| File: | jdk/src/hotspot/share/opto/block.cpp |
| Warning: | line 816, column 9 Value stored to 'bnext' is never read |
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| 1 | /* |
| 2 | * Copyright (c) 1997, 2021, 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 "libadt/vectset.hpp" |
| 27 | #include "memory/allocation.inline.hpp" |
| 28 | #include "memory/resourceArea.hpp" |
| 29 | #include "compiler/compilerDirectives.hpp" |
| 30 | #include "opto/block.hpp" |
| 31 | #include "opto/cfgnode.hpp" |
| 32 | #include "opto/chaitin.hpp" |
| 33 | #include "opto/loopnode.hpp" |
| 34 | #include "opto/machnode.hpp" |
| 35 | #include "opto/matcher.hpp" |
| 36 | #include "opto/opcodes.hpp" |
| 37 | #include "opto/rootnode.hpp" |
| 38 | #include "utilities/copy.hpp" |
| 39 | #include "utilities/powerOfTwo.hpp" |
| 40 | |
| 41 | void Block_Array::grow( uint i ) { |
| 42 | assert(i >= Max(), "must be an overflow")do { if (!(i >= Max())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 42, "assert(" "i >= Max()" ") failed", "must be an overflow" ); ::breakpoint(); } } while (0); |
| 43 | debug_only(_limit = i+1)_limit = i+1; |
| 44 | if( i < _size ) return; |
| 45 | if( !_size ) { |
| 46 | _size = 1; |
| 47 | _blocks = (Block**)_arena->Amalloc( _size * sizeof(Block*) ); |
| 48 | _blocks[0] = NULL__null; |
| 49 | } |
| 50 | uint old = _size; |
| 51 | _size = next_power_of_2(i); |
| 52 | _blocks = (Block**)_arena->Arealloc( _blocks, old*sizeof(Block*),_size*sizeof(Block*)); |
| 53 | Copy::zero_to_bytes( &_blocks[old], (_size-old)*sizeof(Block*) ); |
| 54 | } |
| 55 | |
| 56 | void Block_List::remove(uint i) { |
| 57 | assert(i < _cnt, "index out of bounds")do { if (!(i < _cnt)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 57, "assert(" "i < _cnt" ") failed", "index out of bounds" ); ::breakpoint(); } } while (0); |
| 58 | Copy::conjoint_words_to_lower((HeapWord*)&_blocks[i+1], (HeapWord*)&_blocks[i], ((_cnt-i-1)*sizeof(Block*))); |
| 59 | pop(); // shrink list by one block |
| 60 | } |
| 61 | |
| 62 | void Block_List::insert(uint i, Block *b) { |
| 63 | push(b); // grow list by one block |
| 64 | Copy::conjoint_words_to_higher((HeapWord*)&_blocks[i], (HeapWord*)&_blocks[i+1], ((_cnt-i-1)*sizeof(Block*))); |
| 65 | _blocks[i] = b; |
| 66 | } |
| 67 | |
| 68 | #ifndef PRODUCT |
| 69 | void Block_List::print() { |
| 70 | for (uint i=0; i < size(); i++) { |
| 71 | tty->print("B%d ", _blocks[i]->_pre_order); |
| 72 | } |
| 73 | tty->print("size = %d\n", size()); |
| 74 | } |
| 75 | #endif |
| 76 | |
| 77 | uint Block::code_alignment() const { |
| 78 | // Check for Root block |
| 79 | if (_pre_order == 0) return CodeEntryAlignment; |
| 80 | // Check for Start block |
| 81 | if (_pre_order == 1) return InteriorEntryAlignment; |
| 82 | // Check for loop alignment |
| 83 | if (has_loop_alignment()) return loop_alignment(); |
| 84 | |
| 85 | return relocInfo::addr_unit(); // no particular alignment |
| 86 | } |
| 87 | |
| 88 | uint Block::compute_loop_alignment() { |
| 89 | Node *h = head(); |
| 90 | int unit_sz = relocInfo::addr_unit(); |
| 91 | if (h->is_Loop() && h->as_Loop()->is_inner_loop()) { |
| 92 | // Pre- and post-loops have low trip count so do not bother with |
| 93 | // NOPs for align loop head. The constants are hidden from tuning |
| 94 | // but only because my "divide by 4" heuristic surely gets nearly |
| 95 | // all possible gain (a "do not align at all" heuristic has a |
| 96 | // chance of getting a really tiny gain). |
| 97 | if (h->is_CountedLoop() && (h->as_CountedLoop()->is_pre_loop() || |
| 98 | h->as_CountedLoop()->is_post_loop())) { |
| 99 | return (OptoLoopAlignment > 4*unit_sz) ? (OptoLoopAlignment>>2) : unit_sz; |
| 100 | } |
| 101 | // Loops with low backedge frequency should not be aligned. |
| 102 | Node *n = h->in(LoopNode::LoopBackControl)->in(0); |
| 103 | if (n->is_MachIf() && n->as_MachIf()->_prob < 0.01) { |
| 104 | return unit_sz; // Loop does not loop, more often than not! |
| 105 | } |
| 106 | return OptoLoopAlignment; // Otherwise align loop head |
| 107 | } |
| 108 | |
| 109 | return unit_sz; // no particular alignment |
| 110 | } |
| 111 | |
| 112 | // Compute the size of first 'inst_cnt' instructions in this block. |
| 113 | // Return the number of instructions left to compute if the block has |
| 114 | // less then 'inst_cnt' instructions. Stop, and return 0 if sum_size |
| 115 | // exceeds OptoLoopAlignment. |
| 116 | uint Block::compute_first_inst_size(uint& sum_size, uint inst_cnt, |
| 117 | PhaseRegAlloc* ra) { |
| 118 | uint last_inst = number_of_nodes(); |
| 119 | for( uint j = 0; j < last_inst && inst_cnt > 0; j++ ) { |
| 120 | uint inst_size = get_node(j)->size(ra); |
| 121 | if( inst_size > 0 ) { |
| 122 | inst_cnt--; |
| 123 | uint sz = sum_size + inst_size; |
| 124 | if( sz <= (uint)OptoLoopAlignment ) { |
| 125 | // Compute size of instructions which fit into fetch buffer only |
| 126 | // since all inst_cnt instructions will not fit even if we align them. |
| 127 | sum_size = sz; |
| 128 | } else { |
| 129 | return 0; |
| 130 | } |
| 131 | } |
| 132 | } |
| 133 | return inst_cnt; |
| 134 | } |
| 135 | |
| 136 | uint Block::find_node( const Node *n ) const { |
| 137 | for( uint i = 0; i < number_of_nodes(); i++ ) { |
| 138 | if( get_node(i) == n ) |
| 139 | return i; |
| 140 | } |
| 141 | ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 141); ::breakpoint(); } while (0); |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | // Find and remove n from block list |
| 146 | void Block::find_remove( const Node *n ) { |
| 147 | remove_node(find_node(n)); |
| 148 | } |
| 149 | |
| 150 | bool Block::contains(const Node *n) const { |
| 151 | return _nodes.contains(n); |
| 152 | } |
| 153 | |
| 154 | // Return empty status of a block. Empty blocks contain only the head, other |
| 155 | // ideal nodes, and an optional trailing goto. |
| 156 | int Block::is_Empty() const { |
| 157 | |
| 158 | // Root or start block is not considered empty |
| 159 | if (head()->is_Root() || head()->is_Start()) { |
| 160 | return not_empty; |
| 161 | } |
| 162 | |
| 163 | int success_result = completely_empty; |
| 164 | int end_idx = number_of_nodes() - 1; |
| 165 | |
| 166 | // Check for ending goto |
| 167 | if ((end_idx > 0) && (get_node(end_idx)->is_MachGoto())) { |
| 168 | success_result = empty_with_goto; |
| 169 | end_idx--; |
| 170 | } |
| 171 | |
| 172 | // Unreachable blocks are considered empty |
| 173 | if (num_preds() <= 1) { |
| 174 | return success_result; |
| 175 | } |
| 176 | |
| 177 | // Ideal nodes are allowable in empty blocks: skip them Only MachNodes |
| 178 | // turn directly into code, because only MachNodes have non-trivial |
| 179 | // emit() functions. |
| 180 | while ((end_idx > 0) && !get_node(end_idx)->is_Mach()) { |
| 181 | end_idx--; |
| 182 | } |
| 183 | |
| 184 | // No room for any interesting instructions? |
| 185 | if (end_idx == 0) { |
| 186 | return success_result; |
| 187 | } |
| 188 | |
| 189 | return not_empty; |
| 190 | } |
| 191 | |
| 192 | // Return true if the block's code implies that it is likely to be |
| 193 | // executed infrequently. Check to see if the block ends in a Halt or |
| 194 | // a low probability call. |
| 195 | bool Block::has_uncommon_code() const { |
| 196 | Node* en = end(); |
| 197 | |
| 198 | if (en->is_MachGoto()) |
| 199 | en = en->in(0); |
| 200 | if (en->is_Catch()) |
| 201 | en = en->in(0); |
| 202 | if (en->is_MachProj() && en->in(0)->is_MachCall()) { |
| 203 | MachCallNode* call = en->in(0)->as_MachCall(); |
| 204 | if (call->cnt() != COUNT_UNKNOWN(-1.0f) && call->cnt() <= PROB_UNLIKELY_MAG(4)(1e-4f)) { |
| 205 | // This is true for slow-path stubs like new_{instance,array}, |
| 206 | // slow_arraycopy, complete_monitor_locking, uncommon_trap. |
| 207 | // The magic number corresponds to the probability of an uncommon_trap, |
| 208 | // even though it is a count not a probability. |
| 209 | return true; |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | int op = en->is_Mach() ? en->as_Mach()->ideal_Opcode() : en->Opcode(); |
| 214 | return op == Op_Halt; |
| 215 | } |
| 216 | |
| 217 | // True if block is low enough frequency or guarded by a test which |
| 218 | // mostly does not go here. |
| 219 | bool PhaseCFG::is_uncommon(const Block* block) { |
| 220 | // Initial blocks must never be moved, so are never uncommon. |
| 221 | if (block->head()->is_Root() || block->head()->is_Start()) return false; |
| 222 | |
| 223 | // Check for way-low freq |
| 224 | if(block->_freq < BLOCK_FREQUENCY(0.00001f)((0.00001f * (double) 1500) / FreqCountInvocations) ) return true; |
| 225 | |
| 226 | // Look for code shape indicating uncommon_trap or slow path |
| 227 | if (block->has_uncommon_code()) return true; |
| 228 | |
| 229 | const float epsilon = 0.05f; |
| 230 | const float guard_factor = PROB_UNLIKELY_MAG(4)(1e-4f) / (1.f - epsilon); |
| 231 | uint uncommon_preds = 0; |
| 232 | uint freq_preds = 0; |
| 233 | uint uncommon_for_freq_preds = 0; |
| 234 | |
| 235 | for( uint i=1; i< block->num_preds(); i++ ) { |
| 236 | Block* guard = get_block_for_node(block->pred(i)); |
| 237 | // Check to see if this block follows its guard 1 time out of 10000 |
| 238 | // or less. |
| 239 | // |
| 240 | // See list of magnitude-4 unlikely probabilities in cfgnode.hpp which |
| 241 | // we intend to be "uncommon", such as slow-path TLE allocation, |
| 242 | // predicted call failure, and uncommon trap triggers. |
| 243 | // |
| 244 | // Use an epsilon value of 5% to allow for variability in frequency |
| 245 | // predictions and floating point calculations. The net effect is |
| 246 | // that guard_factor is set to 9500. |
| 247 | // |
| 248 | // Ignore low-frequency blocks. |
| 249 | // The next check is (guard->_freq < 1.e-5 * 9500.). |
| 250 | if(guard->_freq*BLOCK_FREQUENCY(guard_factor)((guard_factor * (double) 1500) / FreqCountInvocations) < BLOCK_FREQUENCY(0.00001f)((0.00001f * (double) 1500) / FreqCountInvocations)) { |
| 251 | uncommon_preds++; |
| 252 | } else { |
| 253 | freq_preds++; |
| 254 | if(block->_freq < guard->_freq * guard_factor ) { |
| 255 | uncommon_for_freq_preds++; |
| 256 | } |
| 257 | } |
| 258 | } |
| 259 | if( block->num_preds() > 1 && |
| 260 | // The block is uncommon if all preds are uncommon or |
| 261 | (uncommon_preds == (block->num_preds()-1) || |
| 262 | // it is uncommon for all frequent preds. |
| 263 | uncommon_for_freq_preds == freq_preds) ) { |
| 264 | return true; |
| 265 | } |
| 266 | return false; |
| 267 | } |
| 268 | |
| 269 | #ifndef PRODUCT |
| 270 | void Block::dump_bidx(const Block* orig, outputStream* st) const { |
| 271 | if (_pre_order) st->print("B%d", _pre_order); |
| 272 | else st->print("N%d", head()->_idx); |
| 273 | |
| 274 | if (Verbose && orig != this) { |
