--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/ci/ciTypeFlow.hpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,714 @@
+/*
+ * Copyright 2000-2006 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.
+ *
+ */
+
+
+class ciTypeFlow : public ResourceObj {
+private:
+  ciEnv*    _env;
+  ciMethod* _method;
+  ciMethodBlocks* _methodBlocks;
+  int       _osr_bci;
+
+  // information cached from the method:
+  int _max_locals;
+  int _max_stack;
+  int _code_size;
+
+  const char* _failure_reason;
+
+public:
+  class StateVector;
+  class Block;
+
+  // Build a type flow analyzer
+  // Do an OSR analysis if osr_bci >= 0.
+  ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci = InvocationEntryBci);
+
+  // Accessors
+  ciMethod* method() const     { return _method; }
+  ciEnv*    env()              { return _env; }
+  Arena*    arena()            { return _env->arena(); }
+  bool      is_osr_flow() const{ return _osr_bci != InvocationEntryBci; }
+  int       start_bci() const  { return is_osr_flow()? _osr_bci: 0; }
+  int       max_locals() const { return _max_locals; }
+  int       max_stack() const  { return _max_stack; }
+  int       max_cells() const  { return _max_locals + _max_stack; }
+  int       code_size() const  { return _code_size; }
+
+  // Represents information about an "active" jsr call.  This
+  // class represents a call to the routine at some entry address
+  // with some distinct return address.
+  class JsrRecord : public ResourceObj {
+  private:
+    int _entry_address;
+    int _return_address;
+  public:
+    JsrRecord(int entry_address, int return_address) {
+      _entry_address = entry_address;
+      _return_address = return_address;
+    }
+
+    int entry_address() const  { return _entry_address; }
+    int return_address() const { return _return_address; }
+
+    void print_on(outputStream* st) const {
+#ifndef PRODUCT
+      st->print("%d->%d", entry_address(), return_address());
+#endif
+    }
+  };
+
+  // A JsrSet represents some set of JsrRecords.  This class
+  // is used to record a set of all jsr routines which we permit
+  // execution to return (ret) from.
+  //
+  // During abstract interpretation, JsrSets are used to determine
+  // whether two paths which reach a given block are unique, and
+  // should be cloned apart, or are compatible, and should merge
+  // together.
+  //
+  // Note that different amounts of effort can be expended determining
+  // if paths are compatible.  <DISCUSSION>
+  class JsrSet : public ResourceObj {
+  private:
+    GrowableArray<JsrRecord*>* _set;
+
+    JsrRecord* record_at(int i) {
+      return _set->at(i);
+    }
+
+    // Insert the given JsrRecord into the JsrSet, maintaining the order
+    // of the set and replacing any element with the same entry address.
+    void insert_jsr_record(JsrRecord* record);
+
+    // Remove the JsrRecord with the given return address from the JsrSet.
+    void remove_jsr_record(int return_address);
+
+  public:
+    JsrSet(Arena* arena, int default_len = 4);
+
+    // Copy this JsrSet.
+    void copy_into(JsrSet* jsrs);
+
+    // Is this JsrSet compatible with some other JsrSet?
+    bool is_compatible_with(JsrSet* other);
+
+    // Apply the effect of a single bytecode to the JsrSet.
+    void apply_control(ciTypeFlow* analyzer,
+                       ciBytecodeStream* str,
+                       StateVector* state);
+
+    // What is the cardinality of this set?
+    int size() const { return _set->length(); }
+
+    void print_on(outputStream* st) const PRODUCT_RETURN;
+  };
+
+  // Used as a combined index for locals and temps
+  enum Cell {
+    Cell_0
+  };
+
+  // A StateVector summarizes the type information at some
+  // point in the program
+  class StateVector : public ResourceObj {
+  private:
+    ciType**    _types;
+    int         _stack_size;
+    int         _monitor_count;
+    ciTypeFlow* _outer;
+
+    int         _trap_bci;
+    int         _trap_index;
+
+    static ciType* type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer);
+
+  public:
+    // Special elements in our type lattice.
+    enum {
+      T_TOP     = T_VOID,      // why not?
