1 /*
  2  * Copyright (c) 2005, 2025, 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_C1_C1_LIRGENERATOR_HPP
 26 #define SHARE_C1_C1_LIRGENERATOR_HPP
 27 
 28 #include "c1/c1_Decorators.hpp"
 29 #include "c1/c1_Instruction.hpp"
 30 #include "c1/c1_LIR.hpp"
 31 #include "gc/shared/barrierSet.hpp"
 32 #include "utilities/macros.hpp"
 33 #include "utilities/sizes.hpp"
 34 
 35 class BarrierSetC1;
 36 
 37 // The classes responsible for code emission and register allocation
 38 
 39 
 40 class LIRGenerator;
 41 class LIREmitter;
 42 class Invoke;
 43 class LIRItem;
 44 
 45 typedef GrowableArray<LIRItem*> LIRItemList;
 46 
 47 class C1SwitchRange: public CompilationResourceObj {
 48  private:
 49   int _low_key;
 50   int _high_key;
 51   BlockBegin* _sux;
 52  public:
 53   C1SwitchRange(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<C1SwitchRange*> SwitchRangeArray;
 62 typedef GrowableArray<C1SwitchRange*> 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 each 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();
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);
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  // LIRGenerator should never get instatiated on the heap.
156  private:
157   void* operator new(size_t size) throw();
158   void* operator new[](size_t size) throw();
159   void operator delete(void* p) { ShouldNotReachHere(); }
160   void operator delete[](void* p) { ShouldNotReachHere(); }
161 
162   Compilation*  _compilation;
163   ciMethod*     _method;    // method that we are compiling
164   PhiResolverState  _resolver_state;
165   BlockBegin*   _block;
166   int           _virtual_register_number;
167 #ifdef ASSERT
168   Values        _instruction_for_operand;
169 #endif
170   BitMap2D      _vreg_flags; // flags which can be set on a per-vreg basis
171   LIR_List*     _lir;
172   bool          _in_conditional_code;
173 
174   LIRGenerator* gen() {
175     return this;
176   }
177 
178   void print_if_not_loaded(const NewInstance* new_instance) PRODUCT_RETURN;
179 
180  public:
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  private:
192   // a simple cache of constants used within a block
193   GrowableArray<LIR_Const*>       _constants;
194   LIR_OprList                     _reg_for_constants;
195   Values                          _unpinned_constants;
196 
197   friend class PhiResolver;
198 
199   void set_in_conditional_code(bool v);
200  public:
201   // unified bailout support
202   void bailout(const char* msg) const            { compilation()->bailout(msg); }
203   bool bailed_out() const                        { return compilation()->bailed_out(); }
204 
205   void block_do_prolog(BlockBegin* block);
206   void block_do_epilog(BlockBegin* block);
207 
208   // register allocation
209   LIR_Opr rlock(Value instr);                      // lock a free register
210   LIR_Opr rlock_result(Value instr);
211   LIR_Opr rlock_result(Value instr, BasicType type);
212   LIR_Opr rlock_byte(BasicType type);
213   LIR_Opr rlock_callee_saved(BasicType type);
214 
215   // get a constant into a register and get track of what register was used
216   LIR_Opr load_constant(Constant* x);
217   LIR_Opr load_constant(LIR_Const* constant);
218 
219   bool in_conditional_code() { return _in_conditional_code; }
220   // Given an immediate value, return an operand usable in logical ops.
