1 /*
   2  * Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_C1_C1_LIRGENERATOR_HPP
  26 #define SHARE_VM_C1_C1_LIRGENERATOR_HPP
  27 
  28 #include "c1/c1_Instruction.hpp"
  29 #include "c1/c1_LIR.hpp"
  30 #include "ci/ciMethodData.hpp"
  31 #include "utilities/sizes.hpp"
  32 
  33 // The classes responsible for code emission and register allocation
  34 
  35 
  36 class LIRGenerator;
  37 class LIREmitter;
  38 class Invoke;
  39 class SwitchRange;
  40 class LIRItem;
  41 
  42 define_array(LIRItemArray, LIRItem*)
  43 define_stack(LIRItemList, LIRItemArray)
  44 
  45 class SwitchRange: public CompilationResourceObj {
  46  private:
  47   int _low_key;
  48   int _high_key;
  49   BlockBegin* _sux;
  50  public:
  51   SwitchRange(int start_key, BlockBegin* sux): _low_key(start_key), _high_key(start_key), _sux(sux) {}
  52   void set_high_key(int key) { _high_key = key; }
  53 
  54   int high_key() const { return _high_key; }
  55   int low_key() const { return _low_key; }
  56   BlockBegin* sux() const { return _sux; }
  57 };
  58 
  59 define_array(SwitchRangeArray, SwitchRange*)
  60 define_stack(SwitchRangeList, SwitchRangeArray)
  61 
  62 
  63 class ResolveNode;
  64 
  65 define_array(NodeArray, ResolveNode*);
  66 define_stack(NodeList, NodeArray);
  67 
  68 
  69 // Node objects form a directed graph of LIR_Opr
  70 // Edges between Nodes represent moves from one Node to its destinations
  71 class ResolveNode: public CompilationResourceObj {
  72  private:
  73   LIR_Opr    _operand;       // the source or destinaton
  74   NodeList   _destinations;  // for the operand
  75   bool       _assigned;      // Value assigned to this Node?
  76   bool       _visited;       // Node already visited?
  77   bool       _start_node;    // Start node already visited?
  78 
  79  public:
  80   ResolveNode(LIR_Opr operand)
  81     : _operand(operand)
  82     , _assigned(false)
  83     , _visited(false)
  84     , _start_node(false) {};
  85 
  86   // accessors
  87   LIR_Opr operand() const           { return _operand; }
  88   int no_of_destinations() const    { return _destinations.length(); }
  89   ResolveNode* destination_at(int i)     { return _destinations[i]; }
  90   bool assigned() const             { return _assigned; }
  91   bool visited() const              { return _visited; }
  92   bool start_node() const           { return _start_node; }
  93 
  94   // modifiers
  95   void append(ResolveNode* dest)         { _destinations.append(dest); }
  96   void set_assigned()               { _assigned = true; }
  97   void set_visited()                { _visited = true; }
  98   void set_start_node()             { _start_node = true; }
  99 };
 100 
 101 
 102 // This is shared state to be used by the PhiResolver so the operand
 103 // arrays don't have to be reallocated for reach resolution.