| 275 | // Dump the original block's idx |
| 276 | st->print(" ("); |
| 277 | orig->dump_bidx(orig, st); |
| 278 | st->print(")"); |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | void Block::dump_pred(const PhaseCFG* cfg, Block* orig, outputStream* st) const { |
| 283 | if (is_connector()) { |
| 284 | for (uint i=1; i<num_preds(); i++) { |
| 285 | Block *p = cfg->get_block_for_node(pred(i)); |
| 286 | p->dump_pred(cfg, orig, st); |
| 287 | } |
| 288 | } else { |
| 289 | dump_bidx(orig, st); |
| 290 | st->print(" "); |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | void Block::dump_head(const PhaseCFG* cfg, outputStream* st) const { |
| 295 | // Print the basic block. |
| 296 | dump_bidx(this, st); |
| 297 | st->print(": "); |
| 298 | |
| 299 | // Print the outgoing CFG edges. |
| 300 | st->print("#\tout( "); |
| 301 | for( uint i=0; i<_num_succs; i++ ) { |
| 302 | non_connector_successor(i)->dump_bidx(_succs[i], st); |
| 303 | st->print(" "); |
| 304 | } |
| 305 | |
| 306 | // Print the incoming CFG edges. |
| 307 | st->print(") <- "); |
| 308 | if( head()->is_block_start() ) { |
| 309 | st->print("in( "); |
| 310 | for (uint i=1; i<num_preds(); i++) { |
| 311 | Node *s = pred(i); |
| 312 | if (cfg != NULL__null) { |
| 313 | Block *p = cfg->get_block_for_node(s); |
| 314 | p->dump_pred(cfg, p, st); |
| 315 | } else { |
| 316 | while (!s->is_block_start()) { |
| 317 | s = s->in(0); |
| 318 | } |
| 319 | st->print("N%d ", s->_idx ); |
| 320 | } |
| 321 | } |
| 322 | st->print(") "); |
| 323 | } else { |
| 324 | st->print("BLOCK HEAD IS JUNK "); |
| 325 | } |
| 326 | |
| 327 | // Print loop, if any |
| 328 | const Block *bhead = this; // Head of self-loop |
| 329 | Node *bh = bhead->head(); |
| 330 | |
| 331 | if ((cfg != NULL__null) && bh->is_Loop() && !head()->is_Root()) { |
| 332 | LoopNode *loop = bh->as_Loop(); |
| 333 | const Block *bx = cfg->get_block_for_node(loop->in(LoopNode::LoopBackControl)); |
| 334 | while (bx->is_connector()) { |
| 335 | bx = cfg->get_block_for_node(bx->pred(1)); |
| 336 | } |
| 337 | st->print("Loop( B%d-B%d ", bhead->_pre_order, bx->_pre_order); |
| 338 | // Dump any loop-specific bits, especially for CountedLoops. |
| 339 | loop->dump_spec(st); |
| 340 | st->print(")"); |
| 341 | } else if (has_loop_alignment()) { |
| 342 | st->print("top-of-loop"); |
| 343 | } |
| 344 | |
| 345 | // Print frequency and other optimization-relevant information |
| 346 | st->print(" Freq: %g",_freq); |
| 347 | if( Verbose || WizardMode ) { |
| 348 | st->print(" IDom: %d/#%d", _idom ? _idom->_pre_order : 0, _dom_depth); |
| 349 | st->print(" RegPressure: %d",_reg_pressure); |
| 350 | st->print(" IHRP Index: %d",_ihrp_index); |
| 351 | st->print(" FRegPressure: %d",_freg_pressure); |
| 352 | st->print(" FHRP Index: %d",_fhrp_index); |
| 353 | } |
| 354 | st->cr(); |
| 355 | } |
| 356 | |
| 357 | void Block::dump() const { |
| 358 | dump(NULL__null); |
| 359 | } |
| 360 | |
| 361 | void Block::dump(const PhaseCFG* cfg) const { |
| 362 | dump_head(cfg); |
| 363 | for (uint i=0; i< number_of_nodes(); i++) { |
| 364 | get_node(i)->dump(); |
| 365 | } |
| 366 | tty->print("\n"); |
| 367 | } |
| 368 | #endif |
| 369 | |
| 370 | PhaseCFG::PhaseCFG(Arena* arena, RootNode* root, Matcher& matcher) |
| 371 | : Phase(CFG) |
| 372 | , _root(root) |
| 373 | , _block_arena(arena) |
| 374 | , _regalloc(NULL__null) |
| 375 | , _scheduling_for_pressure(false) |
| 376 | , _matcher(matcher) |
| 377 | , _node_to_block_mapping(arena) |
| 378 | , _node_latency(NULL__null) |
| 379 | #ifndef PRODUCT |
| 380 | , _trace_opto_pipelining(C->directive()->TraceOptoPipeliningOption) |
| 381 | #endif |
| 382 | #ifdef ASSERT1 |
| 383 | , _raw_oops(arena) |
| 384 | #endif |
| 385 | { |
| 386 | ResourceMark rm; |
| 387 | // I'll need a few machine-specific GotoNodes. Make an Ideal GotoNode, |
| 388 | // then Match it into a machine-specific Node. Then clone the machine |
| 389 | // Node on demand. |
| 390 | Node *x = new GotoNode(NULL__null); |
| 391 | x->init_req(0, x); |
| 392 | _goto = matcher.match_tree(x); |
| 393 | assert(_goto != NULL, "")do { if (!(_goto != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 393, "assert(" "_goto != __null" ") failed", ""); ::breakpoint (); } } while (0); |
| 394 | _goto->set_req(0,_goto); |
| 395 | |
| 396 | // Build the CFG in Reverse Post Order |
| 397 | _number_of_blocks = build_cfg(); |
| 398 | _root_block = get_block_for_node(_root); |
| 399 | } |
| 400 | |
| 401 | // Build a proper looking CFG. Make every block begin with either a StartNode |
| 402 | // or a RegionNode. Make every block end with either a Goto, If or Return. |
| 403 | // The RootNode both starts and ends it's own block. Do this with a recursive |
| 404 | // backwards walk over the control edges. |
| 405 | uint PhaseCFG::build_cfg() { |
| 406 | VectorSet visited; |
| 407 | |
| 408 | // Allocate stack with enough space to avoid frequent realloc |
| 409 | Node_Stack nstack(C->live_nodes() >> 1); |
| 410 | nstack.push(_root, 0); |
| 411 | uint sum = 0; // Counter for blocks |
| 412 | |
| 413 | while (nstack.is_nonempty()) { |
| 414 | // node and in's index from stack's top |
| 415 | // 'np' is _root (see above) or RegionNode, StartNode: we push on stack |
| 416 | // only nodes which point to the start of basic block (see below). |
| 417 | Node *np = nstack.node(); |
| 418 | // idx > 0, except for the first node (_root) pushed on stack |
| 419 | // at the beginning when idx == 0. |
| 420 | // We will use the condition (idx == 0) later to end the build. |
| 421 | uint idx = nstack.index(); |
| 422 | Node *proj = np->in(idx); |
| 423 | const Node *x = proj->is_block_proj(); |
| 424 | // Does the block end with a proper block-ending Node? One of Return, |
| 425 | // If or Goto? (This check should be done for visited nodes also). |
| 426 | if (x == NULL__null) { // Does not end right... |
| 427 | Node *g = _goto->clone(); // Force it to end in a Goto |
| 428 | g->set_req(0, proj); |
| 429 | np->set_req(idx, g); |
| 430 | x = proj = g; |
| 431 | } |
| 432 | if (!visited.test_set(x->_idx)) { // Visit this block once |
| 433 | // Skip any control-pinned middle'in stuff |
| 434 | Node *p = proj; |
| 435 | do { |
| 436 | proj = p; // Update pointer to last Control |
| 437 | p = p->in(0); // Move control forward |
| 438 | } while( !p->is_block_proj() && |
| 439 | !p->is_block_start() ); |
| 440 | // Make the block begin with one of Region or StartNode. |
| 441 | if( !p->is_block_start() ) { |
| 442 | RegionNode *r = new RegionNode( 2 ); |
| 443 | r->init_req(1, p); // Insert RegionNode in the way |
| 444 | proj->set_req(0, r); // Insert RegionNode in the way |
| 445 | p = r; |
| 446 | } |
| 447 | // 'p' now points to the start of this basic block |
| 448 | |
| 449 | // Put self in array of basic blocks |
| 450 | Block *bb = new (_block_arena) Block(_block_arena, p); |
| 451 | map_node_to_block(p, bb); |
| 452 | map_node_to_block(x, bb); |
| 453 | if( x != p ) { // Only for root is x == p |
| 454 | bb->push_node((Node*)x); |
| 455 | } |
| 456 | // Now handle predecessors |
| 457 | ++sum; // Count 1 for self block |
| 458 | uint cnt = bb->num_preds(); |
| 459 | for (int i = (cnt - 1); i > 0; i-- ) { // For all predecessors |
| 460 | Node *prevproj = p->in(i); // Get prior input |
| 461 | assert( !prevproj->is_Con(), "dead input not removed" )do { if (!(!prevproj->is_Con())) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 461, "assert(" "!prevproj->is_Con()" ") failed", "dead input not removed" ); ::breakpoint(); } } while (0); |
| 462 | // Check to see if p->in(i) is a "control-dependent" CFG edge - |
| 463 | // i.e., it splits at the source (via an IF or SWITCH) and merges |
| 464 | // at the destination (via a many-input Region). |
| 465 | // This breaks critical edges. The RegionNode to start the block |
| 466 | // will be added when <p,i> is pulled off the node stack |
| 467 | if ( cnt > 2 ) { // Merging many things? |
| 468 | assert( prevproj== bb->pred(i),"")do { if (!(prevproj== bb->pred(i))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 468, "assert(" "prevproj== bb->pred(i)" ") failed", ""); ::breakpoint(); } } while (0); |
| 469 | if(prevproj->is_block_proj() != prevproj) { // Control-dependent edge? |
| 470 | // Force a block on the control-dependent edge |
| 471 | Node *g = _goto->clone(); // Force it to end in a Goto |
| 472 | g->set_req(0,prevproj); |
| 473 | p->set_req(i,g); |
| 474 | } |
| 475 | } |
| 476 | nstack.push(p, i); // 'p' is RegionNode or StartNode |
| 477 | } |
| 478 | } else { // Post-processing visited nodes |
| 479 | nstack.pop(); // remove node from stack |
| 480 | // Check if it the fist node pushed on stack at the beginning. |
| 481 | if (idx == 0) break; // end of the build |
| 482 | // Find predecessor basic block |
| 483 | Block *pb = get_block_for_node(x); |
| 484 | // Insert into nodes array, if not already there |
| 485 | if (!has_block(proj)) { |
| 486 | assert( x != proj, "" )do { if (!(x != proj)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 486, "assert(" "x != proj" ") failed", ""); ::breakpoint(); } } while (0); |
| 487 | // Map basic block of projection |
| 488 | map_node_to_block(proj, pb); |
| 489 | pb->push_node(proj); |
| 490 | } |
| 491 | // Insert self as a child of my predecessor block |
| 492 | pb->_succs.map(pb->_num_succs++, get_block_for_node(np)); |
| 493 | assert( pb->get_node(pb->number_of_nodes() - pb->_num_succs)->is_block_proj(),do { if (!(pb->get_node(pb->number_of_nodes() - pb-> _num_succs)->is_block_proj())) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 494, "assert(" "pb->get_node(pb->number_of_nodes() - pb->_num_succs)->is_block_proj()" ") failed", "too many control users, not a CFG?"); ::breakpoint (); } } while (0) |
| 494 | "too many control users, not a CFG?" )do { if (!(pb->get_node(pb->number_of_nodes() - pb-> _num_succs)->is_block_proj())) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 494, "assert(" "pb->get_node(pb->number_of_nodes() - pb->_num_succs)->is_block_proj()" ") failed", "too many control users, not a CFG?"); ::breakpoint (); } } while (0); |
| 495 | } |
| 496 | } |
| 497 | // Return number of basic blocks for all children and self |
| 498 | return sum; |
| 499 | } |
| 500 | |
| 501 | // Inserts a goto & corresponding basic block between |
| 502 | // block[block_no] and its succ_no'th successor block |
| 503 | void PhaseCFG::insert_goto_at(uint block_no, uint succ_no) { |
| 504 | // get block with block_no |
| 505 | assert(block_no < number_of_blocks(), "illegal block number")do { if (!(block_no < number_of_blocks())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 505, "assert(" "block_no < number_of_blocks()" ") failed" , "illegal block number"); ::breakpoint(); } } while (0); |
