1 /* 2 * Copyright (c) 1998, 2012, 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/block.hpp" 28 #include "opto/c2compiler.hpp" 29 #include "opto/callnode.hpp" 30 #include "opto/cfgnode.hpp" 31 #include "opto/machnode.hpp" 32 #include "opto/runtime.hpp" 33 #ifdef TARGET_ARCH_MODEL_x86_32 34 # include "adfiles/ad_x86_32.hpp" 35 #endif 36 #ifdef TARGET_ARCH_MODEL_x86_64 37 # include "adfiles/ad_x86_64.hpp" 38 #endif 39 #ifdef TARGET_ARCH_MODEL_sparc 40 # include "adfiles/ad_sparc.hpp" 41 #endif 42 #ifdef TARGET_ARCH_MODEL_zero 43 # include "adfiles/ad_zero.hpp" 44 #endif 45 #ifdef TARGET_ARCH_MODEL_arm 46 # include "adfiles/ad_arm.hpp" 47 #endif 48 #ifdef TARGET_ARCH_MODEL_ppc 49 # include "adfiles/ad_ppc.hpp" 50 #endif 51 52 // Optimization - Graph Style 53 54 //------------------------------implicit_null_check---------------------------- 55 // Detect implicit-null-check opportunities. Basically, find NULL checks 56 // with suitable memory ops nearby. Use the memory op to do the NULL check. 57 // I can generate a memory op if there is not one nearby. 58 // The proj is the control projection for the not-null case. 59 // The val is the pointer being checked for nullness or 60 // decodeHeapOop_not_null node if it did not fold into address. 61 void Block::implicit_null_check(PhaseCFG *cfg, Node *proj, Node *val, int allowed_reasons) { 62 // Assume if null check need for 0 offset then always needed 63 // Intel solaris doesn't support any null checks yet and no 64 // mechanism exists (yet) to set the switches at an os_cpu level 65 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return; 66 67 // Make sure the ptr-is-null path appears to be uncommon! 68 float f = end()->as_MachIf()->_prob; 69 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f; 70 if( f > PROB_UNLIKELY_MAG(4) ) return; 71 72 uint bidx = 0; // Capture index of value into memop 73 bool was_store; // Memory op is a store op 74 75 // Get the successor block for if the test ptr is non-null 76 Block* not_null_block; // this one goes with the proj 77 Block* null_block; 78 if (_nodes[_nodes.size()-1] == proj) { 79 null_block = _succs[0]; 80 not_null_block = _succs[1]; 81 } else { 82 assert(_nodes[_nodes.size()-2] == proj, "proj is one or the other"); 83 not_null_block = _succs[0]; 84 null_block = _succs[1]; 85 } 86 while (null_block->is_Empty() == Block::empty_with_goto) { 87 null_block = null_block->_succs[0]; 88 } 89 90 // Search the exception block for an uncommon trap. 91 // (See Parse::do_if and Parse::do_ifnull for the reason 92 // we need an uncommon trap. Briefly, we need a way to 93 // detect failure of this optimization, as in 6366351.) 94 { 95 bool found_trap = false; 96 for (uint i1 = 0; i1 < null_block->_nodes.size(); i1++) { 97 Node* nn = null_block->_nodes[i1]; 98 if (nn->is_MachCall() && 99 nn->as_MachCall()->entry_point() == SharedRuntime::uncommon_trap_blob()->entry_point()) { 100 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type(); 101 if (trtype->isa_int() && trtype->is_int()->is_con()) { 102 jint tr_con = trtype->is_int()->get_con(); 103 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con); 104 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con); 105 assert((int)reason < (int)BitsPerInt, "recode bit map"); 106 if (is_set_nth_bit(allowed_reasons, (int) reason) 107 && action != Deoptimization::Action_none) { 108 // This uncommon trap is sure to recompile, eventually. 109 // When that happens, C->too_many_traps will prevent 110 // this transformation from happening again. 111 found_trap = true; 112 } 113 } 114 break; 115 } 116 } 117 if (!found_trap) { 118 // We did not find an uncommon trap. 119 return; 120 } 121 } 122 123 // Check for decodeHeapOop_not_null node which did not fold into address 124 bool is_decoden = ((intptr_t)val) & 1; 125 val = (Node*)(((intptr_t)val) & ~1); 126 127 assert(!is_decoden || (val->in(0) == NULL) && val->is_Mach() && 128 (val->as_Mach()->ideal_Opcode() == Op_DecodeN), "sanity"); 129 130 // Search the successor block for a load or store who's base value is also 131 // the tested value. There may be several. 132 Node_List *out = new Node_List(Thread::current()->resource_area()); 133 MachNode *best = NULL; // Best found so far 134 for (DUIterator i = val->outs(); val->has_out(i); i++) { 135 Node *m = val->out(i); 136 if( !m->is_Mach() ) continue; 137 MachNode *mach = m->as_Mach(); 138 was_store = false; 139 int iop = mach->ideal_Opcode(); 140 switch( iop ) { 141 case Op_LoadB: 142 case Op_LoadUB: 143 case Op_LoadUS: 144 case Op_LoadD: 145 case Op_LoadF: 146 case Op_LoadI: 147 case Op_LoadL: 148 case Op_LoadP: 149 case Op_LoadN: 150 case Op_LoadS: 151 case Op_LoadKlass: 152 case Op_LoadNKlass: 153 case Op_LoadRange: 154 case Op_LoadD_unaligned: 155 case Op_LoadL_unaligned: 156 assert(mach->in(2) == val, "should be address"); 157 break; 158 case Op_StoreB: 159 case Op_StoreC: 160 case Op_StoreCM: 161 case Op_StoreD: 162 case Op_StoreF: 163 case Op_StoreI: 164 case Op_StoreL: 165 case Op_StoreP: 166 case Op_StoreN: 167 case Op_StoreNKlass: 168 was_store = true; // Memory op is a store op 169 // Stores will have their address in slot 2 (memory in slot 1). 