Thu, 01 Aug 2013 17:25:10 -0700
Merge
1 /*
2 * Copyright (c) 2005, 2012, 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 */
25 #include "precompiled.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "libadt/vectset.hpp"
28 #include "opto/addnode.hpp"
29 #include "opto/callnode.hpp"
30 #include "opto/cfgnode.hpp"
31 #include "opto/compile.hpp"
32 #include "opto/connode.hpp"
33 #include "opto/locknode.hpp"
34 #include "opto/loopnode.hpp"
35 #include "opto/macro.hpp"
36 #include "opto/memnode.hpp"
37 #include "opto/node.hpp"
38 #include "opto/phaseX.hpp"
39 #include "opto/rootnode.hpp"
40 #include "opto/runtime.hpp"
41 #include "opto/subnode.hpp"
42 #include "opto/type.hpp"
43 #include "runtime/sharedRuntime.hpp"
46 //
47 // Replace any references to "oldref" in inputs to "use" with "newref".
48 // Returns the number of replacements made.
49 //
50 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
51 int nreplacements = 0;
52 uint req = use->req();
53 for (uint j = 0; j < use->len(); j++) {
54 Node *uin = use->in(j);
55 if (uin == oldref) {
56 if (j < req)
57 use->set_req(j, newref);
58 else
59 use->set_prec(j, newref);
60 nreplacements++;
61 } else if (j >= req && uin == NULL) {
62 break;
63 }
64 }
65 return nreplacements;
66 }
68 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
69 // Copy debug information and adjust JVMState information
70 uint old_dbg_start = oldcall->tf()->domain()->cnt();
71 uint new_dbg_start = newcall->tf()->domain()->cnt();
72 int jvms_adj = new_dbg_start - old_dbg_start;
73 assert (new_dbg_start == newcall->req(), "argument count mismatch");
75 Dict* sosn_map = new Dict(cmpkey,hashkey);
76 for (uint i = old_dbg_start; i < oldcall->req(); i++) {
77 Node* old_in = oldcall->in(i);
78 // Clone old SafePointScalarObjectNodes, adjusting their field contents.
79 if (old_in != NULL && old_in->is_SafePointScalarObject()) {
80 SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
81 uint old_unique = C->unique();
82 Node* new_in = old_sosn->clone(jvms_adj, sosn_map);
83 if (old_unique != C->unique()) {
84 new_in->set_req(0, C->root()); // reset control edge
85 new_in = transform_later(new_in); // Register new node.
86 }
87 old_in = new_in;
88 }
89 newcall->add_req(old_in);
90 }
92 newcall->set_jvms(oldcall->jvms());
93 for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
94 jvms->set_map(newcall);
95 jvms->set_locoff(jvms->locoff()+jvms_adj);
96 jvms->set_stkoff(jvms->stkoff()+jvms_adj);
97 jvms->set_monoff(jvms->monoff()+jvms_adj);
98 jvms->set_scloff(jvms->scloff()+jvms_adj);
99 jvms->set_endoff(jvms->endoff()+jvms_adj);
100 }
101 }
103 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) {
104 Node* cmp;
105 if (mask != 0) {
106 Node* and_node = transform_later(new (C) AndXNode(word, MakeConX(mask)));
107 cmp = transform_later(new (C) CmpXNode(and_node, MakeConX(bits)));
108 } else {
109 cmp = word;
110 }
111 Node* bol = transform_later(new (C) BoolNode(cmp, BoolTest::ne));
112 IfNode* iff = new (C) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
113 transform_later(iff);
115 // Fast path taken.
116 Node *fast_taken = transform_later( new (C) IfFalseNode(iff) );
118 // Fast path not-taken, i.e. slow path
119 Node *slow_taken = transform_later( new (C) IfTrueNode(iff) );
121 if (return_fast_path) {
122 region->init_req(edge, slow_taken); // Capture slow-control
123 return fast_taken;
124 } else {
125 region->init_req(edge, fast_taken); // Capture fast-control
126 return slow_taken;
127 }
128 }
130 //--------------------copy_predefined_input_for_runtime_call--------------------
131 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
132 // Set fixed predefined input arguments
133 call->init_req( TypeFunc::Control, ctrl );
134 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) );
135 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
136 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
137 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
138 }
140 //------------------------------make_slow_call---------------------------------
141 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, address slow_call, const char* leaf_name, Node* slow_path, Node* parm0, Node* parm1) {
143 // Slow-path call
144 CallNode *call = leaf_name
145 ? (CallNode*)new (C) CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
146 : (CallNode*)new (C) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
148 // Slow path call has no side-effects, uses few values
149 copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
150 if (parm0 != NULL) call->init_req(TypeFunc::Parms+0, parm0);
151 if (parm1 != NULL) call->init_req(TypeFunc::Parms+1, parm1);
152 copy_call_debug_info(oldcall, call);
153 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
154 _igvn.replace_node(oldcall, call);
155 transform_later(call);
157 return call;
158 }
160 void PhaseMacroExpand::extract_call_projections(CallNode *call) {
161 _fallthroughproj = NULL;
162 _fallthroughcatchproj = NULL;
163 _ioproj_fallthrough = NULL;
164 _ioproj_catchall = NULL;
165 _catchallcatchproj = NULL;
166 _memproj_fallthrough = NULL;
167 _memproj_catchall = NULL;
168 _resproj = NULL;
169 for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
170 ProjNode *pn = call->fast_out(i)->as_Proj();
171 switch (pn->_con) {
172 case TypeFunc::Control:
173 {
174 // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
175 _fallthroughproj = pn;
176 DUIterator_Fast jmax, j = pn->fast_outs(jmax);
177 const Node *cn = pn->fast_out(j);
178 if (cn->is_Catch()) {
179 ProjNode *cpn = NULL;
180 for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
181 cpn = cn->fast_out(k)->as_Proj();
182 assert(cpn->is_CatchProj(), "must be a CatchProjNode");
183 if (cpn->_con == CatchProjNode::fall_through_index)
184 _fallthroughcatchproj = cpn;
185 else {
186 assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
187 _catchallcatchproj = cpn;
188 }
189 }
190 }
191 break;
192 }
193 case TypeFunc::I_O:
194 if (pn->_is_io_use)
195 _ioproj_catchall = pn;
196 else
197 _ioproj_fallthrough = pn;
198 break;
199 case TypeFunc::Memory:
200 if (pn->_is_io_use)
201 _memproj_catchall = pn;
202 else
203 _memproj_fallthrough = pn;
204 break;
205 case TypeFunc::Parms:
206 _resproj = pn;
207 break;
208 default:
209 assert(false, "unexpected projection from allocation node.");
210 }
211 }
213 }
215 // Eliminate a card mark sequence. p2x is a ConvP2XNode
216 void PhaseMacroExpand::eliminate_card_mark(Node* p2x) {
217 assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
218 if (!UseG1GC) {
219 // vanilla/CMS post barrier
220 Node *shift = p2x->unique_out();
221 Node *addp = shift->unique_out();
222 for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
223 Node *mem = addp->last_out(j);
224 if (UseCondCardMark && mem->is_Load()) {
225 assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
226 // The load is checking if the card has been written so
227 // replace it with zero to fold the test.
228 _igvn.replace_node(mem, intcon(0));
229 continue;
230 }
231 assert(mem->is_Store(), "store required");
232 _igvn.replace_node(mem, mem->in(MemNode::Memory));
233 }
234 } else {
235 // G1 pre/post barriers
236 assert(p2x->outcnt() <= 2, "expects 1 or 2 users: Xor and URShift nodes");
237 // It could be only one user, URShift node, in Object.clone() instrinsic
238 // but the new allocation is passed to arraycopy stub and it could not
239 // be scalar replaced. So we don't check the case.
241 // An other case of only one user (Xor) is when the value check for NULL
242 // in G1 post barrier is folded after CCP so the code which used URShift
243 // is removed.
245 // Take Region node before eliminating post barrier since it also
246 // eliminates CastP2X node when it has only one user.
247 Node* this_region = p2x->in(0);
248 assert(this_region != NULL, "");
250 // Remove G1 post barrier.
252 // Search for CastP2X->Xor->URShift->Cmp path which
253 // checks if the store done to a different from the value's region.
254 // And replace Cmp with #0 (false) to collapse G1 post barrier.
255 Node* xorx = NULL;
256 for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) {
257 Node* u = p2x->fast_out(i);
258 if (u->Opcode() == Op_XorX) {
259 xorx = u;
260 break;
261 }
262 }
263 assert(xorx != NULL, "missing G1 post barrier");
264 Node* shift = xorx->unique_out();
265 Node* cmpx = shift->unique_out();
266 assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() &&
267 cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne,
268 "missing region check in G1 post barrier");
269 _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
271 // Remove G1 pre barrier.
273 // Search "if (marking != 0)" check and set it to "false".
274 // There is no G1 pre barrier if previous stored value is NULL
275 // (for example, after initialization).
276 if (this_region->is_Region() && this_region->req() == 3) {
277 int ind = 1;
278 if (!this_region->in(ind)->is_IfFalse()) {
279 ind = 2;
280 }
281 if (this_region->in(ind)->is_IfFalse()) {
282 Node* bol = this_region->in(ind)->in(0)->in(1);
283 assert(bol->is_Bool(), "");
284 cmpx = bol->in(1);
285 if (bol->as_Bool()->_test._test == BoolTest::ne &&
286 cmpx->is_Cmp() && cmpx->in(2) == intcon(0) &&
287 cmpx->in(1)->is_Load()) {
288 Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address);
289 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() +
290 PtrQueue::byte_offset_of_active());
291 if (adr->is_AddP() && adr->in(AddPNode::Base) == top() &&
292 adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal &&
293 adr->in(AddPNode::Offset) == MakeConX(marking_offset)) {
294 _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ));
295 }
296 }
297 }
298 }
299 // Now CastP2X can be removed since it is used only on dead path
300 // which currently still alive until igvn optimize it.
301 assert(p2x->outcnt() == 0 || p2x->unique_out()->Opcode() == Op_URShiftX, "");
302 _igvn.replace_node(p2x, top());
303 }
304 }
306 // Search for a memory operation for the specified memory slice.
307 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) {
308 Node *orig_mem = mem;
309 Node *alloc_mem = alloc->in(TypeFunc::Memory);
310 const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr();
311 while (true) {
312 if (mem == alloc_mem || mem == start_mem ) {
313 return mem; // hit one of our sentinels
314 } else if (mem->is_MergeMem()) {
315 mem = mem->as_MergeMem()->memory_at(alias_idx);
316 } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
317 Node *in = mem->in(0);
318 // we can safely skip over safepoints, calls, locks and membars because we
319 // already know that the object is safe to eliminate.
320 if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
321 return in;
322 } else if (in->is_Call()) {
323 CallNode *call = in->as_Call();
324 if (!call->may_modify(tinst, phase)) {
325 mem = call->in(TypeFunc::Memory);
326 }
327 mem = in->in(TypeFunc::Memory);
328 } else if (in->is_MemBar()) {
329 mem = in->in(TypeFunc::Memory);
330 } else {
331 assert(false, "unexpected projection");
332 }
333 } else if (mem->is_Store()) {
334 const TypePtr* atype = mem->as_Store()->adr_type();
335 int adr_idx = Compile::current()->get_alias_index(atype);
336 if (adr_idx == alias_idx) {
337 assert(atype->isa_oopptr(), "address type must be oopptr");
338 int adr_offset = atype->offset();
339 uint adr_iid = atype->is_oopptr()->instance_id();
340 // Array elements references have the same alias_idx
341 // but different offset and different instance_id.
