1 /* 2 * Copyright (c) 1998, 2018, 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 "asm/macroAssembler.inline.hpp" 27 #include "memory/allocation.inline.hpp" 28 #include "opto/ad.hpp" 29 #include "opto/block.hpp" 30 #include "opto/c2compiler.hpp" 31 #include "opto/callnode.hpp" 32 #include "opto/cfgnode.hpp" 33 #include "opto/machnode.hpp" 34 #include "opto/runtime.hpp" 35 #include "opto/chaitin.hpp" 36 #include "runtime/sharedRuntime.hpp" 37 #include "utilities/macros.hpp" 38 #if INCLUDE_SHENANDOAHGC 39 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp" 40 #endif 41 42 // Optimization - Graph Style 43 44 // Check whether val is not-null-decoded compressed oop, 45 // i.e. will grab into the base of the heap if it represents NULL. 46 static bool accesses_heap_base_zone(Node *val) { 47 if (Universe::narrow_oop_base() != NULL) { // Implies UseCompressedOops. 48 if (val && val->is_Mach()) { 49 if (val->as_Mach()->ideal_Opcode() == Op_DecodeN) { 50 // This assumes all Decodes with TypePtr::NotNull are matched to nodes that 51 // decode NULL to point to the heap base (Decode_NN). 52 if (val->bottom_type()->is_oopptr()->ptr() == TypePtr::NotNull) { 53 return true; 54 } 55 } 56 // Must recognize load operation with Decode matched in memory operand. 57 // We should not reach here exept for PPC/AIX, as os::zero_page_read_protected() 58 // returns true everywhere else. On PPC, no such memory operands 59 // exist, therefore we did not yet implement a check for such operands. 60 NOT_AIX(Unimplemented()); 61 } 62 } 63 return false; 64 } 65 66 static bool needs_explicit_null_check_for_read(Node *val) { 67 // On some OSes (AIX) the page at address 0 is only write protected. 68 // If so, only Store operations will trap. 69 if (os::zero_page_read_protected()) { 70 return false; // Implicit null check will work. 71 } 72 // Also a read accessing the base of a heap-based compressed heap will trap. 73 if (accesses_heap_base_zone(val) && // Hits the base zone page. 74 Universe::narrow_oop_use_implicit_null_checks()) { // Base zone page is protected. 75 return false; 76 } 77 78 return true; 79 } 80 81 //------------------------------implicit_null_check---------------------------- 82 // Detect implicit-null-check opportunities. Basically, find NULL checks 83 // with suitable memory ops nearby. Use the memory op to do the NULL check. 84 // I can generate a memory op if there is not one nearby. 85 // The proj is the control projection for the not-null case. 86 // The val is the pointer being checked for nullness or 87 // decodeHeapOop_not_null node if it did not fold into address. 88 void PhaseCFG::implicit_null_check(Block* block, Node *proj, Node *val, int allowed_reasons) { 89 // Assume if null check need for 0 offset then always needed 90 // Intel solaris doesn't support any null checks yet and no 91 // mechanism exists (yet) to set the switches at an os_cpu level 92 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return; 93 94 // Make sure the ptr-is-null path appears to be uncommon! 95 float f = block->end()->as_MachIf()->_prob; 96 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f; 97 if( f > PROB_UNLIKELY_MAG(4) ) return; 98 99 uint bidx = 0; // Capture index of value into memop 100 bool was_store; // Memory op is a store op 101 102 // Get the successor block for if the test ptr is non-null 103 Block* not_null_block; // this one goes with the proj 104 Block* null_block; 105 if (block->get_node(block->number_of_nodes()-1) == proj) { 106 null_block = block->_succs[0]; 107 not_null_block = block->_succs[1]; 108 } else { 109 assert(block->get_node(block->number_of_nodes()-2) == proj, "proj is one or the other"); 110 not_null_block = block->_succs[0]; 111 null_block = block->_succs[1]; 112 } 113 while (null_block->is_Empty() == Block::empty_with_goto) { 114 null_block = null_block->_succs[0]; 115 } 116 117 // Search the exception block for an uncommon trap. 118 // (See Parse::do_if and Parse::do_ifnull for the reason 119 // we need an uncommon trap. Briefly, we need a way to 120 // detect failure of this optimization, as in 6366351.) 121 { 122 bool found_trap = false; 123 for (uint i1 = 0; i1 < null_block->number_of_nodes(); i1++) { 124 Node* nn = null_block->get_node(i1); 125 if (nn->is_MachCall() && 126 nn->as_MachCall()->entry_point() == SharedRuntime::uncommon_trap_blob()->entry_point()) { 127 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type(); 128 if (trtype->isa_int() && trtype->is_int()->is_con()) { 129 jint tr_con = trtype->is_int()->get_con(); 130 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con); 131 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con); 132 assert((int)reason < (int)BitsPerInt, "recode bit map"); 133 if (is_set_nth_bit(allowed_reasons, (int) reason) 134 && action != Deoptimization::Action_none) { 135 // This uncommon trap is sure to recompile, eventually. 136 // When that happens, C->too_many_traps will prevent 137 // this transformation from happening again. 138 found_trap = true; 139 } 140 } 141 break; 142 } 143 } 144 if (!found_trap) { 145 // We did not find an uncommon trap. 146 return; 147 } 148 } 149 150 // Check for decodeHeapOop_not_null node which did not fold into address 151 bool is_decoden = ((intptr_t)val) & 1; 152 val = (Node*)(((intptr_t)val) & ~1); 153 154 assert(!is_decoden || (val->in(0) == NULL) && val->is_Mach() && 155 (val->as_Mach()->ideal_Opcode() == Op_DecodeN), "sanity"); 156 157 // Search the successor block for a load or store who's base value is also 158 // the tested value. There may be several. 159 Node_List *out = new Node_List(Thread::current()->resource_area()); 160 MachNode *best = NULL; // Best found so far 161 for (DUIterator i = val->outs(); val->has_out(i); i++) { 162 Node *m = val->out(i); 163 if( !m->is_Mach() ) continue; 164 MachNode *mach = m->as_Mach(); 165 was_store = false; 166 int iop = mach->ideal_Opcode(); 167 switch( iop ) { 168 case Op_LoadB: 169 case Op_LoadUB: 170 case Op_LoadUS: 171 case Op_LoadD: 172 case Op_LoadF: 173 case Op_LoadI: 174 case Op_LoadL: 175 case Op_LoadP: 176 case Op_LoadBarrierSlowReg: 177 case Op_LoadBarrierWeakSlowReg: 178 case Op_LoadN: 179 case Op_LoadS: 180 case Op_LoadKlass: 181 case Op_LoadNKlass: 182 case Op_LoadRange: 183 case Op_LoadD_unaligned: 184 case Op_LoadL_unaligned: 185 case Op_ShenandoahReadBarrier: 186 assert(mach->in(2) == val, "should be address"); 187 break; 188 case Op_StoreB: 189 case Op_StoreC: 190 case Op_StoreCM: 191 case Op_StoreD: 192 case Op_StoreF: 193 case Op_StoreI: 194 case Op_StoreL: 195 case Op_StoreP: 196 case Op_StoreN: 197 case Op_StoreNKlass: 198 was_store = true; // Memory op is a store op 199 // Stores will have their address in slot 2 (memory in slot 1). 