170 // If the value being nul-checked is in another slot, it means we 171 // are storing the checked value, which does NOT check the value! 172 if( mach->in(2) != val ) continue; 173 break; // Found a memory op? 174 case Op_StrComp: 175 case Op_StrEquals: 176 case Op_StrIndexOf: 177 case Op_AryEq: 178 case Op_EncodeISOArray: 179 // Not a legit memory op for implicit null check regardless of 180 // embedded loads 181 continue; 182 default: // Also check for embedded loads 183 if( !mach->needs_anti_dependence_check() ) 184 continue; // Not an memory op; skip it 185 if( must_clone[iop] ) { 186 // Do not move nodes which produce flags because 187 // RA will try to clone it to place near branch and 188 // it will cause recompilation, see clone_node(). 189 continue; 190 } 191 { 192 // Check that value is used in memory address in 193 // instructions with embedded load (CmpP val1,(val2+off)). 194 Node* base; 195 Node* index; 196 const MachOper* oper = mach->memory_inputs(base, index); 197 if (oper == NULL || oper == (MachOper*)-1) { 198 continue; // Not an memory op; skip it 199 } 200 if (val == base || 201 val == index && val->bottom_type()->isa_narrowoop()) { 202 break; // Found it 203 } else { 204 continue; // Skip it 205 } 206 } 207 break; 208 } 209 // check if the offset is not too high for implicit exception 210 { 211 intptr_t offset = 0; 212 const TypePtr *adr_type = NULL; // Do not need this return value here 213 const Node* base = mach->get_base_and_disp(offset, adr_type); 214 if (base == NULL || base == NodeSentinel) { 215 // Narrow oop address doesn't have base, only index 216 if( val->bottom_type()->isa_narrowoop() && 217 MacroAssembler::needs_explicit_null_check(offset) ) 218 continue; // Give up if offset is beyond page size 219 // cannot reason about it; is probably not implicit null exception 220 } else { 221 const TypePtr* tptr; 222 if (UseCompressedOops && (Universe::narrow_oop_shift() == 0 || 223 Universe::narrow_klass_shift() == 0)) { 224 // 32-bits narrow oop can be the base of address expressions 225 tptr = base->get_ptr_type(); 226 } else { 227 // only regular oops are expected here 228 tptr = base->bottom_type()->is_ptr(); 229 } 230 // Give up if offset is not a compile-time constant 231 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot ) 232 continue; 233 offset += tptr->_offset; // correct if base is offseted 234 if( MacroAssembler::needs_explicit_null_check(offset) ) 235 continue; // Give up is reference is beyond 4K page size 236 } 237 } 238 239 // Check ctrl input to see if the null-check dominates the memory op 240 Block *cb = cfg->_bbs[mach->_idx]; 241 cb = cb->_idom; // Always hoist at least 1 block 242 if( !was_store ) { // Stores can be hoisted only one block 243 while( cb->_dom_depth > (_dom_depth + 1)) 244 cb = cb->_idom; // Hoist loads as far as we want 245 // The non-null-block should dominate the memory op, too. Live 246 // range spilling will insert a spill in the non-null-block if it is 247 // needs to spill the memory op for an implicit null check. 248 if (cb->_dom_depth == (_dom_depth + 1)) { 249 if (cb != not_null_block) continue; 250 cb = cb->_idom; 251 } 252 } 253 if( cb != this ) continue; 254 255 // Found a memory user; see if it can be hoisted to check-block 256 uint vidx = 0; // Capture index of value into memop 257 uint j; 258 for( j = mach->req()-1; j > 0; j-- ) { 259 if( mach->in(j) == val ) { 260 vidx = j; 261 // Ignore DecodeN val which could be hoisted to where needed. 262 if( is_decoden ) continue; 263 } 264 // Block of memory-op input 265 Block *inb = cfg->_bbs[mach->in(j)->_idx]; 266 Block *b = this; // Start from nul check 267 while( b != inb && b->_dom_depth > inb->_dom_depth ) 268 b = b->_idom; // search upwards for input 269 // See if input dominates null check 270 if( b != inb ) 271 break; 272 } 273 if( j > 0 ) 274 continue; 275 Block *mb = cfg->_bbs[mach->_idx]; 276 // Hoisting stores requires more checks for the anti-dependence case. 277 // Give up hoisting if we have to move the store past any load. 278 if( was_store ) { 279 Block *b = mb; // Start searching here for a local load 280 // mach use (faulting) trying to hoist 281 // n might be blocker to hoisting 282 while( b != this ) { 283 uint k; 284 for( k = 1; k < b->_nodes.size(); k++ ) { 285 Node *n = b->_nodes[k]; 286 if( n->needs_anti_dependence_check() && 287 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) ) 288 break; // Found anti-dependent load 289 } 290 if( k < b->_nodes.size() ) 291 break; // Found anti-dependent load 292 // Make sure control does not do a merge (would have to check allpaths) 293 if( b->num_preds() != 2 ) break; 294 b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block 295 } 296 if( b != this ) continue; 297 } 298 299 // Make sure this memory op is not already being used for a NullCheck 300 Node *e = mb->end(); 301 if( e->is_MachNullCheck() && e->in(1) == mach ) 302 continue; // Already being used as a NULL check 303 304 // Found a candidate! Pick one with least dom depth - the highest 305 // in the dom tree should be closest to the null check. 