1 /*
  2  * Copyright (c) 2005, 2018, 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 "gc/shared/c1/barrierSetC1.hpp"
 29 #include "c1/c1_Decorators.hpp"
 30 #include "c1/c1_Instruction.hpp"
 31 #include "c1/c1_LIR.hpp"
 32 #include "ci/ciMethodData.hpp"
 33 #include "utilities/macros.hpp"
 34 #include "utilities/sizes.hpp"
 35 
 36 // The classes responsible for code emission and register allocation
 37 
 38 
 39 class LIRGenerator;
 40 class LIREmitter;
 41 class Invoke;
 42 class SwitchRange;
 43 class LIRItem;
 44 
 45 typedef GrowableArray<LIRItem*> LIRItemList;
 46 
 47 class SwitchRange: public CompilationResourceObj {
 48  private:
 49   int _low_key;
 50   int _high_key;
 51   BlockBegin* _sux;
 52  public:
 53   SwitchRange(int start_key, BlockBegin* sux): _low_key(start_key), _high_key(start_key), _sux(sux) {}
 54   void set_high_key(int key) { _high_key = key; }
 55 
 56   int high_key() const { return _high_key; }
 57   int low_key() const { return _low_key; }
 58   BlockBegin* sux() const { return _sux; }
 59 };
 60 
 61 typedef GrowableArray<SwitchRange*> SwitchRangeArray;
 62 typedef GrowableArray<SwitchRange*> SwitchRangeList;
 63 
 64 class ResolveNode;
 65 
 66 typedef GrowableArray<ResolveNode*> NodeList;
 67 
 68 // Node objects form a directed graph of LIR_Opr
 69 // Edges between Nodes represent moves from one Node to its destinations
 70 class ResolveNode: public CompilationResourceObj {
 71  private:
 72   LIR_Opr    _operand;       // the source or destinaton
 73   NodeList   _destinations;  // for the operand
 74   bool       _assigned;      // Value assigned to this Node?
 75   bool       _visited;       // Node already visited?
 76   bool       _start_node;    // Start node already visited?
 77 
 78  public:
 79   ResolveNode(LIR_Opr operand)
 80     : _operand(operand)
 81     , _assigned(false)
 82     , _visited(false)
 83     , _start_node(false) {};
 84 
 85   // accessors
 86   LIR_Opr operand() const           { return _operand; }
 87   int no_of_destinations() const    { return _destinations.length(); }
 88   ResolveNode* destination_at(int i)     { return _destinations.at(i); }
 89   bool assigned() const             { return _assigned; }
 90   bool visited() const              { return _visited; }
 91   bool start_node() const           { return _start_node; }
 92 
 93   // modifiers
 94   void append(ResolveNode* dest)         { _destinations.append(dest); }
 95   void set_assigned()               { _assigned = true; }
 96   void set_visited()                { _visited = true; }
 97   void set_start_node()             { _start_node = true; }
 98 };
 99 
100 
101 // This is shared state to be used by the PhiResolver so the operand
102 // arrays don't have to be reallocated for reach resolution.
103 class PhiResolverState: public CompilationResourceObj {
104   friend class PhiResolver;
105 
106  private:
107   NodeList _virtual_operands; // Nodes where the operand is a virtual register
108   NodeList _other_operands;   // Nodes where the operand is not a virtual register
109   NodeList _vreg_table;       // Mapping from virtual register to Node
110 
111  public:
112   PhiResolverState() {}
113 
114   void reset(int max_vregs);
115 };
116 
117 
118 // class used to move value of phi operand to phi function
119 class PhiResolver: public CompilationResourceObj {
120  private:
121   LIRGenerator*     _gen;
122   PhiResolverState& _state; // temporary state cached by LIRGenerator
123 
124   ResolveNode*   _loop;
125   LIR_Opr _temp;
126 
127   // access to shared state arrays
128   NodeList& virtual_operands() { return _state._virtual_operands; }
129   NodeList& other_operands()   { return _state._other_operands;   }
130   NodeList& vreg_table()       { return _state._vreg_table;       }
131 
132   ResolveNode* create_node(LIR_Opr opr, bool source);
133   ResolveNode* source_node(LIR_Opr opr)      { return create_node(opr, true); }
134   ResolveNode* destination_node(LIR_Opr opr) { return create_node(opr, false); }
135 
136   void emit_move(LIR_Opr src, LIR_Opr dest);
137   void move_to_temp(LIR_Opr src);
138   void move_temp_to(LIR_Opr dest);
139   void move(ResolveNode* src, ResolveNode* dest);
140 
141   LIRGenerator* gen() {
142     return _gen;
143   }
144 
145  public:
146   PhiResolver(LIRGenerator* _lir_gen, int max_vregs);
147   ~PhiResolver();
148 
149   void move(LIR_Opr src, LIR_Opr dest);
150 };
151 
152 
153 // only the classes below belong in the same file
154 class LIRGenerator: public InstructionVisitor, public BlockClosure {
155   friend class BarrierSetC1;
156   friend class ModRefBarrierSetC1;
157   friend class CardTableBarrierSetC1;
158   friend class G1BarrierSetC1;
159  // LIRGenerator should never get instatiated on the heap.
