Mercurial > hg > truffle
annotate src/share/vm/opto/memnode.cpp @ 17:ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
Reviewed-by: kvn, rasbold
| author | never |
|---|---|
| date | Wed, 05 Dec 2007 09:01:00 -0800 |
| parents | a61af66fc99e |
| children | d5fc211aea19 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, | |
| 20 * CA 95054 USA or visit www.sun.com if you need additional information or | |
| 21 * have any questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 // Portions of code courtesy of Clifford Click | |
| 26 | |
| 27 // Optimization - Graph Style | |
| 28 | |
| 29 #include "incls/_precompiled.incl" | |
| 30 #include "incls/_memnode.cpp.incl" | |
| 31 | |
| 32 //============================================================================= | |
| 33 uint MemNode::size_of() const { return sizeof(*this); } | |
| 34 | |
| 35 const TypePtr *MemNode::adr_type() const { | |
| 36 Node* adr = in(Address); | |
| 37 const TypePtr* cross_check = NULL; | |
| 38 DEBUG_ONLY(cross_check = _adr_type); | |
| 39 return calculate_adr_type(adr->bottom_type(), cross_check); | |
| 40 } | |
| 41 | |
| 42 #ifndef PRODUCT | |
| 43 void MemNode::dump_spec(outputStream *st) const { | |
| 44 if (in(Address) == NULL) return; // node is dead | |
| 45 #ifndef ASSERT | |
| 46 // fake the missing field | |
| 47 const TypePtr* _adr_type = NULL; | |
| 48 if (in(Address) != NULL) | |
| 49 _adr_type = in(Address)->bottom_type()->isa_ptr(); | |
| 50 #endif | |
| 51 dump_adr_type(this, _adr_type, st); | |
| 52 | |
| 53 Compile* C = Compile::current(); | |
| 54 if( C->alias_type(_adr_type)->is_volatile() ) | |
| 55 st->print(" Volatile!"); | |
| 56 } | |
| 57 | |
| 58 void MemNode::dump_adr_type(const Node* mem, const TypePtr* adr_type, outputStream *st) { | |
| 59 st->print(" @"); | |
| 60 if (adr_type == NULL) { | |
| 61 st->print("NULL"); | |
| 62 } else { | |
| 63 adr_type->dump_on(st); | |
| 64 Compile* C = Compile::current(); | |
| 65 Compile::AliasType* atp = NULL; | |
| 66 if (C->have_alias_type(adr_type)) atp = C->alias_type(adr_type); | |
| 67 if (atp == NULL) | |
| 68 st->print(", idx=?\?;"); | |
| 69 else if (atp->index() == Compile::AliasIdxBot) | |
| 70 st->print(", idx=Bot;"); | |
| 71 else if (atp->index() == Compile::AliasIdxTop) | |
| 72 st->print(", idx=Top;"); | |
| 73 else if (atp->index() == Compile::AliasIdxRaw) | |
| 74 st->print(", idx=Raw;"); | |
| 75 else { | |
| 76 ciField* field = atp->field(); | |
| 77 if (field) { | |
| 78 st->print(", name="); | |
| 79 field->print_name_on(st); | |
| 80 } | |
| 81 st->print(", idx=%d;", atp->index()); | |
| 82 } | |
| 83 } | |
| 84 } | |
| 85 | |
| 86 extern void print_alias_types(); | |
| 87 | |
| 88 #endif | |
| 89 | |
| 90 //--------------------------Ideal_common--------------------------------------- | |
| 91 // Look for degenerate control and memory inputs. Bypass MergeMem inputs. | |
| 92 // Unhook non-raw memories from complete (macro-expanded) initializations. | |
| 93 Node *MemNode::Ideal_common(PhaseGVN *phase, bool can_reshape) { | |
| 94 // If our control input is a dead region, kill all below the region | |
| 95 Node *ctl = in(MemNode::Control); | |
| 96 if (ctl && remove_dead_region(phase, can_reshape)) | |
| 97 return this; | |
| 98 | |
| 99 // Ignore if memory is dead, or self-loop | |
| 100 Node *mem = in(MemNode::Memory); | |
| 101 if( phase->type( mem ) == Type::TOP ) return NodeSentinel; // caller will return NULL | |
| 102 assert( mem != this, "dead loop in MemNode::Ideal" ); | |
| 103 | |
| 104 Node *address = in(MemNode::Address); | |
| 105 const Type *t_adr = phase->type( address ); | |
| 106 if( t_adr == Type::TOP ) return NodeSentinel; // caller will return NULL | |
| 107 | |
| 108 // Avoid independent memory operations | |
| 109 Node* old_mem = mem; | |
| 110 | |
| 111 if (mem->is_Proj() && mem->in(0)->is_Initialize()) { | |
| 112 InitializeNode* init = mem->in(0)->as_Initialize(); | |
| 113 if (init->is_complete()) { // i.e., after macro expansion | |
| 114 const TypePtr* tp = t_adr->is_ptr(); | |
| 115 uint alias_idx = phase->C->get_alias_index(tp); | |
| 116 // Free this slice from the init. It was hooked, temporarily, | |
| 117 // by GraphKit::set_output_for_allocation. | |
| 118 if (alias_idx > Compile::AliasIdxRaw) { | |
| 119 mem = init->memory(alias_idx); | |
| 120 // ...but not with the raw-pointer slice. | |
| 121 } | |
| 122 } | |
| 123 } | |
| 124 | |
| 125 if (mem->is_MergeMem()) { | |
| 126 MergeMemNode* mmem = mem->as_MergeMem(); | |
| 127 const TypePtr *tp = t_adr->is_ptr(); | |
| 128 uint alias_idx = phase->C->get_alias_index(tp); | |
| 129 #ifdef ASSERT | |
| 130 { | |
| 131 // Check that current type is consistent with the alias index used during graph construction | |
| 132 assert(alias_idx >= Compile::AliasIdxRaw, "must not be a bad alias_idx"); | |
| 133 const TypePtr *adr_t = adr_type(); | |
| 134 bool consistent = adr_t == NULL || adr_t->empty() || phase->C->must_alias(adr_t, alias_idx ); | |
| 135 // Sometimes dead array references collapse to a[-1], a[-2], or a[-3] | |
| 136 if( !consistent && adr_t != NULL && !adr_t->empty() && | |
| 137 tp->isa_aryptr() && tp->offset() == Type::OffsetBot && | |
| 138 adr_t->isa_aryptr() && adr_t->offset() != Type::OffsetBot && | |
| 139 ( adr_t->offset() == arrayOopDesc::length_offset_in_bytes() || | |
| 140 adr_t->offset() == oopDesc::klass_offset_in_bytes() || | |
| 141 adr_t->offset() == oopDesc::mark_offset_in_bytes() ) ) { | |
| 142 // don't assert if it is dead code. | |
| 143 consistent = true; | |
| 144 } | |
| 145 if( !consistent ) { | |
| 146 tty->print("alias_idx==%d, adr_type()==", alias_idx); if( adr_t == NULL ) { tty->print("NULL"); } else { adr_t->dump(); } | |
| 147 tty->cr(); | |
| 148 print_alias_types(); | |
| 149 assert(consistent, "adr_type must match alias idx"); | |
| 150 } | |
| 151 } | |
| 152 #endif | |
| 153 // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally | |
| 154 // means an array I have not precisely typed yet. Do not do any | |
| 155 // alias stuff with it any time soon. | |
| 156 const TypeInstPtr *tinst = tp->isa_instptr(); | |
| 157 if( tp->base() != Type::AnyPtr && | |
| 158 !(tinst && | |
| 159 tinst->klass()->is_java_lang_Object() && | |
| 160 tinst->offset() == Type::OffsetBot) ) { | |
| 161 // compress paths and change unreachable cycles to TOP | |
| 162 // If not, we can update the input infinitely along a MergeMem cycle | |
| 163 // Equivalent code in PhiNode::Ideal | |
| 164 Node* m = phase->transform(mmem); | |
| 165 // If tranformed to a MergeMem, get the desired slice | |
| 166 // Otherwise the returned node represents memory for every slice | |
| 167 mem = (m->is_MergeMem())? m->as_MergeMem()->memory_at(alias_idx) : m; | |
| 168 // Update input if it is progress over what we have now | |
| 169 } | |
| 170 } | |
| 171 | |
| 172 if (mem != old_mem) { | |
| 173 set_req(MemNode::Memory, mem); | |
| 174 return this; | |
| 175 } | |
| 176 | |
| 177 // let the subclass continue analyzing... | |
| 178 return NULL; | |
| 179 } | |
| 180 | |
| 181 // Helper function for proving some simple control dominations. | |
| 182 // Attempt to prove that control input 'dom' dominates (or equals) 'sub'. | |
| 183 // Already assumes that 'dom' is available at 'sub', and that 'sub' | |
| 184 // is not a constant (dominated by the method's StartNode). | |
| 185 // Used by MemNode::find_previous_store to prove that the | |
| 186 // control input of a memory operation predates (dominates) | |
| 187 // an allocation it wants to look past. | |
| 188 bool MemNode::detect_dominating_control(Node* dom, Node* sub) { | |
| 189 if (dom == NULL) return false; | |
| 190 if (dom->is_Proj()) dom = dom->in(0); | |
| 191 if (dom->is_Start()) return true; // anything inside the method | |
| 192 if (dom->is_Root()) return true; // dom 'controls' a constant | |
| 193 int cnt = 20; // detect cycle or too much effort | |
| 194 while (sub != NULL) { // walk 'sub' up the chain to 'dom' | |
| 195 if (--cnt < 0) return false; // in a cycle or too complex | |
| 196 if (sub == dom) return true; | |
| 197 if (sub->is_Start()) return false; | |
| 198 if (sub->is_Root()) return false; | |
| 199 Node* up = sub->in(0); | |
| 200 if (sub == up && sub->is_Region()) { | |
| 201 for (uint i = 1; i < sub->req(); i++) { | |
| 202 Node* in = sub->in(i); | |
| 203 if (in != NULL && !in->is_top() && in != sub) { | |
| 204 up = in; break; // take any path on the way up to 'dom' | |
| 205 } | |
| 206 } | |
| 207 } | |
| 208 if (sub == up) return false; // some kind of tight cycle | |
| 209 sub = up; | |
| 210 } | |
| 211 return false; | |
| 212 } | |
| 213 | |
| 214 //---------------------detect_ptr_independence--------------------------------- | |
| 215 // Used by MemNode::find_previous_store to prove that two base | |
| 216 // pointers are never equal. | |
| 217 // The pointers are accompanied by their associated allocations, | |
| 218 // if any, which have been previously discovered by the caller. | |
| 219 bool MemNode::detect_ptr_independence(Node* p1, AllocateNode* a1, | |
| 220 Node* p2, AllocateNode* a2, | |
| 221 PhaseTransform* phase) { | |
| 222 // Attempt to prove that these two pointers cannot be aliased. | |
| 223 // They may both manifestly be allocations, and they should differ. | |
| 224 // Or, if they are not both allocations, they can be distinct constants. | |
| 225 // Otherwise, one is an allocation and the other a pre-existing value. | |
| 226 if (a1 == NULL && a2 == NULL) { // neither an allocation | |
| 227 return (p1 != p2) && p1->is_Con() && p2->is_Con(); | |
| 228 } else if (a1 != NULL && a2 != NULL) { // both allocations | |
| 229 return (a1 != a2); | |
| 230 } else if (a1 != NULL) { // one allocation a1 | |
| 231 // (Note: p2->is_Con implies p2->in(0)->is_Root, which dominates.) | |
| 232 return detect_dominating_control(p2->in(0), a1->in(0)); | |
| 233 } else { //(a2 != NULL) // one allocation a2 | |
| 234 return detect_dominating_control(p1->in(0), a2->in(0)); | |
| 235 } | |
| 236 return false; | |
| 237 } | |
| 238 | |
| 239 | |
| 240 // The logic for reordering loads and stores uses four steps: | |
| 241 // (a) Walk carefully past stores and initializations which we | |
| 242 // can prove are independent of this load. | |
| 243 // (b) Observe that the next memory state makes an exact match | |
| 244 // with self (load or store), and locate the relevant store. | |
| 245 // (c) Ensure that, if we were to wire self directly to the store, | |
| 246 // the optimizer would fold it up somehow. | |
| 247 // (d) Do the rewiring, and return, depending on some other part of | |
| 248 // the optimizer to fold up the load. | |
| 249 // This routine handles steps (a) and (b). Steps (c) and (d) are | |
| 250 // specific to loads and stores, so they are handled by the callers. | |
| 251 // (Currently, only LoadNode::Ideal has steps (c), (d). More later.) | |
| 252 // | |
| 253 Node* MemNode::find_previous_store(PhaseTransform* phase) { | |
| 254 Node* ctrl = in(MemNode::Control); | |
| 255 Node* adr = in(MemNode::Address); | |
| 256 intptr_t offset = 0; | |
| 257 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); | |
| 258 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase); | |
| 259 | |
| 260 if (offset == Type::OffsetBot) | |
| 261 return NULL; // cannot unalias unless there are precise offsets | |
| 262 | |
| 263 intptr_t size_in_bytes = memory_size(); | |
| 264 | |
| 265 Node* mem = in(MemNode::Memory); // start searching here... | |
| 266 | |
| 267 int cnt = 50; // Cycle limiter | |
| 268 for (;;) { // While we can dance past unrelated stores... | |
| 269 if (--cnt < 0) break; // Caught in cycle or a complicated dance? | |
| 270 | |
| 271 if (mem->is_Store()) { | |
| 272 Node* st_adr = mem->in(MemNode::Address); | |
| 273 intptr_t st_offset = 0; | |
| 274 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset); | |
| 275 if (st_base == NULL) | |
| 276 break; // inscrutable pointer | |
| 277 if (st_offset != offset && st_offset != Type::OffsetBot) { | |
| 278 const int MAX_STORE = BytesPerLong; | |
| 279 if (st_offset >= offset + size_in_bytes || | |
| 280 st_offset <= offset - MAX_STORE || | |
| 281 st_offset <= offset - mem->as_Store()->memory_size()) { | |
| 282 // Success: The offsets are provably independent. | |
| 283 // (You may ask, why not just test st_offset != offset and be done? | |
| 284 // The answer is that stores of different sizes can co-exist | |
| 285 // in the same sequence of RawMem effects. We sometimes initialize | |
| 286 // a whole 'tile' of array elements with a single jint or jlong.) | |
| 287 mem = mem->in(MemNode::Memory); | |
| 288 continue; // (a) advance through independent store memory | |
| 289 } | |
| 290 } | |
| 291 if (st_base != base && | |
| 292 detect_ptr_independence(base, alloc, | |
| 293 st_base, | |
| 294 AllocateNode::Ideal_allocation(st_base, phase), | |
| 295 phase)) { | |
| 296 // Success: The bases are provably independent. | |
| 297 mem = mem->in(MemNode::Memory); | |
| 298 continue; // (a) advance through independent store memory | |
| 299 } | |
| 300 | |
| 301 // (b) At this point, if the bases or offsets do not agree, we lose, | |
| 302 // since we have not managed to prove 'this' and 'mem' independent. | |
| 303 if (st_base == base && st_offset == offset) { | |
| 304 return mem; // let caller handle steps (c), (d) | |
| 305 } | |
| 306 | |
| 307 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) { | |
| 308 InitializeNode* st_init = mem->in(0)->as_Initialize(); | |
| 309 AllocateNode* st_alloc = st_init->allocation(); | |
| 310 if (st_alloc == NULL) | |
| 311 break; // something degenerated | |
| 312 bool known_identical = false; | |
| 313 bool known_independent = false; | |
| 314 if (alloc == st_alloc) | |
| 315 known_identical = true; | |
| 316 else if (alloc != NULL) | |
| 317 known_independent = true; | |
| 318 else if (ctrl != NULL && | |
| 319 detect_dominating_control(ctrl, st_alloc->in(0))) | |
| 320 known_independent = true; | |
| 321 | |
| 322 if (known_independent) { | |
| 323 // The bases are provably independent: Either they are | |
| 324 // manifestly distinct allocations, or else the control | |
| 325 // of this load dominates the store's allocation. | |
| 326 int alias_idx = phase->C->get_alias_index(adr_type()); | |
| 327 if (alias_idx == Compile::AliasIdxRaw) { | |
| 328 mem = st_alloc->in(TypeFunc::Memory); | |
| 329 } else { | |
| 330 mem = st_init->memory(alias_idx); | |
| 331 } | |
| 332 continue; // (a) advance through independent store memory | |
| 333 } | |
| 334 | |
| 335 // (b) at this point, if we are not looking at a store initializing | |
| 336 // the same allocation we are loading from, we lose. | |
| 337 if (known_identical) { | |
| 338 // From caller, can_see_stored_value will consult find_captured_store. | |
| 339 return mem; // let caller handle steps (c), (d) | |
| 340 } | |
| 341 | |
| 342 } | |
| 343 | |
| 344 // Unless there is an explicit 'continue', we must bail out here, | |
| 345 // because 'mem' is an inscrutable memory state (e.g., a call). | |
| 346 break; | |
| 347 } | |
| 348 | |
| 349 return NULL; // bail out | |
| 350 } | |
| 351 | |
| 352 //----------------------calculate_adr_type------------------------------------- | |
| 353 // Helper function. Notices when the given type of address hits top or bottom. | |
| 354 // Also, asserts a cross-check of the type against the expected address type. | |
| 355 const TypePtr* MemNode::calculate_adr_type(const Type* t, const TypePtr* cross_check) { | |
| 356 if (t == Type::TOP) return NULL; // does not touch memory any more? | |
| 357 #ifdef PRODUCT | |
| 358 cross_check = NULL; | |
| 359 #else | |
| 360 if (!VerifyAliases || is_error_reported() || Node::in_dump()) cross_check = NULL; | |
| 361 #endif | |
| 362 const TypePtr* tp = t->isa_ptr(); | |
| 363 if (tp == NULL) { | |
| 364 assert(cross_check == NULL || cross_check == TypePtr::BOTTOM, "expected memory type must be wide"); | |
| 365 return TypePtr::BOTTOM; // touches lots of memory | |
| 366 } else { | |
| 367 #ifdef ASSERT | |
| 368 // %%%% [phh] We don't check the alias index if cross_check is | |
| 369 // TypeRawPtr::BOTTOM. Needs to be investigated. | |
| 370 if (cross_check != NULL && | |
| 371 cross_check != TypePtr::BOTTOM && | |
| 372 cross_check != TypeRawPtr::BOTTOM) { | |
| 373 // Recheck the alias index, to see if it has changed (due to a bug). | |
| 374 Compile* C = Compile::current(); | |
| 375 assert(C->get_alias_index(cross_check) == C->get_alias_index(tp), | |
| 376 "must stay in the original alias category"); | |
| 377 // The type of the address must be contained in the adr_type, | |
| 378 // disregarding "null"-ness. | |
| 379 // (We make an exception for TypeRawPtr::BOTTOM, which is a bit bucket.) | |
| 380 const TypePtr* tp_notnull = tp->join(TypePtr::NOTNULL)->is_ptr(); | |
| 381 assert(cross_check->meet(tp_notnull) == cross_check, | |
| 382 "real address must not escape from expected memory type"); | |
| 383 } | |
| 384 #endif | |
| 385 return tp; | |
| 386 } | |
| 387 } | |
| 388 | |
| 389 //------------------------adr_phi_is_loop_invariant---------------------------- | |
| 390 // A helper function for Ideal_DU_postCCP to check if a Phi in a counted | |
| 391 // loop is loop invariant. Make a quick traversal of Phi and associated | |
| 392 // CastPP nodes, looking to see if they are a closed group within the loop. | |
| 393 bool MemNode::adr_phi_is_loop_invariant(Node* adr_phi, Node* cast) { | |
| 394 // The idea is that the phi-nest must boil down to only CastPP nodes | |
| 395 // with the same data. This implies that any path into the loop already | |
| 396 // includes such a CastPP, and so the original cast, whatever its input, | |
| 397 // must be covered by an equivalent cast, with an earlier control input. | |
| 398 ResourceMark rm; | |
| 399 | |
| 400 // The loop entry input of the phi should be the unique dominating | |
| 401 // node for every Phi/CastPP in the loop. | |
| 402 Unique_Node_List closure; | |
| 403 closure.push(adr_phi->in(LoopNode::EntryControl)); | |
| 404 | |
| 405 // Add the phi node and the cast to the worklist. | |
| 406 Unique_Node_List worklist; | |
| 407 worklist.push(adr_phi); | |
| 408 if( cast != NULL ){ | |
| 409 if( !cast->is_ConstraintCast() ) return false; | |
| 410 worklist.push(cast); | |
| 411 } | |
| 412 | |
| 413 // Begin recursive walk of phi nodes. | |
| 414 while( worklist.size() ){ | |
| 415 // Take a node off the worklist | |
| 416 Node *n = worklist.pop(); | |
| 417 if( !closure.member(n) ){ | |
| 418 // Add it to the closure. | |
| 419 closure.push(n); | |
| 420 // Make a sanity check to ensure we don't waste too much time here. | |
| 421 if( closure.size() > 20) return false; | |
| 422 // This node is OK if: | |
| 423 // - it is a cast of an identical value | |
| 424 // - or it is a phi node (then we add its inputs to the worklist) | |
| 425 // Otherwise, the node is not OK, and we presume the cast is not invariant | |
| 426 if( n->is_ConstraintCast() ){ | |
| 427 worklist.push(n->in(1)); | |
| 428 } else if( n->is_Phi() ) { | |
| 429 for( uint i = 1; i < n->req(); i++ ) { | |
| 430 worklist.push(n->in(i)); | |
| 431 } | |
| 432 } else { | |
| 433 return false; | |
| 434 } | |
| 435 } | |
| 436 } | |
| 437 | |
| 438 // Quit when the worklist is empty, and we've found no offending nodes. | |
| 439 return true; | |
| 440 } | |
| 441 | |
| 442 //------------------------------Ideal_DU_postCCP------------------------------- | |
| 443 // Find any cast-away of null-ness and keep its control. Null cast-aways are | |
| 444 // going away in this pass and we need to make this memory op depend on the | |
| 445 // gating null check. | |
| 446 | |
| 447 // I tried to leave the CastPP's in. This makes the graph more accurate in | |
| 448 // some sense; we get to keep around the knowledge that an oop is not-null | |
| 449 // after some test. Alas, the CastPP's interfere with GVN (some values are | |
| 450 // the regular oop, some are the CastPP of the oop, all merge at Phi's which | |
| 451 // cannot collapse, etc). This cost us 10% on SpecJVM, even when I removed | |
| 452 // some of the more trivial cases in the optimizer. Removing more useless | |
| 453 // Phi's started allowing Loads to illegally float above null checks. I gave | |
| 454 // up on this approach. CNC 10/20/2000 | |
| 455 Node *MemNode::Ideal_DU_postCCP( PhaseCCP *ccp ) { | |
| 456 Node *ctr = in(MemNode::Control); | |
| 457 Node *mem = in(MemNode::Memory); | |
| 458 Node *adr = in(MemNode::Address); | |
| 459 Node *skipped_cast = NULL; | |
| 460 // Need a null check? Regular static accesses do not because they are | |
| 461 // from constant addresses. Array ops are gated by the range check (which | |
| 462 // always includes a NULL check). Just check field ops. | |
| 463 if( !ctr ) { | |
| 464 // Scan upwards for the highest location we can place this memory op. | |
| 465 while( true ) { | |
| 466 switch( adr->Opcode() ) { | |
| 467 | |
| 468 case Op_AddP: // No change to NULL-ness, so peek thru AddP's | |
| 469 adr = adr->in(AddPNode::Base); | |
| 470 continue; | |
| 471 | |
| 472 case Op_CastPP: | |
| 473 // If the CastPP is useless, just peek on through it. | |
| 474 if( ccp->type(adr) == ccp->type(adr->in(1)) ) { | |
| 475 // Remember the cast that we've peeked though. If we peek | |
| 476 // through more than one, then we end up remembering the highest | |
| 477 // one, that is, if in a loop, the one closest to the top. | |
| 478 skipped_cast = adr; | |
| 479 adr = adr->in(1); | |
| 480 continue; | |
| 481 } | |
| 482 // CastPP is going away in this pass! We need this memory op to be | |
| 483 // control-dependent on the test that is guarding the CastPP. | |
| 484 ccp->hash_delete(this); | |
| 485 set_req(MemNode::Control, adr->in(0)); | |
| 486 ccp->hash_insert(this); | |
| 487 return this; | |
| 488 | |
| 489 case Op_Phi: | |
| 490 // Attempt to float above a Phi to some dominating point. | |
