1 /* 2 * Copyright 1998-2009 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 // Optimization - Graph Style 26 27 #include "incls/_precompiled.incl" 28 #include "incls/_lcm.cpp.incl" 29 30 //------------------------------implicit_null_check---------------------------- 31 // Detect implicit-null-check opportunities. Basically, find NULL checks 32 // with suitable memory ops nearby. Use the memory op to do the NULL check. 33 // I can generate a memory op if there is not one nearby. 34 // The proj is the control projection for the not-null case. 35 // The val is the pointer being checked for nullness. 36 void Block::implicit_null_check(PhaseCFG *cfg, Node *proj, Node *val, int allowed_reasons) { 37 // Assume if null check need for 0 offset then always needed 38 // Intel solaris doesn't support any null checks yet and no 39 // mechanism exists (yet) to set the switches at an os_cpu level 40 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return; 41 42 // Make sure the ptr-is-null path appears to be uncommon! 43 float f = end()->as_MachIf()->_prob; 44 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f; 45 if( f > PROB_UNLIKELY_MAG(4) ) return; 46 47 uint bidx = 0; // Capture index of value into memop 48 bool was_store; // Memory op is a store op 49 50 // Get the successor block for if the test ptr is non-null 51 Block* not_null_block; // this one goes with the proj 52 Block* null_block; 53 if (_nodes[_nodes.size()-1] == proj) { 54 null_block = _succs[0]; 55 not_null_block = _succs[1]; 56 } else { 57 assert(_nodes[_nodes.size()-2] == proj, "proj is one or the other"); 58 not_null_block = _succs[0]; 59 null_block = _succs[1]; 60 } 61 while (null_block->is_Empty() == Block::empty_with_goto) { 62 null_block = null_block->_succs[0]; 63 } 64 65 // Search the exception block for an uncommon trap. 66 // (See Parse::do_if and Parse::do_ifnull for the reason 67 // we need an uncommon trap. Briefly, we need a way to 68 // detect failure of this optimization, as in 6366351.) 69 { 70 bool found_trap = false; 71 for (uint i1 = 0; i1 < null_block->_nodes.size(); i1++) { 72 Node* nn = null_block->_nodes[i1]; 73 if (nn->is_MachCall() && 74 nn->as_MachCall()->entry_point() == 75 SharedRuntime::uncommon_trap_blob()->instructions_begin()) { 76 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type(); 77 if (trtype->isa_int() && trtype->is_int()->is_con()) { 78 jint tr_con = trtype->is_int()->get_con(); 79 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con); 80 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con); 81 assert((int)reason < (int)BitsPerInt, "recode bit map"); 82 if (is_set_nth_bit(allowed_reasons, (int) reason) 83 && action != Deoptimization::Action_none) { 84 // This uncommon trap is sure to recompile, eventually. 85 // When that happens, C->too_many_traps will prevent 86 // this transformation from happening again. 87 found_trap = true; 88 } 89 } 90 break; 91 } 92 } 93 if (!found_trap) { 94 // We did not find an uncommon trap. 95 return; 96 } 97 } 98 99 // Search the successor block for a load or store who's base value is also 100 // the tested value. There may be several. 101 Node_List *out = new Node_List(Thread::current()->resource_area()); 102 MachNode *best = NULL; // Best found so far 103 for (DUIterator i = val->outs(); val->has_out(i); i++) { 104 Node *m = val->out(i); 105 if( !m->is_Mach() ) continue; 106 MachNode *mach = m->as_Mach(); 107 was_store = false; 108 switch( mach->ideal_Opcode() ) { 109 case Op_LoadB: 110 case Op_LoadUS: 111 case Op_LoadD: 112 case Op_LoadF: 113 case Op_LoadI: 114 case Op_LoadL: 115 case Op_LoadP: 116 case Op_LoadN: 117 case Op_LoadS: 118 case Op_LoadKlass: 119 case Op_LoadNKlass: 120 case Op_LoadRange: 121 case Op_LoadD_unaligned: 122 case Op_LoadL_unaligned: 123 break; 124 case Op_StoreB: 125 case Op_StoreC: 126 case Op_StoreCM: 127 case Op_StoreD: 128 case Op_StoreF: 129 case Op_StoreI: 130 case Op_StoreL: 131 case Op_StoreP: 132 case Op_StoreN: 133 was_store = true; // Memory op is a store op 134 // Stores will have their address in slot 2 (memory in slot 1). 135 // If the value being nul-checked is in another slot, it means we 136 // are storing the checked value, which does NOT check the value! 