160  private:
161   void* operator new(size_t size) throw();
162   void* operator new[](size_t size) throw();
163   void operator delete(void* p) { ShouldNotReachHere(); }
164   void operator delete[](void* p) { ShouldNotReachHere(); }
165 
166   Compilation*  _compilation;
167   ciMethod*     _method;    // method that we are compiling
168   PhiResolverState  _resolver_state;
169   BlockBegin*   _block;
170   int           _virtual_register_number;
171   Values        _instruction_for_operand;
172   BitMap2D      _vreg_flags; // flags which can be set on a per-vreg basis
173   LIR_List*     _lir;
174 
175   LIRGenerator* gen() {
176     return this;
177   }
178 
179   void print_if_not_loaded(const NewInstance* new_instance) PRODUCT_RETURN;
180 
181 #ifdef ASSERT
182   LIR_List* lir(const char * file, int line) const {
183     _lir->set_file_and_line(file, line);
184     return _lir;
185   }
186 #endif
187   LIR_List* lir() const {
188     return _lir;
189   }
190 
191   // a simple cache of constants used within a block
192   GrowableArray<LIR_Const*>       _constants;
193   LIR_OprList                     _reg_for_constants;
194   Values                          _unpinned_constants;
195 
196   friend class PhiResolver;
197 
198   // unified bailout support
199   void bailout(const char* msg) const            { compilation()->bailout(msg); }
200   bool bailed_out() const                        { return compilation()->bailed_out(); }
201 
202   void block_do_prolog(BlockBegin* block);
203   void block_do_epilog(BlockBegin* block);
204 
205   // register allocation
206   LIR_Opr rlock(Value instr);                      // lock a free register
207   LIR_Opr rlock_result(Value instr);
208   LIR_Opr rlock_result(Value instr, BasicType type);
209   LIR_Opr rlock_byte(BasicType type);
210   LIR_Opr rlock_callee_saved(BasicType type);
211 
212   // get a constant into a register and get track of what register was used
213   LIR_Opr load_constant(Constant* x);
214   LIR_Opr load_constant(LIR_Const* constant);
215 
216   // Given an immediate value, return an operand usable in logical ops.