221   LIR_Opr load_immediate(jlong x, BasicType type);
222 
223   void  set_result(Value x, LIR_Opr opr)           {
224     assert(opr->is_valid(), "must set to valid value");
225     assert(x->operand()->is_illegal(), "operand should never change");
226     assert(!opr->is_register() || opr->is_virtual(), "should never set result to a physical register");
227     x->set_operand(opr);
228     assert(opr == x->operand(), "must be");
229 #ifdef ASSERT
230     if (opr->is_virtual()) {
231       _instruction_for_operand.at_put_grow(opr->vreg_number(), x, nullptr);
232     }
233 #endif
234   }
235   void  set_no_result(Value x)                     { assert(!x->has_uses(), "can't have use"); x->clear_operand(); }
236 
237   friend class LIRItem;
238 
239   LIR_Opr force_to_spill(LIR_Opr value, BasicType t);
240 
241   PhiResolverState& resolver_state() { return _resolver_state; }
242 
243   void  move_to_phi(PhiResolver* resolver, Value cur_val, Value sux_val);
244   void  move_to_phi(ValueStack* cur_state);
245 
246   void load_klass(LIR_Opr obj, LIR_Opr klass, CodeEmitInfo* null_check_info);
247 
248   // platform dependent
249   LIR_Opr getThreadPointer();
250 
251  private:
252   // code emission
253   void do_ArithmeticOp_Long(ArithmeticOp* x);
254   void do_ArithmeticOp_Int (ArithmeticOp* x);
255   void do_ArithmeticOp_FPU (ArithmeticOp* x);
256 
257   void do_RegisterFinalizer(Intrinsic* x);
258   void do_isInstance(Intrinsic* x);
259   void do_getClass(Intrinsic* x);
260   void do_getObjectSize(Intrinsic* x);
261   void do_currentCarrierThread(Intrinsic* x);
262   void do_scopedValueCache(Intrinsic* x);
263   void do_vthread(Intrinsic* x);
264   void do_JavaThreadField(Intrinsic* x, ByteSize offset);
265   void do_FmaIntrinsic(Intrinsic* x);
266   void do_MathIntrinsic(Intrinsic* x);
267   void do_LibmIntrinsic(Intrinsic* x);
268   void do_ArrayCopy(Intrinsic* x);
269   void do_CompareAndSwap(Intrinsic* x, ValueType* type);
270   void do_PreconditionsCheckIndex(Intrinsic* x, BasicType type);
271   void do_FPIntrinsics(Intrinsic* x);
272   void do_Reference_get(Intrinsic* x);
273   void do_update_CRC32(Intrinsic* x);
274   void do_update_CRC32C(Intrinsic* x);
275   void do_vectorizedMismatch(Intrinsic* x);
276   void do_blackhole(Intrinsic* x);
277 
278   void access_flat_array(bool is_load, LIRItem& array, LIRItem& index, LIRItem& obj_item, ciField* field = nullptr, int offset = 0);
279   void access_sub_element(LIRItem& array, LIRItem& index, LIR_Opr& result, ciField* field, int sub_offset);
280   LIR_Opr get_and_load_element_address(LIRItem& array, LIRItem& index);
281   bool needs_flat_array_store_check(StoreIndexed* x);
282   void check_flat_array(LIR_Opr array, LIR_Opr value, CodeStub* slow_path);
283   bool needs_null_free_array_store_check(StoreIndexed* x);
284   void check_null_free_array(LIRItem& array, LIRItem& value,  CodeEmitInfo* info);
285   void substitutability_check(IfOp* x, LIRItem& left, LIRItem& right, LIRItem& t_val, LIRItem& f_val);
286   void substitutability_check(If* x, LIRItem& left, LIRItem& right);
287   void substitutability_check_common(Value left_val, Value right_val, LIRItem& left, LIRItem& right,
288                                      LIR_Opr equal_result, LIR_Opr not_equal_result, LIR_Opr result, CodeEmitInfo* info);
289   void init_temps_for_substitutability_check(LIR_Opr& tmp1, LIR_Opr& tmp2);
290 
291  public:
292   LIR_Opr call_runtime(BasicTypeArray* signature, LIRItemList* args, address entry, ValueType* result_type, CodeEmitInfo* info);
293   LIR_Opr call_runtime(BasicTypeArray* signature, LIR_OprList* args, address entry, ValueType* result_type, CodeEmitInfo* info);
294 
295   // convenience functions
296   LIR_Opr call_runtime(Value arg1, address entry, ValueType* result_type, CodeEmitInfo* info);
297   LIR_Opr call_runtime(Value arg1, Value arg2, address entry, ValueType* result_type, CodeEmitInfo* info);
298 
299   // Access API
300 
301  private:
302   BarrierSetC1 *_barrier_set;
