1// Copyright (c) 1994-2006 Sun Microsystems Inc.
2// All Rights Reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8// - Redistributions of source code must retain the above copyright notice,
9// this list of conditions and the following disclaimer.
10//
11// - Redistribution in binary form must reproduce the above copyright
12// notice, this list of conditions and the following disclaimer in the
13// documentation and/or other materials provided with the distribution.
14//
15// - Neither the name of Sun Microsystems or the names of contributors may
16// be used to endorse or promote products derived from this software without
17// specific prior written permission.
18//
19// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
20// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31// The original source code covered by the above license above has been
32// modified significantly by Google Inc.
33// Copyright 2012 the V8 project authors. All rights reserved.
34
35#ifndef V8_ASSEMBLER_H_
36#define V8_ASSEMBLER_H_
37
38#include "v8.h"
39
40#include "allocation.h"
41#include "builtins.h"
42#include "gdb-jit.h"
43#include "isolate.h"
44#include "runtime.h"
45#include "token.h"
46
47namespace v8 {
48
49class ApiFunction;
50
51namespace internal {
52
53class StatsCounter;
54// -----------------------------------------------------------------------------
55// Platform independent assembler base class.
56
57class AssemblerBase: public Malloced {
58 public:
59  AssemblerBase(Isolate* isolate, void* buffer, int buffer_size);
60  virtual ~AssemblerBase();
61
62  Isolate* isolate() const { return isolate_; }
63  int jit_cookie() const { return jit_cookie_; }
64
65  bool emit_debug_code() const { return emit_debug_code_; }
66  void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
67
68  bool predictable_code_size() const { return predictable_code_size_; }
69  void set_predictable_code_size(bool value) { predictable_code_size_ = value; }
70
71  uint64_t enabled_cpu_features() const { return enabled_cpu_features_; }
72  void set_enabled_cpu_features(uint64_t features) {
73    enabled_cpu_features_ = features;
74  }
75  bool IsEnabled(CpuFeature f) {
76    return (enabled_cpu_features_ & (static_cast<uint64_t>(1) << f)) != 0;
77  }
78
79  // Overwrite a host NaN with a quiet target NaN.  Used by mksnapshot for
80  // cross-snapshotting.
81  static void QuietNaN(HeapObject* nan) { }
82
83  int pc_offset() const { return static_cast<int>(pc_ - buffer_); }
84
85  static const int kMinimalBufferSize = 4*KB;
86
87 protected:
88  // The buffer into which code and relocation info are generated. It could
89  // either be owned by the assembler or be provided externally.
90  byte* buffer_;
91  int buffer_size_;
92  bool own_buffer_;
93
94  // The program counter, which points into the buffer above and moves forward.
95  byte* pc_;
96
97 private:
98  Isolate* isolate_;
99  int jit_cookie_;
100  uint64_t enabled_cpu_features_;
101  bool emit_debug_code_;
102  bool predictable_code_size_;
103};
104
105
106// Avoids using instructions that vary in size in unpredictable ways between the
107// snapshot and the running VM.
108class PredictableCodeSizeScope {
109 public:
110  PredictableCodeSizeScope(AssemblerBase* assembler, int expected_size);
111  ~PredictableCodeSizeScope();
112
113 private:
114  AssemblerBase* assembler_;
115  int expected_size_;
116  int start_offset_;
117  bool old_value_;
118};
119
120
121// Enable a specified feature within a scope.
122class CpuFeatureScope BASE_EMBEDDED {
123 public:
124#ifdef DEBUG
125  CpuFeatureScope(AssemblerBase* assembler, CpuFeature f);
126  ~CpuFeatureScope();
127
128 private:
129  AssemblerBase* assembler_;
130  uint64_t old_enabled_;
131#else
132  CpuFeatureScope(AssemblerBase* assembler, CpuFeature f) {}
133#endif
134};
135
136
137// Enable a unsupported feature within a scope for cross-compiling for a
138// different CPU.
139class PlatformFeatureScope BASE_EMBEDDED {
140 public:
141  explicit PlatformFeatureScope(CpuFeature f);
142  ~PlatformFeatureScope();
143
144 private:
145  uint64_t old_cross_compile_;
146};
147
148
149// -----------------------------------------------------------------------------
150// Labels represent pc locations; they are typically jump or call targets.
151// After declaration, a label can be freely used to denote known or (yet)
152// unknown pc location. Assembler::bind() is used to bind a label to the
153// current pc. A label can be bound only once.
154
155class Label BASE_EMBEDDED {
156 public:
157  enum Distance {
158    kNear, kFar
159  };
160
161  INLINE(Label()) {
162    Unuse();
163    UnuseNear();
164  }
165
166  INLINE(~Label()) {
167    ASSERT(!is_linked());
168    ASSERT(!is_near_linked());
169  }
170
171  INLINE(void Unuse()) { pos_ = 0; }
172  INLINE(void UnuseNear()) { near_link_pos_ = 0; }
173
174  INLINE(bool is_bound() const) { return pos_ <  0; }
175  INLINE(bool is_unused() const) { return pos_ == 0 && near_link_pos_ == 0; }
176  INLINE(bool is_linked() const) { return pos_ >  0; }
177  INLINE(bool is_near_linked() const) { return near_link_pos_ > 0; }
178
179  // Returns the position of bound or linked labels. Cannot be used
180  // for unused labels.
