1 /* 2 * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "memory/allocation.inline.hpp" 27 #include "opto/ad.hpp" 28 #include "opto/block.hpp" 29 #include "opto/c2compiler.hpp" 30 #include "opto/callnode.hpp" 31 #include "opto/cfgnode.hpp" 32 #include "opto/machnode.hpp" 33 #include "opto/runtime.hpp" 34 #include "runtime/sharedRuntime.hpp" 35 36 // Optimization - Graph Style 37 38 // Check whether val is not-null-decoded compressed oop, 39 // i.e. will grab into the base of the heap if it represents NULL. 40 static bool accesses_heap_base_zone(Node *val) { 41 if (Universe::narrow_oop_base() > 0) { // Implies UseCompressedOops. 42 if (val && val->is_Mach()) { 43 if (val->as_Mach()->ideal_Opcode() == Op_DecodeN) { 44 // This assumes all Decodes with TypePtr::NotNull are matched to nodes that 45 // decode NULL to point to the heap base (Decode_NN). 46 if (val->bottom_type()->is_oopptr()->ptr() == TypePtr::NotNull) { 47 return true; 48 } 49 } 50 // Must recognize load operation with Decode matched in memory operand. 51 // We should not reach here exept for PPC/AIX, as os::zero_page_read_protected() 52 // returns true everywhere else. On PPC, no such memory operands 53 // exist, therefore we did not yet implement a check for such operands. 54 NOT_AIX(Unimplemented()); 55 } 56 } 57 return false; 58 } 59 60 static bool needs_explicit_null_check_for_read(Node *val) { 61 // On some OSes (AIX) the page at address 0 is only write protected. 62 // If so, only Store operations will trap. 63 if (os::zero_page_read_protected()) { 64 return false; // Implicit null check will work. 65 } 66 // Also a read accessing the base of a heap-based compressed heap will trap. 67 if (accesses_heap_base_zone(val) && // Hits the base zone page. 68 Universe::narrow_oop_use_implicit_null_checks()) { // Base zone page is protected. 69 return false; 70 } 71 72 return true; 73 } 74 75 //------------------------------implicit_null_check---------------------------- 76 // Detect implicit-null-check opportunities. Basically, find NULL checks 77 // with suitable memory ops nearby. Use the memory op to do the NULL check. 78 // I can generate a memory op if there is not one nearby. 79 // The proj is the control projection for the not-null case. 80 // The val is the pointer being checked for nullness or 81 // decodeHeapOop_not_null node if it did not fold into address. 82 void PhaseCFG::implicit_null_check(Block* block, Node *proj, Node *val, int allowed_reasons) { 83 // Assume if null check need for 0 offset then always needed 84 // Intel solaris doesn't support any null checks yet and no 85 // mechanism exists (yet) to set the switches at an os_cpu level 86 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return; 87 88 // Make sure the ptr-is-null path appears to be uncommon! 89 float f = block->end()->as_MachIf()->_prob; 90 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f; 91 if( f > PROB_UNLIKELY_MAG(4) ) return; 92 93 uint bidx = 0; // Capture index of value into memop 94 bool was_store; // Memory op is a store op 95 96 // Get the successor block for if the test ptr is non-null 97 Block* not_null_block; // this one goes with the proj 98 Block* null_block; 99 if (block->get_node(block->number_of_nodes()-1) == proj) { 100 null_block = block->_succs[0]; 101 not_null_block = block->_succs[1]; 102 } else { 103 assert(block->get_node(block->number_of_nodes()-2) == proj, "proj is one or the other"); 104 not_null_block = block->_succs[0]; 105 null_block = block->_succs[1]; 106 } 107 while (null_block->is_Empty() == Block::empty_with_goto) { 108 null_block = null_block->_succs[0]; 109 } 110 111 // Search the exception block for an uncommon trap. 112 // (See Parse::do_if and Parse::do_ifnull for the reason 113 // we need an uncommon trap. Briefly, we need a way to 114 // detect failure of this optimization, as in 6366351.) 115 { 116 bool found_trap = false; 117 for (uint i1 = 0; i1 < null_block->number_of_nodes(); i1++) { 118 Node* nn = null_block->get_node(i1); 119 if (nn->is_MachCall() && 120 nn->as_MachCall()->entry_point() == SharedRuntime::uncommon_trap_blob()->entry_point()) { 121 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type(); 122 if (trtype->isa_int() && trtype->is_int()->is_con()) { 123 jint tr_con = trtype->is_int()->get_con(); 124 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con); 125 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con); 126 assert((int)reason < (int)BitsPerInt, "recode bit map"); 127 if (is_set_nth_bit(allowed_reasons, (int) reason) 128 && action != Deoptimization::Action_none) { 129 // This uncommon trap is sure to recompile, eventually. 130 // When that happens, C->too_many_traps will prevent 131 // this transformation from happening again. 132 found_trap = true; 133 } 134 } 135 break; 136 } 137 } 138 if (!found_trap) { 139 // We did not find an uncommon trap. 140 return; 141 } 142 } 143 144 // Check for decodeHeapOop_not_null node which did not fold into address 145 bool is_decoden = ((intptr_t)val) & 1; 146 val = (Node*)(((intptr_t)val) & ~1); 147 148 assert(!is_decoden || (val->in(0) == NULL) && val->is_Mach() && 149 (val->as_Mach()->ideal_Opcode() == Op_DecodeN), "sanity"); 150 151 // Search the successor block for a load or store who's base value is also 152 // the tested value. There may be several. 