303 
304  public:
305   void access_store_at(DecoratorSet decorators, BasicType type,
306                        LIRItem& base, LIR_Opr offset, LIR_Opr value,
307                        CodeEmitInfo* patch_info = nullptr, CodeEmitInfo* store_emit_info = nullptr, ciInlineKlass* vk = nullptr);
308 
309   void access_load_at(DecoratorSet decorators, BasicType type,
310                       LIRItem& base, LIR_Opr offset, LIR_Opr result,
311                       CodeEmitInfo* patch_info = nullptr, CodeEmitInfo* load_emit_info = nullptr);
312 
313   void access_load(DecoratorSet decorators, BasicType type,
314                    LIR_Opr addr, LIR_Opr result);
315 
316   LIR_Opr access_atomic_cmpxchg_at(DecoratorSet decorators, BasicType type,
317                                    LIRItem& base, LIRItem& offset, LIRItem& cmp_value, LIRItem& new_value);
318 
319   LIR_Opr access_atomic_xchg_at(DecoratorSet decorators, BasicType type,
320                                 LIRItem& base, LIRItem& offset, LIRItem& value);
321 
322   LIR_Opr access_atomic_add_at(DecoratorSet decorators, BasicType type,
323                                LIRItem& base, LIRItem& offset, LIRItem& value);
324 
325   // These need to guarantee JMM volatile semantics are preserved on each platform
326   // and requires one implementation per architecture.
327   LIR_Opr atomic_cmpxchg(BasicType type, LIR_Opr addr, LIRItem& cmp_value, LIRItem& new_value);
328   LIR_Opr atomic_xchg(BasicType type, LIR_Opr addr, LIRItem& new_value);
329   LIR_Opr atomic_add(BasicType type, LIR_Opr addr, LIRItem& new_value);
330 
331 #ifdef CARDTABLEBARRIERSET_POST_BARRIER_HELPER
332   virtual void CardTableBarrierSet_post_barrier_helper(LIR_Opr addr, LIR_Const* card_table_base);
333 #endif
334 
335   // specific implementations
336   void array_store_check(LIR_Opr value, LIR_Opr array, CodeEmitInfo* store_check_info, ciMethod* profiled_method, int profiled_bci);
337 
338   static LIR_Opr result_register_for(ValueType* type, bool callee = false);
339 
340   ciObject* get_jobject_constant(Value value);
341 
342   LIRItemList* invoke_visit_arguments(Invoke* x);
343   void invoke_load_arguments(Invoke* x, LIRItemList* args, const LIR_OprList* arg_list);
344   void invoke_load_one_argument(LIRItem* param, LIR_Opr loc);
345   void trace_block_entry(BlockBegin* block);
346 
347   // volatile field operations are never patchable because a klass
348   // must be loaded to know it's volatile which means that the offset
349   // it always known as well.
350   void volatile_field_store(LIR_Opr value, LIR_Address* address, CodeEmitInfo* info);
351   void volatile_field_load(LIR_Address* address, LIR_Opr result, CodeEmitInfo* info);
352 
353   void put_Object_unsafe(LIR_Opr src, LIR_Opr offset, LIR_Opr data, BasicType type, bool is_volatile);
354   void get_Object_unsafe(LIR_Opr dest, LIR_Opr src, LIR_Opr offset, BasicType type, bool is_volatile);
355 
356   void arithmetic_call_op (Bytecodes::Code code, LIR_Opr result, LIR_OprList* args);
357 
358   void increment_counter(address counter, BasicType type, int step = 1);
359   void increment_counter(LIR_Address* addr, int step = 1);
360 
361   void arithmetic_op(Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, LIR_Opr tmp, CodeEmitInfo* info = nullptr);
362   // machine dependent.  returns true if it emitted code for the multiply
363   bool strength_reduce_multiply(LIR_Opr left, jint constant, LIR_Opr result, LIR_Opr tmp);
364 
365   void store_stack_parameter (LIR_Opr opr, ByteSize offset_from_sp_in_bytes);
366 
367   void klass2reg_with_patching(LIR_Opr r, ciMetadata* obj, CodeEmitInfo* info, bool need_resolve = false);
368 
369   // this loads the length and compares against the index
370   void array_range_check          (LIR_Opr array, LIR_Opr index, CodeEmitInfo* null_check_info, CodeEmitInfo* range_check_info);
371 
372   void arithmetic_op_int  (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, LIR_Opr tmp);
