--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/opto/parse1.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,2166 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_parse1.cpp.incl"
+
+// Static array so we can figure out which bytecodes stop us from compiling
+// the most. Some of the non-static variables are needed in bytecodeInfo.cpp
+// and eventually should be encapsulated in a proper class (gri 8/18/98).
+
+int nodes_created              = 0; int nodes_created_old              = 0;
+int methods_parsed             = 0; int methods_parsed_old             = 0;
+int methods_seen               = 0; int methods_seen_old               = 0;
+
+int explicit_null_checks_inserted = 0, explicit_null_checks_inserted_old = 0;
+int explicit_null_checks_elided   = 0, explicit_null_checks_elided_old   = 0;
+int all_null_checks_found         = 0, implicit_null_checks              = 0;
+int implicit_null_throws          = 0;
+
+int parse_idx = 0;
+size_t parse_arena = 0;
+int reclaim_idx  = 0;
+int reclaim_in   = 0;
+int reclaim_node = 0;
+
+#ifndef PRODUCT
+bool Parse::BytecodeParseHistogram::_initialized = false;
+uint Parse::BytecodeParseHistogram::_bytecodes_parsed [Bytecodes::number_of_codes];
+uint Parse::BytecodeParseHistogram::_nodes_constructed[Bytecodes::number_of_codes];
+uint Parse::BytecodeParseHistogram::_nodes_transformed[Bytecodes::number_of_codes];
+uint Parse::BytecodeParseHistogram::_new_values       [Bytecodes::number_of_codes];
+#endif
+
+//------------------------------print_statistics-------------------------------
+#ifndef PRODUCT
+void Parse::print_statistics() {
+  tty->print_cr("--- Compiler Statistics ---");
+  tty->print("Methods seen: %d  Methods parsed: %d", methods_seen, methods_parsed);
+  tty->print("  Nodes created: %d", nodes_created);
+  tty->cr();
+  if (methods_seen != methods_parsed)
+    tty->print_cr("Reasons for parse failures (NOT cumulative):");
+
+  if( explicit_null_checks_inserted )
+    tty->print_cr("%d original NULL checks - %d elided (%2d%%); optimizer leaves %d,", explicit_null_checks_inserted, explicit_null_checks_elided, (100*explicit_null_checks_elided)/explicit_null_checks_inserted, all_null_checks_found);
+  if( all_null_checks_found )
+    tty->print_cr("%d made implicit (%2d%%)", implicit_null_checks,
+                  (100*implicit_null_checks)/all_null_checks_found);
+  if( implicit_null_throws )
+    tty->print_cr("%d implicit null exceptions at runtime",
+                  implicit_null_throws);
+
+  if( PrintParseStatistics && BytecodeParseHistogram::initialized() ) {
+    BytecodeParseHistogram::print();
+  }
+}
+#endif
+
+//------------------------------ON STACK REPLACEMENT---------------------------
+
+// Construct a node which can be used to get incoming state for
+// on stack replacement.
+Node *Parse::fetch_interpreter_state(int index,
+                                     BasicType bt,
+                                     Node *local_addrs,
+                                     Node *local_addrs_base) {
+  Node *mem = memory(Compile::AliasIdxRaw);
+  Node *adr = basic_plus_adr( local_addrs_base, local_addrs, -index*wordSize );
+
+  // Very similar to LoadNode::make, except we handle un-aligned longs and
+  // doubles on Sparc.  Intel can handle them just fine directly.
+  Node *l;
+  switch( bt ) {                // Signature is flattened
+  case T_INT:     l = new (C, 3) LoadINode( 0, mem, adr, TypeRawPtr::BOTTOM ); break;
+  case T_FLOAT:   l = new (C, 3) LoadFNode( 0, mem, adr, TypeRawPtr::BOTTOM ); break;
+  case T_ADDRESS:
+  case T_OBJECT:  l = new (C, 3) LoadPNode( 0, mem, adr, TypeRawPtr::BOTTOM, TypeInstPtr::BOTTOM ); break;
+  case T_LONG:
+  case T_DOUBLE: {
+    // Since arguments are in reverse order, the argument address 'adr'
+    // refers to the back half of the long/double.  Recompute adr.
+    adr = basic_plus_adr( local_addrs_base, local_addrs, -(index+1)*wordSize );
+    if( Matcher::misaligned_doubles_ok ) {
+      l = (bt == T_DOUBLE)
+        ? (Node*)new (C, 3) LoadDNode( 0, mem, adr, TypeRawPtr::BOTTOM )
+        : (Node*)new (C, 3) LoadLNode( 0, mem, adr, TypeRawPtr::BOTTOM );
+    } else {
+      l = (bt == T_DOUBLE)
+        ? (Node*)new (C, 3) LoadD_unalignedNode( 0, mem, adr, TypeRawPtr::BOTTOM )
+        : (Node*)new (C, 3) LoadL_unalignedNode( 0, mem, adr, TypeRawPtr::BOTTOM );
+    }
+    break;
+  }
+  default: ShouldNotReachHere();
+  }
+  return _gvn.transform(l);
+}
+
+// Helper routine to prevent the interpreter from handing
+// unexpected typestate to an OSR method.
+// The Node l is a value newly dug out of the interpreter frame.
+// The type is the type predicted by ciTypeFlow.  Note that it is
+// not a general type, but can only come from Type::get_typeflow_type.
+// The safepoint is a map which will feed an uncommon trap.
+Node* Parse::check_interpreter_type(Node* l, const Type* type,
+                                    SafePointNode* &bad_type_exit) {
+
+  const TypeOopPtr* tp = type->isa_oopptr();
+
+  // TypeFlow may assert null-ness if a type appears unloaded.
+  if (type == TypePtr::NULL_PTR ||
+      (tp != NULL && !tp->klass()->is_loaded())) {
+    // Value must be null, not a real oop.
+    Node* chk = _gvn.transform( new (C, 3) CmpPNode(l, null()) );
+    Node* tst = _gvn.transform( new (C, 2) BoolNode(chk, BoolTest::eq) );
+    IfNode* iff = create_and_map_if(control(), tst, PROB_MAX, COUNT_UNKNOWN);
+    set_control(_gvn.transform( new (C, 1) IfTrueNode(iff) ));
+    Node* bad_type = _gvn.transform( new (C, 1) IfFalseNode(iff) );
+    bad_type_exit->control()->add_req(bad_type);
+    l = null();
+  }
+
+  // Typeflow can also cut off paths from the CFG, based on
+  // types which appear unloaded, or call sites which appear unlinked.
+  // When paths are cut off, values at later merge points can rise
+  // toward more specific classes.  Make sure these specific classes
+  // are still in effect.
+  if (tp != NULL && tp->klass() != C->env()->Object_klass()) {
+    // TypeFlow asserted a specific object type.  Value must have that type.
+    Node* bad_type_ctrl = NULL;
+    l = gen_checkcast(l, makecon(TypeKlassPtr::make(tp->klass())), &bad_type_ctrl);
+    bad_type_exit->control()->add_req(bad_type_ctrl);
+  }
+
+  BasicType bt_l = _gvn.type(l)->basic_type();
+  BasicType bt_t = type->basic_type();
+  assert(_gvn.type(l)->higher_equal(type), "must constrain OSR typestate");
+  return l;
+}
+
+// Helper routine which sets up elements of the initial parser map when
+// performing a parse for on stack replacement.  Add values into map.
+// The only parameter contains the address of a interpreter arguments.
+void Parse::load_interpreter_state(Node* osr_buf) {
+  int index;
+  int max_locals = jvms()->loc_size();
+  int max_stack  = jvms()->stk_size();
+
+
+  // Mismatch between method and jvms can occur since map briefly held
+  // an OSR entry state (which takes up one RawPtr word).
+  assert(max_locals == method()->max_locals(), "sanity");
+  assert(max_stack  >= method()->max_stack(),  "sanity");
+  assert((int)jvms()->endoff() == TypeFunc::Parms + max_locals + max_stack, "sanity");
+  assert((int)jvms()->endoff() == (int)map()->req(), "sanity");
+
+  // Find the start block.
+  Block* osr_block = start_block();
+  assert(osr_block->start() == osr_bci(), "sanity");
+
+  // Set initial BCI.
+  set_parse_bci(osr_block->start());
+
+  // Set initial stack depth.
+  set_sp(osr_block->start_sp());
+
+  // Check bailouts.  We currently do not perform on stack replacement
+  // of loops in catch blocks or loops which branch with a non-empty stack.
+  if (sp() != 0) {
+    C->record_method_not_compilable("OSR starts with non-empty stack");
+    return;
+  }
+  // Do not OSR inside finally clauses:
+  if (osr_block->has_trap_at(osr_block->start())) {
+    C->record_method_not_compilable("OSR starts with an immediate trap");
+    return;
+  }
+
+  // Commute monitors from interpreter frame to compiler frame.
+  assert(jvms()->monitor_depth() == 0, "should be no active locks at beginning of osr");
+  int mcnt = osr_block->flow()->monitor_count();
+  Node *monitors_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals+mcnt*2-1)*wordSize);
+  for (index = 0; index < mcnt; index++) {
+    // Make a BoxLockNode for the monitor.
+    Node *box = _gvn.transform(new (C, 1) BoxLockNode(next_monitor()));
+
+
+    // Displaced headers and locked objects are interleaved in the
+    // temp OSR buffer.  We only copy the locked objects out here.
+    // Fetch the locked object from the OSR temp buffer and copy to our fastlock node.
+    Node *lock_object = fetch_interpreter_state(index*2, T_OBJECT, monitors_addr, osr_buf);
+    // Try and copy the displaced header to the BoxNode
+    Node *displaced_hdr = fetch_interpreter_state((index*2) + 1, T_ADDRESS, monitors_addr, osr_buf);
+
+
+    store_to_memory(control(), box, displaced_hdr, T_ADDRESS, Compile::AliasIdxRaw);
+
+    // Build a bogus FastLockNode (no code will be generated) and push the
+    // monitor into our debug info.
+    const FastLockNode *flock = _gvn.transform(new (C, 3) FastLockNode( 0, lock_object, box ))->as_FastLock();
+    map()->push_monitor(flock);
+
+    // If the lock is our method synchronization lock, tuck it away in
+    // _sync_lock for return and rethrow exit paths.
+    if (index == 0 && method()->is_synchronized()) {
+      _synch_lock = flock;
+    }
+  }
+
+  MethodLivenessResult live_locals = method()->liveness_at_bci(osr_bci());
+  if (!live_locals.is_valid()) {
+    // Degenerate or breakpointed method.
+    C->record_method_not_compilable("OSR in empty or breakpointed method");
+    return;
+  }
+
+  // Extract the needed locals from the interpreter frame.
+  Node *locals_addr = basic_plus_adr(osr_buf, osr_buf, (max_locals-1)*wordSize);
+
+  // find all the locals that the interpreter thinks contain live oops
+  const BitMap live_oops = method()->live_local_oops_at_bci(osr_bci());
+  for (index = 0; index < max_locals; index++) {
+
+    if (!live_locals.at(index)) {
+      continue;
+    }
+
+    const Type *type = osr_block->local_type_at(index);
+
+    if (type->isa_oopptr() != NULL) {
+
+      // 6403625: Verify that the interpreter oopMap thinks that the oop is live
+      // else we might load a stale oop if the MethodLiveness disagrees with the
+      // result of the interpreter. If the interpreter says it is dead we agree
+      // by making the value go to top.