137 if( mach->in(2) != val ) continue; 138 break; // Found a memory op? 139 case Op_StrComp: 140 case Op_StrEquals: 141 case Op_StrIndexOf: 142 case Op_AryEq: 143 // Not a legit memory op for implicit null check regardless of 144 // embedded loads 145 continue; 146 default: // Also check for embedded loads 147 if( !mach->needs_anti_dependence_check() ) 148 continue; // Not an memory op; skip it 149 break; 150 } 151 // check if the offset is not too high for implicit exception 152 { 153 intptr_t offset = 0; 154 const TypePtr *adr_type = NULL; // Do not need this return value here 155 const Node* base = mach->get_base_and_disp(offset, adr_type); 156 if (base == NULL || base == NodeSentinel) { 157 // Narrow oop address doesn't have base, only index 158 if( val->bottom_type()->isa_narrowoop() && 159 MacroAssembler::needs_explicit_null_check(offset) ) 160 continue; // Give up if offset is beyond page size 161 // cannot reason about it; is probably not implicit null exception 162 } else { 163 const TypePtr* tptr; 164 if (UseCompressedOops && Universe::narrow_oop_shift() == 0) { 165 // 32-bits narrow oop can be the base of address expressions 166 tptr = base->bottom_type()->make_ptr(); 167 } else { 168 // only regular oops are expected here 169 tptr = base->bottom_type()->is_ptr(); 170 } 171 // Give up if offset is not a compile-time constant 172 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot ) 173 continue; 174 offset += tptr->_offset; // correct if base is offseted 175 if( MacroAssembler::needs_explicit_null_check(offset) ) 176 continue; // Give up is reference is beyond 4K page size 177 } 178 } 179 180 // Check ctrl input to see if the null-check dominates the memory op 181 Block *cb = cfg->_bbs[mach->_idx]; 182 cb = cb->_idom; // Always hoist at least 1 block 183 if( !was_store ) { // Stores can be hoisted only one block 184 while( cb->_dom_depth > (_dom_depth + 1)) 185 cb = cb->_idom; // Hoist loads as far as we want 186 // The non-null-block should dominate the memory op, too. Live 187 // range spilling will insert a spill in the non-null-block if it is 188 // needs to spill the memory op for an implicit null check. 189 if (cb->_dom_depth == (_dom_depth + 1)) { 190 if (cb != not_null_block) continue; 191 cb = cb->_idom; 192 } 193 } 194 if( cb != this ) continue; 195 196 // Found a memory user; see if it can be hoisted to check-block 197 uint vidx = 0; // Capture index of value into memop 198 uint j; 199 for( j = mach->req()-1; j > 0; j-- ) { 200 if( mach->in(j) == val ) vidx = j; 201 // Block of memory-op input 202 Block *inb = cfg->_bbs[mach->in(j)->_idx]; 203 Block *b = this; // Start from nul check 204 while( b != inb && b->_dom_depth > inb->_dom_depth ) 205 b = b->_idom; // search upwards for input 206 // See if input dominates null check 207 if( b != inb ) 208 break; 209 } 210 if( j > 0 ) 211 continue; 212 Block *mb = cfg->_bbs[mach->_idx]; 213 // Hoisting stores requires more checks for the anti-dependence case. 214 // Give up hoisting if we have to move the store past any load. 215 if( was_store ) { 216 Block *b = mb; // Start searching here for a local load 217 // mach use (faulting) trying to hoist 218 // n might be blocker to hoisting 219 while( b != this ) { 220 uint k; 221 for( k = 1; k < b->_nodes.size(); k++ ) { 222 Node *n = b->_nodes[k]; 223 if( n->needs_anti_dependence_check() && 224 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) ) 225 break; // Found anti-dependent load 226 } 227 if( k < b->_nodes.size() ) 228 break; // Found anti-dependent load 229 // Make sure control does not do a merge (would have to check allpaths) 230 if( b->num_preds() != 2 ) break; 231 b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block 232 } 233 if( b != this ) continue; 234 } 235 236 // Make sure this memory op is not already being used for a NullCheck 237 Node *e = mb->end(); 238 if( e->is_MachNullCheck() && e->in(1) == mach ) 239 continue; // Already being used as a NULL check 240 241 // Found a candidate! Pick one with least dom depth - the highest 242 // in the dom tree should be closest to the null check. 243 if( !best || 244 cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) { 245 best = mach; 246 bidx = vidx; 247 248 } 249 } 250 // No candidate! 