| File: | jdk/src/hotspot/share/opto/coalesce.cpp |
| Warning: | line 560, column 33 Called C++ object pointer is null |
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| 1 | /* | |||
| 2 | * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. | |||
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |||
| 4 | * | |||
| 5 | * This code is free software; you can redistribute it and/or modify it | |||
| 6 | * under the terms of the GNU General Public License version 2 only, as | |||
| 7 | * published by the Free Software Foundation. | |||
| 8 | * | |||
| 9 | * This code is distributed in the hope that it will be useful, but WITHOUT | |||
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |||
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |||
| 12 | * version 2 for more details (a copy is included in the LICENSE file that | |||
| 13 | * accompanied this code). | |||
| 14 | * | |||
| 15 | * You should have received a copy of the GNU General Public License version | |||
| 16 | * 2 along with this work; if not, write to the Free Software Foundation, | |||
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |||
| 18 | * | |||
| 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |||
| 20 | * or visit www.oracle.com if you need additional information or have any | |||
| 21 | * questions. | |||
| 22 | * | |||
| 23 | */ | |||
| 24 | ||||
| 25 | #include "precompiled.hpp" | |||
| 26 | #include "memory/allocation.inline.hpp" | |||
| 27 | #include "opto/block.hpp" | |||
| 28 | #include "opto/c2compiler.hpp" | |||
| 29 | #include "opto/cfgnode.hpp" | |||
| 30 | #include "opto/chaitin.hpp" | |||
| 31 | #include "opto/coalesce.hpp" | |||
| 32 | #include "opto/connode.hpp" | |||
| 33 | #include "opto/indexSet.hpp" | |||
| 34 | #include "opto/machnode.hpp" | |||
| 35 | #include "opto/matcher.hpp" | |||
| 36 | #include "opto/regmask.hpp" | |||
| 37 | ||||
| 38 | #ifndef PRODUCT | |||
| 39 | void PhaseCoalesce::dump(Node *n) const { | |||
| 40 | // Being a const function means I cannot use 'Find' | |||
| 41 | uint r = _phc._lrg_map.find(n); | |||
| 42 | tty->print("L%d/N%d ",r,n->_idx); | |||
| 43 | } | |||
| 44 | ||||
| 45 | void PhaseCoalesce::dump() const { | |||
| 46 | // I know I have a block layout now, so I can print blocks in a loop | |||
| 47 | for( uint i=0; i<_phc._cfg.number_of_blocks(); i++ ) { | |||
| 48 | uint j; | |||
| 49 | Block* b = _phc._cfg.get_block(i); | |||
| 50 | // Print a nice block header | |||
| 51 | tty->print("B%d: ",b->_pre_order); | |||
| 52 | for( j=1; j<b->num_preds(); j++ ) | |||
| 53 | tty->print("B%d ", _phc._cfg.get_block_for_node(b->pred(j))->_pre_order); | |||
| 54 | tty->print("-> "); | |||
| 55 | for( j=0; j<b->_num_succs; j++ ) | |||
| 56 | tty->print("B%d ",b->_succs[j]->_pre_order); | |||
| 57 | tty->print(" IDom: B%d/#%d\n", b->_idom ? b->_idom->_pre_order : 0, b->_dom_depth); | |||
| 58 | uint cnt = b->number_of_nodes(); | |||
| 59 | for( j=0; j<cnt; j++ ) { | |||
| 60 | Node *n = b->get_node(j); | |||
| 61 | dump( n ); | |||
| 62 | tty->print("\t%s\t",n->Name()); | |||
| 63 | ||||
| 64 | // Dump the inputs | |||
| 65 | uint k; // Exit value of loop | |||
| 66 | for( k=0; k<n->req(); k++ ) // For all required inputs | |||
| 67 | if( n->in(k) ) dump( n->in(k) ); | |||
| 68 | else tty->print("_ "); | |||
| 69 | int any_prec = 0; | |||
| 70 | for( ; k<n->len(); k++ ) // For all precedence inputs | |||
| 71 | if( n->in(k) ) { | |||
| 72 | if( !any_prec++ ) tty->print(" |"); | |||
| 73 | dump( n->in(k) ); | |||
| 74 | } | |||
| 75 | ||||
| 76 | // Dump node-specific info | |||
| 77 | n->dump_spec(tty); | |||
| 78 | tty->print("\n"); | |||
| 79 | ||||
| 80 | } | |||
| 81 | tty->print("\n"); | |||
| 82 | } | |||
| 83 | } | |||
| 84 | #endif | |||
| 85 | ||||
| 86 | // Combine the live ranges def'd by these 2 Nodes. N2 is an input to N1. | |||
| 87 | void PhaseCoalesce::combine_these_two(Node *n1, Node *n2) { | |||
| 88 | uint lr1 = _phc._lrg_map.find(n1); | |||
| 89 | uint lr2 = _phc._lrg_map.find(n2); | |||
| 90 | if( lr1 != lr2 && // Different live ranges already AND | |||
| 91 | !_phc._ifg->test_edge_sq( lr1, lr2 ) ) { // Do not interfere | |||
| 92 | LRG *lrg1 = &_phc.lrgs(lr1); | |||
| 93 | LRG *lrg2 = &_phc.lrgs(lr2); | |||
| 94 | // Not an oop->int cast; oop->oop, int->int, AND int->oop are OK. | |||
| 95 | ||||
| 96 | // Now, why is int->oop OK? We end up declaring a raw-pointer as an oop | |||
| 97 | // and in general that's a bad thing. However, int->oop conversions only | |||
| 98 | // happen at GC points, so the lifetime of the misclassified raw-pointer | |||
| 99 | // is from the CheckCastPP (that converts it to an oop) backwards up | |||
| 100 | // through a merge point and into the slow-path call, and around the | |||
| 101 | // diamond up to the heap-top check and back down into the slow-path call. | |||
| 102 | // The misclassified raw pointer is NOT live across the slow-path call, | |||
| 103 | // and so does not appear in any GC info, so the fact that it is | |||
| 104 | // misclassified is OK. | |||
| 105 | ||||
| 106 | if( (lrg1->_is_oop || !lrg2->_is_oop) && // not an oop->int cast AND | |||
| 107 | // Compatible final mask | |||
| 108 | lrg1->mask().overlap( lrg2->mask() ) ) { | |||
| 109 | // Merge larger into smaller. | |||
| 110 | if( lr1 > lr2 ) { | |||
| 111 | uint tmp = lr1; lr1 = lr2; lr2 = tmp; | |||
| 112 | Node *n = n1; n1 = n2; n2 = n; | |||
| 113 | LRG *ltmp = lrg1; lrg1 = lrg2; lrg2 = ltmp; | |||
| 114 | } | |||
| 115 | // Union lr2 into lr1 | |||
