204 // Now check that the lock is biased to the current thread and has
2205 // the same epoch and bias as Klass::_prototype_header.
2206
2207 // Special-case a fresh allocation to avoid building nodes:
2208 Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2209 if (klass_node == NULL) {
2210 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2211 klass_node = transform_later(LoadKlassNode::make(_igvn, NULL, mem, k_adr, _igvn.type(k_adr)->is_ptr()));
2212 #ifdef _LP64
2213 if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) {
2214 assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2215 klass_node->in(1)->init_req(0, ctrl);
2216 } else
2217 #endif
2218 klass_node->init_req(0, ctrl);
2219 }
2220 Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2221
2222 Node* thread = transform_later(new ThreadLocalNode());
2223 Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2224 Node* o_node = transform_later(new OrXNode(cast_thread, proto_node));
2225 Node* x_node = transform_later(new XorXNode(o_node, mark_node));
2226
2227 // Get slow path - mark word does NOT match the value.
2228 STATIC_ASSERT(markWord::age_mask_in_place <= INT_MAX);
2229 Node* not_biased_ctrl = opt_bits_test(ctrl, region, 3, x_node,
2230 (~(int)markWord::age_mask_in_place), 0);
2231 // region->in(3) is set to fast path - the object is biased to the current thread.
2232 mem_phi->init_req(3, mem);
2233
2234
2235 // Mark word does NOT match the value (thread | Klass::_prototype_header).
2236
2237
2238 // First, check biased pattern.
2239 // Get fast path - _prototype_header has the same biased lock pattern.
2240 ctrl = opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2241 markWord::biased_lock_mask_in_place, 0, true);
2242
2243 not_biased_ctrl = fast_lock_region->in(2); // Slow path
2244 // fast_lock_region->in(2) - the prototype header is no longer biased
2245 // and we have to revoke the bias on this object.
2246 // We are going to try to reset the mark of this object to the prototype
2247 // value and fall through to the CAS-based locking scheme.
2248 Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2249 Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr,
2250 proto_node, mark_node);
2251 transform_later(cas);
2252 Node* proj = transform_later(new SCMemProjNode(cas));
2253 fast_lock_mem_phi->init_req(2, proj);
2254
2255
2256 // Second, check epoch bits.
2257 Node* rebiased_region = new RegionNode(3);
2258 Node* old_phi = new PhiNode( rebiased_region, TypeX_X);
2259 Node* new_phi = new PhiNode( rebiased_region, TypeX_X);
2260
2261 // Get slow path - mark word does NOT match epoch bits.
2262 Node* epoch_ctrl = opt_bits_test(ctrl, rebiased_region, 1, x_node,
2263 markWord::epoch_mask_in_place, 0);
2264 // The epoch of the current bias is not valid, attempt to rebias the object
2265 // toward the current thread.
2266 rebiased_region->init_req(2, epoch_ctrl);
2267 old_phi->init_req(2, mark_node);
2268 new_phi->init_req(2, o_node);
2269
2270 // rebiased_region->in(1) is set to fast path.
2271 // The epoch of the current bias is still valid but we know
2272 // nothing about the owner; it might be set or it might be clear.
2273 Node* cmask = MakeConX(markWord::biased_lock_mask_in_place |
2274 markWord::age_mask_in_place |
2275 markWord::epoch_mask_in_place);
2276 Node* old = transform_later(new AndXNode(mark_node, cmask));
2277 cast_thread = transform_later(new CastP2XNode(ctrl, thread));
2278 Node* new_mark = transform_later(new OrXNode(cast_thread, old));
2279 old_phi->init_req(1, old);
2280 new_phi->init_req(1, new_mark);
2281
2282 transform_later(rebiased_region);
2283 transform_later(old_phi);
2284 transform_later(new_phi);
2285
2286 // Try to acquire the bias of the object using an atomic operation.
2287 // If this fails we will go in to the runtime to revoke the object's bias.