 104 class PhiResolverState: public CompilationResourceObj {
 105   friend class PhiResolver;
 106 
 107  private:
 108   NodeList _virtual_operands; // Nodes where the operand is a virtual register
 109   NodeList _other_operands;   // Nodes where the operand is not a virtual register
 110   NodeList _vreg_table;       // Mapping from virtual register to Node
 111 
 112  public:
 113   PhiResolverState() {}
 114 
 115   void reset(int max_vregs);
 116 };
 117 
 118 
 119 // class used to move value of phi operand to phi function
 120 class PhiResolver: public CompilationResourceObj {
 121  private:
 122   LIRGenerator*     _gen;
 123   PhiResolverState& _state; // temporary state cached by LIRGenerator
 124 
 125   ResolveNode*   _loop;
 126   LIR_Opr _temp;
 127 
 128   // access to shared state arrays
 129   NodeList& virtual_operands() { return _state._virtual_operands; }
 130   NodeList& other_operands()   { return _state._other_operands;   }
 131   NodeList& vreg_table()       { return _state._vreg_table;       }
 132 
 133   ResolveNode* create_node(LIR_Opr opr, bool source);
 134   ResolveNode* source_node(LIR_Opr opr)      { return create_node(opr, true); }
 135   ResolveNode* destination_node(LIR_Opr opr) { return create_node(opr, false); }
 136 
 137   void emit_move(LIR_Opr src, LIR_Opr dest);
 138   void move_to_temp(LIR_Opr src);
 139   void move_temp_to(LIR_Opr dest);
 140   void move(ResolveNode* src, ResolveNode* dest);
 141 
 142   LIRGenerator* gen() {
 143     return _gen;
 144   }
 145 
 146  public:
 147   PhiResolver(LIRGenerator* _lir_gen, int max_vregs);
 148   ~PhiResolver();
 149 
 150   void move(LIR_Opr src, LIR_Opr dest);
 151 };
 152 
 153 
 154 // only the classes below belong in the same file
 155 class LIRGenerator: public InstructionVisitor, public BlockClosure {
 156 
 157  private:
 158   Compilation*  _compilation;
 159   ciMethod*     _method;    // method that we are compiling
 160   PhiResolverState  _resolver_state;
 161   BlockBegin*   _block;
 162   int           _virtual_register_number;
 163   Values        _instruction_for_operand;
 164   BitMap2D      _vreg_flags; // flags which can be set on a per-vreg basis
 165   LIR_List*     _lir;
 166   BarrierSet*   _bs;
 167 
 168   LIRGenerator* gen() {
 169     return this;
 170   }
 171 
 172 #ifdef ASSERT
 173   LIR_List* lir(const char * file, int line) const {
 174     _lir->set_file_and_line(file, line);
 175     return _lir;
 176   }
 177 #endif
 178   LIR_List* lir() const {
 179     return _lir;
 180   }
 181 
 182   // a simple cache of constants used within a block
 183   GrowableArray<LIR_Const*>       _constants;
 184   LIR_OprList                     _reg_for_constants;
 185   Values                          _unpinned_constants;
 186 
 187   friend class PhiResolver;
 188 
 189   // unified bailout support
 190   void bailout(const char* msg) const            { compilation()->bailout(msg); }
 191   bool bailed_out() const                        { return compilation()->bailed_out(); }
 192 
 193   void block_do_prolog(BlockBegin* block);
 194   void block_do_epilog(BlockBegin* block);
 195 
 196   // register allocation
 197   LIR_Opr rlock(Value instr);                      // lock a free register
 198   LIR_Opr rlock_result(Value instr);
 199   LIR_Opr rlock_result(Value instr, BasicType type);
 200   LIR_Opr rlock_byte(BasicType type);
 201   LIR_Opr rlock_callee_saved(BasicType type);
 202 
 203   // get a constant into a register and get track of what register was used
 204   LIR_Opr load_constant(Constant* x);
 205   LIR_Opr load_constant(LIR_Const* constant);
 206 
 207   // Given an immediate value, return an operand usable in logical ops.
