1 /* 2 * Copyright (c) 1997, 2013, 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/callnode.hpp" 28 #include "opto/chaitin.hpp" 29 #include "opto/live.hpp" 30 #include "opto/machnode.hpp" 31 32 33 // Compute live-in/live-out. We use a totally incremental algorithm. The LIVE 34 // problem is monotonic. The steady-state solution looks like this: pull a 35 // block from the worklist. It has a set of delta's - values which are newly 36 // live-in from the block. Push these to the live-out sets of all predecessor 37 // blocks. At each predecessor, the new live-out values are ANDed with what is 38 // already live-out (extra stuff is added to the live-out sets). Then the 39 // remaining new live-out values are ANDed with what is locally defined. 40 // Leftover bits become the new live-in for the predecessor block, and the pred 41 // block is put on the worklist. 42 // The locally live-in stuff is computed once and added to predecessor 43 // live-out sets. This separate compilation is done in the outer loop below. 44 PhaseLive::PhaseLive(const PhaseCFG &cfg, const LRG_List &names, Arena *arena, bool keep_deltas) 45 : Phase(LIVE), 46 _cfg(cfg), 47 _names(names), 48 _arena(arena), 49 _live(0), 50 _livein(0), 51 _keep_deltas(keep_deltas) { 52 } 53 54 void PhaseLive::compute(uint maxlrg) { 55 _maxlrg = maxlrg; 56 _worklist = new (_arena) Block_List(); 57 58 // Init the sparse live arrays. This data is live on exit from here! 59 // The _live info is the live-out info. 60 _live = (IndexSet*)_arena->Amalloc(sizeof(IndexSet) * _cfg.number_of_blocks()); 61 uint i; 62 for (i = 0; i < _cfg.number_of_blocks(); i++) { 63 _live[i].initialize(_maxlrg); 64 } 65 66 if (_keep_deltas) { 67 _livein = (IndexSet*)_arena->Amalloc(sizeof(IndexSet) * _cfg.number_of_blocks()); 68 for (i = 0; i < _cfg.number_of_blocks(); i++) { 69 _livein[i].initialize(_maxlrg); 70 } 71 } 72 73 // Init the sparse arrays for delta-sets. 74 ResourceMark rm; // Nuke temp storage on exit 75 76 // Does the memory used by _defs and _deltas get reclaimed? Does it matter? TT 77 78 // Array of values defined locally in blocks 79 _defs = NEW_RESOURCE_ARRAY(IndexSet,_cfg.number_of_blocks()); 80 for (i = 0; i < _cfg.number_of_blocks(); i++) { 81 _defs[i].initialize(_maxlrg); 82 } 83 84 // Array of delta-set pointers, indexed by block pre_order-1. 85 _deltas = NEW_RESOURCE_ARRAY(IndexSet*,_cfg.number_of_blocks()); 86 memset( _deltas, 0, sizeof(IndexSet*)* _cfg.number_of_blocks()); 87 88 _free_IndexSet = NULL; 89 90 // Blocks having done pass-1 91 VectorSet first_pass(Thread::current()->resource_area()); 92 93 // Outer loop: must compute local live-in sets and push into predecessors. 94 for (uint j = _cfg.number_of_blocks(); j > 0; j--) { 95 Block* block = _cfg.get_block(j - 1); 96 97 // Compute the local live-in set. Start with any new live-out bits. 98 IndexSet* use = getset(block); 99 IndexSet* def = &_defs[block->_pre_order-1]; 100 DEBUG_ONLY(IndexSet *def_outside = getfreeset();) 101 uint i; 102 for (i = block->number_of_nodes(); i > 1; i--) { 103 Node* n = block->get_node(i-1); 104 if (n->is_Phi()) { 105 break; 106 } 107 108 uint r = _names.at(n->_idx); 109 assert(!def_outside->member(r), "Use of external LRG overlaps the same LRG defined in this block"); 