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 const TypePtr *src_adr_type = _igvn.type(src_start)->isa_ptr();
218 Node* inline_block = nullptr;
219 Node* stub_block = nullptr;
220
221 int const_len = -1;
222 const TypeInt* lty = nullptr;
223 uint shift = exact_log2(type2aelembytes(type));
224 if (length->Opcode() == Op_ConvI2L) {
225 lty = _igvn.type(length->in(1))->isa_int();
226 } else {
227 lty = _igvn.type(length)->isa_int();
228 }
229 if (lty && lty->is_con()) {
230 const_len = lty->get_con() << shift;
231 }
232
233 // Return if copy length is greater than partial inline size limit or
234 // target does not supports masked load/stores.
235 int lane_count = ArrayCopyNode::get_partial_inline_vector_lane_count(type, const_len);
236 if ( const_len > ArrayOperationPartialInlineSize ||
237 !Matcher::match_rule_supported_vector(Op_LoadVectorMasked, lane_count, type) ||
238 !Matcher::match_rule_supported_vector(Op_StoreVectorMasked, lane_count, type) ||
239 !Matcher::match_rule_supported_vector(Op_VectorMaskGen, lane_count, type)) {
240 return;
241 }
242
243 int inline_limit = ArrayOperationPartialInlineSize / type2aelembytes(type);
244 Node* casted_length = new CastLLNode(*ctrl, length, TypeLong::make(0, inline_limit, Type::WidenMin));
245 transform_later(casted_length);
246 Node* copy_bytes = new LShiftXNode(length, intcon(shift));
247 transform_later(copy_bytes);
248
249 Node* cmp_le = new CmpULNode(copy_bytes, longcon(ArrayOperationPartialInlineSize));
250 transform_later(cmp_le);
251 Node* bol_le = new BoolNode(cmp_le, BoolTest::le);
252 transform_later(bol_le);
253 inline_block = generate_guard(ctrl, bol_le, nullptr, PROB_FAIR);
254 stub_block = *ctrl;
255
256 Node* mask_gen = VectorMaskGenNode::make(casted_length, type);
257 transform_later(mask_gen);
258
259 unsigned vec_size = lane_count * type2aelembytes(type);
260 if (C->max_vector_size() < vec_size) {
261 C->set_max_vector_size(vec_size);
262 }
263
264 const TypeVect * vt = TypeVect::make(type, lane_count);
265 Node* mm = (*mem)->memory_at(C->get_alias_index(src_adr_type));
266 Node* masked_load = new LoadVectorMaskedNode(inline_block, mm, src_start,
267 src_adr_type, vt, mask_gen);
268 transform_later(masked_load);
269
270 mm = (*mem)->memory_at(C->get_alias_index(adr_type));
271 Node* masked_store = new StoreVectorMaskedNode(inline_block, mm, dst_start,
272 masked_load, adr_type, mask_gen);
273 transform_later(masked_store);
274
275 // Convergence region for inline_block and stub_block.
276 *exit_block = new RegionNode(3);
277 transform_later(*exit_block);
278 (*exit_block)->init_req(1, inline_block);
279 *result_memory = new PhiNode(*exit_block, Type::MEMORY, adr_type);
280 transform_later(*result_memory);
281 (*result_memory)->init_req(1, masked_store);
282
283 *ctrl = stub_block;
284 }
285
286
287 Node* PhaseMacroExpand::generate_nonpositive_guard(Node** ctrl, Node* index, bool never_negative) {
288 if ((*ctrl)->is_top()) return nullptr;
289
290 if (_igvn.type(index)->higher_equal(TypeInt::POS1)) // [1,maxint]
291 return nullptr; // index is already adequately typed
292 Node* cmp_le = new CmpINode(index, intcon(0));
293 transform_later(cmp_le);
294 BoolTest::mask le_or_eq = (never_negative ? BoolTest::eq : BoolTest::le);
295 Node* bol_le = new BoolNode(cmp_le, le_or_eq);
296 transform_later(bol_le);
297 Node* is_notp = generate_guard(ctrl, bol_le, nullptr, PROB_MIN);
298
299 return is_notp;
300 }
301
302 Node* PhaseMacroExpand::mark_word_test(Node** ctrl, Node* obj, MergeMemNode* mem, uintptr_t mask_val, RegionNode* region) {
303 // Load markword and check if obj is locked
304 Node* mark = make_load(nullptr, mem->memory_at(Compile::AliasIdxRaw), obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type());
305 Node* locked_bit = MakeConX(markWord::unlocked_value);
306 locked_bit = transform_later(new AndXNode(locked_bit, mark));
307 Node* cmp = transform_later(new CmpXNode(locked_bit, MakeConX(0)));
308 Node* is_unlocked = transform_later(new BoolNode(cmp, BoolTest::ne));
309 IfNode* iff = transform_later(new IfNode(*ctrl, is_unlocked, PROB_MAX, COUNT_UNKNOWN))->as_If();
310 Node* locked_region = transform_later(new RegionNode(3));
311 Node* mark_phi = transform_later(new PhiNode(locked_region, TypeX_X));
312
313 // Unlocked: Use bits from mark word
314 locked_region->init_req(1, transform_later(new IfTrueNode(iff)));
315 mark_phi->init_req(1, mark);
316
317 // Locked: Load prototype header from klass
318 *ctrl = transform_later(new IfFalseNode(iff));
319 // Make loads control dependent to make sure they are only executed if array is locked
320 Node* klass_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes());
321 Node* klass = transform_later(LoadKlassNode::make(_igvn, C->immutable_memory(), klass_adr, TypeInstPtr::KLASS, TypeInstKlassPtr::OBJECT));
322 Node* proto_adr = basic_plus_adr(klass, in_bytes(Klass::prototype_header_offset()));
323 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));
324
325 locked_region->init_req(2, *ctrl);
326 mark_phi->init_req(2, proto);
327 *ctrl = locked_region;
328
329 // Now check if mark word bits are set
330 Node* mask = MakeConX(mask_val);
331 Node* masked = transform_later(new AndXNode(mark_phi, mask));
332 cmp = transform_later(new CmpXNode(masked, mask));
333 Node* bol = transform_later(new BoolNode(cmp, BoolTest::eq));
334 return generate_fair_guard(ctrl, bol, region);
335 }
336
337 Node* PhaseMacroExpand::generate_flat_array_guard(Node** ctrl, Node* array, MergeMemNode* mem, RegionNode* region) {
338 return mark_word_test(ctrl, array, mem, markWord::flat_array_bit_in_place, region);
339 }
340
341 Node* PhaseMacroExpand::generate_null_free_array_guard(Node** ctrl, Node* array, MergeMemNode* mem, RegionNode* region) {
342 return mark_word_test(ctrl, array, mem, markWord::null_free_array_bit_in_place, region);
343 }
344
345 void PhaseMacroExpand::finish_arraycopy_call(Node* call, Node** ctrl, MergeMemNode** mem, const TypePtr* adr_type) {
346 transform_later(call);
347
348 *ctrl = new ProjNode(call,TypeFunc::Control);
349 transform_later(*ctrl);
350 Node* newmem = new ProjNode(call, TypeFunc::Memory);
351 transform_later(newmem);
352
353 uint alias_idx = C->get_alias_index(adr_type);
354 if (alias_idx != Compile::AliasIdxBot) {
355 *mem = MergeMemNode::make(*mem);
356 (*mem)->set_memory_at(alias_idx, newmem);
357 } else {
358 *mem = MergeMemNode::make(newmem);
359 }
360 transform_later(*mem);
361 }
362
363 address PhaseMacroExpand::basictype2arraycopy(BasicType t,
364 Node* src_offset,
365 Node* dest_offset,
366 bool disjoint_bases,
367 const char* &name,
368 bool dest_uninitialized) {
369 const TypeInt* src_offset_inttype = _igvn.find_int_type(src_offset);
370 const TypeInt* dest_offset_inttype = _igvn.find_int_type(dest_offset);
371
372 bool aligned = false;
373 bool disjoint = disjoint_bases;
374
375 // if the offsets are the same, we can treat the memory regions as
376 // disjoint, because either the memory regions are in different arrays,
377 // or they are identical (which we can treat as disjoint.) We can also
378 // treat a copy with a destination index less that the source index
379 // as disjoint since a low->high copy will work correctly in this case.