251 if( !best ) return; 252 253 // ---- Found an implicit null check 254 extern int implicit_null_checks; 255 implicit_null_checks++; 256 257 // Hoist the memory candidate up to the end of the test block. 258 Block *old_block = cfg->_bbs[best->_idx]; 259 old_block->find_remove(best); 260 add_inst(best); 261 cfg->_bbs.map(best->_idx,this); 262 263 // Move the control dependence 264 if (best->in(0) && best->in(0) == old_block->_nodes[0]) 265 best->set_req(0, _nodes[0]); 266 267 // Check for flag-killing projections that also need to be hoisted 268 // Should be DU safe because no edge updates. 269 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) { 270 Node* n = best->fast_out(j); 271 if( n->Opcode() == Op_MachProj ) { 272 cfg->_bbs[n->_idx]->find_remove(n); 273 add_inst(n); 274 cfg->_bbs.map(n->_idx,this); 275 } 276 } 277 278 Compile *C = cfg->C; 279 // proj==Op_True --> ne test; proj==Op_False --> eq test. 280 // One of two graph shapes got matched: 281 // (IfTrue (If (Bool NE (CmpP ptr NULL)))) 282 // (IfFalse (If (Bool EQ (CmpP ptr NULL)))) 283 // NULL checks are always branch-if-eq. If we see a IfTrue projection 284 // then we are replacing a 'ne' test with a 'eq' NULL check test. 285 // We need to flip the projections to keep the same semantics. 286 if( proj->Opcode() == Op_IfTrue ) { 287 // Swap order of projections in basic block to swap branch targets 288 Node *tmp1 = _nodes[end_idx()+1]; 289 Node *tmp2 = _nodes[end_idx()+2]; 290 _nodes.map(end_idx()+1, tmp2); 291 _nodes.map(end_idx()+2, tmp1); 292 Node *tmp = new (C, 1) Node(C->top()); // Use not NULL input 293 tmp1->replace_by(tmp); 294 tmp2->replace_by(tmp1); 295 tmp->replace_by(tmp2); 296 tmp->destruct(); 297 } 298 299 // Remove the existing null check; use a new implicit null check instead. 300 // Since schedule-local needs precise def-use info, we need to correct 301 // it as well. 302 Node *old_tst = proj->in(0); 303 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx); 304 _nodes.map(end_idx(),nul_chk); 305 cfg->_bbs.map(nul_chk->_idx,this); 306 // Redirect users of old_test to nul_chk 307 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2) 308 old_tst->last_out(i2)->set_req(0, nul_chk); 309 // Clean-up any dead code 310 for (uint i3 = 0; i3 < old_tst->req(); i3++) 311 old_tst->set_req(i3, NULL); 312 313 cfg->latency_from_uses(nul_chk); 314 cfg->latency_from_uses(best); 315 } 316 317 318 //------------------------------select----------------------------------------- 319 // Select a nice fellow from the worklist to schedule next. If there is only 320 // one choice, then use it. Projections take top priority for correctness 321 // reasons - if I see a projection, then it is next. There are a number of 322 // other special cases, for instructions that consume condition codes, et al. 323 // These are chosen immediately. Some instructions are required to immediately 324 // precede the last instruction in the block, and these are taken last. Of the 325 // remaining cases (most), choose the instruction with the greatest latency 326 // (that is, the most number of pseudo-cycles required to the end of the 327 // routine). If there is a tie, choose the instruction with the most inputs. 328 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, int *ready_cnt, VectorSet &next_call, uint sched_slot) { 329 330 // If only a single entry on the stack, use it 331 uint cnt = worklist.size(); 332 if (cnt == 1) { 333 Node *n = worklist[0]; 334 worklist.map(0,worklist.pop()); 335 return n; 336 } 337 338 uint choice = 0; // Bigger is most important 339 uint latency = 0; // Bigger is scheduled first 340 uint score = 0; // Bigger is better 341 int idx = -1; // Index in worklist 342 343 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist 344 // Order in worklist is used to break ties. 345 // See caller for how this is used to delay scheduling 346 // of induction variable increments to after the other 347 // uses of the phi are scheduled. 