153 Node_List *out = new Node_List(Thread::current()->resource_area()); 154 MachNode *best = NULL; // Best found so far 155 for (DUIterator i = val->outs(); val->has_out(i); i++) { 156 Node *m = val->out(i); 157 if( !m->is_Mach() ) continue; 158 MachNode *mach = m->as_Mach(); 159 was_store = false; 160 int iop = mach->ideal_Opcode(); 161 switch( iop ) { 162 case Op_LoadB: 163 case Op_LoadUB: 164 case Op_LoadUS: 165 case Op_LoadD: 166 case Op_LoadF: 167 case Op_LoadI: 168 case Op_LoadL: 169 case Op_LoadP: 170 case Op_LoadN: 171 case Op_LoadS: 172 case Op_LoadKlass: 173 case Op_LoadNKlass: 174 case Op_LoadRange: 175 case Op_LoadD_unaligned: 176 case Op_LoadL_unaligned: 177 assert(mach->in(2) == val, "should be address"); 178 break; 179 case Op_StoreB: 180 case Op_StoreC: 181 case Op_StoreCM: 182 case Op_StoreD: 183 case Op_StoreF: 184 case Op_StoreI: 185 case Op_StoreL: 186 case Op_StoreP: 187 case Op_StoreN: 188 case Op_StoreNKlass: 189 was_store = true; // Memory op is a store op 190 // Stores will have their address in slot 2 (memory in slot 1). 191 // If the value being nul-checked is in another slot, it means we 192 // are storing the checked value, which does NOT check the value! 193 if( mach->in(2) != val ) continue; 194 break; // Found a memory op? 195 case Op_StrComp: 196 case Op_StrEquals: 197 case Op_StrIndexOf: 198 case Op_AryEq: 199 case Op_EncodeISOArray: 200 // Not a legit memory op for implicit null check regardless of 201 // embedded loads 202 continue; 203 default: // Also check for embedded loads 204 if( !mach->needs_anti_dependence_check() ) 205 continue; // Not an memory op; skip it 206 if( must_clone[iop] ) { 207 // Do not move nodes which produce flags because 208 // RA will try to clone it to place near branch and 209 // it will cause recompilation, see clone_node(). 210 continue; 211 } 212 { 213 // Check that value is used in memory address in 214 // instructions with embedded load (CmpP val1,(val2+off)). 215 Node* base; 216 Node* index; 217 const MachOper* oper = mach->memory_inputs(base, index); 218 if (oper == NULL || oper == (MachOper*)-1) { 219 continue; // Not an memory op; skip it 220 } 221 if (val == base || 222 val == index && val->bottom_type()->isa_narrowoop()) { 223 break; // Found it 224 } else { 225 continue; // Skip it 226 } 227 } 228 break; 229 } 230 231 // On some OSes (AIX) the page at address 0 is only write protected. 232 // If so, only Store operations will trap. 233 // But a read accessing the base of a heap-based compressed heap will trap. 234 if (!was_store && needs_explicit_null_check_for_read(val)) { 235 continue; 236 } 237 238 // check if the offset is not too high for implicit exception 239 { 240 intptr_t offset = 0; 241 const TypePtr *adr_type = NULL; // Do not need this return value here 242 const Node* base = mach->get_base_and_disp(offset, adr_type); 243 if (base == NULL || base == NodeSentinel) { 244 // Narrow oop address doesn't have base, only index 245 if( val->bottom_type()->isa_narrowoop() && 246 MacroAssembler::needs_explicit_null_check(offset) ) 247 continue; // Give up if offset is beyond page size 248 // cannot reason about it; is probably not implicit null exception 249 } else { 250 const TypePtr* tptr; 251 if (UseCompressedOops && (Universe::narrow_oop_shift() == 0 || 252 Universe::narrow_klass_shift() == 0)) { 253 // 32-bits narrow oop can be the base of address expressions 254 tptr = base->get_ptr_type(); 255 } else { 256 // only regular oops are expected here 257 tptr = base->bottom_type()->is_ptr(); 258 } 259 // Give up if offset is not a compile-time constant 260 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot ) 261 continue; 262 offset += tptr->_offset; // correct if base is offseted 263 if( MacroAssembler::needs_explicit_null_check(offset) ) 264 continue; // Give up is reference is beyond 4K page size 265 } 266 } 267 268 // Check ctrl input to see if the null-check dominates the memory op 269 Block *cb = get_block_for_node(mach); 270 cb = cb->_idom; // Always hoist at least 1 block 271 if( !was_store ) { // Stores can be hoisted only one block 272 while( cb->_dom_depth > (block->_dom_depth + 1)) 273 cb = cb->_idom; // Hoist loads as far as we want 274 // The non-null-block should dominate the memory op, too. Live 275 // range spilling will insert a spill in the non-null-block if it is 276 // needs to spill the memory op for an implicit null check. 277 if (cb->_dom_depth == (block->_dom_depth + 1)) { 278 if (cb != not_null_block) continue; 279 cb = cb->_idom; 280 } 281 } 282 if( cb != block ) continue; 283 284 // Found a memory user; see if it can be hoisted to check-block 285 uint vidx = 0; // Capture index of value into memop 286 uint j; 287 for( j = mach->req()-1; j > 0; j-- ) { 288 if( mach->in(j) == val ) { 289 vidx = j; 290 // Ignore DecodeN val which could be hoisted to where needed. 