1 /* 2 * Copyright (c) 1998, 2011, 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_LoadUS: 143 case Op_LoadD: 144 case Op_LoadF: 145 case Op_LoadI: 146 case Op_LoadL: 147 case Op_LoadP: 148 case Op_LoadN: 149 case Op_LoadS: 150 case Op_LoadKlass: 151 case Op_LoadNKlass: 152 case Op_LoadRange: 153 case Op_LoadD_unaligned: 154 case Op_LoadL_unaligned: 155 assert(mach->in(2) == val, "should be address"); 156 break; 157 case Op_StoreB: 158 case Op_StoreC: 159 case Op_StoreCM: 160 case Op_StoreD: 161 case Op_StoreF: 162 case Op_StoreI: 163 case Op_StoreL: 164 case Op_StoreP: 165 case Op_StoreN: 166 was_store = true; // Memory op is a store op 167 // Stores will have their address in slot 2 (memory in slot 1). 168 // If the value being nul-checked is in another slot, it means we 169 // are storing the checked value, which does NOT check the value! 170 if( mach->in(2) != val ) continue; 171 break; // Found a memory op? 172 case Op_StrComp: 173 case Op_StrEquals: 174 case Op_StrIndexOf: 175 case Op_AryEq: 176 // Not a legit memory op for implicit null check regardless of 177 // embedded loads 178 continue; 179 default: // Also check for embedded loads 180 if( !mach->needs_anti_dependence_check() ) 181 continue; // Not an memory op; skip it 182 if( must_clone[iop] ) { 183 // Do not move nodes which produce flags because 184 // RA will try to clone it to place near branch and 185 // it will cause recompilation, see clone_node(). 186 continue; 187 } 188 { 189 // Check that value is used in memory address in 190 // instructions with embedded load (CmpP val1,(val2+off)). 191 Node* base; 192 Node* index; 193 const MachOper* oper = mach->memory_inputs(base, index); 194 if (oper == NULL || oper == (MachOper*)-1) { 195 continue; // Not an memory op; skip it 196 } 197 if (val == base || 198 val == index && val->bottom_type()->isa_narrowoop()) { 199 break; // Found it 200 } else { 201 continue; // Skip it 202 } 203 } 204 break; 205 } 206 // check if the offset is not too high for implicit exception 207 { 208 intptr_t offset = 0; 209 const TypePtr *adr_type = NULL; // Do not need this return value here 210 const Node* base = mach->get_base_and_disp(offset, adr_type); 211 if (base == NULL || base == NodeSentinel) { 212 // Narrow oop address doesn't have base, only index 213 if( val->bottom_type()->isa_narrowoop() && 214 MacroAssembler::needs_explicit_null_check(offset) ) 215 continue; // Give up if offset is beyond page size 216 // cannot reason about it; is probably not implicit null exception 217 } else { 218 const TypePtr* tptr; 219 if (UseCompressedOops && Universe::narrow_oop_shift() == 0) { 220 // 32-bits narrow oop can be the base of address expressions 221 tptr = base->bottom_type()->make_ptr(); 222 } else { 223 // only regular oops are expected here 224 tptr = base->bottom_type()->is_ptr(); 225 } 226 // Give up if offset is not a compile-time constant 227 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot ) 228 continue; 229 offset += tptr->_offset; // correct if base is offseted 230 if( MacroAssembler::needs_explicit_null_check(offset) ) 231 continue; // Give up is reference is beyond 4K page size 232 } 233 } 234 235 // Check ctrl input to see if the null-check dominates the memory op 236 Block *cb = cfg->_bbs[mach->_idx]; 237 cb = cb->_idom; // Always hoist at least 1 block 238 if( !was_store ) { // Stores can be hoisted only one block 239 while( cb->_dom_depth > (_dom_depth + 1)) 240 cb = cb->_idom; // Hoist loads as far as we want 241 // The non-null-block should dominate the memory op, too. Live 242 // range spilling will insert a spill in the non-null-block if it is 243 // needs to spill the memory op for an implicit null check. 244 if (cb->_dom_depth == (_dom_depth + 1)) { 245 if (cb != not_null_block) continue; 246 cb = cb->_idom; 247 } 248 } 249 if( cb != this ) continue; 250 251 // Found a memory user; see if it can be hoisted to check-block 252 uint vidx = 0; // Capture index of value into memop 253 uint j; 254 for( j = mach->req()-1; j > 0; j-- ) { 255 if( mach->in(j) == val ) { 256 vidx = j; 257 // Ignore DecodeN val which could be hoisted to where needed. 