Mercurial > hg > truffle
annotate src/share/vm/opto/memnode.cpp @ 64:b8f5ba577b02
6673473: (Escape Analysis) Add the instance's field information to PhiNode
Summary: Avoid an infinite generation of instance's field values Phi nodes.
Reviewed-by: never
| author | kvn |
|---|---|
| date | Thu, 13 Mar 2008 16:31:32 -0700 |
| parents | d821d920b465 |
| children | daf38130e60d |
| 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 | |
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90 static Node *step_through_mergemem(PhaseGVN *phase, MergeMemNode *mmem, const TypePtr *tp, const TypePtr *adr_check, outputStream *st) { |
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91 uint alias_idx = phase->C->get_alias_index(tp); |
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92 Node *mem = mmem; |
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93 #ifdef ASSERT |
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94 { |
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95 // Check that current type is consistent with the alias index used during graph construction |
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96 assert(alias_idx >= Compile::AliasIdxRaw, "must not be a bad alias_idx"); |
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97 bool consistent = adr_check == NULL || adr_check->empty() || |
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98 phase->C->must_alias(adr_check, alias_idx ); |
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99 // Sometimes dead array references collapse to a[-1], a[-2], or a[-3] |
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100 if( !consistent && adr_check != NULL && !adr_check->empty() && |
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101 tp->isa_aryptr() && tp->offset() == Type::OffsetBot && |
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102 adr_check->isa_aryptr() && adr_check->offset() != Type::OffsetBot && |
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103 ( adr_check->offset() == arrayOopDesc::length_offset_in_bytes() || |
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104 adr_check->offset() == oopDesc::klass_offset_in_bytes() || |
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105 adr_check->offset() == oopDesc::mark_offset_in_bytes() ) ) { |
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106 // don't assert if it is dead code. |
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107 consistent = true; |
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108 } |
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109 if( !consistent ) { |
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110 st->print("alias_idx==%d, adr_check==", alias_idx); |
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111 if( adr_check == NULL ) { |
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112 st->print("NULL"); |
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113 } else { |
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114 adr_check->dump(); |
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115 } |
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116 st->cr(); |
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117 print_alias_types(); |
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118 assert(consistent, "adr_check must match alias idx"); |
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119 } |
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120 } |
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121 #endif |
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122 // TypeInstPtr::NOTNULL+any is an OOP with unknown offset - generally |
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123 // means an array I have not precisely typed yet. Do not do any |
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124 // alias stuff with it any time soon. |
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125 const TypeOopPtr *tinst = tp->isa_oopptr(); |
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126 if( tp->base() != Type::AnyPtr && |
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127 !(tinst && |
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128 tinst->klass()->is_java_lang_Object() && |
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129 tinst->offset() == Type::OffsetBot) ) { |
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130 // compress paths and change unreachable cycles to TOP |
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131 // If not, we can update the input infinitely along a MergeMem cycle |
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132 // Equivalent code in PhiNode::Ideal |
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133 Node* m = phase->transform(mmem); |
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134 // If tranformed to a MergeMem, get the desired slice |
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135 // Otherwise the returned node represents memory for every slice |
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136 mem = (m->is_MergeMem())? m->as_MergeMem()->memory_at(alias_idx) : m; |
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137 // Update input if it is progress over what we have now |
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138 } |
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139 return mem; |
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140 } |
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141 |
| 0 | 142 //--------------------------Ideal_common--------------------------------------- |
| 143 // Look for degenerate control and memory inputs. Bypass MergeMem inputs. | |
| 144 // Unhook non-raw memories from complete (macro-expanded) initializations. | |
| 145 Node *MemNode::Ideal_common(PhaseGVN *phase, bool can_reshape) { | |
| 146 // If our control input is a dead region, kill all below the region | |
| 147 Node *ctl = in(MemNode::Control); | |
| 148 if (ctl && remove_dead_region(phase, can_reshape)) | |
| 149 return this; | |
| 150 | |
| 151 // Ignore if memory is dead, or self-loop | |
| 152 Node *mem = in(MemNode::Memory); | |
| 153 if( phase->type( mem ) == Type::TOP ) return NodeSentinel; // caller will return NULL | |
| 154 assert( mem != this, "dead loop in MemNode::Ideal" ); | |
| 155 | |
| 156 Node *address = in(MemNode::Address); | |
| 157 const Type *t_adr = phase->type( address ); | |
| 158 if( t_adr == Type::TOP ) return NodeSentinel; // caller will return NULL | |
| 159 | |
| 160 // Avoid independent memory operations | |
| 161 Node* old_mem = mem; | |
| 162 | |
| 36 | 163 // The code which unhooks non-raw memories from complete (macro-expanded) |
| 164 // initializations was removed. After macro-expansion all stores catched | |
| 165 // by Initialize node became raw stores and there is no information | |
| 166 // which memory slices they modify. So it is unsafe to move any memory | |
| 167 // operation above these stores. Also in most cases hooked non-raw memories | |
| 168 // were already unhooked by using information from detect_ptr_independence() | |
| 169 // and find_previous_store(). | |
| 0 | 170 |
| 171 if (mem->is_MergeMem()) { | |
| 172 MergeMemNode* mmem = mem->as_MergeMem(); | |
| 173 const TypePtr *tp = t_adr->is_ptr(); | |
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174 |
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175 mem = step_through_mergemem(phase, mmem, tp, adr_type(), tty); |
| 0 | 176 } |
| 177 | |
| 178 if (mem != old_mem) { | |
| 179 set_req(MemNode::Memory, mem); | |
| 180 return this; | |
| 181 } | |
| 182 | |
| 183 // let the subclass continue analyzing... | |
| 184 return NULL; | |
| 185 } | |
| 186 | |
| 187 // Helper function for proving some simple control dominations. | |
| 188 // Attempt to prove that control input 'dom' dominates (or equals) 'sub'. | |
| 189 // Already assumes that 'dom' is available at 'sub', and that 'sub' | |
| 190 // is not a constant (dominated by the method's StartNode). | |
| 191 // Used by MemNode::find_previous_store to prove that the | |
| 192 // control input of a memory operation predates (dominates) | |
| 193 // an allocation it wants to look past. | |
| 194 bool MemNode::detect_dominating_control(Node* dom, Node* sub) { | |
| 195 if (dom == NULL) return false; | |
| 196 if (dom->is_Proj()) dom = dom->in(0); | |
| 197 if (dom->is_Start()) return true; // anything inside the method | |
| 198 if (dom->is_Root()) return true; // dom 'controls' a constant | |
| 199 int cnt = 20; // detect cycle or too much effort | |
| 200 while (sub != NULL) { // walk 'sub' up the chain to 'dom' | |
| 201 if (--cnt < 0) return false; // in a cycle or too complex | |
| 202 if (sub == dom) return true; | |
| 203 if (sub->is_Start()) return false; | |
| 204 if (sub->is_Root()) return false; | |
| 205 Node* up = sub->in(0); | |
| 206 if (sub == up && sub->is_Region()) { | |
| 207 for (uint i = 1; i < sub->req(); i++) { | |
| 208 Node* in = sub->in(i); | |
| 209 if (in != NULL && !in->is_top() && in != sub) { | |
| 210 up = in; break; // take any path on the way up to 'dom' | |
| 211 } | |
| 212 } | |
| 213 } | |
| 214 if (sub == up) return false; // some kind of tight cycle | |
| 215 sub = up; | |
| 216 } | |
| 217 return false; | |
| 218 } | |
| 219 | |
| 220 //---------------------detect_ptr_independence--------------------------------- | |
| 221 // Used by MemNode::find_previous_store to prove that two base | |
| 222 // pointers are never equal. | |
| 223 // The pointers are accompanied by their associated allocations, | |
| 224 // if any, which have been previously discovered by the caller. | |
| 225 bool MemNode::detect_ptr_independence(Node* p1, AllocateNode* a1, | |
| 226 Node* p2, AllocateNode* a2, | |
| 227 PhaseTransform* phase) { | |
| 228 // Attempt to prove that these two pointers cannot be aliased. | |
| 229 // They may both manifestly be allocations, and they should differ. | |
| 230 // Or, if they are not both allocations, they can be distinct constants. | |
| 231 // Otherwise, one is an allocation and the other a pre-existing value. | |
| 232 if (a1 == NULL && a2 == NULL) { // neither an allocation | |
| 233 return (p1 != p2) && p1->is_Con() && p2->is_Con(); | |
| 234 } else if (a1 != NULL && a2 != NULL) { // both allocations | |
| 235 return (a1 != a2); | |
| 236 } else if (a1 != NULL) { // one allocation a1 | |
| 237 // (Note: p2->is_Con implies p2->in(0)->is_Root, which dominates.) | |
| 238 return detect_dominating_control(p2->in(0), a1->in(0)); | |
| 239 } else { //(a2 != NULL) // one allocation a2 | |
| 240 return detect_dominating_control(p1->in(0), a2->in(0)); | |
| 241 } | |
| 242 return false; | |
| 243 } | |
| 244 | |
| 245 | |
| 246 // The logic for reordering loads and stores uses four steps: | |
| 247 // (a) Walk carefully past stores and initializations which we | |
| 248 // can prove are independent of this load. | |
| 249 // (b) Observe that the next memory state makes an exact match | |
| 250 // with self (load or store), and locate the relevant store. | |
| 251 // (c) Ensure that, if we were to wire self directly to the store, | |
| 252 // the optimizer would fold it up somehow. | |
| 253 // (d) Do the rewiring, and return, depending on some other part of | |
| 254 // the optimizer to fold up the load. | |
| 255 // This routine handles steps (a) and (b). Steps (c) and (d) are | |
| 256 // specific to loads and stores, so they are handled by the callers. | |
| 257 // (Currently, only LoadNode::Ideal has steps (c), (d). More later.) | |
| 258 // | |
| 259 Node* MemNode::find_previous_store(PhaseTransform* phase) { | |
| 260 Node* ctrl = in(MemNode::Control); | |
| 261 Node* adr = in(MemNode::Address); | |
| 262 intptr_t offset = 0; | |
| 263 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); | |
| 264 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase); | |
| 265 | |
| 266 if (offset == Type::OffsetBot) | |
| 267 return NULL; // cannot unalias unless there are precise offsets | |
| 268 | |
| 269 intptr_t size_in_bytes = memory_size(); | |
| 270 | |
| 271 Node* mem = in(MemNode::Memory); // start searching here... | |
| 272 | |
| 273 int cnt = 50; // Cycle limiter | |
| 274 for (;;) { // While we can dance past unrelated stores... | |
| 275 if (--cnt < 0) break; // Caught in cycle or a complicated dance? | |
| 276 | |
| 277 if (mem->is_Store()) { | |
| 278 Node* st_adr = mem->in(MemNode::Address); | |
| 279 intptr_t st_offset = 0; | |
| 280 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset); | |
| 281 if (st_base == NULL) | |
| 282 break; // inscrutable pointer | |
| 283 if (st_offset != offset && st_offset != Type::OffsetBot) { | |
| 284 const int MAX_STORE = BytesPerLong; | |
| 285 if (st_offset >= offset + size_in_bytes || | |
| 286 st_offset <= offset - MAX_STORE || | |
| 287 st_offset <= offset - mem->as_Store()->memory_size()) { | |
| 288 // Success: The offsets are provably independent. | |
| 289 // (You may ask, why not just test st_offset != offset and be done? | |
| 290 // The answer is that stores of different sizes can co-exist | |
| 291 // in the same sequence of RawMem effects. We sometimes initialize | |
| 292 // a whole 'tile' of array elements with a single jint or jlong.) | |
| 293 mem = mem->in(MemNode::Memory); | |
| 294 continue; // (a) advance through independent store memory | |
| 295 } | |
| 296 } | |
| 297 if (st_base != base && | |
| 298 detect_ptr_independence(base, alloc, | |
| 299 st_base, | |
| 300 AllocateNode::Ideal_allocation(st_base, phase), | |
| 301 phase)) { | |
| 302 // Success: The bases are provably independent. | |
| 303 mem = mem->in(MemNode::Memory); | |
| 304 continue; // (a) advance through independent store memory | |
| 305 } | |
| 306 | |
| 307 // (b) At this point, if the bases or offsets do not agree, we lose, | |
| 308 // since we have not managed to prove 'this' and 'mem' independent. | |
| 309 if (st_base == base && st_offset == offset) { | |
| 310 return mem; // let caller handle steps (c), (d) | |
| 311 } | |
| 312 | |
| 313 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) { | |
| 314 InitializeNode* st_init = mem->in(0)->as_Initialize(); | |
| 315 AllocateNode* st_alloc = st_init->allocation(); | |
| 316 if (st_alloc == NULL) | |
| 317 break; // something degenerated | |
| 318 bool known_identical = false; | |
| 319 bool known_independent = false; | |
| 320 if (alloc == st_alloc) | |
| 321 known_identical = true; | |
| 322 else if (alloc != NULL) | |
| 323 known_independent = true; | |
| 324 else if (ctrl != NULL && | |
| 325 detect_dominating_control(ctrl, st_alloc->in(0))) | |
| 326 known_independent = true; | |
| 327 | |
| 328 if (known_independent) { | |
| 329 // The bases are provably independent: Either they are | |
| 330 // manifestly distinct allocations, or else the control | |
| 331 // of this load dominates the store's allocation. | |
| 332 int alias_idx = phase->C->get_alias_index(adr_type()); | |
| 333 if (alias_idx == Compile::AliasIdxRaw) { | |
| 334 mem = st_alloc->in(TypeFunc::Memory); | |
| 335 } else { | |
| 336 mem = st_init->memory(alias_idx); | |
| 337 } | |
| 338 continue; // (a) advance through independent store memory | |
| 339 } | |
| 340 | |
| 341 // (b) at this point, if we are not looking at a store initializing | |
| 342 // the same allocation we are loading from, we lose. | |
| 343 if (known_identical) { | |
| 344 // From caller, can_see_stored_value will consult find_captured_store. | |
| 345 return mem; // let caller handle steps (c), (d) | |
| 346 } | |
| 347 | |
| 348 } | |
| 349 | |
| 350 // Unless there is an explicit 'continue', we must bail out here, | |
| 351 // because 'mem' is an inscrutable memory state (e.g., a call). | |
| 352 break; | |
| 353 } | |
| 354 | |
| 355 return NULL; // bail out | |
| 356 } | |
| 357 | |
| 358 //----------------------calculate_adr_type------------------------------------- | |
| 359 // Helper function. Notices when the given type of address hits top or bottom. | |
| 360 // Also, asserts a cross-check of the type against the expected address type. | |
| 361 const TypePtr* MemNode::calculate_adr_type(const Type* t, const TypePtr* cross_check) { | |
| 362 if (t == Type::TOP) return NULL; // does not touch memory any more? | |
| 363 #ifdef PRODUCT | |
| 364 cross_check = NULL; | |
| 365 #else | |
| 366 if (!VerifyAliases || is_error_reported() || Node::in_dump()) cross_check = NULL; | |
| 367 #endif | |
| 368 const TypePtr* tp = t->isa_ptr(); | |
| 369 if (tp == NULL) { | |
| 370 assert(cross_check == NULL || cross_check == TypePtr::BOTTOM, "expected memory type must be wide"); | |
| 371 return TypePtr::BOTTOM; // touches lots of memory | |
| 372 } else { | |
| 373 #ifdef ASSERT | |
| 374 // %%%% [phh] We don't check the alias index if cross_check is | |
| 375 // TypeRawPtr::BOTTOM. Needs to be investigated. | |
| 376 if (cross_check != NULL && | |
| 377 cross_check != TypePtr::BOTTOM && | |
| 378 cross_check != TypeRawPtr::BOTTOM) { | |
| 379 // Recheck the alias index, to see if it has changed (due to a bug). | |
| 380 Compile* C = Compile::current(); | |
| 381 assert(C->get_alias_index(cross_check) == C->get_alias_index(tp), | |
| 382 "must stay in the original alias category"); | |
| 383 // The type of the address must be contained in the adr_type, | |
| 384 // disregarding "null"-ness. | |
| 385 // (We make an exception for TypeRawPtr::BOTTOM, which is a bit bucket.) | |
| 386 const TypePtr* tp_notnull = tp->join(TypePtr::NOTNULL)->is_ptr(); | |
| 387 assert(cross_check->meet(tp_notnull) == cross_check, | |
| 388 "real address must not escape from expected memory type"); | |
| 389 } | |
| 390 #endif | |
| 391 return tp; | |
| 392 } | |
| 393 } | |
| 394 | |
| 395 //------------------------adr_phi_is_loop_invariant---------------------------- | |
| 396 // A helper function for Ideal_DU_postCCP to check if a Phi in a counted | |
| 397 // loop is loop invariant. Make a quick traversal of Phi and associated | |
| 398 // CastPP nodes, looking to see if they are a closed group within the loop. | |
| 399 bool MemNode::adr_phi_is_loop_invariant(Node* adr_phi, Node* cast) { | |
| 400 // The idea is that the phi-nest must boil down to only CastPP nodes | |
| 401 // with the same data. This implies that any path into the loop already | |
| 402 // includes such a CastPP, and so the original cast, whatever its input, | |
| 403 // must be covered by an equivalent cast, with an earlier control input. | |
| 404 ResourceMark rm; | |
| 405 | |
| 406 // The loop entry input of the phi should be the unique dominating | |
| 407 // node for every Phi/CastPP in the loop. | |
| 408 Unique_Node_List closure; | |
| 409 closure.push(adr_phi->in(LoopNode::EntryControl)); | |
| 410 | |
| 411 // Add the phi node and the cast to the worklist. | |
| 412 Unique_Node_List worklist; | |
| 413 worklist.push(adr_phi); | |
| 414 if( cast != NULL ){ | |
| 415 if( !cast->is_ConstraintCast() ) return false; | |
| 416 worklist.push(cast); | |
| 417 } | |
| 418 | |
| 419 // Begin recursive walk of phi nodes. | |
| 420 while( worklist.size() ){ | |
| 421 // Take a node off the worklist | |
| 422 Node *n = worklist.pop(); | |
| 423 if( !closure.member(n) ){ | |
| 424 // Add it to the closure. | |
| 425 closure.push(n); | |
| 426 // Make a sanity check to ensure we don't waste too much time here. | |
| 427 if( closure.size() > 20) return false; | |
| 428 // This node is OK if: | |
| 429 // - it is a cast of an identical value | |
| 430 // - or it is a phi node (then we add its inputs to the worklist) | |
| 431 // Otherwise, the node is not OK, and we presume the cast is not invariant | |
| 432 if( n->is_ConstraintCast() ){ | |
| 433 worklist.push(n->in(1)); | |
| 434 } else if( n->is_Phi() ) { | |
| 435 for( uint i = 1; i < n->req(); i++ ) { | |
| 436 worklist.push(n->in(i)); | |
| 437 } | |
| 438 } else { | |
| 439 return false; | |
| 440 } | |
| 441 } | |
| 442 } | |
| 443 | |
| 444 // Quit when the worklist is empty, and we've found no offending nodes. | |
| 445 return true; | |
| 446 } | |
| 447 | |
| 448 //------------------------------Ideal_DU_postCCP------------------------------- | |
| 449 // Find any cast-away of null-ness and keep its control. Null cast-aways are | |
| 450 // going away in this pass and we need to make this memory op depend on the | |
| 451 // gating null check. | |
| 452 | |
| 453 // I tried to leave the CastPP's in. This makes the graph more accurate in | |
| 454 // some sense; we get to keep around the knowledge that an oop is not-null | |
| 455 // after some test. Alas, the CastPP's interfere with GVN (some values are | |
| 456 // the regular oop, some are the CastPP of the oop, all merge at Phi's which | |
| 457 // cannot collapse, etc). This cost us 10% on SpecJVM, even when I removed | |
| 458 // some of the more trivial cases in the optimizer. Removing more useless | |
| 459 // Phi's started allowing Loads to illegally float above null checks. I gave | |
| 460 // up on this approach. CNC 10/20/2000 | |
| 461 Node *MemNode::Ideal_DU_postCCP( PhaseCCP *ccp ) { | |
| 462 Node *ctr = in(MemNode::Control); | |
| 463 Node *mem = in(MemNode::Memory); | |
| 464 Node *adr = in(MemNode::Address); | |
| 465 Node *skipped_cast = NULL; | |
| 466 // Need a null check? Regular static accesses do not because they are | |
| 467 // from constant addresses. Array ops are gated by the range check (which | |
| 468 // always includes a NULL check). Just check field ops. | |
| 469 if( !ctr ) { | |
| 470 // Scan upwards for the highest location we can place this memory op. | |
| 471 while( true ) { | |
| 472 switch( adr->Opcode() ) { | |
| 473 | |
| 474 case Op_AddP: // No change to NULL-ness, so peek thru AddP's | |
| 475 adr = adr->in(AddPNode::Base); | |
| 476 continue; | |
| 477 | |
| 478 case Op_CastPP: | |
| 479 // If the CastPP is useless, just peek on through it. | |
| 480 if( ccp->type(adr) == ccp->type(adr->in(1)) ) { | |
| 481 // Remember the cast that we've peeked though. If we peek | |
| 482 // through more than one, then we end up remembering the highest | |
| 483 // one, that is, if in a loop, the one closest to the top. | |
| 484 skipped_cast = adr; | |
| 485 adr = adr->in(1); | |
| 486 continue; | |
| 487 } | |
| 488 // CastPP is going away in this pass! We need this memory op to be | |
| 489 // control-dependent on the test that is guarding the CastPP. | |
| 490 ccp->hash_delete(this); | |
| 491 set_req(MemNode::Control, adr->in(0)); | |
| 492 ccp->hash_insert(this); | |
| 493 return this; | |
| 494 | |
| 495 case Op_Phi: | |
| 496 // Attempt to float above a Phi to some dominating point. | |
| 497 if (adr->in(0) != NULL && adr->in(0)->is_CountedLoop()) { | |