342 if (adr_offset == offset && adr_iid == alloc->_idx)
343 return mem;
344 } else {
345 assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
346 }
347 mem = mem->in(MemNode::Memory);
348 } else if (mem->is_ClearArray()) {
349 if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) {
350 // Can not bypass initialization of the instance
351 // we are looking.
352 debug_only(intptr_t offset;)
353 assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity");
354 InitializeNode* init = alloc->as_Allocate()->initialization();
355 // We are looking for stored value, return Initialize node
356 // or memory edge from Allocate node.
357 if (init != NULL)
358 return init;
359 else
360 return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers).
361 }
362 // Otherwise skip it (the call updated 'mem' value).
363 } else if (mem->Opcode() == Op_SCMemProj) {
364 mem = mem->in(0);
365 Node* adr = NULL;
366 if (mem->is_LoadStore()) {
367 adr = mem->in(MemNode::Address);
368 } else {
369 assert(mem->Opcode() == Op_EncodeISOArray, "sanity");
370 adr = mem->in(3); // Destination array
371 }
372 const TypePtr* atype = adr->bottom_type()->is_ptr();
373 int adr_idx = Compile::current()->get_alias_index(atype);
374 if (adr_idx == alias_idx) {
375 assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
376 return NULL;
377 }
378 mem = mem->in(MemNode::Memory);
379 } else {
380 return mem;
381 }
382 assert(mem != orig_mem, "dead memory loop");
383 }
384 }
386 //
387 // Given a Memory Phi, compute a value Phi containing the values from stores
388 // on the input paths.
389 // Note: this function is recursive, its depth is limied by the "level" argument
390 // Returns the computed Phi, or NULL if it cannot compute it.
391 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, Node *alloc, Node_Stack *value_phis, int level) {
392 assert(mem->is_Phi(), "sanity");
393 int alias_idx = C->get_alias_index(adr_t);
394 int offset = adr_t->offset();
395 int instance_id = adr_t->instance_id();
397 // Check if an appropriate value phi already exists.
398 Node* region = mem->in(0);
399 for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
400 Node* phi = region->fast_out(k);
401 if (phi->is_Phi() && phi != mem &&
402 phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
403 return phi;
404 }
405 }
406 // Check if an appropriate new value phi already exists.
407 Node* new_phi = value_phis->find(mem->_idx);
408 if (new_phi != NULL)
409 return new_phi;
411 if (level <= 0) {
412 return NULL; // Give up: phi tree too deep
413 }
414 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
415 Node *alloc_mem = alloc->in(TypeFunc::Memory);
417 uint length = mem->req();
418 GrowableArray <Node *> values(length, length, NULL, false);
420 // create a new Phi for the value
421 PhiNode *phi = new (C) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
422 transform_later(phi);
423 value_phis->push(phi, mem->_idx);
425 for (uint j = 1; j < length; j++) {
426 Node *in = mem->in(j);
427 if (in == NULL || in->is_top()) {
428 values.at_put(j, in);
429 } else {
430 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn);
431 if (val == start_mem || val == alloc_mem) {
432 // hit a sentinel, return appropriate 0 value
433 values.at_put(j, _igvn.zerocon(ft));
434 continue;
435 }
436 if (val->is_Initialize()) {
437 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
438 }
439 if (val == NULL) {
440 return NULL; // can't find a value on this path
441 }
442 if (val == mem) {
443 values.at_put(j, mem);
444 } else if (val->is_Store()) {
445 values.at_put(j, val->in(MemNode::ValueIn));
446 } else if(val->is_Proj() && val->in(0) == alloc) {
447 values.at_put(j, _igvn.zerocon(ft));
448 } else if (val->is_Phi()) {
449 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1);
450 if (val == NULL) {
451 return NULL;
452 }
453 values.at_put(j, val);
454 } else if (val->Opcode() == Op_SCMemProj) {
455 assert(val->in(0)->is_LoadStore() || val->in(0)->Opcode() == Op_EncodeISOArray, "sanity");
456 assert(false, "Object is not scalar replaceable if a LoadStore node access its field");
457 return NULL;
458 } else {
459 #ifdef ASSERT
460 val->dump();
461 assert(false, "unknown node on this path");
462 #endif
463 return NULL; // unknown node on this path
464 }
465 }
466 }
467 // Set Phi's inputs
468 for (uint j = 1; j < length; j++) {
469 if (values.at(j) == mem) {
470 phi->init_req(j, phi);
471 } else {
472 phi->init_req(j, values.at(j));
473 }
474 }
475 return phi;
476 }
478 // Search the last value stored into the object's field.
479 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
480 assert(adr_t->is_known_instance_field(), "instance required");
481 int instance_id = adr_t->instance_id();
482 assert((uint)instance_id == alloc->_idx, "wrong allocation");
484 int alias_idx = C->get_alias_index(adr_t);
485 int offset = adr_t->offset();
486 Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
487 Node *alloc_ctrl = alloc->in(TypeFunc::Control);
488 Node *alloc_mem = alloc->in(TypeFunc::Memory);
489 Arena *a = Thread::current()->resource_area();
490 VectorSet visited(a);
493 bool done = sfpt_mem == alloc_mem;
494 Node *mem = sfpt_mem;
495 while (!done) {
496 if (visited.test_set(mem->_idx)) {
497 return NULL; // found a loop, give up
498 }
499 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn);
500 if (mem == start_mem || mem == alloc_mem) {
501 done = true; // hit a sentinel, return appropriate 0 value
502 } else if (mem->is_Initialize()) {
503 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
504 if (mem == NULL) {
505 done = true; // Something go wrong.
506 } else if (mem->is_Store()) {
507 const TypePtr* atype = mem->as_Store()->adr_type();
508 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
509 done = true;
510 }
511 } else if (mem->is_Store()) {
512 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
513 assert(atype != NULL, "address type must be oopptr");
514 assert(C->get_alias_index(atype) == alias_idx &&
515 atype->is_known_instance_field() && atype->offset() == offset &&
516 atype->instance_id() == instance_id, "store is correct memory slice");
517 done = true;
518 } else if (mem->is_Phi()) {
519 // try to find a phi's unique input
520 Node *unique_input = NULL;
521 Node *top = C->top();
522 for (uint i = 1; i < mem->req(); i++) {
523 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn);
524 if (n == NULL || n == top || n == mem) {
525 continue;
526 } else if (unique_input == NULL) {
527 unique_input = n;
528 } else if (unique_input != n) {
529 unique_input = top;
530 break;
531 }
532 }
533 if (unique_input != NULL && unique_input != top) {
534 mem = unique_input;
535 } else {
536 done = true;
537 }
538 } else {
539 assert(false, "unexpected node");
540 }
541 }
542 if (mem != NULL) {
543 if (mem == start_mem || mem == alloc_mem) {
544 // hit a sentinel, return appropriate 0 value
545 return _igvn.zerocon(ft);
546 } else if (mem->is_Store()) {
547 return mem->in(MemNode::ValueIn);
548 } else if (mem->is_Phi()) {
549 // attempt to produce a Phi reflecting the values on the input paths of the Phi
550 Node_Stack value_phis(a, 8);
551 Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit);
552 if (phi != NULL) {
553 return phi;
554 } else {
555 // Kill all new Phis
556 while(value_phis.is_nonempty()) {
557 Node* n = value_phis.node();
558 _igvn.replace_node(n, C->top());
559 value_phis.pop();
560 }
561 }
562 }
563 }
564 // Something go wrong.
565 return NULL;
566 }
568 // Check the possibility of scalar replacement.
569 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
570 // Scan the uses of the allocation to check for anything that would
571 // prevent us from eliminating it.
572 NOT_PRODUCT( const char* fail_eliminate = NULL; )
573 DEBUG_ONLY( Node* disq_node = NULL; )
574 bool can_eliminate = true;
576 Node* res = alloc->result_cast();
577 const TypeOopPtr* res_type = NULL;
578 if (res == NULL) {
579 // All users were eliminated.
580 } else if (!res->is_CheckCastPP()) {
581 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
582 can_eliminate = false;
583 } else {
584 res_type = _igvn.type(res)->isa_oopptr();
585 if (res_type == NULL) {
586 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
587 can_eliminate = false;
588 } else if (res_type->isa_aryptr()) {
589 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
590 if (length < 0) {
591 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
592 can_eliminate = false;
593 }
594 }
595 }
597 if (can_eliminate && res != NULL) {
598 for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
599 j < jmax && can_eliminate; j++) {
600 Node* use = res->fast_out(j);
602 if (use->is_AddP()) {
603 const TypePtr* addp_type = _igvn.type(use)->is_ptr();
604 int offset = addp_type->offset();
606 if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
607 NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
608 can_eliminate = false;
609 break;
610 }
611 for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
612 k < kmax && can_eliminate; k++) {
613 Node* n = use->fast_out(k);
614 if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
615 DEBUG_ONLY(disq_node = n;)
616 if (n->is_Load() || n->is_LoadStore()) {
617 NOT_PRODUCT(fail_eliminate = "Field load";)
618 } else {
619 NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
620 }
621 can_eliminate = false;
622 }
623 }
624 } else if (use->is_SafePoint()) {
625 SafePointNode* sfpt = use->as_SafePoint();
626 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) {
627 // Object is passed as argument.
628 DEBUG_ONLY(disq_node = use;)
629 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
630 can_eliminate = false;
631 }
632 Node* sfptMem = sfpt->memory();
633 if (sfptMem == NULL || sfptMem->is_top()) {
634 DEBUG_ONLY(disq_node = use;)
635 NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
636 can_eliminate = false;
637 } else {
638 safepoints.append_if_missing(sfpt);
639 }
640 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
641 if (use->is_Phi()) {
642 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
643 NOT_PRODUCT(fail_eliminate = "Object is return value";)
644 } else {
645 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
646 }
647 DEBUG_ONLY(disq_node = use;)
648 } else {
649 if (use->Opcode() == Op_Return) {
650 NOT_PRODUCT(fail_eliminate = "Object is return value";)
651 }else {
652 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
653 }
654 DEBUG_ONLY(disq_node = use;)
655 }
656 can_eliminate = false;
657 }
658 }
659 }
661 #ifndef PRODUCT
662 if (PrintEliminateAllocations) {
663 if (can_eliminate) {
664 tty->print("Scalar ");
665 if (res == NULL)
666 alloc->dump();
667 else
668 res->dump();
669 } else if (alloc->_is_scalar_replaceable) {
670 tty->print("NotScalar (%s)", fail_eliminate);
671 if (res == NULL)
672 alloc->dump();
673 else
674 res->dump();
675 #ifdef ASSERT
676 if (disq_node != NULL) {
677 tty->print(" >>>> ");
678 disq_node->dump();
679 }
680 #endif /*ASSERT*/
681 }
682 }
683 #endif
684 return can_eliminate;
685 }
687 // Do scalar replacement.