348 Node *n = worklist[i]; // Get Node on worklist 349 350 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0; 351 if( n->is_Proj() || // Projections always win 352 n->Opcode()== Op_Con || // So does constant 'Top' 353 iop == Op_CreateEx || // Create-exception must start block 354 iop == Op_CheckCastPP 355 ) { 356 worklist.map(i,worklist.pop()); 357 return n; 358 } 359 360 // Final call in a block must be adjacent to 'catch' 361 Node *e = end(); 362 if( e->is_Catch() && e->in(0)->in(0) == n ) 363 continue; 364 365 // Memory op for an implicit null check has to be at the end of the block 366 if( e->is_MachNullCheck() && e->in(1) == n ) 367 continue; 368 369 uint n_choice = 2; 370 371 // See if this instruction is consumed by a branch. If so, then (as the 372 // branch is the last instruction in the basic block) force it to the 373 // end of the basic block 374 if ( must_clone[iop] ) { 375 // See if any use is a branch 376 bool found_machif = false; 377 378 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 379 Node* use = n->fast_out(j); 380 381 // The use is a conditional branch, make them adjacent 382 if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) { 383 found_machif = true; 384 break; 385 } 386 387 // More than this instruction pending for successor to be ready, 388 // don't choose this if other opportunities are ready 389 if (ready_cnt[use->_idx] > 1) 390 n_choice = 1; 391 } 392 393 // loop terminated, prefer not to use this instruction 394 if (found_machif) 395 continue; 396 } 397 398 // See if this has a predecessor that is "must_clone", i.e. sets the 399 // condition code. If so, choose this first 400 for (uint j = 0; j < n->req() ; j++) { 401 Node *inn = n->in(j); 402 if (inn) { 403 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) { 404 n_choice = 3; 405 break; 406 } 407 } 408 } 409 410 // MachTemps should be scheduled last so they are near their uses 411 if (n->is_MachTemp()) { 412 n_choice = 1; 413 } 414 415 uint n_latency = cfg->_node_latency.at_grow(n->_idx); 416 uint n_score = n->req(); // Many inputs get high score to break ties 417 418 // Keep best latency found 419 if( choice < n_choice || 420 ( choice == n_choice && 421 ( latency < n_latency || 422 ( latency == n_latency && 423 ( score < n_score ))))) { 424 choice = n_choice; 425 latency = n_latency; 426 score = n_score; 427 idx = i; // Also keep index in worklist 428 } 429 } // End of for all ready nodes in worklist 430 431 assert(idx >= 0, "index should be set"); 432 Node *n = worklist[(uint)idx]; // Get the winner 433 434 worklist.map((uint)idx, worklist.pop()); // Compress worklist 435 return n; 436 } 437 438 439 //------------------------------set_next_call---------------------------------- 440 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) { 441 if( next_call.test_set(n->_idx) ) return; 442 for( uint i=0; i<n->len(); i++ ) { 443 Node *m = n->in(i); 444 if( !m ) continue; // must see all nodes in block that precede call 445 if( bbs[m->_idx] == this ) 446 set_next_call( m, next_call, bbs ); 447 } 448 } 449 450 //------------------------------needed_for_next_call--------------------------- 451 // Set the flag 'next_call' for each Node that is needed for the next call to 452 // be scheduled. This flag lets me bias scheduling so Nodes needed for the 453 // next subroutine call get priority - basically it moves things NOT needed 454 // for the next call till after the call. This prevents me from trying to 455 // carry lots of stuff live across a call. 456 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) { 457 // Find the next control-defining Node in this block 458 Node* call = NULL; 459 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) { 460 Node* m = this_call->fast_out(i); 461 if( bbs[m->_idx] == this && // Local-block user 462 m != this_call && // Not self-start node 463 m->is_Call() ) 464 call = m; 465 break; 466 } 467 if (call == NULL) return; // No next call (e.g., block end is near) 468 // Set next-call for all inputs to this call 469 set_next_call(call, next_call, bbs); 470 } 471 472 //------------------------------sched_call------------------------------------- 473 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, int *ready_cnt, MachCallNode *mcall, VectorSet &next_call ) { 474 RegMask regs; 475 476 // Schedule all the users of the call right now. All the users are 477 // projection Nodes, so they must be scheduled next to the call. 478 // Collect all the defined registers. 