1 /*
  2  * Copyright (c) 2016, 2026, 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 "ci/ciFlatArrayKlass.hpp"
 26 #include "gc/shared/barrierSet.hpp"
 27 #include "gc/shared/c2/barrierSetC2.hpp"
 28 #include "gc/shared/c2/cardTableBarrierSetC2.hpp"
 29 #include "gc/shared/gc_globals.hpp"
 30 #include "opto/arraycopynode.hpp"
 31 #include "opto/graphKit.hpp"
 32 #include "opto/inlinetypenode.hpp"
 33 #include "utilities/powerOfTwo.hpp"
 34 
 35 const TypeFunc* ArrayCopyNode::_arraycopy_type_Type = nullptr;
 36 
 37 ArrayCopyNode::ArrayCopyNode(Compile* C, bool alloc_tightly_coupled, bool has_negative_length_guard)
 38   : CallNode(arraycopy_type(), nullptr, TypePtr::BOTTOM),
 39     _kind(None),
 40     _alloc_tightly_coupled(alloc_tightly_coupled),
 41     _has_negative_length_guard(has_negative_length_guard),
 42     _arguments_validated(false),
 43     _src_type(TypeOopPtr::BOTTOM),
 44     _dest_type(TypeOopPtr::BOTTOM) {
 45   init_class_id(Class_ArrayCopy);
 46   init_flags(Flag_is_macro);
 47   C->add_macro_node(this);
 48 }
 49 
 50 uint ArrayCopyNode::size_of() const { return sizeof(*this); }
 51 
 52 ArrayCopyNode* ArrayCopyNode::make(GraphKit* kit, bool may_throw,
 53                                    Node* src, Node* src_offset,
 54                                    Node* dest, Node* dest_offset,
 55                                    Node* length,
 56                                    bool alloc_tightly_coupled,
 57                                    bool has_negative_length_guard,
 58                                    Node* src_klass, Node* dest_klass,
 59                                    Node* src_length, Node* dest_length) {
 60 
 61   ArrayCopyNode* ac = new ArrayCopyNode(kit->C, alloc_tightly_coupled, has_negative_length_guard);
 62   kit->set_predefined_input_for_runtime_call(ac);
 63 
 64   ac->init_req(ArrayCopyNode::Src, src);
 65   ac->init_req(ArrayCopyNode::SrcPos, src_offset);
 66   ac->init_req(ArrayCopyNode::Dest, dest);
 67   ac->init_req(ArrayCopyNode::DestPos, dest_offset);
 68   ac->init_req(ArrayCopyNode::Length, length);
 69   ac->init_req(ArrayCopyNode::SrcLen, src_length);
 70   ac->init_req(ArrayCopyNode::DestLen, dest_length);
 71   ac->init_req(ArrayCopyNode::SrcKlass, src_klass);
 72   ac->init_req(ArrayCopyNode::DestKlass, dest_klass);
 73 
 74   if (may_throw) {
 75     ac->set_req(TypeFunc::I_O , kit->i_o());
 76     kit->add_safepoint_edges(ac, false);
 77   }
 78 
 79   return ac;
 80 }
 81 
 82 void ArrayCopyNode::connect_outputs(GraphKit* kit, bool deoptimize_on_exception) {
 83   kit->set_all_memory_call(this, true);
 84   kit->set_control(kit->gvn().transform(new ProjNode(this,TypeFunc::Control)));
 85   kit->set_i_o(kit->gvn().transform(new ProjNode(this, TypeFunc::I_O)));
 86   kit->make_slow_call_ex(this, kit->env()->Throwable_klass(), true, deoptimize_on_exception);
 87   kit->set_all_memory_call(this);
 88 }
 89 
 90 #ifndef PRODUCT
 91 const char* ArrayCopyNode::_kind_names[] = {"arraycopy", "arraycopy, validated arguments", "clone", "oop array clone", "CopyOf", "CopyOfRange"};
 92 
 93 void ArrayCopyNode::dump_spec(outputStream *st) const {
 94   CallNode::dump_spec(st);
 95   st->print(" (%s%s)", _kind_names[_kind], _alloc_tightly_coupled ? ", tightly coupled allocation" : "");
 96 }
 97 
 98 void ArrayCopyNode::dump_compact_spec(outputStream* st) const {
 99   st->print("%s%s", _kind_names[_kind], _alloc_tightly_coupled ? ",tight" : "");
100 }
101 #endif
102 
103 intptr_t ArrayCopyNode::get_length_if_constant(PhaseGVN *phase) const {
104   // check that length is constant
105   Node* length = in(ArrayCopyNode::Length);
106   const Type* length_type = phase->type(length);
107 
108   if (length_type == Type::TOP) {
109     return -1;
110   }
111 
112   assert(is_clonebasic() || is_arraycopy() || is_copyof() || is_copyofrange(), "unexpected array copy type");
113 
114   return is_clonebasic() ? length->find_intptr_t_con(-1) : length->find_int_con(-1);
115 }
116 
117 int ArrayCopyNode::get_count(PhaseGVN *phase) const {
118   if (is_clonebasic()) {
119     Node* src = in(ArrayCopyNode::Src);
120     const Type* src_type = phase->type(src);
121 
122     if (src_type == Type::TOP) {
123       return -1;
124     }
125 
126     if (src_type->isa_instptr()) {
127       const TypeInstPtr* inst_src = src_type->is_instptr();
128       ciInstanceKlass* ik = inst_src->instance_klass();
129       // ciInstanceKlass::nof_nonstatic_fields() doesn't take injected
130       // fields into account. They are rare anyway so easier to simply
131       // skip instances with injected fields.