| 491 if (adr->in(0) != NULL && adr->in(0)->is_CountedLoop()) { | |
| 492 // If we've already peeked through a Cast (which could have set the | |
| 493 // control), we can't float above a Phi, because the skipped Cast | |
| 494 // may not be loop invariant. | |
| 495 if (adr_phi_is_loop_invariant(adr, skipped_cast)) { | |
| 496 adr = adr->in(1); | |
| 497 continue; | |
| 498 } | |
| 499 } | |
| 500 | |
| 501 // Intentional fallthrough! | |
| 502 | |
| 503 // No obvious dominating point. The mem op is pinned below the Phi | |
| 504 // by the Phi itself. If the Phi goes away (no true value is merged) | |
| 505 // then the mem op can float, but not indefinitely. It must be pinned | |
| 506 // behind the controls leading to the Phi. | |
| 507 case Op_CheckCastPP: | |
| 508 // These usually stick around to change address type, however a | |
| 509 // useless one can be elided and we still need to pick up a control edge | |
| 510 if (adr->in(0) == NULL) { | |
| 511 // This CheckCastPP node has NO control and is likely useless. But we | |
| 512 // need check further up the ancestor chain for a control input to keep | |
| 513 // the node in place. 4959717. | |
| 514 skipped_cast = adr; | |
| 515 adr = adr->in(1); | |
| 516 continue; | |
| 517 } | |
| 518 ccp->hash_delete(this); | |
| 519 set_req(MemNode::Control, adr->in(0)); | |
| 520 ccp->hash_insert(this); | |
| 521 return this; | |
| 522 | |
| 523 // List of "safe" opcodes; those that implicitly block the memory | |
| 524 // op below any null check. | |
| 525 case Op_CastX2P: // no null checks on native pointers | |
| 526 case Op_Parm: // 'this' pointer is not null | |
| 527 case Op_LoadP: // Loading from within a klass | |
| 528 case Op_LoadKlass: // Loading from within a klass | |
| 529 case Op_ConP: // Loading from a klass | |
| 530 case Op_CreateEx: // Sucking up the guts of an exception oop | |
| 531 case Op_Con: // Reading from TLS | |
| 532 case Op_CMoveP: // CMoveP is pinned | |
| 533 break; // No progress | |
| 534 | |
| 535 case Op_Proj: // Direct call to an allocation routine | |
| 536 case Op_SCMemProj: // Memory state from store conditional ops | |
| 537 #ifdef ASSERT | |
| 538 { | |
| 539 assert(adr->as_Proj()->_con == TypeFunc::Parms, "must be return value"); | |
| 540 const Node* call = adr->in(0); | |
| 541 if (call->is_CallStaticJava()) { | |
| 542 const CallStaticJavaNode* call_java = call->as_CallStaticJava(); | |
| 543 assert(call_java && call_java->method() == NULL, "must be runtime call"); | |
| 544 // We further presume that this is one of | |
| 545 // new_instance_Java, new_array_Java, or | |
| 546 // the like, but do not assert for this. | |
| 547 } else if (call->is_Allocate()) { | |
| 548 // similar case to new_instance_Java, etc. | |
| 549 } else if (!call->is_CallLeaf()) { | |
| 550 // Projections from fetch_oop (OSR) are allowed as well. | |
| 551 ShouldNotReachHere(); | |
| 552 } | |
| 553 } | |
| 554 #endif | |
| 555 break; | |
| 556 default: | |
| 557 ShouldNotReachHere(); | |
| 558 } | |
| 559 break; | |
| 560 } | |
| 561 } | |
| 562 | |
| 563 return NULL; // No progress | |
| 564 } | |
| 565 | |
| 566 | |
| 567 //============================================================================= | |
| 568 uint LoadNode::size_of() const { return sizeof(*this); } | |
| 569 uint LoadNode::cmp( const Node &n ) const | |
| 570 { return !Type::cmp( _type, ((LoadNode&)n)._type ); } | |
| 571 const Type *LoadNode::bottom_type() const { return _type; } | |
| 572 uint LoadNode::ideal_reg() const { | |
| 573 return Matcher::base2reg[_type->base()]; | |
| 574 } | |
| 575 | |
| 576 #ifndef PRODUCT | |
| 577 void LoadNode::dump_spec(outputStream *st) const { | |
| 578 MemNode::dump_spec(st); | |
| 579 if( !Verbose && !WizardMode ) { | |
| 580 // standard dump does this in Verbose and WizardMode | |
| 581 st->print(" #"); _type->dump_on(st); | |
| 582 } | |
| 583 } | |
| 584 #endif | |
| 585 | |
| 586 | |
| 587 //----------------------------LoadNode::make----------------------------------- | |
| 588 // Polymorphic factory method: | |
| 589 LoadNode *LoadNode::make( Compile *C, Node *ctl, Node *mem, Node *adr, const TypePtr* adr_type, const Type *rt, BasicType bt ) { | |
| 590 // sanity check the alias category against the created node type | |
| 591 assert(!(adr_type->isa_oopptr() && | |
| 592 adr_type->offset() == oopDesc::klass_offset_in_bytes()), | |
| 593 "use LoadKlassNode instead"); | |
| 594 assert(!(adr_type->isa_aryptr() && | |
| 595 adr_type->offset() == arrayOopDesc::length_offset_in_bytes()), | |
| 596 "use LoadRangeNode instead"); | |
| 597 switch (bt) { | |
| 598 case T_BOOLEAN: | |
| 599 case T_BYTE: return new (C, 3) LoadBNode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 600 case T_INT: return new (C, 3) LoadINode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 601 case T_CHAR: return new (C, 3) LoadCNode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 602 case T_SHORT: return new (C, 3) LoadSNode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 603 case T_LONG: return new (C, 3) LoadLNode(ctl, mem, adr, adr_type, rt->is_long() ); | |
| 604 case T_FLOAT: return new (C, 3) LoadFNode(ctl, mem, adr, adr_type, rt ); | |
| 605 case T_DOUBLE: return new (C, 3) LoadDNode(ctl, mem, adr, adr_type, rt ); | |
| 606 case T_ADDRESS: return new (C, 3) LoadPNode(ctl, mem, adr, adr_type, rt->is_ptr() ); | |
| 607 case T_OBJECT: return new (C, 3) LoadPNode(ctl, mem, adr, adr_type, rt->is_oopptr()); | |
| 608 } | |
| 609 ShouldNotReachHere(); | |
| 610 return (LoadNode*)NULL; | |
| 611 } | |
| 612 | |
| 613 LoadLNode* LoadLNode::make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, const Type* rt) { | |
| 614 bool require_atomic = true; | |
| 615 return new (C, 3) LoadLNode(ctl, mem, adr, adr_type, rt->is_long(), require_atomic); | |
| 616 } | |
| 617 | |
| 618 | |
| 619 | |
| 620 | |
| 621 //------------------------------hash------------------------------------------- | |
| 622 uint LoadNode::hash() const { | |
| 623 // unroll addition of interesting fields | |
| 624 return (uintptr_t)in(Control) + (uintptr_t)in(Memory) + (uintptr_t)in(Address); | |
| 625 } | |
| 626 | |
| 627 //---------------------------can_see_stored_value------------------------------ | |
| 628 // This routine exists to make sure this set of tests is done the same | |
| 629 // everywhere. We need to make a coordinated change: first LoadNode::Ideal | |
| 630 // will change the graph shape in a way which makes memory alive twice at the | |
| 631 // same time (uses the Oracle model of aliasing), then some | |
| 632 // LoadXNode::Identity will fold things back to the equivalence-class model | |
| 633 // of aliasing. | |
| 634 Node* MemNode::can_see_stored_value(Node* st, PhaseTransform* phase) const { | |
| 635 Node* ld_adr = in(MemNode::Address); | |
| 636 | |
|
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637 const TypeInstPtr* tp = phase->type(ld_adr)->isa_instptr(); |
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638 Compile::AliasType* atp = tp != NULL ? phase->C->alias_type(tp) : NULL; |
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639 if (EliminateAutoBox && atp != NULL && atp->index() >= Compile::AliasIdxRaw && |
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640 atp->field() != NULL && !atp->field()->is_volatile()) { |
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641 uint alias_idx = atp->index(); |
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642 bool final = atp->field()->is_final(); |
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643 Node* result = NULL; |
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644 Node* current = st; |
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645 // Skip through chains of MemBarNodes checking the MergeMems for |
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646 // new states for the slice of this load. Stop once any other |
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647 // kind of node is encountered. Loads from final memory can skip |
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648 // through any kind of MemBar but normal loads shouldn't skip |
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649 // through MemBarAcquire since the could allow them to move out of |
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650 // a synchronized region. |
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651 while (current->is_Proj()) { |
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652 int opc = current->in(0)->Opcode(); |
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653 if ((final && opc == Op_MemBarAcquire) || |
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654 opc == Op_MemBarRelease || opc == Op_MemBarCPUOrder) { |
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655 Node* mem = current->in(0)->in(TypeFunc::Memory); |
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656 if (mem->is_MergeMem()) { |
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657 MergeMemNode* merge = mem->as_MergeMem(); |
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658 Node* new_st = merge->memory_at(alias_idx); |
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659 if (new_st == merge->base_memory()) { |
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660 // Keep searching |
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661 current = merge->base_memory(); |
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662 continue; |
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663 } |
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664 // Save the new memory state for the slice and fall through |
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665 // to exit. |
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666 result = new_st; |
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667 } |
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668 } |
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669 break; |
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670 } |
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671 if (result != NULL) { |
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672 st = result; |
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673 } |
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674 } |
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675 |
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676 |
| 0 | 677 // Loop around twice in the case Load -> Initialize -> Store. |
| 678 // (See PhaseIterGVN::add_users_to_worklist, which knows about this case.) | |
| 679 for (int trip = 0; trip <= 1; trip++) { | |
| 680 | |
| 681 if (st->is_Store()) { | |
| 682 Node* st_adr = st->in(MemNode::Address); | |
| 683 if (!phase->eqv(st_adr, ld_adr)) { | |
| 684 // Try harder before giving up... Match raw and non-raw pointers. | |
| 685 intptr_t st_off = 0; | |
| 686 AllocateNode* alloc = AllocateNode::Ideal_allocation(st_adr, phase, st_off); | |
| 687 if (alloc == NULL) return NULL; | |
| 688 intptr_t ld_off = 0; | |
| 689 AllocateNode* allo2 = AllocateNode::Ideal_allocation(ld_adr, phase, ld_off); | |
| 690 if (alloc != allo2) return NULL; | |
| 691 if (ld_off != st_off) return NULL; | |
| 692 // At this point we have proven something like this setup: | |
| 693 // A = Allocate(...) | |
| 694 // L = LoadQ(, AddP(CastPP(, A.Parm),, #Off)) | |
| 695 // S = StoreQ(, AddP(, A.Parm , #Off), V) | |
| 696 // (Actually, we haven't yet proven the Q's are the same.) | |
| 697 // In other words, we are loading from a casted version of | |
| 698 // the same pointer-and-offset that we stored to. | |
| 699 // Thus, we are able to replace L by V. | |
| 700 } | |
| 701 // Now prove that we have a LoadQ matched to a StoreQ, for some Q. | |
| 702 if (store_Opcode() != st->Opcode()) | |
| 703 return NULL; | |
| 704 return st->in(MemNode::ValueIn); | |
| 705 } | |
| 706 | |
| 707 intptr_t offset = 0; // scratch | |
| 708 | |
| 709 // A load from a freshly-created object always returns zero. | |
| 710 // (This can happen after LoadNode::Ideal resets the load's memory input | |
| 711 // to find_captured_store, which returned InitializeNode::zero_memory.) | |
| 712 if (st->is_Proj() && st->in(0)->is_Allocate() && | |
| 713 st->in(0) == AllocateNode::Ideal_allocation(ld_adr, phase, offset) && | |
| 714 offset >= st->in(0)->as_Allocate()->minimum_header_size()) { | |
| 715 // return a zero value for the load's basic type | |
| 716 // (This is one of the few places where a generic PhaseTransform | |
| 717 // can create new nodes. Think of it as lazily manifesting | |
| 718 // virtually pre-existing constants.) | |
| 719 return phase->zerocon(memory_type()); | |
| 720 } | |
| 721 | |
| 722 // A load from an initialization barrier can match a captured store. | |
| 723 if (st->is_Proj() && st->in(0)->is_Initialize()) { | |
| 724 InitializeNode* init = st->in(0)->as_Initialize(); | |
| 725 AllocateNode* alloc = init->allocation(); | |
| 726 if (alloc != NULL && | |
| 727 alloc == AllocateNode::Ideal_allocation(ld_adr, phase, offset)) { | |
| 728 // examine a captured store value | |
| 729 st = init->find_captured_store(offset, memory_size(), phase); | |
| 730 if (st != NULL) | |
| 731 continue; // take one more trip around | |
| 732 } | |
| 733 } | |
| 734 | |
| 735 break; | |
| 736 } | |
| 737 | |
| 738 return NULL; | |
| 739 } | |
| 740 | |
| 741 //------------------------------Identity--------------------------------------- | |
| 742 // Loads are identity if previous store is to same address | |
| 743 Node *LoadNode::Identity( PhaseTransform *phase ) { | |
| 744 // If the previous store-maker is the right kind of Store, and the store is | |
| 745 // to the same address, then we are equal to the value stored. | |
| 746 Node* mem = in(MemNode::Memory); | |
| 747 Node* value = can_see_stored_value(mem, phase); | |
| 748 if( value ) { | |
| 749 // byte, short & char stores truncate naturally. | |
| 750 // A load has to load the truncated value which requires | |
| 751 // some sort of masking operation and that requires an | |
| 752 // Ideal call instead of an Identity call. | |
| 753 if (memory_size() < BytesPerInt) { | |
| 754 // If the input to the store does not fit with the load's result type, | |
| 755 // it must be truncated via an Ideal call. | |
| 756 if (!phase->type(value)->higher_equal(phase->type(this))) | |
| 757 return this; | |
| 758 } | |
| 759 // (This works even when value is a Con, but LoadNode::Value | |
| 760 // usually runs first, producing the singleton type of the Con.) | |
| 761 return value; | |
| 762 } | |
| 763 return this; | |
| 764 } | |
| 765 | |
|
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766 |
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767 // Returns true if the AliasType refers to the field that holds the |
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768 // cached box array. Currently only handles the IntegerCache case. |
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769 static bool is_autobox_cache(Compile::AliasType* atp) { |
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770 if (atp != NULL && atp->field() != NULL) { |
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771 ciField* field = atp->field(); |
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772 ciSymbol* klass = field->holder()->name(); |
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773 if (field->name() == ciSymbol::cache_field_name() && |
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774 field->holder()->uses_default_loader() && |
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775 klass == ciSymbol::java_lang_Integer_IntegerCache()) { |
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776 return true; |
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777 } |
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778 } |
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779 return false; |
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780 } |
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diff
changeset
|
781 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
782 // Fetch the base value in the autobox array |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
783 static bool fetch_autobox_base(Compile::AliasType* atp, int& cache_offset) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
784 if (atp != NULL && atp->field() != NULL) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
785 ciField* field = atp->field(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
786 ciSymbol* klass = field->holder()->name(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
787 if (field->name() == ciSymbol::cache_field_name() && |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
788 field->holder()->uses_default_loader() && |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
789 klass == ciSymbol::java_lang_Integer_IntegerCache()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
790 assert(field->is_constant(), "what?"); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
791 ciObjArray* array = field->constant_value().as_object()->as_obj_array(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
792 // Fetch the box object at the base of the array and get its value |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
793 ciInstance* box = array->obj_at(0)->as_instance(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
794 ciInstanceKlass* ik = box->klass()->as_instance_klass(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
795 if (ik->nof_nonstatic_fields() == 1) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
796 // This should be true nonstatic_field_at requires calling |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
797 // nof_nonstatic_fields so check it anyway |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
798 ciConstant c = box->field_value(ik->nonstatic_field_at(0)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
799 cache_offset = c.as_int(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
800 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
801 return true; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
802 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
803 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
804 return false; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
805 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
806 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
807 // Returns true if the AliasType refers to the value field of an |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
808 // autobox object. Currently only handles Integer. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
809 static bool is_autobox_object(Compile::AliasType* atp) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
810 if (atp != NULL && atp->field() != NULL) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
811 ciField* field = atp->field(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
812 ciSymbol* klass = field->holder()->name(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
813 if (field->name() == ciSymbol::value_name() && |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
814 field->holder()->uses_default_loader() && |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
815 klass == ciSymbol::java_lang_Integer()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
816 return true; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
817 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
818 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
819 return false; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
820 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
821 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
822 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
823 // We're loading from an object which has autobox behaviour. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
824 // If this object is result of a valueOf call we'll have a phi |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
825 // merging a newly allocated object and a load from the cache. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
826 // We want to replace this load with the original incoming |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
827 // argument to the valueOf call. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
828 Node* LoadNode::eliminate_autobox(PhaseGVN* phase) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
829 Node* base = in(Address)->in(AddPNode::Base); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
830 if (base->is_Phi() && base->req() == 3) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
831 AllocateNode* allocation = NULL; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
832 int allocation_index = -1; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
833 int load_index = -1; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
834 for (uint i = 1; i < base->req(); i++) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
835 allocation = AllocateNode::Ideal_allocation(base->in(i), phase); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
836 if (allocation != NULL) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
837 allocation_index = i; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
838 load_index = 3 - allocation_index; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
839 break; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
840 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
841 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
842 LoadNode* load = NULL; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
843 if (allocation != NULL && base->in(load_index)->is_Load()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
844 load = base->in(load_index)->as_Load(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