479 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) { 480 Node* n = mcall->fast_out(i); 481 assert( n->Opcode()==Op_MachProj, "" ); 482 --ready_cnt[n->_idx]; 483 assert( !ready_cnt[n->_idx], "" ); 484 // Schedule next to call 485 _nodes.map(node_cnt++, n); 486 // Collect defined registers 487 regs.OR(n->out_RegMask()); 488 // Check for scheduling the next control-definer 489 if( n->bottom_type() == Type::CONTROL ) 490 // Warm up next pile of heuristic bits 491 needed_for_next_call(n, next_call, bbs); 492 493 // Children of projections are now all ready 494 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 495 Node* m = n->fast_out(j); // Get user 496 if( bbs[m->_idx] != this ) continue; 497 if( m->is_Phi() ) continue; 498 if( !--ready_cnt[m->_idx] ) 499 worklist.push(m); 500 } 501 502 } 503 504 // Act as if the call defines the Frame Pointer. 505 // Certainly the FP is alive and well after the call. 506 regs.Insert(matcher.c_frame_pointer()); 507 508 // Set all registers killed and not already defined by the call. 509 uint r_cnt = mcall->tf()->range()->cnt(); 510 int op = mcall->ideal_Opcode(); 511 MachProjNode *proj = new (matcher.C, 1) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj ); 512 bbs.map(proj->_idx,this); 513 _nodes.insert(node_cnt++, proj); 514 515 // Select the right register save policy. 516 const char * save_policy; 517 switch (op) { 518 case Op_CallRuntime: 519 case Op_CallLeaf: 520 case Op_CallLeafNoFP: 521 // Calling C code so use C calling convention 522 save_policy = matcher._c_reg_save_policy; 523 break; 524 525 case Op_CallStaticJava: 526 case Op_CallDynamicJava: 527 // Calling Java code so use Java calling convention 528 save_policy = matcher._register_save_policy; 529 break; 530 531 default: 532 ShouldNotReachHere(); 533 } 534 535 // When using CallRuntime mark SOE registers as killed by the call 536 // so values that could show up in the RegisterMap aren't live in a 537 // callee saved register since the register wouldn't know where to 538 // find them. CallLeaf and CallLeafNoFP are ok because they can't 539 // have debug info on them. Strictly speaking this only needs to be 540 // done for oops since idealreg2debugmask takes care of debug info 541 // references but there no way to handle oops differently than other 542 // pointers as far as the kill mask goes. 543 bool exclude_soe = op == Op_CallRuntime; 544 545 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask()); 546 547 // Fill in the kill mask for the call 548 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) { 549 if( !regs.Member(r) ) { // Not already defined by the call 550 // Save-on-call register? 551 if ((save_policy[r] == 'C') || 552 (save_policy[r] == 'A') || 553 ((save_policy[r] == 'E') && exclude_soe)) { 554 proj->_rout.Insert(r); 555 } 556 } 557 } 558 559 return node_cnt; 560 } 561 562 563 //------------------------------schedule_local--------------------------------- 564 // Topological sort within a block. Someday become a real scheduler. 565 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, int *ready_cnt, VectorSet &next_call) { 566 // Already "sorted" are the block start Node (as the first entry), and 567 // the block-ending Node and any trailing control projections. We leave 568 // these alone. PhiNodes and ParmNodes are made to follow the block start 569 // Node. Everything else gets topo-sorted. 570 571 #ifndef PRODUCT 572 if (cfg->trace_opto_pipelining()) { 573 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order); 574 for (uint i = 0;i < _nodes.size();i++) { 575 tty->print("# "); 576 _nodes[i]->fast_dump(); 577 } 578 tty->print_cr("#"); 579 } 580 #endif 581 582 // RootNode is already sorted 583 if( _nodes.size() == 1 ) return true; 584 585 // Move PhiNodes and ParmNodes from 1 to cnt up to the start 586 uint node_cnt = end_idx(); 587 uint phi_cnt = 1; 588 uint i; 589 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi 590 Node *n = _nodes[i]; 591 if( n->is_Phi() || // Found a PhiNode or ParmNode 592 (n->is_Proj() && n->in(0) == head()) ) { 593 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt 594 _nodes.map(i,_nodes[phi_cnt]); 595 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front 596 } else { // All others 597 // Count block-local inputs to 'n' 598 uint cnt = n->len(); // Input count 599 uint local = 0; 600 for( uint j=0; j<cnt; j++ ) { 601 Node *m = n->in(j); 602 if( m && cfg->_bbs[m->_idx] == this && !m->is_top() ) 603 local++; // One more block-local input 604 } 605 ready_cnt[n->_idx] = local; // Count em up 606 607 // A few node types require changing a required edge to a precedence edge 608 // before allocation. 