+      //
+
+      if (!live_oops.at(index)) {
+        if (C->log() != NULL) {
+          C->log()->elem("OSR_mismatch local_index='%d'",index);
+        }
+        set_local(index, null());
+        // and ignore it for the loads
+        continue;
+      }
+    }
+
+    // Filter out TOP, HALF, and BOTTOM.  (Cf. ensure_phi.)
+    if (type == Type::TOP || type == Type::HALF) {
+      continue;
+    }
+    // If the type falls to bottom, then this must be a local that
+    // is mixing ints and oops or some such.  Forcing it to top
+    // makes it go dead.
+    if (type == Type::BOTTOM) {
+      continue;
+    }
+    // Construct code to access the appropriate local.
+    Node *value = fetch_interpreter_state(index, type->basic_type(), locals_addr, osr_buf);
+    set_local(index, value);
+  }
+
+  // Extract the needed stack entries from the interpreter frame.
+  for (index = 0; index < sp(); index++) {
+    const Type *type = osr_block->stack_type_at(index);
+    if (type != Type::TOP) {
+      // Currently the compiler bails out when attempting to on stack replace
+      // at a bci with a non-empty stack.  We should not reach here.
+      ShouldNotReachHere();
+    }
+  }
+
+  // End the OSR migration
+  make_runtime_call(RC_LEAF, OptoRuntime::osr_end_Type(),
+                    CAST_FROM_FN_PTR(address, SharedRuntime::OSR_migration_end),
+                    "OSR_migration_end", TypeRawPtr::BOTTOM,
+                    osr_buf);
+
+  // Now that the interpreter state is loaded, make sure it will match
+  // at execution time what the compiler is expecting now:
+  SafePointNode* bad_type_exit = clone_map();
+  bad_type_exit->set_control(new (C, 1) RegionNode(1));
+
+  for (index = 0; index < max_locals; index++) {
+    if (stopped())  break;
+    Node* l = local(index);
+    if (l->is_top())  continue;  // nothing here
+    const Type *type = osr_block->local_type_at(index);
+    if (type->isa_oopptr() != NULL) {
+      if (!live_oops.at(index)) {
+        // skip type check for dead oops
+        continue;
+      }
+    }
+    set_local(index, check_interpreter_type(l, type, bad_type_exit));
+  }
+
+  for (index = 0; index < sp(); index++) {
+    if (stopped())  break;
+    Node* l = stack(index);
+    if (l->is_top())  continue;  // nothing here
+    const Type *type = osr_block->stack_type_at(index);
+    set_stack(index, check_interpreter_type(l, type, bad_type_exit));
+  }
+
+  if (bad_type_exit->control()->req() > 1) {
+    // Build an uncommon trap here, if any inputs can be unexpected.
+    bad_type_exit->set_control(_gvn.transform( bad_type_exit->control() ));
+    record_for_igvn(bad_type_exit->control());
+    SafePointNode* types_are_good = map();
+    set_map(bad_type_exit);
+    // The unexpected type happens because a new edge is active
+    // in the CFG, which typeflow had previously ignored.
+    // E.g., Object x = coldAtFirst() && notReached()? "str": new Integer(123).
+    // This x will be typed as Integer if notReached is not yet linked.
+    uncommon_trap(Deoptimization::Reason_unreached,
+                  Deoptimization::Action_reinterpret);
+    set_map(types_are_good);
+  }
+}
+
+//------------------------------Parse------------------------------------------
+// Main parser constructor.
+Parse::Parse(JVMState* caller, ciMethod* parse_method, float expected_uses)
+  : _exits(caller)
+{
+  // Init some variables
+  _caller = caller;
+  _method = parse_method;
+  _expected_uses = expected_uses;
+  _depth = 1 + (caller->has_method() ? caller->depth() : 0);
+  _wrote_final = false;
+  _entry_bci = InvocationEntryBci;
+  _tf = NULL;
+  _block = NULL;
+  debug_only(_block_count = -1);
+  debug_only(_blocks = (Block*)-1);
+#ifndef PRODUCT
+  if (PrintCompilation || PrintOpto) {
+    // Make sure I have an inline tree, so I can print messages about it.
+    JVMState* ilt_caller = is_osr_parse() ? caller->caller() : caller;
+    InlineTree::find_subtree_from_root(C->ilt(), ilt_caller, parse_method, true);
+  }
+  _max_switch_depth = 0;
+  _est_switch_depth = 0;
+#endif
+
+  _tf = TypeFunc::make(method());
+  _iter.reset_to_method(method());
+  _flow = method()->get_flow_analysis();
+  if (_flow->failing()) {
+    C->record_method_not_compilable_all_tiers(_flow->failure_reason());
+  }
+
+  if (_expected_uses <= 0) {
+    _prof_factor = 1;
+  } else {
+    float prof_total = parse_method->interpreter_invocation_count();
+    if (prof_total <= _expected_uses) {
+      _prof_factor = 1;
+    } else {
+      _prof_factor = _expected_uses / prof_total;
+    }
+  }
+
+  CompileLog* log = C->log();
+  if (log != NULL) {
+    log->begin_head("parse method='%d' uses='%g'",
+                    log->identify(parse_method), expected_uses);
+    if (depth() == 1 && C->is_osr_compilation()) {
+      log->print(" osr_bci='%d'", C->entry_bci());
+    }
+    log->stamp();
+    log->end_head();
+  }
+
+  // Accumulate deoptimization counts.
+  // (The range_check and store_check counts are checked elsewhere.)
+  ciMethodData* md = method()->method_data();
+  for (uint reason = 0; reason < md->trap_reason_limit(); reason++) {
+    uint md_count = md->trap_count(reason);
+    if (md_count != 0) {
+      if (md_count == md->trap_count_limit())
+        md_count += md->overflow_trap_count();
+      uint total_count = C->trap_count(reason);
+      uint old_count   = total_count;
+      total_count += md_count;
+      // Saturate the add if it overflows.
+      if (total_count < old_count || total_count < md_count)
+        total_count = (uint)-1;
+      C->set_trap_count(reason, total_count);
+      if (log != NULL)
+        log->elem("observe trap='%s' count='%d' total='%d'",
+                  Deoptimization::trap_reason_name(reason),
+                  md_count, total_count);
+    }
+  }
+  // Accumulate total sum of decompilations, also.
+  C->set_decompile_count(C->decompile_count() + md->decompile_count());
+
+  _count_invocations = C->do_count_invocations();
+  _method_data_update = C->do_method_data_update();
+
+  if (log != NULL && method()->has_exception_handlers()) {
+    log->elem("observe that='has_exception_handlers'");
+  }
+
+  assert(method()->can_be_compiled(),       "Can not parse this method, cutout earlier");
+  assert(method()->has_balanced_monitors(), "Can not parse unbalanced monitors, cutout earlier");
+
+  // Always register dependence if JVMTI is enabled, because
+  // either breakpoint setting or hotswapping of methods may
+  // cause deoptimization.
+  if (JvmtiExport::can_hotswap_or_post_breakpoint()) {
+    C->dependencies()->assert_evol_method(method());
+  }
+
+  methods_seen++;
+
+  // Do some special top-level things.
+  if (depth() == 1 && C->is_osr_compilation()) {
+    _entry_bci = C->entry_bci();
+    _flow = method()->get_osr_flow_analysis(osr_bci());
+    if (_flow->failing()) {
+      C->record_method_not_compilable(_flow->failure_reason());
+#ifndef PRODUCT
+      if (PrintOpto && (Verbose || WizardMode)) {
+        tty->print_cr("OSR @%d type flow bailout: %s", _entry_bci, _flow->failure_reason());
+        if (Verbose) {
+          method()->print_oop();
+          method()->print_codes();
+          _flow->print();
+        }
+      }
+#endif
+    }
+    _tf = C->tf();     // the OSR entry type is different
+  }
+
+#ifdef ASSERT
+  if (depth() == 1) {
+    assert(C->is_osr_compilation() == this->is_osr_parse(), "OSR in sync");
+    if (C->tf() != tf()) {
+      MutexLockerEx ml(Compile_lock, Mutex::_no_safepoint_check_flag);
+      assert(C->env()->system_dictionary_modification_counter_changed(),
+             "Must invalidate if TypeFuncs differ");
+    }
+  } else {
+    assert(!this->is_osr_parse(), "no recursive OSR");
+  }
+#endif
+
+  methods_parsed++;
+#ifndef PRODUCT
+  // add method size here to guarantee that inlined methods are added too
+  if (TimeCompiler)
+    _total_bytes_compiled += method()->code_size();
+
+  show_parse_info();
+#endif
+
+  if (failing()) {
+    if (log)  log->done("parse");
+    return;
+  }
+
+  gvn().set_type(root(), root()->bottom_type());
+  gvn().transform(top());
+
+  // Import the results of the ciTypeFlow.
+  init_blocks();
+
+  // Merge point for all normal exits
+  build_exits();
+
+  // Setup the initial JVM state map.
+  SafePointNode* entry_map = create_entry_map();
+
+  // Check for bailouts during map initialization
+  if (failing() || entry_map == NULL) {
+    if (log)  log->done("parse");
+    return;
+  }
+
+  Node_Notes* caller_nn = C->default_node_notes();
+  // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
+  if (DebugInlinedCalls || depth() == 1) {
+    C->set_default_node_notes(make_node_notes(caller_nn));
+  }
+
+  if (is_osr_parse()) {
+    Node* osr_buf = entry_map->in(TypeFunc::Parms+0);
+    entry_map->set_req(TypeFunc::Parms+0, top());
+    set_map(entry_map);
+    load_interpreter_state(osr_buf);
+  } else {
+    set_map(entry_map);
+    do_method_entry();
+  }
+
+  // Check for bailouts during method entry.
+  if (failing()) {
+    if (log)  log->done("parse");
+    C->set_default_node_notes(caller_nn);
+    return;
+  }
+
+  entry_map = map();  // capture any changes performed by method setup code
+  assert(jvms()->endoff() == map()->req(), "map matches JVMS layout");
+
+  // We begin parsing as if we have just encountered a jump to the
+  // method entry.
+  Block* entry_block = start_block();
+  assert(entry_block->start() == (is_osr_parse() ? osr_bci() : 0), "");
+  set_map_clone(entry_map);
+  merge_common(entry_block, entry_block->next_path_num());
+
+#ifndef PRODUCT
+  BytecodeParseHistogram *parse_histogram_obj = new (C->env()->arena()) BytecodeParseHistogram(this, C);
+  set_parse_histogram( parse_histogram_obj );
+#endif
+
+  // Parse all the basic blocks.
+  do_all_blocks();
+
+  C->set_default_node_notes(caller_nn);
+
+  // Check for bailouts during conversion to graph
+  if (failing()) {
+    if (log)  log->done("parse");
+    return;
+  }
+
+  // Fix up all exiting control flow.
