rev 3898 : 8005031: Some cleanup in c2 to prepare for incremental inlining support
Summary: collection of small changes to prepare for incremental inlining.
Reviewed-by:

   1 /*
   2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "asm/macroAssembler.hpp"
  27 #include "asm/macroAssembler.inline.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "code/exceptionHandlerTable.hpp"
  30 #include "code/nmethod.hpp"
  31 #include "compiler/compileLog.hpp"
  32 #include "compiler/disassembler.hpp"
  33 #include "compiler/oopMap.hpp"
  34 #include "opto/addnode.hpp"
  35 #include "opto/block.hpp"
  36 #include "opto/c2compiler.hpp"
  37 #include "opto/callGenerator.hpp"
  38 #include "opto/callnode.hpp"
  39 #include "opto/cfgnode.hpp"
  40 #include "opto/chaitin.hpp"
  41 #include "opto/compile.hpp"
  42 #include "opto/connode.hpp"
  43 #include "opto/divnode.hpp"
  44 #include "opto/escape.hpp"
  45 #include "opto/idealGraphPrinter.hpp"
  46 #include "opto/loopnode.hpp"
  47 #include "opto/machnode.hpp"
  48 #include "opto/macro.hpp"
  49 #include "opto/matcher.hpp"
  50 #include "opto/memnode.hpp"
  51 #include "opto/mulnode.hpp"
  52 #include "opto/node.hpp"
  53 #include "opto/opcodes.hpp"
  54 #include "opto/output.hpp"
  55 #include "opto/parse.hpp"
  56 #include "opto/phaseX.hpp"
  57 #include "opto/rootnode.hpp"
  58 #include "opto/runtime.hpp"
  59 #include "opto/stringopts.hpp"
  60 #include "opto/type.hpp"
  61 #include "opto/vectornode.hpp"
  62 #include "runtime/arguments.hpp"
  63 #include "runtime/signature.hpp"
  64 #include "runtime/stubRoutines.hpp"
  65 #include "runtime/timer.hpp"
  66 #include "utilities/copy.hpp"
  67 #ifdef TARGET_ARCH_MODEL_x86_32
  68 # include "adfiles/ad_x86_32.hpp"
  69 #endif
  70 #ifdef TARGET_ARCH_MODEL_x86_64
  71 # include "adfiles/ad_x86_64.hpp"
  72 #endif
  73 #ifdef TARGET_ARCH_MODEL_sparc
  74 # include "adfiles/ad_sparc.hpp"
  75 #endif
  76 #ifdef TARGET_ARCH_MODEL_zero
  77 # include "adfiles/ad_zero.hpp"
  78 #endif
  79 #ifdef TARGET_ARCH_MODEL_arm
  80 # include "adfiles/ad_arm.hpp"
  81 #endif
  82 #ifdef TARGET_ARCH_MODEL_ppc
  83 # include "adfiles/ad_ppc.hpp"
  84 #endif
  85 
  86 
  87 // -------------------- Compile::mach_constant_base_node -----------------------
  88 // Constant table base node singleton.
  89 MachConstantBaseNode* Compile::mach_constant_base_node() {
  90   if (_mach_constant_base_node == NULL) {
  91     _mach_constant_base_node = new (C) MachConstantBaseNode();
  92     _mach_constant_base_node->add_req(C->root());
  93   }
  94   return _mach_constant_base_node;
  95 }
  96 
  97 
  98 /// Support for intrinsics.
  99 
 100 // Return the index at which m must be inserted (or already exists).
 101 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 102 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
 103 #ifdef ASSERT
 104   for (int i = 1; i < _intrinsics->length(); i++) {
 105     CallGenerator* cg1 = _intrinsics->at(i-1);
 106     CallGenerator* cg2 = _intrinsics->at(i);
 107     assert(cg1->method() != cg2->method()
 108            ? cg1->method()     < cg2->method()
 109            : cg1->is_virtual() < cg2->is_virtual(),
 110            "compiler intrinsics list must stay sorted");
 111   }
 112 #endif
 113   // Binary search sorted list, in decreasing intervals [lo, hi].
 114   int lo = 0, hi = _intrinsics->length()-1;
 115   while (lo <= hi) {
 116     int mid = (uint)(hi + lo) / 2;
 117     ciMethod* mid_m = _intrinsics->at(mid)->method();
 118     if (m < mid_m) {
 119       hi = mid-1;
 120     } else if (m > mid_m) {
 121       lo = mid+1;
 122     } else {
 123       // look at minor sort key
 124       bool mid_virt = _intrinsics->at(mid)->is_virtual();
 125       if (is_virtual < mid_virt) {
 126         hi = mid-1;
 127       } else if (is_virtual > mid_virt) {
 128         lo = mid+1;
 129       } else {
 130         return mid;  // exact match
 131       }
 132     }
 133   }
 134   return lo;  // inexact match
 135 }
 136 
 137 void Compile::register_intrinsic(CallGenerator* cg) {
 138   if (_intrinsics == NULL) {
 139     _intrinsics = new GrowableArray<CallGenerator*>(60);
 140   }
 141   // This code is stolen from ciObjectFactory::insert.
 142   // Really, GrowableArray should have methods for
 143   // insert_at, remove_at, and binary_search.
 144   int len = _intrinsics->length();
 145   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
 146   if (index == len) {
 147     _intrinsics->append(cg);
 148   } else {
 149 #ifdef ASSERT
 150     CallGenerator* oldcg = _intrinsics->at(index);
 151     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 152 #endif
 153     _intrinsics->append(_intrinsics->at(len-1));
 154     int pos;
 155     for (pos = len-2; pos >= index; pos--) {
 156       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
 157     }
 158     _intrinsics->at_put(index, cg);
 159   }
 160   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 161 }
 162 
 163 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 164   assert(m->is_loaded(), "don't try this on unloaded methods");
 165   if (_intrinsics != NULL) {
 166     int index = intrinsic_insertion_index(m, is_virtual);
 167     if (index < _intrinsics->length()
 168         && _intrinsics->at(index)->method() == m
 169         && _intrinsics->at(index)->is_virtual() == is_virtual) {
 170       return _intrinsics->at(index);
 171     }
 172   }
 173   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 174   if (m->intrinsic_id() != vmIntrinsics::_none &&
 175       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 176     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 177     if (cg != NULL) {
 178       // Save it for next time:
 179       register_intrinsic(cg);
 180       return cg;
 181     } else {
 182       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 183     }
 184   }
 185   return NULL;
 186 }
 187 
 188 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 189 // in library_call.cpp.
 190 
 191 
 192 #ifndef PRODUCT
 193 // statistics gathering...
 194 
 195 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 196 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 197 
 198 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 199   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 200   int oflags = _intrinsic_hist_flags[id];
 201   assert(flags != 0, "what happened?");
 202   if (is_virtual) {
 203     flags |= _intrinsic_virtual;
 204   }
 205   bool changed = (flags != oflags);
 206   if ((flags & _intrinsic_worked) != 0) {
 207     juint count = (_intrinsic_hist_count[id] += 1);
 208     if (count == 1) {
 209       changed = true;           // first time
 210     }
 211     // increment the overall count also:
 212     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
 213   }
 214   if (changed) {
 215     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 216       // Something changed about the intrinsic's virtuality.
 217       if ((flags & _intrinsic_virtual) != 0) {
 218         // This is the first use of this intrinsic as a virtual call.
 219         if (oflags != 0) {
 220           // We already saw it as a non-virtual, so note both cases.
 221           flags |= _intrinsic_both;
 222         }
 223       } else if ((oflags & _intrinsic_both) == 0) {
 224         // This is the first use of this intrinsic as a non-virtual
 225         flags |= _intrinsic_both;
 226       }
 227     }
 228     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
 229   }
 230   // update the overall flags also:
 231   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
 232   return changed;
 233 }
 234 
 235 static char* format_flags(int flags, char* buf) {
 236   buf[0] = 0;
 237   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 238   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 239   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 240   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 241   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 242   if (buf[0] == 0)  strcat(buf, ",");
 243   assert(buf[0] == ',', "must be");
 244   return &buf[1];
 245 }
 246 
 247 void Compile::print_intrinsic_statistics() {
 248   char flagsbuf[100];
 249   ttyLocker ttyl;
 250   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
 251   tty->print_cr("Compiler intrinsic usage:");
 252   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
 253   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 254   #define PRINT_STAT_LINE(name, c, f) \
 255     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 256   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
 257     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
 258     int   flags = _intrinsic_hist_flags[id];
 259     juint count = _intrinsic_hist_count[id];
 260     if ((flags | count) != 0) {
 261       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 262     }
 263   }
 264   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
 265   if (xtty != NULL)  xtty->tail("statistics");
 266 }
 267 
 268 void Compile::print_statistics() {
 269   { ttyLocker ttyl;
 270     if (xtty != NULL)  xtty->head("statistics type='opto'");
 271     Parse::print_statistics();
 272     PhaseCCP::print_statistics();
 273     PhaseRegAlloc::print_statistics();
 274     Scheduling::print_statistics();
 275     PhasePeephole::print_statistics();
 276     PhaseIdealLoop::print_statistics();
 277     if (xtty != NULL)  xtty->tail("statistics");
 278   }
 279   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
 280     // put this under its own <statistics> element.
 281     print_intrinsic_statistics();
 282   }
 283 }
 284 #endif //PRODUCT
 285 
 286 // Support for bundling info
 287 Bundle* Compile::node_bundling(const Node *n) {
 288   assert(valid_bundle_info(n), "oob");
 289   return &_node_bundling_base[n->_idx];
 290 }
 291 
 292 bool Compile::valid_bundle_info(const Node *n) {
 293   return (_node_bundling_limit > n->_idx);
 294 }
 295 
 296 
 297 void Compile::gvn_replace_by(Node* n, Node* nn) {
 298   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 299     Node* use = n->last_out(i);
 300     bool is_in_table = initial_gvn()->hash_delete(use);
 301     uint uses_found = 0;
 302     for (uint j = 0; j < use->len(); j++) {
 303       if (use->in(j) == n) {
 304         if (j < use->req())
 305           use->set_req(j, nn);
 306         else
 307           use->set_prec(j, nn);
 308         uses_found++;
 309       }
 310     }
 311     if (is_in_table) {
 312       // reinsert into table
 313       initial_gvn()->hash_find_insert(use);
 314     }
 315     record_for_igvn(use);
 316     i -= uses_found;    // we deleted 1 or more copies of this edge
 317   }
 318 }
 319 
 320 
 321 static inline bool not_a_node(const Node* n) {
 322   if (n == NULL)                   return true;
 323   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
 324   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
 325   return false;
 326 }
 327 
 328 // Identify all nodes that are reachable from below, useful.
 329 // Use breadth-first pass that records state in a Unique_Node_List,
 330 // recursive traversal is slower.
 331 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 332   int estimated_worklist_size = unique();
 333   useful.map( estimated_worklist_size, NULL );  // preallocate space
 334 
 335   // Initialize worklist
 336   if (root() != NULL)     { useful.push(root()); }
 337   // If 'top' is cached, declare it useful to preserve cached node
 338   if( cached_top_node() ) { useful.push(cached_top_node()); }
 339 
 340   // Push all useful nodes onto the list, breadthfirst
 341   for( uint next = 0; next < useful.size(); ++next ) {
 342     assert( next < unique(), "Unique useful nodes < total nodes");
 343     Node *n  = useful.at(next);
 344     uint max = n->len();
 345     for( uint i = 0; i < max; ++i ) {
 346       Node *m = n->in(i);
 347       if (not_a_node(m))  continue;
 348       useful.push(m);
 349     }
 350   }
 351 }
 352 
 353 // Update dead_node_list with any missing dead nodes using useful
 354 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 355 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 356   uint max_idx = unique();
 357   VectorSet& useful_node_set = useful.member_set();
 358 
 359   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 360     // If node with index node_idx is not in useful set,
 361     // mark it as dead in dead node list.
 362     if (! useful_node_set.test(node_idx) ) {
 363       record_dead_node(node_idx);
 364     }
 365   }
 366 }
 367 
 368 // Disconnect all useless nodes by disconnecting those at the boundary.
 369 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
 370   uint next = 0;
 371   while (next < useful.size()) {
 372     Node *n = useful.at(next++);
 373     // Use raw traversal of out edges since this code removes out edges
 374     int max = n->outcnt();
 375     for (int j = 0; j < max; ++j) {
 376       Node* child = n->raw_out(j);
 377       if (! useful.member(child)) {
 378         assert(!child->is_top() || child != top(),
 379                "If top is cached in Compile object it is in useful list");
 380         // Only need to remove this out-edge to the useless node
 381         n->raw_del_out(j);
 382         --j;
 383         --max;
 384       }
 385     }
 386     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 387       record_for_igvn(n->unique_out());
 388     }
 389   }
 390   // Remove useless macro and predicate opaq nodes
 391   for (int i = C->macro_count()-1; i >= 0; i--) {
 392     Node* n = C->macro_node(i);
 393     if (!useful.member(n)) {
 394       remove_macro_node(n);
 395     }
 396   }
 397   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 398 }
 399 
 400 //------------------------------frame_size_in_words-----------------------------
 401 // frame_slots in units of words
 402 int Compile::frame_size_in_words() const {
 403   // shift is 0 in LP32 and 1 in LP64
 404   const int shift = (LogBytesPerWord - LogBytesPerInt);
 405   int words = _frame_slots >> shift;
 406   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
 407   return words;
 408 }
 409 
 410 // ============================================================================
 411 //------------------------------CompileWrapper---------------------------------
 412 class CompileWrapper : public StackObj {
 413   Compile *const _compile;
 414  public:
 415   CompileWrapper(Compile* compile);
 416 
 417   ~CompileWrapper();
 418 };
 419 
 420 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 421   // the Compile* pointer is stored in the current ciEnv:
 422   ciEnv* env = compile->env();
 423   assert(env == ciEnv::current(), "must already be a ciEnv active");
 424   assert(env->compiler_data() == NULL, "compile already active?");
 425   env->set_compiler_data(compile);
 426   assert(compile == Compile::current(), "sanity");
 427 
 428   compile->set_type_dict(NULL);
 429   compile->set_type_hwm(NULL);
 430   compile->set_type_last_size(0);
 431   compile->set_last_tf(NULL, NULL);
 432   compile->set_indexSet_arena(NULL);
 433   compile->set_indexSet_free_block_list(NULL);
 434   compile->init_type_arena();
 435   Type::Initialize(compile);
 436   _compile->set_scratch_buffer_blob(NULL);
 437   _compile->begin_method();
 438 }
 439 CompileWrapper::~CompileWrapper() {
 440   _compile->end_method();
 441   if (_compile->scratch_buffer_blob() != NULL)
 442     BufferBlob::free(_compile->scratch_buffer_blob());
 443   _compile->env()->set_compiler_data(NULL);
 444 }
 445 
 446 
 447 //----------------------------print_compile_messages---------------------------
 448 void Compile::print_compile_messages() {
 449 #ifndef PRODUCT
 450   // Check if recompiling
 451   if (_subsume_loads == false && PrintOpto) {
 452     // Recompiling without allowing machine instructions to subsume loads
 453     tty->print_cr("*********************************************************");
 454     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 455     tty->print_cr("*********************************************************");
 456   }
 457   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
 458     // Recompiling without escape analysis
 459     tty->print_cr("*********************************************************");
 460     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 461     tty->print_cr("*********************************************************");
 462   }
 463   if (env()->break_at_compile()) {
 464     // Open the debugger when compiling this method.
