1 /*
2 * Copyright (c) 2012, 2025, 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/tlab_globals.hpp"
28 #include "oops/objArrayKlass.hpp"
29 #include "opto/arraycopynode.hpp"
30 #include "opto/castnode.hpp"
31 #include "opto/convertnode.hpp"
32 #include "opto/graphKit.hpp"
33 #include "opto/macro.hpp"
34 #include "opto/runtime.hpp"
35 #include "opto/vectornode.hpp"
36 #include "runtime/stubRoutines.hpp"
37 #include "utilities/align.hpp"
38 #include "utilities/powerOfTwo.hpp"
39
40 void PhaseMacroExpand::insert_mem_bar(Node** ctrl, Node** mem, int opcode, int alias_idx, Node* precedent) {
41 MemBarNode* mb = MemBarNode::make(C, opcode, alias_idx, precedent);
42 mb->init_req(TypeFunc::Control, *ctrl);
43 mb->init_req(TypeFunc::Memory, *mem);
44 transform_later(mb);
45 *ctrl = new ProjNode(mb,TypeFunc::Control);
46 transform_later(*ctrl);
47 Node* mem_proj = new ProjNode(mb,TypeFunc::Memory);
48 transform_later(mem_proj);
49 if (alias_idx == Compile::AliasIdxBot) {
50 *mem = mem_proj;
51 } else {
52 MergeMemNode* mm = (*mem)->clone()->as_MergeMem();
53 mm->set_memory_at(alias_idx, mem_proj);
54 transform_later(mm);
55 *mem = mm;
56 }
57 }
58
59 Node* PhaseMacroExpand::array_element_address(Node* ary, Node* idx, BasicType elembt) {
60 uint shift = exact_log2(type2aelembytes(elembt));
61 const TypeAryPtr* array_type = _igvn.type(ary)->isa_aryptr();
62 if (array_type != nullptr && array_type->is_aryptr()->is_flat()) {
63 // Use T_FLAT_ELEMENT to get proper alignment with COH when fetching the array element address.
64 elembt = T_FLAT_ELEMENT;
65 }
66 uint header = arrayOopDesc::base_offset_in_bytes(elembt);
67 Node* base = basic_plus_adr(ary, header);
68 #ifdef _LP64
69 // see comment in GraphKit::array_element_address
70 int index_max = max_jint - 1; // array size is max_jint, index is one less
71 const TypeLong* lidxtype = TypeLong::make(CONST64(0), index_max, Type::WidenMax);
72 idx = transform_later( new ConvI2LNode(idx, lidxtype) );
73 #endif
74 Node* scale = new LShiftXNode(idx, intcon(shift));
75 transform_later(scale);
76 return basic_plus_adr(ary, base, scale);
77 }
78
79 Node* PhaseMacroExpand::ConvI2L(Node* offset) {
80 return transform_later(new ConvI2LNode(offset));
81 }
82
83 Node* PhaseMacroExpand::make_leaf_call(Node* ctrl, Node* mem,
84 const TypeFunc* call_type, address call_addr,
85 const char* call_name,
86 const TypePtr* adr_type,
87 Node* parm0, Node* parm1,
88 Node* parm2, Node* parm3,
89 Node* parm4, Node* parm5,
90 Node* parm6, Node* parm7) {
91 Node* call = new CallLeafNoFPNode(call_type, call_addr, call_name, adr_type);
92 call->init_req(TypeFunc::Control, ctrl);
93 call->init_req(TypeFunc::I_O , top());
94 call->init_req(TypeFunc::Memory , mem);
95 call->init_req(TypeFunc::ReturnAdr, top());
96 call->init_req(TypeFunc::FramePtr, top());
97
98 // Hook each parm in order. Stop looking at the first null.
99 if (parm0 != nullptr) { call->init_req(TypeFunc::Parms+0, parm0);
100 if (parm1 != nullptr) { call->init_req(TypeFunc::Parms+1, parm1);
101 if (parm2 != nullptr) { call->init_req(TypeFunc::Parms+2, parm2);
102 if (parm3 != nullptr) { call->init_req(TypeFunc::Parms+3, parm3);
103 if (parm4 != nullptr) { call->init_req(TypeFunc::Parms+4, parm4);
104 if (parm5 != nullptr) { call->init_req(TypeFunc::Parms+5, parm5);
105 if (parm6 != nullptr) { call->init_req(TypeFunc::Parms+6, parm6);
106 if (parm7 != nullptr) { call->init_req(TypeFunc::Parms+7, parm7);
107 /* close each nested if ===> */ } } } } } } } }
108 assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
109
110 return call;
111 }
112
113
114 //------------------------------generate_guard---------------------------
115 // Helper function for generating guarded fast-slow graph structures.
116 // The given 'test', if true, guards a slow path. If the test fails
117 // then a fast path can be taken. (We generally hope it fails.)
118 // In all cases, GraphKit::control() is updated to the fast path.
119 // The returned value represents the control for the slow path.
120 // The return value is never 'top'; it is either a valid control
121 // or null if it is obvious that the slow path can never be taken.
122 // Also, if region and the slow control are not null, the slow edge
123 // is appended to the region.
124 Node* PhaseMacroExpand::generate_guard(Node** ctrl, Node* test, RegionNode* region, float true_prob) {
125 if ((*ctrl)->is_top()) {
126 // Already short circuited.
127 return nullptr;
128 }
129 // Build an if node and its projections.
130 // If test is true we take the slow path, which we assume is uncommon.
131 if (_igvn.type(test) == TypeInt::ZERO) {
132 // The slow branch is never taken. No need to build this guard.
133 return nullptr;
134 }
135
136 IfNode* iff = new IfNode(*ctrl, test, true_prob, COUNT_UNKNOWN);
137 transform_later(iff);
138
139 Node* if_slow = new IfTrueNode(iff);
140 transform_later(if_slow);
141
142 if (region != nullptr) {
143 region->add_req(if_slow);
144 }
145
146 Node* if_fast = new IfFalseNode(iff);
147 transform_later(if_fast);
148
149 *ctrl = if_fast;
150
151 return if_slow;
152 }
153
154 Node* PhaseMacroExpand::generate_slow_guard(Node** ctrl, Node* test, RegionNode* region) {
155 return generate_guard(ctrl, test, region, PROB_UNLIKELY_MAG(3));
156 }
157
158 inline Node* PhaseMacroExpand::generate_fair_guard(Node** ctrl, Node* test, RegionNode* region) {
159 return generate_guard(ctrl, test, region, PROB_FAIR);
160 }
161
162 void PhaseMacroExpand::generate_negative_guard(Node** ctrl, Node* index, RegionNode* region) {
163 if ((*ctrl)->is_top())
164 return; // already stopped
165 if (_igvn.type(index)->higher_equal(TypeInt::POS)) // [0,maxint]
166 return; // index is already adequately typed
167 Node* cmp_lt = new CmpINode(index, intcon(0));
168 transform_later(cmp_lt);
169 Node* bol_lt = new BoolNode(cmp_lt, BoolTest::lt);
170 transform_later(bol_lt);
171 generate_guard(ctrl, bol_lt, region, PROB_MIN);
172 }
173
174 void PhaseMacroExpand::generate_limit_guard(Node** ctrl, Node* offset, Node* subseq_length, Node* array_length, RegionNode* region) {
175 if ((*ctrl)->is_top())
176 return; // already stopped
177 bool zero_offset = _igvn.type(offset) == TypeInt::ZERO;
178 if (zero_offset && subseq_length->eqv_uncast(array_length))
179 return; // common case of whole-array copy
180 Node* last = subseq_length;
181 if (!zero_offset) { // last += offset
182 last = new AddINode(last, offset);
183 transform_later(last);
184 }
185 Node* cmp_lt = new CmpUNode(array_length, last);
186 transform_later(cmp_lt);
187 Node* bol_lt = new BoolNode(cmp_lt, BoolTest::lt);
188 transform_later(bol_lt);
189 generate_guard(ctrl, bol_lt, region, PROB_MIN);
190 }
191
192 //
193 // Partial in-lining handling for smaller conjoint/disjoint array copies having
194 // length(in bytes) less than ArrayOperationPartialInlineSize.
195 // if (length <= ArrayOperationPartialInlineSize) {
196 // partial_inlining_block:
197 // mask = Mask_Gen
198 // vload = LoadVectorMasked src , mask
199 // StoreVectorMasked dst, mask, vload
200 // } else {
201 // stub_block:
202 // callstub array_copy
203 // }
204 // exit_block:
205 // Phi = label partial_inlining_block:mem , label stub_block:mem (filled by caller)
206 // mem = MergeMem (Phi)
207 // control = stub_block
208 //
209 // Exit_block and associated phi(memory) are partially initialized for partial_in-lining_block
210 // edges. Remaining edges for exit_block coming from stub_block are connected by the caller
211 // post stub nodes creation.
212 //
213
214 void PhaseMacroExpand::generate_partial_inlining_block(Node** ctrl, MergeMemNode** mem, const TypePtr* adr_type,
215 RegionNode** exit_block, Node** result_memory, Node* length,
216 Node* src_start, Node* dst_start, BasicType type) {
217 int inline_limit = ArrayOperationPartialInlineSize / type2aelembytes(type);
218
219 const TypeLong* length_type = _igvn.type(length)->isa_long();
220 if (length_type == nullptr) {
221 assert(_igvn.type(length) == Type::TOP, "");
222 return;
223 }
224
225 const TypeLong* inline_range = TypeLong::make(0, inline_limit, Type::WidenMin);
226 if (length_type->join(inline_range) == Type::TOP) {
227 // The ranges do not intersect, the inline check will surely fail
228 return;
229 }
230
231 // Return if the target does not supports masked load/stores.