 208   LIR_Opr load_immediate(int x, BasicType type);
 209 
 210   void  set_result(Value x, LIR_Opr opr)           {
 211     assert(opr->is_valid(), "must set to valid value");
 212     assert(x->operand()->is_illegal(), "operand should never change");
 213     assert(!opr->is_register() || opr->is_virtual(), "should never set result to a physical register");
 214     x->set_operand(opr);
 215     assert(opr == x->operand(), "must be");
 216     if (opr->is_virtual()) {
 217       _instruction_for_operand.at_put_grow(opr->vreg_number(), x, NULL);
 218     }
 219   }
 220   void  set_no_result(Value x)                     { assert(!x->has_uses(), "can't have use"); x->clear_operand(); }
 221 
 222   friend class LIRItem;
 223 
 224   LIR_Opr round_item(LIR_Opr opr);
 225   LIR_Opr force_to_spill(LIR_Opr value, BasicType t);
 226 
 227   PhiResolverState& resolver_state() { return _resolver_state; }
 228 
 229   void  move_to_phi(PhiResolver* resolver, Value cur_val, Value sux_val);
 230   void  move_to_phi(ValueStack* cur_state);
 231 
 232   // code emission
 233   void do_ArithmeticOp_Long   (ArithmeticOp*    x);
 234   void do_ArithmeticOp_Int    (ArithmeticOp*    x);
 235   void do_ArithmeticOp_FPU    (ArithmeticOp*    x);
 236 
 237   // platform dependent
 238   LIR_Opr getThreadPointer();
 239 
 240   void do_RegisterFinalizer(Intrinsic* x);
 241   void do_isInstance(Intrinsic* x);
 242   void do_getClass(Intrinsic* x);
 243   void do_currentThread(Intrinsic* x);
 244   void do_MathIntrinsic(Intrinsic* x);
 245   void do_ArrayCopy(Intrinsic* x);
 246   void do_CompareAndSwap(Intrinsic* x, ValueType* type);
 247   void do_NIOCheckIndex(Intrinsic* x);
 248   void do_FPIntrinsics(Intrinsic* x);
 249   void do_Reference_get(Intrinsic* x);
 250 
 251   void do_UnsafePrefetch(UnsafePrefetch* x, bool is_store);
 252 
 253   LIR_Opr call_runtime(BasicTypeArray* signature, LIRItemList* args, address entry, ValueType* result_type, CodeEmitInfo* info);
 254   LIR_Opr call_runtime(BasicTypeArray* signature, LIR_OprList* args, address entry, ValueType* result_type, CodeEmitInfo* info);
 255 
 256   // convenience functions
 257   LIR_Opr call_runtime(Value arg1, address entry, ValueType* result_type, CodeEmitInfo* info);
 258   LIR_Opr call_runtime(Value arg1, Value arg2, address entry, ValueType* result_type, CodeEmitInfo* info);
 259 
 260   // GC Barriers
 261 
 262   // generic interface
 263 
 264   void pre_barrier(LIR_Opr addr_opr, LIR_Opr pre_val, bool do_load, bool patch, CodeEmitInfo* info);
 265   void post_barrier(LIR_OprDesc* addr, LIR_OprDesc* new_val);
 266 
 267   // specific implementations
 268   // pre barriers
 269 
 270   void G1SATBCardTableModRef_pre_barrier(LIR_Opr addr_opr, LIR_Opr pre_val,
 271                                          bool do_load, bool patch, CodeEmitInfo* info);
 272 
 273   // post barriers
 274 
 275   void G1SATBCardTableModRef_post_barrier(LIR_OprDesc* addr, LIR_OprDesc* new_val);
 276   void CardTableModRef_post_barrier(LIR_OprDesc* addr, LIR_OprDesc* new_val);
 277 
 278 
 279   static LIR_Opr result_register_for(ValueType* type, bool callee = false);
 280 
 281   ciObject* get_jobject_constant(Value value);
 282 
 283   LIRItemList* invoke_visit_arguments(Invoke* x);
 284   void invoke_load_arguments(Invoke* x, LIRItemList* args, const LIR_OprList* arg_list);
 285 
 286   void trace_block_entry(BlockBegin* block);
 287 
 288   // volatile field operations are never patchable because a klass
 289   // must be loaded to know it's volatile which means that the offset
 290   // it always known as well.