 465     tty->print("### Breaking when compiling: ");
 466     method()->print_short_name();
 467     tty->cr();
 468     BREAKPOINT;
 469   }
 470 
 471   if( PrintOpto ) {
 472     if (is_osr_compilation()) {
 473       tty->print("[OSR]%3d", _compile_id);
 474     } else {
 475       tty->print("%3d", _compile_id);
 476     }
 477   }
 478 #endif
 479 }
 480 
 481 
 482 //-----------------------init_scratch_buffer_blob------------------------------
 483 // Construct a temporary BufferBlob and cache it for this compile.
 484 void Compile::init_scratch_buffer_blob(int const_size) {
 485   // If there is already a scratch buffer blob allocated and the
 486   // constant section is big enough, use it.  Otherwise free the
 487   // current and allocate a new one.
 488   BufferBlob* blob = scratch_buffer_blob();
 489   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
 490     // Use the current blob.
 491   } else {
 492     if (blob != NULL) {
 493       BufferBlob::free(blob);
 494     }
 495 
 496     ResourceMark rm;
 497     _scratch_const_size = const_size;
 498     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
 499     blob = BufferBlob::create("Compile::scratch_buffer", size);
 500     // Record the buffer blob for next time.
 501     set_scratch_buffer_blob(blob);
 502     // Have we run out of code space?
 503     if (scratch_buffer_blob() == NULL) {
 504       // Let CompilerBroker disable further compilations.
 505       record_failure("Not enough space for scratch buffer in CodeCache");
 506       return;
 507     }
 508   }
 509 
 510   // Initialize the relocation buffers
 511   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
 512   set_scratch_locs_memory(locs_buf);
 513 }
 514 
 515 
 516 //-----------------------scratch_emit_size-------------------------------------
 517 // Helper function that computes size by emitting code
 518 uint Compile::scratch_emit_size(const Node* n) {
 519   // Start scratch_emit_size section.
 520   set_in_scratch_emit_size(true);
 521 
 522   // Emit into a trash buffer and count bytes emitted.
 523   // This is a pretty expensive way to compute a size,
 524   // but it works well enough if seldom used.
 525   // All common fixed-size instructions are given a size
 526   // method by the AD file.
 527   // Note that the scratch buffer blob and locs memory are
 528   // allocated at the beginning of the compile task, and
 529   // may be shared by several calls to scratch_emit_size.
 530   // The allocation of the scratch buffer blob is particularly
 531   // expensive, since it has to grab the code cache lock.
 532   BufferBlob* blob = this->scratch_buffer_blob();
 533   assert(blob != NULL, "Initialize BufferBlob at start");
 534   assert(blob->size() > MAX_inst_size, "sanity");
 535   relocInfo* locs_buf = scratch_locs_memory();
 536   address blob_begin = blob->content_begin();
 537   address blob_end   = (address)locs_buf;
 538   assert(blob->content_contains(blob_end), "sanity");
 539   CodeBuffer buf(blob_begin, blob_end - blob_begin);
 540   buf.initialize_consts_size(_scratch_const_size);
 541   buf.initialize_stubs_size(MAX_stubs_size);
 542   assert(locs_buf != NULL, "sanity");
 543   int lsize = MAX_locs_size / 3;
 544   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
 545   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
 546   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
 547 
 548   // Do the emission.
 549 
 550   Label fakeL; // Fake label for branch instructions.
 551   Label*   saveL = NULL;
 552   uint save_bnum = 0;
 553   bool is_branch = n->is_MachBranch();
 554   if (is_branch) {
 555     MacroAssembler masm(&buf);
 556     masm.bind(fakeL);
 557     n->as_MachBranch()->save_label(&saveL, &save_bnum);
 558     n->as_MachBranch()->label_set(&fakeL, 0);
 559   }
 560   n->emit(buf, this->regalloc());
 561   if (is_branch) // Restore label.
 562     n->as_MachBranch()->label_set(saveL, save_bnum);
 563 
 564   // End scratch_emit_size section.
 565   set_in_scratch_emit_size(false);
 566 
 567   return buf.insts_size();
 568 }
 569 
 570 
 571 // ============================================================================
 572 //------------------------------Compile standard-------------------------------
 573 debug_only( int Compile::_debug_idx = 100000; )
 574 
 575 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 576 // the continuation bci for on stack replacement.
 577 
 578 
 579 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci, bool subsume_loads, bool do_escape_analysis )
 580                 : Phase(Compiler),
 581                   _env(ci_env),
 582                   _log(ci_env->log()),
 583                   _compile_id(ci_env->compile_id()),
 584                   _save_argument_registers(false),
 585                   _stub_name(NULL),
 586                   _stub_function(NULL),
 587                   _stub_entry_point(NULL),
 588                   _method(target),
 589                   _entry_bci(osr_bci),
 590                   _initial_gvn(NULL),
 591                   _for_igvn(NULL),
 592                   _warm_calls(NULL),
 593                   _subsume_loads(subsume_loads),
 594                   _do_escape_analysis(do_escape_analysis),
 595                   _failure_reason(NULL),
 596                   _code_buffer("Compile::Fill_buffer"),
 597                   _orig_pc_slot(0),
 598                   _orig_pc_slot_offset_in_bytes(0),
 599                   _has_method_handle_invokes(false),
 600                   _mach_constant_base_node(NULL),
 601                   _node_bundling_limit(0),
 602                   _node_bundling_base(NULL),
 603                   _java_calls(0),
 604                   _inner_loops(0),
 605                   _scratch_const_size(-1),
 606                   _in_scratch_emit_size(false),
 607                   _dead_node_list(comp_arena()),
 608                   _dead_node_count(0),
 609 #ifndef PRODUCT
 610                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
 611                   _printer(IdealGraphPrinter::printer()),
 612 #endif
 613                   _congraph(NULL) {


 614   C = this;
 615 
 616   CompileWrapper cw(this);
 617 #ifndef PRODUCT
 618   if (TimeCompiler2) {
 619     tty->print(" ");
 620     target->holder()->name()->print();
 621     tty->print(".");
 622     target->print_short_name();
 623     tty->print("  ");
 624   }
 625   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
 626   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
 627   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
 628   if (!print_opto_assembly) {
 629     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
 630     if (print_assembly && !Disassembler::can_decode()) {
 631       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
 632       print_opto_assembly = true;
 633     }
 634   }
 635   set_print_assembly(print_opto_assembly);
 636   set_parsed_irreducible_loop(false);
 637 #endif
 638 
 639   if (ProfileTraps) {
 640     // Make sure the method being compiled gets its own MDO,
 641     // so we can at least track the decompile_count().
 642     method()->ensure_method_data();
 643   }
 644 
 645   Init(::AliasLevel);
 646 
 647 
 648   print_compile_messages();
 649 
 650   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
 651     _ilt = InlineTree::build_inline_tree_root();
 652   else
 653     _ilt = NULL;
 654 
 655   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 656   assert(num_alias_types() >= AliasIdxRaw, "");
 657 
 658 #define MINIMUM_NODE_HASH  1023
 659   // Node list that Iterative GVN will start with
 660   Unique_Node_List for_igvn(comp_arena());
 661   set_for_igvn(&for_igvn);
 662 
 663   // GVN that will be run immediately on new nodes
 664   uint estimated_size = method()->code_size()*4+64;
 665   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 666   PhaseGVN gvn(node_arena(), estimated_size);
 667   set_initial_gvn(&gvn);
 668 



 669   { // Scope for timing the parser
 670     TracePhase t3("parse", &_t_parser, true);
 671 
 672     // Put top into the hash table ASAP.
 673     initial_gvn()->transform_no_reclaim(top());
 674 
 675     // Set up tf(), start(), and find a CallGenerator.
 676     CallGenerator* cg = NULL;
 677     if (is_osr_compilation()) {
 678       const TypeTuple *domain = StartOSRNode::osr_domain();
 679       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 680       init_tf(TypeFunc::make(domain, range));
 681       StartNode* s = new (this) StartOSRNode(root(), domain);
 682       initial_gvn()->set_type_bottom(s);
 683       init_start(s);
 684       cg = CallGenerator::for_osr(method(), entry_bci());
 685     } else {
 686       // Normal case.
 687       init_tf(TypeFunc::make(method()));
 688       StartNode* s = new (this) StartNode(root(), tf()->domain());
 689       initial_gvn()->set_type_bottom(s);
 690       init_start(s);
 691       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
 692         // With java.lang.ref.reference.get() we must go through the
 693         // intrinsic when G1 is enabled - even when get() is the root
 694         // method of the compile - so that, if necessary, the value in
 695         // the referent field of the reference object gets recorded by
 696         // the pre-barrier code.
 697         // Specifically, if G1 is enabled, the value in the referent
 698         // field is recorded by the G1 SATB pre barrier. This will
 699         // result in the referent being marked live and the reference
 700         // object removed from the list of discovered references during
 701         // reference processing.
 702         cg = find_intrinsic(method(), false);
 703       }
 704       if (cg == NULL) {
 705         float past_uses = method()->interpreter_invocation_count();
 706         float expected_uses = past_uses;
 707         cg = CallGenerator::for_inline(method(), expected_uses);
 708       }
 709     }
 710     if (failing())  return;
 711     if (cg == NULL) {
 712       record_method_not_compilable_all_tiers("cannot parse method");
 713       return;
 714     }
 715     JVMState* jvms = build_start_state(start(), tf());
 716     if ((jvms = cg->generate(jvms)) == NULL) {
 717       record_method_not_compilable("method parse failed");
 718       return;
 719     }
 720     GraphKit kit(jvms);
 721 
 722     if (!kit.stopped()) {
 723       // Accept return values, and transfer control we know not where.
 724       // This is done by a special, unique ReturnNode bound to root.
 725       return_values(kit.jvms());
 726     }
 727 
 728     if (kit.has_exceptions()) {
 729       // Any exceptions that escape from this call must be rethrown
 730       // to whatever caller is dynamically above us on the stack.
 731       // This is done by a special, unique RethrowNode bound to root.
 732       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 733     }
 734 
 735     if (!failing() && has_stringbuilder()) {
 736       {
 737         // remove useless nodes to make the usage analysis simpler
 738         ResourceMark rm;
 739         PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 740       }
 741 
 742       {
 743         ResourceMark rm;
 744         print_method("Before StringOpts", 3);
 745         PhaseStringOpts pso(initial_gvn(), &for_igvn);
 746         print_method("After StringOpts", 3);
 747       }
 748 
 749       // now inline anything that we skipped the first time around
 750       while (_late_inlines.length() > 0) {
 751         CallGenerator* cg = _late_inlines.pop();
 752         cg->do_late_inline();
 753         if (failing())  return;
 754       }
 755     }
 756     assert(_late_inlines.length() == 0, "should have been processed");

 757 
 758     print_method("Before RemoveUseless", 3);
 759 
 760     // Remove clutter produced by parsing.
 761     if (!failing()) {
 762       ResourceMark rm;
 763       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
 764     }
 765   }
 766 
 767   // Note:  Large methods are capped off in do_one_bytecode().
 768   if (failing())  return;
 769 
 770   // After parsing, node notes are no longer automagic.
 771   // They must be propagated by register_new_node_with_optimizer(),
 772   // clone(), or the like.
 773   set_default_node_notes(NULL);
 774 
 775   for (;;) {
 776     int successes = Inline_Warm();
 777     if (failing())  return;
 778     if (successes == 0)  break;
 779   }
 780 
 781   // Drain the list.
 782   Finish_Warm();
 783 #ifndef PRODUCT
 784   if (_printer) {
 785     _printer->print_inlining(this);
 786   }
 787 #endif
 788 
 789   if (failing())  return;
 790   NOT_PRODUCT( verify_graph_edges(); )
 791 
 792   // Now optimize
 793   Optimize();
 794   if (failing())  return;
 795   NOT_PRODUCT( verify_graph_edges(); )
 796 
 797 #ifndef PRODUCT
 798   if (PrintIdeal) {
 799     ttyLocker ttyl;  // keep the following output all in one block
 800     // This output goes directly to the tty, not the compiler log.
 801     // To enable tools to match it up with the compilation activity,
 802     // be sure to tag this tty output with the compile ID.
 803     if (xtty != NULL) {
 804       xtty->head("ideal compile_id='%d'%s", compile_id(),
 805                  is_osr_compilation()    ? " compile_kind='osr'" :
 806                  "");
 807     }
 808     root()->dump(9999);
 809     if (xtty != NULL) {
 810       xtty->tail("ideal");
 811     }
 812   }
 813 #endif
 814 
 815   // Now that we know the size of all the monitors we can add a fixed slot
 816   // for the original deopt pc.
 817 
 818   _orig_pc_slot =  fixed_slots();
 819   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
 820   set_fixed_slots(next_slot);
 821 
 822   // Now generate code
 823   Code_Gen();
 824   if (failing())  return;
 825 
 826   // Check if we want to skip execution of all compiled code.
