1 /*
2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciValueKlass.hpp"
27 #include "opto/addnode.hpp"
28 #include "opto/castnode.hpp"
29 #include "opto/graphKit.hpp"
30 #include "opto/rootnode.hpp"
31 #include "opto/valuetypenode.hpp"
32 #include "opto/phaseX.hpp"
33
34 // Clones the values type to handle control flow merges involving multiple value types.
35 // The inputs are replaced by PhiNodes to represent the merged values for the given region.
36 ValueTypeBaseNode* ValueTypeBaseNode::clone_with_phis(PhaseGVN* gvn, Node* region) {
37 assert(!has_phi_inputs(region), "already cloned with phis");
38 ValueTypeBaseNode* vt = clone()->as_ValueTypeBase();
39
40 // Create a PhiNode for merging the oop values
41 const Type* phi_type = Type::get_const_type(value_klass());
42 PhiNode* oop = PhiNode::make(region, vt->get_oop(), phi_type);
43 gvn->set_type(oop, phi_type);
44 vt->set_oop(oop);
45
46 // Create a PhiNode each for merging the field values
47 for (uint i = 0; i < vt->field_count(); ++i) {
48 ciType* type = vt->field_type(i);
49 Node* value = vt->field_value(i);
50 if (type->is_valuetype() && value->isa_ValueType()) {
51 // Handle flattened value type fields recursively
52 value = value->as_ValueType()->clone_with_phis(gvn, region);
53 } else {
54 phi_type = Type::get_const_type(type);
55 value = PhiNode::make(region, value, phi_type);
56 gvn->set_type(value, phi_type);
57 }
58 vt->set_field_value(i, value);
59 }
60 gvn->set_type(vt, vt->bottom_type());
61 return vt;
62 }
63
64 // Checks if the inputs of the ValueBaseTypeNode were replaced by PhiNodes
65 // for the given region (see ValueBaseTypeNode::clone_with_phis).
66 bool ValueTypeBaseNode::has_phi_inputs(Node* region) {
67 // Check oop input
68 bool result = get_oop()->is_Phi() && get_oop()->as_Phi()->region() == region;
69 #ifdef ASSERT
70 if (result) {
71 // Check all field value inputs for consistency
72 for (uint i = Oop; i < field_count(); ++i) {
73 Node* n = in(i);
74 if (n->is_ValueTypeBase()) {
75 assert(n->as_ValueTypeBase()->has_phi_inputs(region), "inconsistent phi inputs");
76 } else {
77 assert(n->is_Phi() && n->as_Phi()->region() == region, "inconsistent phi inputs");
78 }
79 }
80 }
81 #endif
82 return result;
83 }
84
85 // Merges 'this' with 'other' by updating the input PhiNodes added by 'clone_with_phis'
86 ValueTypeBaseNode* ValueTypeBaseNode::merge_with(PhaseGVN* gvn, const ValueTypeBaseNode* other, int pnum, bool transform) {
87 // Merge oop inputs
88 PhiNode* phi = get_oop()->as_Phi();
89 phi->set_req(pnum, other->get_oop());
90 if (transform) {
91 set_oop(gvn->transform(phi));
92 gvn->record_for_igvn(phi);
93 }
94 // Merge field values
95 for (uint i = 0; i < field_count(); ++i) {
96 Node* val1 = field_value(i);
97 Node* val2 = other->field_value(i);
98 if (val1->is_ValueType()) {
99 val1->as_ValueType()->merge_with(gvn, val2->as_ValueType(), pnum, transform);
100 } else {
101 assert(val1->is_Phi(), "must be a phi node");
102 assert(!val2->is_ValueType(), "inconsistent merge values");
103 val1->set_req(pnum, val2);
104 }
105 if (transform) {
106 set_field_value(i, gvn->transform(val1));
107 gvn->record_for_igvn(val1);
108 }
109 }
110 return this;
111 }
112
113 // Adds a new merge path to a valuetype node with phi inputs
114 void ValueTypeBaseNode::add_new_path(Node* region) {
115 assert(has_phi_inputs(region), "must have phi inputs");
116
117 PhiNode* phi = get_oop()->as_Phi();
118 phi->add_req(NULL);
119 assert(phi->req() == region->req(), "must be same size as region");
120
121 for (uint i = 0; i < field_count(); ++i) {
122 Node* val = field_value(i);
123 if (val->is_ValueType()) {
124 val->as_ValueType()->add_new_path(region);
125 } else {
126 val->as_Phi()->add_req(NULL);
127 assert(val->req() == region->req(), "must be same size as region");
128 }
129 }
130 }
131
132 Node* ValueTypeBaseNode::field_value(uint index) const {
133 assert(index < field_count(), "index out of bounds");
134 return in(Values + index);
135 }
136
137 // Get the value of the field at the given offset.
138 // If 'recursive' is true, flattened value type fields will be resolved recursively.
139 Node* ValueTypeBaseNode::field_value_by_offset(int offset, bool recursive) const {
140 // If the field at 'offset' belongs to a flattened value type field, 'index' refers to the
141 // corresponding ValueTypeNode input and 'sub_offset' is the offset in flattened value type.
