1 /*
  2  * Copyright (c) 2016, 2021, 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/ciFlatArrayKlass.hpp"
 27 #include "gc/shared/barrierSet.hpp"
 28 #include "gc/shared/c2/barrierSetC2.hpp"
 29 #include "gc/shared/c2/cardTableBarrierSetC2.hpp"
 30 #include "gc/shared/gc_globals.hpp"
 31 #include "opto/arraycopynode.hpp"
 32 #include "opto/graphKit.hpp"
 33 #include "opto/inlinetypenode.hpp"
 34 #include "runtime/sharedRuntime.hpp"
 35 #include "utilities/macros.hpp"
 36 #include "utilities/powerOfTwo.hpp"
 37 
 38 ArrayCopyNode::ArrayCopyNode(Compile* C, bool alloc_tightly_coupled, bool has_negative_length_guard)
 39   : CallNode(arraycopy_type(), NULL, TypePtr::BOTTOM),
 40     _kind(None),
 41     _alloc_tightly_coupled(alloc_tightly_coupled),
 42     _has_negative_length_guard(has_negative_length_guard),
 43     _arguments_validated(false),
 44     _src_type(TypeOopPtr::BOTTOM),
 45     _dest_type(TypeOopPtr::BOTTOM) {
 46   init_class_id(Class_ArrayCopy);
 47   init_flags(Flag_is_macro);
 48   C->add_macro_node(this);
 49 }
 50 
 51 uint ArrayCopyNode::size_of() const { return sizeof(*this); }
 52 
 53 ArrayCopyNode* ArrayCopyNode::make(GraphKit* kit, bool may_throw,
 54                                    Node* src, Node* src_offset,
 55                                    Node* dest, Node* dest_offset,
 56                                    Node* length,
 57                                    bool alloc_tightly_coupled,
 58                                    bool has_negative_length_guard,
 59                                    Node* src_klass, Node* dest_klass,
 60                                    Node* src_length, Node* dest_length) {
 61 
 62   ArrayCopyNode* ac = new ArrayCopyNode(kit->C, alloc_tightly_coupled, has_negative_length_guard);
 63   kit->set_predefined_input_for_runtime_call(ac);
 64 
 65   ac->init_req(ArrayCopyNode::Src, src);
 66   ac->init_req(ArrayCopyNode::SrcPos, src_offset);
 67   ac->init_req(ArrayCopyNode::Dest, dest);
 68   ac->init_req(ArrayCopyNode::DestPos, dest_offset);
 69   ac->init_req(ArrayCopyNode::Length, length);
 70   ac->init_req(ArrayCopyNode::SrcLen, src_length);
 71   ac->init_req(ArrayCopyNode::DestLen, dest_length);
 72   ac->init_req(ArrayCopyNode::SrcKlass, src_klass);
 73   ac->init_req(ArrayCopyNode::DestKlass, dest_klass);
 74 
 75   if (may_throw) {
 76     ac->set_req(TypeFunc::I_O , kit->i_o());
 77     kit->add_safepoint_edges(ac, false);
 78   }
 79 
 80   return ac;
 81 }
 82 
 83 void ArrayCopyNode::connect_outputs(GraphKit* kit, bool deoptimize_on_exception) {
 84   kit->set_all_memory_call(this, true);
 85   kit->set_control(kit->gvn().transform(new ProjNode(this,TypeFunc::Control)));
 86   kit->set_i_o(kit->gvn().transform(new ProjNode(this, TypeFunc::I_O)));
 87   kit->make_slow_call_ex(this, kit->env()->Throwable_klass(), true, deoptimize_on_exception);
 88   kit->set_all_memory_call(this);
 89 }
 90 
 91 #ifndef PRODUCT
 92 const char* ArrayCopyNode::_kind_names[] = {"arraycopy", "arraycopy, validated arguments", "clone", "oop array clone", "CopyOf", "CopyOfRange"};
 93 
 94 void ArrayCopyNode::dump_spec(outputStream *st) const {
 95   CallNode::dump_spec(st);
 96   st->print(" (%s%s)", _kind_names[_kind], _alloc_tightly_coupled ? ", tightly coupled allocation" : "");
 97 }
 98 
 99 void ArrayCopyNode::dump_compact_spec(outputStream* st) const {
100   st->print("%s%s", _kind_names[_kind], _alloc_tightly_coupled ? ",tight" : "");
101 }
102 #endif
103 
104 intptr_t ArrayCopyNode::get_length_if_constant(PhaseGVN *phase) const {
105   // check that length is constant
106   Node* length = in(ArrayCopyNode::Length);
107   const Type* length_type = phase->type(length);
108 
109   if (length_type == Type::TOP) {
110     return -1;
111   }
112 
113   assert(is_clonebasic() || is_arraycopy() || is_copyof() || is_copyofrange(), "unexpected array copy type");
114 
115   return is_clonebasic() ? length->find_intptr_t_con(-1) : length->find_int_con(-1);
116 }
117 
118 int ArrayCopyNode::get_count(PhaseGVN *phase) const {
119   if (is_clonebasic()) {
120     Node* src = in(ArrayCopyNode::Src);
121     const Type* src_type = phase->type(src);
122 
123     if (src_type == Type::TOP) {
124       return -1;
125     }
126 
127     if (src_type->isa_instptr()) {
128       const TypeInstPtr* inst_src = src_type->is_instptr();
129       ciInstanceKlass* ik = inst_src->klass()->as_instance_klass();
130       // ciInstanceKlass::nof_nonstatic_fields() doesn't take injected
131       // fields into account. They are rare anyway so easier to simply
132       // skip instances with injected fields.