 291   void volatile_field_store(LIR_Opr value, LIR_Address* address, CodeEmitInfo* info);
 292   void volatile_field_load(LIR_Address* address, LIR_Opr result, CodeEmitInfo* info);
 293 
 294   void put_Object_unsafe(LIR_Opr src, LIR_Opr offset, LIR_Opr data, BasicType type, bool is_volatile);
 295   void get_Object_unsafe(LIR_Opr dest, LIR_Opr src, LIR_Opr offset, BasicType type, bool is_volatile);
 296 
 297   void arithmetic_call_op (Bytecodes::Code code, LIR_Opr result, LIR_OprList* args);
 298 
 299   void increment_counter(address counter, BasicType type, int step = 1);
 300   void increment_counter(LIR_Address* addr, int step = 1);
 301 
 302   // is_strictfp is only needed for mul and div (and only generates different code on i486)
 303   void arithmetic_op(Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, bool is_strictfp, LIR_Opr tmp, CodeEmitInfo* info = NULL);
 304   // machine dependent.  returns true if it emitted code for the multiply
 305   bool strength_reduce_multiply(LIR_Opr left, int constant, LIR_Opr result, LIR_Opr tmp);
 306 
 307   void store_stack_parameter (LIR_Opr opr, ByteSize offset_from_sp_in_bytes);
 308 
 309   void klass2reg_with_patching(LIR_Opr r, ciMetadata* obj, CodeEmitInfo* info);
 310 
 311   // this loads the length and compares against the index
 312   void array_range_check          (LIR_Opr array, LIR_Opr index, CodeEmitInfo* null_check_info, CodeEmitInfo* range_check_info);
 313   // For java.nio.Buffer.checkIndex
 314   void nio_range_check            (LIR_Opr buffer, LIR_Opr index, LIR_Opr result, CodeEmitInfo* info);
 315 
 316   void arithmetic_op_int  (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, LIR_Opr tmp);
 317   void arithmetic_op_long (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, CodeEmitInfo* info = NULL);
 318   void arithmetic_op_fpu  (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, bool is_strictfp, LIR_Opr tmp = LIR_OprFact::illegalOpr);
 319 
 320   void shift_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr value, LIR_Opr count, LIR_Opr tmp);
 321 
 322   void logic_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr left, LIR_Opr right);
 323 
 324   void monitor_enter (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, LIR_Opr scratch, int monitor_no, CodeEmitInfo* info_for_exception, CodeEmitInfo* info);
 325   void monitor_exit  (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, LIR_Opr scratch, int monitor_no);
 326 
 327   void new_instance    (LIR_Opr  dst, ciInstanceKlass* klass, LIR_Opr  scratch1, LIR_Opr  scratch2, LIR_Opr  scratch3,  LIR_Opr scratch4, LIR_Opr  klass_reg, CodeEmitInfo* info);
 328 
 329   // machine dependent
 330   void cmp_mem_int(LIR_Condition condition, LIR_Opr base, int disp, int c, CodeEmitInfo* info);
 331   void cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr base, int disp, BasicType type, CodeEmitInfo* info);
 332   void cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr base, LIR_Opr disp, BasicType type, CodeEmitInfo* info);
 333 
 334   void arraycopy_helper(Intrinsic* x, int* flags, ciArrayKlass** expected_type);
 335 
 336   // returns a LIR_Address to address an array location.  May also
 337   // emit some code as part of address calculation.  If
 338   // needs_card_mark is true then compute the full address for use by
 339   // both the store and the card mark.
 340   LIR_Address* generate_address(LIR_Opr base,
 341                                 LIR_Opr index, int shift,
 342                                 int disp,
 343                                 BasicType type);
 344   LIR_Address* generate_address(LIR_Opr base, int disp, BasicType type) {
 345     return generate_address(base, LIR_OprFact::illegalOpr, 0, disp, type);
 346   }
 347   LIR_Address* emit_array_address(LIR_Opr array_opr, LIR_Opr index_opr, BasicType type, bool needs_card_mark);
 348 
 349   // the helper for generate_address
 350   void add_large_constant(LIR_Opr src, int c, LIR_Opr dest);
 351 
 352   // machine preferences and characteristics
 353   bool can_inline_as_constant(Value i) const;
 354   bool can_inline_as_constant(LIR_Const* c) const;
 355   bool can_store_as_constant(Value i, BasicType type) const;
 356 
 357   LIR_Opr safepoint_poll_register();
 358 
 359   void profile_branch(If* if_instr, If::Condition cond);
 360   void increment_event_counter_impl(CodeEmitInfo* info,
 361                                     ciMethod *method, int frequency,
 362                                     int bci, bool backedge, bool notify);
 363   void increment_event_counter(CodeEmitInfo* info, int bci, bool backedge);
 364   void increment_invocation_counter(CodeEmitInfo *info) {
 365     if (compilation()->count_invocations()) {
 366       increment_event_counter(info, InvocationEntryBci, false);
 367     }
 368   }
 369   void increment_backedge_counter(CodeEmitInfo* info, int bci) {
 370     if (compilation()->count_backedges()) {
 371       increment_event_counter(info, bci, true);
 372     }
 373   }
 374 
 375   CodeEmitInfo* state_for(Instruction* x, ValueStack* state, bool ignore_xhandler = false);
 376   CodeEmitInfo* state_for(Instruction* x);
 377 
 378   // allocates a virtual register for this instruction if
 379   // one isn't already allocated.  Only for Phi and Local.
