// Copyright (c) 1994-2006 Sun Microsystems Inc. // All Rights Reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // - Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // // - Redistribution in binary form must reproduce the above copyright // notice, this list of conditions and the following disclaimer in the // documentation and/or other materials provided with the distribution. // // - Neither the name of Sun Microsystems or the names of contributors may // be used to endorse or promote products derived from this software without // specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS // IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, // THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // The original source code covered by the above license above has been // modified significantly by Google Inc. // Copyright 2006-2009 the V8 project authors. All rights reserved. #ifndef V8_ASSEMBLER_H_ #define V8_ASSEMBLER_H_ #include "runtime.h" #include "top.h" #include "token.h" namespace v8 { namespace internal { // ----------------------------------------------------------------------------- // Common double constants. class DoubleConstant: public AllStatic { public: static const double min_int; static const double one_half; static const double negative_infinity; }; // ----------------------------------------------------------------------------- // Labels represent pc locations; they are typically jump or call targets. // After declaration, a label can be freely used to denote known or (yet) // unknown pc location. Assembler::bind() is used to bind a label to the // current pc. A label can be bound only once. class Label BASE_EMBEDDED { public: INLINE(Label()) { Unuse(); } INLINE(~Label()) { ASSERT(!is_linked()); } INLINE(void Unuse()) { pos_ = 0; } INLINE(bool is_bound() const) { return pos_ < 0; } INLINE(bool is_unused() const) { return pos_ == 0; } INLINE(bool is_linked() const) { return pos_ > 0; } // Returns the position of bound or linked labels. Cannot be used // for unused labels. int pos() const; private: // pos_ encodes both the binding state (via its sign) // and the binding position (via its value) of a label. // // pos_ < 0 bound label, pos() returns the jump target position // pos_ == 0 unused label // pos_ > 0 linked label, pos() returns the last reference position int pos_; void bind_to(int pos) { pos_ = -pos - 1; ASSERT(is_bound()); } void link_to(int pos) { pos_ = pos + 1; ASSERT(is_linked()); } friend class Assembler; friend class RegexpAssembler; friend class Displacement; friend class ShadowTarget; friend class RegExpMacroAssemblerIrregexp; }; // ----------------------------------------------------------------------------- // NearLabels are labels used for short jumps (in Intel jargon). // NearLabels should be used if it can be guaranteed that the jump range is // within -128 to +127. We already use short jumps when jumping backwards, // so using a NearLabel will only have performance impact if used for forward // jumps. class NearLabel BASE_EMBEDDED { public: NearLabel() { Unuse(); } ~NearLabel() { ASSERT(!is_linked()); } void Unuse() { pos_ = -1; unresolved_branches_ = 0; #ifdef DEBUG for (int i = 0; i < kMaxUnresolvedBranches; i++) { unresolved_positions_[i] = -1; } #endif } int pos() { ASSERT(is_bound()); return pos_; } bool is_bound() { return pos_ >= 0; } bool is_linked() { return !is_bound() && unresolved_branches_ > 0; } bool is_unused() { return !is_bound() && unresolved_branches_ == 0; } void bind_to(int position) { ASSERT(!is_bound()); pos_ = position; } void link_to(int position) { ASSERT(!is_bound()); ASSERT(unresolved_branches_ < kMaxUnresolvedBranches); unresolved_positions_[unresolved_branches_++] = position; } private: static const int kMaxUnresolvedBranches = 8; int pos_; int unresolved_branches_; int unresolved_positions_[kMaxUnresolvedBranches]; friend class Assembler; }; // ----------------------------------------------------------------------------- // Relocation information // Relocation information consists of the address (pc) of the datum // to which the relocation information applies, the relocation mode // (rmode), and an optional data field. The relocation mode may be // "descriptive" and not indicate a need for relocation, but simply // describe a property of the datum. Such rmodes are useful for GC // and nice disassembly output. class RelocInfo BASE_EMBEDDED { public: // The constant kNoPosition is used with the collecting of source positions // in the relocation information. Two types of source positions are collected // "position" (RelocMode