 827   {
 828 #ifndef PRODUCT
 829     if (OptoNoExecute) {
 830       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
 831       return;
 832     }
 833     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 834 #endif
 835 
 836     if (is_osr_compilation()) {
 837       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
 838       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
 839     } else {
 840       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
 841       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
 842     }
 843 
 844     env()->register_method(_method, _entry_bci,
 845                            &_code_offsets,
 846                            _orig_pc_slot_offset_in_bytes,
 847                            code_buffer(),
 848                            frame_size_in_words(), _oop_map_set,
 849                            &_handler_table, &_inc_table,
 850                            compiler,
 851                            env()->comp_level(),
 852                            has_unsafe_access(),
 853                            SharedRuntime::is_wide_vector(max_vector_size())
 854                            );
 855 
 856     if (log() != NULL) // Print code cache state into compiler log
 857       log()->code_cache_state();
 858   }
 859 }
 860 
 861 //------------------------------Compile----------------------------------------
 862 // Compile a runtime stub
 863 Compile::Compile( ciEnv* ci_env,
 864                   TypeFunc_generator generator,
 865                   address stub_function,
 866                   const char *stub_name,
 867                   int is_fancy_jump,
 868                   bool pass_tls,
 869                   bool save_arg_registers,
 870                   bool return_pc )
 871   : Phase(Compiler),
 872     _env(ci_env),
 873     _log(ci_env->log()),
 874     _compile_id(-1),
 875     _save_argument_registers(save_arg_registers),
 876     _method(NULL),
 877     _stub_name(stub_name),
 878     _stub_function(stub_function),
 879     _stub_entry_point(NULL),
 880     _entry_bci(InvocationEntryBci),
 881     _initial_gvn(NULL),
 882     _for_igvn(NULL),
 883     _warm_calls(NULL),
 884     _orig_pc_slot(0),
 885     _orig_pc_slot_offset_in_bytes(0),
 886     _subsume_loads(true),
 887     _do_escape_analysis(false),
 888     _failure_reason(NULL),
 889     _code_buffer("Compile::Fill_buffer"),
 890     _has_method_handle_invokes(false),
 891     _mach_constant_base_node(NULL),
 892     _node_bundling_limit(0),
 893     _node_bundling_base(NULL),
 894     _java_calls(0),
 895     _inner_loops(0),
 896 #ifndef PRODUCT
 897     _trace_opto_output(TraceOptoOutput),
 898     _printer(NULL),
 899 #endif
 900     _dead_node_list(comp_arena()),
 901     _dead_node_count(0),
 902     _congraph(NULL) {


 903   C = this;
 904 
 905 #ifndef PRODUCT
 906   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
 907   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
 908   set_print_assembly(PrintFrameConverterAssembly);
 909   set_parsed_irreducible_loop(false);
 910 #endif
 911   CompileWrapper cw(this);
 912   Init(/*AliasLevel=*/ 0);
 913   init_tf((*generator)());
 914 
 915   {
 916     // The following is a dummy for the sake of GraphKit::gen_stub
 917     Unique_Node_List for_igvn(comp_arena());
 918     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
 919     PhaseGVN gvn(Thread::current()->resource_area(),255);
 920     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
 921     gvn.transform_no_reclaim(top());
 922 
 923     GraphKit kit;
 924     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
 925   }
 926 
 927   NOT_PRODUCT( verify_graph_edges(); )
 928   Code_Gen();
 929   if (failing())  return;
 930 
 931 
 932   // Entry point will be accessed using compile->stub_entry_point();
 933   if (code_buffer() == NULL) {
 934     Matcher::soft_match_failure();
 935   } else {
 936     if (PrintAssembly && (WizardMode || Verbose))
 937       tty->print_cr("### Stub::%s", stub_name);
 938 
 939     if (!failing()) {
 940       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
 941 
 942       // Make the NMethod
 943       // For now we mark the frame as never safe for profile stackwalking
 944       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
 945                                                       code_buffer(),
 946                                                       CodeOffsets::frame_never_safe,
 947                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
 948                                                       frame_size_in_words(),
 949                                                       _oop_map_set,
 950                                                       save_arg_registers);
 951       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
 952 
 953       _stub_entry_point = rs->entry_point();
 954     }
 955   }
 956 }
 957 
 958 //------------------------------Init-------------------------------------------
 959 // Prepare for a single compilation
 960 void Compile::Init(int aliaslevel) {
 961   _unique  = 0;
 962   _regalloc = NULL;
 963 
 964   _tf      = NULL;  // filled in later
 965   _top     = NULL;  // cached later
 966   _matcher = NULL;  // filled in later
 967   _cfg     = NULL;  // filled in later
 968 
 969   set_24_bit_selection_and_mode(Use24BitFP, false);
 970 
 971   _node_note_array = NULL;
 972   _default_node_notes = NULL;
 973 
 974   _immutable_memory = NULL; // filled in at first inquiry
 975 
 976   // Globally visible Nodes
 977   // First set TOP to NULL to give safe behavior during creation of RootNode
 978   set_cached_top_node(NULL);
 979   set_root(new (this) RootNode());
 980   // Now that you have a Root to point to, create the real TOP
 981   set_cached_top_node( new (this) ConNode(Type::TOP) );
 982   set_recent_alloc(NULL, NULL);
 983 
 984   // Create Debug Information Recorder to record scopes, oopmaps, etc.
 985   env()->set_oop_recorder(new OopRecorder(env()->arena()));
 986   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
 987   env()->set_dependencies(new Dependencies(env()));
 988 
 989   _fixed_slots = 0;
 990   set_has_split_ifs(false);
 991   set_has_loops(has_method() && method()->has_loops()); // first approximation
 992   set_has_stringbuilder(false);
 993   _trap_can_recompile = false;  // no traps emitted yet
 994   _major_progress = true; // start out assuming good things will happen
 995   set_has_unsafe_access(false);
 996   set_max_vector_size(0);
 997   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
 998   set_decompile_count(0);
 999 
1000   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1001   set_num_loop_opts(LoopOptsCount);
1002   set_do_inlining(Inline);
1003   set_max_inline_size(MaxInlineSize);
1004   set_freq_inline_size(FreqInlineSize);
1005   set_do_scheduling(OptoScheduling);
1006   set_do_count_invocations(false);
1007   set_do_method_data_update(false);
1008 
1009   if (debug_info()->recording_non_safepoints()) {
1010     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1011                         (comp_arena(), 8, 0, NULL));
1012     set_default_node_notes(Node_Notes::make(this));
1013   }
1014 
1015   // // -- Initialize types before each compile --
1016   // // Update cached type information
1017   // if( _method && _method->constants() )
1018   //   Type::update_loaded_types(_method, _method->constants());
1019 
1020   // Init alias_type map.
1021   if (!_do_escape_analysis && aliaslevel == 3)
1022     aliaslevel = 2;  // No unique types without escape analysis
1023   _AliasLevel = aliaslevel;
1024   const int grow_ats = 16;
1025   _max_alias_types = grow_ats;
1026   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1027   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1028   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1029   {
1030     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1031   }
1032   // Initialize the first few types.
1033   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1034   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1035   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1036   _num_alias_types = AliasIdxRaw+1;
1037   // Zero out the alias type cache.
1038   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1039   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1040   probe_alias_cache(NULL)->_index = AliasIdxTop;
1041 
1042   _intrinsics = NULL;
1043   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1044   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
1045   register_library_intrinsics();
1046 }
1047 
1048 //---------------------------init_start----------------------------------------
1049 // Install the StartNode on this compile object.
1050 void Compile::init_start(StartNode* s) {
1051   if (failing())
1052     return; // already failing
1053   assert(s == start(), "");
1054 }
1055 
1056 StartNode* Compile::start() const {
1057   assert(!failing(), "");
1058   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1059     Node* start = root()->fast_out(i);
1060     if( start->is_Start() )
1061       return start->as_Start();
1062   }
1063   ShouldNotReachHere();
1064   return NULL;
1065 }
1066 
1067 //-------------------------------immutable_memory-------------------------------------
1068 // Access immutable memory
1069 Node* Compile::immutable_memory() {
1070   if (_immutable_memory != NULL) {
1071     return _immutable_memory;
1072   }
1073   StartNode* s = start();
1074   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1075     Node *p = s->fast_out(i);
1076     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1077       _immutable_memory = p;
1078       return _immutable_memory;
1079     }
1080   }
1081   ShouldNotReachHere();
1082   return NULL;
1083 }
1084 
1085 //----------------------set_cached_top_node------------------------------------
1086 // Install the cached top node, and make sure Node::is_top works correctly.
1087 void Compile::set_cached_top_node(Node* tn) {
1088   if (tn != NULL)  verify_top(tn);
1089   Node* old_top = _top;
1090   _top = tn;
1091   // Calling Node::setup_is_top allows the nodes the chance to adjust
1092   // their _out arrays.
1093   if (_top != NULL)     _top->setup_is_top();
1094   if (old_top != NULL)  old_top->setup_is_top();
1095   assert(_top == NULL || top()->is_top(), "");
1096 }
1097 
1098 #ifdef ASSERT
1099 uint Compile::count_live_nodes_by_graph_walk() {
1100   Unique_Node_List useful(comp_arena());
1101   // Get useful node list by walking the graph.
1102   identify_useful_nodes(useful);
1103   return useful.size();
1104 }
1105 
1106 void Compile::print_missing_nodes() {
1107 
1108   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1109   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1110     return;
1111   }
1112 
1113   // This is an expensive function. It is executed only when the user
1114   // specifies VerifyIdealNodeCount option or otherwise knows the
1115   // additional work that needs to be done to identify reachable nodes
1116   // by walking the flow graph and find the missing ones using
1117   // _dead_node_list.
1118 
1119   Unique_Node_List useful(comp_arena());
1120   // Get useful node list by walking the graph.
1121   identify_useful_nodes(useful);
1122 
1123   uint l_nodes = C->live_nodes();
1124   uint l_nodes_by_walk = useful.size();
1125 
1126   if (l_nodes != l_nodes_by_walk) {
1127     if (_log != NULL) {
1128       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1129       _log->stamp();
1130       _log->end_head();
1131     }
1132     VectorSet& useful_member_set = useful.member_set();
1133     int last_idx = l_nodes_by_walk;
1134     for (int i = 0; i < last_idx; i++) {
1135       if (useful_member_set.test(i)) {
1136         if (_dead_node_list.test(i)) {
1137           if (_log != NULL) {
1138             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1139           }
1140           if (PrintIdealNodeCount) {
1141             // Print the log message to tty
1142               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1143               useful.at(i)->dump();
1144           }
1145         }
1146       }
1147       else if (! _dead_node_list.test(i)) {
1148         if (_log != NULL) {
1149           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1150         }
1151         if (PrintIdealNodeCount) {
1152           // Print the log message to tty
1153           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1154         }
1155       }
1156     }
1157     if (_log != NULL) {
1158       _log->tail("mismatched_nodes");
1159     }
1160   }
1161 }
1162 #endif
1163 
1164 #ifndef PRODUCT
1165 void Compile::verify_top(Node* tn) const {
1166   if (tn != NULL) {
1167     assert(tn->is_Con(), "top node must be a constant");
1168     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1169     assert(tn->in(0) != NULL, "must have live top node");
1170   }
1171 }
1172 #endif
1173 
1174 
1175 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1176 
1177 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1178   guarantee(arr != NULL, "");
1179   int num_blocks = arr->length();
1180   if (grow_by < num_blocks)  grow_by = num_blocks;
1181   int num_notes = grow_by * _node_notes_block_size;
1182   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1183   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1184   while (num_notes > 0) {
1185     arr->append(notes);
1186     notes     += _node_notes_block_size;
1187     num_notes -= _node_notes_block_size;
1188   }
1189   assert(num_notes == 0, "exact multiple, please");
1190 }
1191 
1192 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1193   if (source == NULL || dest == NULL)  return false;
1194 
1195   if (dest->is_Con())
1196     return false;               // Do not push debug info onto constants.
1197 
1198 #ifdef ASSERT
1199   // Leave a bread crumb trail pointing to the original node:
1200   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1201     dest->set_debug_orig(source);
1202   }
1203 #endif
1204 
1205   if (node_note_array() == NULL)
1206     return false;               // Not collecting any notes now.
1207 
1208   // This is a copy onto a pre-existing node, which may already have notes.
1209   // If both nodes have notes, do not overwrite any pre-existing notes.
1210   Node_Notes* source_notes = node_notes_at(source->_idx);
1211   if (source_notes == NULL || source_notes->is_clear())  return false;
1212   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1213   if (dest_notes == NULL || dest_notes->is_clear()) {
1214     return set_node_notes_at(dest->_idx, source_notes);
1215   }
1216 
1217   Node_Notes merged_notes = (*source_notes);
1218   // The order of operations here ensures that dest notes will win...
1219   merged_notes.update_from(dest_notes);
1220   return set_node_notes_at(dest->_idx, &merged_notes);
1221 }
1222 
1223 
1224 //--------------------------allow_range_check_smearing-------------------------
1225 // Gating condition for coalescing similar range checks.
1226 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1227 // single covering check that is at least as strong as any of them.
1228 // If the optimization succeeds, the simplified (strengthened) range check
1229 // will always succeed.  If it fails, we will deopt, and then give up
1230 // on the optimization.
1231 bool Compile::allow_range_check_smearing() const {
1232   // If this method has already thrown a range-check,
1233   // assume it was because we already tried range smearing
1234   // and it failed.
1235   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1236   return !already_trapped;
1237 }
1238 
1239 
1240 //------------------------------flatten_alias_type-----------------------------
1241 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1242   int offset = tj->offset();
1243   TypePtr::PTR ptr = tj->ptr();
1244 
1245   // Known instance (scalarizable allocation) alias only with itself.
1246   bool is_known_inst = tj->isa_oopptr() != NULL &&
1247                        tj->is_oopptr()->is_known_instance();
1248 
1249   // Process weird unsafe references.
1250   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1251     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1252     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1253     tj = TypeOopPtr::BOTTOM;
1254     ptr = tj->ptr();
1255     offset = tj->offset();
1256   }
1257 
1258   // Array pointers need some flattening
1259   const TypeAryPtr *ta = tj->isa_aryptr();
1260   if( ta && is_known_inst ) {
1261     if ( offset != Type::OffsetBot &&
1262          offset > arrayOopDesc::length_offset_in_bytes() ) {
1263       offset = Type::OffsetBot; // Flatten constant access into array body only
1264       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1265     }
1266   } else if( ta && _AliasLevel >= 2 ) {
1267     // For arrays indexed by constant indices, we flatten the alias
1268     // space to include all of the array body.  Only the header, klass
1269     // and array length can be accessed un-aliased.
1270     if( offset != Type::OffsetBot ) {
1271       if( ta->const_oop() ) { // MethodData* or Method*
1272         offset = Type::OffsetBot;   // Flatten constant access into array body
1273         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1274       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1275         // range is OK as-is.