133       if ((!inst_src->klass_is_exact() && (ik->is_interface() || ik->has_subklass())) || ik->has_injected_fields()) {
134         return -1;
135       }
136       int nb_fields = ik->nof_nonstatic_fields();
137       return nb_fields;
138     } else {
139       const TypeAryPtr* ary_src = src_type->isa_aryptr();
140       assert (ary_src != NULL, "not an array or instance?");
141       // clone passes a length as a rounded number of longs. If we're
142       // cloning an array we'll do it element by element. If the
143       // length input to ArrayCopyNode is constant, length of input
144       // array must be too.
145 
146       assert((get_length_if_constant(phase) == -1) != ary_src->size()->is_con() ||
147              (UseFlatArray && ary_src->elem()->make_oopptr() != NULL && ary_src->elem()->make_oopptr()->can_be_inline_type()) ||
148              phase->is_IterGVN() || phase->C->inlining_incrementally() || StressReflectiveCode, "inconsistent");
149 
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   DecoratorSet decorators = C2_READ_ACCESS | C2_CONTROL_DEPENDENT_LOAD | IN_HEAP | C2_ARRAY_COPY;
162   C2AccessValuePtr addr(adr, adr_type);
163   C2OptAccess access(*phase, ctl, mem, decorators, bt, adr->in(AddPNode::Base), addr);
164   Node* res = bs->load_at(access, type);
165   ctl = access.ctl();
166   return res;
167 }
168 
169 void ArrayCopyNode::store(BarrierSetC2* bs, PhaseGVN *phase, Node*& ctl, MergeMemNode* mem, Node* adr, const TypePtr* adr_type, Node* val, const Type *type, BasicType bt) {
170   DecoratorSet decorators = C2_WRITE_ACCESS | IN_HEAP | C2_ARRAY_COPY;
171   if (is_alloc_tightly_coupled()) {
172     decorators |= C2_TIGHTLY_COUPLED_ALLOC;
173   }
174   C2AccessValuePtr addr(adr, adr_type);
175   C2AccessValue value(val, type);
176   C2OptAccess access(*phase, ctl, mem, decorators, bt, adr->in(AddPNode::Base), addr);
177   bs->store_at(access, value);
178   ctl = access.ctl();
179 }
180 
181 
182 Node* ArrayCopyNode::try_clone_instance(PhaseGVN *phase, bool can_reshape, int count) {
183   if (!is_clonebasic()) {
184     return NULL;
185   }
186 
187   Node* base_src = in(ArrayCopyNode::Src);
188   Node* base_dest = in(ArrayCopyNode::Dest);
189   Node* ctl = in(TypeFunc::Control);
190   Node* in_mem = in(TypeFunc::Memory);
191 
192   const Type* src_type = phase->type(base_src);
193   const TypeInstPtr* inst_src = src_type->isa_instptr();
194   if (inst_src == NULL) {
195     return NULL;
196   }
197 
198   MergeMemNode* mem = phase->transform(MergeMemNode::make(in_mem))->as_MergeMem();
199   PhaseIterGVN* igvn = phase->is_IterGVN();
200   phase->record_for_igvn(mem);
201   if (igvn != NULL) {
202     igvn->_worklist.push(mem);
203   }
204 
205   if (!inst_src->klass_is_exact()) {
206     ciInstanceKlass* ik = inst_src->klass()->as_instance_klass();
207     assert(!ik->is_interface(), "inconsistent klass hierarchy");
208     if (ik->has_subklass()) {
209       // Concurrent class loading.
210       // Fail fast and return NodeSentinel to indicate that the transform failed.