688 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
689 GrowableArray <SafePointNode *> safepoints_done;
691 ciKlass* klass = NULL;
692 ciInstanceKlass* iklass = NULL;
693 int nfields = 0;
694 int array_base;
695 int element_size;
696 BasicType basic_elem_type;
697 ciType* elem_type;
699 Node* res = alloc->result_cast();
700 const TypeOopPtr* res_type = NULL;
701 if (res != NULL) { // Could be NULL when there are no users
702 res_type = _igvn.type(res)->isa_oopptr();
703 }
705 if (res != NULL) {
706 klass = res_type->klass();
707 if (res_type->isa_instptr()) {
708 // find the fields of the class which will be needed for safepoint debug information
709 assert(klass->is_instance_klass(), "must be an instance klass.");
710 iklass = klass->as_instance_klass();
711 nfields = iklass->nof_nonstatic_fields();
712 } else {
713 // find the array's elements which will be needed for safepoint debug information
714 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
715 assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
716 elem_type = klass->as_array_klass()->element_type();
717 basic_elem_type = elem_type->basic_type();
718 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
719 element_size = type2aelembytes(basic_elem_type);
720 }
721 }
722 //
723 // Process the safepoint uses
724 //
725 while (safepoints.length() > 0) {
726 SafePointNode* sfpt = safepoints.pop();
727 Node* mem = sfpt->memory();
728 uint first_ind = sfpt->req();
729 SafePointScalarObjectNode* sobj = new (C) SafePointScalarObjectNode(res_type,
730 #ifdef ASSERT
731 alloc,
732 #endif
733 first_ind, nfields);
734 sobj->init_req(0, C->root());
735 transform_later(sobj);
737 // Scan object's fields adding an input to the safepoint for each field.
738 for (int j = 0; j < nfields; j++) {
739 intptr_t offset;
740 ciField* field = NULL;
741 if (iklass != NULL) {
742 field = iklass->nonstatic_field_at(j);
743 offset = field->offset();
744 elem_type = field->type();
745 basic_elem_type = field->layout_type();
746 } else {
747 offset = array_base + j * (intptr_t)element_size;
748 }
750 const Type *field_type;
751 // The next code is taken from Parse::do_get_xxx().
752 if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) {
753 if (!elem_type->is_loaded()) {
754 field_type = TypeInstPtr::BOTTOM;
755 } else if (field != NULL && field->is_constant() && field->is_static()) {
756 // This can happen if the constant oop is non-perm.
757 ciObject* con = field->constant_value().as_object();
758 // Do not "join" in the previous type; it doesn't add value,
759 // and may yield a vacuous result if the field is of interface type.
760 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
761 assert(field_type != NULL, "field singleton type must be consistent");
762 } else {
763 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
764 }
765 if (UseCompressedOops) {
766 field_type = field_type->make_narrowoop();
767 basic_elem_type = T_NARROWOOP;
768 }
769 } else {
770 field_type = Type::get_const_basic_type(basic_elem_type);
771 }
773 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
775 Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
776 if (field_val == NULL) {
777 // We weren't able to find a value for this field,
778 // give up on eliminating this allocation.
780 // Remove any extra entries we added to the safepoint.
781 uint last = sfpt->req() - 1;
782 for (int k = 0; k < j; k++) {
783 sfpt->del_req(last--);
784 }
785 // rollback processed safepoints
786 while (safepoints_done.length() > 0) {
787 SafePointNode* sfpt_done = safepoints_done.pop();
788 // remove any extra entries we added to the safepoint
789 last = sfpt_done->req() - 1;
790 for (int k = 0; k < nfields; k++) {
791 sfpt_done->del_req(last--);
792 }
793 JVMState *jvms = sfpt_done->jvms();
794 jvms->set_endoff(sfpt_done->req());
795 // Now make a pass over the debug information replacing any references
796 // to SafePointScalarObjectNode with the allocated object.
797 int start = jvms->debug_start();
798 int end = jvms->debug_end();
799 for (int i = start; i < end; i++) {
800 if (sfpt_done->in(i)->is_SafePointScalarObject()) {
801 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
802 if (scobj->first_index() == sfpt_done->req() &&
803 scobj->n_fields() == (uint)nfields) {
804 assert(scobj->alloc() == alloc, "sanity");
805 sfpt_done->set_req(i, res);
806 }
807 }
808 }
809 }
810 #ifndef PRODUCT
811 if (PrintEliminateAllocations) {
812 if (field != NULL) {
813 tty->print("=== At SafePoint node %d can't find value of Field: ",
814 sfpt->_idx);
815 field->print();
816 int field_idx = C->get_alias_index(field_addr_type);
817 tty->print(" (alias_idx=%d)", field_idx);
818 } else { // Array's element
819 tty->print("=== At SafePoint node %d can't find value of array element [%d]",
820 sfpt->_idx, j);
821 }
822 tty->print(", which prevents elimination of: ");
823 if (res == NULL)
824 alloc->dump();
825 else
826 res->dump();
827 }
828 #endif
829 return false;
830 }
831 if (UseCompressedOops && field_type->isa_narrowoop()) {
832 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation
833 // to be able scalar replace the allocation.
834 if (field_val->is_EncodeP()) {
835 field_val = field_val->in(1);
836 } else {
837 field_val = transform_later(new (C) DecodeNNode(field_val, field_val->get_ptr_type()));
838 }
839 }
840 sfpt->add_req(field_val);
841 }
842 JVMState *jvms = sfpt->jvms();
843 jvms->set_endoff(sfpt->req());
844 // Now make a pass over the debug information replacing any references
845 // to the allocated object with "sobj"
846 int start = jvms->debug_start();
847 int end = jvms->debug_end();
848 sfpt->replace_edges_in_range(res, sobj, start, end);
849 safepoints_done.append_if_missing(sfpt); // keep it for rollback
850 }
851 return true;
852 }
854 // Process users of eliminated allocation.
855 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) {
856 Node* res = alloc->result_cast();
857 if (res != NULL) {
858 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
859 Node *use = res->last_out(j);
860 uint oc1 = res->outcnt();
862 if (use->is_AddP()) {
863 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
864 Node *n = use->last_out(k);
865 uint oc2 = use->outcnt();
866 if (n->is_Store()) {
867 #ifdef ASSERT
868 // Verify that there is no dependent MemBarVolatile nodes,
869 // they should be removed during IGVN, see MemBarNode::Ideal().
870 for (DUIterator_Fast pmax, p = n->fast_outs(pmax);
871 p < pmax; p++) {
872 Node* mb = n->fast_out(p);
873 assert(mb->is_Initialize() || !mb->is_MemBar() ||
874 mb->req() <= MemBarNode::Precedent ||
875 mb->in(MemBarNode::Precedent) != n,
876 "MemBarVolatile should be eliminated for non-escaping object");
877 }
878 #endif
879 _igvn.replace_node(n, n->in(MemNode::Memory));
880 } else {
881 eliminate_card_mark(n);
882 }
883 k -= (oc2 - use->outcnt());
884 }
885 } else {
886 eliminate_card_mark(use);
887 }
888 j -= (oc1 - res->outcnt());
889 }
890 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
891 _igvn.remove_dead_node(res);
892 }
894 //
895 // Process other users of allocation's projections
896 //
897 if (_resproj != NULL && _resproj->outcnt() != 0) {
898 // First disconnect stores captured by Initialize node.
899 // If Initialize node is eliminated first in the following code,
900 // it will kill such stores and DUIterator_Last will assert.
901 for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax); j < jmax; j++) {
902 Node *use = _resproj->fast_out(j);
903 if (use->is_AddP()) {
904 // raw memory addresses used only by the initialization
905 _igvn.replace_node(use, C->top());
906 --j; --jmax;
907 }
908 }
909 for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
910 Node *use = _resproj->last_out(j);
911 uint oc1 = _resproj->outcnt();
912 if (use->is_Initialize()) {
913 // Eliminate Initialize node.
914 InitializeNode *init = use->as_Initialize();
915 assert(init->outcnt() <= 2, "only a control and memory projection expected");
916 Node *ctrl_proj = init->proj_out(TypeFunc::Control);
917 if (ctrl_proj != NULL) {
918 assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
919 _igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
920 }
921 Node *mem_proj = init->proj_out(TypeFunc::Memory);
922 if (mem_proj != NULL) {
923 Node *mem = init->in(TypeFunc::Memory);
924 #ifdef ASSERT
925 if (mem->is_MergeMem()) {
926 assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
927 } else {
928 assert(mem == _memproj_fallthrough, "allocation memory projection");
929 }
930 #endif
931 _igvn.replace_node(mem_proj, mem);
932 }
933 } else {
934 assert(false, "only Initialize or AddP expected");
935 }
936 j -= (oc1 - _resproj->outcnt());
937 }
938 }
939 if (_fallthroughcatchproj != NULL) {
940 _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
941 }
942 if (_memproj_fallthrough != NULL) {
943 _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
944 }
945 if (_memproj_catchall != NULL) {
946 _igvn.replace_node(_memproj_catchall, C->top());
947 }
948 if (_ioproj_fallthrough != NULL) {
949 _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
950 }
951 if (_ioproj_catchall != NULL) {
952 _igvn.replace_node(_ioproj_catchall, C->top());
953 }
954 if (_catchallcatchproj != NULL) {
955 _igvn.replace_node(_catchallcatchproj, C->top());
956 }
957 }
959 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
960 if (!EliminateAllocations || !alloc->_is_non_escaping) {
961 return false;
962 }
963 Node* klass = alloc->in(AllocateNode::KlassNode);
964 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr();
965 Node* res = alloc->result_cast();
966 // Eliminate boxing allocations which are not used
967 // regardless scalar replacable status.
968 bool boxing_alloc = C->eliminate_boxing() &&
969 tklass->klass()->is_instance_klass() &&
970 tklass->klass()->as_instance_klass()->is_box_klass();
971 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) {
972 return false;
973 }
975 extract_call_projections(alloc);
977 GrowableArray <SafePointNode *> safepoints;
978 if (!can_eliminate_allocation(alloc, safepoints)) {
979 return false;
980 }
982 if (!alloc->_is_scalar_replaceable) {
983 assert(res == NULL, "sanity");
984 // We can only eliminate allocation if all debug info references
985 // are already replaced with SafePointScalarObject because
986 // we can't search for a fields value without instance_id.
987 if (safepoints.length() > 0) {
988 return false;
989 }
990 }
992 if (!scalar_replacement(alloc, safepoints)) {
993 return false;
994 }
996 CompileLog* log = C->log();
997 if (log != NULL) {
998 log->head("eliminate_allocation type='%d'",
999 log->identify(tklass->klass()));
1000 JVMState* p = alloc->jvms();
1001 while (p != NULL) {
1002 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1003 p = p->caller();
1004 }
1005 log->tail("eliminate_allocation");
1006 }
1008 process_users_of_allocation(alloc);
1010 #ifndef PRODUCT
1011 if (PrintEliminateAllocations) {
1012 if (alloc->is_AllocateArray())
1013 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
1014 else
1015 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
1016 }
1017 #endif
1019 return true;
1020 }
1022 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) {
1023 // EA should remove all uses of non-escaping boxing node.