373   void arithmetic_op_long (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, CodeEmitInfo* info = nullptr);
374   void arithmetic_op_fpu  (Bytecodes::Code code, LIR_Opr result, LIR_Opr left, LIR_Opr right, LIR_Opr tmp = LIR_OprFact::illegalOpr);
375 
376   void shift_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr value, LIR_Opr count, LIR_Opr tmp);
377 
378   void logic_op   (Bytecodes::Code code, LIR_Opr dst_reg, LIR_Opr left, LIR_Opr right);
379 
380   void monitor_enter (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, LIR_Opr scratch, int monitor_no, CodeEmitInfo* info_for_exception, CodeEmitInfo* info, CodeStub* throw_ie_stub);
381   void monitor_exit  (LIR_Opr object, LIR_Opr lock, LIR_Opr hdr, LIR_Opr scratch, int monitor_no);
382 
383   void new_instance(LIR_Opr dst, ciInstanceKlass* klass, bool is_unresolved, bool allow_inline, LIR_Opr scratch1, LIR_Opr scratch2, LIR_Opr scratch3, LIR_Opr scratch4, LIR_Opr klass_reg, CodeEmitInfo* info);
384 
385   // machine dependent
386   void cmp_mem_int(LIR_Condition condition, LIR_Opr base, int disp, int c, CodeEmitInfo* info);
387   void cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr base, int disp, BasicType type, CodeEmitInfo* info);
388 
389   void arraycopy_helper(Intrinsic* x, int* flags, ciArrayKlass** expected_type);
390 
391   // returns a LIR_Address to address an array location.  May also
392   // emit some code as part of address calculation.  If
393   // needs_card_mark is true then compute the full address for use by
394   // both the store and the card mark.
395   LIR_Address* generate_address(LIR_Opr base,
396                                 LIR_Opr index, int shift,
397                                 int disp,
398                                 BasicType type);
399   LIR_Address* generate_address(LIR_Opr base, int disp, BasicType type) {
400     return generate_address(base, LIR_OprFact::illegalOpr, 0, disp, type);
401   }
402   LIR_Address* emit_array_address(LIR_Opr array_opr, LIR_Opr index_opr, BasicType type);
403 
404   // the helper for generate_address
405   void add_large_constant(LIR_Opr src, int c, LIR_Opr dest);
406 
407   // machine preferences and characteristics
408   bool can_inline_as_constant(Value i S390_ONLY(COMMA int bits = 20)) const;
409   bool can_inline_as_constant(LIR_Const* c) const;
410   bool can_store_as_constant(Value i, BasicType type) const;
411 
412   LIR_Opr safepoint_poll_register();
413 
414   void profile_branch(If* if_instr, If::Condition cond);
415   void increment_event_counter_impl(CodeEmitInfo* info,
416                                     ciMethod *method, LIR_Opr step, int frequency,
417                                     int bci, bool backedge, bool notify);
418   void increment_event_counter(CodeEmitInfo* info, LIR_Opr step, int bci, bool backedge);
419   void increment_invocation_counter(CodeEmitInfo *info) {
420     if (compilation()->is_profiling()) {
421       increment_event_counter(info, LIR_OprFact::intConst(InvocationCounter::count_increment), InvocationEntryBci, false);
422     }
423   }
424   void increment_backedge_counter(CodeEmitInfo* info, int bci) {
425     if (compilation()->is_profiling()) {
426       increment_event_counter(info, LIR_OprFact::intConst(InvocationCounter::count_increment), bci, true);
427     }
428   }
429   void increment_backedge_counter_conditionally(LIR_Condition cond, LIR_Opr left, LIR_Opr right, CodeEmitInfo* info, int left_bci, int right_bci, int bci);
430   void increment_backedge_counter(CodeEmitInfo* info, LIR_Opr step, int bci) {
431     if (compilation()->is_profiling()) {
432       increment_event_counter(info, step, bci, true);
433     }
434   }
435   CodeEmitInfo* state_for(Instruction* x, ValueStack* state, bool ignore_xhandler = false);
436   CodeEmitInfo* state_for(Instruction* x);
437 
438   // allocates a virtual register for this instruction if
439   // one isn't already allocated.  Only for Phi and Local.