142 int index = value_klass()->field_index_by_offset(offset);
143 int sub_offset = offset - field_offset(index);
144 Node* value = field_value(index);
145 assert(value != NULL, "field value not found");
146 if (recursive && value->is_ValueType()) {
147 ValueTypeNode* vt = value->as_ValueType();
148 if (field_is_flattened(index)) {
149 // Flattened value type field
150 sub_offset += vt->value_klass()->first_field_offset(); // Add header size
151 return vt->field_value_by_offset(sub_offset, recursive);
152 } else {
153 assert(sub_offset == 0, "should not have a sub offset");
154 return vt;
155 }
156 }
157 assert(!(recursive && value->is_ValueType()), "should not be a value type");
158 assert(sub_offset == 0, "offset mismatch");
159 return value;
160 }
161
162 void ValueTypeBaseNode::set_field_value(uint index, Node* value) {
163 assert(index < field_count(), "index out of bounds");
164 set_req(Values + index, value);
165 }
166
167 void ValueTypeBaseNode::set_field_value_by_offset(int offset, Node* value) {
168 uint i = 0;
169 for (; i < field_count() && field_offset(i) != offset; i++) { }
170 assert(i < field_count(), "field not found");
171 set_field_value(i, value);
172 }
173
174 int ValueTypeBaseNode::field_offset(uint index) const {
175 assert(index < field_count(), "index out of bounds");
176 return value_klass()->declared_nonstatic_field_at(index)->offset();
177 }
178
179 ciType* ValueTypeBaseNode::field_type(uint index) const {
180 assert(index < field_count(), "index out of bounds");
181 return value_klass()->declared_nonstatic_field_at(index)->type();
182 }
183
184 bool ValueTypeBaseNode::field_is_flattened(uint index) const {
185 assert(index < field_count(), "index out of bounds");
186 ciField* field = value_klass()->declared_nonstatic_field_at(index);
187 assert(!field->is_flattened() || field->type()->is_valuetype(), "must be a value type");
188 return field->is_flattened();
189 }
190
191 bool ValueTypeBaseNode::field_is_flattenable(uint index) const {
192 assert(index < field_count(), "index out of bounds");
193 ciField* field = value_klass()->declared_nonstatic_field_at(index);
194 assert(!field->is_flattenable() || field->type()->is_valuetype(), "must be a value type");
195 return field->is_flattenable();
196 }
197
198 int ValueTypeBaseNode::make_scalar_in_safepoint(PhaseIterGVN* igvn, Unique_Node_List& worklist, SafePointNode* sfpt) {
199 ciValueKlass* vk = value_klass();
200 uint nfields = vk->nof_nonstatic_fields();
201 JVMState* jvms = sfpt->jvms();
202 int start = jvms->debug_start();
203 int end = jvms->debug_end();
204 // Replace safepoint edge by SafePointScalarObjectNode and add field values
205 assert(jvms != NULL, "missing JVMS");
206 uint first_ind = (sfpt->req() - jvms->scloff());
207 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(value_ptr(),
208 #ifdef ASSERT
209 NULL,
210 #endif
211 first_ind, nfields);
212 sobj->init_req(0, igvn->C->root());
213 // Iterate over the value type fields in order of increasing
214 // offset and add the field values to the safepoint.
215 for (uint j = 0; j < nfields; ++j) {
216 int offset = vk->nonstatic_field_at(j)->offset();
217 Node* value = field_value_by_offset(offset, true /* include flattened value type fields */);
218 if (value->is_ValueType()) {
219 // Add value type field to the worklist to process later
220 worklist.push(value);
221 }
222 sfpt->add_req(value);
223 }
224 jvms->set_endoff(sfpt->req());
225 sobj = igvn->transform(sobj)->as_SafePointScalarObject();
226 igvn->rehash_node_delayed(sfpt);
227 return sfpt->replace_edges_in_range(this, sobj, start, end);
228 }
229
230 void ValueTypeBaseNode::make_scalar_in_safepoints(PhaseIterGVN* igvn) {
231 // Process all safepoint uses and scalarize value type
232 Unique_Node_List worklist;
233 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
234 SafePointNode* sfpt = fast_out(i)->isa_SafePoint();
235 if (sfpt != NULL && !sfpt->is_CallLeaf() && (!sfpt->is_Call() || sfpt->as_Call()->has_debug_use(this))) {
236 int nb = 0;
237 if (is_allocated(igvn) && get_oop()->is_Con()) {
238 // Value type is allocated with a constant oop, link it directly
239 nb = sfpt->replace_edges_in_range(this, get_oop(), sfpt->jvms()->debug_start(), sfpt->jvms()->debug_end());