200 // If the value being nul-checked is in another slot, it means we 201 // are storing the checked value, which does NOT check the value! 202 if( mach->in(2) != val ) continue; 203 break; // Found a memory op? 204 case Op_StrComp: 205 case Op_StrEquals: 206 case Op_StrIndexOf: 207 case Op_StrIndexOfChar: 208 case Op_AryEq: 209 case Op_StrInflatedCopy: 210 case Op_StrCompressedCopy: 211 case Op_EncodeISOArray: 212 case Op_HasNegatives: 213 // Not a legit memory op for implicit null check regardless of 214 // embedded loads 215 continue; 216 default: // Also check for embedded loads 217 if( !mach->needs_anti_dependence_check() ) 218 continue; // Not an memory op; skip it 219 if( must_clone[iop] ) { 220 // Do not move nodes which produce flags because 221 // RA will try to clone it to place near branch and 222 // it will cause recompilation, see clone_node(). 223 continue; 224 } 225 { 226 // Check that value is used in memory address in 227 // instructions with embedded load (CmpP val1,(val2+off)). 228 Node* base; 229 Node* index; 230 const MachOper* oper = mach->memory_inputs(base, index); 231 if (oper == NULL || oper == (MachOper*)-1) { 232 continue; // Not an memory op; skip it 233 } 234 if (val == base || 235 (val == index && val->bottom_type()->isa_narrowoop())) { 236 break; // Found it 237 } else { 238 continue; // Skip it 239 } 240 } 241 break; 242 } 243 244 // On some OSes (AIX) the page at address 0 is only write protected. 245 // If so, only Store operations will trap. 246 // But a read accessing the base of a heap-based compressed heap will trap. 247 if (!was_store && needs_explicit_null_check_for_read(val)) { 248 continue; 249 } 250 251 // Check that node's control edge is not-null block's head or dominates it, 252 // otherwise we can't hoist it because there are other control dependencies. 253 Node* ctrl = mach->in(0); 254 if (ctrl != NULL && !(ctrl == not_null_block->head() || 255 get_block_for_node(ctrl)->dominates(not_null_block))) { 256 continue; 257 } 258 259 // check if the offset is not too high for implicit exception 260 { 261 intptr_t offset = 0; 262 const TypePtr *adr_type = NULL; // Do not need this return value here 263 const Node* base = mach->get_base_and_disp(offset, adr_type); 264 if (base == NULL || base == NodeSentinel) { 265 // Narrow oop address doesn't have base, only index. 266 // Give up if offset is beyond page size or if heap base is not protected. 267 if (val->bottom_type()->isa_narrowoop() && 268 (MacroAssembler::needs_explicit_null_check(offset) || 269 !Universe::narrow_oop_use_implicit_null_checks())) 270 continue; 271 // cannot reason about it; is probably not implicit null exception 272 } else { 273 const TypePtr* tptr; 274 if (UseCompressedOops && (Universe::narrow_oop_shift() == 0 || 275 Universe::narrow_klass_shift() == 0)) { 276 // 32-bits narrow oop can be the base of address expressions 277 tptr = base->get_ptr_type(); 278 } else { 279 // only regular oops are expected here 280 tptr = base->bottom_type()->is_ptr(); 281 } 282 // Give up if offset is not a compile-time constant. 283 if (offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot) 284 continue; 285 offset += tptr->_offset; // correct if base is offseted 286 // Give up if reference is beyond page size. 287 if (MacroAssembler::needs_explicit_null_check(offset)) 288 continue; 289 // Give up if base is a decode node and the heap base is not protected. 290 if (base->is_Mach() && base->as_Mach()->ideal_Opcode() == Op_DecodeN && 291 !Universe::narrow_oop_use_implicit_null_checks()) 292 continue; 293 } 294 } 295 296 // Check ctrl input to see if the null-check dominates the memory op 297 Block *cb = get_block_for_node(mach); 298 cb = cb->_idom; // Always hoist at least 1 block 299 if( !was_store ) { // Stores can be hoisted only one block 300 while( cb->_dom_depth > (block->_dom_depth + 1)) 301 cb = cb->_idom; // Hoist loads as far as we want 302 // The non-null-block should dominate the memory op, too. Live 303 // range spilling will insert a spill in the non-null-block if it is 304 // needs to spill the memory op for an implicit null check. 305 if (cb->_dom_depth == (block->_dom_depth + 1)) { 306 if (cb != not_null_block) continue; 307 cb = cb->_idom; 308 } 309 } 310 if( cb != block ) continue; 311 312 // Found a memory user; see if it can be hoisted to check-block 313 uint vidx = 0; // Capture index of value into memop 314 uint j; 315 for( j = mach->req()-1; j > 0; j-- ) { 316 if( mach->in(j) == val ) { 317 vidx = j; 318 // Ignore DecodeN val which could be hoisted to where needed. 319 if( is_decoden ) continue; 320 } 321 // Block of memory-op input 322 Block *inb = get_block_for_node(mach->in(j)); 323 Block *b = block; // Start from nul check 324 while( b != inb && b->_dom_depth > inb->_dom_depth ) 325 b = b->_idom; // search upwards for input 326 // See if input dominates null check 327 if( b != inb ) 328 break; 329 } 330 if( j > 0 ) 331 continue; 332 Block *mb = get_block_for_node(mach); 333 // Hoisting stores requires more checks for the anti-dependence case. 334 // Give up hoisting if we have to move the store past any load. 335 if( was_store ) { 336 Block *b = mb; // Start searching here for a local load 337 // mach use (faulting) trying to hoist 338 // n might be blocker to hoisting 339 while( b != block ) { 340 uint k; 341 for( k = 1; k < b->number_of_nodes(); k++ ) { 342 Node *n = b->get_node(k); 343 if( n->needs_anti_dependence_check() && 344 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) ) 345 break; // Found anti-dependent load 346 } 347 if( k < b->number_of_nodes() ) 348 break; // Found anti-dependent load 349 // Make sure control does not do a merge (would have to check allpaths) 350 if( b->num_preds() != 2 ) break; 351 b = get_block_for_node(b->pred(1)); // Move up to predecessor block 352 } 353 if( b != block ) continue; 354 } 355 356 // Make sure this memory op is not already being used for a NullCheck 357 Node *e = mb->end(); 358 if( e->is_MachNullCheck() && e->in(1) == mach ) 359 continue; // Already being used as a NULL check 360 361 // Found a candidate! Pick one with least dom depth - the highest 362 // in the dom tree should be closest to the null check. 363 if (best == NULL || get_block_for_node(mach)->_dom_depth < get_block_for_node(best)->_dom_depth) { 364 best = mach; 365 bidx = vidx; 366 } 367 } 368 // No candidate! 