Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  *

  */

 class Block;

 class Bundle;

 class C2Compiler;

 class CallGenerator;

 class ConnectionGraph;

 class InlineTree;

 class Int_Array;

 class Matcher;

 class MachNode;

 class MachSafePointNode;

 class Node;

 class Node_Array;

 class Node_Notes;

 class OptoReg;

 class PhaseCFG;

 class PhaseGVN;

 class PhaseIterGVN;

 class PhaseRegAlloc;

 class PhaseCCP;

 class PhaseCCP_DCE;

 class RootNode;

 class relocInfo;

 class Scope;

 class StartNode;

 class SafePointNode;

 class JVMState;

 class TypeData;

 class TypePtr;

 class TypeFunc;

 class Unique_Node_List;

 class nmethod;

 class WarmCallInfo;

 //------------------------------Compile----------------------------------------

 // This class defines a top-level Compiler invocation.

 class Compile : public Phase {

  public:

   // Fixed alias indexes.  (See also MergeMemNode.)

   enum {

     AliasIdxTop = 1,  // pseudo-index, aliases to nothing (used as sentinel value)

     AliasIdxBot = 2,  // pseudo-index, aliases to everything

     AliasIdxRaw = 3   // hard-wired index for TypeRawPtr::BOTTOM

   };

   // Variant of TraceTime(NULL, &_t_accumulator, TimeCompiler);

   // Integrated with logging.  If logging is turned on, and dolog is true,

   // then brackets are put into the log, with time stamps and node counts.

   // (The time collection itself is always conditionalized on TimeCompiler.)

   class TracePhase : public TraceTime {

    private:

     Compile*    C;

     CompileLog* _log;

    public:

     TracePhase(const char* name, elapsedTimer* accumulator, bool dolog);

     ~TracePhase();

   };

   // Information per category of alias (memory slice)

   class AliasType {

    private:

     friend class Compile;

     int             _index;         // unique index, used with MergeMemNode

     const TypePtr*  _adr_type;      // normalized address type

     ciField*        _field;         // relevant instance field, or null if none

     bool            _is_rewritable; // false if the memory is write-once only

     int             _general_index; // if this is type is an instance, the general

                                     // type that this is an instance of

     void Init(int i, const TypePtr* at);

    public:

     int             index()         const { return _index; }

     const TypePtr*  adr_type()      const { return _adr_type; }

     ciField*        field()         const { return _field; }

     bool            is_rewritable() const { return _is_rewritable; }

     bool            is_volatile()   const { return (_field ? _field->is_volatile() : false); }

     int             general_index() const { return (_general_index != 0) ? _general_index : _index; }

     void set_rewritable(bool z) { _is_rewritable = z; }

     void set_field(ciField* f) {

       assert(!_field,"");

       _field = f;

       if (f->is_final())  _is_rewritable = false;

     }

     void print_on(outputStream* st) PRODUCT_RETURN;

   };

   enum {

     logAliasCacheSize = 6,

     AliasCacheSize = (1<<logAliasCacheSize)

   };

   struct AliasCacheEntry { const TypePtr* _adr_type; int _index; };  // simple duple type

   enum {

     trapHistLength = methodDataOopDesc::_trap_hist_limit

   };

  private:

   // Fixed parameters to this compilation.

   const int             _compile_id;

   const bool            _save_argument_registers; // save/restore arg regs for trampolines

   const bool            _subsume_loads;         // Load can be matched as part of a larger op.

   const bool            _do_escape_analysis;    // Do escape analysis.

   ciMethod*             _method;                // The method being compiled.

   int                   _entry_bci;             // entry bci for osr methods.

   const TypeFunc*       _tf;                    // My kind of signature

   InlineTree*           _ilt;                   // Ditto (temporary).

   address               _stub_function;         // VM entry for stub being compiled, or NULL

   const char*           _stub_name;             // Name of stub or adapter being compiled, or NULL

   address               _stub_entry_point;      // Compile code entry for generated stub, or NULL

   // Control of this compilation.

   int                   _num_loop_opts;         // Number of iterations for doing loop optimiztions

   int                   _max_inline_size;       // Max inline size for this compilation

   int                   _freq_inline_size;      // Max hot method inline size for this compilation

   int                   _fixed_slots;           // count of frame slots not allocated by the register

                                                 // allocator i.e. locks, original deopt pc, etc.