2288 cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi);
2289 transform_later(cas);
2290 proj = transform_later(new SCMemProjNode(cas));
2291
2292 // Get slow path - Failed to CAS.
2293 not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2294 mem_phi->init_req(4, proj);
2295 // region->in(4) is set to fast path - the object is rebiased to the current thread.
2296
2297 // Failed to CAS.
2298 slow_path = new RegionNode(3);
2299 Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2300
2301 slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2302 slow_mem->init_req(1, proj);
2303
2304 // Call CAS-based locking scheme (FastLock node).
2305
2306 transform_later(fast_lock_region);
2307 transform_later(fast_lock_mem_phi);
2308
2309 // Get slow path - FastLock failed to lock the object.
2310 ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2311 mem_phi->init_req(2, fast_lock_mem_phi);
2312 // region->in(2) is set to fast path - the object is locked to the current thread.
2313
2314 slow_path->init_req(2, ctrl); // Capture slow-control
2315 slow_mem->init_req(2, fast_lock_mem_phi);
2316
2317 transform_later(slow_path);
2318 transform_later(slow_mem);
2319 // Reset lock's memory edge.
2320 lock->set_req(TypeFunc::Memory, slow_mem);
2321
2322 } else {
2323 region = new RegionNode(3);
2324 // create a Phi for the memory state
2325 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2326
2327 // Optimize test; set region slot 2
2328 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2329 mem_phi->init_req(2, mem);
2330 }
2331
2332 // Make slow path call
2333 CallNode *call = make_slow_call((CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(),
2334 OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path,
2335 obj, box, NULL);
2336
2337 extract_call_projections(call);
2338
2339 // Slow path can only throw asynchronous exceptions, which are always
2340 // de-opted. So the compiler thinks the slow-call can never throw an
2341 // exception. If it DOES throw an exception we would need the debug
2342 // info removed first (since if it throws there is no monitor).
2343 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2344 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2345
2346 // Capture slow path
2347 // disconnect fall-through projection from call and create a new one
2348 // hook up users of fall-through projection to region
2349 Node *slow_ctrl = _fallthroughproj->clone();
2350 transform_later(slow_ctrl);
2351 _igvn.hash_delete(_fallthroughproj);
2352 _fallthroughproj->disconnect_inputs(NULL, C);
2353 region->init_req(1, slow_ctrl);
2354 // region inputs are now complete
2355 transform_later(region);
2356 _igvn.replace_node(_fallthroughproj, region);
2357
2358 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory));
2359 mem_phi->init_req(1, memproj );
2360 transform_later(mem_phi);
2361 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2362 }
2363
2364 //------------------------------expand_unlock_node----------------------
2365 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2366
2367 Node* ctrl = unlock->in(TypeFunc::Control);
2368 Node* mem = unlock->in(TypeFunc::Memory);
2369 Node* obj = unlock->obj_node();
2370 Node* box = unlock->box_node();
2371
2372 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2373
2374 // No need for a null check on unlock
2375
2376 // Make the merge point
2377 Node *region;
2378 Node *mem_phi;
2379
2380 if (UseOptoBiasInlining) {
2381 // Check for biased locking unlock case, which is a no-op.
2382 // See the full description in MacroAssembler::biased_locking_exit().