240 igvn->rehash_node_delayed(sfpt);
241 } else {
242 nb = make_scalar_in_safepoint(igvn, worklist, sfpt);
243 }
244 --i; imax -= nb;
245 }
246 }
247 // Now scalarize non-flattened fields
248 for (uint i = 0; i < worklist.size(); ++i) {
249 Node* vt = worklist.at(i);
250 vt->as_ValueType()->make_scalar_in_safepoints(igvn);
251 }
252 }
253
254 void ValueTypeBaseNode::initialize(GraphKit* kit, MultiNode* multi, ciValueKlass* vk, int base_offset, uint& base_input, bool in) {
255 assert(base_offset >= 0, "offset in value type must be positive");
256 assert(base_input >= TypeFunc::Parms, "invalid base input");
257 PhaseGVN& gvn = kit->gvn();
258 for (uint i = 0; i < field_count(); i++) {
259 ciType* ft = field_type(i);
260 int offset = base_offset + field_offset(i);
261 if (field_is_flattened(i)) {
262 // Flattened value type field
263 ValueTypeNode* vt = ValueTypeNode::make_uninitialized(gvn, ft->as_value_klass());
264 uint base = base_input;
265 vt->initialize(kit, multi, vk, offset - value_klass()->first_field_offset(), base, in);
266 set_field_value(i, gvn.transform(vt));
267 } else {
268 int j = 0; int extra = 0;
269 for (; j < vk->nof_nonstatic_fields(); j++) {
270 ciField* f = vk->nonstatic_field_at(j);
271 if (offset == f->offset()) {
272 assert(f->type() == ft, "inconsistent field type");
273 break;
274 }
275 BasicType bt = f->type()->basic_type();
276 if (bt == T_LONG || bt == T_DOUBLE) {
277 extra++;
278 }
279 }
280 assert(j != vk->nof_nonstatic_fields(), "must find");
281 Node* parm = NULL;
282 int index = base_input + j + extra;
283
284 ciMethod* method = multi->is_Start()? kit->C->method() : multi->as_CallStaticJava()->method();
285 SigEntry res_entry = method->get_Method()->get_res_entry();
286 if (res_entry._offset != -1 && (index - TypeFunc::Parms) >= res_entry._offset) {
287 // Skip reserved entry
288 index += type2size[res_entry._bt];
289 }
290 if (multi->is_Start()) {
291 assert(in, "return from start?");
292 parm = gvn.transform(new ParmNode(multi->as_Start(), index));
293 } else {
294 if (in) {
295 parm = multi->as_Call()->in(index);
296 } else {
297 parm = gvn.transform(new ProjNode(multi->as_Call(), index));
298 }
299 }
300
301 if (field_is_flattenable(i)) {
302 // Non-flattened but flattenable value type
303 if (ft->as_value_klass()->is_scalarizable()) {
304 parm = ValueTypeNode::make_from_oop(kit, parm, ft->as_value_klass());
305 } else {
306 parm = kit->null2default(parm, ft->as_value_klass());
307 }
308 }
309
310 set_field_value(i, parm);
311 // Record all these guys for later GVN.
312 gvn.record_for_igvn(parm);
313 }
314 }
315 base_input += vk->value_arg_slots();
316 }
317
318 const TypePtr* ValueTypeBaseNode::field_adr_type(Node* base, int offset, ciInstanceKlass* holder, PhaseGVN& gvn) const {
319 const TypeAryPtr* ary_type = gvn.type(base)->isa_aryptr();
320 const TypePtr* adr_type = NULL;
321 bool is_array = ary_type != NULL;
322 if (is_array) {
323 // In the case of a flattened value type array, each field has its own slice
324 adr_type = ary_type->with_field_offset(offset)->add_offset(Type::OffsetBot);
325 } else {
326 ciField* field = holder->get_field_by_offset(offset, false);
327 assert(field != NULL, "field not found");
328 adr_type = gvn.C->alias_type(field)->adr_type();
329 }
330 return adr_type;
331 }
332
333 void ValueTypeBaseNode::load(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset) {
334 // Initialize the value type by loading its field values from
335 // memory and adding the values as input edges to the node.
336 for (uint i = 0; i < field_count(); ++i) {
337 int offset = holder_offset + field_offset(i);
338 Node* value = NULL;
339 ciType* ft = field_type(i);
340 if (field_is_flattened(i)) {
341 // Recursively load the flattened value type field
342 value = ValueTypeNode::make_from_flattened(kit, ft->as_value_klass(), base, ptr, holder, offset);
343 } else {
344 const TypeOopPtr* oop_ptr = kit->gvn().type(base)->isa_oopptr();
345 bool is_array = (oop_ptr->isa_aryptr() != NULL);
346 if (base->is_Con() && !is_array) {
347 // If the oop to the value type is constant (static final field), we can
348 // also treat the fields as constants because the value type is immutable.