   // For deopt

   int                   _orig_pc_slot;

   int                   _orig_pc_slot_offset_in_bytes;

   int                   _major_progress;        // Count of something big happening

   bool                  _has_loops;             // True if the method _may_ have some loops

   bool                  _has_split_ifs;         // True if the method _may_ have some split-if

   bool                  _has_unsafe_access;     // True if the method _may_ produce faults in unsafe loads or stores.

   bool                  _has_stringbuilder;     // True StringBuffers or StringBuilders are allocated

   uint                  _trap_hist[trapHistLength];  // Cumulative traps

   bool                  _trap_can_recompile;    // Have we emitted a recompiling trap?

   uint                  _decompile_count;       // Cumulative decompilation counts.

   bool                  _do_inlining;           // True if we intend to do inlining

   bool                  _do_scheduling;         // True if we intend to do scheduling

   bool                  _do_freq_based_layout;  // True if we intend to do frequency based block layout

   bool                  _do_count_invocations;  // True if we generate code to count invocations

   bool                  _do_method_data_update; // True if we generate code to update methodDataOops

   int                   _AliasLevel;            // Locally-adjusted version of AliasLevel flag.

   bool                  _print_assembly;        // True if we should dump assembly code for this compilation

 #ifndef PRODUCT

   bool                  _trace_opto_output;

   bool                  _parsed_irreducible_loop; // True if ciTypeFlow detected irreducible loops during parsing

 #endif

   // JSR 292

   bool                  _has_method_handle_invokes; // True if this method has MethodHandle invokes.

   // Compilation environment.

   Arena                 _comp_arena;            // Arena with lifetime equivalent to Compile

   ciEnv*                _env;                   // CI interface

   CompileLog*           _log;                   // from CompilerThread

   const char*           _failure_reason;        // for record_failure/failing pattern

   GrowableArray<CallGenerator*>* _intrinsics;   // List of intrinsics.

   GrowableArray<Node*>* _macro_nodes;           // List of nodes which need to be expanded before matching.

   GrowableArray<Node*>* _predicate_opaqs;       // List of Opaque1 nodes for the loop predicates.

   ConnectionGraph*      _congraph;

 #ifndef PRODUCT

   IdealGraphPrinter*    _printer;

 #endif

   // Node management

   uint                  _unique;                // Counter for unique Node indices

   debug_only(static int _debug_idx;)            // Monotonic counter (not reset), use -XX:BreakAtNode=<idx>

   Arena                 _node_arena;            // Arena for new-space Nodes

   Arena                 _old_arena;             // Arena for old-space Nodes, lifetime during xform

   RootNode*             _root;                  // Unique root of compilation, or NULL after bail-out.

   Node*                 _top;                   // Unique top node.  (Reset by various phases.)

   Node*                 _immutable_memory;      // Initial memory state

   Node*                 _recent_alloc_obj;

   Node*                 _recent_alloc_ctl;

   // Blocked array of debugging and profiling information,

   // tracked per node.

   enum { _log2_node_notes_block_size = 8,

          _node_notes_block_size = (1<<_log2_node_notes_block_size)

   };

   GrowableArray<Node_Notes*>* _node_note_array;

   Node_Notes*           _default_node_notes;  // default notes for new nodes

   // After parsing and every bulk phase we hang onto the Root instruction.

   // The RootNode instruction is where the whole program begins.  It produces

   // the initial Control and BOTTOM for everybody else.

   // Type management

   Arena                 _Compile_types;         // Arena for all types

   Arena*                _type_arena;            // Alias for _Compile_types except in Initialize_shared()

   Dict*                 _type_dict;             // Intern table

   void*                 _type_hwm;              // Last allocation (see Type::operator new/delete)

   size_t                _type_last_size;        // Last allocation size (see Type::operator new/delete)

   ciMethod*             _last_tf_m;             // Cache for

   const TypeFunc*       _last_tf;               //  TypeFunc::make

   AliasType**           _alias_types;           // List of alias types seen so far.

   int                   _num_alias_types;       // Logical length of _alias_types

   int                   _max_alias_types;       // Physical length of _alias_types

   AliasCacheEntry       _alias_cache[AliasCacheSize]; // Gets aliases w/o data structure walking

   // Parsing, optimization

   PhaseGVN*             _initial_gvn;           // Results of parse-time PhaseGVN

   Unique_Node_List*     _for_igvn;              // Initial work-list for next round of Iterative GVN

   WarmCallInfo*         _warm_calls;            // Sorted work-list for heat-based inlining.

   GrowableArray<CallGenerator*> _late_inlines;  // List of CallGenerators to be revisited after

                                                 // main parsing has finished.