440   LIR_Opr operand_for_instruction(Instruction *x);
441 
442   void set_block(BlockBegin* block)              { _block = block; }
443 
444   void block_prolog(BlockBegin* block);
445   void block_epilog(BlockBegin* block);
446 
447   void do_root (Instruction* instr);
448   void walk    (Instruction* instr);
449 
450   LIR_Opr new_register(BasicType type);
451   LIR_Opr new_register(Value value)              { return new_register(as_BasicType(value->type())); }
452   LIR_Opr new_register(ValueType* type)          { return new_register(as_BasicType(type)); }
453 
454   // returns a register suitable for doing pointer math
455   LIR_Opr new_pointer_register() {
456 #ifdef _LP64
457     return new_register(T_LONG);
458 #else
459     return new_register(T_INT);
460 #endif
461   }
462 
463   static LIR_Condition lir_cond(If::Condition cond) {
464     LIR_Condition l = lir_cond_unknown;
465     switch (cond) {
466     case If::eql: l = lir_cond_equal;        break;
467     case If::neq: l = lir_cond_notEqual;     break;
468     case If::lss: l = lir_cond_less;         break;
469     case If::leq: l = lir_cond_lessEqual;    break;
470     case If::geq: l = lir_cond_greaterEqual; break;
471     case If::gtr: l = lir_cond_greater;      break;
472     case If::aeq: l = lir_cond_aboveEqual;   break;
473     case If::beq: l = lir_cond_belowEqual;   break;
474     default: fatal("You must pass valid If::Condition");
475     };
476     return l;
477   }
478 
479 #ifdef __SOFTFP__
480   void do_soft_float_compare(If *x);
481 #endif // __SOFTFP__
482 
483   SwitchRangeArray* create_lookup_ranges(TableSwitch* x);
484   SwitchRangeArray* create_lookup_ranges(LookupSwitch* x);
485   void do_SwitchRanges(SwitchRangeArray* x, LIR_Opr value, BlockBegin* default_sux);
486 
487   void do_RuntimeCall(address routine, Intrinsic* x);
488 
489   ciKlass* profile_type(ciMethodData* md, int md_first_offset, int md_offset, intptr_t profiled_k,
490                         Value arg, LIR_Opr& mdp, bool not_null, ciKlass* signature_at_call_k,
491                         ciKlass* callee_signature_k);
492   void profile_arguments(ProfileCall* x);
493   void profile_parameters(Base* x);
494   void profile_parameters_at_call(ProfileCall* x);
495   void profile_flags(ciMethodData* md, ciProfileData* load_store, int flag, LIR_Condition condition = lir_cond_always);
496   template <class ArrayData> void profile_null_free_array(LIRItem array, ciMethodData* md, ArrayData* load_store);
497   template <class ArrayData> void profile_array_type(AccessIndexed* x, ciMethodData*& md, ArrayData*& load_store);
498   void profile_element_type(Value element, ciMethodData* md, ciArrayLoadData* load_store);
499   bool profile_inline_klass(ciMethodData* md, ciProfileData* data, Value value, int flag);
500   LIR_Opr mask_boolean(LIR_Opr array, LIR_Opr value, CodeEmitInfo*& null_check_info);
501 
502  public:
503   Compilation*  compilation() const              { return _compilation; }
504   FrameMap*     frame_map() const                { return _compilation->frame_map(); }
505   ciMethod*     method() const                   { return _method; }
506   BlockBegin*   block() const                    { return _block; }
507   IRScope*      scope() const                    { return block()->scope(); }
508 
509   int max_virtual_register_number() const        { return _virtual_register_number; }
510 
511   void block_do(BlockBegin* block);
512 
513   // Flags that can be set on vregs
514   enum VregFlag {
515       must_start_in_memory = 0  // needs to be assigned a memory location at beginning, but may then be loaded in a register