+      T_BOTTOM  = T_CONFLICT,
+      T_LONG2   = T_SHORT,     // 2nd word of T_LONG
+      T_DOUBLE2 = T_CHAR,      // 2nd word of T_DOUBLE
+      T_NULL    = T_BYTE       // for now.
+    };
+    static ciType* top_type()    { return ciType::make((BasicType)T_TOP); }
+    static ciType* bottom_type() { return ciType::make((BasicType)T_BOTTOM); }
+    static ciType* long2_type()  { return ciType::make((BasicType)T_LONG2); }
+    static ciType* double2_type(){ return ciType::make((BasicType)T_DOUBLE2); }
+    static ciType* null_type()   { return ciType::make((BasicType)T_NULL); }
+
+    static ciType* half_type(ciType* t) {
+      switch (t->basic_type()) {
+      case T_LONG:    return long2_type();
+      case T_DOUBLE:  return double2_type();
+      default:        ShouldNotReachHere(); return NULL;
+      }
+    }
+
+    // The meet operation for our type lattice.
+    ciType* type_meet(ciType* t1, ciType* t2) {
+      return type_meet_internal(t1, t2, outer());
+    }
+
+    // Accessors
+    ciTypeFlow* outer() const          { return _outer; }
+
+    int         stack_size() const     { return _stack_size; }
+    void    set_stack_size(int ss)     { _stack_size = ss; }
+
+    int         monitor_count() const  { return _monitor_count; }
+    void    set_monitor_count(int mc)  { _monitor_count = mc; }
+
+    static Cell start_cell()           { return (Cell)0; }
+    static Cell next_cell(Cell c)      { return (Cell)(((int)c) + 1); }
+    Cell        limit_cell() const {
+      return (Cell)(outer()->max_locals() + stack_size());
+    }
+
+    // Cell creation
+    Cell      local(int lnum) const {
+      assert(lnum < outer()->max_locals(), "index check");
+      return (Cell)(lnum);
+    }
+
+    Cell      stack(int snum) const {
+      assert(snum < stack_size(), "index check");
+      return (Cell)(outer()->max_locals() + snum);
+    }
+
+    Cell      tos() const { return stack(stack_size()-1); }
+
+    // For external use only:
+    ciType* local_type_at(int i) const { return type_at(local(i)); }
+    ciType* stack_type_at(int i) const { return type_at(stack(i)); }
+
+    // Accessors for the type of some Cell c
+    ciType*   type_at(Cell c) const {
+      assert(start_cell() <= c && c < limit_cell(), "out of bounds");
+      return _types[c];
+    }
+
+    void      set_type_at(Cell c, ciType* type) {
+      assert(start_cell() <= c && c < limit_cell(), "out of bounds");
+      _types[c] = type;
+    }
+
+    // Top-of-stack operations.
+    void      set_type_at_tos(ciType* type) { set_type_at(tos(), type); }
+    ciType*   type_at_tos() const           { return type_at(tos()); }
+
+    void      push(ciType* type) {
+      _stack_size++;
+      set_type_at_tos(type);
+    }
+    void      pop() {
+      debug_only(set_type_at_tos(bottom_type()));
+      _stack_size--;
+    }
+    ciType*   pop_value() {
+      ciType* t = type_at_tos();
+      pop();
+      return t;
+    }
+
+    // Convenience operations.