232 int lane_count = ArrayCopyNode::get_partial_inline_vector_lane_count(type, length_type->_hi);
233 if (!Matcher::match_rule_supported_vector(Op_LoadVectorMasked, lane_count, type) ||
234 !Matcher::match_rule_supported_vector(Op_StoreVectorMasked, lane_count, type) ||
235 !Matcher::match_rule_supported_vector(Op_VectorMaskGen, lane_count, type)) {
236 return;
237 }
238
239 Node* cmp_le = new CmpULNode(length, longcon(inline_limit));
240 transform_later(cmp_le);
241 Node* bol_le = new BoolNode(cmp_le, BoolTest::le);
242 transform_later(bol_le);
243 Node* inline_block = generate_guard(ctrl, bol_le, nullptr, PROB_FAIR);
244 Node* stub_block = *ctrl;
245
246 Node* casted_length = new CastLLNode(inline_block, length, inline_range, ConstraintCastNode::DependencyType::FloatingNarrowing);
247 transform_later(casted_length);
248 Node* mask_gen = VectorMaskGenNode::make(casted_length, type);
249 transform_later(mask_gen);
250
251 unsigned vec_size = lane_count * type2aelembytes(type);
252 if (C->max_vector_size() < vec_size) {
253 C->set_max_vector_size(vec_size);
254 }
255
256 const TypePtr* src_adr_type = _igvn.type(src_start)->isa_ptr();
257 const TypeVect * vt = TypeVect::make(type, lane_count);
258 Node* mm = (*mem)->memory_at(C->get_alias_index(src_adr_type));
259 Node* masked_load = new LoadVectorMaskedNode(inline_block, mm, src_start,
260 src_adr_type, vt, mask_gen);
261 transform_later(masked_load);
262
263 mm = (*mem)->memory_at(C->get_alias_index(adr_type));
264 Node* masked_store = new StoreVectorMaskedNode(inline_block, mm, dst_start,
265 masked_load, adr_type, mask_gen);
266 transform_later(masked_store);
267
268 // Convergence region for inline_block and stub_block.
269 *exit_block = new RegionNode(3);
270 transform_later(*exit_block);
271 (*exit_block)->init_req(1, inline_block);
272 *result_memory = new PhiNode(*exit_block, Type::MEMORY, adr_type);
273 transform_later(*result_memory);
274 (*result_memory)->init_req(1, masked_store);
275
276 *ctrl = stub_block;
277 }
278
279
280 Node* PhaseMacroExpand::generate_nonpositive_guard(Node** ctrl, Node* index, bool never_negative) {
281 if ((*ctrl)->is_top()) return nullptr;
282
283 if (_igvn.type(index)->higher_equal(TypeInt::POS1)) // [1,maxint]
284 return nullptr; // index is already adequately typed
285 Node* cmp_le = new CmpINode(index, intcon(0));
286 transform_later(cmp_le);
287 BoolTest::mask le_or_eq = (never_negative ? BoolTest::eq : BoolTest::le);
288 Node* bol_le = new BoolNode(cmp_le, le_or_eq);
289 transform_later(bol_le);
290 Node* is_notp = generate_guard(ctrl, bol_le, nullptr, PROB_MIN);
291
292 return is_notp;
293 }
294
295 Node* PhaseMacroExpand::mark_word_test(Node** ctrl, Node* obj, MergeMemNode* mem, uintptr_t mask_val, RegionNode* region) {
296 // Load markword and check if obj is locked
297 Node* mark = make_load_raw(nullptr, mem->memory_at(Compile::AliasIdxRaw), obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
298 Node* locked_bit = MakeConX(markWord::unlocked_value);
299 locked_bit = transform_later(new AndXNode(locked_bit, mark));
300 Node* cmp = transform_later(new CmpXNode(locked_bit, MakeConX(0)));
301 Node* is_unlocked = transform_later(new BoolNode(cmp, BoolTest::ne));
302 IfNode* iff = transform_later(new IfNode(*ctrl, is_unlocked, PROB_MAX, COUNT_UNKNOWN))->as_If();
303 Node* locked_region = transform_later(new RegionNode(3));
304 Node* mark_phi = transform_later(new PhiNode(locked_region, TypeX_X));
305
306 // Unlocked: Use bits from mark word
307 locked_region->init_req(1, transform_later(new IfTrueNode(iff)));
308 mark_phi->init_req(1, mark);
309
310 // Locked: Load prototype header from klass
311 *ctrl = transform_later(new IfFalseNode(iff));
312 // Make loads control dependent to make sure they are only executed if array is locked
313 Node* klass_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
314 Node* klass = transform_later(LoadKlassNode::make(_igvn, C->immutable_memory(), klass_adr, TypeInstPtr::KLASS, TypeInstKlassPtr::OBJECT));
315 Node* proto_adr = basic_plus_adr(top(), klass, in_bytes(Klass::prototype_header_offset()));
316 Node* proto = transform_later(LoadNode::make(_igvn, *ctrl, C->immutable_memory(), proto_adr, proto_adr->bottom_type()->is_ptr(), TypeX_X, TypeX_X->basic_type(), MemNode::unordered));
317
318 locked_region->init_req(2, *ctrl);
319 mark_phi->init_req(2, proto);
320 *ctrl = locked_region;
321
322 // Now check if mark word bits are set
323 Node* mask = MakeConX(mask_val);
324 Node* masked = transform_later(new AndXNode(mark_phi, mask));
325 cmp = transform_later(new CmpXNode(masked, mask));
326 Node* bol = transform_later(new BoolNode(cmp, BoolTest::eq));
327 return generate_fair_guard(ctrl, bol, region);
328 }
329
330 Node* PhaseMacroExpand::generate_flat_array_guard(Node** ctrl, Node* array, MergeMemNode* mem, RegionNode* region) {
331 return mark_word_test(ctrl, array, mem, markWord::flat_array_bit_in_place, region);
332 }
333
334 Node* PhaseMacroExpand::generate_null_free_array_guard(Node** ctrl, Node* array, MergeMemNode* mem, RegionNode* region) {
335 return mark_word_test(ctrl, array, mem, markWord::null_free_array_bit_in_place, region);
336 }
337
338 void PhaseMacroExpand::finish_arraycopy_call(Node* call, Node** ctrl, MergeMemNode** mem, const TypePtr* adr_type) {
339 transform_later(call);
340
341 *ctrl = new ProjNode(call,TypeFunc::Control);
342 transform_later(*ctrl);
343 Node* newmem = new ProjNode(call, TypeFunc::Memory);
344 transform_later(newmem);
345
346 uint alias_idx = C->get_alias_index(adr_type);
347 if (alias_idx != Compile::AliasIdxBot) {
348 *mem = MergeMemNode::make(*mem);
349 (*mem)->set_memory_at(alias_idx, newmem);
350 } else {
351 *mem = MergeMemNode::make(newmem);
352 }
353 transform_later(*mem);
354 }
355
356 address PhaseMacroExpand::basictype2arraycopy(BasicType t,
357 Node* src_offset,
358 Node* dest_offset,
359 bool disjoint_bases,
360 const char* &name,
361 bool dest_uninitialized) {
362 const TypeInt* src_offset_inttype = _igvn.find_int_type(src_offset);
363 const TypeInt* dest_offset_inttype = _igvn.find_int_type(dest_offset);
364
365 bool aligned = false;
366 bool disjoint = disjoint_bases;
367
368 // if the offsets are the same, we can treat the memory regions as
369 // disjoint, because either the memory regions are in different arrays,
370 // or they are identical (which we can treat as disjoint.) We can also
371 // treat a copy with a destination index less that the source index
372 // as disjoint since a low->high copy will work correctly in this case.
373 if (src_offset_inttype != nullptr && src_offset_inttype->is_con() &&
374 dest_offset_inttype != nullptr && dest_offset_inttype->is_con()) {
375 // both indices are constants
376 int s_offs = src_offset_inttype->get_con();
377 int d_offs = dest_offset_inttype->get_con();
378 int element_size = type2aelembytes(t);
379 aligned = ((arrayOopDesc::base_offset_in_bytes(t) + (uint)s_offs * element_size) % HeapWordSize == 0) &&
380 ((arrayOopDesc::base_offset_in_bytes(t) + (uint)d_offs * element_size) % HeapWordSize == 0);
381 if (s_offs >= d_offs) disjoint = true;
382 } else if (src_offset == dest_offset && src_offset != nullptr) {
383 // This can occur if the offsets are identical non-constants.
384 disjoint = true;
385 }
386
387 return StubRoutines::select_arraycopy_function(t, aligned, disjoint, name, dest_uninitialized);
388 }
389
390 #define XTOP LP64_ONLY(COMMA top())
391
392 // Generate an optimized call to arraycopy.
393 // Caller must guard against non-arrays.
394 // Caller must determine a common array basic-type for both arrays.
395 // Caller must validate offsets against array bounds.
396 // The slow_region has already collected guard failure paths
397 // (such as out of bounds length or non-conformable array types).