211       return NodeSentinel;
212     } else {
213       phase->C->dependencies()->assert_leaf_type(ik);
214     }
215   }
216 
217   ciInstanceKlass* ik = inst_src->klass()->as_instance_klass();
218   assert(ik->nof_nonstatic_fields() <= ArrayCopyLoadStoreMaxElem, "too many fields");
219 
220   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
221   for (int i = 0; i < count; i++) {
222     ciField* field = ik->nonstatic_field_at(i);
223     const TypePtr* adr_type = phase->C->alias_type(field)->adr_type();
224     Node* off = phase->MakeConX(field->offset());
225     Node* next_src = phase->transform(new AddPNode(base_src,base_src,off));
226     Node* next_dest = phase->transform(new AddPNode(base_dest,base_dest,off));
227     BasicType bt = field->layout_type();
228 
229     const Type *type;
230     if (bt == T_OBJECT) {
231       if (!field->type()->is_loaded()) {
232         type = TypeInstPtr::BOTTOM;
233       } else {
234         ciType* field_klass = field->type();
235         type = TypeOopPtr::make_from_klass(field_klass->as_klass());
236       }
237     } else {
238       type = Type::get_const_basic_type(bt);
239     }
240 
241     Node* v = load(bs, phase, ctl, mem, next_src, adr_type, type, bt);
242     store(bs, phase, ctl, mem, next_dest, adr_type, v, type, bt);
243   }
244 
245   if (!finish_transform(phase, can_reshape, ctl, mem)) {
246     // Return NodeSentinel to indicate that the transform failed
247     return NodeSentinel;
248   }
249 
250   return mem;
251 }
252 
253 bool ArrayCopyNode::prepare_array_copy(PhaseGVN *phase, bool can_reshape,
254                                        Node*& adr_src,
255                                        Node*& base_src,
256                                        Node*& adr_dest,
257                                        Node*& base_dest,
258                                        BasicType& copy_type,
259                                        const Type*& value_type,
260                                        bool& disjoint_bases) {
261   base_src = in(ArrayCopyNode::Src);
262   base_dest = in(ArrayCopyNode::Dest);
263   const Type* src_type = phase->type(base_src);
264   const TypeAryPtr* ary_src = src_type->isa_aryptr();
265 
266   Node* src_offset = in(ArrayCopyNode::SrcPos);
267   Node* dest_offset = in(ArrayCopyNode::DestPos);
268 
269   if (is_arraycopy() || is_copyofrange() || is_copyof()) {
270     const Type* dest_type = phase->type(base_dest);
271     const TypeAryPtr* ary_dest = dest_type->isa_aryptr();
272 
273     // newly allocated object is guaranteed to not overlap with source object
274     disjoint_bases = is_alloc_tightly_coupled();
275 
276     if (ary_src  == NULL || ary_src->klass()  == NULL ||
277         ary_dest == NULL || ary_dest->klass() == NULL) {
278       // We don't know if arguments are arrays
279       return false;
280     }
281 
282     BasicType src_elem  = ary_src->klass()->as_array_klass()->element_type()->basic_type();
283     BasicType dest_elem = ary_dest->klass()->as_array_klass()->element_type()->basic_type();
284     if (src_elem == T_ARRAY || (src_elem == T_INLINE_TYPE && ary_src->klass()->is_obj_array_klass())) {
285       src_elem  = T_OBJECT;
286     }
287     if (dest_elem == T_ARRAY || (dest_elem == T_INLINE_TYPE && ary_dest->klass()->is_obj_array_klass())) {
288       dest_elem = T_OBJECT;
289     }
290 
291     if (src_elem != dest_elem || dest_elem == T_VOID) {
292       // We don't know if arguments are arrays of the same type
293       return false;
294     }
295 
296     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
297     if (bs->array_copy_requires_gc_barriers(is_alloc_tightly_coupled(), dest_elem, false, false, BarrierSetC2::Optimization) ||
298         (src_elem == T_INLINE_TYPE && ary_src->elem()->inline_klass()->contains_oops() &&
299          bs->array_copy_requires_gc_barriers(is_alloc_tightly_coupled(), T_OBJECT, false, false, BarrierSetC2::Optimization))) {
300       // It's an object array copy but we can't emit the card marking that is needed
301       return false;
302     }
303 
304     value_type = ary_src->elem();
305 
306     uint shift  = exact_log2(type2aelembytes(dest_elem));
307     if (dest_elem == T_INLINE_TYPE) {
308       ciFlatArrayKlass* vak = ary_src->klass()->as_flat_array_klass();
309       shift = vak->log2_element_size();
310     }
311     uint header = arrayOopDesc::base_offset_in_bytes(dest_elem);
312 
313     src_offset = Compile::conv_I2X_index(phase, src_offset, ary_src->size());
314     dest_offset = Compile::conv_I2X_index(phase, dest_offset, ary_dest->size());
315     if (src_offset->is_top() || dest_offset->is_top()) {
316       // Offset is out of bounds (the ArrayCopyNode will be removed)
317       return false;
318     }
319 
320     Node* src_scale  = phase->transform(new LShiftXNode(src_offset, phase->intcon(shift)));