306 if( !best || 307 cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) { 308 best = mach; 309 bidx = vidx; 310 311 } 312 } 313 // No candidate! 314 if( !best ) return; 315 316 // ---- Found an implicit null check 317 extern int implicit_null_checks; 318 implicit_null_checks++; 319 320 if( is_decoden ) { 321 // Check if we need to hoist decodeHeapOop_not_null first. 322 Block *valb = cfg->_bbs[val->_idx]; 323 if( this != valb && this->_dom_depth < valb->_dom_depth ) { 324 // Hoist it up to the end of the test block. 325 valb->find_remove(val); 326 this->add_inst(val); 327 cfg->_bbs.map(val->_idx,this); 328 // DecodeN on x86 may kill flags. Check for flag-killing projections 329 // that also need to be hoisted. 330 for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) { 331 Node* n = val->fast_out(j); 332 if( n->is_MachProj() ) { 333 cfg->_bbs[n->_idx]->find_remove(n); 334 this->add_inst(n); 335 cfg->_bbs.map(n->_idx,this); 336 } 337 } 338 } 339 } 340 // Hoist the memory candidate up to the end of the test block. 341 Block *old_block = cfg->_bbs[best->_idx]; 342 old_block->find_remove(best); 343 add_inst(best); 344 cfg->_bbs.map(best->_idx,this); 345 346 // Move the control dependence 347 if (best->in(0) && best->in(0) == old_block->_nodes[0]) 348 best->set_req(0, _nodes[0]); 349 350 // Check for flag-killing projections that also need to be hoisted 351 // Should be DU safe because no edge updates. 352 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) { 353 Node* n = best->fast_out(j); 354 if( n->is_MachProj() ) { 355 cfg->_bbs[n->_idx]->find_remove(n); 356 add_inst(n); 357 cfg->_bbs.map(n->_idx,this); 358 } 359 } 360 361 Compile *C = cfg->C; 362 // proj==Op_True --> ne test; proj==Op_False --> eq test. 363 // One of two graph shapes got matched: 364 // (IfTrue (If (Bool NE (CmpP ptr NULL)))) 365 // (IfFalse (If (Bool EQ (CmpP ptr NULL)))) 366 // NULL checks are always branch-if-eq. If we see a IfTrue projection 367 // then we are replacing a 'ne' test with a 'eq' NULL check test. 368 // We need to flip the projections to keep the same semantics. 369 if( proj->Opcode() == Op_IfTrue ) { 370 // Swap order of projections in basic block to swap branch targets 371 Node *tmp1 = _nodes[end_idx()+1]; 372 Node *tmp2 = _nodes[end_idx()+2]; 373 _nodes.map(end_idx()+1, tmp2); 374 _nodes.map(end_idx()+2, tmp1); 375 Node *tmp = new (C) Node(C->top()); // Use not NULL input 376 tmp1->replace_by(tmp); 377 tmp2->replace_by(tmp1); 378 tmp->replace_by(tmp2); 379 tmp->destruct(); 380 } 381 382 // Remove the existing null check; use a new implicit null check instead. 383 // Since schedule-local needs precise def-use info, we need to correct 384 // it as well. 385 Node *old_tst = proj->in(0); 386 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx); 387 _nodes.map(end_idx(),nul_chk); 388 cfg->_bbs.map(nul_chk->_idx,this); 389 // Redirect users of old_test to nul_chk 390 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2) 391 old_tst->last_out(i2)->set_req(0, nul_chk); 392 // Clean-up any dead code 393 for (uint i3 = 0; i3 < old_tst->req(); i3++) 394 old_tst->set_req(i3, NULL); 395 396 cfg->latency_from_uses(nul_chk); 397 cfg->latency_from_uses(best); 398 } 399 400 401 //------------------------------select----------------------------------------- 402 // Select a nice fellow from the worklist to schedule next. If there is only 403 // one choice, then use it. Projections take top priority for correctness 404 // reasons - if I see a projection, then it is next. There are a number of 405 // other special cases, for instructions that consume condition codes, et al. 406 // These are chosen immediately. Some instructions are required to immediately 407 // precede the last instruction in the block, and these are taken last. Of the 408 // remaining cases (most), choose the instruction with the greatest latency 409 // (that is, the most number of pseudo-cycles required to the end of the 410 // routine). If there is a tie, choose the instruction with the most inputs. 