845 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
846 if (load != NULL && in(Memory)->is_Phi() && in(Memory)->in(0) == base->in(0)) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
847 // Push the loads from the phi that comes from valueOf up |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
848 // through it to allow elimination of the loads and the recovery |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
849 // of the original value. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
850 Node* mem_phi = in(Memory); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
851 Node* offset = in(Address)->in(AddPNode::Offset); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
852 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
853 Node* in1 = clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
854 Node* in1_addr = in1->in(Address)->clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
855 in1_addr->set_req(AddPNode::Base, base->in(allocation_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
856 in1_addr->set_req(AddPNode::Address, base->in(allocation_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
857 in1_addr->set_req(AddPNode::Offset, offset); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
858 in1->set_req(0, base->in(allocation_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
859 in1->set_req(Address, in1_addr); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
860 in1->set_req(Memory, mem_phi->in(allocation_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
861 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
862 Node* in2 = clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
863 Node* in2_addr = in2->in(Address)->clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
864 in2_addr->set_req(AddPNode::Base, base->in(load_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
865 in2_addr->set_req(AddPNode::Address, base->in(load_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
866 in2_addr->set_req(AddPNode::Offset, offset); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
867 in2->set_req(0, base->in(load_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
868 in2->set_req(Address, in2_addr); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
869 in2->set_req(Memory, mem_phi->in(load_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
870 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
871 in1_addr = phase->transform(in1_addr); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
872 in1 = phase->transform(in1); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
873 in2_addr = phase->transform(in2_addr); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
874 in2 = phase->transform(in2); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
875 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
876 PhiNode* result = PhiNode::make_blank(base->in(0), this); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
877 result->set_req(allocation_index, in1); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
878 result->set_req(load_index, in2); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
879 return result; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
880 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
881 } else if (base->is_Load()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
882 // Eliminate the load of Integer.value for integers from the cache |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
883 // array by deriving the value from the index into the array. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
884 // Capture the offset of the load and then reverse the computation. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
885 Node* load_base = base->in(Address)->in(AddPNode::Base); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
886 if (load_base != NULL) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
887 Compile::AliasType* atp = phase->C->alias_type(load_base->adr_type()); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
888 intptr_t cache_offset; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
889 int shift = -1; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
890 Node* cache = NULL; |
|
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891 if (is_autobox_cache(atp)) { |
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892 shift = exact_log2(type2aelembytes[T_OBJECT]); |
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893 cache = AddPNode::Ideal_base_and_offset(load_base->in(Address), phase, cache_offset); |
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894 } |
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895 if (cache != NULL && base->in(Address)->is_AddP()) { |
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896 Node* elements[4]; |
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897 int count = base->in(Address)->as_AddP()->unpack_offsets(elements, ARRAY_SIZE(elements)); |
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898 int cache_low; |
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899 if (count > 0 && fetch_autobox_base(atp, cache_low)) { |
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900 int offset = arrayOopDesc::base_offset_in_bytes(memory_type()) - (cache_low << shift); |
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901 // Add up all the offsets making of the address of the load |
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902 Node* result = elements[0]; |
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903 for (int i = 1; i < count; i++) { |
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904 result = phase->transform(new (phase->C, 3) AddXNode(result, elements[i])); |
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905 } |
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906 // Remove the constant offset from the address and then |
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907 // remove the scaling of the offset to recover the original index. |
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908 result = phase->transform(new (phase->C, 3) AddXNode(result, phase->MakeConX(-offset))); |
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909 if (result->Opcode() == Op_LShiftX && result->in(2) == phase->intcon(shift)) { |
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910 // Peel the shift off directly but wrap it in a dummy node |
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911 // since Ideal can't return existing nodes |
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912 result = new (phase->C, 3) RShiftXNode(result->in(1), phase->intcon(0)); |
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913 } else { |
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914 result = new (phase->C, 3) RShiftXNode(result, phase->intcon(shift)); |
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915 } |
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916 #ifdef _LP64 |
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917 result = new (phase->C, 2) ConvL2INode(phase->transform(result)); |
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918 #endif |
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919 return result; |
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920 } |
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921 } |
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922 } |
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923 } |
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924 return NULL; |
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925 } |
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926 |
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927 |
| 0 | 928 //------------------------------Ideal------------------------------------------ |
| 929 // If the load is from Field memory and the pointer is non-null, we can | |
| 930 // zero out the control input. | |
| 931 // If the offset is constant and the base is an object allocation, | |
| 932 // try to hook me up to the exact initializing store. | |
| 933 Node *LoadNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 934 Node* p = MemNode::Ideal_common(phase, can_reshape); | |
| 935 if (p) return (p == NodeSentinel) ? NULL : p; | |
| 936 | |
| 937 Node* ctrl = in(MemNode::Control); | |
| 938 Node* address = in(MemNode::Address); | |
| 939 | |
| 940 // Skip up past a SafePoint control. Cannot do this for Stores because | |
| 941 // pointer stores & cardmarks must stay on the same side of a SafePoint. | |
| 942 if( ctrl != NULL && ctrl->Opcode() == Op_SafePoint && | |
| 943 phase->C->get_alias_index(phase->type(address)->is_ptr()) != Compile::AliasIdxRaw ) { | |
| 944 ctrl = ctrl->in(0); | |
| 945 set_req(MemNode::Control,ctrl); | |
| 946 } | |
| 947 | |
| 948 // Check for useless control edge in some common special cases | |
| 949 if (in(MemNode::Control) != NULL) { | |
| 950 intptr_t ignore = 0; | |
| 951 Node* base = AddPNode::Ideal_base_and_offset(address, phase, ignore); | |
| 952 if (base != NULL | |
| 953 && phase->type(base)->higher_equal(TypePtr::NOTNULL) | |
| 954 && detect_dominating_control(base->in(0), phase->C->start())) { | |
| 955 // A method-invariant, non-null address (constant or 'this' argument). | |
| 956 set_req(MemNode::Control, NULL); | |
| 957 } | |
| 958 } | |
| 959 | |
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960 if (EliminateAutoBox && can_reshape && in(Address)->is_AddP()) { |
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961 Node* base = in(Address)->in(AddPNode::Base); |
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962 if (base != NULL) { |
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963 Compile::AliasType* atp = phase->C->alias_type(adr_type()); |
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964 if (is_autobox_object(atp)) { |
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965 Node* result = eliminate_autobox(phase); |
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966 if (result != NULL) return result; |
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967 } |
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968 } |
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969 } |
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970 |
| 0 | 971 // Check for prior store with a different base or offset; make Load |
| 972 // independent. Skip through any number of them. Bail out if the stores | |
| 973 // are in an endless dead cycle and report no progress. This is a key | |
| 974 // transform for Reflection. However, if after skipping through the Stores | |
| 975 // we can't then fold up against a prior store do NOT do the transform as | |
| 976 // this amounts to using the 'Oracle' model of aliasing. It leaves the same | |
| 977 // array memory alive twice: once for the hoisted Load and again after the | |
| 978 // bypassed Store. This situation only works if EVERYBODY who does | |
| 979 // anti-dependence work knows how to bypass. I.e. we need all | |
| 980 // anti-dependence checks to ask the same Oracle. Right now, that Oracle is | |
| 981 // the alias index stuff. So instead, peek through Stores and IFF we can | |
| 982 // fold up, do so. | |
| 983 Node* prev_mem = find_previous_store(phase); | |
| 984 // Steps (a), (b): Walk past independent stores to find an exact match. | |
| 985 if (prev_mem != NULL && prev_mem != in(MemNode::Memory)) { | |
| 986 // (c) See if we can fold up on the spot, but don't fold up here. | |
| 987 // Fold-up might require truncation (for LoadB/LoadS/LoadC) or | |
| 988 // just return a prior value, which is done by Identity calls. | |
| 989 if (can_see_stored_value(prev_mem, phase)) { | |
| 990 // Make ready for step (d): | |
| 991 set_req(MemNode::Memory, prev_mem); | |
| 992 return this; | |
| 993 } | |
| 994 } | |
| 995 | |
| 996 return NULL; // No further progress | |
| 997 } | |
| 998 | |
| 999 // Helper to recognize certain Klass fields which are invariant across | |
| 1000 // some group of array types (e.g., int[] or all T[] where T < Object). | |
| 1001 const Type* | |
| 1002 LoadNode::load_array_final_field(const TypeKlassPtr *tkls, | |
| 1003 ciKlass* klass) const { | |
| 1004 if (tkls->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1005 // The field is Klass::_modifier_flags. Return its (constant) value. | |
| 1006 // (Folds up the 2nd indirection in aClassConstant.getModifiers().) | |
| 1007 assert(this->Opcode() == Op_LoadI, "must load an int from _modifier_flags"); | |
| 1008 return TypeInt::make(klass->modifier_flags()); | |
| 1009 } | |
| 1010 if (tkls->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1011 // The field is Klass::_access_flags. Return its (constant) value. | |
| 1012 // (Folds up the 2nd indirection in Reflection.getClassAccessFlags(aClassConstant).) | |
| 1013 assert(this->Opcode() == Op_LoadI, "must load an int from _access_flags"); | |
| 1014 return TypeInt::make(klass->access_flags()); | |
| 1015 } | |
| 1016 if (tkls->offset() == Klass::layout_helper_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1017 // The field is Klass::_layout_helper. Return its constant value if known. | |
| 1018 assert(this->Opcode() == Op_LoadI, "must load an int from _layout_helper"); | |
| 1019 return TypeInt::make(klass->layout_helper()); | |
| 1020 } | |
| 1021 | |
| 1022 // No match. | |
| 1023 return NULL; | |
| 1024 } | |
| 1025 | |
| 1026 //------------------------------Value----------------------------------------- | |
| 1027 const Type *LoadNode::Value( PhaseTransform *phase ) const { | |
| 1028 // Either input is TOP ==> the result is TOP | |
| 1029 Node* mem = in(MemNode::Memory); | |
| 1030 const Type *t1 = phase->type(mem); | |
| 1031 if (t1 == Type::TOP) return Type::TOP; | |
| 1032 Node* adr = in(MemNode::Address); | |
| 1033 const TypePtr* tp = phase->type(adr)->isa_ptr(); | |
| 1034 if (tp == NULL || tp->empty()) return Type::TOP; | |
| 1035 int off = tp->offset(); | |
| 1036 assert(off != Type::OffsetTop, "case covered by TypePtr::empty"); | |
| 1037 | |
| 1038 // Try to guess loaded type from pointer type | |
| 1039 if (tp->base() == Type::AryPtr) { | |
| 1040 const Type *t = tp->is_aryptr()->elem(); | |
| 1041 // Don't do this for integer types. There is only potential profit if | |
| 1042 // the element type t is lower than _type; that is, for int types, if _type is | |
| 1043 // more restrictive than t. This only happens here if one is short and the other | |
| 1044 // char (both 16 bits), and in those cases we've made an intentional decision | |
| 1045 // to use one kind of load over the other. See AndINode::Ideal and 4965907. | |
| 1046 // Also, do not try to narrow the type for a LoadKlass, regardless of offset. | |
| 1047 // | |
| 1048 // Yes, it is possible to encounter an expression like (LoadKlass p1:(AddP x x 8)) | |
| 1049 // where the _gvn.type of the AddP is wider than 8. This occurs when an earlier | |
| 1050 // copy p0 of (AddP x x 8) has been proven equal to p1, and the p0 has been | |
| 1051 // subsumed by p1. If p1 is on the worklist but has not yet been re-transformed, | |
| 1052 // it is possible that p1 will have a type like Foo*[int+]:NotNull*+any. | |
| 1053 // In fact, that could have been the original type of p1, and p1 could have | |
| 1054 // had an original form like p1:(AddP x x (LShiftL quux 3)), where the | |
| 1055 // expression (LShiftL quux 3) independently optimized to the constant 8. | |
| 1056 if ((t->isa_int() == NULL) && (t->isa_long() == NULL) | |
| 1057 && Opcode() != Op_LoadKlass) { | |
| 1058 // t might actually be lower than _type, if _type is a unique | |
| 1059 // concrete subclass of abstract class t. | |
| 1060 // Make sure the reference is not into the header, by comparing | |
| 1061 // the offset against the offset of the start of the array's data. | |
| 1062 // Different array types begin at slightly different offsets (12 vs. 16). | |
| 1063 // We choose T_BYTE as an example base type that is least restrictive | |
| 1064 // as to alignment, which will therefore produce the smallest | |
| 1065 // possible base offset. | |
| 1066 const int min_base_off = arrayOopDesc::base_offset_in_bytes(T_BYTE); | |
| 1067 if ((uint)off >= (uint)min_base_off) { // is the offset beyond the header? | |
| 1068 const Type* jt = t->join(_type); | |
| 1069 // In any case, do not allow the join, per se, to empty out the type. | |
| 1070 if (jt->empty() && !t->empty()) { | |
| 1071 // This can happen if a interface-typed array narrows to a class type. | |
| 1072 jt = _type; | |
| 1073 } | |
|
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1074 |
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1075 if (EliminateAutoBox) { |
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1076 // The pointers in the autobox arrays are always non-null |
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1077 Node* base = in(Address)->in(AddPNode::Base); |
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1078 if (base != NULL) { |
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1079 Compile::AliasType* atp = phase->C->alias_type(base->adr_type()); |
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1080 if (is_autobox_cache(atp)) { |
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1081 return jt->join(TypePtr::NOTNULL)->is_ptr(); |
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1082 } |
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1083 } |
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1084 } |
| 0 | 1085 return jt; |
| 1086 } | |
| 1087 } | |
| 1088 } else if (tp->base() == Type::InstPtr) { | |
| 1089 assert( off != Type::OffsetBot || | |
| 1090 // arrays can be cast to Objects | |
| 1091 tp->is_oopptr()->klass()->is_java_lang_Object() || | |
| 1092 // unsafe field access may not have a constant offset | |
| 1093 phase->C->has_unsafe_access(), | |
| 1094 "Field accesses must be precise" ); | |
| 1095 // For oop loads, we expect the _type to be precise | |
| 1096 } else if (tp->base() == Type::KlassPtr) { | |
| 1097 assert( off != Type::OffsetBot || | |
| 1098 // arrays can be cast to Objects | |
| 1099 tp->is_klassptr()->klass()->is_java_lang_Object() || | |
| 1100 // also allow array-loading from the primary supertype | |
| 1101 // array during subtype checks | |
| 1102 Opcode() == Op_LoadKlass, | |
| 1103 "Field accesses must be precise" ); | |
| 1104 // For klass/static loads, we expect the _type to be precise | |
| 1105 } | |
| 1106 | |
| 1107 const TypeKlassPtr *tkls = tp->isa_klassptr(); | |
| 1108 if (tkls != NULL && !StressReflectiveCode) { | |
| 1109 ciKlass* klass = tkls->klass(); | |
| 1110 if (klass->is_loaded() && tkls->klass_is_exact()) { | |
| 1111 // We are loading a field from a Klass metaobject whose identity | |
| 1112 // is known at compile time (the type is "exact" or "precise"). | |
| 1113 // Check for fields we know are maintained as constants by the VM. | |
| 1114 if (tkls->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1115 // The field is Klass::_super_check_offset. Return its (constant) value. | |
| 1116 // (Folds up type checking code.) | |
| 1117 assert(Opcode() == Op_LoadI, "must load an int from _super_check_offset"); | |
| 1118 return TypeInt::make(klass->super_check_offset()); | |
| 1119 } | |
| 1120 // Compute index into primary_supers array | |
| 1121 juint depth = (tkls->offset() - (Klass::primary_supers_offset_in_bytes() + (int)sizeof(oopDesc))) / sizeof(klassOop); | |
| 1122 // Check for overflowing; use unsigned compare to handle the negative case. | |
| 1123 if( depth < ciKlass::primary_super_limit() ) { | |
| 1124 // The field is an element of Klass::_primary_supers. Return its (constant) value. | |
| 1125 // (Folds up type checking code.) | |
| 1126 assert(Opcode() == Op_LoadKlass, "must load a klass from _primary_supers"); | |
| 1127 ciKlass *ss = klass->super_of_depth(depth); | |
| 1128 return ss ? TypeKlassPtr::make(ss) : TypePtr::NULL_PTR; | |
| 1129 } | |
| 1130 const Type* aift = load_array_final_field(tkls, klass); | |
| 1131 if (aift != NULL) return aift; | |
| 1132 if (tkls->offset() == in_bytes(arrayKlass::component_mirror_offset()) + (int)sizeof(oopDesc) | |
| 1133 && klass->is_array_klass()) { | |
| 1134 // The field is arrayKlass::_component_mirror. Return its (constant) value. | |
| 1135 // (Folds up aClassConstant.getComponentType, common in Arrays.copyOf.) | |
| 1136 assert(Opcode() == Op_LoadP, "must load an oop from _component_mirror"); | |
| 1137 return TypeInstPtr::make(klass->as_array_klass()->component_mirror()); | |
| 1138 } | |
| 1139 if (tkls->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1140 // The field is Klass::_java_mirror. Return its (constant) value. | |
| 1141 // (Folds up the 2nd indirection in anObjConstant.getClass().) | |
| 1142 assert(Opcode() == Op_LoadP, "must load an oop from _java_mirror"); | |
| 1143 return TypeInstPtr::make(klass->java_mirror()); | |
| 1144 } | |
| 1145 } | |
| 1146 | |
| 1147 // We can still check if we are loading from the primary_supers array at a | |
| 1148 // shallow enough depth. Even though the klass is not exact, entries less | |
| 1149 // than or equal to its super depth are correct. | |
| 1150 if (klass->is_loaded() ) { | |
| 1151 ciType *inner = klass->klass(); | |
| 1152 while( inner->is_obj_array_klass() ) | |
| 1153 inner = inner->as_obj_array_klass()->base_element_type(); | |
| 1154 if( inner->is_instance_klass() && | |
| 1155 !inner->as_instance_klass()->flags().is_interface() ) { | |
| 1156 // Compute index into primary_supers array | |
| 1157 juint depth = (tkls->offset() - (Klass::primary_supers_offset_in_bytes() + (int)sizeof(oopDesc))) / sizeof(klassOop); | |
| 1158 // Check for overflowing; use unsigned compare to handle the negative case. | |
| 1159 if( depth < ciKlass::primary_super_limit() && | |
| 1160 depth <= klass->super_depth() ) { // allow self-depth checks to handle self-check case | |