380 if (src_offset_inttype != nullptr && src_offset_inttype->is_con() &&
381 dest_offset_inttype != nullptr && dest_offset_inttype->is_con()) {
382 // both indices are constants
383 int s_offs = src_offset_inttype->get_con();
384 int d_offs = dest_offset_inttype->get_con();
385 int element_size = type2aelembytes(t);
386 aligned = ((arrayOopDesc::base_offset_in_bytes(t) + (uint)s_offs * element_size) % HeapWordSize == 0) &&
387 ((arrayOopDesc::base_offset_in_bytes(t) + (uint)d_offs * element_size) % HeapWordSize == 0);
388 if (s_offs >= d_offs) disjoint = true;
389 } else if (src_offset == dest_offset && src_offset != nullptr) {
390 // This can occur if the offsets are identical non-constants.
391 disjoint = true;
392 }
393
394 return StubRoutines::select_arraycopy_function(t, aligned, disjoint, name, dest_uninitialized);
395 }
396
397 #define XTOP LP64_ONLY(COMMA top())
398
399 // Generate an optimized call to arraycopy.
400 // Caller must guard against non-arrays.
401 // Caller must determine a common array basic-type for both arrays.
402 // Caller must validate offsets against array bounds.
403 // The slow_region has already collected guard failure paths
404 // (such as out of bounds length or non-conformable array types).
405 // The generated code has this shape, in general:
406 //
407 // if (length == 0) return // via zero_path
408 // slowval = -1
409 // if (types unknown) {
410 // slowval = call generic copy loop
411 // if (slowval == 0) return // via checked_path
412 // } else if (indexes in bounds) {
413 // if ((is object array) && !(array type check)) {
414 // slowval = call checked copy loop
415 // if (slowval == 0) return // via checked_path
416 // } else {
417 // call bulk copy loop
418 // return // via fast_path
419 // }
420 // }
421 // // adjust params for remaining work:
422 // if (slowval != -1) {
423 // n = -1^slowval; src_offset += n; dest_offset += n; length -= n
424 // }
425 // slow_region:
426 // call slow arraycopy(src, src_offset, dest, dest_offset, length)
427 // return // via slow_call_path
428 //
429 // This routine is used from several intrinsics: System.arraycopy,
430 // Object.clone (the array subcase), and Arrays.copyOf[Range].
431 //
432 Node* PhaseMacroExpand::generate_arraycopy(ArrayCopyNode *ac, AllocateArrayNode* alloc,
433 Node** ctrl, MergeMemNode* mem, Node** io,
434 const TypePtr* adr_type,
435 BasicType basic_elem_type,
436 Node* src, Node* src_offset,
437 Node* dest, Node* dest_offset,
438 Node* copy_length,
439 Node* dest_length,
440 bool disjoint_bases,
441 bool length_never_negative,
442 RegionNode* slow_region) {
443 if (slow_region == nullptr) {
444 slow_region = new RegionNode(1);
445 transform_later(slow_region);
446 }
447
448 Node* original_dest = dest;
449 bool dest_needs_zeroing = false;
450 bool acopy_to_uninitialized = false;
451 Node* init_value = nullptr;
452 Node* raw_init_value = nullptr;
453
454 // See if this is the initialization of a newly-allocated array.
455 // If so, we will take responsibility here for initializing it to zero.
456 // (Note: Because tightly_coupled_allocation performs checks on the
457 // out-edges of the dest, we need to avoid making derived pointers
458 // from it until we have checked its uses.)
459 if (ReduceBulkZeroing
460 && !(UseTLAB && ZeroTLAB) // pointless if already zeroed
461 && basic_elem_type != T_CONFLICT // avoid corner case
462 && !src->eqv_uncast(dest)
463 && alloc != nullptr
464 && _igvn.find_int_con(alloc->in(AllocateNode::ALength), 1) > 0) {
465 assert(ac->is_alloc_tightly_coupled(), "sanity");
466 // acopy to uninitialized tightly coupled allocations
467 // needs zeroing outside the copy range
468 // and the acopy itself will be to uninitialized memory
469 acopy_to_uninitialized = true;
470 if (alloc->maybe_set_complete(&_igvn)) {
471 // "You break it, you buy it."
472 InitializeNode* init = alloc->initialization();
473 assert(init->is_complete(), "we just did this");
474 init->set_complete_with_arraycopy();
475 assert(dest->is_CheckCastPP(), "sanity");
476 assert(dest->in(0)->in(0) == init, "dest pinned");
477 adr_type = TypeRawPtr::BOTTOM; // all initializations are into raw memory
478 // From this point on, every exit path is responsible for
479 // initializing any non-copied parts of the object to zero.
480 // Also, if this flag is set we make sure that arraycopy interacts properly
481 // with G1, eliding pre-barriers. See CR 6627983.
482 dest_needs_zeroing = true;
483 init_value = alloc->in(AllocateNode::InitValue);
484 raw_init_value = alloc->in(AllocateNode::RawInitValue);
485 } else {
486 // dest_need_zeroing = false;
487 }
488 } else {
489 // No zeroing elimination needed here.
490 alloc = nullptr;
491 acopy_to_uninitialized = false;
492 //original_dest = dest;
493 //dest_needs_zeroing = false;
494 }
495
496 uint alias_idx = C->get_alias_index(adr_type);
497
498 // Results are placed here:
499 enum { fast_path = 1, // normal void-returning assembly stub
500 checked_path = 2, // special assembly stub with cleanup
501 slow_call_path = 3, // something went wrong; call the VM
502 zero_path = 4, // bypass when length of copy is zero
503 bcopy_path = 5, // copy primitive array by 64-bit blocks
504 PATH_LIMIT = 6
505 };
506 RegionNode* result_region = new RegionNode(PATH_LIMIT);
507 PhiNode* result_i_o = new PhiNode(result_region, Type::ABIO);
508 PhiNode* result_memory = new PhiNode(result_region, Type::MEMORY, adr_type);
509 assert(adr_type != TypePtr::BOTTOM, "must be RawMem or a T[] slice");
510 transform_later(result_region);
511 transform_later(result_i_o);
512 transform_later(result_memory);
513
514 // The slow_control path:
515 Node* slow_control;
516 Node* slow_i_o = *io;
517 Node* slow_mem = mem->memory_at(alias_idx);
518 DEBUG_ONLY(slow_control = (Node*) badAddress);
519
520 // Checked control path:
521 Node* checked_control = top();
522 Node* checked_mem = nullptr;
523 Node* checked_i_o = nullptr;
524 Node* checked_value = nullptr;
525
526 if (basic_elem_type == T_CONFLICT) {
527 assert(!dest_needs_zeroing, "");
528 Node* cv = generate_generic_arraycopy(ctrl, &mem,
529 adr_type,
530 src, src_offset, dest, dest_offset,
531 copy_length, acopy_to_uninitialized);
532 if (cv == nullptr) cv = intcon(-1); // failure (no stub available)
533 checked_control = *ctrl;
534 checked_i_o = *io;
535 checked_mem = mem->memory_at(alias_idx);
536 checked_value = cv;
537 *ctrl = top();
538 }
539
540 Node* not_pos = generate_nonpositive_guard(ctrl, copy_length, length_never_negative);
541 if (not_pos != nullptr) {
542 Node* local_ctrl = not_pos, *local_io = *io;
543 MergeMemNode* local_mem = MergeMemNode::make(mem);
544 transform_later(local_mem);
545
546 // (6) length must not be negative.
547 if (!length_never_negative) {
548 generate_negative_guard(&local_ctrl, copy_length, slow_region);
549 }
550
551 // copy_length is 0.
552 if (dest_needs_zeroing) {
553 assert(!local_ctrl->is_top(), "no ctrl?");
554 if (copy_length->eqv_uncast(dest_length)
555 || _igvn.find_int_con(dest_length, 1) <= 0) {
556 // There is no zeroing to do. No need for a secondary raw memory barrier.
557 } else {
558 // Clear the whole thing since there are no source elements to copy.
559 generate_clear_array(local_ctrl, local_mem,
560 adr_type, dest,
561 init_value, raw_init_value,
562 basic_elem_type,
563 intcon(0), nullptr,
564 alloc->in(AllocateNode::AllocSize));
565 // Use a secondary InitializeNode as raw memory barrier.
566 // Currently it is needed only on this path since other
567 // paths have stub or runtime calls as raw memory barriers.