217   LIR_Opr load_immediate(int x, BasicType type);
218 
219   void  set_result(Value x, LIR_Opr opr)           {
220     assert(opr->is_valid(), "must set to valid value");
221     assert(x->operand()->is_illegal(), "operand should never change");
222     assert(!opr->is_register() || opr->is_virtual(), "should never set result to a physical register");
223     x->set_operand(opr);
224     assert(opr == x->operand(), "must be");
225     if (opr->is_virtual()) {
226       _instruction_for_operand.at_put_grow(opr->vreg_number(), x, NULL);
227     }
228   }
229   void  set_no_result(Value x)                     { assert(!x->has_uses(), "can't have use"); x->clear_operand(); }
230 
231   friend class LIRItem;
232 
233   LIR_Opr round_item(LIR_Opr opr);
234   LIR_Opr force_to_spill(LIR_Opr value, BasicType t);
235 
236   PhiResolverState& resolver_state() { return _resolver_state; }
237 
238   void  move_to_phi(PhiResolver* resolver, Value cur_val, Value sux_val);
239   void  move_to_phi(ValueStack* cur_state);
240 
241   // code emission
242   void do_ArithmeticOp_Long   (ArithmeticOp*    x);
243   void do_ArithmeticOp_Int    (ArithmeticOp*    x);
244   void do_ArithmeticOp_FPU    (ArithmeticOp*    x);
245 
246   // platform dependent
247   LIR_Opr getThreadPointer();
248 
249   void do_RegisterFinalizer(Intrinsic* x);
250   void do_isInstance(Intrinsic* x);
251   void do_isPrimitive(Intrinsic* x);
252   void do_getClass(Intrinsic* x);
253   void do_currentThread(Intrinsic* x);
254   void do_FmaIntrinsic(Intrinsic* x);
255   void do_MathIntrinsic(Intrinsic* x);
256   void do_LibmIntrinsic(Intrinsic* x);
257   void do_ArrayCopy(Intrinsic* x);
258   void do_CompareAndSwap(Intrinsic* x, ValueType* type);
259   void do_NIOCheckIndex(Intrinsic* x);
260   void do_FPIntrinsics(Intrinsic* x);
261   void do_Reference_get(Intrinsic* x);
262   void do_update_CRC32(Intrinsic* x);
263   void do_update_CRC32C(Intrinsic* x);
264   void do_vectorizedMismatch(Intrinsic* x);
265 
266   LIR_Opr call_runtime(BasicTypeArray* signature, LIRItemList* args, address entry, ValueType* result_type, CodeEmitInfo* info);
267   LIR_Opr call_runtime(BasicTypeArray* signature, LIR_OprList* args, address entry, ValueType* result_type, CodeEmitInfo* info);
268 
269   // convenience functions
270   LIR_Opr call_runtime(Value arg1, address entry, ValueType* result_type, CodeEmitInfo* info);
271   LIR_Opr call_runtime(Value arg1, Value arg2, address entry, ValueType* result_type, CodeEmitInfo* info);
272 
273   // GC Barriers
274 
275   // generic interface
276 
277   void access_store_at(DecoratorSet decorators, BasicType type,
278                        LIRItem& base, LIR_Opr offset, LIR_Opr value,
279                        CodeEmitInfo* patch_info, CodeEmitInfo* store_emit_info);
280 
281   void access_load_at(DecoratorSet decorators, BasicType type,
282                       LIRItem& base, LIR_Opr offset, LIR_Opr result,
283                       CodeEmitInfo* patch_info, CodeEmitInfo* load_emit_info);
284 
285   LIR_Opr access_atomic_cmpxchg_at(DecoratorSet decorators, BasicType type,
286                                    LIRItem& base, LIRItem& offset, LIRItem& cmp_value, LIRItem& new_value);
287 
288   LIR_Opr access_atomic_xchg_at(DecoratorSet decorators, BasicType type,
289                                 LIRItem& base, LIRItem& offset, LIRItem& value);
290 
291   LIR_Opr access_atomic_add_at(DecoratorSet decorators, BasicType type,
292                                LIRItem& base, LIRItem& offset, LIRItem& value);
293 
294   // These need to guarantee JMM volatile semantics are preserved on each platform
295   // and requires one implementation per architecture.
296   LIR_Opr atomic_cmpxchg(BasicType type, LIR_Opr addr, LIRItem& cmp_value, LIRItem& new_value);
297   LIR_Opr atomic_xchg(BasicType type, LIR_Opr addr, LIRItem& new_value);
298   LIR_Opr atomic_add(BasicType type, LIR_Opr addr, LIRItem& new_value);
299 
300   // specific implementations
301   void array_store_check(LIR_Opr value, LIR_Opr array, CodeEmitInfo* store_check_info, ciMethod* profiled_method, int profiled_bci);
302 
303   static LIR_Opr result_register_for(ValueType* type, bool callee = false);
304 
305   ciObject* get_jobject_constant(Value value);
306 
307   LIRItemList* invoke_visit_arguments(Invoke* x);
308   void invoke_load_arguments(Invoke* x, LIRItemList* args, const LIR_OprList* arg_list);
309 
310   void trace_block_entry(BlockBegin* block);
311 
312   // volatile field operations are never patchable because a klass
313   // must be loaded to know it's volatile which means that the offset
314   // it always known as well.