258 if( is_decoden ) continue; 259 } 260 // Block of memory-op input 261 Block *inb = cfg->_bbs[mach->in(j)->_idx]; 262 Block *b = this; // Start from nul check 263 while( b != inb && b->_dom_depth > inb->_dom_depth ) 264 b = b->_idom; // search upwards for input 265 // See if input dominates null check 266 if( b != inb ) 267 break; 268 } 269 if( j > 0 ) 270 continue; 271 Block *mb = cfg->_bbs[mach->_idx]; 272 // Hoisting stores requires more checks for the anti-dependence case. 273 // Give up hoisting if we have to move the store past any load. 274 if( was_store ) { 275 Block *b = mb; // Start searching here for a local load 276 // mach use (faulting) trying to hoist 277 // n might be blocker to hoisting 278 while( b != this ) { 279 uint k; 280 for( k = 1; k < b->_nodes.size(); k++ ) { 281 Node *n = b->_nodes[k]; 282 if( n->needs_anti_dependence_check() && 283 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) ) 284 break; // Found anti-dependent load 285 } 286 if( k < b->_nodes.size() ) 287 break; // Found anti-dependent load 288 // Make sure control does not do a merge (would have to check allpaths) 289 if( b->num_preds() != 2 ) break; 290 b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block 291 } 292 if( b != this ) continue; 293 } 294 295 // Make sure this memory op is not already being used for a NullCheck 296 Node *e = mb->end(); 297 if( e->is_MachNullCheck() && e->in(1) == mach ) 298 continue; // Already being used as a NULL check 299 300 // Found a candidate! Pick one with least dom depth - the highest 301 // in the dom tree should be closest to the null check. 302 if( !best || 303 cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) { 304 best = mach; 305 bidx = vidx; 306 307 } 308 } 309 // No candidate! 310 if( !best ) return; 311 312 // ---- Found an implicit null check 313 extern int implicit_null_checks; 314 implicit_null_checks++; 315 316 if( is_decoden ) { 317 // Check if we need to hoist decodeHeapOop_not_null first. 318 Block *valb = cfg->_bbs[val->_idx]; 319 if( this != valb && this->_dom_depth < valb->_dom_depth ) { 320 // Hoist it up to the end of the test block. 321 valb->find_remove(val); 322 this->add_inst(val); 323 cfg->_bbs.map(val->_idx,this); 324 // DecodeN on x86 may kill flags. Check for flag-killing projections 325 // that also need to be hoisted. 326 for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) { 327 Node* n = val->fast_out(j); 328 if( n->Opcode() == Op_MachProj ) { 329 cfg->_bbs[n->_idx]->find_remove(n); 330 this->add_inst(n); 331 cfg->_bbs.map(n->_idx,this); 332 } 333 } 334 } 335 } 336 // Hoist the memory candidate up to the end of the test block. 337 Block *old_block = cfg->_bbs[best->_idx]; 338 old_block->find_remove(best); 339 add_inst(best); 340 cfg->_bbs.map(best->_idx,this); 341 342 // Move the control dependence 343 if (best->in(0) && best->in(0) == old_block->_nodes[0]) 344 best->set_req(0, _nodes[0]); 345 346 // Check for flag-killing projections that also need to be hoisted 347 // Should be DU safe because no edge updates. 348 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) { 349 Node* n = best->fast_out(j); 350 if( n->Opcode() == Op_MachProj ) { 351 cfg->_bbs[n->_idx]->find_remove(n); 352 add_inst(n); 353 cfg->_bbs.map(n->_idx,this); 354 } 355 } 356 357 Compile *C = cfg->C; 358 // proj==Op_True --> ne test; proj==Op_False --> eq test. 359 // One of two graph shapes got matched: 360 // (IfTrue (If (Bool NE (CmpP ptr NULL)))) 361 // (IfFalse (If (Bool EQ (CmpP ptr NULL)))) 362 // NULL checks are always branch-if-eq. If we see a IfTrue projection 363 // then we are replacing a 'ne' test with a 'eq' NULL check test. 364 // We need to flip the projections to keep the same semantics. 