349 ciObject* constant_oop = oop_ptr->const_oop();
350 ciField* field = holder->get_field_by_offset(offset, false);
351 assert(field != NULL, "field not found");
352 ciConstant constant = constant_oop->as_instance()->field_value(field);
353 const Type* con_type = Type::make_from_constant(constant, /*require_const=*/ true);
354 assert(con_type != NULL, "type not found");
355 value = kit->gvn().transform(kit->makecon(con_type));
356 } else {
357 // Load field value from memory
358 const TypePtr* adr_type = field_adr_type(base, offset, holder, kit->gvn());
359 Node* adr = kit->basic_plus_adr(base, ptr, offset);
360 BasicType bt = type2field[ft->basic_type()];
361 assert(is_java_primitive(bt) || adr->bottom_type()->is_ptr_to_narrowoop() == UseCompressedOops, "inconsistent");
362 const Type* val_type = Type::get_const_type(ft);
363 DecoratorSet decorators = IN_HEAP | MO_UNORDERED;
364 if (is_array) {
365 decorators |= IS_ARRAY;
366 }
367 value = kit->access_load_at(base, adr, adr_type, val_type, bt, decorators);
368 }
369 if (field_is_flattenable(i)) {
370 // Loading a non-flattened but flattenable value type from memory
371 if (ft->as_value_klass()->is_scalarizable()) {
372 value = ValueTypeNode::make_from_oop(kit, value, ft->as_value_klass());
373 } else {
374 value = kit->null2default(value, ft->as_value_klass());
375 }
376 }
377 }
378 set_field_value(i, value);
379 }
380 }
381
382 void ValueTypeBaseNode::store_flattened(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset) const {
383 // The value type is embedded into the object without an oop header. Subtract the
384 // offset of the first field to account for the missing header when storing the values.
385 if (holder == NULL) {
386 holder = value_klass();
387 }
388 holder_offset -= value_klass()->first_field_offset();
389 store(kit, base, ptr, holder, holder_offset);
390 }
391
392 void ValueTypeBaseNode::store(GraphKit* kit, Node* base, Node* ptr, ciInstanceKlass* holder, int holder_offset, bool deoptimize_on_exception) const {
393 // Write field values to memory
394 for (uint i = 0; i < field_count(); ++i) {
395 int offset = holder_offset + field_offset(i);
396 Node* value = field_value(i);
397 ciType* ft = field_type(i);
398 if (field_is_flattened(i)) {
399 // Recursively store the flattened value type field
400 if (!value->is_ValueType()) {
401 assert(!kit->gvn().type(value)->maybe_null(), "should never be null");
402 value = ValueTypeNode::make_from_oop(kit, value, ft->as_value_klass());
403 }
404 value->as_ValueType()->store_flattened(kit, base, ptr, holder, offset);
405 } else {
406 // Store field value to memory
407 const TypePtr* adr_type = field_adr_type(base, offset, holder, kit->gvn());
408 Node* adr = kit->basic_plus_adr(base, ptr, offset);
409 BasicType bt = type2field[ft->basic_type()];
410 assert(is_java_primitive(bt) || adr->bottom_type()->is_ptr_to_narrowoop() == UseCompressedOops, "inconsistent");
411 const Type* val_type = Type::get_const_type(ft);
412 const TypeAryPtr* ary_type = kit->gvn().type(base)->isa_aryptr();
413 DecoratorSet decorators = IN_HEAP | MO_UNORDERED;
414 if (ary_type != NULL) {
415 decorators |= IS_ARRAY;
416 }
417 kit->access_store_at(base, adr, adr_type, value, val_type, bt, decorators, deoptimize_on_exception);
418 }
419 }
420 }
421
422 ValueTypeBaseNode* ValueTypeBaseNode::allocate(GraphKit* kit, bool deoptimize_on_exception) {
423 // Check if value type is already allocated
424 Node* null_ctl = kit->top();
425 Node* not_null_oop = kit->null_check_oop(get_oop(), &null_ctl);
426 if (null_ctl->is_top()) {
427 // Value type is allocated
428 return this;
429 }
430 assert(!is_allocated(&kit->gvn()), "should not be allocated");
431 RegionNode* region = new RegionNode(3);
432
433 // Oop is non-NULL, use it
434 region->init_req(1, kit->control());
435 PhiNode* oop = PhiNode::make(region, not_null_oop, value_ptr());
436 PhiNode* io = PhiNode::make(region, kit->i_o(), Type::ABIO);
437 PhiNode* mem = PhiNode::make(region, kit->merged_memory(), Type::MEMORY, TypePtr::BOTTOM);
438
439 {
440 // Oop is NULL, allocate and initialize buffer
441 PreserveJVMState pjvms(kit);
442 kit->set_control(null_ctl);
443 kit->kill_dead_locals();
444 ciValueKlass* vk = value_klass();
445 Node* klass_node = kit->makecon(TypeKlassPtr::make(vk));
446 Node* alloc_oop = kit->new_instance(klass_node, NULL, NULL, deoptimize_on_exception, this);
447 store(kit, alloc_oop, alloc_oop, vk, 0, deoptimize_on_exception);
448 region->init_req(2, kit->control());
449 oop ->init_req(2, alloc_oop);
450 io ->init_req(2, kit->i_o());
451 mem ->init_req(2, kit->merged_memory());
452 }
453
454 // Update GraphKit
455 kit->set_control(kit->gvn().transform(region));
456 kit->set_i_o(kit->gvn().transform(io));
457 kit->set_all_memory(kit->gvn().transform(mem));
458 kit->record_for_igvn(region);
459 kit->record_for_igvn(oop);
460 kit->record_for_igvn(io);
461 kit->record_for_igvn(mem);
462
463 // Use cloned ValueTypeNode to propagate oop from now on
464 Node* res_oop = kit->gvn().transform(oop);
465 ValueTypeBaseNode* vt = clone()->as_ValueTypeBase();
466 vt->set_oop(res_oop);
467 vt = kit->gvn().transform(vt)->as_ValueTypeBase();
468 kit->replace_in_map(this, vt);
469 return vt;
470 }
471
472 bool ValueTypeBaseNode::is_allocated(PhaseGVN* phase) const {
473 Node* oop = get_oop();
474 const Type* oop_type = (phase != NULL) ? phase->type(oop) : oop->bottom_type();
475 return !oop_type->maybe_null();
476 }
477
478 // When a call returns multiple values, it has several result
479 // projections, one per field. Replacing the result of the call by a
480 // value type node (after late inlining) requires that for each result
481 // projection, we find the corresponding value type field.