   // Matching, CFG layout, allocation, code generation

   PhaseCFG*             _cfg;                   // Results of CFG finding

   bool                  _select_24_bit_instr;   // We selected an instruction with a 24-bit result

   bool                  _in_24_bit_fp_mode;     // We are emitting instructions with 24-bit results

   int                   _java_calls;            // Number of java calls in the method

   int                   _inner_loops;           // Number of inner loops in the method

   Matcher*              _matcher;               // Engine to map ideal to machine instructions

   PhaseRegAlloc*        _regalloc;              // Results of register allocation.

   int                   _frame_slots;           // Size of total frame in stack slots

   CodeOffsets           _code_offsets;          // Offsets into the code for various interesting entries

   RegMask               _FIRST_STACK_mask;      // All stack slots usable for spills (depends on frame layout)

   Arena*                _indexSet_arena;        // control IndexSet allocation within PhaseChaitin

   void*                 _indexSet_free_block_list; // free list of IndexSet bit blocks

   uint                  _node_bundling_limit;

   Bundle*               _node_bundling_base;    // Information for instruction bundling

   // Instruction bits passed off to the VM

   int                   _method_size;           // Size of nmethod code segment in bytes

   CodeBuffer            _code_buffer;           // Where the code is assembled

   int                   _first_block_size;      // Size of unvalidated entry point code / OSR poison code

   ExceptionHandlerTable _handler_table;         // Table of native-code exception handlers

   ImplicitExceptionTable _inc_table;            // Table of implicit null checks in native code

   OopMapSet*            _oop_map_set;           // Table of oop maps (one for each safepoint location)

   static int            _CompiledZap_count;     // counter compared against CompileZap[First/Last]

   BufferBlob*           _scratch_buffer_blob;   // For temporary code buffers.

   relocInfo*            _scratch_locs_memory;   // For temporary code buffers.

  public:

   // Accessors

   // The Compile instance currently active in this (compiler) thread.

   static Compile* current() {

     return (Compile*) ciEnv::current()->compiler_data();

   }

   // ID for this compilation.  Useful for setting breakpoints in the debugger.

   int               compile_id() const          { return _compile_id; }

   // Does this compilation allow instructions to subsume loads?  User

   // instructions that subsume a load may result in an unschedulable

   // instruction sequence.

   bool              subsume_loads() const       { return _subsume_loads; }

   // Do escape analysis.

   bool              do_escape_analysis() const  { return _do_escape_analysis; }

   bool              save_argument_registers() const { return _save_argument_registers; }

   // Other fixed compilation parameters.

   ciMethod*         method() const              { return _method; }

   int               entry_bci() const           { return _entry_bci; }

   bool              is_osr_compilation() const  { return _entry_bci != InvocationEntryBci; }

   bool              is_method_compilation() const { return (_method != NULL && !_method->flags().is_native()); }

   const TypeFunc*   tf() const                  { assert(_tf!=NULL, ""); return _tf; }

   void         init_tf(const TypeFunc* tf)      { assert(_tf==NULL, ""); _tf = tf; }

   InlineTree*       ilt() const                 { return _ilt; }

   address           stub_function() const       { return _stub_function; }

   const char*       stub_name() const           { return _stub_name; }

   address           stub_entry_point() const    { return _stub_entry_point; }

   // Control of this compilation.

   int               fixed_slots() const         { assert(_fixed_slots >= 0, "");         return _fixed_slots; }

   void          set_fixed_slots(int n)          { _fixed_slots = n; }

   int               major_progress() const      { return _major_progress; }

   void          set_major_progress()            { _major_progress++; }

   void        clear_major_progress()            { _major_progress = 0; }

   int               num_loop_opts() const       { return _num_loop_opts; }

   void          set_num_loop_opts(int n)        { _num_loop_opts = n; }

   int               max_inline_size() const     { return _max_inline_size; }

   void          set_freq_inline_size(int n)     { _freq_inline_size = n; }

   int               freq_inline_size() const    { return _freq_inline_size; }

   void          set_max_inline_size(int n)      { _max_inline_size = n; }

   bool              has_loops() const           { return _has_loops; }

   void          set_has_loops(bool z)           { _has_loops = z; }

   bool              has_split_ifs() const       { return _has_split_ifs; }

   void          set_has_split_ifs(bool z)       { _has_split_ifs = z; }

   bool              has_unsafe_access() const   { return _has_unsafe_access; }

   void          set_has_unsafe_access(bool z)   { _has_unsafe_access = z; }

   bool              has_stringbuilder() const   { return _has_stringbuilder; }

   void          set_has_stringbuilder(bool z)   { _has_stringbuilder = z; }

   void          set_trap_count(uint r, uint c)  { assert(r < trapHistLength, "oob");        _trap_hist[r] = c; }