181  int pos() const;
182  int near_link_pos() const { return near_link_pos_ - 1; }
183
184 private:
185  // pos_ encodes both the binding state (via its sign)
186  // and the binding position (via its value) of a label.
187  //
188  // pos_ <  0  bound label, pos() returns the jump target position
189  // pos_ == 0  unused label
190  // pos_ >  0  linked label, pos() returns the last reference position
191  int pos_;
192
193  // Behaves like |pos_| in the "> 0" case, but for near jumps to this label.
194  int near_link_pos_;
195
196  void bind_to(int pos)  {
197    pos_ = -pos - 1;
198    ASSERT(is_bound());
199  }
200  void link_to(int pos, Distance distance = kFar) {
201    if (distance == kNear) {
202      near_link_pos_ = pos + 1;
203      ASSERT(is_near_linked());
204    } else {
205      pos_ = pos + 1;
206      ASSERT(is_linked());
207    }
208  }
209
210  friend class Assembler;
211  friend class Displacement;
212  friend class RegExpMacroAssemblerIrregexp;
213};
214
215
216enum SaveFPRegsMode { kDontSaveFPRegs, kSaveFPRegs };
217
218
219// -----------------------------------------------------------------------------
220// Relocation information
221
222
223// Relocation information consists of the address (pc) of the datum
224// to which the relocation information applies, the relocation mode
225// (rmode), and an optional data field. The relocation mode may be
226// "descriptive" and not indicate a need for relocation, but simply
227// describe a property of the datum. Such rmodes are useful for GC
228// and nice disassembly output.
229
230class RelocInfo BASE_EMBEDDED {
231 public:
232  // The constant kNoPosition is used with the collecting of source positions
233  // in the relocation information. Two types of source positions are collected
234  // "position" (RelocMode position) and "statement position" (RelocMode
235  // statement_position). The "position" is collected at places in the source
236  // code which are of interest when making stack traces to pin-point the source
237  // location of a stack frame as close as possible. The "statement position" is
238  // collected at the beginning at each statement, and is used to indicate
239  // possible break locations. kNoPosition is used to indicate an
240  // invalid/uninitialized position value.
241  static const int kNoPosition = -1;
242
243  // This string is used to add padding comments to the reloc info in cases
244  // where we are not sure to have enough space for patching in during
245  // lazy deoptimization. This is the case if we have indirect calls for which
246  // we do not normally record relocation info.
247  static const char* const kFillerCommentString;
248
249  // The minimum size of a comment is equal to three bytes for the extra tagged
250  // pc + the tag for the data, and kPointerSize for the actual pointer to the
251  // comment.
252  static const int kMinRelocCommentSize = 3 + kPointerSize;
253
254  // The maximum size for a call instruction including pc-jump.
255  static const int kMaxCallSize = 6;
256
257  // The maximum pc delta that will use the short encoding.
258  static const int kMaxSmallPCDelta;
259
260  enum Mode {
261    // Please note the order is important (see IsCodeTarget, IsGCRelocMode).
262    CODE_TARGET,  // Code target which is not any of the above.
263    CODE_TARGET_WITH_ID,
264    CONSTRUCT_CALL,  // code target that is a call to a JavaScript constructor.
265    CODE_TARGET_CONTEXT,  // Code target used for contextual loads and stores.
266    DEBUG_BREAK,  // Code target for the debugger statement.
267    EMBEDDED_OBJECT,
268    CELL,
269
270    // Everything after runtime_entry (inclusive) is not GC'ed.
271    RUNTIME_ENTRY,
272    JS_RETURN,  // Marks start of the ExitJSFrame code.
273    COMMENT,
274    POSITION,  // See comment for kNoPosition above.
275    STATEMENT_POSITION,  // See comment for kNoPosition above.
276    DEBUG_BREAK_SLOT,  // Additional code inserted for debug break slot.
277    EXTERNAL_REFERENCE,  // The address of an external C++ function.
278    INTERNAL_REFERENCE,  // An address inside the same function.
279
280    // Marks a constant pool. Only used on ARM.
281    // It uses a custom noncompact encoding.
282    CONST_POOL,
283
284    // add more as needed
285    // Pseudo-types
286    NUMBER_OF_MODES,  // There are at most 15 modes with noncompact encoding.
287    NONE32,  // never recorded 32-bit value
288    NONE64,  // never recorded 64-bit value
289    CODE_AGE_SEQUENCE,  // Not stored in RelocInfo array, used explictly by
290                        // code aging.
291    FIRST_REAL_RELOC_MODE = CODE_TARGET,
292    LAST_REAL_RELOC_MODE = CONST_POOL,
293    FIRST_PSEUDO_RELOC_MODE = CODE_AGE_SEQUENCE,
294    LAST_PSEUDO_RELOC_MODE = CODE_AGE_SEQUENCE,
295    LAST_CODE_ENUM = DEBUG_BREAK,
296    LAST_GCED_ENUM = CELL,
297    // Modes <= LAST_COMPACT_ENUM are guaranteed to have compact encoding.