482 void ValueTypeBaseNode::replace_call_results(GraphKit* kit, Node* call, Compile* C) {
483 ciValueKlass* vk = value_klass();
484 for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
485 ProjNode* pn = call->fast_out(i)->as_Proj();
486 uint con = pn->_con;
487 if (con >= TypeFunc::Parms+1) {
488 uint field_nb = con - (TypeFunc::Parms+1);
489 int extra = 0;
490 for (uint j = 0; j < field_nb - extra; j++) {
491 ciField* f = vk->nonstatic_field_at(j);
492 BasicType bt = f->type()->basic_type();
493 if (bt == T_LONG || bt == T_DOUBLE) {
494 extra++;
495 }
496 }
497 ciField* f = vk->nonstatic_field_at(field_nb - extra);
498 Node* field = field_value_by_offset(f->offset(), true);
499 if (field->is_ValueType()) {
500 assert(f->is_flattened(), "should be flattened");
501 field = field->as_ValueType()->allocate(kit)->get_oop();
502 }
503 C->gvn_replace_by(pn, field);
504 C->initial_gvn()->hash_delete(pn);
505 pn->set_req(0, C->top());
506 --i; --imax;
507 }
508 }
509 }
510
511 ValueTypeNode* ValueTypeNode::make_uninitialized(PhaseGVN& gvn, ciValueKlass* vk) {
512 // Create a new ValueTypeNode with uninitialized values and NULL oop
513 return new ValueTypeNode(vk, gvn.zerocon(T_VALUETYPE));
514 }
515
516 Node* ValueTypeNode::default_oop(PhaseGVN& gvn, ciValueKlass* vk) {
517 // Returns the constant oop of the default value type allocation
518 return gvn.makecon(TypeInstPtr::make(vk->default_value_instance()));
519 }
520
521 ValueTypeNode* ValueTypeNode::make_default(PhaseGVN& gvn, ciValueKlass* vk) {
522 // Create a new ValueTypeNode with default values
523 ValueTypeNode* vt = new ValueTypeNode(vk, default_oop(gvn, vk));
524 for (uint i = 0; i < vt->field_count(); ++i) {
525 ciType* field_type = vt->field_type(i);
526 Node* value = NULL;
527 if (field_type->is_valuetype() && vt->field_is_flattenable(i)) {
528 ciValueKlass* field_klass = field_type->as_value_klass();
529 if (field_klass->is_scalarizable() || vt->field_is_flattened(i)) {
530 value = ValueTypeNode::make_default(gvn, field_klass);
531 } else {
532 value = default_oop(gvn, field_klass);
533 }
534 } else {
535 value = gvn.zerocon(field_type->basic_type());
536 }
537 vt->set_field_value(i, value);
538 }
539 vt = gvn.transform(vt)->as_ValueType();
540 assert(vt->is_default(gvn), "must be the default value type");
541 return vt;
542 }
543
544 bool ValueTypeNode::is_default(PhaseGVN& gvn) const {
545 for (uint i = 0; i < field_count(); ++i) {
546 Node* value = field_value(i);
547 if (!gvn.type(value)->is_zero_type() &&
548 !(value->is_ValueType() && value->as_ValueType()->is_default(gvn)) &&
549 !(field_type(i)->is_valuetype() && value == default_oop(gvn, field_type(i)->as_value_klass()))) {
550 return false;
551 }
552 }
553 return true;
554 }
555
556 ValueTypeNode* ValueTypeNode::make_from_oop(GraphKit* kit, Node* oop, ciValueKlass* vk) {
557 PhaseGVN& gvn = kit->gvn();
558
559 // Create and initialize a ValueTypeNode by loading all field
560 // values from a heap-allocated version and also save the oop.