398 // The generated code has this shape, in general:
399 //
400 // if (length == 0) return // via zero_path
401 // slowval = -1
402 // if (types unknown) {
403 // slowval = call generic copy loop
404 // if (slowval == 0) return // via checked_path
405 // } else if (indexes in bounds) {
406 // if ((is object array) && !(array type check)) {
407 // slowval = call checked copy loop
408 // if (slowval == 0) return // via checked_path
409 // } else {
410 // call bulk copy loop
411 // return // via fast_path
412 // }
413 // }
414 // // adjust params for remaining work:
415 // if (slowval != -1) {
416 // n = -1^slowval; src_offset += n; dest_offset += n; length -= n
417 // }
418 // slow_region:
419 // call slow arraycopy(src, src_offset, dest, dest_offset, length)
420 // return // via slow_call_path
421 //
422 // This routine is used from several intrinsics: System.arraycopy,
423 // Object.clone (the array subcase), and Arrays.copyOf[Range].
424 //
425 Node* PhaseMacroExpand::generate_arraycopy(ArrayCopyNode *ac, AllocateArrayNode* alloc,
426 Node** ctrl, MergeMemNode* mem, Node** io,
427 const TypePtr* adr_type,
428 BasicType basic_elem_type,
429 Node* src, Node* src_offset,
430 Node* dest, Node* dest_offset,
431 Node* copy_length,
432 Node* dest_length,
433 bool disjoint_bases,
434 bool length_never_negative,
435 RegionNode* slow_region) {
436 if (slow_region == nullptr) {
437 slow_region = new RegionNode(1);
438 transform_later(slow_region);
439 }
440
441 bool dest_needs_zeroing = false;
442 bool acopy_to_uninitialized = false;
443 Node* init_value = nullptr;
444 Node* raw_init_value = nullptr;
445
446 // See if this is the initialization of a newly-allocated array.
447 // If so, we will take responsibility here for initializing it to zero.
448 // (Note: Because tightly_coupled_allocation performs checks on the
449 // out-edges of the dest, we need to avoid making derived pointers
450 // from it until we have checked its uses.)
451 if (ReduceBulkZeroing
452 && !(UseTLAB && ZeroTLAB) // pointless if already zeroed
453 && basic_elem_type != T_CONFLICT // avoid corner case
454 && !src->eqv_uncast(dest)
455 && alloc != nullptr
456 && _igvn.find_int_con(alloc->in(AllocateNode::ALength), 1) > 0) {
457 assert(ac->is_alloc_tightly_coupled(), "sanity");
458 // acopy to uninitialized tightly coupled allocations
459 // needs zeroing outside the copy range
460 // and the acopy itself will be to uninitialized memory
461 acopy_to_uninitialized = true;
462 if (alloc->maybe_set_complete(&_igvn)) {
463 // "You break it, you buy it."
464 InitializeNode* init = alloc->initialization();
465 assert(init->is_complete(), "we just did this");
466 init->set_complete_with_arraycopy();
467 assert(dest->is_CheckCastPP(), "sanity");
468 assert(dest->in(0)->in(0) == init, "dest pinned");
469 adr_type = TypeRawPtr::BOTTOM; // all initializations are into raw memory
470 // From this point on, every exit path is responsible for
471 // initializing any non-copied parts of the object to zero.
472 // Also, if this flag is set we make sure that arraycopy interacts properly
473 // with G1, eliding pre-barriers. See CR 6627983.
474 dest_needs_zeroing = true;
475 init_value = alloc->in(AllocateNode::InitValue);
476 raw_init_value = alloc->in(AllocateNode::RawInitValue);
477 } else {
478 // dest_need_zeroing = false;
479 }
480 } else {
481 // No zeroing elimination needed here.
482 alloc = nullptr;
483 acopy_to_uninitialized = false;
484 //dest_needs_zeroing = false;
485 }
486
487 uint alias_idx = C->get_alias_index(adr_type);
488
489 // Results are placed here:
490 enum { fast_path = 1, // normal void-returning assembly stub
491 checked_path = 2, // special assembly stub with cleanup
492 slow_call_path = 3, // something went wrong; call the VM
493 zero_path = 4, // bypass when length of copy is zero
494 bcopy_path = 5, // copy primitive array by 64-bit blocks
495 PATH_LIMIT = 6
496 };
497 RegionNode* result_region = new RegionNode(PATH_LIMIT);
498 PhiNode* result_i_o = new PhiNode(result_region, Type::ABIO);
499 PhiNode* result_memory = new PhiNode(result_region, Type::MEMORY, adr_type);
500 assert(adr_type != TypePtr::BOTTOM, "must be RawMem or a T[] slice");
501 transform_later(result_region);
502 transform_later(result_i_o);
503 transform_later(result_memory);
504
505 // The slow_control path:
506 Node* slow_control;
507 Node* slow_i_o = *io;
508 Node* slow_mem = mem->memory_at(alias_idx);
509 DEBUG_ONLY(slow_control = (Node*) badAddress);
510
511 // Checked control path:
512 Node* checked_control = top();
513 Node* checked_mem = nullptr;
514 Node* checked_i_o = nullptr;
515 Node* checked_value = nullptr;
516
517 if (basic_elem_type == T_CONFLICT) {
518 assert(!dest_needs_zeroing, "");
519 Node* cv = generate_generic_arraycopy(ctrl, &mem,
520 adr_type,
521 src, src_offset, dest, dest_offset,
522 copy_length, acopy_to_uninitialized);
523 if (cv == nullptr) cv = intcon(-1); // failure (no stub available)
524 checked_control = *ctrl;
525 checked_i_o = *io;
526 checked_mem = mem->memory_at(alias_idx);
527 checked_value = cv;
528 *ctrl = top();
529 }
530
531 Node* not_pos = generate_nonpositive_guard(ctrl, copy_length, length_never_negative);
532 if (not_pos != nullptr) {
533 Node* local_ctrl = not_pos, *local_io = *io;
534 MergeMemNode* local_mem = MergeMemNode::make(mem);
535 transform_later(local_mem);
536
537 // (6) length must not be negative.
538 if (!length_never_negative) {
539 generate_negative_guard(&local_ctrl, copy_length, slow_region);
540 }
541
542 // copy_length is 0.
543 if (dest_needs_zeroing) {
544 assert(!local_ctrl->is_top(), "no ctrl?");
545 if (copy_length->eqv_uncast(dest_length)
546 || _igvn.find_int_con(dest_length, 1) <= 0) {
547 // There is no zeroing to do. No need for a secondary raw memory barrier.
548 } else {
549 // Clear the whole thing since there are no source elements to copy.
550 generate_clear_array(local_ctrl, local_mem,
551 adr_type, dest,
552 init_value, raw_init_value,
553 basic_elem_type,
554 intcon(0), nullptr,
555 alloc->in(AllocateNode::AllocSize));
556 // Use a secondary InitializeNode as raw memory barrier.
557 // Currently it is needed only on this path since other
558 // paths have stub or runtime calls as raw memory barriers.
559 MemBarNode* mb = MemBarNode::make(C, Op_Initialize,
560 Compile::AliasIdxRaw,
561 top());
562 transform_later(mb);
563 mb->set_req(TypeFunc::Control,local_ctrl);
564 mb->set_req(TypeFunc::Memory, local_mem->memory_at(Compile::AliasIdxRaw));
565 local_ctrl = transform_later(new ProjNode(mb, TypeFunc::Control));
566 local_mem->set_memory_at(Compile::AliasIdxRaw, transform_later(new ProjNode(mb, TypeFunc::Memory)));
567
568 InitializeNode* init = mb->as_Initialize();
569 init->set_complete(&_igvn); // (there is no corresponding AllocateNode)
570 }
571 }
572
573 // Present the results of the fast call.
574 result_region->init_req(zero_path, local_ctrl);
575 result_i_o ->init_req(zero_path, local_io);
576 result_memory->init_req(zero_path, local_mem->memory_at(alias_idx));
577 }
578
579 if (!(*ctrl)->is_top() && dest_needs_zeroing) {
580 // We have to initialize the *uncopied* part of the array to zero.
581 // The copy destination is the slice dest[off..off+len]. The other slices
582 // are dest_head = dest[0..off] and dest_tail = dest[off+len..dest.length].
583 Node* dest_size = alloc->in(AllocateNode::AllocSize);
584 Node* dest_tail = transform_later( new AddINode(dest_offset, copy_length));
585
586 // If there is a head section that needs zeroing, do it now.
587 if (_igvn.find_int_con(dest_offset, -1) != 0) {
588 generate_clear_array(*ctrl, mem,
589 adr_type, dest,
590 init_value, raw_init_value,
591 basic_elem_type,
592 intcon(0), dest_offset,
593 nullptr);
594 }
595
596 // Next, perform a dynamic check on the tail length.
597 // It is often zero, and we can win big if we prove this.
598 // There are two wins: Avoid generating the ClearArray
599 // with its attendant messy index arithmetic, and upgrade
600 // the copy to a more hardware-friendly word size of 64 bits.
601 Node* tail_ctl = nullptr;
602 if (!(*ctrl)->is_top() && !dest_tail->eqv_uncast(dest_length)) {
603 Node* cmp_lt = transform_later( new CmpINode(dest_tail, dest_length) );
604 Node* bol_lt = transform_later( new BoolNode(cmp_lt, BoolTest::lt) );
605 tail_ctl = generate_slow_guard(ctrl, bol_lt, nullptr);
606 assert(tail_ctl != nullptr || !(*ctrl)->is_top(), "must be an outcome");
607 }
608
609 // At this point, let's assume there is no tail.