568 MemBarNode* mb = MemBarNode::make(C, Op_Initialize,
569 Compile::AliasIdxRaw,
570 top());
571 transform_later(mb);
572 mb->set_req(TypeFunc::Control,local_ctrl);
573 mb->set_req(TypeFunc::Memory, local_mem->memory_at(Compile::AliasIdxRaw));
574 local_ctrl = transform_later(new ProjNode(mb, TypeFunc::Control));
575 local_mem->set_memory_at(Compile::AliasIdxRaw, transform_later(new ProjNode(mb, TypeFunc::Memory)));
576
577 InitializeNode* init = mb->as_Initialize();
578 init->set_complete(&_igvn); // (there is no corresponding AllocateNode)
579 }
580 }
581
582 // Present the results of the fast call.
583 result_region->init_req(zero_path, local_ctrl);
584 result_i_o ->init_req(zero_path, local_io);
585 result_memory->init_req(zero_path, local_mem->memory_at(alias_idx));
586 }
587
588 if (!(*ctrl)->is_top() && dest_needs_zeroing) {
589 // We have to initialize the *uncopied* part of the array to zero.
590 // The copy destination is the slice dest[off..off+len]. The other slices
591 // are dest_head = dest[0..off] and dest_tail = dest[off+len..dest.length].
592 Node* dest_size = alloc->in(AllocateNode::AllocSize);
593 Node* dest_tail = transform_later( new AddINode(dest_offset, copy_length));
594
595 // If there is a head section that needs zeroing, do it now.
596 if (_igvn.find_int_con(dest_offset, -1) != 0) {
597 generate_clear_array(*ctrl, mem,
598 adr_type, dest,
599 init_value, raw_init_value,
600 basic_elem_type,
601 intcon(0), dest_offset,
602 nullptr);
603 }
604
605 // Next, perform a dynamic check on the tail length.
606 // It is often zero, and we can win big if we prove this.
607 // There are two wins: Avoid generating the ClearArray
608 // with its attendant messy index arithmetic, and upgrade
609 // the copy to a more hardware-friendly word size of 64 bits.
610 Node* tail_ctl = nullptr;
611 if (!(*ctrl)->is_top() && !dest_tail->eqv_uncast(dest_length)) {
612 Node* cmp_lt = transform_later( new CmpINode(dest_tail, dest_length) );
613 Node* bol_lt = transform_later( new BoolNode(cmp_lt, BoolTest::lt) );
614 tail_ctl = generate_slow_guard(ctrl, bol_lt, nullptr);
615 assert(tail_ctl != nullptr || !(*ctrl)->is_top(), "must be an outcome");
616 }
617
618 // At this point, let's assume there is no tail.
619 if (!(*ctrl)->is_top() && alloc != nullptr && basic_elem_type != T_OBJECT) {
620 // There is no tail. Try an upgrade to a 64-bit copy.
621 bool didit = false;
622 {
623 Node* local_ctrl = *ctrl, *local_io = *io;
624 MergeMemNode* local_mem = MergeMemNode::make(mem);
625 transform_later(local_mem);
626
627 didit = generate_block_arraycopy(&local_ctrl, &local_mem, local_io,
628 adr_type, basic_elem_type, alloc,
629 src, src_offset, dest, dest_offset,
630 dest_size, acopy_to_uninitialized);
631 if (didit) {
632 // Present the results of the block-copying fast call.
633 result_region->init_req(bcopy_path, local_ctrl);
634 result_i_o ->init_req(bcopy_path, local_io);
635 result_memory->init_req(bcopy_path, local_mem->memory_at(alias_idx));
636 }
637 }
638 if (didit) {
639 *ctrl = top(); // no regular fast path
640 }
641 }
642
643 // Clear the tail, if any.
644 if (tail_ctl != nullptr) {
645 Node* notail_ctl = (*ctrl)->is_top() ? nullptr : *ctrl;
646 *ctrl = tail_ctl;
647 if (notail_ctl == nullptr) {
648 generate_clear_array(*ctrl, mem,
649 adr_type, dest,
650 init_value, raw_init_value,
651 basic_elem_type,
652 dest_tail, nullptr,
653 dest_size);
654 } else {
655 // Make a local merge.
656 Node* done_ctl = transform_later(new RegionNode(3));
657 Node* done_mem = transform_later(new PhiNode(done_ctl, Type::MEMORY, adr_type));
658 done_ctl->init_req(1, notail_ctl);
659 done_mem->init_req(1, mem->memory_at(alias_idx));
660 generate_clear_array(*ctrl, mem,
661 adr_type, dest,
662 init_value, raw_init_value,
663 basic_elem_type,
664 dest_tail, nullptr,
665 dest_size);
666 done_ctl->init_req(2, *ctrl);
667 done_mem->init_req(2, mem->memory_at(alias_idx));
668 *ctrl = done_ctl;
669 mem->set_memory_at(alias_idx, done_mem);
670 }
671 }
672 }
673
674 BasicType copy_type = basic_elem_type;
675 assert(basic_elem_type != T_ARRAY, "caller must fix this");
676 if (!(*ctrl)->is_top() && copy_type == T_OBJECT) {
677 // If src and dest have compatible element types, we can copy bits.
678 // Types S[] and D[] are compatible if D is a supertype of S.
679 //
680 // If they are not, we will use checked_oop_disjoint_arraycopy,
681 // which performs a fast optimistic per-oop check, and backs off
682 // further to JVM_ArrayCopy on the first per-oop check that fails.
683 // (Actually, we don't move raw bits only; the GC requires card marks.)
684
685 // We don't need a subtype check for validated copies and Object[].clone()
686 bool skip_subtype_check = ac->is_arraycopy_validated() || ac->is_copyof_validated() ||
687 ac->is_copyofrange_validated() || ac->is_clone_oop_array();
688 if (!skip_subtype_check) {
689 // Get the klass* for both src and dest
690 Node* src_klass = ac->in(ArrayCopyNode::SrcKlass);
691 Node* dest_klass = ac->in(ArrayCopyNode::DestKlass);
692
693 assert(src_klass != nullptr && dest_klass != nullptr, "should have klasses");
694
695 // Generate the subtype check.
696 // This might fold up statically, or then again it might not.
697 //
698 // Non-static example: Copying List<String>.elements to a new String[].
699 // The backing store for a List<String> is always an Object[],
700 // but its elements are always type String, if the generic types
701 // are correct at the source level.
702 //
703 // Test S[] against D[], not S against D, because (probably)
704 // the secondary supertype cache is less busy for S[] than S.
705 // This usually only matters when D is an interface.
706 Node* not_subtype_ctrl = Phase::gen_subtype_check(src_klass, dest_klass, ctrl, mem, _igvn, nullptr, -1);
707 // Plug failing path into checked_oop_disjoint_arraycopy
708 if (not_subtype_ctrl != top()) {
709 Node* local_ctrl = not_subtype_ctrl;
710 MergeMemNode* local_mem = MergeMemNode::make(mem);
711 transform_later(local_mem);
712
713 // (At this point we can assume disjoint_bases, since types differ.)
714 int ek_offset = in_bytes(ObjArrayKlass::element_klass_offset());
715 Node* p1 = basic_plus_adr(dest_klass, ek_offset);
716 Node* n1 = LoadKlassNode::make(_igvn, C->immutable_memory(), p1, TypeRawPtr::BOTTOM);
717 Node* dest_elem_klass = transform_later(n1);
718 Node* cv = generate_checkcast_arraycopy(&local_ctrl, &local_mem,
719 adr_type,
720 dest_elem_klass,
721 src, src_offset, dest, dest_offset,
722 ConvI2X(copy_length), acopy_to_uninitialized);
723 if (cv == nullptr) cv = intcon(-1); // failure (no stub available)
724 checked_control = local_ctrl;
725 checked_i_o = *io;
726 checked_mem = local_mem->memory_at(alias_idx);
727 checked_value = cv;
728 }
729 }
730 // At this point we know we do not need type checks on oop stores.
731
732 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
733 if (!bs->array_copy_requires_gc_barriers(alloc != nullptr, copy_type, false, false, BarrierSetC2::Expansion)) {
734 // If we do not need gc barriers, copy using the jint or jlong stub.
735 copy_type = LP64_ONLY(UseCompressedOops ? T_INT : T_LONG) NOT_LP64(T_INT);
736 assert(type2aelembytes(basic_elem_type) == type2aelembytes(copy_type),
737 "sizes agree");
738 }
739 }
740
741 if (!(*ctrl)->is_top()) {
742 // Generate the fast path, if possible.