609 if( UseConcMarkSweepGC || UseG1GC ) { 610 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) { 611 // Note: Required edges with an index greater than oper_input_base 612 // are not supported by the allocator. 613 // Note2: Can only depend on unmatched edge being last, 614 // can not depend on its absolute position. 615 Node *oop_store = n->in(n->req() - 1); 616 n->del_req(n->req() - 1); 617 n->add_prec(oop_store); 618 assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark"); 619 } 620 } 621 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire && 622 n->req() > TypeFunc::Parms ) { 623 // MemBarAcquire could be created without Precedent edge. 624 // del_req() replaces the specified edge with the last input edge 625 // and then removes the last edge. If the specified edge > number of 626 // edges the last edge will be moved outside of the input edges array 627 // and the edge will be lost. This is why this code should be 628 // executed only when Precedent (== TypeFunc::Parms) edge is present. 629 Node *x = n->in(TypeFunc::Parms); 630 n->del_req(TypeFunc::Parms); 631 n->add_prec(x); 632 } 633 } 634 } 635 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count 636 ready_cnt[_nodes[i2]->_idx] = 0; 637 638 // All the prescheduled guys do not hold back internal nodes 639 uint i3; 640 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled 641 Node *n = _nodes[i3]; // Get pre-scheduled 642 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 643 Node* m = n->fast_out(j); 644 if( cfg->_bbs[m->_idx] ==this ) // Local-block user 645 ready_cnt[m->_idx]--; // Fix ready count 646 } 647 } 648 649 Node_List delay; 650 // Make a worklist 651 Node_List worklist; 652 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist 653 Node *m = _nodes[i4]; 654 if( !ready_cnt[m->_idx] ) { // Zero ready count? 655 if (m->is_iteratively_computed()) { 656 // Push induction variable increments last to allow other uses 657 // of the phi to be scheduled first. The select() method breaks 658 // ties in scheduling by worklist order. 659 delay.push(m); 660 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) { 661 // Force the CreateEx to the top of the list so it's processed 662 // first and ends up at the start of the block. 663 worklist.insert(0, m); 664 } else { 665 worklist.push(m); // Then on to worklist! 666 } 667 } 668 } 669 while (delay.size()) { 670 Node* d = delay.pop(); 671 worklist.push(d); 672 } 673 674 // Warm up the 'next_call' heuristic bits 675 needed_for_next_call(_nodes[0], next_call, cfg->_bbs); 676 677 #ifndef PRODUCT 678 if (cfg->trace_opto_pipelining()) { 679 for (uint j=0; j<_nodes.size(); j++) { 680 Node *n = _nodes[j]; 681 int idx = n->_idx; 682 tty->print("# ready cnt:%3d ", ready_cnt[idx]); 683 tty->print("latency:%3d ", cfg->_node_latency.at_grow(idx)); 684 tty->print("%4d: %s\n", idx, n->Name()); 685 } 686 } 687 #endif 688 689 // Pull from worklist and schedule 690 while( worklist.size() ) { // Worklist is not ready 691 692 #ifndef PRODUCT 693 if (cfg->trace_opto_pipelining()) { 694 tty->print("# ready list:"); 695 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 696 Node *n = worklist[i]; // Get Node on worklist 697 tty->print(" %d", n->_idx); 698 } 699 tty->cr(); 700 } 701 #endif 702 703 // Select and pop a ready guy from worklist 704 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt); 705 _nodes.map(phi_cnt++,n); // Schedule him next 706 707 #ifndef PRODUCT 708 if (cfg->trace_opto_pipelining()) { 709 tty->print("# select %d: %s", n->_idx, n->Name()); 710 tty->print(", latency:%d", cfg->_node_latency.at_grow(n->_idx)); 711 n->dump(); 712 if (Verbose) { 713 tty->print("# ready list:"); 714 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 715 Node *n = worklist[i]; // Get Node on worklist 716 tty->print(" %d", n->_idx); 717 } 718 tty->cr(); 719 } 720 } 721 722 #endif 723 if( n->is_MachCall() ) { 724 MachCallNode *mcall = n->as_MachCall(); 725 phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call); 726 continue; 727 } 728 // Children are now all ready 729 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) { 730 Node* m = n->fast_out(i5); // Get user 731 if( cfg->_bbs[m->_idx] != this ) continue; 732 if( m->is_Phi() ) continue; 733 if( !