+  set_map(entry_map);
+  do_exits();
+
+  // Collect a few more statistics.
+  parse_idx += C->unique();
+  parse_arena += C->node_arena()->used();
+
+  if (log)  log->done("parse nodes='%d' memory='%d'",
+                      C->unique(), C->node_arena()->used());
+}
+
+//---------------------------do_all_blocks-------------------------------------
+void Parse::do_all_blocks() {
+  _blocks_merged = 0;
+  _blocks_parsed = 0;
+
+  int old_blocks_merged = -1;
+  int old_blocks_parsed = -1;
+
+  for (int tries = 0; ; tries++) {
+    visit_blocks();
+    if (failing())  return; // Check for bailout
+
+    // No need for a work list.  The outer loop is hardly ever repeated.
+    // The following loop traverses the blocks in a reasonable pre-order,
+    // as produced by the ciTypeFlow pass.
+
+    // This loop can be taken more than once if there are two entries to
+    // a loop (irreduceable CFG), and the edge which ciTypeFlow chose
+    // as the first predecessor to the loop goes dead in the parser,
+    // due to parse-time optimization.  (Could happen with obfuscated code.)
+
+    // Look for progress, or the lack of it:
+    if (_blocks_parsed == block_count()) {
+      // That's all, folks.
+      if (TraceOptoParse) {
+        tty->print_cr("All blocks parsed.");
+      }
+      break;
+    }
+
+    // How much work was done this time around?
+    int new_blocks_merged = _blocks_merged - old_blocks_merged;
+    int new_blocks_parsed = _blocks_parsed - old_blocks_parsed;
+    if (new_blocks_merged == 0) {
+      if (TraceOptoParse) {
+        tty->print_cr("All live blocks parsed; %d dead blocks.", block_count() - _blocks_parsed);
+      }
+      // No new blocks have become parseable.  Some blocks are just dead.
+      break;
+    }
+    assert(new_blocks_parsed > 0, "must make progress");
+    assert(tries < block_count(), "the pre-order cannot be this bad!");
+
+    old_blocks_merged = _blocks_merged;
+    old_blocks_parsed = _blocks_parsed;
+  }
+
+#ifndef PRODUCT
+  // Make sure there are no half-processed blocks remaining.
+  // Every remaining unprocessed block is dead and may be ignored now.
+  for (int po = 0; po < block_count(); po++) {
+    Block* block = pre_order_at(po);
+    if (!block->is_parsed()) {
+      if (TraceOptoParse) {
+        tty->print("Skipped dead block %d at bci:%d", po, block->start());
+        assert(!block->is_merged(), "no half-processed blocks");
+      }
+    }
+  }
+#endif
+}
+
+//---------------------------visit_blocks--------------------------------------
+void Parse::visit_blocks() {
+  // Walk over all blocks, parsing every one that has been reached (merged).
+  for (int po = 0; po < block_count(); po++) {
+    Block* block = pre_order_at(po);
+
+    if (block->is_parsed()) {
+      // Do not parse twice.
+      continue;
+    }
+
+    if (!block->is_merged()) {
+      // No state on this block.  It had not yet been reached.
+      // Delay reaching it until later.
+      continue;
+    }
+
+    // Prepare to parse this block.
+    load_state_from(block);
+
+    if (stopped()) {
+      // Block is dead.
+      continue;
+    }
+
+    if (!block->is_ready() || block->is_handler()) {
+      // Not all preds have been parsed.  We must build phis everywhere.
+      // (Note that dead locals do not get phis built, ever.)
+      ensure_phis_everywhere();
+
+      // Leave behind an undisturbed copy of the map, for future merges.
+      set_map(clone_map());
+    }
+
+    // Ready or not, parse the block.
+    do_one_block();
+
+    // Check for bailouts.
+    if (failing())  return;
+  }
+}
+
+//-------------------------------build_exits----------------------------------
+// Build normal and exceptional exit merge points.
+void Parse::build_exits() {
+  // make a clone of caller to prevent sharing of side-effects
+  _exits.set_map(_exits.clone_map());
+  _exits.clean_stack(_exits.sp());
+  _exits.sync_jvms();
+
+  RegionNode* region = new (C, 1) RegionNode(1);
+  record_for_igvn(region);
+  gvn().set_type_bottom(region);
+  _exits.set_control(region);
+
+  // Note:  iophi and memphi are not transformed until do_exits.
+  Node* iophi  = new (C, region->req()) PhiNode(region, Type::ABIO);
+  Node* memphi = new (C, region->req()) PhiNode(region, Type::MEMORY, TypePtr::BOTTOM);
+  _exits.set_i_o(iophi);
+  _exits.set_all_memory(memphi);
+
+  // Add a return value to the exit state.  (Do not push it yet.)
+  if (tf()->range()->cnt() > TypeFunc::Parms) {
+    const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
+    // Don't "bind" an unloaded return klass to the ret_phi. If the klass
+    // becomes loaded during the subsequent parsing, the loaded and unloaded
+    // types will not join when we transform and push in do_exits().
+    const TypeOopPtr* ret_oop_type = ret_type->isa_oopptr();
+    if (ret_oop_type && !ret_oop_type->klass()->is_loaded()) {
+      ret_type = TypeOopPtr::BOTTOM;
+    }
+    int         ret_size = type2size[ret_type->basic_type()];
+    Node*       ret_phi  = new (C, region->req()) PhiNode(region, ret_type);
+    _exits.ensure_stack(ret_size);
+    assert((int)(tf()->range()->cnt() - TypeFunc::Parms) == ret_size, "good tf range");
+    assert(method()->return_type()->size() == ret_size, "tf agrees w/ method");
+    _exits.set_argument(0, ret_phi);  // here is where the parser finds it
+    // Note:  ret_phi is not yet pushed, until do_exits.
+  }
+}
+
+
+//----------------------------build_start_state-------------------------------
+// Construct a state which contains only the incoming arguments from an
+// unknown caller.  The method & bci will be NULL & InvocationEntryBci.
+JVMState* Compile::build_start_state(StartNode* start, const TypeFunc* tf) {
+  int        arg_size = tf->domain()->cnt();
+  int        max_size = MAX2(arg_size, (int)tf->range()->cnt());
+  JVMState*  jvms     = new (this) JVMState(max_size - TypeFunc::Parms);
+  SafePointNode* map  = new (this, max_size) SafePointNode(max_size, NULL);
+  record_for_igvn(map);
+  assert(arg_size == TypeFunc::Parms + (is_osr_compilation() ? 1 : method()->arg_size()), "correct arg_size");
+  Node_Notes* old_nn = default_node_notes();
+  if (old_nn != NULL && has_method()) {
+    Node_Notes* entry_nn = old_nn->clone(this);
+    JVMState* entry_jvms = new(this) JVMState(method(), old_nn->jvms());
+    entry_jvms->set_offsets(0);
+    entry_jvms->set_bci(entry_bci());
+    entry_nn->set_jvms(entry_jvms);
+    set_default_node_notes(entry_nn);
+  }
+  uint i;
+  for (i = 0; i < (uint)arg_size; i++) {
+    Node* parm = initial_gvn()->transform(new (this, 1) ParmNode(start, i));
+    map->init_req(i, parm);
+    // Record all these guys for later GVN.
+    record_for_igvn(parm);
+  }
+  for (; i < map->req(); i++) {
+    map->init_req(i, top());
+  }
+  assert(jvms->argoff() == TypeFunc::Parms, "parser gets arguments here");
+  set_default_node_notes(old_nn);
+  map->set_jvms(jvms);
+  jvms->set_map(map);
+  return jvms;
+}
+
+//-----------------------------make_node_notes---------------------------------
+Node_Notes* Parse::make_node_notes(Node_Notes* caller_nn) {
+  if (caller_nn == NULL)  return NULL;
+  Node_Notes* nn = caller_nn->clone(C);
+  JVMState* caller_jvms = nn->jvms();
+  JVMState* jvms = new (C) JVMState(method(), caller_jvms);
+  jvms->set_offsets(0);
+  jvms->set_bci(_entry_bci);
+  nn->set_jvms(jvms);
+  return nn;
+}
+
+
+//--------------------------return_values--------------------------------------
+void Compile::return_values(JVMState* jvms) {
+  GraphKit kit(jvms);
+  Node* ret = new (this, TypeFunc::Parms) ReturnNode(TypeFunc::Parms,
+                             kit.control(),
+                             kit.i_o(),
+                             kit.reset_memory(),
+                             kit.frameptr(),
+                             kit.returnadr());
+  // Add zero or 1 return values
+  int ret_size = tf()->range()->cnt() - TypeFunc::Parms;
+  if (ret_size > 0) {
+    kit.inc_sp(-ret_size);  // pop the return value(s)
+    kit.sync_jvms();
+    ret->add_req(kit.argument(0));
+    // Note:  The second dummy edge is not needed by a ReturnNode.
+  }
+  // bind it to root
+  root()->add_req(ret);
+  record_for_igvn(ret);
+  initial_gvn()->transform_no_reclaim(ret);
+}
+
+//------------------------rethrow_exceptions-----------------------------------
+// Bind all exception states in the list into a single RethrowNode.
+void Compile::rethrow_exceptions(JVMState* jvms) {
+  GraphKit kit(jvms);
+  if (!kit.has_exceptions())  return;  // nothing to generate
+  // Load my combined exception state into the kit, with all phis transformed:
+  SafePointNode* ex_map = kit.combine_and_pop_all_exception_states();
+  Node* ex_oop = kit.use_exception_state(ex_map);
+  RethrowNode* exit = new (this, TypeFunc::Parms + 1) RethrowNode(kit.control(),
+                                      kit.i_o(), kit.reset_memory(),
+                                      kit.frameptr(), kit.returnadr(),
+                                      // like a return but with exception input
+                                      ex_oop);
+  // bind to root
+  root()->add_req(exit);
+  record_for_igvn(exit);
+  initial_gvn()->transform_no_reclaim(exit);
+}
+
+bool Parse::can_rerun_bytecode() {
+  switch (bc()) {
+  case Bytecodes::_ldc:
+  case Bytecodes::_ldc_w:
+  case Bytecodes::_ldc2_w:
+  case Bytecodes::_getfield:
+  case Bytecodes::_putfield:
+  case Bytecodes::_getstatic:
+  case Bytecodes::_putstatic:
+  case Bytecodes::_arraylength:
+  case Bytecodes::_baload:
+  case Bytecodes::_caload:
+  case Bytecodes::_iaload:
+  case Bytecodes::_saload:
+  case Bytecodes::_faload:
+  case Bytecodes::_aaload:
+  case Bytecodes::_laload:
+  case Bytecodes::_daload:
+  case Bytecodes::_bastore:
+  case Bytecodes::_castore:
+  case Bytecodes::_iastore:
+  case Bytecodes::_sastore:
+  case Bytecodes::_fastore:
+  case Bytecodes::_aastore:
+  case Bytecodes::_lastore:
+  case Bytecodes::_dastore:
+  case Bytecodes::_irem:
+  case Bytecodes::_idiv:
+  case Bytecodes::_lrem:
+  case Bytecodes::_ldiv:
+  case Bytecodes::_frem:
+  case Bytecodes::_fdiv:
+  case Bytecodes::_drem:
+  case Bytecodes::_ddiv:
+  case Bytecodes::_checkcast:
+  case Bytecodes::_instanceof:
+  case Bytecodes::_athrow:
+  case Bytecodes::_anewarray:
+  case Bytecodes::_newarray:
+  case Bytecodes::_multianewarray:
+  case Bytecodes::_new:
+  case Bytecodes::_monitorenter:  // can re-run initial null check, only
+  case Bytecodes::_return:
+    return true;
+    break;
+
+  case Bytecodes::_invokestatic:
+  case Bytecodes::_invokespecial:
+  case Bytecodes::_invokevirtual:
+  case Bytecodes::_invokeinterface:
+    return false;
+    break;
+
+  default:
+    assert(false, "unexpected bytecode produced an exception");
+    return true;
+  }
+}
+
+//---------------------------do_exceptions-------------------------------------
+// Process exceptions arising from the current bytecode.