| 1161 // The field is an element of Klass::_primary_supers. Return its (constant) value. | |
| 1162 // (Folds up type checking code.) | |
| 1163 assert(Opcode() == Op_LoadKlass, "must load a klass from _primary_supers"); | |
| 1164 ciKlass *ss = klass->super_of_depth(depth); | |
| 1165 return ss ? TypeKlassPtr::make(ss) : TypePtr::NULL_PTR; | |
| 1166 } | |
| 1167 } | |
| 1168 } | |
| 1169 | |
| 1170 // If the type is enough to determine that the thing is not an array, | |
| 1171 // we can give the layout_helper a positive interval type. | |
| 1172 // This will help short-circuit some reflective code. | |
| 1173 if (tkls->offset() == Klass::layout_helper_offset_in_bytes() + (int)sizeof(oopDesc) | |
| 1174 && !klass->is_array_klass() // not directly typed as an array | |
| 1175 && !klass->is_interface() // specifically not Serializable & Cloneable | |
| 1176 && !klass->is_java_lang_Object() // not the supertype of all T[] | |
| 1177 ) { | |
| 1178 // Note: When interfaces are reliable, we can narrow the interface | |
| 1179 // test to (klass != Serializable && klass != Cloneable). | |
| 1180 assert(Opcode() == Op_LoadI, "must load an int from _layout_helper"); | |
| 1181 jint min_size = Klass::instance_layout_helper(oopDesc::header_size(), false); | |
| 1182 // The key property of this type is that it folds up tests | |
| 1183 // for array-ness, since it proves that the layout_helper is positive. | |
| 1184 // Thus, a generic value like the basic object layout helper works fine. | |
| 1185 return TypeInt::make(min_size, max_jint, Type::WidenMin); | |
| 1186 } | |
| 1187 } | |
| 1188 | |
| 1189 // If we are loading from a freshly-allocated object, produce a zero, | |
| 1190 // if the load is provably beyond the header of the object. | |
| 1191 // (Also allow a variable load from a fresh array to produce zero.) | |
| 1192 if (ReduceFieldZeroing) { | |
| 1193 Node* value = can_see_stored_value(mem,phase); | |
| 1194 if (value != NULL && value->is_Con()) | |
| 1195 return value->bottom_type(); | |
| 1196 } | |
| 1197 | |
| 1198 return _type; | |
| 1199 } | |
| 1200 | |
| 1201 //------------------------------match_edge------------------------------------- | |
| 1202 // Do we Match on this edge index or not? Match only the address. | |
| 1203 uint LoadNode::match_edge(uint idx) const { | |
| 1204 return idx == MemNode::Address; | |
| 1205 } | |
| 1206 | |
| 1207 //--------------------------LoadBNode::Ideal-------------------------------------- | |
| 1208 // | |
| 1209 // If the previous store is to the same address as this load, | |
| 1210 // and the value stored was larger than a byte, replace this load | |
| 1211 // with the value stored truncated to a byte. If no truncation is | |
| 1212 // needed, the replacement is done in LoadNode::Identity(). | |
| 1213 // | |
| 1214 Node *LoadBNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1215 Node* mem = in(MemNode::Memory); | |
| 1216 Node* value = can_see_stored_value(mem,phase); | |
| 1217 if( value && !phase->type(value)->higher_equal( _type ) ) { | |
| 1218 Node *result = phase->transform( new (phase->C, 3) LShiftINode(value, phase->intcon(24)) ); | |
| 1219 return new (phase->C, 3) RShiftINode(result, phase->intcon(24)); | |
| 1220 } | |
| 1221 // Identity call will handle the case where truncation is not needed. | |
| 1222 return LoadNode::Ideal(phase, can_reshape); | |
| 1223 } | |
| 1224 | |
| 1225 //--------------------------LoadCNode::Ideal-------------------------------------- | |
| 1226 // | |
| 1227 // If the previous store is to the same address as this load, | |
| 1228 // and the value stored was larger than a char, replace this load | |
| 1229 // with the value stored truncated to a char. If no truncation is | |
| 1230 // needed, the replacement is done in LoadNode::Identity(). | |
| 1231 // | |
| 1232 Node *LoadCNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1233 Node* mem = in(MemNode::Memory); | |
| 1234 Node* value = can_see_stored_value(mem,phase); | |
| 1235 if( value && !phase->type(value)->higher_equal( _type ) ) | |
| 1236 return new (phase->C, 3) AndINode(value,phase->intcon(0xFFFF)); | |
| 1237 // Identity call will handle the case where truncation is not needed. | |
| 1238 return LoadNode::Ideal(phase, can_reshape); | |
| 1239 } | |
| 1240 | |
| 1241 //--------------------------LoadSNode::Ideal-------------------------------------- | |
| 1242 // | |
| 1243 // If the previous store is to the same address as this load, | |
| 1244 // and the value stored was larger than a short, replace this load | |
| 1245 // with the value stored truncated to a short. If no truncation is | |
| 1246 // needed, the replacement is done in LoadNode::Identity(). | |
| 1247 // | |
| 1248 Node *LoadSNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1249 Node* mem = in(MemNode::Memory); | |
| 1250 Node* value = can_see_stored_value(mem,phase); | |
| 1251 if( value && !phase->type(value)->higher_equal( _type ) ) { | |
| 1252 Node *result = phase->transform( new (phase->C, 3) LShiftINode(value, phase->intcon(16)) ); | |
| 1253 return new (phase->C, 3) RShiftINode(result, phase->intcon(16)); | |
| 1254 } | |
| 1255 // Identity call will handle the case where truncation is not needed. | |
| 1256 return LoadNode::Ideal(phase, can_reshape); | |
| 1257 } | |
| 1258 | |
| 1259 //============================================================================= | |
| 1260 //------------------------------Value------------------------------------------ | |
| 1261 const Type *LoadKlassNode::Value( PhaseTransform *phase ) const { | |
| 1262 // Either input is TOP ==> the result is TOP | |
| 1263 const Type *t1 = phase->type( in(MemNode::Memory) ); | |
| 1264 if (t1 == Type::TOP) return Type::TOP; | |
| 1265 Node *adr = in(MemNode::Address); | |
| 1266 const Type *t2 = phase->type( adr ); | |
| 1267 if (t2 == Type::TOP) return Type::TOP; | |
| 1268 const TypePtr *tp = t2->is_ptr(); | |
| 1269 if (TypePtr::above_centerline(tp->ptr()) || | |
| 1270 tp->ptr() == TypePtr::Null) return Type::TOP; | |
| 1271 | |
| 1272 // Return a more precise klass, if possible | |
| 1273 const TypeInstPtr *tinst = tp->isa_instptr(); | |
| 1274 if (tinst != NULL) { | |
| 1275 ciInstanceKlass* ik = tinst->klass()->as_instance_klass(); | |
| 1276 int offset = tinst->offset(); | |
| 1277 if (ik == phase->C->env()->Class_klass() | |
| 1278 && (offset == java_lang_Class::klass_offset_in_bytes() || | |
| 1279 offset == java_lang_Class::array_klass_offset_in_bytes())) { | |
| 1280 // We are loading a special hidden field from a Class mirror object, | |
| 1281 // the field which points to the VM's Klass metaobject. | |
| 1282 ciType* t = tinst->java_mirror_type(); | |
| 1283 // java_mirror_type returns non-null for compile-time Class constants. | |
| 1284 if (t != NULL) { | |
| 1285 // constant oop => constant klass | |
| 1286 if (offset == java_lang_Class::array_klass_offset_in_bytes()) { | |
| 1287 return TypeKlassPtr::make(ciArrayKlass::make(t)); | |
| 1288 } | |
| 1289 if (!t->is_klass()) { | |
| 1290 // a primitive Class (e.g., int.class) has NULL for a klass field | |
| 1291 return TypePtr::NULL_PTR; | |
| 1292 } | |
| 1293 // (Folds up the 1st indirection in aClassConstant.getModifiers().) | |
| 1294 return TypeKlassPtr::make(t->as_klass()); | |
| 1295 } | |
| 1296 // non-constant mirror, so we can't tell what's going on | |
| 1297 } | |
| 1298 if( !ik->is_loaded() ) | |
| 1299 return _type; // Bail out if not loaded | |
| 1300 if (offset == oopDesc::klass_offset_in_bytes()) { | |
| 1301 if (tinst->klass_is_exact()) { | |
| 1302 return TypeKlassPtr::make(ik); | |
| 1303 } | |
| 1304 // See if we can become precise: no subklasses and no interface | |
| 1305 // (Note: We need to support verified interfaces.) | |
| 1306 if (!ik->is_interface() && !ik->has_subklass()) { | |
| 1307 //assert(!UseExactTypes, "this code should be useless with exact types"); | |
| 1308 // Add a dependence; if any subclass added we need to recompile | |
| 1309 if (!ik->is_final()) { | |
| 1310 // %%% should use stronger assert_unique_concrete_subtype instead | |
| 1311 phase->C->dependencies()->assert_leaf_type(ik); | |
| 1312 } | |
| 1313 // Return precise klass | |
| 1314 return TypeKlassPtr::make(ik); | |
| 1315 } | |
| 1316 | |
| 1317 // Return root of possible klass | |
| 1318 return TypeKlassPtr::make(TypePtr::NotNull, ik, 0/*offset*/); | |
| 1319 } | |
| 1320 } | |
| 1321 | |
| 1322 // Check for loading klass from an array | |
| 1323 const TypeAryPtr *tary = tp->isa_aryptr(); | |
| 1324 if( tary != NULL ) { | |
| 1325 ciKlass *tary_klass = tary->klass(); | |
| 1326 if (tary_klass != NULL // can be NULL when at BOTTOM or TOP | |
| 1327 && tary->offset() == oopDesc::klass_offset_in_bytes()) { | |
| 1328 if (tary->klass_is_exact()) { | |
| 1329 return TypeKlassPtr::make(tary_klass); | |
| 1330 } | |
| 1331 ciArrayKlass *ak = tary->klass()->as_array_klass(); | |
| 1332 // If the klass is an object array, we defer the question to the | |
| 1333 // array component klass. | |
| 1334 if( ak->is_obj_array_klass() ) { | |
| 1335 assert( ak->is_loaded(), "" ); | |
| 1336 ciKlass *base_k = ak->as_obj_array_klass()->base_element_klass(); | |
| 1337 if( base_k->is_loaded() && base_k->is_instance_klass() ) { | |
| 1338 ciInstanceKlass* ik = base_k->as_instance_klass(); | |
| 1339 // See if we can become precise: no subklasses and no interface | |
| 1340 if (!ik->is_interface() && !ik->has_subklass()) { | |
| 1341 //assert(!UseExactTypes, "this code should be useless with exact types"); | |
| 1342 // Add a dependence; if any subclass added we need to recompile | |
| 1343 if (!ik->is_final()) { | |
| 1344 phase->C->dependencies()->assert_leaf_type(ik); | |
| 1345 } | |
| 1346 // Return precise array klass | |
| 1347 return TypeKlassPtr::make(ak); | |
| 1348 } | |
| 1349 } | |
| 1350 return TypeKlassPtr::make(TypePtr::NotNull, ak, 0/*offset*/); | |
| 1351 } else { // Found a type-array? | |
| 1352 //assert(!UseExactTypes, "this code should be useless with exact types"); | |
| 1353 assert( ak->is_type_array_klass(), "" ); | |
| 1354 return TypeKlassPtr::make(ak); // These are always precise | |
| 1355 } | |
| 1356 } | |
| 1357 } | |
| 1358 | |
| 1359 // Check for loading klass from an array klass | |
| 1360 const TypeKlassPtr *tkls = tp->isa_klassptr(); | |
| 1361 if (tkls != NULL && !StressReflectiveCode) { | |
| 1362 ciKlass* klass = tkls->klass(); | |
| 1363 if( !klass->is_loaded() ) | |
| 1364 return _type; // Bail out if not loaded | |
| 1365 if( klass->is_obj_array_klass() && | |
| 1366 (uint)tkls->offset() == objArrayKlass::element_klass_offset_in_bytes() + sizeof(oopDesc)) { | |
| 1367 ciKlass* elem = klass->as_obj_array_klass()->element_klass(); | |
| 1368 // // Always returning precise element type is incorrect, | |
| 1369 // // e.g., element type could be object and array may contain strings | |
| 1370 // return TypeKlassPtr::make(TypePtr::Constant, elem, 0); | |
| 1371 | |
| 1372 // The array's TypeKlassPtr was declared 'precise' or 'not precise' | |
| 1373 // according to the element type's subclassing. | |
| 1374 return TypeKlassPtr::make(tkls->ptr(), elem, 0/*offset*/); | |
| 1375 } | |
| 1376 if( klass->is_instance_klass() && tkls->klass_is_exact() && | |
| 1377 (uint)tkls->offset() == Klass::super_offset_in_bytes() + sizeof(oopDesc)) { | |
| 1378 ciKlass* sup = klass->as_instance_klass()->super(); | |
| 1379 // The field is Klass::_super. Return its (constant) value. | |
| 1380 // (Folds up the 2nd indirection in aClassConstant.getSuperClass().) | |
| 1381 return sup ? TypeKlassPtr::make(sup) : TypePtr::NULL_PTR; | |
| 1382 } | |
| 1383 } | |
| 1384 | |
| 1385 // Bailout case | |
| 1386 return LoadNode::Value(phase); | |
| 1387 } | |
| 1388 | |
| 1389 //------------------------------Identity--------------------------------------- | |
| 1390 // To clean up reflective code, simplify k.java_mirror.as_klass to plain k. | |
| 1391 // Also feed through the klass in Allocate(...klass...)._klass. | |
| 1392 Node* LoadKlassNode::Identity( PhaseTransform *phase ) { | |
| 1393 Node* x = LoadNode::Identity(phase); | |
| 1394 if (x != this) return x; | |
| 1395 | |
| 1396 // Take apart the address into an oop and and offset. | |
| 1397 // Return 'this' if we cannot. | |
| 1398 Node* adr = in(MemNode::Address); | |
| 1399 intptr_t offset = 0; | |
| 1400 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); | |
| 1401 if (base == NULL) return this; | |
| 1402 const TypeOopPtr* toop = phase->type(adr)->isa_oopptr(); | |
| 1403 if (toop == NULL) return this; | |
| 1404 | |
| 1405 // We can fetch the klass directly through an AllocateNode. | |
| 1406 // This works even if the klass is not constant (clone or newArray). | |
| 1407 if (offset == oopDesc::klass_offset_in_bytes()) { | |
| 1408 Node* allocated_klass = AllocateNode::Ideal_klass(base, phase); | |
| 1409 if (allocated_klass != NULL) { | |
| 1410 return allocated_klass; | |
| 1411 } | |
| 1412 } | |
| 1413 | |
| 1414 // Simplify k.java_mirror.as_klass to plain k, where k is a klassOop. | |
| 1415 // Simplify ak.component_mirror.array_klass to plain ak, ak an arrayKlass. | |
| 1416 // See inline_native_Class_query for occurrences of these patterns. | |
| 1417 // Java Example: x.getClass().isAssignableFrom(y) | |
| 1418 // Java Example: Array.newInstance(x.getClass().getComponentType(), n) | |
| 1419 // | |
| 1420 // This improves reflective code, often making the Class | |
| 1421 // mirror go completely dead. (Current exception: Class | |
| 1422 // mirrors may appear in debug info, but we could clean them out by | |
| 1423 // introducing a new debug info operator for klassOop.java_mirror). | |
| 1424 if (toop->isa_instptr() && toop->klass() == phase->C->env()->Class_klass() | |
| 1425 && (offset == java_lang_Class::klass_offset_in_bytes() || | |
| 1426 offset == java_lang_Class::array_klass_offset_in_bytes())) { | |
| 1427 // We are loading a special hidden field from a Class mirror, | |
| 1428 // the field which points to its Klass or arrayKlass metaobject. | |
| 1429 if (base->is_Load()) { | |
| 1430 Node* adr2 = base->in(MemNode::Address); | |
| 1431 const TypeKlassPtr* tkls = phase->type(adr2)->isa_klassptr(); | |
| 1432 if (tkls != NULL && !tkls->empty() | |
| 1433 && (tkls->klass()->is_instance_klass() || | |
| 1434 tkls->klass()->is_array_klass()) | |
| 1435 && adr2->is_AddP() | |
| 1436 ) { | |
| 1437 int mirror_field = Klass::java_mirror_offset_in_bytes(); | |
| 1438 if (offset == java_lang_Class::array_klass_offset_in_bytes()) { | |
| 1439 mirror_field = in_bytes(arrayKlass::component_mirror_offset()); | |
| 1440 } | |
| 1441 if (tkls->offset() == mirror_field + (int)sizeof(oopDesc)) { | |
| 1442 return adr2->in(AddPNode::Base); | |
| 1443 } | |
| 1444 } | |
| 1445 } | |
| 1446 } | |
| 1447 | |
| 1448 return this; | |
| 1449 } | |
| 1450 | |
| 1451 //------------------------------Value----------------------------------------- | |
| 1452 const Type *LoadRangeNode::Value( PhaseTransform *phase ) const { | |
| 1453 // Either input is TOP ==> the result is TOP | |
| 1454 const Type *t1 = phase->type( in(MemNode::Memory) ); | |
| 1455 if( t1 == Type::TOP ) return Type::TOP; | |
| 1456 Node *adr = in(MemNode::Address); | |
| 1457 const Type *t2 = phase->type( adr ); | |
| 1458 if( t2 == Type::TOP ) return Type::TOP; | |
| 1459 const TypePtr *tp = t2->is_ptr(); | |
| 1460 if (TypePtr::above_centerline(tp->ptr())) return Type::TOP; | |
| 1461 const TypeAryPtr *tap = tp->isa_aryptr(); | |
| 1462 if( !tap ) return _type; | |
| 1463 return tap->size(); | |
| 1464 } | |
| 1465 | |
| 1466 //------------------------------Identity--------------------------------------- | |
| 1467 // Feed through the length in AllocateArray(...length...)._length. | |
| 1468 Node* LoadRangeNode::Identity( PhaseTransform *phase ) { | |
| 1469 Node* x = LoadINode::Identity(phase); | |
| 1470 if (x != this) return x; | |
| 1471 | |
| 1472 // Take apart the address into an oop and and offset. | |
| 1473 // Return 'this' if we cannot. | |
| 1474 Node* adr = in(MemNode::Address); | |
| 1475 intptr_t offset = 0; | |
| 1476 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); | |
| 1477 if (base == NULL) return this; | |
| 1478 const TypeAryPtr* tary = phase->type(adr)->isa_aryptr(); | |
| 1479 if (tary == NULL) return this; | |
| 1480 | |
| 1481 // We can fetch the length directly through an AllocateArrayNode. | |
| 1482 // This works even if the length is not constant (clone or newArray). | |
| 1483 if (offset == arrayOopDesc::length_offset_in_bytes()) { | |
| 1484 Node* allocated_length = AllocateArrayNode::Ideal_length(base, phase); | |
| 1485 if (allocated_length != NULL) { | |
| 1486 return allocated_length; | |
| 1487 } | |
| 1488 } | |
| 1489 | |
| 1490 return this; | |
| 1491 | |
| 1492 } | |
| 1493 //============================================================================= | |
| 1494 //---------------------------StoreNode::make----------------------------------- | |
| 1495 // Polymorphic factory method: | |
| 1496 StoreNode* StoreNode::make( Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, BasicType bt ) { | |
| 1497 switch (bt) { | |
| 1498 case T_BOOLEAN: | |
| 1499 case T_BYTE: return new (C, 4) StoreBNode(ctl, mem, adr, adr_type, val); | |
| 1500 case T_INT: return new (C, 4) StoreINode(ctl, mem, adr, adr_type, val); | |
| 1501 case T_CHAR: | |
| 1502 case T_SHORT: return new (C, 4) StoreCNode(ctl, mem, adr, adr_type, val); | |
| 1503 case T_LONG: return new (C, 4) StoreLNode(ctl, mem, adr, adr_type, val); | |
| 1504 case T_FLOAT: return new (C, 4) StoreFNode(ctl, mem, adr, adr_type, val); | |
| 1505 case T_DOUBLE: return new (C, 4) StoreDNode(ctl, mem, adr, adr_type, val); | |
| 1506 case T_ADDRESS: | |
| 1507 case T_OBJECT: return new (C, 4) StorePNode(ctl, mem, adr, adr_type, val); | |
| 1508 } | |
| 1509 ShouldNotReachHere(); | |
| 1510 return (StoreNode*)NULL; | |
| 1511 } | |
| 1512 | |
| 1513 StoreLNode* StoreLNode::make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val) { | |
| 1514 bool require_atomic = true; | |
| 1515 return new (C, 4) StoreLNode(ctl, mem, adr, adr_type, val, require_atomic); | |
| 1516 } | |
| 1517 | |
| 1518 | |
| 1519 //--------------------------bottom_type---------------------------------------- | |
| 1520 const Type *StoreNode::bottom_type() const { | |
| 1521 return Type::MEMORY; | |
| 1522 } | |
| 1523 | |
| 1524 //------------------------------hash------------------------------------------- | |
| 1525 uint StoreNode::hash() const { | |
| 1526 // unroll addition of interesting fields | |
| 1527 //return (uintptr_t)in(Control) + (uintptr_t)in(Memory) + (uintptr_t)in(Address) + (uintptr_t)in(ValueIn); | |
| 1528 | |
| 1529 // Since they are not commoned, do not hash them: | |
| 1530 return NO_HASH; | |
| 1531 } | |
| 1532 | |
| 1533 //------------------------------Ideal------------------------------------------ | |
| 1534 // Change back-to-back Store(, p, x) -> Store(m, p, y) to Store(m, p, x). | |
| 1535 // When a store immediately follows a relevant allocation/initialization, | |
| 1536 // try to capture it into the initialization, or hoist it above. | |
| 1537 Node *StoreNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1538 Node* p = MemNode::Ideal_common(phase, can_reshape); | |
| 1539 if (p) return (p == NodeSentinel) ? NULL : p; | |
| 1540 | |
| 1541 Node* mem = in(MemNode::Memory); | |
| 1542 Node* address = in(MemNode::Address); | |
| 1543 | |
| 1544 // Back-to-back stores to same address? Fold em up. | |
| 1545 // Generally unsafe if I have intervening uses... | |
| 1546 if (mem->is_Store() && phase->eqv_uncast(mem->in(MemNode::Address), address)) { | |
| 1547 // Looking at a dead closed cycle of memory? | |
| 1548 assert(mem != mem->in(MemNode::Memory), "dead loop in StoreNode::Ideal"); | |
| 1549 | |
| 1550 assert(Opcode() == mem->Opcode() || | |
| 1551 phase->C->get_alias_index(adr_type()) == Compile::AliasIdxRaw, | |
| 1552 "no mismatched stores, except on raw memory"); | |
| 1553 | |
| 1554 if (mem->outcnt() == 1 && // check for intervening uses | |
| 1555 mem->as_Store()->memory_size() <= this->memory_size()) { | |
| 1556 // If anybody other than 'this' uses 'mem', we cannot fold 'mem' away. | |
| 1557 // For example, 'mem' might be the final state at a conditional return. | |
| 1558 // Or, 'mem' might be used by some node which is live at the same time | |
| 1559 // 'this' is live, which might be unschedulable. So, require exactly | |
| 1560 // ONE user, the 'this' store, until such time as we clone 'mem' for | |
| 1561 // each of 'mem's uses (thus making the exactly-1-user-rule hold true). | |
| 1562 if (can_reshape) { // (%%% is this an anachronism?) | |
| 1563 set_req_X(MemNode::Memory, mem->in(MemNode::Memory), | |
| 1564 phase->is_IterGVN()); | |
| 1565 } else { | |
| 1566 // It's OK to do this in the parser, since DU info is always accurate, | |
| 1567 // and the parser always refers to nodes via SafePointNode maps. | |
| 1568 set_req(MemNode::Memory, mem->in(MemNode::Memory)); | |
| 1569 } | |
| 1570 return this; | |
| 1571 } | |
| 1572 } | |
| 1573 | |
| 1574 // Capture an unaliased, unconditional, simple store into an initializer. | |
| 1575 // Or, if it is independent of the allocation, hoist it above the allocation. | |
| 1576 if (ReduceFieldZeroing && /*can_reshape &&*/ | |
| 1577 mem->is_Proj() && mem->in(0)->is_Initialize()) { | |
| 1578 InitializeNode* init = mem->in(0)->as_Initialize(); | |
| 1579 intptr_t offset = init->can_capture_store(this, phase); | |
| 1580 if (offset > 0) { | |
| 1581 Node* moved = init->capture_store(this, offset, phase); | |
| 1582 // If the InitializeNode captured me, it made a raw copy of me, | |
| 1583 // and I need to disappear. | |
| 1584 if (moved != NULL) { | |
| 1585 // %%% hack to ensure that Ideal returns a new node: | |
| 1586 mem = MergeMemNode::make(phase->C, mem); | |
| 1587 return mem; // fold me away | |
| 1588 } | |
| 1589 } | |
| 1590 } | |