610 if (!(*ctrl)->is_top() && alloc != nullptr && basic_elem_type != T_OBJECT) {
611 // There is no tail. Try an upgrade to a 64-bit copy.
612 bool didit = false;
613 {
614 Node* local_ctrl = *ctrl, *local_io = *io;
615 MergeMemNode* local_mem = MergeMemNode::make(mem);
616 transform_later(local_mem);
617
618 didit = generate_block_arraycopy(&local_ctrl, &local_mem, adr_type,
619 basic_elem_type, src, src_offset,
620 dest, dest_offset, dest_size, acopy_to_uninitialized);
621 if (didit) {
622 // Present the results of the block-copying fast call.
623 result_region->init_req(bcopy_path, local_ctrl);
624 result_i_o ->init_req(bcopy_path, local_io);
625 result_memory->init_req(bcopy_path, local_mem->memory_at(alias_idx));
626 }
627 }
628 if (didit) {
629 *ctrl = top(); // no regular fast path
630 }
631 }
632
633 // Clear the tail, if any.
634 if (tail_ctl != nullptr) {
635 Node* notail_ctl = (*ctrl)->is_top() ? nullptr : *ctrl;
636 *ctrl = tail_ctl;
637 if (notail_ctl == nullptr) {
638 generate_clear_array(*ctrl, mem,
639 adr_type, dest,
640 init_value, raw_init_value,
641 basic_elem_type,
642 dest_tail, nullptr,
643 dest_size);
644 } else {
645 // Make a local merge.
646 Node* done_ctl = transform_later(new RegionNode(3));
647 Node* done_mem = transform_later(new PhiNode(done_ctl, Type::MEMORY, adr_type));
648 done_ctl->init_req(1, notail_ctl);
649 done_mem->init_req(1, mem->memory_at(alias_idx));
650 generate_clear_array(*ctrl, mem,
651 adr_type, dest,
652 init_value, raw_init_value,
653 basic_elem_type,
654 dest_tail, nullptr,
655 dest_size);
656 done_ctl->init_req(2, *ctrl);
657 done_mem->init_req(2, mem->memory_at(alias_idx));
658 *ctrl = done_ctl;
659 mem->set_memory_at(alias_idx, done_mem);
660 }
661 }
662 }
663
664 BasicType copy_type = basic_elem_type;
665 assert(basic_elem_type != T_ARRAY, "caller must fix this");
666 if (!(*ctrl)->is_top() && copy_type == T_OBJECT) {
667 // If src and dest have compatible element types, we can copy bits.
668 // Types S[] and D[] are compatible if D is a supertype of S.
669 //
670 // If they are not, we will use checked_oop_disjoint_arraycopy,
671 // which performs a fast optimistic per-oop check, and backs off
672 // further to JVM_ArrayCopy on the first per-oop check that fails.
673 // (Actually, we don't move raw bits only; the GC requires card marks.)
674
675 // We don't need a subtype check for validated copies and Object[].clone()
676 bool skip_subtype_check = ac->is_arraycopy_validated() || ac->is_copyof_validated() ||
677 ac->is_copyofrange_validated() || ac->is_clone_oop_array();
678 if (!skip_subtype_check) {
679 // Get the klass* for both src and dest
680 Node* src_klass = ac->in(ArrayCopyNode::SrcKlass);
681 Node* dest_klass = ac->in(ArrayCopyNode::DestKlass);
682
683 assert(src_klass != nullptr && dest_klass != nullptr, "should have klasses");
684
685 // Generate the subtype check.
686 // This might fold up statically, or then again it might not.
687 //
688 // Non-static example: Copying List<String>.elements to a new String[].
689 // The backing store for a List<String> is always an Object[],
690 // but its elements are always type String, if the generic types
691 // are correct at the source level.
692 //
693 // Test S[] against D[], not S against D, because (probably)
694 // the secondary supertype cache is less busy for S[] than S.
695 // This usually only matters when D is an interface.
696 Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, _igvn, nullptr, -1);
697 // Plug failing path into checked_oop_disjoint_arraycopy
698 if (not_subtype_ctrl != top()) {
699 Node* local_ctrl = not_subtype_ctrl;
700 MergeMemNode* local_mem = MergeMemNode::make(mem);
701 transform_later(local_mem);
702
703 // (At this point we can assume disjoint_bases, since types differ.)
704 int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
705 Node* p1 = basic_plus_adr(top(), dest_klass, ek_offset);
706 Node* n1 = LoadKlassNode::make(_igvn, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
707 Node* dest_elem_klass = transform_later(n1);
708 Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
709 adr_type,
710 dest_elem_klass,
711 src, src_offset, dest, dest_offset,
712 ConvI2X(copy_length), acopy_to_uninitialized);
713 if (cv == nullptr) cv = intcon(-1); // failure (no stub available)
714 checked_control = local_ctrl;
715 checked_i_o = *io;
716 checked_mem = local_mem->memory_at(alias_idx);
717 checked_value = cv;
718 }
719 }
720 // At this point we know we do not need type checks on oop stores.
721
722 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
723 if (!bs->array_copy_requires_gc_barriers(alloc != nullptr, copy_type, false, false, BarrierSetC2::Expansion)) {
724 // If we do not need gc barriers, copy using the jint or jlong stub.
725 copy_type = LP64_ONLY(UseCompressedOops ? T_INT : T_LONG) NOT_LP64(T_INT);
726 assert(type2aelembytes(basic_elem_type) == type2aelembytes(copy_type),
727 "sizes agree");
728 }
729 }
730
731 if (!(*ctrl)->is_top()) {
732 // Generate the fast path, if possible.
733 Node* local_ctrl = *ctrl;
734 MergeMemNode* local_mem = MergeMemNode::make(mem);
735 transform_later(local_mem);
736 generate_unchecked_arraycopy(&local_ctrl, &local_mem,
737 adr_type, copy_type, disjoint_bases,
738 src, src_offset, dest, dest_offset,
739 ConvI2X(copy_length), acopy_to_uninitialized);
740
741 // Present the results of the fast call.
742 result_region->init_req(fast_path, local_ctrl);
743 result_i_o ->init_req(fast_path, *io);
744 result_memory->init_req(fast_path, local_mem->memory_at(alias_idx));
745 }
746
747 // Here are all the slow paths up to this point, in one bundle:
748 assert(slow_region != nullptr, "allocated on entry");
749 slow_control = slow_region;
750 DEBUG_ONLY(slow_region = (RegionNode*)badAddress);
751
752 *ctrl = checked_control;
753 if (!(*ctrl)->is_top()) {
754 // Clean up after the checked call.
755 // The returned value is either 0 or -1^K,
756 // where K = number of partially transferred array elements.
757 Node* cmp = new CmpINode(checked_value, intcon(0));
758 transform_later(cmp);
759 Node* bol = new BoolNode(cmp, BoolTest::eq);
760 transform_later(bol);
761 IfNode* iff = new IfNode(*ctrl, bol, PROB_MAX, COUNT_UNKNOWN);
762 transform_later(iff);
763
764 // If it is 0, we are done, so transfer to the end.
765 Node* checks_done = new IfTrueNode(iff);
766 transform_later(checks_done);
767 result_region->init_req(checked_path, checks_done);
768 result_i_o ->init_req(checked_path, checked_i_o);
769 result_memory->init_req(checked_path, checked_mem);
770
771 // If it is not zero, merge into the slow call.
772 *ctrl = new IfFalseNode(iff);
773 transform_later(*ctrl);
774 RegionNode* slow_reg2 = new RegionNode(3);
775 PhiNode* slow_i_o2 = new PhiNode(slow_reg2, Type::ABIO);
776 PhiNode* slow_mem2 = new PhiNode(slow_reg2, Type::MEMORY, adr_type);
777 transform_later(slow_reg2);
778 transform_later(slow_i_o2);
779 transform_later(slow_mem2);
780 slow_reg2 ->init_req(1, slow_control);
781 slow_i_o2 ->init_req(1, slow_i_o);
782 slow_mem2 ->init_req(1, slow_mem);
783 slow_reg2 ->init_req(2, *ctrl);
784 slow_i_o2 ->init_req(2, checked_i_o);
785 slow_mem2 ->init_req(2, checked_mem);
786
787 slow_control = slow_reg2;
788 slow_i_o = slow_i_o2;
789 slow_mem = slow_mem2;
790
791 if (alloc != nullptr) {
792 // We'll restart from the very beginning, after zeroing the whole thing.
793 // This can cause double writes, but that's OK since dest is brand new.
794 // So we ignore the low 31 bits of the value returned from the stub.
795 } else {
796 // We must continue the copy exactly where it failed, or else
797 // another thread might see the wrong number of writes to dest.
798 Node* checked_offset = new XorINode(checked_value, intcon(-1));
799 Node* slow_offset = new PhiNode(slow_reg2, TypeInt::INT);
800 transform_later(checked_offset);
801 transform_later(slow_offset);
802 slow_offset->init_req(1, intcon(0));
803 slow_offset->init_req(2, checked_offset);
804
805 // Adjust the arguments by the conditionally incoming offset.