298    LAST_COMPACT_ENUM = CODE_TARGET_WITH_ID,
299    LAST_STANDARD_NONCOMPACT_ENUM = INTERNAL_REFERENCE
300  };
301
302
303  RelocInfo() {}
304
305  RelocInfo(byte* pc, Mode rmode, intptr_t data, Code* host)
306      : pc_(pc), rmode_(rmode), data_(data), host_(host) {
307  }
308  RelocInfo(byte* pc, double data64)
309      : pc_(pc), rmode_(NONE64), data64_(data64), host_(NULL) {
310  }
311
312  static inline bool IsRealRelocMode(Mode mode) {
313    return mode >= FIRST_REAL_RELOC_MODE &&
314        mode <= LAST_REAL_RELOC_MODE;
315  }
316  static inline bool IsPseudoRelocMode(Mode mode) {
317    ASSERT(!IsRealRelocMode(mode));
318    return mode >= FIRST_PSEUDO_RELOC_MODE &&
319        mode <= LAST_PSEUDO_RELOC_MODE;
320  }
321  static inline bool IsConstructCall(Mode mode) {
322    return mode == CONSTRUCT_CALL;
323  }
324  static inline bool IsCodeTarget(Mode mode) {
325    return mode <= LAST_CODE_ENUM;
326  }
327  static inline bool IsEmbeddedObject(Mode mode) {
328    return mode == EMBEDDED_OBJECT;
329  }
330  static inline bool IsRuntimeEntry(Mode mode) {
331    return mode == RUNTIME_ENTRY;
332  }
333  // Is the relocation mode affected by GC?
334  static inline bool IsGCRelocMode(Mode mode) {
335    return mode <= LAST_GCED_ENUM;
336  }
337  static inline bool IsJSReturn(Mode mode) {
338    return mode == JS_RETURN;
339  }
340  static inline bool IsComment(Mode mode) {
341    return mode == COMMENT;
342  }
343  static inline bool IsConstPool(Mode mode) {
344    return mode == CONST_POOL;
345  }
346  static inline bool IsPosition(Mode mode) {
347    return mode == POSITION || mode == STATEMENT_POSITION;
348  }
349  static inline bool IsStatementPosition(Mode mode) {
350    return mode == STATEMENT_POSITION;
351  }
352  static inline bool IsExternalReference(Mode mode) {
353    return mode == EXTERNAL_REFERENCE;
354  }
355  static inline bool IsInternalReference(Mode mode) {
356    return mode == INTERNAL_REFERENCE;
357  }
358  static inline bool IsDebugBreakSlot(Mode mode) {
359    return mode == DEBUG_BREAK_SLOT;
360  }
361  static inline bool IsNone(Mode mode) {
362    return mode == NONE32 || mode == NONE64;
363  }
364  static inline bool IsCodeAgeSequence(Mode mode) {
365    return mode == CODE_AGE_SEQUENCE;
366  }
367  static inline int ModeMask(Mode mode) { return 1 << mode; }
368
369  // Accessors
370  byte* pc() const { return pc_; }
371  void set_pc(byte* pc) { pc_ = pc; }
372  Mode rmode() const {  return rmode_; }
373  intptr_t data() const { return data_; }
374  double data64() const { return data64_; }
375  uint64_t raw_data64() {
376    return BitCast<uint64_t>(data64_);
377  }
378  Code* host() const { return host_; }
379
380  // Apply a relocation by delta bytes
381  INLINE(void apply(intptr_t delta));
382
383  // Is the pointer this relocation info refers to coded like a plain pointer
384  // or is it strange in some way (e.g. relative or patched into a series of
385  // instructions).
386  bool IsCodedSpecially();
387
388  // Read/modify the code target in the branch/call instruction
389  // this relocation applies to;
390  // can only be called if IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_)
391  INLINE(Address target_address());
392  INLINE(void set_target_address(Address target,
393                                 WriteBarrierMode mode = UPDATE_WRITE_BARRIER));
394  INLINE(Object* target_object());
395  INLINE(Handle<Object> target_object_handle(Assembler* origin));
396  INLINE(void set_target_object(Object* target,
397                                WriteBarrierMode mode = UPDATE_WRITE_BARRIER));
398  INLINE(Address target_runtime_entry(Assembler* origin));
399  INLINE(void set_target_runtime_entry(Address target,
400                                       WriteBarrierMode mode =
401                                           UPDATE_WRITE_BARRIER));
402  INLINE(Cell* target_cell());
403  INLINE(Handle<Cell> target_cell_handle());
404  INLINE(void set_target_cell(Cell* cell,
405                              WriteBarrierMode mode = UPDATE_WRITE_BARRIER));
406  INLINE(Handle<Object> code_age_stub_handle(Assembler* origin));
407  INLINE(Code* code_age_stub());
408  INLINE(void set_code_age_stub(Code* stub));
409
410  // Read the address of the word containing the target_address in an
411  // instruction stream.  What this means exactly is architecture-independent.
412  // The only architecture-independent user of this function is the serializer.
413  // The serializer uses it to find out how many raw bytes of instruction to
414  // output before the next target.  Architecture-independent code shouldn't
415  // dereference the pointer it gets back from this.