743 Node* local_ctrl = *ctrl;
744 MergeMemNode* local_mem = MergeMemNode::make(mem);
745 transform_later(local_mem);
746 generate_unchecked_arraycopy(&local_ctrl, &local_mem,
747 adr_type, copy_type, disjoint_bases,
748 src, src_offset, dest, dest_offset,
749 ConvI2X(copy_length), acopy_to_uninitialized);
750
751 // Present the results of the fast call.
752 result_region->init_req(fast_path, local_ctrl);
753 result_i_o ->init_req(fast_path, *io);
754 result_memory->init_req(fast_path, local_mem->memory_at(alias_idx));
755 }
756
757 // Here are all the slow paths up to this point, in one bundle:
758 assert(slow_region != nullptr, "allocated on entry");
759 slow_control = slow_region;
760 DEBUG_ONLY(slow_region = (RegionNode*)badAddress);
761
762 *ctrl = checked_control;
763 if (!(*ctrl)->is_top()) {
764 // Clean up after the checked call.
765 // The returned value is either 0 or -1^K,
766 // where K = number of partially transferred array elements.
767 Node* cmp = new CmpINode(checked_value, intcon(0));
768 transform_later(cmp);
769 Node* bol = new BoolNode(cmp, BoolTest::eq);
770 transform_later(bol);
771 IfNode* iff = new IfNode(*ctrl, bol, PROB_MAX, COUNT_UNKNOWN);
772 transform_later(iff);
773
774 // If it is 0, we are done, so transfer to the end.
775 Node* checks_done = new IfTrueNode(iff);
776 transform_later(checks_done);
777 result_region->init_req(checked_path, checks_done);
778 result_i_o ->init_req(checked_path, checked_i_o);
779 result_memory->init_req(checked_path, checked_mem);
780
781 // If it is not zero, merge into the slow call.
782 *ctrl = new IfFalseNode(iff);
783 transform_later(*ctrl);
784 RegionNode* slow_reg2 = new RegionNode(3);
785 PhiNode* slow_i_o2 = new PhiNode(slow_reg2, Type::ABIO);
786 PhiNode* slow_mem2 = new PhiNode(slow_reg2, Type::MEMORY, adr_type);
787 transform_later(slow_reg2);
788 transform_later(slow_i_o2);
789 transform_later(slow_mem2);
790 slow_reg2 ->init_req(1, slow_control);
791 slow_i_o2 ->init_req(1, slow_i_o);
792 slow_mem2 ->init_req(1, slow_mem);
793 slow_reg2 ->init_req(2, *ctrl);
794 slow_i_o2 ->init_req(2, checked_i_o);
795 slow_mem2 ->init_req(2, checked_mem);
796
797 slow_control = slow_reg2;
798 slow_i_o = slow_i_o2;
799 slow_mem = slow_mem2;
800
801 if (alloc != nullptr) {
802 // We'll restart from the very beginning, after zeroing the whole thing.
803 // This can cause double writes, but that's OK since dest is brand new.
804 // So we ignore the low 31 bits of the value returned from the stub.
805 } else {
806 // We must continue the copy exactly where it failed, or else
807 // another thread might see the wrong number of writes to dest.
808 Node* checked_offset = new XorINode(checked_value, intcon(-1));
809 Node* slow_offset = new PhiNode(slow_reg2, TypeInt::INT);
810 transform_later(checked_offset);
811 transform_later(slow_offset);
812 slow_offset->init_req(1, intcon(0));
813 slow_offset->init_req(2, checked_offset);
814
815 // Adjust the arguments by the conditionally incoming offset.
816 Node* src_off_plus = new AddINode(src_offset, slow_offset);
817 transform_later(src_off_plus);
818 Node* dest_off_plus = new AddINode(dest_offset, slow_offset);
819 transform_later(dest_off_plus);
820 Node* length_minus = new SubINode(copy_length, slow_offset);
821 transform_later(length_minus);
822
823 // Tweak the node variables to adjust the code produced below:
824 src_offset = src_off_plus;
825 dest_offset = dest_off_plus;
826 copy_length = length_minus;
827 }
828 }
829 *ctrl = slow_control;
830 if (!(*ctrl)->is_top()) {
831 Node* local_ctrl = *ctrl, *local_io = slow_i_o;
832 MergeMemNode* local_mem = MergeMemNode::make(mem);
833 transform_later(local_mem);
834
835 // Generate the slow path, if needed.
836 local_mem->set_memory_at(alias_idx, slow_mem);
837
838 if (dest_needs_zeroing) {
839 generate_clear_array(local_ctrl, local_mem,
840 adr_type, dest,
841 init_value, raw_init_value,
842 basic_elem_type,
843 intcon(0), nullptr,
844 alloc->in(AllocateNode::AllocSize));
845 }
846
847 local_mem = generate_slow_arraycopy(ac,
848 &local_ctrl, local_mem, &local_io,
849 adr_type,
850 src, src_offset, dest, dest_offset,
851 copy_length, /*dest_uninitialized*/false);
852
853 result_region->init_req(slow_call_path, local_ctrl);
854 result_i_o ->init_req(slow_call_path, local_io);
855 result_memory->init_req(slow_call_path, local_mem->memory_at(alias_idx));
856 } else {
857 ShouldNotReachHere(); // no call to generate_slow_arraycopy:
858 // projections were not extracted
859 }
860
861 // Remove unused edges.
862 for (uint i = 1; i < result_region->req(); i++) {
863 if (result_region->in(i) == nullptr) {
864 result_region->init_req(i, top());
865 }
866 }
867
868 // Finished; return the combined state.
869 *ctrl = result_region;
870 *io = result_i_o;
871 mem->set_memory_at(alias_idx, result_memory);
872
873 // mem no longer guaranteed to stay a MergeMemNode
874 Node* out_mem = mem;
875 DEBUG_ONLY(mem = nullptr);
876
877 // The memory edges above are precise in order to model effects around
878 // array copies accurately to allow value numbering of field loads around
879 // arraycopy. Such field loads, both before and after, are common in Java
880 // collections and similar classes involving header/array data structures.
881 //
882 // But with low number of register or when some registers are used or killed
883 // by arraycopy calls it causes registers spilling on stack. See 6544710.
884 // The next memory barrier is added to avoid it. If the arraycopy can be
885 // optimized away (which it can, sometimes) then we can manually remove
886 // the membar also.
887 //
888 // Do not let reads from the cloned object float above the arraycopy.
889 if (alloc != nullptr && !alloc->initialization()->does_not_escape()) {
890 // Do not let stores that initialize this object be reordered with
891 // a subsequent store that would make this object accessible by
892 // other threads.
893 assert(ac->_dest_type == TypeOopPtr::BOTTOM, "non escaping destination shouldn't have narrow slice");
894 insert_mem_bar(ctrl, &out_mem, Op_MemBarStoreStore, Compile::AliasIdxBot);
895 } else {
896 int mem_bar_alias_idx = Compile::AliasIdxBot;
897 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
898 // The graph was transformed under the assumption the ArrayCopy node only had an effect on a narrow slice. We can't
899 // insert a wide membar now that it's being expanded: a load that uses the input memory state of the ArrayCopy
900 // could then become anti dependent on the membar when it was not anti dependent on the ArrayCopy leading to a
901 // broken graph.
902 mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
903 }
904 insert_mem_bar(ctrl, &out_mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
905 }
906
907 assert((*ctrl)->is_Proj(), "MemBar control projection");
908 assert((*ctrl)->in(0)->isa_MemBar(), "MemBar node");
909 (*ctrl)->in(0)->isa_MemBar()->set_trailing_expanded_array_copy();
910
911 _igvn.replace_node(_callprojs->fallthrough_memproj, out_mem);
912 if (_callprojs->fallthrough_ioproj != nullptr) {
913 _igvn.replace_node(_callprojs->fallthrough_ioproj, *io);
914 }
915 _igvn.replace_node(_callprojs->fallthrough_catchproj, *ctrl);
916
917 #ifdef ASSERT
918 const TypeOopPtr* dest_t = _igvn.type(dest)->is_oopptr();
919 if (dest_t->is_known_instance()) {
920 ArrayCopyNode* ac = nullptr;
921 assert(ArrayCopyNode::may_modify(dest_t, (*ctrl)->in(0)->as_MemBar(), &_igvn, ac), "dependency on arraycopy lost");
922 assert(ac == nullptr, "no arraycopy anymore");
923 }
924 #endif
925
926 return out_mem;
927 }
928
929 // Helper for initialization of arrays, creating a ClearArray.