| 506 | Block* in = get_block(block_no); |
| 507 | // get successor block succ_no |
| 508 | assert(succ_no < in->_num_succs, "illegal successor number")do { if (!(succ_no < in->_num_succs)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 508, "assert(" "succ_no < in->_num_succs" ") failed", "illegal successor number"); ::breakpoint(); } } while (0); |
| 509 | Block* out = in->_succs[succ_no]; |
| 510 | // Compute frequency of the new block. Do this before inserting |
| 511 | // new block in case succ_prob() needs to infer the probability from |
| 512 | // surrounding blocks. |
| 513 | float freq = in->_freq * in->succ_prob(succ_no); |
| 514 | // get ProjNode corresponding to the succ_no'th successor of the in block |
| 515 | ProjNode* proj = in->get_node(in->number_of_nodes() - in->_num_succs + succ_no)->as_Proj(); |
| 516 | // create region for basic block |
| 517 | RegionNode* region = new RegionNode(2); |
| 518 | region->init_req(1, proj); |
| 519 | // setup corresponding basic block |
| 520 | Block* block = new (_block_arena) Block(_block_arena, region); |
| 521 | map_node_to_block(region, block); |
| 522 | C->regalloc()->set_bad(region->_idx); |
| 523 | // add a goto node |
| 524 | Node* gto = _goto->clone(); // get a new goto node |
| 525 | gto->set_req(0, region); |
| 526 | // add it to the basic block |
| 527 | block->push_node(gto); |
| 528 | map_node_to_block(gto, block); |
| 529 | C->regalloc()->set_bad(gto->_idx); |
| 530 | // hook up successor block |
| 531 | block->_succs.map(block->_num_succs++, out); |
| 532 | // remap successor's predecessors if necessary |
| 533 | for (uint i = 1; i < out->num_preds(); i++) { |
| 534 | if (out->pred(i) == proj) out->head()->set_req(i, gto); |
| 535 | } |
| 536 | // remap predecessor's successor to new block |
| 537 | in->_succs.map(succ_no, block); |
| 538 | // Set the frequency of the new block |
| 539 | block->_freq = freq; |
| 540 | // add new basic block to basic block list |
| 541 | add_block_at(block_no + 1, block); |
| 542 | } |
| 543 | |
| 544 | // Does this block end in a multiway branch that cannot have the default case |
| 545 | // flipped for another case? |
| 546 | static bool no_flip_branch(Block *b) { |
| 547 | int branch_idx = b->number_of_nodes() - b->_num_succs-1; |
| 548 | if (branch_idx < 1) { |
| 549 | return false; |
| 550 | } |
| 551 | Node *branch = b->get_node(branch_idx); |
| 552 | if (branch->is_Catch()) { |
| 553 | return true; |
| 554 | } |
| 555 | if (branch->is_Mach()) { |
| 556 | if (branch->is_MachNullCheck()) { |
| 557 | return true; |
| 558 | } |
| 559 | int iop = branch->as_Mach()->ideal_Opcode(); |
| 560 | if (iop == Op_FastLock || iop == Op_FastUnlock) { |
| 561 | return true; |
| 562 | } |
| 563 | // Don't flip if branch has an implicit check. |
| 564 | if (branch->as_Mach()->is_TrapBasedCheckNode()) { |
| 565 | return true; |
| 566 | } |
| 567 | } |
| 568 | return false; |
| 569 | } |
| 570 | |
| 571 | // Check for NeverBranch at block end. This needs to become a GOTO to the |
| 572 | // true target. NeverBranch are treated as a conditional branch that always |
| 573 | // goes the same direction for most of the optimizer and are used to give a |
| 574 | // fake exit path to infinite loops. At this late stage they need to turn |
| 575 | // into Goto's so that when you enter the infinite loop you indeed hang. |
| 576 | void PhaseCFG::convert_NeverBranch_to_Goto(Block *b) { |
| 577 | // Find true target |
| 578 | int end_idx = b->end_idx(); |
| 579 | int idx = b->get_node(end_idx+1)->as_Proj()->_con; |
| 580 | Block *succ = b->_succs[idx]; |
| 581 | Node* gto = _goto->clone(); // get a new goto node |
| 582 | gto->set_req(0, b->head()); |
| 583 | Node *bp = b->get_node(end_idx); |
| 584 | b->map_node(gto, end_idx); // Slam over NeverBranch |
| 585 | map_node_to_block(gto, b); |
| 586 | C->regalloc()->set_bad(gto->_idx); |
| 587 | b->pop_node(); // Yank projections |
| 588 | b->pop_node(); // Yank projections |
| 589 | b->_succs.map(0,succ); // Map only successor |
| 590 | b->_num_succs = 1; |
| 591 | // remap successor's predecessors if necessary |
| 592 | uint j; |
| 593 | for( j = 1; j < succ->num_preds(); j++) |
| 594 | if( succ->pred(j)->in(0) == bp ) |
| 595 | succ->head()->set_req(j, gto); |
| 596 | // Kill alternate exit path |
| 597 | Block *dead = b->_succs[1-idx]; |
| 598 | for( j = 1; j < dead->num_preds(); j++) |
| 599 | if( dead->pred(j)->in(0) == bp ) |
| 600 | break; |
| 601 | // Scan through block, yanking dead path from |
| 602 | // all regions and phis. |
| 603 | dead->head()->del_req(j); |
| 604 | for( int k = 1; dead->get_node(k)->is_Phi(); k++ ) |
| 605 | dead->get_node(k)->del_req(j); |
| 606 | } |
| 607 | |
| 608 | // Helper function to move block bx to the slot following b_index. Return |
| 609 | // true if the move is successful, otherwise false |
| 610 | bool PhaseCFG::move_to_next(Block* bx, uint b_index) { |
| 611 | if (bx == NULL__null) return false; |
| 612 | |
| 613 | // Return false if bx is already scheduled. |
| 614 | uint bx_index = bx->_pre_order; |
| 615 | if ((bx_index <= b_index) && (get_block(bx_index) == bx)) { |
| 616 | return false; |
| 617 | } |
| 618 | |
| 619 | // Find the current index of block bx on the block list |
| 620 | bx_index = b_index + 1; |
| 621 | while (bx_index < number_of_blocks() && get_block(bx_index) != bx) { |
| 622 | bx_index++; |
| 623 | } |
| 624 | assert(get_block(bx_index) == bx, "block not found")do { if (!(get_block(bx_index) == bx)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 624, "assert(" "get_block(bx_index) == bx" ") failed", "block not found" ); ::breakpoint(); } } while (0); |
| 625 | |
| 626 | // If the previous block conditionally falls into bx, return false, |
| 627 | // because moving bx will create an extra jump. |
| 628 | for(uint k = 1; k < bx->num_preds(); k++ ) { |
| 629 | Block* pred = get_block_for_node(bx->pred(k)); |
| 630 | if (pred == get_block(bx_index - 1)) { |
| 631 | if (pred->_num_succs != 1) { |
| 632 | return false; |
| 633 | } |
| 634 | } |
| 635 | } |
| 636 | |
| 637 | // Reinsert bx just past block 'b' |
| 638 | _blocks.remove(bx_index); |
| 639 | _blocks.insert(b_index + 1, bx); |
| 640 | return true; |
| 641 | } |
| 642 | |
| 643 | // Move empty and uncommon blocks to the end. |
| 644 | void PhaseCFG::move_to_end(Block *b, uint i) { |
| 645 | int e = b->is_Empty(); |
| 646 | if (e != Block::not_empty) { |
| 647 | if (e == Block::empty_with_goto) { |
| 648 | // Remove the goto, but leave the block. |
| 649 | b->pop_node(); |
| 650 | } |
| 651 | // Mark this block as a connector block, which will cause it to be |
| 652 | // ignored in certain functions such as non_connector_successor(). |
| 653 | b->set_connector(); |
| 654 | } |
| 655 | // Move the empty block to the end, and don't recheck. |
| 656 | _blocks.remove(i); |
| 657 | _blocks.push(b); |
| 658 | } |
| 659 | |
| 660 | // Set loop alignment for every block |
| 661 | void PhaseCFG::set_loop_alignment() { |
| 662 | uint last = number_of_blocks(); |
| 663 | assert(get_block(0) == get_root_block(), "")do { if (!(get_block(0) == get_root_block())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 663, "assert(" "get_block(0) == get_root_block()" ") failed" , ""); ::breakpoint(); } } while (0); |
| 664 | |
| 665 | for (uint i = 1; i < last; i++) { |
| 666 | Block* block = get_block(i); |
| 667 | if (block->head()->is_Loop()) { |
| 668 | block->set_loop_alignment(block); |
| 669 | } |
| 670 | } |
| 671 | } |
| 672 | |
| 673 | // Make empty basic blocks to be "connector" blocks, Move uncommon blocks |
| 674 | // to the end. |
| 675 | void PhaseCFG::remove_empty_blocks() { |
| 676 | // Move uncommon blocks to the end |
| 677 | uint last = number_of_blocks(); |
| 678 | assert(get_block(0) == get_root_block(), "")do { if (!(get_block(0) == get_root_block())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 678, "assert(" "get_block(0) == get_root_block()" ") failed" , ""); ::breakpoint(); } } while (0); |
| 679 | |
| 680 | for (uint i = 1; i < last; i++) { |
| 681 | Block* block = get_block(i); |
| 682 | if (block->is_connector()) { |
| 683 | break; |
| 684 | } |
| 685 | |
| 686 | // Check for NeverBranch at block end. This needs to become a GOTO to the |
| 687 | // true target. NeverBranch are treated as a conditional branch that |
| 688 | // always goes the same direction for most of the optimizer and are used |
| 689 | // to give a fake exit path to infinite loops. At this late stage they |
| 690 | // need to turn into Goto's so that when you enter the infinite loop you |
| 691 | // indeed hang. |
| 692 | if (block->get_node(block->end_idx())->Opcode() == Op_NeverBranch) { |
| 693 | convert_NeverBranch_to_Goto(block); |
| 694 | } |
| 695 | |
| 696 | // Look for uncommon blocks and move to end. |
| 697 | if (!C->do_freq_based_layout()) { |
| 698 | if (is_uncommon(block)) { |
| 699 | move_to_end(block, i); |
| 700 | last--; // No longer check for being uncommon! |
| 701 | if (no_flip_branch(block)) { // Fall-thru case must follow? |
| 702 | // Find the fall-thru block |
| 703 | block = get_block(i); |
| 704 | move_to_end(block, i); |
| 705 | last--; |
| 706 | } |
| 707 | // backup block counter post-increment |
| 708 | i--; |
| 709 | } |
| 710 | } |
| 711 | } |
| 712 | |
| 713 | // Move empty blocks to the end |
| 714 | last = number_of_blocks(); |
| 715 | for (uint i = 1; i < last; i++) { |
| 716 | Block* block = get_block(i); |
| 717 | if (block->is_Empty() != Block::not_empty) { |
| 718 | move_to_end(block, i); |
| 719 | last--; |
| 720 | i--; |
| 721 | } |
| 722 | } // End of for all blocks |
| 723 | } |
| 724 | |
| 725 | Block *PhaseCFG::fixup_trap_based_check(Node *branch, Block *block, int block_pos, Block *bnext) { |
| 726 | // Trap based checks must fall through to the successor with |
| 727 | // PROB_ALWAYS. |
| 728 | // They should be an If with 2 successors. |
| 729 | assert(branch->is_MachIf(), "must be If")do { if (!(branch->is_MachIf())) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 729, "assert(" "branch->is_MachIf()" ") failed", "must be If" ); ::breakpoint(); } } while (0); |
| 730 | assert(block->_num_succs == 2, "must have 2 successors")do { if (!(block->_num_succs == 2)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 730, "assert(" "block->_num_succs == 2" ") failed", "must have 2 successors" ); ::breakpoint(); } } while (0); |
| 731 | |
| 732 | // Get the If node and the projection for the first successor. |
| 733 | MachIfNode *iff = block->get_node(block->number_of_nodes()-3)->as_MachIf(); |
| 734 | ProjNode *proj0 = block->get_node(block->number_of_nodes()-2)->as_Proj(); |
| 735 | ProjNode *proj1 = block->get_node(block->number_of_nodes()-1)->as_Proj(); |