369 if (best == NULL) { 370 return; 371 } 372 373 // ---- Found an implicit null check 374 #ifndef PRODUCT 375 extern int implicit_null_checks; 376 implicit_null_checks++; 377 #endif 378 379 if( is_decoden ) { 380 // Check if we need to hoist decodeHeapOop_not_null first. 381 Block *valb = get_block_for_node(val); 382 if( block != valb && block->_dom_depth < valb->_dom_depth ) { 383 // Hoist it up to the end of the test block. 384 valb->find_remove(val); 385 block->add_inst(val); 386 map_node_to_block(val, block); 387 // DecodeN on x86 may kill flags. Check for flag-killing projections 388 // that also need to be hoisted. 389 for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) { 390 Node* n = val->fast_out(j); 391 if( n->is_MachProj() ) { 392 get_block_for_node(n)->find_remove(n); 393 block->add_inst(n); 394 map_node_to_block(n, block); 395 } 396 } 397 } 398 } 399 // Hoist the memory candidate up to the end of the test block. 400 Block *old_block = get_block_for_node(best); 401 old_block->find_remove(best); 402 block->add_inst(best); 403 map_node_to_block(best, block); 404 405 // Move the control dependence if it is pinned to not-null block. 406 // Don't change it in other cases: NULL or dominating control. 407 if (best->in(0) == not_null_block->head()) { 408 // Set it to control edge of null check. 409 best->set_req(0, proj->in(0)->in(0)); 410 } 411 412 // Check for flag-killing projections that also need to be hoisted 413 // Should be DU safe because no edge updates. 414 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) { 415 Node* n = best->fast_out(j); 416 if( n->is_MachProj() ) { 417 get_block_for_node(n)->find_remove(n); 418 block->add_inst(n); 419 map_node_to_block(n, block); 420 } 421 } 422 423 // proj==Op_True --> ne test; proj==Op_False --> eq test. 424 // One of two graph shapes got matched: 425 // (IfTrue (If (Bool NE (CmpP ptr NULL)))) 426 // (IfFalse (If (Bool EQ (CmpP ptr NULL)))) 427 // NULL checks are always branch-if-eq. If we see a IfTrue projection 428 // then we are replacing a 'ne' test with a 'eq' NULL check test. 429 // We need to flip the projections to keep the same semantics. 430 if( proj->Opcode() == Op_IfTrue ) { 431 // Swap order of projections in basic block to swap branch targets 432 Node *tmp1 = block->get_node(block->end_idx()+1); 433 Node *tmp2 = block->get_node(block->end_idx()+2); 434 block->map_node(tmp2, block->end_idx()+1); 435 block->map_node(tmp1, block->end_idx()+2); 436 Node *tmp = new Node(C->top()); // Use not NULL input 437 tmp1->replace_by(tmp); 438 tmp2->replace_by(tmp1); 439 tmp->replace_by(tmp2); 440 tmp->destruct(); 441 } 442 443 // Remove the existing null check; use a new implicit null check instead. 444 // Since schedule-local needs precise def-use info, we need to correct 445 // it as well. 446 Node *old_tst = proj->in(0); 447 MachNode *nul_chk = new MachNullCheckNode(old_tst->in(0),best,bidx); 448 block->map_node(nul_chk, block->end_idx()); 449 map_node_to_block(nul_chk, block); 450 // Redirect users of old_test to nul_chk 451 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2) 452 old_tst->last_out(i2)->set_req(0, nul_chk); 453 // Clean-up any dead code 454 for (uint i3 = 0; i3 < old_tst->req(); i3++) { 455 Node* in = old_tst->in(i3); 456 old_tst->set_req(i3, NULL); 457 if (in->outcnt() == 0) { 458 // Remove dead input node 459 in->disconnect_inputs(NULL, C); 460 block->find_remove(in); 461 } 462 } 463 464 latency_from_uses(nul_chk); 465 latency_from_uses(best); 466 467 // insert anti-dependences to defs in this block 468 if (! best->needs_anti_dependence_check()) { 469 for (uint k = 1; k < block->number_of_nodes(); k++) { 470 Node *n = block->get_node(k); 471 if (n->needs_anti_dependence_check() && 472 n->in(LoadNode::Memory) == best->in(StoreNode::Memory)) { 473 // Found anti-dependent load 474 insert_anti_dependences(block, n); 475 } 476 } 477 } 478 } 479 480 481 //------------------------------select----------------------------------------- 482 // Select a nice fellow from the worklist to schedule next. If there is only 483 // one choice, then use it. Projections take top priority for correctness 484 // reasons - if I see a projection, then it is next. There are a number of 485 // other special cases, for instructions that consume condition codes, et al. 486 // These are chosen immediately. Some instructions are required to immediately 487 // precede the last instruction in the block, and these are taken last. Of the 488 // remaining cases (most), choose the instruction with the greatest latency 489 // (that is, the most number of pseudo-cycles required to the end of the 490 // routine). If there is a tie, choose the instruction with the most inputs. 491 Node* PhaseCFG::select( 492 Block* block, 493 Node_List &worklist, 494 GrowableArray<int> &ready_cnt, 495 VectorSet &next_call, 496 uint sched_slot, 497 intptr_t* recalc_pressure_nodes) { 498 499 // If only a single entry on the stack, use it 500 uint cnt = worklist.size(); 501 if (cnt == 1) { 502 Node *n = worklist[0]; 503 worklist.map(0,worklist.pop()); 504 return n; 505 } 506 507 uint choice = 0; // Bigger is most important 508 uint latency = 0; // Bigger is scheduled first 509 uint score = 0; // Bigger is better 510 int idx = -1; // Index in worklist 511 int cand_cnt = 0; // Candidate count 512 bool block_size_threshold_ok = (block->number_of_nodes() > 10) ? true : false; 513 514 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist 515 // Order in worklist is used to break ties. 516 // See caller for how this is used to delay scheduling 517 // of induction variable increments to after the other 518 // uses of the phi are scheduled. 