315   void volatile_field_store(LIR_Opr value, LIR_Address* address, CodeEmitInfo* info);
316   void volatile_field_load(LIR_Address* address, LIR_Opr result, CodeEmitInfo* info);
317 
318   void put_Object_unsafe(LIR_Opr src, LIR_Opr offset, LIR_Opr data, BasicType type, bool is_volatile);
319   void get_Object_unsafe(LIR_Opr dest, LIR_Opr src, LIR_Opr offset, BasicType type, bool is_volatile);
320 
321   void arithmetic_call_op (Bytecodes::Code code, LIR_Opr result, LIR_OprList* args);
322 
323   void increment_counter(address counter, BasicType type, int step = 1);
324   void increment_counter(LIR_Address* addr, int step = 1);
325 
326   // is_strictfp is only needed for mul and div (and only generates different code on i486)
327   void arithmetic_op(Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, bool is_strictfp, LIR_Opr tmp, CodeEmitInfo* info = NULL);
328   // machine dependent.  returns true if it emitted code for the multiply
329   bool strength_reduce_multiply(LIR_Opr left, jint constant, LIR_Opr result, LIR_Opr tmp);
330 
331   void store_stack_parameter (LIR_Opr opr, ByteSize offset_from_sp_in_bytes);
332 
333   void klass2reg_with_patching(LIR_Opr r, ciMetadata* obj, CodeEmitInfo* info, bool need_resolve = false);
334 
335   // this loads the length and compares against the index
336   void array_range_check          (LIR_Opr array, LIR_Opr index, CodeEmitInfo* null_check_info, CodeEmitInfo* range_check_info);
337   // For java.nio.Buffer.checkIndex
338   void nio_range_check            (LIR_Opr buffer, LIR_Opr index, LIR_Opr result, CodeEmitInfo* info);
339 
340   void arithmetic_op_int  (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, LIR_Opr tmp);
341   void arithmetic_op_long (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, CodeEmitInfo* info = NULL);
342   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);
343 
344   void shift_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr value, LIR_Opr count, LIR_Opr tmp);
345 
346   void logic_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr left, LIR_Opr right);
347 
348   void monitor_enter (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, LIR_Opr scratch, int monitor_no, CodeEmitInfo* info_for_exception, CodeEmitInfo* info);
349   void monitor_exit  (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, LIR_Opr scratch, int monitor_no);
350 
351   void new_instance    (LIR_Opr  dst, ciInstanceKlass* klass, bool is_unresolved, LIR_Opr  scratch1, LIR_Opr  scratch2, LIR_Opr  scratch3,  LIR_Opr scratch4, LIR_Opr  klass_reg, CodeEmitInfo* info);
352 
353   // machine dependent
354   void cmp_mem_int(LIR_Condition condition, LIR_Opr base, int disp, int c, CodeEmitInfo* info);
355   void cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr base, int disp, BasicType type, CodeEmitInfo* info);
356 
357   void arraycopy_helper(Intrinsic* x, int* flags, ciArrayKlass** expected_type);
358 
359   // returns a LIR_Address to address an array location.  May also
360   // emit some code as part of address calculation.  If
361   // needs_card_mark is true then compute the full address for use by
362   // both the store and the card mark.
363   LIR_Address* generate_address(LIR_Opr base,
364                                 LIR_Opr index, int shift,
365                                 int disp,
366                                 BasicType type);
367   LIR_Address* generate_address(LIR_Opr base, int disp, BasicType type) {
368     return generate_address(base, LIR_OprFact::illegalOpr, 0, disp, type);
369   }
370   LIR_Address* emit_array_address(LIR_Opr array_opr, LIR_Opr index_opr, BasicType type);
371 
372   // the helper for generate_address
373   void add_large_constant(LIR_Opr src, int c, LIR_Opr dest);
374 
375   // machine preferences and characteristics
376   bool can_inline_as_constant(Value i S390_ONLY(COMMA int bits = 20)) const;
377   bool can_inline_as_constant(LIR_Const* c) const;
378   bool can_store_as_constant(Value i, BasicType type) const;
379 
380   LIR_Opr safepoint_poll_register();
381 
382   void profile_branch(If* if_instr, If::Condition cond);
383   void increment_event_counter_impl(CodeEmitInfo* info,
384                                     ciMethod *method, int frequency,
385                                     int bci, bool backedge, bool notify);
386   void increment_event_counter(CodeEmitInfo* info, int bci, bool backedge);
387   void increment_invocation_counter(CodeEmitInfo *info) {
388     if (compilation()->count_invocations()) {
389       increment_event_counter(info, InvocationEntryBci, false);
390     }
391   }
392   void increment_backedge_counter(CodeEmitInfo* info, int bci) {
393     if (compilation()->count_backedges()) {
394       increment_event_counter(info, bci, true);
395     }
396   }
397   void decrement_age(CodeEmitInfo* info);
398   CodeEmitInfo* state_for(Instruction* x, ValueStack* state, bool ignore_xhandler = false);
399   CodeEmitInfo* state_for(Instruction* x);
400 
401   // allocates a virtual register for this instruction if
402   // one isn't already allocated.  Only for Phi and Local.