| 116 | _phc.Union( n1, n2 ); | |||
| 117 | if (lrg1->_maxfreq < lrg2->_maxfreq) | |||
| 118 | lrg1->_maxfreq = lrg2->_maxfreq; | |||
| 119 | // Merge in the IFG | |||
| 120 | _phc._ifg->Union( lr1, lr2 ); | |||
| 121 | // Combine register restrictions | |||
| 122 | lrg1->AND(lrg2->mask()); | |||
| 123 | } | |||
| 124 | } | |||
| 125 | } | |||
| 126 | ||||
| 127 | // Copy coalescing | |||
| 128 | void PhaseCoalesce::coalesce_driver() { | |||
| 129 | verify(); | |||
| 130 | // Coalesce from high frequency to low | |||
| 131 | for (uint i = 0; i < _phc._cfg.number_of_blocks(); i++) { | |||
| 132 | coalesce(_phc._blks[i]); | |||
| 133 | } | |||
| 134 | } | |||
| 135 | ||||
| 136 | // I am inserting copies to come out of SSA form. In the general case, I am | |||
| 137 | // doing a parallel renaming. I'm in the Named world now, so I can't do a | |||
| 138 | // general parallel renaming. All the copies now use "names" (live-ranges) | |||
| 139 | // to carry values instead of the explicit use-def chains. Suppose I need to | |||
| 140 | // insert 2 copies into the same block. They copy L161->L128 and L128->L132. | |||
| 141 | // If I insert them in the wrong order then L128 will get clobbered before it | |||
| 142 | // can get used by the second copy. This cannot happen in the SSA model; | |||
| 143 | // direct use-def chains get me the right value. It DOES happen in the named | |||
| 144 | // model so I have to handle the reordering of copies. | |||
| 145 | // | |||
| 146 | // In general, I need to topo-sort the placed copies to avoid conflicts. | |||
| 147 | // Its possible to have a closed cycle of copies (e.g., recirculating the same | |||
| 148 | // values around a loop). In this case I need a temp to break the cycle. | |||
| 149 | void PhaseAggressiveCoalesce::insert_copy_with_overlap( Block *b, Node *copy, uint dst_name, uint src_name ) { | |||
| 150 | ||||
| 151 | // Scan backwards for the locations of the last use of the dst_name. | |||
| 152 | // I am about to clobber the dst_name, so the copy must be inserted | |||
| 153 | // after the last use. Last use is really first-use on a backwards scan. | |||
| 154 | uint i = b->end_idx()-1; | |||
| 155 | while(1) { | |||
| 156 | Node *n = b->get_node(i); | |||
| 157 | // Check for end of virtual copies; this is also the end of the | |||
| 158 | // parallel renaming effort. | |||
| 159 | if (n->_idx < _unique) { | |||
| 160 | break; | |||
| 161 | } | |||
| 162 | uint idx = n->is_Copy(); | |||
| 163 | assert( idx || n->is_Con() || n->is_MachProj(), "Only copies during parallel renaming" )do { if (!(idx || n->is_Con() || n->is_MachProj())) { ( *g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 163, "assert(" "idx || n->is_Con() || n->is_MachProj()" ") failed", "Only copies during parallel renaming"); ::breakpoint (); } } while (0); | |||
| 164 | if (idx && _phc._lrg_map.find(n->in(idx)) == dst_name) { | |||
| 165 | break; | |||
| 166 | } | |||
| 167 | i--; | |||
| 168 | } | |||
| 169 | uint last_use_idx = i; | |||
| 170 | ||||
| 171 | // Also search for any kill of src_name that exits the block. | |||
| 172 | // Since the copy uses src_name, I have to come before any kill. | |||
| 173 | uint kill_src_idx = b->end_idx(); | |||
| 174 | // There can be only 1 kill that exits any block and that is | |||
| 175 | // the last kill. Thus it is the first kill on a backwards scan. | |||
| 176 | i = b->end_idx()-1; | |||
| 177 | while (1) { | |||
| 178 | Node *n = b->get_node(i); | |||
| 179 | // Check for end of virtual copies; this is also the end of the | |||
| 180 | // parallel renaming effort. | |||
| 181 | if (n->_idx < _unique) { | |||
| 182 | break; | |||
| 183 | } | |||
| 184 | assert( n->is_Copy() || n->is_Con() || n->is_MachProj(), "Only copies during parallel renaming" )do { if (!(n->is_Copy() || n->is_Con() || n->is_MachProj ())) { (*g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 184, "assert(" "n->is_Copy() || n->is_Con() || n->is_MachProj()" ") failed", "Only copies during parallel renaming"); ::breakpoint (); } } while (0); | |||
| 185 | if (_phc._lrg_map.find(n) == src_name) { | |||
| 186 | kill_src_idx = i; | |||
| 187 | break; | |||
| 188 | } | |||
| 189 | i--; | |||
| 190 | } | |||
| 191 | // Need a temp? Last use of dst comes after the kill of src? | |||
| 192 | if (last_use_idx >= kill_src_idx) { | |||
| 193 | // Need to break a cycle with a temp | |||
| 194 | uint idx = copy->is_Copy(); | |||
| 195 | Node *tmp = copy->clone(); | |||
| 196 | uint max_lrg_id = _phc._lrg_map.max_lrg_id(); | |||
| 197 | _phc.new_lrg(tmp, max_lrg_id); | |||
| 198 | _phc._lrg_map.set_max_lrg_id(max_lrg_id + 1); | |||
| 199 | ||||
| 200 | // Insert new temp between copy and source | |||
| 201 | tmp ->set_req(idx,copy->in(idx)); | |||
| 202 | copy->set_req(idx,tmp); | |||
| 203 | // Save source in temp early, before source is killed | |||
| 204 | b->insert_node(tmp, kill_src_idx); | |||
| 205 | _phc._cfg.map_node_to_block(tmp, b); | |||
| 206 | last_use_idx++; | |||
| 207 | } | |||
| 208 | ||||
| 209 | // Insert just after last use | |||
| 210 | b->insert_node(copy, last_use_idx + 1); | |||
| 211 | } | |||
| 212 | ||||
| 213 | void PhaseAggressiveCoalesce::insert_copies( Matcher &matcher ) { | |||
| 214 | // We do LRGs compressing and fix a liveout data only here since the other | |||
| 215 | // place in Split() is guarded by the assert which we never hit. | |||
| 216 | _phc._lrg_map.compress_uf_map_for_nodes(); | |||
| 217 | // Fix block's liveout data for compressed live ranges. | |||