| 498 // If we've already peeked through a Cast (which could have set the | |
| 499 // control), we can't float above a Phi, because the skipped Cast | |
| 500 // may not be loop invariant. | |
| 501 if (adr_phi_is_loop_invariant(adr, skipped_cast)) { | |
| 502 adr = adr->in(1); | |
| 503 continue; | |
| 504 } | |
| 505 } | |
| 506 | |
| 507 // Intentional fallthrough! | |
| 508 | |
| 509 // No obvious dominating point. The mem op is pinned below the Phi | |
| 510 // by the Phi itself. If the Phi goes away (no true value is merged) | |
| 511 // then the mem op can float, but not indefinitely. It must be pinned | |
| 512 // behind the controls leading to the Phi. | |
| 513 case Op_CheckCastPP: | |
| 514 // These usually stick around to change address type, however a | |
| 515 // useless one can be elided and we still need to pick up a control edge | |
| 516 if (adr->in(0) == NULL) { | |
| 517 // This CheckCastPP node has NO control and is likely useless. But we | |
| 518 // need check further up the ancestor chain for a control input to keep | |
| 519 // the node in place. 4959717. | |
| 520 skipped_cast = adr; | |
| 521 adr = adr->in(1); | |
| 522 continue; | |
| 523 } | |
| 524 ccp->hash_delete(this); | |
| 525 set_req(MemNode::Control, adr->in(0)); | |
| 526 ccp->hash_insert(this); | |
| 527 return this; | |
| 528 | |
| 529 // List of "safe" opcodes; those that implicitly block the memory | |
| 530 // op below any null check. | |
| 531 case Op_CastX2P: // no null checks on native pointers | |
| 532 case Op_Parm: // 'this' pointer is not null | |
| 533 case Op_LoadP: // Loading from within a klass | |
| 534 case Op_LoadKlass: // Loading from within a klass | |
| 535 case Op_ConP: // Loading from a klass | |
| 536 case Op_CreateEx: // Sucking up the guts of an exception oop | |
| 537 case Op_Con: // Reading from TLS | |
| 538 case Op_CMoveP: // CMoveP is pinned | |
| 539 break; // No progress | |
| 540 | |
| 541 case Op_Proj: // Direct call to an allocation routine | |
| 542 case Op_SCMemProj: // Memory state from store conditional ops | |
| 543 #ifdef ASSERT | |
| 544 { | |
| 545 assert(adr->as_Proj()->_con == TypeFunc::Parms, "must be return value"); | |
| 546 const Node* call = adr->in(0); | |
| 547 if (call->is_CallStaticJava()) { | |
| 548 const CallStaticJavaNode* call_java = call->as_CallStaticJava(); | |
|
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549 const TypeTuple *r = call_java->tf()->range(); |
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550 assert(r->cnt() > TypeFunc::Parms, "must return value"); |
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551 const Type* ret_type = r->field_at(TypeFunc::Parms); |
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552 assert(ret_type && ret_type->isa_ptr(), "must return pointer"); |
| 0 | 553 // We further presume that this is one of |
| 554 // new_instance_Java, new_array_Java, or | |
| 555 // the like, but do not assert for this. | |
| 556 } else if (call->is_Allocate()) { | |
| 557 // similar case to new_instance_Java, etc. | |
| 558 } else if (!call->is_CallLeaf()) { | |
| 559 // Projections from fetch_oop (OSR) are allowed as well. | |
| 560 ShouldNotReachHere(); | |
| 561 } | |
| 562 } | |
| 563 #endif | |
| 564 break; | |
| 565 default: | |
| 566 ShouldNotReachHere(); | |
| 567 } | |
| 568 break; | |
| 569 } | |
| 570 } | |
| 571 | |
| 572 return NULL; // No progress | |
| 573 } | |
| 574 | |
| 575 | |
| 576 //============================================================================= | |
| 577 uint LoadNode::size_of() const { return sizeof(*this); } | |
| 578 uint LoadNode::cmp( const Node &n ) const | |
| 579 { return !Type::cmp( _type, ((LoadNode&)n)._type ); } | |
| 580 const Type *LoadNode::bottom_type() const { return _type; } | |
| 581 uint LoadNode::ideal_reg() const { | |
| 582 return Matcher::base2reg[_type->base()]; | |
| 583 } | |
| 584 | |
| 585 #ifndef PRODUCT | |
| 586 void LoadNode::dump_spec(outputStream *st) const { | |
| 587 MemNode::dump_spec(st); | |
| 588 if( !Verbose && !WizardMode ) { | |
| 589 // standard dump does this in Verbose and WizardMode | |
| 590 st->print(" #"); _type->dump_on(st); | |
| 591 } | |
| 592 } | |
| 593 #endif | |
| 594 | |
| 595 | |
| 596 //----------------------------LoadNode::make----------------------------------- | |
| 597 // Polymorphic factory method: | |
| 598 LoadNode *LoadNode::make( Compile *C, Node *ctl, Node *mem, Node *adr, const TypePtr* adr_type, const Type *rt, BasicType bt ) { | |
| 599 // sanity check the alias category against the created node type | |
| 600 assert(!(adr_type->isa_oopptr() && | |
| 601 adr_type->offset() == oopDesc::klass_offset_in_bytes()), | |
| 602 "use LoadKlassNode instead"); | |
| 603 assert(!(adr_type->isa_aryptr() && | |
| 604 adr_type->offset() == arrayOopDesc::length_offset_in_bytes()), | |
| 605 "use LoadRangeNode instead"); | |
| 606 switch (bt) { | |
| 607 case T_BOOLEAN: | |
| 608 case T_BYTE: return new (C, 3) LoadBNode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 609 case T_INT: return new (C, 3) LoadINode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 610 case T_CHAR: return new (C, 3) LoadCNode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 611 case T_SHORT: return new (C, 3) LoadSNode(ctl, mem, adr, adr_type, rt->is_int() ); | |
| 612 case T_LONG: return new (C, 3) LoadLNode(ctl, mem, adr, adr_type, rt->is_long() ); | |
| 613 case T_FLOAT: return new (C, 3) LoadFNode(ctl, mem, adr, adr_type, rt ); | |
| 614 case T_DOUBLE: return new (C, 3) LoadDNode(ctl, mem, adr, adr_type, rt ); | |
| 615 case T_ADDRESS: return new (C, 3) LoadPNode(ctl, mem, adr, adr_type, rt->is_ptr() ); | |
| 616 case T_OBJECT: return new (C, 3) LoadPNode(ctl, mem, adr, adr_type, rt->is_oopptr()); | |
| 617 } | |
| 618 ShouldNotReachHere(); | |
| 619 return (LoadNode*)NULL; | |
| 620 } | |
| 621 | |
| 622 LoadLNode* LoadLNode::make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, const Type* rt) { | |
| 623 bool require_atomic = true; | |
| 624 return new (C, 3) LoadLNode(ctl, mem, adr, adr_type, rt->is_long(), require_atomic); | |
| 625 } | |
| 626 | |
| 627 | |
| 628 | |
| 629 | |
| 630 //------------------------------hash------------------------------------------- | |
| 631 uint LoadNode::hash() const { | |
| 632 // unroll addition of interesting fields | |
| 633 return (uintptr_t)in(Control) + (uintptr_t)in(Memory) + (uintptr_t)in(Address); | |
| 634 } | |
| 635 | |
| 636 //---------------------------can_see_stored_value------------------------------ | |
| 637 // This routine exists to make sure this set of tests is done the same | |
| 638 // everywhere. We need to make a coordinated change: first LoadNode::Ideal | |
| 639 // will change the graph shape in a way which makes memory alive twice at the | |
| 640 // same time (uses the Oracle model of aliasing), then some | |
| 641 // LoadXNode::Identity will fold things back to the equivalence-class model | |
| 642 // of aliasing. | |
| 643 Node* MemNode::can_see_stored_value(Node* st, PhaseTransform* phase) const { | |
| 644 Node* ld_adr = in(MemNode::Address); | |
| 645 | |
|
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646 const TypeInstPtr* tp = phase->type(ld_adr)->isa_instptr(); |
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647 Compile::AliasType* atp = tp != NULL ? phase->C->alias_type(tp) : NULL; |
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648 if (EliminateAutoBox && atp != NULL && atp->index() >= Compile::AliasIdxRaw && |
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649 atp->field() != NULL && !atp->field()->is_volatile()) { |
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650 uint alias_idx = atp->index(); |
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651 bool final = atp->field()->is_final(); |
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652 Node* result = NULL; |
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653 Node* current = st; |
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654 // Skip through chains of MemBarNodes checking the MergeMems for |
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655 // new states for the slice of this load. Stop once any other |
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656 // kind of node is encountered. Loads from final memory can skip |
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657 // through any kind of MemBar but normal loads shouldn't skip |
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658 // through MemBarAcquire since the could allow them to move out of |
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659 // a synchronized region. |
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660 while (current->is_Proj()) { |
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661 int opc = current->in(0)->Opcode(); |
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662 if ((final && opc == Op_MemBarAcquire) || |
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663 opc == Op_MemBarRelease || opc == Op_MemBarCPUOrder) { |
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664 Node* mem = current->in(0)->in(TypeFunc::Memory); |
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665 if (mem->is_MergeMem()) { |
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666 MergeMemNode* merge = mem->as_MergeMem(); |
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667 Node* new_st = merge->memory_at(alias_idx); |
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668 if (new_st == merge->base_memory()) { |
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669 // Keep searching |
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670 current = merge->base_memory(); |
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671 continue; |
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672 } |
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673 // Save the new memory state for the slice and fall through |
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674 // to exit. |
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675 result = new_st; |
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676 } |
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|
677 } |
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678 break; |
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|
679 } |
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|
680 if (result != NULL) { |
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681 st = result; |
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|
682 } |
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|
683 } |
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|
684 |
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|
685 |
| 0 | 686 // Loop around twice in the case Load -> Initialize -> Store. |
| 687 // (See PhaseIterGVN::add_users_to_worklist, which knows about this case.) | |
| 688 for (int trip = 0; trip <= 1; trip++) { | |
| 689 | |
| 690 if (st->is_Store()) { | |
| 691 Node* st_adr = st->in(MemNode::Address); | |
| 692 if (!phase->eqv(st_adr, ld_adr)) { | |
| 693 // Try harder before giving up... Match raw and non-raw pointers. | |
| 694 intptr_t st_off = 0; | |
| 695 AllocateNode* alloc = AllocateNode::Ideal_allocation(st_adr, phase, st_off); | |
| 696 if (alloc == NULL) return NULL; | |
| 697 intptr_t ld_off = 0; | |
| 698 AllocateNode* allo2 = AllocateNode::Ideal_allocation(ld_adr, phase, ld_off); | |
| 699 if (alloc != allo2) return NULL; | |
| 700 if (ld_off != st_off) return NULL; | |
| 701 // At this point we have proven something like this setup: | |
| 702 // A = Allocate(...) | |
| 703 // L = LoadQ(, AddP(CastPP(, A.Parm),, #Off)) | |
| 704 // S = StoreQ(, AddP(, A.Parm , #Off), V) | |
| 705 // (Actually, we haven't yet proven the Q's are the same.) | |
| 706 // In other words, we are loading from a casted version of | |
| 707 // the same pointer-and-offset that we stored to. | |
| 708 // Thus, we are able to replace L by V. | |
| 709 } | |
| 710 // Now prove that we have a LoadQ matched to a StoreQ, for some Q. | |
| 711 if (store_Opcode() != st->Opcode()) | |
| 712 return NULL; | |
| 713 return st->in(MemNode::ValueIn); | |
| 714 } | |
| 715 | |
| 716 intptr_t offset = 0; // scratch | |
| 717 | |
| 718 // A load from a freshly-created object always returns zero. | |
| 719 // (This can happen after LoadNode::Ideal resets the load's memory input | |
| 720 // to find_captured_store, which returned InitializeNode::zero_memory.) | |
| 721 if (st->is_Proj() && st->in(0)->is_Allocate() && | |
| 722 st->in(0) == AllocateNode::Ideal_allocation(ld_adr, phase, offset) && | |
| 723 offset >= st->in(0)->as_Allocate()->minimum_header_size()) { | |
| 724 // return a zero value for the load's basic type | |
| 725 // (This is one of the few places where a generic PhaseTransform | |
| 726 // can create new nodes. Think of it as lazily manifesting | |
| 727 // virtually pre-existing constants.) | |
| 728 return phase->zerocon(memory_type()); | |
| 729 } | |
| 730 | |
| 731 // A load from an initialization barrier can match a captured store. | |
| 732 if (st->is_Proj() && st->in(0)->is_Initialize()) { | |
| 733 InitializeNode* init = st->in(0)->as_Initialize(); | |
| 734 AllocateNode* alloc = init->allocation(); | |
| 735 if (alloc != NULL && | |
| 736 alloc == AllocateNode::Ideal_allocation(ld_adr, phase, offset)) { | |
| 737 // examine a captured store value | |
| 738 st = init->find_captured_store(offset, memory_size(), phase); | |
| 739 if (st != NULL) | |
| 740 continue; // take one more trip around | |
| 741 } | |
| 742 } | |
| 743 | |
| 744 break; | |
| 745 } | |
| 746 | |
| 747 return NULL; | |
| 748 } | |
| 749 | |
|
64
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750 //----------------------is_instance_field_load_with_local_phi------------------ |
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751 bool LoadNode::is_instance_field_load_with_local_phi(Node* ctrl) { |
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752 if( in(MemNode::Memory)->is_Phi() && in(MemNode::Memory)->in(0) == ctrl && |
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753 in(MemNode::Address)->is_AddP() ) { |
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754 const TypeOopPtr* t_oop = in(MemNode::Address)->bottom_type()->isa_oopptr(); |
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755 // Only instances. |
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756 if( t_oop != NULL && t_oop->is_instance_field() && |
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757 t_oop->offset() != Type::OffsetBot && |
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|
758 t_oop->offset() != Type::OffsetTop) { |
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|
759 return true; |
|
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|
760 } |
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|
761 } |
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|
762 return false; |
|
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|
763 } |
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|
764 |
| 0 | 765 //------------------------------Identity--------------------------------------- |
| 766 // Loads are identity if previous store is to same address | |
| 767 Node *LoadNode::Identity( PhaseTransform *phase ) { | |
| 768 // If the previous store-maker is the right kind of Store, and the store is | |
| 769 // to the same address, then we are equal to the value stored. | |
| 770 Node* mem = in(MemNode::Memory); | |
| 771 Node* value = can_see_stored_value(mem, phase); | |
| 772 if( value ) { | |
| 773 // byte, short & char stores truncate naturally. | |
| 774 // A load has to load the truncated value which requires | |
| 775 // some sort of masking operation and that requires an | |
| 776 // Ideal call instead of an Identity call. | |
| 777 if (memory_size() < BytesPerInt) { | |
| 778 // If the input to the store does not fit with the load's result type, | |
| 779 // it must be truncated via an Ideal call. | |
| 780 if (!phase->type(value)->higher_equal(phase->type(this))) | |
| 781 return this; | |
| 782 } | |
| 783 // (This works even when value is a Con, but LoadNode::Value | |
| 784 // usually runs first, producing the singleton type of the Con.) | |
| 785 return value; | |
| 786 } | |
|
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|
787 |
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788 // Search for an existing data phi which was generated before for the same |
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789 // instance's field to avoid infinite genertion of phis in a loop. |
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790 Node *region = mem->in(0); |
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791 if (is_instance_field_load_with_local_phi(region)) { |
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792 const TypePtr *addr_t = in(MemNode::Address)->bottom_type()->isa_ptr(); |
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793 int this_index = phase->C->get_alias_index(addr_t); |
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794 int this_offset = addr_t->offset(); |
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795 int this_id = addr_t->is_oopptr()->instance_id(); |
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796 const Type* this_type = bottom_type(); |
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|
797 for (DUIterator_Fast imax, i = region->fast_outs(imax); i < imax; i++) { |
|
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798 Node* phi = region->fast_out(i); |
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|
799 if (phi->is_Phi() && phi != mem && |
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800 phi->as_Phi()->is_same_inst_field(this_type, this_id, this_index, this_offset)) { |
|
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801 return phi; |
|
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|
802 } |
|
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|
803 } |
|
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|
804 } |
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|
805 |
| 0 | 806 return this; |
| 807 } | |
| 808 | |
|
17
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|
809 |
|
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|
810 // Returns true if the AliasType refers to the field that holds the |
|
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|
811 // cached box array. Currently only handles the IntegerCache case. |
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|
812 static bool is_autobox_cache(Compile::AliasType* atp) { |
|
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|
813 if (atp != NULL && atp->field() != NULL) { |
|
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|
814 ciField* field = atp->field(); |
|
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|
815 ciSymbol* klass = field->holder()->name(); |
|
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|
816 if (field->name() == ciSymbol::cache_field_name() && |
|
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|
817 field->holder()->uses_default_loader() && |
|
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|
818 klass == ciSymbol::java_lang_Integer_IntegerCache()) { |
|
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|
819 return true; |
|
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|
820 } |
|
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|
821 } |
|
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|
822 return false; |
|
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|
823 } |
|
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|
824 |
|
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|
825 // Fetch the base value in the autobox array |
|
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|
826 static bool fetch_autobox_base(Compile::AliasType* atp, int& cache_offset) { |
|
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|
827 if (atp != NULL && atp->field() != NULL) { |
|
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|
828 ciField* field = atp->field(); |
|
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|
829 ciSymbol* klass = field->holder()->name(); |
|
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|
830 if (field->name() == ciSymbol::cache_field_name() && |
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|
831 field->holder()->uses_default_loader() && |
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changeset
|
832 klass == ciSymbol::java_lang_Integer_IntegerCache()) { |
|
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|
833 assert(field->is_constant(), "what?"); |
|
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|
834 ciObjArray* array = field->constant_value().as_object()->as_obj_array(); |
|
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|
835 // Fetch the box object at the base of the array and get its value |
|
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|
836 ciInstance* box = array->obj_at(0)->as_instance(); |
|
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|
837 ciInstanceKlass* ik = box->klass()->as_instance_klass(); |
|
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changeset
|
838 if (ik->nof_nonstatic_fields() == 1) { |
|
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changeset
|
839 // This should be true nonstatic_field_at requires calling |
|
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|
840 // nof_nonstatic_fields so check it anyway |
|
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changeset
|
841 ciConstant c = box->field_value(ik->nonstatic_field_at(0)); |
|
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|
842 cache_offset = c.as_int(); |
|
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diff
changeset
|
843 } |
|
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diff
changeset
|
844 return true; |
|
ff5961f4c095
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changeset
|
845 } |
|
ff5961f4c095
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diff
changeset
|
846 } |
|
ff5961f4c095
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diff
changeset
|
847 return false; |
|
ff5961f4c095
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diff
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|
848 } |
|
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diff
changeset
|
849 |
|
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changeset
|
850 // Returns true if the AliasType refers to the value field of an |
|
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0
diff
changeset
|