132       if ((!inst_src->klass_is_exact() && (ik->is_interface() || ik->has_subklass())) || ik->has_injected_fields()) {
133         return -1;
134       }
135       int nb_fields = ik->nof_nonstatic_fields();
136       return nb_fields;
137     } else {
138       const TypeAryPtr* ary_src = src_type->isa_aryptr();
139       assert (ary_src != nullptr, "not an array or instance?");
140       // clone passes a length as a rounded number of longs. If we're
141       // cloning an array we'll do it element by element. If the
142       // length of the input array is constant, ArrayCopyNode::Length
143       // must be too. Note that the opposite does not need to hold,
144       // because different input array lengths (e.g. int arrays with
145       // 3 or 4 elements) might lead to the same length input
146       // (e.g. 2 double-words).
147       assert(!ary_src->size()->is_con() || (get_length_if_constant(phase) >= 0) ||
148              (UseArrayFlattening && ary_src->elem()->make_oopptr() != nullptr && ary_src->elem()->make_oopptr()->can_be_inline_type()) ||
149              phase->is_IterGVN() || phase->C->inlining_incrementally() || StressReflectiveCode, "inconsistent");
150       if (ary_src->size()->is_con()) {
151         return ary_src->size()->get_con();
152       }
153       return -1;
154     }
155   }
156 
157   return get_length_if_constant(phase);
158 }
159 
160 Node* ArrayCopyNode::load(BarrierSetC2* bs, PhaseGVN *phase, Node*& ctl, MergeMemNode* mem, Node* adr, const TypePtr* adr_type, const Type *type, BasicType bt) {
161   // Pin the load: if this is an array load, it's going to be dependent on a condition that's not a range check for that
162   // access. If that condition is replaced by an identical dominating one, then an unpinned load would risk floating
163   // above runtime checks that guarantee it is within bounds.
164   DecoratorSet decorators = C2_READ_ACCESS | C2_CONTROL_DEPENDENT_LOAD | IN_HEAP | C2_ARRAY_COPY | C2_UNKNOWN_CONTROL_LOAD;
165   C2AccessValuePtr addr(adr, adr_type);
166   C2OptAccess access(*phase, ctl, mem, decorators, bt, adr->in(AddPNode::Base), addr);
167   Node* res = bs->load_at(access, type);
168   ctl = access.ctl();
169   return res;
170 }
171 
172 void ArrayCopyNode::store(BarrierSetC2* bs, PhaseGVN *phase, Node*& ctl, MergeMemNode* mem, Node* adr, const TypePtr* adr_type, Node* val, const Type *type, BasicType bt) {
173   DecoratorSet decorators = C2_WRITE_ACCESS | IN_HEAP | C2_ARRAY_COPY;
174   if (is_alloc_tightly_coupled()) {
175     decorators |= C2_TIGHTLY_COUPLED_ALLOC;
176   }
177   C2AccessValuePtr addr(adr, adr_type);
178   C2AccessValue value(val, type);
179   C2OptAccess access(*phase, ctl, mem, decorators, bt, adr->in(AddPNode::Base), addr);
180   bs->store_at(access, value);
181   ctl = access.ctl();
182 }
183 
184 
185 Node* ArrayCopyNode::try_clone_instance(PhaseGVN *phase, bool can_reshape, int count) {
186   if (!is_clonebasic()) {
187     return nullptr;
188   }
189 
190   Node* base_src = in(ArrayCopyNode::Src);
191   Node* base_dest = in(ArrayCopyNode::Dest);
192   Node* ctl = in(TypeFunc::Control);
193   Node* in_mem = in(TypeFunc::Memory);
194 
195   const Type* src_type = phase->type(base_src);
196   const TypeInstPtr* inst_src = src_type->isa_instptr();
197   if (inst_src == nullptr) {
198     return nullptr;
199   }
200 
201   MergeMemNode* mem = phase->transform(MergeMemNode::make(in_mem))->as_MergeMem();
202   phase->record_for_igvn(mem);
203   if (can_reshape) {
204     phase->is_IterGVN()->_worklist.push(mem);
205   }
206 
207 
208   ciInstanceKlass* ik = inst_src->instance_klass();
209 
210   if (!inst_src->klass_is_exact()) {
211     assert(!ik->is_interface(), "inconsistent klass hierarchy");
212     if (ik->has_subklass()) {
213       // Concurrent class loading.
214       // Fail fast and return NodeSentinel to indicate that the transform failed.
215       return NodeSentinel;
216     } else {
217       phase->C->dependencies()->assert_leaf_type(ik);
218     }
219   }
220 
221   const TypeInstPtr* dest_type = phase->type(base_dest)->is_instptr();
222   if (dest_type->instance_klass() != ik) {
223     // At parse time, the exact type of the object to clone was not known. That inexact type was captured by the CheckCastPP
224     // of the newly allocated cloned object (in dest). The exact type is now known (in src), but the type for the cloned object
225     // (dest) was not updated. When copying the fields below, Store nodes may write to offsets for fields that don't exist in
226     // the inexact class. The stores would then be assigned an incorrect slice.