411 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, GrowableArray<int> &ready_cnt, VectorSet &next_call, uint sched_slot) { 412 413 // If only a single entry on the stack, use it 414 uint cnt = worklist.size(); 415 if (cnt == 1) { 416 Node *n = worklist[0]; 417 worklist.map(0,worklist.pop()); 418 return n; 419 } 420 421 uint choice = 0; // Bigger is most important 422 uint latency = 0; // Bigger is scheduled first 423 uint score = 0; // Bigger is better 424 int idx = -1; // Index in worklist 425 int cand_cnt = 0; // Candidate count 426 427 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist 428 // Order in worklist is used to break ties. 429 // See caller for how this is used to delay scheduling 430 // of induction variable increments to after the other 431 // uses of the phi are scheduled. 432 Node *n = worklist[i]; // Get Node on worklist 433 434 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0; 435 if( n->is_Proj() || // Projections always win 436 n->Opcode()== Op_Con || // So does constant 'Top' 437 iop == Op_CreateEx || // Create-exception must start block 438 iop == Op_CheckCastPP 439 ) { 440 worklist.map(i,worklist.pop()); 441 return n; 442 } 443 444 // Final call in a block must be adjacent to 'catch' 445 Node *e = end(); 446 if( e->is_Catch() && e->in(0)->in(0) == n ) 447 continue; 448 449 // Memory op for an implicit null check has to be at the end of the block 450 if( e->is_MachNullCheck() && e->in(1) == n ) 451 continue; 452 453 // Schedule IV increment last. 454 if (e->is_Mach() && e->as_Mach()->ideal_Opcode() == Op_CountedLoopEnd && 455 e->in(1)->in(1) == n && n->is_iteratively_computed()) 456 continue; 457 458 uint n_choice = 2; 459 460 // See if this instruction is consumed by a branch. If so, then (as the 461 // branch is the last instruction in the basic block) force it to the 462 // end of the basic block 463 if ( must_clone[iop] ) { 464 // See if any use is a branch 465 bool found_machif = false; 466 467 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 468 Node* use = n->fast_out(j); 469 470 // The use is a conditional branch, make them adjacent 471 if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) { 472 found_machif = true; 473 break; 474 } 475 476 // More than this instruction pending for successor to be ready, 477 // don't choose this if other opportunities are ready 478 if (ready_cnt.at(use->_idx) > 1) 479 n_choice = 1; 480 } 481 482 // loop terminated, prefer not to use this instruction 483 if (found_machif) 484 continue; 485 } 486 487 // See if this has a predecessor that is "must_clone", i.e. sets the 488 // condition code. If so, choose this first 489 for (uint j = 0; j < n->req() ; j++) { 490 Node *inn = n->in(j); 491 if (inn) { 492 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) { 493 n_choice = 3; 494 break; 495 } 496 } 497 } 498 499 // MachTemps should be scheduled last so they are near their uses 500 if (n->is_MachTemp()) { 501 n_choice = 1; 502 } 503 504 uint n_latency = cfg->_node_latency->at_grow(n->_idx); 505 uint n_score = n->req(); // Many inputs get high score to break ties 506 507 // Keep best latency found 508 cand_cnt++; 509 if (choice < n_choice || 510 (choice == n_choice && 511 ((StressLCM && Compile::randomized_select(cand_cnt)) || 512 (!StressLCM && 513 (latency < n_latency || 514 (latency == n_latency && 515 (score < n_score))))))) { 516 choice = n_choice; 517 latency = n_latency; 518 score = n_score; 519 idx = i; // Also keep index in worklist 520 } 521 } // End of for all ready nodes in worklist 522 523 assert(idx >= 0, "index should be set"); 524 Node *n = worklist[(uint)idx]; // Get the winner 525 526 worklist.map((uint)idx, worklist.pop()); // Compress worklist 527 return n; 528 } 529 530 531 //------------------------------set_next_call---------------------------------- 532 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) { 533 if( next_call.test_set(n->_idx) ) return; 534 for( uint i=0; i<n->len(); i++ ) { 535 Node *m = n->in(i); 536 if( !m ) continue; // must see all nodes in block that precede call 537 if( bbs[m->_idx] == this ) 538 set_next_call( m, next_call, bbs ); 539 } 540 } 541 542 //------------------------------needed_for_next_call--------------------------- 543 // Set the flag 'next_call' for each Node that is needed for the next call to 544 // be scheduled. This flag lets me bias scheduling so Nodes needed for the 545 // next subroutine call get priority - basically it moves things NOT needed 546 // for the next call till after the call. This prevents me from trying to 547 // carry lots of stuff live across a call. 548 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) { 549 // Find the next control-defining Node in this block 550 Node* call = NULL; 551 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) { 552 Node* m = this_call->fast_out(i); 553 if( bbs[m->_idx] == this && // Local-block user 554 m != this_call && // Not self-start node 555 m->is_MachCall() ) 556 call = m; 557 break; 558 } 559 if (call == NULL) return; // No next call (e.g., block end is near) 560 // Set next-call for all inputs to this call 561 set_next_call(call, next_call, bbs); 562 } 563 564 //------------------------------add_call_kills------------------------------------- 565 void Block::add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe) { 566 // Fill in the kill mask for the call 567 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) { 568 if( !regs.Member(r) ) { // Not already defined by the call 569 // Save-on-call register? 