851 // autobox object. Currently only handles Integer. |
|
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diff
changeset
|
852 static bool is_autobox_object(Compile::AliasType* atp) { |
|
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changeset
|
853 if (atp != NULL && atp->field() != NULL) { |
|
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diff
changeset
|
854 ciField* field = atp->field(); |
|
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diff
changeset
|
855 ciSymbol* klass = field->holder()->name(); |
|
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0
diff
changeset
|
856 if (field->name() == ciSymbol::value_name() && |
|
ff5961f4c095
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diff
changeset
|
857 field->holder()->uses_default_loader() && |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
858 klass == ciSymbol::java_lang_Integer()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
859 return true; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
860 } |
|
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 return false; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
863 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
864 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
865 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
866 // 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
|
867 // 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
|
868 // 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)
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parents:
0
diff
changeset
|
869 // We want to replace this load with the original incoming |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
870 // argument to the valueOf call. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
871 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
|
872 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
|
873 if (base->is_Phi() && base->req() == 3) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
874 AllocateNode* allocation = NULL; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
875 int allocation_index = -1; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
876 int load_index = -1; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
877 for (uint i = 1; i < base->req(); i++) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
878 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
|
879 if (allocation != NULL) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
880 allocation_index = i; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
881 load_index = 3 - allocation_index; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
882 break; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
883 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
884 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
885 LoadNode* load = NULL; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
886 if (allocation != NULL && base->in(load_index)->is_Load()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
887 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
|
888 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
889 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)
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parents:
0
diff
changeset
|
890 // 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)
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parents:
0
diff
changeset
|
891 // 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)
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parents:
0
diff
changeset
|
892 // of the original value. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
893 Node* mem_phi = in(Memory); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
894 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
|
895 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
896 Node* in1 = clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
897 Node* in1_addr = in1->in(Address)->clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
898 in1_addr->set_req(AddPNode::Base, base->in(allocation_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
899 in1_addr->set_req(AddPNode::Address, base->in(allocation_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
900 in1_addr->set_req(AddPNode::Offset, offset); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
901 in1->set_req(0, base->in(allocation_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
902 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
|
903 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
|
904 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
905 Node* in2 = clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
906 Node* in2_addr = in2->in(Address)->clone(); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
907 in2_addr->set_req(AddPNode::Base, base->in(load_index)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
908 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
|
909 in2_addr->set_req(AddPNode::Offset, offset); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
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parents:
0
diff
changeset
|
910 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
|
911 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
|
912 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
|
913 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
914 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
|
915 in1 = phase->transform(in1); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
916 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
|
917 in2 = phase->transform(in2); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
918 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
919 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
|
920 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
|
921 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
|
922 return result; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
923 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
924 } else if (base->is_Load()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
925 // 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
|
926 // 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
|
927 // 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
|
928 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
|
929 if (load_base != NULL) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
930 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
|
931 intptr_t cache_offset; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
932 int shift = -1; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
933 Node* cache = NULL; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
934 if (is_autobox_cache(atp)) { |
|
29
d5fc211aea19
6633953: type2aelembytes{T_ADDRESS} should be 8 bytes in 64 bit VM
kvn
parents:
17
diff
changeset
|
935 shift = exact_log2(type2aelembytes(T_OBJECT)); |
|
17
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
936 cache = AddPNode::Ideal_base_and_offset(load_base->in(Address), phase, cache_offset); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
937 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
938 if (cache != NULL && base->in(Address)->is_AddP()) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
939 Node* elements[4]; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
940 int count = base->in(Address)->as_AddP()->unpack_offsets(elements, ARRAY_SIZE(elements)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
941 int cache_low; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
942 if (count > 0 && fetch_autobox_base(atp, cache_low)) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
943 int offset = arrayOopDesc::base_offset_in_bytes(memory_type()) - (cache_low << shift); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
944 // Add up all the offsets making of the address of the load |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
945 Node* result = elements[0]; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
946 for (int i = 1; i < count; i++) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
947 result = phase->transform(new (phase->C, 3) AddXNode(result, elements[i])); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
948 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
949 // Remove the constant offset from the address and then |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
950 // remove the scaling of the offset to recover the original index. |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
951 result = phase->transform(new (phase->C, 3) AddXNode(result, phase->MakeConX(-offset))); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
952 if (result->Opcode() == Op_LShiftX && result->in(2) == phase->intcon(shift)) { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
953 // Peel the shift off directly but wrap it in a dummy node |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
954 // since Ideal can't return existing nodes |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
955 result = new (phase->C, 3) RShiftXNode(result->in(1), phase->intcon(0)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
956 } else { |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
957 result = new (phase->C, 3) RShiftXNode(result, phase->intcon(shift)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
958 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
959 #ifdef _LP64 |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
960 result = new (phase->C, 2) ConvL2INode(phase->transform(result)); |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
961 #endif |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
962 return result; |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
963 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
964 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
changeset
|
965 } |
|
ff5961f4c095
6395208: Elide autoboxing for calls to HashMap.get(int) and HashMap.get(long)
never
parents:
0
diff
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966 } |
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967 return NULL; |
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968 } |
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969 |
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970 |
| 0 | 971 //------------------------------Ideal------------------------------------------ |
| 972 // If the load is from Field memory and the pointer is non-null, we can | |
| 973 // zero out the control input. | |
| 974 // If the offset is constant and the base is an object allocation, | |
| 975 // try to hook me up to the exact initializing store. | |
| 976 Node *LoadNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 977 Node* p = MemNode::Ideal_common(phase, can_reshape); | |
| 978 if (p) return (p == NodeSentinel) ? NULL : p; | |
| 979 | |
| 980 Node* ctrl = in(MemNode::Control); | |
| 981 Node* address = in(MemNode::Address); | |
| 982 | |
| 983 // Skip up past a SafePoint control. Cannot do this for Stores because | |
| 984 // pointer stores & cardmarks must stay on the same side of a SafePoint. | |
| 985 if( ctrl != NULL && ctrl->Opcode() == Op_SafePoint && | |
| 986 phase->C->get_alias_index(phase->type(address)->is_ptr()) != Compile::AliasIdxRaw ) { | |
| 987 ctrl = ctrl->in(0); | |
| 988 set_req(MemNode::Control,ctrl); | |
| 989 } | |
| 990 | |
| 991 // Check for useless control edge in some common special cases | |
| 992 if (in(MemNode::Control) != NULL) { | |
| 993 intptr_t ignore = 0; | |
| 994 Node* base = AddPNode::Ideal_base_and_offset(address, phase, ignore); | |
| 995 if (base != NULL | |
| 996 && phase->type(base)->higher_equal(TypePtr::NOTNULL) | |
| 997 && detect_dominating_control(base->in(0), phase->C->start())) { | |
| 998 // A method-invariant, non-null address (constant or 'this' argument). | |
| 999 set_req(MemNode::Control, NULL); | |
| 1000 } | |
| 1001 } | |
| 1002 | |
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1003 if (EliminateAutoBox && can_reshape && in(Address)->is_AddP()) { |
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1004 Node* base = in(Address)->in(AddPNode::Base); |
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1005 if (base != NULL) { |
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1006 Compile::AliasType* atp = phase->C->alias_type(adr_type()); |
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1007 if (is_autobox_object(atp)) { |
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1008 Node* result = eliminate_autobox(phase); |
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1009 if (result != NULL) return result; |
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1010 } |
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1011 } |
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1012 } |
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1013 |
| 0 | 1014 // Check for prior store with a different base or offset; make Load |
| 1015 // independent. Skip through any number of them. Bail out if the stores | |
| 1016 // are in an endless dead cycle and report no progress. This is a key | |
| 1017 // transform for Reflection. However, if after skipping through the Stores | |
| 1018 // we can't then fold up against a prior store do NOT do the transform as | |
| 1019 // this amounts to using the 'Oracle' model of aliasing. It leaves the same | |
| 1020 // array memory alive twice: once for the hoisted Load and again after the | |
| 1021 // bypassed Store. This situation only works if EVERYBODY who does | |
| 1022 // anti-dependence work knows how to bypass. I.e. we need all | |
| 1023 // anti-dependence checks to ask the same Oracle. Right now, that Oracle is | |
| 1024 // the alias index stuff. So instead, peek through Stores and IFF we can | |
| 1025 // fold up, do so. | |
| 1026 Node* prev_mem = find_previous_store(phase); | |
| 1027 // Steps (a), (b): Walk past independent stores to find an exact match. | |
| 1028 if (prev_mem != NULL && prev_mem != in(MemNode::Memory)) { | |
| 1029 // (c) See if we can fold up on the spot, but don't fold up here. | |
| 1030 // Fold-up might require truncation (for LoadB/LoadS/LoadC) or | |
| 1031 // just return a prior value, which is done by Identity calls. | |
| 1032 if (can_see_stored_value(prev_mem, phase)) { | |
| 1033 // Make ready for step (d): | |
| 1034 set_req(MemNode::Memory, prev_mem); | |
| 1035 return this; | |
| 1036 } | |
| 1037 } | |
| 1038 | |
| 1039 return NULL; // No further progress | |
| 1040 } | |
| 1041 | |
| 1042 // Helper to recognize certain Klass fields which are invariant across | |
| 1043 // some group of array types (e.g., int[] or all T[] where T < Object). | |
| 1044 const Type* | |
| 1045 LoadNode::load_array_final_field(const TypeKlassPtr *tkls, | |
| 1046 ciKlass* klass) const { | |
| 1047 if (tkls->offset() == Klass::modifier_flags_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1048 // The field is Klass::_modifier_flags. Return its (constant) value. | |
| 1049 // (Folds up the 2nd indirection in aClassConstant.getModifiers().) | |
| 1050 assert(this->Opcode() == Op_LoadI, "must load an int from _modifier_flags"); | |
| 1051 return TypeInt::make(klass->modifier_flags()); | |
| 1052 } | |
| 1053 if (tkls->offset() == Klass::access_flags_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1054 // The field is Klass::_access_flags. Return its (constant) value. | |
| 1055 // (Folds up the 2nd indirection in Reflection.getClassAccessFlags(aClassConstant).) | |
| 1056 assert(this->Opcode() == Op_LoadI, "must load an int from _access_flags"); | |
| 1057 return TypeInt::make(klass->access_flags()); | |
| 1058 } | |
| 1059 if (tkls->offset() == Klass::layout_helper_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1060 // The field is Klass::_layout_helper. Return its constant value if known. | |
| 1061 assert(this->Opcode() == Op_LoadI, "must load an int from _layout_helper"); | |
| 1062 return TypeInt::make(klass->layout_helper()); | |
| 1063 } | |
| 1064 | |
| 1065 // No match. | |
| 1066 return NULL; | |
| 1067 } | |
| 1068 | |
| 1069 //------------------------------Value----------------------------------------- | |
| 1070 const Type *LoadNode::Value( PhaseTransform *phase ) const { | |
| 1071 // Either input is TOP ==> the result is TOP | |
| 1072 Node* mem = in(MemNode::Memory); | |
| 1073 const Type *t1 = phase->type(mem); | |
| 1074 if (t1 == Type::TOP) return Type::TOP; | |
| 1075 Node* adr = in(MemNode::Address); | |
| 1076 const TypePtr* tp = phase->type(adr)->isa_ptr(); | |
| 1077 if (tp == NULL || tp->empty()) return Type::TOP; | |
| 1078 int off = tp->offset(); | |
| 1079 assert(off != Type::OffsetTop, "case covered by TypePtr::empty"); | |
| 1080 | |
| 1081 // Try to guess loaded type from pointer type | |
| 1082 if (tp->base() == Type::AryPtr) { | |
| 1083 const Type *t = tp->is_aryptr()->elem(); | |
| 1084 // Don't do this for integer types. There is only potential profit if | |
| 1085 // the element type t is lower than _type; that is, for int types, if _type is | |
| 1086 // more restrictive than t. This only happens here if one is short and the other | |
| 1087 // char (both 16 bits), and in those cases we've made an intentional decision | |
| 1088 // to use one kind of load over the other. See AndINode::Ideal and 4965907. | |
| 1089 // Also, do not try to narrow the type for a LoadKlass, regardless of offset. | |
| 1090 // | |
| 1091 // Yes, it is possible to encounter an expression like (LoadKlass p1:(AddP x x 8)) | |
| 1092 // where the _gvn.type of the AddP is wider than 8. This occurs when an earlier | |
| 1093 // copy p0 of (AddP x x 8) has been proven equal to p1, and the p0 has been | |
| 1094 // subsumed by p1. If p1 is on the worklist but has not yet been re-transformed, | |
| 1095 // it is possible that p1 will have a type like Foo*[int+]:NotNull*+any. | |
| 1096 // In fact, that could have been the original type of p1, and p1 could have | |
| 1097 // had an original form like p1:(AddP x x (LShiftL quux 3)), where the | |
| 1098 // expression (LShiftL quux 3) independently optimized to the constant 8. | |
| 1099 if ((t->isa_int() == NULL) && (t->isa_long() == NULL) | |
| 1100 && Opcode() != Op_LoadKlass) { | |
| 1101 // t might actually be lower than _type, if _type is a unique | |
| 1102 // concrete subclass of abstract class t. | |
| 1103 // Make sure the reference is not into the header, by comparing | |
| 1104 // the offset against the offset of the start of the array's data. | |
| 1105 // Different array types begin at slightly different offsets (12 vs. 16). | |
| 1106 // We choose T_BYTE as an example base type that is least restrictive | |
| 1107 // as to alignment, which will therefore produce the smallest | |
| 1108 // possible base offset. | |
| 1109 const int min_base_off = arrayOopDesc::base_offset_in_bytes(T_BYTE); | |
| 1110 if ((uint)off >= (uint)min_base_off) { // is the offset beyond the header? | |
| 1111 const Type* jt = t->join(_type); | |
| 1112 // In any case, do not allow the join, per se, to empty out the type. | |
| 1113 if (jt->empty() && !t->empty()) { | |
| 1114 // This can happen if a interface-typed array narrows to a class type. | |
| 1115 jt = _type; | |
| 1116 } | |
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1117 |
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1118 if (EliminateAutoBox) { |
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1119 // The pointers in the autobox arrays are always non-null |
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1120 Node* base = in(Address)->in(AddPNode::Base); |
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1121 if (base != NULL) { |
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1122 Compile::AliasType* atp = phase->C->alias_type(base->adr_type()); |
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1123 if (is_autobox_cache(atp)) { |
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1124 return jt->join(TypePtr::NOTNULL)->is_ptr(); |
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1125 } |
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1126 } |
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1127 } |
| 0 | 1128 return jt; |
| 1129 } | |
| 1130 } | |
| 1131 } else if (tp->base() == Type::InstPtr) { | |
| 1132 assert( off != Type::OffsetBot || | |
| 1133 // arrays can be cast to Objects | |
| 1134 tp->is_oopptr()->klass()->is_java_lang_Object() || | |
| 1135 // unsafe field access may not have a constant offset | |
| 1136 phase->C->has_unsafe_access(), | |
| 1137 "Field accesses must be precise" ); | |
| 1138 // For oop loads, we expect the _type to be precise | |
| 1139 } else if (tp->base() == Type::KlassPtr) { | |
| 1140 assert( off != Type::OffsetBot || | |
| 1141 // arrays can be cast to Objects | |
| 1142 tp->is_klassptr()->klass()->is_java_lang_Object() || | |
| 1143 // also allow array-loading from the primary supertype | |
| 1144 // array during subtype checks | |
| 1145 Opcode() == Op_LoadKlass, | |
| 1146 "Field accesses must be precise" ); | |
| 1147 // For klass/static loads, we expect the _type to be precise | |
| 1148 } | |
| 1149 | |
| 1150 const TypeKlassPtr *tkls = tp->isa_klassptr(); | |
| 1151 if (tkls != NULL && !StressReflectiveCode) { | |
| 1152 ciKlass* klass = tkls->klass(); | |
| 1153 if (klass->is_loaded() && tkls->klass_is_exact()) { | |
| 1154 // We are loading a field from a Klass metaobject whose identity | |
| 1155 // is known at compile time (the type is "exact" or "precise"). | |
| 1156 // Check for fields we know are maintained as constants by the VM. | |
| 1157 if (tkls->offset() == Klass::super_check_offset_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1158 // The field is Klass::_super_check_offset. Return its (constant) value. | |
| 1159 // (Folds up type checking code.) | |
| 1160 assert(Opcode() == Op_LoadI, "must load an int from _super_check_offset"); | |
| 1161 return TypeInt::make(klass->super_check_offset()); | |
| 1162 } | |
| 1163 // Compute index into primary_supers array | |
| 1164 juint depth = (tkls->offset() - (Klass::primary_supers_offset_in_bytes() + (int)sizeof(oopDesc))) / sizeof(klassOop); | |
| 1165 // Check for overflowing; use unsigned compare to handle the negative case. | |
| 1166 if( depth < ciKlass::primary_super_limit() ) { | |
| 1167 // The field is an element of Klass::_primary_supers. Return its (constant) value. | |
| 1168 // (Folds up type checking code.) | |
| 1169 assert(Opcode() == Op_LoadKlass, "must load a klass from _primary_supers"); | |
| 1170 ciKlass *ss = klass->super_of_depth(depth); | |