561 ValueTypeNode* vt = new ValueTypeNode(vk, oop);
562
563 if (oop->isa_ValueTypePtr()) {
564 // Can happen with late inlining
565 ValueTypePtrNode* vtptr = oop->as_ValueTypePtr();
566 vt->set_oop(vtptr->get_oop());
567 for (uint i = Oop+1; i < vtptr->req(); ++i) {
568 vt->init_req(i, vtptr->in(i));
569 }
570 } else if (gvn.type(oop)->maybe_null()) {
571 // Add a null check because the oop may be null
572 Node* null_ctl = kit->top();
573 Node* not_null_oop = kit->null_check_oop(oop, &null_ctl);
574 if (kit->stopped()) {
575 // Constant null
576 kit->set_control(null_ctl);
577 return make_default(gvn, vk);
578 }
579 vt->set_oop(not_null_oop);
580 vt->load(kit, not_null_oop, not_null_oop, vk, /* holder_offset */ 0);
581
582 if (null_ctl != kit->top()) {
583 // Return default value type if oop is null
584 ValueTypeNode* def = make_default(gvn, vk);
585 Node* region = new RegionNode(3);
586 region->init_req(1, kit->control());
587 region->init_req(2, null_ctl);
588
589 vt = vt->clone_with_phis(&gvn, region)->as_ValueType();
590 vt->merge_with(&gvn, def, 2, true);
591 kit->set_control(gvn.transform(region));
592 }
593 } else {
594 // Oop can never be null
595 Node* init_ctl = kit->control();
596 vt->load(kit, oop, oop, vk, /* holder_offset */ 0);
597 assert(init_ctl != kit->control() || oop->is_Con() || oop->is_CheckCastPP() || oop->Opcode() == Op_ValueTypePtr ||
598 vt->is_loaded(&gvn) == oop, "value type should be loaded");
599 }
600
601 assert(vt->is_allocated(&gvn), "value type should be allocated");
602 return gvn.transform(vt)->as_ValueType();
603 }
604
605 // GraphKit wrapper for the 'make_from_flattened' method
606 ValueTypeNode* ValueTypeNode::make_from_flattened(GraphKit* kit, ciValueKlass* vk, Node* obj, Node* ptr, ciInstanceKlass* holder, int holder_offset) {
607 // Create and initialize a ValueTypeNode by loading all field values from
608 // a flattened value type field at 'holder_offset' or from a value type array.
609 ValueTypeNode* vt = make_uninitialized(kit->gvn(), vk);
610 // The value type is flattened into the object without an oop header. Subtract the
611 // offset of the first field to account for the missing header when loading the values.
612 holder_offset -= vk->first_field_offset();
613 vt->load(kit, obj, ptr, holder, holder_offset);
614 assert(vt->is_loaded(&kit->gvn()) != obj, "holder oop should not be used as flattened value type oop");
615 return kit->gvn().transform(vt)->as_ValueType();
616 }
617
618 ValueTypeNode* ValueTypeNode::make_from_multi(GraphKit* kit, MultiNode* multi, ciValueKlass* vk, uint& base_input, bool in) {
619 ValueTypeNode* vt = ValueTypeNode::make_uninitialized(kit->gvn(), vk);
620 vt->initialize(kit, multi, vk, 0, base_input, in);
621 return kit->gvn().transform(vt)->as_ValueType();
622 }
623
624 Node* ValueTypeNode::is_loaded(PhaseGVN* phase, ciValueKlass* vk, Node* base, int holder_offset) {
625 if (vk == NULL) {
626 vk = value_klass();
627 }
628 if (field_count() == 0) {
629 assert(is_allocated(phase), "must be allocated");
630 return get_oop();
631 }
632 for (uint i = 0; i < field_count(); ++i) {
633 int offset = holder_offset + field_offset(i);
634 Node* value = field_value(i);
635 if (value->is_ValueType()) {
636 ValueTypeNode* vt = value->as_ValueType();
637 if (field_is_flattened(i)) {
638 // Check value type field load recursively
639 base = vt->is_loaded(phase, vk, base, offset - vt->value_klass()->first_field_offset());
640 if (base == NULL) {
641 return NULL;
642 }
643 continue;
644 } else {
645 value = vt->get_oop();
646 if (value->Opcode() == Op_CastPP) {
647 // Skip CastPP
648 value = value->in(1);
649 }
650 }
651 }
652 if (value->isa_DecodeN()) {
653 // Skip DecodeN
654 value = value->in(1);
655 }
656 if (value->isa_Load()) {
657 // Check if base and offset of field load matches value type layout
658 intptr_t loffset = 0;
659 Node* lbase = AddPNode::Ideal_base_and_offset(value->in(MemNode::Address), phase, loffset);
660 if (lbase == NULL || (lbase != base && base != NULL) || loffset != offset) {
661 return NULL;
662 } else if (base == NULL) {
663 // Set base and check if pointer type matches
664 base = lbase;
665 const TypeInstPtr* vtptr = phase->type(base)->isa_instptr();
666 if (vtptr == NULL || !vtptr->klass()->equals(vk)) {
667 return NULL;
668 }
669 }
670 } else {
671 return NULL;
672 }
673 }
674 return base;
675 }
676
677 Node* ValueTypeNode::allocate_fields(GraphKit* kit) {