1024 if (!C->eliminate_boxing() || boxing->proj_out(TypeFunc::Parms) != NULL) {
1025 return false;
1026 }
1028 extract_call_projections(boxing);
1030 const TypeTuple* r = boxing->tf()->range();
1031 assert(r->cnt() > TypeFunc::Parms, "sanity");
1032 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr();
1033 assert(t != NULL, "sanity");
1035 CompileLog* log = C->log();
1036 if (log != NULL) {
1037 log->head("eliminate_boxing type='%d'",
1038 log->identify(t->klass()));
1039 JVMState* p = boxing->jvms();
1040 while (p != NULL) {
1041 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
1042 p = p->caller();
1043 }
1044 log->tail("eliminate_boxing");
1045 }
1047 process_users_of_allocation(boxing);
1049 #ifndef PRODUCT
1050 if (PrintEliminateAllocations) {
1051 tty->print("++++ Eliminated: %d ", boxing->_idx);
1052 boxing->method()->print_short_name(tty);
1053 tty->cr();
1054 }
1055 #endif
1057 return true;
1058 }
1060 //---------------------------set_eden_pointers-------------------------
1061 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
1062 if (UseTLAB) { // Private allocation: load from TLS
1063 Node* thread = transform_later(new (C) ThreadLocalNode());
1064 int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
1065 int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
1066 eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
1067 eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
1068 } else { // Shared allocation: load from globals
1069 CollectedHeap* ch = Universe::heap();
1070 address top_adr = (address)ch->top_addr();
1071 address end_adr = (address)ch->end_addr();
1072 eden_top_adr = makecon(TypeRawPtr::make(top_adr));
1073 eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
1074 }
1075 }
1078 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
1079 Node* adr = basic_plus_adr(base, offset);
1080 const TypePtr* adr_type = adr->bottom_type()->is_ptr();
1081 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
1082 transform_later(value);
1083 return value;
1084 }
1087 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
1088 Node* adr = basic_plus_adr(base, offset);
1089 mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
1090 transform_later(mem);
1091 return mem;
1092 }
1094 //=============================================================================
1095 //
1096 // A L L O C A T I O N
1097 //
1098 // Allocation attempts to be fast in the case of frequent small objects.
1099 // It breaks down like this:
1100 //
1101 // 1) Size in doublewords is computed. This is a constant for objects and
1102 // variable for most arrays. Doubleword units are used to avoid size
1103 // overflow of huge doubleword arrays. We need doublewords in the end for
1104 // rounding.
1105 //
1106 // 2) Size is checked for being 'too large'. Too-large allocations will go
1107 // the slow path into the VM. The slow path can throw any required
1108 // exceptions, and does all the special checks for very large arrays. The
1109 // size test can constant-fold away for objects. For objects with
1110 // finalizers it constant-folds the otherway: you always go slow with
1111 // finalizers.
1112 //
1113 // 3) If NOT using TLABs, this is the contended loop-back point.
1114 // Load-Locked the heap top. If using TLABs normal-load the heap top.
1115 //
1116 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
1117 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
1118 // "size*8" we always enter the VM, where "largish" is a constant picked small
1119 // enough that there's always space between the eden max and 4Gig (old space is
1120 // there so it's quite large) and large enough that the cost of entering the VM
1121 // is dwarfed by the cost to initialize the space.
1122 //
1123 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
1124 // down. If contended, repeat at step 3. If using TLABs normal-store
1125 // adjusted heap top back down; there is no contention.
1126 //
1127 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
1128 // fields.
1129 //
1130 // 7) Merge with the slow-path; cast the raw memory pointer to the correct
1131 // oop flavor.
1132 //
1133 //=============================================================================
1134 // FastAllocateSizeLimit value is in DOUBLEWORDS.
1135 // Allocations bigger than this always go the slow route.
1136 // This value must be small enough that allocation attempts that need to
1137 // trigger exceptions go the slow route. Also, it must be small enough so
1138 // that heap_top + size_in_bytes does not wrap around the 4Gig limit.
1139 //=============================================================================j//
1140 // %%% Here is an old comment from parseHelper.cpp; is it outdated?
1141 // The allocator will coalesce int->oop copies away. See comment in
1142 // coalesce.cpp about how this works. It depends critically on the exact
1143 // code shape produced here, so if you are changing this code shape
1144 // make sure the GC info for the heap-top is correct in and around the
1145 // slow-path call.
1146 //
1148 void PhaseMacroExpand::expand_allocate_common(
1149 AllocateNode* alloc, // allocation node to be expanded
1150 Node* length, // array length for an array allocation
1151 const TypeFunc* slow_call_type, // Type of slow call
1152 address slow_call_address // Address of slow call
1153 )
1154 {
1156 Node* ctrl = alloc->in(TypeFunc::Control);
1157 Node* mem = alloc->in(TypeFunc::Memory);
1158 Node* i_o = alloc->in(TypeFunc::I_O);
1159 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
1160 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1161 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
1163 assert(ctrl != NULL, "must have control");
1164 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
1165 // they will not be used if "always_slow" is set
1166 enum { slow_result_path = 1, fast_result_path = 2 };
1167 Node *result_region;
1168 Node *result_phi_rawmem;
1169 Node *result_phi_rawoop;
1170 Node *result_phi_i_o;
1172 // The initial slow comparison is a size check, the comparison
1173 // we want to do is a BoolTest::gt
1174 bool always_slow = false;
1175 int tv = _igvn.find_int_con(initial_slow_test, -1);
1176 if (tv >= 0) {
1177 always_slow = (tv == 1);
1178 initial_slow_test = NULL;
1179 } else {
1180 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
1181 }
1183 if (C->env()->dtrace_alloc_probes() ||
1184 !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() ||
1185 (UseConcMarkSweepGC && CMSIncrementalMode))) {
1186 // Force slow-path allocation
1187 always_slow = true;
1188 initial_slow_test = NULL;
1189 }
1192 enum { too_big_or_final_path = 1, need_gc_path = 2 };
1193 Node *slow_region = NULL;
1194 Node *toobig_false = ctrl;
1196 assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
1197 // generate the initial test if necessary
1198 if (initial_slow_test != NULL ) {
1199 slow_region = new (C) RegionNode(3);
1201 // Now make the initial failure test. Usually a too-big test but
1202 // might be a TRUE for finalizers or a fancy class check for
1203 // newInstance0.
1204 IfNode *toobig_iff = new (C) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
1205 transform_later(toobig_iff);
1206 // Plug the failing-too-big test into the slow-path region
1207 Node *toobig_true = new (C) IfTrueNode( toobig_iff );
1208 transform_later(toobig_true);
1209 slow_region ->init_req( too_big_or_final_path, toobig_true );
1210 toobig_false = new (C) IfFalseNode( toobig_iff );
1211 transform_later(toobig_false);
1212 } else { // No initial test, just fall into next case
1213 toobig_false = ctrl;
1214 debug_only(slow_region = NodeSentinel);
1215 }
1217 Node *slow_mem = mem; // save the current memory state for slow path
1218 // generate the fast allocation code unless we know that the initial test will always go slow
1219 if (!always_slow) {
1220 // Fast path modifies only raw memory.
1221 if (mem->is_MergeMem()) {
1222 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
1223 }
1225 Node* eden_top_adr;
1226 Node* eden_end_adr;
1228 set_eden_pointers(eden_top_adr, eden_end_adr);
1230 // Load Eden::end. Loop invariant and hoisted.
1231 //
1232 // Note: We set the control input on "eden_end" and "old_eden_top" when using
1233 // a TLAB to work around a bug where these values were being moved across
1234 // a safepoint. These are not oops, so they cannot be include in the oop
1235 // map, but they can be changed by a GC. The proper way to fix this would
1236 // be to set the raw memory state when generating a SafepointNode. However
1237 // this will require extensive changes to the loop optimization in order to
1238 // prevent a degradation of the optimization.
1239 // See comment in memnode.hpp, around line 227 in class LoadPNode.
1240 Node *eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
1242 // allocate the Region and Phi nodes for the result
1243 result_region = new (C) RegionNode(3);
1244 result_phi_rawmem = new (C) PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1245 result_phi_rawoop = new (C) PhiNode(result_region, TypeRawPtr::BOTTOM);
1246 result_phi_i_o = new (C) PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch
1248 // We need a Region for the loop-back contended case.
1249 enum { fall_in_path = 1, contended_loopback_path = 2 };
1250 Node *contended_region;
1251 Node *contended_phi_rawmem;
1252 if (UseTLAB) {
1253 contended_region = toobig_false;
1254 contended_phi_rawmem = mem;
1255 } else {
1256 contended_region = new (C) RegionNode(3);
1257 contended_phi_rawmem = new (C) PhiNode(contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
1258 // Now handle the passing-too-big test. We fall into the contended
1259 // loop-back merge point.
1260 contended_region ->init_req(fall_in_path, toobig_false);
1261 contended_phi_rawmem->init_req(fall_in_path, mem);
1262 transform_later(contended_region);
1263 transform_later(contended_phi_rawmem);
1264 }
1266 // Load(-locked) the heap top.
1267 // See note above concerning the control input when using a TLAB
1268 Node *old_eden_top = UseTLAB
1269 ? new (C) LoadPNode (ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM)
1270 : new (C) LoadPLockedNode(contended_region, contended_phi_rawmem, eden_top_adr);
1272 transform_later(old_eden_top);
1273 // Add to heap top to get a new heap top
1274 Node *new_eden_top = new (C) AddPNode(top(), old_eden_top, size_in_bytes);
1275 transform_later(new_eden_top);
1276 // Check for needing a GC; compare against heap end
1277 Node *needgc_cmp = new (C) CmpPNode(new_eden_top, eden_end);
1278 transform_later(needgc_cmp);
1279 Node *needgc_bol = new (C) BoolNode(needgc_cmp, BoolTest::ge);
1280 transform_later(needgc_bol);
1281 IfNode *needgc_iff = new (C) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
1282 transform_later(needgc_iff);
1284 // Plug the failing-heap-space-need-gc test into the slow-path region
1285 Node *needgc_true = new (C) IfTrueNode(needgc_iff);
1286 transform_later(needgc_true);
1287 if (initial_slow_test) {
1288 slow_region->init_req(need_gc_path, needgc_true);
1289 // This completes all paths into the slow merge point
1290 transform_later(slow_region);
1291 } else { // No initial slow path needed!
1292 // Just fall from the need-GC path straight into the VM call.
1293 slow_region = needgc_true;
1294 }
1295 // No need for a GC. Setup for the Store-Conditional
1296 Node *needgc_false = new (C) IfFalseNode(needgc_iff);
1297 transform_later(needgc_false);
1299 // Grab regular I/O before optional prefetch may change it.
1300 // Slow-path does no I/O so just set it to the original I/O.
1301 result_phi_i_o->init_req(slow_result_path, i_o);
1303 i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
1304 old_eden_top, new_eden_top, length);
1306 // Name successful fast-path variables
1307 Node* fast_oop = old_eden_top;
1308 Node* fast_oop_ctrl;
1309 Node* fast_oop_rawmem;
1311 // Store (-conditional) the modified eden top back down.
1312 // StorePConditional produces flags for a test PLUS a modified raw
1313 // memory state.
1314 if (UseTLAB) {
1315 Node* store_eden_top =
1316 new (C) StorePNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1317 TypeRawPtr::BOTTOM, new_eden_top);
1318 transform_later(store_eden_top);
1319 fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
1320 fast_oop_rawmem = store_eden_top;
1321 } else {
1322 Node* store_eden_top =
1323 new (C) StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr,
1324 new_eden_top, fast_oop/*old_eden_top*/);
1325 transform_later(store_eden_top);
1326 Node *contention_check = new (C) BoolNode(store_eden_top, BoolTest::ne);
1327 transform_later(contention_check);
1328 store_eden_top = new (C) SCMemProjNode(store_eden_top);
1329 transform_later(store_eden_top);
1331 // If not using TLABs, check to see if there was contention.
1332 IfNode *contention_iff = new (C) IfNode (needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN);
1333 transform_later(contention_iff);
1334 Node *contention_true = new (C) IfTrueNode(contention_iff);
1335 transform_later(contention_true);
1336 // If contention, loopback and try again.