227     return NodeSentinel;
228   }
229 
230   assert(ik->nof_nonstatic_fields() <= ArrayCopyLoadStoreMaxElem, "too many fields");
231 
232   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
233   for (int i = 0; i < count; i++) {
234     ciField* field = ik->nonstatic_field_at(i);
235     const TypePtr* adr_type = phase->C->alias_type(field)->adr_type();
236     Node* off = phase->MakeConX(field->offset_in_bytes());
237     Node* next_src = phase->transform(AddPNode::make_with_base(base_src, off));
238     Node* next_dest = phase->transform(AddPNode::make_with_base(base_dest, off));
239     assert(phase->C->get_alias_index(adr_type) == phase->C->get_alias_index(phase->type(next_src)->isa_ptr()),
240       "slice of address and input slice don't match");
241     assert(phase->C->get_alias_index(adr_type) == phase->C->get_alias_index(phase->type(next_dest)->isa_ptr()),
242       "slice of address and input slice don't match");
243     BasicType bt = field->layout_type();
244 
245     const Type *type;
246     if (bt == T_OBJECT) {
247       if (!field->type()->is_loaded()) {
248         type = TypeInstPtr::BOTTOM;
249       } else {
250         ciType* field_klass = field->type();
251         type = TypeOopPtr::make_from_klass(field_klass->as_klass());
252       }
253     } else {
254       type = Type::get_const_basic_type(bt);
255     }
256 
257     Node* v = load(bs, phase, ctl, mem, next_src, adr_type, type, bt);
258     store(bs, phase, ctl, mem, next_dest, adr_type, v, type, bt);
259   }
260 
261   if (!finish_transform(phase, can_reshape, ctl, mem)) {
262     // Return NodeSentinel to indicate that the transform failed
263     return NodeSentinel;
264   }
265 
266   return mem;
267 }
268 
269 // We may have narrowed the type of base because this runs with PhaseIterGVN::_delay_transform true, explicitly
270 // update the type of the AddP so it's consistent with its base and load() picks the right memory slice.
271 Node* ArrayCopyNode::make_and_transform_addp(PhaseGVN* phase, Node* base, Node* offset) {
272   return make_and_transform_addp(phase, base, base, offset);
273 }
274 
275 Node* ArrayCopyNode::make_and_transform_addp(PhaseGVN* phase, Node* base, Node* ptr, Node* offset) {
276   assert(phase->is_IterGVN() == nullptr || phase->is_IterGVN()->delay_transform(), "helper method when delay transform is set");
277   Node* addp = phase->transform(AddPNode::make_with_base(base, ptr, offset));
278   phase->set_type(addp, addp->Value(phase));
279   return addp;
280 }
281 
282 bool ArrayCopyNode::prepare_array_copy(PhaseGVN *phase, bool can_reshape,
283                                        Node*& adr_src,
284                                        Node*& base_src,
285                                        Node*& adr_dest,
286                                        Node*& base_dest,
287                                        BasicType& copy_type,
288                                        const Type*& value_type,
289                                        bool& disjoint_bases) {
290   base_src = in(ArrayCopyNode::Src);
291   base_dest = in(ArrayCopyNode::Dest);
292   const Type* src_type = phase->type(base_src);
293   const TypeAryPtr* ary_src = src_type->isa_aryptr();
294 
295   Node* src_offset = in(ArrayCopyNode::SrcPos);
296   Node* dest_offset = in(ArrayCopyNode::DestPos);
297 
298   if (is_arraycopy() || is_copyofrange() || is_copyof()) {
299     const Type* dest_type = phase->type(base_dest);
300     const TypeAryPtr* ary_dest = dest_type->isa_aryptr();
301 
302     // newly allocated object is guaranteed to not overlap with source object
303     disjoint_bases = is_alloc_tightly_coupled();
304     if (ary_src  == nullptr || ary_src->elem()  == Type::BOTTOM ||
305         ary_dest == nullptr || ary_dest->elem() == Type::BOTTOM) {
306       // We don't know if arguments are arrays
307       return false;
308     }
309 
310     BasicType src_elem = ary_src->elem()->array_element_basic_type();
311     BasicType dest_elem = ary_dest->elem()->array_element_basic_type();
312     if (is_reference_type(src_elem, true)) src_elem = T_OBJECT;
313     if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
314 
315     // TODO 8251971 What about atomicity?