570 if ((save_policy[r] == 'C') || 571 (save_policy[r] == 'A') || 572 ((save_policy[r] == 'E') && exclude_soe)) { 573 proj->_rout.Insert(r); 574 } 575 } 576 } 577 } 578 579 580 //------------------------------sched_call------------------------------------- 581 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, GrowableArray<int> &ready_cnt, MachCallNode *mcall, VectorSet &next_call ) { 582 RegMask regs; 583 584 // Schedule all the users of the call right now. All the users are 585 // projection Nodes, so they must be scheduled next to the call. 586 // Collect all the defined registers. 587 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) { 588 Node* n = mcall->fast_out(i); 589 assert( n->is_MachProj(), "" ); 590 int n_cnt = ready_cnt.at(n->_idx)-1; 591 ready_cnt.at_put(n->_idx, n_cnt); 592 assert( n_cnt == 0, "" ); 593 // Schedule next to call 594 _nodes.map(node_cnt++, n); 595 // Collect defined registers 596 regs.OR(n->out_RegMask()); 597 // Check for scheduling the next control-definer 598 if( n->bottom_type() == Type::CONTROL ) 599 // Warm up next pile of heuristic bits 600 needed_for_next_call(n, next_call, bbs); 601 602 // Children of projections are now all ready 603 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 604 Node* m = n->fast_out(j); // Get user 605 if( bbs[m->_idx] != this ) continue; 606 if( m->is_Phi() ) continue; 607 int m_cnt = ready_cnt.at(m->_idx)-1; 608 ready_cnt.at_put(m->_idx, m_cnt); 609 if( m_cnt == 0 ) 610 worklist.push(m); 611 } 612 613 } 614 615 // Act as if the call defines the Frame Pointer. 616 // Certainly the FP is alive and well after the call. 617 regs.Insert(matcher.c_frame_pointer()); 618 619 // Set all registers killed and not already defined by the call. 620 uint r_cnt = mcall->tf()->range()->cnt(); 621 int op = mcall->ideal_Opcode(); 622 MachProjNode *proj = new (matcher.C) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj ); 623 bbs.map(proj->_idx,this); 624 _nodes.insert(node_cnt++, proj); 625 626 // Select the right register save policy. 627 const char * save_policy; 628 switch (op) { 629 case Op_CallRuntime: 630 case Op_CallLeaf: 631 case Op_CallLeafNoFP: 632 // Calling C code so use C calling convention 633 save_policy = matcher._c_reg_save_policy; 634 break; 635 636 case Op_CallStaticJava: 637 case Op_CallDynamicJava: 638 // Calling Java code so use Java calling convention 639 save_policy = matcher._register_save_policy; 640 break; 641 642 default: 643 ShouldNotReachHere(); 644 } 645 646 // When using CallRuntime mark SOE registers as killed by the call 647 // so values that could show up in the RegisterMap aren't live in a 648 // callee saved register since the register wouldn't know where to 649 // find them. CallLeaf and CallLeafNoFP are ok because they can't 650 // have debug info on them. Strictly speaking this only needs to be 651 // done for oops since idealreg2debugmask takes care of debug info 652 // references but there no way to handle oops differently than other 653 // pointers as far as the kill mask goes. 654 bool exclude_soe = op == Op_CallRuntime; 655 656 // If the call is a MethodHandle invoke, we need to exclude the 657 // register which is used to save the SP value over MH invokes from 658 // the mask. Otherwise this register could be used for 659 // deoptimization information. 660 if (op == Op_CallStaticJava) { 661 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall; 662 if (mcallstaticjava->_method_handle_invoke) 663 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask()); 664 } 665 666 add_call_kills(proj, regs, save_policy, exclude_soe); 667 668 return node_cnt; 669 } 670 671 672 //------------------------------schedule_local--------------------------------- 673 // Topological sort within a block. Someday become a real scheduler. 674 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, GrowableArray<int> &ready_cnt, VectorSet &next_call) { 675 // Already "sorted" are the block start Node (as the first entry), and 676 // the block-ending Node and any trailing control projections. We leave 677 // these alone. PhiNodes and ParmNodes are made to follow the block start 678 // Node. Everything else gets topo-sorted. 