| 1171 return ss ? TypeKlassPtr::make(ss) : TypePtr::NULL_PTR; | |
| 1172 } | |
| 1173 const Type* aift = load_array_final_field(tkls, klass); | |
| 1174 if (aift != NULL) return aift; | |
| 1175 if (tkls->offset() == in_bytes(arrayKlass::component_mirror_offset()) + (int)sizeof(oopDesc) | |
| 1176 && klass->is_array_klass()) { | |
| 1177 // The field is arrayKlass::_component_mirror. Return its (constant) value. | |
| 1178 // (Folds up aClassConstant.getComponentType, common in Arrays.copyOf.) | |
| 1179 assert(Opcode() == Op_LoadP, "must load an oop from _component_mirror"); | |
| 1180 return TypeInstPtr::make(klass->as_array_klass()->component_mirror()); | |
| 1181 } | |
| 1182 if (tkls->offset() == Klass::java_mirror_offset_in_bytes() + (int)sizeof(oopDesc)) { | |
| 1183 // The field is Klass::_java_mirror. Return its (constant) value. | |
| 1184 // (Folds up the 2nd indirection in anObjConstant.getClass().) | |
| 1185 assert(Opcode() == Op_LoadP, "must load an oop from _java_mirror"); | |
| 1186 return TypeInstPtr::make(klass->java_mirror()); | |
| 1187 } | |
| 1188 } | |
| 1189 | |
| 1190 // We can still check if we are loading from the primary_supers array at a | |
| 1191 // shallow enough depth. Even though the klass is not exact, entries less | |
| 1192 // than or equal to its super depth are correct. | |
| 1193 if (klass->is_loaded() ) { | |
| 1194 ciType *inner = klass->klass(); | |
| 1195 while( inner->is_obj_array_klass() ) | |
| 1196 inner = inner->as_obj_array_klass()->base_element_type(); | |
| 1197 if( inner->is_instance_klass() && | |
| 1198 !inner->as_instance_klass()->flags().is_interface() ) { | |
| 1199 // Compute index into primary_supers array | |
| 1200 juint depth = (tkls->offset() - (Klass::primary_supers_offset_in_bytes() + (int)sizeof(oopDesc))) / sizeof(klassOop); | |
| 1201 // Check for overflowing; use unsigned compare to handle the negative case. | |
| 1202 if( depth < ciKlass::primary_super_limit() && | |
| 1203 depth <= klass->super_depth() ) { // allow self-depth checks to handle self-check case | |
| 1204 // The field is an element of Klass::_primary_supers. Return its (constant) value. | |
| 1205 // (Folds up type checking code.) | |
| 1206 assert(Opcode() == Op_LoadKlass, "must load a klass from _primary_supers"); | |
| 1207 ciKlass *ss = klass->super_of_depth(depth); | |
| 1208 return ss ? TypeKlassPtr::make(ss) : TypePtr::NULL_PTR; | |
| 1209 } | |
| 1210 } | |
| 1211 } | |
| 1212 | |
| 1213 // If the type is enough to determine that the thing is not an array, | |
| 1214 // we can give the layout_helper a positive interval type. | |
| 1215 // This will help short-circuit some reflective code. | |
| 1216 if (tkls->offset() == Klass::layout_helper_offset_in_bytes() + (int)sizeof(oopDesc) | |
| 1217 && !klass->is_array_klass() // not directly typed as an array | |
| 1218 && !klass->is_interface() // specifically not Serializable & Cloneable | |
| 1219 && !klass->is_java_lang_Object() // not the supertype of all T[] | |
| 1220 ) { | |
| 1221 // Note: When interfaces are reliable, we can narrow the interface | |
| 1222 // test to (klass != Serializable && klass != Cloneable). | |
| 1223 assert(Opcode() == Op_LoadI, "must load an int from _layout_helper"); | |
| 1224 jint min_size = Klass::instance_layout_helper(oopDesc::header_size(), false); | |
| 1225 // The key property of this type is that it folds up tests | |
| 1226 // for array-ness, since it proves that the layout_helper is positive. | |
| 1227 // Thus, a generic value like the basic object layout helper works fine. | |
| 1228 return TypeInt::make(min_size, max_jint, Type::WidenMin); | |
| 1229 } | |
| 1230 } | |
| 1231 | |
| 1232 // If we are loading from a freshly-allocated object, produce a zero, | |
| 1233 // if the load is provably beyond the header of the object. | |
| 1234 // (Also allow a variable load from a fresh array to produce zero.) | |
| 1235 if (ReduceFieldZeroing) { | |
| 1236 Node* value = can_see_stored_value(mem,phase); | |
| 1237 if (value != NULL && value->is_Con()) | |
| 1238 return value->bottom_type(); | |
| 1239 } | |
| 1240 | |
|
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1241 const TypeOopPtr *tinst = tp->isa_oopptr(); |
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1242 if (tinst != NULL && tinst->is_instance_field()) { |
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1243 // If we have an instance type and our memory input is the |
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1244 // programs's initial memory state, there is no matching store, |
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1245 // so just return a zero of the appropriate type |
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1246 Node *mem = in(MemNode::Memory); |
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1247 if (mem->is_Parm() && mem->in(0)->is_Start()) { |
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1248 assert(mem->as_Parm()->_con == TypeFunc::Memory, "must be memory Parm"); |
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1249 return Type::get_zero_type(_type->basic_type()); |
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1250 } |
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1251 } |
| 0 | 1252 return _type; |
| 1253 } | |
| 1254 | |
| 1255 //------------------------------match_edge------------------------------------- | |
| 1256 // Do we Match on this edge index or not? Match only the address. | |
| 1257 uint LoadNode::match_edge(uint idx) const { | |
| 1258 return idx == MemNode::Address; | |
| 1259 } | |
| 1260 | |
| 1261 //--------------------------LoadBNode::Ideal-------------------------------------- | |
| 1262 // | |
| 1263 // If the previous store is to the same address as this load, | |
| 1264 // and the value stored was larger than a byte, replace this load | |
| 1265 // with the value stored truncated to a byte. If no truncation is | |
| 1266 // needed, the replacement is done in LoadNode::Identity(). | |
| 1267 // | |
| 1268 Node *LoadBNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1269 Node* mem = in(MemNode::Memory); | |
| 1270 Node* value = can_see_stored_value(mem,phase); | |
| 1271 if( value && !phase->type(value)->higher_equal( _type ) ) { | |
| 1272 Node *result = phase->transform( new (phase->C, 3) LShiftINode(value, phase->intcon(24)) ); | |
| 1273 return new (phase->C, 3) RShiftINode(result, phase->intcon(24)); | |
| 1274 } | |
| 1275 // Identity call will handle the case where truncation is not needed. | |
| 1276 return LoadNode::Ideal(phase, can_reshape); | |
| 1277 } | |
| 1278 | |
| 1279 //--------------------------LoadCNode::Ideal-------------------------------------- | |
| 1280 // | |
| 1281 // If the previous store is to the same address as this load, | |
| 1282 // and the value stored was larger than a char, replace this load | |
| 1283 // with the value stored truncated to a char. If no truncation is | |
| 1284 // needed, the replacement is done in LoadNode::Identity(). | |
| 1285 // | |
| 1286 Node *LoadCNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1287 Node* mem = in(MemNode::Memory); | |
| 1288 Node* value = can_see_stored_value(mem,phase); | |
| 1289 if( value && !phase->type(value)->higher_equal( _type ) ) | |
| 1290 return new (phase->C, 3) AndINode(value,phase->intcon(0xFFFF)); | |
| 1291 // Identity call will handle the case where truncation is not needed. | |
| 1292 return LoadNode::Ideal(phase, can_reshape); | |
| 1293 } | |
| 1294 | |
| 1295 //--------------------------LoadSNode::Ideal-------------------------------------- | |
| 1296 // | |
| 1297 // If the previous store is to the same address as this load, | |
| 1298 // and the value stored was larger than a short, replace this load | |
| 1299 // with the value stored truncated to a short. If no truncation is | |
| 1300 // needed, the replacement is done in LoadNode::Identity(). | |
| 1301 // | |
| 1302 Node *LoadSNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1303 Node* mem = in(MemNode::Memory); | |
| 1304 Node* value = can_see_stored_value(mem,phase); | |
| 1305 if( value && !phase->type(value)->higher_equal( _type ) ) { | |
| 1306 Node *result = phase->transform( new (phase->C, 3) LShiftINode(value, phase->intcon(16)) ); | |
| 1307 return new (phase->C, 3) RShiftINode(result, phase->intcon(16)); | |
| 1308 } | |
| 1309 // Identity call will handle the case where truncation is not needed. | |
| 1310 return LoadNode::Ideal(phase, can_reshape); | |
| 1311 } | |
| 1312 | |
| 1313 //============================================================================= | |
| 1314 //------------------------------Value------------------------------------------ | |
| 1315 const Type *LoadKlassNode::Value( PhaseTransform *phase ) const { | |
| 1316 // Either input is TOP ==> the result is TOP | |
| 1317 const Type *t1 = phase->type( in(MemNode::Memory) ); | |
| 1318 if (t1 == Type::TOP) return Type::TOP; | |
| 1319 Node *adr = in(MemNode::Address); | |
| 1320 const Type *t2 = phase->type( adr ); | |
| 1321 if (t2 == Type::TOP) return Type::TOP; | |
| 1322 const TypePtr *tp = t2->is_ptr(); | |
| 1323 if (TypePtr::above_centerline(tp->ptr()) || | |
| 1324 tp->ptr() == TypePtr::Null) return Type::TOP; | |
| 1325 | |
| 1326 // Return a more precise klass, if possible | |
| 1327 const TypeInstPtr *tinst = tp->isa_instptr(); | |
| 1328 if (tinst != NULL) { | |
| 1329 ciInstanceKlass* ik = tinst->klass()->as_instance_klass(); | |
| 1330 int offset = tinst->offset(); | |
| 1331 if (ik == phase->C->env()->Class_klass() | |
| 1332 && (offset == java_lang_Class::klass_offset_in_bytes() || | |
| 1333 offset == java_lang_Class::array_klass_offset_in_bytes())) { | |
| 1334 // We are loading a special hidden field from a Class mirror object, | |
| 1335 // the field which points to the VM's Klass metaobject. | |
| 1336 ciType* t = tinst->java_mirror_type(); | |
| 1337 // java_mirror_type returns non-null for compile-time Class constants. | |
| 1338 if (t != NULL) { | |
| 1339 // constant oop => constant klass | |
| 1340 if (offset == java_lang_Class::array_klass_offset_in_bytes()) { | |
| 1341 return TypeKlassPtr::make(ciArrayKlass::make(t)); | |
| 1342 } | |
| 1343 if (!t->is_klass()) { | |
| 1344 // a primitive Class (e.g., int.class) has NULL for a klass field | |
| 1345 return TypePtr::NULL_PTR; | |
| 1346 } | |
| 1347 // (Folds up the 1st indirection in aClassConstant.getModifiers().) | |
| 1348 return TypeKlassPtr::make(t->as_klass()); | |
| 1349 } | |
| 1350 // non-constant mirror, so we can't tell what's going on | |
| 1351 } | |
| 1352 if( !ik->is_loaded() ) | |
| 1353 return _type; // Bail out if not loaded | |
| 1354 if (offset == oopDesc::klass_offset_in_bytes()) { | |
| 1355 if (tinst->klass_is_exact()) { | |
| 1356 return TypeKlassPtr::make(ik); | |
| 1357 } | |
| 1358 // See if we can become precise: no subklasses and no interface | |
| 1359 // (Note: We need to support verified interfaces.) | |
| 1360 if (!ik->is_interface() && !ik->has_subklass()) { | |
| 1361 //assert(!UseExactTypes, "this code should be useless with exact types"); | |
| 1362 // Add a dependence; if any subclass added we need to recompile | |
| 1363 if (!ik->is_final()) { | |
| 1364 // %%% should use stronger assert_unique_concrete_subtype instead | |
| 1365 phase->C->dependencies()->assert_leaf_type(ik); | |
| 1366 } | |
| 1367 // Return precise klass | |
| 1368 return TypeKlassPtr::make(ik); | |
| 1369 } | |
| 1370 | |
| 1371 // Return root of possible klass | |
| 1372 return TypeKlassPtr::make(TypePtr::NotNull, ik, 0/*offset*/); | |
| 1373 } | |
| 1374 } | |
| 1375 | |
| 1376 // Check for loading klass from an array | |
| 1377 const TypeAryPtr *tary = tp->isa_aryptr(); | |
| 1378 if( tary != NULL ) { | |
| 1379 ciKlass *tary_klass = tary->klass(); | |
| 1380 if (tary_klass != NULL // can be NULL when at BOTTOM or TOP | |
| 1381 && tary->offset() == oopDesc::klass_offset_in_bytes()) { | |
| 1382 if (tary->klass_is_exact()) { | |
| 1383 return TypeKlassPtr::make(tary_klass); | |
| 1384 } | |
| 1385 ciArrayKlass *ak = tary->klass()->as_array_klass(); | |
| 1386 // If the klass is an object array, we defer the question to the | |
| 1387 // array component klass. | |
| 1388 if( ak->is_obj_array_klass() ) { | |
| 1389 assert( ak->is_loaded(), "" ); | |
| 1390 ciKlass *base_k = ak->as_obj_array_klass()->base_element_klass(); | |
| 1391 if( base_k->is_loaded() && base_k->is_instance_klass() ) { | |
| 1392 ciInstanceKlass* ik = base_k->as_instance_klass(); | |
| 1393 // See if we can become precise: no subklasses and no interface | |
| 1394 if (!ik->is_interface() && !ik->has_subklass()) { | |
| 1395 //assert(!UseExactTypes, "this code should be useless with exact types"); | |
| 1396 // Add a dependence; if any subclass added we need to recompile | |
| 1397 if (!ik->is_final()) { | |
| 1398 phase->C->dependencies()->assert_leaf_type(ik); | |
| 1399 } | |
| 1400 // Return precise array klass | |
| 1401 return TypeKlassPtr::make(ak); | |
| 1402 } | |
| 1403 } | |
| 1404 return TypeKlassPtr::make(TypePtr::NotNull, ak, 0/*offset*/); | |
| 1405 } else { // Found a type-array? | |
| 1406 //assert(!UseExactTypes, "this code should be useless with exact types"); | |
| 1407 assert( ak->is_type_array_klass(), "" ); | |
| 1408 return TypeKlassPtr::make(ak); // These are always precise | |
| 1409 } | |
| 1410 } | |
| 1411 } | |
| 1412 | |
| 1413 // Check for loading klass from an array klass | |
| 1414 const TypeKlassPtr *tkls = tp->isa_klassptr(); | |
| 1415 if (tkls != NULL && !StressReflectiveCode) { | |
| 1416 ciKlass* klass = tkls->klass(); | |
| 1417 if( !klass->is_loaded() ) | |
| 1418 return _type; // Bail out if not loaded | |
| 1419 if( klass->is_obj_array_klass() && | |
| 1420 (uint)tkls->offset() == objArrayKlass::element_klass_offset_in_bytes() + sizeof(oopDesc)) { | |
| 1421 ciKlass* elem = klass->as_obj_array_klass()->element_klass(); | |
| 1422 // // Always returning precise element type is incorrect, | |
| 1423 // // e.g., element type could be object and array may contain strings | |
| 1424 // return TypeKlassPtr::make(TypePtr::Constant, elem, 0); | |
| 1425 | |
| 1426 // The array's TypeKlassPtr was declared 'precise' or 'not precise' | |
| 1427 // according to the element type's subclassing. | |
| 1428 return TypeKlassPtr::make(tkls->ptr(), elem, 0/*offset*/); | |
| 1429 } | |
| 1430 if( klass->is_instance_klass() && tkls->klass_is_exact() && | |
| 1431 (uint)tkls->offset() == Klass::super_offset_in_bytes() + sizeof(oopDesc)) { | |
| 1432 ciKlass* sup = klass->as_instance_klass()->super(); | |
| 1433 // The field is Klass::_super. Return its (constant) value. | |
| 1434 // (Folds up the 2nd indirection in aClassConstant.getSuperClass().) | |
| 1435 return sup ? TypeKlassPtr::make(sup) : TypePtr::NULL_PTR; | |
| 1436 } | |
| 1437 } | |
| 1438 | |
| 1439 // Bailout case | |
| 1440 return LoadNode::Value(phase); | |
| 1441 } | |
| 1442 | |
| 1443 //------------------------------Identity--------------------------------------- | |
| 1444 // To clean up reflective code, simplify k.java_mirror.as_klass to plain k. | |
| 1445 // Also feed through the klass in Allocate(...klass...)._klass. | |
| 1446 Node* LoadKlassNode::Identity( PhaseTransform *phase ) { | |
| 1447 Node* x = LoadNode::Identity(phase); | |
| 1448 if (x != this) return x; | |
| 1449 | |
| 1450 // Take apart the address into an oop and and offset. | |
| 1451 // Return 'this' if we cannot. | |
| 1452 Node* adr = in(MemNode::Address); | |
| 1453 intptr_t offset = 0; | |
| 1454 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); | |
| 1455 if (base == NULL) return this; | |
| 1456 const TypeOopPtr* toop = phase->type(adr)->isa_oopptr(); | |
| 1457 if (toop == NULL) return this; | |
| 1458 | |
| 1459 // We can fetch the klass directly through an AllocateNode. | |
| 1460 // This works even if the klass is not constant (clone or newArray). | |
| 1461 if (offset == oopDesc::klass_offset_in_bytes()) { | |
| 1462 Node* allocated_klass = AllocateNode::Ideal_klass(base, phase); | |
| 1463 if (allocated_klass != NULL) { | |
| 1464 return allocated_klass; | |
| 1465 } | |
| 1466 } | |
| 1467 | |
| 1468 // Simplify k.java_mirror.as_klass to plain k, where k is a klassOop. | |
| 1469 // Simplify ak.component_mirror.array_klass to plain ak, ak an arrayKlass. | |
| 1470 // See inline_native_Class_query for occurrences of these patterns. | |
| 1471 // Java Example: x.getClass().isAssignableFrom(y) | |
| 1472 // Java Example: Array.newInstance(x.getClass().getComponentType(), n) | |
| 1473 // | |
| 1474 // This improves reflective code, often making the Class | |
| 1475 // mirror go completely dead. (Current exception: Class | |
| 1476 // mirrors may appear in debug info, but we could clean them out by | |
| 1477 // introducing a new debug info operator for klassOop.java_mirror). | |
| 1478 if (toop->isa_instptr() && toop->klass() == phase->C->env()->Class_klass() | |
| 1479 && (offset == java_lang_Class::klass_offset_in_bytes() || | |
| 1480 offset == java_lang_Class::array_klass_offset_in_bytes())) { | |
| 1481 // We are loading a special hidden field from a Class mirror, | |
| 1482 // the field which points to its Klass or arrayKlass metaobject. | |
| 1483 if (base->is_Load()) { | |
| 1484 Node* adr2 = base->in(MemNode::Address); | |
| 1485 const TypeKlassPtr* tkls = phase->type(adr2)->isa_klassptr(); | |
| 1486 if (tkls != NULL && !tkls->empty() | |
| 1487 && (tkls->klass()->is_instance_klass() || | |
| 1488 tkls->klass()->is_array_klass()) | |
| 1489 && adr2->is_AddP() | |
| 1490 ) { | |
| 1491 int mirror_field = Klass::java_mirror_offset_in_bytes(); | |
| 1492 if (offset == java_lang_Class::array_klass_offset_in_bytes()) { | |
| 1493 mirror_field = in_bytes(arrayKlass::component_mirror_offset()); | |
| 1494 } | |
| 1495 if (tkls->offset() == mirror_field + (int)sizeof(oopDesc)) { | |
| 1496 return adr2->in(AddPNode::Base); | |
| 1497 } | |
| 1498 } | |
| 1499 } | |
| 1500 } | |
| 1501 | |
| 1502 return this; | |
| 1503 } | |
| 1504 | |
| 1505 //------------------------------Value----------------------------------------- | |
| 1506 const Type *LoadRangeNode::Value( PhaseTransform *phase ) const { | |
| 1507 // Either input is TOP ==> the result is TOP | |
| 1508 const Type *t1 = phase->type( in(MemNode::Memory) ); | |
| 1509 if( t1 == Type::TOP ) return Type::TOP; | |
| 1510 Node *adr = in(MemNode::Address); | |
| 1511 const Type *t2 = phase->type( adr ); | |
| 1512 if( t2 == Type::TOP ) return Type::TOP; | |
| 1513 const TypePtr *tp = t2->is_ptr(); | |
| 1514 if (TypePtr::above_centerline(tp->ptr())) return Type::TOP; | |
| 1515 const TypeAryPtr *tap = tp->isa_aryptr(); | |
| 1516 if( !tap ) return _type; | |
| 1517 return tap->size(); | |
| 1518 } | |
| 1519 | |
| 1520 //------------------------------Identity--------------------------------------- | |
| 1521 // Feed through the length in AllocateArray(...length...)._length. | |
| 1522 Node* LoadRangeNode::Identity( PhaseTransform *phase ) { | |
| 1523 Node* x = LoadINode::Identity(phase); | |
| 1524 if (x != this) return x; | |
| 1525 | |
| 1526 // Take apart the address into an oop and and offset. | |
| 1527 // Return 'this' if we cannot. | |
| 1528 Node* adr = in(MemNode::Address); | |
| 1529 intptr_t offset = 0; | |
| 1530 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); | |
| 1531 if (base == NULL) return this; | |
| 1532 const TypeAryPtr* tary = phase->type(adr)->isa_aryptr(); | |
| 1533 if (tary == NULL) return this; | |
| 1534 | |
| 1535 // We can fetch the length directly through an AllocateArrayNode. | |
| 1536 // This works even if the length is not constant (clone or newArray). | |
| 1537 if (offset == arrayOopDesc::length_offset_in_bytes()) { | |
| 1538 Node* allocated_length = AllocateArrayNode::Ideal_length(base, phase); | |
| 1539 if (allocated_length != NULL) { | |
| 1540 return allocated_length; | |
| 1541 } | |
| 1542 } | |
| 1543 | |
| 1544 return this; | |
| 1545 | |
| 1546 } | |
| 1547 //============================================================================= | |
| 1548 //---------------------------StoreNode::make----------------------------------- | |
| 1549 // Polymorphic factory method: | |
| 1550 StoreNode* StoreNode::make( Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val, BasicType bt ) { | |
| 1551 switch (bt) { | |
| 1552 case T_BOOLEAN: | |
| 1553 case T_BYTE: return new (C, 4) StoreBNode(ctl, mem, adr, adr_type, val); | |
| 1554 case T_INT: return new (C, 4) StoreINode(ctl, mem, adr, adr_type, val); | |
| 1555 case T_CHAR: | |
| 1556 case T_SHORT: return new (C, 4) StoreCNode(ctl, mem, adr, adr_type, val); | |
| 1557 case T_LONG: return new (C, 4) StoreLNode(ctl, mem, adr, adr_type, val); | |
| 1558 case T_FLOAT: return new (C, 4) StoreFNode(ctl, mem, adr, adr_type, val); | |
| 1559 case T_DOUBLE: return new (C, 4) StoreDNode(ctl, mem, adr, adr_type, val); | |
| 1560 case T_ADDRESS: | |
| 1561 case T_OBJECT: return new (C, 4) StorePNode(ctl, mem, adr, adr_type, val); | |
| 1562 } | |
| 1563 ShouldNotReachHere(); | |
| 1564 return (StoreNode*)NULL; | |
| 1565 } | |
| 1566 | |
| 1567 StoreLNode* StoreLNode::make_atomic(Compile *C, Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type, Node* val) { | |
| 1568 bool require_atomic = true; | |
| 1569 return new (C, 4) StoreLNode(ctl, mem, adr, adr_type, val, require_atomic); | |
| 1570 } | |
| 1571 | |
| 1572 | |
| 1573 //--------------------------bottom_type---------------------------------------- | |
| 1574 const Type *StoreNode::bottom_type() const { | |
| 1575 return Type::MEMORY; | |
| 1576 } | |
| 1577 | |
| 1578 //------------------------------hash------------------------------------------- | |
| 1579 uint StoreNode::hash() const { | |
| 1580 // unroll addition of interesting fields | |
| 1581 //return (uintptr_t)in(Control) + (uintptr_t)in(Memory) + (uintptr_t)in(Address) + (uintptr_t)in(ValueIn); | |
| 1582 | |
| 1583 // Since they are not commoned, do not hash them: | |
| 1584 return NO_HASH; | |
| 1585 } | |
| 1586 | |
| 1587 //------------------------------Ideal------------------------------------------ | |
| 1588 // Change back-to-back Store(, p, x) -> Store(m, p, y) to Store(m, p, x). | |
| 1589 // When a store immediately follows a relevant allocation/initialization, | |
| 1590 // try to capture it into the initialization, or hoist it above. | |
| 1591 Node *StoreNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 1592 Node* p = MemNode::Ideal_common(phase, can_reshape); | |
| 1593 if (p) return (p == NodeSentinel) ? NULL : p; | |
| 1594 | |
| 1595 Node* mem = in(MemNode::Memory); | |
| 1596 Node* address = in(MemNode::Address); | |
| 1597 | |
| 1598 // Back-to-back stores to same address? Fold em up. | |