316     if (src_elem != dest_elem || ary_src->is_null_free() != ary_dest->is_null_free() || ary_src->is_flat() != ary_dest->is_flat() || dest_elem == T_VOID) {
317       // We don't know if arguments are arrays of the same type
318       return false;
319     }
320 
321     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
322     if ((!ary_dest->is_flat() && bs->array_copy_requires_gc_barriers(is_alloc_tightly_coupled(), dest_elem, false, false, BarrierSetC2::Optimization)) ||
323         (ary_dest->is_flat() && ary_src->elem()->inline_klass()->contains_oops() &&
324          bs->array_copy_requires_gc_barriers(is_alloc_tightly_coupled(), T_OBJECT, false, false, BarrierSetC2::Optimization))) {
325       // It's an object array copy but we can't emit the card marking that is needed
326       return false;
327     }
328 
329     value_type = ary_src->elem();
330 
331     uint shift  = exact_log2(type2aelembytes(dest_elem));
332     if (ary_dest->is_flat()) {
333       assert(ary_src->is_flat(), "src and dest must be flat");
334       shift = ary_src->flat_log_elem_size();
335       src_elem = T_FLAT_ELEMENT;
336       dest_elem = T_FLAT_ELEMENT;
337     }
338 
339     const uint header = arrayOopDesc::base_offset_in_bytes(dest_elem);
340 
341     src_offset = Compile::conv_I2X_index(phase, src_offset, ary_src->size());
342     if (src_offset->is_top()) {
343       // Offset is out of bounds (the ArrayCopyNode will be removed)
344       return false;
345     }
346     dest_offset = Compile::conv_I2X_index(phase, dest_offset, ary_dest->size());
347     if (dest_offset->is_top()) {
348       // Offset is out of bounds (the ArrayCopyNode will be removed)
349       if (can_reshape) {
350         // record src_offset, so it can be deleted later (if it is dead)
351         phase->is_IterGVN()->_worklist.push(src_offset);
352       }
353       return false;
354     }
355 
356     Node* hook = new Node(1);
357     hook->init_req(0, dest_offset);
358 
359     Node* src_scale  = phase->transform(new LShiftXNode(src_offset, phase->intcon(shift)));
360 
361     hook->destruct(phase);
362 
363     Node* dest_scale = phase->transform(new LShiftXNode(dest_offset, phase->intcon(shift)));
364 
365     adr_src = make_and_transform_addp(phase, base_src, src_scale);
366     adr_dest = make_and_transform_addp(phase, base_dest, dest_scale);
367 
368     adr_src = make_and_transform_addp(phase, base_src, adr_src, phase->MakeConX(header));
369     adr_dest = make_and_transform_addp(phase, base_dest, adr_dest, phase->MakeConX(header));
370     copy_type = dest_elem;
371   } else {
372     assert(ary_src != nullptr, "should be a clone");
373     assert(is_clonebasic(), "should be");
374 
375     disjoint_bases = true;
376 
377     if (ary_src->elem()->make_oopptr() != nullptr &&
378         ary_src->elem()->make_oopptr()->can_be_inline_type()) {
379       return false;
380     }
381 
382     BasicType elem = ary_src->isa_aryptr()->elem()->array_element_basic_type();
383     if (is_reference_type(elem, true)) {
384       elem = T_OBJECT;
385     }
386 
387     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
388     if ((!ary_src->is_flat() && bs->array_copy_requires_gc_barriers(true, elem, true, is_clone_inst(), BarrierSetC2::Optimization)) ||
389         (ary_src->is_flat() && ary_src->elem()->inline_klass()->contains_oops() &&
390          bs->array_copy_requires_gc_barriers(true, T_OBJECT, true, is_clone_inst(), BarrierSetC2::Optimization))) {
391       // It's an object array copy but we can't emit the card marking that is needed
392       return false;
393     }
394 
395     adr_src = make_and_transform_addp(phase, base_src, src_offset);
396     adr_dest = make_and_transform_addp(phase, base_dest, dest_offset);
397 
398     // The address is offsetted to an aligned address where a raw copy would start.
399     // If the clone copy is decomposed into load-stores - the address is adjusted to
400     // point at where the array starts.
401     const Type* toff = phase->type(src_offset);
402     int offset = toff->isa_long() ? (int) toff->is_long()->get_con() : (int) toff->is_int()->get_con();
403     int diff = arrayOopDesc::base_offset_in_bytes(elem) - offset;
404     assert(diff >= 0, "clone should not start after 1st array element");
405     if (diff > 0) {
406       adr_src = make_and_transform_addp(phase, base_src, adr_src, phase->MakeConX(diff));
407       adr_dest = make_and_transform_addp(phase, base_dest, adr_dest, phase->MakeConX(diff));
408     }
409     copy_type = elem;
410     value_type = ary_src->elem();
411   }
412   return true;
413 }
414 
415 const TypeAryPtr* ArrayCopyNode::get_address_type(PhaseGVN* phase, const TypePtr* atp, Node* n) {
416   if (atp == TypeOopPtr::BOTTOM) {
417     atp = phase->type(n)->isa_ptr();
418   }
419   // adjust atp to be the correct array element address type
420   return atp->add_offset(Type::OffsetBot)->is_aryptr();
421 }
422 
423 const TypePtr* ArrayCopyNode::get_src_adr_type(PhaseGVN* phase) const {
424   return get_address_type(phase, _src_type, in(Src));
425 }
426 
427 void ArrayCopyNode::array_copy_test_overlap(GraphKit& kit, bool disjoint_bases, int count, Node*& backward_ctl) {
428   Node* ctl = kit.control();
429   if (!disjoint_bases && count > 1) {
430     PhaseGVN& gvn = kit.gvn();
431     Node* src_offset = in(ArrayCopyNode::SrcPos);
432     Node* dest_offset = in(ArrayCopyNode::DestPos);
433     assert(src_offset != nullptr && dest_offset != nullptr, "should be");
434     Node* cmp = gvn.transform(new CmpINode(src_offset, dest_offset));
435     Node *bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
436     IfNode *iff = new IfNode(ctl, bol, PROB_FAIR, COUNT_UNKNOWN);
437 
438     gvn.transform(iff);
439 
440     kit.set_control(gvn.transform(new IfFalseNode(iff)));