321     Node* dest_scale = phase->transform(new LShiftXNode(dest_offset, phase->intcon(shift)));
322 
323     adr_src          = phase->transform(new AddPNode(base_src, base_src, src_scale));
324     adr_dest         = phase->transform(new AddPNode(base_dest, base_dest, dest_scale));
325 
326     adr_src          = phase->transform(new AddPNode(base_src, adr_src, phase->MakeConX(header)));
327     adr_dest         = phase->transform(new AddPNode(base_dest, adr_dest, phase->MakeConX(header)));
328 
329     copy_type = dest_elem;
330   } else {
331     assert(ary_src != NULL, "should be a clone");
332     assert(is_clonebasic(), "should be");
333 
334     disjoint_bases = true;
335 
336     if (ary_src->elem()->make_oopptr() != NULL &&
337         ary_src->elem()->make_oopptr()->can_be_inline_type()) {
338       return false;
339     }
340 
341     BasicType elem = ary_src->klass()->as_array_klass()->element_type()->basic_type();
342     if (elem == T_ARRAY || (elem == T_INLINE_TYPE && ary_src->klass()->is_obj_array_klass())) {
343       elem = T_OBJECT;
344     }
345 
346     BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
347     if (bs->array_copy_requires_gc_barriers(true, elem, true, is_clone_inst(), BarrierSetC2::Optimization) ||
348         (elem == T_INLINE_TYPE && ary_src->elem()->inline_klass()->contains_oops() &&
349          bs->array_copy_requires_gc_barriers(true, T_OBJECT, true, is_clone_inst(), BarrierSetC2::Optimization))) {
350       // It's an object array copy but we can't emit the card marking that is needed
351       return false;
352     }
353 
354     adr_src  = phase->transform(new AddPNode(base_src, base_src, src_offset));
355     adr_dest = phase->transform(new AddPNode(base_dest, base_dest, dest_offset));
356 
357     // The address is offseted to an aligned address where a raw copy would start.
358     // If the clone copy is decomposed into load-stores - the address is adjusted to
359     // point at where the array starts.
360     const Type* toff = phase->type(src_offset);
361     int offset = toff->isa_long() ? (int) toff->is_long()->get_con() : (int) toff->is_int()->get_con();
362     int diff = arrayOopDesc::base_offset_in_bytes(elem) - offset;
363     assert(diff >= 0, "clone should not start after 1st array element");
364     if (diff > 0) {
365       adr_src = phase->transform(new AddPNode(base_src, adr_src, phase->MakeConX(diff)));
366       adr_dest = phase->transform(new AddPNode(base_dest, adr_dest, phase->MakeConX(diff)));
367     }
368     copy_type = elem;
369     value_type = ary_src->elem();
370   }
371   return true;
372 }
373 
374 const TypeAryPtr* ArrayCopyNode::get_address_type(PhaseGVN* phase, const TypePtr* atp, Node* n) {
375   if (atp == TypeOopPtr::BOTTOM) {
376     atp = phase->type(n)->isa_ptr();
377   }
378   // adjust atp to be the correct array element address type
379   return atp->add_offset(Type::OffsetBot)->is_aryptr();
380 }
381 
382 void ArrayCopyNode::array_copy_test_overlap(GraphKit& kit, bool disjoint_bases, int count, Node*& backward_ctl) {
383   Node* ctl = kit.control();
384   if (!disjoint_bases && count > 1) {
385     PhaseGVN& gvn = kit.gvn();
386     Node* src_offset = in(ArrayCopyNode::SrcPos);
387     Node* dest_offset = in(ArrayCopyNode::DestPos);
388     assert(src_offset != NULL && dest_offset != NULL, "should be");
389     Node* cmp = gvn.transform(new CmpINode(src_offset, dest_offset));
390     Node *bol = gvn.transform(new BoolNode(cmp, BoolTest::lt));
391     IfNode *iff = new IfNode(ctl, bol, PROB_FAIR, COUNT_UNKNOWN);
392 
393     gvn.transform(iff);
394 
395     kit.set_control(gvn.transform(new IfFalseNode(iff)));
396     backward_ctl = gvn.transform(new IfTrueNode(iff));
397   }
398 }
399 
400 void ArrayCopyNode::copy(GraphKit& kit,
401                          const TypeAryPtr* atp_src,
402                          const TypeAryPtr* atp_dest,
403                          int i,
404                          Node* base_src,
405                          Node* base_dest,
406                          Node* adr_src,
407                          Node* adr_dest,
408                          BasicType copy_type,
409                          const Type* value_type) {
410   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
411   Node* ctl = kit.control();
412   if (copy_type == T_INLINE_TYPE) {
413     ciFlatArrayKlass* vak = atp_src->klass()->as_flat_array_klass();
414     ciInlineKlass* vk = vak->element_klass()->as_inline_klass();
415     for (int j = 0; j < vk->nof_nonstatic_fields(); j++) {
416       ciField* field = vk->nonstatic_field_at(j);
417       int off_in_vt = field->offset() - vk->first_field_offset();
418       Node* off  = kit.MakeConX(off_in_vt + i * vak->element_byte_size());
419       ciType* ft = field->type();