2383 region = new RegionNode(4);
2384 // create a Phi for the memory state
2385 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2386 mem_phi->init_req(3, mem);
2387
2388 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2389 ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2390 markWord::biased_lock_mask_in_place,
2391 markWord::biased_lock_pattern);
2392 } else {
2393 region = new RegionNode(3);
2394 // create a Phi for the memory state
2395 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2396 }
2397
2398 FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box );
2399 funlock = transform_later( funlock )->as_FastUnlock();
2400 // Optimize test; set region slot 2
2401 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2402 Node *thread = transform_later(new ThreadLocalNode());
2403
2404 CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(),
2405 CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C),
2406 "complete_monitor_unlocking_C", slow_path, obj, box, thread);
2407
2408 extract_call_projections(call);
2409
2410 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2411 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2412
2413 // No exceptions for unlocking
2414 // Capture slow path
2415 // disconnect fall-through projection from call and create a new one
2416 // hook up users of fall-through projection to region
2417 Node *slow_ctrl = _fallthroughproj->clone();
2418 transform_later(slow_ctrl);
2419 _igvn.hash_delete(_fallthroughproj);
2420 _fallthroughproj->disconnect_inputs(NULL, C);
2421 region->init_req(1, slow_ctrl);
2422 // region inputs are now complete
2423 transform_later(region);
2424 _igvn.replace_node(_fallthroughproj, region);
2425
2426 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) );
2427 mem_phi->init_req(1, memproj );
2428 mem_phi->init_req(2, mem);
2429 transform_later(mem_phi);
2430 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2431 }
2432
2433 //---------------------------eliminate_macro_nodes----------------------
2434 // Eliminate scalar replaced allocations and associated locks.
2435 void PhaseMacroExpand::eliminate_macro_nodes() {
2436 if (C->macro_count() == 0)
2437 return;
2438
2439 // First, attempt to eliminate locks
2440 int cnt = C->macro_count();
2441 for (int i=0; i < cnt; i++) {
2442 Node *n = C->macro_node(i);
2443 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2444 // Before elimination mark all associated (same box and obj)
2445 // lock and unlock nodes.
2446 mark_eliminated_locking_nodes(n->as_AbstractLock());
2447 }
2448 }
2449 bool progress = true;
2450 while (progress) {
2451 progress = false;
2452 for (int i = C->macro_count(); i > 0; i--) {
2453 Node * n = C->macro_node(i-1);
2454 bool success = false;
2455 debug_only(int old_macro_count = C->macro_count(););
2456 if (n->is_AbstractLock()) {
2457 success = eliminate_locking_node(n->as_AbstractLock());
2458 }
2459 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2460 progress = progress || success;
2461 }
2462 }
2463 // Next, attempt to eliminate allocations
2464 _has_locks = false;
2465 progress = true;
2466 while (progress) {
2467 progress = false;
2468 for (int i = C->macro_count(); i > 0; i--) {
2469 Node * n = C->macro_node(i-1);
2470 bool success = false;
2471 debug_only(int old_macro_count = C->macro_count(););
2472 switch (n->class_id()) {
2473 case Node::Class_Allocate:
2474 case Node::Class_AllocateArray:
2475 success = eliminate_allocate_node(n->as_Allocate());
2476 break;
2477 case Node::Class_CallStaticJava:
2478 success = eliminate_boxing_node(n->as_CallStaticJava());
2479 break;
2480 case Node::Class_Lock:
2481 case Node::Class_Unlock:
2482 assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2483 _has_locks = true;
2484 break;
2485 case Node::Class_ArrayCopy:
2486 break;
2487 case Node::Class_OuterStripMinedLoop:
2488 break;
2489 default:
2490 assert(n->Opcode() == Op_LoopLimit ||
2491 n->Opcode() == Op_Opaque1 ||
2492 n->Opcode() == Op_Opaque2 ||
2493 n->Opcode() == Op_Opaque3 ||
2494 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(n),
2495 "unknown node type in macro list");
2496 }
2497 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2498 progress = progress || success;
2499 }
2500 }
2501 }
2502
2503 //------------------------------expand_macro_nodes----------------------
2504 // Returns true if a failure occurred.
2505 bool PhaseMacroExpand::expand_macro_nodes() {
2506 // Last attempt to eliminate macro nodes.
2507 eliminate_macro_nodes();
2508
2509 // Make sure expansion will not cause node limit to be exceeded.
2510 // Worst case is a macro node gets expanded into about 200 nodes.
2511 // Allow 50% more for optimization.