291 if( is_decoden ) continue; 292 } 293 // Block of memory-op input 294 Block *inb = get_block_for_node(mach->in(j)); 295 Block *b = block; // Start from nul check 296 while( b != inb && b->_dom_depth > inb->_dom_depth ) 297 b = b->_idom; // search upwards for input 298 // See if input dominates null check 299 if( b != inb ) 300 break; 301 } 302 if( j > 0 ) 303 continue; 304 Block *mb = get_block_for_node(mach); 305 // Hoisting stores requires more checks for the anti-dependence case. 306 // Give up hoisting if we have to move the store past any load. 307 if( was_store ) { 308 Block *b = mb; // Start searching here for a local load 309 // mach use (faulting) trying to hoist 310 // n might be blocker to hoisting 311 while( b != block ) { 312 uint k; 313 for( k = 1; k < b->number_of_nodes(); k++ ) { 314 Node *n = b->get_node(k); 315 if( n->needs_anti_dependence_check() && 316 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) ) 317 break; // Found anti-dependent load 318 } 319 if( k < b->number_of_nodes() ) 320 break; // Found anti-dependent load 321 // Make sure control does not do a merge (would have to check allpaths) 322 if( b->num_preds() != 2 ) break; 323 b = get_block_for_node(b->pred(1)); // Move up to predecessor block 324 } 325 if( b != block ) continue; 326 } 327 328 // Make sure this memory op is not already being used for a NullCheck 329 Node *e = mb->end(); 330 if( e->is_MachNullCheck() && e->in(1) == mach ) 331 continue; // Already being used as a NULL check 332 333 // Found a candidate! Pick one with least dom depth - the highest 334 // in the dom tree should be closest to the null check. 335 if (best == NULL || get_block_for_node(mach)->_dom_depth < get_block_for_node(best)->_dom_depth) { 336 best = mach; 337 bidx = vidx; 338 } 339 } 340 // No candidate! 341 if (best == NULL) { 342 return; 343 } 344 345 // ---- Found an implicit null check 346 extern int implicit_null_checks; 347 implicit_null_checks++; 348 349 if( is_decoden ) { 350 // Check if we need to hoist decodeHeapOop_not_null first. 351 Block *valb = get_block_for_node(val); 352 if( block != valb && block->_dom_depth < valb->_dom_depth ) { 353 // Hoist it up to the end of the test block. 354 valb->find_remove(val); 355 block->add_inst(val); 356 map_node_to_block(val, block); 357 // DecodeN on x86 may kill flags. Check for flag-killing projections 358 // that also need to be hoisted. 359 for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) { 360 Node* n = val->fast_out(j); 361 if( n->is_MachProj() ) { 362 get_block_for_node(n)->find_remove(n); 363 block->add_inst(n); 364 map_node_to_block(n, block); 365 } 366 } 367 } 368 } 369 // Hoist the memory candidate up to the end of the test block. 370 Block *old_block = get_block_for_node(best); 371 old_block->find_remove(best); 372 block->add_inst(best); 373 map_node_to_block(best, block); 374 375 // Move the control dependence 376 if (best->in(0) && best->in(0) == old_block->head()) 377 best->set_req(0, block->head()); 378 379 // Check for flag-killing projections that also need to be hoisted 380 // Should be DU safe because no edge updates. 381 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) { 382 Node* n = best->fast_out(j); 383 if( n->is_MachProj() ) { 384 get_block_for_node(n)->find_remove(n); 385 block->add_inst(n); 386 map_node_to_block(n, block); 387 } 388 } 389 390 // proj==Op_True --> ne test; proj==Op_False --> eq test. 391 // One of two graph shapes got matched: 392 // (IfTrue (If (Bool NE (CmpP ptr NULL)))) 393 // (IfFalse (If (Bool EQ (CmpP ptr NULL)))) 394 // NULL checks are always branch-if-eq. If we see a IfTrue projection 395 // then we are replacing a 'ne' test with a 'eq' NULL check test. 396 // We need to flip the projections to keep the same semantics. 397 if( proj->Opcode() == Op_IfTrue ) { 398 // Swap order of projections in basic block to swap branch targets 399 Node *tmp1 = block->get_node(block->end_idx()+1); 400 Node *tmp2 = block->get_node(block->end_idx()+2); 401 block->map_node(tmp2, block->end_idx()+1); 402 block->map_node(tmp1, block->end_idx()+2); 403 Node *tmp = new Node(C->top()); // Use not NULL input 404 tmp1->replace_by(tmp); 405 tmp2->replace_by(tmp1); 406 tmp->replace_by(tmp2); 407 tmp->destruct(); 408 } 409 410 // Remove the existing null check; use a new implicit null check instead. 411 // Since schedule-local needs precise def-use info, we need to correct 412 // it as well. 413 Node *old_tst = proj->in(0); 414 MachNode *nul_chk = new MachNullCheckNode(old_tst->in(0),best,bidx); 415 block->map_node(nul_chk, block->end_idx()); 416 map_node_to_block(nul_chk, block); 417 // Redirect users of old_test to nul_chk 418 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2) 419 old_tst->last_out(i2)->set_req(0, nul_chk); 420 // Clean-up any dead code 421 for (uint i3 = 0; i3 < old_tst->req(); i3++) { 422 Node* in = old_tst->in(i3); 423 old_tst->set_req(i3, NULL); 424 if (in->outcnt() == 0) { 425 // Remove dead input node 426 in->disconnect_inputs(NULL, C); 427 block->find_remove(in); 428 } 429 } 430 431 latency_from_uses(nul_chk); 432 latency_from_uses(best); 433 } 434 435 436 //------------------------------select----------------------------------------- 437 // Select a nice fellow from the worklist to schedule next. If there is only 438 // one choice, then use it. Projections take top priority for correctness 439 // reasons - if I see a projection, then it is next. There are a number of 440 // other special cases, for instructions that consume condition codes, et al. 441 // These are chosen immediately. Some instructions are required to immediately 442 // precede the last instruction in the block, and these are taken last. Of the 443 // remaining cases (most), choose the instruction with the greatest latency 444 // (that is, the most number of pseudo-cycles required to the end of the 445 // routine). If there is a tie, choose the instruction with the most inputs. 446 Node* PhaseCFG::select(Block* block, Node_List &worklist, GrowableArray<int> &ready_cnt, VectorSet &next_call, uint sched_slot) { 447 448 // If only a single entry on the stack, use it 449 uint cnt = worklist.size(); 450 if (cnt == 1) { 451 Node *n = worklist[0]; 452 worklist.map(0,worklist.pop()); 453 return n; 454 } 455 456 uint choice = 0; // Bigger is most important 457 uint latency = 0; // Bigger is scheduled first 458 uint score = 0; // Bigger is better 459 int idx = -1; // Index in worklist 460 int cand_cnt = 0; // Candidate count 461 462 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist 463 // Order in worklist is used to break ties. 464 // See caller for how this is used to delay scheduling 465 // of induction variable increments to after the other 466 // uses of the phi are scheduled. 467 Node *n = worklist[i]; // Get Node on worklist 468 469 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0; 470 if( n->is_Proj() || // Projections always win 471 n->Opcode()== Op_Con || // So does constant 'Top' 472 iop == Op_CreateEx || // Create-exception must start block 473 iop == Op_CheckCastPP 474 ) { 475 worklist.map(i,worklist.pop()); 476 return n; 477 } 478 479 // Final call in a block must be adjacent to 'catch' 480 Node *e = block->end(); 481 if( e->is_Catch() && e->in(0)->in(0) == n ) 482 continue; 483 484 // Memory op for an implicit null check has to be at the end of the block 485 if( e->is_MachNullCheck() && e->in(1) == n ) 486 continue; 487 488 // Schedule IV increment last. 489 if (e->is_Mach() && e->as_Mach()->ideal_Opcode() == Op_CountedLoopEnd && 490 e->in(1)->in(1) == n && n->is_iteratively_computed()) 491 continue; 492 493 uint n_choice = 2; 494 495 // See if this instruction is consumed by a branch. If so, then (as the 496 // branch is the last instruction in the basic block) force it to the 497 // end of the basic block 498 if ( must_clone[iop] ) { 499 // See if any use is a branch 500 bool found_machif = false; 501 502 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 503 Node* use = n->fast_out(j); 504 505 // The use is a conditional branch, make them adjacent 506 if (use->is_MachIf() && get_block_for_node(use) == block) { 507 found_machif = true; 508 break; 509 } 510 511 // More than this instruction pending for successor to be ready, 512 // don't choose this if other opportunities are ready 513 if (ready_cnt.at(use->_idx) > 1) 514 n_choice = 1; 515 } 516 517 // loop terminated, prefer not to use this instruction 518 if (found_machif) 519 continue; 520 } 521 522 // See if this has a predecessor that is "must_clone", i.e. sets the 523 // condition code. If so, choose this first 524 for (uint j = 0; j < n->req() ; j++) { 525 Node *inn = n->in(j); 526 if (inn) { 527 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) { 528 n_choice = 3; 529 break; 530 } 531 } 532 } 533 534 // MachTemps should be scheduled last so they are near their uses 535 if (n->is_MachTemp()) { 536 n_choice = 1; 537 } 538 539 uint n_latency = get_latency_for_node(n); 540 uint n_score = n->req(); // Many inputs get high score to break ties 541 542 // Keep best latency found 543 cand_cnt++; 544 if (choice < n_choice || 545 (choice == n_choice && 546 ((StressLCM && Compile::randomized_select(cand_cnt)) || 547 (!StressLCM && 548 (latency < n_latency || 549 (latency == n_latency && 550 (score < n_score))))))) { 551 choice = n_choice; 552 latency = n_latency; 553 score = n_score; 554 idx = i; // Also keep index in worklist 555 } 556 } // End of for all ready nodes in worklist 557 558 assert(idx >= 0, "index should be set"); 559 Node *n = worklist[(uint)idx]; // Get the winner 560 561 worklist.map((uint)idx, worklist.pop()); // Compress worklist 562 return n; 563 } 564 565 566 //------------------------------set_next_call---------------------------------- 567 void PhaseCFG::set_next_call(Block* block, Node* n, VectorSet& next_call) { 568 if( next_call.test_set(n->_idx) ) return; 569 for( uint i=0; i<n->len(); i++ ) { 570 Node *m = n->in(i); 571 if( !m ) continue; // must see all nodes in block that precede call 572 if (get_block_for_node(m) == block) { 573 set_next_call(block, m, next_call); 574 } 575 } 576 } 577 578 //------------------------------needed_for_next_call--------------------------- 579 // Set the flag 'next_call' for each Node that is needed for the