416  INLINE(Address target_address_address());
417  // This indicates how much space a target takes up when deserializing a code
418  // stream.  For most architectures this is just the size of a pointer.  For
419  // an instruction like movw/movt where the target bits are mixed into the
420  // instruction bits the size of the target will be zero, indicating that the
421  // serializer should not step forwards in memory after a target is resolved
422  // and written.  In this case the target_address_address function above
423  // should return the end of the instructions to be patched, allowing the
424  // deserializer to deserialize the instructions as raw bytes and put them in
425  // place, ready to be patched with the target.
426  INLINE(int target_address_size());
427
428  // Read/modify the reference in the instruction this relocation
429  // applies to; can only be called if rmode_ is external_reference
430  INLINE(Address target_reference());
431
432  // Read/modify the address of a call instruction. This is used to relocate
433  // the break points where straight-line code is patched with a call
434  // instruction.
435  INLINE(Address call_address());
436  INLINE(void set_call_address(Address target));
437  INLINE(Object* call_object());
438  INLINE(void set_call_object(Object* target));
439  INLINE(Object** call_object_address());
440
441  // Wipe out a relocation to a fixed value, used for making snapshots
442  // reproducible.
443  INLINE(void WipeOut());
444
445  template<typename StaticVisitor> inline void Visit(Heap* heap);
446  inline void Visit(Isolate* isolate, ObjectVisitor* v);
447
448  // Patch the code with some other code.
449  void PatchCode(byte* instructions, int instruction_count);
450
451  // Patch the code with a call.
452  void PatchCodeWithCall(Address target, int guard_bytes);
453
454  // Check whether this return sequence has been patched
455  // with a call to the debugger.
456  INLINE(bool IsPatchedReturnSequence());
457
458  // Check whether this debug break slot has been patched with a call to the
459  // debugger.
460  INLINE(bool IsPatchedDebugBreakSlotSequence());
461
462#ifdef DEBUG
463  // Check whether the given code contains relocation information that
464  // either is position-relative or movable by the garbage collector.
465  static bool RequiresRelocation(const CodeDesc& desc);
466#endif
467
468#ifdef ENABLE_DISASSEMBLER
469  // Printing
470  static const char* RelocModeName(Mode rmode);
471  void Print(Isolate* isolate, FILE* out);
472#endif  // ENABLE_DISASSEMBLER
473#ifdef VERIFY_HEAP
474  void Verify();
475#endif
476
477  static const int kCodeTargetMask = (1 << (LAST_CODE_ENUM + 1)) - 1;
478  static const int kPositionMask = 1 << POSITION | 1 << STATEMENT_POSITION;
479  static const int kDataMask =
480      (1 << CODE_TARGET_WITH_ID) | kPositionMask | (1 << COMMENT);
481  static const int kApplyMask;  // Modes affected by apply. Depends on arch.
482
483 private:
484  // On ARM, note that pc_ is the address of the constant pool entry
485  // to be relocated and not the address of the instruction
486  // referencing the constant pool entry (except when rmode_ ==
487  // comment).
488  byte* pc_;
489  Mode rmode_;
490  union {
491    intptr_t data_;
492    double data64_;
493  };
494  Code* host_;
495  // External-reference pointers are also split across instruction-pairs
496  // on some platforms, but are accessed via indirect pointers. This location
497  // provides a place for that pointer to exist naturally. Its address
498  // is returned by RelocInfo::target_reference_address().
499  Address reconstructed_adr_ptr_;
500  friend class RelocIterator;
501};
502
503
504// RelocInfoWriter serializes a stream of relocation info. It writes towards
505// lower addresses.
506class RelocInfoWriter BASE_EMBEDDED {
507 public:
508  RelocInfoWriter() : pos_(NULL),
509                      last_pc_(NULL),
510                      last_id_(0),
511                      last_position_(0) {}
512  RelocInfoWriter(byte* pos, byte* pc) : pos_(pos),
513                                         last_pc_(pc),
514                                         last_id_(0),
515                                         last_position_(0) {}
516
517  byte* pos() const { return pos_; }
518  byte* last_pc() const { return last_pc_; }
519
520  void Write(const RelocInfo* rinfo);
521
522  // Update the state of the stream after reloc info buffer
523  // and/or code is moved while the stream is active.
524  void Reposition(byte* pos, byte* pc) {
525    pos_ = pos;
526    last_pc_ = pc;
527  }
528
529  // Max size (bytes) of a written RelocInfo. Longest encoding is
530  // ExtraTag, VariableLengthPCJump, ExtraTag, pc_delta, ExtraTag, data_delta.
531  // On ia32 and arm this is 1 + 4 + 1 + 1 + 1 + 4 = 12.
532  // On x64 this is 1 + 4 + 1 + 1 + 1 + 8 == 16;
533  // Here we use the maximum of the two.