2512 if (C->check_node_count(C->macro_count() * 300, "out of nodes before macro expansion" ) )
2513 return true;
2514
2515 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2516 bool progress = true;
2517 while (progress) {
2518 progress = false;
2519 for (int i = C->macro_count(); i > 0; i--) {
2520 Node * n = C->macro_node(i-1);
2521 bool success = false;
2522 debug_only(int old_macro_count = C->macro_count(););
2523 if (n->Opcode() == Op_LoopLimit) {
2524 // Remove it from macro list and put on IGVN worklist to optimize.
2525 C->remove_macro_node(n);
2526 _igvn._worklist.push(n);
2527 success = true;
2528 } else if (n->Opcode() == Op_CallStaticJava) {
2529 // Remove it from macro list and put on IGVN worklist to optimize.
2530 C->remove_macro_node(n);
2531 _igvn._worklist.push(n);
2532 success = true;
2533 } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2534 _igvn.replace_node(n, n->in(1));
2535 success = true;
2536 #if INCLUDE_RTM_OPT
2537 } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) {
2538 assert(C->profile_rtm(), "should be used only in rtm deoptimization code");
2539 assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), "");
2540 Node* cmp = n->unique_out();
2541 #ifdef ASSERT
2542 // Validate graph.
2543 assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), "");
2544 BoolNode* bol = cmp->unique_out()->as_Bool();
2545 assert((bol->outcnt() == 1) && bol->unique_out()->is_If() &&
2546 (bol->_test._test == BoolTest::ne), "");
2547 IfNode* ifn = bol->unique_out()->as_If();
2548 assert((ifn->outcnt() == 2) &&
2549 ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change) != NULL, "");
2550 #endif
2551 Node* repl = n->in(1);
2552 if (!_has_locks) {
2553 // Remove RTM state check if there are no locks in the code.
2554 // Replace input to compare the same value.
2555 repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1);
2556 }
2557 _igvn.replace_node(n, repl);
2558 success = true;
2559 #endif
2560 } else if (n->Opcode() == Op_OuterStripMinedLoop) {
2561 n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn);
2562 C->remove_macro_node(n);
2563 success = true;
2564 }
2565 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2566 progress = progress || success;
2567 }
2568 }
2569
2570 // expand arraycopy "macro" nodes first
2571 // For ReduceBulkZeroing, we must first process all arraycopy nodes
2572 // before the allocate nodes are expanded.
2573 int macro_idx = C->macro_count() - 1;
2574 while (macro_idx >= 0) {
2575 Node * n = C->macro_node(macro_idx);
2576 assert(n->is_macro(), "only macro nodes expected here");
2577 if (_igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) {
2578 // node is unreachable, so don't try to expand it
2579 C->remove_macro_node(n);
2580 } else if (n->is_ArrayCopy()){
2581 int macro_count = C->macro_count();
2582 expand_arraycopy_node(n->as_ArrayCopy());
2583 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2584 }
2585 if (C->failing()) return true;
2586 macro_idx --;
2587 }
2588
2589 // expand "macro" nodes
2590 // nodes are removed from the macro list as they are processed
2591 while (C->macro_count() > 0) {
2592 int macro_count = C->macro_count();
2593 Node * n = C->macro_node(macro_count-1);
2594 assert(n->is_macro(), "only macro nodes expected here");
2595 if (_igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) {
2596 // node is unreachable, so don't try to expand it
2597 C->remove_macro_node(n);
2598 continue;
2599 }
2600 switch (n->class_id()) {
2601 case Node::Class_Allocate:
2602 expand_allocate(n->as_Allocate());
2603 break;
2604 case Node::Class_AllocateArray:
2605 expand_allocate_array(n->as_AllocateArray());
2606 break;
2607 case Node::Class_Lock:
2608 expand_lock_node(n->as_Lock());
2609 break;
2610 case Node::Class_Unlock:
2611 expand_unlock_node(n->as_Unlock());
2612 break;
2613 default:
2614 assert(false, "unknown node type in macro list");
2615 }
2616 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2617 if (C->failing()) return true;
2618 }
2619
2620 _igvn.set_delay_transform(false);
2621 _igvn.optimize();
2622 if (C->failing()) return true;
2623 return false;
2624 }