 380   LIR_Opr operand_for_instruction(Instruction *x);
 381 
 382   void set_block(BlockBegin* block)              { _block = block; }
 383 
 384   void block_prolog(BlockBegin* block);
 385   void block_epilog(BlockBegin* block);
 386 
 387   void do_root (Instruction* instr);
 388   void walk    (Instruction* instr);
 389 
 390   void bind_block_entry(BlockBegin* block);
 391   void start_block(BlockBegin* block);
 392 
 393   LIR_Opr new_register(BasicType type);
 394   LIR_Opr new_register(Value value)              { return new_register(as_BasicType(value->type())); }
 395   LIR_Opr new_register(ValueType* type)          { return new_register(as_BasicType(type)); }
 396 
 397   // returns a register suitable for doing pointer math
 398   LIR_Opr new_pointer_register() {
 399 #ifdef _LP64
 400     return new_register(T_LONG);
 401 #else
 402     return new_register(T_INT);
 403 #endif
 404   }
 405 
 406   static LIR_Condition lir_cond(If::Condition cond) {
 407     LIR_Condition l;
 408     switch (cond) {
 409     case If::eql: l = lir_cond_equal;        break;
 410     case If::neq: l = lir_cond_notEqual;     break;
 411     case If::lss: l = lir_cond_less;         break;
 412     case If::leq: l = lir_cond_lessEqual;    break;
 413     case If::geq: l = lir_cond_greaterEqual; break;
 414     case If::gtr: l = lir_cond_greater;      break;
 415     };
 416     return l;
 417   }
 418 
 419 #ifdef __SOFTFP__
 420   void do_soft_float_compare(If *x);
 421 #endif // __SOFTFP__
 422 
 423   void init();
 424 
 425   SwitchRangeArray* create_lookup_ranges(TableSwitch* x);
 426   SwitchRangeArray* create_lookup_ranges(LookupSwitch* x);
 427   void do_SwitchRanges(SwitchRangeArray* x, LIR_Opr value, BlockBegin* default_sux);
 428 
 429   void do_RuntimeCall(address routine, int expected_arguments, Intrinsic* x);
 430 #ifdef TRACE_HAVE_INTRINSICS
 431   void do_ThreadIDIntrinsic(Intrinsic* x);
 432   void do_ClassIDIntrinsic(Intrinsic* x);
 433 #endif
 434 
 435  public:
 436   Compilation*  compilation() const              { return _compilation; }
 437   FrameMap*     frame_map() const                { return _compilation->frame_map(); }
 438   ciMethod*     method() const                   { return _method; }
 439   BlockBegin*   block() const                    { return _block; }
 440   IRScope*      scope() const                    { return block()->scope(); }
 441 
 442   int max_virtual_register_number() const        { return _virtual_register_number; }
 443 
 444   void block_do(BlockBegin* block);
 445 
 446   // Flags that can be set on vregs
 447   enum VregFlag {
 448       must_start_in_memory = 0  // needs to be assigned a memory location at beginning, but may then be loaded in a register
 449     , callee_saved     = 1    // must be in a callee saved register
 450     , byte_reg         = 2    // must be in a byte register
 451     , num_vreg_flags
 452 
 453   };
 454 
 455   LIRGenerator(Compilation* compilation, ciMethod* method)
 456     : _compilation(compilation)
 457     , _method(method)
 458     , _virtual_register_number(LIR_OprDesc::vreg_base)
 459     , _vreg_flags(NULL, 0, num_vreg_flags) {
 460     init();
 461   }
 462 
 463   // for virtual registers, maps them back to Phi's or Local's
 464   Instruction* instruction_for_opr(LIR_Opr opr);