| 1591 | |
| 1592 return NULL; // No further progress | |
| 1593 } | |
| 1594 | |
| 1595 //------------------------------Value----------------------------------------- | |
| 1596 const Type *StoreNode::Value( PhaseTransform *phase ) const { | |
| 1597 // Either input is TOP ==> the result is TOP | |
| 1598 const Type *t1 = phase->type( in(MemNode::Memory) ); | |
| 1599 if( t1 == Type::TOP ) return Type::TOP; | |
| 1600 const Type *t2 = phase->type( in(MemNode::Address) ); | |
| 1601 if( t2 == Type::TOP ) return Type::TOP; | |
| 1602 const Type *t3 = phase->type( in(MemNode::ValueIn) ); | |
| 1603 if( t3 == Type::TOP ) return Type::TOP; | |
| 1604 return Type::MEMORY; | |
| 1605 } | |
| 1606 | |
| 1607 //------------------------------Identity--------------------------------------- | |
| 1608 // Remove redundant stores: | |
| 1609 // Store(m, p, Load(m, p)) changes to m. | |
| 1610 // Store(, p, x) -> Store(m, p, x) changes to Store(m, p, x). | |
| 1611 Node *StoreNode::Identity( PhaseTransform *phase ) { | |
| 1612 Node* mem = in(MemNode::Memory); | |
| 1613 Node* adr = in(MemNode::Address); | |
| 1614 Node* val = in(MemNode::ValueIn); | |
| 1615 | |
| 1616 // Load then Store? Then the Store is useless | |
| 1617 if (val->is_Load() && | |
| 1618 phase->eqv_uncast( val->in(MemNode::Address), adr ) && | |
| 1619 phase->eqv_uncast( val->in(MemNode::Memory ), mem ) && | |
| 1620 val->as_Load()->store_Opcode() == Opcode()) { | |
| 1621 return mem; | |
| 1622 } | |
| 1623 | |
| 1624 // Two stores in a row of the same value? | |
| 1625 if (mem->is_Store() && | |
| 1626 phase->eqv_uncast( mem->in(MemNode::Address), adr ) && | |
| 1627 phase->eqv_uncast( mem->in(MemNode::ValueIn), val ) && | |
| 1628 mem->Opcode() == Opcode()) { | |
| 1629 return mem; | |
| 1630 } | |
| 1631 | |
| 1632 // Store of zero anywhere into a freshly-allocated object? | |
| 1633 // Then the store is useless. | |
| 1634 // (It must already have been captured by the InitializeNode.) | |
| 1635 if (ReduceFieldZeroing && phase->type(val)->is_zero_type()) { | |
| 1636 // a newly allocated object is already all-zeroes everywhere | |
| 1637 if (mem->is_Proj() && mem->in(0)->is_Allocate()) { | |
| 1638 return mem; | |
| 1639 } | |
| 1640 | |
| 1641 // the store may also apply to zero-bits in an earlier object | |
| 1642 Node* prev_mem = find_previous_store(phase); | |
| 1643 // Steps (a), (b): Walk past independent stores to find an exact match. | |
| 1644 if (prev_mem != NULL) { | |
| 1645 Node* prev_val = can_see_stored_value(prev_mem, phase); | |
| 1646 if (prev_val != NULL && phase->eqv(prev_val, val)) { | |
| 1647 // prev_val and val might differ by a cast; it would be good | |
| 1648 // to keep the more informative of the two. | |
| 1649 return mem; | |
| 1650 } | |
| 1651 } | |
| 1652 } | |
| 1653 | |
| 1654 return this; | |
| 1655 } | |
| 1656 | |
| 1657 //------------------------------match_edge------------------------------------- | |
| 1658 // Do we Match on this edge index or not? Match only memory & value | |
| 1659 uint StoreNode::match_edge(uint idx) const { | |
| 1660 return idx == MemNode::Address || idx == MemNode::ValueIn; | |
| 1661 } | |
| 1662 | |
| 1663 //------------------------------cmp-------------------------------------------- | |
| 1664 // Do not common stores up together. They generally have to be split | |
| 1665 // back up anyways, so do not bother. | |
| 1666 uint StoreNode::cmp( const Node &n ) const { | |
| 1667 return (&n == this); // Always fail except on self | |
| 1668 } | |
| 1669 | |
| 1670 //------------------------------Ideal_masked_input----------------------------- | |
| 1671 // Check for a useless mask before a partial-word store | |
| 1672 // (StoreB ... (AndI valIn conIa) ) | |
| 1673 // If (conIa & mask == mask) this simplifies to | |
| 1674 // (StoreB ... (valIn) ) | |
| 1675 Node *StoreNode::Ideal_masked_input(PhaseGVN *phase, uint mask) { | |
| 1676 Node *val = in(MemNode::ValueIn); | |
| 1677 if( val->Opcode() == Op_AndI ) { | |
| 1678 const TypeInt *t = phase->type( val->in(2) )->isa_int(); | |
| 1679 if( t && t->is_con() && (t->get_con() & mask) == mask ) { | |
| 1680 set_req(MemNode::ValueIn, val->in(1)); | |
| 1681 return this; | |
| 1682 } | |
| 1683 } | |
| 1684 return NULL; | |
| 1685 } | |
| 1686 | |
| 1687 | |
| 1688 //------------------------------Ideal_sign_extended_input---------------------- | |
| 1689 // Check for useless sign-extension before a partial-word store | |
| 1690 // (StoreB ... (RShiftI _ (LShiftI _ valIn conIL ) conIR) ) | |
| 1691 // If (conIL == conIR && conIR <= num_bits) this simplifies to | |
| 1692 // (StoreB ... (valIn) ) | |
| 1693 Node *StoreNode::Ideal_sign_extended_input(PhaseGVN *phase, int num_bits) { | |
| 1694 Node *val = in(MemNode::ValueIn); | |
| 1695 if( val->Opcode() == Op_RShiftI ) { | |
| 1696 const TypeInt *t = phase->type( val->in(2) )->isa_int(); | |
| 1697 if( t && t->is_con() && (t->get_con() <= num_bits) ) { | |
| 1698 Node *shl = val->in(1); | |
| 1699 if( shl->Opcode() == Op_LShiftI ) { | |
| 1700 const TypeInt *t2 = phase->type( shl->in(2) )->isa_int(); | |
| 1701 if( t2 && t2->is_con() && (t2->get_con() == t->get_con()) ) { | |
| 1702 set_req(MemNode::ValueIn, shl->in(1)); | |
| 1703 return this; | |
| 1704 } | |
| 1705 } | |
| 1706 } | |
| 1707 } | |
| 1708 return NULL; | |
| 1709 } | |
| 1710 | |
| 1711 //------------------------------value_never_loaded----------------------------------- | |
| 1712 // Determine whether there are any possible loads of the value stored. | |
| 1713 // For simplicity, we actually check if there are any loads from the | |
| 1714 // address stored to, not just for loads of the value stored by this node. | |
| 1715 // | |
| 1716 bool StoreNode::value_never_loaded( PhaseTransform *phase) const { | |
| 1717 Node *adr = in(Address); | |
| 1718 const TypeOopPtr *adr_oop = phase->type(adr)->isa_oopptr(); | |
| 1719 if (adr_oop == NULL) | |
| 1720 return false; | |
| 1721 if (!adr_oop->is_instance()) | |
| 1722 return false; // if not a distinct instance, there may be aliases of the address | |
| 1723 for (DUIterator_Fast imax, i = adr->fast_outs(imax); i < imax; i++) { | |
| 1724 Node *use = adr->fast_out(i); | |
| 1725 int opc = use->Opcode(); | |
| 1726 if (use->is_Load() || use->is_LoadStore()) { | |
| 1727 return false; | |
| 1728 } | |
| 1729 } | |
| 1730 return true; | |
| 1731 } | |
| 1732 | |
| 1733 //============================================================================= | |
| 1734 //------------------------------Ideal------------------------------------------ | |
| 1735 // If the store is from an AND mask that leaves the low bits untouched, then | |
| 1736 // we can skip the AND operation. If the store is from a sign-extension | |
| 1737 // (a left shift, then right shift) we can skip both. | |
| 1738 Node *StoreBNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 1739 Node *progress = StoreNode::Ideal_masked_input(phase, 0xFF); | |
| 1740 if( progress != NULL ) return progress; | |
| 1741 | |
| 1742 progress = StoreNode::Ideal_sign_extended_input(phase, 24); | |
| 1743 if( progress != NULL ) return progress; | |
| 1744 | |
| 1745 // Finally check the default case | |
| 1746 return StoreNode::Ideal(phase, can_reshape); | |
| 1747 } | |
| 1748 | |
| 1749 //============================================================================= | |
| 1750 //------------------------------Ideal------------------------------------------ | |
| 1751 // If the store is from an AND mask that leaves the low bits untouched, then | |
| 1752 // we can skip the AND operation | |
| 1753 Node *StoreCNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 1754 Node *progress = StoreNode::Ideal_masked_input(phase, 0xFFFF); | |
| 1755 if( progress != NULL ) return progress; | |
| 1756 | |
| 1757 progress = StoreNode::Ideal_sign_extended_input(phase, 16); | |
| 1758 if( progress != NULL ) return progress; | |
| 1759 | |
| 1760 // Finally check the default case | |
| 1761 return StoreNode::Ideal(phase, can_reshape); | |
| 1762 } | |
| 1763 | |
| 1764 //============================================================================= | |
| 1765 //------------------------------Identity--------------------------------------- | |
| 1766 Node *StoreCMNode::Identity( PhaseTransform *phase ) { | |
| 1767 // No need to card mark when storing a null ptr | |
| 1768 Node* my_store = in(MemNode::OopStore); | |
| 1769 if (my_store->is_Store()) { | |
| 1770 const Type *t1 = phase->type( my_store->in(MemNode::ValueIn) ); | |
| 1771 if( t1 == TypePtr::NULL_PTR ) { | |
| 1772 return in(MemNode::Memory); | |
| 1773 } | |
| 1774 } | |
| 1775 return this; | |
| 1776 } | |
| 1777 | |
| 1778 //------------------------------Value----------------------------------------- | |
| 1779 const Type *StoreCMNode::Value( PhaseTransform *phase ) const { | |
| 1780 // If extra input is TOP ==> the result is TOP | |
| 1781 const Type *t1 = phase->type( in(MemNode::OopStore) ); | |
| 1782 if( t1 == Type::TOP ) return Type::TOP; | |
| 1783 | |
| 1784 return StoreNode::Value( phase ); | |
| 1785 } | |
| 1786 | |
| 1787 | |
| 1788 //============================================================================= | |
| 1789 //----------------------------------SCMemProjNode------------------------------ | |
| 1790 const Type * SCMemProjNode::Value( PhaseTransform *phase ) const | |
| 1791 { | |
| 1792 return bottom_type(); | |
| 1793 } | |
| 1794 | |
| 1795 //============================================================================= | |
| 1796 LoadStoreNode::LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex ) : Node(5) { | |
| 1797 init_req(MemNode::Control, c ); | |
| 1798 init_req(MemNode::Memory , mem); | |
| 1799 init_req(MemNode::Address, adr); | |
| 1800 init_req(MemNode::ValueIn, val); | |
| 1801 init_req( ExpectedIn, ex ); | |
| 1802 init_class_id(Class_LoadStore); | |
| 1803 | |
| 1804 } | |
| 1805 | |
| 1806 //============================================================================= | |
| 1807 //-------------------------------adr_type-------------------------------------- | |
| 1808 // Do we Match on this edge index or not? Do not match memory | |
| 1809 const TypePtr* ClearArrayNode::adr_type() const { | |
| 1810 Node *adr = in(3); | |
| 1811 return MemNode::calculate_adr_type(adr->bottom_type()); | |
| 1812 } | |
| 1813 | |
| 1814 //------------------------------match_edge------------------------------------- | |
| 1815 // Do we Match on this edge index or not? Do not match memory | |
| 1816 uint ClearArrayNode::match_edge(uint idx) const { | |
| 1817 return idx > 1; | |
| 1818 } | |
| 1819 | |
| 1820 //------------------------------Identity--------------------------------------- | |
| 1821 // Clearing a zero length array does nothing | |
| 1822 Node *ClearArrayNode::Identity( PhaseTransform *phase ) { | |
| 1823 return phase->type(in(2))->higher_equal(TypeInt::ZERO) ? in(1) : this; | |
| 1824 } | |
| 1825 | |
| 1826 //------------------------------Idealize--------------------------------------- | |
| 1827 // Clearing a short array is faster with stores | |
| 1828 Node *ClearArrayNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 1829 const int unit = BytesPerLong; | |
| 1830 const TypeX* t = phase->type(in(2))->isa_intptr_t(); | |
| 1831 if (!t) return NULL; | |
| 1832 if (!t->is_con()) return NULL; | |
| 1833 intptr_t raw_count = t->get_con(); | |
| 1834 intptr_t size = raw_count; | |
| 1835 if (!Matcher::init_array_count_is_in_bytes) size *= unit; | |
| 1836 // Clearing nothing uses the Identity call. | |
| 1837 // Negative clears are possible on dead ClearArrays | |
| 1838 // (see jck test stmt114.stmt11402.val). | |
| 1839 if (size <= 0 || size % unit != 0) return NULL; | |
| 1840 intptr_t count = size / unit; | |
| 1841 // Length too long; use fast hardware clear | |
| 1842 if (size > Matcher::init_array_short_size) return NULL; | |
| 1843 Node *mem = in(1); | |
| 1844 if( phase->type(mem)==Type::TOP ) return NULL; | |
| 1845 Node *adr = in(3); | |
| 1846 const Type* at = phase->type(adr); | |
| 1847 if( at==Type::TOP ) return NULL; | |
| 1848 const TypePtr* atp = at->isa_ptr(); | |
| 1849 // adjust atp to be the correct array element address type | |
| 1850 if (atp == NULL) atp = TypePtr::BOTTOM; | |
| 1851 else atp = atp->add_offset(Type::OffsetBot); | |
| 1852 // Get base for derived pointer purposes | |
| 1853 if( adr->Opcode() != Op_AddP ) Unimplemented(); | |
| 1854 Node *base = adr->in(1); | |
| 1855 | |
| 1856 Node *zero = phase->makecon(TypeLong::ZERO); | |
| 1857 Node *off = phase->MakeConX(BytesPerLong); | |
| 1858 mem = new (phase->C, 4) StoreLNode(in(0),mem,adr,atp,zero); | |
| 1859 count--; | |
| 1860 while( count-- ) { | |
| 1861 mem = phase->transform(mem); | |
| 1862 adr = phase->transform(new (phase->C, 4) AddPNode(base,adr,off)); | |
| 1863 mem = new (phase->C, 4) StoreLNode(in(0),mem,adr,atp,zero); | |
| 1864 } | |
| 1865 return mem; | |
| 1866 } | |
| 1867 | |
| 1868 //----------------------------clear_memory------------------------------------- | |
| 1869 // Generate code to initialize object storage to zero. | |
| 1870 Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest, | |
| 1871 intptr_t start_offset, | |
| 1872 Node* end_offset, | |
| 1873 PhaseGVN* phase) { | |
| 1874 Compile* C = phase->C; | |
| 1875 intptr_t offset = start_offset; | |
| 1876 | |
| 1877 int unit = BytesPerLong; | |
| 1878 if ((offset % unit) != 0) { | |
| 1879 Node* adr = new (C, 4) AddPNode(dest, dest, phase->MakeConX(offset)); | |
| 1880 adr = phase->transform(adr); | |
| 1881 const TypePtr* atp = TypeRawPtr::BOTTOM; | |
| 1882 mem = StoreNode::make(C, ctl, mem, adr, atp, phase->zerocon(T_INT), T_INT); | |
| 1883 mem = phase->transform(mem); | |
| 1884 offset += BytesPerInt; | |
| 1885 } | |
| 1886 assert((offset % unit) == 0, ""); | |
| 1887 | |
| 1888 // Initialize the remaining stuff, if any, with a ClearArray. | |
| 1889 return clear_memory(ctl, mem, dest, phase->MakeConX(offset), end_offset, phase); | |
| 1890 } | |
| 1891 | |
| 1892 Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest, | |
| 1893 Node* start_offset, | |
| 1894 Node* end_offset, | |
| 1895 PhaseGVN* phase) { | |
| 1896 Compile* C = phase->C; | |
| 1897 int unit = BytesPerLong; | |
| 1898 Node* zbase = start_offset; | |
| 1899 Node* zend = end_offset; | |
| 1900 | |
| 1901 // Scale to the unit required by the CPU: | |
| 1902 if (!Matcher::init_array_count_is_in_bytes) { | |
| 1903 Node* shift = phase->intcon(exact_log2(unit)); | |
| 1904 zbase = phase->transform( new(C,3) URShiftXNode(zbase, shift) ); | |
| 1905 zend = phase->transform( new(C,3) URShiftXNode(zend, shift) ); | |
| 1906 } | |
| 1907 | |
| 1908 Node* zsize = phase->transform( new(C,3) SubXNode(zend, zbase) ); | |
| 1909 Node* zinit = phase->zerocon((unit == BytesPerLong) ? T_LONG : T_INT); | |
| 1910 | |
| 1911 // Bulk clear double-words | |
| 1912 Node* adr = phase->transform( new(C,4) AddPNode(dest, dest, start_offset) ); | |
| 1913 mem = new (C, 4) ClearArrayNode(ctl, mem, zsize, adr); | |
| 1914 return phase->transform(mem); | |
| 1915 } | |
| 1916 | |
| 1917 Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest, | |
| 1918 intptr_t start_offset, | |
| 1919 intptr_t end_offset, | |
| 1920 PhaseGVN* phase) { | |
| 1921 Compile* C = phase->C; | |
| 1922 assert((end_offset % BytesPerInt) == 0, "odd end offset"); | |
| 1923 intptr_t done_offset = end_offset; | |
| 1924 if ((done_offset % BytesPerLong) != 0) { | |
| 1925 done_offset -= BytesPerInt; | |
| 1926 } | |
| 1927 if (done_offset > start_offset) { | |
| 1928 mem = clear_memory(ctl, mem, dest, | |
| 1929 start_offset, phase->MakeConX(done_offset), phase); | |
| 1930 } | |
| 1931 if (done_offset < end_offset) { // emit the final 32-bit store | |
| 1932 Node* adr = new (C, 4) AddPNode(dest, dest, phase->MakeConX(done_offset)); | |
| 1933 adr = phase->transform(adr); | |
| 1934 const TypePtr* atp = TypeRawPtr::BOTTOM; | |
| 1935 mem = StoreNode::make(C, ctl, mem, adr, atp, phase->zerocon(T_INT), T_INT); | |
| 1936 mem = phase->transform(mem); | |
| 1937 done_offset += BytesPerInt; | |
| 1938 } | |
| 1939 assert(done_offset == end_offset, ""); | |
| 1940 return mem; | |
| 1941 } | |
| 1942 | |
| 1943 //============================================================================= | |
| 1944 // Do we match on this edge? No memory edges | |
| 1945 uint StrCompNode::match_edge(uint idx) const { | |
| 1946 return idx == 5 || idx == 6; | |
| 1947 } | |
| 1948 | |
| 1949 //------------------------------Ideal------------------------------------------ | |
| 1950 // Return a node which is more "ideal" than the current node. Strip out | |
| 1951 // control copies | |
| 1952 Node *StrCompNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 1953 return remove_dead_region(phase, can_reshape) ? this : NULL; | |
| 1954 } | |
| 1955 | |
| 1956 | |
| 1957 //============================================================================= | |
| 1958 MemBarNode::MemBarNode(Compile* C, int alias_idx, Node* precedent) | |
| 1959 : MultiNode(TypeFunc::Parms + (precedent == NULL? 0: 1)), | |
| 1960 _adr_type(C->get_adr_type(alias_idx)) | |
| 1961 { | |
| 1962 init_class_id(Class_MemBar); | |
| 1963 Node* top = C->top(); | |
| 1964 init_req(TypeFunc::I_O,top); | |
| 1965 init_req(TypeFunc::FramePtr,top); | |
| 1966 init_req(TypeFunc::ReturnAdr,top); | |
| 1967 if (precedent != NULL) | |
| 1968 init_req(TypeFunc::Parms, precedent); | |
| 1969 } | |
| 1970 | |
| 1971 //------------------------------cmp-------------------------------------------- | |
| 1972 uint MemBarNode::hash() const { return NO_HASH; } | |
| 1973 uint MemBarNode::cmp( const Node &n ) const { | |
| 1974 return (&n == this); // Always fail except on self | |
| 1975 } | |
| 1976 | |
| 1977 //------------------------------make------------------------------------------- | |
| 1978 MemBarNode* MemBarNode::make(Compile* C, int opcode, int atp, Node* pn) { | |
| 1979 int len = Precedent + (pn == NULL? 0: 1); | |
| 1980 switch (opcode) { | |
| 1981 case Op_MemBarAcquire: return new(C, len) MemBarAcquireNode(C, atp, pn); | |
| 1982 case Op_MemBarRelease: return new(C, len) MemBarReleaseNode(C, atp, pn); | |
| 1983 case Op_MemBarVolatile: return new(C, len) MemBarVolatileNode(C, atp, pn); | |
| 1984 case Op_MemBarCPUOrder: return new(C, len) MemBarCPUOrderNode(C, atp, pn); | |
| 1985 case Op_Initialize: return new(C, len) InitializeNode(C, atp, pn); | |
| 1986 default: ShouldNotReachHere(); return NULL; | |
| 1987 } | |
| 1988 } | |
| 1989 | |
| 1990 //------------------------------Ideal------------------------------------------ | |
| 1991 // Return a node which is more "ideal" than the current node. Strip out | |
| 1992 // control copies | |
| 1993 Node *MemBarNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1994 if (remove_dead_region(phase, can_reshape)) return this; | |
| 1995 return NULL; | |
| 1996 } | |
| 1997 | |
| 1998 //------------------------------Value------------------------------------------ | |
| 1999 const Type *MemBarNode::Value( PhaseTransform *phase ) const { | |
| 2000 if( !in(0) ) return Type::TOP; | |
| 2001 if( phase->type(in(0)) == Type::TOP ) | |
| 2002 return Type::TOP; | |
| 2003 return TypeTuple::MEMBAR; | |
| 2004 } | |
| 2005 | |
| 2006 //------------------------------match------------------------------------------ | |
| 2007 // Construct projections for memory. | |
| 2008 Node *MemBarNode::match( const ProjNode *proj, const Matcher *m ) { | |
| 2009 switch (proj->_con) { | |
| 2010 case TypeFunc::Control: | |
| 2011 case TypeFunc::Memory: | |
| 2012 return new (m->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj); | |
| 2013 } | |
| 2014 ShouldNotReachHere(); | |
| 2015 return NULL; | |
| 2016 } | |
| 2017 | |
| 2018 //===========================InitializeNode==================================== | |
| 2019 // SUMMARY: | |
| 2020 // This node acts as a memory barrier on raw memory, after some raw stores. | |
| 2021 // The 'cooked' oop value feeds from the Initialize, not the Allocation. | |
| 2022 // The Initialize can 'capture' suitably constrained stores as raw inits. | |
| 2023 // It can coalesce related raw stores into larger units (called 'tiles'). | |
| 2024 // It can avoid zeroing new storage for memory units which have raw inits. | |
| 2025 // At macro-expansion, it is marked 'complete', and does not optimize further. | |
| 2026 // | |
| 2027 // EXAMPLE: | |
| 2028 // The object 'new short[2]' occupies 16 bytes in a 32-bit machine. | |
| 2029 // ctl = incoming control; mem* = incoming memory | |
| 2030 // (Note: A star * on a memory edge denotes I/O and other standard edges.) | |
| 2031 // First allocate uninitialized memory and fill in the header: | |
| 2032 // alloc = (Allocate ctl mem* 16 #short[].klass ...) | |
| 2033 // ctl := alloc.Control; mem* := alloc.Memory* | |
| 2034 // rawmem = alloc.Memory; rawoop = alloc.RawAddress | |
| 2035 // Then initialize to zero the non-header parts of the raw memory block: | |
| 2036 // init = (Initialize alloc.Control alloc.Memory* alloc.RawAddress) | |
| 2037 // ctl := init.Control; mem.SLICE(#short[*]) := init.Memory | |
| 2038 // After the initialize node executes, the object is ready for service: | |
| 2039 // oop := (CheckCastPP init.Control alloc.RawAddress #short[]) | |
| 2040 // Suppose its body is immediately initialized as {1,2}: | |
| 2041 // store1 = (StoreC init.Control init.Memory (+ oop 12) 1) | |
| 2042 // store2 = (StoreC init.Control store1 (+ oop 14) 2) | |
| 2043 // mem.SLICE(#short[*]) := store2 | |
| 2044 // | |
| 2045 // DETAILS: | |
| 2046 // An InitializeNode collects and isolates object initialization after | |
| 2047 // an AllocateNode and before the next possible safepoint. As a | |
| 2048 // memory barrier (MemBarNode), it keeps critical stores from drifting | |
| 2049 // down past any safepoint or any publication of the allocation. | |