| 1599 // Generally unsafe if I have intervening uses... | |
| 1600 if (mem->is_Store() && phase->eqv_uncast(mem->in(MemNode::Address), address)) { | |
| 1601 // Looking at a dead closed cycle of memory? | |
| 1602 assert(mem != mem->in(MemNode::Memory), "dead loop in StoreNode::Ideal"); | |
| 1603 | |
| 1604 assert(Opcode() == mem->Opcode() || | |
| 1605 phase->C->get_alias_index(adr_type()) == Compile::AliasIdxRaw, | |
| 1606 "no mismatched stores, except on raw memory"); | |
| 1607 | |
| 1608 if (mem->outcnt() == 1 && // check for intervening uses | |
| 1609 mem->as_Store()->memory_size() <= this->memory_size()) { | |
| 1610 // If anybody other than 'this' uses 'mem', we cannot fold 'mem' away. | |
| 1611 // For example, 'mem' might be the final state at a conditional return. | |
| 1612 // Or, 'mem' might be used by some node which is live at the same time | |
| 1613 // 'this' is live, which might be unschedulable. So, require exactly | |
| 1614 // ONE user, the 'this' store, until such time as we clone 'mem' for | |
| 1615 // each of 'mem's uses (thus making the exactly-1-user-rule hold true). | |
| 1616 if (can_reshape) { // (%%% is this an anachronism?) | |
| 1617 set_req_X(MemNode::Memory, mem->in(MemNode::Memory), | |
| 1618 phase->is_IterGVN()); | |
| 1619 } else { | |
| 1620 // It's OK to do this in the parser, since DU info is always accurate, | |
| 1621 // and the parser always refers to nodes via SafePointNode maps. | |
| 1622 set_req(MemNode::Memory, mem->in(MemNode::Memory)); | |
| 1623 } | |
| 1624 return this; | |
| 1625 } | |
| 1626 } | |
| 1627 | |
| 1628 // Capture an unaliased, unconditional, simple store into an initializer. | |
| 1629 // Or, if it is independent of the allocation, hoist it above the allocation. | |
| 1630 if (ReduceFieldZeroing && /*can_reshape &&*/ | |
| 1631 mem->is_Proj() && mem->in(0)->is_Initialize()) { | |
| 1632 InitializeNode* init = mem->in(0)->as_Initialize(); | |
| 1633 intptr_t offset = init->can_capture_store(this, phase); | |
| 1634 if (offset > 0) { | |
| 1635 Node* moved = init->capture_store(this, offset, phase); | |
| 1636 // If the InitializeNode captured me, it made a raw copy of me, | |
| 1637 // and I need to disappear. | |
| 1638 if (moved != NULL) { | |
| 1639 // %%% hack to ensure that Ideal returns a new node: | |
| 1640 mem = MergeMemNode::make(phase->C, mem); | |
| 1641 return mem; // fold me away | |
| 1642 } | |
| 1643 } | |
| 1644 } | |
| 1645 | |
| 1646 return NULL; // No further progress | |
| 1647 } | |
| 1648 | |
| 1649 //------------------------------Value----------------------------------------- | |
| 1650 const Type *StoreNode::Value( PhaseTransform *phase ) const { | |
| 1651 // Either input is TOP ==> the result is TOP | |
| 1652 const Type *t1 = phase->type( in(MemNode::Memory) ); | |
| 1653 if( t1 == Type::TOP ) return Type::TOP; | |
| 1654 const Type *t2 = phase->type( in(MemNode::Address) ); | |
| 1655 if( t2 == Type::TOP ) return Type::TOP; | |
| 1656 const Type *t3 = phase->type( in(MemNode::ValueIn) ); | |
| 1657 if( t3 == Type::TOP ) return Type::TOP; | |
| 1658 return Type::MEMORY; | |
| 1659 } | |
| 1660 | |
| 1661 //------------------------------Identity--------------------------------------- | |
| 1662 // Remove redundant stores: | |
| 1663 // Store(m, p, Load(m, p)) changes to m. | |
| 1664 // Store(, p, x) -> Store(m, p, x) changes to Store(m, p, x). | |
| 1665 Node *StoreNode::Identity( PhaseTransform *phase ) { | |
| 1666 Node* mem = in(MemNode::Memory); | |
| 1667 Node* adr = in(MemNode::Address); | |
| 1668 Node* val = in(MemNode::ValueIn); | |
| 1669 | |
| 1670 // Load then Store? Then the Store is useless | |
| 1671 if (val->is_Load() && | |
| 1672 phase->eqv_uncast( val->in(MemNode::Address), adr ) && | |
| 1673 phase->eqv_uncast( val->in(MemNode::Memory ), mem ) && | |
| 1674 val->as_Load()->store_Opcode() == Opcode()) { | |
| 1675 return mem; | |
| 1676 } | |
| 1677 | |
| 1678 // Two stores in a row of the same value? | |
| 1679 if (mem->is_Store() && | |
| 1680 phase->eqv_uncast( mem->in(MemNode::Address), adr ) && | |
| 1681 phase->eqv_uncast( mem->in(MemNode::ValueIn), val ) && | |
| 1682 mem->Opcode() == Opcode()) { | |
| 1683 return mem; | |
| 1684 } | |
| 1685 | |
| 1686 // Store of zero anywhere into a freshly-allocated object? | |
| 1687 // Then the store is useless. | |
| 1688 // (It must already have been captured by the InitializeNode.) | |
| 1689 if (ReduceFieldZeroing && phase->type(val)->is_zero_type()) { | |
| 1690 // a newly allocated object is already all-zeroes everywhere | |
| 1691 if (mem->is_Proj() && mem->in(0)->is_Allocate()) { | |
| 1692 return mem; | |
| 1693 } | |
| 1694 | |
| 1695 // the store may also apply to zero-bits in an earlier object | |
| 1696 Node* prev_mem = find_previous_store(phase); | |
| 1697 // Steps (a), (b): Walk past independent stores to find an exact match. | |
| 1698 if (prev_mem != NULL) { | |
| 1699 Node* prev_val = can_see_stored_value(prev_mem, phase); | |
| 1700 if (prev_val != NULL && phase->eqv(prev_val, val)) { | |
| 1701 // prev_val and val might differ by a cast; it would be good | |
| 1702 // to keep the more informative of the two. | |
| 1703 return mem; | |
| 1704 } | |
| 1705 } | |
| 1706 } | |
| 1707 | |
| 1708 return this; | |
| 1709 } | |
| 1710 | |
| 1711 //------------------------------match_edge------------------------------------- | |
| 1712 // Do we Match on this edge index or not? Match only memory & value | |
| 1713 uint StoreNode::match_edge(uint idx) const { | |
| 1714 return idx == MemNode::Address || idx == MemNode::ValueIn; | |
| 1715 } | |
| 1716 | |
| 1717 //------------------------------cmp-------------------------------------------- | |
| 1718 // Do not common stores up together. They generally have to be split | |
| 1719 // back up anyways, so do not bother. | |
| 1720 uint StoreNode::cmp( const Node &n ) const { | |
| 1721 return (&n == this); // Always fail except on self | |
| 1722 } | |
| 1723 | |
| 1724 //------------------------------Ideal_masked_input----------------------------- | |
| 1725 // Check for a useless mask before a partial-word store | |
| 1726 // (StoreB ... (AndI valIn conIa) ) | |
| 1727 // If (conIa & mask == mask) this simplifies to | |
| 1728 // (StoreB ... (valIn) ) | |
| 1729 Node *StoreNode::Ideal_masked_input(PhaseGVN *phase, uint mask) { | |
| 1730 Node *val = in(MemNode::ValueIn); | |
| 1731 if( val->Opcode() == Op_AndI ) { | |
| 1732 const TypeInt *t = phase->type( val->in(2) )->isa_int(); | |
| 1733 if( t && t->is_con() && (t->get_con() & mask) == mask ) { | |
| 1734 set_req(MemNode::ValueIn, val->in(1)); | |
| 1735 return this; | |
| 1736 } | |
| 1737 } | |
| 1738 return NULL; | |
| 1739 } | |
| 1740 | |
| 1741 | |
| 1742 //------------------------------Ideal_sign_extended_input---------------------- | |
| 1743 // Check for useless sign-extension before a partial-word store | |
| 1744 // (StoreB ... (RShiftI _ (LShiftI _ valIn conIL ) conIR) ) | |
| 1745 // If (conIL == conIR && conIR <= num_bits) this simplifies to | |
| 1746 // (StoreB ... (valIn) ) | |
| 1747 Node *StoreNode::Ideal_sign_extended_input(PhaseGVN *phase, int num_bits) { | |
| 1748 Node *val = in(MemNode::ValueIn); | |
| 1749 if( val->Opcode() == Op_RShiftI ) { | |
| 1750 const TypeInt *t = phase->type( val->in(2) )->isa_int(); | |
| 1751 if( t && t->is_con() && (t->get_con() <= num_bits) ) { | |
| 1752 Node *shl = val->in(1); | |
| 1753 if( shl->Opcode() == Op_LShiftI ) { | |
| 1754 const TypeInt *t2 = phase->type( shl->in(2) )->isa_int(); | |
| 1755 if( t2 && t2->is_con() && (t2->get_con() == t->get_con()) ) { | |
| 1756 set_req(MemNode::ValueIn, shl->in(1)); | |
| 1757 return this; | |
| 1758 } | |
| 1759 } | |
| 1760 } | |
| 1761 } | |
| 1762 return NULL; | |
| 1763 } | |
| 1764 | |
| 1765 //------------------------------value_never_loaded----------------------------------- | |
| 1766 // Determine whether there are any possible loads of the value stored. | |
| 1767 // For simplicity, we actually check if there are any loads from the | |
| 1768 // address stored to, not just for loads of the value stored by this node. | |
| 1769 // | |
| 1770 bool StoreNode::value_never_loaded( PhaseTransform *phase) const { | |
| 1771 Node *adr = in(Address); | |
| 1772 const TypeOopPtr *adr_oop = phase->type(adr)->isa_oopptr(); | |
| 1773 if (adr_oop == NULL) | |
| 1774 return false; | |
|
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|
1775 if (!adr_oop->is_instance_field()) |
| 0 | 1776 return false; // if not a distinct instance, there may be aliases of the address |
| 1777 for (DUIterator_Fast imax, i = adr->fast_outs(imax); i < imax; i++) { | |
| 1778 Node *use = adr->fast_out(i); | |
| 1779 int opc = use->Opcode(); | |
| 1780 if (use->is_Load() || use->is_LoadStore()) { | |
| 1781 return false; | |
| 1782 } | |
| 1783 } | |
| 1784 return true; | |
| 1785 } | |
| 1786 | |
| 1787 //============================================================================= | |
| 1788 //------------------------------Ideal------------------------------------------ | |
| 1789 // If the store is from an AND mask that leaves the low bits untouched, then | |
| 1790 // we can skip the AND operation. If the store is from a sign-extension | |
| 1791 // (a left shift, then right shift) we can skip both. | |
| 1792 Node *StoreBNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 1793 Node *progress = StoreNode::Ideal_masked_input(phase, 0xFF); | |
| 1794 if( progress != NULL ) return progress; | |
| 1795 | |
| 1796 progress = StoreNode::Ideal_sign_extended_input(phase, 24); | |
| 1797 if( progress != NULL ) return progress; | |
| 1798 | |
| 1799 // Finally check the default case | |
| 1800 return StoreNode::Ideal(phase, can_reshape); | |
| 1801 } | |
| 1802 | |
| 1803 //============================================================================= | |
| 1804 //------------------------------Ideal------------------------------------------ | |
| 1805 // If the store is from an AND mask that leaves the low bits untouched, then | |
| 1806 // we can skip the AND operation | |
| 1807 Node *StoreCNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 1808 Node *progress = StoreNode::Ideal_masked_input(phase, 0xFFFF); | |
| 1809 if( progress != NULL ) return progress; | |
| 1810 | |
| 1811 progress = StoreNode::Ideal_sign_extended_input(phase, 16); | |
| 1812 if( progress != NULL ) return progress; | |
| 1813 | |
| 1814 // Finally check the default case | |
| 1815 return StoreNode::Ideal(phase, can_reshape); | |
| 1816 } | |
| 1817 | |
| 1818 //============================================================================= | |
| 1819 //------------------------------Identity--------------------------------------- | |
| 1820 Node *StoreCMNode::Identity( PhaseTransform *phase ) { | |
| 1821 // No need to card mark when storing a null ptr | |
| 1822 Node* my_store = in(MemNode::OopStore); | |
| 1823 if (my_store->is_Store()) { | |
| 1824 const Type *t1 = phase->type( my_store->in(MemNode::ValueIn) ); | |
| 1825 if( t1 == TypePtr::NULL_PTR ) { | |
| 1826 return in(MemNode::Memory); | |
| 1827 } | |
| 1828 } | |
| 1829 return this; | |
| 1830 } | |
| 1831 | |
| 1832 //------------------------------Value----------------------------------------- | |
| 1833 const Type *StoreCMNode::Value( PhaseTransform *phase ) const { | |
| 43 | 1834 // Either input is TOP ==> the result is TOP |
| 1835 const Type *t = phase->type( in(MemNode::Memory) ); | |
| 1836 if( t == Type::TOP ) return Type::TOP; | |
| 1837 t = phase->type( in(MemNode::Address) ); | |
| 1838 if( t == Type::TOP ) return Type::TOP; | |
| 1839 t = phase->type( in(MemNode::ValueIn) ); | |
| 1840 if( t == Type::TOP ) return Type::TOP; | |
| 0 | 1841 // If extra input is TOP ==> the result is TOP |
| 43 | 1842 t = phase->type( in(MemNode::OopStore) ); |
| 1843 if( t == Type::TOP ) return Type::TOP; | |
| 0 | 1844 |
| 1845 return StoreNode::Value( phase ); | |
| 1846 } | |
| 1847 | |
| 1848 | |
| 1849 //============================================================================= | |
| 1850 //----------------------------------SCMemProjNode------------------------------ | |
| 1851 const Type * SCMemProjNode::Value( PhaseTransform *phase ) const | |
| 1852 { | |
| 1853 return bottom_type(); | |
| 1854 } | |
| 1855 | |
| 1856 //============================================================================= | |
| 1857 LoadStoreNode::LoadStoreNode( Node *c, Node *mem, Node *adr, Node *val, Node *ex ) : Node(5) { | |
| 1858 init_req(MemNode::Control, c ); | |
| 1859 init_req(MemNode::Memory , mem); | |
| 1860 init_req(MemNode::Address, adr); | |
| 1861 init_req(MemNode::ValueIn, val); | |
| 1862 init_req( ExpectedIn, ex ); | |
| 1863 init_class_id(Class_LoadStore); | |
| 1864 | |
| 1865 } | |
| 1866 | |
| 1867 //============================================================================= | |
| 1868 //-------------------------------adr_type-------------------------------------- | |
| 1869 // Do we Match on this edge index or not? Do not match memory | |
| 1870 const TypePtr* ClearArrayNode::adr_type() const { | |
| 1871 Node *adr = in(3); | |
| 1872 return MemNode::calculate_adr_type(adr->bottom_type()); | |
| 1873 } | |
| 1874 | |
| 1875 //------------------------------match_edge------------------------------------- | |
| 1876 // Do we Match on this edge index or not? Do not match memory | |
| 1877 uint ClearArrayNode::match_edge(uint idx) const { | |
| 1878 return idx > 1; | |
| 1879 } | |
| 1880 | |
| 1881 //------------------------------Identity--------------------------------------- | |
| 1882 // Clearing a zero length array does nothing | |
| 1883 Node *ClearArrayNode::Identity( PhaseTransform *phase ) { | |
| 1884 return phase->type(in(2))->higher_equal(TypeInt::ZERO) ? in(1) : this; | |
| 1885 } | |
| 1886 | |
| 1887 //------------------------------Idealize--------------------------------------- | |
| 1888 // Clearing a short array is faster with stores | |
| 1889 Node *ClearArrayNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 1890 const int unit = BytesPerLong; | |
| 1891 const TypeX* t = phase->type(in(2))->isa_intptr_t(); | |
| 1892 if (!t) return NULL; | |
| 1893 if (!t->is_con()) return NULL; | |
| 1894 intptr_t raw_count = t->get_con(); | |
| 1895 intptr_t size = raw_count; | |
| 1896 if (!Matcher::init_array_count_is_in_bytes) size *= unit; | |
| 1897 // Clearing nothing uses the Identity call. | |
| 1898 // Negative clears are possible on dead ClearArrays | |
| 1899 // (see jck test stmt114.stmt11402.val). | |
| 1900 if (size <= 0 || size % unit != 0) return NULL; | |
| 1901 intptr_t count = size / unit; | |
| 1902 // Length too long; use fast hardware clear | |
| 1903 if (size > Matcher::init_array_short_size) return NULL; | |
| 1904 Node *mem = in(1); | |
| 1905 if( phase->type(mem)==Type::TOP ) return NULL; | |
| 1906 Node *adr = in(3); | |
| 1907 const Type* at = phase->type(adr); | |
| 1908 if( at==Type::TOP ) return NULL; | |
| 1909 const TypePtr* atp = at->isa_ptr(); | |
| 1910 // adjust atp to be the correct array element address type | |
| 1911 if (atp == NULL) atp = TypePtr::BOTTOM; | |
| 1912 else atp = atp->add_offset(Type::OffsetBot); | |
| 1913 // Get base for derived pointer purposes | |
| 1914 if( adr->Opcode() != Op_AddP ) Unimplemented(); | |
| 1915 Node *base = adr->in(1); | |
| 1916 | |
| 1917 Node *zero = phase->makecon(TypeLong::ZERO); | |
| 1918 Node *off = phase->MakeConX(BytesPerLong); | |
| 1919 mem = new (phase->C, 4) StoreLNode(in(0),mem,adr,atp,zero); | |
| 1920 count--; | |
| 1921 while( count-- ) { | |
| 1922 mem = phase->transform(mem); | |
| 1923 adr = phase->transform(new (phase->C, 4) AddPNode(base,adr,off)); | |
| 1924 mem = new (phase->C, 4) StoreLNode(in(0),mem,adr,atp,zero); | |
| 1925 } | |
| 1926 return mem; | |
| 1927 } | |
| 1928 | |
| 1929 //----------------------------clear_memory------------------------------------- | |
| 1930 // Generate code to initialize object storage to zero. | |
| 1931 Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest, | |
| 1932 intptr_t start_offset, | |
| 1933 Node* end_offset, | |
| 1934 PhaseGVN* phase) { | |
| 1935 Compile* C = phase->C; | |
| 1936 intptr_t offset = start_offset; | |
| 1937 | |
| 1938 int unit = BytesPerLong; | |
| 1939 if ((offset % unit) != 0) { | |
| 1940 Node* adr = new (C, 4) AddPNode(dest, dest, phase->MakeConX(offset)); | |
| 1941 adr = phase->transform(adr); | |
| 1942 const TypePtr* atp = TypeRawPtr::BOTTOM; | |
| 1943 mem = StoreNode::make(C, ctl, mem, adr, atp, phase->zerocon(T_INT), T_INT); | |
| 1944 mem = phase->transform(mem); | |
| 1945 offset += BytesPerInt; | |
| 1946 } | |
| 1947 assert((offset % unit) == 0, ""); | |
| 1948 | |
| 1949 // Initialize the remaining stuff, if any, with a ClearArray. | |
| 1950 return clear_memory(ctl, mem, dest, phase->MakeConX(offset), end_offset, phase); | |
| 1951 } | |
| 1952 | |
| 1953 Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest, | |
| 1954 Node* start_offset, | |
| 1955 Node* end_offset, | |
| 1956 PhaseGVN* phase) { | |
| 1957 Compile* C = phase->C; | |
| 1958 int unit = BytesPerLong; | |
| 1959 Node* zbase = start_offset; | |
| 1960 Node* zend = end_offset; | |
| 1961 | |
| 1962 // Scale to the unit required by the CPU: | |
| 1963 if (!Matcher::init_array_count_is_in_bytes) { | |
| 1964 Node* shift = phase->intcon(exact_log2(unit)); | |
| 1965 zbase = phase->transform( new(C,3) URShiftXNode(zbase, shift) ); | |
| 1966 zend = phase->transform( new(C,3) URShiftXNode(zend, shift) ); | |
| 1967 } | |
| 1968 | |
| 1969 Node* zsize = phase->transform( new(C,3) SubXNode(zend, zbase) ); | |
| 1970 Node* zinit = phase->zerocon((unit == BytesPerLong) ? T_LONG : T_INT); | |
| 1971 | |
| 1972 // Bulk clear double-words | |
| 1973 Node* adr = phase->transform( new(C,4) AddPNode(dest, dest, start_offset) ); | |
| 1974 mem = new (C, 4) ClearArrayNode(ctl, mem, zsize, adr); | |
| 1975 return phase->transform(mem); | |
| 1976 } | |
| 1977 | |
| 1978 Node* ClearArrayNode::clear_memory(Node* ctl, Node* mem, Node* dest, | |
| 1979 intptr_t start_offset, | |
| 1980 intptr_t end_offset, | |
| 1981 PhaseGVN* phase) { | |
| 1982 Compile* C = phase->C; | |
| 1983 assert((end_offset % BytesPerInt) == 0, "odd end offset"); | |
| 1984 intptr_t done_offset = end_offset; | |
| 1985 if ((done_offset % BytesPerLong) != 0) { | |
| 1986 done_offset -= BytesPerInt; | |
| 1987 } | |
| 1988 if (done_offset > start_offset) { | |
| 1989 mem = clear_memory(ctl, mem, dest, | |
| 1990 start_offset, phase->MakeConX(done_offset), phase); | |
| 1991 } | |
| 1992 if (done_offset < end_offset) { // emit the final 32-bit store | |
| 1993 Node* adr = new (C, 4) AddPNode(dest, dest, phase->MakeConX(done_offset)); | |
| 1994 adr = phase->transform(adr); | |
| 1995 const TypePtr* atp = TypeRawPtr::BOTTOM; | |
| 1996 mem = StoreNode::make(C, ctl, mem, adr, atp, phase->zerocon(T_INT), T_INT); | |
| 1997 mem = phase->transform(mem); | |
| 1998 done_offset += BytesPerInt; | |
| 1999 } | |
| 2000 assert(done_offset == end_offset, ""); | |
| 2001 return mem; | |
| 2002 } | |
| 2003 | |
| 2004 //============================================================================= | |
| 2005 // Do we match on this edge? No memory edges | |
| 2006 uint StrCompNode::match_edge(uint idx) const { | |
| 2007 return idx == 5 || idx == 6; | |
| 2008 } | |
| 2009 | |
| 2010 //------------------------------Ideal------------------------------------------ | |
| 2011 // Return a node which is more "ideal" than the current node. Strip out | |
| 2012 // control copies | |
| 2013 Node *StrCompNode::Ideal(PhaseGVN *phase, bool can_reshape){ | |
| 2014 return remove_dead_region(phase, can_reshape) ? this : NULL; | |
| 2015 } | |
| 2016 | |
| 2017 | |
| 2018 //============================================================================= | |
| 2019 MemBarNode::MemBarNode(Compile* C, int alias_idx, Node* precedent) | |
| 2020 : MultiNode(TypeFunc::Parms + (precedent == NULL? 0: 1)), | |
| 2021 _adr_type(C->get_adr_type(alias_idx)) | |
| 2022 { | |
| 2023 init_class_id(Class_MemBar); | |
| 2024 Node* top = C->top(); | |
| 2025 init_req(TypeFunc::I_O,top); | |
| 2026 init_req(TypeFunc::FramePtr,top); | |
| 2027 init_req(TypeFunc::ReturnAdr,top); | |
| 2028 if (precedent != NULL) | |
| 2029 init_req(TypeFunc::Parms, precedent); | |
| 2030 } | |
| 2031 | |
| 2032 //------------------------------cmp-------------------------------------------- | |
| 2033 uint MemBarNode::hash() const { return NO_HASH; } | |
| 2034 uint MemBarNode::cmp( const Node &n ) const { | |
| 2035 return (&n == this); // Always fail except on self | |
| 2036 } | |
| 2037 | |
| 2038 //------------------------------make------------------------------------------- | |
| 2039 MemBarNode* MemBarNode::make(Compile* C, int opcode, int atp, Node* pn) { | |
| 2040 int len = Precedent + (pn == NULL? 0: 1); | |
| 2041 switch (opcode) { | |
| 2042 case Op_MemBarAcquire: return new(C, len) MemBarAcquireNode(C, atp, pn); | |
| 2043 case Op_MemBarRelease: return new(C, len) MemBarReleaseNode(C, atp, pn); | |
| 2044 case Op_MemBarVolatile: return new(C, len) MemBarVolatileNode(C, atp, pn); | |
| 2045 case Op_MemBarCPUOrder: return new(C, len) MemBarCPUOrderNode(C, atp, pn); | |
| 2046 case Op_Initialize: return new(C, len) InitializeNode(C, atp, pn); | |
| 2047 default: ShouldNotReachHere(); return NULL; | |
| 2048 } | |
| 2049 } | |
| 2050 | |
| 2051 //------------------------------Ideal------------------------------------------ | |
| 2052 // Return a node which is more "ideal" than the current node. Strip out | |
| 2053 // control copies | |
| 2054 Node *MemBarNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 2055 if (remove_dead_region(phase, can_reshape)) return this; | |
| 2056 return NULL; | |
| 2057 } | |
| 2058 | |
| 2059 //------------------------------Value------------------------------------------ | |
| 2060 const Type *MemBarNode::Value( PhaseTransform *phase ) const { | |
| 2061 if( !in(0) ) return Type::TOP; | |
| 2062 if( phase->type(in(0)) == Type::TOP ) | |
| 2063 return Type::TOP; | |
| 2064 return TypeTuple::MEMBAR; | |
| 2065 } | |
| 2066 | |
| 2067 //------------------------------match------------------------------------------ | |
| 2068 // Construct projections for memory. | |
| 2069 Node *MemBarNode::match( const ProjNode *proj, const Matcher *m ) { | |
| 2070 switch (proj->_con) { | |
| 2071 case TypeFunc::Control: | |
| 2072 case TypeFunc::Memory: | |
| 2073 return new (m->C, 1) MachProjNode(this,proj->_con,RegMask::Empty,MachProjNode::unmatched_proj); | |
| 2074 } | |
| 2075 ShouldNotReachHere(); | |
| 2076 return NULL; | |
| 2077 } | |
| 2078 | |