679 680 #ifndef PRODUCT 681 if (cfg->trace_opto_pipelining()) { 682 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order); 683 for (uint i = 0;i < _nodes.size();i++) { 684 tty->print("# "); 685 _nodes[i]->fast_dump(); 686 } 687 tty->print_cr("#"); 688 } 689 #endif 690 691 // RootNode is already sorted 692 if( _nodes.size() == 1 ) return true; 693 694 // Move PhiNodes and ParmNodes from 1 to cnt up to the start 695 uint node_cnt = end_idx(); 696 uint phi_cnt = 1; 697 uint i; 698 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi 699 Node *n = _nodes[i]; 700 if( n->is_Phi() || // Found a PhiNode or ParmNode 701 (n->is_Proj() && n->in(0) == head()) ) { 702 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt 703 _nodes.map(i,_nodes[phi_cnt]); 704 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front 705 } else { // All others 706 // Count block-local inputs to 'n' 707 uint cnt = n->len(); // Input count 708 uint local = 0; 709 for( uint j=0; j<cnt; j++ ) { 710 Node *m = n->in(j); 711 if( m && cfg->_bbs[m->_idx] == this && !m->is_top() ) 712 local++; // One more block-local input 713 } 714 ready_cnt.at_put(n->_idx, local); // Count em up 715 716 #ifdef ASSERT 717 if( UseConcMarkSweepGC || UseG1GC ) { 718 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) { 719 // Check the precedence edges 720 for (uint prec = n->req(); prec < n->len(); prec++) { 721 Node* oop_store = n->in(prec); 722 if (oop_store != NULL) { 723 assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark"); 724 } 725 } 726 } 727 } 728 #endif 729 730 // A few node types require changing a required edge to a precedence edge 731 // before allocation. 732 if( n->is_Mach() && n->req() > TypeFunc::Parms && 733 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire || 734 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) { 735 // MemBarAcquire could be created without Precedent edge. 736 // del_req() replaces the specified edge with the last input edge 737 // and then removes the last edge. If the specified edge > number of 738 // edges the last edge will be moved outside of the input edges array 739 // and the edge will be lost. This is why this code should be 740 // executed only when Precedent (== TypeFunc::Parms) edge is present. 741 Node *x = n->in(TypeFunc::Parms); 742 n->del_req(TypeFunc::Parms); 743 n->add_prec(x); 744 } 745 } 746 } 747 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count 748 ready_cnt.at_put(_nodes[i2]->_idx, 0); 749 750 // All the prescheduled guys do not hold back internal nodes 751 uint i3; 752 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled 753 Node *n = _nodes[i3]; // Get pre-scheduled 754 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 755 Node* m = n->fast_out(j); 756 if( cfg->_bbs[m->_idx] ==this ) { // Local-block user 757 int m_cnt = ready_cnt.at(m->_idx)-1; 758 ready_cnt.at_put(m->_idx, m_cnt); // Fix ready count 759 } 760 } 761 } 762 763 Node_List delay; 764 // Make a worklist 765 Node_List worklist; 766 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist 767 Node *m = _nodes[i4]; 768 if( !ready_cnt.at(m->_idx) ) { // Zero ready count? 769 if (m->is_iteratively_computed()) { 770 // Push induction variable increments last to allow other uses 771 // of the phi to be scheduled first. The select() method breaks 772 // ties in scheduling by worklist order. 773 delay.push(m); 774 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) { 775 // Force the CreateEx to the top of the list so it's processed 776 // first and ends up at the start of the block. 777 worklist.insert(0, m); 778 } else { 779 worklist.push(m); // Then on to worklist! 780 } 781 } 782 } 783 while (delay.size()) { 784 Node* d = delay.pop(); 785 worklist.push(d); 786 } 787 788 // Warm up the 'next_call' heuristic bits 789 needed_for_next_call(_nodes[0], next_call, cfg->_bbs); 790 791 #ifndef PRODUCT 792 if (cfg->trace_opto_pipelining()) { 793 for (uint j=0; j<_nodes.size(); j++) { 794 Node *n = _nodes[j]; 795 int idx = n->_idx; 796 tty->print("# ready cnt:%3d ", ready_cnt.at(idx)); 797 tty->print("latency:%3d ", cfg->_node_latency->at_grow(idx)); 798 tty->print("%4d: %s\n", idx, n->Name()); 799 } 800 } 801 #endif 802 803 uint max_idx = (uint)ready_cnt.length(); 804 // Pull from worklist and schedule 805 while( worklist.size() ) { // Worklist is not ready 806 807 #ifndef PRODUCT 808 if (cfg->trace_opto_pipelining()) { 809 tty->print("# ready list:"); 810 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 811 Node *n = worklist[i]; // Get Node on worklist 812 tty->print(" %d", n->_idx); 813 } 814 tty->cr(); 815 } 816 #endif 817 818 // Select and pop a ready guy from worklist 819 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt); 