519 Node *n = worklist[i]; // Get Node on worklist 520 521 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0; 522 if( n->is_Proj() || // Projections always win 523 n->Opcode()== Op_Con || // So does constant 'Top' 524 iop == Op_CreateEx || // Create-exception must start block 525 iop == Op_CheckCastPP 526 ) { 527 worklist.map(i,worklist.pop()); 528 return n; 529 } 530 531 // Final call in a block must be adjacent to 'catch' 532 Node *e = block->end(); 533 if( e->is_Catch() && e->in(0)->in(0) == n ) 534 continue; 535 536 // Memory op for an implicit null check has to be at the end of the block 537 if( e->is_MachNullCheck() && e->in(1) == n ) 538 continue; 539 540 // Schedule IV increment last. 541 if (e->is_Mach() && e->as_Mach()->ideal_Opcode() == Op_CountedLoopEnd) { 542 // Cmp might be matched into CountedLoopEnd node. 543 Node *cmp = (e->in(1)->ideal_reg() == Op_RegFlags) ? e->in(1) : e; 544 if (cmp->req() > 1 && cmp->in(1) == n && n->is_iteratively_computed()) { 545 continue; 546 } 547 } 548 549 uint n_choice = 2; 550 551 // See if this instruction is consumed by a branch. If so, then (as the 552 // branch is the last instruction in the basic block) force it to the 553 // end of the basic block 554 if ( must_clone[iop] ) { 555 // See if any use is a branch 556 bool found_machif = false; 557 558 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 559 Node* use = n->fast_out(j); 560 561 // The use is a conditional branch, make them adjacent 562 if (use->is_MachIf() && get_block_for_node(use) == block) { 563 found_machif = true; 564 break; 565 } 566 567 // More than this instruction pending for successor to be ready, 568 // don't choose this if other opportunities are ready 569 if (ready_cnt.at(use->_idx) > 1) 570 n_choice = 1; 571 } 572 573 // loop terminated, prefer not to use this instruction 574 if (found_machif) 575 continue; 576 } 577 578 // See if this has a predecessor that is "must_clone", i.e. sets the 579 // condition code. If so, choose this first 580 for (uint j = 0; j < n->req() ; j++) { 581 Node *inn = n->in(j); 582 if (inn) { 583 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) { 584 n_choice = 3; 585 break; 586 } 587 } 588 } 589 590 // MachTemps should be scheduled last so they are near their uses 591 if (n->is_MachTemp()) { 592 n_choice = 1; 593 } 594 595 uint n_latency = get_latency_for_node(n); 596 uint n_score = n->req(); // Many inputs get high score to break ties 597 598 if (OptoRegScheduling && block_size_threshold_ok) { 599 if (recalc_pressure_nodes[n->_idx] == 0x7fff7fff) { 600 _regalloc->_scratch_int_pressure.init(_regalloc->_sched_int_pressure.high_pressure_limit()); 601 _regalloc->_scratch_float_pressure.init(_regalloc->_sched_float_pressure.high_pressure_limit()); 602 // simulate the notion that we just picked this node to schedule 603 n->add_flag(Node::Flag_is_scheduled); 604 // now caculate its effect upon the graph if we did 605 adjust_register_pressure(n, block, recalc_pressure_nodes, false); 606 // return its state for finalize in case somebody else wins 607 n->remove_flag(Node::Flag_is_scheduled); 608 // now save the two final pressure components of register pressure, limiting pressure calcs to short size 609 short int_pressure = (short)_regalloc->_scratch_int_pressure.current_pressure(); 610 short float_pressure = (short)_regalloc->_scratch_float_pressure.current_pressure(); 611 recalc_pressure_nodes[n->_idx] = int_pressure; 612 recalc_pressure_nodes[n->_idx] |= (float_pressure << 16); 613 } 614 615 if (_scheduling_for_pressure) { 616 latency = n_latency; 617 if (n_choice != 3) { 618 // Now evaluate each register pressure component based on threshold in the score. 619 // In general the defining register type will dominate the score, ergo we will not see register pressure grow on both banks 620 // on a single instruction, but we might see it shrink on both banks. 621 // For each use of register that has a register class that is over the high pressure limit, we build n_score up for 622 // live ranges that terminate on this instruction. 623 if (_regalloc->_sched_int_pressure.current_pressure() > _regalloc->_sched_int_pressure.high_pressure_limit()) { 624 short int_pressure = (short)recalc_pressure_nodes[n->_idx]; 625 n_score = (int_pressure < 0) ? ((score + n_score) - int_pressure) : (int_pressure > 0) ? 1 : n_score; 626 } 627 if (_regalloc->_sched_float_pressure.current_pressure() > _regalloc->_sched_float_pressure.high_pressure_limit()) { 628 short float_pressure = (short)(recalc_pressure_nodes[n->_idx] >> 16); 629 n_score = (float_pressure < 0) ? ((score + n_score) - float_pressure) : (float_pressure > 0) ? 1 : n_score; 630 } 631 } else { 632 // make sure we choose these candidates 633 score = 0; 634 } 635 } 636 } 637 638 // Keep best latency found 639 cand_cnt++; 640 if (choice < n_choice || 641 (choice == n_choice && 642 ((StressLCM && Compile::randomized_select(cand_cnt)) || 643 (!StressLCM && 644 (latency < n_latency || 645 (latency == n_latency && 646 (score < n_score))))))) { 647 choice = n_choice; 648 latency = n_latency; 649 score = n_score; 650 idx = i; // Also keep index in worklist 651 } 652 } // End of for all ready nodes in worklist 653 654 guarantee(idx >= 0, "index should be set"); 655 Node *n = worklist[(uint)idx]; // Get the winner 656 657 worklist.map((uint)idx, worklist.pop()); // Compress worklist 658 return n; 659 } 660 661 //-------------------------adjust_register_pressure---------------------------- 662 void PhaseCFG::adjust_register_pressure(Node* n, Block* block, intptr_t* recalc_pressure_nodes, bool finalize_mode) { 663 PhaseLive* liveinfo = _regalloc->get_live(); 664 IndexSet* liveout = liveinfo->live(block); 665 // first adjust the register pressure for the sources 666 for (uint i = 1; i < n->req(); i++) { 667 bool lrg_ends = false; 668 Node *src_n = n->in(i); 669 if (src_n == NULL) continue; 670 if (!src_n->is_Mach()) continue; 671 uint src = _regalloc->_lrg_map.find(src_n); 672 if (src == 0) continue; 673 LRG& lrg_src = _regalloc->lrgs(src); 674 // detect if the live range ends or not 675 if (liveout->member(src) == false) { 676 lrg_ends = true; 677 for (DUIterator_Fast jmax, j = src_n->fast_outs(jmax); j < jmax; j++) { 678 Node* m = src_n->fast_out(j); // Get user 679 if (m == n) continue; 680 if (!m->is_Mach()) continue; 681 MachNode *mach = m->as_Mach(); 682 bool src_matches = false; 683 int iop = mach->ideal_Opcode(); 684 685 switch (iop) { 686 case Op_StoreB: 687 case Op_StoreC: 688 case Op_StoreCM: 689 case Op_StoreD: 690 case Op_StoreF: 691 case Op_StoreI: 692 case Op_StoreL: 693 case Op_StoreP: 694 case Op_StoreN: 695 case Op_StoreVector: 696 case Op_StoreNKlass: 697 for (uint k = 1; k < m->req(); k++) { 698 Node *in = m->in(k); 699 if (in == src_n) { 700 src_matches = true; 701 break; 702 } 703 } 704 break; 705 706 default: 707 src_matches = true; 708 break; 709 } 710 711 // If we have a store as our use, ignore the non source operands 712 if (src_matches == false) continue; 713 714 // Mark every unscheduled use which is not n with a recalculation 715 if ((get_block_for_node(m) == block) && (!m->is_scheduled())) { 716 if (finalize_mode && !m->is_Phi()) { 717 recalc_pressure_nodes[m->_idx] = 0x7fff7fff; 718 } 719 lrg_ends = false; 720 } 721 } 722 } 723 // if none, this live range ends and we can adjust register pressure 724 if (lrg_ends) { 725 if (finalize_mode) { 726 _regalloc->lower_pressure(block, 0, lrg_src, NULL, _regalloc->_sched_int_pressure, _regalloc->_sched_float_pressure); 727 } else { 728 _regalloc->lower_pressure(block, 