516     , callee_saved     = 1    // must be in a callee saved register
517     , byte_reg         = 2    // must be in a byte register
518     , num_vreg_flags
519 
520   };
521 
522   LIRGenerator(Compilation* compilation, ciMethod* method)
523     : _compilation(compilation)
524     , _method(method)
525     , _virtual_register_number(LIR_Opr::vreg_base)
526     , _vreg_flags(num_vreg_flags)
527     , _in_conditional_code(false)
528     , _barrier_set(BarrierSet::barrier_set()->barrier_set_c1()) {
529   }
530 
531 #ifdef ASSERT
532   // for virtual registers, maps them back to Phi's or Local's
533   Instruction* instruction_for_vreg(int reg_num);
534 #endif
535 
536   void set_vreg_flag   (int vreg_num, VregFlag f);
537   bool is_vreg_flag_set(int vreg_num, VregFlag f);
538   void set_vreg_flag   (LIR_Opr opr,  VregFlag f) { set_vreg_flag(opr->vreg_number(), f); }
539   bool is_vreg_flag_set(LIR_Opr opr,  VregFlag f) { return is_vreg_flag_set(opr->vreg_number(), f); }
540 
541   // statics
542   static LIR_Opr exceptionOopOpr();
543   static LIR_Opr exceptionPcOpr();
544   static LIR_Opr divInOpr();
545   static LIR_Opr divOutOpr();
546   static LIR_Opr remOutOpr();
547 #ifdef S390
548   // On S390 we can do ldiv, lrem without RT call.
549   static LIR_Opr ldivInOpr();
550   static LIR_Opr ldivOutOpr();
551   static LIR_Opr lremOutOpr();
552 #endif
553   static LIR_Opr shiftCountOpr();
554   LIR_Opr syncLockOpr();
555   LIR_Opr syncTempOpr();
556   LIR_Opr atomicLockOpr();
557 
558   // Intrinsic for Class::isInstance
559   address isInstance_entry();
560 
561   // returns a register suitable for saving the thread in a
562   // call_runtime_leaf if one is needed.
563   LIR_Opr getThreadTemp();
564 
565   // visitor functionality
566   virtual void do_Phi            (Phi*             x);
567   virtual void do_Local          (Local*           x);
568   virtual void do_Constant       (Constant*        x);
569   virtual void do_LoadField      (LoadField*       x);
570   virtual void do_StoreField     (StoreField*      x);
571   virtual void do_ArrayLength    (ArrayLength*     x);
572   virtual void do_LoadIndexed    (LoadIndexed*     x);
573   virtual void do_StoreIndexed   (StoreIndexed*    x);
574   virtual void do_NegateOp       (NegateOp*        x);
575   virtual void do_ArithmeticOp   (ArithmeticOp*    x);
576   virtual void do_ShiftOp        (ShiftOp*         x);
577   virtual void do_LogicOp        (LogicOp*         x);
578   virtual void do_CompareOp      (CompareOp*       x);
579   virtual void do_IfOp           (IfOp*            x);
580   virtual void do_Convert        (Convert*         x);
581   virtual void do_NullCheck      (NullCheck*       x);
582   virtual void do_TypeCast       (TypeCast*        x);
583   virtual void do_Invoke         (Invoke*          x);
584   virtual void do_NewInstance    (NewInstance*     x);
585   virtual void do_NewTypeArray   (NewTypeArray*    x);
586   virtual void do_NewObjectArray (NewObjectArray*  x);
587   virtual void do_NewMultiArray  (NewMultiArray*   x);
588   virtual void do_CheckCast      (CheckCast*       x);
589   virtual void do_InstanceOf     (InstanceOf*      x);
590   virtual void do_MonitorEnter   (MonitorEnter*    x);
591   virtual void do_MonitorExit    (MonitorExit*     x);
592   virtual void do_Intrinsic      (Intrinsic*       x);
593   virtual void do_BlockBegin     (BlockBegin*      x);
594   virtual void do_Goto           (Goto*            x);
595   virtual void do_If             (If*              x);
596   virtual void do_TableSwitch    (TableSwitch*     x);
597   virtual void do_LookupSwitch   (LookupSwitch*    x);