| 736 | ProjNode *projt = (proj0->Opcode() == Op_IfTrue) ? proj0 : proj1; |
| 737 | ProjNode *projf = (proj0->Opcode() == Op_IfFalse) ? proj0 : proj1; |
| 738 | |
| 739 | // Assert that proj0 and succs[0] match up. Similarly for proj1 and succs[1]. |
| 740 | assert(proj0->raw_out(0) == block->_succs[0]->head(), "Mismatch successor 0")do { if (!(proj0->raw_out(0) == block->_succs[0]->head ())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 740, "assert(" "proj0->raw_out(0) == block->_succs[0]->head()" ") failed", "Mismatch successor 0"); ::breakpoint(); } } while (0); |
| 741 | assert(proj1->raw_out(0) == block->_succs[1]->head(), "Mismatch successor 1")do { if (!(proj1->raw_out(0) == block->_succs[1]->head ())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 741, "assert(" "proj1->raw_out(0) == block->_succs[1]->head()" ") failed", "Mismatch successor 1"); ::breakpoint(); } } while (0); |
| 742 | |
| 743 | ProjNode *proj_always; |
| 744 | ProjNode *proj_never; |
| 745 | // We must negate the branch if the implicit check doesn't follow |
| 746 | // the branch's TRUE path. Then, the new TRUE branch target will |
| 747 | // be the old FALSE branch target. |
| 748 | if (iff->_prob <= 2*PROB_NEVER(1e-6f)) { // There are small rounding errors. |
| 749 | proj_never = projt; |
| 750 | proj_always = projf; |
| 751 | } else { |
| 752 | // We must negate the branch if the trap doesn't follow the |
| 753 | // branch's TRUE path. Then, the new TRUE branch target will |
| 754 | // be the old FALSE branch target. |
| 755 | proj_never = projf; |
| 756 | proj_always = projt; |
| 757 | iff->negate(); |
| 758 | } |
| 759 | assert(iff->_prob <= 2*PROB_NEVER, "Trap based checks are expected to trap never!")do { if (!(iff->_prob <= 2*(1e-6f))) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 759, "assert(" "iff->_prob <= 2*(1e-6f)" ") failed", "Trap based checks are expected to trap never!" ); ::breakpoint(); } } while (0); |
| 760 | // Map the successors properly |
| 761 | block->_succs.map(0, get_block_for_node(proj_never ->raw_out(0))); // The target of the trap. |
| 762 | block->_succs.map(1, get_block_for_node(proj_always->raw_out(0))); // The fall through target. |
| 763 | |
| 764 | if (block->get_node(block->number_of_nodes() - block->_num_succs + 1) != proj_always) { |
| 765 | block->map_node(proj_never, block->number_of_nodes() - block->_num_succs + 0); |
| 766 | block->map_node(proj_always, block->number_of_nodes() - block->_num_succs + 1); |
| 767 | } |
| 768 | |
| 769 | // Place the fall through block after this block. |
| 770 | Block *bs1 = block->non_connector_successor(1); |
| 771 | if (bs1 != bnext && move_to_next(bs1, block_pos)) { |
| 772 | bnext = bs1; |
| 773 | } |
| 774 | // If the fall through block still is not the next block, insert a goto. |
| 775 | if (bs1 != bnext) { |
| 776 | insert_goto_at(block_pos, 1); |
| 777 | } |
| 778 | return bnext; |
| 779 | } |
| 780 | |
| 781 | // Fix up the final control flow for basic blocks. |
| 782 | void PhaseCFG::fixup_flow() { |
| 783 | // Fixup final control flow for the blocks. Remove jump-to-next |
| 784 | // block. If neither arm of an IF follows the conditional branch, we |
| 785 | // have to add a second jump after the conditional. We place the |
| 786 | // TRUE branch target in succs[0] for both GOTOs and IFs. |
| 787 | for (uint i = 0; i < number_of_blocks(); i++) { |
| 788 | Block* block = get_block(i); |
| 789 | block->_pre_order = i; // turn pre-order into block-index |
| 790 | |
| 791 | // Connector blocks need no further processing. |
| 792 | if (block->is_connector()) { |
| 793 | assert((i+1) == number_of_blocks() || get_block(i + 1)->is_connector(), "All connector blocks should sink to the end")do { if (!((i+1) == number_of_blocks() || get_block(i + 1)-> is_connector())) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 793, "assert(" "(i+1) == number_of_blocks() || get_block(i + 1)->is_connector()" ") failed", "All connector blocks should sink to the end"); :: breakpoint(); } } while (0); |
| 794 | continue; |
| 795 | } |
| 796 | assert(block->is_Empty() != Block::completely_empty, "Empty blocks should be connectors")do { if (!(block->is_Empty() != Block::completely_empty)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 796, "assert(" "block->is_Empty() != Block::completely_empty" ") failed", "Empty blocks should be connectors"); ::breakpoint (); } } while (0); |
| 797 | |
| 798 | Block* bnext = (i < number_of_blocks() - 1) ? get_block(i + 1) : NULL__null; |
| 799 | Block* bs0 = block->non_connector_successor(0); |
| 800 | |
| 801 | // Check for multi-way branches where I cannot negate the test to |
| 802 | // exchange the true and false targets. |
| 803 | if (no_flip_branch(block)) { |
| 804 | // Find fall through case - if must fall into its target. |
| 805 | // Get the index of the branch's first successor. |
| 806 | int branch_idx = block->number_of_nodes() - block->_num_succs; |
| 807 | |
| 808 | // The branch is 1 before the branch's first successor. |
| 809 | Node *branch = block->get_node(branch_idx-1); |
| 810 | |
| 811 | // Handle no-flip branches which have implicit checks and which require |
| 812 | // special block ordering and individual semantics of the 'fall through |
| 813 | // case'. |
| 814 | if ((TrapBasedNullChecks || TrapBasedRangeChecks) && |
| 815 | branch->is_Mach() && branch->as_Mach()->is_TrapBasedCheckNode()) { |
| 816 | bnext = fixup_trap_based_check(branch, block, i, bnext); |
Value stored to 'bnext' is never read | |
| 817 | } else { |
| 818 | // Else, default handling for no-flip branches |
| 819 | for (uint j2 = 0; j2 < block->_num_succs; j2++) { |
| 820 | const ProjNode* p = block->get_node(branch_idx + j2)->as_Proj(); |
| 821 | if (p->_con == 0) { |
| 822 | // successor j2 is fall through case |
| 823 | if (block->non_connector_successor(j2) != bnext) { |
| 824 | // but it is not the next block => insert a goto |
| 825 | insert_goto_at(i, j2); |
| 826 | } |
| 827 | // Put taken branch in slot 0 |
| 828 | if (j2 == 0 && block->_num_succs == 2) { |
| 829 | // Flip targets in succs map |
| 830 | Block *tbs0 = block->_succs[0]; |
| 831 | Block *tbs1 = block->_succs[1]; |
| 832 | block->_succs.map(0, tbs1); |
| 833 | block->_succs.map(1, tbs0); |
| 834 | } |
| 835 | break; |
| 836 | } |
| 837 | } |
| 838 | } |
| 839 | |
| 840 | // Remove all CatchProjs |
| 841 | for (uint j = 0; j < block->_num_succs; j++) { |
| 842 | block->pop_node(); |
| 843 | } |
| 844 | |
| 845 | } else if (block->_num_succs == 1) { |
| 846 | // Block ends in a Goto? |
| 847 | if (bnext == bs0) { |
| 848 | // We fall into next block; remove the Goto |
| 849 | block->pop_node(); |
| 850 | } |
| 851 | |
| 852 | } else if(block->_num_succs == 2) { // Block ends in a If? |
| 853 | // Get opcode of 1st projection (matches _succs[0]) |
| 854 | // Note: Since this basic block has 2 exits, the last 2 nodes must |
| 855 | // be projections (in any order), the 3rd last node must be |
| 856 | // the IfNode (we have excluded other 2-way exits such as |
| 857 | // CatchNodes already). |
| 858 | MachNode* iff = block->get_node(block->number_of_nodes() - 3)->as_Mach(); |
| 859 | ProjNode* proj0 = block->get_node(block->number_of_nodes() - 2)->as_Proj(); |
| 860 | ProjNode* proj1 = block->get_node(block->number_of_nodes() - 1)->as_Proj(); |
| 861 | |
| 862 | // Assert that proj0 and succs[0] match up. Similarly for proj1 and succs[1]. |
| 863 | assert(proj0->raw_out(0) == block->_succs[0]->head(), "Mismatch successor 0")do { if (!(proj0->raw_out(0) == block->_succs[0]->head ())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 863, "assert(" "proj0->raw_out(0) == block->_succs[0]->head()" ") failed", "Mismatch successor 0"); ::breakpoint(); } } while (0); |
| 864 | assert(proj1->raw_out(0) == block->_succs[1]->head(), "Mismatch successor 1")do { if (!(proj1->raw_out(0) == block->_succs[1]->head ())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 864, "assert(" "proj1->raw_out(0) == block->_succs[1]->head()" ") failed", "Mismatch successor 1"); ::breakpoint(); } } while (0); |
| 865 | |
| 866 | Block* bs1 = block->non_connector_successor(1); |
| 867 | |
| 868 | // Check for neither successor block following the current |
| 869 | // block ending in a conditional. If so, move one of the |
| 870 | // successors after the current one, provided that the |
| 871 | // successor was previously unscheduled, but moveable |
| 872 | // (i.e., all paths to it involve a branch). |
| 873 | if (!C->do_freq_based_layout() && bnext != bs0 && bnext != bs1) { |
| 874 | // Choose the more common successor based on the probability |
| 875 | // of the conditional branch. |
| 876 | Block* bx = bs0; |
| 877 | Block* by = bs1; |
| 878 | |
| 879 | // _prob is the probability of taking the true path. Make |
| 880 | // p the probability of taking successor #1. |
| 881 | float p = iff->as_MachIf()->_prob; |
| 882 | if (proj0->Opcode() == Op_IfTrue) { |
| 883 | p = 1.0 - p; |
| 884 | } |
| 885 | |
| 886 | // Prefer successor #1 if p > 0.5 |
| 887 | if (p > PROB_FAIR(0.5f)) { |
| 888 | bx = bs1; |
| 889 | by = bs0; |
| 890 | } |
| 891 | |
| 892 | // Attempt the more common successor first |
| 893 | if (move_to_next(bx, i)) { |
| 894 | bnext = bx; |
| 895 | } else if (move_to_next(by, i)) { |
| 896 | bnext = by; |
| 897 | } |
| 898 | } |
| 899 | |
| 900 | // Check for conditional branching the wrong way. Negate |
| 901 | // conditional, if needed, so it falls into the following block |
| 902 | // and branches to the not-following block. |
| 903 | |
| 904 | // Check for the next block being in succs[0]. We are going to branch |
| 905 | // to succs[0], so we want the fall-thru case as the next block in |
| 906 | // succs[1]. |
| 907 | if (bnext == bs0) { |
| 908 | // Fall-thru case in succs[0], should be in succs[1], so flip targets in _succs map |
| 909 | Block* tbs0 = block->_succs[0]; |
| 910 | Block* tbs1 = block->_succs[1]; |
| 911 | block->_succs.map(0, tbs1); |
| 912 | block->_succs.map(1, tbs0); |
| 913 | // Flip projection for each target |
| 914 | swap(proj0, proj1); |
| 915 | } else if(bnext != bs1) { |
| 916 | // Need a double-branch |
| 917 | // The existing conditional branch need not change. |
| 918 | // Add a unconditional branch to the false target. |
| 919 | // Alas, it must appear in its own block and adding a |
| 920 | // block this late in the game is complicated. Sigh. |
| 921 | insert_goto_at(i, 1); |
| 922 | } |
| 923 | |
| 924 | // Make sure we TRUE branch to the target |
| 925 | if (proj0->Opcode() == Op_IfFalse) { |
| 926 | iff->as_MachIf()->negate(); |
| 927 | } |
| 928 | |
| 929 | block->pop_node(); // Remove IfFalse & IfTrue projections |
| 930 | block->pop_node(); |
| 931 | |
| 932 | } else { |
| 933 | // Multi-exit block, e.g. a switch statement |