| 2050 // Before this barrier, a newly-allocated object may have uninitialized bits. | |
| 2051 // After this barrier, it may be treated as a real oop, and GC is allowed. | |
| 2052 // | |
| 2053 // The semantics of the InitializeNode include an implicit zeroing of | |
| 2054 // the new object from object header to the end of the object. | |
| 2055 // (The object header and end are determined by the AllocateNode.) | |
| 2056 // | |
| 2057 // Certain stores may be added as direct inputs to the InitializeNode. | |
| 2058 // These stores must update raw memory, and they must be to addresses | |
| 2059 // derived from the raw address produced by AllocateNode, and with | |
| 2060 // a constant offset. They must be ordered by increasing offset. | |
| 2061 // The first one is at in(RawStores), the last at in(req()-1). | |
| 2062 // Unlike most memory operations, they are not linked in a chain, | |
| 2063 // but are displayed in parallel as users of the rawmem output of | |
| 2064 // the allocation. | |
| 2065 // | |
| 2066 // (See comments in InitializeNode::capture_store, which continue | |
| 2067 // the example given above.) | |
| 2068 // | |
| 2069 // When the associated Allocate is macro-expanded, the InitializeNode | |
| 2070 // may be rewritten to optimize collected stores. A ClearArrayNode | |
| 2071 // may also be created at that point to represent any required zeroing. | |
| 2072 // The InitializeNode is then marked 'complete', prohibiting further | |
| 2073 // capturing of nearby memory operations. | |
| 2074 // | |
| 2075 // During macro-expansion, all captured initializations which store | |
| 2076 // constant values of 32 bits or smaller are coalesced (if advantagous) | |
| 2077 // into larger 'tiles' 32 or 64 bits. This allows an object to be | |
| 2078 // initialized in fewer memory operations. Memory words which are | |
| 2079 // covered by neither tiles nor non-constant stores are pre-zeroed | |
| 2080 // by explicit stores of zero. (The code shape happens to do all | |
| 2081 // zeroing first, then all other stores, with both sequences occurring | |
| 2082 // in order of ascending offsets.) | |
| 2083 // | |
| 2084 // Alternatively, code may be inserted between an AllocateNode and its | |
| 2085 // InitializeNode, to perform arbitrary initialization of the new object. | |
| 2086 // E.g., the object copying intrinsics insert complex data transfers here. | |
| 2087 // The initialization must then be marked as 'complete' disable the | |
| 2088 // built-in zeroing semantics and the collection of initializing stores. | |
| 2089 // | |
| 2090 // While an InitializeNode is incomplete, reads from the memory state | |
| 2091 // produced by it are optimizable if they match the control edge and | |
| 2092 // new oop address associated with the allocation/initialization. | |
| 2093 // They return a stored value (if the offset matches) or else zero. | |
| 2094 // A write to the memory state, if it matches control and address, | |
| 2095 // and if it is to a constant offset, may be 'captured' by the | |
| 2096 // InitializeNode. It is cloned as a raw memory operation and rewired | |
| 2097 // inside the initialization, to the raw oop produced by the allocation. | |
| 2098 // Operations on addresses which are provably distinct (e.g., to | |
| 2099 // other AllocateNodes) are allowed to bypass the initialization. | |
| 2100 // | |
| 2101 // The effect of all this is to consolidate object initialization | |
| 2102 // (both arrays and non-arrays, both piecewise and bulk) into a | |
| 2103 // single location, where it can be optimized as a unit. | |
| 2104 // | |
| 2105 // Only stores with an offset less than TrackedInitializationLimit words | |
| 2106 // will be considered for capture by an InitializeNode. This puts a | |
| 2107 // reasonable limit on the complexity of optimized initializations. | |
| 2108 | |
| 2109 //---------------------------InitializeNode------------------------------------ | |
| 2110 InitializeNode::InitializeNode(Compile* C, int adr_type, Node* rawoop) | |
| 2111 : _is_complete(false), | |
| 2112 MemBarNode(C, adr_type, rawoop) | |
| 2113 { | |
| 2114 init_class_id(Class_Initialize); | |
| 2115 | |
| 2116 assert(adr_type == Compile::AliasIdxRaw, "only valid atp"); | |
| 2117 assert(in(RawAddress) == rawoop, "proper init"); | |
| 2118 // Note: allocation() can be NULL, for secondary initialization barriers | |
| 2119 } | |
| 2120 | |
| 2121 // Since this node is not matched, it will be processed by the | |
| 2122 // register allocator. Declare that there are no constraints | |
| 2123 // on the allocation of the RawAddress edge. | |
| 2124 const RegMask &InitializeNode::in_RegMask(uint idx) const { | |
| 2125 // This edge should be set to top, by the set_complete. But be conservative. | |
| 2126 if (idx == InitializeNode::RawAddress) | |
| 2127 return *(Compile::current()->matcher()->idealreg2spillmask[in(idx)->ideal_reg()]); | |
| 2128 return RegMask::Empty; | |
| 2129 } | |
| 2130 | |
| 2131 Node* InitializeNode::memory(uint alias_idx) { | |
| 2132 Node* mem = in(Memory); | |
| 2133 if (mem->is_MergeMem()) { | |
| 2134 return mem->as_MergeMem()->memory_at(alias_idx); | |
| 2135 } else { | |
| 2136 // incoming raw memory is not split | |
| 2137 return mem; | |
| 2138 } | |
| 2139 } | |
| 2140 | |
| 2141 bool InitializeNode::is_non_zero() { | |
| 2142 if (is_complete()) return false; | |
| 2143 remove_extra_zeroes(); | |
| 2144 return (req() > RawStores); | |
| 2145 } | |
| 2146 | |
| 2147 void InitializeNode::set_complete(PhaseGVN* phase) { | |
| 2148 assert(!is_complete(), "caller responsibility"); | |
| 2149 _is_complete = true; | |
| 2150 | |
| 2151 // After this node is complete, it contains a bunch of | |
| 2152 // raw-memory initializations. There is no need for | |
| 2153 // it to have anything to do with non-raw memory effects. | |
| 2154 // Therefore, tell all non-raw users to re-optimize themselves, | |
| 2155 // after skipping the memory effects of this initialization. | |
| 2156 PhaseIterGVN* igvn = phase->is_IterGVN(); | |
| 2157 if (igvn) igvn->add_users_to_worklist(this); | |
| 2158 } | |
| 2159 | |
| 2160 // convenience function | |
| 2161 // return false if the init contains any stores already | |
| 2162 bool AllocateNode::maybe_set_complete(PhaseGVN* phase) { | |
| 2163 InitializeNode* init = initialization(); | |
| 2164 if (init == NULL || init->is_complete()) return false; | |
| 2165 init->remove_extra_zeroes(); | |
| 2166 // for now, if this allocation has already collected any inits, bail: | |
| 2167 if (init->is_non_zero()) return false; | |
| 2168 init->set_complete(phase); | |
| 2169 return true; | |
| 2170 } | |
| 2171 | |
| 2172 void InitializeNode::remove_extra_zeroes() { | |
| 2173 if (req() == RawStores) return; | |
| 2174 Node* zmem = zero_memory(); | |
| 2175 uint fill = RawStores; | |
| 2176 for (uint i = fill; i < req(); i++) { | |
| 2177 Node* n = in(i); | |
| 2178 if (n->is_top() || n == zmem) continue; // skip | |
| 2179 if (fill < i) set_req(fill, n); // compact | |
| 2180 ++fill; | |
| 2181 } | |
| 2182 // delete any empty spaces created: | |
| 2183 while (fill < req()) { | |
| 2184 del_req(fill); | |
| 2185 } | |
| 2186 } | |
| 2187 | |
| 2188 // Helper for remembering which stores go with which offsets. | |
| 2189 intptr_t InitializeNode::get_store_offset(Node* st, PhaseTransform* phase) { | |
| 2190 if (!st->is_Store()) return -1; // can happen to dead code via subsume_node | |
| 2191 intptr_t offset = -1; | |
| 2192 Node* base = AddPNode::Ideal_base_and_offset(st->in(MemNode::Address), | |
| 2193 phase, offset); | |
| 2194 if (base == NULL) return -1; // something is dead, | |
| 2195 if (offset < 0) return -1; // dead, dead | |
| 2196 return offset; | |
| 2197 } | |
| 2198 | |
| 2199 // Helper for proving that an initialization expression is | |
| 2200 // "simple enough" to be folded into an object initialization. | |
| 2201 // Attempts to prove that a store's initial value 'n' can be captured | |
| 2202 // within the initialization without creating a vicious cycle, such as: | |
| 2203 // { Foo p = new Foo(); p.next = p; } | |
| 2204 // True for constants and parameters and small combinations thereof. | |
| 2205 bool InitializeNode::detect_init_independence(Node* n, | |
| 2206 bool st_is_pinned, | |
| 2207 int& count) { | |
| 2208 if (n == NULL) return true; // (can this really happen?) | |
| 2209 if (n->is_Proj()) n = n->in(0); | |
| 2210 if (n == this) return false; // found a cycle | |
| 2211 if (n->is_Con()) return true; | |
| 2212 if (n->is_Start()) return true; // params, etc., are OK | |
| 2213 if (n->is_Root()) return true; // even better | |
| 2214 | |
| 2215 Node* ctl = n->in(0); | |
| 2216 if (ctl != NULL && !ctl->is_top()) { | |
| 2217 if (ctl->is_Proj()) ctl = ctl->in(0); | |
| 2218 if (ctl == this) return false; | |
| 2219 | |
| 2220 // If we already know that the enclosing memory op is pinned right after | |
| 2221 // the init, then any control flow that the store has picked up | |
| 2222 // must have preceded the init, or else be equal to the init. | |
| 2223 // Even after loop optimizations (which might change control edges) | |
| 2224 // a store is never pinned *before* the availability of its inputs. | |
| 2225 if (!MemNode::detect_dominating_control(ctl, this->in(0))) | |
| 2226 return false; // failed to prove a good control | |
| 2227 | |
| 2228 } | |
| 2229 | |
| 2230 // Check data edges for possible dependencies on 'this'. | |
| 2231 if ((count += 1) > 20) return false; // complexity limit | |
| 2232 for (uint i = 1; i < n->req(); i++) { | |
| 2233 Node* m = n->in(i); | |
| 2234 if (m == NULL || m == n || m->is_top()) continue; | |
| 2235 uint first_i = n->find_edge(m); | |
| 2236 if (i != first_i) continue; // process duplicate edge just once | |
| 2237 if (!detect_init_independence(m, st_is_pinned, count)) { | |
| 2238 return false; | |
| 2239 } | |
| 2240 } | |
| 2241 | |
| 2242 return true; | |
| 2243 } | |
| 2244 | |
| 2245 // Here are all the checks a Store must pass before it can be moved into | |
| 2246 // an initialization. Returns zero if a check fails. | |
| 2247 // On success, returns the (constant) offset to which the store applies, | |
| 2248 // within the initialized memory. | |
| 2249 intptr_t InitializeNode::can_capture_store(StoreNode* st, PhaseTransform* phase) { | |
| 2250 const int FAIL = 0; | |
| 2251 if (st->req() != MemNode::ValueIn + 1) | |
| 2252 return FAIL; // an inscrutable StoreNode (card mark?) | |
| 2253 Node* ctl = st->in(MemNode::Control); | |
| 2254 if (!(ctl != NULL && ctl->is_Proj() && ctl->in(0) == this)) | |
| 2255 return FAIL; // must be unconditional after the initialization | |
| 2256 Node* mem = st->in(MemNode::Memory); | |
| 2257 if (!(mem->is_Proj() && mem->in(0) == this)) | |
| 2258 return FAIL; // must not be preceded by other stores | |
| 2259 Node* adr = st->in(MemNode::Address); | |
| 2260 intptr_t offset; | |
| 2261 AllocateNode* alloc = AllocateNode::Ideal_allocation(adr, phase, offset); | |
| 2262 if (alloc == NULL) | |
| 2263 return FAIL; // inscrutable address | |
| 2264 if (alloc != allocation()) | |
| 2265 return FAIL; // wrong allocation! (store needs to float up) | |
| 2266 Node* val = st->in(MemNode::ValueIn); | |
| 2267 int complexity_count = 0; | |
| 2268 if (!detect_init_independence(val, true, complexity_count)) | |
| 2269 return FAIL; // stored value must be 'simple enough' | |
| 2270 | |
| 2271 return offset; // success | |
| 2272 } | |
| 2273 | |
| 2274 // Find the captured store in(i) which corresponds to the range | |
| 2275 // [start..start+size) in the initialized object. | |
| 2276 // If there is one, return its index i. If there isn't, return the | |
| 2277 // negative of the index where it should be inserted. | |
| 2278 // Return 0 if the queried range overlaps an initialization boundary | |
| 2279 // or if dead code is encountered. | |
| 2280 // If size_in_bytes is zero, do not bother with overlap checks. | |
| 2281 int InitializeNode::captured_store_insertion_point(intptr_t start, | |
| 2282 int size_in_bytes, | |
| 2283 PhaseTransform* phase) { | |
| 2284 const int FAIL = 0, MAX_STORE = BytesPerLong; | |
| 2285 | |
| 2286 if (is_complete()) | |
| 2287 return FAIL; // arraycopy got here first; punt | |
| 2288 | |
| 2289 assert(allocation() != NULL, "must be present"); | |
| 2290 | |
| 2291 // no negatives, no header fields: | |
| 2292 if (start < (intptr_t) sizeof(oopDesc)) return FAIL; | |
| 2293 if (start < (intptr_t) sizeof(arrayOopDesc) && | |
| 2294 start < (intptr_t) allocation()->minimum_header_size()) return FAIL; | |
| 2295 | |
| 2296 // after a certain size, we bail out on tracking all the stores: | |
| 2297 intptr_t ti_limit = (TrackedInitializationLimit * HeapWordSize); | |
| 2298 if (start >= ti_limit) return FAIL; | |
| 2299 | |
| 2300 for (uint i = InitializeNode::RawStores, limit = req(); ; ) { | |
| 2301 if (i >= limit) return -(int)i; // not found; here is where to put it | |
| 2302 | |
| 2303 Node* st = in(i); | |
| 2304 intptr_t st_off = get_store_offset(st, phase); | |
| 2305 if (st_off < 0) { | |
| 2306 if (st != zero_memory()) { | |
| 2307 return FAIL; // bail out if there is dead garbage | |
| 2308 } | |
| 2309 } else if (st_off > start) { | |
| 2310 // ...we are done, since stores are ordered | |
| 2311 if (st_off < start + size_in_bytes) { | |
| 2312 return FAIL; // the next store overlaps | |
| 2313 } | |
| 2314 return -(int)i; // not found; here is where to put it | |
| 2315 } else if (st_off < start) { | |
| 2316 if (size_in_bytes != 0 && | |
| 2317 start < st_off + MAX_STORE && | |
| 2318 start < st_off + st->as_Store()->memory_size()) { | |
| 2319 return FAIL; // the previous store overlaps | |
| 2320 } | |
| 2321 } else { | |
| 2322 if (size_in_bytes != 0 && | |
| 2323 st->as_Store()->memory_size() != size_in_bytes) { | |
| 2324 return FAIL; // mismatched store size | |
| 2325 } | |
| 2326 return i; | |
| 2327 } | |
| 2328 | |
| 2329 ++i; | |
| 2330 } | |
| 2331 } | |
| 2332 | |
| 2333 // Look for a captured store which initializes at the offset 'start' | |
| 2334 // with the given size. If there is no such store, and no other | |
| 2335 // initialization interferes, then return zero_memory (the memory | |
| 2336 // projection of the AllocateNode). | |
| 2337 Node* InitializeNode::find_captured_store(intptr_t start, int size_in_bytes, | |
| 2338 PhaseTransform* phase) { | |
| 2339 assert(stores_are_sane(phase), ""); | |
| 2340 int i = captured_store_insertion_point(start, size_in_bytes, phase); | |
| 2341 if (i == 0) { | |
| 2342 return NULL; // something is dead | |
| 2343 } else if (i < 0) { | |
| 2344 return zero_memory(); // just primordial zero bits here | |
| 2345 } else { | |
| 2346 Node* st = in(i); // here is the store at this position | |
| 2347 assert(get_store_offset(st->as_Store(), phase) == start, "sanity"); | |
| 2348 return st; | |
| 2349 } | |
| 2350 } | |
| 2351 | |
| 2352 // Create, as a raw pointer, an address within my new object at 'offset'. | |
| 2353 Node* InitializeNode::make_raw_address(intptr_t offset, | |
| 2354 PhaseTransform* phase) { | |
| 2355 Node* addr = in(RawAddress); | |
| 2356 if (offset != 0) { | |
| 2357 Compile* C = phase->C; | |
| 2358 addr = phase->transform( new (C, 4) AddPNode(C->top(), addr, | |
| 2359 phase->MakeConX(offset)) ); | |
| 2360 } | |
| 2361 return addr; | |
| 2362 } | |
| 2363 | |
| 2364 // Clone the given store, converting it into a raw store | |
| 2365 // initializing a field or element of my new object. | |
| 2366 // Caller is responsible for retiring the original store, | |
| 2367 // with subsume_node or the like. | |
| 2368 // | |
| 2369 // From the example above InitializeNode::InitializeNode, | |
| 2370 // here are the old stores to be captured: | |
| 2371 // store1 = (StoreC init.Control init.Memory (+ oop 12) 1) | |
| 2372 // store2 = (StoreC init.Control store1 (+ oop 14) 2) | |
| 2373 // | |
| 2374 // Here is the changed code; note the extra edges on init: | |
| 2375 // alloc = (Allocate ...) | |
| 2376 // rawoop = alloc.RawAddress | |
| 2377 // rawstore1 = (StoreC alloc.Control alloc.Memory (+ rawoop 12) 1) | |
| 2378 // rawstore2 = (StoreC alloc.Control alloc.Memory (+ rawoop 14) 2) | |
| 2379 // init = (Initialize alloc.Control alloc.Memory rawoop | |
| 2380 // rawstore1 rawstore2) | |
| 2381 // | |
| 2382 Node* InitializeNode::capture_store(StoreNode* st, intptr_t start, | |
| 2383 PhaseTransform* phase) { | |
| 2384 assert(stores_are_sane(phase), ""); | |
| 2385 | |
| 2386 if (start < 0) return NULL; | |
| 2387 assert(can_capture_store(st, phase) == start, "sanity"); | |
| 2388 | |
| 2389 Compile* C = phase->C; | |
| 2390 int size_in_bytes = st->memory_size(); | |
| 2391 int i = captured_store_insertion_point(start, size_in_bytes, phase); | |
| 2392 if (i == 0) return NULL; // bail out | |
| 2393 Node* prev_mem = NULL; // raw memory for the captured store | |
| 2394 if (i > 0) { | |
| 2395 prev_mem = in(i); // there is a pre-existing store under this one | |
| 2396 set_req(i, C->top()); // temporarily disconnect it | |
| 2397 // See StoreNode::Ideal 'st->outcnt() == 1' for the reason to disconnect. | |
| 2398 } else { | |
| 2399 i = -i; // no pre-existing store | |
| 2400 prev_mem = zero_memory(); // a slice of the newly allocated object | |
| 2401 if (i > InitializeNode::RawStores && in(i-1) == prev_mem) | |
| 2402 set_req(--i, C->top()); // reuse this edge; it has been folded away | |
| 2403 else | |
| 2404 ins_req(i, C->top()); // build a new edge | |
| 2405 } | |
| 2406 Node* new_st = st->clone(); | |
| 2407 new_st->set_req(MemNode::Control, in(Control)); | |
| 2408 new_st->set_req(MemNode::Memory, prev_mem); | |
| 2409 new_st->set_req(MemNode::Address, make_raw_address(start, phase)); | |
| 2410 new_st = phase->transform(new_st); | |
| 2411 | |
| 2412 // At this point, new_st might have swallowed a pre-existing store | |
| 2413 // at the same offset, or perhaps new_st might have disappeared, | |
| 2414 // if it redundantly stored the same value (or zero to fresh memory). | |
| 2415 | |
| 2416 // In any case, wire it in: | |
| 2417 set_req(i, new_st); | |
| 2418 | |
| 2419 // The caller may now kill the old guy. | |
| 2420 DEBUG_ONLY(Node* check_st = find_captured_store(start, size_in_bytes, phase)); | |
| 2421 assert(check_st == new_st || check_st == NULL, "must be findable"); | |
| 2422 assert(!is_complete(), ""); | |
| 2423 return new_st; | |
| 2424 } | |
| 2425 | |
| 2426 static bool store_constant(jlong* tiles, int num_tiles, | |
| 2427 intptr_t st_off, int st_size, | |
| 2428 jlong con) { | |
| 2429 if ((st_off & (st_size-1)) != 0) | |
| 2430 return false; // strange store offset (assume size==2**N) | |
| 2431 address addr = (address)tiles + st_off; | |
| 2432 assert(st_off >= 0 && addr+st_size <= (address)&tiles[num_tiles], "oob"); | |
| 2433 switch (st_size) { | |
| 2434 case sizeof(jbyte): *(jbyte*) addr = (jbyte) con; break; | |
| 2435 case sizeof(jchar): *(jchar*) addr = (jchar) con; break; | |
| 2436 case sizeof(jint): *(jint*) addr = (jint) con; break; | |
| 2437 case sizeof(jlong): *(jlong*) addr = (jlong) con; break; | |
| 2438 default: return false; // strange store size (detect size!=2**N here) | |
| 2439 } | |
| 2440 return true; // return success to caller | |
| 2441 } | |
| 2442 | |
| 2443 // Coalesce subword constants into int constants and possibly | |
| 2444 // into long constants. The goal, if the CPU permits, | |
| 2445 // is to initialize the object with a small number of 64-bit tiles. | |
| 2446 // Also, convert floating-point constants to bit patterns. | |
| 2447 // Non-constants are not relevant to this pass. | |
| 2448 // | |
| 2449 // In terms of the running example on InitializeNode::InitializeNode | |
| 2450 // and InitializeNode::capture_store, here is the transformation | |
| 2451 // of rawstore1 and rawstore2 into rawstore12: | |
| 2452 // alloc = (Allocate ...) | |
| 2453 // rawoop = alloc.RawAddress | |
| 2454 // tile12 = 0x00010002 | |
| 2455 // rawstore12 = (StoreI alloc.Control alloc.Memory (+ rawoop 12) tile12) | |
| 2456 // init = (Initialize alloc.Control alloc.Memory rawoop rawstore12) | |
| 2457 // | |
| 2458 void | |
| 2459 InitializeNode::coalesce_subword_stores(intptr_t header_size, | |
| 2460 Node* size_in_bytes, | |
| 2461 PhaseGVN* phase) { | |
| 2462 Compile* C = phase->C; | |
| 2463 | |
| 2464 assert(stores_are_sane(phase), ""); | |
| 2465 // Note: After this pass, they are not completely sane, | |
| 2466 // since there may be some overlaps. | |
| 2467 | |
| 2468 int old_subword = 0, old_long = 0, new_int = 0, new_long = 0; | |
| 2469 | |
| 2470 intptr_t ti_limit = (TrackedInitializationLimit * HeapWordSize); | |
| 2471 intptr_t size_limit = phase->find_intptr_t_con(size_in_bytes, ti_limit); | |
| 2472 size_limit = MIN2(size_limit, ti_limit); | |
| 2473 size_limit = align_size_up(size_limit, BytesPerLong); | |
| 2474 int num_tiles = size_limit / BytesPerLong; | |
| 2475 | |
| 2476 // allocate space for the tile map: | |
| 2477 const int small_len = DEBUG_ONLY(true ? 3 :) 30; // keep stack frames small | |
| 2478 jlong tiles_buf[small_len]; | |
| 2479 Node* nodes_buf[small_len]; | |
| 2480 jlong inits_buf[small_len]; | |
| 2481 jlong* tiles = ((num_tiles <= small_len) ? &tiles_buf[0] | |
| 2482 : NEW_RESOURCE_ARRAY(jlong, num_tiles)); | |
| 2483 Node** nodes = ((num_tiles <= small_len) ? &nodes_buf[0] | |
| 2484 : NEW_RESOURCE_ARRAY(Node*, num_tiles)); | |
| 2485 jlong* inits = ((num_tiles <= small_len) ? &inits_buf[0] | |
| 2486 : NEW_RESOURCE_ARRAY(jlong, num_tiles)); | |
| 2487 // tiles: exact bitwise model of all primitive constants | |
| 2488 // nodes: last constant-storing node subsumed into the tiles model | |
| 2489 // inits: which bytes (in each tile) are touched by any initializations | |
| 2490 | |
| 2491 //// Pass A: Fill in the tile model with any relevant stores. | |
| 2492 | |
| 2493 Copy::zero_to_bytes(tiles, sizeof(tiles[0]) * num_tiles); | |
| 2494 Copy::zero_to_bytes(nodes, sizeof(nodes[0]) * num_tiles); | |