365 if( proj->Opcode() == Op_IfTrue ) { 366 // Swap order of projections in basic block to swap branch targets 367 Node *tmp1 = _nodes[end_idx()+1]; 368 Node *tmp2 = _nodes[end_idx()+2]; 369 _nodes.map(end_idx()+1, tmp2); 370 _nodes.map(end_idx()+2, tmp1); 371 Node *tmp = new (C, 1) Node(C->top()); // Use not NULL input 372 tmp1->replace_by(tmp); 373 tmp2->replace_by(tmp1); 374 tmp->replace_by(tmp2); 375 tmp->destruct(); 376 } 377 378 // Remove the existing null check; use a new implicit null check instead. 379 // Since schedule-local needs precise def-use info, we need to correct 380 // it as well. 381 Node *old_tst = proj->in(0); 382 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx); 383 _nodes.map(end_idx(),nul_chk); 384 cfg->_bbs.map(nul_chk->_idx,this); 385 // Redirect users of old_test to nul_chk 386 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2) 387 old_tst->last_out(i2)->set_req(0, nul_chk); 388 // Clean-up any dead code 389 for (uint i3 = 0; i3 < old_tst->req(); i3++) 390 old_tst->set_req(i3, NULL); 391 392 cfg->latency_from_uses(nul_chk); 393 cfg->latency_from_uses(best); 394 } 395 396 397 //------------------------------select----------------------------------------- 398 // Select a nice fellow from the worklist to schedule next. If there is only 399 // one choice, then use it. Projections take top priority for correctness 400 // reasons - if I see a projection, then it is next. There are a number of 401 // other special cases, for instructions that consume condition codes, et al. 402 // These are chosen immediately. Some instructions are required to immediately 403 // precede the last instruction in the block, and these are taken last. Of the 404 // remaining cases (most), choose the instruction with the greatest latency 405 // (that is, the most number of pseudo-cycles required to the end of the 406 // routine). If there is a tie, choose the instruction with the most inputs. 407 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, int *ready_cnt, VectorSet &next_call, uint sched_slot) { 408 409 // If only a single entry on the stack, use it 410 uint cnt = worklist.size(); 411 if (cnt == 1) { 412 Node *n = worklist[0]; 413 worklist.map(0,worklist.pop()); 414 return n; 415 } 416 417 uint choice = 0; // Bigger is most important 418 uint latency = 0; // Bigger is scheduled first 419 uint score = 0; // Bigger is better 420 int idx = -1; // Index in worklist 421 422 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist 423 // Order in worklist is used to break ties. 424 // See caller for how this is used to delay scheduling 425 // of induction variable increments to after the other 426 // uses of the phi are scheduled. 427 Node *n = worklist[i]; // Get Node on worklist 428 429 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0; 430 if( n->is_Proj() || // Projections always win 431 n->Opcode()== Op_Con || // So does constant 'Top' 432 iop == Op_CreateEx || // Create-exception must start block 433 iop == Op_CheckCastPP 434 ) { 435 worklist.map(i,worklist.pop()); 436 return n; 437 } 438 439 // Final call in a block must be adjacent to 'catch' 440 Node *e = end(); 441 if( e->is_Catch() && e->in(0)->in(0) == n ) 442 continue; 443 444 // Memory op for an implicit null check has to be at the end of the block 445 if( e->is_MachNullCheck() && e->in(1) == n ) 446 continue; 447 448 uint n_choice = 2; 449 450 // See if this instruction is consumed by a branch. If so, then (as the 451 // branch is the last instruction in the basic block) force it to the 452 // end of the basic block 453 if ( must_clone[iop] ) { 454 // See if any use is a branch 455 bool found_machif = false; 456 457 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 458 Node* use = n->fast_out(j); 459 460 // The use is a conditional branch, make them adjacent 461 if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) { 462 found_machif = true; 463 break; 464 } 465 466 // More than this instruction pending for successor to be ready, 467 // don't choose this if other opportunities are ready 468 if (ready_cnt[use->_idx] > 1) 469 n_choice = 1; 470 } 471 472 // loop terminated, prefer not to use this instruction 473 if (found_machif) 474 continue; 475 } 476 477 // See if this has a predecessor