| 934 | // But we don't need to do anything here |
| 935 | } |
| 936 | } // End of for all blocks |
| 937 | } |
| 938 | |
| 939 | |
| 940 | // postalloc_expand: Expand nodes after register allocation. |
| 941 | // |
| 942 | // postalloc_expand has to be called after register allocation, just |
| 943 | // before output (i.e. scheduling). It only gets called if |
| 944 | // Matcher::require_postalloc_expand is true. |
| 945 | // |
| 946 | // Background: |
| 947 | // |
| 948 | // Nodes that are expandend (one compound node requiring several |
| 949 | // assembler instructions to be implemented split into two or more |
| 950 | // non-compound nodes) after register allocation are not as nice as |
| 951 | // the ones expanded before register allocation - they don't |
| 952 | // participate in optimizations as global code motion. But after |
| 953 | // register allocation we can expand nodes that use registers which |
| 954 | // are not spillable or registers that are not allocated, because the |
| 955 | // old compound node is simply replaced (in its location in the basic |
| 956 | // block) by a new subgraph which does not contain compound nodes any |
| 957 | // more. The scheduler called during output can later on process these |
| 958 | // non-compound nodes. |
| 959 | // |
| 960 | // Implementation: |
| 961 | // |
| 962 | // Nodes requiring postalloc expand are specified in the ad file by using |
| 963 | // a postalloc_expand statement instead of ins_encode. A postalloc_expand |
| 964 | // contains a single call to an encoding, as does an ins_encode |
| 965 | // statement. Instead of an emit() function a postalloc_expand() function |
| 966 | // is generated that doesn't emit assembler but creates a new |
| 967 | // subgraph. The code below calls this postalloc_expand function for each |
| 968 | // node with the appropriate attribute. This function returns the new |
| 969 | // nodes generated in an array passed in the call. The old node, |
| 970 | // potential MachTemps before and potential Projs after it then get |
| 971 | // disconnected and replaced by the new nodes. The instruction |
| 972 | // generating the result has to be the last one in the array. In |
| 973 | // general it is assumed that Projs after the node expanded are |
| 974 | // kills. These kills are not required any more after expanding as |
| 975 | // there are now explicitly visible def-use chains and the Projs are |
| 976 | // removed. This does not hold for calls: They do not only have |
| 977 | // kill-Projs but also Projs defining values. Therefore Projs after |
| 978 | // the node expanded are removed for all but for calls. If a node is |
| 979 | // to be reused, it must be added to the nodes list returned, and it |
| 980 | // will be added again. |
| 981 | // |
| 982 | // Implementing the postalloc_expand function for a node in an enc_class |
| 983 | // is rather tedious. It requires knowledge about many node details, as |
| 984 | // the nodes and the subgraph must be hand crafted. To simplify this, |
| 985 | // adlc generates some utility variables into the postalloc_expand function, |
| 986 | // e.g., holding the operands as specified by the postalloc_expand encoding |
| 987 | // specification, e.g.: |
| 988 | // * unsigned idx_<par_name> holding the index of the node in the ins |
| 989 | // * Node *n_<par_name> holding the node loaded from the ins |
| 990 | // * MachOpnd *op_<par_name> holding the corresponding operand |
| 991 | // |
| 992 | // The ordering of operands can not be determined by looking at a |
| 993 | // rule. Especially if a match rule matches several different trees, |
| 994 | // several nodes are generated from one instruct specification with |
| 995 | // different operand orderings. In this case the adlc generated |
| 996 | // variables are the only way to access the ins and operands |
| 997 | // deterministically. |
| 998 | // |
| 999 | // If assigning a register to a node that contains an oop, don't |
| 1000 | // forget to call ra_->set_oop() for the node. |
| 1001 | void PhaseCFG::postalloc_expand(PhaseRegAlloc* _ra) { |
| 1002 | GrowableArray <Node *> new_nodes(32); // Array with new nodes filled by postalloc_expand function of node. |
| 1003 | GrowableArray <Node *> remove(32); |
| 1004 | GrowableArray <Node *> succs(32); |
| 1005 | unsigned int max_idx = C->unique(); // Remember to distinguish new from old nodes. |
| 1006 | DEBUG_ONLY(bool foundNode = false)bool foundNode = false; |
| 1007 | |
| 1008 | // for all blocks |
| 1009 | for (uint i = 0; i < number_of_blocks(); i++) { |
| 1010 | Block *b = _blocks[i]; |
| 1011 | // For all instructions in the current block. |
| 1012 | for (uint j = 0; j < b->number_of_nodes(); j++) { |
| 1013 | Node *n = b->get_node(j); |
| 1014 | if (n->is_Mach() && n->as_Mach()->requires_postalloc_expand()) { |
| 1015 | #ifdef ASSERT1 |
| 1016 | if (TracePostallocExpand) { |
| 1017 | if (!foundNode) { |
| 1018 | foundNode = true; |
| 1019 | tty->print("POSTALLOC EXPANDING %d %s\n", C->compile_id(), |
| 1020 | C->method() ? C->method()->name()->as_utf8() : C->stub_name()); |
| 1021 | } |
| 1022 | tty->print(" postalloc expanding "); n->dump(); |
| 1023 | if (Verbose) { |
| 1024 | tty->print(" with ins:\n"); |
| 1025 | for (uint k = 0; k < n->len(); ++k) { |
| 1026 | if (n->in(k)) { tty->print(" "); n->in(k)->dump(); } |
| 1027 | } |
| 1028 | } |
| 1029 | } |
| 1030 | #endif |
| 1031 | new_nodes.clear(); |
| 1032 | // Collect nodes that have to be removed from the block later on. |
| 1033 | uint req = n->req(); |
| 1034 | remove.clear(); |
| 1035 | for (uint k = 0; k < req; ++k) { |
| 1036 | if (n->in(k) && n->in(k)->is_MachTemp()) { |
| 1037 | remove.push(n->in(k)); // MachTemps which are inputs to the old node have to be removed. |
| 1038 | n->in(k)->del_req(0); |
| 1039 | j--; |
| 1040 | } |
| 1041 | } |
| 1042 | |
| 1043 | // Check whether we can allocate enough nodes. We set a fix limit for |
| 1044 | // the size of postalloc expands with this. |
| 1045 | uint unique_limit = C->unique() + 40; |
| 1046 | if (unique_limit >= _ra->node_regs_max_index()) { |
| 1047 | Compile::current()->record_failure("out of nodes in postalloc expand"); |
| 1048 | return; |
| 1049 | } |
| 1050 | |
| 1051 | // Emit (i.e. generate new nodes). |
| 1052 | n->as_Mach()->postalloc_expand(&new_nodes, _ra); |
| 1053 | |
| 1054 | assert(C->unique() < unique_limit, "You allocated too many nodes in your postalloc expand.")do { if (!(C->unique() < unique_limit)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1054, "assert(" "C->unique() < unique_limit" ") failed" , "You allocated too many nodes in your postalloc expand."); :: breakpoint(); } } while (0); |
| 1055 | |
| 1056 | // Disconnect the inputs of the old node. |
| 1057 | // |
| 1058 | // We reuse MachSpillCopy nodes. If we need to expand them, there |
| 1059 | // are many, so reusing pays off. If reused, the node already |
| 1060 | // has the new ins. n must be the last node on new_nodes list. |
| 1061 | if (!n->is_MachSpillCopy()) { |
| 1062 | for (int k = req - 1; k >= 0; --k) { |
| 1063 | n->del_req(k); |
| 1064 | } |
| 1065 | } |
| 1066 | |
| 1067 | #ifdef ASSERT1 |
| 1068 | // Check that all nodes have proper operands. |
| 1069 | for (int k = 0; k < new_nodes.length(); ++k) { |
| 1070 | if (new_nodes.at(k)->_idx < max_idx || !new_nodes.at(k)->is_Mach()) continue; // old node, Proj ... |
| 1071 | MachNode *m = new_nodes.at(k)->as_Mach(); |
| 1072 | for (unsigned int l = 0; l < m->num_opnds(); ++l) { |
| 1073 | if (MachOper::notAnOper(m->_opnds[l])) { |
| 1074 | outputStream *os = tty; |
| 1075 | os->print("Node %s ", m->Name()); |
| 1076 | os->print("has invalid opnd %d: %p\n", l, m->_opnds[l]); |
| 1077 | assert(0, "Invalid operands, see inline trace in hs_err_pid file.")do { if (!(0)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1077, "assert(" "0" ") failed", "Invalid operands, see inline trace in hs_err_pid file." ); ::breakpoint(); } } while (0); |
| 1078 | } |
| 1079 | } |
| 1080 | } |
| 1081 | #endif |
| 1082 | |
| 1083 | // Collect succs of old node in remove (for projections) and in succs (for |
| 1084 | // all other nodes) do _not_ collect projections in remove (but in succs) |
| 1085 | // in case the node is a call. We need the projections for calls as they are |
| 1086 | // associated with registes (i.e. they are defs). |
| 1087 | succs.clear(); |
| 1088 | for (DUIterator k = n->outs(); n->has_out(k); k++) { |
| 1089 | if (n->out(k)->is_Proj() && !n->is_MachCall() && !n->is_MachBranch()) { |
| 1090 | remove.push(n->out(k)); |
| 1091 | } else { |
| 1092 | succs.push(n->out(k)); |
| 1093 | } |
| 1094 | } |
| 1095 | // Replace old node n as input of its succs by last of the new nodes. |
| 1096 | for (int k = 0; k < succs.length(); ++k) { |
| 1097 | Node *succ = succs.at(k); |
| 1098 | for (uint l = 0; l < succ->req(); ++l) { |
| 1099 | if (succ->in(l) == n) { |
| 1100 | succ->set_req(l, new_nodes.at(new_nodes.length() - 1)); |
| 1101 | } |
| 1102 | } |
| 1103 | for (uint l = succ->req(); l < succ->len(); ++l) { |
| 1104 | if (succ->in(l) == n) { |
| 1105 | succ->set_prec(l, new_nodes.at(new_nodes.length() - 1)); |
| 1106 | } |
| 1107 | } |
| 1108 | } |
| 1109 | |
| 1110 | // Index of old node in block. |
| 1111 | uint index = b->find_node(n); |
| 1112 | // Insert new nodes into block and map them in nodes->blocks array |
| 1113 | // and remember last node in n2. |
| 1114 | Node *n2 = NULL__null; |
| 1115 | for (int k = 0; k < new_nodes.length(); ++k) { |
| 1116 | n2 = new_nodes.at(k); |
| 1117 | b->insert_node(n2, ++index); |
| 1118 | map_node_to_block(n2, b); |
| 1119 | } |
| 1120 | |
| 1121 | // Add old node n to remove and remove them all from block. |
| 1122 | remove.push(n); |
| 1123 | j--; |
| 1124 | #ifdef ASSERT1 |
| 1125 | if (TracePostallocExpand && Verbose) { |
| 1126 | tty->print(" removing:\n"); |
| 1127 | for (int k = 0; k < remove.length(); ++k) { |
| 1128 | tty->print(" "); remove.at(k)->dump(); |
| 1129 | } |
| 1130 | tty->print(" inserting:\n"); |
| 1131 | for (int k = 0; k < new_nodes.length(); ++k) { |
| 1132 | tty->print(" "); new_nodes.at(k)->dump(); |
| 1133 | } |
| 1134 | } |
| 1135 | #endif |
| 1136 | for (int k = 0; k < remove.length(); ++k) { |
| 1137 | if (b->contains(remove.at(k))) { |
| 1138 | b->find_remove(remove.at(k)); |
| 1139 | } else { |
| 1140 | assert(remove.at(k)->is_Proj() && (remove.at(k)->in(0)->is_MachBranch()), "")do { if (!(remove.at(k)->is_Proj() && (remove.at(k )->in(0)->is_MachBranch()))) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1140, "assert(" "remove.at(k)->is_Proj() && (remove.at(k)->in(0)->is_MachBranch())" ") failed", ""); ::breakpoint(); } } while (0); |
| 1141 | } |
| 1142 | } |
| 1143 | // If anything has been inserted (n2 != NULL), continue after last node inserted. |