| 2495 Copy::zero_to_bytes(inits, sizeof(inits[0]) * num_tiles); | |
| 2496 Node* zmem = zero_memory(); // initially zero memory state | |
| 2497 for (uint i = InitializeNode::RawStores, limit = req(); i < limit; i++) { | |
| 2498 Node* st = in(i); | |
| 2499 intptr_t st_off = get_store_offset(st, phase); | |
| 2500 | |
| 2501 // Figure out the store's offset and constant value: | |
| 2502 if (st_off < header_size) continue; //skip (ignore header) | |
| 2503 if (st->in(MemNode::Memory) != zmem) continue; //skip (odd store chain) | |
| 2504 int st_size = st->as_Store()->memory_size(); | |
| 2505 if (st_off + st_size > size_limit) break; | |
| 2506 | |
| 2507 // Record which bytes are touched, whether by constant or not. | |
| 2508 if (!store_constant(inits, num_tiles, st_off, st_size, (jlong) -1)) | |
| 2509 continue; // skip (strange store size) | |
| 2510 | |
| 2511 const Type* val = phase->type(st->in(MemNode::ValueIn)); | |
| 2512 if (!val->singleton()) continue; //skip (non-con store) | |
| 2513 BasicType type = val->basic_type(); | |
| 2514 | |
| 2515 jlong con = 0; | |
| 2516 switch (type) { | |
| 2517 case T_INT: con = val->is_int()->get_con(); break; | |
| 2518 case T_LONG: con = val->is_long()->get_con(); break; | |
| 2519 case T_FLOAT: con = jint_cast(val->getf()); break; | |
| 2520 case T_DOUBLE: con = jlong_cast(val->getd()); break; | |
| 2521 default: continue; //skip (odd store type) | |
| 2522 } | |
| 2523 | |
| 2524 if (type == T_LONG && Matcher::isSimpleConstant64(con) && | |
| 2525 st->Opcode() == Op_StoreL) { | |
| 2526 continue; // This StoreL is already optimal. | |
| 2527 } | |
| 2528 | |
| 2529 // Store down the constant. | |
| 2530 store_constant(tiles, num_tiles, st_off, st_size, con); | |
| 2531 | |
| 2532 intptr_t j = st_off >> LogBytesPerLong; | |
| 2533 | |
| 2534 if (type == T_INT && st_size == BytesPerInt | |
| 2535 && (st_off & BytesPerInt) == BytesPerInt) { | |
| 2536 jlong lcon = tiles[j]; | |
| 2537 if (!Matcher::isSimpleConstant64(lcon) && | |
| 2538 st->Opcode() == Op_StoreI) { | |
| 2539 // This StoreI is already optimal by itself. | |
| 2540 jint* intcon = (jint*) &tiles[j]; | |
| 2541 intcon[1] = 0; // undo the store_constant() | |
| 2542 | |
| 2543 // If the previous store is also optimal by itself, back up and | |
| 2544 // undo the action of the previous loop iteration... if we can. | |
| 2545 // But if we can't, just let the previous half take care of itself. | |
| 2546 st = nodes[j]; | |
| 2547 st_off -= BytesPerInt; | |
| 2548 con = intcon[0]; | |
| 2549 if (con != 0 && st != NULL && st->Opcode() == Op_StoreI) { | |
| 2550 assert(st_off >= header_size, "still ignoring header"); | |
| 2551 assert(get_store_offset(st, phase) == st_off, "must be"); | |
| 2552 assert(in(i-1) == zmem, "must be"); | |
| 2553 DEBUG_ONLY(const Type* tcon = phase->type(st->in(MemNode::ValueIn))); | |
| 2554 assert(con == tcon->is_int()->get_con(), "must be"); | |
| 2555 // Undo the effects of the previous loop trip, which swallowed st: | |
| 2556 intcon[0] = 0; // undo store_constant() | |
| 2557 set_req(i-1, st); // undo set_req(i, zmem) | |
| 2558 nodes[j] = NULL; // undo nodes[j] = st | |
| 2559 --old_subword; // undo ++old_subword | |
| 2560 } | |
| 2561 continue; // This StoreI is already optimal. | |
| 2562 } | |
| 2563 } | |
| 2564 | |
| 2565 // This store is not needed. | |
| 2566 set_req(i, zmem); | |
| 2567 nodes[j] = st; // record for the moment | |
| 2568 if (st_size < BytesPerLong) // something has changed | |
| 2569 ++old_subword; // includes int/float, but who's counting... | |
| 2570 else ++old_long; | |
| 2571 } | |
| 2572 | |
| 2573 if ((old_subword + old_long) == 0) | |
| 2574 return; // nothing more to do | |
| 2575 | |
| 2576 //// Pass B: Convert any non-zero tiles into optimal constant stores. | |
| 2577 // Be sure to insert them before overlapping non-constant stores. | |
| 2578 // (E.g., byte[] x = { 1,2,y,4 } => x[int 0] = 0x01020004, x[2]=y.) | |
| 2579 for (int j = 0; j < num_tiles; j++) { | |
| 2580 jlong con = tiles[j]; | |
| 2581 jlong init = inits[j]; | |
| 2582 if (con == 0) continue; | |
| 2583 jint con0, con1; // split the constant, address-wise | |
| 2584 jint init0, init1; // split the init map, address-wise | |
| 2585 { union { jlong con; jint intcon[2]; } u; | |
| 2586 u.con = con; | |
| 2587 con0 = u.intcon[0]; | |
| 2588 con1 = u.intcon[1]; | |
| 2589 u.con = init; | |
| 2590 init0 = u.intcon[0]; | |
| 2591 init1 = u.intcon[1]; | |
| 2592 } | |
| 2593 | |
| 2594 Node* old = nodes[j]; | |
| 2595 assert(old != NULL, "need the prior store"); | |
| 2596 intptr_t offset = (j * BytesPerLong); | |
| 2597 | |
| 2598 bool split = !Matcher::isSimpleConstant64(con); | |
| 2599 | |
| 2600 if (offset < header_size) { | |
| 2601 assert(offset + BytesPerInt >= header_size, "second int counts"); | |
| 2602 assert(*(jint*)&tiles[j] == 0, "junk in header"); | |
| 2603 split = true; // only the second word counts | |
| 2604 // Example: int a[] = { 42 ... } | |
| 2605 } else if (con0 == 0 && init0 == -1) { | |
| 2606 split = true; // first word is covered by full inits | |
| 2607 // Example: int a[] = { ... foo(), 42 ... } | |
| 2608 } else if (con1 == 0 && init1 == -1) { | |
| 2609 split = true; // second word is covered by full inits | |
| 2610 // Example: int a[] = { ... 42, foo() ... } | |
| 2611 } | |
| 2612 | |
| 2613 // Here's a case where init0 is neither 0 nor -1: | |
| 2614 // byte a[] = { ... 0,0,foo(),0, 0,0,0,42 ... } | |
| 2615 // Assuming big-endian memory, init0, init1 are 0x0000FF00, 0x000000FF. | |
| 2616 // In this case the tile is not split; it is (jlong)42. | |
| 2617 // The big tile is stored down, and then the foo() value is inserted. | |
| 2618 // (If there were foo(),foo() instead of foo(),0, init0 would be -1.) | |
| 2619 | |
| 2620 Node* ctl = old->in(MemNode::Control); | |
| 2621 Node* adr = make_raw_address(offset, phase); | |
| 2622 const TypePtr* atp = TypeRawPtr::BOTTOM; | |
| 2623 | |
| 2624 // One or two coalesced stores to plop down. | |
| 2625 Node* st[2]; | |
| 2626 intptr_t off[2]; | |
| 2627 int nst = 0; | |
| 2628 if (!split) { | |
| 2629 ++new_long; | |
| 2630 off[nst] = offset; | |
| 2631 st[nst++] = StoreNode::make(C, ctl, zmem, adr, atp, | |
| 2632 phase->longcon(con), T_LONG); | |
| 2633 } else { | |
| 2634 // Omit either if it is a zero. | |
| 2635 if (con0 != 0) { | |
| 2636 ++new_int; | |
| 2637 off[nst] = offset; | |
| 2638 st[nst++] = StoreNode::make(C, ctl, zmem, adr, atp, | |
| 2639 phase->intcon(con0), T_INT); | |
| 2640 } | |
| 2641 if (con1 != 0) { | |
| 2642 ++new_int; | |
| 2643 offset += BytesPerInt; | |
| 2644 adr = make_raw_address(offset, phase); | |
| 2645 off[nst] = offset; | |
| 2646 st[nst++] = StoreNode::make(C, ctl, zmem, adr, atp, | |
| 2647 phase->intcon(con1), T_INT); | |
| 2648 } | |
| 2649 } | |
| 2650 | |
| 2651 // Insert second store first, then the first before the second. | |
| 2652 // Insert each one just before any overlapping non-constant stores. | |
| 2653 while (nst > 0) { | |
| 2654 Node* st1 = st[--nst]; | |
| 2655 C->copy_node_notes_to(st1, old); | |
| 2656 st1 = phase->transform(st1); | |
| 2657 offset = off[nst]; | |
| 2658 assert(offset >= header_size, "do not smash header"); | |
| 2659 int ins_idx = captured_store_insertion_point(offset, /*size:*/0, phase); | |
| 2660 guarantee(ins_idx != 0, "must re-insert constant store"); | |
| 2661 if (ins_idx < 0) ins_idx = -ins_idx; // never overlap | |
| 2662 if (ins_idx > InitializeNode::RawStores && in(ins_idx-1) == zmem) | |
| 2663 set_req(--ins_idx, st1); | |
| 2664 else | |
| 2665 ins_req(ins_idx, st1); | |
| 2666 } | |
| 2667 } | |
| 2668 | |
| 2669 if (PrintCompilation && WizardMode) | |
| 2670 tty->print_cr("Changed %d/%d subword/long constants into %d/%d int/long", | |
| 2671 old_subword, old_long, new_int, new_long); | |
| 2672 if (C->log() != NULL) | |
| 2673 C->log()->elem("comment that='%d/%d subword/long to %d/%d int/long'", | |
| 2674 old_subword, old_long, new_int, new_long); | |
| 2675 | |
| 2676 // Clean up any remaining occurrences of zmem: | |
| 2677 remove_extra_zeroes(); | |
| 2678 } | |
| 2679 | |
| 2680 // Explore forward from in(start) to find the first fully initialized | |
| 2681 // word, and return its offset. Skip groups of subword stores which | |
| 2682 // together initialize full words. If in(start) is itself part of a | |
| 2683 // fully initialized word, return the offset of in(start). If there | |
| 2684 // are no following full-word stores, or if something is fishy, return | |
| 2685 // a negative value. | |
| 2686 intptr_t InitializeNode::find_next_fullword_store(uint start, PhaseGVN* phase) { | |
| 2687 int int_map = 0; | |
| 2688 intptr_t int_map_off = 0; | |
| 2689 const int FULL_MAP = right_n_bits(BytesPerInt); // the int_map we hope for | |
| 2690 | |
| 2691 for (uint i = start, limit = req(); i < limit; i++) { | |
| 2692 Node* st = in(i); | |
| 2693 | |
| 2694 intptr_t st_off = get_store_offset(st, phase); | |
| 2695 if (st_off < 0) break; // return conservative answer | |
| 2696 | |
| 2697 int st_size = st->as_Store()->memory_size(); | |
| 2698 if (st_size >= BytesPerInt && (st_off % BytesPerInt) == 0) { | |
| 2699 return st_off; // we found a complete word init | |
| 2700 } | |
| 2701 | |
| 2702 // update the map: | |
| 2703 | |
| 2704 intptr_t this_int_off = align_size_down(st_off, BytesPerInt); | |
| 2705 if (this_int_off != int_map_off) { | |
| 2706 // reset the map: | |
| 2707 int_map = 0; | |
| 2708 int_map_off = this_int_off; | |
| 2709 } | |
| 2710 | |
| 2711 int subword_off = st_off - this_int_off; | |
| 2712 int_map |= right_n_bits(st_size) << subword_off; | |
| 2713 if ((int_map & FULL_MAP) == FULL_MAP) { | |
| 2714 return this_int_off; // we found a complete word init | |
| 2715 } | |
| 2716 | |
| 2717 // Did this store hit or cross the word boundary? | |
| 2718 intptr_t next_int_off = align_size_down(st_off + st_size, BytesPerInt); | |
| 2719 if (next_int_off == this_int_off + BytesPerInt) { | |
| 2720 // We passed the current int, without fully initializing it. | |
| 2721 int_map_off = next_int_off; | |
| 2722 int_map >>= BytesPerInt; | |
| 2723 } else if (next_int_off > this_int_off + BytesPerInt) { | |
| 2724 // We passed the current and next int. | |
| 2725 return this_int_off + BytesPerInt; | |
| 2726 } | |
| 2727 } | |
| 2728 | |
| 2729 return -1; | |
| 2730 } | |
| 2731 | |
| 2732 | |
| 2733 // Called when the associated AllocateNode is expanded into CFG. | |
| 2734 // At this point, we may perform additional optimizations. | |
| 2735 // Linearize the stores by ascending offset, to make memory | |
| 2736 // activity as coherent as possible. | |
| 2737 Node* InitializeNode::complete_stores(Node* rawctl, Node* rawmem, Node* rawptr, | |
| 2738 intptr_t header_size, | |
| 2739 Node* size_in_bytes, | |
| 2740 PhaseGVN* phase) { | |
| 2741 assert(!is_complete(), "not already complete"); | |
| 2742 assert(stores_are_sane(phase), ""); | |
| 2743 assert(allocation() != NULL, "must be present"); | |
| 2744 | |
| 2745 remove_extra_zeroes(); | |
| 2746 | |
| 2747 if (ReduceFieldZeroing || ReduceBulkZeroing) | |
| 2748 // reduce instruction count for common initialization patterns | |
| 2749 coalesce_subword_stores(header_size, size_in_bytes, phase); | |
| 2750 | |
| 2751 Node* zmem = zero_memory(); // initially zero memory state | |
| 2752 Node* inits = zmem; // accumulating a linearized chain of inits | |
| 2753 #ifdef ASSERT | |
| 2754 intptr_t last_init_off = sizeof(oopDesc); // previous init offset | |
| 2755 intptr_t last_init_end = sizeof(oopDesc); // previous init offset+size | |
| 2756 intptr_t last_tile_end = sizeof(oopDesc); // previous tile offset+size | |
| 2757 #endif | |
| 2758 intptr_t zeroes_done = header_size; | |
| 2759 | |
| 2760 bool do_zeroing = true; // we might give up if inits are very sparse | |
| 2761 int big_init_gaps = 0; // how many large gaps have we seen? | |
| 2762 | |
| 2763 if (ZeroTLAB) do_zeroing = false; | |
| 2764 if (!ReduceFieldZeroing && !ReduceBulkZeroing) do_zeroing = false; | |
| 2765 | |
| 2766 for (uint i = InitializeNode::RawStores, limit = req(); i < limit; i++) { | |
| 2767 Node* st = in(i); | |
| 2768 intptr_t st_off = get_store_offset(st, phase); | |
| 2769 if (st_off < 0) | |
| 2770 break; // unknown junk in the inits | |
| 2771 if (st->in(MemNode::Memory) != zmem) | |
| 2772 break; // complicated store chains somehow in list | |
| 2773 | |
| 2774 int st_size = st->as_Store()->memory_size(); | |
| 2775 intptr_t next_init_off = st_off + st_size; | |
| 2776 | |
| 2777 if (do_zeroing && zeroes_done < next_init_off) { | |
| 2778 // See if this store needs a zero before it or under it. | |
| 2779 intptr_t zeroes_needed = st_off; | |
| 2780 | |
| 2781 if (st_size < BytesPerInt) { | |
| 2782 // Look for subword stores which only partially initialize words. | |
| 2783 // If we find some, we must lay down some word-level zeroes first, | |
| 2784 // underneath the subword stores. | |
| 2785 // | |
| 2786 // Examples: | |
| 2787 // byte[] a = { p,q,r,s } => a[0]=p,a[1]=q,a[2]=r,a[3]=s | |
| 2788 // byte[] a = { x,y,0,0 } => a[0..3] = 0, a[0]=x,a[1]=y | |
| 2789 // byte[] a = { 0,0,z,0 } => a[0..3] = 0, a[2]=z | |
| 2790 // | |
| 2791 // Note: coalesce_subword_stores may have already done this, | |
| 2792 // if it was prompted by constant non-zero subword initializers. | |
| 2793 // But this case can still arise with non-constant stores. | |
| 2794 | |
| 2795 intptr_t next_full_store = find_next_fullword_store(i, phase); | |
| 2796 | |
| 2797 // In the examples above: | |
| 2798 // in(i) p q r s x y z | |
| 2799 // st_off 12 13 14 15 12 13 14 | |
| 2800 // st_size 1 1 1 1 1 1 1 | |
| 2801 // next_full_s. 12 16 16 16 16 16 16 | |
| 2802 // z's_done 12 16 16 16 12 16 12 | |
| 2803 // z's_needed 12 16 16 16 16 16 16 | |
| 2804 // zsize 0 0 0 0 4 0 4 | |
| 2805 if (next_full_store < 0) { | |
| 2806 // Conservative tack: Zero to end of current word. | |
| 2807 zeroes_needed = align_size_up(zeroes_needed, BytesPerInt); | |
| 2808 } else { | |
| 2809 // Zero to beginning of next fully initialized word. | |
| 2810 // Or, don't zero at all, if we are already in that word. | |
| 2811 assert(next_full_store >= zeroes_needed, "must go forward"); | |
| 2812 assert((next_full_store & (BytesPerInt-1)) == 0, "even boundary"); | |
| 2813 zeroes_needed = next_full_store; | |
| 2814 } | |
| 2815 } | |
| 2816 | |
| 2817 if (zeroes_needed > zeroes_done) { | |
| 2818 intptr_t zsize = zeroes_needed - zeroes_done; | |
| 2819 // Do some incremental zeroing on rawmem, in parallel with inits. | |
| 2820 zeroes_done = align_size_down(zeroes_done, BytesPerInt); | |
| 2821 rawmem = ClearArrayNode::clear_memory(rawctl, rawmem, rawptr, | |
| 2822 zeroes_done, zeroes_needed, | |
| 2823 phase); | |
| 2824 zeroes_done = zeroes_needed; | |
| 2825 if (zsize > Matcher::init_array_short_size && ++big_init_gaps > 2) | |
| 2826 do_zeroing = false; // leave the hole, next time | |
| 2827 } | |
| 2828 } | |
| 2829 | |
| 2830 // Collect the store and move on: | |
| 2831 st->set_req(MemNode::Memory, inits); | |
| 2832 inits = st; // put it on the linearized chain | |
| 2833 set_req(i, zmem); // unhook from previous position | |
| 2834 | |
| 2835 if (zeroes_done == st_off) | |
| 2836 zeroes_done = next_init_off; | |
| 2837 | |
| 2838 assert(!do_zeroing || zeroes_done >= next_init_off, "don't miss any"); | |
| 2839 | |
| 2840 #ifdef ASSERT | |
| 2841 // Various order invariants. Weaker than stores_are_sane because | |
| 2842 // a large constant tile can be filled in by smaller non-constant stores. | |
| 2843 assert(st_off >= last_init_off, "inits do not reverse"); | |
| 2844 last_init_off = st_off; | |
| 2845 const Type* val = NULL; | |
| 2846 if (st_size >= BytesPerInt && | |
| 2847 (val = phase->type(st->in(MemNode::ValueIn)))->singleton() && | |
| 2848 (int)val->basic_type() < (int)T_OBJECT) { | |
| 2849 assert(st_off >= last_tile_end, "tiles do not overlap"); | |
| 2850 assert(st_off >= last_init_end, "tiles do not overwrite inits"); | |
| 2851 last_tile_end = MAX2(last_tile_end, next_init_off); | |
| 2852 } else { | |
| 2853 intptr_t st_tile_end = align_size_up(next_init_off, BytesPerLong); | |
| 2854 assert(st_tile_end >= last_tile_end, "inits stay with tiles"); | |
| 2855 assert(st_off >= last_init_end, "inits do not overlap"); | |
| 2856 last_init_end = next_init_off; // it's a non-tile | |
| 2857 } | |
| 2858 #endif //ASSERT | |
| 2859 } | |
| 2860 | |
| 2861 remove_extra_zeroes(); // clear out all the zmems left over | |
| 2862 add_req(inits); | |
| 2863 | |
| 2864 if (!ZeroTLAB) { | |
| 2865 // If anything remains to be zeroed, zero it all now. | |
| 2866 zeroes_done = align_size_down(zeroes_done, BytesPerInt); | |
| 2867 // if it is the last unused 4 bytes of an instance, forget about it | |
| 2868 intptr_t size_limit = phase->find_intptr_t_con(size_in_bytes, max_jint); | |
| 2869 if (zeroes_done + BytesPerLong >= size_limit) { | |
| 2870 assert(allocation() != NULL, ""); | |
| 2871 Node* klass_node = allocation()->in(AllocateNode::KlassNode); | |
| 2872 ciKlass* k = phase->type(klass_node)->is_klassptr()->klass(); | |
| 2873 if (zeroes_done == k->layout_helper()) | |
| 2874 zeroes_done = size_limit; | |
| 2875 } | |
| 2876 if (zeroes_done < size_limit) { | |
| 2877 rawmem = ClearArrayNode::clear_memory(rawctl, rawmem, rawptr, | |
| 2878 zeroes_done, size_in_bytes, phase); | |
| 2879 } | |
| 2880 } | |
| 2881 | |
| 2882 set_complete(phase); | |
| 2883 return rawmem; | |
| 2884 } | |
| 2885 | |
| 2886 | |
| 2887 #ifdef ASSERT | |
| 2888 bool InitializeNode::stores_are_sane(PhaseTransform* phase) { | |
| 2889 if (is_complete()) | |
| 2890 return true; // stores could be anything at this point | |
| 2891 intptr_t last_off = sizeof(oopDesc); | |
| 2892 for (uint i = InitializeNode::RawStores; i < req(); i++) { | |
| 2893 Node* st = in(i); | |
| 2894 intptr_t st_off = get_store_offset(st, phase); | |
| 2895 if (st_off < 0) continue; // ignore dead garbage | |
| 2896 if (last_off > st_off) { | |
| 2897 tty->print_cr("*** bad store offset at %d: %d > %d", i, last_off, st_off); | |
| 2898 this->dump(2); | |
| 2899 assert(false, "ascending store offsets"); | |
| 2900 return false; | |
| 2901 } | |
| 2902 last_off = st_off + st->as_Store()->memory_size(); | |
| 2903 } | |
| 2904 return true; | |
| 2905 } | |
| 2906 #endif //ASSERT | |
| 2907 | |
| 2908 | |
| 2909 | |
| 2910 | |
| 2911 //============================MergeMemNode===================================== | |
| 2912 // | |
| 2913 // SEMANTICS OF MEMORY MERGES: A MergeMem is a memory state assembled from several | |
| 2914 // contributing store or call operations. Each contributor provides the memory | |
| 2915 // state for a particular "alias type" (see Compile::alias_type). For example, | |
| 2916 // if a MergeMem has an input X for alias category #6, then any memory reference | |
| 2917 // to alias category #6 may use X as its memory state input, as an exact equivalent | |
| 2918 // to using the MergeMem as a whole. | |
| 2919 // Load<6>( MergeMem(<6>: X, ...), p ) <==> Load<6>(X,p) | |
| 2920 // | |
| 2921 // (Here, the <N> notation gives the index of the relevant adr_type.) | |
| 2922 // | |
| 2923 // In one special case (and more cases in the future), alias categories overlap. | |
| 2924 // The special alias category "Bot" (Compile::AliasIdxBot) includes all memory | |
| 2925 // states. Therefore, if a MergeMem has only one contributing input W for Bot, | |
| 2926 // it is exactly equivalent to that state W: | |
| 2927 // MergeMem(<Bot>: W) <==> W | |
| 2928 // | |
| 2929 // Usually, the merge has more than one input. In that case, where inputs | |
| 2930 // overlap (i.e., one is Bot), the narrower alias type determines the memory | |
| 2931 // state for that type, and the wider alias type (Bot) fills in everywhere else: | |
| 2932 // Load<5>( MergeMem(<Bot>: W, <6>: X), p ) <==> Load<5>(W,p) | |
| 2933 // Load<6>( MergeMem(<Bot>: W, <6>: X), p ) <==> Load<6>(X,p) | |
| 2934 // | |
| 2935 // A merge can take a "wide" memory state as one of its narrow inputs. | |
| 2936 // This simply means that the merge observes out only the relevant parts of | |
| 2937 // the wide input. That is, wide memory states arriving at narrow merge inputs | |
| 2938 // are implicitly "filtered" or "sliced" as necessary. (This is rare.) | |
| 2939 // | |
| 2940 // These rules imply that MergeMem nodes may cascade (via their <Bot> links), | |
| 2941 // and that memory slices "leak through": | |
| 2942 // MergeMem(<Bot>: MergeMem(<Bot>: W, <7>: Y)) <==> MergeMem(<Bot>: W, <7>: Y) | |
| 2943 // | |
| 2944 // But, in such a cascade, repeated memory slices can "block the leak": | |
| 2945 // MergeMem(<Bot>: MergeMem(<Bot>: W, <7>: Y), <7>: Y') <==> MergeMem(<Bot>: W, <7>: Y') | |
| 2946 // | |
| 2947 // In the last example, Y is not part of the combined memory state of the | |
| 2948 // outermost MergeMem. The system must, of course, prevent unschedulable | |
| 2949 // memory states from arising, so you can be sure that the state Y is somehow | |
| 2950 // a precursor to state Y'. | |
| 2951 // | |
| 2952 // | |
| 2953 // REPRESENTATION OF MEMORY MERGES: The indexes used to address the Node::in array | |
| 2954 // of each MergeMemNode array are exactly the numerical alias indexes, including | |
| 2955 // but not limited to AliasIdxTop, AliasIdxBot, and AliasIdxRaw. The functions | |
| 2956 // Compile::alias_type (and kin) produce and manage these indexes. | |
| 2957 // | |
| 2958 // By convention, the value of in(AliasIdxTop) (i.e., in(1)) is always the top node. | |
| 2959 // (Note that this provides quick access to the top node inside MergeMem methods, | |
| 2960 // without the need to reach out via TLS to Compile::current.) | |
| 2961 // | |
| 2962 // As a consequence of what was just described, a MergeMem that represents a full | |
| 2963 // memory state has an edge in(AliasIdxBot) which is a "wide" memory state, | |