930 // It writes zero bits in [start..end), within the body of an array object.
931 // The memory effects are all chained onto the 'adr_type' alias category.
932 //
933 // Since the object is otherwise uninitialized, we are free
934 // to put a little "slop" around the edges of the cleared area,
935 // as long as it does not go back into the array's header,
936 // or beyond the array end within the heap.
937 //
938 // The lower edge can be rounded down to the nearest jint and the
939 // upper edge can be rounded up to the nearest MinObjAlignmentInBytes.
940 //
941 // Arguments:
942 // adr_type memory slice where writes are generated
943 // dest oop of the destination array
944 // basic_elem_type element type of the destination
945 // slice_idx array index of first element to store
946 // slice_len number of elements to store (or null)
947 // dest_size total size in bytes of the array object
948 //
949 // Exactly one of slice_len or dest_size must be non-null.
950 // If dest_size is non-null, zeroing extends to the end of the object.
951 // If slice_len is non-null, the slice_idx value must be a constant.
952 void PhaseMacroExpand::generate_clear_array(Node* ctrl, MergeMemNode* merge_mem,
953 const TypePtr* adr_type,
954 Node* dest,
955 Node* val,
956 Node* raw_val,
957 BasicType basic_elem_type,
958 Node* slice_idx,
959 Node* slice_len,
960 Node* dest_size) {
961 // one or the other but not both of slice_len and dest_size:
962 assert((slice_len != nullptr? 1: 0) + (dest_size != nullptr? 1: 0) == 1, "");
963 if (slice_len == nullptr) slice_len = top();
964 if (dest_size == nullptr) dest_size = top();
965
966 uint alias_idx = C->get_alias_index(adr_type);
967
968 // operate on this memory slice:
969 Node* mem = merge_mem->memory_at(alias_idx); // memory slice to operate on
970
971 // scaling and rounding of indexes:
972 int scale = exact_log2(type2aelembytes(basic_elem_type));
973 int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
974 int clear_low = (-1 << scale) & (BytesPerInt - 1);
975 int bump_bit = (-1 << scale) & BytesPerInt;
976
977 // determine constant starts and ends
978 const intptr_t BIG_NEG = -128;
979 assert(BIG_NEG + 2*abase < 0, "neg enough");
980 intptr_t slice_idx_con = (intptr_t) _igvn.find_int_con(slice_idx, BIG_NEG);
981 intptr_t slice_len_con = (intptr_t) _igvn.find_int_con(slice_len, BIG_NEG);
982 if (slice_len_con == 0) {
983 return; // nothing to do here
984 }
985 intptr_t start_con = (abase + (slice_idx_con << scale)) & ~clear_low;
986 intptr_t end_con = _igvn.find_intptr_t_con(dest_size, -1);
987 if (slice_idx_con >= 0 && slice_len_con >= 0) {
988 assert(end_con < 0, "not two cons");
989 end_con = align_up(abase + ((slice_idx_con + slice_len_con) << scale),
990 BytesPerLong);
991 }
992
993 if (start_con >= 0 && end_con >= 0) {
994 // Constant start and end. Simple.
995 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
996 start_con, end_con, &_igvn);
997 } else if (start_con >= 0 && dest_size != top()) {
998 // Constant start, pre-rounded end after the tail of the array.
999 Node* end = dest_size;
1000 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
1001 start_con, end, &_igvn);
1002 } else if (start_con >= 0 && slice_len != top()) {
1003 // Constant start, non-constant end. End needs rounding up.
1004 // End offset = round_up(abase + ((slice_idx_con + slice_len) << scale), 8)
1005 intptr_t end_base = abase + (slice_idx_con << scale);
1006 int end_round = (-1 << scale) & (BytesPerLong - 1);
1007 Node* end = ConvI2X(slice_len);
1008 if (scale != 0)
1009 end = transform_later(new LShiftXNode(end, intcon(scale) ));
1010 end_base += end_round;
1011 end = transform_later(new AddXNode(end, MakeConX(end_base)) );
1012 end = transform_later(new AndXNode(end, MakeConX(~end_round)) );
1013 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, val, raw_val,
1014 start_con, end, &_igvn);
1015 } else if (start_con < 0 && dest_size != top()) {
1016 // Non-constant start, pre-rounded end after the tail of the array.
1017 // This is almost certainly a "round-to-end" operation.
1018 Node* start = slice_idx;
1019 start = ConvI2X(start);
1020 if (scale != 0)
1021 start = transform_later(new LShiftXNode( start, intcon(scale) ));
1022 start = transform_later(new AddXNode(start, MakeConX(abase)) );
1023 if ((bump_bit | clear_low) != 0) {
1024 int to_clear = (bump_bit | clear_low);
1025 // Align up mod 8, then store a jint zero unconditionally
1026 // just before the mod-8 boundary.
1027 if (((abase + bump_bit) & ~to_clear) - bump_bit
1028 < arrayOopDesc::length_offset_in_bytes() + BytesPerInt) {
1029 bump_bit = 0;
1030 assert((abase & to_clear) == 0, "array base must be long-aligned");
1031 } else {
1032 // Bump 'start' up to (or past) the next jint boundary:
1033 start = transform_later( new AddXNode(start, MakeConX(bump_bit)) );
1034 assert((abase & clear_low) == 0, "array base must be int-aligned");
1035 }
1036 // Round bumped 'start' down to jlong boundary in body of array.
1037 start = transform_later(new AndXNode(start, MakeConX(~to_clear)) );
1038 if (bump_bit != 0) {
1039 // Store a zero to the immediately preceding jint:
1040 Node* x1 = transform_later(new AddXNode(start, MakeConX(-bump_bit)) );
1041 Node* p1 = basic_plus_adr(dest, x1);
1042 if (val == nullptr) {
1043 assert(raw_val == nullptr, "val may not be null");
1044 mem = StoreNode::make(_igvn, ctrl, mem, p1, adr_type, intcon(0), T_INT, MemNode::unordered);
1045 } else {
1046 assert(_igvn.type(val)->isa_narrowoop(), "should be narrow oop");
1047 mem = new StoreNNode(ctrl, mem, p1, adr_type, val, MemNode::unordered);
1048 }
1049 mem = transform_later(mem);
1050 }
1051 }
1052 Node* end = dest_size; // pre-rounded
1053 mem = ClearArrayNode::clear_memory(ctrl, mem, dest, raw_val,
1054 start, end, &_igvn);
1055 } else {
1056 // Non-constant start, unrounded non-constant end.
1057 // (Nobody zeroes a random midsection of an array using this routine.)
1058 ShouldNotReachHere(); // fix caller
1059 }
1060
1061 // Done.
1062 merge_mem->set_memory_at(alias_idx, mem);
1063 }
1064
1065 bool PhaseMacroExpand::generate_block_arraycopy(Node** ctrl, MergeMemNode** mem, Node* io,
1066 const TypePtr* adr_type,
1067 BasicType basic_elem_type,
1068 AllocateNode* alloc,
1069 Node* src, Node* src_offset,
1070 Node* dest, Node* dest_offset,
1071 Node* dest_size, bool dest_uninitialized) {
1072 // See if there is an advantage from block transfer.
1073 int scale = exact_log2(type2aelembytes(basic_elem_type));
1074 if (scale >= LogBytesPerLong)
1075 return false; // it is already a block transfer
1076
1077 // Look at the alignment of the starting offsets.
1078 int abase = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
1079
1080 intptr_t src_off_con = (intptr_t) _igvn.find_int_con(src_offset, -1);
1081 intptr_t dest_off_con = (intptr_t) _igvn.find_int_con(dest_offset, -1);
1082 if (src_off_con < 0 || dest_off_con < 0) {
1083 // At present, we can only understand constants.
1084 return false;
1085 }
1086
1087 intptr_t src_off = abase + (src_off_con << scale);
1088 intptr_t dest_off = abase + (dest_off_con << scale);
1089
1090 if (((src_off | dest_off) & (BytesPerLong-1)) != 0) {
1091 // Non-aligned; too bad.
1092 // One more chance: Pick off an initial 32-bit word.
1093 // This is a common case, since abase can be odd mod 8.