441     backward_ctl = gvn.transform(new IfTrueNode(iff));
442   }
443 }
444 
445 void ArrayCopyNode::copy(GraphKit& kit,
446                          const TypeAryPtr* atp_src,
447                          const TypeAryPtr* atp_dest,
448                          int i,
449                          Node* base_src,
450                          Node* base_dest,
451                          Node* adr_src,
452                          Node* adr_dest,
453                          BasicType copy_type,
454                          const Type* value_type) {
455   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
456   Node* ctl = kit.control();
457   if (atp_dest->is_flat()) {
458     ciInlineKlass* vk = atp_src->elem()->inline_klass();
459     for (int j = 0; j < vk->nof_nonstatic_fields(); j++) {
460       ciField* field = vk->nonstatic_field_at(j);
461       int off_in_vt = field->offset_in_bytes() - vk->payload_offset();
462       Node* off  = kit.MakeConX(off_in_vt + i * atp_src->flat_elem_size());
463       ciType* ft = field->type();
464       BasicType bt = type2field[ft->basic_type()];
465       assert(!field->is_flat(), "flat field encountered");
466       const Type* rt = Type::get_const_type(ft);
467       const TypePtr* adr_type = atp_src->with_field_offset(off_in_vt)->add_offset(Type::OffsetBot);
468       assert(!bs->array_copy_requires_gc_barriers(is_alloc_tightly_coupled(), bt, false, false, BarrierSetC2::Optimization), "GC barriers required");
469       Node* next_src = make_and_transform_addp(&kit.gvn(), base_src, adr_src, off);
470       Node* next_dest = make_and_transform_addp(&kit.gvn(), base_dest, adr_dest, off);
471       Node* v = load(bs, &kit.gvn(), ctl, kit.merged_memory(), next_src, adr_type, rt, bt);
472       store(bs, &kit.gvn(), ctl, kit.merged_memory(), next_dest, adr_type, v, rt, bt);
473     }
474   } else {
475     Node* off = kit.MakeConX(type2aelembytes(copy_type) * i);
476     Node* next_src = make_and_transform_addp(&kit.gvn(), base_src, adr_src, off);
477     Node* next_dest = make_and_transform_addp(&kit.gvn(), base_dest, adr_dest, off);
478     Node* v = load(bs, &kit.gvn(), ctl, kit.merged_memory(), next_src, atp_src, value_type, copy_type);
479     store(bs, &kit.gvn(), ctl, kit.merged_memory(), next_dest, atp_dest, v, value_type, copy_type);
480   }
481   kit.set_control(ctl);
482 }
483 
484 
485 void ArrayCopyNode::array_copy_forward(GraphKit& kit,
486                                        bool can_reshape,
487                                        const TypeAryPtr* atp_src,
488                                        const TypeAryPtr* atp_dest,
489                                        Node* adr_src,
490                                        Node* base_src,
491                                        Node* adr_dest,
492                                        Node* base_dest,
493                                        BasicType copy_type,
494                                        const Type* value_type,
495                                        int count) {
496   if (!kit.stopped()) {
497     // copy forward
498     if (count > 0) {
499       for (int i = 0; i < count; i++) {
500         copy(kit, atp_src, atp_dest, i, base_src, base_dest, adr_src, adr_dest, copy_type, value_type);
501       }
502     } else if (can_reshape) {
503       PhaseGVN& gvn = kit.gvn();
504       assert(gvn.is_IterGVN(), "");
505       gvn.record_for_igvn(adr_src);
506       gvn.record_for_igvn(adr_dest);
507     }
508   }
509 }
510 
511 void ArrayCopyNode::array_copy_backward(GraphKit& kit,
512                                         bool can_reshape,
513                                         const TypeAryPtr* atp_src,
514                                         const TypeAryPtr* atp_dest,
515                                         Node* adr_src,
516                                         Node* base_src,
517                                         Node* adr_dest,
518                                         Node* base_dest,
519                                         BasicType copy_type,
520                                         const Type* value_type,
521                                         int count) {
522   if (!kit.stopped()) {
523     // copy backward
524 
525     if (count > 0) {
526       for (int i = count-1; i >= 0; i--) {
527         copy(kit, atp_src, atp_dest, i, base_src, base_dest, adr_src, adr_dest, copy_type, value_type);
528       }
529     } else if(can_reshape) {
530       PhaseGVN& gvn = kit.gvn();
531       assert(gvn.is_IterGVN(), "");
532       gvn.record_for_igvn(adr_src);
533       gvn.record_for_igvn(adr_dest);
534     }
535   }
536 }
537 
538 bool ArrayCopyNode::finish_transform(PhaseGVN *phase, bool can_reshape,
539                                      Node* ctl, Node *mem) {
540   if (can_reshape) {
541     PhaseIterGVN* igvn = phase->is_IterGVN();
542     igvn->set_delay_transform(false);
543     if (is_clonebasic()) {
544       Node* out_mem = proj_out(TypeFunc::Memory);
545 
546       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
547       if (out_mem->outcnt() != 1 || !out_mem->raw_out(0)->is_MergeMem() ||
548           out_mem->raw_out(0)->outcnt() != 1 || !out_mem->raw_out(0)->raw_out(0)->is_MemBar()) {
549         assert(bs->array_copy_requires_gc_barriers(true, T_OBJECT, true, is_clone_inst(), BarrierSetC2::Optimization), "can only happen with card marking");
550         return false;
551       }
552 
553       igvn->replace_node(out_mem->raw_out(0), mem);
554 
555       Node* out_ctl = proj_out(TypeFunc::Control);
556       igvn->replace_node(out_ctl, ctl);
557     } else {
558       // replace fallthrough projections of the ArrayCopyNode by the
559       // new memory, control and the input IO.