806 Node* src_off_plus = new AddINode(src_offset, slow_offset);
807 transform_later(src_off_plus);
808 Node* dest_off_plus = new AddINode(dest_offset, slow_offset);
809 transform_later(dest_off_plus);
810 Node* length_minus = new SubINode(copy_length, slow_offset);
811 transform_later(length_minus);
812
813 // Tweak the node variables to adjust the code produced below:
814 src_offset = src_off_plus;
815 dest_offset = dest_off_plus;
816 copy_length = length_minus;
817 }
818 }
819 *ctrl = slow_control;
820 if (!(*ctrl)->is_top()) {
821 Node* local_ctrl = *ctrl, *local_io = slow_i_o;
822 MergeMemNode* local_mem = MergeMemNode::make(mem);
823 transform_later(local_mem);
824
825 // Generate the slow path, if needed.
826 local_mem->set_memory_at(alias_idx, slow_mem);
827
828 if (dest_needs_zeroing) {
829 generate_clear_array(local_ctrl, local_mem,
830 adr_type, dest,
831 init_value, raw_init_value,
832 basic_elem_type,
833 intcon(0), nullptr,
834 alloc->in(AllocateNode::AllocSize));
835 }
836
837 local_mem = generate_slow_arraycopy(ac,
838 &local_ctrl, local_mem, &local_io,
839 adr_type,
840 src, src_offset, dest, dest_offset,
841 copy_length, /*dest_uninitialized*/false);
842
843 result_region->init_req(slow_call_path, local_ctrl);
844 result_i_o ->init_req(slow_call_path, local_io);
845 result_memory->init_req(slow_call_path, local_mem->memory_at(alias_idx));
846 } else {
847 ShouldNotReachHere(); // no call to generate_slow_arraycopy:
848 // projections were not extracted
849 }
850
851 // Remove unused edges.
852 for (uint i = 1; i < result_region->req(); i++) {
853 if (result_region->in(i) == nullptr) {
854 result_region->init_req(i, top());
855 }
856 }
857
858 // Finished; return the combined state.
859 *ctrl = result_region;
860 *io = result_i_o;
861 mem->set_memory_at(alias_idx, result_memory);
862
863 // mem no longer guaranteed to stay a MergeMemNode
864 Node* out_mem = mem;
865 DEBUG_ONLY(mem = nullptr);
866
867 // The memory edges above are precise in order to model effects around
868 // array copies accurately to allow value numbering of field loads around
869 // arraycopy. Such field loads, both before and after, are common in Java
870 // collections and similar classes involving header/array data structures.
871 //
872 // But with low number of register or when some registers are used or killed
873 // by arraycopy calls it causes registers spilling on stack. See 6544710.
874 // The next memory barrier is added to avoid it. If the arraycopy can be
875 // optimized away (which it can, sometimes) then we can manually remove
876 // the membar also.
877 //
878 // Do not let reads from the cloned object float above the arraycopy.
879 if (alloc != nullptr && !alloc->initialization()->does_not_escape()) {
880 // Do not let stores that initialize this object be reordered with
881 // a subsequent store that would make this object accessible by
882 // other threads.
883 assert(ac->_dest_type == TypeOopPtr::BOTTOM, "non escaping destination shouldn't have narrow slice");
884 insert_mem_bar(ctrl, &out_mem, Op_MemBarStoreStore, Compile::AliasIdxBot);
885 } else {
886 int mem_bar_alias_idx = Compile::AliasIdxBot;
887 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
888 // The graph was transformed under the assumption the ArrayCopy node only had an effect on a narrow slice. We can't
889 // insert a wide membar now that it's being expanded: a load that uses the input memory state of the ArrayCopy
890 // could then become anti dependent on the membar when it was not anti dependent on the ArrayCopy leading to a
891 // broken graph.
892 mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
893 }
894 insert_mem_bar(ctrl, &out_mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
895 }
896
897 assert((*ctrl)->is_Proj(), "MemBar control projection");
898 assert((*ctrl)->in(0)->isa_MemBar(), "MemBar node");
899 (*ctrl)->in(0)->isa_MemBar()->set_trailing_expanded_array_copy();
900
901 _igvn.replace_node(_callprojs->fallthrough_memproj, out_mem);
902 if (_callprojs->fallthrough_ioproj != nullptr) {
903 _igvn.replace_node(_callprojs->fallthrough_ioproj, *io);
904 }
905 _igvn.replace_node(_callprojs->fallthrough_catchproj, *ctrl);
906
907 #ifdef ASSERT
908 const TypeOopPtr* dest_t = _igvn.type(dest)->is_oopptr();
909 if (dest_t->is_known_instance()) {
910 ArrayCopyNode* ac = nullptr;
911 assert(ArrayCopyNode::may_modify(dest_t, (*ctrl)->in(0)->as_MemBar(), &_igvn, ac), "dependency on arraycopy lost");
912 assert(ac == nullptr, "no arraycopy anymore");
913 }
914 #endif
915
916 return out_mem;
917 }
918
919 // Helper for initialization of arrays, creating a ClearArray.
920 // It writes zero bits in [start..end), within the body of an array object.
921 // The memory effects are all chained onto the 'adr_type' alias category.
922 //
923 // Since the object is otherwise uninitialized, we are free
924 // to put a little "slop" around the edges of the cleared area,
925 // as long as it does not go back into the array's header,
926 // or beyond the array end within the heap.
927 //
928 // The lower edge can be rounded down to the nearest jint and the
929 // upper edge can be rounded up to the nearest MinObjAlignmentInBytes.
930 //
931 // Arguments:
932 // adr_type memory slice where writes are generated
933 // dest oop of the destination array
934 // basic_elem_type element type of the destination
935 // slice_idx array index of first element to store
936 // slice_len number of elements to store (or null)
937 // dest_size total size in bytes of the array object
938 //
939 // Exactly one of slice_len or dest_size must be non-null.
940 // If dest_size is non-null, zeroing extends to the end of the object.
941 // If slice_len is non-null, the slice_idx value must be a constant.
942 void PhaseMacroExpand::generate_clear_array(Node* ctrl, MergeMemNode* merge_mem,
943 const TypePtr* adr_type,
944 Node* dest,
945 Node* val,
946 Node* raw_val,
947 BasicType basic_elem_type,
948 Node* slice_idx,
949 Node* slice_len,
950 Node* dest_size) {
951 // one or the other but not both of slice_len and dest_size:
952 assert((slice_len != nullptr? 1: 0) + (dest_size != nullptr? 1: 0) == 1, "");
953 if (slice_len == nullptr) slice_len = top();
954 if (dest_size == nullptr) dest_size = top();
955
956 uint alias_idx = C->get_alias_index(adr_type);
957
958 // operate on this memory slice:
959 Node* mem = merge_mem->memory_at(alias_idx); // memory slice to operate on
960
961 // scaling and rounding of indexes:
962 int scale = exact_log2(type2aelembytes(basic_elem_type));
963 int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
964 int clear_low = (-1 << scale) & (BytesPerInt - 1);
965 int bump_bit = (-1 << scale) & BytesPerInt;
966
967 // determine constant starts and ends
968 const intptr_t BIG_NEG = -128;
969 assert(BIG_NEG + 2*abase < 0, "neg enough");
970 intptr_t slice_idx_con = (intptr_t) _igvn.find_int_con(slice_idx, BIG_NEG);
971 intptr_t slice_len_con = (intptr_t) _igvn.find_int_con(slice_len, BIG_NEG);
972 if (slice_len_con == 0) {
973 return; // nothing to do here
974 }
975 intptr_t start_con = (abase + (slice_idx_con << scale)) & ~clear_low;
976 intptr_t end_con = _igvn.find_intptr_t_con(dest_size, -1);
977 if (slice_idx_con >= 0 && slice_len_con >= 0) {
978 assert(end_con < 0, "not two cons");
979 end_con = align_up(abase + ((slice_idx_con + slice_len_con) << scale),
980 BytesPerLong);
981 }
982
983 if (start_con >= 0 && end_con >= 0) {
984 // Constant start and end. Simple.
985 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
986 start_con, end_con, false, &_igvn);
987 } else if (start_con >= 0 && dest_size != top()) {
988 // Constant start, pre-rounded end after the tail of the array.
989 Node* end = dest_size;
990 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
991 start_con, end, false, &_igvn);
992 } else if (start_con >= 0 && slice_len != top()) {
993 // Constant start, non-constant end. End needs rounding up.
994 // End offset = round_up(abase + ((slice_idx_con + slice_len) << scale), 8)
995 intptr_t end_base = abase + (slice_idx_con << scale);
996 int end_round = (-1 << scale) & (BytesPerLong - 1);
997 Node* end = ConvI2X(slice_len);
998 if (scale != 0)
999 end = transform_later(new LShiftXNode(end, intcon(scale) ));
1000 end_base += end_round;
1001 end = transform_later(new AddXNode(end, MakeConX(end_base)) );
1002 end = transform_later(new AndXNode(end, MakeConX(~end_round)) );
1003 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
1004 start_con, end, false, &_igvn);
1005 } else if (start_con < 0 && dest_size != top()) {
1006 // Non-constant start, pre-rounded end after the tail of the array.
1007 // This is almost certainly a "round-to-end" operation.