| 1144 | // This does not always work. Some postalloc expands don't insert any nodes, if they |
| 1145 | // do optimizations (e.g., max(x,x)). In this case we decrement j accordingly. |
| 1146 | j = n2 ? b->find_node(n2) : j; |
| 1147 | } |
| 1148 | } |
| 1149 | } |
| 1150 | |
| 1151 | #ifdef ASSERT1 |
| 1152 | if (foundNode) { |
| 1153 | tty->print("FINISHED %d %s\n", C->compile_id(), |
| 1154 | C->method() ? C->method()->name()->as_utf8() : C->stub_name()); |
| 1155 | tty->flush(); |
| 1156 | } |
| 1157 | #endif |
| 1158 | } |
| 1159 | |
| 1160 | |
| 1161 | //------------------------------dump------------------------------------------- |
| 1162 | #ifndef PRODUCT |
| 1163 | void PhaseCFG::_dump_cfg( const Node *end, VectorSet &visited ) const { |
| 1164 | const Node *x = end->is_block_proj(); |
| 1165 | assert( x, "not a CFG" )do { if (!(x)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1165, "assert(" "x" ") failed", "not a CFG"); ::breakpoint( ); } } while (0); |
| 1166 | |
| 1167 | // Do not visit this block again |
| 1168 | if( visited.test_set(x->_idx) ) return; |
| 1169 | |
| 1170 | // Skip through this block |
| 1171 | const Node *p = x; |
| 1172 | do { |
| 1173 | p = p->in(0); // Move control forward |
| 1174 | assert( !p->is_block_proj() || p->is_Root(), "not a CFG" )do { if (!(!p->is_block_proj() || p->is_Root())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1174, "assert(" "!p->is_block_proj() || p->is_Root()" ") failed", "not a CFG"); ::breakpoint(); } } while (0); |
| 1175 | } while( !p->is_block_start() ); |
| 1176 | |
| 1177 | // Recursively visit |
| 1178 | for (uint i = 1; i < p->req(); i++) { |
| 1179 | _dump_cfg(p->in(i), visited); |
| 1180 | } |
| 1181 | |
| 1182 | // Dump the block |
| 1183 | get_block_for_node(p)->dump(this); |
| 1184 | } |
| 1185 | |
| 1186 | void PhaseCFG::dump( ) const { |
| 1187 | tty->print("\n--- CFG --- %d BBs\n", number_of_blocks()); |
| 1188 | if (_blocks.size()) { // Did we do basic-block layout? |
| 1189 | for (uint i = 0; i < number_of_blocks(); i++) { |
| 1190 | const Block* block = get_block(i); |
| 1191 | block->dump(this); |
| 1192 | } |
| 1193 | } else { // Else do it with a DFS |
| 1194 | VectorSet visited(_block_arena); |
| 1195 | _dump_cfg(_root,visited); |
| 1196 | } |
| 1197 | } |
| 1198 | |
| 1199 | void PhaseCFG::dump_headers() { |
| 1200 | for (uint i = 0; i < number_of_blocks(); i++) { |
| 1201 | Block* block = get_block(i); |
| 1202 | if (block != NULL__null) { |
| 1203 | block->dump_head(this); |
| 1204 | } |
| 1205 | } |
| 1206 | } |
| 1207 | #endif // !PRODUCT |
| 1208 | |
| 1209 | #ifdef ASSERT1 |
| 1210 | void PhaseCFG::verify_memory_writer_placement(const Block* b, const Node* n) const { |
| 1211 | if (!n->is_memory_writer()) { |
| 1212 | return; |
| 1213 | } |
| 1214 | CFGLoop* home_or_ancestor = find_block_for_node(n->in(0))->_loop; |
| 1215 | bool found = false; |
| 1216 | do { |
| 1217 | if (b->_loop == home_or_ancestor) { |
| 1218 | found = true; |
| 1219 | break; |
| 1220 | } |
| 1221 | home_or_ancestor = home_or_ancestor->parent(); |
| 1222 | } while (home_or_ancestor != NULL__null); |
| 1223 | assert(found, "block b is not in n's home loop or an ancestor of it")do { if (!(found)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1223, "assert(" "found" ") failed", "block b is not in n's home loop or an ancestor of it" ); ::breakpoint(); } } while (0); |
| 1224 | } |
| 1225 | |
| 1226 | void PhaseCFG::verify() const { |
| 1227 | // Verify sane CFG |
| 1228 | for (uint i = 0; i < number_of_blocks(); i++) { |
| 1229 | Block* block = get_block(i); |
| 1230 | uint cnt = block->number_of_nodes(); |
| 1231 | uint j; |
| 1232 | for (j = 0; j < cnt; j++) { |
| 1233 | Node *n = block->get_node(j); |
| 1234 | assert(get_block_for_node(n) == block, "")do { if (!(get_block_for_node(n) == block)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1234, "assert(" "get_block_for_node(n) == block" ") failed" , ""); ::breakpoint(); } } while (0); |
| 1235 | if (j >= 1 && n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_CreateEx) { |
| 1236 | assert(j == 1 || block->get_node(j-1)->is_Phi(), "CreateEx must be first instruction in block")do { if (!(j == 1 || block->get_node(j-1)->is_Phi())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1236, "assert(" "j == 1 || block->get_node(j-1)->is_Phi()" ") failed", "CreateEx must be first instruction in block"); :: breakpoint(); } } while (0); |
| 1237 | } |
| 1238 | verify_memory_writer_placement(block, n); |
| 1239 | if (n->needs_anti_dependence_check()) { |
| 1240 | verify_anti_dependences(block, n); |
| 1241 | } |
| 1242 | for (uint k = 0; k < n->req(); k++) { |
| 1243 | Node *def = n->in(k); |
| 1244 | if (def && def != n) { |
| 1245 | Block* def_block = get_block_for_node(def); |
| 1246 | assert(def_block || def->is_Con(), "must have block; constants for debug info ok")do { if (!(def_block || def->is_Con())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1246, "assert(" "def_block || def->is_Con()" ") failed", "must have block; constants for debug info ok"); ::breakpoint (); } } while (0); |
| 1247 | // Verify that all definitions dominate their uses (except for virtual |
| 1248 | // instructions merging multiple definitions). |
| 1249 | assert(n->is_Root() || n->is_Region() || n->is_Phi() || n->is_MachMerge() ||do { if (!(n->is_Root() || n->is_Region() || n->is_Phi () || n->is_MachMerge() || def_block->dominates(block)) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1251, "assert(" "n->is_Root() || n->is_Region() || n->is_Phi() || n->is_MachMerge() || def_block->dominates(block)" ") failed", "uses must be dominated by definitions"); ::breakpoint (); } } while (0) |
| 1250 | def_block->dominates(block),do { if (!(n->is_Root() || n->is_Region() || n->is_Phi () || n->is_MachMerge() || def_block->dominates(block)) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1251, "assert(" "n->is_Root() || n->is_Region() || n->is_Phi() || n->is_MachMerge() || def_block->dominates(block)" ") failed", "uses must be dominated by definitions"); ::breakpoint (); } } while (0) |
| 1251 | "uses must be dominated by definitions")do { if (!(n->is_Root() || n->is_Region() || n->is_Phi () || n->is_MachMerge() || def_block->dominates(block)) ) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1251, "assert(" "n->is_Root() || n->is_Region() || n->is_Phi() || n->is_MachMerge() || def_block->dominates(block)" ") failed", "uses must be dominated by definitions"); ::breakpoint (); } } while (0); |
| 1252 | // Verify that instructions in the block are in correct order. |
| 1253 | // Uses must follow their definition if they are at the same block. |
| 1254 | // Mostly done to check that MachSpillCopy nodes are placed correctly |
| 1255 | // when CreateEx node is moved in build_ifg_physical(). |
| 1256 | if (def_block == block && !(block->head()->is_Loop() && n->is_Phi()) && |
| 1257 | // See (+++) comment in reg_split.cpp |
| 1258 | !(n->jvms() != NULL__null && n->jvms()->is_monitor_use(k))) { |
| 1259 | bool is_loop = false; |
| 1260 | if (n->is_Phi()) { |
| 1261 | for (uint l = 1; l < def->req(); l++) { |
| 1262 | if (n == def->in(l)) { |
| 1263 | is_loop = true; |
| 1264 | break; // Some kind of loop |
| 1265 | } |
| 1266 | } |
| 1267 | } |
| 1268 | assert(is_loop || block->find_node(def) < j, "uses must follow definitions")do { if (!(is_loop || block->find_node(def) < j)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1268, "assert(" "is_loop || block->find_node(def) < j" ") failed", "uses must follow definitions"); ::breakpoint(); } } while (0); |
| 1269 | } |
| 1270 | } |
| 1271 | } |
| 1272 | if (n->is_Proj()) { |
| 1273 | assert(j >= 1, "a projection cannot be the first instruction in a block")do { if (!(j >= 1)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1273, "assert(" "j >= 1" ") failed", "a projection cannot be the first instruction in a block" ); ::breakpoint(); } } while (0); |
| 1274 | Node* pred = block->get_node(j - 1); |
| 1275 | Node* parent = n->in(0); |
| 1276 | assert(parent != NULL, "projections must have a parent")do { if (!(parent != __null)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1276, "assert(" "parent != __null" ") failed", "projections must have a parent" ); ::breakpoint(); } } while (0); |
| 1277 | assert(pred == parent || (pred->is_Proj() && pred->in(0) == parent),do { if (!(pred == parent || (pred->is_Proj() && pred ->in(0) == parent))) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1278, "assert(" "pred == parent || (pred->is_Proj() && pred->in(0) == parent)" ") failed", "projections must follow their parents or other sibling projections" ); ::breakpoint(); } } while (0) |
| 1278 | "projections must follow their parents or other sibling projections")do { if (!(pred == parent || (pred->is_Proj() && pred ->in(0) == parent))) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1278, "assert(" "pred == parent || (pred->is_Proj() && pred->in(0) == parent)" ") failed", "projections must follow their parents or other sibling projections" ); ::breakpoint(); } } while (0); |
| 1279 | } |
| 1280 | } |
| 1281 | |
| 1282 | j = block->end_idx(); |
| 1283 | Node* bp = (Node*)block->get_node(block->number_of_nodes() - 1)->is_block_proj(); |
| 1284 | assert(bp, "last instruction must be a block proj")do { if (!(bp)) { (*g_assert_poison) = 'X';; report_vm_error( "/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1284, "assert(" "bp" ") failed", "last instruction must be a block proj" ); ::breakpoint(); } } while (0); |
| 1285 | assert(bp == block->get_node(j), "wrong number of successors for this block")do { if (!(bp == block->get_node(j))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1285, "assert(" "bp == block->get_node(j)" ") failed", "wrong number of successors for this block" ); ::breakpoint(); } } while (0); |
| 1286 | if (bp->is_Catch()) { |
| 1287 | while (block->get_node(--j)->is_MachProj()) { |
| 1288 | ; |
| 1289 | } |
| 1290 | assert(block->get_node(j)->is_MachCall(), "CatchProj must follow call")do { if (!(block->get_node(j)->is_MachCall())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1290, "assert(" "block->get_node(j)->is_MachCall()" ") failed" , "CatchProj must follow call"); ::breakpoint(); } } while (0 ); |
| 1291 | } else if (bp->is_Mach() && bp->as_Mach()->ideal_Opcode() == Op_If) { |
| 1292 | assert(block->_num_succs == 2, "Conditional branch must have two targets")do { if (!(block->_num_succs == 2)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1292, "assert(" "block->_num_succs == 2" ") failed", "Conditional branch must have two targets" ); ::breakpoint(); } } while (0); |
| 1293 | } |
| 1294 | } |
| 1295 | } |
| 1296 | #endif // ASSERT |
| 1297 | |