678 ValueTypeNode* vt = clone()->as_ValueType();
679 for (uint i = 0; i < field_count(); i++) {
680 ValueTypeNode* value = field_value(i)->isa_ValueType();
681 if (field_is_flattened(i)) {
682 // Flattened value type field
683 vt->set_field_value(i, value->allocate_fields(kit));
684 } else if (value != NULL){
685 // Non-flattened value type field
686 vt->set_field_value(i, value->allocate(kit));
687 }
688 }
689 vt = kit->gvn().transform(vt)->as_ValueType();
690 kit->replace_in_map(this, vt);
691 return vt;
692 }
693
694 Node* ValueTypeNode::tagged_klass(PhaseGVN& gvn) {
695 ciValueKlass* vk = value_klass();
696 const TypeKlassPtr* tk = TypeKlassPtr::make(vk);
697 intptr_t bits = tk->get_con();
698 set_nth_bit(bits, 0);
699 return gvn.makecon(TypeRawPtr::make((address)bits));
700 }
701
702 uint ValueTypeNode::pass_fields(Node* n, int base_input, GraphKit& kit, bool assert_allocated, ciValueKlass* base_vk, int base_offset) {
703 assert(base_input >= TypeFunc::Parms, "invalid base input");
704 ciValueKlass* vk = value_klass();
705 if (base_vk == NULL) {
706 base_vk = vk;
707 }
708 uint edges = 0;
709 for (uint i = 0; i < field_count(); i++) {
710 int offset = base_offset + field_offset(i) - (base_offset > 0 ? vk->first_field_offset() : 0);
711 Node* arg = field_value(i);
712 if (field_is_flattened(i)) {
713 // Flattened value type field
714 edges += arg->as_ValueType()->pass_fields(n, base_input, kit, assert_allocated, base_vk, offset);
715 } else {
716 int j = 0; int extra = 0;
717 for (; j < base_vk->nof_nonstatic_fields(); j++) {
718 ciField* field = base_vk->nonstatic_field_at(j);
719 if (offset == field->offset()) {
720 assert(field->type() == field_type(i), "inconsistent field type");
721 break;
722 }
723 BasicType bt = field->type()->basic_type();
724 if (bt == T_LONG || bt == T_DOUBLE) {
725 extra++;
726 }
727 }
728 if (arg->is_ValueType()) {
729 // non-flattened value type field
730 ValueTypeNode* vt = arg->as_ValueType();
731 assert(!assert_allocated || vt->is_allocated(&kit.gvn()), "value type field should be allocated");
732 arg = vt->allocate(&kit)->get_oop();
733 }
734
735 int index = base_input + j + extra;
736 n->init_req(index++, arg);
737 edges++;
738 BasicType bt = field_type(i)->basic_type();
739 if (bt == T_LONG || bt == T_DOUBLE) {
740 n->init_req(index++, kit.top());
741 edges++;
742 }
743 if (n->isa_CallJava()) {
744 Method* m = n->as_CallJava()->method()->get_Method();
745 SigEntry res_entry = m->get_res_entry();
746 if ((index - TypeFunc::Parms) == res_entry._offset) {
747 // Skip reserved entry
748 int size = type2size[res_entry._bt];
749 n->init_req(index++, kit.top());
750 if (size == 2) {
751 n->init_req(index++, kit.top());
752 }
753 base_input += size;
754 edges += size;
755 }
756 }
757 }
758 }
759 return edges;
760 }
761
762 Node* ValueTypeNode::Ideal(PhaseGVN* phase, bool can_reshape) {
763 Node* oop = get_oop();
764 if (is_default(*phase) && (!oop->is_Con() || phase->type(oop)->is_zero_type())) {
765 // Use the pre-allocated oop for default value types
766 set_oop(default_oop(*phase, value_klass()));
767 return this;
768 } else if (oop->isa_ValueTypePtr()) {
769 // Can happen with late inlining
770 ValueTypePtrNode* vtptr = oop->as_ValueTypePtr();
771 set_oop(vtptr->get_oop());
772 for (uint i = Oop+1; i < vtptr->req(); ++i) {
773 set_req(i, vtptr->in(i));
774 }
775 return this;
776 }
777
778 if (!is_allocated(phase)) {
779 // Save base oop if fields are loaded from memory and the value
780 // type is not buffered (in this case we should not use the oop).
781 Node* base = is_loaded(phase);
782 if (base != NULL) {
783 set_oop(base);
784 assert(is_allocated(phase), "should now be allocated");
785 return this;
786 }
787 }
788
789 if (can_reshape) {
790 PhaseIterGVN* igvn = phase->is_IterGVN();
791
792 if (is_default(*phase)) {
793 // Search for users of the default value type
794 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
795 Node* user = fast_out(i);
796 AllocateNode* alloc = user->isa_Allocate();
797 if (alloc != NULL && alloc->result_cast() != NULL && alloc->in(AllocateNode::ValueNode) == this) {
798 // Found an allocation of the default value type.
799 // If the code in StoreNode::Identity() that removes useless stores was not yet
800 // executed or ReduceFieldZeroing is disabled, there can still be initializing
801 // stores (only zero-type or default value stores, because value types are immutable).