   uint              trap_count(uint r) const    { assert(r < trapHistLength, "oob"); return _trap_hist[r]; }

   bool              trap_can_recompile() const  { return _trap_can_recompile; }

   void          set_trap_can_recompile(bool z)  { _trap_can_recompile = z; }

   uint              decompile_count() const     { return _decompile_count; }

   void          set_decompile_count(uint c)     { _decompile_count = c; }

   bool              allow_range_check_smearing() const;

   bool              do_inlining() const         { return _do_inlining; }

   void          set_do_inlining(bool z)         { _do_inlining = z; }

   bool              do_scheduling() const       { return _do_scheduling; }

   void          set_do_scheduling(bool z)       { _do_scheduling = z; }

   bool              do_freq_based_layout() const{ return _do_freq_based_layout; }

   void          set_do_freq_based_layout(bool z){ _do_freq_based_layout = z; }

   bool              do_count_invocations() const{ return _do_count_invocations; }

   void          set_do_count_invocations(bool z){ _do_count_invocations = z; }

   bool              do_method_data_update() const { return _do_method_data_update; }

   void          set_do_method_data_update(bool z) { _do_method_data_update = z; }

   int               AliasLevel() const          { return _AliasLevel; }

   bool              print_assembly() const       { return _print_assembly; }

   void          set_print_assembly(bool z)       { _print_assembly = z; }

   // check the CompilerOracle for special behaviours for this compile

   bool          method_has_option(const char * option) {

     return method() != NULL && method()->has_option(option);

   }

 #ifndef PRODUCT

   bool          trace_opto_output() const       { return _trace_opto_output; }

   bool              parsed_irreducible_loop() const { return _parsed_irreducible_loop; }

   void          set_parsed_irreducible_loop(bool z) { _parsed_irreducible_loop = z; }

 #endif

   // JSR 292

   bool              has_method_handle_invokes() const { return _has_method_handle_invokes;     }

   void          set_has_method_handle_invokes(bool z) {        _has_method_handle_invokes = z; }

   void begin_method() {

 #ifndef PRODUCT

     if (_printer) _printer->begin_method(this);

 #endif

   }

   void print_method(const char * name, int level = 1) {

 #ifndef PRODUCT

     if (_printer) _printer->print_method(this, name, level);

 #endif

   }

   void end_method() {

 #ifndef PRODUCT

     if (_printer) _printer->end_method();

 #endif

   }

   int           macro_count()                   { return _macro_nodes->length(); }

   int           predicate_count()               { return _predicate_opaqs->length();}

   Node*         macro_node(int idx)             { return _macro_nodes->at(idx); }

   Node*         predicate_opaque1_node(int idx) { return _predicate_opaqs->at(idx);}

   ConnectionGraph* congraph()                   { return _congraph;}

   void set_congraph(ConnectionGraph* congraph)  { _congraph = congraph;}

   void add_macro_node(Node * n) {

     //assert(n->is_macro(), "must be a macro node");

     assert(!_macro_nodes->contains(n), " duplicate entry in expand list");

     _macro_nodes->append(n);

   }

   void remove_macro_node(Node * n) {

     // this function may be called twice for a node so check

     // that the node is in the array before attempting to remove it

     if (_macro_nodes->contains(n))

       _macro_nodes->remove(n);

     // remove from _predicate_opaqs list also if it is there

     if (predicate_count() > 0 && _predicate_opaqs->contains(n)){

       _predicate_opaqs->remove(n);

     }

   }

   void add_predicate_opaq(Node * n) {

     assert(!_predicate_opaqs->contains(n), " duplicate entry in predicate opaque1");

     assert(_macro_nodes->contains(n), "should have already been in macro list");

     _predicate_opaqs->append(n);

   }

   // remove the opaque nodes that protect the predicates so that the unused checks and

   // uncommon traps will be eliminated from the graph.

   void cleanup_loop_predicates(PhaseIterGVN &igvn);

   // Compilation environment.