| 1298 | UnionFind::UnionFind( uint max ) : _cnt(max), _max(max), _indices(NEW_RESOURCE_ARRAY(uint,max)(uint*) resource_allocate_bytes((max) * sizeof(uint))) { |
| 1299 | Copy::zero_to_bytes( _indices, sizeof(uint)*max ); |
| 1300 | } |
| 1301 | |
| 1302 | void UnionFind::extend( uint from_idx, uint to_idx ) { |
| 1303 | _nesting.check(); |
| 1304 | if( from_idx >= _max ) { |
| 1305 | uint size = 16; |
| 1306 | while( size <= from_idx ) size <<=1; |
| 1307 | _indices = REALLOC_RESOURCE_ARRAY( uint, _indices, _max, size )(uint*) resource_reallocate_bytes((char*)(_indices), (_max) * sizeof(uint), (size) * sizeof(uint)); |
| 1308 | _max = size; |
| 1309 | } |
| 1310 | while( _cnt <= from_idx ) _indices[_cnt++] = 0; |
| 1311 | _indices[from_idx] = to_idx; |
| 1312 | } |
| 1313 | |
| 1314 | void UnionFind::reset( uint max ) { |
| 1315 | // Force the Union-Find mapping to be at least this large |
| 1316 | extend(max,0); |
| 1317 | // Initialize to be the ID mapping. |
| 1318 | for( uint i=0; i<max; i++ ) map(i,i); |
| 1319 | } |
| 1320 | |
| 1321 | // Straight out of Tarjan's union-find algorithm |
| 1322 | uint UnionFind::Find_compress( uint idx ) { |
| 1323 | uint cur = idx; |
| 1324 | uint next = lookup(cur); |
| 1325 | while( next != cur ) { // Scan chain of equivalences |
| 1326 | assert( next < cur, "always union smaller" )do { if (!(next < cur)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1326, "assert(" "next < cur" ") failed", "always union smaller" ); ::breakpoint(); } } while (0); |
| 1327 | cur = next; // until find a fixed-point |
| 1328 | next = lookup(cur); |
| 1329 | } |
| 1330 | // Core of union-find algorithm: update chain of |
| 1331 | // equivalences to be equal to the root. |
| 1332 | while( idx != next ) { |
| 1333 | uint tmp = lookup(idx); |
| 1334 | map(idx, next); |
| 1335 | idx = tmp; |
| 1336 | } |
| 1337 | return idx; |
| 1338 | } |
| 1339 | |
| 1340 | // Like Find above, but no path compress, so bad asymptotic behavior |
| 1341 | uint UnionFind::Find_const( uint idx ) const { |
| 1342 | if( idx == 0 ) return idx; // Ignore the zero idx |
| 1343 | // Off the end? This can happen during debugging dumps |
| 1344 | // when data structures have not finished being updated. |
| 1345 | if( idx >= _max ) return idx; |
| 1346 | uint next = lookup(idx); |
| 1347 | while( next != idx ) { // Scan chain of equivalences |
| 1348 | idx = next; // until find a fixed-point |
| 1349 | next = lookup(idx); |
| 1350 | } |
| 1351 | return next; |
| 1352 | } |
| 1353 | |
| 1354 | // union 2 sets together. |
| 1355 | void UnionFind::Union( uint idx1, uint idx2 ) { |
| 1356 | uint src = Find(idx1); |
| 1357 | uint dst = Find(idx2); |
| 1358 | assert( src, "" )do { if (!(src)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1358, "assert(" "src" ") failed", ""); ::breakpoint(); } } while (0); |
| 1359 | assert( dst, "" )do { if (!(dst)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1359, "assert(" "dst" ") failed", ""); ::breakpoint(); } } while (0); |
| 1360 | assert( src < _max, "oob" )do { if (!(src < _max)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1360, "assert(" "src < _max" ") failed", "oob"); ::breakpoint (); } } while (0); |
| 1361 | assert( dst < _max, "oob" )do { if (!(dst < _max)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1361, "assert(" "dst < _max" ") failed", "oob"); ::breakpoint (); } } while (0); |
| 1362 | assert( src < dst, "always union smaller" )do { if (!(src < dst)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1362, "assert(" "src < dst" ") failed", "always union smaller" ); ::breakpoint(); } } while (0); |
| 1363 | map(dst,src); |
| 1364 | } |
| 1365 | |
| 1366 | #ifndef PRODUCT |
| 1367 | void Trace::dump( ) const { |
| 1368 | tty->print_cr("Trace (freq %f)", first_block()->_freq); |
| 1369 | for (Block *b = first_block(); b != NULL__null; b = next(b)) { |
| 1370 | tty->print(" B%d", b->_pre_order); |
| 1371 | if (b->head()->is_Loop()) { |
| 1372 | tty->print(" (L%d)", b->compute_loop_alignment()); |
| 1373 | } |
| 1374 | if (b->has_loop_alignment()) { |
| 1375 | tty->print(" (T%d)", b->code_alignment()); |
| 1376 | } |
| 1377 | } |
| 1378 | tty->cr(); |
| 1379 | } |
| 1380 | |
| 1381 | void CFGEdge::dump( ) const { |
| 1382 | tty->print(" B%d --> B%d Freq: %f out:%3d%% in:%3d%% State: ", |
| 1383 | from()->_pre_order, to()->_pre_order, freq(), _from_pct, _to_pct); |
| 1384 | switch(state()) { |
| 1385 | case connected: |
| 1386 | tty->print("connected"); |
| 1387 | break; |
| 1388 | case open: |
| 1389 | tty->print("open"); |
| 1390 | break; |
| 1391 | case interior: |
| 1392 | tty->print("interior"); |
| 1393 | break; |
| 1394 | } |
| 1395 | if (infrequent()) { |
| 1396 | tty->print(" infrequent"); |
| 1397 | } |
| 1398 | tty->cr(); |
| 1399 | } |
| 1400 | #endif |
| 1401 | |
| 1402 | // Comparison function for edges |
| 1403 | static int edge_order(CFGEdge **e0, CFGEdge **e1) { |
| 1404 | float freq0 = (*e0)->freq(); |
| 1405 | float freq1 = (*e1)->freq(); |
| 1406 | if (freq0 != freq1) { |
| 1407 | return freq0 > freq1 ? -1 : 1; |
| 1408 | } |
| 1409 | |
| 1410 | int dist0 = (*e0)->to()->_rpo - (*e0)->from()->_rpo; |
| 1411 | int dist1 = (*e1)->to()->_rpo - (*e1)->from()->_rpo; |
| 1412 | |
| 1413 | return dist1 - dist0; |
| 1414 | } |
| 1415 | |
| 1416 | // Comparison function for edges |
| 1417 | extern "C" int trace_frequency_order(const void *p0, const void *p1) { |
| 1418 | Trace *tr0 = *(Trace **) p0; |
| 1419 | Trace *tr1 = *(Trace **) p1; |
| 1420 | Block *b0 = tr0->first_block(); |
| 1421 | Block *b1 = tr1->first_block(); |
| 1422 | |
| 1423 | // The trace of connector blocks goes at the end; |
| 1424 | // we only expect one such trace |
| 1425 | if (b0->is_connector() != b1->is_connector()) { |
| 1426 | return b1->is_connector() ? -1 : 1; |
| 1427 | } |
| 1428 | |
| 1429 | // Pull more frequently executed blocks to the beginning |
| 1430 | float freq0 = b0->_freq; |
| 1431 | float freq1 = b1->_freq; |
| 1432 | if (freq0 != freq1) { |
| 1433 | return freq0 > freq1 ? -1 : 1; |
| 1434 | } |
| 1435 | |
| 1436 | int diff = tr0->first_block()->_rpo - tr1->first_block()->_rpo; |
| 1437 | |
| 1438 | return diff; |
| 1439 | } |
| 1440 | |
| 1441 | // Find edges of interest, i.e, those which can fall through. Presumes that |
| 1442 | // edges which don't fall through are of low frequency and can be generally |
| 1443 | // ignored. Initialize the list of traces. |
| 1444 | void PhaseBlockLayout::find_edges() { |
| 1445 | // Walk the blocks, creating edges and Traces |
| 1446 | uint i; |
| 1447 | Trace *tr = NULL__null; |
| 1448 | for (i = 0; i < _cfg.number_of_blocks(); i++) { |
| 1449 | Block* b = _cfg.get_block(i); |
| 1450 | tr = new Trace(b, next, prev); |
| 1451 | traces[tr->id()] = tr; |
| 1452 | |
| 1453 | // All connector blocks should be at the end of the list |
| 1454 | if (b->is_connector()) break; |
| 1455 | |
| 1456 | // If this block and the next one have a one-to-one successor |
| 1457 | // predecessor relationship, simply append the next block |
| 1458 | int nfallthru = b->num_fall_throughs(); |
| 1459 | while (nfallthru == 1 && |
| 1460 | b->succ_fall_through(0)) { |
| 1461 | Block *n = b->_succs[0]; |
| 1462 | |
| 1463 | // Skip over single-entry connector blocks, we don't want to |
| 1464 | // add them to the trace. |
| 1465 | while (n->is_connector() && n->num_preds() == 1) { |
| 1466 | n = n->_succs[0]; |
| 1467 | } |
| 1468 | |
| 1469 | // We see a merge point, so stop search for the next block |
| 1470 | if (n->num_preds() != 1) break; |
| 1471 | |
| 1472 | i++; |
| 1473 | assert(n == _cfg.get_block(i), "expecting next block")do { if (!(n == _cfg.get_block(i))) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1473, "assert(" "n == _cfg.get_block(i)" ") failed", "expecting next block" ); ::breakpoint(); } } while (0); |
| 1474 | tr->append(n); |
| 1475 | uf->map(n->_pre_order, tr->id()); |
| 1476 | traces[n->_pre_order] = NULL__null; |
| 1477 | nfallthru = b->num_fall_throughs(); |
| 1478 | b = n; |
| 1479 | } |
| 1480 | |
| 1481 | if (nfallthru > 0) { |
| 1482 | // Create a CFGEdge for each outgoing |
| 1483 | // edge that could be a fall-through. |
| 1484 | for (uint j = 0; j < b->_num_succs; j++ ) { |
| 1485 | if (b->succ_fall_through(j)) { |
| 1486 | Block *target = b->non_connector_successor(j); |
| 1487 | float freq = b->_freq * b->succ_prob(j); |
| 1488 | int from_pct = (int) ((100 * freq) / b->_freq); |
| 1489 | int to_pct = (int) ((100 * freq) / target->_freq); |
| 1490 | edges->append(new CFGEdge(b, target, freq, from_pct, to_pct)); |
| 1491 | } |
| 1492 | } |
| 1493 | } |
| 1494 | } |
| 1495 | |
| 1496 | // Group connector blocks into one trace |
| 1497 | for (i++; i < _cfg.number_of_blocks(); i++) { |
| 1498 | Block *b = _cfg.get_block(i); |
| 1499 | assert(b->is_connector(), "connector blocks at the end")do { if (!(b->is_connector())) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1499, "assert(" "b->is_connector()" ") failed", "connector blocks at the end" ); ::breakpoint(); } } while (0); |
| 1500 | tr->append(b); |
| 1501 | uf->map(b->_pre_order, tr->id()); |
| 1502 | traces[b->_pre_order] = NULL__null; |
| 1503 | } |
| 1504 | } |
| 1505 | |
| 1506 | // Union two traces together in uf, and null out the trace in the list |
| 1507 | void PhaseBlockLayout::union_traces(Trace* updated_trace, Trace* old_trace) { |
| 1508 | uint old_id = old_trace->id(); |
| 1509 | uint updated_id = updated_trace->id(); |
| 1510 | |
| 1511 | uint lo_id = updated_id; |
| 1512 | uint hi_id = old_id; |
| 1513 | |
| 1514 | // If from is greater than to, swap values to meet |
| 1515 | // UnionFind guarantee. |
| 1516 | if (updated_id > old_id) { |
| 1517 | lo_id = old_id; |
| 1518 | hi_id = updated_id; |
| 1519 | |
| 1520 | // Fix up the trace ids |
| 1521 | traces[lo_id] = traces[updated_id]; |
| 1522 | updated_trace->set_id(lo_id); |
| 1523 | } |
| 1524 | |
| 1525 | // Union the lower with the higher and remove the pointer |
| 1526 | // to the higher. |
| 1527 | uf->Union(lo_id, hi_id); |
| 1528 | traces[hi_id] = NULL__null; |
| 1529 | } |
| 1530 | |
| 1531 | // Append traces together via the most frequently executed edges |
| 1532 | void PhaseBlockLayout::grow_traces() { |
| 1533 | // Order the edges, and drive the growth of Traces via the most |
| 1534 | // frequently executed edges. |
| 1535 | edges->sort(edge_order); |
| 1536 | for (int i = 0; i < edges->length(); i++) { |
| 1537 | CFGEdge *e = edges->at(i); |
| 1538 | |
| 1539 | if (e->state() != CFGEdge::open) continue; |
| 1540 | |
| 1541 | Block *src_block = e->from(); |
| 1542 | Block *targ_block = e->to(); |
| 1543 | |
| 1544 | // Don't grow traces along backedges? |
| 1545 | if (!BlockLayoutRotateLoops) { |
| 1546 | if (targ_block->_rpo <= src_block->_rpo) { |