| 218 | for (uint lrg = 1; lrg < _phc._lrg_map.max_lrg_id(); lrg++) { | |||
| 219 | uint compressed_lrg = _phc._lrg_map.find(lrg); | |||
| 220 | if (lrg != compressed_lrg) { | |||
| 221 | for (uint bidx = 0; bidx < _phc._cfg.number_of_blocks(); bidx++) { | |||
| 222 | IndexSet *liveout = _phc._live->live(_phc._cfg.get_block(bidx)); | |||
| 223 | if (liveout->member(lrg)) { | |||
| 224 | liveout->remove(lrg); | |||
| 225 | liveout->insert(compressed_lrg); | |||
| 226 | } | |||
| 227 | } | |||
| 228 | } | |||
| 229 | } | |||
| 230 | ||||
| 231 | // All new nodes added are actual copies to replace virtual copies. | |||
| 232 | // Nodes with index less than '_unique' are original, non-virtual Nodes. | |||
| 233 | _unique = C->unique(); | |||
| 234 | ||||
| 235 | for (uint i = 0; i < _phc._cfg.number_of_blocks(); i++) { | |||
| 236 | C->check_node_count(NodeLimitFudgeFactor, "out of nodes in coalesce"); | |||
| 237 | if (C->failing()) return; | |||
| 238 | Block *b = _phc._cfg.get_block(i); | |||
| 239 | uint cnt = b->num_preds(); // Number of inputs to the Phi | |||
| 240 | ||||
| 241 | for( uint l = 1; l<b->number_of_nodes(); l++ ) { | |||
| 242 | Node *n = b->get_node(l); | |||
| 243 | ||||
| 244 | // Do not use removed-copies, use copied value instead | |||
| 245 | uint ncnt = n->req(); | |||
| 246 | for( uint k = 1; k<ncnt; k++ ) { | |||
| 247 | Node *copy = n->in(k); | |||
| 248 | uint cidx = copy->is_Copy(); | |||
| 249 | if( cidx ) { | |||
| 250 | Node *def = copy->in(cidx); | |||
| 251 | if (_phc._lrg_map.find(copy) == _phc._lrg_map.find(def)) { | |||
| 252 | n->set_req(k, def); | |||
| 253 | } | |||
| 254 | } | |||
| 255 | } | |||
| 256 | ||||
| 257 | // Remove any explicit copies that get coalesced. | |||
| 258 | uint cidx = n->is_Copy(); | |||
| 259 | if( cidx ) { | |||
| 260 | Node *def = n->in(cidx); | |||
| 261 | if (_phc._lrg_map.find(n) == _phc._lrg_map.find(def)) { | |||
| 262 | n->replace_by(def); | |||
| 263 | n->set_req(cidx,NULL__null); | |||
| 264 | b->remove_node(l); | |||
| 265 | l--; | |||
| 266 | continue; | |||
| 267 | } | |||
| 268 | } | |||
| 269 | ||||
| 270 | if (n->is_Phi()) { | |||
| 271 | // Get the chosen name for the Phi | |||
| 272 | uint phi_name = _phc._lrg_map.find(n); | |||
| 273 | // Ignore the pre-allocated specials | |||
| 274 | if (!phi_name) { | |||
| 275 | continue; | |||
| 276 | } | |||
| 277 | // Check for mismatch inputs to Phi | |||
| 278 | for (uint j = 1; j < cnt; j++) { | |||
| 279 | Node *m = n->in(j); | |||
| 280 | uint src_name = _phc._lrg_map.find(m); | |||
| 281 | if (src_name != phi_name) { | |||
| 282 | Block *pred = _phc._cfg.get_block_for_node(b->pred(j)); | |||
| 283 | Node *copy; | |||
| 284 | assert(!m->is_Con() || m->is_Mach(), "all Con must be Mach")do { if (!(!m->is_Con() || m->is_Mach())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 284, "assert(" "!m->is_Con() || m->is_Mach()" ") failed" , "all Con must be Mach"); ::breakpoint(); } } while (0); | |||
| 285 | // Rematerialize constants instead of copying them. | |||
| 286 | // We do this only for immediate constants, we avoid constant table loads | |||
| 287 | // because that will unsafely extend the live range of the constant table base. | |||
| 288 | if (m->is_Mach() && m->as_Mach()->is_Con() && !m->as_Mach()->is_MachConstant() && | |||
| 289 | m->as_Mach()->rematerialize()) { | |||
| 290 | copy = m->clone(); | |||
| 291 | // Insert the copy in the predecessor basic block | |||
| 292 | pred->add_inst(copy); | |||
| 293 | // Copy any flags as well | |||
| 294 | _phc.clone_projs(pred, pred->end_idx(), m, copy, _phc._lrg_map); | |||
| 295 | } else { | |||
| 296 | uint ireg = m->ideal_reg(); | |||
| 297 | if (ireg == 0 || ireg == Op_RegFlags) { | |||
| 298 | if (C->subsume_loads()) { | |||
| 299 | C->record_failure(C2Compiler::retry_no_subsuming_loads()); | |||
| 300 | } else { | |||
| 301 | assert(false, "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s",do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 302, "assert(" "false" ") failed", "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s" , m->_idx, m->Name(), ireg, MachSpillCopyNode::spill_type (MachSpillCopyNode::PhiInput)); ::breakpoint(); } } while (0) | |||
| 302 | m->_idx, m->Name(), ireg, MachSpillCopyNode::spill_type(MachSpillCopyNode::PhiInput))do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 302, "assert(" "false" ") failed", "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s" , m->_idx, m->Name(), ireg, MachSpillCopyNode::spill_type (MachSpillCopyNode::PhiInput)); ::breakpoint(); } } while (0); | |||
| 303 | C->record_method_not_compilable("attempted to spill a non-spillable item"); | |||
| 304 | } | |||
| 305 | return; | |||
| 306 | } | |||
| 307 | const RegMask *rm = C->matcher()->idealreg2spillmask[ireg]; | |||
| 308 | copy = new MachSpillCopyNode(MachSpillCopyNode::PhiInput, m, *rm, *rm); | |||
| 309 | // Find a good place to insert. Kinda tricky, use a subroutine | |||
| 310 | insert_copy_with_overlap(pred,copy,phi_name,src_name); | |||
| 311 | } | |||
| 312 | // Insert the copy in the use-def chain | |||
| 313 | n->set_req(j, copy); | |||
| 314 | _phc._cfg.map_node_to_block(copy, pred); | |||
| 315 | // Extend ("register allocate") the names array for the copy. | |||
| 316 | _phc._lrg_map.extend(copy->_idx, phi_name); | |||
| 317 | } // End of if Phi names do not match | |||
| 318 | } // End of for all inputs to Phi | |||
| 319 | } else { // End of if Phi | |||
| 320 | ||||
| 321 | // Now check for 2-address instructions | |||