+    bool      is_reference(ciType* type) const {
+      return type == null_type() || !type->is_primitive_type();
+    }
+    bool      is_int(ciType* type) const {
+      return type->basic_type() == T_INT;
+    }
+    bool      is_long(ciType* type) const {
+      return type->basic_type() == T_LONG;
+    }
+    bool      is_float(ciType* type) const {
+      return type->basic_type() == T_FLOAT;
+    }
+    bool      is_double(ciType* type) const {
+      return type->basic_type() == T_DOUBLE;
+    }
+
+    void      push_translate(ciType* type);
+
+    void      push_int() {
+      push(ciType::make(T_INT));
+    }
+    void      pop_int() {
+      assert(is_int(type_at_tos()), "must be integer");
+      pop();
+    }
+    void      check_int(Cell c) {
+      assert(is_int(type_at(c)), "must be integer");
+    }
+    void      push_double() {
+      push(ciType::make(T_DOUBLE));
+      push(double2_type());
+    }
+    void      pop_double() {
+      assert(type_at_tos() == double2_type(), "must be 2nd half");
+      pop();
+      assert(is_double(type_at_tos()), "must be double");
+      pop();
+    }
+    void      push_float() {
+      push(ciType::make(T_FLOAT));
+    }
+    void      pop_float() {
+      assert(is_float(type_at_tos()), "must be float");
+      pop();
+    }
+    void      push_long() {
+      push(ciType::make(T_LONG));
+      push(long2_type());
+    }
+    void      pop_long() {
+      assert(type_at_tos() == long2_type(), "must be 2nd half");
+      pop();
+      assert(is_long(type_at_tos()), "must be long");
+      pop();
+    }
+    void      push_object(ciKlass* klass) {
+      push(klass);
+    }
+    void      pop_object() {
+      assert(is_reference(type_at_tos()), "must be reference type");
+      pop();
+    }
+    void      pop_array() {
+      assert(type_at_tos() == null_type() ||
+             type_at_tos()->is_array_klass(), "must be array type");
+      pop();
+    }
+    // pop_objArray and pop_typeArray narrow the tos to ciObjArrayKlass
+    // or ciTypeArrayKlass (resp.).  In the rare case that an explicit
+    // null is popped from the stack, we return NULL.  Caller beware.
+    ciObjArrayKlass* pop_objArray() {
+      ciType* array = pop_value();
+      if (array == null_type())  return NULL;
+      assert(array->is_obj_array_klass(), "must be object array type");
+      return array->as_obj_array_klass();
+    }
+    ciTypeArrayKlass* pop_typeArray() {
+      ciType* array = pop_value();
+      if (array == null_type())  return NULL;
+      assert(array->is_type_array_klass(), "must be prim array type");
+      return array->as_type_array_klass();
+    }
+    void      push_null() {
+      push(null_type());
+    }
+    void      do_null_assert(ciKlass* unloaded_klass);
+
+    // Helper convenience routines.
+    void do_aaload(ciBytecodeStream* str);
+    void do_checkcast(ciBytecodeStream* str);
+    void do_getfield(ciBytecodeStream* str);
+    void do_getstatic(ciBytecodeStream* str);
+    void do_invoke(ciBytecodeStream* str, bool has_receiver);
+    void do_jsr(ciBytecodeStream* str);
+    void do_ldc(ciBytecodeStream* str);
+    void do_multianewarray(ciBytecodeStream* str);
+    void do_new(ciBytecodeStream* str);
+    void do_newarray(ciBytecodeStream* str);
+    void do_putfield(ciBytecodeStream* str);
+    void do_putstatic(ciBytecodeStream* str);
+    void do_ret(ciBytecodeStream* str);
+
+    void overwrite_local_double_long(int index) {
+      // Invalidate the previous local if it contains first half of
+      // a double or long value since it's seconf half is being overwritten.