+// Send caught exceptions to the proper handler within this method.
+// Unhandled exceptions feed into _exit.
+void Parse::do_exceptions() {
+  if (!has_exceptions())  return;
+
+  if (failing()) {
+    // Pop them all off and throw them away.
+    while (pop_exception_state() != NULL) ;
+    return;
+  }
+
+  // Make sure we can classify this bytecode if we need to.
+  debug_only(can_rerun_bytecode());
+
+  PreserveJVMState pjvms(this, false);
+
+  SafePointNode* ex_map;
+  while ((ex_map = pop_exception_state()) != NULL) {
+    if (!method()->has_exception_handlers()) {
+      // Common case:  Transfer control outward.
+      // Doing it this early allows the exceptions to common up
+      // even between adjacent method calls.
+      throw_to_exit(ex_map);
+    } else {
+      // Have to look at the exception first.
+      assert(stopped(), "catch_inline_exceptions trashes the map");
+      catch_inline_exceptions(ex_map);
+      stop_and_kill_map();      // we used up this exception state; kill it
+    }
+  }
+
+  // We now return to our regularly scheduled program:
+}
+
+//---------------------------throw_to_exit-------------------------------------
+// Merge the given map into an exception exit from this method.
+// The exception exit will handle any unlocking of receiver.
+// The ex_oop must be saved within the ex_map, unlike merge_exception.
+void Parse::throw_to_exit(SafePointNode* ex_map) {
+  // Pop the JVMS to (a copy of) the caller.
+  GraphKit caller;
+  caller.set_map_clone(_caller->map());
+  caller.set_bci(_caller->bci());
+  caller.set_sp(_caller->sp());
+  // Copy out the standard machine state:
+  for (uint i = 0; i < TypeFunc::Parms; i++) {
+    caller.map()->set_req(i, ex_map->in(i));
+  }
+  // ...and the exception:
+  Node*          ex_oop        = saved_ex_oop(ex_map);
+  SafePointNode* caller_ex_map = caller.make_exception_state(ex_oop);
+  // Finally, collect the new exception state in my exits:
+  _exits.add_exception_state(caller_ex_map);
+}
+
+//------------------------------do_exits---------------------------------------
+void Parse::do_exits() {
+  set_parse_bci(InvocationEntryBci);
+
+  // Now peephole on the return bits
+  Node* region = _exits.control();
+  _exits.set_control(gvn().transform(region));
+
+  Node* iophi = _exits.i_o();
+  _exits.set_i_o(gvn().transform(iophi));
+
+  if (wrote_final()) {
+    // This method (which must be a constructor by the rules of Java)
+    // wrote a final.  The effects of all initializations must be
+    // committed to memory before any code after the constructor
+    // publishes the reference to the newly constructor object.
+    // Rather than wait for the publication, we simply block the
+    // writes here.  Rather than put a barrier on only those writes
+    // which are required to complete, we force all writes to complete.
+    //
+    // "All bets are off" unless the first publication occurs after a
+    // normal return from the constructor.  We do not attempt to detect
+    // such unusual early publications.  But no barrier is needed on
+    // exceptional returns, since they cannot publish normally.
+    //
+    _exits.insert_mem_bar(Op_MemBarRelease);
+#ifndef PRODUCT
+    if (PrintOpto && (Verbose || WizardMode)) {
+      method()->print_name();
+      tty->print_cr(" writes finals and needs a memory barrier");
+    }
+#endif
+  }
+
+  for (MergeMemStream mms(_exits.merged_memory()); mms.next_non_empty(); ) {
+    // transform each slice of the original memphi:
+    mms.set_memory(_gvn.transform(mms.memory()));
+  }
+
+  if (tf()->range()->cnt() > TypeFunc::Parms) {
+    const Type* ret_type = tf()->range()->field_at(TypeFunc::Parms);
+    Node*       ret_phi  = _gvn.transform( _exits.argument(0) );
+    assert(_exits.control()->is_top() || !_gvn.type(ret_phi)->empty(), "return value must be well defined");
+    _exits.push_node(ret_type->basic_type(), ret_phi);
+  }
+
+  // Note:  Logic for creating and optimizing the ReturnNode is in Compile.
+
+  // Unlock along the exceptional paths.
+  // This is done late so that we can common up equivalent exceptions
+  // (e.g., null checks) arising from multiple points within this method.
+  // See GraphKit::add_exception_state, which performs the commoning.
+  bool do_synch = method()->is_synchronized() && GenerateSynchronizationCode;
+
+  // record exit from a method if compiled while Dtrace is turned on.
+  if (do_synch || DTraceMethodProbes) {
+    // First move the exception list out of _exits:
+    GraphKit kit(_exits.transfer_exceptions_into_jvms());
+    SafePointNode* normal_map = kit.map();  // keep this guy safe
+    // Now re-collect the exceptions into _exits:
+    SafePointNode* ex_map;
+    while ((ex_map = kit.pop_exception_state()) != NULL) {
+      Node* ex_oop = kit.use_exception_state(ex_map);
+      // Force the exiting JVM state to have this method at InvocationEntryBci.
+      // The exiting JVM state is otherwise a copy of the calling JVMS.
+      JVMState* caller = kit.jvms();
+      JVMState* ex_jvms = caller->clone_shallow(C);
+      ex_jvms->set_map(kit.clone_map());
+      ex_jvms->map()->set_jvms(ex_jvms);
+      ex_jvms->set_bci(   InvocationEntryBci);
+      kit.set_jvms(ex_jvms);
+      if (do_synch) {
+        // Add on the synchronized-method box/object combo
+        kit.map()->push_monitor(_synch_lock);
+        // Unlock!
+        kit.shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
+      }
+      if (DTraceMethodProbes) {
+        kit.make_dtrace_method_exit(method());
+      }
+      // Done with exception-path processing.
+      ex_map = kit.make_exception_state(ex_oop);
+      assert(ex_jvms->same_calls_as(ex_map->jvms()), "sanity");
+      // Pop the last vestige of this method:
+      ex_map->set_jvms(caller->clone_shallow(C));
+      ex_map->jvms()->set_map(ex_map);
+      _exits.push_exception_state(ex_map);
+    }
+    assert(_exits.map() == normal_map, "keep the same return state");
+  }
+
+  {
+    // Capture very early exceptions (receiver null checks) from caller JVMS
+    GraphKit caller(_caller);
+    SafePointNode* ex_map;
+    while ((ex_map = caller.pop_exception_state()) != NULL) {
+      _exits.add_exception_state(ex_map);
+    }
+  }
+}
+
+//-----------------------------create_entry_map-------------------------------
+// Initialize our parser map to contain the types at method entry.
+// For OSR, the map contains a single RawPtr parameter.
+// Initial monitor locking for sync. methods is performed by do_method_entry.
+SafePointNode* Parse::create_entry_map() {
+  // Check for really stupid bail-out cases.
+  uint len = TypeFunc::Parms + method()->max_locals() + method()->max_stack();
+  if (len >= 32760) {
+    C->record_method_not_compilable_all_tiers("too many local variables");
+    return NULL;
+  }
+
+  // If this is an inlined method, we may have to do a receiver null check.
+  if (_caller->has_method() && is_normal_parse() && !method()->is_static()) {
+    GraphKit kit(_caller);
+    kit.null_check_receiver(method());
+    _caller = kit.transfer_exceptions_into_jvms();
+    if (kit.stopped()) {
+      _exits.add_exception_states_from(_caller);
+      _exits.set_jvms(_caller);
+      return NULL;
+    }
+  }
+
+  assert(method() != NULL, "parser must have a method");
+
+  // Create an initial safepoint to hold JVM state during parsing
+  JVMState* jvms = new (C) JVMState(method(), _caller->has_method() ? _caller : NULL);
+  set_map(new (C, len) SafePointNode(len, jvms));
+  jvms->set_map(map());
+  record_for_igvn(map());
+  assert(jvms->endoff() == len, "correct jvms sizing");
+
+  SafePointNode* inmap = _caller->map();
+  assert(inmap != NULL, "must have inmap");
+
+  uint i;
+
+  // Pass thru the predefined input parameters.
+  for (i = 0; i < TypeFunc::Parms; i++) {
+    map()->init_req(i, inmap->in(i));
+  }
+
+  if (depth() == 1) {
+    assert(map()->memory()->Opcode() == Op_Parm, "");
+    // Insert the memory aliasing node
+    set_all_memory(reset_memory());
+  }
+  assert(merged_memory(), "");
+
+  // Now add the locals which are initially bound to arguments:
+  uint arg_size = tf()->domain()->cnt();
+  ensure_stack(arg_size - TypeFunc::Parms);  // OSR methods have funny args
+  for (i = TypeFunc::Parms; i < arg_size; i++) {
+    map()->init_req(i, inmap->argument(_caller, i - TypeFunc::Parms));
+  }
+
+  // Clear out the rest of the map (locals and stack)
+  for (i = arg_size; i < len; i++) {
+    map()->init_req(i, top());
+  }
+
+  SafePointNode* entry_map = stop();
+  return entry_map;
+}
+
+//-----------------------------do_method_entry--------------------------------
+// Emit any code needed in the pseudo-block before BCI zero.
+// The main thing to do is lock the receiver of a synchronized method.
+void Parse::do_method_entry() {
+  set_parse_bci(InvocationEntryBci); // Pseudo-BCP
+  set_sp(0);                      // Java Stack Pointer
+
+  NOT_PRODUCT( count_compiled_calls(true/*at_method_entry*/, false/*is_inline*/); )
+
+  if (DTraceMethodProbes) {
+    make_dtrace_method_entry(method());
+  }
+
+  // If the method is synchronized, we need to construct a lock node, attach
+  // it to the Start node, and pin it there.