0, lrg_src, NULL, _regalloc->_scratch_int_pressure, _regalloc->_scratch_float_pressure); 729 } 730 } 731 } 732 733 // now add the register pressure from the dest and evaluate which heuristic we should use: 734 // 1.) The default, latency scheduling 735 // 2.) Register pressure scheduling based on the high pressure limit threshold for int or float register stacks 736 uint dst = _regalloc->_lrg_map.find(n); 737 if (dst != 0) { 738 LRG& lrg_dst = _regalloc->lrgs(dst); 739 if (finalize_mode) { 740 _regalloc->raise_pressure(block, lrg_dst, _regalloc->_sched_int_pressure, _regalloc->_sched_float_pressure); 741 // check to see if we fall over the register pressure cliff here 742 if (_regalloc->_sched_int_pressure.current_pressure() > _regalloc->_sched_int_pressure.high_pressure_limit()) { 743 _scheduling_for_pressure = true; 744 } else if (_regalloc->_sched_float_pressure.current_pressure() > _regalloc->_sched_float_pressure.high_pressure_limit()) { 745 _scheduling_for_pressure = true; 746 } else { 747 // restore latency scheduling mode 748 _scheduling_for_pressure = false; 749 } 750 } else { 751 _regalloc->raise_pressure(block, lrg_dst, _regalloc->_scratch_int_pressure, _regalloc->_scratch_float_pressure); 752 } 753 } 754 } 755 756 //------------------------------set_next_call---------------------------------- 757 void PhaseCFG::set_next_call(Block* block, Node* n, VectorSet& next_call) { 758 if( next_call.test_set(n->_idx) ) return; 759 for( uint i=0; i<n->len(); i++ ) { 760 Node *m = n->in(i); 761 if( !m ) continue; // must see all nodes in block that precede call 762 if (get_block_for_node(m) == block) { 763 set_next_call(block, m, next_call); 764 } 765 } 766 } 767 768 //------------------------------needed_for_next_call--------------------------- 769 // Set the flag 'next_call' for each Node that is needed for the next call to 770 // be scheduled. This flag lets me bias scheduling so Nodes needed for the 771 // next subroutine call get priority - basically it moves things NOT needed 772 // for the next call till after the call. This prevents me from trying to 773 // carry lots of stuff live across a call. 774 void PhaseCFG::needed_for_next_call(Block* block, Node* this_call, VectorSet& next_call) { 775 // Find the next control-defining Node in this block 776 Node* call = NULL; 777 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) { 778 Node* m = this_call->fast_out(i); 779 if (get_block_for_node(m) == block && // Local-block user 780 m != this_call && // Not self-start node 781 m->is_MachCall()) { 782 call = m; 783 break; 784 } 785 } 786 if (call == NULL) return; // No next call (e.g., block end is near) 787 // Set next-call for all inputs to this call 788 set_next_call(block, call, next_call); 789 } 790 791 //------------------------------add_call_kills------------------------------------- 792 // helper function that adds caller save registers to MachProjNode 793 static void add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe, bool exclude_fp) { 794 // Fill in the kill mask for the call 795 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) { 796 if (exclude_fp && (register_save_type[r] == Op_RegF || register_save_type[r] == Op_RegD)) { 797 continue; 798 } 799 if( !regs.Member(r) ) { // Not already defined by the call 800 // Save-on-call register? 801 if ((save_policy[r] == 'C') || 802 (save_policy[r] == 'A') || 803 ((save_policy[r] == 'E') && exclude_soe)) { 804 proj->_rout.Insert(r); 805 } 806 } 807 } 808 } 809 810 811 //------------------------------sched_call------------------------------------- 812 uint PhaseCFG::sched_call(Block* block, uint node_cnt, Node_List& worklist, GrowableArray<int>& ready_cnt, MachCallNode* mcall, VectorSet& next_call) { 813 RegMask regs; 814 815 // Schedule all the users of the call right now. All the users are 816 // projection Nodes, so they must be scheduled next to the call. 817 // Collect all the defined registers. 818 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) { 819 Node* n = mcall->fast_out(i); 820 assert( n->is_MachProj(), "" ); 821 int n_cnt = ready_cnt.at(n->_idx)-1; 822 ready_cnt.at_put(n->_idx, n_cnt); 823 assert( n_cnt == 0, "" ); 824 // Schedule next to call 825 block->map_node(n, node_cnt++); 826 // Collect defined registers 827 regs.OR(n->out_RegMask()); 828 // Check for scheduling the next control-definer 829 if( n->bottom_type() == Type::CONTROL ) 830 // Warm up next pile of heuristic bits 831 needed_for_next_call(block, n, next_call); 832 833 // Children of projections are now all ready 834 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 835 Node* m = n->fast_out(j); // Get user 836 if(get_block_for_node(m) != block) { 837 continue; 838 } 839 if( m->is_Phi() ) continue; 840 int m_cnt = ready_cnt.at(m->_idx) - 1; 841 ready_cnt.at_put(m->_idx, m_cnt); 842 if( m_cnt == 0 ) 843 worklist.push(m); 844 } 845 846 } 847 848 // Act as if the call defines the Frame Pointer. 849 // Certainly the FP is alive and well after the call. 850 regs.Insert(_matcher.c_frame_pointer()); 851 852 // Set all registers killed and not already defined by the call. 853 uint r_cnt = mcall->tf()->range()->cnt(); 854 int op = mcall->ideal_Opcode(); 855 MachProjNode *proj = new MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj ); 856 map_node_to_block(proj, block); 857 block->insert_node(proj, node_cnt++); 858 859 // Select the right register save policy. 860 const char *save_policy = NULL; 861 switch (op) { 862 case Op_CallRuntime: 863 case Op_CallLeaf: 864 case Op_CallLeafNoFP: 865 // Calling C code so use C calling convention 866 save_policy = _matcher._c_reg_save_policy; 867 break; 868 869 case Op_CallStaticJava: 870 case Op_CallDynamicJava: 871 // Calling Java code so use Java calling convention 872 save_policy = _matcher._register_save_policy; 873 break; 874 875 default: 876 ShouldNotReachHere(); 877 } 878 879 // When using CallRuntime mark SOE registers as killed by the call 880 // so values that could show up in the RegisterMap aren't live in a 881 // callee saved register since the register wouldn't know where to 882 // find them. CallLeaf and CallLeafNoFP are ok because they can't 883 // have debug info on them. Strictly speaking this only needs to be 884 // done for oops since idealreg2debugmask takes care of debug info 885 // references but there no way to handle oops differently than other 886 // pointers as far as the kill mask goes. 887 bool exclude_soe = op == Op_CallRuntime; 888 889 // If the call is a MethodHandle invoke, we need to exclude the 890 // register which is used to save the SP value over MH invokes from 891 // the mask. Otherwise this register could be used for 892 // deoptimization information. 