820 _nodes.map(phi_cnt++,n); // Schedule him next 821 822 #ifndef PRODUCT 823 if (cfg->trace_opto_pipelining()) { 824 tty->print("# select %d: %s", n->_idx, n->Name()); 825 tty->print(", latency:%d", cfg->_node_latency->at_grow(n->_idx)); 826 n->dump(); 827 if (Verbose) { 828 tty->print("# ready list:"); 829 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 830 Node *n = worklist[i]; // Get Node on worklist 831 tty->print(" %d", n->_idx); 832 } 833 tty->cr(); 834 } 835 } 836 837 #endif 838 if( n->is_MachCall() ) { 839 MachCallNode *mcall = n->as_MachCall(); 840 phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call); 841 continue; 842 } 843 844 if (n->is_Mach() && n->as_Mach()->has_call()) { 845 RegMask regs; 846 regs.Insert(matcher.c_frame_pointer()); 847 regs.OR(n->out_RegMask()); 848 849 MachProjNode *proj = new (matcher.C) MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj ); 850 cfg->_bbs.map(proj->_idx,this); 851 _nodes.insert(phi_cnt++, proj); 852 853 add_call_kills(proj, regs, matcher._c_reg_save_policy, false); 854 } 855 856 // Children are now all ready 857 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) { 858 Node* m = n->fast_out(i5); // Get user 859 if( cfg->_bbs[m->_idx] != this ) continue; 860 if( m->is_Phi() ) continue; 861 if (m->_idx >= max_idx) { // new node, skip it 862 assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types"); 863 continue; 864 } 865 int m_cnt = ready_cnt.at(m->_idx)-1; 866 ready_cnt.at_put(m->_idx, m_cnt); 867 if( m_cnt == 0 ) 868 worklist.push(m); 869 } 870 } 871 872 if( phi_cnt != end_idx() ) { 873 // did not schedule all. Retry, Bailout, or Die 874 Compile* C = matcher.C; 875 if (C->subsume_loads() == true && !C->failing()) { 876 // Retry with subsume_loads == false 877 // If this is the first failure, the sentinel string will "stick" 878 // to the Compile object, and the C2Compiler will see it and retry. 879 C->record_failure(C2Compiler::retry_no_subsuming_loads()); 880 } 881 // assert( phi_cnt == end_idx(), "did not schedule all" ); 882 return false; 883 } 884 885 #ifndef PRODUCT 886 if (cfg->trace_opto_pipelining()) { 887 tty->print_cr("#"); 888 tty->print_cr("# after schedule_local"); 889 for (uint i = 0;i < _nodes.size();i++) { 890 tty->print("# "); 891 _nodes[i]->fast_dump(); 892 } 893 tty->cr(); 894 } 895 #endif 896 897 898 return true; 899 } 900 901 //--------------------------catch_cleanup_fix_all_inputs----------------------- 902 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) { 903 for (uint l = 0; l < use->len(); l++) { 904 if (use->in(l) == old_def) { 905 if (l < use->req()) { 906 use->set_req(l, new_def); 907 } else { 908 use->rm_prec(l); 909 use->add_prec(new_def); 910 l--; 911 } 912 } 913 } 914 } 915 916 //------------------------------catch_cleanup_find_cloned_def------------------ 917 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) { 918 assert( use_blk != def_blk, "Inter-block cleanup only"); 919 920 // The use is some block below the Catch. Find and return the clone of the def 921 // that dominates the use. If there is no clone in a dominating block, then 922 // create a phi for the def in a dominating block. 923 924 // Find which successor block dominates this use. The successor 925 // blocks must all be single-entry (from the Catch only; I will have 926 // split blocks to make this so), hence they all dominate. 927 while( use_blk->_dom_depth > def_blk->_dom_depth+1 ) 928 use_blk = use_blk->_idom; 929 930 // Find the successor 931 Node *fixup = NULL; 932 933 uint j; 934 for( j = 0; j < def_blk->_num_succs; j++ ) 935 if( use_blk == def_blk->_succs[j] ) 936 break; 937 938 if( j == def_blk->_num_succs ) { 939 // Block at same level in dom-tree is not a successor. It needs a 940 // PhiNode, the PhiNode uses from the def and IT's uses need fixup. 941 Node_Array inputs = new Node_List(Thread::current()->resource_area()); 942 for(uint k = 1; k < use_blk->num_preds(); k++) { 943 inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx)); 944 } 945 946 // Check to see if the use_blk already has an identical phi inserted. 947 // If it exists, it will be at the first position since all uses of a 948 // def are processed together. 949 Node *phi = use_blk->_nodes[1]; 950 if( phi->is_Phi() ) { 951 fixup = phi; 952 for (uint k = 1; k < use_blk->num_preds(); k++) { 953 if (phi->in(k) != inputs[k]) { 954 // Not a match 955 fixup = NULL; 956 break; 957 } 958 } 959 } 960 961 // If an existing PhiNode was not found, make a new one. 962 if (fixup == NULL) { 963 Node *new_phi = PhiNode::make(use_blk->head(), def); 964 use_blk->_nodes.insert(1, new_phi); 965 bbs.map(new_phi->_idx, use_blk); 966 for (uint k = 1; k < use_blk->num_preds(); k++) { 967 new_phi->set_req(k, inputs[k]); 968 } 969 fixup = new_phi; 970 } 971 972 } else { 973 // Found the use just below the Catch. Make it use the clone. 