1094 if (((src_off | dest_off) & (BytesPerLong-1)) == BytesPerInt &&
1095 ((src_off ^ dest_off) & (BytesPerLong-1)) == 0) {
1096 Node* sptr = basic_plus_adr(src, src_off);
1097 Node* dptr = basic_plus_adr(dest, dest_off);
1098 const TypePtr* s_adr_type = _igvn.type(sptr)->is_ptr();
1099 assert(s_adr_type->isa_aryptr(), "impossible slice");
1100 uint s_alias_idx = C->get_alias_index(s_adr_type);
1101 uint d_alias_idx = C->get_alias_index(adr_type);
1102 bool is_mismatched = (basic_elem_type != T_INT);
1103 Node* sval = transform_later(
1104 LoadNode::make(_igvn, *ctrl, (*mem)->memory_at(s_alias_idx), sptr, s_adr_type,
1105 TypeInt::INT, T_INT, MemNode::unordered, LoadNode::DependsOnlyOnTest,
1106 false /*require_atomic_access*/, false /*unaligned*/, is_mismatched));
1107 Node* st = transform_later(
1108 StoreNode::make(_igvn, *ctrl, (*mem)->memory_at(d_alias_idx), dptr, adr_type,
1109 sval, T_INT, MemNode::unordered));
1110 if (is_mismatched) {
1111 st->as_Store()->set_mismatched_access();
1112 }
1113 (*mem)->set_memory_at(d_alias_idx, st);
1114 src_off += BytesPerInt;
1115 dest_off += BytesPerInt;
1116 } else {
1117 return false;
1118 }
1119 }
1120 assert(src_off % BytesPerLong == 0, "");
1121 assert(dest_off % BytesPerLong == 0, "");
1122
1123 // Do this copy by giant steps.
1124 Node* sptr = basic_plus_adr(src, src_off);
1125 Node* dptr = basic_plus_adr(dest, dest_off);
1126 Node* countx = dest_size;
1127 countx = transform_later(new SubXNode(countx, MakeConX(dest_off)));
1128 countx = transform_later(new URShiftXNode(countx, intcon(LogBytesPerLong)));
1129
1130 bool disjoint_bases = true; // since alloc isn't null
1131 generate_unchecked_arraycopy(ctrl, mem,
1132 adr_type, T_LONG, disjoint_bases,
1133 sptr, nullptr, dptr, nullptr, countx, dest_uninitialized);
1134
1135 return true;
1136 }
1137
1138 // Helper function; generates code for the slow case.
1139 // We make a call to a runtime method which emulates the native method,
1140 // but without the native wrapper overhead.
1141 MergeMemNode* PhaseMacroExpand::generate_slow_arraycopy(ArrayCopyNode *ac,
1142 Node** ctrl, Node* mem, Node** io,
1143 const TypePtr* adr_type,
1144 Node* src, Node* src_offset,
1145 Node* dest, Node* dest_offset,
1146 Node* copy_length, bool dest_uninitialized) {
1147 assert(!dest_uninitialized, "Invariant");
1148
1149 const TypeFunc* call_type = OptoRuntime::slow_arraycopy_Type();
1150 CallNode* call = new CallStaticJavaNode(call_type, OptoRuntime::slow_arraycopy_Java(),
1151 "slow_arraycopy", TypePtr::BOTTOM);
1152
1153 call->init_req(TypeFunc::Control, *ctrl);
1154 call->init_req(TypeFunc::I_O , *io);
1155 call->init_req(TypeFunc::Memory , mem);
1156 call->init_req(TypeFunc::ReturnAdr, top());
1157 call->init_req(TypeFunc::FramePtr, top());
1158 call->init_req(TypeFunc::Parms+0, src);
1159 call->init_req(TypeFunc::Parms+1, src_offset);
1160 call->init_req(TypeFunc::Parms+2, dest);
1161 call->init_req(TypeFunc::Parms+3, dest_offset);
1162 call->init_req(TypeFunc::Parms+4, copy_length);
1163 call->copy_call_debug_info(&_igvn, ac);
1164
1165 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
1166 _igvn.replace_node(ac, call);
1167 transform_later(call);
1168
1169 _callprojs = call->extract_projections(false /*separate_io_proj*/, false /*do_asserts*/);
1170 *ctrl = _callprojs->fallthrough_catchproj->clone();
1171 transform_later(*ctrl);
1172
1173 Node* m = _callprojs->fallthrough_memproj->clone();
1174 transform_later(m);
1175
1176 uint alias_idx = C->get_alias_index(adr_type);
1177 MergeMemNode* out_mem;
1178 if (alias_idx != Compile::AliasIdxBot) {
1179 out_mem = MergeMemNode::make(mem);
1180 out_mem->set_memory_at(alias_idx, m);
1181 } else {
1182 out_mem = MergeMemNode::make(m);
1183 }
1184 transform_later(out_mem);
1185
1186 // When src is negative and arraycopy is before an infinite loop,_callprojs.fallthrough_ioproj
1187 // could be nullptr. Skip clone and update nullptr fallthrough_ioproj.
1188 if (_callprojs->fallthrough_ioproj != nullptr) {
1189 *io = _callprojs->fallthrough_ioproj->clone();
1190 transform_later(*io);
1191 } else {
1192 *io = nullptr;
1193 }
1194
1195 return out_mem;
1196 }
1197
1198 // Helper function; generates code for cases requiring runtime checks.
1199 Node* PhaseMacroExpand::generate_checkcast_arraycopy(Node** ctrl, MergeMemNode** mem,
1200 const TypePtr* adr_type,
1201 Node* dest_elem_klass,
1202 Node* src, Node* src_offset,
1203 Node* dest, Node* dest_offset,
1204 Node* copy_length, bool dest_uninitialized) {
1205 if ((*ctrl)->is_top()) return nullptr;
1206
1207 address copyfunc_addr = StubRoutines::checkcast_arraycopy(dest_uninitialized);
1208 if (copyfunc_addr == nullptr) { // Stub was not generated, go slow path.
1209 return nullptr;
1210 }
1211
1212 // Pick out the parameters required to perform a store-check
1213 // for the target array. This is an optimistic check. It will
1214 // look in each non-null element's class, at the desired klass's
1215 // super_check_offset, for the desired klass.
1216 int sco_offset = in_bytes(Klass::super_check_offset_offset());
1217 Node* p3 = basic_plus_adr(dest_elem_klass, sco_offset);
1218 Node* n3 = new LoadINode(nullptr, *mem /*memory(p3)*/, p3, _igvn.type(p3)->is_ptr(), TypeInt::INT, MemNode::unordered);
1219 Node* check_offset = ConvI2X(transform_later(n3));
1220 Node* check_value = dest_elem_klass;
1221
1222 Node* src_start = array_element_address(src, src_offset, T_OBJECT);
1223 Node* dest_start = array_element_address(dest, dest_offset, T_OBJECT);
1224
1225 const TypeFunc* call_type = OptoRuntime::checkcast_arraycopy_Type();
1226 Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "checkcast_arraycopy", adr_type,
1227 src_start, dest_start, copy_length XTOP, check_offset XTOP, check_value);
1228
1229 finish_arraycopy_call(call, ctrl, mem, adr_type);
1230
1231 Node* proj = new ProjNode(call, TypeFunc::Parms);
1232 transform_later(proj);
1233
1234 return proj;
1235 }
1236
1237 // Helper function; generates code for cases requiring runtime checks.
1238 Node* PhaseMacroExpand::generate_generic_arraycopy(Node** ctrl, MergeMemNode** mem,
1239 const TypePtr* adr_type,
1240 Node* src, Node* src_offset,
1241 Node* dest, Node* dest_offset,
1242 Node* copy_length, bool dest_uninitialized) {
1243 if ((*ctrl)->is_top()) return nullptr;
1244 assert(!dest_uninitialized, "Invariant");
1245
1246 address copyfunc_addr = StubRoutines::generic_arraycopy();
1247 if (copyfunc_addr == nullptr) { // Stub was not generated, go slow path.
1248 return nullptr;
1249 }
1250
1251 const TypeFunc* call_type = OptoRuntime::generic_arraycopy_Type();
1252 Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, "generic_arraycopy", adr_type,
1253 src, src_offset, dest, dest_offset, copy_length);
1254
1255 finish_arraycopy_call(call, ctrl, mem, adr_type);
1256
1257 Node* proj = new ProjNode(call, TypeFunc::Parms);
1258 transform_later(proj);
1259
1260 return proj;
1261 }
1262
1263 // Helper function; generates the fast out-of-line call to an arraycopy stub.