| 2079 //===========================InitializeNode==================================== | |
| 2080 // SUMMARY: | |
| 2081 // This node acts as a memory barrier on raw memory, after some raw stores. | |
| 2082 // The 'cooked' oop value feeds from the Initialize, not the Allocation. | |
| 2083 // The Initialize can 'capture' suitably constrained stores as raw inits. | |
| 2084 // It can coalesce related raw stores into larger units (called 'tiles'). | |
| 2085 // It can avoid zeroing new storage for memory units which have raw inits. | |
| 2086 // At macro-expansion, it is marked 'complete', and does not optimize further. | |
| 2087 // | |
| 2088 // EXAMPLE: | |
| 2089 // The object 'new short[2]' occupies 16 bytes in a 32-bit machine. | |
| 2090 // ctl = incoming control; mem* = incoming memory | |
| 2091 // (Note: A star * on a memory edge denotes I/O and other standard edges.) | |
| 2092 // First allocate uninitialized memory and fill in the header: | |
| 2093 // alloc = (Allocate ctl mem* 16 #short[].klass ...) | |
| 2094 // ctl := alloc.Control; mem* := alloc.Memory* | |
| 2095 // rawmem = alloc.Memory; rawoop = alloc.RawAddress | |
| 2096 // Then initialize to zero the non-header parts of the raw memory block: | |
| 2097 // init = (Initialize alloc.Control alloc.Memory* alloc.RawAddress) | |
| 2098 // ctl := init.Control; mem.SLICE(#short[*]) := init.Memory | |
| 2099 // After the initialize node executes, the object is ready for service: | |
| 2100 // oop := (CheckCastPP init.Control alloc.RawAddress #short[]) | |
| 2101 // Suppose its body is immediately initialized as {1,2}: | |
| 2102 // store1 = (StoreC init.Control init.Memory (+ oop 12) 1) | |
| 2103 // store2 = (StoreC init.Control store1 (+ oop 14) 2) | |
| 2104 // mem.SLICE(#short[*]) := store2 | |
| 2105 // | |
| 2106 // DETAILS: | |
| 2107 // An InitializeNode collects and isolates object initialization after | |
| 2108 // an AllocateNode and before the next possible safepoint. As a | |
| 2109 // memory barrier (MemBarNode), it keeps critical stores from drifting | |
| 2110 // down past any safepoint or any publication of the allocation. | |
| 2111 // Before this barrier, a newly-allocated object may have uninitialized bits. | |
| 2112 // After this barrier, it may be treated as a real oop, and GC is allowed. | |
| 2113 // | |
| 2114 // The semantics of the InitializeNode include an implicit zeroing of | |
| 2115 // the new object from object header to the end of the object. | |
| 2116 // (The object header and end are determined by the AllocateNode.) | |
| 2117 // | |
| 2118 // Certain stores may be added as direct inputs to the InitializeNode. | |
| 2119 // These stores must update raw memory, and they must be to addresses | |
| 2120 // derived from the raw address produced by AllocateNode, and with | |
| 2121 // a constant offset. They must be ordered by increasing offset. | |
| 2122 // The first one is at in(RawStores), the last at in(req()-1). | |
| 2123 // Unlike most memory operations, they are not linked in a chain, | |
| 2124 // but are displayed in parallel as users of the rawmem output of | |
| 2125 // the allocation. | |
| 2126 // | |
| 2127 // (See comments in InitializeNode::capture_store, which continue | |
| 2128 // the example given above.) | |
| 2129 // | |
| 2130 // When the associated Allocate is macro-expanded, the InitializeNode | |
| 2131 // may be rewritten to optimize collected stores. A ClearArrayNode | |
| 2132 // may also be created at that point to represent any required zeroing. | |
| 2133 // The InitializeNode is then marked 'complete', prohibiting further | |
| 2134 // capturing of nearby memory operations. | |
| 2135 // | |
| 2136 // During macro-expansion, all captured initializations which store | |
| 2137 // constant values of 32 bits or smaller are coalesced (if advantagous) | |
| 2138 // into larger 'tiles' 32 or 64 bits. This allows an object to be | |
| 2139 // initialized in fewer memory operations. Memory words which are | |
| 2140 // covered by neither tiles nor non-constant stores are pre-zeroed | |
| 2141 // by explicit stores of zero. (The code shape happens to do all | |
| 2142 // zeroing first, then all other stores, with both sequences occurring | |
| 2143 // in order of ascending offsets.) | |
| 2144 // | |
| 2145 // Alternatively, code may be inserted between an AllocateNode and its | |
| 2146 // InitializeNode, to perform arbitrary initialization of the new object. | |
| 2147 // E.g., the object copying intrinsics insert complex data transfers here. | |
| 2148 // The initialization must then be marked as 'complete' disable the | |
| 2149 // built-in zeroing semantics and the collection of initializing stores. | |
| 2150 // | |
| 2151 // While an InitializeNode is incomplete, reads from the memory state | |
| 2152 // produced by it are optimizable if they match the control edge and | |
| 2153 // new oop address associated with the allocation/initialization. | |
| 2154 // They return a stored value (if the offset matches) or else zero. | |
| 2155 // A write to the memory state, if it matches control and address, | |
| 2156 // and if it is to a constant offset, may be 'captured' by the | |
| 2157 // InitializeNode. It is cloned as a raw memory operation and rewired | |
| 2158 // inside the initialization, to the raw oop produced by the allocation. | |
| 2159 // Operations on addresses which are provably distinct (e.g., to | |
| 2160 // other AllocateNodes) are allowed to bypass the initialization. | |
| 2161 // | |
| 2162 // The effect of all this is to consolidate object initialization | |
| 2163 // (both arrays and non-arrays, both piecewise and bulk) into a | |
| 2164 // single location, where it can be optimized as a unit. | |
| 2165 // | |
| 2166 // Only stores with an offset less than TrackedInitializationLimit words | |
| 2167 // will be considered for capture by an InitializeNode. This puts a | |
| 2168 // reasonable limit on the complexity of optimized initializations. | |
| 2169 | |
| 2170 //---------------------------InitializeNode------------------------------------ | |
| 2171 InitializeNode::InitializeNode(Compile* C, int adr_type, Node* rawoop) | |
| 2172 : _is_complete(false), | |
| 2173 MemBarNode(C, adr_type, rawoop) | |
| 2174 { | |
| 2175 init_class_id(Class_Initialize); | |
| 2176 | |
| 2177 assert(adr_type == Compile::AliasIdxRaw, "only valid atp"); | |
| 2178 assert(in(RawAddress) == rawoop, "proper init"); | |
| 2179 // Note: allocation() can be NULL, for secondary initialization barriers | |
| 2180 } | |
| 2181 | |
| 2182 // Since this node is not matched, it will be processed by the | |
| 2183 // register allocator. Declare that there are no constraints | |
| 2184 // on the allocation of the RawAddress edge. | |
| 2185 const RegMask &InitializeNode::in_RegMask(uint idx) const { | |
| 2186 // This edge should be set to top, by the set_complete. But be conservative. | |
| 2187 if (idx == InitializeNode::RawAddress) | |
| 2188 return *(Compile::current()->matcher()->idealreg2spillmask[in(idx)->ideal_reg()]); | |
| 2189 return RegMask::Empty; | |
| 2190 } | |
| 2191 | |
| 2192 Node* InitializeNode::memory(uint alias_idx) { | |
| 2193 Node* mem = in(Memory); | |
| 2194 if (mem->is_MergeMem()) { | |
| 2195 return mem->as_MergeMem()->memory_at(alias_idx); | |
| 2196 } else { | |
| 2197 // incoming raw memory is not split | |
| 2198 return mem; | |
| 2199 } | |
| 2200 } | |
| 2201 | |
| 2202 bool InitializeNode::is_non_zero() { | |
| 2203 if (is_complete()) return false; | |
| 2204 remove_extra_zeroes(); | |
| 2205 return (req() > RawStores); | |
| 2206 } | |
| 2207 | |
| 2208 void InitializeNode::set_complete(PhaseGVN* phase) { | |
| 2209 assert(!is_complete(), "caller responsibility"); | |
| 2210 _is_complete = true; | |
| 2211 | |
| 2212 // After this node is complete, it contains a bunch of | |
| 2213 // raw-memory initializations. There is no need for | |
| 2214 // it to have anything to do with non-raw memory effects. | |
| 2215 // Therefore, tell all non-raw users to re-optimize themselves, | |
| 2216 // after skipping the memory effects of this initialization. | |
| 2217 PhaseIterGVN* igvn = phase->is_IterGVN(); | |
| 2218 if (igvn) igvn->add_users_to_worklist(this); | |
| 2219 } | |
| 2220 | |
| 2221 // convenience function | |
| 2222 // return false if the init contains any stores already | |
| 2223 bool AllocateNode::maybe_set_complete(PhaseGVN* phase) { | |
| 2224 InitializeNode* init = initialization(); | |
| 2225 if (init == NULL || init->is_complete()) return false; | |
| 2226 init->remove_extra_zeroes(); | |
| 2227 // for now, if this allocation has already collected any inits, bail: | |
| 2228 if (init->is_non_zero()) return false; | |
| 2229 init->set_complete(phase); | |
| 2230 return true; | |
| 2231 } | |
| 2232 | |
| 2233 void InitializeNode::remove_extra_zeroes() { | |
| 2234 if (req() == RawStores) return; | |
| 2235 Node* zmem = zero_memory(); | |
| 2236 uint fill = RawStores; | |
| 2237 for (uint i = fill; i < req(); i++) { | |
| 2238 Node* n = in(i); | |
| 2239 if (n->is_top() || n == zmem) continue; // skip | |
| 2240 if (fill < i) set_req(fill, n); // compact | |
| 2241 ++fill; | |
| 2242 } | |
| 2243 // delete any empty spaces created: | |
| 2244 while (fill < req()) { | |
| 2245 del_req(fill); | |
| 2246 } | |
| 2247 } | |
| 2248 | |
| 2249 // Helper for remembering which stores go with which offsets. | |
| 2250 intptr_t InitializeNode::get_store_offset(Node* st, PhaseTransform* phase) { | |
| 2251 if (!st->is_Store()) return -1; // can happen to dead code via subsume_node | |
| 2252 intptr_t offset = -1; | |
| 2253 Node* base = AddPNode::Ideal_base_and_offset(st->in(MemNode::Address), | |
| 2254 phase, offset); | |
| 2255 if (base == NULL) return -1; // something is dead, | |
| 2256 if (offset < 0) return -1; // dead, dead | |
| 2257 return offset; | |
| 2258 } | |
| 2259 | |
| 2260 // Helper for proving that an initialization expression is | |
| 2261 // "simple enough" to be folded into an object initialization. | |
| 2262 // Attempts to prove that a store's initial value 'n' can be captured | |
| 2263 // within the initialization without creating a vicious cycle, such as: | |
| 2264 // { Foo p = new Foo(); p.next = p; } | |
| 2265 // True for constants and parameters and small combinations thereof. | |
| 2266 bool InitializeNode::detect_init_independence(Node* n, | |
| 2267 bool st_is_pinned, | |
| 2268 int& count) { | |
| 2269 if (n == NULL) return true; // (can this really happen?) | |
| 2270 if (n->is_Proj()) n = n->in(0); | |
| 2271 if (n == this) return false; // found a cycle | |
| 2272 if (n->is_Con()) return true; | |
| 2273 if (n->is_Start()) return true; // params, etc., are OK | |
| 2274 if (n->is_Root()) return true; // even better | |
| 2275 | |
| 2276 Node* ctl = n->in(0); | |
| 2277 if (ctl != NULL && !ctl->is_top()) { | |
| 2278 if (ctl->is_Proj()) ctl = ctl->in(0); | |
| 2279 if (ctl == this) return false; | |
| 2280 | |
| 2281 // If we already know that the enclosing memory op is pinned right after | |
| 2282 // the init, then any control flow that the store has picked up | |
| 2283 // must have preceded the init, or else be equal to the init. | |
| 2284 // Even after loop optimizations (which might change control edges) | |
| 2285 // a store is never pinned *before* the availability of its inputs. | |
| 2286 if (!MemNode::detect_dominating_control(ctl, this->in(0))) | |
| 2287 return false; // failed to prove a good control | |
| 2288 | |
| 2289 } | |
| 2290 | |
| 2291 // Check data edges for possible dependencies on 'this'. | |
| 2292 if ((count += 1) > 20) return false; // complexity limit | |
| 2293 for (uint i = 1; i < n->req(); i++) { | |
| 2294 Node* m = n->in(i); | |
| 2295 if (m == NULL || m == n || m->is_top()) continue; | |
| 2296 uint first_i = n->find_edge(m); | |
| 2297 if (i != first_i) continue; // process duplicate edge just once | |
| 2298 if (!detect_init_independence(m, st_is_pinned, count)) { | |
| 2299 return false; | |
| 2300 } | |
| 2301 } | |
| 2302 | |
| 2303 return true; | |
| 2304 } | |
| 2305 | |
| 2306 // Here are all the checks a Store must pass before it can be moved into | |
| 2307 // an initialization. Returns zero if a check fails. | |
| 2308 // On success, returns the (constant) offset to which the store applies, | |
| 2309 // within the initialized memory. | |
| 2310 intptr_t InitializeNode::can_capture_store(StoreNode* st, PhaseTransform* phase) { | |
| 2311 const int FAIL = 0; | |
| 2312 if (st->req() != MemNode::ValueIn + 1) | |
| 2313 return FAIL; // an inscrutable StoreNode (card mark?) | |
| 2314 Node* ctl = st->in(MemNode::Control); | |
| 2315 if (!(ctl != NULL && ctl->is_Proj() && ctl->in(0) == this)) | |
| 2316 return FAIL; // must be unconditional after the initialization | |
| 2317 Node* mem = st->in(MemNode::Memory); | |
| 2318 if (!(mem->is_Proj() && mem->in(0) == this)) | |
| 2319 return FAIL; // must not be preceded by other stores | |
| 2320 Node* adr = st->in(MemNode::Address); | |
| 2321 intptr_t offset; | |
| 2322 AllocateNode* alloc = AllocateNode::Ideal_allocation(adr, phase, offset); | |
| 2323 if (alloc == NULL) | |
| 2324 return FAIL; // inscrutable address | |
| 2325 if (alloc != allocation()) | |
| 2326 return FAIL; // wrong allocation! (store needs to float up) | |
| 2327 Node* val = st->in(MemNode::ValueIn); | |
| 2328 int complexity_count = 0; | |
| 2329 if (!detect_init_independence(val, true, complexity_count)) | |
| 2330 return FAIL; // stored value must be 'simple enough' | |
| 2331 | |
| 2332 return offset; // success | |
| 2333 } | |
| 2334 | |
| 2335 // Find the captured store in(i) which corresponds to the range | |
| 2336 // [start..start+size) in the initialized object. | |
| 2337 // If there is one, return its index i. If there isn't, return the | |
| 2338 // negative of the index where it should be inserted. | |
| 2339 // Return 0 if the queried range overlaps an initialization boundary | |
| 2340 // or if dead code is encountered. | |
| 2341 // If size_in_bytes is zero, do not bother with overlap checks. | |
| 2342 int InitializeNode::captured_store_insertion_point(intptr_t start, | |
| 2343 int size_in_bytes, | |
| 2344 PhaseTransform* phase) { | |
| 2345 const int FAIL = 0, MAX_STORE = BytesPerLong; | |
| 2346 | |
| 2347 if (is_complete()) | |
| 2348 return FAIL; // arraycopy got here first; punt | |
| 2349 | |
| 2350 assert(allocation() != NULL, "must be present"); | |
| 2351 | |
| 2352 // no negatives, no header fields: | |
| 2353 if (start < (intptr_t) sizeof(oopDesc)) return FAIL; | |
| 2354 if (start < (intptr_t) sizeof(arrayOopDesc) && | |
| 2355 start < (intptr_t) allocation()->minimum_header_size()) return FAIL; | |
| 2356 | |
| 2357 // after a certain size, we bail out on tracking all the stores: | |
| 2358 intptr_t ti_limit = (TrackedInitializationLimit * HeapWordSize); | |
| 2359 if (start >= ti_limit) return FAIL; | |
| 2360 | |
| 2361 for (uint i = InitializeNode::RawStores, limit = req(); ; ) { | |
| 2362 if (i >= limit) return -(int)i; // not found; here is where to put it | |
| 2363 | |
| 2364 Node* st = in(i); | |
| 2365 intptr_t st_off = get_store_offset(st, phase); | |
| 2366 if (st_off < 0) { | |
| 2367 if (st != zero_memory()) { | |
| 2368 return FAIL; // bail out if there is dead garbage | |
| 2369 } | |
| 2370 } else if (st_off > start) { | |
| 2371 // ...we are done, since stores are ordered | |
| 2372 if (st_off < start + size_in_bytes) { | |
| 2373 return FAIL; // the next store overlaps | |
| 2374 } | |
| 2375 return -(int)i; // not found; here is where to put it | |
| 2376 } else if (st_off < start) { | |
| 2377 if (size_in_bytes != 0 && | |
| 2378 start < st_off + MAX_STORE && | |
| 2379 start < st_off + st->as_Store()->memory_size()) { | |
| 2380 return FAIL; // the previous store overlaps | |
| 2381 } | |
| 2382 } else { | |
| 2383 if (size_in_bytes != 0 && | |
| 2384 st->as_Store()->memory_size() != size_in_bytes) { | |
| 2385 return FAIL; // mismatched store size | |
| 2386 } | |
| 2387 return i; | |
| 2388 } | |
| 2389 | |
| 2390 ++i; | |
| 2391 } | |
| 2392 } | |
| 2393 | |
| 2394 // Look for a captured store which initializes at the offset 'start' | |
| 2395 // with the given size. If there is no such store, and no other | |
| 2396 // initialization interferes, then return zero_memory (the memory | |
| 2397 // projection of the AllocateNode). | |
| 2398 Node* InitializeNode::find_captured_store(intptr_t start, int size_in_bytes, | |
| 2399 PhaseTransform* phase) { | |
| 2400 assert(stores_are_sane(phase), ""); | |
| 2401 int i = captured_store_insertion_point(start, size_in_bytes, phase); | |
| 2402 if (i == 0) { | |
| 2403 return NULL; // something is dead | |
| 2404 } else if (i < 0) { | |
| 2405 return zero_memory(); // just primordial zero bits here | |
| 2406 } else { | |
| 2407 Node* st = in(i); // here is the store at this position | |
| 2408 assert(get_store_offset(st->as_Store(), phase) == start, "sanity"); | |
| 2409 return st; | |
| 2410 } | |
| 2411 } | |
| 2412 | |
| 2413 // Create, as a raw pointer, an address within my new object at 'offset'. | |
| 2414 Node* InitializeNode::make_raw_address(intptr_t offset, | |
| 2415 PhaseTransform* phase) { | |
| 2416 Node* addr = in(RawAddress); | |
| 2417 if (offset != 0) { | |
| 2418 Compile* C = phase->C; | |
| 2419 addr = phase->transform( new (C, 4) AddPNode(C->top(), addr, | |
| 2420 phase->MakeConX(offset)) ); | |
| 2421 } | |
| 2422 return addr; | |
| 2423 } | |
| 2424 | |
| 2425 // Clone the given store, converting it into a raw store | |
| 2426 // initializing a field or element of my new object. | |
| 2427 // Caller is responsible for retiring the original store, | |
| 2428 // with subsume_node or the like. | |
| 2429 // | |
| 2430 // From the example above InitializeNode::InitializeNode, | |
| 2431 // here are the old stores to be captured: | |
| 2432 // store1 = (StoreC init.Control init.Memory (+ oop 12) 1) | |
| 2433 // store2 = (StoreC init.Control store1 (+ oop 14) 2) | |
| 2434 // | |
| 2435 // Here is the changed code; note the extra edges on init: | |
| 2436 // alloc = (Allocate ...) | |
| 2437 // rawoop = alloc.RawAddress | |
| 2438 // rawstore1 = (StoreC alloc.Control alloc.Memory (+ rawoop 12) 1) | |
| 2439 // rawstore2 = (StoreC alloc.Control alloc.Memory (+ rawoop 14) 2) | |
| 2440 // init = (Initialize alloc.Control alloc.Memory rawoop | |
| 2441 // rawstore1 rawstore2) | |
| 2442 // | |
| 2443 Node* InitializeNode::capture_store(StoreNode* st, intptr_t start, | |
| 2444 PhaseTransform* phase) { | |
| 2445 assert(stores_are_sane(phase), ""); | |
| 2446 | |
| 2447 if (start < 0) return NULL; | |
| 2448 assert(can_capture_store(st, phase) == start, "sanity"); | |
| 2449 | |
| 2450 Compile* C = phase->C; | |
| 2451 int size_in_bytes = st->memory_size(); | |
| 2452 int i = captured_store_insertion_point(start, size_in_bytes, phase); | |
| 2453 if (i == 0) return NULL; // bail out | |
| 2454 Node* prev_mem = NULL; // raw memory for the captured store | |
| 2455 if (i > 0) { | |
| 2456 prev_mem = in(i); // there is a pre-existing store under this one | |
| 2457 set_req(i, C->top()); // temporarily disconnect it | |
| 2458 // See StoreNode::Ideal 'st->outcnt() == 1' for the reason to disconnect. | |
| 2459 } else { | |
| 2460 i = -i; // no pre-existing store | |
| 2461 prev_mem = zero_memory(); // a slice of the newly allocated object | |
| 2462 if (i > InitializeNode::RawStores && in(i-1) == prev_mem) | |
| 2463 set_req(--i, C->top()); // reuse this edge; it has been folded away | |
| 2464 else | |
| 2465 ins_req(i, C->top()); // build a new edge | |
| 2466 } | |
| 2467 Node* new_st = st->clone(); | |
| 2468 new_st->set_req(MemNode::Control, in(Control)); | |
| 2469 new_st->set_req(MemNode::Memory, prev_mem); | |
| 2470 new_st->set_req(MemNode::Address, make_raw_address(start, phase)); | |
| 2471 new_st = phase->transform(new_st); | |
| 2472 | |
| 2473 // At this point, new_st might have swallowed a pre-existing store | |
| 2474 // at the same offset, or perhaps new_st might have disappeared, | |
| 2475 // if it redundantly stored the same value (or zero to fresh memory). | |
| 2476 | |
| 2477 // In any case, wire it in: | |
| 2478 set_req(i, new_st); | |
| 2479 | |
| 2480 // The caller may now kill the old guy. | |
| 2481 DEBUG_ONLY(Node* check_st = find_captured_store(start, size_in_bytes, phase)); | |
| 2482 assert(check_st == new_st || check_st == NULL, "must be findable"); | |
| 2483 assert(!is_complete(), ""); | |
| 2484 return new_st; | |
| 2485 } | |
| 2486 | |
| 2487 static bool store_constant(jlong* tiles, int num_tiles, | |
| 2488 intptr_t st_off, int st_size, | |
| 2489 jlong con) { | |
| 2490 if ((st_off & (st_size-1)) != 0) | |
| 2491 return false; // strange store offset (assume size==2**N) | |
| 2492 address addr = (address)tiles + st_off; | |
| 2493 assert(st_off >= 0 && addr+st_size <= (address)&tiles[num_tiles], "oob"); | |
| 2494 switch (st_size) { | |
| 2495 case sizeof(jbyte): *(jbyte*) addr = (jbyte) con; break; | |
| 2496 case sizeof(jchar): *(jchar*) addr = (jchar) con; break; | |
| 2497 case sizeof(jint): *(jint*) addr = (jint) con; break; | |
| 2498 case sizeof(jlong): *(jlong*) addr = (jlong) con; break; | |
| 2499 default: return false; // strange store size (detect size!=2**N here) | |
| 2500 } | |
| 2501 return true; // return success to caller | |
| 2502 } | |
| 2503 | |
| 2504 // Coalesce subword constants into int constants and possibly | |
| 2505 // into long constants. The goal, if the CPU permits, | |
| 2506 // is to initialize the object with a small number of 64-bit tiles. | |
| 2507 // Also, convert floating-point constants to bit patterns. | |
| 2508 // Non-constants are not relevant to this pass. | |
| 2509 // | |
| 2510 // In terms of the running example on InitializeNode::InitializeNode | |
| 2511 // and InitializeNode::capture_store, here is the transformation | |
| 2512 // of rawstore1 and rawstore2 into rawstore12: | |
| 2513 // alloc = (Allocate ...) | |
| 2514 // rawoop = alloc.RawAddress | |
| 2515 // tile12 = 0x00010002 | |
| 2516 // rawstore12 = (StoreI alloc.Control alloc.Memory (+ rawoop 12) tile12) | |
| 2517 // init = (Initialize alloc.Control alloc.Memory rawoop rawstore12) | |
| 2518 // | |
| 2519 void | |
| 2520 InitializeNode::coalesce_subword_stores(intptr_t header_size, | |
| 2521 Node* size_in_bytes, | |
| 2522 PhaseGVN* phase) { | |
| 2523 Compile* C = phase->C; | |
| 2524 | |
| 2525 assert(stores_are_sane(phase), ""); | |
| 2526 // Note: After this pass, they are not completely sane, | |
| 2527 // since there may be some overlaps. | |
| 2528 | |
| 2529 int old_subword = 0, old_long = 0, new_int = 0, new_long = 0; | |