--ready_cnt[m->_idx] ) 734 worklist.push(m); 735 } 736 } 737 738 if( phi_cnt != end_idx() ) { 739 // did not schedule all. Retry, Bailout, or Die 740 Compile* C = matcher.C; 741 if (C->subsume_loads() == true && !C->failing()) { 742 // Retry with subsume_loads == false 743 // If this is the first failure, the sentinel string will "stick" 744 // to the Compile object, and the C2Compiler will see it and retry. 745 C->record_failure(C2Compiler::retry_no_subsuming_loads()); 746 } 747 // assert( phi_cnt == end_idx(), "did not schedule all" ); 748 return false; 749 } 750 751 #ifndef PRODUCT 752 if (cfg->trace_opto_pipelining()) { 753 tty->print_cr("#"); 754 tty->print_cr("# after schedule_local"); 755 for (uint i = 0;i < _nodes.size();i++) { 756 tty->print("# "); 757 _nodes[i]->fast_dump(); 758 } 759 tty->cr(); 760 } 761 #endif 762 763 764 return true; 765 } 766 767 //--------------------------catch_cleanup_fix_all_inputs----------------------- 768 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) { 769 for (uint l = 0; l < use->len(); l++) { 770 if (use->in(l) == old_def) { 771 if (l < use->req()) { 772 use->set_req(l, new_def); 773 } else { 774 use->rm_prec(l); 775 use->add_prec(new_def); 776 l--; 777 } 778 } 779 } 780 } 781 782 //------------------------------catch_cleanup_find_cloned_def------------------ 783 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) { 784 assert( use_blk != def_blk, "Inter-block cleanup only"); 785 786 // The use is some block below the Catch. Find and return the clone of the def 787 // that dominates the use. If there is no clone in a dominating block, then 788 // create a phi for the def in a dominating block. 789 790 // Find which successor block dominates this use. The successor 791 // blocks must all be single-entry (from the Catch only; I will have 792 // split blocks to make this so), hence they all dominate. 793 while( use_blk->_dom_depth > def_blk->_dom_depth+1 ) 794 use_blk = use_blk->_idom; 795 796 // Find the successor 797 Node *fixup = NULL; 798 799 uint j; 800 for( j = 0; j < def_blk->_num_succs; j++ ) 801 if( use_blk == def_blk->_succs[j] ) 802 break; 803 804 if( j == def_blk->_num_succs ) { 805 // Block at same level in dom-tree is not a successor. It needs a 806 // PhiNode, the PhiNode uses from the def and IT's uses need fixup. 807 Node_Array inputs = new Node_List(Thread::current()->resource_area()); 808 for(uint k = 1; k < use_blk->num_preds(); k++) { 809 inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx)); 810 } 811 812 // Check to see if the use_blk already has an identical phi inserted. 813 // If it exists, it will be at the first position since all uses of a 814 // def are processed together. 815 Node *phi = use_blk->_nodes[1]; 816 if( phi->is_Phi() ) { 817 fixup = phi; 818 for (uint k = 1; k < use_blk->num_preds(); k++) { 819 if (phi->in(k) != inputs[k]) { 820 // Not a match 821 fixup = NULL; 822 break; 823 } 824 } 825 } 826 827 // If an existing PhiNode was not found, make a new one. 828 if (fixup == NULL) { 829 Node *new_phi = PhiNode::make(use_blk->head(), def); 830 use_blk->_nodes.insert(1, new_phi); 831 bbs.map(new_phi->_idx, use_blk); 832 for (uint k = 1; k < use_blk->num_preds(); k++) { 833 new_phi->set_req(k, inputs[k]); 834 } 835 fixup = new_phi; 836 } 837 838 } else { 839 // Found the use just below the Catch. Make it use the clone. 840 fixup = use_blk->_nodes[n_clone_idx]; 841 } 842 843 return fixup; 844 } 845 846 //--------------------------catch_cleanup_intra_block-------------------------- 847 // Fix all input edges in use that reference "def". The use is in the same 848 // block as the def and both have been cloned in each successor block. 