560       CallProjections* callprojs = extract_projections(true, false);
561 
562       if (callprojs->fallthrough_ioproj != nullptr) {
563         igvn->replace_node(callprojs->fallthrough_ioproj, in(TypeFunc::I_O));
564       }
565       if (callprojs->fallthrough_memproj != nullptr) {
566         igvn->replace_node(callprojs->fallthrough_memproj, mem);
567       }
568       if (callprojs->fallthrough_catchproj != nullptr) {
569         igvn->replace_node(callprojs->fallthrough_catchproj, ctl);
570       }
571 
572       // The ArrayCopyNode is not disconnected. It still has the
573       // projections for the exception case. Replace current
574       // ArrayCopyNode with a dummy new one with a top() control so
575       // that this part of the graph stays consistent but is
576       // eventually removed.
577 
578       set_req(0, phase->C->top());
579       remove_dead_region(phase, can_reshape);
580     }
581   } else {
582     if (in(TypeFunc::Control) != ctl) {
583       // we can't return new memory and control from Ideal at parse time
584       assert(!is_clonebasic() || UseShenandoahGC, "added control for clone?");
585       phase->record_for_igvn(this);
586       return false;
587     }
588   }
589   return true;
590 }
591 
592 
593 Node *ArrayCopyNode::Ideal(PhaseGVN *phase, bool can_reshape) {
594   // Perform any generic optimizations first
595   Node* result = SafePointNode::Ideal(phase, can_reshape);
596   if (result != nullptr) {
597     return result;
598   }
599 
600   if (StressArrayCopyMacroNode && !can_reshape) {
601     phase->record_for_igvn(this);
602     return nullptr;
603   }
604 
605   // See if it's a small array copy and we can inline it as
606   // loads/stores
607   // Here we can only do:
608   // - arraycopy if all arguments were validated before and we don't
609   // need card marking
610   // - clone for which we don't need to do card marking
611 
612   if (!is_clonebasic() && !is_arraycopy_validated() &&
613       !is_copyofrange_validated() && !is_copyof_validated()) {
614     return nullptr;
615   }
616 
617   assert(in(TypeFunc::Control) != nullptr &&
618          in(TypeFunc::Memory) != nullptr &&
619          in(ArrayCopyNode::Src) != nullptr &&
620          in(ArrayCopyNode::Dest) != nullptr &&
621          in(ArrayCopyNode::Length) != nullptr &&
622          in(ArrayCopyNode::SrcPos) != nullptr &&
623          in(ArrayCopyNode::DestPos) != nullptr, "broken inputs");
624 
625   if (in(TypeFunc::Control)->is_top() ||
626       in(TypeFunc::Memory)->is_top() ||
627       phase->type(in(ArrayCopyNode::Src)) == Type::TOP ||
628       phase->type(in(ArrayCopyNode::Dest)) == Type::TOP ||
629       (in(ArrayCopyNode::SrcPos) != nullptr && in(ArrayCopyNode::SrcPos)->is_top()) ||
630       (in(ArrayCopyNode::DestPos) != nullptr && in(ArrayCopyNode::DestPos)->is_top())) {
631     return nullptr;
632   }
633 
634   int count = get_count(phase);
635 
636   if (count < 0 || count > ArrayCopyLoadStoreMaxElem) {
637     return nullptr;
638   }
639 
640   Node* src = in(ArrayCopyNode::Src);
641   Node* dest = in(ArrayCopyNode::Dest);
642   const Type* src_type = phase->type(src);
643   const Type* dest_type = phase->type(dest);
644 
645   if (src_type->isa_aryptr() && dest_type->isa_instptr()) {
646     // clone used for load of unknown inline type can't be optimized at
647     // this point
648     return nullptr;
649   }
650 
651   Node* mem = try_clone_instance(phase, can_reshape, count);
652   if (mem != nullptr) {
653     return (mem == NodeSentinel) ? nullptr : mem;
654   }
655 
656   Node* adr_src = nullptr;
657   Node* base_src = nullptr;
658   Node* adr_dest = nullptr;
659   Node* base_dest = nullptr;
660   BasicType copy_type = T_ILLEGAL;
661   const Type* value_type = nullptr;
662   bool disjoint_bases = false;
663 
664   // EA may have moved an input to a new slice. EA stores the new address types in the ArrayCopy node itself
665   // (_src_type/_dest_type). phase->type(src) and _src_type or phase->type(dest) and _dest_type may be different
666   // when this transformation runs if igvn hasn't had a chance to propagate the new types yet. Make sure the new
667   // types are taken into account so new Load/Store nodes are created on the right slice.
668   const TypeAryPtr* atp_src = get_address_type(phase, _src_type, src);
669   const TypeAryPtr* atp_dest = get_address_type(phase, _dest_type, dest);
670   phase->set_type(src, phase->type(src)->join_speculative(atp_src));
671   phase->set_type(dest, phase->type(dest)->join_speculative(atp_dest));
672 
673   // Control flow is going to be created, it's easier to do with _delay_transform set to true.
674 
675   // prepare_array_copy() doesn't build control flow, but it creates AddP nodes. The src/dest type possibly gets
676   // narrowed above. If a newly created AddP node is commoned with a pre-existing one, then the type narrowing is lost.