403   LIR_Opr operand_for_instruction(Instruction *x);
404 
405   void set_block(BlockBegin* block)              { _block = block; }
406 
407   void block_prolog(BlockBegin* block);
408   void block_epilog(BlockBegin* block);
409 
410   void do_root (Instruction* instr);
411   void walk    (Instruction* instr);
412 
413   void bind_block_entry(BlockBegin* block);
414   void start_block(BlockBegin* block);
415 
416   LIR_Opr new_register(BasicType type);
417   LIR_Opr new_register(Value value)              { return new_register(as_BasicType(value->type())); }
418   LIR_Opr new_register(ValueType* type)          { return new_register(as_BasicType(type)); }
419 
420   // returns a register suitable for doing pointer math
421   LIR_Opr new_pointer_register() {
422 #ifdef _LP64
423     return new_register(T_LONG);
424 #else
425     return new_register(T_INT);
426 #endif
427   }
428 
429   static LIR_Condition lir_cond(If::Condition cond) {
430     LIR_Condition l = lir_cond_unknown;
431     switch (cond) {
432     case If::eql: l = lir_cond_equal;        break;
433     case If::neq: l = lir_cond_notEqual;     break;
434     case If::lss: l = lir_cond_less;         break;
435     case If::leq: l = lir_cond_lessEqual;    break;
436     case If::geq: l = lir_cond_greaterEqual; break;
437     case If::gtr: l = lir_cond_greater;      break;
438     case If::aeq: l = lir_cond_aboveEqual;   break;
439     case If::beq: l = lir_cond_belowEqual;   break;
440     default: fatal("You must pass valid If::Condition");
441     };
442     return l;
443   }
444 
445 #ifdef __SOFTFP__
446   void do_soft_float_compare(If *x);
447 #endif // __SOFTFP__
448 
449   SwitchRangeArray* create_lookup_ranges(TableSwitch* x);
450   SwitchRangeArray* create_lookup_ranges(LookupSwitch* x);
451   void do_SwitchRanges(SwitchRangeArray* x, LIR_Opr value, BlockBegin* default_sux);
452 
453 #ifdef TRACE_HAVE_INTRINSICS
454   void do_ClassIDIntrinsic(Intrinsic* x);
455   void do_getBufferWriter(Intrinsic* x);
456 #endif
457 
458   void do_RuntimeCall(address routine, Intrinsic* x);
459 
460   ciKlass* profile_type(ciMethodData* md, int md_first_offset, int md_offset, intptr_t profiled_k,
461                         Value arg, LIR_Opr& mdp, bool not_null, ciKlass* signature_at_call_k,
462                         ciKlass* callee_signature_k);
463   void profile_arguments(ProfileCall* x);
464   void profile_parameters(Base* x);
465   void profile_parameters_at_call(ProfileCall* x);
466   LIR_Opr mask_boolean(LIR_Opr array, LIR_Opr value, CodeEmitInfo*& null_check_info);
467   LIR_Opr maybe_mask_boolean(StoreIndexed* x, LIR_Opr array, LIR_Opr value, CodeEmitInfo*& null_check_info);
468 
469  public:
470   Compilation*  compilation() const              { return _compilation; }
471   FrameMap*     frame_map() const                { return _compilation->frame_map(); }
472   ciMethod*     method() const                   { return _method; }
473   BlockBegin*   block() const                    { return _block; }
474   IRScope*      scope() const                    { return block()->scope(); }
475 
476   int max_virtual_register_number() const        { return _virtual_register_number; }
477 
478   void block_do(BlockBegin* block);
479 
480   // Flags that can be set on vregs
481   enum VregFlag {
482       must_start_in_memory = 0  // needs to be assigned a memory location at beginning, but may then be loaded in a register
483     , callee_saved     = 1    // must be in a callee saved register
484     , byte_reg         = 2    // must be in a byte register
485     , num_vreg_flags