893 if (op == Op_CallStaticJava) { 894 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall; 895 if (mcallstaticjava->_method_handle_invoke) 896 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask()); 897 } 898 899 #if INCLUDE_SHENANDOAHGC 900 if (UseShenandoahGC && 901 ShenandoahBarrierSetAssembler::is_shenandoah_wb_C_call(mcall->entry_point())) { 902 assert(op == Op_CallLeafNoFP, "shenandoah_wb_C should be called with Op_CallLeafNoFP"); 903 add_call_kills(proj, regs, save_policy, exclude_soe, true); 904 } else 905 #endif 906 { 907 add_call_kills(proj, regs, save_policy, exclude_soe, false); 908 } 909 return node_cnt; 910 } 911 912 void PhaseCFG::push_ready_nodes(Node* n, Node* m, Block* block, GrowableArray<int>& ready_cnt, Node_List& worklist, uint max_idx, int c) { 913 if (get_block_for_node(m) != block) { 914 return; 915 } 916 if (m->is_Phi()) { 917 return; 918 } 919 if (m->_idx >= max_idx) { // new node, skip it 920 assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types"); 921 return; 922 } 923 int m_cnt = ready_cnt.at(m->_idx) - c; 924 ready_cnt.at_put(m->_idx, m_cnt); 925 if (m_cnt == 0) { 926 worklist.push(m); 927 } 928 } 929 930 //------------------------------schedule_local--------------------------------- 931 // Topological sort within a block. Someday become a real scheduler. 932 bool PhaseCFG::schedule_local(Block* block, GrowableArray<int>& ready_cnt, VectorSet& next_call, intptr_t *recalc_pressure_nodes) { 933 // Already "sorted" are the block start Node (as the first entry), and 934 // the block-ending Node and any trailing control projections. We leave 935 // these alone. PhiNodes and ParmNodes are made to follow the block start 936 // Node. Everything else gets topo-sorted. 937 938 #ifndef PRODUCT 939 if (trace_opto_pipelining()) { 940 tty->print_cr("# --- schedule_local B%d, before: ---", block->_pre_order); 941 for (uint i = 0;i < block->number_of_nodes(); i++) { 942 tty->print("# "); 943 block->get_node(i)->fast_dump(); 944 } 945 tty->print_cr("#"); 946 } 947 #endif 948 949 // RootNode is already sorted 950 if (block->number_of_nodes() == 1) { 951 return true; 952 } 953 954 bool block_size_threshold_ok = (block->number_of_nodes() > 10) ? true : false; 955 956 // We track the uses of local definitions as input dependences so that 957 // we know when a given instruction is avialable to be scheduled. 958 uint i; 959 if (OptoRegScheduling && block_size_threshold_ok) { 960 for (i = 1; i < block->number_of_nodes(); i++) { // setup nodes for pressure calc 961 Node *n = block->get_node(i); 962 n->remove_flag(Node::Flag_is_scheduled); 963 if (!n->is_Phi()) { 964 recalc_pressure_nodes[n->_idx] = 0x7fff7fff; 965 } 966 } 967 } else { 968 #ifdef ASSERT 969 for (i = 1; i < block->number_of_nodes(); i++) { 970 Node *n = block->get_node(i); 971 assert(!n->is_scheduled(), "shouldn't be scheduled yet"); 972 } 973 #endif 974 } 975 976 // Move PhiNodes and ParmNodes from 1 to cnt up to the start 977 uint node_cnt = block->end_idx(); 978 uint phi_cnt = 1; 979 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi 980 Node *n = block->get_node(i); 981 if( n->is_Phi() || // Found a PhiNode or ParmNode 982 (n->is_Proj() && n->in(0) == block->head()) ) { 983 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt 984 block->map_node(block->get_node(phi_cnt), i); 985 block->map_node(n, phi_cnt++); // swap Phi/Parm up front 986 // mark n as scheduled 987 n->add_flag(Node::Flag_is_scheduled); 988 } else { // All others 989 // Count block-local inputs to 'n' 990 uint cnt = n->len(); // Input count 991 uint local = 0; 992 for( uint j=0; j<cnt; j++ ) { 993 Node *m = n->in(j); 994 if( m && get_block_for_node(m) == block && !m->is_top() ) 995 local++; // One more block-local input 996 } 997 ready_cnt.at_put(n->_idx, local); // Count em up 998 999 #ifdef ASSERT 1000 if( UseConcMarkSweepGC || UseG1GC ) { 1001 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) { 1002 // Check the precedence edges 1003 for (uint prec = n->req(); prec < n->len(); prec++) { 1004 Node* oop_store = n->in(prec); 1005 if (oop_store != NULL) { 1006 assert(get_block_for_node(oop_store)->_dom_depth <= block->_dom_depth, "oop_store must dominate card-mark"); 1007 } 1008 } 1009 } 1010 } 1011 #endif 1012 1013 // A few node types require changing a required edge to a precedence edge 1014 // before allocation. 1015 if( n->is_Mach() && n->req() > TypeFunc::Parms && 1016 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire || 1017 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) { 1018 // MemBarAcquire could be created without Precedent edge. 1019 // del_req() replaces the specified edge with the last input edge 1020 // and then removes the last edge. If the specified edge > number of 1021 // edges the last edge will be moved outside of the input edges array 1022 // and the edge will be lost. This is why this code should be 1023 // executed only when Precedent (== TypeFunc::Parms) edge is present. 1024 Node *x = n->in(TypeFunc::Parms); 1025 if (x != NULL && get_block_for_node(x) == block && n->find_prec_edge(x) != -1) { 1026 // Old edge to node within same block will get removed, but no precedence 1027 // edge will get added because it already exists. Update ready count. 1028 int cnt = ready_cnt.at(n->_idx); 1029 assert(cnt > 1, "MemBar node %d must not get ready here", n->_idx); 1030 ready_cnt.at_put(n->_idx, cnt-1); 1031 } 1032 n->del_req(TypeFunc::Parms); 1033 n->add_prec(x); 1034 } 1035 } 1036 } 1037 for(uint i2=i; i2< block->number_of_nodes(); i2++ ) // Trailing guys get zapped count 1038 ready_cnt.at_put(block->get_node(i2)->_idx, 0); 1039 1040 // All the prescheduled guys do not hold back internal nodes 1041 uint i3; 1042 for (i3 = 0; i3 < phi_cnt; i3++) { // For all pre-scheduled 1043 Node *n = block->get_node(i3); // Get pre-scheduled 1044 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 1045 Node* m = n->fast_out(j); 1046 if (get_block_for_node(m) == block) { // Local-block user 1047 int m_cnt = ready_cnt.at(m->_idx)-1; 1048 // mark m as scheduled 1049 if (m_cnt < 0) { 1050 m->add_flag(Node::Flag_is_scheduled); 1051 } 1052 ready_cnt.at_put(m->_idx, m_cnt); // Fix ready count 1053 } 1054 } 1055 } 1056 1057 Node_List delay; 1058 // Make a worklist 1059 Node_List worklist; 1060 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist 1061 Node *m = block->get_node(i4); 1062 if( !ready_cnt.at(m->_idx) ) { // Zero ready count? 