+      int prev_index = index - 1;
+      if (prev_index >= 0 &&
+          (is_double(type_at(local(prev_index))) ||
+           is_long(type_at(local(prev_index))))) {
+        set_type_at(local(prev_index), bottom_type());
+      }
+    }
+
+    void load_local_object(int index) {
+      ciType* type = type_at(local(index));
+      assert(is_reference(type), "must be reference type");
+      push(type);
+    }
+    void store_local_object(int index) {
+      ciType* type = pop_value();
+      assert(is_reference(type) || type->is_return_address(),
+             "must be reference type or return address");
+      overwrite_local_double_long(index);
+      set_type_at(local(index), type);
+    }
+
+    void load_local_double(int index) {
+      ciType* type = type_at(local(index));
+      ciType* type2 = type_at(local(index+1));
+      assert(is_double(type), "must be double type");
+      assert(type2 == double2_type(), "must be 2nd half");
+      push(type);
+      push(double2_type());
+    }
+    void store_local_double(int index) {
+      ciType* type2 = pop_value();
+      ciType* type = pop_value();
+      assert(is_double(type), "must be double");
+      assert(type2 == double2_type(), "must be 2nd half");
+      overwrite_local_double_long(index);
+      set_type_at(local(index), type);
+      set_type_at(local(index+1), type2);
+    }
+
+    void load_local_float(int index) {
+      ciType* type = type_at(local(index));
+      assert(is_float(type), "must be float type");
+      push(type);
+    }
+    void store_local_float(int index) {
+      ciType* type = pop_value();
+      assert(is_float(type), "must be float type");
+      overwrite_local_double_long(index);
+      set_type_at(local(index), type);
+    }
+
+    void load_local_int(int index) {
+      ciType* type = type_at(local(index));
+      assert(is_int(type), "must be int type");
+      push(type);
+    }
+    void store_local_int(int index) {
+      ciType* type = pop_value();
+      assert(is_int(type), "must be int type");
+      overwrite_local_double_long(index);
+      set_type_at(local(index), type);
+    }
+
+    void load_local_long(int index) {
+      ciType* type = type_at(local(index));
+      ciType* type2 = type_at(local(index+1));
+      assert(is_long(type), "must be long type");
+      assert(type2 == long2_type(), "must be 2nd half");
+      push(type);
+      push(long2_type());
+    }
+    void store_local_long(int index) {
+      ciType* type2 = pop_value();
+      ciType* type = pop_value();
+      assert(is_long(type), "must be long");
+      assert(type2 == long2_type(), "must be 2nd half");
+      overwrite_local_double_long(index);
+      set_type_at(local(index), type);
+      set_type_at(local(index+1), type2);
+    }
+
+    // Stop interpretation of this path with a trap.
+    void trap(ciBytecodeStream* str, ciKlass* klass, int index);
+
+  public:
+    StateVector(ciTypeFlow* outer);
+
+    // Copy our value into some other StateVector
+    void copy_into(StateVector* copy) const;
+
+    // Meets this StateVector with another, destructively modifying this
+    // one.  Returns true if any modification takes place.
+    bool meet(const StateVector* incoming);
+
+    // Ditto, except that the incoming state is coming from an exception.
+    bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming);
+
+    // Apply the effect of one bytecode to this StateVector
+    bool apply_one_bytecode(ciBytecodeStream* stream);
+
+    // What is the bci of the trap?
+    int  trap_bci() { return _trap_bci; }
+
+    // What is the index associated with the trap?
+    int  trap_index() { return _trap_index; }
+
+    void print_cell_on(outputStream* st, Cell c) const PRODUCT_RETURN;
+    void print_on(outputStream* st) const              PRODUCT_RETURN;
+  };
+
+  // Parameter for "find_block" calls:
+  // Describes the difference between a public and private copy.
+  enum CreateOption {
+    create_public_copy,
+    create_private_copy,
+    no_create
+  };
+
+  // A basic block
+  class Block : public ResourceObj {
+  private:
+    ciBlock*                          _ciblock;
+    GrowableArray<Block*>*           _exceptions;
+    GrowableArray<ciInstanceKlass*>* _exc_klasses;
+    GrowableArray<Block*>*           _successors;
+    StateVector*                     _state;
+    JsrSet*                          _jsrs;
+
+    int                              _trap_bci;
+    int                              _trap_index;
+
+    // A reasonable approximation to pre-order, provided.to the client.
+    int                              _pre_order;
+
+    // Has this block been cloned for some special purpose?
+    bool                             _private_copy;
+
+    // A pointer used for our internal work list
+    Block*                 _next;
+    bool                   _on_work_list;
+
+    ciBlock*     ciblock() const     { return _ciblock; }
+    StateVector* state() const     { return _state; }
+
+    // Compute the exceptional successors and types for this Block.