598   virtual void do_Return         (Return*          x);
599   virtual void do_Throw          (Throw*           x);
600   virtual void do_Base           (Base*            x);
601   virtual void do_OsrEntry       (OsrEntry*        x);
602   virtual void do_ExceptionObject(ExceptionObject* x);
603   virtual void do_UnsafeGet      (UnsafeGet*       x);
604   virtual void do_UnsafePut      (UnsafePut*       x);
605   virtual void do_UnsafeGetAndSet(UnsafeGetAndSet* x);
606   virtual void do_ProfileCall    (ProfileCall*     x);
607   virtual void do_ProfileReturnType (ProfileReturnType* x);
608   virtual void do_ProfileInvoke  (ProfileInvoke*   x);
609   virtual void do_ProfileACmpTypes(ProfileACmpTypes* x);
610   virtual void do_RuntimeCall    (RuntimeCall*     x);
611   virtual void do_MemBar         (MemBar*          x);
612   virtual void do_RangeCheckPredicate(RangeCheckPredicate* x);
613 #ifdef ASSERT
614   virtual void do_Assert         (Assert*          x);
615 #endif
616 
617 #ifdef C1_LIRGENERATOR_MD_HPP
618 #include C1_LIRGENERATOR_MD_HPP
619 #endif
620 };
621 
622 
623 class LIRItem: public CompilationResourceObj {
624  private:
625   Value         _value;
626   LIRGenerator* _gen;
627   LIR_Opr       _result;
628   bool          _destroys_register;
629   LIR_Opr       _new_result;
630 
631   LIRGenerator* gen() const { return _gen; }
632 
633  public:
634   LIRItem(Value value, LIRGenerator* gen) {
635     _destroys_register = false;
636     _gen = gen;
637     set_instruction(value);
638   }
639 
640   LIRItem(LIRGenerator* gen) {
641     _destroys_register = false;
642     _gen = gen;
643     _result = LIR_OprFact::illegalOpr;
644     set_instruction(nullptr);
645   }
646 
647   void set_instruction(Value value) {
648     _value = value;
649     _result = LIR_OprFact::illegalOpr;
650     if (_value != nullptr) {
651       _gen->walk(_value);
652       _result = _value->operand();
653     }
654     _new_result = LIR_OprFact::illegalOpr;
655   }
656 
657   Value value() const          { return _value;          }
658   ValueType* type() const      { return value()->type(); }
659   LIR_Opr result()             {
660     assert(!_destroys_register || (!_result->is_register() || _result->is_virtual()),
661            "shouldn't use set_destroys_register with physical registers");
662     if (_destroys_register && _result->is_register()) {
663       if (_new_result->is_illegal()) {
664         _new_result = _gen->new_register(type());
665         gen()->lir()->move(_result, _new_result);
666       }
667       return _new_result;
668     } else {
669       return _result;
670     }
671   }
672 
673   void set_result(LIR_Opr opr);
674 
675   void load_item();
676   void load_byte_item();
677   void load_nonconstant(S390_ONLY(int bits = 20));
678   // load any values which can't be expressed as part of a single store instruction
679   void load_for_store(BasicType store_type);
680   void load_item_force(LIR_Opr reg);
681 
682   void dont_load_item() {
683     // do nothing
684   }
685 
686   void set_destroys_register() {
687     _destroys_register = true;
688   }
689 
690   bool is_constant() const { return value()->as_Constant() != nullptr; }
691   bool is_stack()          { return result()->is_stack(); }
692   bool is_register()       { return result()->is_register(); }
693 
694   ciObject* get_jobject_constant() const;
695   jint      get_jint_constant() const;
696   jlong     get_jlong_constant() const;
697   jfloat    get_jfloat_constant() const;
698   jdouble   get_jdouble_constant() const;
699   jint      get_address_constant() const;
700 };
701 
702 #endif // SHARE_C1_C1_LIRGENERATOR_HPP