1276         tj = ta = TypeAryPtr::RANGE;
1277       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1278         tj = TypeInstPtr::KLASS; // all klass loads look alike
1279         ta = TypeAryPtr::RANGE; // generic ignored junk
1280         ptr = TypePtr::BotPTR;
1281       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1282         tj = TypeInstPtr::MARK;
1283         ta = TypeAryPtr::RANGE; // generic ignored junk
1284         ptr = TypePtr::BotPTR;
1285       } else {                  // Random constant offset into array body
1286         offset = Type::OffsetBot;   // Flatten constant access into array body
1287         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1288       }
1289     }
1290     // Arrays of fixed size alias with arrays of unknown size.
1291     if (ta->size() != TypeInt::POS) {
1292       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1293       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1294     }
1295     // Arrays of known objects become arrays of unknown objects.
1296     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1297       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1298       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1299     }
1300     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1301       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1302       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1303     }
1304     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1305     // cannot be distinguished by bytecode alone.
1306     if (ta->elem() == TypeInt::BOOL) {
1307       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1308       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1309       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1310     }
1311     // During the 2nd round of IterGVN, NotNull castings are removed.
1312     // Make sure the Bottom and NotNull variants alias the same.
1313     // Also, make sure exact and non-exact variants alias the same.
1314     if( ptr == TypePtr::NotNull || ta->klass_is_exact() ) {
1315       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1316     }
1317   }
1318 
1319   // Oop pointers need some flattening
1320   const TypeInstPtr *to = tj->isa_instptr();
1321   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1322     ciInstanceKlass *k = to->klass()->as_instance_klass();
1323     if( ptr == TypePtr::Constant ) {
1324       if (to->klass() != ciEnv::current()->Class_klass() ||
1325           offset < k->size_helper() * wordSize) {
1326         // No constant oop pointers (such as Strings); they alias with
1327         // unknown strings.
1328         assert(!is_known_inst, "not scalarizable allocation");
1329         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1330       }
1331     } else if( is_known_inst ) {
1332       tj = to; // Keep NotNull and klass_is_exact for instance type
1333     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1334       // During the 2nd round of IterGVN, NotNull castings are removed.
1335       // Make sure the Bottom and NotNull variants alias the same.
1336       // Also, make sure exact and non-exact variants alias the same.
1337       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1338     }
1339     // Canonicalize the holder of this field
1340     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1341       // First handle header references such as a LoadKlassNode, even if the
1342       // object's klass is unloaded at compile time (4965979).
1343       if (!is_known_inst) { // Do it only for non-instance types
1344         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1345       }
1346     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1347       // Static fields are in the space above the normal instance
1348       // fields in the java.lang.Class instance.
1349       if (to->klass() != ciEnv::current()->Class_klass()) {
1350         to = NULL;
1351         tj = TypeOopPtr::BOTTOM;
1352         offset = tj->offset();
1353       }
1354     } else {
1355       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1356       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1357         if( is_known_inst ) {
1358           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1359         } else {
1360           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1361         }
1362       }
1363     }
1364   }
1365 
1366   // Klass pointers to object array klasses need some flattening
1367   const TypeKlassPtr *tk = tj->isa_klassptr();
1368   if( tk ) {
1369     // If we are referencing a field within a Klass, we need
1370     // to assume the worst case of an Object.  Both exact and
1371     // inexact types must flatten to the same alias class so
1372     // use NotNull as the PTR.
1373     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1374 
1375       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1376                                    TypeKlassPtr::OBJECT->klass(),
1377                                    offset);
1378     }
1379 
1380     ciKlass* klass = tk->klass();
1381     if( klass->is_obj_array_klass() ) {
1382       ciKlass* k = TypeAryPtr::OOPS->klass();
1383       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1384         k = TypeInstPtr::BOTTOM->klass();
1385       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1386     }
1387 
1388     // Check for precise loads from the primary supertype array and force them
1389     // to the supertype cache alias index.  Check for generic array loads from
1390     // the primary supertype array and also force them to the supertype cache
1391     // alias index.  Since the same load can reach both, we need to merge
1392     // these 2 disparate memories into the same alias class.  Since the
1393     // primary supertype array is read-only, there's no chance of confusion
1394     // where we bypass an array load and an array store.
1395     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1396     if (offset == Type::OffsetBot ||
1397         (offset >= primary_supers_offset &&
1398          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1399         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1400       offset = in_bytes(Klass::secondary_super_cache_offset());
1401       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1402     }
1403   }
1404 
1405   // Flatten all Raw pointers together.
1406   if (tj->base() == Type::RawPtr)
1407     tj = TypeRawPtr::BOTTOM;
1408 
1409   if (tj->base() == Type::AnyPtr)
1410     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1411 
1412   // Flatten all to bottom for now
1413   switch( _AliasLevel ) {
1414   case 0:
1415     tj = TypePtr::BOTTOM;
1416     break;
1417   case 1:                       // Flatten to: oop, static, field or array
1418     switch (tj->base()) {
1419     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1420     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1421     case Type::AryPtr:   // do not distinguish arrays at all
1422     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1423     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1424     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1425     default: ShouldNotReachHere();
1426     }
1427     break;
1428   case 2:                       // No collapsing at level 2; keep all splits
1429   case 3:                       // No collapsing at level 3; keep all splits
1430     break;
1431   default:
1432     Unimplemented();
1433   }
1434 
1435   offset = tj->offset();
1436   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1437 
1438   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1439           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1440           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1441           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1442           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1443           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1444           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
1445           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1446   assert( tj->ptr() != TypePtr::TopPTR &&
1447           tj->ptr() != TypePtr::AnyNull &&
1448           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1449 //    assert( tj->ptr() != TypePtr::Constant ||
1450 //            tj->base() == Type::RawPtr ||
1451 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1452 
1453   return tj;
1454 }
1455 
1456 void Compile::AliasType::Init(int i, const TypePtr* at) {
1457   _index = i;
1458   _adr_type = at;
1459   _field = NULL;
1460   _is_rewritable = true; // default
1461   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1462   if (atoop != NULL && atoop->is_known_instance()) {
1463     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1464     _general_index = Compile::current()->get_alias_index(gt);
1465   } else {
1466     _general_index = 0;
1467   }
1468 }
1469 
1470 //---------------------------------print_on------------------------------------
1471 #ifndef PRODUCT
1472 void Compile::AliasType::print_on(outputStream* st) {
1473   if (index() < 10)
1474         st->print("@ <%d> ", index());
1475   else  st->print("@ <%d>",  index());
1476   st->print(is_rewritable() ? "   " : " RO");
1477   int offset = adr_type()->offset();
1478   if (offset == Type::OffsetBot)
1479         st->print(" +any");
1480   else  st->print(" +%-3d", offset);
1481   st->print(" in ");
1482   adr_type()->dump_on(st);
1483   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1484   if (field() != NULL && tjp) {
1485     if (tjp->klass()  != field()->holder() ||
1486         tjp->offset() != field()->offset_in_bytes()) {
1487       st->print(" != ");
1488       field()->print();
1489       st->print(" ***");
1490     }
1491   }
1492 }
1493 
1494 void print_alias_types() {
1495   Compile* C = Compile::current();
1496   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1497   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1498     C->alias_type(idx)->print_on(tty);
1499     tty->cr();
1500   }
1501 }
1502 #endif
1503 
1504 
1505 //----------------------------probe_alias_cache--------------------------------
1506 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1507   intptr_t key = (intptr_t) adr_type;
1508   key ^= key >> logAliasCacheSize;
1509   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1510 }
1511 
1512 
1513 //-----------------------------grow_alias_types--------------------------------
1514 void Compile::grow_alias_types() {
1515   const int old_ats  = _max_alias_types; // how many before?
1516   const int new_ats  = old_ats;          // how many more?
1517   const int grow_ats = old_ats+new_ats;  // how many now?
1518   _max_alias_types = grow_ats;
1519   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1520   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1521   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1522   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1523 }
1524 
1525 
1526 //--------------------------------find_alias_type------------------------------
1527 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1528   if (_AliasLevel == 0)
1529     return alias_type(AliasIdxBot);
1530 
1531   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1532   if (ace->_adr_type == adr_type) {
1533     return alias_type(ace->_index);
1534   }
1535 
1536   // Handle special cases.
1537   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1538   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1539 
1540   // Do it the slow way.
1541   const TypePtr* flat = flatten_alias_type(adr_type);
1542 
1543 #ifdef ASSERT
1544   assert(flat == flatten_alias_type(flat), "idempotent");
1545   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
1546   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1547     const TypeOopPtr* foop = flat->is_oopptr();
1548     // Scalarizable allocations have exact klass always.
1549     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1550     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1551     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1552   }
1553   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1554 #endif
1555 
1556   int idx = AliasIdxTop;
1557   for (int i = 0; i < num_alias_types(); i++) {
1558     if (alias_type(i)->adr_type() == flat) {
1559       idx = i;
1560       break;
1561     }
1562   }
1563 
1564   if (idx == AliasIdxTop) {
1565     if (no_create)  return NULL;
1566     // Grow the array if necessary.
1567     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1568     // Add a new alias type.
1569     idx = _num_alias_types++;
1570     _alias_types[idx]->Init(idx, flat);
1571     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1572     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1573     if (flat->isa_instptr()) {
1574       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1575           && flat->is_instptr()->klass() == env()->Class_klass())
1576         alias_type(idx)->set_rewritable(false);
1577     }
1578     if (flat->isa_klassptr()) {
1579       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1580         alias_type(idx)->set_rewritable(false);
1581       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1582         alias_type(idx)->set_rewritable(false);
1583       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1584         alias_type(idx)->set_rewritable(false);
1585       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1586         alias_type(idx)->set_rewritable(false);
1587     }
1588     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1589     // but the base pointer type is not distinctive enough to identify
1590     // references into JavaThread.)
1591 
1592     // Check for final fields.
1593     const TypeInstPtr* tinst = flat->isa_instptr();
1594     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1595       ciField* field;
1596       if (tinst->const_oop() != NULL &&
1597           tinst->klass() == ciEnv::current()->Class_klass() &&
1598           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1599         // static field
1600         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1601         field = k->get_field_by_offset(tinst->offset(), true);
1602       } else {
1603         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1604         field = k->get_field_by_offset(tinst->offset(), false);
1605       }
1606       assert(field == NULL ||
1607              original_field == NULL ||
1608              (field->holder() == original_field->holder() &&
1609               field->offset() == original_field->offset() &&
1610               field->is_static() == original_field->is_static()), "wrong field?");
1611       // Set field() and is_rewritable() attributes.
1612       if (field != NULL)  alias_type(idx)->set_field(field);
1613     }
1614   }
1615 
1616   // Fill the cache for next time.
1617   ace->_adr_type = adr_type;
1618   ace->_index    = idx;
1619   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1620 
1621   // Might as well try to fill the cache for the flattened version, too.
1622   AliasCacheEntry* face = probe_alias_cache(flat);
1623   if (face->_adr_type == NULL) {
1624     face->_adr_type = flat;
1625     face->_index    = idx;
1626     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1627   }
1628 
1629   return alias_type(idx);
1630 }
1631 
1632 
1633 Compile::AliasType* Compile::alias_type(ciField* field) {
1634   const TypeOopPtr* t;
1635   if (field->is_static())
1636     t = TypeInstPtr::make(field->holder()->java_mirror());
1637   else
1638     t = TypeOopPtr::make_from_klass_raw(field->holder());
1639   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1640   assert(field->is_final() == !atp->is_rewritable(), "must get the rewritable bits correct");
1641   return atp;
1642 }
1643 
1644 
1645 //------------------------------have_alias_type--------------------------------
1646 bool Compile::have_alias_type(const TypePtr* adr_type) {
1647   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1648   if (ace->_adr_type == adr_type) {
1649     return true;
1650   }
1651 
1652   // Handle special cases.
1653   if (adr_type == NULL)             return true;
1654   if (adr_type == TypePtr::BOTTOM)  return true;
1655 
1656   return find_alias_type(adr_type, true, NULL) != NULL;
1657 }
1658 
1659 //-----------------------------must_alias--------------------------------------
1660 // True if all values of the given address type are in the given alias category.
1661 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1662   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1663   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1664   if (alias_idx == AliasIdxTop)         return false; // the empty category
1665   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1666 
1667   // the only remaining possible overlap is identity
1668   int adr_idx = get_alias_index(adr_type);
1669   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1670   assert(adr_idx == alias_idx ||
1671          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1672           && adr_type                       != TypeOopPtr::BOTTOM),
1673          "should not be testing for overlap with an unsafe pointer");
1674   return adr_idx == alias_idx;
1675 }
1676 
1677 //------------------------------can_alias--------------------------------------
1678 // True if any values of the given address type are in the given alias category.
1679 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1680   if (alias_idx == AliasIdxTop)         return false; // the empty category
1681   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1682   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1683   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
1684 
1685   // the only remaining possible overlap is identity
1686   int adr_idx = get_alias_index(adr_type);
1687   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1688   return adr_idx == alias_idx;
1689 }
1690 
1691 
1692 
1693 //---------------------------pop_warm_call-------------------------------------
1694 WarmCallInfo* Compile::pop_warm_call() {
1695   WarmCallInfo* wci = _warm_calls;
1696   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1697   return wci;
1698 }
1699 
1700 //----------------------------Inline_Warm--------------------------------------
1701 int Compile::Inline_Warm() {
1702   // If there is room, try to inline some more warm call sites.
1703   // %%% Do a graph index compaction pass when we think we're out of space?
1704   if (!InlineWarmCalls)  return 0;
1705 
1706   int calls_made_hot = 0;
1707   int room_to_grow   = NodeCountInliningCutoff - unique();
1708   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1709   int amount_grown   = 0;
1710   WarmCallInfo* call;
1711   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1712     int est_size = (int)call->size();
1713     if (est_size > (room_to_grow - amount_grown)) {
1714       // This one won't fit anyway.  Get rid of it.
1715       call->make_cold();
1716       continue;
1717     }
1718     call->make_hot();
1719     calls_made_hot++;
1720     amount_grown   += est_size;
1721     amount_to_grow -= est_size;
1722   }
1723 
1724   if (calls_made_hot > 0)  set_major_progress();
1725   return calls_made_hot;
1726 }
1727 
1728 
1729 //----------------------------Finish_Warm--------------------------------------
1730 void Compile::Finish_Warm() {
1731   if (!InlineWarmCalls)  return;
1732   if (failing())  return;
1733   if (warm_calls() == NULL)  return;
1734 
1735   // Clean up loose ends, if we are out of space for inlining.