   Arena*            comp_arena()                { return &_comp_arena; }

   ciEnv*            env() const                 { return _env; }

   CompileLog*       log() const                 { return _log; }

   bool              failing() const             { return _env->failing() || _failure_reason != NULL; }

   const char* failure_reason() { return _failure_reason; }

   bool              failure_reason_is(const char* r) { return (r==_failure_reason) || (r!=NULL && _failure_reason!=NULL && strcmp(r, _failure_reason)==0); }

   void record_failure(const char* reason);

   void record_method_not_compilable(const char* reason, bool all_tiers = false) {

     // All bailouts cover "all_tiers" when TieredCompilation is off.

     if (!TieredCompilation) all_tiers = true;

     env()->record_method_not_compilable(reason, all_tiers);

     // Record failure reason.

     record_failure(reason);

   }

   void record_method_not_compilable_all_tiers(const char* reason) {

     record_method_not_compilable(reason, true);

   }

   bool check_node_count(uint margin, const char* reason) {

     if (unique() + margin > (uint)MaxNodeLimit) {

       record_method_not_compilable(reason);

       return true;

     } else {

       return false;

     }

   }

   // Node management

   uint              unique() const              { return _unique; }

   uint         next_unique()                    { return _unique++; }

   void          set_unique(uint i)              { _unique = i; }

   static int        debug_idx()                 { return debug_only(_debug_idx)+0; }

   static void   set_debug_idx(int i)            { debug_only(_debug_idx = i); }

   Arena*            node_arena()                { return &_node_arena; }

   Arena*            old_arena()                 { return &_old_arena; }

   RootNode*         root() const                { return _root; }

   void          set_root(RootNode* r)           { _root = r; }

   StartNode*        start() const;              // (Derived from root.)

   void         init_start(StartNode* s);

   Node*             immutable_memory();

   Node*             recent_alloc_ctl() const    { return _recent_alloc_ctl; }

   Node*             recent_alloc_obj() const    { return _recent_alloc_obj; }

   void          set_recent_alloc(Node* ctl, Node* obj) {

                                                   _recent_alloc_ctl = ctl;

                                                   _recent_alloc_obj = obj;

                                                 }

   // Handy undefined Node

   Node*             top() const                 { return _top; }

   // these are used by guys who need to know about creation and transformation of top:

   Node*             cached_top_node()           { return _top; }

   void          set_cached_top_node(Node* tn);

   GrowableArray<Node_Notes*>* node_note_array() const { return _node_note_array; }

   void set_node_note_array(GrowableArray<Node_Notes*>* arr) { _node_note_array = arr; }

   Node_Notes* default_node_notes() const        { return _default_node_notes; }

   void    set_default_node_notes(Node_Notes* n) { _default_node_notes = n; }

   Node_Notes*       node_notes_at(int idx) {

     return locate_node_notes(_node_note_array, idx, false);

   }

   inline bool   set_node_notes_at(int idx, Node_Notes* value);

   // Copy notes from source to dest, if they exist.

   // Overwrite dest only if source provides something.

   // Return true if information was moved.

   bool copy_node_notes_to(Node* dest, Node* source);

   // Workhorse function to sort out the blocked Node_Notes array:

   inline Node_Notes* locate_node_notes(GrowableArray<Node_Notes*>* arr,

                                        int idx, bool can_grow = false);

   void grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by);

   // Type management

   Arena*            type_arena()                { return _type_arena; }

   Dict*             type_dict()                 { return _type_dict; }

   void*             type_hwm()                  { return _type_hwm; }

   size_t            type_last_size()            { return _type_last_size; }

   int               num_alias_types()           { return _num_alias_types; }

   void          init_type_arena()                       { _type_arena = &_Compile_types; }

   void          set_type_arena(Arena* a)                { _type_arena = a; }

   void          set_type_dict(Dict* d)                  { _type_dict = d; }

   void          set_type_hwm(void* p)                   { _type_hwm = p; }

   void          set_type_last_size(size_t sz)           { _type_last_size = sz; }

   const TypeFunc* last_tf(ciMethod* m) {

     return (m == _last_tf_m) ? _last_tf : NULL;

   }

   void set_last_tf(ciMethod* m, const TypeFunc* tf) {

     assert(m != NULL || tf == NULL, "");

     _last_tf_m = m;

     _last_tf = tf;

   }

   AliasType*        alias_type(int                idx)  { assert(idx < num_alias_types(), "oob"); return _alias_types[idx]; }

   AliasType*        alias_type(const TypePtr* adr_type) { return find_alias_type(adr_type, false); }

   bool         have_alias_type(const TypePtr* adr_type);

   AliasType*        alias_type(ciField*         field);

   int               get_alias_index(const TypePtr* at)  { return alias_type(at)->index(); }

   const TypePtr*    get_adr_type(uint aidx)             { return alias_type(aidx)->adr_type(); }

   int               get_general_index(uint aidx)        { return alias_type(aidx)->general_index(); }

   // Building nodes

   void              rethrow_exceptions(JVMState* jvms);

   void              return_values(JVMState* jvms);

   JVMState*         build_start_state(StartNode* start, const TypeFunc* tf);

   // Decide how to build a call.