1337 contended_region->init_req(contended_loopback_path, contention_true);
1338 contended_phi_rawmem->init_req(contended_loopback_path, store_eden_top);
1340 // Fast-path succeeded with no contention!
1341 Node *contention_false = new (C) IfFalseNode(contention_iff);
1342 transform_later(contention_false);
1343 fast_oop_ctrl = contention_false;
1345 // Bump total allocated bytes for this thread
1346 Node* thread = new (C) ThreadLocalNode();
1347 transform_later(thread);
1348 Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread,
1349 in_bytes(JavaThread::allocated_bytes_offset()));
1350 Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1351 0, TypeLong::LONG, T_LONG);
1352 #ifdef _LP64
1353 Node* alloc_size = size_in_bytes;
1354 #else
1355 Node* alloc_size = new (C) ConvI2LNode(size_in_bytes);
1356 transform_later(alloc_size);
1357 #endif
1358 Node* new_alloc_bytes = new (C) AddLNode(alloc_bytes, alloc_size);
1359 transform_later(new_alloc_bytes);
1360 fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr,
1361 0, new_alloc_bytes, T_LONG);
1362 }
1364 InitializeNode* init = alloc->initialization();
1365 fast_oop_rawmem = initialize_object(alloc,
1366 fast_oop_ctrl, fast_oop_rawmem, fast_oop,
1367 klass_node, length, size_in_bytes);
1369 // If initialization is performed by an array copy, any required
1370 // MemBarStoreStore was already added. If the object does not
1371 // escape no need for a MemBarStoreStore. Otherwise we need a
1372 // MemBarStoreStore so that stores that initialize this object
1373 // can't be reordered with a subsequent store that makes this
1374 // object accessible by other threads.
1375 if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) {
1376 if (init == NULL || init->req() < InitializeNode::RawStores) {
1377 // No InitializeNode or no stores captured by zeroing
1378 // elimination. Simply add the MemBarStoreStore after object
1379 // initialization.
1380 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1381 transform_later(mb);
1383 mb->init_req(TypeFunc::Memory, fast_oop_rawmem);
1384 mb->init_req(TypeFunc::Control, fast_oop_ctrl);
1385 fast_oop_ctrl = new (C) ProjNode(mb,TypeFunc::Control);
1386 transform_later(fast_oop_ctrl);
1387 fast_oop_rawmem = new (C) ProjNode(mb,TypeFunc::Memory);
1388 transform_later(fast_oop_rawmem);
1389 } else {
1390 // Add the MemBarStoreStore after the InitializeNode so that
1391 // all stores performing the initialization that were moved
1392 // before the InitializeNode happen before the storestore
1393 // barrier.
1395 Node* init_ctrl = init->proj_out(TypeFunc::Control);
1396 Node* init_mem = init->proj_out(TypeFunc::Memory);
1398 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot);
1399 transform_later(mb);
1401 Node* ctrl = new (C) ProjNode(init,TypeFunc::Control);
1402 transform_later(ctrl);
1403 Node* mem = new (C) ProjNode(init,TypeFunc::Memory);
1404 transform_later(mem);
1406 // The MemBarStoreStore depends on control and memory coming
1407 // from the InitializeNode
1408 mb->init_req(TypeFunc::Memory, mem);
1409 mb->init_req(TypeFunc::Control, ctrl);
1411 ctrl = new (C) ProjNode(mb,TypeFunc::Control);
1412 transform_later(ctrl);
1413 mem = new (C) ProjNode(mb,TypeFunc::Memory);
1414 transform_later(mem);
1416 // All nodes that depended on the InitializeNode for control
1417 // and memory must now depend on the MemBarNode that itself
1418 // depends on the InitializeNode
1419 _igvn.replace_node(init_ctrl, ctrl);
1420 _igvn.replace_node(init_mem, mem);
1421 }
1422 }
1424 if (C->env()->dtrace_extended_probes()) {
1425 // Slow-path call
1426 int size = TypeFunc::Parms + 2;
1427 CallLeafNode *call = new (C) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
1428 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
1429 "dtrace_object_alloc",
1430 TypeRawPtr::BOTTOM);
1432 // Get base of thread-local storage area
1433 Node* thread = new (C) ThreadLocalNode();
1434 transform_later(thread);
1436 call->init_req(TypeFunc::Parms+0, thread);
1437 call->init_req(TypeFunc::Parms+1, fast_oop);
1438 call->init_req(TypeFunc::Control, fast_oop_ctrl);
1439 call->init_req(TypeFunc::I_O , top()); // does no i/o
1440 call->init_req(TypeFunc::Memory , fast_oop_rawmem);
1441 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr));
1442 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr));
1443 transform_later(call);
1444 fast_oop_ctrl = new (C) ProjNode(call,TypeFunc::Control);
1445 transform_later(fast_oop_ctrl);
1446 fast_oop_rawmem = new (C) ProjNode(call,TypeFunc::Memory);
1447 transform_later(fast_oop_rawmem);
1448 }
1450 // Plug in the successful fast-path into the result merge point
1451 result_region ->init_req(fast_result_path, fast_oop_ctrl);
1452 result_phi_rawoop->init_req(fast_result_path, fast_oop);
1453 result_phi_i_o ->init_req(fast_result_path, i_o);
1454 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem);
1455 } else {
1456 slow_region = ctrl;
1457 result_phi_i_o = i_o; // Rename it to use in the following code.
1458 }
1460 // Generate slow-path call
1461 CallNode *call = new (C) CallStaticJavaNode(slow_call_type, slow_call_address,
1462 OptoRuntime::stub_name(slow_call_address),
1463 alloc->jvms()->bci(),
1464 TypePtr::BOTTOM);
1465 call->init_req( TypeFunc::Control, slow_region );
1466 call->init_req( TypeFunc::I_O , top() ) ; // does no i/o
1467 call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
1468 call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
1469 call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
1471 call->init_req(TypeFunc::Parms+0, klass_node);
1472 if (length != NULL) {
1473 call->init_req(TypeFunc::Parms+1, length);
1474 }
1476 // Copy debug information and adjust JVMState information, then replace
1477 // allocate node with the call
1478 copy_call_debug_info((CallNode *) alloc, call);
1479 if (!always_slow) {
1480 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1481 } else {
1482 // Hook i_o projection to avoid its elimination during allocation
1483 // replacement (when only a slow call is generated).
1484 call->set_req(TypeFunc::I_O, result_phi_i_o);
1485 }
1486 _igvn.replace_node(alloc, call);
1487 transform_later(call);
1489 // Identify the output projections from the allocate node and
1490 // adjust any references to them.
1491 // The control and io projections look like:
1492 //
1493 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
1494 // Allocate Catch
1495 // ^---Proj(io) <-------+ ^---CatchProj(io)
1496 //
1497 // We are interested in the CatchProj nodes.
1498 //
1499 extract_call_projections(call);
1501 // An allocate node has separate memory projections for the uses on
1502 // the control and i_o paths. Replace the control memory projection with
1503 // result_phi_rawmem (unless we are only generating a slow call when
1504 // both memory projections are combined)
1505 if (!always_slow && _memproj_fallthrough != NULL) {
1506 for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
1507 Node *use = _memproj_fallthrough->fast_out(i);
1508 _igvn.rehash_node_delayed(use);
1509 imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
1510 // back up iterator
1511 --i;
1512 }
1513 }
1514 // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete
1515 // _memproj_catchall so we end up with a call that has only 1 memory projection.
1516 if (_memproj_catchall != NULL ) {
1517 if (_memproj_fallthrough == NULL) {
1518 _memproj_fallthrough = new (C) ProjNode(call, TypeFunc::Memory);
1519 transform_later(_memproj_fallthrough);
1520 }
1521 for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
1522 Node *use = _memproj_catchall->fast_out(i);
1523 _igvn.rehash_node_delayed(use);
1524 imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
1525 // back up iterator
1526 --i;
1527 }
1528 assert(_memproj_catchall->outcnt() == 0, "all uses must be deleted");
1529 _igvn.remove_dead_node(_memproj_catchall);
1530 }
1532 // An allocate node has separate i_o projections for the uses on the control
1533 // and i_o paths. Always replace the control i_o projection with result i_o
1534 // otherwise incoming i_o become dead when only a slow call is generated
1535 // (it is different from memory projections where both projections are
1536 // combined in such case).
1537 if (_ioproj_fallthrough != NULL) {
1538 for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
1539 Node *use = _ioproj_fallthrough->fast_out(i);
1540 _igvn.rehash_node_delayed(use);
1541 imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
1542 // back up iterator
1543 --i;
1544 }
1545 }
1546 // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete
1547 // _ioproj_catchall so we end up with a call that has only 1 i_o projection.
1548 if (_ioproj_catchall != NULL ) {
1549 if (_ioproj_fallthrough == NULL) {
1550 _ioproj_fallthrough = new (C) ProjNode(call, TypeFunc::I_O);
1551 transform_later(_ioproj_fallthrough);
1552 }
1553 for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
1554 Node *use = _ioproj_catchall->fast_out(i);
1555 _igvn.rehash_node_delayed(use);
1556 imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
1557 // back up iterator
1558 --i;
1559 }
1560 assert(_ioproj_catchall->outcnt() == 0, "all uses must be deleted");
1561 _igvn.remove_dead_node(_ioproj_catchall);
1562 }
1564 // if we generated only a slow call, we are done
1565 if (always_slow) {
1566 // Now we can unhook i_o.
1567 if (result_phi_i_o->outcnt() > 1) {
1568 call->set_req(TypeFunc::I_O, top());
1569 } else {
1570 assert(result_phi_i_o->unique_ctrl_out() == call, "");
1571 // Case of new array with negative size known during compilation.
1572 // AllocateArrayNode::Ideal() optimization disconnect unreachable
1573 // following code since call to runtime will throw exception.
1574 // As result there will be no users of i_o after the call.
1575 // Leave i_o attached to this call to avoid problems in preceding graph.
1576 }
1577 return;
1578 }
1581 if (_fallthroughcatchproj != NULL) {
1582 ctrl = _fallthroughcatchproj->clone();
1583 transform_later(ctrl);
1584 _igvn.replace_node(_fallthroughcatchproj, result_region);
1585 } else {
1586 ctrl = top();
1587 }
1588 Node *slow_result;
1589 if (_resproj == NULL) {
1590 // no uses of the allocation result
1591 slow_result = top();
1592 } else {
1593 slow_result = _resproj->clone();
1594 transform_later(slow_result);
1595 _igvn.replace_node(_resproj, result_phi_rawoop);
1596 }
1598 // Plug slow-path into result merge point
1599 result_region ->init_req( slow_result_path, ctrl );
1600 result_phi_rawoop->init_req( slow_result_path, slow_result);
1601 result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
1602 transform_later(result_region);
1603 transform_later(result_phi_rawoop);
1604 transform_later(result_phi_rawmem);
1605 transform_later(result_phi_i_o);
1606 // This completes all paths into the result merge point
1607 }
1610 // Helper for PhaseMacroExpand::expand_allocate_common.
1611 // Initializes the newly-allocated storage.