that is "must_clone", i.e. sets the 478 // condition code. If so, choose this first 479 for (uint j = 0; j < n->req() ; j++) { 480 Node *inn = n->in(j); 481 if (inn) { 482 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) { 483 n_choice = 3; 484 break; 485 } 486 } 487 } 488 489 // MachTemps should be scheduled last so they are near their uses 490 if (n->is_MachTemp()) { 491 n_choice = 1; 492 } 493 494 uint n_latency = cfg->_node_latency->at_grow(n->_idx); 495 uint n_score = n->req(); // Many inputs get high score to break ties 496 497 // Keep best latency found 498 if( choice < n_choice || 499 ( choice == n_choice && 500 ( latency < n_latency || 501 ( latency == n_latency && 502 ( score < n_score ))))) { 503 choice = n_choice; 504 latency = n_latency; 505 score = n_score; 506 idx = i; // Also keep index in worklist 507 } 508 } // End of for all ready nodes in worklist 509 510 assert(idx >= 0, "index should be set"); 511 Node *n = worklist[(uint)idx]; // Get the winner 512 513 worklist.map((uint)idx, worklist.pop()); // Compress worklist 514 return n; 515 } 516 517 518 //------------------------------set_next_call---------------------------------- 519 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) { 520 if( next_call.test_set(n->_idx) ) return; 521 for( uint i=0; i<n->len(); i++ ) { 522 Node *m = n->in(i); 523 if( !m ) continue; // must see all nodes in block that precede call 524 if( bbs[m->_idx] == this ) 525 set_next_call( m, next_call, bbs ); 526 } 527 } 528 529 //------------------------------needed_for_next_call--------------------------- 530 // Set the flag 'next_call' for each Node that is needed for the next call to 531 // be scheduled. This flag lets me bias scheduling so Nodes needed for the 532 // next subroutine call get priority - basically it moves things NOT needed 533 // for the next call till after the call. This prevents me from trying to 534 // carry lots of stuff live across a call. 535 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) { 536 // Find the next control-defining Node in this block 537 Node* call = NULL; 538 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) { 539 Node* m = this_call->fast_out(i); 540 if( bbs[m->_idx] == this && // Local-block user 541 m != this_call && // Not self-start node 542 m->is_Call() ) 543 call = m; 544 break; 545 } 546 if (call == NULL) return; // No next call (e.g., block end is near) 547 // Set next-call for all inputs to this call 548 set_next_call(call, next_call, bbs); 549 } 550 551 //------------------------------sched_call------------------------------------- 552 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, int *ready_cnt, MachCallNode *mcall, VectorSet &next_call ) { 553 RegMask regs; 554 555 // Schedule all the users of the call right now. All the users are 556 // projection Nodes, so they must be scheduled next to the call. 557 // Collect all the defined registers. 558 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) { 559 Node* n = mcall->fast_out(i); 560 assert( n->Opcode()==Op_MachProj, "" ); 561 --ready_cnt[n->_idx]; 562 assert( !ready_cnt[n->_idx], "" ); 563 // Schedule next to call 564 _nodes.map(node_cnt++, n); 565 // Collect defined registers 566 regs.OR(n->out_RegMask()); 567 // Check for scheduling the next control-definer 568 if( n->bottom_type() == Type::CONTROL ) 569 // Warm up next pile of heuristic bits 570 needed_for_next_call(n, next_call, bbs); 571 572 // Children of projections are now all ready 573 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 574 Node* m = n->fast_out(j); // Get user 575 if( bbs[m->_idx] != this ) continue; 576 if( m->is_Phi() ) continue; 577 if( !--ready_cnt[m->_idx] ) 578 worklist.push(m); 579 } 580 581 } 582 583 // Act as if the call defines the Frame Pointer. 584 // Certainly the FP is alive and well after the call. 585 regs.Insert(matcher.c_frame_pointer()); 586 587 // Set all registers killed and not already defined by the call. 588 uint r_cnt = mcall->tf()->range()->cnt(); 589 int op = mcall->ideal_Opcode(); 590 MachProjNode *proj = new (matcher.C, 1) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj ); 591 bbs.map(proj->_idx,this); 592 _nodes.insert(node_cnt++, proj); 593 594 // Select the right register save policy. 