1063 if (m->is_iteratively_computed()) { 1064 // Push induction variable increments last to allow other uses 1065 // of the phi to be scheduled first. The select() method breaks 1066 // ties in scheduling by worklist order. 1067 delay.push(m); 1068 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) { 1069 // Force the CreateEx to the top of the list so it's processed 1070 // first and ends up at the start of the block. 1071 worklist.insert(0, m); 1072 } else { 1073 worklist.push(m); // Then on to worklist! 1074 } 1075 } 1076 } 1077 while (delay.size()) { 1078 Node* d = delay.pop(); 1079 worklist.push(d); 1080 } 1081 1082 if (OptoRegScheduling && block_size_threshold_ok) { 1083 // To stage register pressure calculations we need to examine the live set variables 1084 // breaking them up by register class to compartmentalize the calculations. 1085 uint float_pressure = Matcher::float_pressure(FLOATPRESSURE); 1086 _regalloc->_sched_int_pressure.init(INTPRESSURE); 1087 _regalloc->_sched_float_pressure.init(float_pressure); 1088 _regalloc->_scratch_int_pressure.init(INTPRESSURE); 1089 _regalloc->_scratch_float_pressure.init(float_pressure); 1090 1091 _regalloc->compute_entry_block_pressure(block); 1092 } 1093 1094 // Warm up the 'next_call' heuristic bits 1095 needed_for_next_call(block, block->head(), next_call); 1096 1097 #ifndef PRODUCT 1098 if (trace_opto_pipelining()) { 1099 for (uint j=0; j< block->number_of_nodes(); j++) { 1100 Node *n = block->get_node(j); 1101 int idx = n->_idx; 1102 tty->print("# ready cnt:%3d ", ready_cnt.at(idx)); 1103 tty->print("latency:%3d ", get_latency_for_node(n)); 1104 tty->print("%4d: %s\n", idx, n->Name()); 1105 } 1106 } 1107 #endif 1108 1109 uint max_idx = (uint)ready_cnt.length(); 1110 // Pull from worklist and schedule 1111 while( worklist.size() ) { // Worklist is not ready 1112 1113 #ifndef PRODUCT 1114 if (trace_opto_pipelining()) { 1115 tty->print("# ready list:"); 1116 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 1117 Node *n = worklist[i]; // Get Node on worklist 1118 tty->print(" %d", n->_idx); 1119 } 1120 tty->cr(); 1121 } 1122 #endif 1123 1124 // Select and pop a ready guy from worklist 1125 Node* n = select(block, worklist, ready_cnt, next_call, phi_cnt, recalc_pressure_nodes); 1126 block->map_node(n, phi_cnt++); // Schedule him next 1127 1128 n->add_flag(Node::Flag_is_scheduled); 1129 1130 if (OptoRegScheduling && block_size_threshold_ok) { 1131 // Now adjust the resister pressure with the node we selected 1132 if (!n->is_Phi()) { 1133 adjust_register_pressure(n, block, recalc_pressure_nodes, true); 1134 } 1135 } 1136 1137 #ifndef PRODUCT 1138 if (trace_opto_pipelining()) { 1139 tty->print("# select %d: %s", n->_idx, n->Name()); 1140 tty->print(", latency:%d", get_latency_for_node(n)); 1141 n->dump(); 1142 if (Verbose) { 1143 tty->print("# ready list:"); 1144 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 1145 Node *n = worklist[i]; // Get Node on worklist 1146 tty->print(" %d", n->_idx); 1147 } 1148 tty->cr(); 1149 } 1150 } 1151 1152 #endif 1153 if( n->is_MachCall() ) { 1154 MachCallNode *mcall = n->as_MachCall(); 1155 phi_cnt = sched_call(block, phi_cnt, worklist, ready_cnt, mcall, next_call); 1156 continue; 1157 } 1158 1159 if (n->is_Mach() && n->as_Mach()->has_call()) { 1160 RegMask regs; 1161 regs.Insert(_matcher.c_frame_pointer()); 1162 regs.OR(n->out_RegMask()); 1163 1164 MachProjNode *proj = new MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj ); 1165 map_node_to_block(proj, block); 1166 block->insert_node(proj, phi_cnt++); 1167 1168 add_call_kills(proj, regs, _matcher._c_reg_save_policy, false, false); 1169 } 1170 1171 // Children are now all ready 1172 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) { 1173 Node* m = n->fast_out(i5); // Get user 1174 push_ready_nodes(n, m, block, ready_cnt, worklist, max_idx, 1); 1175 } 1176 1177 #if INCLUDE_SHENANDOAHGC 1178 replace_uses_with_shenandoah_barrier(n, block, worklist, ready_cnt, max_idx, phi_cnt); 1179 #endif 1180 } 1181 1182 if( phi_cnt != block->end_idx() ) { 1183 // did not schedule all. Retry, Bailout, or Die 1184 if (C->subsume_loads() == true && !C->failing()) { 1185 // Retry with subsume_loads == false 1186 // If this is the first failure, the sentinel string will "stick" 1187 // to the Compile object, and the C2Compiler will see it and retry. 1188 C->record_failure(C2Compiler::retry_no_subsuming_loads()); 1189 } else { 1190 assert(false, "graph should be schedulable"); 1191 } 1192 // assert( phi_cnt == end_idx(), "did not schedule all" ); 1193 return false; 1194 } 1195 1196 if (OptoRegScheduling && block_size_threshold_ok) { 1197 _regalloc->compute_exit_block_pressure(block); 1198 block->_reg_pressure = _regalloc->_sched_int_pressure.final_pressure(); 1199 block->_freg_pressure = _regalloc->_sched_float_pressure.final_pressure(); 1200 } 1201 1202 #ifndef PRODUCT 1203 if (trace_opto_pipelining()) { 1204 tty->print_cr("#"); 1205 tty->print_cr("# after schedule_local"); 1206 for (uint i = 0;i < block->number_of_nodes();i++) { 1207 tty->print("# "); 1208 block->get_node(i)->fast_dump(); 1209 } 1210 tty->print_cr("# "); 1211 1212 if (OptoRegScheduling && block_size_threshold_ok) { 1213 tty->print_cr("# pressure info : %d", block->_pre_order); 1214 _regalloc->print_pressure_info(_regalloc->_sched_int_pressure, "int register info"); 1215 _regalloc->print_pressure_info(_regalloc->_sched_float_pressure, "float register info"); 1216 } 1217 tty->cr(); 1218 } 1219 #endif 1220 1221 return true; 1222 } 1223 1224 //--------------------------catch_cleanup_fix_all_inputs----------------------- 1225 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) { 1226 for (uint l = 0; l < use->len(); l++) { 1227 if (use->in(l) == old_def) { 1228 if (l < use->req()) { 1229 use->set_req(l, new_def); 1230 } else { 1231 use->rm_prec(l); 1232 use->add_prec(new_def); 1233 l--; 1234 } 1235 } 1236 } 1237 } 1238 1239 //------------------------------catch_cleanup_find_cloned_def------------------ 1240 Node* PhaseCFG::catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, int n_clone_idx) { 1241 assert( use_blk != def_blk, "Inter-block cleanup only"); 1242 1243 // The use is some block below the Catch. Find and return the clone of the def 1244 // that dominates the use. If there is no clone in a dominating block, then 1245 // create a phi for the def in a dominating block. 1246 1247 // Find which successor block dominates this use. The successor 1248 // blocks must all be single-entry (from the Catch only; I will have 1249 // split blocks to make this so), hence they all dominate. 