1612 Node*
1613 PhaseMacroExpand::initialize_object(AllocateNode* alloc,
1614 Node* control, Node* rawmem, Node* object,
1615 Node* klass_node, Node* length,
1616 Node* size_in_bytes) {
1617 InitializeNode* init = alloc->initialization();
1618 // Store the klass & mark bits
1619 Node* mark_node = NULL;
1620 // For now only enable fast locking for non-array types
1621 if (UseBiasedLocking && (length == NULL)) {
1622 mark_node = make_load(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeRawPtr::BOTTOM, T_ADDRESS);
1623 } else {
1624 mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
1625 }
1626 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
1628 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA);
1629 int header_size = alloc->minimum_header_size(); // conservatively small
1631 // Array length
1632 if (length != NULL) { // Arrays need length field
1633 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
1634 // conservatively small header size:
1635 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1636 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1637 if (k->is_array_klass()) // we know the exact header size in most cases:
1638 header_size = Klass::layout_helper_header_size(k->layout_helper());
1639 }
1641 // Clear the object body, if necessary.
1642 if (init == NULL) {
1643 // The init has somehow disappeared; be cautious and clear everything.
1644 //
1645 // This can happen if a node is allocated but an uncommon trap occurs
1646 // immediately. In this case, the Initialize gets associated with the
1647 // trap, and may be placed in a different (outer) loop, if the Allocate
1648 // is in a loop. If (this is rare) the inner loop gets unrolled, then
1649 // there can be two Allocates to one Initialize. The answer in all these
1650 // edge cases is safety first. It is always safe to clear immediately
1651 // within an Allocate, and then (maybe or maybe not) clear some more later.
1652 if (!ZeroTLAB)
1653 rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
1654 header_size, size_in_bytes,
1655 &_igvn);
1656 } else {
1657 if (!init->is_complete()) {
1658 // Try to win by zeroing only what the init does not store.
1659 // We can also try to do some peephole optimizations,
1660 // such as combining some adjacent subword stores.
1661 rawmem = init->complete_stores(control, rawmem, object,
1662 header_size, size_in_bytes, &_igvn);
1663 }
1664 // We have no more use for this link, since the AllocateNode goes away:
1665 init->set_req(InitializeNode::RawAddress, top());
1666 // (If we keep the link, it just confuses the register allocator,
1667 // who thinks he sees a real use of the address by the membar.)
1668 }
1670 return rawmem;
1671 }
1673 // Generate prefetch instructions for next allocations.
1674 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
1675 Node*& contended_phi_rawmem,
1676 Node* old_eden_top, Node* new_eden_top,
1677 Node* length) {
1678 enum { fall_in_path = 1, pf_path = 2 };
1679 if( UseTLAB && AllocatePrefetchStyle == 2 ) {
1680 // Generate prefetch allocation with watermark check.
1681 // As an allocation hits the watermark, we will prefetch starting
1682 // at a "distance" away from watermark.
1684 Node *pf_region = new (C) RegionNode(3);
1685 Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
1686 TypeRawPtr::BOTTOM );
1687 // I/O is used for Prefetch
1688 Node *pf_phi_abio = new (C) PhiNode( pf_region, Type::ABIO );
1690 Node *thread = new (C) ThreadLocalNode();
1691 transform_later(thread);
1693 Node *eden_pf_adr = new (C) AddPNode( top()/*not oop*/, thread,
1694 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
1695 transform_later(eden_pf_adr);
1697 Node *old_pf_wm = new (C) LoadPNode( needgc_false,
1698 contended_phi_rawmem, eden_pf_adr,
1699 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
1700 transform_later(old_pf_wm);
1702 // check against new_eden_top
1703 Node *need_pf_cmp = new (C) CmpPNode( new_eden_top, old_pf_wm );
1704 transform_later(need_pf_cmp);
1705 Node *need_pf_bol = new (C) BoolNode( need_pf_cmp, BoolTest::ge );
1706 transform_later(need_pf_bol);
1707 IfNode *need_pf_iff = new (C) IfNode( needgc_false, need_pf_bol,
1708 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
1709 transform_later(need_pf_iff);
1711 // true node, add prefetchdistance
1712 Node *need_pf_true = new (C) IfTrueNode( need_pf_iff );
1713 transform_later(need_pf_true);
1715 Node *need_pf_false = new (C) IfFalseNode( need_pf_iff );
1716 transform_later(need_pf_false);
1718 Node *new_pf_wmt = new (C) 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);
1723 Node *store_new_wmt = new (C) StorePNode( need_pf_true,
1724 contended_phi_rawmem, eden_pf_adr,
1725 TypeRawPtr::BOTTOM, new_pf_wmt );
1726 transform_later(store_new_wmt);
1728 // adding prefetches
1729 pf_phi_abio->init_req( fall_in_path, i_o );
1731 Node *prefetch_adr;
1732 Node *prefetch;
1733 uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
1734 uint step_size = AllocatePrefetchStepSize;
1735 uint distance = 0;
1737 for ( uint i = 0; i < lines; i++ ) {
1738 prefetch_adr = new (C) AddPNode( old_pf_wm, new_pf_wmt,
1739 _igvn.MakeConX(distance) );
1740 transform_later(prefetch_adr);
1741 prefetch = new (C) 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 );
1748 pf_region->init_req( fall_in_path, need_pf_false );
1749 pf_region->init_req( pf_path, need_pf_true );
1751 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
1752 pf_phi_rawmem->init_req( pf_path, store_new_wmt );
1754 transform_later(pf_region);
1755 transform_later(pf_phi_rawmem);
1756 transform_later(pf_phi_abio);
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 for each allocation.
1763 // This code is used for Sparc with BIS.
1764 Node *pf_region = new (C) RegionNode(3);
1765 Node *pf_phi_rawmem = new (C) PhiNode( pf_region, Type::MEMORY,
1766 TypeRawPtr::BOTTOM );
1768 // Generate several prefetch instructions.
1769 uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1770 uint step_size = AllocatePrefetchStepSize;
1771 uint distance = AllocatePrefetchDistance;
1773 // Next cache address.
1774 Node *cache_adr = new (C) AddPNode(old_eden_top, old_eden_top,
1775 _igvn.MakeConX(distance));
1776 transform_later(cache_adr);
1777 cache_adr = new (C) CastP2XNode(needgc_false, cache_adr);
1778 transform_later(cache_adr);
1779 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1));
1780 cache_adr = new (C) AndXNode(cache_adr, mask);
1781 transform_later(cache_adr);
1782 cache_adr = new (C) CastX2PNode(cache_adr);
1783 transform_later(cache_adr);
1785 // Prefetch
1786 Node *prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, cache_adr );
1787 prefetch->set_req(0, needgc_false);
1788 transform_later(prefetch);
1789 contended_phi_rawmem = prefetch;
1790 Node *prefetch_adr;
1791 distance = step_size;
1792 for ( uint i = 1; i < lines; i++ ) {
1793 prefetch_adr = new (C) AddPNode( cache_adr, cache_adr,
1794 _igvn.MakeConX(distance) );
1795 transform_later(prefetch_adr);
1796 prefetch = new (C) PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr );
1797 transform_later(prefetch);
1798 distance += step_size;
1799 contended_phi_rawmem = prefetch;
1800 }
1801 } else if( AllocatePrefetchStyle > 0 ) {
1802 // Insert a prefetch for each allocation only on the fast-path
1803 Node *prefetch_adr;
1804 Node *prefetch;
1805 // Generate several prefetch instructions.
1806 uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines;
1807 uint step_size = AllocatePrefetchStepSize;
1808 uint distance = AllocatePrefetchDistance;
1809 for ( uint i = 0; i < lines; i++ ) {
1810 prefetch_adr = new (C) AddPNode( old_eden_top, new_eden_top,
1811 _igvn.MakeConX(distance) );
1812 transform_later(prefetch_adr);
1813 prefetch = new (C) PrefetchAllocationNode( i_o, prefetch_adr );
1814 // Do not let it float too high, since if eden_top == eden_end,
1815 // both might be null.
1816 if( i == 0 ) { // Set control for first prefetch, next follows it
1817 prefetch->init_req(0, needgc_false);
1818 }
1819 transform_later(prefetch);
1820 distance += step_size;
1821 i_o = prefetch;
1822 }
1823 }
1824 return i_o;
1825 }
1828 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
1829 expand_allocate_common(alloc, NULL,
1830 OptoRuntime::new_instance_Type(),
1831 OptoRuntime::new_instance_Java());
1832 }
1834 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
1835 Node* length = alloc->in(AllocateNode::ALength);
1836 InitializeNode* init = alloc->initialization();
1837 Node* klass_node = alloc->in(AllocateNode::KlassNode);
1838 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
1839 address slow_call_address; // Address of slow call
1840 if (init != NULL && init->is_complete_with_arraycopy() &&
1841 k->is_type_array_klass()) {
1842 // Don't zero type array during slow allocation in VM since
1843 // it will be initialized later by arraycopy in compiled code.
1844 slow_call_address = OptoRuntime::new_array_nozero_Java();
1845 } else {
1846 slow_call_address = OptoRuntime::new_array_Java();
1847 }
1848 expand_allocate_common(alloc, length,
1849 OptoRuntime::new_array_Type(),
1850 slow_call_address);
1851 }
1853 //-------------------mark_eliminated_box----------------------------------
1854 //
1855 // During EA obj may point to several objects but after few ideal graph
1856 // transformations (CCP) it may point to only one non escaping object
1857 // (but still using phi), corresponding locks and unlocks will be marked
1858 // for elimination. Later obj could be replaced with a new node (new phi)
1859 // and which does not have escape information. And later after some graph
1860 // reshape other locks and unlocks (which were not marked for elimination
1861 // before) are connected to this new obj (phi) but they still will not be
1862 // marked for elimination since new obj has no escape information.
1863 // Mark all associated (same box and obj) lock and unlock nodes for
1864 // elimination if some of them marked already.
1865 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) {
1866 if (oldbox->as_BoxLock()->is_eliminated())
1867 return; // This BoxLock node was processed already.
1869 // New implementation (EliminateNestedLocks) has separate BoxLock
1870 // node for each locked region so mark all associated locks/unlocks as
1871 // eliminated even if different objects are referenced in one locked region
1872 // (for example, OSR compilation of nested loop inside locked scope).
1873 if (EliminateNestedLocks ||
1874 oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) {
1875 // Box is used only in one lock region. Mark this box as eliminated.
1876 _igvn.hash_delete(oldbox);
1877 oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value
1878 _igvn.hash_insert(oldbox);
1880 for (uint i = 0; i < oldbox->outcnt(); i++) {
1881 Node* u = oldbox->raw_out(i);
1882 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) {
1883 AbstractLockNode* alock = u->as_AbstractLock();
1884 // Check lock's box since box could be referenced by Lock's debug info.
1885 if (alock->box_node() == oldbox) {
1886 // Mark eliminated all related locks and unlocks.
1887 alock->set_non_esc_obj();
1888 }
1889 }
1890 }
1891 return;
1892 }
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();
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);
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;
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 alock->set_non_esc_obj();
1914 _igvn.rehash_node_delayed(alock);
1915 alock->set_box_node(newbox);
1916 next_edge = false;
1917 }
1918 }
1919 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) {
1920 FastLockNode* flock = u->as_FastLock();
1921 assert(flock->box_node() == oldbox, "sanity");
1922 _igvn.rehash_node_delayed(flock);
1923 flock->set_box_node(newbox);
1924 next_edge = false;
1925 }
1927 // Replace old box in monitor debug info.