486 
487   };
488 
489   LIRGenerator(Compilation* compilation, ciMethod* method)
490     : _compilation(compilation)
491     , _method(method)
492     , _virtual_register_number(LIR_OprDesc::vreg_base)
493     , _vreg_flags(num_vreg_flags) {
494   }
495 
496   // for virtual registers, maps them back to Phi's or Local's
497   Instruction* instruction_for_opr(LIR_Opr opr);
498   Instruction* instruction_for_vreg(int reg_num);
499 
500   void set_vreg_flag   (int vreg_num, VregFlag f);
501   bool is_vreg_flag_set(int vreg_num, VregFlag f);
502   void set_vreg_flag   (LIR_Opr opr,  VregFlag f) { set_vreg_flag(opr->vreg_number(), f); }
503   bool is_vreg_flag_set(LIR_Opr opr,  VregFlag f) { return is_vreg_flag_set(opr->vreg_number(), f); }
504 
505   // statics
506   static LIR_Opr exceptionOopOpr();
507   static LIR_Opr exceptionPcOpr();
508   static LIR_Opr divInOpr();
509   static LIR_Opr divOutOpr();
510   static LIR_Opr remOutOpr();
511 #ifdef S390
512   // On S390 we can do ldiv, lrem without RT call.
513   static LIR_Opr ldivInOpr();
514   static LIR_Opr ldivOutOpr();
515   static LIR_Opr lremOutOpr();
516 #endif
517   static LIR_Opr shiftCountOpr();
518   LIR_Opr syncLockOpr();
519   LIR_Opr syncTempOpr();
520   LIR_Opr atomicLockOpr();
521 
522   // returns a register suitable for saving the thread in a
523   // call_runtime_leaf if one is needed.
524   LIR_Opr getThreadTemp();
525 
526   // visitor functionality
527   virtual void do_Phi            (Phi*             x);
528   virtual void do_Local          (Local*           x);
529   virtual void do_Constant       (Constant*        x);
530   virtual void do_LoadField      (LoadField*       x);
531   virtual void do_StoreField     (StoreField*      x);
532   virtual void do_ArrayLength    (ArrayLength*     x);
533   virtual void do_LoadIndexed    (LoadIndexed*     x);
534   virtual void do_StoreIndexed   (StoreIndexed*    x);
535   virtual void do_NegateOp       (NegateOp*        x);
536   virtual void do_ArithmeticOp   (ArithmeticOp*    x);
537   virtual void do_ShiftOp        (ShiftOp*         x);
538   virtual void do_LogicOp        (LogicOp*         x);
539   virtual void do_CompareOp      (CompareOp*       x);
540   virtual void do_IfOp           (IfOp*            x);
541   virtual void do_Convert        (Convert*         x);
542   virtual void do_NullCheck      (NullCheck*       x);
543   virtual void do_TypeCast       (TypeCast*        x);
544   virtual void do_Invoke         (Invoke*          x);
545   virtual void do_NewInstance    (NewInstance*     x);
546   virtual void do_NewTypeArray   (NewTypeArray*    x);
547   virtual void do_NewObjectArray (NewObjectArray*  x);
548   virtual void do_NewMultiArray  (NewMultiArray*   x);
549   virtual void do_CheckCast      (CheckCast*       x);
550   virtual void do_InstanceOf     (InstanceOf*      x);
551   virtual void do_MonitorEnter   (MonitorEnter*    x);
552   virtual void do_MonitorExit    (MonitorExit*     x);
553   virtual void do_Intrinsic      (Intrinsic*       x);
554   virtual void do_BlockBegin     (BlockBegin*      x);
555   virtual void do_Goto           (Goto*            x);
556   virtual void do_If             (If*              x);
557   virtual void do_IfInstanceOf   (IfInstanceOf*    x);
558   virtual void do_TableSwitch    (TableSwitch*     x);
559   virtual void do_LookupSwitch   (LookupSwitch*    x);
560   virtual void do_Return         (Return*          x);
561   virtual void do_Throw          (Throw*           x);
562   virtual void do_Base           (Base*            x);
563   virtual void do_OsrEntry       (OsrEntry*        x);