position) and "statement position" (RelocMode // statement_position). The "position" is collected at places in the source // code which are of interest when making stack traces to pin-point the source // location of a stack frame as close as possible. The "statement position" is // collected at the beginning at each statement, and is used to indicate // possible break locations. kNoPosition is used to indicate an // invalid/uninitialized position value. static const int kNoPosition = -1; enum Mode { // Please note the order is important (see IsCodeTarget, IsGCRelocMode). CONSTRUCT_CALL, // code target that is a call to a JavaScript constructor. CODE_TARGET_CONTEXT, // Code target used for contextual loads. DEBUG_BREAK, // Code target for the debugger statement. CODE_TARGET, // Code target which is not any of the above. EMBEDDED_OBJECT, GLOBAL_PROPERTY_CELL, // Everything after runtime_entry (inclusive) is not GC'ed. RUNTIME_ENTRY, JS_RETURN, // Marks start of the ExitJSFrame code. COMMENT, POSITION, // See comment for kNoPosition above. STATEMENT_POSITION, // See comment for kNoPosition above. DEBUG_BREAK_SLOT, // Additional code inserted for debug break slot. EXTERNAL_REFERENCE, // The address of an external C++ function. INTERNAL_REFERENCE, // An address inside the same function. // add more as needed // Pseudo-types NUMBER_OF_MODES, // must be no greater than 14 - see RelocInfoWriter NONE, // never recorded LAST_CODE_ENUM = CODE_TARGET, LAST_GCED_ENUM = EMBEDDED_OBJECT }; RelocInfo() {} RelocInfo(byte* pc, Mode rmode, intptr_t data) : pc_(pc), rmode_(rmode), data_(data) { } static inline bool IsConstructCall(Mode mode) { return mode == CONSTRUCT_CALL; } static inline bool IsCodeTarget(Mode mode) { return mode <= LAST_CODE_ENUM; } // Is the relocation mode affected by GC? static inline bool IsGCRelocMode(Mode mode) { return mode <= LAST_GCED_ENUM; } static inline bool IsJSReturn(Mode mode) { return mode == JS_RETURN; } static inline bool IsComment(Mode mode) { return mode == COMMENT; } static inline bool IsPosition(Mode mode) { return mode == POSITION || mode == STATEMENT_POSITION; } static inline bool IsStatementPosition(Mode mode) { return mode == STATEMENT_POSITION; } static inline bool IsExternalReference(Mode mode) { return mode == EXTERNAL_REFERENCE; } static inline bool IsInternalReference(Mode mode) { return mode == INTERNAL_REFERENCE; } static inline bool IsDebugBreakSlot(Mode mode) { return mode == DEBUG_BREAK_SLOT; } static inline int ModeMask(Mode mode) { return 1 << mode; } // Accessors byte* pc() const { return pc_; } void set_pc(byte* pc) { pc_ = pc; } Mode rmode() const { return rmode_; } intptr_t data() const { return data_; } // Apply a relocation by delta bytes INLINE(void apply(intptr_t delta)); // Is the pointer this relocation info refers to coded like a plain pointer // or is it strange in some way (eg relative or patched into a series of // instructions). bool IsCodedSpecially(); // Read/modify the code target in the branch/call instruction // this relocation applies to; // can only be called if IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY INLINE(Address target_address()); INLINE(void set_target_address(Address target)); INLINE(Object* target_object()); INLINE(Handle target_object_handle(Assembler* origin)); INLINE(Object** target_object_address()); INLINE(void set_target_object(Object* target)); INLINE(JSGlobalPropertyCell* target_cell()); INLINE(Handle target_cell_handle()); INLINE(void set_target_cell(JSGlobalPropertyCell* cell)); // Read the address of the word containing the target_address in an // instruction stream. What this means exactly is architecture-independent. // The only architecture-independent user of this function is the serializer. // The serializer uses it to find out how many raw bytes of instruction to // output before the next target. Architecture-independent code shouldn't // dereference the pointer it gets back from this. INLINE(Address target_address_address()); // This indicates how much space a target takes up when deserializing a code // stream. For most architectures this is just the size of a pointer. For // an instruction like movw/movt where the target bits are mixed into the // instruction bits the size of the target will be zero, indicating that the // serializer should not step forwards in memory after a target is resolved // and written. In this case the target_address_address function above // should return the end of the instructions to be patched, allowing the // deserializer to deserialize the instructions as raw bytes and put