| 2530 | |
| 2531 intptr_t ti_limit = (TrackedInitializationLimit * HeapWordSize); | |
| 2532 intptr_t size_limit = phase->find_intptr_t_con(size_in_bytes, ti_limit); | |
| 2533 size_limit = MIN2(size_limit, ti_limit); | |
| 2534 size_limit = align_size_up(size_limit, BytesPerLong); | |
| 2535 int num_tiles = size_limit / BytesPerLong; | |
| 2536 | |
| 2537 // allocate space for the tile map: | |
| 2538 const int small_len = DEBUG_ONLY(true ? 3 :) 30; // keep stack frames small | |
| 2539 jlong tiles_buf[small_len]; | |
| 2540 Node* nodes_buf[small_len]; | |
| 2541 jlong inits_buf[small_len]; | |
| 2542 jlong* tiles = ((num_tiles <= small_len) ? &tiles_buf[0] | |
| 2543 : NEW_RESOURCE_ARRAY(jlong, num_tiles)); | |
| 2544 Node** nodes = ((num_tiles <= small_len) ? &nodes_buf[0] | |
| 2545 : NEW_RESOURCE_ARRAY(Node*, num_tiles)); | |
| 2546 jlong* inits = ((num_tiles <= small_len) ? &inits_buf[0] | |
| 2547 : NEW_RESOURCE_ARRAY(jlong, num_tiles)); | |
| 2548 // tiles: exact bitwise model of all primitive constants | |
| 2549 // nodes: last constant-storing node subsumed into the tiles model | |
| 2550 // inits: which bytes (in each tile) are touched by any initializations | |
| 2551 | |
| 2552 //// Pass A: Fill in the tile model with any relevant stores. | |
| 2553 | |
| 2554 Copy::zero_to_bytes(tiles, sizeof(tiles[0]) * num_tiles); | |
| 2555 Copy::zero_to_bytes(nodes, sizeof(nodes[0]) * num_tiles); | |
| 2556 Copy::zero_to_bytes(inits, sizeof(inits[0]) * num_tiles); | |
| 2557 Node* zmem = zero_memory(); // initially zero memory state | |
| 2558 for (uint i = InitializeNode::RawStores, limit = req(); i < limit; i++) { | |
| 2559 Node* st = in(i); | |
| 2560 intptr_t st_off = get_store_offset(st, phase); | |
| 2561 | |
| 2562 // Figure out the store's offset and constant value: | |
| 2563 if (st_off < header_size) continue; //skip (ignore header) | |
| 2564 if (st->in(MemNode::Memory) != zmem) continue; //skip (odd store chain) | |
| 2565 int st_size = st->as_Store()->memory_size(); | |
| 2566 if (st_off + st_size > size_limit) break; | |
| 2567 | |
| 2568 // Record which bytes are touched, whether by constant or not. | |
| 2569 if (!store_constant(inits, num_tiles, st_off, st_size, (jlong) -1)) | |
| 2570 continue; // skip (strange store size) | |
| 2571 | |
| 2572 const Type* val = phase->type(st->in(MemNode::ValueIn)); | |
| 2573 if (!val->singleton()) continue; //skip (non-con store) | |
| 2574 BasicType type = val->basic_type(); | |
| 2575 | |
| 2576 jlong con = 0; | |
| 2577 switch (type) { | |
| 2578 case T_INT: con = val->is_int()->get_con(); break; | |
| 2579 case T_LONG: con = val->is_long()->get_con(); break; | |
| 2580 case T_FLOAT: con = jint_cast(val->getf()); break; | |
| 2581 case T_DOUBLE: con = jlong_cast(val->getd()); break; | |
| 2582 default: continue; //skip (odd store type) | |
| 2583 } | |
| 2584 | |
| 2585 if (type == T_LONG && Matcher::isSimpleConstant64(con) && | |
| 2586 st->Opcode() == Op_StoreL) { | |
| 2587 continue; // This StoreL is already optimal. | |
| 2588 } | |
| 2589 | |
| 2590 // Store down the constant. | |
| 2591 store_constant(tiles, num_tiles, st_off, st_size, con); | |
| 2592 | |
| 2593 intptr_t j = st_off >> LogBytesPerLong; | |
| 2594 | |
| 2595 if (type == T_INT && st_size == BytesPerInt | |
| 2596 && (st_off & BytesPerInt) == BytesPerInt) { | |
| 2597 jlong lcon = tiles[j]; | |
| 2598 if (!Matcher::isSimpleConstant64(lcon) && | |
| 2599 st->Opcode() == Op_StoreI) { | |
| 2600 // This StoreI is already optimal by itself. | |
| 2601 jint* intcon = (jint*) &tiles[j]; | |
| 2602 intcon[1] = 0; // undo the store_constant() | |
| 2603 | |
| 2604 // If the previous store is also optimal by itself, back up and | |
| 2605 // undo the action of the previous loop iteration... if we can. | |
| 2606 // But if we can't, just let the previous half take care of itself. | |
| 2607 st = nodes[j]; | |
| 2608 st_off -= BytesPerInt; | |
| 2609 con = intcon[0]; | |
| 2610 if (con != 0 && st != NULL && st->Opcode() == Op_StoreI) { | |
| 2611 assert(st_off >= header_size, "still ignoring header"); | |
| 2612 assert(get_store_offset(st, phase) == st_off, "must be"); | |
| 2613 assert(in(i-1) == zmem, "must be"); | |
| 2614 DEBUG_ONLY(const Type* tcon = phase->type(st->in(MemNode::ValueIn))); | |
| 2615 assert(con == tcon->is_int()->get_con(), "must be"); | |
| 2616 // Undo the effects of the previous loop trip, which swallowed st: | |
| 2617 intcon[0] = 0; // undo store_constant() | |
| 2618 set_req(i-1, st); // undo set_req(i, zmem) | |
| 2619 nodes[j] = NULL; // undo nodes[j] = st | |
| 2620 --old_subword; // undo ++old_subword | |
| 2621 } | |
| 2622 continue; // This StoreI is already optimal. | |
| 2623 } | |
| 2624 } | |
| 2625 | |
| 2626 // This store is not needed. | |
| 2627 set_req(i, zmem); | |
| 2628 nodes[j] = st; // record for the moment | |
| 2629 if (st_size < BytesPerLong) // something has changed | |
| 2630 ++old_subword; // includes int/float, but who's counting... | |
| 2631 else ++old_long; | |
| 2632 } | |
| 2633 | |
| 2634 if ((old_subword + old_long) == 0) | |
| 2635 return; // nothing more to do | |
| 2636 | |
| 2637 //// Pass B: Convert any non-zero tiles into optimal constant stores. | |
| 2638 // Be sure to insert them before overlapping non-constant stores. | |
| 2639 // (E.g., byte[] x = { 1,2,y,4 } => x[int 0] = 0x01020004, x[2]=y.) | |
| 2640 for (int j = 0; j < num_tiles; j++) { | |
| 2641 jlong con = tiles[j]; | |
| 2642 jlong init = inits[j]; | |
| 2643 if (con == 0) continue; | |
| 2644 jint con0, con1; // split the constant, address-wise | |
| 2645 jint init0, init1; // split the init map, address-wise | |
| 2646 { union { jlong con; jint intcon[2]; } u; | |
| 2647 u.con = con; | |
| 2648 con0 = u.intcon[0]; | |
| 2649 con1 = u.intcon[1]; | |
| 2650 u.con = init; | |
| 2651 init0 = u.intcon[0]; | |
| 2652 init1 = u.intcon[1]; | |
| 2653 } | |
| 2654 | |
| 2655 Node* old = nodes[j]; | |
| 2656 assert(old != NULL, "need the prior store"); | |
| 2657 intptr_t offset = (j * BytesPerLong); | |
| 2658 | |
| 2659 bool split = !Matcher::isSimpleConstant64(con); | |
| 2660 | |
| 2661 if (offset < header_size) { | |
| 2662 assert(offset + BytesPerInt >= header_size, "second int counts"); | |
| 2663 assert(*(jint*)&tiles[j] == 0, "junk in header"); | |
| 2664 split = true; // only the second word counts | |
| 2665 // Example: int a[] = { 42 ... } | |
| 2666 } else if (con0 == 0 && init0 == -1) { | |
| 2667 split = true; // first word is covered by full inits | |
| 2668 // Example: int a[] = { ... foo(), 42 ... } | |
| 2669 } else if (con1 == 0 && init1 == -1) { | |
| 2670 split = true; // second word is covered by full inits | |
| 2671 // Example: int a[] = { ... 42, foo() ... } | |
| 2672 } | |
| 2673 | |
| 2674 // Here's a case where init0 is neither 0 nor -1: | |
| 2675 // byte a[] = { ... 0,0,foo(),0, 0,0,0,42 ... } | |
| 2676 // Assuming big-endian memory, init0, init1 are 0x0000FF00, 0x000000FF. | |
| 2677 // In this case the tile is not split; it is (jlong)42. | |
| 2678 // The big tile is stored down, and then the foo() value is inserted. | |
| 2679 // (If there were foo(),foo() instead of foo(),0, init0 would be -1.) | |
| 2680 | |
| 2681 Node* ctl = old->in(MemNode::Control); | |
| 2682 Node* adr = make_raw_address(offset, phase); | |
| 2683 const TypePtr* atp = TypeRawPtr::BOTTOM; | |
| 2684 | |
| 2685 // One or two coalesced stores to plop down. | |
| 2686 Node* st[2]; | |
| 2687 intptr_t off[2]; | |
| 2688 int nst = 0; | |
| 2689 if (!split) { | |
| 2690 ++new_long; | |
| 2691 off[nst] = offset; | |
| 2692 st[nst++] = StoreNode::make(C, ctl, zmem, adr, atp, | |
| 2693 phase->longcon(con), T_LONG); | |
| 2694 } else { | |
| 2695 // Omit either if it is a zero. | |
| 2696 if (con0 != 0) { | |
| 2697 ++new_int; | |
| 2698 off[nst] = offset; | |
| 2699 st[nst++] = StoreNode::make(C, ctl, zmem, adr, atp, | |
| 2700 phase->intcon(con0), T_INT); | |
| 2701 } | |
| 2702 if (con1 != 0) { | |
| 2703 ++new_int; | |
| 2704 offset += BytesPerInt; | |
| 2705 adr = make_raw_address(offset, phase); | |
| 2706 off[nst] = offset; | |
| 2707 st[nst++] = StoreNode::make(C, ctl, zmem, adr, atp, | |
| 2708 phase->intcon(con1), T_INT); | |
| 2709 } | |
| 2710 } | |
| 2711 | |
| 2712 // Insert second store first, then the first before the second. | |
| 2713 // Insert each one just before any overlapping non-constant stores. | |
| 2714 while (nst > 0) { | |
| 2715 Node* st1 = st[--nst]; | |
| 2716 C->copy_node_notes_to(st1, old); | |
| 2717 st1 = phase->transform(st1); | |
| 2718 offset = off[nst]; | |
| 2719 assert(offset >= header_size, "do not smash header"); | |
| 2720 int ins_idx = captured_store_insertion_point(offset, /*size:*/0, phase); | |
| 2721 guarantee(ins_idx != 0, "must re-insert constant store"); | |
| 2722 if (ins_idx < 0) ins_idx = -ins_idx; // never overlap | |
| 2723 if (ins_idx > InitializeNode::RawStores && in(ins_idx-1) == zmem) | |
| 2724 set_req(--ins_idx, st1); | |
| 2725 else | |
| 2726 ins_req(ins_idx, st1); | |
| 2727 } | |
| 2728 } | |
| 2729 | |
| 2730 if (PrintCompilation && WizardMode) | |
| 2731 tty->print_cr("Changed %d/%d subword/long constants into %d/%d int/long", | |
| 2732 old_subword, old_long, new_int, new_long); | |
| 2733 if (C->log() != NULL) | |
| 2734 C->log()->elem("comment that='%d/%d subword/long to %d/%d int/long'", | |
| 2735 old_subword, old_long, new_int, new_long); | |
| 2736 | |
| 2737 // Clean up any remaining occurrences of zmem: | |
| 2738 remove_extra_zeroes(); | |
| 2739 } | |
| 2740 | |
| 2741 // Explore forward from in(start) to find the first fully initialized | |
| 2742 // word, and return its offset. Skip groups of subword stores which | |
| 2743 // together initialize full words. If in(start) is itself part of a | |
| 2744 // fully initialized word, return the offset of in(start). If there | |
| 2745 // are no following full-word stores, or if something is fishy, return | |
| 2746 // a negative value. | |
| 2747 intptr_t InitializeNode::find_next_fullword_store(uint start, PhaseGVN* phase) { | |
| 2748 int int_map = 0; | |
| 2749 intptr_t int_map_off = 0; | |
| 2750 const int FULL_MAP = right_n_bits(BytesPerInt); // the int_map we hope for | |
| 2751 | |
| 2752 for (uint i = start, limit = req(); i < limit; i++) { | |
| 2753 Node* st = in(i); | |
| 2754 | |
| 2755 intptr_t st_off = get_store_offset(st, phase); | |
| 2756 if (st_off < 0) break; // return conservative answer | |
| 2757 | |
| 2758 int st_size = st->as_Store()->memory_size(); | |
| 2759 if (st_size >= BytesPerInt && (st_off % BytesPerInt) == 0) { | |
| 2760 return st_off; // we found a complete word init | |
| 2761 } | |
| 2762 | |
| 2763 // update the map: | |
| 2764 | |
| 2765 intptr_t this_int_off = align_size_down(st_off, BytesPerInt); | |
| 2766 if (this_int_off != int_map_off) { | |
| 2767 // reset the map: | |
| 2768 int_map = 0; | |
| 2769 int_map_off = this_int_off; | |
| 2770 } | |
| 2771 | |
| 2772 int subword_off = st_off - this_int_off; | |
| 2773 int_map |= right_n_bits(st_size) << subword_off; | |
| 2774 if ((int_map & FULL_MAP) == FULL_MAP) { | |
| 2775 return this_int_off; // we found a complete word init | |
| 2776 } | |
| 2777 | |
| 2778 // Did this store hit or cross the word boundary? | |
| 2779 intptr_t next_int_off = align_size_down(st_off + st_size, BytesPerInt); | |
| 2780 if (next_int_off == this_int_off + BytesPerInt) { | |
| 2781 // We passed the current int, without fully initializing it. | |
| 2782 int_map_off = next_int_off; | |
| 2783 int_map >>= BytesPerInt; | |
| 2784 } else if (next_int_off > this_int_off + BytesPerInt) { | |
| 2785 // We passed the current and next int. | |
| 2786 return this_int_off + BytesPerInt; | |
| 2787 } | |
| 2788 } | |
| 2789 | |
| 2790 return -1; | |
| 2791 } | |
| 2792 | |
| 2793 | |
| 2794 // Called when the associated AllocateNode is expanded into CFG. | |
| 2795 // At this point, we may perform additional optimizations. | |
| 2796 // Linearize the stores by ascending offset, to make memory | |
| 2797 // activity as coherent as possible. | |
| 2798 Node* InitializeNode::complete_stores(Node* rawctl, Node* rawmem, Node* rawptr, | |
| 2799 intptr_t header_size, | |
| 2800 Node* size_in_bytes, | |
| 2801 PhaseGVN* phase) { | |
| 2802 assert(!is_complete(), "not already complete"); | |
| 2803 assert(stores_are_sane(phase), ""); | |
| 2804 assert(allocation() != NULL, "must be present"); | |
| 2805 | |
| 2806 remove_extra_zeroes(); | |
| 2807 | |
| 2808 if (ReduceFieldZeroing || ReduceBulkZeroing) | |
| 2809 // reduce instruction count for common initialization patterns | |
| 2810 coalesce_subword_stores(header_size, size_in_bytes, phase); | |
| 2811 | |
| 2812 Node* zmem = zero_memory(); // initially zero memory state | |
| 2813 Node* inits = zmem; // accumulating a linearized chain of inits | |
| 2814 #ifdef ASSERT | |
| 2815 intptr_t last_init_off = sizeof(oopDesc); // previous init offset | |
| 2816 intptr_t last_init_end = sizeof(oopDesc); // previous init offset+size | |
| 2817 intptr_t last_tile_end = sizeof(oopDesc); // previous tile offset+size | |
| 2818 #endif | |
| 2819 intptr_t zeroes_done = header_size; | |
| 2820 | |
| 2821 bool do_zeroing = true; // we might give up if inits are very sparse | |
| 2822 int big_init_gaps = 0; // how many large gaps have we seen? | |
| 2823 | |
| 2824 if (ZeroTLAB) do_zeroing = false; | |
| 2825 if (!ReduceFieldZeroing && !ReduceBulkZeroing) do_zeroing = false; | |
| 2826 | |
| 2827 for (uint i = InitializeNode::RawStores, limit = req(); i < limit; i++) { | |
| 2828 Node* st = in(i); | |
| 2829 intptr_t st_off = get_store_offset(st, phase); | |
| 2830 if (st_off < 0) | |
| 2831 break; // unknown junk in the inits | |
| 2832 if (st->in(MemNode::Memory) != zmem) | |
| 2833 break; // complicated store chains somehow in list | |
| 2834 | |
| 2835 int st_size = st->as_Store()->memory_size(); | |
| 2836 intptr_t next_init_off = st_off + st_size; | |
| 2837 | |
| 2838 if (do_zeroing && zeroes_done < next_init_off) { | |
| 2839 // See if this store needs a zero before it or under it. | |
| 2840 intptr_t zeroes_needed = st_off; | |
| 2841 | |
| 2842 if (st_size < BytesPerInt) { | |
| 2843 // Look for subword stores which only partially initialize words. | |
| 2844 // If we find some, we must lay down some word-level zeroes first, | |
| 2845 // underneath the subword stores. | |
| 2846 // | |
| 2847 // Examples: | |
| 2848 // byte[] a = { p,q,r,s } => a[0]=p,a[1]=q,a[2]=r,a[3]=s | |
| 2849 // byte[] a = { x,y,0,0 } => a[0..3] = 0, a[0]=x,a[1]=y | |
| 2850 // byte[] a = { 0,0,z,0 } => a[0..3] = 0, a[2]=z | |
| 2851 // | |
| 2852 // Note: coalesce_subword_stores may have already done this, | |
| 2853 // if it was prompted by constant non-zero subword initializers. | |
| 2854 // But this case can still arise with non-constant stores. | |
| 2855 | |
| 2856 intptr_t next_full_store = find_next_fullword_store(i, phase); | |
| 2857 | |
| 2858 // In the examples above: | |
| 2859 // in(i) p q r s x y z | |
| 2860 // st_off 12 13 14 15 12 13 14 | |
| 2861 // st_size 1 1 1 1 1 1 1 | |
| 2862 // next_full_s. 12 16 16 16 16 16 16 | |
| 2863 // z's_done 12 16 16 16 12 16 12 | |
| 2864 // z's_needed 12 16 16 16 16 16 16 | |
| 2865 // zsize 0 0 0 0 4 0 4 | |
| 2866 if (next_full_store < 0) { | |
| 2867 // Conservative tack: Zero to end of current word. | |
| 2868 zeroes_needed = align_size_up(zeroes_needed, BytesPerInt); | |
| 2869 } else { | |
| 2870 // Zero to beginning of next fully initialized word. | |
| 2871 // Or, don't zero at all, if we are already in that word. | |
| 2872 assert(next_full_store >= zeroes_needed, "must go forward"); | |
| 2873 assert((next_full_store & (BytesPerInt-1)) == 0, "even boundary"); | |
| 2874 zeroes_needed = next_full_store; | |
| 2875 } | |
| 2876 } | |
| 2877 | |
| 2878 if (zeroes_needed > zeroes_done) { | |
| 2879 intptr_t zsize = zeroes_needed - zeroes_done; | |
| 2880 // Do some incremental zeroing on rawmem, in parallel with inits. | |
| 2881 zeroes_done = align_size_down(zeroes_done, BytesPerInt); | |
| 2882 rawmem = ClearArrayNode::clear_memory(rawctl, rawmem, rawptr, | |
| 2883 zeroes_done, zeroes_needed, | |
| 2884 phase); | |
| 2885 zeroes_done = zeroes_needed; | |
| 2886 if (zsize > Matcher::init_array_short_size && ++big_init_gaps > 2) | |
| 2887 do_zeroing = false; // leave the hole, next time | |
| 2888 } | |
| 2889 } | |
| 2890 | |
| 2891 // Collect the store and move on: | |
| 2892 st->set_req(MemNode::Memory, inits); | |
| 2893 inits = st; // put it on the linearized chain | |
| 2894 set_req(i, zmem); // unhook from previous position | |
| 2895 | |
| 2896 if (zeroes_done == st_off) | |
| 2897 zeroes_done = next_init_off; | |
| 2898 | |
| 2899 assert(!do_zeroing || zeroes_done >= next_init_off, "don't miss any"); | |
| 2900 | |
| 2901 #ifdef ASSERT | |
| 2902 // Various order invariants. Weaker than stores_are_sane because | |
| 2903 // a large constant tile can be filled in by smaller non-constant stores. | |
| 2904 assert(st_off >= last_init_off, "inits do not reverse"); | |
| 2905 last_init_off = st_off; | |
| 2906 const Type* val = NULL; | |
| 2907 if (st_size >= BytesPerInt && | |
| 2908 (val = phase->type(st->in(MemNode::ValueIn)))->singleton() && | |
| 2909 (int)val->basic_type() < (int)T_OBJECT) { | |
| 2910 assert(st_off >= last_tile_end, "tiles do not overlap"); | |
| 2911 assert(st_off >= last_init_end, "tiles do not overwrite inits"); | |
| 2912 last_tile_end = MAX2(last_tile_end, next_init_off); | |
| 2913 } else { | |
| 2914 intptr_t st_tile_end = align_size_up(next_init_off, BytesPerLong); | |
| 2915 assert(st_tile_end >= last_tile_end, "inits stay with tiles"); | |
| 2916 assert(st_off >= last_init_end, "inits do not overlap"); | |
| 2917 last_init_end = next_init_off; // it's a non-tile | |
| 2918 } | |
| 2919 #endif //ASSERT | |
| 2920 } | |
| 2921 | |
| 2922 remove_extra_zeroes(); // clear out all the zmems left over | |
| 2923 add_req(inits); | |
| 2924 | |
| 2925 if (!ZeroTLAB) { | |
| 2926 // If anything remains to be zeroed, zero it all now. | |
| 2927 zeroes_done = align_size_down(zeroes_done, BytesPerInt); | |
| 2928 // if it is the last unused 4 bytes of an instance, forget about it | |
| 2929 intptr_t size_limit = phase->find_intptr_t_con(size_in_bytes, max_jint); | |
| 2930 if (zeroes_done + BytesPerLong >= size_limit) { | |
| 2931 assert(allocation() != NULL, ""); | |
| 2932 Node* klass_node = allocation()->in(AllocateNode::KlassNode); | |
| 2933 ciKlass* k = phase->type(klass_node)->is_klassptr()->klass(); | |
| 2934 if (zeroes_done == k->layout_helper()) | |
| 2935 zeroes_done = size_limit; | |
| 2936 } | |
| 2937 if (zeroes_done < size_limit) { | |
| 2938 rawmem = ClearArrayNode::clear_memory(rawctl, rawmem, rawptr, | |
| 2939 zeroes_done, size_in_bytes, phase); | |
| 2940 } | |
| 2941 } | |
| 2942 | |
| 2943 set_complete(phase); | |
| 2944 return rawmem; | |
| 2945 } | |
| 2946 | |
| 2947 | |
| 2948 #ifdef ASSERT | |
| 2949 bool InitializeNode::stores_are_sane(PhaseTransform* phase) { | |
| 2950 if (is_complete()) | |
| 2951 return true; // stores could be anything at this point | |
| 2952 intptr_t last_off = sizeof(oopDesc); | |
| 2953 for (uint i = InitializeNode::RawStores; i < req(); i++) { | |
| 2954 Node* st = in(i); | |
| 2955 intptr_t st_off = get_store_offset(st, phase); | |
| 2956 if (st_off < 0) continue; // ignore dead garbage | |
| 2957 if (last_off > st_off) { | |
| 2958 tty->print_cr("*** bad store offset at %d: %d > %d", i, last_off, st_off); | |
| 2959 this->dump(2); | |
| 2960 assert(false, "ascending store offsets"); | |
| 2961 return false; | |
| 2962 } | |
| 2963 last_off = st_off + st->as_Store()->memory_size(); | |
| 2964 } | |
| 2965 return true; | |
| 2966 } | |
| 2967 #endif //ASSERT | |
| 2968 | |
| 2969 | |
| 2970 | |
| 2971 | |
| 2972 //============================MergeMemNode===================================== | |
| 2973 // | |
| 2974 // SEMANTICS OF MEMORY MERGES: A MergeMem is a memory state assembled from several | |
| 2975 // contributing store or call operations. Each contributor provides the memory | |
| 2976 // state for a particular "alias type" (see Compile::alias_type). For example, | |
| 2977 // if a MergeMem has an input X for alias category #6, then any memory reference | |
| 2978 // to alias category #6 may use X as its memory state input, as an exact equivalent | |
| 2979 // to using the MergeMem as a whole. | |
| 2980 // Load<6>( MergeMem(<6>: X, ...), p ) <==> Load<6>(X,p) | |
| 2981 // | |
| 2982 // (Here, the <N> notation gives the index of the relevant adr_type.) | |
| 2983 // | |
| 2984 // In one special case (and more cases in the future), alias categories overlap. | |
| 2985 // The special alias category "Bot" (Compile::AliasIdxBot) includes all memory | |
| 2986 // states. Therefore, if a MergeMem has only one contributing input W for Bot, | |
| 2987 // it is exactly equivalent to that state W: | |
| 2988 // MergeMem(<Bot>: W) <==> W | |
| 2989 // | |
| 2990 // Usually, the merge has more than one input. In that case, where inputs | |
| 2991 // overlap (i.e., one is Bot), the narrower alias type determines the memory | |
| 2992 // state for that type, and the wider alias type (Bot) fills in everywhere else: | |
| 2993 // Load<5>( MergeMem(<Bot>: W, <6>: X), p ) <==> Load<5>(W,p) | |
| 2994 // Load<6>( MergeMem(<Bot>: W, <6>: X), p ) <==> Load<6>(X,p) | |
| 2995 // | |
| 2996 // A merge can take a "wide" memory state as one of its narrow inputs. | |
| 2997 // This simply means that the merge observes out only the relevant parts of | |
| 2998 // the wide input. That is, wide memory states arriving at narrow merge inputs | |
| 2999 // are implicitly "filtered" or "sliced" as necessary. (This is rare.) | |
| 3000 // | |
| 3001 // These rules imply that MergeMem nodes may cascade (via their <Bot> links), | |
| 3002 // and that memory slices "leak through": | |
| 3003 // MergeMem(<Bot>: MergeMem(<Bot>: W, <7>: Y)) <==> MergeMem(<Bot>: W, <7>: Y) | |
| 3004 // | |
| 3005 // But, in such a cascade, repeated memory slices can "block the leak": | |
| 3006 // MergeMem(<Bot>: MergeMem(<Bot>: W, <7>: Y), <7>: Y') <==> MergeMem(<Bot>: W, <7>: Y') | |
| 3007 // | |
| 3008 // In the last example, Y is not part of the combined memory state of the | |
| 3009 // outermost MergeMem. The system must, of course, prevent unschedulable | |
| 3010 // memory states from arising, so you can be sure that the state Y is somehow | |
| 3011 // a precursor to state Y'. | |
| 3012 // | |
| 3013 // | |
| 3014 // REPRESENTATION OF MEMORY MERGES: The indexes used to address the Node::in array | |
| 3015 // of each MergeMemNode array are exactly the numerical alias indexes, including | |