110 def->insert( r ); 111 use->remove( r ); 112 uint cnt = n->req(); 113 for (uint k = 1; k < cnt; k++) { 114 Node *nk = n->in(k); 115 uint nkidx = nk->_idx; 116 if (_cfg.get_block_for_node(nk) != block) { 117 uint u = _names.at(nkidx); 118 use->insert(u); 119 DEBUG_ONLY(def_outside->insert(u);) 120 } 121 } 122 } 123 #ifdef ASSERT 124 def_outside->set_next(_free_IndexSet); 125 _free_IndexSet = def_outside; // Drop onto free list 126 #endif 127 // Remove anything defined by Phis and the block start instruction 128 for (uint k = i; k > 0; k--) { 129 uint r = _names.at(block->get_node(k - 1)->_idx); 130 def->insert(r); 131 use->remove(r); 132 } 133 134 // Push these live-in things to predecessors 135 for (uint l = 1; l < block->num_preds(); l++) { 136 Block* p = _cfg.get_block_for_node(block->pred(l)); 137 add_liveout(p, use, first_pass); 138 139 // PhiNode uses go in the live-out set of prior blocks. 140 for (uint k = i; k > 0; k--) { 141 Node *phi = block->get_node(k - 1); 142 if (l < phi->req()) { 143 add_liveout(p, _names.at(phi->in(l)->_idx), first_pass); 144 } 145 } 146 } 147 freeset(block); 148 first_pass.set(block->_pre_order); 149 150 // Inner loop: blocks that picked up new live-out values to be propagated 151 while (_worklist->size()) { 152 Block* block = _worklist->pop(); 153 IndexSet *delta = getset(block); 154 assert( delta->count(), "missing delta set" ); 155 156 // Add new-live-in to predecessors live-out sets 157 for (uint l = 1; l < block->num_preds(); l++) { 158 Block* predecessor = _cfg.get_block_for_node(block->pred(l)); 159 add_liveout(predecessor, delta, first_pass); 160 } 161 162 freeset(block); 163 } // End of while-worklist-not-empty 164 165 } // End of for-all-blocks-outer-loop 166 167 // We explicitly clear all of the IndexSets which we are about to release. 168 // This allows us to recycle their internal memory into IndexSet's free list. 169 170 for (i = 0; i < _cfg.number_of_blocks(); i++) { 171 _defs[i].clear(); 172 if (_deltas[i]) { 173 // Is this always true? 174 _deltas[i]->clear(); 175 } 176 } 177 IndexSet *free = _free_IndexSet; 178 while (free != NULL) { 179 IndexSet *temp = free; 180 free = free->next(); 181 temp->clear(); 182 } 183 184 } 185 186 #ifndef PRODUCT 187 void PhaseLive::stats(uint iters) const { 188 } 189 #endif 190 191 // Get an IndexSet for a block. Return existing one, if any. Make a new 192 // empty one if a prior one does not exist. 193 IndexSet *PhaseLive::getset( Block *p ) { 194 IndexSet *delta = _deltas[p->_pre_order-1]; 195 if( !delta ) // Not on worklist? 196 // Get a free set; flag as being on worklist 197 delta = _deltas[p->_pre_order-1] = getfreeset(); 198 return delta; // Return set of new live-out items 199 } 200 201 // Pull from free list, or allocate. Internal allocation on the returned set 202 // is always from thread local storage. 203 IndexSet *PhaseLive::getfreeset( ) { 204 IndexSet *f = _free_IndexSet; 205 if( !f ) { 206 f = new IndexSet; 207 // f->set_arena(Thread::current()->resource_area()); 208 f->initialize(_maxlrg, Thread::current()->resource_area()); 209 } else { 210 // Pull from free list 211 _free_IndexSet = f->next(); 212 //f->_cnt = 0; // Reset to empty 213 // f->set_arena(Thread::current()->resource_area()); 214 f->initialize(_maxlrg, Thread::current()->resource_area()); 215 } 216 return f; 217 } 218 219 // Free an IndexSet from a block. 