+  if (method()->is_synchronized()) {
+    // Insert a FastLockNode right after the Start which takes as arguments
+    // the current thread pointer, the "this" pointer & the address of the
+    // stack slot pair used for the lock.  The "this" pointer is a projection
+    // off the start node, but the locking spot has to be constructed by
+    // creating a ConLNode of 0, and boxing it with a BoxLockNode.  The BoxLockNode
+    // becomes the second argument to the FastLockNode call.  The
+    // FastLockNode becomes the new control parent to pin it to the start.
+
+    // Setup Object Pointer
+    Node *lock_obj = NULL;
+    if(method()->is_static()) {
+      ciInstance* mirror = _method->holder()->java_mirror();
+      const TypeInstPtr *t_lock = TypeInstPtr::make(mirror);
+      lock_obj = makecon(t_lock);
+    } else {                  // Else pass the "this" pointer,
+      lock_obj = local(0);    // which is Parm0 from StartNode
+    }
+    // Clear out dead values from the debug info.
+    kill_dead_locals();
+    // Build the FastLockNode
+    _synch_lock = shared_lock(lock_obj);
+  }
+
+  if (depth() == 1) {
+    increment_and_test_invocation_counter(Tier2CompileThreshold);
+  }
+}
+
+//------------------------------init_blocks------------------------------------
+// Initialize our parser map to contain the types/monitors at method entry.
+void Parse::init_blocks() {
+  // Create the blocks.
+  _block_count = flow()->block_count();
+  _blocks = NEW_RESOURCE_ARRAY(Block, _block_count);
+  Copy::zero_to_bytes(_blocks, sizeof(Block)*_block_count);
+
+  int po;
+
+  // Initialize the structs.
+  for (po = 0; po < block_count(); po++) {
+    Block* block = pre_order_at(po);
+    block->init_node(this, po);
+  }
+
+  // Collect predecessor and successor information.
+  for (po = 0; po < block_count(); po++) {
+    Block* block = pre_order_at(po);
+    block->init_graph(this);
+  }
+}
+
+//-------------------------------init_node-------------------------------------
+void Parse::Block::init_node(Parse* outer, int po) {
+  _flow = outer->flow()->pre_order_at(po);
+  _pred_count = 0;
+  _preds_parsed = 0;
+  _count = 0;
+  assert(pred_count() == 0 && preds_parsed() == 0, "sanity");
+  assert(!(is_merged() || is_parsed() || is_handler()), "sanity");
+  assert(_live_locals.size() == 0, "sanity");
+
+  // entry point has additional predecessor
+  if (flow()->is_start())  _pred_count++;
+  assert(flow()->is_start() == (this == outer->start_block()), "");
+}
+
+//-------------------------------init_graph------------------------------------
+void Parse::Block::init_graph(Parse* outer) {
+  // Create the successor list for this parser block.
+  GrowableArray<ciTypeFlow::Block*>* tfs = flow()->successors();
+  GrowableArray<ciTypeFlow::Block*>* tfe = flow()->exceptions();
+  int ns = tfs->length();
+  int ne = tfe->length();
+  _num_successors = ns;
+  _all_successors = ns+ne;
+  _successors = (ns+ne == 0) ? NULL : NEW_RESOURCE_ARRAY(Block*, ns+ne);
+  int p = 0;
+  for (int i = 0; i < ns+ne; i++) {
+    ciTypeFlow::Block* tf2 = (i < ns) ? tfs->at(i) : tfe->at(i-ns);
+    Block* block2 = outer->pre_order_at(tf2->pre_order());
+    _successors[i] = block2;
+
+    // Accumulate pred info for the other block, too.
+    if (i < ns) {
+      block2->_pred_count++;
+    } else {
+      block2->_is_handler = true;
+    }
+
+    #ifdef ASSERT
+    // A block's successors must be distinguishable by BCI.
+    // That is, no bytecode is allowed to branch to two different
+    // clones of the same code location.
+    for (int j = 0; j < i; j++) {
+      Block* block1 = _successors[j];
+      if (block1 == block2)  continue;  // duplicates are OK
+      assert(block1->start() != block2->start(), "successors have unique bcis");
+    }
+    #endif
+  }
+
+  // Note: We never call next_path_num along exception paths, so they
+  // never get processed as "ready".  Also, the input phis of exception
+  // handlers get specially processed, so that
+}
+
+//---------------------------successor_for_bci---------------------------------
+Parse::Block* Parse::Block::successor_for_bci(int bci) {
+  for (int i = 0; i < all_successors(); i++) {
+    Block* block2 = successor_at(i);
+    if (block2->start() == bci)  return block2;
+  }
+  // We can actually reach here if ciTypeFlow traps out a block
+  // due to an unloaded class, and concurrently with compilation the
+  // class is then loaded, so that a later phase of the parser is
+  // able to see more of the bytecode CFG.  Or, the flow pass and
+  // the parser can have a minor difference of opinion about executability
+  // of bytecodes.  For example, "obj.field = null" is executable even
+  // if the field's type is an unloaded class; the flow pass used to
+  // make a trap for such code.
+  return NULL;
+}
+
+
+//-----------------------------stack_type_at-----------------------------------
+const Type* Parse::Block::stack_type_at(int i) const {
+  return get_type(flow()->stack_type_at(i));
+}
+
+
+//-----------------------------local_type_at-----------------------------------
+const Type* Parse::Block::local_type_at(int i) const {
+  // Make dead locals fall to bottom.
+  if (_live_locals.size() == 0) {
+    MethodLivenessResult live_locals = flow()->outer()->method()->liveness_at_bci(start());
+    // This bitmap can be zero length if we saw a breakpoint.
+    // In such cases, pretend they are all live.
+    ((Block*)this)->_live_locals = live_locals;
+  }
+  if (_live_locals.size() > 0 && !_live_locals.at(i))
+    return Type::BOTTOM;
+
+  return get_type(flow()->local_type_at(i));
+}
+
+
+#ifndef PRODUCT
+
+//----------------------------name_for_bc--------------------------------------
+// helper method for BytecodeParseHistogram
+static const char* name_for_bc(int i) {
+  return Bytecodes::is_defined(i) ? Bytecodes::name(Bytecodes::cast(i)) : "xxxunusedxxx";
+}
+
+//----------------------------BytecodeParseHistogram------------------------------------
+Parse::BytecodeParseHistogram::BytecodeParseHistogram(Parse *p, Compile *c) {
+  _parser   = p;
+  _compiler = c;
+  if( ! _initialized ) { _initialized = true; reset(); }
+}
+
+//----------------------------current_count------------------------------------
+int Parse::BytecodeParseHistogram::current_count(BPHType bph_type) {
+  switch( bph_type ) {
+  case BPH_transforms: { return _parser->gvn().made_progress(); }
+  case BPH_values:     { return _parser->gvn().made_new_values(); }
+  default: { ShouldNotReachHere(); return 0; }
+  }
+}
+
+//----------------------------initialized--------------------------------------
+bool Parse::BytecodeParseHistogram::initialized() { return _initialized; }
+
+//----------------------------reset--------------------------------------------
+void Parse::BytecodeParseHistogram::reset() {
+  int i = Bytecodes::number_of_codes;
+  while (i-- > 0) { _bytecodes_parsed[i] = 0; _nodes_constructed[i] = 0; _nodes_transformed[i] = 0; _new_values[i] = 0; }
+}
+
+//----------------------------set_initial_state--------------------------------
+// Record info when starting to parse one bytecode
+void Parse::BytecodeParseHistogram::set_initial_state( Bytecodes::Code bc ) {
+  if( PrintParseStatistics && !_parser->is_osr_parse() ) {
+    _initial_bytecode    = bc;
+    _initial_node_count  = _compiler->unique();
+    _initial_transforms  = current_count(BPH_transforms);
+    _initial_values      = current_count(BPH_values);
+  }
+}
+
+//----------------------------record_change--------------------------------
+// Record results of parsing one bytecode
+void Parse::BytecodeParseHistogram::record_change() {
+  if( PrintParseStatistics && !_parser->is_osr_parse() ) {
+    ++_bytecodes_parsed[_initial_bytecode];
+    _nodes_constructed [_initial_bytecode] += (_compiler->unique() - _initial_node_count);
+    _nodes_transformed [_initial_bytecode] += (current_count(BPH_transforms) - _initial_transforms);
+    _new_values        [_initial_bytecode] += (current_count(BPH_values)     - _initial_values);
+  }
+}
+
+
+//----------------------------print--------------------------------------------
+void Parse::BytecodeParseHistogram::print(float cutoff) {
+  ResourceMark rm;
+  // print profile
+  int total  = 0;
+  int i      = 0;
+  for( i = 0; i < Bytecodes::number_of_codes; ++i ) { total += _bytecodes_parsed[i]; }
+  int abs_sum = 0;
+  tty->cr();   //0123456789012345678901234567890123456789012345678901234567890123456789
+  tty->print_cr("Histogram of %d parsed bytecodes:", total);
+  if( total == 0 ) { return; }
+  tty->cr();
+  tty->print_cr("absolute:  count of compiled bytecodes of this type");
+  tty->print_cr("relative:  percentage contribution to compiled nodes");
+  tty->print_cr("nodes   :  Average number of nodes constructed per bytecode");
+  tty->print_cr("rnodes  :  Significance towards total nodes constructed, (nodes*relative)");
+  tty->print_cr("transforms: Average amount of tranform progress per bytecode compiled");
+  tty->print_cr("values  :  Average number of node values improved per bytecode");
+  tty->print_cr("name    :  Bytecode name");
+  tty->cr();
+  tty->print_cr("  absolute  relative   nodes  rnodes  transforms  values   name");
+  tty->print_cr("----------------------------------------------------------------------");
+  while (--i > 0) {
+    int       abs = _bytecodes_parsed[i];
+    float     rel = abs * 100.0F / total;
+    float   nodes = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_constructed[i])/_bytecodes_parsed[i];
+    float  rnodes = _bytecodes_parsed[i] == 0 ? 0 :  rel * nodes;
+    float  xforms = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _nodes_transformed[i])/_bytecodes_parsed[i];
+    float  values = _bytecodes_parsed[i] == 0 ? 0 : (1.0F * _new_values       [i])/_bytecodes_parsed[i];
+    if (cutoff <= rel) {
+      tty->print_cr("%10d  %7.2f%%  %6.1f  %6.2f   %6.1f   %6.1f     %s", abs, rel, nodes, rnodes, xforms, values, name_for_bc(i));
+      abs_sum += abs;
+    }
+  }
+  tty->print_cr("----------------------------------------------------------------------");
+  float rel_sum = abs_sum * 100.0F / total;
+  tty->print_cr("%10d  %7.2f%%    (cutoff = %.2f%%)", abs_sum, rel_sum, cutoff);
+  tty->print_cr("----------------------------------------------------------------------");
+  tty->cr();
+}
+#endif
+
+//----------------------------load_state_from----------------------------------
+// Load block/map/sp.  But not do not touch iter/bci.