next call to 580 // be scheduled. This flag lets me bias scheduling so Nodes needed for the 581 // next subroutine call get priority - basically it moves things NOT needed 582 // for the next call till after the call. This prevents me from trying to 583 // carry lots of stuff live across a call. 584 void PhaseCFG::needed_for_next_call(Block* block, Node* this_call, VectorSet& next_call) { 585 // Find the next control-defining Node in this block 586 Node* call = NULL; 587 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) { 588 Node* m = this_call->fast_out(i); 589 if (get_block_for_node(m) == block && // Local-block user 590 m != this_call && // Not self-start node 591 m->is_MachCall()) { 592 call = m; 593 break; 594 } 595 } 596 if (call == NULL) return; // No next call (e.g., block end is near) 597 // Set next-call for all inputs to this call 598 set_next_call(block, call, next_call); 599 } 600 601 //------------------------------add_call_kills------------------------------------- 602 // helper function that adds caller save registers to MachProjNode 603 static void add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe) { 604 // Fill in the kill mask for the call 605 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) { 606 if( !regs.Member(r) ) { // Not already defined by the call 607 // Save-on-call register? 608 if ((save_policy[r] == 'C') || 609 (save_policy[r] == 'A') || 610 ((save_policy[r] == 'E') && exclude_soe)) { 611 proj->_rout.Insert(r); 612 } 613 } 614 } 615 } 616 617 618 //------------------------------sched_call------------------------------------- 619 uint PhaseCFG::sched_call(Block* block, uint node_cnt, Node_List& worklist, GrowableArray<int>& ready_cnt, MachCallNode* mcall, VectorSet& next_call) { 620 RegMask regs; 621 622 // Schedule all the users of the call right now. All the users are 623 // projection Nodes, so they must be scheduled next to the call. 624 // Collect all the defined registers. 625 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) { 626 Node* n = mcall->fast_out(i); 627 assert( n->is_MachProj(), "" ); 628 int n_cnt = ready_cnt.at(n->_idx)-1; 629 ready_cnt.at_put(n->_idx, n_cnt); 630 assert( n_cnt == 0, "" ); 631 // Schedule next to call 632 block->map_node(n, node_cnt++); 633 // Collect defined registers 634 regs.OR(n->out_RegMask()); 635 // Check for scheduling the next control-definer 636 if( n->bottom_type() == Type::CONTROL ) 637 // Warm up next pile of heuristic bits 638 needed_for_next_call(block, n, next_call); 639 640 // Children of projections are now all ready 641 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 642 Node* m = n->fast_out(j); // Get user 643 if(get_block_for_node(m) != block) { 644 continue; 645 } 646 if( m->is_Phi() ) continue; 647 int m_cnt = ready_cnt.at(m->_idx)-1; 648 ready_cnt.at_put(m->_idx, m_cnt); 649 if( m_cnt == 0 ) 650 worklist.push(m); 651 } 652 653 } 654 655 // Act as if the call defines the Frame Pointer. 656 // Certainly the FP is alive and well after the call. 657 regs.Insert(_matcher.c_frame_pointer()); 658 659 // Set all registers killed and not already defined by the call. 660 uint r_cnt = mcall->tf()->range()->cnt(); 661 int op = mcall->ideal_Opcode(); 662 MachProjNode *proj = new MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj ); 663 map_node_to_block(proj, block); 664 block->insert_node(proj, node_cnt++); 665 666 // Select the right register save policy. 667 const char * save_policy; 668 switch (op) { 669 case Op_CallRuntime: 670 case Op_CallLeaf: 671 case Op_CallLeafNoFP: 672 // Calling C code so use C calling convention 673 save_policy = _matcher._c_reg_save_policy; 674 break; 675 676 case Op_CallStaticJava: 677 case Op_CallDynamicJava: 678 // Calling Java code so use Java calling convention 679 save_policy = _matcher._register_save_policy; 680 break; 681 682 default: 683 ShouldNotReachHere(); 684 } 685 686 // When using CallRuntime mark SOE registers as killed by the call 687 // so values that could show up in the RegisterMap aren't live in a 688 // callee saved register since the register wouldn't know where to 689 // find them. CallLeaf and CallLeafNoFP are ok because they can't 690 // have debug info on them. Strictly speaking this only needs to be 691 // done for oops since idealreg2debugmask takes care of debug info 692 // references but there no way to handle oops differently than other 693 // pointers as far as the kill mask goes. 694 bool exclude_soe = op == Op_CallRuntime; 695 696 // If the call is a MethodHandle invoke, we need to exclude the 697 // register which is used to save the SP value over MH invokes from 698 // the mask. Otherwise this register could be used for 699 // deoptimization information. 700 if (op == Op_CallStaticJava) { 701 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall; 702 if (mcallstaticjava->_method_handle_invoke) 703 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask()); 704 } 705 706 add_call_kills(proj, regs, save_policy, exclude_soe); 707 708 return node_cnt; 709 } 710 711 712 //------------------------------schedule_local--------------------------------- 713 // Topological sort within a block. Someday become a real scheduler. 