1928 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) {
1929 SafePointNode* sfn = u->as_SafePoint();
1930 JVMState* youngest_jvms = sfn->jvms();
1931 int max_depth = youngest_jvms->depth();
1932 for (int depth = 1; depth <= max_depth; depth++) {
1933 JVMState* jvms = youngest_jvms->of_depth(depth);
1934 int num_mon = jvms->nof_monitors();
1935 // Loop over monitors
1936 for (int idx = 0; idx < num_mon; idx++) {
1937 Node* obj_node = sfn->monitor_obj(jvms, idx);
1938 Node* box_node = sfn->monitor_box(jvms, idx);
1939 if (box_node == oldbox && obj_node->eqv_uncast(obj)) {
1940 int j = jvms->monitor_box_offset(idx);
1941 _igvn.replace_input_of(u, j, newbox);
1942 next_edge = false;
1943 }
1944 }
1945 }
1946 }
1947 if (next_edge) i++;
1948 }
1949 }
1951 //-----------------------mark_eliminated_locking_nodes-----------------------
1952 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) {
1953 if (EliminateNestedLocks) {
1954 if (alock->is_nested()) {
1955 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity");
1956 return;
1957 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened
1958 // Only Lock node has JVMState needed here.
1959 if (alock->jvms() != NULL && alock->as_Lock()->is_nested_lock_region()) {
1960 // Mark eliminated related nested locks and unlocks.
1961 Node* obj = alock->obj_node();
1962 BoxLockNode* box_node = alock->box_node()->as_BoxLock();
1963 assert(!box_node->is_eliminated(), "should not be marked yet");
1964 // Note: BoxLock node is marked eliminated only here
1965 // and it is used to indicate that all associated lock
1966 // and unlock nodes are marked for elimination.
1967 box_node->set_eliminated(); // Box's hash is always NO_HASH here
1968 for (uint i = 0; i < box_node->outcnt(); i++) {
1969 Node* u = box_node->raw_out(i);
1970 if (u->is_AbstractLock()) {
1971 alock = u->as_AbstractLock();
1972 if (alock->box_node() == box_node) {
1973 // Verify that this Box is referenced only by related locks.
1974 assert(alock->obj_node()->eqv_uncast(obj), "");
1975 // Mark all related locks and unlocks.
1976 alock->set_nested();
1977 }
1978 }
1979 }
1980 }
1981 return;
1982 }
1983 // Process locks for non escaping object
1984 assert(alock->is_non_esc_obj(), "");
1985 } // EliminateNestedLocks
1987 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object
1988 // Look for all locks of this object and mark them and
1989 // corresponding BoxLock nodes as eliminated.
1990 Node* obj = alock->obj_node();
1991 for (uint j = 0; j < obj->outcnt(); j++) {
1992 Node* o = obj->raw_out(j);
1993 if (o->is_AbstractLock() &&
1994 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) {
1995 alock = o->as_AbstractLock();
1996 Node* box = alock->box_node();
1997 // Replace old box node with new eliminated box for all users
1998 // of the same object and mark related locks as eliminated.
1999 mark_eliminated_box(box, obj);
2000 }
2001 }
2002 }
2003 }
2005 // we have determined that this lock/unlock can be eliminated, we simply
2006 // eliminate the node without expanding it.
2007 //
2008 // Note: The membar's associated with the lock/unlock are currently not
2009 // eliminated. This should be investigated as a future enhancement.
2010 //
2011 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
2013 if (!alock->is_eliminated()) {
2014 return false;
2015 }
2016 #ifdef ASSERT
2017 if (!alock->is_coarsened()) {
2018 // Check that new "eliminated" BoxLock node is created.
2019 BoxLockNode* oldbox = alock->box_node()->as_BoxLock();
2020 assert(oldbox->is_eliminated(), "should be done already");
2021 }
2022 #endif
2023 CompileLog* log = C->log();
2024 if (log != NULL) {
2025 log->head("eliminate_lock lock='%d'",
2026 alock->is_Lock());
2027 JVMState* p = alock->jvms();
2028 while (p != NULL) {
2029 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
2030 p = p->caller();
2031 }
2032 log->tail("eliminate_lock");
2033 }
2035 #ifndef PRODUCT
2036 if (PrintEliminateLocks) {
2037 if (alock->is_Lock()) {
2038 tty->print_cr("++++ Eliminated: %d Lock", alock->_idx);
2039 } else {
2040 tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx);
2041 }
2042 }
2043 #endif
2045 Node* mem = alock->in(TypeFunc::Memory);
2046 Node* ctrl = alock->in(TypeFunc::Control);
2048 extract_call_projections(alock);
2049 // There are 2 projections from the lock. The lock node will
2050 // be deleted when its last use is subsumed below.
2051 assert(alock->outcnt() == 2 &&
2052 _fallthroughproj != NULL &&
2053 _memproj_fallthrough != NULL,
2054 "Unexpected projections from Lock/Unlock");
2056 Node* fallthroughproj = _fallthroughproj;
2057 Node* memproj_fallthrough = _memproj_fallthrough;
2059 // The memory projection from a lock/unlock is RawMem
2060 // The input to a Lock is merged memory, so extract its RawMem input
2061 // (unless the MergeMem has been optimized away.)
2062 if (alock->is_Lock()) {
2063 // Seach for MemBarAcquireLock node and delete it also.
2064 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
2065 assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, "");
2066 Node* ctrlproj = membar->proj_out(TypeFunc::Control);
2067 Node* memproj = membar->proj_out(TypeFunc::Memory);
2068 _igvn.replace_node(ctrlproj, fallthroughproj);
2069 _igvn.replace_node(memproj, memproj_fallthrough);
2071 // Delete FastLock node also if this Lock node is unique user
2072 // (a loop peeling may clone a Lock node).
2073 Node* flock = alock->as_Lock()->fastlock_node();
2074 if (flock->outcnt() == 1) {
2075 assert(flock->unique_out() == alock, "sanity");
2076 _igvn.replace_node(flock, top());
2077 }
2078 }
2080 // Seach for MemBarReleaseLock node and delete it also.
2081 if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
2082 ctrl->in(0)->is_MemBar()) {
2083 MemBarNode* membar = ctrl->in(0)->as_MemBar();
2084 assert(membar->Opcode() == Op_MemBarReleaseLock &&
2085 mem->is_Proj() && membar == mem->in(0), "");
2086 _igvn.replace_node(fallthroughproj, ctrl);
2087 _igvn.replace_node(memproj_fallthrough, mem);
2088 fallthroughproj = ctrl;
2089 memproj_fallthrough = mem;
2090 ctrl = membar->in(TypeFunc::Control);
2091 mem = membar->in(TypeFunc::Memory);
2092 }
2094 _igvn.replace_node(fallthroughproj, ctrl);
2095 _igvn.replace_node(memproj_fallthrough, mem);
2096 return true;
2097 }
2100 //------------------------------expand_lock_node----------------------
2101 void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
2103 Node* ctrl = lock->in(TypeFunc::Control);
2104 Node* mem = lock->in(TypeFunc::Memory);
2105 Node* obj = lock->obj_node();
2106 Node* box = lock->box_node();
2107 Node* flock = lock->fastlock_node();
2109 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2111 // Make the merge point
2112 Node *region;
2113 Node *mem_phi;
2114 Node *slow_path;
2116 if (UseOptoBiasInlining) {
2117 /*
2118 * See the full description in MacroAssembler::biased_locking_enter().
2119 *
2120 * if( (mark_word & biased_lock_mask) == biased_lock_pattern ) {
2121 * // The object is biased.
2122 * proto_node = klass->prototype_header;
2123 * o_node = thread | proto_node;
2124 * x_node = o_node ^ mark_word;
2125 * if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ?
2126 * // Done.
2127 * } else {
2128 * if( (x_node & biased_lock_mask) != 0 ) {
2129 * // The klass's prototype header is no longer biased.
2130 * cas(&mark_word, mark_word, proto_node)
2131 * goto cas_lock;
2132 * } else {
2133 * // The klass's prototype header is still biased.
2134 * if( (x_node & epoch_mask) != 0 ) { // Expired epoch?
2135 * old = mark_word;
2136 * new = o_node;
2137 * } else {
2138 * // Different thread or anonymous biased.
2139 * old = mark_word & (epoch_mask | age_mask | biased_lock_mask);
2140 * new = thread | old;
2141 * }
2142 * // Try to rebias.
2143 * if( cas(&mark_word, old, new) == 0 ) {
2144 * // Done.
2145 * } else {
2146 * goto slow_path; // Failed.
2147 * }
2148 * }
2149 * }
2150 * } else {
2151 * // The object is not biased.
2152 * cas_lock:
2153 * if( FastLock(obj) == 0 ) {
2154 * // Done.
2155 * } else {
2156 * slow_path:
2157 * OptoRuntime::complete_monitor_locking_Java(obj);
2158 * }
2159 * }
2160 */
2162 region = new (C) RegionNode(5);
2163 // create a Phi for the memory state
2164 mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2166 Node* fast_lock_region = new (C) RegionNode(3);
2167 Node* fast_lock_mem_phi = new (C) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM);
2169 // First, check mark word for the biased lock pattern.
2170 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2172 // Get fast path - mark word has the biased lock pattern.
2173 ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node,
2174 markOopDesc::biased_lock_mask_in_place,
2175 markOopDesc::biased_lock_pattern, true);
2176 // fast_lock_region->in(1) is set to slow path.
2177 fast_lock_mem_phi->init_req(1, mem);
2179 // Now check that the lock is biased to the current thread and has
2180 // the same epoch and bias as Klass::_prototype_header.
2182 // Special-case a fresh allocation to avoid building nodes:
2183 Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn);
2184 if (klass_node == NULL) {
2185 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
2186 klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) );
2187 #ifdef _LP64
2188 if (UseCompressedKlassPointers && klass_node->is_DecodeNKlass()) {
2189 assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity");
2190 klass_node->in(1)->init_req(0, ctrl);
2191 } else
2192 #endif
2193 klass_node->init_req(0, ctrl);
2194 }
2195 Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type());
2197 Node* thread = transform_later(new (C) ThreadLocalNode());
2198 Node* cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
2199 Node* o_node = transform_later(new (C) OrXNode(cast_thread, proto_node));
2200 Node* x_node = transform_later(new (C) XorXNode(o_node, mark_node));
2202 // Get slow path - mark word does NOT match the value.
2203 Node* not_biased_ctrl = opt_bits_test(ctrl, region, 3, x_node,
2204 (~markOopDesc::age_mask_in_place), 0);
2205 // region->in(3) is set to fast path - the object is biased to the current thread.
2206 mem_phi->init_req(3, mem);
2209 // Mark word does NOT match the value (thread | Klass::_prototype_header).
2212 // First, check biased pattern.
2213 // Get fast path - _prototype_header has the same biased lock pattern.
2214 ctrl = opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node,
2215 markOopDesc::biased_lock_mask_in_place, 0, true);
2217 not_biased_ctrl = fast_lock_region->in(2); // Slow path
2218 // fast_lock_region->in(2) - the prototype header is no longer biased
2219 // and we have to revoke the bias on this object.
2220 // We are going to try to reset the mark of this object to the prototype
2221 // value and fall through to the CAS-based locking scheme.
2222 Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes());
2223 Node* cas = new (C) StoreXConditionalNode(not_biased_ctrl, mem, adr,
2224 proto_node, mark_node);
2225 transform_later(cas);
2226 Node* proj = transform_later( new (C) SCMemProjNode(cas));
2227 fast_lock_mem_phi->init_req(2, proj);
2230 // Second, check epoch bits.