1008 Node* start = slice_idx;
1009 start = ConvI2X(start);
1010 if (scale != 0)
1011 start = transform_later(new LShiftXNode( start, intcon(scale) ));
1012 start = transform_later(new AddXNode(start, MakeConX(abase)) );
1013 if ((bump_bit | clear_low) != 0) {
1014 int to_clear = (bump_bit | clear_low);
1015 // Align up mod 8, then store a jint zero unconditionally
1016 // just before the mod-8 boundary.
1017 if (((abase + bump_bit) & ~to_clear) - bump_bit
1018 < arrayOopDesc::length_offset_in_bytes() + BytesPerInt) {
1019 bump_bit = 0;
1020 assert((abase & to_clear) == 0, "array base must be long-aligned");
1021 } else {
1022 // Bump 'start' up to (or past) the next jint boundary:
1023 start = transform_later( new AddXNode(start, MakeConX(bump_bit)) );
1024 assert((abase & clear_low) == 0, "array base must be int-aligned");
1025 }
1026 // Round bumped 'start' down to jlong boundary in body of array.
1027 start = transform_later(new AndXNode(start, MakeConX(~to_clear)) );
1028 if (bump_bit != 0) {
1029 // Store a zero to the immediately preceding jint:
1030 Node* x1 = transform_later(new AddXNode(start, MakeConX(-bump_bit)) );
1031 Node* p1 = basic_plus_adr(dest, x1);
1032 if (val == nullptr) {
1033 assert(raw_val == nullptr, "val may not be null");
1034 mem = StoreNode::make(_igvn, ctrl, mem, p1, adr_type, intcon(0), T_INT, MemNode::unordered);
1035 } else {
1036 assert(_igvn.type(val)->isa_narrowoop(), "should be narrow oop");
1037 mem = new StoreNNode(ctrl, mem, p1, adr_type, val, MemNode::unordered);
1038 }
1039 mem = transform_later(mem);
1040 }
1041 }
1042 Node* end = dest_size; // pre-rounded
1043 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, raw_val,
1044 start, end, false, &_igvn);
1045 } else {
1046 // Non-constant start, unrounded non-constant end.
1047 // (Nobody zeroes a random midsection of an array using this routine.)
1048 ShouldNotReachHere(); // fix caller
1049 }
1050
1051 // Done.
1052 merge_mem->set_memory_at(alias_idx, mem);
1053 }
1054
1055 bool PhaseMacroExpand::generate_block_arraycopy(Node** ctrl, MergeMemNode** mem,
1056 const TypePtr* adr_type,
1057 BasicType basic_elem_type,
1058 Node* src, Node* src_offset,
1059 Node* dest, Node* dest_offset,
1060 Node* dest_size, bool dest_uninitialized) {
1061 // See if there is an advantage from block transfer.
1062 int scale = exact_log2(type2aelembytes(basic_elem_type));
1063 if (scale >= LogBytesPerLong)
1064 return false; // it is already a block transfer
1065
1066 // Look at the alignment of the starting offsets.
1067 int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
1068
1069 intptr_t src_off_con = (intptr_t) _igvn.find_int_con(src_offset, -1);
1070 intptr_t dest_off_con = (intptr_t) _igvn.find_int_con(dest_offset, -1);
1071 if (src_off_con < 0 || dest_off_con < 0) {
1072 // At present, we can only understand constants.
1073 return false;
1074 }
1075
1076 intptr_t src_off = abase + (src_off_con << scale);
1077 intptr_t dest_off = abase + (dest_off_con << scale);
1078
1079 if (((src_off | dest_off) & (BytesPerLong-1)) != 0) {
1080 // Non-aligned; too bad.
1081 // One more chance: Pick off an initial 32-bit word.
1082 // This is a common case, since abase can be odd mod 8.
1083 if (((src_off | dest_off) & (BytesPerLong-1)) == BytesPerInt &&
1084 ((src_off ^ dest_off) & (BytesPerLong-1)) == 0) {
1085 Node* sptr = basic_plus_adr(src, src_off);
1086 Node* dptr = basic_plus_adr(dest, dest_off);
1087 const TypePtr* s_adr_type = _igvn.type(sptr)->is_ptr();
1088 assert(s_adr_type->isa_aryptr(), "impossible slice");
1089 uint s_alias_idx = C->get_alias_index(s_adr_type);
1090 uint d_alias_idx = C->get_alias_index(adr_type);
1091 bool is_mismatched = (basic_elem_type != T_INT);
1092 Node* sval = transform_later(
1093 LoadNode::make(_igvn, *ctrl, (*mem)->memory_at(s_alias_idx), sptr, s_adr_type,
1094 TypeInt::INT, T_INT, MemNode::unordered, LoadNode::DependsOnlyOnTest,
1095 false /*require_atomic_access*/, false /*unaligned*/, is_mismatched));
1096 Node* st = transform_later(
1097 StoreNode::make(_igvn, *ctrl, (*mem)->memory_at(d_alias_idx), dptr, adr_type,
1098 sval, T_INT, MemNode::unordered));
1099 if (is_mismatched) {
1100 st->as_Store()->set_mismatched_access();
1101 }
1102 (*mem)->set_memory_at(d_alias_idx, st);
1103 src_off += BytesPerInt;
1104 dest_off += BytesPerInt;
1105 } else {
1106 return false;
1107 }
1108 }
1109 assert(src_off % BytesPerLong == 0, "");
1110 assert(dest_off % BytesPerLong == 0, "");
1111
1112 // Do this copy by giant steps.
1113 Node* sptr = basic_plus_adr(src, src_off);
1114 Node* dptr = basic_plus_adr(dest, dest_off);
1115 Node* countx = dest_size;
1116 countx = transform_later(new SubXNode(countx, MakeConX(dest_off)));
1117 countx = transform_later(new URShiftXNode(countx, intcon(LogBytesPerLong)));
1118
1119 bool disjoint_bases = true; // since alloc isn't null
1120 generate_unchecked_arraycopy(ctrl, mem,
1121 adr_type, T_LONG, disjoint_bases,
1122 sptr, nullptr, dptr, nullptr, countx, dest_uninitialized);
1123
1124 return true;
1125 }
1126
1127 // Helper function; generates code for the slow case.
1128 // We make a call to a runtime method which emulates the native method,
1129 // but without the native wrapper overhead.
1130 MergeMemNode* PhaseMacroExpand::generate_slow_arraycopy(ArrayCopyNode *ac,
1131 Node** ctrl, Node* mem, Node** io,
1132 const TypePtr* adr_type,
1133 Node* src, Node* src_offset,
1134 Node* dest, Node* dest_offset,
1135 Node* copy_length, bool dest_uninitialized) {
1136 assert(!dest_uninitialized, "Invariant");
1137
1138 const TypeFunc* call_type = OptoRuntime::slow_arraycopy_Type();
1139 CallNode* call = new CallStaticJavaNode(call_type, OptoRuntime::slow_arraycopy_Java(),
1140 "slow_arraycopy", TypePtr::BOTTOM);
1141
1142 call->init_req(TypeFunc::Control, *ctrl);
1143 call->init_req(TypeFunc::I_O , *io);
1144 call->init_req(TypeFunc::Memory , mem);
1145 call->init_req(TypeFunc::ReturnAdr, top());
1146 call->init_req(TypeFunc::FramePtr, top());
1147 call->init_req(TypeFunc::Parms+0, src);
1148 call->init_req(TypeFunc::Parms+1, src_offset);
1149 call->init_req(TypeFunc::Parms+2, dest);
1150 call->init_req(TypeFunc::Parms+3, dest_offset);
1151 call->init_req(TypeFunc::Parms+4, copy_length);
1152 call->copy_call_debug_info(&_igvn, ac);
1153
1154 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1155 _igvn.replace_node(ac, call);
1156 transform_later(call);
1157
1158 _callprojs = call->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
1159 *ctrl = _callprojs->fallthrough_catchproj->clone();
1160 transform_later(*ctrl);
1161
1162 Node* m = _callprojs->fallthrough_memproj->clone();
1163 transform_later(m);
1164
1165 uint alias_idx = C->get_alias_index(adr_type);
1166 MergeMemNode* out_mem;
1167 if (alias_idx != Compile::AliasIdxBot) {
1168 out_mem = MergeMemNode::make(mem);
1169 out_mem->set_memory_at(alias_idx, m);
1170 } else {
1171 out_mem = MergeMemNode::make(m);
1172 }
1173 transform_later(out_mem);
1174
1175 // When src is negative and arraycopy is before an infinite loop,_callprojs.fallthrough_ioproj
1176 // could be nullptr. Skip clone and update nullptr fallthrough_ioproj.
1177 if (_callprojs->fallthrough_ioproj != nullptr) {
1178 *io = _callprojs->fallthrough_ioproj->clone();
1179 transform_later(*io);
1180 } else {
1181 *io = nullptr;
1182 }
1183
1184 return out_mem;
1185 }
1186
1187 // Helper function; generates code for cases requiring runtime checks.
1188 Node* PhaseMacroExpand::generate_checkcast_arraycopy(Node** ctrl, MergeMemNode** mem,
1189 const TypePtr* adr_type,
1190 Node* dest_elem_klass,
1191 Node* src, Node* src_offset,
1192 Node* dest, Node* dest_offset,
1193 Node* copy_length, bool dest_uninitialized) {
1194 if ((*ctrl)->is_top()) return nullptr;
1195
1196 address copyfunc_addr = StubRoutines::checkcast_arraycopy(dest_uninitialized);
1197 if (copyfunc_addr == nullptr) { // Stub was not generated, go slow path.