1736   WarmCallInfo* call;
1737   while ((call = pop_warm_call()) != NULL) {
1738     call->make_cold();
1739   }
1740 }
1741 
1742 //---------------------cleanup_loop_predicates-----------------------
1743 // Remove the opaque nodes that protect the predicates so that all unused
1744 // checks and uncommon_traps will be eliminated from the ideal graph
1745 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1746   if (predicate_count()==0) return;
1747   for (int i = predicate_count(); i > 0; i--) {
1748     Node * n = predicate_opaque1_node(i-1);
1749     assert(n->Opcode() == Op_Opaque1, "must be");
1750     igvn.replace_node(n, n->in(1));
1751   }
1752   assert(predicate_count()==0, "should be clean!");
1753 }
1754 
1755 //------------------------------Optimize---------------------------------------
1756 // Given a graph, optimize it.
1757 void Compile::Optimize() {
1758   TracePhase t1("optimizer", &_t_optimizer, true);
1759 
1760 #ifndef PRODUCT
1761   if (env()->break_at_compile()) {
1762     BREAKPOINT;
1763   }
1764 
1765 #endif
1766 
1767   ResourceMark rm;
1768   int          loop_opts_cnt;
1769 
1770   NOT_PRODUCT( verify_graph_edges(); )
1771 
1772   print_method("After Parsing");
1773 
1774  {
1775   // Iterative Global Value Numbering, including ideal transforms
1776   // Initialize IterGVN with types and values from parse-time GVN
1777   PhaseIterGVN igvn(initial_gvn());
1778   {
1779     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
1780     igvn.optimize();
1781   }
1782 
1783   print_method("Iter GVN 1", 2);
1784 
1785   if (failing())  return;
1786 
1787   // Perform escape analysis
1788   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
1789     if (has_loops()) {
1790       // Cleanup graph (remove dead nodes).
1791       TracePhase t2("idealLoop", &_t_idealLoop, true);
1792       PhaseIdealLoop ideal_loop( igvn, false, true );
1793       if (major_progress()) print_method("PhaseIdealLoop before EA", 2);
1794       if (failing())  return;
1795     }
1796     ConnectionGraph::do_analysis(this, &igvn);
1797 
1798     if (failing())  return;
1799 
1800     // Optimize out fields loads from scalar replaceable allocations.
1801     igvn.optimize();
1802     print_method("Iter GVN after EA", 2);
1803 
1804     if (failing())  return;
1805 
1806     if (congraph() != NULL && macro_count() > 0) {
1807       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
1808       PhaseMacroExpand mexp(igvn);
1809       mexp.eliminate_macro_nodes();
1810       igvn.set_delay_transform(false);
1811 
1812       igvn.optimize();
1813       print_method("Iter GVN after eliminating allocations and locks", 2);
1814 
1815       if (failing())  return;
1816     }
1817   }
1818 
1819   // Loop transforms on the ideal graph.  Range Check Elimination,
1820   // peeling, unrolling, etc.
1821 
1822   // Set loop opts counter
1823   loop_opts_cnt = num_loop_opts();
1824   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
1825     {
1826       TracePhase t2("idealLoop", &_t_idealLoop, true);
1827       PhaseIdealLoop ideal_loop( igvn, true );
1828       loop_opts_cnt--;
1829       if (major_progress()) print_method("PhaseIdealLoop 1", 2);
1830       if (failing())  return;
1831     }
1832     // Loop opts pass if partial peeling occurred in previous pass
1833     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
1834       TracePhase t3("idealLoop", &_t_idealLoop, true);
1835       PhaseIdealLoop ideal_loop( igvn, false );
1836       loop_opts_cnt--;
1837       if (major_progress()) print_method("PhaseIdealLoop 2", 2);
1838       if (failing())  return;
1839     }
1840     // Loop opts pass for loop-unrolling before CCP
1841     if(major_progress() && (loop_opts_cnt > 0)) {
1842       TracePhase t4("idealLoop", &_t_idealLoop, true);
1843       PhaseIdealLoop ideal_loop( igvn, false );
1844       loop_opts_cnt--;
1845       if (major_progress()) print_method("PhaseIdealLoop 3", 2);
1846     }
1847     if (!failing()) {
1848       // Verify that last round of loop opts produced a valid graph
1849       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
1850       PhaseIdealLoop::verify(igvn);
1851     }
1852   }
1853   if (failing())  return;
1854 
1855   // Conditional Constant Propagation;
1856   PhaseCCP ccp( &igvn );
1857   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
1858   {
1859     TracePhase t2("ccp", &_t_ccp, true);
1860     ccp.do_transform();
1861   }
1862   print_method("PhaseCPP 1", 2);
1863 
1864   assert( true, "Break here to ccp.dump_old2new_map()");
1865 
1866   // Iterative Global Value Numbering, including ideal transforms
1867   {
1868     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
1869     igvn = ccp;
1870     igvn.optimize();
1871   }
1872 
1873   print_method("Iter GVN 2", 2);
1874 
1875   if (failing())  return;
1876 
1877   // Loop transforms on the ideal graph.  Range Check Elimination,
1878   // peeling, unrolling, etc.
1879   if(loop_opts_cnt > 0) {
1880     debug_only( int cnt = 0; );
1881     while(major_progress() && (loop_opts_cnt > 0)) {
1882       TracePhase t2("idealLoop", &_t_idealLoop, true);
1883       assert( cnt++ < 40, "infinite cycle in loop optimization" );
1884       PhaseIdealLoop ideal_loop( igvn, true);
1885       loop_opts_cnt--;
1886       if (major_progress()) print_method("PhaseIdealLoop iterations", 2);
1887       if (failing())  return;
1888     }
1889   }
1890 
1891   {
1892     // Verify that all previous optimizations produced a valid graph
1893     // at least to this point, even if no loop optimizations were done.
1894     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
1895     PhaseIdealLoop::verify(igvn);
1896   }
1897 
1898   {
1899     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
1900     PhaseMacroExpand  mex(igvn);
1901     if (mex.expand_macro_nodes()) {
1902       assert(failing(), "must bail out w/ explicit message");
1903       return;
1904     }
1905   }
1906 
1907  } // (End scope of igvn; run destructor if necessary for asserts.)
1908 
1909   // A method with only infinite loops has no edges entering loops from root
1910   {
1911     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
1912     if (final_graph_reshaping()) {
1913       assert(failing(), "must bail out w/ explicit message");
1914       return;
1915     }
1916   }
1917 
1918   print_method("Optimize finished", 2);
1919 }
1920 
1921 
1922 //------------------------------Code_Gen---------------------------------------
1923 // Given a graph, generate code for it
1924 void Compile::Code_Gen() {
1925   if (failing())  return;
1926 
1927   // Perform instruction selection.  You might think we could reclaim Matcher
1928   // memory PDQ, but actually the Matcher is used in generating spill code.
1929   // Internals of the Matcher (including some VectorSets) must remain live
1930   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
1931   // set a bit in reclaimed memory.
1932 
1933   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1934   // nodes.  Mapping is only valid at the root of each matched subtree.
1935   NOT_PRODUCT( verify_graph_edges(); )
1936 
1937   Node_List proj_list;
1938   Matcher m(proj_list);
1939   _matcher = &m;
1940   {
1941     TracePhase t2("matcher", &_t_matcher, true);
1942     m.match();
1943   }
1944   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
1945   // nodes.  Mapping is only valid at the root of each matched subtree.
1946   NOT_PRODUCT( verify_graph_edges(); )
1947 
1948   // If you have too many nodes, or if matching has failed, bail out
1949   check_node_count(0, "out of nodes matching instructions");
1950   if (failing())  return;
1951 
1952   // Build a proper-looking CFG
1953   PhaseCFG cfg(node_arena(), root(), m);
1954   _cfg = &cfg;
1955   {
1956     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
1957     cfg.Dominators();
1958     if (failing())  return;
1959 
1960     NOT_PRODUCT( verify_graph_edges(); )
1961 
1962     cfg.Estimate_Block_Frequency();
1963     cfg.GlobalCodeMotion(m,unique(),proj_list);
1964     if (failing())  return;
1965 
1966     print_method("Global code motion", 2);
1967 
1968     NOT_PRODUCT( verify_graph_edges(); )
1969 
1970     debug_only( cfg.verify(); )
1971   }
1972   NOT_PRODUCT( verify_graph_edges(); )
1973 
1974   PhaseChaitin regalloc(unique(),cfg,m);
1975   _regalloc = &regalloc;
1976   {
1977     TracePhase t2("regalloc", &_t_registerAllocation, true);
1978     // Perform any platform dependent preallocation actions.  This is used,
1979     // for example, to avoid taking an implicit null pointer exception
1980     // using the frame pointer on win95.
1981     _regalloc->pd_preallocate_hook();
1982 
1983     // Perform register allocation.  After Chaitin, use-def chains are
1984     // no longer accurate (at spill code) and so must be ignored.
1985     // Node->LRG->reg mappings are still accurate.
1986     _regalloc->Register_Allocate();
1987 
1988     // Bail out if the allocator builds too many nodes
1989     if (failing())  return;
1990   }
1991 
1992   // Prior to register allocation we kept empty basic blocks in case the
1993   // the allocator needed a place to spill.  After register allocation we
1994   // are not adding any new instructions.  If any basic block is empty, we
1995   // can now safely remove it.
1996   {
1997     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
1998     cfg.remove_empty();
1999     if (do_freq_based_layout()) {
2000       PhaseBlockLayout layout(cfg);
2001     } else {
2002       cfg.set_loop_alignment();
2003     }
2004     cfg.fixup_flow();
2005   }
2006 
2007   // Perform any platform dependent postallocation verifications.
2008   debug_only( _regalloc->pd_postallocate_verify_hook(); )
2009 
2010   // Apply peephole optimizations
2011   if( OptoPeephole ) {
2012     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2013     PhasePeephole peep( _regalloc, cfg);
2014     peep.do_transform();
2015   }
2016 
2017   // Convert Nodes to instruction bits in a buffer
2018   {
2019     // %%%% workspace merge brought two timers together for one job
2020     TracePhase t2a("output", &_t_output, true);
2021     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2022     Output();
2023   }
2024 
2025   print_method("Final Code");
2026 
2027   // He's dead, Jim.
2028   _cfg     = (PhaseCFG*)0xdeadbeef;
2029   _regalloc = (PhaseChaitin*)0xdeadbeef;
2030 }
2031 
2032 
2033 //------------------------------dump_asm---------------------------------------
2034 // Dump formatted assembly
2035 #ifndef PRODUCT
2036 void Compile::dump_asm(int *pcs, uint pc_limit) {
2037   bool cut_short = false;
2038   tty->print_cr("#");
2039   tty->print("#  ");  _tf->dump();  tty->cr();
2040   tty->print_cr("#");
2041 
2042   // For all blocks
2043   int pc = 0x0;                 // Program counter
2044   char starts_bundle = ' ';
2045   _regalloc->dump_frame();
2046 
2047   Node *n = NULL;
2048   for( uint i=0; i<_cfg->_num_blocks; i++ ) {
2049     if (VMThread::should_terminate()) { cut_short = true; break; }
2050     Block *b = _cfg->_blocks[i];
2051     if (b->is_connector() && !Verbose) continue;
2052     n = b->_nodes[0];
2053     if (pcs && n->_idx < pc_limit)
2054       tty->print("%3.3x   ", pcs[n->_idx]);
2055     else
2056       tty->print("      ");
2057     b->dump_head( &_cfg->_bbs );
2058     if (b->is_connector()) {
2059       tty->print_cr("        # Empty connector block");
2060     } else if (b->num_preds() == 2 && b->pred(1)->is_CatchProj() && b->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2061       tty->print_cr("        # Block is sole successor of call");
2062     }
2063 
2064     // For all instructions
2065     Node *delay = NULL;
2066     for( uint j = 0; j<b->_nodes.size(); j++ ) {
2067       if (VMThread::should_terminate()) { cut_short = true; break; }
2068       n = b->_nodes[j];
2069       if (valid_bundle_info(n)) {
2070         Bundle *bundle = node_bundling(n);
2071         if (bundle->used_in_unconditional_delay()) {
2072           delay = n;
2073           continue;
2074         }
2075         if (bundle->starts_bundle())
2076           starts_bundle = '+';
2077       }
2078 
2079       if (WizardMode) n->dump();
2080 
2081       if( !n->is_Region() &&    // Dont print in the Assembly
2082           !n->is_Phi() &&       // a few noisely useless nodes
2083           !n->is_Proj() &&
2084           !n->is_MachTemp() &&
2085           !n->is_SafePointScalarObject() &&
2086           !n->is_Catch() &&     // Would be nice to print exception table targets
2087           !n->is_MergeMem() &&  // Not very interesting
2088           !n->is_top() &&       // Debug info table constants
2089           !(n->is_Con() && !n->is_Mach())// Debug info table constants
2090           ) {
2091         if (pcs && n->_idx < pc_limit)
2092           tty->print("%3.3x", pcs[n->_idx]);
2093         else
2094           tty->print("   ");
2095         tty->print(" %c ", starts_bundle);
2096         starts_bundle = ' ';
2097         tty->print("\t");
2098         n->format(_regalloc, tty);
2099         tty->cr();
2100       }
2101 
2102       // If we have an instruction with a delay slot, and have seen a delay,
2103       // then back up and print it
2104       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2105         assert(delay != NULL, "no unconditional delay instruction");
2106         if (WizardMode) delay->dump();
2107 
2108         if (node_bundling(delay)->starts_bundle())
2109           starts_bundle = '+';
2110         if (pcs && n->_idx < pc_limit)
2111           tty->print("%3.3x", pcs[n->_idx]);
2112         else
2113           tty->print("   ");
2114         tty->print(" %c ", starts_bundle);
2115         starts_bundle = ' ';
2116         tty->print("\t");
2117         delay->format(_regalloc, tty);
2118         tty->print_cr("");
2119         delay = NULL;
2120       }
2121 
2122       // Dump the exception table as well
2123       if( n->is_Catch() && (Verbose || WizardMode) ) {
2124         // Print the exception table for this offset
2125         _handler_table.print_subtable_for(pc);
2126       }
2127     }
2128 
2129     if (pcs && n->_idx < pc_limit)
2130       tty->print_cr("%3.3x", pcs[n->_idx]);
2131     else
2132       tty->print_cr("");
2133 
2134     assert(cut_short || delay == NULL, "no unconditional delay branch");
2135 
2136   } // End of per-block dump
2137   tty->print_cr("");
2138 
2139   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
2140 }
2141 #endif
2142 
2143 //------------------------------Final_Reshape_Counts---------------------------
2144 // This class defines counters to help identify when a method
2145 // may/must be executed using hardware with only 24-bit precision.