them in // place, ready to be patched with the target. INLINE(int target_address_size()); // Read/modify the reference in the instruction this relocation // applies to; can only be called if rmode_ is external_reference INLINE(Address* target_reference_address()); // Read/modify the address of a call instruction. This is used to relocate // the break points where straight-line code is patched with a call // instruction. INLINE(Address call_address()); INLINE(void set_call_address(Address target)); INLINE(Object* call_object()); INLINE(void set_call_object(Object* target)); INLINE(Object** call_object_address()); template inline void Visit(); inline void Visit(ObjectVisitor* v); // Patch the code with some other code. void PatchCode(byte* instructions, int instruction_count); // Patch the code with a call. void PatchCodeWithCall(Address target, int guard_bytes); // Check whether this return sequence has been patched // with a call to the debugger. INLINE(bool IsPatchedReturnSequence()); // Check whether this debug break slot has been patched with a call to the // debugger. INLINE(bool IsPatchedDebugBreakSlotSequence()); #ifdef ENABLE_DISASSEMBLER // Printing static const char* RelocModeName(Mode rmode); void Print(FILE* out); #endif // ENABLE_DISASSEMBLER #ifdef DEBUG // Debugging void Verify(); #endif static const int kCodeTargetMask = (1 << (LAST_CODE_ENUM + 1)) - 1; static const int kPositionMask = 1 << POSITION | 1 << STATEMENT_POSITION; static const int kDebugMask = kPositionMask | 1 << COMMENT; static const int kApplyMask; // Modes affected by apply. Depends on arch. private: // On ARM, note that pc_ is the address of the constant pool entry // to be relocated and not the address of the instruction // referencing the constant pool entry (except when rmode_ == // comment). byte* pc_; Mode rmode_; intptr_t data_; friend class RelocIterator; }; // RelocInfoWriter serializes a stream of relocation info. It writes towards // lower addresses. class RelocInfoWriter BASE_EMBEDDED { public: RelocInfoWriter() : pos_(NULL), last_pc_(NULL), last_data_(0) {} RelocInfoWriter(byte* pos, byte* pc) : pos_(pos), last_pc_(pc), last_data_(0) {} byte* pos() const { return pos_; } byte* last_pc() const { return last_pc_; } void Write(const RelocInfo* rinfo); // Update the state of the stream after reloc info buffer // and/or code is moved while the stream is active. void Reposition(byte* pos, byte* pc) { pos_ = pos; last_pc_ = pc; } // Max size (bytes) of a written RelocInfo. Longest encoding is // ExtraTag, VariableLengthPCJump, ExtraTag, pc_delta, ExtraTag, data_delta. // On ia32 and arm this is 1 + 4 + 1 + 1 + 1 + 4 = 12. // On x64 this is 1 + 4 + 1 + 1 + 1 + 8 == 16; // Here we use the maximum of the two. static const int kMaxSize = 16; private: inline uint32_t WriteVariableLengthPCJump(uint32_t pc_delta); inline void WriteTaggedPC(uint32_t pc_delta, int tag); inline void WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag); inline void WriteExtraTaggedData(intptr_t data_delta, int top_tag); inline void WriteTaggedData(intptr_t data_delta, int tag); inline void WriteExtraTag(int extra_tag, int top_tag); byte* pos_; byte* last_pc_; intptr_t last_data_; DISALLOW_COPY_AND_ASSIGN(RelocInfoWriter); }; // A RelocIterator iterates over relocation information. // Typical use: // // for (RelocIterator it(code); !it.done(); it.next()) { // // do something with it.rinfo() here // } // // A mask can be specified to skip unwanted modes. class RelocIterator: public Malloced { public: // Create a new iterator positioned at // the beginning of the reloc info. // Relocation information with mode k is included in the // iteration iff bit k of mode_mask is set. explicit RelocIterator(Code* code, int mode_mask = -1); explicit RelocIterator(const CodeDesc& desc, int mode_mask = -1); // Iteration bool done() const { return done_; } void next(); // Return pointer valid until next next(). RelocInfo* rinfo() { ASSERT(!done()); return &rinfo_; } private: // Advance* moves the position before/after reading. // *Read* reads from current byte(s) into rinfo_. // *Get* just reads and returns info on current byte. void Advance(int bytes = 1) { pos_ -= bytes; } int AdvanceGetTag(); int GetExtraTag(); int GetTopTag(); void ReadTaggedPC(); void AdvanceReadPC(); void AdvanceReadData(); void AdvanceReadVariableLengthPCJump(); int GetPositionTypeTag(); void ReadTaggedData(); static RelocInfo::Mode DebugInfoModeFromTag(int tag); // If the given mode is wanted, set it in rinfo_ and return true. // Else return false. Used for efficiently skipping unwanted