1198 return nullptr;
1199 }
1200
1201 // Pick out the parameters required to perform a store-check
1202 // for the target array. This is an optimistic check. It will
1203 // look in each non-null element's class, at the desired klass's
1204 // super_check_offset, for the desired klass.
1205 int sco_offset = in_bytes(Klass::super_check_offset_offset());
1206 Node* p3 = basic_plus_adr(top(), dest_elem_klass, sco_offset);
1207 Node* n3 = new LoadINode(nullptr, *mem /*memory(p3)*/, p3, _igvn.type(p3)->is_ptr(), TypeInt::INT, MemNode::unordered);
1208 Node* check_offset = ConvI2X(transform_later(n3));
1209 Node* check_value = dest_elem_klass;
1210
1211 Node* src_start = array_element_address(src, src_offset, T_OBJECT);
1212 Node* dest_start = array_element_address(dest, dest_offset, T_OBJECT);
1213
1214 const TypeFunc* call_type = OptoRuntime::checkcast_arraycopy_Type();
1215 Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "checkcast_arraycopy", adr_type,
1216 src_start, dest_start, copy_length XTOP, check_offset XTOP, check_value);
1217
1218 finish_arraycopy_call(call, ctrl, mem, adr_type);
1219
1220 Node* proj = new ProjNode(call, TypeFunc::Parms);
1221 transform_later(proj);
1222
1223 return proj;
1224 }
1225
1226 // Helper function; generates code for cases requiring runtime checks.
1227 Node* PhaseMacroExpand::generate_generic_arraycopy(Node** ctrl, MergeMemNode** mem,
1228 const TypePtr* adr_type,
1229 Node* src, Node* src_offset,
1230 Node* dest, Node* dest_offset,
1231 Node* copy_length, bool dest_uninitialized) {
1232 if ((*ctrl)->is_top()) return nullptr;
1233 assert(!dest_uninitialized, "Invariant");
1234
1235 address copyfunc_addr = StubRoutines::generic_arraycopy();
1236 if (copyfunc_addr == nullptr) { // Stub was not generated, go slow path.
1237 return nullptr;
1238 }
1239
1240 const TypeFunc* call_type = OptoRuntime::generic_arraycopy_Type();
1241 Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "generic_arraycopy", adr_type,
1242 src, src_offset, dest, dest_offset, copy_length);
1243
1244 finish_arraycopy_call(call, ctrl, mem, adr_type);
1245
1246 Node* proj = new ProjNode(call, TypeFunc::Parms);
1247 transform_later(proj);
1248
1249 return proj;
1250 }
1251
1252 // Helper function; generates the fast out-of-line call to an arraycopy stub.
1253 void PhaseMacroExpand::generate_unchecked_arraycopy(Node** ctrl, MergeMemNode** mem,
1254 const TypePtr* adr_type,
1255 BasicType basic_elem_type,
1256 bool disjoint_bases,
1257 Node* src, Node* src_offset,
1258 Node* dest, Node* dest_offset,
1259 Node* copy_length, bool dest_uninitialized) {
1260 if ((*ctrl)->is_top()) {
1261 return;
1262 }
1263
1264 Node* src_start = src;
1265 Node* dest_start = dest;
1266 if (src_offset != nullptr || dest_offset != nullptr) {
1267 src_start = array_element_address(src, src_offset, basic_elem_type);
1268 dest_start = array_element_address(dest, dest_offset, basic_elem_type);
1269 }
1270
1271 // Figure out which arraycopy runtime method to call.
1272 const char* copyfunc_name = "arraycopy";
1273 address copyfunc_addr =
1274 basictype2arraycopy(basic_elem_type, src_offset, dest_offset,
1275 disjoint_bases, copyfunc_name, dest_uninitialized);
1276
1277 Node* result_memory = nullptr;
1278 RegionNode* exit_block = nullptr;
1279 if (ArrayOperationPartialInlineSize > 0 && is_subword_type(basic_elem_type) &&
1280 Matcher::vector_width_in_bytes(basic_elem_type) >= 16) {
1281 generate_partial_inlining_block(ctrl, mem, adr_type, &exit_block, &result_memory,
1282 copy_length, src_start, dest_start, basic_elem_type);
1283 }
1284
1285 const TypeFunc* call_type = OptoRuntime::fast_arraycopy_Type();
1286 Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, copyfunc_name, adr_type,
1287 src_start, dest_start, copy_length XTOP);
1288
1289 finish_arraycopy_call(call, ctrl, mem, adr_type);
1290
1291 // Connecting remaining edges for exit_block coming from stub_block.
1292 if (exit_block) {
1293 exit_block->init_req(2, *ctrl);
1294
1295 // Memory edge corresponding to stub_region.
1296 result_memory->init_req(2, *mem);
1297
1298 uint alias_idx = C->get_alias_index(adr_type);
1299 if (alias_idx != Compile::AliasIdxBot) {
1300 *mem = MergeMemNode::make(*mem);
1301 (*mem)->set_memory_at(alias_idx, result_memory);
1302 } else {
1303 *mem = MergeMemNode::make(result_memory);
1304 }
1305 transform_later(*mem);
1306 *ctrl = exit_block;
1307 }
1308 }
1309
1310 const TypePtr* PhaseMacroExpand::adjust_for_flat_array(const TypeAryPtr* top_dest, Node*& src_offset,
1311 Node*& dest_offset, Node*& length, BasicType& dest_elem,
1312 Node*& dest_length) {
1313 #ifdef ASSERT
1314 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1315 bool needs_barriers = top_dest->elem()->inline_klass()->contains_oops() &&
1316 bs->array_copy_requires_gc_barriers(dest_length != nullptr, T_OBJECT, false, false, BarrierSetC2::Optimization);
1317 assert(!needs_barriers || StressReflectiveCode, "Flat arracopy would require GC barriers");
1318 #endif
1319 int elem_size = top_dest->flat_elem_size();
1320 if (elem_size >= 8) {
1321 if (elem_size > 8) {
1322 // treat as array of long but scale length, src offset and dest offset
1323 assert((elem_size % 8) == 0, "not a power of 2?");
1324 int factor = elem_size / 8;
1325 length = transform_later(new MulINode(length, intcon(factor)));
1326 src_offset = transform_later(new MulINode(src_offset, intcon(factor)));
1327 dest_offset = transform_later(new MulINode(dest_offset, intcon(factor)));
1328 if (dest_length != nullptr) {
1329 dest_length = transform_later(new MulINode(dest_length, intcon(factor)));
1330 }
1331 elem_size = 8;
1332 }
1333 dest_elem = T_LONG;
1334 } else if (elem_size == 4) {
1335 dest_elem = T_INT;
1336 } else if (elem_size == 2) {
1337 dest_elem = T_CHAR;
1338 } else if (elem_size == 1) {
1339 dest_elem = T_BYTE;
1340 } else {
1341 ShouldNotReachHere();
1342 }
1343 return TypeRawPtr::BOTTOM;
1344 }
1345
1346 #undef XTOP
1347
1348 void PhaseMacroExpand::expand_arraycopy_node(ArrayCopyNode *ac) {
1349 Node* ctrl = ac->in(TypeFunc::Control);
1350 Node* io = ac->in(TypeFunc::I_O);
1351 Node* src = ac->in(ArrayCopyNode::Src);
1352 Node* src_offset = ac->in(ArrayCopyNode::SrcPos);
1353 Node* dest = ac->in(ArrayCopyNode::Dest);
1354 Node* dest_offset = ac->in(ArrayCopyNode::DestPos);
1355 Node* length = ac->in(ArrayCopyNode::Length);
1356 MergeMemNode* merge_mem = nullptr;
1357
1358 if (ac->is_clonebasic()) {
1359 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1360 bs->clone_at_expansion(this, ac);
1361 return;
1362 } else if (ac->is_copyof() || ac->is_copyofrange() || ac->is_clone_oop_array()) {
1363 const Type* src_type = _igvn.type(src);
1364 const Type* dest_type = _igvn.type(dest);
1365 const TypeAryPtr* top_src = src_type->isa_aryptr();
1366 // Note: The destination could have type Object (i.e. non-array) when directly invoking the protected method
1367 // Object::clone() with reflection on a declared Object that is an array at runtime. top_dest is then null.
1368 const TypeAryPtr* top_dest = dest_type->isa_aryptr();
1369 BasicType dest_elem = T_OBJECT;
1370 if (top_dest != nullptr && top_dest->elem() != Type::BOTTOM) {
1371 dest_elem = top_dest->elem()->array_element_basic_type();
1372 }
1373 if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
1374
1375 if (top_src != nullptr && top_src->is_flat()) {
1376 // If src is flat, dest is guaranteed to be flat as well
1377 top_dest = top_src;
1378 }
1379
1380 AllocateArrayNode* alloc = nullptr;
1381 Node* dest_length = nullptr;
1382 if (ac->is_alloc_tightly_coupled()) {
1383 alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1384 assert(alloc != nullptr, "expect alloc");
1385 dest_length = alloc->in(AllocateNode::ALength);
1386 }
1387
1388 Node* mem = ac->in(TypeFunc::Memory);
1389 const TypePtr* adr_type = nullptr;
1390 if (top_dest != nullptr && top_dest->is_flat()) {
1391 assert(dest_length != nullptr || StressReflectiveCode, "must be tightly coupled");
1392 // Copy to a flat array modifies multiple memory slices. Conservatively insert a barrier
1393 // on all slices to prevent writes into the source from floating below the arraycopy.