2146 struct Final_Reshape_Counts : public StackObj {
2147   int  _call_count;             // count non-inlined 'common' calls
2148   int  _float_count;            // count float ops requiring 24-bit precision
2149   int  _double_count;           // count double ops requiring more precision
2150   int  _java_call_count;        // count non-inlined 'java' calls
2151   int  _inner_loop_count;       // count loops which need alignment
2152   VectorSet _visited;           // Visitation flags
2153   Node_List _tests;             // Set of IfNodes & PCTableNodes
2154 
2155   Final_Reshape_Counts() :
2156     _call_count(0), _float_count(0), _double_count(0),
2157     _java_call_count(0), _inner_loop_count(0),
2158     _visited( Thread::current()->resource_area() ) { }
2159 
2160   void inc_call_count  () { _call_count  ++; }
2161   void inc_float_count () { _float_count ++; }
2162   void inc_double_count() { _double_count++; }
2163   void inc_java_call_count() { _java_call_count++; }
2164   void inc_inner_loop_count() { _inner_loop_count++; }
2165 
2166   int  get_call_count  () const { return _call_count  ; }
2167   int  get_float_count () const { return _float_count ; }
2168   int  get_double_count() const { return _double_count; }
2169   int  get_java_call_count() const { return _java_call_count; }
2170   int  get_inner_loop_count() const { return _inner_loop_count; }
2171 };
2172 
2173 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2174   ciInstanceKlass *k = tp->klass()->as_instance_klass();
2175   // Make sure the offset goes inside the instance layout.
2176   return k->contains_field_offset(tp->offset());
2177   // Note that OffsetBot and OffsetTop are very negative.
2178 }
2179 
2180 // Eliminate trivially redundant StoreCMs and accumulate their
2181 // precedence edges.
2182 void Compile::eliminate_redundant_card_marks(Node* n) {
2183   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2184   if (n->in(MemNode::Address)->outcnt() > 1) {
2185     // There are multiple users of the same address so it might be
2186     // possible to eliminate some of the StoreCMs
2187     Node* mem = n->in(MemNode::Memory);
2188     Node* adr = n->in(MemNode::Address);
2189     Node* val = n->in(MemNode::ValueIn);
2190     Node* prev = n;
2191     bool done = false;
2192     // Walk the chain of StoreCMs eliminating ones that match.  As
2193     // long as it's a chain of single users then the optimization is
2194     // safe.  Eliminating partially redundant StoreCMs would require
2195     // cloning copies down the other paths.
2196     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2197       if (adr == mem->in(MemNode::Address) &&
2198           val == mem->in(MemNode::ValueIn)) {
2199         // redundant StoreCM
2200         if (mem->req() > MemNode::OopStore) {
2201           // Hasn't been processed by this code yet.
2202           n->add_prec(mem->in(MemNode::OopStore));
2203         } else {
2204           // Already converted to precedence edge
2205           for (uint i = mem->req(); i < mem->len(); i++) {
2206             // Accumulate any precedence edges
2207             if (mem->in(i) != NULL) {
2208               n->add_prec(mem->in(i));
2209             }
2210           }
2211           // Everything above this point has been processed.
2212           done = true;
2213         }
2214         // Eliminate the previous StoreCM
2215         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2216         assert(mem->outcnt() == 0, "should be dead");
2217         mem->disconnect_inputs(NULL, this);
2218       } else {
2219         prev = mem;
2220       }
2221       mem = prev->in(MemNode::Memory);
2222     }
2223   }
2224 }
2225 
2226 //------------------------------final_graph_reshaping_impl----------------------
2227 // Implement items 1-5 from final_graph_reshaping below.
2228 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2229 
2230   if ( n->outcnt() == 0 ) return; // dead node
2231   uint nop = n->Opcode();
2232 
2233   // Check for 2-input instruction with "last use" on right input.
2234   // Swap to left input.  Implements item (2).
2235   if( n->req() == 3 &&          // two-input instruction
2236       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2237       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2238       n->in(2)->outcnt() == 1 &&// right use IS a last use
2239       !n->in(2)->is_Con() ) {   // right use is not a constant
2240     // Check for commutative opcode
2241     switch( nop ) {
2242     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2243     case Op_MaxI:  case Op_MinI:
2244     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2245     case Op_AndL:  case Op_XorL:  case Op_OrL:
2246     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2247       // Move "last use" input to left by swapping inputs
2248       n->swap_edges(1, 2);
2249       break;
2250     }
2251     default:
2252       break;
2253     }
2254   }
2255 
2256 #ifdef ASSERT
2257   if( n->is_Mem() ) {
2258     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2259     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2260             // oop will be recorded in oop map if load crosses safepoint
2261             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2262                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2263             "raw memory operations should have control edge");
2264   }
2265 #endif
2266   // Count FPU ops and common calls, implements item (3)
2267   switch( nop ) {
2268   // Count all float operations that may use FPU
2269   case Op_AddF:
2270   case Op_SubF:
2271   case Op_MulF:
2272   case Op_DivF:
2273   case Op_NegF:
2274   case Op_ModF:
2275   case Op_ConvI2F:
2276   case Op_ConF:
2277   case Op_CmpF:
2278   case Op_CmpF3:
2279   // case Op_ConvL2F: // longs are split into 32-bit halves
2280     frc.inc_float_count();
2281     break;
2282 
2283   case Op_ConvF2D:
2284   case Op_ConvD2F:
2285     frc.inc_float_count();
2286     frc.inc_double_count();
2287     break;
2288 
2289   // Count all double operations that may use FPU
2290   case Op_AddD:
2291   case Op_SubD:
2292   case Op_MulD:
2293   case Op_DivD:
2294   case Op_NegD:
2295   case Op_ModD:
2296   case Op_ConvI2D:
2297   case Op_ConvD2I:
2298   // case Op_ConvL2D: // handled by leaf call
2299   // case Op_ConvD2L: // handled by leaf call
2300   case Op_ConD:
2301   case Op_CmpD:
2302   case Op_CmpD3:
2303     frc.inc_double_count();
2304     break;
2305   case Op_Opaque1:              // Remove Opaque Nodes before matching
2306   case Op_Opaque2:              // Remove Opaque Nodes before matching
2307     n->subsume_by(n->in(1), this);
2308     break;
2309   case Op_CallStaticJava:
2310   case Op_CallJava:
2311   case Op_CallDynamicJava:
2312     frc.inc_java_call_count(); // Count java call site;
2313   case Op_CallRuntime:
2314   case Op_CallLeaf:
2315   case Op_CallLeafNoFP: {
2316     assert( n->is_Call(), "" );
2317     CallNode *call = n->as_Call();
2318     // Count call sites where the FP mode bit would have to be flipped.
2319     // Do not count uncommon runtime calls:
2320     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2321     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2322     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2323       frc.inc_call_count();   // Count the call site
2324     } else {                  // See if uncommon argument is shared
2325       Node *n = call->in(TypeFunc::Parms);
2326       int nop = n->Opcode();
2327       // Clone shared simple arguments to uncommon calls, item (1).
2328       if( n->outcnt() > 1 &&
2329           !n->is_Proj() &&
2330           nop != Op_CreateEx &&
2331           nop != Op_CheckCastPP &&
2332           nop != Op_DecodeN &&
2333           nop != Op_DecodeNKlass &&
2334           !n->is_Mem() ) {
2335         Node *x = n->clone();
2336         call->set_req( TypeFunc::Parms, x );
2337       }
2338     }
2339     break;
2340   }
2341 
2342   case Op_StoreD:
2343   case Op_LoadD:
2344   case Op_LoadD_unaligned:
2345     frc.inc_double_count();
2346     goto handle_mem;
2347   case Op_StoreF:
2348   case Op_LoadF:
2349     frc.inc_float_count();
2350     goto handle_mem;
2351 
2352   case Op_StoreCM:
2353     {
2354       // Convert OopStore dependence into precedence edge
2355       Node* prec = n->in(MemNode::OopStore);
2356       n->del_req(MemNode::OopStore);
2357       n->add_prec(prec);
2358       eliminate_redundant_card_marks(n);
2359     }
2360 
2361     // fall through
2362 
2363   case Op_StoreB:
2364   case Op_StoreC:
2365   case Op_StorePConditional:
2366   case Op_StoreI:
2367   case Op_StoreL:
2368   case Op_StoreIConditional:
2369   case Op_StoreLConditional:
2370   case Op_CompareAndSwapI:
2371   case Op_CompareAndSwapL:
2372   case Op_CompareAndSwapP:
2373   case Op_CompareAndSwapN:
2374   case Op_GetAndAddI:
2375   case Op_GetAndAddL:
2376   case Op_GetAndSetI:
2377   case Op_GetAndSetL:
2378   case Op_GetAndSetP:
2379   case Op_GetAndSetN:
2380   case Op_StoreP:
2381   case Op_StoreN:
2382   case Op_StoreNKlass:
2383   case Op_LoadB:
2384   case Op_LoadUB:
2385   case Op_LoadUS:
2386   case Op_LoadI:
2387   case Op_LoadKlass:
2388   case Op_LoadNKlass:
2389   case Op_LoadL:
2390   case Op_LoadL_unaligned:
2391   case Op_LoadPLocked:
2392   case Op_LoadP:
2393   case Op_LoadN:
2394   case Op_LoadRange:
2395   case Op_LoadS: {
2396   handle_mem:
2397 #ifdef ASSERT
2398     if( VerifyOptoOopOffsets ) {
2399       assert( n->is_Mem(), "" );
2400       MemNode *mem  = (MemNode*)n;
2401       // Check to see if address types have grounded out somehow.
2402       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2403       assert( !tp || oop_offset_is_sane(tp), "" );
2404     }
2405 #endif
2406     break;
2407   }
2408 
2409   case Op_AddP: {               // Assert sane base pointers
2410     Node *addp = n->in(AddPNode::Address);
2411     assert( !addp->is_AddP() ||
2412             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2413             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2414             "Base pointers must match" );
2415 #ifdef _LP64
2416     if ((UseCompressedOops || UseCompressedKlassPointers) &&
2417         addp->Opcode() == Op_ConP &&
2418         addp == n->in(AddPNode::Base) &&
2419         n->in(AddPNode::Offset)->is_Con()) {
2420       // Use addressing with narrow klass to load with offset on x86.
2421       // On sparc loading 32-bits constant and decoding it have less
2422       // instructions (4) then load 64-bits constant (7).
2423       // Do this transformation here since IGVN will convert ConN back to ConP.
2424       const Type* t = addp->bottom_type();
2425       if (t->isa_oopptr() || t->isa_klassptr()) {
2426         Node* nn = NULL;
2427 
2428         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2429 
2430         // Look for existing ConN node of the same exact type.
2431         Node* r  = root();
2432         uint cnt = r->outcnt();
2433         for (uint i = 0; i < cnt; i++) {
2434           Node* m = r->raw_out(i);
2435           if (m!= NULL && m->Opcode() == op &&
2436               m->bottom_type()->make_ptr() == t) {
2437             nn = m;
2438             break;
2439           }
2440         }
2441         if (nn != NULL) {
2442           // Decode a narrow oop to match address
2443           // [R12 + narrow_oop_reg<<3 + offset]
2444           if (t->isa_oopptr()) {
2445             nn = new (this) DecodeNNode(nn, t);
2446           } else {
2447             nn = new (this) DecodeNKlassNode(nn, t);
2448           }
2449           n->set_req(AddPNode::Base, nn);
2450           n->set_req(AddPNode::Address, nn);
2451           if (addp->outcnt() == 0) {
2452             addp->disconnect_inputs(NULL, this);
2453           }
2454         }
2455       }
2456     }
2457 #endif
2458     break;
2459   }
2460 
2461 #ifdef _LP64
2462   case Op_CastPP:
2463     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2464       Node* in1 = n->in(1);
2465       const Type* t = n->bottom_type();
2466       Node* new_in1 = in1->clone();
2467       new_in1->as_DecodeN()->set_type(t);
2468 
2469       if (!Matcher::narrow_oop_use_complex_address()) {
2470         //
2471         // x86, ARM and friends can handle 2 adds in addressing mode
2472         // and Matcher can fold a DecodeN node into address by using
2473         // a narrow oop directly and do implicit NULL check in address:
2474         //
2475         // [R12 + narrow_oop_reg<<3 + offset]
2476         // NullCheck narrow_oop_reg
2477         //
2478         // On other platforms (Sparc) we have to keep new DecodeN node and
2479         // use it to do implicit NULL check in address:
2480         //
2481         // decode_not_null narrow_oop_reg, base_reg
2482         // [base_reg + offset]
2483         // NullCheck base_reg
2484         //
2485         // Pin the new DecodeN node to non-null path on these platform (Sparc)
2486         // to keep the information to which NULL check the new DecodeN node
2487         // corresponds to use it as value in implicit_null_check().
2488         //
2489         new_in1->set_req(0, n->in(0));
2490       }
2491 
2492       n->subsume_by(new_in1, this);
2493       if (in1->outcnt() == 0) {
2494         in1->disconnect_inputs(NULL, this);
2495       }
2496     }
2497     break;
2498 
2499   case Op_CmpP:
2500     // Do this transformation here to preserve CmpPNode::sub() and
2501     // other TypePtr related Ideal optimizations (for example, ptr nullness).
2502     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2503       Node* in1 = n->in(1);
2504       Node* in2 = n->in(2);
2505       if (!in1->is_DecodeNarrowPtr()) {
2506         in2 = in1;
2507         in1 = n->in(2);
2508       }
2509       assert(in1->is_DecodeNarrowPtr(), "sanity");
2510 
2511       Node* new_in2 = NULL;
2512       if (in2->is_DecodeNarrowPtr()) {
2513         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2514         new_in2 = in2->in(1);
2515       } else if (in2->Opcode() == Op_ConP) {
2516         const Type* t = in2->bottom_type();
2517         if (t == TypePtr::NULL_PTR) {
2518           assert(in1->is_DecodeN(), "compare klass to null?");
2519           // Don't convert CmpP null check into CmpN if compressed
2520           // oops implicit null check is not generated.
2521           // This will allow to generate normal oop implicit null check.
2522           if (Matcher::gen_narrow_oop_implicit_null_checks())
2523             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2524           //
2525           // This transformation together with CastPP transformation above
2526           // will generated code for implicit NULL checks for compressed oops.