| 3016 // but not limited to AliasIdxTop, AliasIdxBot, and AliasIdxRaw. The functions | |
| 3017 // Compile::alias_type (and kin) produce and manage these indexes. | |
| 3018 // | |
| 3019 // By convention, the value of in(AliasIdxTop) (i.e., in(1)) is always the top node. | |
| 3020 // (Note that this provides quick access to the top node inside MergeMem methods, | |
| 3021 // without the need to reach out via TLS to Compile::current.) | |
| 3022 // | |
| 3023 // As a consequence of what was just described, a MergeMem that represents a full | |
| 3024 // memory state has an edge in(AliasIdxBot) which is a "wide" memory state, | |
| 3025 // containing all alias categories. | |
| 3026 // | |
| 3027 // MergeMem nodes never (?) have control inputs, so in(0) is NULL. | |
| 3028 // | |
| 3029 // All other edges in(N) (including in(AliasIdxRaw), which is in(3)) are either | |
| 3030 // a memory state for the alias type <N>, or else the top node, meaning that | |
| 3031 // there is no particular input for that alias type. Note that the length of | |
| 3032 // a MergeMem is variable, and may be extended at any time to accommodate new | |
| 3033 // memory states at larger alias indexes. When merges grow, they are of course | |
| 3034 // filled with "top" in the unused in() positions. | |
| 3035 // | |
| 3036 // This use of top is named "empty_memory()", or "empty_mem" (no-memory) as a variable. | |
| 3037 // (Top was chosen because it works smoothly with passes like GCM.) | |
| 3038 // | |
| 3039 // For convenience, we hardwire the alias index for TypeRawPtr::BOTTOM. (It is | |
| 3040 // the type of random VM bits like TLS references.) Since it is always the | |
| 3041 // first non-Bot memory slice, some low-level loops use it to initialize an | |
| 3042 // index variable: for (i = AliasIdxRaw; i < req(); i++). | |
| 3043 // | |
| 3044 // | |
| 3045 // ACCESSORS: There is a special accessor MergeMemNode::base_memory which returns | |
| 3046 // the distinguished "wide" state. The accessor MergeMemNode::memory_at(N) returns | |
| 3047 // the memory state for alias type <N>, or (if there is no particular slice at <N>, | |
| 3048 // it returns the base memory. To prevent bugs, memory_at does not accept <Top> | |
| 3049 // or <Bot> indexes. The iterator MergeMemStream provides robust iteration over | |
| 3050 // MergeMem nodes or pairs of such nodes, ensuring that the non-top edges are visited. | |
| 3051 // | |
| 3052 // %%%% We may get rid of base_memory as a separate accessor at some point; it isn't | |
| 3053 // really that different from the other memory inputs. An abbreviation called | |
| 3054 // "bot_memory()" for "memory_at(AliasIdxBot)" would keep code tidy. | |
| 3055 // | |
| 3056 // | |
| 3057 // PARTIAL MEMORY STATES: During optimization, MergeMem nodes may arise that represent | |
| 3058 // partial memory states. When a Phi splits through a MergeMem, the copy of the Phi | |
| 3059 // that "emerges though" the base memory will be marked as excluding the alias types | |
| 3060 // of the other (narrow-memory) copies which "emerged through" the narrow edges: | |
| 3061 // | |
| 3062 // Phi<Bot>(U, MergeMem(<Bot>: W, <8>: Y)) | |
| 3063 // ==Ideal=> MergeMem(<Bot>: Phi<Bot-8>(U, W), Phi<8>(U, Y)) | |
| 3064 // | |
| 3065 // This strange "subtraction" effect is necessary to ensure IGVN convergence. | |
| 3066 // (It is currently unimplemented.) As you can see, the resulting merge is | |
| 3067 // actually a disjoint union of memory states, rather than an overlay. | |
| 3068 // | |
| 3069 | |
| 3070 //------------------------------MergeMemNode----------------------------------- | |
| 3071 Node* MergeMemNode::make_empty_memory() { | |
| 3072 Node* empty_memory = (Node*) Compile::current()->top(); | |
| 3073 assert(empty_memory->is_top(), "correct sentinel identity"); | |
| 3074 return empty_memory; | |
| 3075 } | |
| 3076 | |
| 3077 MergeMemNode::MergeMemNode(Node *new_base) : Node(1+Compile::AliasIdxRaw) { | |
| 3078 init_class_id(Class_MergeMem); | |
| 3079 // all inputs are nullified in Node::Node(int) | |
| 3080 // set_input(0, NULL); // no control input | |
| 3081 | |
| 3082 // Initialize the edges uniformly to top, for starters. | |
| 3083 Node* empty_mem = make_empty_memory(); | |
| 3084 for (uint i = Compile::AliasIdxTop; i < req(); i++) { | |
| 3085 init_req(i,empty_mem); | |
| 3086 } | |
| 3087 assert(empty_memory() == empty_mem, ""); | |
| 3088 | |
| 3089 if( new_base != NULL && new_base->is_MergeMem() ) { | |
| 3090 MergeMemNode* mdef = new_base->as_MergeMem(); | |
| 3091 assert(mdef->empty_memory() == empty_mem, "consistent sentinels"); | |
| 3092 for (MergeMemStream mms(this, mdef); mms.next_non_empty2(); ) { | |
| 3093 mms.set_memory(mms.memory2()); | |
| 3094 } | |
| 3095 assert(base_memory() == mdef->base_memory(), ""); | |
| 3096 } else { | |
| 3097 set_base_memory(new_base); | |
| 3098 } | |
| 3099 } | |
| 3100 | |
| 3101 // Make a new, untransformed MergeMem with the same base as 'mem'. | |
| 3102 // If mem is itself a MergeMem, populate the result with the same edges. | |
| 3103 MergeMemNode* MergeMemNode::make(Compile* C, Node* mem) { | |
| 3104 return new(C, 1+Compile::AliasIdxRaw) MergeMemNode(mem); | |
| 3105 } | |
| 3106 | |
| 3107 //------------------------------cmp-------------------------------------------- | |
| 3108 uint MergeMemNode::hash() const { return NO_HASH; } | |
| 3109 uint MergeMemNode::cmp( const Node &n ) const { | |
| 3110 return (&n == this); // Always fail except on self | |
| 3111 } | |
| 3112 | |
| 3113 //------------------------------Identity--------------------------------------- | |
| 3114 Node* MergeMemNode::Identity(PhaseTransform *phase) { | |
| 3115 // Identity if this merge point does not record any interesting memory | |
| 3116 // disambiguations. | |
| 3117 Node* base_mem = base_memory(); | |
| 3118 Node* empty_mem = empty_memory(); | |
| 3119 if (base_mem != empty_mem) { // Memory path is not dead? | |
| 3120 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3121 Node* mem = in(i); | |
| 3122 if (mem != empty_mem && mem != base_mem) { | |
| 3123 return this; // Many memory splits; no change | |
| 3124 } | |
| 3125 } | |
| 3126 } | |
| 3127 return base_mem; // No memory splits; ID on the one true input | |
| 3128 } | |
| 3129 | |
| 3130 //------------------------------Ideal------------------------------------------ | |
| 3131 // This method is invoked recursively on chains of MergeMem nodes | |
| 3132 Node *MergeMemNode::Ideal(PhaseGVN *phase, bool can_reshape) { | |
| 3133 // Remove chain'd MergeMems | |
| 3134 // | |
| 3135 // This is delicate, because the each "in(i)" (i >= Raw) is interpreted | |
| 3136 // relative to the "in(Bot)". Since we are patching both at the same time, | |
| 3137 // we have to be careful to read each "in(i)" relative to the old "in(Bot)", | |
| 3138 // but rewrite each "in(i)" relative to the new "in(Bot)". | |
| 3139 Node *progress = NULL; | |
| 3140 | |
| 3141 | |
| 3142 Node* old_base = base_memory(); | |
| 3143 Node* empty_mem = empty_memory(); | |
| 3144 if (old_base == empty_mem) | |
| 3145 return NULL; // Dead memory path. | |
| 3146 | |
| 3147 MergeMemNode* old_mbase; | |
| 3148 if (old_base != NULL && old_base->is_MergeMem()) | |
| 3149 old_mbase = old_base->as_MergeMem(); | |
| 3150 else | |
| 3151 old_mbase = NULL; | |
| 3152 Node* new_base = old_base; | |
| 3153 | |
| 3154 // simplify stacked MergeMems in base memory | |
| 3155 if (old_mbase) new_base = old_mbase->base_memory(); | |
| 3156 | |
| 3157 // the base memory might contribute new slices beyond my req() | |
| 3158 if (old_mbase) grow_to_match(old_mbase); | |
| 3159 | |
| 3160 // Look carefully at the base node if it is a phi. | |
| 3161 PhiNode* phi_base; | |
| 3162 if (new_base != NULL && new_base->is_Phi()) | |
| 3163 phi_base = new_base->as_Phi(); | |
| 3164 else | |
| 3165 phi_base = NULL; | |
| 3166 | |
| 3167 Node* phi_reg = NULL; | |
| 3168 uint phi_len = (uint)-1; | |
| 3169 if (phi_base != NULL && !phi_base->is_copy()) { | |
| 3170 // do not examine phi if degraded to a copy | |
| 3171 phi_reg = phi_base->region(); | |
| 3172 phi_len = phi_base->req(); | |
| 3173 // see if the phi is unfinished | |
| 3174 for (uint i = 1; i < phi_len; i++) { | |
| 3175 if (phi_base->in(i) == NULL) { | |
| 3176 // incomplete phi; do not look at it yet! | |
| 3177 phi_reg = NULL; | |
| 3178 phi_len = (uint)-1; | |
| 3179 break; | |
| 3180 } | |
| 3181 } | |
| 3182 } | |
| 3183 | |
| 3184 // Note: We do not call verify_sparse on entry, because inputs | |
| 3185 // can normalize to the base_memory via subsume_node or similar | |
| 3186 // mechanisms. This method repairs that damage. | |
| 3187 | |
| 3188 assert(!old_mbase || old_mbase->is_empty_memory(empty_mem), "consistent sentinels"); | |
| 3189 | |
| 3190 // Look at each slice. | |
| 3191 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3192 Node* old_in = in(i); | |
| 3193 // calculate the old memory value | |
| 3194 Node* old_mem = old_in; | |
| 3195 if (old_mem == empty_mem) old_mem = old_base; | |
| 3196 assert(old_mem == memory_at(i), ""); | |
| 3197 | |
| 3198 // maybe update (reslice) the old memory value | |
| 3199 | |
| 3200 // simplify stacked MergeMems | |
| 3201 Node* new_mem = old_mem; | |
| 3202 MergeMemNode* old_mmem; | |
| 3203 if (old_mem != NULL && old_mem->is_MergeMem()) | |
| 3204 old_mmem = old_mem->as_MergeMem(); | |
| 3205 else | |
| 3206 old_mmem = NULL; | |
| 3207 if (old_mmem == this) { | |
| 3208 // This can happen if loops break up and safepoints disappear. | |
| 3209 // A merge of BotPtr (default) with a RawPtr memory derived from a | |
| 3210 // safepoint can be rewritten to a merge of the same BotPtr with | |
| 3211 // the BotPtr phi coming into the loop. If that phi disappears | |
| 3212 // also, we can end up with a self-loop of the mergemem. | |
| 3213 // In general, if loops degenerate and memory effects disappear, | |
| 3214 // a mergemem can be left looking at itself. This simply means | |
| 3215 // that the mergemem's default should be used, since there is | |
| 3216 // no longer any apparent effect on this slice. | |
| 3217 // Note: If a memory slice is a MergeMem cycle, it is unreachable | |
| 3218 // from start. Update the input to TOP. | |
| 3219 new_mem = (new_base == this || new_base == empty_mem)? empty_mem : new_base; | |
| 3220 } | |
| 3221 else if (old_mmem != NULL) { | |
| 3222 new_mem = old_mmem->memory_at(i); | |
| 3223 } | |
| 3224 // else preceeding memory was not a MergeMem | |
| 3225 | |
| 3226 // replace equivalent phis (unfortunately, they do not GVN together) | |
| 3227 if (new_mem != NULL && new_mem != new_base && | |
| 3228 new_mem->req() == phi_len && new_mem->in(0) == phi_reg) { | |
| 3229 if (new_mem->is_Phi()) { | |
| 3230 PhiNode* phi_mem = new_mem->as_Phi(); | |
| 3231 for (uint i = 1; i < phi_len; i++) { | |
| 3232 if (phi_base->in(i) != phi_mem->in(i)) { | |
| 3233 phi_mem = NULL; | |
| 3234 break; | |
| 3235 } | |
| 3236 } | |
| 3237 if (phi_mem != NULL) { | |
| 3238 // equivalent phi nodes; revert to the def | |
| 3239 new_mem = new_base; | |
| 3240 } | |
| 3241 } | |
| 3242 } | |
| 3243 | |
| 3244 // maybe store down a new value | |
| 3245 Node* new_in = new_mem; | |
| 3246 if (new_in == new_base) new_in = empty_mem; | |
| 3247 | |
| 3248 if (new_in != old_in) { | |
| 3249 // Warning: Do not combine this "if" with the previous "if" | |
| 3250 // A memory slice might have be be rewritten even if it is semantically | |
| 3251 // unchanged, if the base_memory value has changed. | |
| 3252 set_req(i, new_in); | |
| 3253 progress = this; // Report progress | |
| 3254 } | |
| 3255 } | |
| 3256 | |
| 3257 if (new_base != old_base) { | |
| 3258 set_req(Compile::AliasIdxBot, new_base); | |
| 3259 // Don't use set_base_memory(new_base), because we need to update du. | |
| 3260 assert(base_memory() == new_base, ""); | |
| 3261 progress = this; | |
| 3262 } | |
| 3263 | |
| 3264 if( base_memory() == this ) { | |
| 3265 // a self cycle indicates this memory path is dead | |
| 3266 set_req(Compile::AliasIdxBot, empty_mem); | |
| 3267 } | |
| 3268 | |
| 3269 // Resolve external cycles by calling Ideal on a MergeMem base_memory | |
| 3270 // Recursion must occur after the self cycle check above | |
| 3271 if( base_memory()->is_MergeMem() ) { | |
| 3272 MergeMemNode *new_mbase = base_memory()->as_MergeMem(); | |
| 3273 Node *m = phase->transform(new_mbase); // Rollup any cycles | |
| 3274 if( m != NULL && (m->is_top() || | |
| 3275 m->is_MergeMem() && m->as_MergeMem()->base_memory() == empty_mem) ) { | |
| 3276 // propagate rollup of dead cycle to self | |
| 3277 set_req(Compile::AliasIdxBot, empty_mem); | |
| 3278 } | |
| 3279 } | |
| 3280 | |
| 3281 if( base_memory() == empty_mem ) { | |
| 3282 progress = this; | |
| 3283 // Cut inputs during Parse phase only. | |
| 3284 // During Optimize phase a dead MergeMem node will be subsumed by Top. | |
| 3285 if( !can_reshape ) { | |
| 3286 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3287 if( in(i) != empty_mem ) { set_req(i, empty_mem); } | |
| 3288 } | |
| 3289 } | |
| 3290 } | |
| 3291 | |
| 3292 if( !progress && base_memory()->is_Phi() && can_reshape ) { | |
| 3293 // Check if PhiNode::Ideal's "Split phis through memory merges" | |
| 3294 // transform should be attempted. Look for this->phi->this cycle. | |
| 3295 uint merge_width = req(); | |
| 3296 if (merge_width > Compile::AliasIdxRaw) { | |
| 3297 PhiNode* phi = base_memory()->as_Phi(); | |
| 3298 for( uint i = 1; i < phi->req(); ++i ) {// For all paths in | |
| 3299 if (phi->in(i) == this) { | |
| 3300 phase->is_IterGVN()->_worklist.push(phi); | |
| 3301 break; | |
| 3302 } | |
| 3303 } | |
| 3304 } | |
| 3305 } | |
| 3306 | |
|
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|
3307 assert(progress || verify_sparse(), "please, no dups of base"); |
| 0 | 3308 return progress; |
| 3309 } | |
| 3310 | |
| 3311 //-------------------------set_base_memory------------------------------------- | |
| 3312 void MergeMemNode::set_base_memory(Node *new_base) { | |
| 3313 Node* empty_mem = empty_memory(); | |
| 3314 set_req(Compile::AliasIdxBot, new_base); | |
| 3315 assert(memory_at(req()) == new_base, "must set default memory"); | |
| 3316 // Clear out other occurrences of new_base: | |
| 3317 if (new_base != empty_mem) { | |
| 3318 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3319 if (in(i) == new_base) set_req(i, empty_mem); | |
| 3320 } | |
| 3321 } | |
| 3322 } | |
| 3323 | |
| 3324 //------------------------------out_RegMask------------------------------------ | |
| 3325 const RegMask &MergeMemNode::out_RegMask() const { | |
| 3326 return RegMask::Empty; | |
| 3327 } | |
| 3328 | |
| 3329 //------------------------------dump_spec-------------------------------------- | |
| 3330 #ifndef PRODUCT | |
| 3331 void MergeMemNode::dump_spec(outputStream *st) const { | |
| 3332 st->print(" {"); | |
| 3333 Node* base_mem = base_memory(); | |
| 3334 for( uint i = Compile::AliasIdxRaw; i < req(); i++ ) { | |
| 3335 Node* mem = memory_at(i); | |
| 3336 if (mem == base_mem) { st->print(" -"); continue; } | |
| 3337 st->print( " N%d:", mem->_idx ); | |
| 3338 Compile::current()->get_adr_type(i)->dump_on(st); | |
| 3339 } | |
| 3340 st->print(" }"); | |
| 3341 } | |
| 3342 #endif // !PRODUCT | |
| 3343 | |
| 3344 | |
| 3345 #ifdef ASSERT | |
| 3346 static bool might_be_same(Node* a, Node* b) { | |
| 3347 if (a == b) return true; | |
| 3348 if (!(a->is_Phi() || b->is_Phi())) return false; | |
| 3349 // phis shift around during optimization | |
| 3350 return true; // pretty stupid... | |
| 3351 } | |
| 3352 | |
| 3353 // verify a narrow slice (either incoming or outgoing) | |
| 3354 static void verify_memory_slice(const MergeMemNode* m, int alias_idx, Node* n) { | |
| 3355 if (!VerifyAliases) return; // don't bother to verify unless requested | |
| 3356 if (is_error_reported()) return; // muzzle asserts when debugging an error | |
| 3357 if (Node::in_dump()) return; // muzzle asserts when printing | |
| 3358 assert(alias_idx >= Compile::AliasIdxRaw, "must not disturb base_memory or sentinel"); | |
| 3359 assert(n != NULL, ""); | |
| 3360 // Elide intervening MergeMem's | |
| 3361 while (n->is_MergeMem()) { | |
| 3362 n = n->as_MergeMem()->memory_at(alias_idx); | |
| 3363 } | |
| 3364 Compile* C = Compile::current(); | |
| 3365 const TypePtr* n_adr_type = n->adr_type(); | |
| 3366 if (n == m->empty_memory()) { | |
| 3367 // Implicit copy of base_memory() | |
| 3368 } else if (n_adr_type != TypePtr::BOTTOM) { | |
| 3369 assert(n_adr_type != NULL, "new memory must have a well-defined adr_type"); | |
| 3370 assert(C->must_alias(n_adr_type, alias_idx), "new memory must match selected slice"); | |
| 3371 } else { | |
| 3372 // A few places like make_runtime_call "know" that VM calls are narrow, | |
| 3373 // and can be used to update only the VM bits stored as TypeRawPtr::BOTTOM. | |
| 3374 bool expected_wide_mem = false; | |
| 3375 if (n == m->base_memory()) { | |
| 3376 expected_wide_mem = true; | |
| 3377 } else if (alias_idx == Compile::AliasIdxRaw || | |
| 3378 n == m->memory_at(Compile::AliasIdxRaw)) { | |
| 3379 expected_wide_mem = true; | |
| 3380 } else if (!C->alias_type(alias_idx)->is_rewritable()) { | |
| 3381 // memory can "leak through" calls on channels that | |
| 3382 // are write-once. Allow this also. | |
| 3383 expected_wide_mem = true; | |
| 3384 } | |
| 3385 assert(expected_wide_mem, "expected narrow slice replacement"); | |
| 3386 } | |
| 3387 } | |
| 3388 #else // !ASSERT | |
| 3389 #define verify_memory_slice(m,i,n) (0) // PRODUCT version is no-op | |
| 3390 #endif | |
| 3391 | |
| 3392 | |
| 3393 //-----------------------------memory_at--------------------------------------- | |
| 3394 Node* MergeMemNode::memory_at(uint alias_idx) const { | |
| 3395 assert(alias_idx >= Compile::AliasIdxRaw || | |
| 3396 alias_idx == Compile::AliasIdxBot && Compile::current()->AliasLevel() == 0, | |
| 3397 "must avoid base_memory and AliasIdxTop"); | |
| 3398 | |
| 3399 // Otherwise, it is a narrow slice. | |
| 3400 Node* n = alias_idx < req() ? in(alias_idx) : empty_memory(); | |
| 3401 Compile *C = Compile::current(); | |
| 3402 if (is_empty_memory(n)) { | |
| 3403 // the array is sparse; empty slots are the "top" node | |
| 3404 n = base_memory(); | |
| 3405 assert(Node::in_dump() | |
| 3406 || n == NULL || n->bottom_type() == Type::TOP | |
| 3407 || n->adr_type() == TypePtr::BOTTOM | |
| 3408 || n->adr_type() == TypeRawPtr::BOTTOM | |
| 3409 || Compile::current()->AliasLevel() == 0, | |
| 3410 "must be a wide memory"); | |
| 3411 // AliasLevel == 0 if we are organizing the memory states manually. | |
| 3412 // See verify_memory_slice for comments on TypeRawPtr::BOTTOM. | |
| 3413 } else { | |
| 3414 // make sure the stored slice is sane | |
| 3415 #ifdef ASSERT | |
| 3416 if (is_error_reported() || Node::in_dump()) { | |
| 3417 } else if (might_be_same(n, base_memory())) { | |
| 3418 // Give it a pass: It is a mostly harmless repetition of the base. | |
| 3419 // This can arise normally from node subsumption during optimization. | |
| 3420 } else { | |
| 3421 verify_memory_slice(this, alias_idx, n); | |
| 3422 } | |
| 3423 #endif | |
| 3424 } | |
| 3425 return n; | |
| 3426 } | |
| 3427 | |
| 3428 //---------------------------set_memory_at------------------------------------- | |
| 3429 void MergeMemNode::set_memory_at(uint alias_idx, Node *n) { | |
| 3430 verify_memory_slice(this, alias_idx, n); | |
| 3431 Node* empty_mem = empty_memory(); | |
| 3432 if (n == base_memory()) n = empty_mem; // collapse default | |
| 3433 uint need_req = alias_idx+1; | |
| 3434 if (req() < need_req) { | |
| 3435 if (n == empty_mem) return; // already the default, so do not grow me | |
| 3436 // grow the sparse array | |
| 3437 do { | |
| 3438 add_req(empty_mem); | |
| 3439 } while (req() < need_req); | |
| 3440 } | |
| 3441 set_req( alias_idx, n ); | |
| 3442 } | |
| 3443 | |
| 3444 | |
| 3445 | |
| 3446 //--------------------------iteration_setup------------------------------------ | |
| 3447 void MergeMemNode::iteration_setup(const MergeMemNode* other) { | |
| 3448 if (other != NULL) { | |
| 3449 grow_to_match(other); | |
| 3450 // invariant: the finite support of mm2 is within mm->req() | |
| 3451 #ifdef ASSERT | |
| 3452 for (uint i = req(); i < other->req(); i++) { | |
| 3453 assert(other->is_empty_memory(other->in(i)), "slice left uncovered"); | |
| 3454 } | |
| 3455 #endif | |
| 3456 } | |
| 3457 // Replace spurious copies of base_memory by top. | |
| 3458 Node* base_mem = base_memory(); | |
| 3459 if (base_mem != NULL && !base_mem->is_top()) { | |
| 3460 for (uint i = Compile::AliasIdxBot+1, imax = req(); i < imax; i++) { | |
| 3461 if (in(i) == base_mem) | |
| 3462 set_req(i, empty_memory()); | |
| 3463 } | |
| 3464 } | |
| 3465 } | |
| 3466 | |
| 3467 //---------------------------grow_to_match------------------------------------- | |
| 3468 void MergeMemNode::grow_to_match(const MergeMemNode* other) { | |
| 3469 Node* empty_mem = empty_memory(); | |
| 3470 assert(other->is_empty_memory(empty_mem), "consistent sentinels"); | |
| 3471 // look for the finite support of the other memory | |
| 3472 for (uint i = other->req(); --i >= req(); ) { | |
| 3473 if (other->in(i) != empty_mem) { | |
| 3474 uint new_len = i+1; | |
| 3475 while (req() < new_len) add_req(empty_mem); | |
| 3476 break; | |
| 3477 } | |
| 3478 } | |
| 3479 } | |
| 3480 | |
| 3481 //---------------------------verify_sparse------------------------------------- | |
| 3482 #ifndef PRODUCT | |
| 3483 bool MergeMemNode::verify_sparse() const { | |
| 3484 assert(is_empty_memory(make_empty_memory()), "sane sentinel"); | |
| 3485 Node* base_mem = base_memory(); | |
| 3486 // The following can happen in degenerate cases, since empty==top. | |
| 3487 if (is_empty_memory(base_mem)) return true; | |
| 3488 for (uint i = Compile::AliasIdxRaw; i < req(); i++) { | |
| 3489 assert(in(i) != NULL, "sane slice"); | |
| 3490 if (in(i) == base_mem) return false; // should have been the sentinel value! | |
| 3491 } | |
| 3492 return true; | |
| 3493 } | |
| 3494 | |
| 3495 bool MergeMemStream::match_memory(Node* mem, const MergeMemNode* mm, int idx) { | |
| 3496 Node* n; | |
| 3497 n = mm->in(idx); | |
| 3498 if (mem == n) return true; // might be empty_memory() | |
| 3499 n = (idx == Compile::AliasIdxBot)? mm->base_memory(): mm->memory_at(idx); | |
| 3500 if (mem == n) return true; | |
| 3501 while (n->is_Phi() && (n = n->as_Phi()->is_copy()) != NULL) { | |
| 3502 if (mem == n) return true; | |
| 3503 if (n == NULL) break; | |
| 3504 } | |
| 3505 return false; | |
| 3506 } | |
| 3507 #endif // !PRODUCT |