1394 int mem_bar_alias_idx = Compile::AliasIdxBot;
1395 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1396 mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
1397 }
1398 insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
1399 adr_type = adjust_for_flat_array(top_dest, src_offset, dest_offset, length, dest_elem, dest_length);
1400 } else {
1401 adr_type = dest_type->is_oopptr()->add_offset(Type::OffsetBot);
1402 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1403 adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
1404 }
1405 if (ac->_src_type != ac->_dest_type) {
1406 adr_type = TypeRawPtr::BOTTOM;
1407 }
1408 }
1409 merge_mem = MergeMemNode::make(mem);
1410 transform_later(merge_mem);
1411
1412 generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1413 adr_type, dest_elem,
1414 src, src_offset, dest, dest_offset, length,
1415 dest_length,
1416 true, ac->has_negative_length_guard());
1417
1418 return;
1419 }
1420
1421 AllocateArrayNode* alloc = nullptr;
1422 if (ac->is_alloc_tightly_coupled()) {
1423 alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1424 assert(alloc != nullptr, "expect alloc");
1425 }
1426
1427 assert(ac->is_arraycopy() || ac->is_arraycopy_validated(), "should be an arraycopy");
1428
1429 // Compile time checks. If any of these checks cannot be verified at compile time,
1430 // we do not make a fast path for this call. Instead, we let the call remain as it
1431 // is. The checks we choose to mandate at compile time are:
1432 //
1433 // (1) src and dest are arrays.
1434 const Type* src_type = src->Value(&_igvn);
1435 const Type* dest_type = dest->Value(&_igvn);
1436 const TypeAryPtr* top_src = src_type->isa_aryptr();
1437 const TypeAryPtr* top_dest = dest_type->isa_aryptr();
1438
1439 BasicType src_elem = T_CONFLICT;
1440 BasicType dest_elem = T_CONFLICT;
1441
1442 if (top_src != nullptr && top_src->elem() != Type::BOTTOM) {
1443 src_elem = top_src->elem()->array_element_basic_type();
1444 }
1445 if (top_dest != nullptr && top_dest->elem() != Type::BOTTOM) {
1446 dest_elem = top_dest->elem()->array_element_basic_type();
1447 }
1448 if (is_reference_type(src_elem, true)) src_elem = T_OBJECT;
1449 if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
1450
1451 if (ac->is_arraycopy_validated() && dest_elem != T_CONFLICT && src_elem == T_CONFLICT) {
1452 src_elem = dest_elem;
1453 }
1454
1455 if (src_elem == T_CONFLICT || dest_elem == T_CONFLICT) {
1456 // Conservatively insert a memory barrier on all memory slices.
1457 // Do not let writes into the source float below the arraycopy.
1458 {
1459 Node* mem = ac->in(TypeFunc::Memory);
1460 insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1461
1462 merge_mem = MergeMemNode::make(mem);
1463 transform_later(merge_mem);
1464 }
1465
1466 // Call StubRoutines::generic_arraycopy stub.
1467 generate_arraycopy(ac, nullptr, &ctrl, merge_mem, &io,
1468 TypeRawPtr::BOTTOM, T_CONFLICT,
1469 src, src_offset, dest, dest_offset, length,
1470 nullptr,
1471 // If a negative length guard was generated for the ArrayCopyNode,
1472 // the length of the array can never be negative.
1473 false, ac->has_negative_length_guard());
1474 return;
1475 }
1476
1477 assert(!ac->is_arraycopy_validated() || (src_elem == dest_elem && dest_elem != T_VOID), "validated but different basic types");
1478
1479 // (2) src and dest arrays must have elements of the same BasicType
1480 // Figure out the size and type of the elements we will be copying.
1481 //
1482 // We have no stub to copy flat inline type arrays with oop
1483 // fields if we need to emit write barriers.
1484 //
1485 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1486 if (src_elem != dest_elem || top_src->is_flat() != top_dest->is_flat() || dest_elem == T_VOID ||
1487 (top_src->is_flat() && top_dest->elem()->inline_klass()->contains_oops() &&
1488 bs->array_copy_requires_gc_barriers(alloc != nullptr, T_OBJECT, false, false, BarrierSetC2::Optimization))) {
1489 // The component types are not the same or are not recognized. Punt.
1490 // (But, avoid the native method wrapper to JVM_ArrayCopy.)
1491 {
1492 Node* mem = ac->in(TypeFunc::Memory);
1493 merge_mem = generate_slow_arraycopy(ac, &ctrl, mem, &io, TypePtr::BOTTOM, src, src_offset, dest, dest_offset, length, false);
1494 }
1495
1496 _igvn.replace_node(_callprojs->fallthrough_memproj, merge_mem);
1497 if (_callprojs->fallthrough_ioproj != nullptr) {
1498 _igvn.replace_node(_callprojs->fallthrough_ioproj, io);
1499 }
1500 _igvn.replace_node(_callprojs->fallthrough_catchproj, ctrl);
1501 return;
1502 }
1503
1504 //---------------------------------------------------------------------------
1505 // We will make a fast path for this call to arraycopy.
1506
1507 // We have the following tests left to perform:
1508 //
1509 // (3) src and dest must not be null.
1510 // (4) src_offset must not be negative.
1511 // (5) dest_offset must not be negative.
1512 // (6) length must not be negative.
1513 // (7) src_offset + length must not exceed length of src.
1514 // (8) dest_offset + length must not exceed length of dest.
1515 // (9) each element of an oop array must be assignable
1516
1517 Node* mem = ac->in(TypeFunc::Memory);
1518 if (top_dest->is_flat()) {
1519 // Copy to a flat array modifies multiple memory slices. Conservatively insert a barrier
1520 // on all slices to prevent writes into the source from floating below the arraycopy.
1521 int mem_bar_alias_idx = Compile::AliasIdxBot;
1522 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1523 mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
1524 }
1525 insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
1526 }
1527 merge_mem = MergeMemNode::make(mem);
1528 transform_later(merge_mem);
1529
1530 RegionNode* slow_region = new RegionNode(1);
1531 transform_later(slow_region);
1532
1533 if (!ac->is_arraycopy_validated()) {
1534 // (3) operands must not be null
1535 // We currently perform our null checks with the null_check routine.
1536 // This means that the null exceptions will be reported in the caller
1537 // rather than (correctly) reported inside of the native arraycopy call.
1538 // This should be corrected, given time. We do our null check with the
1539 // stack pointer restored.
1540 // null checks done library_call.cpp
1541
1542 // (4) src_offset must not be negative.
1543 generate_negative_guard(&ctrl, src_offset, slow_region);
1544
1545 // (5) dest_offset must not be negative.
1546 generate_negative_guard(&ctrl, dest_offset, slow_region);
1547
1548 // (6) length must not be negative (moved to generate_arraycopy()).
1549 // generate_negative_guard(length, slow_region);
1550
1551 // (7) src_offset + length must not exceed length of src.
1552 Node* alen = ac->in(ArrayCopyNode::SrcLen);
1553 assert(alen != nullptr, "need src len");
1554 generate_limit_guard(&ctrl,
1555 src_offset, length,
1556 alen,
1557 slow_region);
1558
1559 // (8) dest_offset + length must not exceed length of dest.
1560 alen = ac->in(ArrayCopyNode::DestLen);
1561 assert(alen != nullptr, "need dest len");
1562 generate_limit_guard(&ctrl,
1563 dest_offset, length,
1564 alen,
1565 slow_region);
1566
1567 // (9) each element of an oop array must be assignable
1568 // The generate_arraycopy subroutine checks this.
1569
1570 // TODO 8350865 This is too strong
1571 // We need to be careful here because 'adjust_for_flat_array' will adjust offsets/length etc. which then does not work anymore for the slow call to SharedRuntime::slow_arraycopy_C.
1572 if (!(top_src->is_flat() && top_dest->is_flat() && top_src->is_null_free() == top_dest->is_null_free())) {
1573 generate_flat_array_guard(&ctrl, src, merge_mem, slow_region);
1574 generate_flat_array_guard(&ctrl, dest, merge_mem, slow_region);
1575 generate_null_free_array_guard(&ctrl, dest, merge_mem, slow_region);
1576 }
1577 }
1578
1579 // This is where the memory effects are placed:
1580 const TypePtr* adr_type = nullptr;
1581 Node* dest_length = (alloc != nullptr) ? alloc->in(AllocateNode::ALength) : nullptr;
1582
1583 if (top_src->is_flat() && top_dest->is_flat() &&
1584 top_src->is_null_free() == top_dest->is_null_free()) {
1585 adr_type = adjust_for_flat_array(top_dest, src_offset, dest_offset, length, dest_elem, dest_length);
1586 } else if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1587 adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
1588 } else {
1589 adr_type = TypeAryPtr::get_array_body_type(dest_elem);
1590 }
1591
1592 generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1593 adr_type, dest_elem,
1594 src, src_offset, dest, dest_offset, length,
1595 dest_length,
1596 // If a negative length guard was generated for the ArrayCopyNode,
1597 // the length of the array can never be negative.
1598 false, ac->has_negative_length_guard(),
1599 slow_region);
1600 }