849 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) { 850 851 // Both the use and def have been cloned. For each successor block, 852 // get the clone of the use, and make its input the clone of the def 853 // found in that block. 854 855 uint use_idx = blk->find_node(use); 856 uint offset_idx = use_idx - beg; 857 for( uint k = 0; k < blk->_num_succs; k++ ) { 858 // Get clone in each successor block 859 Block *sb = blk->_succs[k]; 860 Node *clone = sb->_nodes[offset_idx+1]; 861 assert( clone->Opcode() == use->Opcode(), "" ); 862 863 // Make use-clone reference the def-clone 864 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]); 865 } 866 } 867 868 //------------------------------catch_cleanup_inter_block--------------------- 869 // Fix all input edges in use that reference "def". The use is in a different 870 // block than the def. 871 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) { 872 if( !use_blk ) return; // Can happen if the use is a precedence edge 873 874 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx); 875 catch_cleanup_fix_all_inputs(use, def, new_def); 876 } 877 878 //------------------------------call_catch_cleanup----------------------------- 879 // If we inserted any instructions between a Call and his CatchNode, 880 // clone the instructions on all paths below the Catch. 881 void Block::call_catch_cleanup(Block_Array &bbs) { 882 883 // End of region to clone 884 uint end = end_idx(); 885 if( !_nodes[end]->is_Catch() ) return; 886 // Start of region to clone 887 uint beg = end; 888 while( _nodes[beg-1]->Opcode() != Op_MachProj || 889 !_nodes[beg-1]->in(0)->is_Call() ) { 890 beg--; 891 assert(beg > 0,"Catch cleanup walking beyond block boundary"); 892 } 893 // Range of inserted instructions is [beg, end) 894 if( beg == end ) return; 895 896 // Clone along all Catch output paths. Clone area between the 'beg' and 897 // 'end' indices. 898 for( uint i = 0; i < _num_succs; i++ ) { 899 Block *sb = _succs[i]; 900 // Clone the entire area; ignoring the edge fixup for now. 901 for( uint j = end; j > beg; j-- ) { 902 Node *clone = _nodes[j-1]->clone(); 903 sb->_nodes.insert( 1, clone ); 904 bbs.map(clone->_idx,sb); 905 } 906 } 907 908 909 // Fixup edges. Check the def-use info per cloned Node 910 for(uint i2 = beg; i2 < end; i2++ ) { 911 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block 912 Node *n = _nodes[i2]; // Node that got cloned 913 // Need DU safe iterator because of edge manipulation in calls. 914 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area()); 915 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) { 916 out->push(n->fast_out(j1)); 917 } 918 uint max = out->size(); 919 for (uint j = 0; j < max; j++) {// For all users 920 Node *use = out->pop(); 921 Block *buse = bbs[use->_idx]; 922 if( use->is_Phi() ) { 923 for( uint k = 1; k < use->req(); k++ ) 924 if( use->in(k) == n ) { 925 Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx); 926 use->set_req(k, fixup); 927 } 928 } else { 929 if (this == buse) { 930 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx); 931 } else { 932 catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx); 933 } 934 } 935 } // End for all users 936 937 } // End of for all Nodes in cloned area 938 939 // Remove the now-dead cloned ops 940 for(uint i3 = beg; i3 < end; i3++ ) { 941 _nodes[beg]->disconnect_inputs(NULL); 942 _nodes.remove(beg); 943 } 944 945 // If the successor blocks have a CreateEx node, move it back to the top 946 for(uint i4 = 0; i4 < _num_succs; i4++ ) { 947 Block *sb = _succs[i4]; 948 uint new_cnt = end - beg; 949 // Remove any newly created, but dead, nodes. 950 for( uint j = new_cnt; j > 0; j-- ) { 951 Node *n = sb->_nodes[j]; 952 if (n->outcnt() == 0 && 953 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){ 954 n->disconnect_inputs(NULL); 955 sb->_nodes.remove(j); 956 new_cnt--; 957 } 958 } 959 // If any newly created nodes remain, move the CreateEx node to the top 960 if (new_cnt > 0) { 961 Node *cex = sb->_nodes[1+new_cnt]; 962 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) { 963 sb->_nodes.remove(1+new_cnt); 964 sb->_nodes.insert(1,cex); 965 } 966 } 967 } 968 }