595 const char * save_policy; 596 switch (op) { 597 case Op_CallRuntime: 598 case Op_CallLeaf: 599 case Op_CallLeafNoFP: 600 // Calling C code so use C calling convention 601 save_policy = matcher._c_reg_save_policy; 602 break; 603 604 case Op_CallStaticJava: 605 case Op_CallDynamicJava: 606 // Calling Java code so use Java calling convention 607 save_policy = matcher._register_save_policy; 608 break; 609 610 default: 611 ShouldNotReachHere(); 612 } 613 614 // When using CallRuntime mark SOE registers as killed by the call 615 // so values that could show up in the RegisterMap aren't live in a 616 // callee saved register since the register wouldn't know where to 617 // find them. CallLeaf and CallLeafNoFP are ok because they can't 618 // have debug info on them. Strictly speaking this only needs to be 619 // done for oops since idealreg2debugmask takes care of debug info 620 // references but there no way to handle oops differently than other 621 // pointers as far as the kill mask goes. 622 bool exclude_soe = op == Op_CallRuntime; 623 624 // If the call is a MethodHandle invoke, we need to exclude the 625 // register which is used to save the SP value over MH invokes from 626 // the mask. Otherwise this register could be used for 627 // deoptimization information. 628 if (op == Op_CallStaticJava) { 629 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall; 630 if (mcallstaticjava->_method_handle_invoke) 631 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask()); 632 } 633 634 // Fill in the kill mask for the call 635 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) { 636 if( !regs.Member(r) ) { // Not already defined by the call 637 // Save-on-call register? 638 if ((save_policy[r] == 'C') || 639 (save_policy[r] == 'A') || 640 ((save_policy[r] == 'E') && exclude_soe)) { 641 proj->_rout.Insert(r); 642 } 643 } 644 } 645 646 return node_cnt; 647 } 648 649 650 //------------------------------schedule_local--------------------------------- 651 // Topological sort within a block. Someday become a real scheduler. 652 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, int *ready_cnt, VectorSet &next_call) { 653 // Already "sorted" are the block start Node (as the first entry), and 654 // the block-ending Node and any trailing control projections. We leave 655 // these alone. PhiNodes and ParmNodes are made to follow the block start 656 // Node. Everything else gets topo-sorted. 657 658 #ifndef PRODUCT 659 if (cfg->trace_opto_pipelining()) { 660 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order); 661 for (uint i = 0;i < _nodes.size();i++) { 662 tty->print("# "); 663 _nodes[i]->fast_dump(); 664 } 665 tty->print_cr("#"); 666 } 667 #endif 668 669 // RootNode is already sorted 670 if( _nodes.size() == 1 ) return true; 671 672 // Move PhiNodes and ParmNodes from 1 to cnt up to the start 673 uint node_cnt = end_idx(); 674 uint phi_cnt = 1; 675 uint i; 676 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi 677 Node *n = _nodes[i]; 678 if( n->is_Phi() || // Found a PhiNode or ParmNode 679 (n->is_Proj() && n->in(0) == head()) ) { 680 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt 681 _nodes.map(i,_nodes[phi_cnt]); 682 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front 683 } else { // All others 684 // Count block-local inputs to 'n' 685 uint cnt = n->len(); // Input count 686 uint local = 0; 687 for( uint j=0; j<cnt; j++ ) { 688 Node *m = n->in(j); 689 if( m && cfg->_bbs[m->_idx] == this && !m->is_top() ) 690 local++; // One more block-local input 691 } 692 ready_cnt[n->_idx] = local; // Count em up 693 694 #ifdef ASSERT 695 if( UseConcMarkSweepGC || UseG1GC ) { 696 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) { 697 // Check the precedence edges 698 for (uint prec = n->req(); prec < n->len(); prec++) { 699 Node* oop_store = n->in(prec); 700 if (oop_store != NULL) { 701 assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark"); 702 } 703 } 704 } 705 } 706 #endif 707 708 // A few node types require changing a required edge to a precedence edge 709 // before allocation. 