+    void compute_exceptions();
+
+  public:
+    // constructors
+    Block(ciTypeFlow* outer, ciBlock* ciblk, JsrSet* jsrs);
+
+    void set_trap(int trap_bci, int trap_index) {
+      _trap_bci = trap_bci;
+      _trap_index = trap_index;
+      assert(has_trap(), "");
+    }
+    bool has_trap()   const  { return _trap_bci != -1; }
+    int  trap_bci()   const  { assert(has_trap(), ""); return _trap_bci; }
+    int  trap_index() const  { assert(has_trap(), ""); return _trap_index; }
+
+    // accessors
+    ciTypeFlow* outer() const { return state()->outer(); }
+    int start() const         { return _ciblock->start_bci(); }
+    int limit() const         { return _ciblock->limit_bci(); }
+    int control() const       { return _ciblock->control_bci(); }
+
+    bool    is_private_copy() const       { return _private_copy; }
+    void   set_private_copy(bool z);
+    int        private_copy_count() const { return outer()->private_copy_count(ciblock()->index(), _jsrs); }
+
+    // access to entry state
+    int     stack_size() const         { return _state->stack_size(); }
+    int     monitor_count() const      { return _state->monitor_count(); }
+    ciType* local_type_at(int i) const { return _state->local_type_at(i); }
+    ciType* stack_type_at(int i) const { return _state->stack_type_at(i); }
+
+    // Get the successors for this Block.
+    GrowableArray<Block*>* successors(ciBytecodeStream* str,
+                                      StateVector* state,
+                                      JsrSet* jsrs);
+    GrowableArray<Block*>* successors() {
+      assert(_successors != NULL, "must be filled in");
+      return _successors;
+    }
+
+    // Helper function for "successors" when making private copies of
+    // loop heads for C2.
+    Block * clone_loop_head(ciTypeFlow* analyzer,
+                            int branch_bci,
+                            Block* target,
+                            JsrSet* jsrs);
+
+    // Get the exceptional successors for this Block.
+    GrowableArray<Block*>* exceptions() {
+      if (_exceptions == NULL) {
+        compute_exceptions();
+      }
+      return _exceptions;
+    }
+
+    // Get the exception klasses corresponding to the
+    // exceptional successors for this Block.
+    GrowableArray<ciInstanceKlass*>* exc_klasses() {
+      if (_exc_klasses == NULL) {
+        compute_exceptions();
+      }
+      return _exc_klasses;
+    }
+
+    // Is this Block compatible with a given JsrSet?
+    bool is_compatible_with(JsrSet* other) {
+      return _jsrs->is_compatible_with(other);
+    }
+
+    // Copy the value of our state vector into another.
+    void copy_state_into(StateVector* copy) const {
+      _state->copy_into(copy);
+    }
+
+    // Copy the value of our JsrSet into another
+    void copy_jsrs_into(JsrSet* copy) const {
+      _jsrs->copy_into(copy);
+    }
+
+    // Meets the start state of this block with another state, destructively
+    // modifying this one.  Returns true if any modification takes place.
+    bool meet(const StateVector* incoming) {
+      return state()->meet(incoming);
+    }
+
+    // Ditto, except that the incoming state is coming from an
+    // exception path.  This means the stack is replaced by the
+    // appropriate exception type.
+    bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming) {
+      return state()->meet_exception(exc, incoming);
+    }
+
+    // Work list manipulation
+    void   set_next(Block* block) { _next = block; }
+    Block* next() const           { return _next; }
+
+    void   set_on_work_list(bool c) { _on_work_list = c; }
+    bool   is_on_work_list() const  { return _on_work_list; }
+
+    bool   has_pre_order() const  { return _pre_order >= 0; }
+    void   set_pre_order(int po)  { assert(!has_pre_order() && po >= 0, ""); _pre_order = po; }
+    int    pre_order() const      { assert(has_pre_order(), ""); return _pre_order; }
+    bool   is_start() const       { return _pre_order == outer()->start_block_num(); }
+
+    // A ranking used in determining order within the work list.
+    bool   is_simpler_than(Block* other);
+
+    void   print_value_on(outputStream* st) const PRODUCT_RETURN;
+    void   print_on(outputStream* st) const       PRODUCT_RETURN;
+  };
+
+  // Standard indexes of successors, for various bytecodes.
+  enum {
+    FALL_THROUGH   = 0,  // normal control
+    IF_NOT_TAKEN   = 0,  // the not-taken branch of an if (i.e., fall-through)
+    IF_TAKEN       = 1,  // the taken branch of an if
+    GOTO_TARGET    = 0,  // unique successor for goto, jsr, or ret
+    SWITCH_DEFAULT = 0,  // default branch of a switch
+    SWITCH_CASES   = 1   // first index for any non-default switch branches
+    // Unlike in other blocks, the successors of a switch are listed uniquely.