   // The profile factor is a discount to apply to this site's interp. profile.

   CallGenerator*    call_generator(ciMethod* call_method, int vtable_index, bool call_is_virtual, JVMState* jvms, bool allow_inline, float profile_factor);

   bool should_delay_inlining(ciMethod* call_method, JVMState* jvms);

   // Report if there were too many traps at a current method and bci.

   // Report if a trap was recorded, and/or PerMethodTrapLimit was exceeded.

   // If there is no MDO at all, report no trap unless told to assume it.

   bool too_many_traps(ciMethod* method, int bci, Deoptimization::DeoptReason reason);

   // This version, unspecific to a particular bci, asks if

   // PerMethodTrapLimit was exceeded for all inlined methods seen so far.

   bool too_many_traps(Deoptimization::DeoptReason reason,

                       // Privately used parameter for logging:

                       ciMethodData* logmd = NULL);

   // Report if there were too many recompiles at a method and bci.

   bool too_many_recompiles(ciMethod* method, int bci, Deoptimization::DeoptReason reason);

   // Parsing, optimization

   PhaseGVN*         initial_gvn()               { return _initial_gvn; }

   Unique_Node_List* for_igvn()                  { return _for_igvn; }

   inline void       record_for_igvn(Node* n);   // Body is after class Unique_Node_List.

   void          set_initial_gvn(PhaseGVN *gvn)           { _initial_gvn = gvn; }

   void          set_for_igvn(Unique_Node_List *for_igvn) { _for_igvn = for_igvn; }

   // Replace n by nn using initial_gvn, calling hash_delete and

   // record_for_igvn as needed.

   void gvn_replace_by(Node* n, Node* nn);

   void              identify_useful_nodes(Unique_Node_List &useful);

   void              remove_useless_nodes  (Unique_Node_List &useful);

   WarmCallInfo*     warm_calls() const          { return _warm_calls; }

   void          set_warm_calls(WarmCallInfo* l) { _warm_calls = l; }

   WarmCallInfo* pop_warm_call();

   // Record this CallGenerator for inlining at the end of parsing.

   void              add_late_inline(CallGenerator* cg) { _late_inlines.push(cg); }

   // Matching, CFG layout, allocation, code generation

   PhaseCFG*         cfg()                       { return _cfg; }

   bool              select_24_bit_instr() const { return _select_24_bit_instr; }

   bool              in_24_bit_fp_mode() const   { return _in_24_bit_fp_mode; }

   bool              has_java_calls() const      { return _java_calls > 0; }

   int               java_calls() const          { return _java_calls; }

   int               inner_loops() const         { return _inner_loops; }

   Matcher*          matcher()                   { return _matcher; }

   PhaseRegAlloc*    regalloc()                  { return _regalloc; }

   int               frame_slots() const         { return _frame_slots; }

   int               frame_size_in_words() const; // frame_slots in units of the polymorphic 'words'

   RegMask&          FIRST_STACK_mask()          { return _FIRST_STACK_mask; }

   Arena*            indexSet_arena()            { return _indexSet_arena; }

   void*             indexSet_free_block_list()  { return _indexSet_free_block_list; }

   uint              node_bundling_limit()       { return _node_bundling_limit; }

   Bundle*           node_bundling_base()        { return _node_bundling_base; }

   void          set_node_bundling_limit(uint n) { _node_bundling_limit = n; }

   void          set_node_bundling_base(Bundle* b) { _node_bundling_base = b; }

   bool          starts_bundle(const Node *n) const;

   bool          need_stack_bang(int frame_size_in_bytes) const;

   bool          need_register_stack_bang() const;

   void          set_matcher(Matcher* m)                 { _matcher = m; }

 //void          set_regalloc(PhaseRegAlloc* ra)           { _regalloc = ra; }

   void          set_indexSet_arena(Arena* a)            { _indexSet_arena = a; }

   void          set_indexSet_free_block_list(void* p)   { _indexSet_free_block_list = p; }

   // Remember if this compilation changes hardware mode to 24-bit precision

   void set_24_bit_selection_and_mode(bool selection, bool mode) {

     _select_24_bit_instr = selection;

     _in_24_bit_fp_mode   = mode;