714 bool PhaseCFG::schedule_local(Block* block, GrowableArray<int>& ready_cnt, VectorSet& next_call) { 715 // Already "sorted" are the block start Node (as the first entry), and 716 // the block-ending Node and any trailing control projections. We leave 717 // these alone. PhiNodes and ParmNodes are made to follow the block start 718 // Node. Everything else gets topo-sorted. 719 720 #ifndef PRODUCT 721 if (trace_opto_pipelining()) { 722 tty->print_cr("# --- schedule_local B%d, before: ---", block->_pre_order); 723 for (uint i = 0;i < block->number_of_nodes(); i++) { 724 tty->print("# "); 725 block->get_node(i)->fast_dump(); 726 } 727 tty->print_cr("#"); 728 } 729 #endif 730 731 // RootNode is already sorted 732 if (block->number_of_nodes() == 1) { 733 return true; 734 } 735 736 // Move PhiNodes and ParmNodes from 1 to cnt up to the start 737 uint node_cnt = block->end_idx(); 738 uint phi_cnt = 1; 739 uint i; 740 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi 741 Node *n = block->get_node(i); 742 if( n->is_Phi() || // Found a PhiNode or ParmNode 743 (n->is_Proj() && n->in(0) == block->head()) ) { 744 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt 745 block->map_node(block->get_node(phi_cnt), i); 746 block->map_node(n, phi_cnt++); // swap Phi/Parm up front 747 } else { // All others 748 // Count block-local inputs to 'n' 749 uint cnt = n->len(); // Input count 750 uint local = 0; 751 for( uint j=0; j<cnt; j++ ) { 752 Node *m = n->in(j); 753 if( m && get_block_for_node(m) == block && !m->is_top() ) 754 local++; // One more block-local input 755 } 756 ready_cnt.at_put(n->_idx, local); // Count em up 757 758 #ifdef ASSERT 759 if( UseConcMarkSweepGC || UseG1GC ) { 760 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) { 761 // Check the precedence edges 762 for (uint prec = n->req(); prec < n->len(); prec++) { 763 Node* oop_store = n->in(prec); 764 if (oop_store != NULL) { 765 assert(get_block_for_node(oop_store)->_dom_depth <= block->_dom_depth, "oop_store must dominate card-mark"); 766 } 767 } 768 } 769 } 770 #endif 771 772 // A few node types require changing a required edge to a precedence edge 773 // before allocation. 774 if( n->is_Mach() && n->req() > TypeFunc::Parms && 775 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire || 776 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) { 777 // MemBarAcquire could be created without Precedent edge. 778 // del_req() replaces the specified edge with the last input edge 779 // and then removes the last edge. If the specified edge > number of 780 // edges the last edge will be moved outside of the input edges array 781 // and the edge will be lost. This is why this code should be 782 // executed only when Precedent (== TypeFunc::Parms) edge is present. 783 Node *x = n->in(TypeFunc::Parms); 784 n->del_req(TypeFunc::Parms); 785 n->add_prec(x); 786 } 787 } 788 } 789 for(uint i2=i; i2< block->number_of_nodes(); i2++ ) // Trailing guys get zapped count 790 ready_cnt.at_put(block->get_node(i2)->_idx, 0); 791 792 // All the prescheduled guys do not hold back internal nodes 793 uint i3; 794 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled 795 Node *n = block->get_node(i3); // Get pre-scheduled 796 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 797 Node* m = n->fast_out(j); 798 if (get_block_for_node(m) == block) { // Local-block user 799 int m_cnt = ready_cnt.at(m->_idx)-1; 800 ready_cnt.at_put(m->_idx, m_cnt); // Fix ready count 801 } 802 } 803 } 804 805 Node_List delay; 806 // Make a worklist 807 Node_List worklist; 808 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist 809 Node *m = block->get_node(i4); 810 if( !ready_cnt.at(m->_idx) ) { // Zero ready count? 811 if (m->is_iteratively_computed()) { 812 // Push induction variable increments last to allow other uses 813 // of the phi to be scheduled first. The select() method breaks 814 // ties in scheduling by worklist order. 815 delay.push(m); 816 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) { 817 // Force the CreateEx to the top of the list so it's processed 818 // first and ends up at the start of the block. 819 worklist.insert(0, m); 820 } else { 821 worklist.push(m); // Then on to worklist! 822 } 823 } 824 } 825 while (delay.size()) { 826 Node* d = delay.pop(); 827 worklist.push(d); 828 } 829 830 // Warm up the 'next_call' heuristic bits 831 needed_for_next_call(block, block->head(), next_call); 832 833 #ifndef PRODUCT 834 if (trace_opto_pipelining()) { 835 for (uint j=0; j< block->number_of_nodes(); j++) { 836 Node *n = block->get_node(j); 837 int idx = n->_idx; 838 tty->print("# ready cnt:%3d ", ready_cnt.at(idx)); 839 tty->print("latency:%3d ", get_latency_for_node(n)); 840 tty->print("%4d: %s\n", idx, n->Name()); 841 } 842 } 843 #endif 844 845 uint max_idx = (uint)ready_cnt.length(); 846 // Pull from worklist and schedule 847 while( worklist.size() ) { // Worklist is not ready 848 849 #ifndef PRODUCT 850 if (trace_opto_pipelining()) { 851 tty->print("# ready list:"); 852 