1250 while( use_blk->_dom_depth > def_blk->_dom_depth+1 ) 1251 use_blk = use_blk->_idom; 1252 1253 // Find the successor 1254 Node *fixup = NULL; 1255 1256 uint j; 1257 for( j = 0; j < def_blk->_num_succs; j++ ) 1258 if( use_blk == def_blk->_succs[j] ) 1259 break; 1260 1261 if( j == def_blk->_num_succs ) { 1262 // Block at same level in dom-tree is not a successor. It needs a 1263 // PhiNode, the PhiNode uses from the def and IT's uses need fixup. 1264 Node_Array inputs = new Node_List(Thread::current()->resource_area()); 1265 for(uint k = 1; k < use_blk->num_preds(); k++) { 1266 Block* block = get_block_for_node(use_blk->pred(k)); 1267 inputs.map(k, catch_cleanup_find_cloned_def(block, def, def_blk, n_clone_idx)); 1268 } 1269 1270 // Check to see if the use_blk already has an identical phi inserted. 1271 // If it exists, it will be at the first position since all uses of a 1272 // def are processed together. 1273 Node *phi = use_blk->get_node(1); 1274 if( phi->is_Phi() ) { 1275 fixup = phi; 1276 for (uint k = 1; k < use_blk->num_preds(); k++) { 1277 if (phi->in(k) != inputs[k]) { 1278 // Not a match 1279 fixup = NULL; 1280 break; 1281 } 1282 } 1283 } 1284 1285 // If an existing PhiNode was not found, make a new one. 1286 if (fixup == NULL) { 1287 Node *new_phi = PhiNode::make(use_blk->head(), def); 1288 use_blk->insert_node(new_phi, 1); 1289 map_node_to_block(new_phi, use_blk); 1290 for (uint k = 1; k < use_blk->num_preds(); k++) { 1291 new_phi->set_req(k, inputs[k]); 1292 } 1293 fixup = new_phi; 1294 } 1295 1296 } else { 1297 // Found the use just below the Catch. Make it use the clone. 1298 fixup = use_blk->get_node(n_clone_idx); 1299 } 1300 1301 return fixup; 1302 } 1303 1304 //--------------------------catch_cleanup_intra_block-------------------------- 1305 // Fix all input edges in use that reference "def". The use is in the same 1306 // block as the def and both have been cloned in each successor block. 1307 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) { 1308 1309 // Both the use and def have been cloned. For each successor block, 1310 // get the clone of the use, and make its input the clone of the def 1311 // found in that block. 1312 1313 uint use_idx = blk->find_node(use); 1314 uint offset_idx = use_idx - beg; 1315 for( uint k = 0; k < blk->_num_succs; k++ ) { 1316 // Get clone in each successor block 1317 Block *sb = blk->_succs[k]; 1318 Node *clone = sb->get_node(offset_idx+1); 1319 assert( clone->Opcode() == use->Opcode(), "" ); 1320 1321 // Make use-clone reference the def-clone 1322 catch_cleanup_fix_all_inputs(clone, def, sb->get_node(n_clone_idx)); 1323 } 1324 } 1325 1326 //------------------------------catch_cleanup_inter_block--------------------- 1327 // Fix all input edges in use that reference "def". The use is in a different 1328 // block than the def. 1329 void PhaseCFG::catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, int n_clone_idx) { 1330 if( !use_blk ) return; // Can happen if the use is a precedence edge 1331 1332 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, n_clone_idx); 1333 catch_cleanup_fix_all_inputs(use, def, new_def); 1334 } 1335 1336 //------------------------------call_catch_cleanup----------------------------- 1337 // If we inserted any instructions between a Call and his CatchNode, 1338 // clone the instructions on all paths below the Catch. 1339 void PhaseCFG::call_catch_cleanup(Block* block) { 1340 1341 // End of region to clone 1342 uint end = block->end_idx(); 1343 if( !block->get_node(end)->is_Catch() ) return; 1344 // Start of region to clone 1345 uint beg = end; 1346 while(!block->get_node(beg-1)->is_MachProj() || 1347 !block->get_node(beg-1)->in(0)->is_MachCall() ) { 1348 beg--; 1349 assert(beg > 0,"Catch cleanup walking beyond block boundary"); 1350 } 1351 // Range of inserted instructions is [beg, end) 1352 if( beg == end ) return; 1353 1354 // Clone along all Catch output paths. Clone area between the 'beg' and 1355 // 'end' indices. 1356 for( uint i = 0; i < block->_num_succs; i++ ) { 1357 Block *sb = block->_succs[i]; 1358 // Clone the entire area; ignoring the edge fixup for now. 1359 for( uint j = end; j > beg; j-- ) { 1360 Node *clone = block->get_node(j-1)->clone(); 1361 sb->insert_node(clone, 1); 1362 map_node_to_block(clone, sb); 1363 if (clone->needs_anti_dependence_check()) { 1364 insert_anti_dependences(sb, clone); 1365 } 1366 } 1367 } 1368 1369 1370 // Fixup edges. Check the def-use info per cloned Node 1371 for(uint i2 = beg; i2 < end; i2++ ) { 1372 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block 1373 Node *n = block->get_node(i2); // Node that got cloned 1374 // Need DU safe iterator because of edge manipulation in calls. 1375 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area()); 1376 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) { 1377 out->push(n->fast_out(j1)); 1378 } 1379 uint max = out->size(); 1380 for (uint j = 0; j < max; j++) {// For all users 1381 Node *use = out->pop(); 1382 Block *buse = get_block_for_node(use); 1383 if( use->is_Phi() ) { 1384 for( uint k = 1; k < use->req(); k++ ) 1385 if( use->in(k) == n ) { 1386 Block* b = get_block_for_node(buse->pred(k)); 1387 Node *fixup = catch_cleanup_find_cloned_def(b, n, block, n_clone_idx); 1388 use->set_req(k, fixup); 1389 } 1390 } else { 1391 if (block == buse) { 1392 catch_cleanup_intra_block(use, n, block, beg, n_clone_idx); 1393 } else { 1394 catch_cleanup_inter_block(use, buse, n, block, n_clone_idx); 1395 } 1396 } 1397 } // End for all users 1398 1399 } // End of for all Nodes in cloned area 1400 1401 // Remove the now-dead cloned ops 1402 for(uint i3 = beg; i3 < end; i3++ ) { 1403 block->get_node(beg)->disconnect_inputs(NULL, C); 1404 block->remove_node(beg); 1405 } 1406 1407 // If the successor blocks have a CreateEx node, move it back to the top 1408 for(uint i4 = 0; i4 < block->_num_succs; i4++ ) { 1409 Block *sb = block->_succs[i4]; 1410 uint new_cnt = end - beg; 1411 // Remove any newly created, but dead, nodes. 1412 for( uint j = new_cnt; j > 0; j-- ) { 1413 Node *n = sb->get_node(j); 1414 if (n->outcnt() == 0 && 1415 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){ 1416 n->disconnect_inputs(NULL, C); 1417 sb->remove_node(j); 1418 new_cnt--; 1419 } 1420 } 1421 // If any newly created nodes remain, move the CreateEx node to the top 1422 if (new_cnt > 0) { 1423 Node *cex = sb->get_node(1+new_cnt); 1424 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) { 1425 sb->remove_node(1+new_cnt); 1426 sb->insert_node(cex, 1); 1427 } 1428 } 1429 } 1430 }