   }

   void  set_java_calls(int z) { _java_calls  = z; }

   void set_inner_loops(int z) { _inner_loops = z; }

   // Instruction bits passed off to the VM

   int               code_size()                 { return _method_size; }

   CodeBuffer*       code_buffer()               { return &_code_buffer; }

   int               first_block_size()          { return _first_block_size; }

   void              set_frame_complete(int off) { _code_offsets.set_value(CodeOffsets::Frame_Complete, off); }

   ExceptionHandlerTable*  handler_table()       { return &_handler_table; }

   ImplicitExceptionTable* inc_table()           { return &_inc_table; }

   OopMapSet*        oop_map_set()               { return _oop_map_set; }

   DebugInformationRecorder* debug_info()        { return env()->debug_info(); }

   Dependencies*     dependencies()              { return env()->dependencies(); }

   static int        CompiledZap_count()         { return _CompiledZap_count; }

   BufferBlob*       scratch_buffer_blob()       { return _scratch_buffer_blob; }

   void         init_scratch_buffer_blob();

   void          set_scratch_buffer_blob(BufferBlob* b) { _scratch_buffer_blob = b; }

   relocInfo*        scratch_locs_memory()       { return _scratch_locs_memory; }

   void          set_scratch_locs_memory(relocInfo* b)  { _scratch_locs_memory = b; }

   // emit to scratch blob, report resulting size

   uint              scratch_emit_size(const Node* n);

   enum ScratchBufferBlob {

     MAX_inst_size       = 1024,

     MAX_locs_size       = 128, // number of relocInfo elements

     MAX_const_size      = 128,

     MAX_stubs_size      = 128

   };

   // Major entry point.  Given a Scope, compile the associated method.

   // For normal compilations, entry_bci is InvocationEntryBci.  For on stack

   // replacement, entry_bci indicates the bytecode for which to compile a

   // continuation.

   Compile(ciEnv* ci_env, C2Compiler* compiler, ciMethod* target,

           int entry_bci, bool subsume_loads, bool do_escape_analysis);

   // Second major entry point.  From the TypeFunc signature, generate code

   // to pass arguments from the Java calling convention to the C calling

   // convention.

   Compile(ciEnv* ci_env, const TypeFunc *(*gen)(),

           address stub_function, const char *stub_name,

           int is_fancy_jump, bool pass_tls,

           bool save_arg_registers, bool return_pc);

   // From the TypeFunc signature, generate code to pass arguments

   // from Compiled calling convention to Interpreter's calling convention

   void Generate_Compiled_To_Interpreter_Graph(const TypeFunc *tf, address interpreter_entry);

   // From the TypeFunc signature, generate code to pass arguments

   // from Interpreter's calling convention to Compiler's calling convention

   void Generate_Interpreter_To_Compiled_Graph(const TypeFunc *tf);

   // Are we compiling a method?

   bool has_method() { return method() != NULL; }

   // Maybe print some information about this compile.

   void print_compile_messages();

   // Final graph reshaping, a post-pass after the regular optimizer is done.

   bool final_graph_reshaping();

   // returns true if adr is completely contained in the given alias category

   bool must_alias(const TypePtr* adr, int alias_idx);

   // returns true if adr overlaps with the given alias category

   bool can_alias(const TypePtr* adr, int alias_idx);

   // Driver for converting compiler's IR into machine code bits

   void Output();

   // Accessors for node bundling info.

   Bundle* node_bundling(const Node *n);

   bool valid_bundle_info(const Node *n);

   // Schedule and Bundle the instructions

   void ScheduleAndBundle();

   // Build OopMaps for each GC point

   void BuildOopMaps();

   // Append debug info for the node "local" at safepoint node "sfpt" to the

   // "array",   May also consult and add to "objs", which describes the

   // scalar-replaced objects.

   void FillLocArray( int idx, MachSafePointNode* sfpt,

                      Node *local, GrowableArray<ScopeValue*> *array,

                      GrowableArray<ScopeValue*> *objs );

   // If "objs" contains an ObjectValue whose id is "id", returns it, else NULL.

   static ObjectValue* sv_for_node_id(GrowableArray<ScopeValue*> *objs, int id);

   // Requres that "objs" does not contains an ObjectValue whose id matches

   // that of "sv.  Appends "sv".

   static void set_sv_for_object_node(GrowableArray<ScopeValue*> *objs,

                                      ObjectValue* sv );

   // Process an OopMap Element while emitting nodes

   void Process_OopMap_Node(MachNode *mach, int code_offset);

   // Write out basic block data to code buffer

   void Fill_buffer();

   // Determine which variable sized branches can be shortened

   void Shorten_branches(Label *labels, int& code_size, int& reloc_size, int& stub_size, int& const_size);

   // Compute the size of first NumberOfLoopInstrToAlign instructions

   // at the head of a loop.

   void compute_loop_first_inst_sizes();

   // Compute the information for the exception tables

   void FillExceptionTables(uint cnt, uint *call_returns, uint *inct_starts, Label *blk_labels);

   // Stack slots that may be unused by the calling convention but must

   // otherwise be preserved.  On Intel this includes the return address.