534  static const int kMaxSize = 16;
535
536 private:
537  inline uint32_t WriteVariableLengthPCJump(uint32_t pc_delta);
538  inline void WriteTaggedPC(uint32_t pc_delta, int tag);
539  inline void WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag);
540  inline void WriteExtraTaggedIntData(int data_delta, int top_tag);
541  inline void WriteExtraTaggedConstPoolData(int data);
542  inline void WriteExtraTaggedData(intptr_t data_delta, int top_tag);
543  inline void WriteTaggedData(intptr_t data_delta, int tag);
544  inline void WriteExtraTag(int extra_tag, int top_tag);
545
546  byte* pos_;
547  byte* last_pc_;
548  int last_id_;
549  int last_position_;
550  DISALLOW_COPY_AND_ASSIGN(RelocInfoWriter);
551};
552
553
554// A RelocIterator iterates over relocation information.
555// Typical use:
556//
557//   for (RelocIterator it(code); !it.done(); it.next()) {
558//     // do something with it.rinfo() here
559//   }
560//
561// A mask can be specified to skip unwanted modes.
562class RelocIterator: public Malloced {
563 public:
564  // Create a new iterator positioned at
565  // the beginning of the reloc info.
566  // Relocation information with mode k is included in the
567  // iteration iff bit k of mode_mask is set.
568  explicit RelocIterator(Code* code, int mode_mask = -1);
569  explicit RelocIterator(const CodeDesc& desc, int mode_mask = -1);
570
571  // Iteration
572  bool done() const { return done_; }
573  void next();
574
575  // Return pointer valid until next next().
576  RelocInfo* rinfo() {
577    ASSERT(!done());
578    return &rinfo_;
579  }
580
581 private:
582  // Advance* moves the position before/after reading.
583  // *Read* reads from current byte(s) into rinfo_.
584  // *Get* just reads and returns info on current byte.
585  void Advance(int bytes = 1) { pos_ -= bytes; }
586  int AdvanceGetTag();
587  int GetExtraTag();
588  int GetTopTag();
589  void ReadTaggedPC();
590  void AdvanceReadPC();
591  void AdvanceReadId();
592  void AdvanceReadConstPoolData();
593  void AdvanceReadPosition();
594  void AdvanceReadData();
595  void AdvanceReadVariableLengthPCJump();
596  int GetLocatableTypeTag();
597  void ReadTaggedId();
598  void ReadTaggedPosition();
599
600  // If the given mode is wanted, set it in rinfo_ and return true.
601  // Else return false. Used for efficiently skipping unwanted modes.
602  bool SetMode(RelocInfo::Mode mode) {
603    return (mode_mask_ & (1 << mode)) ? (rinfo_.rmode_ = mode, true) : false;
604  }
605
606  byte* pos_;
607  byte* end_;
608  byte* code_age_sequence_;
609  RelocInfo rinfo_;
610  bool done_;
611  int mode_mask_;
612  int last_id_;
613  int last_position_;
614  DISALLOW_COPY_AND_ASSIGN(RelocIterator);
615};
616
617
618//------------------------------------------------------------------------------
619// External function
620
621//----------------------------------------------------------------------------
622class IC_Utility;
623class SCTableReference;
624#ifdef ENABLE_DEBUGGER_SUPPORT
625class Debug_Address;
626#endif
627
628
629// An ExternalReference represents a C++ address used in the generated
630// code. All references to C++ functions and variables must be encapsulated in
631// an ExternalReference instance. This is done in order to track the origin of
632// all external references in the code so that they can be bound to the correct
633// addresses when deserializing a heap.
634class ExternalReference BASE_EMBEDDED {
635 public:
636  // Used in the simulator to support different native api calls.
637  enum Type {
638    // Builtin call.
639    // MaybeObject* f(v8::internal::Arguments).
640    BUILTIN_CALL,  // default
641
642    // Builtin that takes float arguments and returns an int.
643    // int f(double, double).
644    BUILTIN_COMPARE_CALL,
645
646    // Builtin call that returns floating point.
647    // double f(double, double).
648    BUILTIN_FP_FP_CALL,
649
650    // Builtin call that returns floating point.
651    // double f(double).
652    BUILTIN_FP_CALL,
653
654    // Builtin call that returns floating point.
655    // double f(double, int).
656    BUILTIN_FP_INT_CALL,
657
658    // Direct call to API function callback.
659    // void f(v8::FunctionCallbackInfo&)
660    DIRECT_API_CALL,
661
662    // Call to function callback via InvokeFunctionCallback.
663    // void f(v8::FunctionCallbackInfo&, v8::FunctionCallback)
664    PROFILING_API_CALL,
665
666    // Direct call to accessor getter callback.
667    // void f(Local<String> property, PropertyCallbackInfo& info)
668    DIRECT_GETTER_CALL,
669
670    // Call to accessor getter callback via InvokeAccessorGetterCallback.