+void Parse::load_state_from(Block* block) {
+  set_block(block);
+  // load the block's JVM state:
+  set_map(block->start_map());
+  set_sp( block->start_sp());
+}
+
+
+//-----------------------------record_state------------------------------------
+void Parse::Block::record_state(Parse* p) {
+  assert(!is_merged(), "can only record state once, on 1st inflow");
+  assert(start_sp() == p->sp(), "stack pointer must agree with ciTypeFlow");
+  set_start_map(p->stop());
+}
+
+
+//------------------------------do_one_block-----------------------------------
+void Parse::do_one_block() {
+  if (TraceOptoParse) {
+    Block *b = block();
+    int ns = b->num_successors();
+    int nt = b->all_successors();
+
+    tty->print("Parsing block #%d at bci [%d,%d), successors: ",
+                  block()->pre_order(), block()->start(), block()->limit());
+    for (int i = 0; i < nt; i++) {
+      tty->print((( i < ns) ? " %d" : " %d(e)"), b->successor_at(i)->pre_order());
+    }
+    tty->print_cr("");
+  }
+
+  assert(block()->is_merged(), "must be merged before being parsed");
+  block()->mark_parsed();
+  ++_blocks_parsed;
+
+  // Set iterator to start of block.
+  iter().reset_to_bci(block()->start());
+
+  CompileLog* log = C->log();
+
+  // Parse bytecodes
+  while (!stopped() && !failing()) {
+    iter().next();
+
+    // Learn the current bci from the iterator:
+    set_parse_bci(iter().cur_bci());
+
+    if (bci() == block()->limit()) {
+      // Do not walk into the next block until directed by do_all_blocks.
+      merge(bci());
+      break;
+    }
+    assert(bci() < block()->limit(), "bci still in block");
+
+    if (log != NULL) {
+      // Output an optional context marker, to help place actions
+      // that occur during parsing of this BC.  If there is no log
+      // output until the next context string, this context string
+      // will be silently ignored.
+      log->context()->reset();
+      log->context()->print_cr("<bc code='%d' bci='%d'/>", (int)bc(), bci());
+    }
+
+    if (block()->has_trap_at(bci())) {
+      // We must respect the flow pass's traps, because it will refuse
+      // to produce successors for trapping blocks.
+      int trap_index = block()->flow()->trap_index();
+      assert(trap_index != 0, "trap index must be valid");
+      uncommon_trap(trap_index);
+      break;
+    }
+
+    NOT_PRODUCT( parse_histogram()->set_initial_state(bc()); );
+
+#ifdef ASSERT
+    int pre_bc_sp = sp();
+    int inputs, depth;
+    bool have_se = !stopped() && compute_stack_effects(inputs, depth);
+    assert(!have_se || pre_bc_sp >= inputs, "have enough stack to execute this BC");
+#endif //ASSERT
+
+    do_one_bytecode();
+
+    assert(!have_se || stopped() || failing() || (sp() - pre_bc_sp) == depth, "correct depth prediction");
+
+    do_exceptions();
+
+    NOT_PRODUCT( parse_histogram()->record_change(); );
+
+    if (log != NULL)  log->context()->reset();  // done w/ this one
+
+    // Fall into next bytecode.  Each bytecode normally has 1 sequential
+    // successor which is typically made ready by visiting this bytecode.
+    // If the successor has several predecessors, then it is a merge
+    // point, starts a new basic block, and is handled like other basic blocks.
+  }
+}
+
+
+//------------------------------merge------------------------------------------
+void Parse::set_parse_bci(int bci) {
+  set_bci(bci);
+  Node_Notes* nn = C->default_node_notes();
+  if (nn == NULL)  return;
+
+  // Collect debug info for inlined calls unless -XX:-DebugInlinedCalls.
+  if (!DebugInlinedCalls && depth() > 1) {
+    return;
+  }
+
+  // Update the JVMS annotation, if present.
+  JVMState* jvms = nn->jvms();
+  if (jvms != NULL && jvms->bci() != bci) {
+    // Update the JVMS.
+    jvms = jvms->clone_shallow(C);
+    jvms->set_bci(bci);
+    nn->set_jvms(jvms);
+  }
+}
+
+//------------------------------merge------------------------------------------
+// Merge the current mapping into the basic block starting at bci
+void Parse::merge(int target_bci) {
+  Block* target = successor_for_bci(target_bci);
+  if (target == NULL) { handle_missing_successor(target_bci); return; }
+  assert(!target->is_ready(), "our arrival must be expected");
+  int pnum = target->next_path_num();
+  merge_common(target, pnum);
+}
+
+//-------------------------merge_new_path--------------------------------------
+// Merge the current mapping into the basic block, using a new path
+void Parse::merge_new_path(int target_bci) {
+  Block* target = successor_for_bci(target_bci);
+  if (target == NULL) { handle_missing_successor(target_bci); return; }
+  assert(!target->is_ready(), "new path into frozen graph");
+  int pnum = target->add_new_path();
+  merge_common(target, pnum);
+}
+
+//-------------------------merge_exception-------------------------------------
+// Merge the current mapping into the basic block starting at bci
+// The ex_oop must be pushed on the stack, unlike throw_to_exit.
+void Parse::merge_exception(int target_bci) {
+  assert(sp() == 1, "must have only the throw exception on the stack");
+  Block* target = successor_for_bci(target_bci);
+  if (target == NULL) { handle_missing_successor(target_bci); return; }
+  assert(target->is_handler(), "exceptions are handled by special blocks");
+  int pnum = target->add_new_path();
+  merge_common(target, pnum);
+}
+
+//--------------------handle_missing_successor---------------------------------
+void Parse::handle_missing_successor(int target_bci) {
+#ifndef PRODUCT
+  Block* b = block();
+  int trap_bci = b->flow()->has_trap()? b->flow()->trap_bci(): -1;
+  tty->print_cr("### Missing successor at bci:%d for block #%d (trap_bci:%d)", target_bci, b->pre_order(), trap_bci);
+#endif
+  ShouldNotReachHere();
+}
+
+//--------------------------merge_common---------------------------------------
+void Parse::merge_common(Parse::Block* target, int pnum) {
+  if (TraceOptoParse) {
+    tty->print("Merging state at block #%d bci:%d", target->pre_order(), target->start());
+  }
+
+  // Zap extra stack slots to top
+  assert(sp() == target->start_sp(), "");
+  clean_stack(sp());
+
+  if (!target->is_merged()) {   // No prior mapping at this bci
+    if (TraceOptoParse) { tty->print(" with empty state");  }
+
+    // If this path is dead, do not bother capturing it as a merge.
+    // It is "as if" we had 1 fewer predecessors from the beginning.
+    if (stopped()) {
+      if (TraceOptoParse)  tty->print_cr(", but path is dead and doesn't count");
+      return;
+    }
+
+    // Record that a new block has been merged.
+    ++_blocks_merged;
+
+    // Make a region if we know there are multiple or unpredictable inputs.
+    // (Also, if this is a plain fall-through, we might see another region,
+    // which must not be allowed into this block's map.)
+    if (pnum > PhiNode::Input         // Known multiple inputs.
+        || target->is_handler()       // These have unpredictable inputs.
+        || control()->is_Region()) {  // We must hide this guy.
+      // Add a Region to start the new basic block.  Phis will be added
+      // later lazily.
+      int edges = target->pred_count();
+      if (edges < pnum)  edges = pnum;  // might be a new path!
+      Node *r = new (C, edges+1) RegionNode(edges+1);
+      gvn().set_type(r, Type::CONTROL);
+      record_for_igvn(r);
+      // zap all inputs to NULL for debugging (done in Node(uint) constructor)
+      // for (int j = 1; j < edges+1; j++) { r->init_req(j, NULL); }
+      r->init_req(pnum, control());
+      set_control(r);
+    }
+
+    // Convert the existing Parser mapping into a mapping at this bci.
+    store_state_to(target);
+    assert(target->is_merged(), "do not come here twice");
+
+  } else {                      // Prior mapping at this bci
+    if (TraceOptoParse) {  tty->print(" with previous state"); }
+
+    // We must not manufacture more phis if the target is already parsed.
+    bool nophi = target->is_parsed();
+
+    SafePointNode* newin = map();// Hang on to incoming mapping
+    Block* save_block = block(); // Hang on to incoming block;
+    load_state_from(target);    // Get prior mapping
+
+    assert(newin->jvms()->locoff() == jvms()->locoff(), "JVMS layouts agree");
+    assert(newin->jvms()->stkoff() == jvms()->stkoff(), "JVMS layouts agree");
+    assert(newin->jvms()->monoff() == jvms()->monoff(), "JVMS layouts agree");
+    assert(newin->jvms()->endoff() == jvms()->endoff(), "JVMS layouts agree");
+
+    // Iterate over my current mapping and the old mapping.
+    // Where different, insert Phi functions.
+    // Use any existing Phi functions.
+    assert(control()->is_Region(), "must be merging to a region");
+    RegionNode* r = control()->as_Region();
+
+    // Compute where to merge into
+    // Merge incoming control path
+    r->set_req(pnum, newin->control());
+
+    if (pnum == 1) {            // Last merge for this Region?
+      _gvn.transform_no_reclaim(r);
+      record_for_igvn(r);
+    }
+
+    // Update all the non-control inputs to map:
+    assert(TypeFunc::Parms == newin->jvms()->locoff(), "parser map should contain only youngest jvms");
+    for (uint j = 1; j < newin->req(); j++) {
+      Node* m = map()->in(j);   // Current state of target.
+      Node* n = newin->in(j);   // Incoming change to target state.
+      PhiNode* phi;
+      if (m->is_Phi() && m->as_Phi()->region() == r)
+        phi = m->as_Phi();
+      else
+        phi = NULL;
+      if (m != n) {             // Different; must merge
+        switch (j) {
+        // Frame pointer and Return Address never changes
+        case TypeFunc::FramePtr:// Drop m, use the original value
+        case TypeFunc::ReturnAdr:
+          break;
+        case TypeFunc::Memory:  // Merge inputs to the MergeMem node
+          assert(phi == NULL, "the merge contains phis, not vice versa");
+          merge_memory_edges(n->as_MergeMem(), pnum, nophi);
+          continue;
+        default:                // All normal stuff
+          if (phi == NULL)  phi = ensure_phi(j, nophi);
+          break;
+        }
+      }
+      // At this point, n might be top if:
+      //  - there is no phi (because TypeFlow detected a conflict), or
+      //  - the corresponding control edges is top (a dead incoming path)
+      // It is a bug if we create a phi which sees a garbage value on a live path.
+
+      if (phi != NULL) {
+        assert(n != top() || r->in(pnum) == top(), "live value must not be garbage");
+        assert(phi->region() == r, "");
+        phi->set_req(pnum, n);  // Then add 'n' to the merge
+        if (pnum == PhiNode::Input) {
+          // Last merge for this Phi.
+          // So far, Phis have had a reasonable type from ciTypeFlow.
+          // Now _gvn will join that with the meet of current inputs.
+          // BOTTOM is never permissible here, 'cause pessimistically
+          // Phis of pointers cannot lose the basic pointer type.