564   virtual void do_ExceptionObject(ExceptionObject* x);
565   virtual void do_RoundFP        (RoundFP*         x);
566   virtual void do_UnsafeGetRaw   (UnsafeGetRaw*    x);
567   virtual void do_UnsafePutRaw   (UnsafePutRaw*    x);
568   virtual void do_UnsafeGetObject(UnsafeGetObject* x);
569   virtual void do_UnsafePutObject(UnsafePutObject* x);
570   virtual void do_UnsafeGetAndSetObject(UnsafeGetAndSetObject* x);
571   virtual void do_ProfileCall    (ProfileCall*     x);
572   virtual void do_ProfileReturnType (ProfileReturnType* x);
573   virtual void do_ProfileInvoke  (ProfileInvoke*   x);
574   virtual void do_RuntimeCall    (RuntimeCall*     x);
575   virtual void do_MemBar         (MemBar*          x);
576   virtual void do_RangeCheckPredicate(RangeCheckPredicate* x);
577 #ifdef ASSERT
578   virtual void do_Assert         (Assert*          x);
579 #endif
580 
581 #ifdef C1_LIRGENERATOR_MD_HPP
582 #include C1_LIRGENERATOR_MD_HPP
583 #endif
584 };
585 
586 
587 class LIRItem: public CompilationResourceObj {
588  private:
589   Value         _value;
590   LIRGenerator* _gen;
591   LIR_Opr       _result;
592   bool          _destroys_register;
593   LIR_Opr       _new_result;
594 
595   LIRGenerator* gen() const { return _gen; }
596 
597  public:
598   LIRItem(Value value, LIRGenerator* gen) {
599     _destroys_register = false;
600     _gen = gen;
601     set_instruction(value);
602   }
603 
604   LIRItem(LIRGenerator* gen) {
605     _destroys_register = false;
606     _gen = gen;
607     _result = LIR_OprFact::illegalOpr;
608     set_instruction(NULL);
609   }
610 
611   void set_instruction(Value value) {
612     _value = value;
613     _result = LIR_OprFact::illegalOpr;
614     if (_value != NULL) {
615       _gen->walk(_value);
616       _result = _value->operand();
617     }
618     _new_result = LIR_OprFact::illegalOpr;
619   }
620 
621   Value value() const          { return _value;          }
622   ValueType* type() const      { return value()->type(); }
623   LIR_Opr result()             {
624     assert(!_destroys_register || (!_result->is_register() || _result->is_virtual()),
625            "shouldn't use set_destroys_register with physical regsiters");
626     if (_destroys_register && _result->is_register()) {
627       if (_new_result->is_illegal()) {
628         _new_result = _gen->new_register(type());
629         gen()->lir()->move(_result, _new_result);
630       }
631       return _new_result;
632     } else {
633       return _result;
634     }
635     return _result;
636   }
637 
638   void set_result(LIR_Opr opr);
639 
640   void load_item();
641   void load_byte_item();
642   void load_nonconstant(S390_ONLY(int bits = 20));
643   // load any values which can't be expressed as part of a single store instruction
644   void load_for_store(BasicType store_type);
645   void load_item_force(LIR_Opr reg);
646 
647   void dont_load_item() {
648     // do nothing
649   }
650 
651   void set_destroys_register() {
652     _destroys_register = true;
653   }
654 
655   bool is_constant() const { return value()->as_Constant() != NULL; }
656   bool is_stack()          { return result()->is_stack(); }
657   bool is_register()       { return result()->is_register(); }
658 
659   ciObject* get_jobject_constant() const;
660   jint      get_jint_constant() const;
661   jlong     get_jlong_constant() const;
662   jfloat    get_jfloat_constant() const;
663   jdouble   get_jdouble_constant() const;
664   jint      get_address_constant() const;
665 };
666 
667 #endif // SHARE_VM_C1_C1_LIRGENERATOR_HPP