| 322 | uint idx; | |||
| 323 | if( n->is_Mach() && (idx=n->as_Mach()->two_adr()) ) { | |||
| 324 | // Get the chosen name for the Node | |||
| 325 | uint name = _phc._lrg_map.find(n); | |||
| 326 | assert (name, "no 2-address specials")do { if (!(name)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 326, "assert(" "name" ") failed", "no 2-address specials"); ::breakpoint(); } } while (0); | |||
| 327 | // Check for name mis-match on the 2-address input | |||
| 328 | Node *m = n->in(idx); | |||
| 329 | if (_phc._lrg_map.find(m) != name) { | |||
| 330 | Node *copy; | |||
| 331 | assert(!m->is_Con() || m->is_Mach(), "all Con must be Mach")do { if (!(!m->is_Con() || m->is_Mach())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 331, "assert(" "!m->is_Con() || m->is_Mach()" ") failed" , "all Con must be Mach"); ::breakpoint(); } } while (0); | |||
| 332 | // At this point it is unsafe to extend live ranges (6550579). | |||
| 333 | // Rematerialize only constants as we do for Phi above. | |||
| 334 | if (m->is_Mach() && m->as_Mach()->is_Con() && !m->as_Mach()->is_MachConstant() && | |||
| 335 | m->as_Mach()->rematerialize()) { | |||
| 336 | copy = m->clone(); | |||
| 337 | // Insert the copy in the basic block, just before us | |||
| 338 | b->insert_node(copy, l++); | |||
| 339 | l += _phc.clone_projs(b, l, m, copy, _phc._lrg_map); | |||
| 340 | } else { | |||
| 341 | uint ireg = m->ideal_reg(); | |||
| 342 | if (ireg == 0 || ireg == Op_RegFlags) { | |||
| 343 | assert(false, "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s",do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 344, "assert(" "false" ") failed", "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s" , m->_idx, m->Name(), ireg, MachSpillCopyNode::spill_type (MachSpillCopyNode::TwoAddress)); ::breakpoint(); } } while ( 0) | |||
| 344 | m->_idx, m->Name(), ireg, MachSpillCopyNode::spill_type(MachSpillCopyNode::TwoAddress))do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 344, "assert(" "false" ") failed", "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s" , m->_idx, m->Name(), ireg, MachSpillCopyNode::spill_type (MachSpillCopyNode::TwoAddress)); ::breakpoint(); } } while ( 0); | |||
| 345 | C->record_method_not_compilable("attempted to spill a non-spillable item"); | |||
| 346 | return; | |||
| 347 | } | |||
| 348 | const RegMask *rm = C->matcher()->idealreg2spillmask[ireg]; | |||
| 349 | copy = new MachSpillCopyNode(MachSpillCopyNode::TwoAddress, m, *rm, *rm); | |||
| 350 | // Insert the copy in the basic block, just before us | |||
| 351 | b->insert_node(copy, l++); | |||
| 352 | } | |||
| 353 | // Insert the copy in the use-def chain | |||
| 354 | n->set_req(idx, copy); | |||
| 355 | // Extend ("register allocate") the names array for the copy. | |||
| 356 | _phc._lrg_map.extend(copy->_idx, name); | |||
| 357 | _phc._cfg.map_node_to_block(copy, b); | |||
| 358 | } | |||
| 359 | ||||
| 360 | } // End of is two-adr | |||
| 361 | ||||
| 362 | // Insert a copy at a debug use for a lrg which has high frequency | |||
| 363 | if (b->_freq < OPTO_DEBUG_SPLIT_FREQ((0.001 * (double) 1500) / FreqCountInvocations) || _phc._cfg.is_uncommon(b)) { | |||
| 364 | // Walk the debug inputs to the node and check for lrg freq | |||
| 365 | JVMState* jvms = n->jvms(); | |||
| 366 | uint debug_start = jvms ? jvms->debug_start() : 999999; | |||
| 367 | uint debug_end = jvms ? jvms->debug_end() : 999999; | |||
| 368 | for(uint inpidx = debug_start; inpidx < debug_end; inpidx++) { | |||
| 369 | // Do not split monitors; they are only needed for debug table | |||
| 370 | // entries and need no code. | |||
| 371 | if (jvms->is_monitor_use(inpidx)) { | |||
| 372 | continue; | |||
| 373 | } | |||
| 374 | Node *inp = n->in(inpidx); | |||
| 375 | uint nidx = _phc._lrg_map.live_range_id(inp); | |||
| 376 | LRG &lrg = lrgs(nidx); | |||
| 377 | ||||
| 378 | // If this lrg has a high frequency use/def | |||
| 379 | if( lrg._maxfreq >= _phc.high_frequency_lrg() ) { | |||
| 380 | // If the live range is also live out of this block (like it | |||
| 381 | // would be for a fast/slow idiom), the normal spill mechanism | |||
| 382 | // does an excellent job. If it is not live out of this block | |||
| 383 | // (like it would be for debug info to uncommon trap) splitting | |||
| 384 | // the live range now allows a better allocation in the high | |||
| 385 | // frequency blocks. | |||
| 386 | // Build_IFG_virtual has converted the live sets to | |||
| 387 | // live-IN info, not live-OUT info. | |||
| 388 | uint k; | |||
| 389 | for( k=0; k < b->_num_succs; k++ ) | |||
| 390 | if( _phc._live->live(b->_succs[k])->member( nidx ) ) | |||
| 391 | break; // Live in to some successor block? | |||
| 392 | if( k < b->_num_succs ) | |||
| 393 | continue; // Live out; do not pre-split | |||
| 394 | // Split the lrg at this use | |||
| 395 | uint ireg = inp->ideal_reg(); | |||
| 396 | if (ireg == 0 || ireg == Op_RegFlags) { | |||
| 397 | assert(false, "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s",do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 398, "assert(" "false" ") failed", "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s" , inp->_idx, inp->Name(), ireg, MachSpillCopyNode::spill_type (MachSpillCopyNode::DebugUse)); ::breakpoint(); } } while (0) | |||