+          debug_only(const Type* bt1 = phi->bottom_type());
+          assert(bt1 != Type::BOTTOM, "should not be building conflict phis");
+          map()->set_req(j, _gvn.transform_no_reclaim(phi));
+          debug_only(const Type* bt2 = phi->bottom_type());
+          assert(bt2->higher_equal(bt1), "must be consistent with type-flow");
+          record_for_igvn(phi);
+        }
+      }
+    } // End of for all values to be merged
+
+    if (pnum == PhiNode::Input &&
+        !r->in(0)) {         // The occasional useless Region
+      assert(control() == r, "");
+      set_control(r->nonnull_req());
+    }
+
+    // newin has been subsumed into the lazy merge, and is now dead.
+    set_block(save_block);
+
+    stop();                     // done with this guy, for now
+  }
+
+  if (TraceOptoParse) {
+    tty->print_cr(" on path %d", pnum);
+  }
+
+  // Done with this parser state.
+  assert(stopped(), "");
+}
+
+
+//--------------------------merge_memory_edges---------------------------------
+void Parse::merge_memory_edges(MergeMemNode* n, int pnum, bool nophi) {
+  // (nophi means we must not create phis, because we already parsed here)
+  assert(n != NULL, "");
+  // Merge the inputs to the MergeMems
+  MergeMemNode* m = merged_memory();
+
+  assert(control()->is_Region(), "must be merging to a region");
+  RegionNode* r = control()->as_Region();
+
+  PhiNode* base = NULL;
+  MergeMemNode* remerge = NULL;
+  for (MergeMemStream mms(m, n); mms.next_non_empty2(); ) {
+    Node *p = mms.force_memory();
+    Node *q = mms.memory2();
+    if (mms.is_empty() && nophi) {
+      // Trouble:  No new splits allowed after a loop body is parsed.
+      // Instead, wire the new split into a MergeMem on the backedge.
+      // The optimizer will sort it out, slicing the phi.
+      if (remerge == NULL) {
+        assert(base != NULL, "");
+        assert(base->in(0) != NULL, "should not be xformed away");
+        remerge = MergeMemNode::make(C, base->in(pnum));
+        gvn().set_type(remerge, Type::MEMORY);
+        base->set_req(pnum, remerge);
+      }
+      remerge->set_memory_at(mms.alias_idx(), q);
+      continue;
+    }
+    assert(!q->is_MergeMem(), "");
+    PhiNode* phi;
+    if (p != q) {
+      phi = ensure_memory_phi(mms.alias_idx(), nophi);
+    } else {
+      if (p->is_Phi() && p->as_Phi()->region() == r)
+        phi = p->as_Phi();
+      else
+        phi = NULL;
+    }
+    // Insert q into local phi
+    if (phi != NULL) {
+      assert(phi->region() == r, "");
+      p = phi;
+      phi->set_req(pnum, q);
+      if (mms.at_base_memory()) {
+        base = phi;  // delay transforming it
+      } else if (pnum == 1) {
+        record_for_igvn(phi);
+        p = _gvn.transform_no_reclaim(phi);
+      }
+      mms.set_memory(p);// store back through the iterator
+    }
+  }
+  // Transform base last, in case we must fiddle with remerging.
+  if (base != NULL && pnum == 1) {
+    record_for_igvn(base);
+    m->set_base_memory( _gvn.transform_no_reclaim(base) );
+  }
+}
+
+
+//------------------------ensure_phis_everywhere-------------------------------
+void Parse::ensure_phis_everywhere() {
+  ensure_phi(TypeFunc::I_O);
+
+  // Ensure a phi on all currently known memories.
+  for (MergeMemStream mms(merged_memory()); mms.next_non_empty(); ) {
+    ensure_memory_phi(mms.alias_idx());
+    debug_only(mms.set_memory());  // keep the iterator happy
+  }
+
+  // Note:  This is our only chance to create phis for memory slices.
+  // If we miss a slice that crops up later, it will have to be
+  // merged into the base-memory phi that we are building here.
+  // Later, the optimizer will comb out the knot, and build separate
+  // phi-loops for each memory slice that matters.
+
+  // Monitors must nest nicely and not get confused amongst themselves.
+  // Phi-ify everything up to the monitors, though.
+  uint monoff = map()->jvms()->monoff();
+  uint nof_monitors = map()->jvms()->nof_monitors();
+
+  assert(TypeFunc::Parms == map()->jvms()->locoff(), "parser map should contain only youngest jvms");
+  for (uint i = TypeFunc::Parms; i < monoff; i++) {
+    ensure_phi(i);
+  }
+  // Even monitors need Phis, though they are well-structured.
+  // This is true for OSR methods, and also for the rare cases where
+  // a monitor object is the subject of a replace_in_map operation.
+  // See bugs 4426707 and 5043395.
+  for (uint m = 0; m < nof_monitors; m++) {
+    ensure_phi(map()->jvms()->monitor_obj_offset(m));
+  }
+}
+
+
+//-----------------------------add_new_path------------------------------------
+// Add a previously unaccounted predecessor to this block.
+int Parse::Block::add_new_path() {
+  // If there is no map, return the lowest unused path number.
+  if (!is_merged())  return pred_count()+1;  // there will be a map shortly
+
+  SafePointNode* map = start_map();
+  if (!map->control()->is_Region())
+    return pred_count()+1;  // there may be a region some day
+  RegionNode* r = map->control()->as_Region();
+
+  // Add new path to the region.
+  uint pnum = r->req();
+  r->add_req(NULL);
+
+  for (uint i = 1; i < map->req(); i++) {
+    Node* n = map->in(i);
+    if (i == TypeFunc::Memory) {
+      // Ensure a phi on all currently known memories.
+      for (MergeMemStream mms(n->as_MergeMem()); mms.next_non_empty(); ) {
+        Node* phi = mms.memory();
+        if (phi->is_Phi() && phi->as_Phi()->region() == r) {
+          assert(phi->req() == pnum, "must be same size as region");
+          phi->add_req(NULL);
+        }
+      }
+    } else {
+      if (n->is_Phi() && n->as_Phi()->region() == r) {
+        assert(n->req() == pnum, "must be same size as region");
+        n->add_req(NULL);
+      }
+    }
+  }
+
+  return pnum;
+}
+
+//------------------------------ensure_phi-------------------------------------
+// Turn the idx'th entry of the current map into a Phi
+PhiNode *Parse::ensure_phi(int idx, bool nocreate) {
+  SafePointNode* map = this->map();
+  Node* region = map->control();
+  assert(region->is_Region(), "");
+
+  Node* o = map->in(idx);
+  assert(o != NULL, "");
+
+  if (o == top())  return NULL; // TOP always merges into TOP
+
+  if (o->is_Phi() && o->as_Phi()->region() == region) {
+    return o->as_Phi();
+  }
+
+  // Now use a Phi here for merging
+  assert(!nocreate, "Cannot build a phi for a block already parsed.");
+  const JVMState* jvms = map->jvms();
+  const Type* t;
+  if (jvms->is_loc(idx)) {
+    t = block()->local_type_at(idx - jvms->locoff());
+  } else if (jvms->is_stk(idx)) {
+    t = block()->stack_type_at(idx - jvms->stkoff());
+  } else if (jvms->is_mon(idx)) {
+    assert(!jvms->is_monitor_box(idx), "no phis for boxes");
+    t = TypeInstPtr::BOTTOM; // this is sufficient for a lock object
+  } else if ((uint)idx < TypeFunc::Parms) {
+    t = o->bottom_type();  // Type::RETURN_ADDRESS or such-like.
+  } else {
+    assert(false, "no type information for this phi");
+  }
+
+  // If the type falls to bottom, then this must be a local that
+  // is mixing ints and oops or some such.  Forcing it to top
+  // makes it go dead.
+  if (t == Type::BOTTOM) {
+    map->set_req(idx, top());
+    return NULL;
+  }
+
+  // Do not create phis for top either.
+  // A top on a non-null control flow must be an unused even after the.phi.
+  if (t == Type::TOP || t == Type::HALF) {
+    map->set_req(idx, top());
+    return NULL;
+  }
+
+  PhiNode* phi = PhiNode::make(region, o, t);
+  gvn().set_type(phi, t);
+  if (DoEscapeAnalysis) record_for_igvn(phi);
+  map->set_req(idx, phi);
+  return phi;
+}
+
+//--------------------------ensure_memory_phi----------------------------------
+// Turn the idx'th slice of the current memory into a Phi
+PhiNode *Parse::ensure_memory_phi(int idx, bool nocreate) {
+  MergeMemNode* mem = merged_memory();
+  Node* region = control();
+  assert(region->is_Region(), "");
+
+  Node *o = (idx == Compile::AliasIdxBot)? mem->base_memory(): mem->memory_at(idx);
+  assert(o != NULL && o != top(), "");
+
+  PhiNode* phi;
+  if (o->is_Phi() && o->as_Phi()->region() == region) {
+    phi = o->as_Phi();
+    if (phi == mem->base_memory() && idx >= Compile::AliasIdxRaw) {
+      // clone the shared base memory phi to make a new memory split
+      assert(!nocreate, "Cannot build a phi for a block already parsed.");
+      const Type* t = phi->bottom_type();
+      const TypePtr* adr_type = C->get_adr_type(idx);
+      phi = phi->slice_memory(adr_type);
+      gvn().set_type(phi, t);
+    }
+    return phi;
+  }
+
+  // Now use a Phi here for merging
+  assert(!nocreate, "Cannot build a phi for a block already parsed.");
+  const Type* t = o->bottom_type();
+  const TypePtr* adr_type = C->get_adr_type(idx);
+  phi = PhiNode::make(region, o, t, adr_type);
+  gvn().set_type(phi, t);
+  if (idx == Compile::AliasIdxBot)
+    mem->set_base_memory(phi);
+  else
+    mem->set_memory_at(idx, phi);
+  return phi;
+}
+
+//------------------------------call_register_finalizer-----------------------
+// Check the klass of the receiver and call register_finalizer if the
+// class need finalization.
+void Parse::call_register_finalizer() {
+  Node* receiver = local(0);
+  assert(receiver != NULL && receiver->bottom_type()->isa_instptr() != NULL,
+         "must have non-null instance type");
+
+  const TypeInstPtr *tinst = receiver->bottom_type()->isa_instptr();
+  if (tinst != NULL && tinst->klass()->is_loaded() && !tinst->klass_is_exact()) {
+    // The type isn't known exactly so see if CHA tells us anything.
+    ciInstanceKlass* ik = tinst->klass()->as_instance_klass();
+    if (!Dependencies::has_finalizable_subclass(ik)) {
+      // No finalizable subclasses so skip the dynamic check.
+      C->dependencies()->assert_has_no_finalizable_subclasses(ik);
+      return;
+    }
+  }
+
+  // Insert a dynamic test for whether the instance needs
+  // finalization.  In general this will fold up since the concrete
+  // class is often visible so the access flags are constant.