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 853 Node *n = worklist[i]; // Get Node on worklist 854 tty->print(" %d", n->_idx); 855 } 856 tty->cr(); 857 } 858 #endif 859 860 // Select and pop a ready guy from worklist 861 Node* n = select(block, worklist, ready_cnt, next_call, phi_cnt); 862 block->map_node(n, phi_cnt++); // Schedule him next 863 864 #ifndef PRODUCT 865 if (trace_opto_pipelining()) { 866 tty->print("# select %d: %s", n->_idx, n->Name()); 867 tty->print(", latency:%d", get_latency_for_node(n)); 868 n->dump(); 869 if (Verbose) { 870 tty->print("# ready list:"); 871 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 872 Node *n = worklist[i]; // Get Node on worklist 873 tty->print(" %d", n->_idx); 874 } 875 tty->cr(); 876 } 877 } 878 879 #endif 880 if( n->is_MachCall() ) { 881 MachCallNode *mcall = n->as_MachCall(); 882 phi_cnt = sched_call(block, phi_cnt, worklist, ready_cnt, mcall, next_call); 883 continue; 884 } 885 886 if (n->is_Mach() && n->as_Mach()->has_call()) { 887 RegMask regs; 888 regs.Insert(_matcher.c_frame_pointer()); 889 regs.OR(n->out_RegMask()); 890 891 MachProjNode *proj = new MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj ); 892 map_node_to_block(proj, block); 893 block->insert_node(proj, phi_cnt++); 894 895 add_call_kills(proj, regs, _matcher._c_reg_save_policy, false); 896 } 897 898 // Children are now all ready 899 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) { 900 Node* m = n->fast_out(i5); // Get user 901 if (get_block_for_node(m) != block) { 902 continue; 903 } 904 if( m->is_Phi() ) continue; 905 if (m->_idx >= max_idx) { // new node, skip it 906 assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types"); 907 continue; 908 } 909 int m_cnt = ready_cnt.at(m->_idx)-1; 910 ready_cnt.at_put(m->_idx, m_cnt); 911 if( m_cnt == 0 ) 912 worklist.push(m); 913 } 914 } 915 916 if( phi_cnt != block->end_idx() ) { 917 // did not schedule all. Retry, Bailout, or Die 918 if (C->subsume_loads() == true && !C->failing()) { 919 // Retry with subsume_loads == false 920 // If this is the first failure, the sentinel string will "stick" 921 // to the Compile object, and the C2Compiler will see it and retry. 922 C->record_failure(C2Compiler::retry_no_subsuming_loads()); 923 } 924 // assert( phi_cnt == end_idx(), "did not schedule all" ); 925 return false; 926 } 927 928 #ifndef PRODUCT 929 if (trace_opto_pipelining()) { 930 tty->print_cr("#"); 931 tty->print_cr("# after schedule_local"); 932 for (uint i = 0;i < block->number_of_nodes();i++) { 933 tty->print("# "); 934 block->get_node(i)->fast_dump(); 935 } 936 tty->cr(); 937 } 938 #endif 939 940 941 return true; 942 } 943 944 //--------------------------catch_cleanup_fix_all_inputs----------------------- 945 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) { 946 for (uint l = 0; l < use->len(); l++) { 947 if (use->in(l) == old_def) { 948 if (l < use->req()) { 949 use->set_req(l, new_def); 950 } else { 951 use->rm_prec(l); 952 use->add_prec(new_def); 953 l--; 954 } 955 } 956 } 957 } 958 959 //------------------------------catch_cleanup_find_cloned_def------------------ 960 Node* PhaseCFG::catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, int n_clone_idx) { 961 assert( use_blk != def_blk, "Inter-block cleanup only"); 962 963 // The use is some block below the Catch. Find and return the clone of the def 964 // that dominates the use. If there is no clone in a dominating block, then 965 // create a phi for the def in a dominating block. 966 967 // Find which successor block dominates this use. The successor 968 // blocks must all be single-entry (from the Catch only; I will have 969 // split blocks to make this so), hence they all dominate. 970 while( use_blk->_dom_depth > def_blk->_dom_depth+1 ) 971 use_blk = use_blk->_idom; 972 973 // Find the successor 974 Node *fixup = NULL; 975 976 uint j; 977 for( j = 0; j < def_blk->_num_succs; j++ ) 978 if( use_blk == def_blk->_succs[j] ) 979 break; 980 981 if( j == def_blk->_num_succs ) { 982 // Block at same level in dom-tree is not a successor. It needs a 983 // PhiNode, the PhiNode uses from the def and IT's uses need fixup. 984 Node_Array inputs = new Node_List(Thread::current()->resource_area()); 985 for(uint k = 1; k < use_blk->num_preds(); k++) { 986 Block* block = get_block_for_node(use_blk->pred(k)); 987 inputs.map(k, catch_cleanup_find_cloned_def(block, def, def_blk, n_clone_idx)); 988 } 989 990 // Check to see if the use_blk already has an identical phi inserted. 991 // If it exists, it will be at the first position since all uses of a 992 // def are processed together. 993 Node *phi = use_blk->get_node(1); 994 if( phi->is_Phi() ) { 995 fixup = phi; 996 for (uint k = 1; k < use_blk->num_preds(); k++) { 997 if (phi->in(k) != inputs[k]) { 998 // Not a match 999 fixup = NULL; 1000 break; 1001 } 1002 } 1003 } 1004 1005 // If an existing PhiNode was not found, make a new one. 1006 if (fixup == NULL) { 1007 Node *new_phi = PhiNode::make(use_blk->head(), def); 1008 use_blk->insert_node(new_phi, 1); 1009 map_node_to_block(new_phi, use_blk); 1010 for (uint k = 1; k < use_blk->num_preds(); k++) { 1011 new_phi->set_req(k, inputs[k]); 1012 } 1013 fixup = new_phi; 1014 } 1015 1016 } else { 1017 // Found the use just below the Catch. Make it use the clone. 