| 398 | inp->_idx, inp->Name(), ireg, MachSpillCopyNode::spill_type(MachSpillCopyNode::DebugUse))do { if (!(false)) { (*g_assert_poison) = 'X';; report_vm_error ("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 398, "assert(" "false" ") failed", "attempted to spill a non-spillable item: %d: %s, ireg = %u, spill_type: %s" , inp->_idx, inp->Name(), ireg, MachSpillCopyNode::spill_type (MachSpillCopyNode::DebugUse)); ::breakpoint(); } } while (0); | |||
| 399 | C->record_method_not_compilable("attempted to spill a non-spillable item"); | |||
| 400 | return; | |||
| 401 | } | |||
| 402 | const RegMask *rm = C->matcher()->idealreg2spillmask[ireg]; | |||
| 403 | Node* copy = new MachSpillCopyNode(MachSpillCopyNode::DebugUse, inp, *rm, *rm); | |||
| 404 | // Insert the copy in the use-def chain | |||
| 405 | n->set_req(inpidx, copy ); | |||
| 406 | // Insert the copy in the basic block, just before us | |||
| 407 | b->insert_node(copy, l++); | |||
| 408 | // Extend ("register allocate") the names array for the copy. | |||
| 409 | uint max_lrg_id = _phc._lrg_map.max_lrg_id(); | |||
| 410 | _phc.new_lrg(copy, max_lrg_id); | |||
| 411 | _phc._lrg_map.set_max_lrg_id(max_lrg_id + 1); | |||
| 412 | _phc._cfg.map_node_to_block(copy, b); | |||
| 413 | //tty->print_cr("Split a debug use in Aggressive Coalesce"); | |||
| 414 | } // End of if high frequency use/def | |||
| 415 | } // End of for all debug inputs | |||
| 416 | } // End of if low frequency safepoint | |||
| 417 | ||||
| 418 | } // End of if Phi | |||
| 419 | ||||
| 420 | } // End of for all instructions | |||
| 421 | } // End of for all blocks | |||
| 422 | } | |||
| 423 | ||||
| 424 | ||||
| 425 | // Aggressive (but pessimistic) copy coalescing of a single block | |||
| 426 | ||||
| 427 | // The following coalesce pass represents a single round of aggressive | |||
| 428 | // pessimistic coalesce. "Aggressive" means no attempt to preserve | |||
| 429 | // colorability when coalescing. This occasionally means more spills, but | |||
| 430 | // it also means fewer rounds of coalescing for better code - and that means | |||
| 431 | // faster compiles. | |||
| 432 | ||||
| 433 | // "Pessimistic" means we do not hit the fixed point in one pass (and we are | |||
| 434 | // reaching for the least fixed point to boot). This is typically solved | |||
| 435 | // with a few more rounds of coalescing, but the compiler must run fast. We | |||
| 436 | // could optimistically coalescing everything touching PhiNodes together | |||
| 437 | // into one big live range, then check for self-interference. Everywhere | |||
| 438 | // the live range interferes with self it would have to be split. Finding | |||
| 439 | // the right split points can be done with some heuristics (based on | |||
| 440 | // expected frequency of edges in the live range). In short, it's a real | |||
| 441 | // research problem and the timeline is too short to allow such research. | |||
| 442 | // Further thoughts: (1) build the LR in a pass, (2) find self-interference | |||
| 443 | // in another pass, (3) per each self-conflict, split, (4) split by finding | |||
| 444 | // the low-cost cut (min-cut) of the LR, (5) edges in the LR are weighted | |||
| 445 | // according to the GCM algorithm (or just exec freq on CFG edges). | |||
| 446 | ||||
| 447 | void PhaseAggressiveCoalesce::coalesce( Block *b ) { | |||
| 448 | // Copies are still "virtual" - meaning we have not made them explicitly | |||
| 449 | // copies. Instead, Phi functions of successor blocks have mis-matched | |||
| 450 | // live-ranges. If I fail to coalesce, I'll have to insert a copy to line | |||
| 451 | // up the live-ranges. Check for Phis in successor blocks. | |||
| 452 | uint i; | |||
| 453 | for( i=0; i<b->_num_succs; i++ ) { | |||
| 454 | Block *bs = b->_succs[i]; | |||
| 455 | // Find index of 'b' in 'bs' predecessors | |||
| 456 | uint j=1; | |||
| 457 | while (_phc._cfg.get_block_for_node(bs->pred(j)) != b) { | |||
| 458 | j++; | |||
| 459 | } | |||
| 460 | ||||
| 461 | // Visit all the Phis in successor block | |||
| 462 | for( uint k = 1; k<bs->number_of_nodes(); k++ ) { | |||
| 463 | Node *n = bs->get_node(k); | |||
| 464 | if( !n->is_Phi() ) break; | |||
| 465 | combine_these_two( n, n->in(j) ); | |||
| 466 | } | |||
| 467 | } // End of for all successor blocks | |||
| 468 | ||||
| 469 | ||||
| 470 | // Check _this_ block for 2-address instructions and copies. | |||
| 471 | uint cnt = b->end_idx(); | |||
| 472 | for( i = 1; i<cnt; i++ ) { | |||
| 473 | Node *n = b->get_node(i); | |||
| 474 | uint idx; | |||
| 475 | // 2-address instructions have a virtual Copy matching their input | |||
| 476 | // to their output | |||
| 477 | if (n->is_Mach() && (idx = n->as_Mach()->two_adr())) { | |||
| 478 | MachNode *mach = n->as_Mach(); | |||
| 479 | combine_these_two(mach, mach->in(idx)); | |||
| 480 | } | |||
| 481 | } // End of for all instructions in block | |||
| 482 | } | |||
| 483 | ||||
| 484 | PhaseConservativeCoalesce::PhaseConservativeCoalesce(PhaseChaitin &chaitin) : PhaseCoalesce(chaitin) { | |||
| 485 | _ulr.initialize(_phc._lrg_map.max_lrg_id()); | |||
| 486 | } | |||
| 487 | ||||
| 488 | void PhaseConservativeCoalesce::verify() { | |||
| 489 | #ifdef ASSERT1 | |||
| 490 | _phc.set_was_low(); | |||
| 491 | #endif | |||
| 492 | } | |||
| 493 | ||||
| 494 | void PhaseConservativeCoalesce::union_helper( Node *lr1_node, Node *lr2_node, uint lr1, uint lr2, Node *src_def, Node *dst_copy, Node *src_copy, Block *b, uint bindex ) { | |||
| 495 | // Join live ranges. Merge larger into smaller. Union lr2 into lr1 in the | |||
| 496 | // union-find tree | |||
| 497 | _phc.Union( lr1_node, lr2_node ); | |||
| 498 | ||||
| 499 | // Single-def live range ONLY if both live ranges are single-def. | |||