974 fixup = use_blk->_nodes[n_clone_idx]; 975 } 976 977 return fixup; 978 } 979 980 //--------------------------catch_cleanup_intra_block-------------------------- 981 // Fix all input edges in use that reference "def". The use is in the same 982 // block as the def and both have been cloned in each successor block. 983 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) { 984 985 // Both the use and def have been cloned. For each successor block, 986 // get the clone of the use, and make its input the clone of the def 987 // found in that block. 988 989 uint use_idx = blk->find_node(use); 990 uint offset_idx = use_idx - beg; 991 for( uint k = 0; k < blk->_num_succs; k++ ) { 992 // Get clone in each successor block 993 Block *sb = blk->_succs[k]; 994 Node *clone = sb->_nodes[offset_idx+1]; 995 assert( clone->Opcode() == use->Opcode(), "" ); 996 997 // Make use-clone reference the def-clone 998 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]); 999 } 1000 } 1001 1002 //------------------------------catch_cleanup_inter_block--------------------- 1003 // Fix all input edges in use that reference "def". The use is in a different 1004 // block than the def. 1005 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) { 1006 if( !use_blk ) return; // Can happen if the use is a precedence edge 1007 1008 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx); 1009 catch_cleanup_fix_all_inputs(use, def, new_def); 1010 } 1011 1012 //------------------------------call_catch_cleanup----------------------------- 1013 // If we inserted any instructions between a Call and his CatchNode, 1014 // clone the instructions on all paths below the Catch. 1015 void Block::call_catch_cleanup(Block_Array &bbs, Compile* C) { 1016 1017 // End of region to clone 1018 uint end = end_idx(); 1019 if( !_nodes[end]->is_Catch() ) return; 1020 // Start of region to clone 1021 uint beg = end; 1022 while(!_nodes[beg-1]->is_MachProj() || 1023 !_nodes[beg-1]->in(0)->is_MachCall() ) { 1024 beg--; 1025 assert(beg > 0,"Catch cleanup walking beyond block boundary"); 1026 } 1027 // Range of inserted instructions is [beg, end) 1028 if( beg == end ) return; 1029 1030 // Clone along all Catch output paths. Clone area between the 'beg' and 1031 // 'end' indices. 1032 for( uint i = 0; i < _num_succs; i++ ) { 1033 Block *sb = _succs[i]; 1034 // Clone the entire area; ignoring the edge fixup for now. 1035 for( uint j = end; j > beg; j-- ) { 1036 // It is safe here to clone a node with anti_dependence 1037 // since clones dominate on each path. 1038 Node *clone = _nodes[j-1]->clone(); 1039 sb->_nodes.insert( 1, clone ); 1040 bbs.map(clone->_idx,sb); 1041 } 1042 } 1043 1044 1045 // Fixup edges. Check the def-use info per cloned Node 1046 for(uint i2 = beg; i2 < end; i2++ ) { 1047 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block 1048 Node *n = _nodes[i2]; // Node that got cloned 1049 // Need DU safe iterator because of edge manipulation in calls. 1050 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area()); 1051 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) { 1052 out->push(n->fast_out(j1)); 1053 } 1054 uint max = out->size(); 1055 for (uint j = 0; j < max; j++) {// For all users 1056 Node *use = out->pop(); 1057 Block *buse = bbs[use->_idx]; 1058 if( use->is_Phi() ) { 1059 for( uint k = 1; k < use->req(); k++ ) 1060 if( use->in(k) == n ) { 1061 Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx); 1062 use->set_req(k, fixup); 1063 } 1064 } else { 1065 if (this == buse) { 1066 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx); 1067 } else { 1068 catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx); 1069 } 1070 } 1071 } // End for all users 1072 1073 } // End of for all Nodes in cloned area 1074 1075 // Remove the now-dead cloned ops 1076 for(uint i3 = beg; i3 < end; i3++ ) { 1077 _nodes[beg]->disconnect_inputs(NULL, C); 1078 _nodes.remove(beg); 1079 } 1080 1081 // If the successor blocks have a CreateEx node, move it back to the top 1082 for(uint i4 = 0; i4 < _num_succs; i4++ ) { 1083 Block *sb = _succs[i4]; 1084 uint new_cnt = end - beg; 1085 // Remove any newly created, but dead, nodes. 1086 for( uint j = new_cnt; j > 0; j-- ) { 1087 Node *n = sb->_nodes[j]; 1088 if (n->outcnt() == 0 && 1089 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){ 1090 n->disconnect_inputs(NULL, C); 1091 sb->_nodes.remove(j); 1092 new_cnt--; 1093 } 1094 } 1095 // If any newly created nodes remain, move the CreateEx node to the top 1096 if (new_cnt > 0) { 1097 Node *cex = sb->_nodes[1+new_cnt]; 1098 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) { 1099 sb->_nodes.remove(1+new_cnt); 1100 sb->_nodes.insert(1,cex); 1101 } 1102 } 1103 } 1104 }