420       BasicType bt = type2field[ft->basic_type()];
421       assert(!field->is_flattened(), "flattened field encountered");
422       if (bt == T_INLINE_TYPE) {
423         bt = T_OBJECT;
424       }
425       const Type* rt = Type::get_const_type(ft);
426       const TypePtr* adr_type = atp_src->with_field_offset(off_in_vt)->add_offset(Type::OffsetBot);
427       assert(!bs->array_copy_requires_gc_barriers(is_alloc_tightly_coupled(), bt, false, false, BarrierSetC2::Optimization), "GC barriers required");
428       Node* next_src = kit.gvn().transform(new AddPNode(base_src, adr_src, off));
429       Node* next_dest = kit.gvn().transform(new AddPNode(base_dest, adr_dest, off));
430       Node* v = load(bs, &kit.gvn(), ctl, kit.merged_memory(), next_src, adr_type, rt, bt);
431       store(bs, &kit.gvn(), ctl, kit.merged_memory(), next_dest, adr_type, v, rt, bt);
432     }
433   } else {
434     Node* off = kit.MakeConX(type2aelembytes(copy_type) * i);
435     Node* next_src = kit.gvn().transform(new AddPNode(base_src, adr_src, off));
436     Node* next_dest = kit.gvn().transform(new AddPNode(base_dest, adr_dest, off));
437     Node* v = load(bs, &kit.gvn(), ctl, kit.merged_memory(), next_src, atp_src, value_type, copy_type);
438     store(bs, &kit.gvn(), ctl, kit.merged_memory(), next_dest, atp_dest, v, value_type, copy_type);
439   }
440   kit.set_control(ctl);
441 }
442 
443 
444 void ArrayCopyNode::array_copy_forward(GraphKit& kit,
445                                        bool can_reshape,
446                                        const TypeAryPtr* atp_src,
447                                        const TypeAryPtr* atp_dest,
448                                        Node* adr_src,
449                                        Node* base_src,
450                                        Node* adr_dest,
451                                        Node* base_dest,
452                                        BasicType copy_type,
453                                        const Type* value_type,
454                                        int count) {
455   if (!kit.stopped()) {
456     // copy forward
457     if (count > 0) {
458       for (int i = 0; i < count; i++) {
459         copy(kit, atp_src, atp_dest, i, base_src, base_dest, adr_src, adr_dest, copy_type, value_type);
460       }
461     } else if (can_reshape) {
462       PhaseGVN& gvn = kit.gvn();
463       assert(gvn.is_IterGVN(), "");
464       gvn.record_for_igvn(adr_src);
465       gvn.record_for_igvn(adr_dest);
466     }
467   }
468 }
469 
470 void ArrayCopyNode::array_copy_backward(GraphKit& kit,
471                                         bool can_reshape,
472                                         const TypeAryPtr* atp_src,
473                                         const TypeAryPtr* atp_dest,
474                                         Node* adr_src,
475                                         Node* base_src,
476                                         Node* adr_dest,
477                                         Node* base_dest,
478                                         BasicType copy_type,
479                                         const Type* value_type,
480                                         int count) {
481   if (!kit.stopped()) {
482     // copy backward
483     PhaseGVN& gvn = kit.gvn();
484 
485     if (count > 0) {
486       for (int i = count-1; i >= 0; i--) {
487         copy(kit, atp_src, atp_dest, i, base_src, base_dest, adr_src, adr_dest, copy_type, value_type);
488       }
489     } else if(can_reshape) {
490       PhaseGVN& gvn = kit.gvn();
491       assert(gvn.is_IterGVN(), "");
492       gvn.record_for_igvn(adr_src);
493       gvn.record_for_igvn(adr_dest);
494     }
495   }
496 }
497 
498 bool ArrayCopyNode::finish_transform(PhaseGVN *phase, bool can_reshape,
499                                      Node* ctl, Node *mem) {
500   if (can_reshape) {
501     PhaseIterGVN* igvn = phase->is_IterGVN();
502     igvn->set_delay_transform(false);
503     if (is_clonebasic()) {
504       Node* out_mem = proj_out(TypeFunc::Memory);
505 
506       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
507       if (out_mem->outcnt() != 1 || !out_mem->raw_out(0)->is_MergeMem() ||
508           out_mem->raw_out(0)->outcnt() != 1 || !out_mem->raw_out(0)->raw_out(0)->is_MemBar()) {
509         assert(bs->array_copy_requires_gc_barriers(true, T_OBJECT, true, is_clone_inst(), BarrierSetC2::Optimization), "can only happen with card marking");
510         return false;
511       }
512 
513       igvn->replace_node(out_mem->raw_out(0), mem);
514 
515       Node* out_ctl = proj_out(TypeFunc::Control);
516       igvn->replace_node(out_ctl, ctl);
517     } else {
518       // replace fallthrough projections of the ArrayCopyNode by the
519       // new memory, control and the input IO.