| 500 | // If both are single def, then src_def powers one live range | |||
| 501 | // and def_copy powers the other. After merging, src_def powers | |||
| 502 | // the combined live range. | |||
| 503 | lrgs(lr1)._def = (lrgs(lr1).is_multidef() || | |||
| 504 | lrgs(lr2).is_multidef() ) | |||
| 505 | ? NodeSentinel(Node*)-1 : src_def; | |||
| 506 | lrgs(lr2)._def = NULL__null; // No def for lrg 2 | |||
| 507 | lrgs(lr2).Clear(); // Force empty mask for LRG 2 | |||
| 508 | //lrgs(lr2)._size = 0; // Live-range 2 goes dead | |||
| 509 | lrgs(lr1)._is_oop |= lrgs(lr2)._is_oop; | |||
| 510 | lrgs(lr2)._is_oop = 0; // In particular, not an oop for GC info | |||
| 511 | ||||
| 512 | if (lrgs(lr1)._maxfreq < lrgs(lr2)._maxfreq) | |||
| 513 | lrgs(lr1)._maxfreq = lrgs(lr2)._maxfreq; | |||
| 514 | ||||
| 515 | // Copy original value instead. Intermediate copies go dead, and | |||
| 516 | // the dst_copy becomes useless. | |||
| 517 | int didx = dst_copy->is_Copy(); | |||
| 518 | dst_copy->set_req( didx, src_def ); | |||
| 519 | // Add copy to free list | |||
| 520 | // _phc.free_spillcopy(b->_nodes[bindex]); | |||
| 521 | assert( b->get_node(bindex) == dst_copy, "" )do { if (!(b->get_node(bindex) == dst_copy)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 521, "assert(" "b->get_node(bindex) == dst_copy" ") failed" , ""); ::breakpoint(); } } while (0); | |||
| 522 | dst_copy->replace_by( dst_copy->in(didx) ); | |||
| 523 | dst_copy->set_req( didx, NULL__null); | |||
| 524 | b->remove_node(bindex); | |||
| 525 | if( bindex < b->_ihrp_index ) b->_ihrp_index--; | |||
| 526 | if( bindex < b->_fhrp_index ) b->_fhrp_index--; | |||
| 527 | ||||
| 528 | // Stretched lr1; add it to liveness of intermediate blocks | |||
| 529 | Block *b2 = _phc._cfg.get_block_for_node(src_copy); | |||
| 530 | while( b != b2 ) { | |||
| 531 | b = _phc._cfg.get_block_for_node(b->pred(1)); | |||
| 532 | _phc._live->live(b)->insert(lr1); | |||
| 533 | } | |||
| 534 | } | |||
| 535 | ||||
| 536 | // Factored code from copy_copy that computes extra interferences from | |||
| 537 | // lengthening a live range by double-coalescing. | |||
| 538 | uint PhaseConservativeCoalesce::compute_separating_interferences(Node *dst_copy, Node *src_copy, Block *b, uint bindex, RegMask &rm, uint rm_size, uint reg_degree, uint lr1, uint lr2 ) { | |||
| 539 | ||||
| 540 | assert(!lrgs(lr1)._fat_proj, "cannot coalesce fat_proj")do { if (!(!lrgs(lr1)._fat_proj)) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 540, "assert(" "!lrgs(lr1)._fat_proj" ") failed", "cannot coalesce fat_proj" ); ::breakpoint(); } } while (0); | |||
| ||||
| 541 | assert(!lrgs(lr2)._fat_proj, "cannot coalesce fat_proj")do { if (!(!lrgs(lr2)._fat_proj)) { (*g_assert_poison) = 'X'; ; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 541, "assert(" "!lrgs(lr2)._fat_proj" ") failed", "cannot coalesce fat_proj" ); ::breakpoint(); } } while (0); | |||
| 542 | Node *prev_copy = dst_copy->in(dst_copy->is_Copy()); | |||
| 543 | Block *b2 = b; | |||
| 544 | uint bindex2 = bindex; | |||
| 545 | while( 1 ) { | |||
| 546 | // Find previous instruction | |||
| 547 | bindex2--; // Chain backwards 1 instruction | |||
| 548 | while( bindex2 == 0 ) { // At block start, find prior block | |||
| 549 | assert( b2->num_preds() == 2, "cannot double coalesce across c-flow" )do { if (!(b2->num_preds() == 2)) { (*g_assert_poison) = 'X' ;; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 549, "assert(" "b2->num_preds() == 2" ") failed", "cannot double coalesce across c-flow" ); ::breakpoint(); } } while (0); | |||
| 550 | b2 = _phc._cfg.get_block_for_node(b2->pred(1)); | |||
| 551 | bindex2 = b2->end_idx()-1; | |||
| 552 | } | |||
| 553 | // Get prior instruction | |||
| 554 | assert(bindex2 < b2->number_of_nodes(), "index out of bounds")do { if (!(bindex2 < b2->number_of_nodes())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 554, "assert(" "bindex2 < b2->number_of_nodes()" ") failed" , "index out of bounds"); ::breakpoint(); } } while (0); | |||
| 555 | Node *x = b2->get_node(bindex2); | |||
| 556 | if( x == prev_copy ) { // Previous copy in copy chain? | |||
| 557 | if( prev_copy == src_copy)// Found end of chain and all interferences | |||
| 558 | break; // So break out of loop | |||
| 559 | // Else work back one in copy chain | |||
| 560 | prev_copy = prev_copy->in(prev_copy->is_Copy()); | |||
| ||||
| 561 | } else { // Else collect interferences | |||
| 562 | uint lidx = _phc._lrg_map.find(x); | |||
| 563 | // Found another def of live-range being stretched? | |||
| 564 | if(lidx == lr1) { | |||
| 565 | return max_juint; | |||
| 566 | } | |||
| 567 | if(lidx == lr2) { | |||
| 568 | return max_juint; | |||
| 569 | } | |||
| 570 | ||||
| 571 | // If we attempt to coalesce across a bound def | |||
| 572 | if( lrgs(lidx).is_bound() ) { | |||
| 573 | // Do not let the coalesced LRG expect to get the bound color | |||
| 574 | rm.SUBTRACT( lrgs(lidx).mask() ); | |||
| 575 | // Recompute rm_size | |||
| 576 | rm_size = rm.Size(); | |||
| 577 | //if( rm._flags ) rm_size += 1000000; | |||
| 578 | if( reg_degree >= rm_size ) return max_juint; | |||
| 579 | } | |||
| 580 | if( rm.overlap(lrgs(lidx).mask()) ) { | |||
| 581 | // Insert lidx into union LRG; returns TRUE if actually inserted | |||
| 582 | if( _ulr.insert(lidx) ) { | |||
| 583 | // Infinite-stack neighbors do not alter colorability, as they | |||
| 584 | // can always color to some other color. | |||