   // On PowerPC it includes the 4 words holding the old TOC & LR glue.

   uint in_preserve_stack_slots();

   // "Top of Stack" slots that may be unused by the calling convention but must

   // otherwise be preserved.

   // On Intel these are not necessary and the value can be zero.

   // On Sparc this describes the words reserved for storing a register window

   // when an interrupt occurs.

   static uint out_preserve_stack_slots();

   // Number of outgoing stack slots killed above the out_preserve_stack_slots

   // for calls to C.  Supports the var-args backing area for register parms.

   uint varargs_C_out_slots_killed() const;

   // Number of Stack Slots consumed by a synchronization entry

   int sync_stack_slots() const;

   // Compute the name of old_SP.  See <arch>.ad for frame layout.

   OptoReg::Name compute_old_SP();

 #ifdef ENABLE_ZAP_DEAD_LOCALS

   static bool is_node_getting_a_safepoint(Node*);

   void Insert_zap_nodes();

   Node* call_zap_node(MachSafePointNode* n, int block_no);

 #endif

  private:

   // Phase control:

   void Init(int aliaslevel);                     // Prepare for a single compilation

   int  Inline_Warm();                            // Find more inlining work.

   void Finish_Warm();                            // Give up on further inlines.

   void Optimize();                               // Given a graph, optimize it

   void Code_Gen();                               // Generate code from a graph

   // Management of the AliasType table.

   void grow_alias_types();

   AliasCacheEntry* probe_alias_cache(const TypePtr* adr_type);

   const TypePtr *flatten_alias_type(const TypePtr* adr_type) const;

   AliasType* find_alias_type(const TypePtr* adr_type, bool no_create);

   void verify_top(Node*) const PRODUCT_RETURN;

   // Intrinsic setup.

   void           register_library_intrinsics();                            // initializer

   CallGenerator* make_vm_intrinsic(ciMethod* m, bool is_virtual);          // constructor

   int            intrinsic_insertion_index(ciMethod* m, bool is_virtual);  // helper

   CallGenerator* find_intrinsic(ciMethod* m, bool is_virtual);             // query fn

   void           register_intrinsic(CallGenerator* cg);                    // update fn

 #ifndef PRODUCT

   static juint  _intrinsic_hist_count[vmIntrinsics::ID_LIMIT];

   static jubyte _intrinsic_hist_flags[vmIntrinsics::ID_LIMIT];

 #endif

  public:

   // Note:  Histogram array size is about 1 Kb.

   enum {                        // flag bits:

     _intrinsic_worked = 1,      // succeeded at least once

     _intrinsic_failed = 2,      // tried it but it failed

     _intrinsic_disabled = 4,    // was requested but disabled (e.g., -XX:-InlineUnsafeOps)

     _intrinsic_virtual = 8,     // was seen in the virtual form (rare)

     _intrinsic_both = 16        // was seen in the non-virtual form (usual)

   };

   // Update histogram.  Return boolean if this is a first-time occurrence.

   static bool gather_intrinsic_statistics(vmIntrinsics::ID id,

                                           bool is_virtual, int flags) PRODUCT_RETURN0;

   static void print_intrinsic_statistics() PRODUCT_RETURN;

   // Graph verification code

   // Walk the node list, verifying that there is a one-to-one

   // correspondence between Use-Def edges and Def-Use edges

   // The option no_dead_code enables stronger checks that the

   // graph is strongly connected from root in both directions.

   void verify_graph_edges(bool no_dead_code = false) PRODUCT_RETURN;

   // Print bytecodes, including the scope inlining tree

   void print_codes();

   // End-of-run dumps.

   static void print_statistics() PRODUCT_RETURN;

   // Dump formatted assembly

   void dump_asm(int *pcs = NULL, uint pc_limit = 0) PRODUCT_RETURN;

   void dump_pc(int *pcs, int pc_limit, Node *n);

   // Verify ADLC assumptions during startup

   static void adlc_verification() PRODUCT_RETURN;

   // Definitions of pd methods

   static void pd_compiler2_init();

 };