520       CallProjections* callprojs = extract_projections(true, false);
521 
522       if (callprojs->fallthrough_ioproj != NULL) {
523         igvn->replace_node(callprojs->fallthrough_ioproj, in(TypeFunc::I_O));
524       }
525       if (callprojs->fallthrough_memproj != NULL) {
526         igvn->replace_node(callprojs->fallthrough_memproj, mem);
527       }
528       if (callprojs->fallthrough_catchproj != NULL) {
529         igvn->replace_node(callprojs->fallthrough_catchproj, ctl);
530       }
531 
532       // The ArrayCopyNode is not disconnected. It still has the
533       // projections for the exception case. Replace current
534       // ArrayCopyNode with a dummy new one with a top() control so
535       // that this part of the graph stays consistent but is
536       // eventually removed.
537 
538       set_req(0, phase->C->top());
539       remove_dead_region(phase, can_reshape);
540     }
541   } else {
542     if (in(TypeFunc::Control) != ctl) {
543       // we can't return new memory and control from Ideal at parse time
544 #ifdef ASSERT
545       Node* src = in(ArrayCopyNode::Src);
546       const Type* src_type = phase->type(src);
547       const TypeAryPtr* ary_src = src_type->isa_aryptr();
548       BasicType elem = ary_src != NULL ? ary_src->klass()->as_array_klass()->element_type()->basic_type() : T_CONFLICT;
549       BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
550       assert(!is_clonebasic() || bs->array_copy_requires_gc_barriers(true, T_OBJECT, true, is_clone_inst(), BarrierSetC2::Optimization) ||
551              (ary_src != NULL && elem == T_INLINE_TYPE && ary_src->klass()->is_obj_array_klass()), "added control for clone?");
552 #endif
553       assert(!is_clonebasic() || UseShenandoahGC, "added control for clone?");
554       phase->record_for_igvn(this);
555       return false;
556     }
557   }
558   return true;
559 }
560 
561 
562 Node *ArrayCopyNode::Ideal(PhaseGVN *phase, bool can_reshape) {
563   // Perform any generic optimizations first
564   Node* result = SafePointNode::Ideal(phase, can_reshape);
565   if (result != NULL) {
566     return result;
567   }
568 
569   if (StressArrayCopyMacroNode && !can_reshape) {
570     phase->record_for_igvn(this);
571     return NULL;
572   }
573 
574   // See if it's a small array copy and we can inline it as
575   // loads/stores
576   // Here we can only do:
577   // - arraycopy if all arguments were validated before and we don't
578   // need card marking
579   // - clone for which we don't need to do card marking
580 
581   if (!is_clonebasic() && !is_arraycopy_validated() &&
582       !is_copyofrange_validated() && !is_copyof_validated()) {
583     return NULL;
584   }
585 
586   assert(in(TypeFunc::Control) != NULL &&
587          in(TypeFunc::Memory) != NULL &&
588          in(ArrayCopyNode::Src) != NULL &&
589          in(ArrayCopyNode::Dest) != NULL &&
590          in(ArrayCopyNode::Length) != NULL &&
591          in(ArrayCopyNode::SrcPos) != NULL &&
592          in(ArrayCopyNode::DestPos) != NULL, "broken inputs");
593 
594   if (in(TypeFunc::Control)->is_top() ||
595       in(TypeFunc::Memory)->is_top() ||
596       phase->type(in(ArrayCopyNode::Src)) == Type::TOP ||
597       phase->type(in(ArrayCopyNode::Dest)) == Type::TOP ||
598       (in(ArrayCopyNode::SrcPos) != NULL && in(ArrayCopyNode::SrcPos)->is_top()) ||
599       (in(ArrayCopyNode::DestPos) != NULL && in(ArrayCopyNode::DestPos)->is_top())) {
600     return NULL;
601   }
602 
603   int count = get_count(phase);
604 
605   if (count < 0 || count > ArrayCopyLoadStoreMaxElem) {
606     return NULL;
607   }
608 
609   Node* src = in(ArrayCopyNode::Src);
610   Node* dest = in(ArrayCopyNode::Dest);
611   const Type* src_type = phase->type(src);
612   const Type* dest_type = phase->type(dest);
613 
614   if (src_type->isa_aryptr() && dest_type->isa_instptr()) {
615     // clone used for load of unknown inline type can't be optimized at
616     // this point
617     return NULL;
618   }
619 
620   Node* mem = try_clone_instance(phase, can_reshape, count);
621   if (mem != NULL) {
622     return (mem == NodeSentinel) ? NULL : mem;
623   }
624 
625   Node* adr_src = NULL;
626   Node* base_src = NULL;
627   Node* adr_dest = NULL;
628   Node* base_dest = NULL;
629   BasicType copy_type = T_ILLEGAL;
630   const Type* value_type = NULL;