| 585 | if( !lrgs(lidx).mask().is_AllStack() ) { | |||
| 586 | // If this coalesce will make any new neighbor uncolorable, | |||
| 587 | // do not coalesce. | |||
| 588 | if( lrgs(lidx).just_lo_degree() ) | |||
| 589 | return max_juint; | |||
| 590 | // Bump our degree | |||
| 591 | if( ++reg_degree >= rm_size ) | |||
| 592 | return max_juint; | |||
| 593 | } // End of if not infinite-stack neighbor | |||
| 594 | } // End of if actually inserted | |||
| 595 | } // End of if live range overlaps | |||
| 596 | } // End of else collect interferences for 1 node | |||
| 597 | } // End of while forever, scan back for interferences | |||
| 598 | return reg_degree; | |||
| 599 | } | |||
| 600 | ||||
| 601 | void PhaseConservativeCoalesce::update_ifg(uint lr1, uint lr2, IndexSet *n_lr1, IndexSet *n_lr2) { | |||
| 602 | // Some original neighbors of lr1 might have gone away | |||
| 603 | // because the constrained register mask prevented them. | |||
| 604 | // Remove lr1 from such neighbors. | |||
| 605 | uint neighbor = 0; | |||
| 606 | LRG &lrg1 = lrgs(lr1); | |||
| 607 | if (!n_lr1->is_empty()) { | |||
| 608 | IndexSetIterator one(n_lr1); | |||
| 609 | while ((neighbor = one.next()) != 0) { | |||
| 610 | if (!_ulr.member(neighbor)) { | |||
| 611 | if (_phc._ifg->neighbors(neighbor)->remove(lr1)) { | |||
| 612 | lrgs(neighbor).inc_degree(-lrg1.compute_degree(lrgs(neighbor))); | |||
| 613 | } | |||
| 614 | } | |||
| 615 | } | |||
| 616 | } | |||
| 617 | ||||
| 618 | ||||
| 619 | // lr2 is now called (coalesced into) lr1. | |||
| 620 | // Remove lr2 from the IFG. | |||
| 621 | LRG &lrg2 = lrgs(lr2); | |||
| 622 | if (!n_lr2->is_empty()) { | |||
| 623 | IndexSetIterator two(n_lr2); | |||
| 624 | while ((neighbor = two.next()) != 0) { | |||
| 625 | if (_phc._ifg->neighbors(neighbor)->remove(lr2)) { | |||
| 626 | lrgs(neighbor).inc_degree(-lrg2.compute_degree(lrgs(neighbor))); | |||
| 627 | } | |||
| 628 | } | |||
| 629 | } | |||
| 630 | ||||
| 631 | // Some neighbors of intermediate copies now interfere with the | |||
| 632 | // combined live range. | |||
| 633 | if (!_ulr.is_empty()) { | |||
| 634 | IndexSetIterator three(&_ulr); | |||
| 635 | while ((neighbor = three.next()) != 0) { | |||
| 636 | if (_phc._ifg->neighbors(neighbor)->insert(lr1)) { | |||
| 637 | lrgs(neighbor).inc_degree(lrg1.compute_degree(lrgs(neighbor))); | |||
| 638 | } | |||
| 639 | } | |||
| 640 | } | |||
| 641 | } | |||
| 642 | ||||
| 643 | static void record_bias( const PhaseIFG *ifg, int lr1, int lr2 ) { | |||
| 644 | // Tag copy bias here | |||
| 645 | if( !ifg->lrgs(lr1)._copy_bias ) | |||
| 646 | ifg->lrgs(lr1)._copy_bias = lr2; | |||
| 647 | if( !ifg->lrgs(lr2)._copy_bias ) | |||
| 648 | ifg->lrgs(lr2)._copy_bias = lr1; | |||
| 649 | } | |||
| 650 | ||||
| 651 | // See if I can coalesce a series of multiple copies together. I need the | |||
| 652 | // final dest copy and the original src copy. They can be the same Node. | |||
| 653 | // Compute the compatible register masks. | |||
| 654 | bool PhaseConservativeCoalesce::copy_copy(Node *dst_copy, Node *src_copy, Block *b, uint bindex) { | |||
| 655 | ||||
| 656 | if (!dst_copy->is_SpillCopy()) { | |||
| 657 | return false; | |||
| 658 | } | |||
| 659 | if (!src_copy->is_SpillCopy()) { | |||
| 660 | return false; | |||
| 661 | } | |||
| 662 | Node *src_def = src_copy->in(src_copy->is_Copy()); | |||
| 663 | uint lr1 = _phc._lrg_map.find(dst_copy); | |||
| 664 | uint lr2 = _phc._lrg_map.find(src_def); | |||
| 665 | ||||
| 666 | // Same live ranges already? | |||
| 667 | if (lr1 == lr2) { | |||
| 668 | return false; | |||
| 669 | } | |||
| 670 | ||||
| 671 | // Interfere? | |||
| 672 | if (_phc._ifg->test_edge_sq(lr1, lr2)) { | |||
| 673 | return false; | |||
| 674 | } | |||
| 675 | ||||
| 676 | // Not an oop->int cast; oop->oop, int->int, AND int->oop are OK. | |||
| 677 | if (!lrgs(lr1)._is_oop && lrgs(lr2)._is_oop) { // not an oop->int cast | |||
| 678 | return false; | |||
| 679 | } | |||
| 680 | ||||
| 681 | // Coalescing between an aligned live range and a mis-aligned live range? | |||
| 682 | // No, no! Alignment changes how we count degree. | |||
| 683 | if (lrgs(lr1)._fat_proj != lrgs(lr2)._fat_proj) { | |||
| 684 | return false; | |||
| 685 | } | |||
| 686 | ||||
| 687 | // Sort; use smaller live-range number | |||
| 688 | Node *lr1_node = dst_copy; | |||
| 689 | Node *lr2_node = src_def; | |||
| 690 | if (lr1 > lr2) { | |||
| 691 | uint tmp = lr1; lr1 = lr2; lr2 = tmp; | |||
| 692 | lr1_node = src_def; lr2_node = dst_copy; | |||
| 693 | } | |||
| 694 | ||||
| 695 | // Check for compatibility of the 2 live ranges by | |||
| 696 | // intersecting their allowed register sets. | |||
| 697 | RegMask rm = lrgs(lr1).mask(); | |||
| 698 | rm.AND(lrgs(lr2).mask()); | |||
| 699 | // Number of bits free | |||
| 700 | uint rm_size = rm.Size(); | |||
| 701 | ||||
| 702 | if (UseFPUForSpilling && rm.is_AllStack() ) { | |||
| 703 | // Don't coalesce when frequency difference is large | |||
| 704 | Block *dst_b = _phc._cfg.get_block_for_node(dst_copy); | |||
| 705 | Block *src_def_b = _phc._cfg.get_block_for_node(src_def); | |||
| 706 | if (src_def_b->_freq > 10*dst_b->_freq ) | |||
| 707 | return false; | |||
| 708 | } | |||
| 709 | ||||
| 710 | // If we can use any stack slot, then effective size is infinite | |||
| 711 | if( rm.is_AllStack() ) rm_size += 1000000; | |||
| 712 | // Incompatible masks, no way to coalesce | |||
| 713 | if( rm_size == 0 ) return false; | |||
| 714 | ||||
| 715 | // Another early bail-out test is when we are double-coalescing and the | |||