2527           //
2528           // The original code after Optimize()
2529           //
2530           //    LoadN memory, narrow_oop_reg
2531           //    decode narrow_oop_reg, base_reg
2532           //    CmpP base_reg, NULL
2533           //    CastPP base_reg // NotNull
2534           //    Load [base_reg + offset], val_reg
2535           //
2536           // after these transformations will be
2537           //
2538           //    LoadN memory, narrow_oop_reg
2539           //    CmpN narrow_oop_reg, NULL
2540           //    decode_not_null narrow_oop_reg, base_reg
2541           //    Load [base_reg + offset], val_reg
2542           //
2543           // and the uncommon path (== NULL) will use narrow_oop_reg directly
2544           // since narrow oops can be used in debug info now (see the code in
2545           // final_graph_reshaping_walk()).
2546           //
2547           // At the end the code will be matched to
2548           // on x86:
2549           //
2550           //    Load_narrow_oop memory, narrow_oop_reg
2551           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2552           //    NullCheck narrow_oop_reg
2553           //
2554           // and on sparc:
2555           //
2556           //    Load_narrow_oop memory, narrow_oop_reg
2557           //    decode_not_null narrow_oop_reg, base_reg
2558           //    Load [base_reg + offset], val_reg
2559           //    NullCheck base_reg
2560           //
2561         } else if (t->isa_oopptr()) {
2562           new_in2 = ConNode::make(this, t->make_narrowoop());
2563         } else if (t->isa_klassptr()) {
2564           new_in2 = ConNode::make(this, t->make_narrowklass());
2565         }
2566       }
2567       if (new_in2 != NULL) {
2568         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2569         n->subsume_by(cmpN, this);
2570         if (in1->outcnt() == 0) {
2571           in1->disconnect_inputs(NULL, this);
2572         }
2573         if (in2->outcnt() == 0) {
2574           in2->disconnect_inputs(NULL, this);
2575         }
2576       }
2577     }
2578     break;
2579 
2580   case Op_DecodeN:
2581   case Op_DecodeNKlass:
2582     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2583     // DecodeN could be pinned when it can't be fold into
2584     // an address expression, see the code for Op_CastPP above.
2585     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2586     break;
2587 
2588   case Op_EncodeP:
2589   case Op_EncodePKlass: {
2590     Node* in1 = n->in(1);
2591     if (in1->is_DecodeNarrowPtr()) {
2592       n->subsume_by(in1->in(1), this);
2593     } else if (in1->Opcode() == Op_ConP) {
2594       const Type* t = in1->bottom_type();
2595       if (t == TypePtr::NULL_PTR) {
2596         assert(t->isa_oopptr(), "null klass?");
2597         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2598       } else if (t->isa_oopptr()) {
2599         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2600       } else if (t->isa_klassptr()) {
2601         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2602       }
2603     }
2604     if (in1->outcnt() == 0) {
2605       in1->disconnect_inputs(NULL, this);
2606     }
2607     break;
2608   }
2609 
2610   case Op_Proj: {
2611     if (OptimizeStringConcat) {
2612       ProjNode* p = n->as_Proj();
2613       if (p->_is_io_use) {
2614         // Separate projections were used for the exception path which
2615         // are normally removed by a late inline.  If it wasn't inlined
2616         // then they will hang around and should just be replaced with
2617         // the original one.
2618         Node* proj = NULL;
2619         // Replace with just one
2620         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2621           Node *use = i.get();
2622           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2623             proj = use;
2624             break;
2625           }
2626         }
2627         assert(proj != NULL, "must be found");
2628         p->subsume_by(proj, this);
2629       }
2630     }
2631     break;
2632   }
2633 
2634   case Op_Phi:
2635     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2636       // The EncodeP optimization may create Phi with the same edges
2637       // for all paths. It is not handled well by Register Allocator.
2638       Node* unique_in = n->in(1);
2639       assert(unique_in != NULL, "");
2640       uint cnt = n->req();
2641       for (uint i = 2; i < cnt; i++) {
2642         Node* m = n->in(i);
2643         assert(m != NULL, "");
2644         if (unique_in != m)
2645           unique_in = NULL;
2646       }
2647       if (unique_in != NULL) {
2648         n->subsume_by(unique_in, this);
2649       }
2650     }
2651     break;
2652 
2653 #endif
2654 
2655   case Op_ModI:
2656     if (UseDivMod) {
2657       // Check if a%b and a/b both exist
2658       Node* d = n->find_similar(Op_DivI);
2659       if (d) {
2660         // Replace them with a fused divmod if supported
2661         if (Matcher::has_match_rule(Op_DivModI)) {
2662           DivModINode* divmod = DivModINode::make(this, n);
2663           d->subsume_by(divmod->div_proj(), this);
2664           n->subsume_by(divmod->mod_proj(), this);
2665         } else {
2666           // replace a%b with a-((a/b)*b)
2667           Node* mult = new (this) MulINode(d, d->in(2));
2668           Node* sub  = new (this) SubINode(d->in(1), mult);
2669           n->subsume_by(sub, this);
2670         }
2671       }
2672     }
2673     break;
2674 
2675   case Op_ModL:
2676     if (UseDivMod) {
2677       // Check if a%b and a/b both exist
2678       Node* d = n->find_similar(Op_DivL);
2679       if (d) {
2680         // Replace them with a fused divmod if supported
2681         if (Matcher::has_match_rule(Op_DivModL)) {
2682           DivModLNode* divmod = DivModLNode::make(this, n);
2683           d->subsume_by(divmod->div_proj(), this);
2684           n->subsume_by(divmod->mod_proj(), this);
2685         } else {
2686           // replace a%b with a-((a/b)*b)
2687           Node* mult = new (this) MulLNode(d, d->in(2));
2688           Node* sub  = new (this) SubLNode(d->in(1), mult);
2689           n->subsume_by(sub, this);
2690         }
2691       }
2692     }
2693     break;
2694 
2695   case Op_LoadVector:
2696   case Op_StoreVector:
2697     break;
2698 
2699   case Op_PackB:
2700   case Op_PackS:
2701   case Op_PackI:
2702   case Op_PackF:
2703   case Op_PackL:
2704   case Op_PackD:
2705     if (n->req()-1 > 2) {
2706       // Replace many operand PackNodes with a binary tree for matching
2707       PackNode* p = (PackNode*) n;
2708       Node* btp = p->binary_tree_pack(this, 1, n->req());
2709       n->subsume_by(btp, this);
2710     }
2711     break;
2712   case Op_Loop:
2713   case Op_CountedLoop:
2714     if (n->as_Loop()->is_inner_loop()) {
2715       frc.inc_inner_loop_count();
2716     }
2717     break;
2718   case Op_LShiftI:
2719   case Op_RShiftI:
2720   case Op_URShiftI:
2721   case Op_LShiftL:
2722   case Op_RShiftL:
2723   case Op_URShiftL:
2724     if (Matcher::need_masked_shift_count) {
2725       // The cpu's shift instructions don't restrict the count to the
2726       // lower 5/6 bits. We need to do the masking ourselves.
2727       Node* in2 = n->in(2);
2728       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
2729       const TypeInt* t = in2->find_int_type();
2730       if (t != NULL && t->is_con()) {
2731         juint shift = t->get_con();
2732         if (shift > mask) { // Unsigned cmp
2733           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
2734         }
2735       } else {
2736         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
2737           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
2738           n->set_req(2, shift);
2739         }
2740       }
2741       if (in2->outcnt() == 0) { // Remove dead node
2742         in2->disconnect_inputs(NULL, this);
2743       }
2744     }
2745     break;
2746   default:
2747     assert( !n->is_Call(), "" );
2748     assert( !n->is_Mem(), "" );
2749     break;
2750   }
2751 
2752   // Collect CFG split points
2753   if (n->is_MultiBranch())
2754     frc._tests.push(n);
2755 }
2756 
2757 //------------------------------final_graph_reshaping_walk---------------------
2758 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
2759 // requires that the walk visits a node's inputs before visiting the node.
2760 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
2761   ResourceArea *area = Thread::current()->resource_area();
2762   Unique_Node_List sfpt(area);
2763 
2764   frc._visited.set(root->_idx); // first, mark node as visited
2765   uint cnt = root->req();
2766   Node *n = root;
2767   uint  i = 0;
2768   while (true) {
2769     if (i < cnt) {
2770       // Place all non-visited non-null inputs onto stack
2771       Node* m = n->in(i);
2772       ++i;
2773       if (m != NULL && !frc._visited.test_set(m->_idx)) {
2774         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
2775           sfpt.push(m);
2776         cnt = m->req();
2777         nstack.push(n, i); // put on stack parent and next input's index
2778         n = m;
2779         i = 0;
2780       }
2781     } else {
2782       // Now do post-visit work
2783       final_graph_reshaping_impl( n, frc );
2784       if (nstack.is_empty())
2785         break;             // finished
2786       n = nstack.node();   // Get node from stack
2787       cnt = n->req();
2788       i = nstack.index();
2789       nstack.pop();        // Shift to the next node on stack
2790     }
2791   }
2792 
2793   // Skip next transformation if compressed oops are not used.
2794   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
2795       (!UseCompressedOops && !UseCompressedKlassPointers))
2796     return;
2797 
2798   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
2799   // It could be done for an uncommon traps or any safepoints/calls
2800   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
2801   while (sfpt.size() > 0) {
2802     n = sfpt.pop();
2803     JVMState *jvms = n->as_SafePoint()->jvms();
2804     assert(jvms != NULL, "sanity");
2805     int start = jvms->debug_start();
2806     int end   = n->req();
2807     bool is_uncommon = (n->is_CallStaticJava() &&
2808                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
2809     for (int j = start; j < end; j++) {
2810       Node* in = n->in(j);
2811       if (in->is_DecodeNarrowPtr()) {
2812         bool safe_to_skip = true;
2813         if (!is_uncommon ) {
2814           // Is it safe to skip?
2815           for (uint i = 0; i < in->outcnt(); i++) {
2816             Node* u = in->raw_out(i);
2817             if (!u->is_SafePoint() ||
2818                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
2819               safe_to_skip = false;
2820             }
2821           }
2822         }
2823         if (safe_to_skip) {
2824           n->set_req(j, in->in(1));
2825         }
2826         if (in->outcnt() == 0) {
2827           in->disconnect_inputs(NULL, this);
2828         }
2829       }
2830     }
2831   }
2832 }
2833 
2834 //------------------------------final_graph_reshaping--------------------------
2835 // Final Graph Reshaping.
2836 //
2837 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
2838 //     and not commoned up and forced early.  Must come after regular
2839 //     optimizations to avoid GVN undoing the cloning.  Clone constant
2840 //     inputs to Loop Phis; these will be split by the allocator anyways.
2841 //     Remove Opaque nodes.
2842 // (2) Move last-uses by commutative operations to the left input to encourage
2843 //     Intel update-in-place two-address operations and better register usage
2844 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
2845 //     calls canonicalizing them back.
2846 // (3) Count the number of double-precision FP ops, single-precision FP ops
2847 //     and call sites.  On Intel, we can get correct rounding either by
2848 //     forcing singles to memory (requires extra stores and loads after each
2849 //     FP bytecode) or we can set a rounding mode bit (requires setting and
2850 //     clearing the mode bit around call sites).  The mode bit is only used
2851 //     if the relative frequency of single FP ops to calls is low enough.
2852 //     This is a key transform for SPEC mpeg_audio.
2853 // (4) Detect infinite loops; blobs of code reachable from above but not
2854 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
2855 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
2856 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
2857 //     Detection is by looking for IfNodes where only 1 projection is
2858 //     reachable from below or CatchNodes missing some targets.
2859 // (5) Assert for insane oop offsets in debug mode.
2860 
2861 bool Compile::final_graph_reshaping() {
2862   // an infinite loop may have been eliminated by the optimizer,
2863   // in which case the graph will be empty.
2864   if (root()->req() == 1) {
2865     record_method_not_compilable("trivial infinite loop");
2866     return true;
2867   }
2868 
2869   Final_Reshape_Counts frc;
2870 
2871   // Visit everybody reachable!
2872   // Allocate stack of size C->unique()/2 to avoid frequent realloc
2873   Node_Stack nstack(unique() >> 1);
2874   final_graph_reshaping_walk(nstack, root(), frc);
2875 
2876   // Check for unreachable (from below) code (i.e., infinite loops).
2877   for( uint i = 0; i < frc._tests.size(); i++ ) {
2878     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
2879     // Get number of CFG targets.
2880     // Note that PCTables include exception targets after calls.
2881     uint required_outcnt = n->required_outcnt();
2882     if (n->outcnt() != required_outcnt) {
2883       // Check for a few special cases.  Rethrow Nodes never take the
2884       // 'fall-thru' path, so expected kids is 1 less.
2885       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
2886         if (n->in(0)->in(0)->is_Call()) {
2887           CallNode *call = n->in(0)->in(0)->as_Call();
2888           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
2889             required_outcnt--;      // Rethrow always has 1 less kid
2890           } else if (call->req() > TypeFunc::Parms &&
2891                      call->is_CallDynamicJava()) {
2892             // Check for null receiver. In such case, the optimizer has
2893             // detected that the virtual call will always result in a null
2894             // pointer exception. The fall-through projection of this CatchNode
2895             // will not be populated.
2896             Node *arg0 = call->in(TypeFunc::Parms);
2897             if (arg0->is_Type() &&
2898                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
2899               required_outcnt--;
2900             }
2901           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
2902                      call->req() > TypeFunc::Parms+1 &&
2903                      call->is_CallStaticJava()) {
2904             // Check for negative array length. In such case, the optimizer has
2905             // detected that the allocation attempt will always result in an
2906             // exception. There is no fall-through projection of this CatchNode .
2907             Node *arg1 = call->in(TypeFunc::Parms+1);
2908             if (arg1->is_Type() &&
2909                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
2910               required_outcnt--;
2911             }
2912           }
2913         }
2914       }
2915       // Recheck with a better notion of 'required_outcnt'
2916       if (n->outcnt() != required_outcnt) {
2917         record_method_not_compilable("malformed control flow");
2918         return true;            // Not all targets reachable!
2919       }
2920     }
2921     // Check that I actually visited all kids.  Unreached kids
2922     // must be infinite loops.