 465   Instruction* instruction_for_vreg(int reg_num);
 466 
 467   void set_vreg_flag   (int vreg_num, VregFlag f);
 468   bool is_vreg_flag_set(int vreg_num, VregFlag f);
 469   void set_vreg_flag   (LIR_Opr opr,  VregFlag f) { set_vreg_flag(opr->vreg_number(), f); }
 470   bool is_vreg_flag_set(LIR_Opr opr,  VregFlag f) { return is_vreg_flag_set(opr->vreg_number(), f); }
 471 
 472   // statics
 473   static LIR_Opr exceptionOopOpr();
 474   static LIR_Opr exceptionPcOpr();
 475   static LIR_Opr divInOpr();
 476   static LIR_Opr divOutOpr();
 477   static LIR_Opr remOutOpr();
 478   static LIR_Opr shiftCountOpr();
 479   LIR_Opr syncTempOpr();
 480   LIR_Opr atomicLockOpr();
 481 
 482   // returns a register suitable for saving the thread in a
 483   // call_runtime_leaf if one is needed.
 484   LIR_Opr getThreadTemp();
 485 
 486   // visitor functionality
 487   virtual void do_Phi            (Phi*             x);
 488   virtual void do_Local          (Local*           x);
 489   virtual void do_Constant       (Constant*        x);
 490   virtual void do_LoadField      (LoadField*       x);
 491   virtual void do_StoreField     (StoreField*      x);
 492   virtual void do_ArrayLength    (ArrayLength*     x);
 493   virtual void do_LoadIndexed    (LoadIndexed*     x);
 494   virtual void do_StoreIndexed   (StoreIndexed*    x);
 495   virtual void do_NegateOp       (NegateOp*        x);
 496   virtual void do_ArithmeticOp   (ArithmeticOp*    x);
 497   virtual void do_ShiftOp        (ShiftOp*         x);
 498   virtual void do_LogicOp        (LogicOp*         x);
 499   virtual void do_CompareOp      (CompareOp*       x);
 500   virtual void do_IfOp           (IfOp*            x);
 501   virtual void do_Convert        (Convert*         x);
 502   virtual void do_NullCheck      (NullCheck*       x);
 503   virtual void do_TypeCast       (TypeCast*        x);
 504   virtual void do_Invoke         (Invoke*          x);
 505   virtual void do_NewInstance    (NewInstance*     x);
 506   virtual void do_NewTypeArray   (NewTypeArray*    x);
 507   virtual void do_NewObjectArray (NewObjectArray*  x);
 508   virtual void do_NewMultiArray  (NewMultiArray*   x);
 509   virtual void do_CheckCast      (CheckCast*       x);
 510   virtual void do_InstanceOf     (InstanceOf*      x);
 511   virtual void do_MonitorEnter   (MonitorEnter*    x);
 512   virtual void do_MonitorExit    (MonitorExit*     x);
 513   virtual void do_Intrinsic      (Intrinsic*       x);
 514   virtual void do_BlockBegin     (BlockBegin*      x);
 515   virtual void do_Goto           (Goto*            x);
 516   virtual void do_If             (If*              x);
 517   virtual void do_IfInstanceOf   (IfInstanceOf*    x);
 518   virtual void do_TableSwitch    (TableSwitch*     x);
 519   virtual void do_LookupSwitch   (LookupSwitch*    x);
 520   virtual void do_Return         (Return*          x);
 521   virtual void do_Throw          (Throw*           x);
 522   virtual void do_Base           (Base*            x);
 523   virtual void do_OsrEntry       (OsrEntry*        x);
 524   virtual void do_ExceptionObject(ExceptionObject* x);
 525   virtual void do_RoundFP        (RoundFP*         x);
 526   virtual void do_UnsafeGetRaw   (UnsafeGetRaw*    x);