710 if( n->is_Mach() && n->req() > TypeFunc::Parms && 711 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire || 712 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) { 713 // MemBarAcquire could be created without Precedent edge. 714 // del_req() replaces the specified edge with the last input edge 715 // and then removes the last edge. If the specified edge > number of 716 // edges the last edge will be moved outside of the input edges array 717 // and the edge will be lost. This is why this code should be 718 // executed only when Precedent (== TypeFunc::Parms) edge is present. 719 Node *x = n->in(TypeFunc::Parms); 720 n->del_req(TypeFunc::Parms); 721 n->add_prec(x); 722 } 723 } 724 } 725 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count 726 ready_cnt[_nodes[i2]->_idx] = 0; 727 728 // All the prescheduled guys do not hold back internal nodes 729 uint i3; 730 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled 731 Node *n = _nodes[i3]; // Get pre-scheduled 732 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) { 733 Node* m = n->fast_out(j); 734 if( cfg->_bbs[m->_idx] ==this ) // Local-block user 735 ready_cnt[m->_idx]--; // Fix ready count 736 } 737 } 738 739 Node_List delay; 740 // Make a worklist 741 Node_List worklist; 742 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist 743 Node *m = _nodes[i4]; 744 if( !ready_cnt[m->_idx] ) { // Zero ready count? 745 if (m->is_iteratively_computed()) { 746 // Push induction variable increments last to allow other uses 747 // of the phi to be scheduled first. The select() method breaks 748 // ties in scheduling by worklist order. 749 delay.push(m); 750 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) { 751 // Force the CreateEx to the top of the list so it's processed 752 // first and ends up at the start of the block. 753 worklist.insert(0, m); 754 } else { 755 worklist.push(m); // Then on to worklist! 756 } 757 } 758 } 759 while (delay.size()) { 760 Node* d = delay.pop(); 761 worklist.push(d); 762 } 763 764 // Warm up the 'next_call' heuristic bits 765 needed_for_next_call(_nodes[0], next_call, cfg->_bbs); 766 767 #ifndef PRODUCT 768 if (cfg->trace_opto_pipelining()) { 769 for (uint j=0; j<_nodes.size(); j++) { 770 Node *n = _nodes[j]; 771 int idx = n->_idx; 772 tty->print("# ready cnt:%3d ", ready_cnt[idx]); 773 tty->print("latency:%3d ", cfg->_node_latency->at_grow(idx)); 774 tty->print("%4d: %s\n", idx, n->Name()); 775 } 776 } 777 #endif 778 779 // Pull from worklist and schedule 780 while( worklist.size() ) { // Worklist is not ready 781 782 #ifndef PRODUCT 783 if (cfg->trace_opto_pipelining()) { 784 tty->print("# ready list:"); 785 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 786 Node *n = worklist[i]; // Get Node on worklist 787 tty->print(" %d", n->_idx); 788 } 789 tty->cr(); 790 } 791 #endif 792 793 // Select and pop a ready guy from worklist 794 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt); 795 _nodes.map(phi_cnt++,n); // Schedule him next 796 797 #ifndef PRODUCT 798 if (cfg->trace_opto_pipelining()) { 799 tty->print("# select %d: %s", n->_idx, n->Name()); 800 tty->print(", latency:%d", cfg->_node_latency->at_grow(n->_idx)); 801 n->dump(); 802 if (Verbose) { 803 tty->print("# ready list:"); 804 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist 805 Node *n = worklist[i]; // Get Node on worklist 806 tty->print(" %d", n->_idx); 807 } 808 tty->cr(); 809 } 810 } 811 812 #endif 813 if( n->is_MachCall() ) { 814 MachCallNode *mcall = n->as_MachCall(); 815 phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call); 816 continue; 817 } 818 // Children are now all ready 819 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) { 820 Node* m = n->fast_out(i5); // Get user 821 if( cfg->_bbs[m->_idx] != this ) continue; 822 if( m->is_Phi() ) continue; 823 if( !