220 void PhaseLive::freeset( Block *p ) { 221 IndexSet *f = _deltas[p->_pre_order-1]; 222 if ( _keep_deltas ) { 223 add_livein(p, f); 224 } 225 f->set_next(_free_IndexSet); 226 _free_IndexSet = f; // Drop onto free list 227 _deltas[p->_pre_order-1] = NULL; 228 } 229 230 // Add a live-out value to a given blocks live-out set. If it is new, then 231 // also add it to the delta set and stick the block on the worklist. 232 void PhaseLive::add_liveout( Block *p, uint r, VectorSet &first_pass ) { 233 IndexSet *live = &_live[p->_pre_order-1]; 234 if( live->insert(r) ) { // If actually inserted... 235 // We extended the live-out set. See if the value is generated locally. 236 // If it is not, then we must extend the live-in set. 237 if( !_defs[p->_pre_order-1].member( r ) ) { 238 if( !_deltas[p->_pre_order-1] && // Not on worklist? 239 first_pass.test(p->_pre_order) ) 240 _worklist->push(p); // Actually go on worklist if already 1st pass 241 getset(p)->insert(r); 242 } 243 } 244 } 245 246 // Add a vector of live-out values to a given blocks live-out set. 247 void PhaseLive::add_liveout( Block *p, IndexSet *lo, VectorSet &first_pass ) { 248 IndexSet *live = &_live[p->_pre_order-1]; 249 IndexSet *defs = &_defs[p->_pre_order-1]; 250 IndexSet *on_worklist = _deltas[p->_pre_order-1]; 251 IndexSet *delta = on_worklist ? on_worklist : getfreeset(); 252 253 IndexSetIterator elements(lo); 254 uint r; 255 while ((r = elements.next()) != 0) { 256 if( live->insert(r) && // If actually inserted... 257 !defs->member( r ) ) // and not defined locally 258 delta->insert(r); // Then add to live-in set 259 } 260 261 if( delta->count() ) { // If actually added things 262 _deltas[p->_pre_order-1] = delta; // Flag as on worklist now 263 if( !on_worklist && // Not on worklist? 264 first_pass.test(p->_pre_order) ) 265 _worklist->push(p); // Actually go on worklist if already 1st pass 266 } else { // Nothing there; just free it 267 delta->set_next(_free_IndexSet); 268 _free_IndexSet = delta; // Drop onto free list 269 } 270 } 271 272 // Add a vector of live-in values to a given blocks live-in set. 273 void PhaseLive::add_livein(Block *p, IndexSet *lo) { 274 IndexSet *livein = &_livein[p->_pre_order-1]; 275 IndexSetIterator elements(lo); 276 uint r; 277 while ((r = elements.next()) != 0) { 278 livein->insert(r); // Then add to live-in set 279 } 280 } 281 282 #ifndef PRODUCT 283 // Dump the live-out set for a block 284 void PhaseLive::dump( const Block *b ) const { 285 tty->print("Block %d: ",b->_pre_order); 286 if ( _keep_deltas ) { 287 tty->print("LiveIn: "); _livein[b->_pre_order-1].dump(); 288 } 289 tty->print("LiveOut: "); _live[b->_pre_order-1].dump(); 290 uint cnt = b->number_of_nodes(); 291 for( uint i=0; i<cnt; i++ ) { 292 tty->print("L%d/", _names.at(b->get_node(i)->_idx)); 293 b->get_node(i)->dump(); 294 } 295 tty->print("\n"); 296 } 297 298 // Verify that base pointers and derived pointers are still sane. 299 void PhaseChaitin::verify_base_ptrs( ResourceArea *a ) const { 300 #ifdef ASSERT 301 Unique_Node_List worklist(a); 302 for (uint i = 0; i < _cfg.number_of_blocks(); i++) { 303 Block* block = _cfg.get_block(i); 304 for (uint j = block->end_idx() + 1; j > 1; j--) { 305 Node* n = block->get_node(j-1); 306 if (n->is_Phi()) { 307 break; 308 } 309 // Found a safepoint? 