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