+  Node* klass_addr = basic_plus_adr( receiver, receiver, oopDesc::klass_offset_in_bytes() );
+  Node* klass = _gvn.transform(new (C, 3) LoadKlassNode(NULL, immutable_memory(), klass_addr, TypeInstPtr::KLASS));
+
+  Node* access_flags_addr = basic_plus_adr(klass, klass, Klass::access_flags_offset_in_bytes() + sizeof(oopDesc));
+  Node* access_flags = make_load(NULL, access_flags_addr, TypeInt::INT, T_INT);
+
+  Node* mask  = _gvn.transform(new (C, 3) AndINode(access_flags, intcon(JVM_ACC_HAS_FINALIZER)));
+  Node* check = _gvn.transform(new (C, 3) CmpINode(mask, intcon(0)));
+  Node* test  = _gvn.transform(new (C, 2) BoolNode(check, BoolTest::ne));
+
+  IfNode* iff = create_and_map_if(control(), test, PROB_MAX, COUNT_UNKNOWN);
+
+  RegionNode* result_rgn = new (C, 3) RegionNode(3);
+  record_for_igvn(result_rgn);
+
+  Node *skip_register = _gvn.transform(new (C, 1) IfFalseNode(iff));
+  result_rgn->init_req(1, skip_register);
+
+  Node *needs_register = _gvn.transform(new (C, 1) IfTrueNode(iff));
+  set_control(needs_register);
+  if (stopped()) {
+    // There is no slow path.
+    result_rgn->init_req(2, top());
+  } else {
+    Node *call = make_runtime_call(RC_NO_LEAF,
+                                   OptoRuntime::register_finalizer_Type(),
+                                   OptoRuntime::register_finalizer_Java(),
+                                   NULL, TypePtr::BOTTOM,
+                                   receiver);
+    make_slow_call_ex(call, env()->Throwable_klass(), true);
+
+    Node* fast_io  = call->in(TypeFunc::I_O);
+    Node* fast_mem = call->in(TypeFunc::Memory);
+    // These two phis are pre-filled with copies of of the fast IO and Memory
+    Node* io_phi   = PhiNode::make(result_rgn, fast_io,  Type::ABIO);
+    Node* mem_phi  = PhiNode::make(result_rgn, fast_mem, Type::MEMORY, TypePtr::BOTTOM);
+
+    result_rgn->init_req(2, control());
+    io_phi    ->init_req(2, i_o());
+    mem_phi   ->init_req(2, reset_memory());
+
+    set_all_memory( _gvn.transform(mem_phi) );
+    set_i_o(        _gvn.transform(io_phi) );
+  }
+
+  set_control( _gvn.transform(result_rgn) );
+}
+
+//------------------------------return_current---------------------------------
+// Append current _map to _exit_return
+void Parse::return_current(Node* value) {
+  if (RegisterFinalizersAtInit &&
+      method()->intrinsic_id() == vmIntrinsics::_Object_init) {
+    call_register_finalizer();
+  }
+
+  // Do not set_parse_bci, so that return goo is credited to the return insn.
+  set_bci(InvocationEntryBci);
+  if (method()->is_synchronized() && GenerateSynchronizationCode) {
+    shared_unlock(_synch_lock->box_node(), _synch_lock->obj_node());
+  }
+  if (DTraceMethodProbes) {
+    make_dtrace_method_exit(method());
+  }
+  SafePointNode* exit_return = _exits.map();
+  exit_return->in( TypeFunc::Control  )->add_req( control() );
+  exit_return->in( TypeFunc::I_O      )->add_req( i_o    () );
+  Node *mem = exit_return->in( TypeFunc::Memory   );
+  for (MergeMemStream mms(mem->as_MergeMem(), merged_memory()); mms.next_non_empty2(); ) {
+    if (mms.is_empty()) {
+      // get a copy of the base memory, and patch just this one input
+      const TypePtr* adr_type = mms.adr_type(C);
+      Node* phi = mms.force_memory()->as_Phi()->slice_memory(adr_type);
+      assert(phi->as_Phi()->region() == mms.base_memory()->in(0), "");
+      gvn().set_type_bottom(phi);
+      phi->del_req(phi->req()-1);  // prepare to re-patch
+      mms.set_memory(phi);
+    }
+    mms.memory()->add_req(mms.memory2());
+  }
+
+  // frame pointer is always same, already captured
+  if (value != NULL) {
+    // If returning oops to an interface-return, there is a silent free
+    // cast from oop to interface allowed by the Verifier.  Make it explicit
+    // here.
+    Node* phi = _exits.argument(0);
+    const TypeInstPtr *tr = phi->bottom_type()->isa_instptr();
+    if( tr && tr->klass()->is_loaded() &&
+        tr->klass()->is_interface() ) {
+      const TypeInstPtr *tp = value->bottom_type()->isa_instptr();
+      if (tp && tp->klass()->is_loaded() &&
+          !tp->klass()->is_interface()) {
+        // sharpen the type eagerly; this eases certain assert checking
+        if (tp->higher_equal(TypeInstPtr::NOTNULL))
+          tr = tr->join(TypeInstPtr::NOTNULL)->is_instptr();
+        value = _gvn.transform(new (C, 2) CheckCastPPNode(0,value,tr));
+      }
+    }
+    phi->add_req(value);
+  }
+
+  stop_and_kill_map();          // This CFG path dies here
+}
+
+
+//------------------------------add_safepoint----------------------------------
+void Parse::add_safepoint() {
+  // See if we can avoid this safepoint.  No need for a SafePoint immediately
+  // after a Call (except Leaf Call) or another SafePoint.
+  Node *proj = control();
+  bool add_poll_param = SafePointNode::needs_polling_address_input();
+  uint parms = add_poll_param ? TypeFunc::Parms+1 : TypeFunc::Parms;
+  if( proj->is_Proj() ) {
+    Node *n0 = proj->in(0);
+    if( n0->is_Catch() ) {
+      n0 = n0->in(0)->in(0);
+      assert( n0->is_Call(), "expect a call here" );
+    }
+    if( n0->is_Call() ) {
+      if( n0->as_Call()->guaranteed_safepoint() )
+        return;
+    } else if( n0->is_SafePoint() && n0->req() >= parms ) {
+      return;
+    }
+  }
+
+  // Clear out dead values from the debug info.
+  kill_dead_locals();
+
+  // Clone the JVM State
+  SafePointNode *sfpnt = new (C, parms) SafePointNode(parms, NULL);
+
+  // Capture memory state BEFORE a SafePoint.  Since we can block at a
+  // SafePoint we need our GC state to be safe; i.e. we need all our current
+  // write barriers (card marks) to not float down after the SafePoint so we
+  // must read raw memory.  Likewise we need all oop stores to match the card
+  // marks.  If deopt can happen, we need ALL stores (we need the correct JVM
+  // state on a deopt).
+
+  // We do not need to WRITE the memory state after a SafePoint.  The control
+  // edge will keep card-marks and oop-stores from floating up from below a
+  // SafePoint and our true dependency added here will keep them from floating
+  // down below a SafePoint.
+
+  // Clone the current memory state
+  Node* mem = MergeMemNode::make(C, map()->memory());
+
+  mem = _gvn.transform(mem);
+
+  // Pass control through the safepoint
+  sfpnt->init_req(TypeFunc::Control  , control());
+  // Fix edges normally used by a call
+  sfpnt->init_req(TypeFunc::I_O      , top() );
+  sfpnt->init_req(TypeFunc::Memory   , mem   );
+  sfpnt->init_req(TypeFunc::ReturnAdr, top() );
+  sfpnt->init_req(TypeFunc::FramePtr , top() );
+
+  // Create a node for the polling address
+  if( add_poll_param ) {
+    Node *polladr = ConPNode::make(C, (address)os::get_polling_page());
+    sfpnt->init_req(TypeFunc::Parms+0, _gvn.transform(polladr));
+  }
+
+  // Fix up the JVM State edges
+  add_safepoint_edges(sfpnt);
+  Node *transformed_sfpnt = _gvn.transform(sfpnt);
+  set_control(transformed_sfpnt);
+
+  // Provide an edge from root to safepoint.  This makes the safepoint
+  // appear useful until the parse has completed.
+  if( OptoRemoveUseless && transformed_sfpnt->is_SafePoint() ) {
+    assert(C->root() != NULL, "Expect parse is still valid");
+    C->root()->add_prec(transformed_sfpnt);
+  }
+}
+
+#ifndef PRODUCT
+//------------------------show_parse_info--------------------------------------
+void Parse::show_parse_info() {
+  InlineTree* ilt = NULL;
+  if (C->ilt() != NULL) {
+    JVMState* caller_jvms = is_osr_parse() ? caller()->caller() : caller();
+    ilt = InlineTree::find_subtree_from_root(C->ilt(), caller_jvms, method());
+  }
+  if (PrintCompilation && Verbose) {
+    if (depth() == 1) {
+      if( ilt->count_inlines() ) {
+        tty->print("    __inlined %d (%d bytes)", ilt->count_inlines(),
+                     ilt->count_inline_bcs());
+        tty->cr();
+      }
+    } else {
+      if (method()->is_synchronized())         tty->print("s");
+      if (method()->has_exception_handlers())  tty->print("!");
+      // Check this is not the final compiled version
+      if (C->trap_can_recompile()) {
+        tty->print("-");
+      } else {
+        tty->print(" ");
+      }
+      method()->print_short_name();
+      if (is_osr_parse()) {
+        tty->print(" @ %d", osr_bci());
+      }
+      tty->print(" (%d bytes)",method()->code_size());
+      if (ilt->count_inlines()) {
+        tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
+                   ilt->count_inline_bcs());
+      }
+      tty->cr();
+    }
+  }
+  if (PrintOpto && (depth() == 1 || PrintOptoInlining)) {
+    // Print that we succeeded; suppress this message on the first osr parse.
+
+    if (method()->is_synchronized())         tty->print("s");
+    if (method()->has_exception_handlers())  tty->print("!");
+    // Check this is not the final compiled version
+    if (C->trap_can_recompile() && depth() == 1) {
+      tty->print("-");
+    } else {
+      tty->print(" ");
+    }
+    if( depth() != 1 ) { tty->print("   "); }  // missing compile count
+    for (int i = 1; i < depth(); ++i) { tty->print("  "); }
+    method()->print_short_name();
+    if (is_osr_parse()) {
+      tty->print(" @ %d", osr_bci());
+    }
+    if (ilt->caller_bci() != -1) {
+      tty->print(" @ %d", ilt->caller_bci());
+    }
+    tty->print(" (%d bytes)",method()->code_size());
+    if (ilt->count_inlines()) {
+      tty->print(" __inlined %d (%d bytes)", ilt->count_inlines(),
+                 ilt->count_inline_bcs());
+    }
+    tty->cr();
+  }
+}
+
+
+//------------------------------dump-------------------------------------------
+// Dump information associated with the bytecodes of current _method
+void Parse::dump() {
+  if( method() != NULL ) {
+    // Iterate over bytecodes
+    ciBytecodeStream iter(method());
+    for( Bytecodes::Code bc = iter.next(); bc != ciBytecodeStream::EOBC() ; bc = iter.next() ) {
+      dump_bci( iter.cur_bci() );
+      tty->cr();
+    }
+  }
+}
+
+// Dump information associated with a byte code index, 'bci'
+void Parse::dump_bci(int bci) {
+  // Output info on merge-points, cloning, and within _jsr..._ret
+  // NYI
+  tty->print(" bci:%d", bci);
+}
+
+#endif