1018 fixup = use_blk->get_node(n_clone_idx); 1019 } 1020 1021 return fixup; 1022 } 1023 1024 //--------------------------catch_cleanup_intra_block-------------------------- 1025 // Fix all input edges in use that reference "def". The use is in the same 1026 // block as the def and both have been cloned in each successor block. 1027 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) { 1028 1029 // Both the use and def have been cloned. For each successor block, 1030 // get the clone of the use, and make its input the clone of the def 1031 // found in that block. 1032 1033 uint use_idx = blk->find_node(use); 1034 uint offset_idx = use_idx - beg; 1035 for( uint k = 0; k < blk->_num_succs; k++ ) { 1036 // Get clone in each successor block 1037 Block *sb = blk->_succs[k]; 1038 Node *clone = sb->get_node(offset_idx+1); 1039 assert( clone->Opcode() == use->Opcode(), "" ); 1040 1041 // Make use-clone reference the def-clone 1042 catch_cleanup_fix_all_inputs(clone, def, sb->get_node(n_clone_idx)); 1043 } 1044 } 1045 1046 //------------------------------catch_cleanup_inter_block--------------------- 1047 // Fix all input edges in use that reference "def". The use is in a different 1048 // block than the def. 1049 void PhaseCFG::catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, int n_clone_idx) { 1050 if( !use_blk ) return; // Can happen if the use is a precedence edge 1051 1052 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, n_clone_idx); 1053 catch_cleanup_fix_all_inputs(use, def, new_def); 1054 } 1055 1056 //------------------------------call_catch_cleanup----------------------------- 1057 // If we inserted any instructions between a Call and his CatchNode, 1058 // clone the instructions on all paths below the Catch. 1059 void PhaseCFG::call_catch_cleanup(Block* block) { 1060 1061 // End of region to clone 1062 uint end = block->end_idx(); 1063 if( !block->get_node(end)->is_Catch() ) return; 1064 // Start of region to clone 1065 uint beg = end; 1066 while(!block->get_node(beg-1)->is_MachProj() || 1067 !block->get_node(beg-1)->in(0)->is_MachCall() ) { 1068 beg--; 1069 assert(beg > 0,"Catch cleanup walking beyond block boundary"); 1070 } 1071 // Range of inserted instructions is [beg, end) 1072 if( beg == end ) return; 1073 1074 // Clone along all Catch output paths. Clone area between the 'beg' and 1075 // 'end' indices. 1076 for( uint i = 0; i < block->_num_succs; i++ ) { 1077 Block *sb = block->_succs[i]; 1078 // Clone the entire area; ignoring the edge fixup for now. 1079 for( uint j = end; j > beg; j-- ) { 1080 // It is safe here to clone a node with anti_dependence 1081 // since clones dominate on each path. 1082 Node *clone = block->get_node(j-1)->clone(); 1083 sb->insert_node(clone, 1); 1084 map_node_to_block(clone, sb); 1085 } 1086 } 1087 1088 1089 // Fixup edges. Check the def-use info per cloned Node 1090 for(uint i2 = beg; i2 < end; i2++ ) { 1091 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block 1092 Node *n = block->get_node(i2); // Node that got cloned 1093 // Need DU safe iterator because of edge manipulation in calls. 1094 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area()); 1095 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) { 1096 out->push(n->fast_out(j1)); 1097 } 1098 uint max = out->size(); 1099 for (uint j = 0; j < max; j++) {// For all users 1100 Node *use = out->pop(); 1101 Block *buse = get_block_for_node(use); 1102 if( use->is_Phi() ) { 1103 for( uint k = 1; k < use->req(); k++ ) 1104 if( use->in(k) == n ) { 1105 Block* b = get_block_for_node(buse->pred(k)); 1106 Node *fixup = catch_cleanup_find_cloned_def(b, n, block, n_clone_idx); 1107 use->set_req(k, fixup); 1108 } 1109 } else { 1110 if (block == buse) { 1111 catch_cleanup_intra_block(use, n, block, beg, n_clone_idx); 1112 } else { 1113 catch_cleanup_inter_block(use, buse, n, block, n_clone_idx); 1114 } 1115 } 1116 } // End for all users 1117 1118 } // End of for all Nodes in cloned area 1119 1120 // Remove the now-dead cloned ops 1121 for(uint i3 = beg; i3 < end; i3++ ) { 1122 block->get_node(beg)->disconnect_inputs(NULL, C); 1123 block->remove_node(beg); 1124 } 1125 1126 // If the successor blocks have a CreateEx node, move it back to the top 1127 for(uint i4 = 0; i4 < block->_num_succs; i4++ ) { 1128 Block *sb = block->_succs[i4]; 1129 uint new_cnt = end - beg; 1130 // Remove any newly created, but dead, nodes. 1131 for( uint j = new_cnt; j > 0; j-- ) { 1132 Node *n = sb->get_node(j); 1133 if (n->outcnt() == 0 && 1134 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){ 1135 n->disconnect_inputs(NULL, C); 1136 sb->remove_node(j); 1137 new_cnt--; 1138 } 1139 } 1140 // If any newly created nodes remain, move the CreateEx node to the top 1141 if (new_cnt > 0) { 1142 Node *cex = sb->get_node(1+new_cnt); 1143 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) { 1144 sb->remove_node(1+new_cnt); 1145 sb->insert_node(cex, 1); 1146 } 1147 } 1148 } 1149 }