671    // void f(Local<String> property, PropertyCallbackInfo& info,
672    //     AccessorGetterCallback callback)
673    PROFILING_GETTER_CALL
674  };
675
676  static void SetUp();
677  static void InitializeMathExpData();
678  static void TearDownMathExpData();
679
680  typedef void* ExternalReferenceRedirector(void* original, Type type);
681
682  ExternalReference() : address_(NULL) {}
683
684  ExternalReference(Builtins::CFunctionId id, Isolate* isolate);
685
686  ExternalReference(ApiFunction* ptr, Type type, Isolate* isolate);
687
688  ExternalReference(Builtins::Name name, Isolate* isolate);
689
690  ExternalReference(Runtime::FunctionId id, Isolate* isolate);
691
692  ExternalReference(const Runtime::Function* f, Isolate* isolate);
693
694  ExternalReference(const IC_Utility& ic_utility, Isolate* isolate);
695
696#ifdef ENABLE_DEBUGGER_SUPPORT
697  ExternalReference(const Debug_Address& debug_address, Isolate* isolate);
698#endif
699
700  explicit ExternalReference(StatsCounter* counter);
701
702  ExternalReference(Isolate::AddressId id, Isolate* isolate);
703
704  explicit ExternalReference(const SCTableReference& table_ref);
705
706  // Isolate as an external reference.
707  static ExternalReference isolate_address(Isolate* isolate);
708
709  // One-of-a-kind references. These references are not part of a general
710  // pattern. This means that they have to be added to the
711  // ExternalReferenceTable in serialize.cc manually.
712
713  static ExternalReference incremental_marking_record_write_function(
714      Isolate* isolate);
715  static ExternalReference incremental_evacuation_record_write_function(
716      Isolate* isolate);
717  static ExternalReference store_buffer_overflow_function(
718      Isolate* isolate);
719  static ExternalReference flush_icache_function(Isolate* isolate);
720  static ExternalReference perform_gc_function(Isolate* isolate);
721  static ExternalReference transcendental_cache_array_address(Isolate* isolate);
722  static ExternalReference delete_handle_scope_extensions(Isolate* isolate);
723
724  static ExternalReference get_date_field_function(Isolate* isolate);
725  static ExternalReference date_cache_stamp(Isolate* isolate);
726
727  static ExternalReference get_make_code_young_function(Isolate* isolate);
728  static ExternalReference get_mark_code_as_executed_function(Isolate* isolate);
729
730  // Deoptimization support.
731  static ExternalReference new_deoptimizer_function(Isolate* isolate);
732  static ExternalReference compute_output_frames_function(Isolate* isolate);
733
734  // Log support.
735  static ExternalReference log_enter_external_function(Isolate* isolate);
736  static ExternalReference log_leave_external_function(Isolate* isolate);
737
738  // Static data in the keyed lookup cache.
739  static ExternalReference keyed_lookup_cache_keys(Isolate* isolate);
740  static ExternalReference keyed_lookup_cache_field_offsets(Isolate* isolate);
741
742  // Static variable Heap::roots_array_start()
743  static ExternalReference roots_array_start(Isolate* isolate);
744
745  // Static variable Heap::allocation_sites_list_address()
746  static ExternalReference allocation_sites_list_address(Isolate* isolate);
747
748  // Static variable StackGuard::address_of_jslimit()
749  static ExternalReference address_of_stack_limit(Isolate* isolate);
750
751  // Static variable StackGuard::address_of_real_jslimit()
752  static ExternalReference address_of_real_stack_limit(Isolate* isolate);
753
754  // Static variable RegExpStack::limit_address()
755  static ExternalReference address_of_regexp_stack_limit(Isolate* isolate);
756
757  // Static variables for RegExp.
758  static ExternalReference address_of_static_offsets_vector(Isolate* isolate);
759  static ExternalReference address_of_regexp_stack_memory_address(
760      Isolate* isolate);
761  static ExternalReference address_of_regexp_stack_memory_size(
762      Isolate* isolate);
763
764  // Static variable Heap::NewSpaceStart()
765  static ExternalReference new_space_start(Isolate* isolate);
766  static ExternalReference new_space_mask(Isolate* isolate);
767  static ExternalReference heap_always_allocate_scope_depth(Isolate* isolate);
768  static ExternalReference new_space_mark_bits(Isolate* isolate);
769
770  // Write barrier.
771  static ExternalReference store_buffer_top(Isolate* isolate);
772
773  // Used for fast allocation in generated code.
774  static ExternalReference new_space_allocation_top_address(Isolate* isolate);
775  static ExternalReference new_space_allocation_limit_address(Isolate* isolate);
776  static ExternalReference old_pointer_space_allocation_top_address(
777      Isolate* isolate);
778  static ExternalReference old_pointer_space_allocation_limit_address(
779      Isolate* isolate);
780  static ExternalReference old_data_space_allocation_top_address(
781      Isolate* isolate);
782  static ExternalReference old_data_space_allocation_limit_address(
783      Isolate* isolate);
784  static ExternalReference new_space_high_promotion_mode_active_address(
785      Isolate* isolate);
786
787  static ExternalReference double_fp_operation(Token::Value operation,
788                                               Isolate* isolate);
789  static ExternalReference compare_doubles(Isolate* isolate);
790  static ExternalReference power_double_double_function(Isolate* isolate);
791  static ExternalReference power_double_int_function(Isolate* isolate);
792
793  static ExternalReference handle_scope_next_address(Isolate* isolate);
794  static ExternalReference handle_scope_limit_address(Isolate* isolate);
795  static ExternalReference handle_scope_level_address(Isolate* isolate);
796
797  static ExternalReference scheduled_exception_address(Isolate* isolate);
798  static ExternalReference address_of_pending_message_obj(Isolate* isolate);
799  static ExternalReference address_of_has_pending_message(Isolate* isolate);
800  static ExternalReference address_of_pending_message_script(Isolate* isolate);
801
802  // Static variables containing common double constants.