+  };
+
+private:
+  // A mapping from pre_order to Blocks.  This array is created
+  // only at the end of the flow.
+  Block** _block_map;
+
+  // For each ciBlock index, a list of Blocks which share this ciBlock.
+  GrowableArray<Block*>** _idx_to_blocklist;
+  // count of ciBlocks
+  int _ciblock_count;
+
+  // Tells if a given instruction is able to generate an exception edge.
+  bool can_trap(ciBytecodeStream& str);
+
+public:
+  // Return the block beginning at bci which has a JsrSet compatible
+  // with jsrs.
+  Block* block_at(int bci, JsrSet* set, CreateOption option = create_public_copy);
+
+  // block factory
+  Block* get_block_for(int ciBlockIndex, JsrSet* jsrs, CreateOption option = create_public_copy);
+
+  // How many of the blocks have the private_copy bit set?
+  int private_copy_count(int ciBlockIndex, JsrSet* jsrs) const;
+
+  // Return an existing block containing bci which has a JsrSet compatible
+  // with jsrs, or NULL if there is none.
+  Block* existing_block_at(int bci, JsrSet* set) { return block_at(bci, set, no_create); }
+
+  // Tell whether the flow analysis has encountered an error of some sort.
+  bool failing() { return env()->failing() || _failure_reason != NULL; }
+
+  // Reason this compilation is failing, such as "too many basic blocks".
+  const char* failure_reason() { return _failure_reason; }
+
+  // Note a failure.
+  void record_failure(const char* reason);
+
+  // Return the block of a given pre-order number.
+  int have_block_count() const      { return _block_map != NULL; }
+  int block_count() const           { assert(have_block_count(), "");
+                                      return _next_pre_order; }
+  Block* pre_order_at(int po) const { assert(0 <= po && po < block_count(), "out of bounds");
+                                      return _block_map[po]; }
+  Block* start_block() const        { return pre_order_at(start_block_num()); }
+  int start_block_num() const       { return 0; }
+
+private:
+  // A work list used during flow analysis.
+  Block* _work_list;
+
+  // Next Block::_pre_order.  After mapping, doubles as block_count.
+  int _next_pre_order;
+
+  // Are there more blocks on the work list?
+  bool work_list_empty() { return _work_list == NULL; }
+
+  // Get the next basic block from our work list.
+  Block* work_list_next();
+
+  // Add a basic block to our work list.
+  void add_to_work_list(Block* block);
+
+  // State used for make_jsr_record
+  int _jsr_count;
+  GrowableArray<JsrRecord*>* _jsr_records;
+
+public:
+  // Make a JsrRecord for a given (entry, return) pair, if such a record
+  // does not already exist.
+  JsrRecord* make_jsr_record(int entry_address, int return_address);
+
+private:
+  // Get the initial state for start_bci:
+  const StateVector* get_start_state();
+
+  // Merge the current state into all exceptional successors at the
+  // current point in the code.
+  void flow_exceptions(GrowableArray<Block*>* exceptions,
+                       GrowableArray<ciInstanceKlass*>* exc_klasses,
+                       StateVector* state);
+
+  // Merge the current state into all successors at the current point
+  // in the code.
+  void flow_successors(GrowableArray<Block*>* successors,
+                       StateVector* state);
+
+  // Interpret the effects of the bytecodes on the incoming state
+  // vector of a basic block.  Push the changed state to succeeding
+  // basic blocks.
+  void flow_block(Block* block,
+                  StateVector* scratch_state,
+                  JsrSet* scratch_jsrs);
+
+  // Perform the type flow analysis, creating and cloning Blocks as
+  // necessary.
+  void flow_types();
+
+  // Create the block map, which indexes blocks in pre_order.
+  void map_blocks();
+
+public:
+  // Perform type inference flow analysis.
+  void do_flow();
+
+  void print_on(outputStream* st) const PRODUCT_RETURN;
+};