310 if (n->is_MachSafePoint()) { 311 MachSafePointNode *sfpt = n->as_MachSafePoint(); 312 JVMState* jvms = sfpt->jvms(); 313 if (jvms != NULL) { 314 // Now scan for a live derived pointer 315 if (jvms->oopoff() < sfpt->req()) { 316 // Check each derived/base pair 317 for (uint idx = jvms->oopoff(); idx < sfpt->req(); idx++) { 318 Node *check = sfpt->in(idx); 319 bool is_derived = ((idx - jvms->oopoff()) & 1) == 0; 320 // search upwards through spills and spill phis for AddP 321 worklist.clear(); 322 worklist.push(check); 323 uint k = 0; 324 while( k < worklist.size() ) { 325 check = worklist.at(k); 326 assert(check,"Bad base or derived pointer"); 327 // See PhaseChaitin::find_base_for_derived() for all cases. 328 int isc = check->is_Copy(); 329 if( isc ) { 330 worklist.push(check->in(isc)); 331 } else if( check->is_Phi() ) { 332 for (uint m = 1; m < check->req(); m++) 333 worklist.push(check->in(m)); 334 } else if( check->is_Con() ) { 335 if (is_derived) { 336 // Derived is NULL+offset 337 assert(!is_derived || check->bottom_type()->is_ptr()->ptr() == TypePtr::Null,"Bad derived pointer"); 338 } else { 339 assert(check->bottom_type()->is_ptr()->_offset == 0,"Bad base pointer"); 340 // Base either ConP(NULL) or loadConP 341 if (check->is_Mach()) { 342 assert(check->as_Mach()->ideal_Opcode() == Op_ConP,"Bad base pointer"); 343 } else { 344 assert(check->Opcode() == Op_ConP && 345 check->bottom_type()->is_ptr()->ptr() == TypePtr::Null,"Bad base pointer"); 346 } 347 } 348 } else if( check->bottom_type()->is_ptr()->_offset == 0 ) { 349 if(check->is_Proj() || check->is_Mach() && 350 (check->as_Mach()->ideal_Opcode() == Op_CreateEx || 351 check->as_Mach()->ideal_Opcode() == Op_ThreadLocal || 352 check->as_Mach()->ideal_Opcode() == Op_CMoveP || 353 check->as_Mach()->ideal_Opcode() == Op_CheckCastPP || 354 #ifdef _LP64 355 UseCompressedOops && check->as_Mach()->ideal_Opcode() == Op_CastPP || 356 UseCompressedOops && check->as_Mach()->ideal_Opcode() == Op_DecodeN || 357 UseCompressedClassPointers && check->as_Mach()->ideal_Opcode() == Op_DecodeNKlass || 358 #endif 359 check->as_Mach()->ideal_Opcode() == Op_LoadP || 360 check->as_Mach()->ideal_Opcode() == Op_LoadKlass)) { 361 // Valid nodes 362 } else { 363 check->dump(); 364 assert(false,"Bad base or derived pointer"); 365 } 366 } else { 367 assert(is_derived,"Bad base pointer"); 368 assert(check->is_Mach() && check->as_Mach()->ideal_Opcode() == Op_AddP,"Bad derived pointer"); 369 } 370 k++; 371 assert(k < 100000,"Derived pointer checking in infinite loop"); 372 } // End while 373 } 374 } // End of check for derived pointers 375 } // End of Kcheck for debug info 376 } // End of if found a safepoint 377 } // End of forall instructions in block 378 } // End of forall blocks 379 #endif 380 } 381 382 // Verify that graphs and base pointers are still sane. 383 void PhaseChaitin::verify( ResourceArea *a, bool verify_ifg ) const { 384 #ifdef ASSERT 385 if( VerifyOpto || VerifyRegisterAllocator ) { 386 _cfg.verify(); 387 verify_base_ptrs(a); 388 if(verify_ifg) 389 _ifg->verify(this); 390 } 391 #endif 392 } 393 394 #endif