 527   virtual void do_UnsafePutRaw   (UnsafePutRaw*    x);
 528   virtual void do_UnsafeGetObject(UnsafeGetObject* x);
 529   virtual void do_UnsafePutObject(UnsafePutObject* x);
 530   virtual void do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x);
 531   virtual void do_UnsafePrefetchRead (UnsafePrefetchRead*  x);
 532   virtual void do_UnsafePrefetchWrite(UnsafePrefetchWrite* x);
 533   virtual void do_ProfileCall    (ProfileCall*     x);
 534   virtual void do_ProfileInvoke  (ProfileInvoke*   x);
 535   virtual void do_RuntimeCall    (RuntimeCall*     x);
 536   virtual void do_MemBar         (MemBar*          x);
 537 };
 538 
 539 
 540 class LIRItem: public CompilationResourceObj {
 541  private:
 542   Value         _value;
 543   LIRGenerator* _gen;
 544   LIR_Opr       _result;
 545   bool          _destroys_register;
 546   LIR_Opr       _new_result;
 547 
 548   LIRGenerator* gen() const { return _gen; }
 549 
 550  public:
 551   LIRItem(Value value, LIRGenerator* gen) {
 552     _destroys_register = false;
 553     _gen = gen;
 554     set_instruction(value);
 555   }
 556 
 557   LIRItem(LIRGenerator* gen) {
 558     _destroys_register = false;
 559     _gen = gen;
 560     _result = LIR_OprFact::illegalOpr;
 561     set_instruction(NULL);
 562   }
 563 
 564   void set_instruction(Value value) {
 565     _value = value;
 566     _result = LIR_OprFact::illegalOpr;
 567     if (_value != NULL) {
 568       _gen->walk(_value);
 569       _result = _value->operand();
 570     }
 571     _new_result = LIR_OprFact::illegalOpr;
 572   }
 573 
 574   Value value() const          { return _value;          }
 575   ValueType* type() const      { return value()->type(); }
 576   LIR_Opr result()             {
 577     assert(!_destroys_register || (!_result->is_register() || _result->is_virtual()),
 578            "shouldn't use set_destroys_register with physical regsiters");
 579     if (_destroys_register && _result->is_register()) {
 580       if (_new_result->is_illegal()) {
 581         _new_result = _gen->new_register(type());
 582         gen()->lir()->move(_result, _new_result);
 583       }
 584       return _new_result;
 585     } else {
 586       return _result;
 587     }
 588     return _result;
 589   }
 590 
 591   void set_result(LIR_Opr opr);
 592 
 593   void load_item();
 594   void load_byte_item();
 595   void load_nonconstant();
 596   // load any values which can't be expressed as part of a single store instruction
 597   void load_for_store(BasicType store_type);
 598   void load_item_force(LIR_Opr reg);
 599 
 600   void dont_load_item() {
 601     // do nothing
 602   }
 603 
 604   void set_destroys_register() {
 605     _destroys_register = true;
 606   }
 607 
 608   bool is_constant() const { return value()->as_Constant() != NULL; }
 609   bool is_stack()          { return result()->is_stack(); }
 610   bool is_register()       { return result()->is_register(); }
 611 
 612   ciObject* get_jobject_constant() const;
 613   jint      get_jint_constant() const;
 614   jlong     get_jlong_constant() const;
 615   jfloat    get_jfloat_constant() const;
 616   jdouble   get_jdouble_constant() const;
 617   jint      get_address_constant() const;
 618 };
 619 
 620 #endif // SHARE_VM_C1_C1_LIRGENERATOR_HPP