802 Node* res = alloc->result_cast();
803 for (DUIterator_Fast jmax, j = res->fast_outs(jmax); j < jmax; j++) {
804 AddPNode* addp = res->fast_out(j)->isa_AddP();
805 if (addp != NULL) {
806 for (DUIterator_Fast kmax, k = addp->fast_outs(kmax); k < kmax; k++) {
807 StoreNode* store = addp->fast_out(k)->isa_Store();
808 if (store != NULL && store->outcnt() != 0) {
809 // Remove the useless store
810 igvn->replace_in_uses(store, store->in(MemNode::Memory));
811 }
812 }
813 }
814 }
815 // Replace allocation by pre-allocated oop
816 igvn->replace_node(res, default_oop(*phase, value_klass()));
817 } else if (user->is_ValueType()) {
818 // Add value type user to worklist to give it a chance to get optimized as well
819 igvn->_worklist.push(user);
820 }
821 }
822 }
823
824 if (is_allocated(igvn)) {
825 // Value type is heap allocated, search for safepoint uses
826 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
827 Node* out = fast_out(i);
828 if (out->is_SafePoint()) {
829 // Let SafePointNode::Ideal() take care of re-wiring the
830 // safepoint to the oop input instead of the value type node.
831 igvn->rehash_node_delayed(out);
832 }
833 }
834 }
835 }
836 return NULL;
837 }
838
839 // Search for multiple allocations of this value type
840 // and try to replace them by dominating allocations.
841 void ValueTypeNode::remove_redundant_allocations(PhaseIterGVN* igvn, PhaseIdealLoop* phase) {
842 assert(EliminateAllocations, "allocation elimination should be enabled");
843 // Search for allocations of this value type
844 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
845 AllocateNode* alloc = fast_out(i)->isa_Allocate();
846 if (alloc != NULL && alloc->result_cast() != NULL && alloc->in(AllocateNode::ValueNode) == this) {
847 assert(!is_default(*igvn), "default value type allocation");
848 Node* res_dom = NULL;
849 if (is_allocated(igvn)) {
850 // The value type is already allocated but still connected to an AllocateNode.
851 // This can happen with late inlining when we first allocate a value type argument
852 // but later decide to inline the call with the callee code also allocating.
853 res_dom = get_oop();
854 } else {
855 // Search for a dominating allocation of the same value type
856 for (DUIterator_Fast jmax, j = fast_outs(jmax); j < jmax; j++) {
857 Node* out2 = fast_out(j);
858 if (alloc != out2 && out2->is_Allocate() && out2->in(AllocateNode::ValueNode) == this &&
859 phase->is_dominator(out2, alloc)) {
860 AllocateNode* alloc_dom = out2->as_Allocate();
861 assert(alloc->in(AllocateNode::KlassNode) == alloc_dom->in(AllocateNode::KlassNode), "klasses should match");
862 res_dom = alloc_dom->result_cast();
863 break;
864 }
865 }
866 }
867 if (res_dom != NULL) {
868 // Move users to dominating allocation
869 Node* res = alloc->result_cast();
870 igvn->replace_node(res, res_dom);
871 // The result of the dominated allocation is now unused and will be
872 // removed later in AllocateNode::Ideal() to not confuse loop opts.
873 igvn->record_for_igvn(alloc);
874 #ifdef ASSERT
875 if (PrintEliminateAllocations) {
876 tty->print("++++ Eliminated: %d Allocate ", alloc->_idx);
877 dump_spec(tty);
878 tty->cr();
879 }
880 #endif
881 }
882 }
883 }
884
885 // Process users
886 for (DUIterator_Fast imax, i = fast_outs(imax); i < imax; i++) {
887 Node* out = fast_out(i);
888 if (out->is_ValueType()) {
889 // Recursively process value type users
890 out->as_ValueType()->remove_redundant_allocations(igvn, phase);
891 } else if (out->isa_Allocate() != NULL) {
892 // Allocate users should be linked
893 assert(out->in(AllocateNode::ValueNode) == this, "should be linked");
894 } else {
895 #ifdef ASSERT
896 // The value type should not have any other users at this time
897 out->dump();
898 assert(false, "unexpected user of value type");
899 #endif
900 }
901 }
902 }
903
904 ValueTypePtrNode* ValueTypePtrNode::make_from_value_type(GraphKit* kit, ValueTypeNode* vt, bool deoptimize_on_exception) {
905 Node* oop = vt->allocate(kit, deoptimize_on_exception)->get_oop();
906 ValueTypePtrNode* vtptr = new ValueTypePtrNode(vt->value_klass(), oop);
907 for (uint i = Oop+1; i < vt->req(); i++) {
908 vtptr->init_req(i, vt->in(i));
909 }
910 return kit->gvn().transform(vtptr)->as_ValueTypePtr();
911 }
912
913 ValueTypePtrNode* ValueTypePtrNode::make_from_oop(GraphKit* kit, Node* oop) {
914 // Create and initialize a ValueTypePtrNode by loading all field
915 // values from a heap-allocated version and also save the oop.
916 ciValueKlass* vk = kit->gvn().type(oop)->value_klass();
917 ValueTypePtrNode* vtptr = new ValueTypePtrNode(vk, oop);
918 vtptr->load(kit, oop, oop, vk);
919 return kit->gvn().transform(vtptr)->as_ValueTypePtr();
920 }