803  static ExternalReference address_of_min_int();
804  static ExternalReference address_of_one_half();
805  static ExternalReference address_of_minus_one_half();
806  static ExternalReference address_of_minus_zero();
807  static ExternalReference address_of_zero();
808  static ExternalReference address_of_uint8_max_value();
809  static ExternalReference address_of_negative_infinity();
810  static ExternalReference address_of_canonical_non_hole_nan();
811  static ExternalReference address_of_the_hole_nan();
812  static ExternalReference address_of_uint32_bias();
813
814  static ExternalReference math_sin_double_function(Isolate* isolate);
815  static ExternalReference math_cos_double_function(Isolate* isolate);
816  static ExternalReference math_tan_double_function(Isolate* isolate);
817  static ExternalReference math_log_double_function(Isolate* isolate);
818
819  static ExternalReference math_exp_constants(int constant_index);
820  static ExternalReference math_exp_log_table();
821
822  static ExternalReference page_flags(Page* page);
823
824  static ExternalReference ForDeoptEntry(Address entry);
825
826  static ExternalReference cpu_features();
827
828  Address address() const { return reinterpret_cast<Address>(address_); }
829
830#ifdef ENABLE_DEBUGGER_SUPPORT
831  // Function Debug::Break()
832  static ExternalReference debug_break(Isolate* isolate);
833
834  // Used to check if single stepping is enabled in generated code.
835  static ExternalReference debug_step_in_fp_address(Isolate* isolate);
836#endif
837
838#ifndef V8_INTERPRETED_REGEXP
839  // C functions called from RegExp generated code.
840
841  // Function NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16()
842  static ExternalReference re_case_insensitive_compare_uc16(Isolate* isolate);
843
844  // Function RegExpMacroAssembler*::CheckStackGuardState()
845  static ExternalReference re_check_stack_guard_state(Isolate* isolate);
846
847  // Function NativeRegExpMacroAssembler::GrowStack()
848  static ExternalReference re_grow_stack(Isolate* isolate);
849
850  // byte NativeRegExpMacroAssembler::word_character_bitmap
851  static ExternalReference re_word_character_map();
852
853#endif
854
855  // This lets you register a function that rewrites all external references.
856  // Used by the ARM simulator to catch calls to external references.
857  static void set_redirector(Isolate* isolate,
858                             ExternalReferenceRedirector* redirector) {
859    // We can't stack them.
860    ASSERT(isolate->external_reference_redirector() == NULL);
861    isolate->set_external_reference_redirector(
862        reinterpret_cast<ExternalReferenceRedirectorPointer*>(redirector));
863  }
864
865  static ExternalReference stress_deopt_count(Isolate* isolate);
866
867  bool operator==(const ExternalReference& other) const {
868    return address_ == other.address_;
869  }
870
871  bool operator!=(const ExternalReference& other) const {
872    return !(*this == other);
873  }
874
875 private:
876  explicit ExternalReference(void* address)
877      : address_(address) {}
878
879  static void* Redirect(Isolate* isolate,
880                        void* address,
881                        Type type = ExternalReference::BUILTIN_CALL) {
882    ExternalReferenceRedirector* redirector =
883        reinterpret_cast<ExternalReferenceRedirector*>(
884            isolate->external_reference_redirector());
885    if (redirector == NULL) return address;
886    void* answer = (*redirector)(address, type);
887    return answer;
888  }
889
890  static void* Redirect(Isolate* isolate,
891                        Address address_arg,
892                        Type type = ExternalReference::BUILTIN_CALL) {
893    ExternalReferenceRedirector* redirector =
894        reinterpret_cast<ExternalReferenceRedirector*>(
895            isolate->external_reference_redirector());
896    void* address = reinterpret_cast<void*>(address_arg);
897    void* answer = (redirector == NULL) ?
898                   address :
899                   (*redirector)(address, type);
900    return answer;
901  }
902
903  void* address_;
904};
905
906
907// -----------------------------------------------------------------------------
908// Position recording support
909
910struct PositionState {
911  PositionState() : current_position(RelocInfo::kNoPosition),
912                    written_position(RelocInfo::kNoPosition),
913                    current_statement_position(RelocInfo::kNoPosition),
914                    written_statement_position(RelocInfo::kNoPosition) {}
915
916  int current_position;
917  int written_position;
918
919  int current_statement_position;
920  int written_statement_position;
921};
922
923
924class PositionsRecorder BASE_EMBEDDED {
925 public:
926  explicit PositionsRecorder(Assembler* assembler)
927      : assembler_(assembler) {
928#ifdef ENABLE_GDB_JIT_INTERFACE
929    gdbjit_lineinfo_ = NULL;
930#endif
931    jit_handler_data_ = NULL;
932  }
933
934#ifdef ENABLE_GDB_JIT_INTERFACE
935  ~PositionsRecorder() {
936    delete gdbjit_lineinfo_;
937  }
938
939  void StartGDBJITLineInfoRecording() {
940    if (FLAG_gdbjit) {
941      gdbjit_lineinfo_ = new GDBJITLineInfo();
942    }
943  }
944
945  GDBJITLineInfo* DetachGDBJITLineInfo() {
946    GDBJITLineInfo* lineinfo = gdbjit_lineinfo_;
947    gdbjit_lineinfo_ = NULL;  // To prevent deallocation in destructor.