631   bool disjoint_bases = false;
632 
633   if (!prepare_array_copy(phase, can_reshape,
634                           adr_src, base_src, adr_dest, base_dest,
635                           copy_type, value_type, disjoint_bases)) {
636     return NULL;
637   }
638 
639   JVMState* new_jvms = NULL;
640   SafePointNode* new_map = NULL;
641   if (!is_clonebasic()) {
642     new_jvms = jvms()->clone_shallow(phase->C);
643     new_map = new SafePointNode(req(), new_jvms);
644     for (uint i = TypeFunc::FramePtr; i < req(); i++) {
645       new_map->init_req(i, in(i));
646     }
647     new_jvms->set_map(new_map);
648   } else {
649     new_jvms = new (phase->C) JVMState(0);
650     new_map = new SafePointNode(TypeFunc::Parms, new_jvms);
651     new_jvms->set_map(new_map);
652   }
653   new_map->set_control(in(TypeFunc::Control));
654   new_map->set_memory(MergeMemNode::make(in(TypeFunc::Memory)));
655   new_map->set_i_o(in(TypeFunc::I_O));
656   phase->record_for_igvn(new_map);
657 
658   const TypeAryPtr* atp_src = get_address_type(phase, _src_type, src);
659   const TypeAryPtr* atp_dest = get_address_type(phase, _dest_type, dest);
660 
661   if (can_reshape) {
662     assert(!phase->is_IterGVN()->delay_transform(), "cannot delay transforms");
663     phase->is_IterGVN()->set_delay_transform(true);
664   }
665 
666   GraphKit kit(new_jvms, phase);
667 
668   SafePointNode* backward_map = NULL;
669   SafePointNode* forward_map = NULL;
670   Node* backward_ctl = phase->C->top();
671 
672   array_copy_test_overlap(kit, disjoint_bases, count, backward_ctl);
673 
674   {
675     PreserveJVMState pjvms(&kit);
676 
677     array_copy_forward(kit, can_reshape,
678                        atp_src, atp_dest,
679                        adr_src, base_src, adr_dest, base_dest,
680                        copy_type, value_type, count);
681 
682     forward_map = kit.stop();
683   }
684 
685   kit.set_control(backward_ctl);
686   array_copy_backward(kit, can_reshape,
687                       atp_src, atp_dest,
688                       adr_src, base_src, adr_dest, base_dest,
689                       copy_type, value_type, count);
690 
691   backward_map = kit.stop();
692 
693   if (!forward_map->control()->is_top() && !backward_map->control()->is_top()) {
694     assert(forward_map->i_o() == backward_map->i_o(), "need a phi on IO?");
695     Node* ctl = new RegionNode(3);
696     Node* mem = new PhiNode(ctl, Type::MEMORY, TypePtr::BOTTOM);
697     kit.set_map(forward_map);
698     ctl->init_req(1, kit.control());
699     mem->init_req(1, kit.reset_memory());
700     kit.set_map(backward_map);
701     ctl->init_req(2, kit.control());
702     mem->init_req(2, kit.reset_memory());
703     kit.set_control(phase->transform(ctl));
704     kit.set_all_memory(phase->transform(mem));
705   } else if (!forward_map->control()->is_top()) {
706     kit.set_map(forward_map);
707   } else {
708     assert(!backward_map->control()->is_top(), "no copy?");
709     kit.set_map(backward_map);
710   }
711 
712   if (can_reshape) {
713     assert(phase->is_IterGVN()->delay_transform(), "should be delaying transforms");
714     phase->is_IterGVN()->set_delay_transform(false);
715   }
716 
717   mem = kit.map()->memory();
718   if (!finish_transform(phase, can_reshape, kit.control(), mem)) {
719     if (!can_reshape) {
720       phase->record_for_igvn(this);
721     }
722     return NULL;
723   }
724 
725   return mem;
726 }
727 
728 bool ArrayCopyNode::may_modify(const TypeOopPtr *t_oop, PhaseTransform *phase) {
729   Node* dest = in(ArrayCopyNode::Dest);
730   if (dest->is_top()) {
731     return false;
732   }
733   const TypeOopPtr* dest_t = phase->type(dest)->is_oopptr();
734   assert(!dest_t->is_known_instance() || _dest_type->is_known_instance(), "result of EA not recorded");
735   assert(in(ArrayCopyNode::Src)->is_top() || !phase->type(in(ArrayCopyNode::Src))->is_oopptr()->is_known_instance() ||
736          _src_type->is_known_instance(), "result of EA not recorded");
737 
738   if (_dest_type != TypeOopPtr::BOTTOM || t_oop->is_known_instance()) {
739     assert(_dest_type == TypeOopPtr::BOTTOM || _dest_type->is_known_instance(), "result of EA is known instance");
740     return t_oop->instance_id() == _dest_type->instance_id();
741   }
742 
743   return CallNode::may_modify_arraycopy_helper(dest_t, t_oop, phase);
744 }
745 