2923     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
2924       if (!frc._visited.test(n->fast_out(j)->_idx)) {
2925         record_method_not_compilable("infinite loop");
2926         return true;            // Found unvisited kid; must be unreach
2927       }
2928   }
2929 
2930   // If original bytecodes contained a mixture of floats and doubles
2931   // check if the optimizer has made it homogenous, item (3).
2932   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
2933       frc.get_float_count() > 32 &&
2934       frc.get_double_count() == 0 &&
2935       (10 * frc.get_call_count() < frc.get_float_count()) ) {
2936     set_24_bit_selection_and_mode( false,  true );
2937   }
2938 
2939   set_java_calls(frc.get_java_call_count());
2940   set_inner_loops(frc.get_inner_loop_count());
2941 
2942   // No infinite loops, no reason to bail out.
2943   return false;
2944 }
2945 
2946 //-----------------------------too_many_traps----------------------------------
2947 // Report if there are too many traps at the current method and bci.
2948 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
2949 bool Compile::too_many_traps(ciMethod* method,
2950                              int bci,
2951                              Deoptimization::DeoptReason reason) {
2952   ciMethodData* md = method->method_data();
2953   if (md->is_empty()) {
2954     // Assume the trap has not occurred, or that it occurred only
2955     // because of a transient condition during start-up in the interpreter.
2956     return false;
2957   }
2958   if (md->has_trap_at(bci, reason) != 0) {
2959     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
2960     // Also, if there are multiple reasons, or if there is no per-BCI record,
2961     // assume the worst.
2962     if (log())
2963       log()->elem("observe trap='%s' count='%d'",
2964                   Deoptimization::trap_reason_name(reason),
2965                   md->trap_count(reason));
2966     return true;
2967   } else {
2968     // Ignore method/bci and see if there have been too many globally.
2969     return too_many_traps(reason, md);
2970   }
2971 }
2972 
2973 // Less-accurate variant which does not require a method and bci.
2974 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
2975                              ciMethodData* logmd) {
2976  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
2977     // Too many traps globally.
2978     // Note that we use cumulative trap_count, not just md->trap_count.
2979     if (log()) {
2980       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
2981       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
2982                   Deoptimization::trap_reason_name(reason),
2983                   mcount, trap_count(reason));
2984     }
2985     return true;
2986   } else {
2987     // The coast is clear.
2988     return false;
2989   }
2990 }
2991 
2992 //--------------------------too_many_recompiles--------------------------------
2993 // Report if there are too many recompiles at the current method and bci.
2994 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
2995 // Is not eager to return true, since this will cause the compiler to use
2996 // Action_none for a trap point, to avoid too many recompilations.
2997 bool Compile::too_many_recompiles(ciMethod* method,
2998                                   int bci,
2999                                   Deoptimization::DeoptReason reason) {
3000   ciMethodData* md = method->method_data();
3001   if (md->is_empty()) {
3002     // Assume the trap has not occurred, or that it occurred only
3003     // because of a transient condition during start-up in the interpreter.
3004     return false;
3005   }
3006   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3007   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3008   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3009   Deoptimization::DeoptReason per_bc_reason
3010     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3011   if ((per_bc_reason == Deoptimization::Reason_none
3012        || md->has_trap_at(bci, reason) != 0)
3013       // The trap frequency measure we care about is the recompile count:
3014       && md->trap_recompiled_at(bci)
3015       && md->overflow_recompile_count() >= bc_cutoff) {
3016     // Do not emit a trap here if it has already caused recompilations.
3017     // Also, if there are multiple reasons, or if there is no per-BCI record,
3018     // assume the worst.
3019     if (log())
3020       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3021                   Deoptimization::trap_reason_name(reason),
3022                   md->trap_count(reason),
3023                   md->overflow_recompile_count());
3024     return true;
3025   } else if (trap_count(reason) != 0
3026              && decompile_count() >= m_cutoff) {
3027     // Too many recompiles globally, and we have seen this sort of trap.
3028     // Use cumulative decompile_count, not just md->decompile_count.
3029     if (log())
3030       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3031                   Deoptimization::trap_reason_name(reason),
3032                   md->trap_count(reason), trap_count(reason),
3033                   md->decompile_count(), decompile_count());
3034     return true;
3035   } else {
3036     // The coast is clear.
3037     return false;
3038   }
3039 }
3040 
3041 
3042 #ifndef PRODUCT
3043 //------------------------------verify_graph_edges---------------------------
3044 // Walk the Graph and verify that there is a one-to-one correspondence
3045 // between Use-Def edges and Def-Use edges in the graph.
3046 void Compile::verify_graph_edges(bool no_dead_code) {
3047   if (VerifyGraphEdges) {
3048     ResourceArea *area = Thread::current()->resource_area();
3049     Unique_Node_List visited(area);
3050     // Call recursive graph walk to check edges
3051     _root->verify_edges(visited);
3052     if (no_dead_code) {
3053       // Now make sure that no visited node is used by an unvisited node.
3054       bool dead_nodes = 0;
3055       Unique_Node_List checked(area);
3056       while (visited.size() > 0) {
3057         Node* n = visited.pop();
3058         checked.push(n);
3059         for (uint i = 0; i < n->outcnt(); i++) {
3060           Node* use = n->raw_out(i);
3061           if (checked.member(use))  continue;  // already checked
3062           if (visited.member(use))  continue;  // already in the graph
3063           if (use->is_Con())        continue;  // a dead ConNode is OK
3064           // At this point, we have found a dead node which is DU-reachable.
3065           if (dead_nodes++ == 0)
3066             tty->print_cr("*** Dead nodes reachable via DU edges:");
3067           use->dump(2);
3068           tty->print_cr("---");
3069           checked.push(use);  // No repeats; pretend it is now checked.
3070         }
3071       }
3072       assert(dead_nodes == 0, "using nodes must be reachable from root");
3073     }
3074   }
3075 }
3076 #endif
3077 
3078 // The Compile object keeps track of failure reasons separately from the ciEnv.
3079 // This is required because there is not quite a 1-1 relation between the
3080 // ciEnv and its compilation task and the Compile object.  Note that one
3081 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3082 // to backtrack and retry without subsuming loads.  Other than this backtracking
3083 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3084 // by the logic in C2Compiler.
3085 void Compile::record_failure(const char* reason) {
3086   if (log() != NULL) {
3087     log()->elem("failure reason='%s' phase='compile'", reason);
3088   }
3089   if (_failure_reason == NULL) {
3090     // Record the first failure reason.
3091     _failure_reason = reason;
3092   }
3093   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3094     C->print_method(_failure_reason);
3095   }
3096   _root = NULL;  // flush the graph, too
3097 }
3098 
3099 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3100   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3101     _phase_name(name), _dolog(dolog)
3102 {
3103   if (dolog) {
3104     C = Compile::current();
3105     _log = C->log();
3106   } else {
3107     C = NULL;
3108     _log = NULL;
3109   }
3110   if (_log != NULL) {
3111     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3112     _log->stamp();
3113     _log->end_head();
3114   }
3115 }
3116 
3117 Compile::TracePhase::~TracePhase() {
3118 
3119   C = Compile::current();
3120   if (_dolog) {
3121     _log = C->log();
3122   } else {
3123     _log = NULL;
3124   }
3125 
3126 #ifdef ASSERT
3127   if (PrintIdealNodeCount) {
3128     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3129                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3130   }
3131 
3132   if (VerifyIdealNodeCount) {
3133     Compile::current()->print_missing_nodes();
3134   }
3135 #endif
3136 
3137   if (_log != NULL) {
3138     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3139   }
3140 }
3141 
3142 //=============================================================================
3143 // Two Constant's are equal when the type and the value are equal.
3144 bool Compile::Constant::operator==(const Constant& other) {
3145   if (type()          != other.type()         )  return false;
3146   if (can_be_reused() != other.can_be_reused())  return false;
3147   // For floating point values we compare the bit pattern.
3148   switch (type()) {
3149   case T_FLOAT:   return (_v._value.i == other._v._value.i);
3150   case T_LONG:
3151   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
3152   case T_OBJECT:
3153   case T_ADDRESS: return (_v._value.l == other._v._value.l);
3154   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
3155   case T_METADATA: return (_v._metadata == other._v._metadata);
3156   default: ShouldNotReachHere();
3157   }
3158   return false;
3159 }
3160 
3161 static int type_to_size_in_bytes(BasicType t) {
3162   switch (t) {
3163   case T_LONG:    return sizeof(jlong  );
3164   case T_FLOAT:   return sizeof(jfloat );
3165   case T_DOUBLE:  return sizeof(jdouble);
3166   case T_METADATA: return sizeof(Metadata*);
3167     // We use T_VOID as marker for jump-table entries (labels) which
3168     // need an internal word relocation.
3169   case T_VOID:
3170   case T_ADDRESS:
3171   case T_OBJECT:  return sizeof(jobject);
3172   }
3173 
3174   ShouldNotReachHere();
3175   return -1;
3176 }
3177 
3178 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3179   // sort descending
3180   if (a->freq() > b->freq())  return -1;
3181   if (a->freq() < b->freq())  return  1;
3182   return 0;
3183 }
3184 
3185 void Compile::ConstantTable::calculate_offsets_and_size() {
3186   // First, sort the array by frequencies.
3187   _constants.sort(qsort_comparator);
3188 
3189 #ifdef ASSERT
3190   // Make sure all jump-table entries were sorted to the end of the
3191   // array (they have a negative frequency).
3192   bool found_void = false;
3193   for (int i = 0; i < _constants.length(); i++) {
3194     Constant con = _constants.at(i);
3195     if (con.type() == T_VOID)
3196       found_void = true;  // jump-tables
3197     else
3198       assert(!found_void, "wrong sorting");
3199   }
3200 #endif
3201 
3202   int offset = 0;
3203   for (int i = 0; i < _constants.length(); i++) {
3204     Constant* con = _constants.adr_at(i);
3205 
3206     // Align offset for type.
3207     int typesize = type_to_size_in_bytes(con->type());
3208     offset = align_size_up(offset, typesize);
3209     con->set_offset(offset);   // set constant's offset
3210 
3211     if (con->type() == T_VOID) {
3212       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3213       offset = offset + typesize * n->outcnt();  // expand jump-table
3214     } else {
3215       offset = offset + typesize;
3216     }
3217   }
3218 
3219   // Align size up to the next section start (which is insts; see
3220   // CodeBuffer::align_at_start).
3221   assert(_size == -1, "already set?");
3222   _size = align_size_up(offset, CodeEntryAlignment);
3223 }
3224 
3225 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3226   MacroAssembler _masm(&cb);
3227   for (int i = 0; i < _constants.length(); i++) {
3228     Constant con = _constants.at(i);
3229     address constant_addr;
3230     switch (con.type()) {
3231     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
3232     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3233     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3234     case T_OBJECT: {
3235       jobject obj = con.get_jobject();
3236       int oop_index = _masm.oop_recorder()->find_index(obj);
3237       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3238       break;
3239     }
3240     case T_ADDRESS: {
3241       address addr = (address) con.get_jobject();
3242       constant_addr = _masm.address_constant(addr);
3243       break;
3244     }
3245     // We use T_VOID as marker for jump-table entries (labels) which
3246     // need an internal word relocation.
3247     case T_VOID: {
3248       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3249       // Fill the jump-table with a dummy word.  The real value is
3250       // filled in later in fill_jump_table.
3251       address dummy = (address) n;
3252       constant_addr = _masm.address_constant(dummy);
3253       // Expand jump-table
3254       for (uint i = 1; i < n->outcnt(); i++) {
3255         address temp_addr = _masm.address_constant(dummy + i);
3256         assert(temp_addr, "consts section too small");
3257       }
3258       break;
3259     }
3260     case T_METADATA: {
3261       Metadata* obj = con.get_metadata();
3262       int metadata_index = _masm.oop_recorder()->find_index(obj);
3263       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3264       break;
3265     }
3266     default: ShouldNotReachHere();
3267     }
3268     assert(constant_addr, "consts section too small");
3269     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg_res("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
3270   }
3271 }
3272 
3273 int Compile::ConstantTable::find_offset(Constant& con) const {
3274   int idx = _constants.find(con);
3275   assert(idx != -1, "constant must be in constant table");
3276   int offset = _constants.at(idx).offset();
3277   assert(offset != -1, "constant table not emitted yet?");
3278   return offset;
3279 }
3280 
3281 void Compile::ConstantTable::add(Constant& con) {
3282   if (con.can_be_reused()) {
3283     int idx = _constants.find(con);
3284     if (idx != -1 && _constants.at(idx).can_be_reused()) {
3285       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
3286       return;
3287     }
3288   }
3289   (void) _constants.append(con);
3290 }
3291 
3292 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3293   Block* b = Compile::current()->cfg()->_bbs[n->_idx];
3294   Constant con(type, value, b->_freq);
3295   add(con);
3296   return con;
3297 }
3298 
3299 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3300   Constant con(metadata);
3301   add(con);
3302   return con;
3303 }
3304 
3305 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3306   jvalue value;
3307   BasicType type = oper->type()->basic_type();
3308   switch (type) {
3309   case T_LONG:    value.j = oper->constantL(); break;
3310   case T_FLOAT:   value.f = oper->constantF(); break;
3311   case T_DOUBLE:  value.d = oper->constantD(); break;
3312   case T_OBJECT:
3313   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3314   case T_METADATA: return add((Metadata*)oper->constant()); break;
3315   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3316   }
3317   return add(n, type, value);
3318 }
3319 
3320 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3321   jvalue value;
3322   // We can use the node pointer here to identify the right jump-table
3323   // as this method is called from Compile::Fill_buffer right before
3324   // the MachNodes are emitted and the jump-table is filled (means the
3325   // MachNode pointers do not change anymore).
3326   value.l = (jobject) n;
3327   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
3328   add(con);
3329   return con;
3330 }
3331 
3332 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3333   // If called from Compile::scratch_emit_size do nothing.
3334   if (Compile::current()->in_scratch_emit_size())  return;
3335 
3336   assert(labels.is_nonempty(), "must be");
3337   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3338 
3339   // Since MachConstantNode::constant_offset() also contains
3340   // table_base_offset() we need to subtract the table_base_offset()
3341   // to get the plain offset into the constant table.
3342   int offset = n->constant_offset() - table_base_offset();
3343 
3344   MacroAssembler _masm(&cb);
3345   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3346 
3347   for (uint i = 0; i < n->outcnt(); i++) {
3348     address* constant_addr = &jump_table_base[i];
3349     assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, *constant_addr, (((address) n) + i)));
3350     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3351     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);








3352   }
3353 }
--- EOF ---