948    return lineinfo;
949  }
950#endif
951  void AttachJITHandlerData(void* user_data) {
952    jit_handler_data_ = user_data;
953  }
954
955  void* DetachJITHandlerData() {
956    void* old_data = jit_handler_data_;
957    jit_handler_data_ = NULL;
958    return old_data;
959  }
960  // Set current position to pos.
961  void RecordPosition(int pos);
962
963  // Set current statement position to pos.
964  void RecordStatementPosition(int pos);
965
966  // Write recorded positions to relocation information.
967  bool WriteRecordedPositions();
968
969  int current_position() const { return state_.current_position; }
970
971  int current_statement_position() const {
972    return state_.current_statement_position;
973  }
974
975 private:
976  Assembler* assembler_;
977  PositionState state_;
978#ifdef ENABLE_GDB_JIT_INTERFACE
979  GDBJITLineInfo* gdbjit_lineinfo_;
980#endif
981
982  // Currently jit_handler_data_ is used to store JITHandler-specific data
983  // over the lifetime of a PositionsRecorder
984  void* jit_handler_data_;
985  friend class PreservePositionScope;
986
987  DISALLOW_COPY_AND_ASSIGN(PositionsRecorder);
988};
989
990
991class PreservePositionScope BASE_EMBEDDED {
992 public:
993  explicit PreservePositionScope(PositionsRecorder* positions_recorder)
994      : positions_recorder_(positions_recorder),
995        saved_state_(positions_recorder->state_) {}
996
997  ~PreservePositionScope() {
998    positions_recorder_->state_ = saved_state_;
999  }
1000
1001 private:
1002  PositionsRecorder* positions_recorder_;
1003  const PositionState saved_state_;
1004
1005  DISALLOW_COPY_AND_ASSIGN(PreservePositionScope);
1006};
1007
1008
1009// -----------------------------------------------------------------------------
1010// Utility functions
1011
1012inline bool is_intn(int x, int n)  {
1013  return -(1 << (n-1)) <= x && x < (1 << (n-1));
1014}
1015
1016inline bool is_int8(int x)  { return is_intn(x, 8); }
1017inline bool is_int16(int x)  { return is_intn(x, 16); }
1018inline bool is_int18(int x)  { return is_intn(x, 18); }
1019inline bool is_int24(int x)  { return is_intn(x, 24); }
1020
1021inline bool is_uintn(int x, int n) {
1022  return (x & -(1 << n)) == 0;
1023}
1024
1025inline bool is_uint2(int x)  { return is_uintn(x, 2); }
1026inline bool is_uint3(int x)  { return is_uintn(x, 3); }
1027inline bool is_uint4(int x)  { return is_uintn(x, 4); }
1028inline bool is_uint5(int x)  { return is_uintn(x, 5); }
1029inline bool is_uint6(int x)  { return is_uintn(x, 6); }
1030inline bool is_uint8(int x)  { return is_uintn(x, 8); }
1031inline bool is_uint10(int x)  { return is_uintn(x, 10); }
1032inline bool is_uint12(int x)  { return is_uintn(x, 12); }
1033inline bool is_uint16(int x)  { return is_uintn(x, 16); }
1034inline bool is_uint24(int x)  { return is_uintn(x, 24); }
1035inline bool is_uint26(int x)  { return is_uintn(x, 26); }
1036inline bool is_uint28(int x)  { return is_uintn(x, 28); }
1037
1038inline int NumberOfBitsSet(uint32_t x) {
1039  unsigned int num_bits_set;
1040  for (num_bits_set = 0; x; x >>= 1) {
1041    num_bits_set += x & 1;
1042  }
1043  return num_bits_set;
1044}
1045
1046bool EvalComparison(Token::Value op, double op1, double op2);
1047
1048// Computes pow(x, y) with the special cases in the spec for Math.pow.
1049double power_helper(double x, double y);
1050double power_double_int(double x, int y);
1051double power_double_double(double x, double y);
1052
1053// Helper class for generating code or data associated with the code
1054// right after a call instruction. As an example this can be used to
1055// generate safepoint data after calls for crankshaft.
1056class CallWrapper {
1057 public:
1058  CallWrapper() { }
1059  virtual ~CallWrapper() { }
1060  // Called just before emitting a call. Argument is the size of the generated
1061  // call code.
1062  virtual void BeforeCall(int call_size) const = 0;
1063  // Called just after emitting a call, i.e., at the return site for the call.
1064  virtual void AfterCall() const = 0;
1065};
1066
1067class NullCallWrapper : public CallWrapper {
1068 public:
1069  NullCallWrapper() { }
1070  virtual ~NullCallWrapper() { }
1071  virtual void BeforeCall(int call_size) const { }
1072  virtual void AfterCall() const { }
1073};
1074
1075} }  // namespace v8::internal
1076
1077#endif  // V8_ASSEMBLER_H_
1078