1264 void PhaseMacroExpand::generate_unchecked_arraycopy(Node** ctrl, MergeMemNode** mem,
1265 const TypePtr* adr_type,
1266 BasicType basic_elem_type,
1267 bool disjoint_bases,
1268 Node* src, Node* src_offset,
1269 Node* dest, Node* dest_offset,
1270 Node* copy_length, bool dest_uninitialized) {
1271 if ((*ctrl)->is_top()) {
1272 return;
1273 }
1274
1275 Node* src_start = src;
1276 Node* dest_start = dest;
1277 if (src_offset != nullptr || dest_offset != nullptr) {
1278 src_start = array_element_address(src, src_offset, basic_elem_type);
1279 dest_start = array_element_address(dest, dest_offset, basic_elem_type);
1280 }
1281
1282 // Figure out which arraycopy runtime method to call.
1283 const char* copyfunc_name = "arraycopy";
1284 address copyfunc_addr =
1285 basictype2arraycopy(basic_elem_type, src_offset, dest_offset,
1286 disjoint_bases, copyfunc_name, dest_uninitialized);
1287
1288 Node* result_memory = nullptr;
1289 RegionNode* exit_block = nullptr;
1290 if (ArrayOperationPartialInlineSize > 0 && is_subword_type(basic_elem_type) &&
1291 Matcher::vector_width_in_bytes(basic_elem_type) >= 16) {
1292 generate_partial_inlining_block(ctrl, mem, adr_type, &exit_block, &result_memory,
1293 copy_length, src_start, dest_start, basic_elem_type);
1294 }
1295
1296 const TypeFunc* call_type = OptoRuntime::fast_arraycopy_Type();
1297 Node* call = make_leaf_call(*ctrl, *mem, call_type, copyfunc_addr, copyfunc_name, adr_type,
1298 src_start, dest_start, copy_length XTOP);
1299
1300 finish_arraycopy_call(call, ctrl, mem, adr_type);
1301
1302 // Connecting remaining edges for exit_block coming from stub_block.
1303 if (exit_block) {
1304 exit_block->init_req(2, *ctrl);
1305
1306 // Memory edge corresponding to stub_region.
1307 result_memory->init_req(2, *mem);
1308
1309 uint alias_idx = C->get_alias_index(adr_type);
1310 if (alias_idx != Compile::AliasIdxBot) {
1311 *mem = MergeMemNode::make(*mem);
1312 (*mem)->set_memory_at(alias_idx, result_memory);
1313 } else {
1314 *mem = MergeMemNode::make(result_memory);
1315 }
1316 transform_later(*mem);
1317 *ctrl = exit_block;
1318 }
1319 }
1320
1321 const TypePtr* PhaseMacroExpand::adjust_for_flat_array(const TypeAryPtr* top_dest, Node*& src_offset,
1322 Node*& dest_offset, Node*& length, BasicType& dest_elem,
1323 Node*& dest_length) {
1324 #ifdef ASSERT
1325 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1326 bool needs_barriers = top_dest->elem()->inline_klass()->contains_oops() &&
1327 bs->array_copy_requires_gc_barriers(dest_length != nullptr, T_OBJECT, false, false, BarrierSetC2::Optimization);
1328 assert(!needs_barriers || StressReflectiveCode, "Flat arracopy would require GC barriers");
1329 #endif
1330 int elem_size = top_dest->flat_elem_size();
1331 if (elem_size >= 8) {
1332 if (elem_size > 8) {
1333 // treat as array of long but scale length, src offset and dest offset
1334 assert((elem_size % 8) == 0, "not a power of 2?");
1335 int factor = elem_size / 8;
1336 length = transform_later(new MulINode(length, intcon(factor)));
1337 src_offset = transform_later(new MulINode(src_offset, intcon(factor)));
1338 dest_offset = transform_later(new MulINode(dest_offset, intcon(factor)));
1339 if (dest_length != nullptr) {
1340 dest_length = transform_later(new MulINode(dest_length, intcon(factor)));
1341 }
1342 elem_size = 8;
1343 }
1344 dest_elem = T_LONG;
1345 } else if (elem_size == 4) {
1346 dest_elem = T_INT;
1347 } else if (elem_size == 2) {
1348 dest_elem = T_CHAR;
1349 } else if (elem_size == 1) {
1350 dest_elem = T_BYTE;
1351 } else {
1352 ShouldNotReachHere();
1353 }
1354 return TypeRawPtr::BOTTOM;
1355 }
1356
1357 #undef XTOP
1358
1359 void PhaseMacroExpand::expand_arraycopy_node(ArrayCopyNode *ac) {
1360 Node* ctrl = ac->in(TypeFunc::Control);
1361 Node* io = ac->in(TypeFunc::I_O);
1362 Node* src = ac->in(ArrayCopyNode::Src);
1363 Node* src_offset = ac->in(ArrayCopyNode::SrcPos);
1364 Node* dest = ac->in(ArrayCopyNode::Dest);
1365 Node* dest_offset = ac->in(ArrayCopyNode::DestPos);
1366 Node* length = ac->in(ArrayCopyNode::Length);
1367 MergeMemNode* merge_mem = nullptr;
1368
1369 if (ac->is_clonebasic()) {
1370 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1371 bs->clone_at_expansion(this, ac);
1372 return;
1373 } else if (ac->is_copyof() || ac->is_copyofrange() || ac->is_clone_oop_array()) {
1374 const Type* src_type = _igvn.type(src);
1375 const Type* dest_type = _igvn.type(dest);
1376 const TypeAryPtr* top_src = src_type->isa_aryptr();
1377 // Note: The destination could have type Object (i.e. non-array) when directly invoking the protected method
1378 // Object::clone() with reflection on a declared Object that is an array at runtime. top_dest is then null.
1379 const TypeAryPtr* top_dest = dest_type->isa_aryptr();
1380 BasicType dest_elem = T_OBJECT;
1381 if (top_dest != nullptr && top_dest->elem() != Type::BOTTOM) {
1382 dest_elem = top_dest->elem()->array_element_basic_type();
1383 }
1384 if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
1385
1386 if (top_src != nullptr && top_src->is_flat()) {
1387 // If src is flat, dest is guaranteed to be flat as well
1388 top_dest = top_src;
1389 }
1390
1391 AllocateArrayNode* alloc = nullptr;
1392 Node* dest_length = nullptr;
1393 if (ac->is_alloc_tightly_coupled()) {
1394 alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1395 assert(alloc != nullptr, "expect alloc");
1396 dest_length = alloc->in(AllocateNode::ALength);
1397 }
1398
1399 Node* mem = ac->in(TypeFunc::Memory);
1400 const TypePtr* adr_type = nullptr;
1401 if (top_dest != nullptr && top_dest->is_flat()) {
1402 assert(dest_length != nullptr || StressReflectiveCode, "must be tightly coupled");
1403 // Copy to a flat array modifies multiple memory slices. Conservatively insert a barrier
1404 // on all slices to prevent writes into the source from floating below the arraycopy.
1405 int mem_bar_alias_idx = Compile::AliasIdxBot;
1406 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1407 mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
1408 }
1409 insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
1410 adr_type = adjust_for_flat_array(top_dest, src_offset, dest_offset, length, dest_elem, dest_length);
1411 } else {
1412 adr_type = dest_type->is_oopptr()->add_offset(Type::OffsetBot);
1413 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1414 adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
1415 }
1416 if (ac->_src_type != ac->_dest_type) {
1417 adr_type = TypeRawPtr::BOTTOM;
1418 }
1419 }
1420 merge_mem = MergeMemNode::make(mem);
1421 transform_later(merge_mem);
1422
1423 generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1424 adr_type, dest_elem,
1425 src, src_offset, dest, dest_offset, length,
1426 dest_length,
1427 true, ac->has_negative_length_guard());
1428
1429 return;
1430 }
1431
1432 AllocateArrayNode* alloc = nullptr;
1433 if (ac->is_alloc_tightly_coupled()) {
1434 alloc = AllocateArrayNode::Ideal_array_allocation(dest);
1435 assert(alloc != nullptr, "expect alloc");
1436 }
1437
1438 assert(ac->is_arraycopy() || ac->is_arraycopy_validated(), "should be an arraycopy");
1439
1440 // Compile time checks. If any of these checks cannot be verified at compile time,
1441 // we do not make a fast path for this call. Instead, we let the call remain as it
1442 // is. The checks we choose to mandate at compile time are:
1443 //
1444 // (1) src and dest are arrays.