677   // Setting _delay_transform before prepare_array_copy() guarantees this doesn't happen.
678   if (can_reshape) {
679     assert(!phase->is_IterGVN()->delay_transform(), "cannot delay transforms");
680     phase->is_IterGVN()->set_delay_transform(true);
681   }
682 
683   if (!prepare_array_copy(phase, can_reshape,
684                           adr_src, base_src, adr_dest, base_dest,
685                           copy_type, value_type, disjoint_bases)) {
686     assert(adr_src == nullptr, "no node can be left behind");
687     assert(adr_dest == nullptr, "no node can be left behind");
688     if (can_reshape) {
689       assert(phase->is_IterGVN()->delay_transform(), "cannot delay transforms");
690       phase->is_IterGVN()->set_delay_transform(false);
691     }
692 
693     return nullptr;
694   }
695 
696   JVMState* new_jvms = nullptr;
697   SafePointNode* new_map = nullptr;
698   if (!is_clonebasic()) {
699     new_jvms = jvms()->clone_shallow(phase->C);
700     new_map = new SafePointNode(req(), new_jvms);
701     for (uint i = TypeFunc::FramePtr; i < req(); i++) {
702       new_map->init_req(i, in(i));
703     }
704     new_jvms->set_map(new_map);
705   } else {
706     new_jvms = new (phase->C) JVMState(0);
707     new_map = new SafePointNode(TypeFunc::Parms, new_jvms);
708     new_jvms->set_map(new_map);
709   }
710   new_map->set_control(in(TypeFunc::Control));
711   new_map->set_memory(MergeMemNode::make(in(TypeFunc::Memory)));
712   new_map->set_i_o(in(TypeFunc::I_O));
713   phase->record_for_igvn(new_map);
714 
715   GraphKit kit(new_jvms, phase);
716 
717   SafePointNode* backward_map = nullptr;
718   SafePointNode* forward_map = nullptr;
719   Node* backward_ctl = phase->C->top();
720 
721   array_copy_test_overlap(kit, disjoint_bases, count, backward_ctl);
722 
723   {
724     PreserveJVMState pjvms(&kit);
725 
726     array_copy_forward(kit, can_reshape,
727                        atp_src, atp_dest,
728                        adr_src, base_src, adr_dest, base_dest,
729                        copy_type, value_type, count);
730 
731     forward_map = kit.stop();
732   }
733 
734   kit.set_control(backward_ctl);
735   array_copy_backward(kit, can_reshape,
736                       atp_src, atp_dest,
737                       adr_src, base_src, adr_dest, base_dest,
738                       copy_type, value_type, count);
739 
740   backward_map = kit.stop();
741 
742   if (!forward_map->control()->is_top() && !backward_map->control()->is_top()) {
743     assert(forward_map->i_o() == backward_map->i_o(), "need a phi on IO?");
744     Node* ctl = new RegionNode(3);
745     Node* mem = new PhiNode(ctl, Type::MEMORY, TypePtr::BOTTOM);
746     kit.set_map(forward_map);
747     ctl->init_req(1, kit.control());
748     mem->init_req(1, kit.reset_memory());
749     kit.set_map(backward_map);
750     ctl->init_req(2, kit.control());
751     mem->init_req(2, kit.reset_memory());
752     kit.set_control(phase->transform(ctl));
753     kit.set_all_memory(phase->transform(mem));
754   } else if (!forward_map->control()->is_top()) {
755     kit.set_map(forward_map);
756   } else {
757     assert(!backward_map->control()->is_top(), "no copy?");
758     kit.set_map(backward_map);
759   }
760 
761   if (can_reshape) {
762     assert(phase->is_IterGVN()->delay_transform(), "should be delaying transforms");
763     phase->is_IterGVN()->set_delay_transform(false);
764   }
765 
766   mem = kit.map()->memory();
767   if (!finish_transform(phase, can_reshape, kit.control(), mem)) {
768     if (!can_reshape) {
769       phase->record_for_igvn(this);
770     } else {
771       // put in worklist, so that if it happens to be dead it is removed
772       phase->is_IterGVN()->_worklist.push(mem);
773     }
774     return nullptr;
775   }
776 
777   return mem;
778 }
779 
780 bool ArrayCopyNode::may_modify(const TypeOopPtr* t_oop, PhaseValues* phase) const {
781   Node* dest = in(ArrayCopyNode::Dest);
782   if (dest->is_top()) {
783     return false;
784   }
785   const TypeOopPtr* dest_t = phase->type(dest)->is_oopptr();
786   assert(!dest_t->is_known_instance() || _dest_type->is_known_instance(), "result of EA not recorded");
787   assert(in(ArrayCopyNode::Src)->is_top() || !phase->type(in(ArrayCopyNode::Src))->is_oopptr()->is_known_instance() ||
788          _src_type->is_known_instance(), "result of EA not recorded");
789 
790   if (_dest_type != TypeOopPtr::BOTTOM || t_oop->is_known_instance()) {
791     assert(_dest_type == TypeOopPtr::BOTTOM || _dest_type->is_known_instance(), "result of EA is known instance");
792     return t_oop->instance_id() == _dest_type->instance_id();