| 1547 | targ_block->set_loop_alignment(targ_block); |
| 1548 | continue; |
| 1549 | } |
| 1550 | } |
| 1551 | |
| 1552 | Trace *src_trace = trace(src_block); |
| 1553 | Trace *targ_trace = trace(targ_block); |
| 1554 | |
| 1555 | // If the edge in question can join two traces at their ends, |
| 1556 | // append one trace to the other. |
| 1557 | if (src_trace->last_block() == src_block) { |
| 1558 | if (src_trace == targ_trace) { |
| 1559 | e->set_state(CFGEdge::interior); |
| 1560 | if (targ_trace->backedge(e)) { |
| 1561 | // Reset i to catch any newly eligible edge |
| 1562 | // (Or we could remember the first "open" edge, and reset there) |
| 1563 | i = 0; |
| 1564 | } |
| 1565 | } else if (targ_trace->first_block() == targ_block) { |
| 1566 | e->set_state(CFGEdge::connected); |
| 1567 | src_trace->append(targ_trace); |
| 1568 | union_traces(src_trace, targ_trace); |
| 1569 | } |
| 1570 | } |
| 1571 | } |
| 1572 | } |
| 1573 | |
| 1574 | // Embed one trace into another, if the fork or join points are sufficiently |
| 1575 | // balanced. |
| 1576 | void PhaseBlockLayout::merge_traces(bool fall_thru_only) { |
| 1577 | // Walk the edge list a another time, looking at unprocessed edges. |
| 1578 | // Fold in diamonds |
| 1579 | for (int i = 0; i < edges->length(); i++) { |
| 1580 | CFGEdge *e = edges->at(i); |
| 1581 | |
| 1582 | if (e->state() != CFGEdge::open) continue; |
| 1583 | if (fall_thru_only) { |
| 1584 | if (e->infrequent()) continue; |
| 1585 | } |
| 1586 | |
| 1587 | Block *src_block = e->from(); |
| 1588 | Trace *src_trace = trace(src_block); |
| 1589 | bool src_at_tail = src_trace->last_block() == src_block; |
| 1590 | |
| 1591 | Block *targ_block = e->to(); |
| 1592 | Trace *targ_trace = trace(targ_block); |
| 1593 | bool targ_at_start = targ_trace->first_block() == targ_block; |
| 1594 | |
| 1595 | if (src_trace == targ_trace) { |
| 1596 | // This may be a loop, but we can't do much about it. |
| 1597 | e->set_state(CFGEdge::interior); |
| 1598 | continue; |
| 1599 | } |
| 1600 | |
| 1601 | if (fall_thru_only) { |
| 1602 | // If the edge links the middle of two traces, we can't do anything. |
| 1603 | // Mark the edge and continue. |
| 1604 | if (!src_at_tail & !targ_at_start) { |
| 1605 | continue; |
| 1606 | } |
| 1607 | |
| 1608 | // Don't grow traces along backedges? |
| 1609 | if (!BlockLayoutRotateLoops && (targ_block->_rpo <= src_block->_rpo)) { |
| 1610 | continue; |
| 1611 | } |
| 1612 | |
| 1613 | // If both ends of the edge are available, why didn't we handle it earlier? |
| 1614 | assert(src_at_tail ^ targ_at_start, "Should have caught this edge earlier.")do { if (!(src_at_tail ^ targ_at_start)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1614, "assert(" "src_at_tail ^ targ_at_start" ") failed", "Should have caught this edge earlier." ); ::breakpoint(); } } while (0); |
| 1615 | |
| 1616 | if (targ_at_start) { |
| 1617 | // Insert the "targ" trace in the "src" trace if the insertion point |
| 1618 | // is a two way branch. |
| 1619 | // Better profitability check possible, but may not be worth it. |
| 1620 | // Someday, see if the this "fork" has an associated "join"; |
| 1621 | // then make a policy on merging this trace at the fork or join. |
| 1622 | // For example, other things being equal, it may be better to place this |
| 1623 | // trace at the join point if the "src" trace ends in a two-way, but |
| 1624 | // the insertion point is one-way. |
| 1625 | assert(src_block->num_fall_throughs() == 2, "unexpected diamond")do { if (!(src_block->num_fall_throughs() == 2)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1625, "assert(" "src_block->num_fall_throughs() == 2" ") failed" , "unexpected diamond"); ::breakpoint(); } } while (0); |
| 1626 | e->set_state(CFGEdge::connected); |
| 1627 | src_trace->insert_after(src_block, targ_trace); |
| 1628 | union_traces(src_trace, targ_trace); |
| 1629 | } else if (src_at_tail) { |
| 1630 | if (src_trace != trace(_cfg.get_root_block())) { |
| 1631 | e->set_state(CFGEdge::connected); |
| 1632 | targ_trace->insert_before(targ_block, src_trace); |
| 1633 | union_traces(targ_trace, src_trace); |
| 1634 | } |
| 1635 | } |
| 1636 | } else if (e->state() == CFGEdge::open) { |
| 1637 | // Append traces, even without a fall-thru connection. |
| 1638 | // But leave root entry at the beginning of the block list. |
| 1639 | if (targ_trace != trace(_cfg.get_root_block())) { |
| 1640 | e->set_state(CFGEdge::connected); |
| 1641 | src_trace->append(targ_trace); |
| 1642 | union_traces(src_trace, targ_trace); |
| 1643 | } |
| 1644 | } |
| 1645 | } |
| 1646 | } |
| 1647 | |
| 1648 | // Order the sequence of the traces in some desirable way |
| 1649 | void PhaseBlockLayout::reorder_traces(int count) { |
| 1650 | ResourceArea *area = Thread::current()->resource_area(); |
| 1651 | Trace ** new_traces = NEW_ARENA_ARRAY(area, Trace *, count)(Trace **) (area)->Amalloc((count) * sizeof(Trace *)); |
| 1652 | Block_List worklist; |
| 1653 | int new_count = 0; |
| 1654 | |
| 1655 | // Compact the traces. |
| 1656 | for (int i = 0; i < count; i++) { |
| 1657 | Trace *tr = traces[i]; |
| 1658 | if (tr != NULL__null) { |
| 1659 | new_traces[new_count++] = tr; |
| 1660 | } |
| 1661 | } |
| 1662 | |
| 1663 | // The entry block should be first on the new trace list. |
| 1664 | Trace *tr = trace(_cfg.get_root_block()); |
| 1665 | assert(tr == new_traces[0], "entry trace misplaced")do { if (!(tr == new_traces[0])) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1665, "assert(" "tr == new_traces[0]" ") failed", "entry trace misplaced" ); ::breakpoint(); } } while (0); |
| 1666 | |
| 1667 | // Sort the new trace list by frequency |
| 1668 | qsort(new_traces + 1, new_count - 1, sizeof(new_traces[0]), trace_frequency_order); |
| 1669 | |
| 1670 | // Collect all blocks from existing Traces |
| 1671 | _cfg.clear_blocks(); |
| 1672 | for (int i = 0; i < new_count; i++) { |
| 1673 | Trace *tr = new_traces[i]; |
| 1674 | if (tr != NULL__null) { |
| 1675 | // push blocks onto the CFG list |
| 1676 | for (Block* b = tr->first_block(); b != NULL__null; b = tr->next(b)) { |
| 1677 | _cfg.add_block(b); |
| 1678 | } |
| 1679 | } |
| 1680 | } |
| 1681 | } |
| 1682 | |
| 1683 | // Order basic blocks based on frequency |
| 1684 | PhaseBlockLayout::PhaseBlockLayout(PhaseCFG &cfg) |
| 1685 | : Phase(BlockLayout) |
| 1686 | , _cfg(cfg) { |
| 1687 | ResourceMark rm; |
| 1688 | ResourceArea *area = Thread::current()->resource_area(); |
| 1689 | |
| 1690 | // List of traces |
| 1691 | int size = _cfg.number_of_blocks() + 1; |
| 1692 | traces = NEW_ARENA_ARRAY(area, Trace *, size)(Trace **) (area)->Amalloc((size) * sizeof(Trace *)); |
| 1693 | memset(traces, 0, size*sizeof(Trace*)); |
| 1694 | next = NEW_ARENA_ARRAY(area, Block *, size)(Block **) (area)->Amalloc((size) * sizeof(Block *)); |
| 1695 | memset(next, 0, size*sizeof(Block *)); |
| 1696 | prev = NEW_ARENA_ARRAY(area, Block *, size)(Block **) (area)->Amalloc((size) * sizeof(Block *)); |
| 1697 | memset(prev , 0, size*sizeof(Block *)); |
| 1698 | |
| 1699 | // List of edges |
| 1700 | edges = new GrowableArray<CFGEdge*>; |
| 1701 | |
| 1702 | // Mapping block index --> block_trace |
| 1703 | uf = new UnionFind(size); |
| 1704 | uf->reset(size); |
| 1705 | |
| 1706 | // Find edges and create traces. |
| 1707 | find_edges(); |
| 1708 | |
| 1709 | // Grow traces at their ends via most frequent edges. |
| 1710 | grow_traces(); |
| 1711 | |
| 1712 | // Merge one trace into another, but only at fall-through points. |
| 1713 | // This may make diamonds and other related shapes in a trace. |
| 1714 | merge_traces(true); |
| 1715 | |
| 1716 | // Run merge again, allowing two traces to be catenated, even if |
| 1717 | // one does not fall through into the other. This appends loosely |
| 1718 | // related traces to be near each other. |
| 1719 | merge_traces(false); |
| 1720 | |
| 1721 | // Re-order all the remaining traces by frequency |
| 1722 | reorder_traces(size); |
| 1723 | |
| 1724 | assert(_cfg.number_of_blocks() >= (uint) (size - 1), "number of blocks can not shrink")do { if (!(_cfg.number_of_blocks() >= (uint) (size - 1))) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1724, "assert(" "_cfg.number_of_blocks() >= (uint) (size - 1)" ") failed", "number of blocks can not shrink"); ::breakpoint (); } } while (0); |
| 1725 | } |
| 1726 | |
| 1727 | |
| 1728 | // Edge e completes a loop in a trace. If the target block is head of the |
| 1729 | // loop, rotate the loop block so that the loop ends in a conditional branch. |
| 1730 | bool Trace::backedge(CFGEdge *e) { |
| 1731 | bool loop_rotated = false; |
| 1732 | Block *src_block = e->from(); |
| 1733 | Block *targ_block = e->to(); |
| 1734 | |
| 1735 | assert(last_block() == src_block, "loop discovery at back branch")do { if (!(last_block() == src_block)) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/block.cpp" , 1735, "assert(" "last_block() == src_block" ") failed", "loop discovery at back branch" ); ::breakpoint(); } } while (0); |
| 1736 | if (first_block() == targ_block) { |
| 1737 | if (BlockLayoutRotateLoops && last_block()->num_fall_throughs() < 2) { |
| 1738 | // Find the last block in the trace that has a conditional |
| 1739 | // branch. |
| 1740 | Block *b; |
| 1741 | for (b = last_block(); b != NULL__null; b = prev(b)) { |
| 1742 | if (b->num_fall_throughs() == 2) { |
| 1743 | break; |
| 1744 | } |
| 1745 | } |
| 1746 | |
| 1747 | if (b != last_block() && b != NULL__null) { |
| 1748 | loop_rotated = true; |
| 1749 | |
| 1750 | // Rotate the loop by doing two-part linked-list surgery. |
| 1751 | append(first_block()); |
| 1752 | break_loop_after(b); |
| 1753 | } |
| 1754 | } |
| 1755 | |
| 1756 | // Backbranch to the top of a trace |
| 1757 | // Scroll forward through the trace from the targ_block. If we find |
| 1758 | // a loop head before another loop top, use the the loop head alignment. |
| 1759 | for (Block *b = targ_block; b != NULL__null; b = next(b)) { |
| 1760 | if (b->has_loop_alignment()) { |
| 1761 | break; |
| 1762 | } |
| 1763 | if (b->head()->is_Loop()) { |
| 1764 | targ_block = b; |
| 1765 | break; |
| 1766 | } |
| 1767 | } |
| 1768 | |
| 1769 | first_block()->set_loop_alignment(targ_block); |
| 1770 | |
| 1771 | } else { |
| 1772 | // That loop may already have a loop top (we're reaching it again |
| 1773 | // through the backedge of an outer loop) |
| 1774 | Block* b = prev(targ_block); |
| 1775 | bool has_top = targ_block->head()->is_Loop() && b->has_loop_alignment() && !b->head()->is_Loop(); |
| 1776 | if (!has_top) { |
| 1777 | // Backbranch into the middle of a trace |
| 1778 | targ_block->set_loop_alignment(targ_block); |
| 1779 | } |
| 1780 | } |
| 1781 | |
| 1782 | return loop_rotated; |
| 1783 | } |