1445 const Type* src_type = src->Value(&_igvn);
1446 const Type* dest_type = dest->Value(&_igvn);
1447 const TypeAryPtr* top_src = src_type->isa_aryptr();
1448 const TypeAryPtr* top_dest = dest_type->isa_aryptr();
1449
1450 BasicType src_elem = T_CONFLICT;
1451 BasicType dest_elem = T_CONFLICT;
1452
1453 if (top_src != nullptr && top_src->elem() != Type::BOTTOM) {
1454 src_elem = top_src->elem()->array_element_basic_type();
1455 }
1456 if (top_dest != nullptr && top_dest->elem() != Type::BOTTOM) {
1457 dest_elem = top_dest->elem()->array_element_basic_type();
1458 }
1459 if (is_reference_type(src_elem, true)) src_elem = T_OBJECT;
1460 if (is_reference_type(dest_elem, true)) dest_elem = T_OBJECT;
1461
1462 if (ac->is_arraycopy_validated() && dest_elem != T_CONFLICT && src_elem == T_CONFLICT) {
1463 src_elem = dest_elem;
1464 }
1465
1466 if (src_elem == T_CONFLICT || dest_elem == T_CONFLICT) {
1467 // Conservatively insert a memory barrier on all memory slices.
1468 // Do not let writes into the source float below the arraycopy.
1469 {
1470 Node* mem = ac->in(TypeFunc::Memory);
1471 insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, Compile::AliasIdxBot);
1472
1473 merge_mem = MergeMemNode::make(mem);
1474 transform_later(merge_mem);
1475 }
1476
1477 // Call StubRoutines::generic_arraycopy stub.
1478 generate_arraycopy(ac, nullptr, &ctrl, merge_mem, &io,
1479 TypeRawPtr::BOTTOM, T_CONFLICT,
1480 src, src_offset, dest, dest_offset, length,
1481 nullptr,
1482 // If a negative length guard was generated for the ArrayCopyNode,
1483 // the length of the array can never be negative.
1484 false, ac->has_negative_length_guard());
1485 return;
1486 }
1487
1488 assert(!ac->is_arraycopy_validated() || (src_elem == dest_elem && dest_elem != T_VOID), "validated but different basic types");
1489
1490 // (2) src and dest arrays must have elements of the same BasicType
1491 // Figure out the size and type of the elements we will be copying.
1492 //
1493 // We have no stub to copy flat inline type arrays with oop
1494 // fields if we need to emit write barriers.
1495 //
1496 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
1497 if (src_elem != dest_elem || top_src->is_flat() != top_dest->is_flat() || dest_elem == T_VOID ||
1498 (top_src->is_flat() && top_dest->elem()->inline_klass()->contains_oops() &&
1499 bs->array_copy_requires_gc_barriers(alloc != nullptr, T_OBJECT, false, false, BarrierSetC2::Optimization))) {
1500 // The component types are not the same or are not recognized. Punt.
1501 // (But, avoid the native method wrapper to JVM_ArrayCopy.)
1502 {
1503 Node* mem = ac->in(TypeFunc::Memory);
1504 merge_mem = generate_slow_arraycopy(ac, &ctrl, mem, &io, TypePtr::BOTTOM, src, src_offset, dest, dest_offset, length, false);
1505 }
1506
1507 _igvn.replace_node(_callprojs->fallthrough_memproj, merge_mem);
1508 if (_callprojs->fallthrough_ioproj != nullptr) {
1509 _igvn.replace_node(_callprojs->fallthrough_ioproj, io);
1510 }
1511 _igvn.replace_node(_callprojs->fallthrough_catchproj, ctrl);
1512 return;
1513 }
1514
1515 //---------------------------------------------------------------------------
1516 // We will make a fast path for this call to arraycopy.
1517
1518 // We have the following tests left to perform:
1519 //
1520 // (3) src and dest must not be null.
1521 // (4) src_offset must not be negative.
1522 // (5) dest_offset must not be negative.
1523 // (6) length must not be negative.
1524 // (7) src_offset + length must not exceed length of src.
1525 // (8) dest_offset + length must not exceed length of dest.
1526 // (9) each element of an oop array must be assignable
1527
1528 Node* mem = ac->in(TypeFunc::Memory);
1529 if (top_dest->is_flat()) {
1530 // Copy to a flat array modifies multiple memory slices. Conservatively insert a barrier
1531 // on all slices to prevent writes into the source from floating below the arraycopy.
1532 int mem_bar_alias_idx = Compile::AliasIdxBot;
1533 if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1534 mem_bar_alias_idx = C->get_alias_index(ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr());
1535 }
1536 insert_mem_bar(&ctrl, &mem, Op_MemBarCPUOrder, mem_bar_alias_idx);
1537 }
1538 merge_mem = MergeMemNode::make(mem);
1539 transform_later(merge_mem);
1540
1541 RegionNode* slow_region = new RegionNode(1);
1542 transform_later(slow_region);
1543
1544 if (!ac->is_arraycopy_validated()) {
1545 // (3) operands must not be null
1546 // We currently perform our null checks with the null_check routine.
1547 // This means that the null exceptions will be reported in the caller
1548 // rather than (correctly) reported inside of the native arraycopy call.
1549 // This should be corrected, given time. We do our null check with the
1550 // stack pointer restored.
1551 // null checks done library_call.cpp
1552
1553 // (4) src_offset must not be negative.
1554 generate_negative_guard(&ctrl, src_offset, slow_region);
1555
1556 // (5) dest_offset must not be negative.
1557 generate_negative_guard(&ctrl, dest_offset, slow_region);
1558
1559 // (6) length must not be negative (moved to generate_arraycopy()).
1560 // generate_negative_guard(length, slow_region);
1561
1562 // (7) src_offset + length must not exceed length of src.
1563 Node* alen = ac->in(ArrayCopyNode::SrcLen);
1564 assert(alen != nullptr, "need src len");
1565 generate_limit_guard(&ctrl,
1566 src_offset, length,
1567 alen,
1568 slow_region);
1569
1570 // (8) dest_offset + length must not exceed length of dest.
1571 alen = ac->in(ArrayCopyNode::DestLen);
1572 assert(alen != nullptr, "need dest len");
1573 generate_limit_guard(&ctrl,
1574 dest_offset, length,
1575 alen,
1576 slow_region);
1577
1578 // (9) each element of an oop array must be assignable
1579 // The generate_arraycopy subroutine checks this.
1580
1581 // TODO 8350865 Fix below logic. Also handle atomicity.
1582 // 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.
1583 if (!(top_src->is_flat() && top_dest->is_flat())) {
1584 generate_flat_array_guard(&ctrl, src, merge_mem, slow_region);
1585 generate_flat_array_guard(&ctrl, dest, merge_mem, slow_region);
1586 }
1587
1588 // Handle inline type arrays
1589 if (!top_src->is_flat()) {
1590 if (UseArrayFlattening && !top_src->is_not_flat()) {
1591 // Src might be flat and dest might not be flat. Go to the slow path if src is flat.
1592 generate_flat_array_guard(&ctrl, src, merge_mem, slow_region);
1593 }
1594 if (EnableValhalla) {
1595 // No validation. The subtype check emitted at macro expansion time will not go to the slow
1596 // path but call checkcast_arraycopy which can not handle flat/null-free inline type arrays.
1597 generate_null_free_array_guard(&ctrl, dest, merge_mem, slow_region);
1598 }
1599 } else {
1600 assert(top_dest->is_flat(), "dest array must be flat");
1601 }
1602 }
1603
1604 // This is where the memory effects are placed:
1605 const TypePtr* adr_type = nullptr;
1606 Node* dest_length = (alloc != nullptr) ? alloc->in(AllocateNode::ALength) : nullptr;
1607
1608 if (top_src->is_flat() && top_dest->is_flat()) {
1609 adr_type = adjust_for_flat_array(top_dest, src_offset, dest_offset, length, dest_elem, dest_length);
1610 } else if (ac->_dest_type != TypeOopPtr::BOTTOM) {
1611 adr_type = ac->_dest_type->add_offset(Type::OffsetBot)->is_ptr();
1612 } else {
1613 adr_type = TypeAryPtr::get_array_body_type(dest_elem);
1614 }
1615
1616 generate_arraycopy(ac, alloc, &ctrl, merge_mem, &io,
1617 adr_type, dest_elem,
1618 src, src_offset, dest, dest_offset, length,
1619 dest_length,
1620 // If a negative length guard was generated for the ArrayCopyNode,
1621 // the length of the array can never be negative.
1622 false, ac->has_negative_length_guard(),
1623 slow_region);
1624 }