--ready_cnt[m->_idx] ) 824 worklist.push(m); 825 } 826 } 827 828 if( phi_cnt != end_idx() ) { 829 // did not schedule all. Retry, Bailout, or Die 830 Compile* C = matcher.C; 831 if (C->subsume_loads() == true && !C->failing()) { 832 // Retry with subsume_loads == false 833 // If this is the first failure, the sentinel string will "stick" 834 // to the Compile object, and the C2Compiler will see it and retry. 835 C->record_failure(C2Compiler::retry_no_subsuming_loads()); 836 } 837 // assert( phi_cnt == end_idx(), "did not schedule all" ); 838 return false; 839 } 840 841 #ifndef PRODUCT 842 if (cfg->trace_opto_pipelining()) { 843 tty->print_cr("#"); 844 tty->print_cr("# after schedule_local"); 845 for (uint i = 0;i < _nodes.size();i++) { 846 tty->print("# "); 847 _nodes[i]->fast_dump(); 848 } 849 tty->cr(); 850 } 851 #endif 852 853 854 return true; 855 } 856 857 //--------------------------catch_cleanup_fix_all_inputs----------------------- 858 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) { 859 for (uint l = 0; l < use->len(); l++) { 860 if (use->in(l) == old_def) { 861 if (l < use->req()) { 862 use->set_req(l, new_def); 863 } else { 864 use->rm_prec(l); 865 use->add_prec(new_def); 866 l--; 867 } 868 } 869 } 870 } 871 872 //------------------------------catch_cleanup_find_cloned_def------------------ 873 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) { 874 assert( use_blk != def_blk, "Inter-block cleanup only"); 875 876 // The use is some block below the Catch. Find and return the clone of the def 877 // that dominates the use. If there is no clone in a dominating block, then 878 // create a phi for the def in a dominating block. 879 880 // Find which successor block dominates this use. The successor 881 // blocks must all be single-entry (from the Catch only; I will have 882 // split blocks to make this so), hence they all dominate. 883 while( use_blk->_dom_depth > def_blk->_dom_depth+1 ) 884 use_blk = use_blk->_idom; 885 886 // Find the successor 887 Node *fixup = NULL; 888 889 uint j; 890 for( j = 0; j < def_blk->_num_succs; j++ ) 891 if( use_blk == def_blk->_succs[j] ) 892 break; 893 894 if( j == def_blk->_num_succs ) { 895 // Block at same level in dom-tree is not a successor. It needs a 896 // PhiNode, the PhiNode uses from the def and IT's uses need fixup. 897 Node_Array inputs = new Node_List(Thread::current()->resource_area()); 898 for(uint k = 1; k < use_blk->num_preds(); k++) { 899 inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx)); 900 } 901 902 // Check to see if the use_blk already has an identical phi inserted. 903 // If it exists, it will be at the first position since all uses of a 904 // def are processed together. 905 Node *phi = use_blk->_nodes[1]; 906 if( phi->is_Phi() ) { 907 fixup = phi; 908 for (uint k = 1; k < use_blk->num_preds(); k++) { 909 if (phi->in(k) != inputs[k]) { 910 // Not a match 911 fixup = NULL; 912 break; 913 } 914 } 915 } 916 917 // If an existing PhiNode was not found, make a new one. 918 if (fixup == NULL) { 919 Node *new_phi = PhiNode::make(use_blk->head(), def); 920 use_blk->_nodes.insert(1, new_phi); 921 bbs.map(new_phi->_idx, use_blk); 922 for (uint k = 1; k < use_blk->num_preds(); k++) { 923 new_phi->set_req(k, inputs[k]); 924 } 925 fixup = new_phi; 926 } 927 928 } else { 929 // Found the use just below the Catch. Make it use the clone. 930 fixup = use_blk->_nodes[n_clone_idx]; 931 } 932 933 return fixup; 934 } 935 936 //--------------------------catch_cleanup_intra_block-------------------------- 937 // Fix all input edges in use that reference "def". The use is in the same 938 // block as the def and both have been cloned in each successor block. 939 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) { 940 941 // Both the use and def have been cloned. For each successor block, 942 // get the clone of the use, and make its input the clone of the def 943 // found in that block. 