| 2964 // containing all alias categories. | |
| 2965 // | |
| 2966 // MergeMem nodes never (?) have control inputs, so in(0) is NULL. | |
| 2967 // | |
| 2968 // All other edges in(N) (including in(AliasIdxRaw), which is in(3)) are either | |
| 2969 // a memory state for the alias type <N>, or else the top node, meaning that | |
| 2970 // there is no particular input for that alias type. Note that the length of | |
| 2971 // a MergeMem is variable, and may be extended at any time to accommodate new | |
| 2972 // memory states at larger alias indexes. When merges grow, they are of course | |
| 2973 // filled with "top" in the unused in() positions. | |
| 2974 // | |
| 2975 // This use of top is named "empty_memory()", or "empty_mem" (no-memory) as a variable. | |
| 2976 // (Top was chosen because it works smoothly with passes like GCM.) | |
| 2977 // | |
| 2978 // For convenience, we hardwire the alias index for TypeRawPtr::BOTTOM. (It is | |
| 2979 // the type of random VM bits like TLS references.) Since it is always the | |
| 2980 // first non-Bot memory slice, some low-level loops use it to initialize an | |
| 2981 // index variable: for (i = AliasIdxRaw; i < req(); i++). | |
| 2982 // | |
| 2983 // | |
| 2984 // ACCESSORS: There is a special accessor MergeMemNode::base_memory which returns | |
| 2985 // the distinguished "wide" state. The accessor MergeMemNode::memory_at(N) returns | |
| 2986 // the memory state for alias type <N>, or (if there is no particular slice at <N>, | |
| 2987 // it returns the base memory. To prevent bugs, memory_at does not accept <Top> | |
| 2988 // or <Bot> indexes. The iterator MergeMemStream provides robust iteration over | |
| 2989 // MergeMem nodes or pairs of such nodes, ensuring that the non-top edges are visited. | |
| 2990 // | |
| 2991 // %%%% We may get rid of base_memory as a separate accessor at some point; it isn't | |
| 2992 // really that different from the other memory inputs. An abbreviation called | |
| 2993 // "bot_memory()" for "memory_at(AliasIdxBot)" would keep code tidy. | |
| 2994 // | |
| 2995 // | |
| 2996 // PARTIAL MEMORY STATES: During optimization, MergeMem nodes may arise that represent | |
| 2997 // partial memory states. When a Phi splits through a MergeMem, the copy of the Phi | |
| 2998 // that "emerges though" the base memory will be marked as excluding the alias types | |
| 2999 // of the other (narrow-memory) copies which "emerged through" the narrow edges: | |
| 3000 // | |
| 3001 // Phi<Bot>(U, MergeMem(<Bot>: W, <8>: Y)) | |
| 3002 // ==Ideal=> MergeMem(<Bot>: Phi<Bot-8>(U, W), Phi<8>(U, Y)) | |
| 3003 // | |
| 3004 // This strange "subtraction" effect is necessary to ensure IGVN convergence. | |
| 3005 // (It is currently unimplemented.) As you can see, the resulting merge is | |
| 3006 // actually a disjoint union of memory states, rather than an overlay. | |
| 3007 // | |
| 3008 | |
| 3009 //------------------------------MergeMemNode----------------------------------- | |
| 3010 Node* MergeMemNode::make_empty_memory() { | |
| 3011 Node* empty_memory = (Node*) Compile::current()->top(); | |
| 3012 assert(empty_memory->is_top(), "correct sentinel identity"); | |
| 3013 return empty_memory; | |
| 3014 } | |
| 3015 | |
| 3016 MergeMemNode::MergeMemNode(Node *new_base) : Node(1+Compile::AliasIdxRaw) { | |
| 3017 init_class_id(Class_MergeMem); | |
| 3018 // all inputs are nullified in Node::Node(int) | |
| 3019 // set_input(0, NULL); // no control input | |
| 3020 | |
| 3021 // Initialize the edges uniformly to top, for starters. | |
| 3022 Node* empty_mem = make_empty_memory(); | |
| 3023 for (uint i = Compile::AliasIdxTop; i < req(); i++) { | |
| 3024 init_req(i,empty_mem); | |
| 3025 } | |
| 3026 assert(empty_memory() == empty_mem, ""); | |
| 3027 | |
| 3028 if( new_base != NULL && new_base->is_MergeMem() ) { | |
| 3029 MergeMemNode* mdef = new_base->as_MergeMem(); | |
| 3030 assert(mdef->empty_memory() == empty_mem, "consistent sentinels"); | |
| 3031 for (MergeMemStream mms(this, mdef); mms.next_non_empty2(); ) { | |
| 3032 mms.set_memory(mms.memory2()); | |
| 3033 } | |
| 3034 assert(base_memory() == mdef->base_memory(), ""); | |
| 3035 } else { | |
| 3036 set_base_memory(new_base); | |
| 3037 } | |
| 3038 } | |
| 3039 | |
| 3040 // Make a new, untransformed MergeMem with the same base as 'mem'. | |
| 3041 // If mem is itself a MergeMem, populate the result with the same edges. | |
| 3042 MergeMemNode* MergeMemNode::make(Compile* C, Node* mem) { | |
| 3043 return new(C, 1+Compile::AliasIdxRaw) MergeMemNode(mem); | |
| 3044 } | |
| 3045 | |
| 3046 //------------------------------cmp-------------------------------------------- | |
| 3047 uint MergeMemNode::hash() const { return NO_HASH; } | |
| 3048 uint MergeMemNode::cmp( const Node &n ) const { | |
| 3049 return (&n == this); // Always fail except on self | |
| 3050 } | |
| 3051 | |
| 3052 //------------------------------Identity--------------------------------------- | |
| 3053 Node* MergeMemNode::Identity(PhaseTransform *phase) { | |
| 3054 // Identity if this merge point does not record any interesting memory | |
| 3055 // disambiguations. | |
| 3056 Node* base_mem = base_memory(); | |
| 3057 Node* empty_mem = empty_memory(); | |
| 3058 if (base_mem != empty_mem) { // Memory path is not dead? | |
| 3059 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3060 Node* mem = in(i); | |
| 3061 if (mem != empty_mem && mem != base_mem) { | |
| 3062 return this; // Many memory splits; no change | |
| 3063 } | |
| 3064 } | |
| 3065 } | |
| 3066 return base_mem; // No memory splits; ID on the one true input | |
| 3067 } | |
| 3068 | |
| 3069 //------------------------------Ideal------------------------------------------ | |
| 3070 // This method is invoked recursively on chains of MergeMem nodes | |
| 3071 Node *MergeMemNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 3072 // Remove chain'd MergeMems | |
| 3073 // | |
| 3074 // This is delicate, because the each "in(i)" (i >= Raw) is interpreted | |
| 3075 // relative to the "in(Bot)". Since we are patching both at the same time, | |
| 3076 // we have to be careful to read each "in(i)" relative to the old "in(Bot)", | |
| 3077 // but rewrite each "in(i)" relative to the new "in(Bot)". | |
| 3078 Node *progress = NULL; | |
| 3079 | |
| 3080 | |
| 3081 Node* old_base = base_memory(); | |
| 3082 Node* empty_mem = empty_memory(); | |
| 3083 if (old_base == empty_mem) | |
| 3084 return NULL; // Dead memory path. | |
| 3085 | |
| 3086 MergeMemNode* old_mbase; | |
| 3087 if (old_base != NULL && old_base->is_MergeMem()) | |
| 3088 old_mbase = old_base->as_MergeMem(); | |
| 3089 else | |
| 3090 old_mbase = NULL; | |
| 3091 Node* new_base = old_base; | |
| 3092 | |
| 3093 // simplify stacked MergeMems in base memory | |
| 3094 if (old_mbase) new_base = old_mbase->base_memory(); | |
| 3095 | |
| 3096 // the base memory might contribute new slices beyond my req() | |
| 3097 if (old_mbase) grow_to_match(old_mbase); | |
| 3098 | |
| 3099 // Look carefully at the base node if it is a phi. | |
| 3100 PhiNode* phi_base; | |
| 3101 if (new_base != NULL && new_base->is_Phi()) | |
| 3102 phi_base = new_base->as_Phi(); | |
| 3103 else | |
| 3104 phi_base = NULL; | |
| 3105 | |
| 3106 Node* phi_reg = NULL; | |
| 3107 uint phi_len = (uint)-1; | |
| 3108 if (phi_base != NULL && !phi_base->is_copy()) { | |
| 3109 // do not examine phi if degraded to a copy | |
| 3110 phi_reg = phi_base->region(); | |
| 3111 phi_len = phi_base->req(); | |
| 3112 // see if the phi is unfinished | |
| 3113 for (uint i = 1; i < phi_len; i++) { | |
| 3114 if (phi_base->in(i) == NULL) { | |
| 3115 // incomplete phi; do not look at it yet! | |
| 3116 phi_reg = NULL; | |
| 3117 phi_len = (uint)-1; | |
| 3118 break; | |
| 3119 } | |
| 3120 } | |
| 3121 } | |
| 3122 | |
| 3123 // Note: We do not call verify_sparse on entry, because inputs | |
| 3124 // can normalize to the base_memory via subsume_node or similar | |
| 3125 // mechanisms. This method repairs that damage. | |
| 3126 | |
| 3127 assert(!old_mbase || old_mbase->is_empty_memory(empty_mem), "consistent sentinels"); | |
| 3128 | |
| 3129 // Look at each slice. | |
| 3130 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3131 Node* old_in = in(i); | |
| 3132 // calculate the old memory value | |
| 3133 Node* old_mem = old_in; | |
| 3134 if (old_mem == empty_mem) old_mem = old_base; | |
| 3135 assert(old_mem == memory_at(i), ""); | |
| 3136 | |
| 3137 // maybe update (reslice) the old memory value | |
| 3138 | |
| 3139 // simplify stacked MergeMems | |
| 3140 Node* new_mem = old_mem; | |
| 3141 MergeMemNode* old_mmem; | |
| 3142 if (old_mem != NULL && old_mem->is_MergeMem()) | |
| 3143 old_mmem = old_mem->as_MergeMem(); | |
| 3144 else | |
| 3145 old_mmem = NULL; | |
| 3146 if (old_mmem == this) { | |
| 3147 // This can happen if loops break up and safepoints disappear. | |
| 3148 // A merge of BotPtr (default) with a RawPtr memory derived from a | |
| 3149 // safepoint can be rewritten to a merge of the same BotPtr with | |
| 3150 // the BotPtr phi coming into the loop. If that phi disappears | |
| 3151 // also, we can end up with a self-loop of the mergemem. | |
| 3152 // In general, if loops degenerate and memory effects disappear, | |
| 3153 // a mergemem can be left looking at itself. This simply means | |
| 3154 // that the mergemem's default should be used, since there is | |
| 3155 // no longer any apparent effect on this slice. | |
| 3156 // Note: If a memory slice is a MergeMem cycle, it is unreachable | |
| 3157 // from start. Update the input to TOP. | |
| 3158 new_mem = (new_base == this || new_base == empty_mem)? empty_mem : new_base; | |
| 3159 } | |
| 3160 else if (old_mmem != NULL) { | |
| 3161 new_mem = old_mmem->memory_at(i); | |
| 3162 } | |
| 3163 // else preceeding memory was not a MergeMem | |
| 3164 | |
| 3165 // replace equivalent phis (unfortunately, they do not GVN together) | |
| 3166 if (new_mem != NULL && new_mem != new_base && | |
| 3167 new_mem->req() == phi_len && new_mem->in(0) == phi_reg) { | |
| 3168 if (new_mem->is_Phi()) { | |
| 3169 PhiNode* phi_mem = new_mem->as_Phi(); | |
| 3170 for (uint i = 1; i < phi_len; i++) { | |
| 3171 if (phi_base->in(i) != phi_mem->in(i)) { | |
| 3172 phi_mem = NULL; | |
| 3173 break; | |
| 3174 } | |
| 3175 } | |
| 3176 if (phi_mem != NULL) { | |
| 3177 // equivalent phi nodes; revert to the def | |
| 3178 new_mem = new_base; | |
| 3179 } | |
| 3180 } | |
| 3181 } | |
| 3182 | |
| 3183 // maybe store down a new value | |
| 3184 Node* new_in = new_mem; | |
| 3185 if (new_in == new_base) new_in = empty_mem; | |
| 3186 | |
| 3187 if (new_in != old_in) { | |
| 3188 // Warning: Do not combine this "if" with the previous "if" | |
| 3189 // A memory slice might have be be rewritten even if it is semantically | |
| 3190 // unchanged, if the base_memory value has changed. | |
| 3191 set_req(i, new_in); | |
| 3192 progress = this; // Report progress | |
| 3193 } | |
| 3194 } | |
| 3195 | |
| 3196 if (new_base != old_base) { | |
| 3197 set_req(Compile::AliasIdxBot, new_base); | |
| 3198 // Don't use set_base_memory(new_base), because we need to update du. | |
| 3199 assert(base_memory() == new_base, ""); | |
| 3200 progress = this; | |
| 3201 } | |
| 3202 | |
| 3203 if( base_memory() == this ) { | |
| 3204 // a self cycle indicates this memory path is dead | |
| 3205 set_req(Compile::AliasIdxBot, empty_mem); | |
| 3206 } | |
| 3207 | |
| 3208 // Resolve external cycles by calling Ideal on a MergeMem base_memory | |
| 3209 // Recursion must occur after the self cycle check above | |
| 3210 if( base_memory()->is_MergeMem() ) { | |
| 3211 MergeMemNode *new_mbase = base_memory()->as_MergeMem(); | |
| 3212 Node *m = phase->transform(new_mbase); // Rollup any cycles | |
| 3213 if( m != NULL && (m->is_top() || | |
| 3214 m->is_MergeMem() && m->as_MergeMem()->base_memory() == empty_mem) ) { | |
| 3215 // propagate rollup of dead cycle to self | |
| 3216 set_req(Compile::AliasIdxBot, empty_mem); | |
| 3217 } | |
| 3218 } | |
| 3219 | |
| 3220 if( base_memory() == empty_mem ) { | |
| 3221 progress = this; | |
| 3222 // Cut inputs during Parse phase only. | |
| 3223 // During Optimize phase a dead MergeMem node will be subsumed by Top. | |
| 3224 if( !can_reshape ) { | |
| 3225 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3226 if( in(i) != empty_mem ) { set_req(i, empty_mem); } | |
| 3227 } | |
| 3228 } | |
| 3229 } | |
| 3230 | |
| 3231 if( !progress && base_memory()->is_Phi() && can_reshape ) { | |
| 3232 // Check if PhiNode::Ideal's "Split phis through memory merges" | |
| 3233 // transform should be attempted. Look for this->phi->this cycle. | |
| 3234 uint merge_width = req(); | |
| 3235 if (merge_width > Compile::AliasIdxRaw) { | |
| 3236 PhiNode* phi = base_memory()->as_Phi(); | |
| 3237 for( uint i = 1; i < phi->req(); ++i ) {// For all paths in | |
| 3238 if (phi->in(i) == this) { | |
| 3239 phase->is_IterGVN()->_worklist.push(phi); | |
| 3240 break; | |
| 3241 } | |
| 3242 } | |
| 3243 } | |
| 3244 } | |
| 3245 | |
| 3246 assert(verify_sparse(), "please, no dups of base"); | |
| 3247 return progress; | |
| 3248 } | |
| 3249 | |
| 3250 //-------------------------set_base_memory------------------------------------- | |
| 3251 void MergeMemNode::set_base_memory(Node *new_base) { | |
| 3252 Node* empty_mem = empty_memory(); | |
| 3253 set_req(Compile::AliasIdxBot, new_base); | |
| 3254 assert(memory_at(req()) == new_base, "must set default memory"); | |
| 3255 // Clear out other occurrences of new_base: | |
| 3256 if (new_base != empty_mem) { | |
| 3257 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3258 if (in(i) == new_base) set_req(i, empty_mem); | |
| 3259 } | |
| 3260 } | |
| 3261 } | |
| 3262 | |
| 3263 //------------------------------out_RegMask------------------------------------ | |
| 3264 const RegMask &MergeMemNode::out_RegMask() const { | |
| 3265 return RegMask::Empty; | |
| 3266 } | |
| 3267 | |
| 3268 //------------------------------dump_spec-------------------------------------- | |
| 3269 #ifndef PRODUCT | |
| 3270 void MergeMemNode::dump_spec(outputStream *st) const { | |
| 3271 st->print(" {"); | |
| 3272 Node* base_mem = base_memory(); | |
| 3273 for( uint i = Compile::AliasIdxRaw; i < req(); i++ ) { | |
| 3274 Node* mem = memory_at(i); | |
| 3275 if (mem == base_mem) { st->print(" -"); continue; } | |
| 3276 st->print( " N%d:", mem->_idx ); | |
| 3277 Compile::current()->get_adr_type(i)->dump_on(st); | |
| 3278 } | |
| 3279 st->print(" }"); | |
| 3280 } | |
| 3281 #endif // !PRODUCT | |
| 3282 | |
| 3283 | |
| 3284 #ifdef ASSERT | |
| 3285 static bool might_be_same(Node* a, Node* b) { | |
| 3286 if (a == b) return true; | |
| 3287 if (!(a->is_Phi() || b->is_Phi())) return false; | |
| 3288 // phis shift around during optimization | |
| 3289 return true; // pretty stupid... | |
| 3290 } | |
| 3291 | |
| 3292 // verify a narrow slice (either incoming or outgoing) | |
| 3293 static void verify_memory_slice(const MergeMemNode* m, int alias_idx, Node* n) { | |
| 3294 if (!VerifyAliases) return; // don't bother to verify unless requested | |
| 3295 if (is_error_reported()) return; // muzzle asserts when debugging an error | |
| 3296 if (Node::in_dump()) return; // muzzle asserts when printing | |
| 3297 assert(alias_idx >= Compile::AliasIdxRaw, "must not disturb base_memory or sentinel"); | |
| 3298 assert(n != NULL, ""); | |
| 3299 // Elide intervening MergeMem's | |
| 3300 while (n->is_MergeMem()) { | |
| 3301 n = n->as_MergeMem()->memory_at(alias_idx); | |
| 3302 } | |
| 3303 Compile* C = Compile::current(); | |
| 3304 const TypePtr* n_adr_type = n->adr_type(); | |
| 3305 if (n == m->empty_memory()) { | |
| 3306 // Implicit copy of base_memory() | |
| 3307 } else if (n_adr_type != TypePtr::BOTTOM) { | |
| 3308 assert(n_adr_type != NULL, "new memory must have a well-defined adr_type"); | |
| 3309 assert(C->must_alias(n_adr_type, alias_idx), "new memory must match selected slice"); | |
| 3310 } else { | |
| 3311 // A few places like make_runtime_call "know" that VM calls are narrow, | |
| 3312 // and can be used to update only the VM bits stored as TypeRawPtr::BOTTOM. | |
| 3313 bool expected_wide_mem = false; | |
| 3314 if (n == m->base_memory()) { | |
| 3315 expected_wide_mem = true; | |
| 3316 } else if (alias_idx == Compile::AliasIdxRaw || | |
| 3317 n == m->memory_at(Compile::AliasIdxRaw)) { | |
| 3318 expected_wide_mem = true; | |
| 3319 } else if (!C->alias_type(alias_idx)->is_rewritable()) { | |
| 3320 // memory can "leak through" calls on channels that | |
| 3321 // are write-once. Allow this also. | |
| 3322 expected_wide_mem = true; | |
| 3323 } | |
| 3324 assert(expected_wide_mem, "expected narrow slice replacement"); | |
| 3325 } | |
| 3326 } | |
| 3327 #else // !ASSERT | |
| 3328 #define verify_memory_slice(m,i,n) (0) // PRODUCT version is no-op | |
| 3329 #endif | |
| 3330 | |
| 3331 | |
| 3332 //-----------------------------memory_at--------------------------------------- | |
| 3333 Node* MergeMemNode::memory_at(uint alias_idx) const { | |
| 3334 assert(alias_idx >= Compile::AliasIdxRaw || | |
| 3335 alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0, | |
| 3336 "must avoid base_memory and AliasIdxTop"); | |
| 3337 | |
| 3338 // Otherwise, it is a narrow slice. | |
| 3339 Node* n = alias_idx < req() ? in(alias_idx) : empty_memory(); | |
| 3340 Compile *C = Compile::current(); | |
| 3341 if (is_empty_memory(n)) { | |
| 3342 // the array is sparse; empty slots are the "top" node | |
| 3343 n = base_memory(); | |
| 3344 assert(Node::in_dump() | |
| 3345 || n == NULL || n->bottom_type() == Type::TOP | |
| 3346 || n->adr_type() == TypePtr::BOTTOM | |
| 3347 || n->adr_type() == TypeRawPtr::BOTTOM | |
| 3348 || Compile::current()->AliasLevel() == 0, | |
| 3349 "must be a wide memory"); | |
| 3350 // AliasLevel == 0 if we are organizing the memory states manually. | |
| 3351 // See verify_memory_slice for comments on TypeRawPtr::BOTTOM. | |
| 3352 } else { | |
| 3353 // make sure the stored slice is sane | |
| 3354 #ifdef ASSERT | |
| 3355 if (is_error_reported() || Node::in_dump()) { | |
| 3356 } else if (might_be_same(n, base_memory())) { | |
| 3357 // Give it a pass: It is a mostly harmless repetition of the base. | |
| 3358 // This can arise normally from node subsumption during optimization. | |
| 3359 } else { | |
| 3360 verify_memory_slice(this, alias_idx, n); | |
| 3361 } | |
| 3362 #endif | |
| 3363 } | |
| 3364 return n; | |
| 3365 } | |
| 3366 | |
| 3367 //---------------------------set_memory_at------------------------------------- | |
| 3368 void MergeMemNode::set_memory_at(uint alias_idx, Node *n) { | |
| 3369 verify_memory_slice(this, alias_idx, n); | |
| 3370 Node* empty_mem = empty_memory(); | |
| 3371 if (n == base_memory()) n = empty_mem; // collapse default | |
| 3372 uint need_req = alias_idx+1; | |
| 3373 if (req() < need_req) { | |
| 3374 if (n == empty_mem) return; // already the default, so do not grow me | |
| 3375 // grow the sparse array | |
| 3376 do { | |
| 3377 add_req(empty_mem); | |
| 3378 } while (req() < need_req); | |
| 3379 } | |
| 3380 set_req( alias_idx, n ); | |
| 3381 } | |
| 3382 | |
| 3383 | |
| 3384 | |
| 3385 //--------------------------iteration_setup------------------------------------ | |
| 3386 void MergeMemNode::iteration_setup(const MergeMemNode* other) { | |
| 3387 if (other != NULL) { | |
| 3388 grow_to_match(other); | |
| 3389 // invariant: the finite support of mm2 is within mm->req() | |
| 3390 #ifdef ASSERT | |
| 3391 for (uint i = req(); i < other->req(); i++) { | |
| 3392 assert(other->is_empty_memory(other->in(i)), "slice left uncovered"); | |
| 3393 } | |
| 3394 #endif | |
| 3395 } | |
| 3396 // Replace spurious copies of base_memory by top. | |
| 3397 Node* base_mem = base_memory(); | |
| 3398 if (base_mem != NULL && !base_mem->is_top()) { | |
| 3399 for (uint i = Compile::AliasIdxBot+1, imax = req(); i < imax; i++) { | |
| 3400 if (in(i) == base_mem) | |
| 3401 set_req(i, empty_memory()); | |
| 3402 } | |
| 3403 } | |
| 3404 } | |
| 3405 | |
| 3406 //---------------------------grow_to_match------------------------------------- | |
| 3407 void MergeMemNode::grow_to_match(const MergeMemNode* other) { | |
| 3408 Node* empty_mem = empty_memory(); | |
| 3409 assert(other->is_empty_memory(empty_mem), "consistent sentinels"); | |
| 3410 // look for the finite support of the other memory | |
| 3411 for (uint i = other->req(); --i >= req(); ) { | |
| 3412 if (other->in(i) != empty_mem) { | |
| 3413 uint new_len = i+1; | |
| 3414 while (req() < new_len) add_req(empty_mem); | |
| 3415 break; | |
| 3416 } | |
| 3417 } | |
| 3418 } | |
| 3419 | |
| 3420 //---------------------------verify_sparse------------------------------------- | |
| 3421 #ifndef PRODUCT | |
| 3422 bool MergeMemNode::verify_sparse() const { | |
| 3423 assert(is_empty_memory(make_empty_memory()), "sane sentinel"); | |
| 3424 Node* base_mem = base_memory(); | |
| 3425 // The following can happen in degenerate cases, since empty==top. | |
| 3426 if (is_empty_memory(base_mem)) return true; | |
| 3427 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3428 assert(in(i) != NULL, "sane slice"); | |
| 3429 if (in(i) == base_mem) return false; // should have been the sentinel value! | |
| 3430 } | |
| 3431 return true; | |
| 3432 } | |
| 3433 | |
| 3434 bool MergeMemStream::match_memory(Node* mem, const MergeMemNode* mm, int idx) { | |
| 3435 Node* n; | |
| 3436 n = mm->in(idx); | |
| 3437 if (mem == n) return true; // might be empty_memory() | |
| 3438 n = (idx == Compile::AliasIdxBot)? mm->base_memory(): mm->memory_at(idx); | |
| 3439 if (mem == n) return true; | |
| 3440 while (n->is_Phi() && (n = n->as_Phi()->is_copy()) != NULL) { | |
| 3441 if (mem == n) return true; | |
| 3442 if (n == NULL) break; | |
| 3443 } | |
| 3444 return false; | |
| 3445 } | |
| 3446 #endif // !PRODUCT |