2231 Node* rebiased_region = new (C) RegionNode(3);
2232 Node* old_phi = new (C) PhiNode( rebiased_region, TypeX_X);
2233 Node* new_phi = new (C) PhiNode( rebiased_region, TypeX_X);
2235 // Get slow path - mark word does NOT match epoch bits.
2236 Node* epoch_ctrl = opt_bits_test(ctrl, rebiased_region, 1, x_node,
2237 markOopDesc::epoch_mask_in_place, 0);
2238 // The epoch of the current bias is not valid, attempt to rebias the object
2239 // toward the current thread.
2240 rebiased_region->init_req(2, epoch_ctrl);
2241 old_phi->init_req(2, mark_node);
2242 new_phi->init_req(2, o_node);
2244 // rebiased_region->in(1) is set to fast path.
2245 // The epoch of the current bias is still valid but we know
2246 // nothing about the owner; it might be set or it might be clear.
2247 Node* cmask = MakeConX(markOopDesc::biased_lock_mask_in_place |
2248 markOopDesc::age_mask_in_place |
2249 markOopDesc::epoch_mask_in_place);
2250 Node* old = transform_later(new (C) AndXNode(mark_node, cmask));
2251 cast_thread = transform_later(new (C) CastP2XNode(ctrl, thread));
2252 Node* new_mark = transform_later(new (C) OrXNode(cast_thread, old));
2253 old_phi->init_req(1, old);
2254 new_phi->init_req(1, new_mark);
2256 transform_later(rebiased_region);
2257 transform_later(old_phi);
2258 transform_later(new_phi);
2260 // Try to acquire the bias of the object using an atomic operation.
2261 // If this fails we will go in to the runtime to revoke the object's bias.
2262 cas = new (C) StoreXConditionalNode(rebiased_region, mem, adr,
2263 new_phi, old_phi);
2264 transform_later(cas);
2265 proj = transform_later( new (C) SCMemProjNode(cas));
2267 // Get slow path - Failed to CAS.
2268 not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0);
2269 mem_phi->init_req(4, proj);
2270 // region->in(4) is set to fast path - the object is rebiased to the current thread.
2272 // Failed to CAS.
2273 slow_path = new (C) RegionNode(3);
2274 Node *slow_mem = new (C) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM);
2276 slow_path->init_req(1, not_biased_ctrl); // Capture slow-control
2277 slow_mem->init_req(1, proj);
2279 // Call CAS-based locking scheme (FastLock node).
2281 transform_later(fast_lock_region);
2282 transform_later(fast_lock_mem_phi);
2284 // Get slow path - FastLock failed to lock the object.
2285 ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0);
2286 mem_phi->init_req(2, fast_lock_mem_phi);
2287 // region->in(2) is set to fast path - the object is locked to the current thread.
2289 slow_path->init_req(2, ctrl); // Capture slow-control
2290 slow_mem->init_req(2, fast_lock_mem_phi);
2292 transform_later(slow_path);
2293 transform_later(slow_mem);
2294 // Reset lock's memory edge.
2295 lock->set_req(TypeFunc::Memory, slow_mem);
2297 } else {
2298 region = new (C) RegionNode(3);
2299 // create a Phi for the memory state
2300 mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2302 // Optimize test; set region slot 2
2303 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0);
2304 mem_phi->init_req(2, mem);
2305 }
2307 // Make slow path call
2308 CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
2310 extract_call_projections(call);
2312 // Slow path can only throw asynchronous exceptions, which are always
2313 // de-opted. So the compiler thinks the slow-call can never throw an
2314 // exception. If it DOES throw an exception we would need the debug
2315 // info removed first (since if it throws there is no monitor).
2316 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2317 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2319 // Capture slow path
2320 // disconnect fall-through projection from call and create a new one
2321 // hook up users of fall-through projection to region
2322 Node *slow_ctrl = _fallthroughproj->clone();
2323 transform_later(slow_ctrl);
2324 _igvn.hash_delete(_fallthroughproj);
2325 _fallthroughproj->disconnect_inputs(NULL, C);
2326 region->init_req(1, slow_ctrl);
2327 // region inputs are now complete
2328 transform_later(region);
2329 _igvn.replace_node(_fallthroughproj, region);
2331 Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
2332 mem_phi->init_req(1, memproj );
2333 transform_later(mem_phi);
2334 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2335 }
2337 //------------------------------expand_unlock_node----------------------
2338 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
2340 Node* ctrl = unlock->in(TypeFunc::Control);
2341 Node* mem = unlock->in(TypeFunc::Memory);
2342 Node* obj = unlock->obj_node();
2343 Node* box = unlock->box_node();
2345 assert(!box->as_BoxLock()->is_eliminated(), "sanity");
2347 // No need for a null check on unlock
2349 // Make the merge point
2350 Node *region;
2351 Node *mem_phi;
2353 if (UseOptoBiasInlining) {
2354 // Check for biased locking unlock case, which is a no-op.
2355 // See the full description in MacroAssembler::biased_locking_exit().
2356 region = new (C) RegionNode(4);
2357 // create a Phi for the memory state
2358 mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2359 mem_phi->init_req(3, mem);
2361 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
2362 ctrl = opt_bits_test(ctrl, region, 3, mark_node,
2363 markOopDesc::biased_lock_mask_in_place,
2364 markOopDesc::biased_lock_pattern);
2365 } else {
2366 region = new (C) RegionNode(3);
2367 // create a Phi for the memory state
2368 mem_phi = new (C) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
2369 }
2371 FastUnlockNode *funlock = new (C) FastUnlockNode( ctrl, obj, box );
2372 funlock = transform_later( funlock )->as_FastUnlock();
2373 // Optimize test; set region slot 2
2374 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0);
2376 CallNode *call = make_slow_call( (CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), "complete_monitor_unlocking_C", slow_path, obj, box );
2378 extract_call_projections(call);
2380 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
2381 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
2383 // No exceptions for unlocking
2384 // Capture slow path
2385 // disconnect fall-through projection from call and create a new one
2386 // hook up users of fall-through projection to region
2387 Node *slow_ctrl = _fallthroughproj->clone();
2388 transform_later(slow_ctrl);
2389 _igvn.hash_delete(_fallthroughproj);
2390 _fallthroughproj->disconnect_inputs(NULL, C);
2391 region->init_req(1, slow_ctrl);
2392 // region inputs are now complete
2393 transform_later(region);
2394 _igvn.replace_node(_fallthroughproj, region);
2396 Node *memproj = transform_later( new(C) ProjNode(call, TypeFunc::Memory) );
2397 mem_phi->init_req(1, memproj );
2398 mem_phi->init_req(2, mem);
2399 transform_later(mem_phi);
2400 _igvn.replace_node(_memproj_fallthrough, mem_phi);
2401 }
2403 //---------------------------eliminate_macro_nodes----------------------
2404 // Eliminate scalar replaced allocations and associated locks.
2405 void PhaseMacroExpand::eliminate_macro_nodes() {
2406 if (C->macro_count() == 0)
2407 return;
2409 // First, attempt to eliminate locks
2410 int cnt = C->macro_count();
2411 for (int i=0; i < cnt; i++) {
2412 Node *n = C->macro_node(i);
2413 if (n->is_AbstractLock()) { // Lock and Unlock nodes
2414 // Before elimination mark all associated (same box and obj)
2415 // lock and unlock nodes.
2416 mark_eliminated_locking_nodes(n->as_AbstractLock());
2417 }
2418 }
2419 bool progress = true;
2420 while (progress) {
2421 progress = false;
2422 for (int i = C->macro_count(); i > 0; i--) {
2423 Node * n = C->macro_node(i-1);
2424 bool success = false;
2425 debug_only(int old_macro_count = C->macro_count(););
2426 if (n->is_AbstractLock()) {
2427 success = eliminate_locking_node(n->as_AbstractLock());
2428 }
2429 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2430 progress = progress || success;
2431 }
2432 }
2433 // Next, attempt to eliminate allocations
2434 progress = true;
2435 while (progress) {
2436 progress = false;
2437 for (int i = C->macro_count(); i > 0; i--) {
2438 Node * n = C->macro_node(i-1);
2439 bool success = false;
2440 debug_only(int old_macro_count = C->macro_count(););
2441 switch (n->class_id()) {
2442 case Node::Class_Allocate:
2443 case Node::Class_AllocateArray:
2444 success = eliminate_allocate_node(n->as_Allocate());
2445 break;
2446 case Node::Class_CallStaticJava:
2447 success = eliminate_boxing_node(n->as_CallStaticJava());
2448 break;
2449 case Node::Class_Lock:
2450 case Node::Class_Unlock:
2451 assert(!n->as_AbstractLock()->is_eliminated(), "sanity");
2452 break;
2453 default:
2454 assert(n->Opcode() == Op_LoopLimit ||
2455 n->Opcode() == Op_Opaque1 ||
2456 n->Opcode() == Op_Opaque2, "unknown node type in macro list");
2457 }
2458 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2459 progress = progress || success;
2460 }
2461 }
2462 }
2464 //------------------------------expand_macro_nodes----------------------
2465 // Returns true if a failure occurred.
2466 bool PhaseMacroExpand::expand_macro_nodes() {
2467 // Last attempt to eliminate macro nodes.
2468 eliminate_macro_nodes();
2470 // Make sure expansion will not cause node limit to be exceeded.
2471 // Worst case is a macro node gets expanded into about 50 nodes.
2472 // Allow 50% more for optimization.
2473 if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
2474 return true;
2476 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations.
2477 bool progress = true;
2478 while (progress) {
2479 progress = false;
2480 for (int i = C->macro_count(); i > 0; i--) {
2481 Node * n = C->macro_node(i-1);
2482 bool success = false;
2483 debug_only(int old_macro_count = C->macro_count(););
2484 if (n->Opcode() == Op_LoopLimit) {
2485 // Remove it from macro list and put on IGVN worklist to optimize.
2486 C->remove_macro_node(n);
2487 _igvn._worklist.push(n);
2488 success = true;
2489 } else if (n->Opcode() == Op_CallStaticJava) {
2490 // Remove it from macro list and put on IGVN worklist to optimize.
2491 C->remove_macro_node(n);
2492 _igvn._worklist.push(n);
2493 success = true;
2494 } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) {
2495 _igvn.replace_node(n, n->in(1));
2496 success = true;
2497 }
2498 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
2499 progress = progress || success;
2500 }
2501 }
2503 // expand "macro" nodes
2504 // nodes are removed from the macro list as they are processed
2505 while (C->macro_count() > 0) {
2506 int macro_count = C->macro_count();
2507 Node * n = C->macro_node(macro_count-1);
2508 assert(n->is_macro(), "only macro nodes expected here");
2509 if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
2510 // node is unreachable, so don't try to expand it
2511 C->remove_macro_node(n);
2512 continue;
2513 }
2514 switch (n->class_id()) {
2515 case Node::Class_Allocate:
2516 expand_allocate(n->as_Allocate());
2517 break;
2518 case Node::Class_AllocateArray:
2519 expand_allocate_array(n->as_AllocateArray());
2520 break;
2521 case Node::Class_Lock:
2522 expand_lock_node(n->as_Lock());
2523 break;
2524 case Node::Class_Unlock:
2525 expand_unlock_node(n->as_Unlock());
2526 break;
2527 default:
2528 assert(false, "unknown node type in macro list");
2529 }
2530 assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
2531 if (C->failing()) return true;
2532 }
2534 _igvn.set_delay_transform(false);
2535 _igvn.optimize();
2536 if (C->failing()) return true;
2537 return false;
2538 }