944 945 uint use_idx = blk->find_node(use); 946 uint offset_idx = use_idx - beg; 947 for( uint k = 0; k < blk->_num_succs; k++ ) { 948 // Get clone in each successor block 949 Block *sb = blk->_succs[k]; 950 Node *clone = sb->_nodes[offset_idx+1]; 951 assert( clone->Opcode() == use->Opcode(), "" ); 952 953 // Make use-clone reference the def-clone 954 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]); 955 } 956 } 957 958 //------------------------------catch_cleanup_inter_block--------------------- 959 // Fix all input edges in use that reference "def". The use is in a different 960 // block than the def. 961 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) { 962 if( !use_blk ) return; // Can happen if the use is a precedence edge 963 964 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx); 965 catch_cleanup_fix_all_inputs(use, def, new_def); 966 } 967 968 //------------------------------call_catch_cleanup----------------------------- 969 // If we inserted any instructions between a Call and his CatchNode, 970 // clone the instructions on all paths below the Catch. 971 void Block::call_catch_cleanup(Block_Array &bbs) { 972 973 // End of region to clone 974 uint end = end_idx(); 975 if( !_nodes[end]->is_Catch() ) return; 976 // Start of region to clone 977 uint beg = end; 978 while( _nodes[beg-1]->Opcode() != Op_MachProj || 979 !_nodes[beg-1]->in(0)->is_Call() ) { 980 beg--; 981 assert(beg > 0,"Catch cleanup walking beyond block boundary"); 982 } 983 // Range of inserted instructions is [beg, end) 984 if( beg == end ) return; 985 986 // Clone along all Catch output paths. Clone area between the 'beg' and 987 // 'end' indices. 988 for( uint i = 0; i < _num_succs; i++ ) { 989 Block *sb = _succs[i]; 990 // Clone the entire area; ignoring the edge fixup for now. 991 for( uint j = end; j > beg; j-- ) { 992 // It is safe here to clone a node with anti_dependence 993 // since clones dominate on each path. 994 Node *clone = _nodes[j-1]->clone(); 995 sb->_nodes.insert( 1, clone ); 996 bbs.map(clone->_idx,sb); 997 } 998 } 999 1000 1001 // Fixup edges. Check the def-use info per cloned Node 1002 for(uint i2 = beg; i2 < end; i2++ ) { 1003 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block 1004 Node *n = _nodes[i2]; // Node that got cloned 1005 // Need DU safe iterator because of edge manipulation in calls. 1006 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area()); 1007 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) { 1008 out->push(n->fast_out(j1)); 1009 } 1010 uint max = out->size(); 1011 for (uint j = 0; j < max; j++) {// For all users 1012 Node *use = out->pop(); 1013 Block *buse = bbs[use->_idx]; 1014 if( use->is_Phi() ) { 1015 for( uint k = 1; k < use->req(); k++ ) 1016 if( use->in(k) == n ) { 1017 Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx); 1018 use->set_req(k, fixup); 1019 } 1020 } else { 1021 if (this == buse) { 1022 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx); 1023 } else { 1024 catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx); 1025 } 1026 } 1027 } // End for all users 1028 1029 } // End of for all Nodes in cloned area 1030 1031 // Remove the now-dead cloned ops 1032 for(uint i3 = beg; i3 < end; i3++ ) { 1033 _nodes[beg]->disconnect_inputs(NULL); 1034 _nodes.remove(beg); 1035 } 1036 1037 // If the successor blocks have a CreateEx node, move it back to the top 1038 for(uint i4 = 0; i4 < _num_succs; i4++ ) { 1039 Block *sb = _succs[i4]; 1040 uint new_cnt = end - beg; 1041 // Remove any newly created, but dead, nodes. 1042 for( uint j = new_cnt; j > 0; j-- ) { 1043 Node *n = sb->_nodes[j]; 1044 if (n->outcnt() == 0 && 1045 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){ 1046 n->disconnect_inputs(NULL); 1047 sb->_nodes.remove(j); 1048 new_cnt--; 1049 } 1050 } 1051 // If any newly created nodes remain, move the CreateEx node to the top 1052 if (new_cnt > 0) { 1053 Node *cex = sb->_nodes[1+new_cnt]; 1054 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) { 1055 sb->_nodes.remove(1+new_cnt); 1056 sb->_nodes.insert(1,cex); 1057 } 1058 } 1059 } 1060 }