| 716 | // 2 copies are separated by some control flow. | |||
| 717 | if( dst_copy != src_copy ) { | |||
| 718 | Block *src_b = _phc._cfg.get_block_for_node(src_copy); | |||
| 719 | Block *b2 = b; | |||
| 720 | while( b2 != src_b ) { | |||
| 721 | if( b2->num_preds() > 2 ){// Found merge-point | |||
| 722 | _phc._lost_opp_cflow_coalesce++; | |||
| 723 | // extra record_bias commented out because Chris believes it is not | |||
| 724 | // productive. Since we can record only 1 bias, we want to choose one | |||
| 725 | // that stands a chance of working and this one probably does not. | |||
| 726 | //record_bias( _phc._lrgs, lr1, lr2 ); | |||
| 727 | return false; // To hard to find all interferences | |||
| 728 | } | |||
| 729 | b2 = _phc._cfg.get_block_for_node(b2->pred(1)); | |||
| 730 | } | |||
| 731 | } | |||
| 732 | ||||
| 733 | // Union the two interference sets together into '_ulr' | |||
| 734 | uint reg_degree = _ulr.lrg_union( lr1, lr2, rm_size, _phc._ifg, rm ); | |||
| 735 | ||||
| 736 | if( reg_degree >= rm_size ) { | |||
| 737 | record_bias( _phc._ifg, lr1, lr2 ); | |||
| 738 | return false; | |||
| 739 | } | |||
| 740 | ||||
| 741 | // Now I need to compute all the interferences between dst_copy and | |||
| 742 | // src_copy. I'm not willing visit the entire interference graph, so | |||
| 743 | // I limit my search to things in dst_copy's block or in a straight | |||
| 744 | // line of previous blocks. I give up at merge points or when I get | |||
| 745 | // more interferences than my degree. I can stop when I find src_copy. | |||
| 746 | if( dst_copy != src_copy ) { | |||
| 747 | reg_degree = compute_separating_interferences(dst_copy, src_copy, b, bindex, rm, rm_size, reg_degree, lr1, lr2 ); | |||
| 748 | if( reg_degree == max_juint ) { | |||
| 749 | record_bias( _phc._ifg, lr1, lr2 ); | |||
| 750 | return false; | |||
| 751 | } | |||
| 752 | } // End of if dst_copy & src_copy are different | |||
| 753 | ||||
| 754 | ||||
| 755 | // ---- THE COMBINED LRG IS COLORABLE ---- | |||
| 756 | ||||
| 757 | // YEAH - Now coalesce this copy away | |||
| 758 | assert( lrgs(lr1).num_regs() == lrgs(lr2).num_regs(), "" )do { if (!(lrgs(lr1).num_regs() == lrgs(lr2).num_regs())) { ( *g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/opto/coalesce.cpp" , 758, "assert(" "lrgs(lr1).num_regs() == lrgs(lr2).num_regs()" ") failed", ""); ::breakpoint(); } } while (0); | |||
| 759 | ||||
| 760 | IndexSet *n_lr1 = _phc._ifg->neighbors(lr1); | |||
| 761 | IndexSet *n_lr2 = _phc._ifg->neighbors(lr2); | |||
| 762 | ||||
| 763 | // Update the interference graph | |||
| 764 | update_ifg(lr1, lr2, n_lr1, n_lr2); | |||
| 765 | ||||
| 766 | _ulr.remove(lr1); | |||
| 767 | ||||
| 768 | // Uncomment the following code to trace Coalescing in great detail. | |||
| 769 | // | |||
| 770 | //if (false) { | |||
| 771 | // tty->cr(); | |||
| 772 | // tty->print_cr("#######################################"); | |||
| 773 | // tty->print_cr("union %d and %d", lr1, lr2); | |||
| 774 | // n_lr1->dump(); | |||
| 775 | // n_lr2->dump(); | |||
| 776 | // tty->print_cr("resulting set is"); | |||
| 777 | // _ulr.dump(); | |||
| 778 | //} | |||
| 779 | ||||
| 780 | // Replace n_lr1 with the new combined live range. _ulr will use | |||
| 781 | // n_lr1's old memory on the next iteration. n_lr2 is cleared to | |||
| 782 | // send its internal memory to the free list. | |||
| 783 | _ulr.swap(n_lr1); | |||
| 784 | _ulr.clear(); | |||
| 785 | n_lr2->clear(); | |||
| 786 | ||||
| 787 | lrgs(lr1).set_degree( _phc._ifg->effective_degree(lr1) ); | |||
| 788 | lrgs(lr2).set_degree( 0 ); | |||
| 789 | ||||
| 790 | // Join live ranges. Merge larger into smaller. Union lr2 into lr1 in the | |||
| 791 | // union-find tree | |||
| 792 | union_helper( lr1_node, lr2_node, lr1, lr2, src_def, dst_copy, src_copy, b, bindex ); | |||
| 793 | // Combine register restrictions | |||
| 794 | lrgs(lr1).set_mask(rm); | |||
| 795 | lrgs(lr1).compute_set_mask_size(); | |||
| 796 | lrgs(lr1)._cost += lrgs(lr2)._cost; | |||
| 797 | lrgs(lr1)._area += lrgs(lr2)._area; | |||
| 798 | ||||
| 799 | // While its uncommon to successfully coalesce live ranges that started out | |||
| 800 | // being not-lo-degree, it can happen. In any case the combined coalesced | |||
| 801 | // live range better Simplify nicely. | |||
| 802 | lrgs(lr1)._was_lo = 1; | |||
| 803 | ||||
| 804 | // kinda expensive to do all the time | |||
| 805 | //tty->print_cr("warning: slow verify happening"); | |||
| 806 | //_phc._ifg->verify( &_phc ); | |||
| 807 | return true; | |||
| 808 | } | |||
| 809 | ||||
| 810 | // Conservative (but pessimistic) copy coalescing of a single block | |||
| 811 | void PhaseConservativeCoalesce::coalesce( Block *b ) { | |||
| 812 | // Bail out on infrequent blocks | |||
| 813 | if (_phc._cfg.is_uncommon(b)) { | |||
| 814 | return; | |||
| 815 | } | |||
| 816 | // Check this block for copies. | |||
| 817 | for( uint i = 1; i<b->end_idx(); i++ ) { | |||
| 818 | // Check for actual copies on inputs. Coalesce a copy into its | |||
| 819 | // input if use and copy's input are compatible. | |||
| 820 | Node *copy1 = b->get_node(i); | |||
| 821 | uint idx1 = copy1->is_Copy(); | |||
| 822 | if( !idx1 ) continue; // Not a copy | |||
| 823 | ||||
| 824 | if( copy_copy(copy1,copy1,b,i) ) { | |||
| 825 | i--; // Retry, same location in block | |||
| 826 | PhaseChaitin::_conserv_coalesce++; // Collect stats on success | |||
| 827 | continue; | |||
| 828 | } | |||
| 829 | } | |||
| 830 | } |