793   }
794 
795   return CallNode::may_modify_arraycopy_helper(dest_t, t_oop, phase);
796 }
797 
798 bool ArrayCopyNode::may_modify_helper(const TypeOopPtr* t_oop, Node* n, PhaseValues* phase, ArrayCopyNode*& ac) {
799   if (n != nullptr &&
800       n->is_ArrayCopy() &&
801       n->as_ArrayCopy()->may_modify(t_oop, phase)) {
802     ac = n->as_ArrayCopy();
803     return true;
804   }
805   return false;
806 }
807 
808 bool ArrayCopyNode::may_modify(const TypeOopPtr* t_oop, MemBarNode* mb, PhaseValues* phase, ArrayCopyNode*& ac) {
809   if (mb->trailing_expanded_array_copy()) {
810     return true;
811   }
812 
813   Node* c = mb->in(0);
814 
815   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
816   // step over g1 gc barrier if we're at e.g. a clone with ReduceInitialCardMarks off
817   c = bs->step_over_gc_barrier(c);
818 
819   CallNode* call = nullptr;
820   guarantee(c != nullptr, "step_over_gc_barrier failed, there must be something to step to.");
821   if (c->is_Region()) {
822     for (uint i = 1; i < c->req(); i++) {
823       if (c->in(i) != nullptr) {
824         Node* n = c->in(i)->in(0);
825         if (may_modify_helper(t_oop, n, phase, ac)) {
826           assert(c == mb->in(0), "only for clone");
827           return true;
828         }
829       }
830     }
831   } else if (may_modify_helper(t_oop, c->in(0), phase, ac)) {
832 #ifdef ASSERT
833     bool use_ReduceInitialCardMarks = BarrierSet::barrier_set()->is_a(BarrierSet::CardTableBarrierSet) &&
834       static_cast<CardTableBarrierSetC2*>(bs)->use_ReduceInitialCardMarks();
835     assert(c == mb->in(0) || (ac->is_clonebasic() && !use_ReduceInitialCardMarks), "only for clone");
836 #endif
837     return true;
838   }
839 
840   return false;
841 }
842 
843 // Does this array copy modify offsets between offset_lo and offset_hi
844 // in the destination array
845 // if must_modify is false, return true if the copy could write
846 // between offset_lo and offset_hi
847 // if must_modify is true, return true if the copy is guaranteed to
848 // write between offset_lo and offset_hi
849 bool ArrayCopyNode::modifies(intptr_t offset_lo, intptr_t offset_hi, PhaseValues* phase, bool must_modify) const {
850   assert(_kind == ArrayCopy || _kind == CopyOf || _kind == CopyOfRange, "only for real array copies");
851 
852   Node* dest = in(Dest);
853   Node* dest_pos = in(DestPos);
854   Node* len = in(Length);
855 
856   const TypeInt *dest_pos_t = phase->type(dest_pos)->isa_int();
857   const TypeInt *len_t = phase->type(len)->isa_int();
858   const TypeAryPtr* ary_t = phase->type(dest)->isa_aryptr();
859 
860   if (dest_pos_t == nullptr || len_t == nullptr || ary_t == nullptr) {
861     return !must_modify;
862   }
863 
864   BasicType ary_elem = ary_t->isa_aryptr()->elem()->array_element_basic_type();
865   if (is_reference_type(ary_elem, true)) ary_elem = T_OBJECT;
866 
867   uint header;
868   uint elem_size;
869   if (ary_t->is_flat()) {
870     header = arrayOopDesc::base_offset_in_bytes(T_FLAT_ELEMENT);
871     elem_size = ary_t->flat_elem_size();
872   } else {
873     header = arrayOopDesc::base_offset_in_bytes(ary_elem);
874     elem_size = type2aelembytes(ary_elem);
875   }
876 
877   jlong dest_pos_plus_len_lo = (((jlong)dest_pos_t->_lo) + len_t->_lo) * elem_size + header;
878   jlong dest_pos_plus_len_hi = (((jlong)dest_pos_t->_hi) + len_t->_hi) * elem_size + header;
879   jlong dest_pos_lo = ((jlong)dest_pos_t->_lo) * elem_size + header;
880   jlong dest_pos_hi = ((jlong)dest_pos_t->_hi) * elem_size + header;
881 
882   if (must_modify) {
883     if (offset_lo >= dest_pos_hi && offset_hi < dest_pos_plus_len_lo) {
884       return true;
885     }
886   } else {
887     if (offset_hi >= dest_pos_lo && offset_lo < dest_pos_plus_len_hi) {
888       return true;
889     }
890   }
891   return false;
892 }
893 
894 // As an optimization, choose the optimal vector size for bounded copy length
895 int ArrayCopyNode::get_partial_inline_vector_lane_count(BasicType type, jlong max_len) {
896   assert(max_len > 0, JLONG_FORMAT, max_len);
897   // We only care whether max_size_in_bytes is not larger than 32, we also want to avoid
898   // multiplication overflow, so clamp max_len to [0, 64]
899   int max_size_in_bytes = MIN2<jlong>(max_len, 64) * type2aelembytes(type);
900   if (ArrayOperationPartialInlineSize > 16 && max_size_in_bytes <= 16) {
901     return 16 / type2aelembytes(type);
902   } else if (ArrayOperationPartialInlineSize > 32 && max_size_in_bytes <= 32) {
903     return 32 / type2aelembytes(type);
904   } else {
905     return ArrayOperationPartialInlineSize / type2aelembytes(type);
906   }
907 }