746 bool ArrayCopyNode::may_modify_helper(const TypeOopPtr *t_oop, Node* n, PhaseTransform *phase, CallNode*& call) {
747   if (n != NULL &&
748       n->is_Call() &&
749       n->as_Call()->may_modify(t_oop, phase) &&
750       (n->as_Call()->is_ArrayCopy() || n->as_Call()->is_call_to_arraycopystub())) {
751     call = n->as_Call();
752     return true;
753   }
754   return false;
755 }
756 
757 bool ArrayCopyNode::may_modify(const TypeOopPtr *t_oop, MemBarNode* mb, PhaseTransform *phase, ArrayCopyNode*& ac) {
758 
759   Node* c = mb->in(0);
760 
761   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
762   // step over g1 gc barrier if we're at e.g. a clone with ReduceInitialCardMarks off
763   c = bs->step_over_gc_barrier(c);
764 
765   CallNode* call = NULL;
766   guarantee(c != NULL, "step_over_gc_barrier failed, there must be something to step to.");
767   if (c->is_Region()) {
768     for (uint i = 1; i < c->req(); i++) {
769       if (c->in(i) != NULL) {
770         Node* n = c->in(i)->in(0);
771         if (may_modify_helper(t_oop, n, phase, call)) {
772           ac = call->isa_ArrayCopy();
773           assert(c == mb->in(0), "only for clone");
774           return true;
775         }
776       }
777     }
778   } else if (may_modify_helper(t_oop, c->in(0), phase, call)) {
779     ac = call->isa_ArrayCopy();
780 #ifdef ASSERT
781     bool use_ReduceInitialCardMarks = BarrierSet::barrier_set()->is_a(BarrierSet::CardTableBarrierSet) &&
782       static_cast<CardTableBarrierSetC2*>(bs)->use_ReduceInitialCardMarks();
783     assert(c == mb->in(0) || (ac != NULL && ac->is_clonebasic() && !use_ReduceInitialCardMarks), "only for clone");
784 #endif
785     return true;
786   } else if (mb->trailing_partial_array_copy()) {
787     return true;
788   }
789 
790   return false;
791 }
792 
793 // Does this array copy modify offsets between offset_lo and offset_hi
794 // in the destination array
795 // if must_modify is false, return true if the copy could write
796 // between offset_lo and offset_hi
797 // if must_modify is true, return true if the copy is guaranteed to
798 // write between offset_lo and offset_hi
799 bool ArrayCopyNode::modifies(intptr_t offset_lo, intptr_t offset_hi, PhaseTransform* phase, bool must_modify) const {
800   assert(_kind == ArrayCopy || _kind == CopyOf || _kind == CopyOfRange, "only for real array copies");
801 
802   Node* dest = in(Dest);
803   Node* dest_pos = in(DestPos);
804   Node* len = in(Length);
805 
806   const TypeInt *dest_pos_t = phase->type(dest_pos)->isa_int();
807   const TypeInt *len_t = phase->type(len)->isa_int();
808   const TypeAryPtr* ary_t = phase->type(dest)->isa_aryptr();
809 
810   if (dest_pos_t == NULL || len_t == NULL || ary_t == NULL) {
811     return !must_modify;
812   }
813 
814   ciArrayKlass* klass = ary_t->klass()->as_array_klass();
815   BasicType ary_elem = klass->element_type()->basic_type();
816   uint header = arrayOopDesc::base_offset_in_bytes(ary_elem);
817   uint elemsize = type2aelembytes(ary_elem);
818   if (klass->is_flat_array_klass()) {
819     elemsize = klass->as_flat_array_klass()->element_byte_size();
820   }
821 
822   jlong dest_pos_plus_len_lo = (((jlong)dest_pos_t->_lo) + len_t->_lo) * elemsize + header;
823   jlong dest_pos_plus_len_hi = (((jlong)dest_pos_t->_hi) + len_t->_hi) * elemsize + header;
824   jlong dest_pos_lo = ((jlong)dest_pos_t->_lo) * elemsize + header;
825   jlong dest_pos_hi = ((jlong)dest_pos_t->_hi) * elemsize + header;
826 
827   if (must_modify) {
828     if (offset_lo >= dest_pos_hi && offset_hi < dest_pos_plus_len_lo) {
829       return true;
830     }
831   } else {
832     if (offset_hi >= dest_pos_lo && offset_lo < dest_pos_plus_len_hi) {
833       return true;
834     }
835   }
836   return false;
837 }
838 
839 // As an optimization, choose optimum vector size for copy length known at compile time.
840 int ArrayCopyNode::get_partial_inline_vector_lane_count(BasicType type, int const_len) {
841   int lane_count = ArrayOperationPartialInlineSize/type2aelembytes(type);
842   if (const_len > 0) {
843     int size_in_bytes = const_len * type2aelembytes(type);
844     if (size_in_bytes <= 16)
845       lane_count = 16/type2aelembytes(type);
846     else if (size_in_bytes > 16 && size_in_bytes <= 32)
847       lane_count = 32/type2aelembytes(type);
848   }
849   return lane_count;
850 }