modes. bool SetMode(RelocInfo::Mode mode) { return (mode_mask_ & (1 << mode)) ? (rinfo_.rmode_ = mode, true) : false; } byte* pos_; byte* end_; RelocInfo rinfo_; bool done_; int mode_mask_; DISALLOW_COPY_AND_ASSIGN(RelocIterator); }; //------------------------------------------------------------------------------ // External function //---------------------------------------------------------------------------- class IC_Utility; class SCTableReference; #ifdef ENABLE_DEBUGGER_SUPPORT class Debug_Address; #endif typedef void* ExternalReferenceRedirector(void* original, bool fp_return); // An ExternalReference represents a C++ address used in the generated // code. All references to C++ functions and variables must be encapsulated in // an ExternalReference instance. This is done in order to track the origin of // all external references in the code so that they can be bound to the correct // addresses when deserializing a heap. class ExternalReference BASE_EMBEDDED { public: explicit ExternalReference(Builtins::CFunctionId id); explicit ExternalReference(ApiFunction* ptr); explicit ExternalReference(Builtins::Name name); explicit ExternalReference(Runtime::FunctionId id); explicit ExternalReference(Runtime::Function* f); explicit ExternalReference(const IC_Utility& ic_utility); #ifdef ENABLE_DEBUGGER_SUPPORT explicit ExternalReference(const Debug_Address& debug_address); #endif explicit ExternalReference(StatsCounter* counter); explicit ExternalReference(Top::AddressId id); explicit ExternalReference(const SCTableReference& table_ref); // One-of-a-kind references. These references are not part of a general // pattern. This means that they have to be added to the // ExternalReferenceTable in serialize.cc manually. static ExternalReference perform_gc_function(); static ExternalReference fill_heap_number_with_random_function(); static ExternalReference random_uint32_function(); static ExternalReference transcendental_cache_array_address(); static ExternalReference delete_handle_scope_extensions(); // Deoptimization support. static ExternalReference new_deoptimizer_function(); static ExternalReference compute_output_frames_function(); static ExternalReference global_contexts_list(); // Static data in the keyed lookup cache. static ExternalReference keyed_lookup_cache_keys(); static ExternalReference keyed_lookup_cache_field_offsets(); // Static variable Factory::the_hole_value.location() static ExternalReference the_hole_value_location(); // Static variable Heap::roots_address() static ExternalReference roots_address(); // Static variable StackGuard::address_of_jslimit() static ExternalReference address_of_stack_limit(); // Static variable StackGuard::address_of_real_jslimit() static ExternalReference address_of_real_stack_limit(); // Static variable RegExpStack::limit_address() static ExternalReference address_of_regexp_stack_limit(); // Static variables for RegExp. static ExternalReference address_of_static_offsets_vector(); static ExternalReference address_of_regexp_stack_memory_address(); static ExternalReference address_of_regexp_stack_memory_size(); // Static variable Heap::NewSpaceStart() static ExternalReference new_space_start(); static ExternalReference new_space_mask(); static ExternalReference heap_always_allocate_scope_depth(); // Used for fast allocation in generated code. static ExternalReference new_space_allocation_top_address(); static ExternalReference new_space_allocation_limit_address(); static ExternalReference double_fp_operation(Token::Value operation); static ExternalReference compare_doubles(); static ExternalReference power_double_double_function(); static ExternalReference power_double_int_function(); static ExternalReference handle_scope_next_address(); static ExternalReference handle_scope_limit_address(); static ExternalReference handle_scope_level_address(); static ExternalReference scheduled_exception_address(); // Static variables containing common double constants. static ExternalReference address_of_min_int(); static ExternalReference address_of_one_half(); static ExternalReference address_of_negative_infinity(); Address address() const {return reinterpret_cast
(address_);} #ifdef ENABLE_DEBUGGER_SUPPORT // Function Debug::Break() static ExternalReference debug_break(); // Used to check if single stepping is enabled in generated code. static ExternalReference debug_step_in_fp_address(); #endif #ifndef V8_INTERPRETED_REGEXP // C functions called from RegExp generated code. // Function NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16() static ExternalReference re_case_insensitive_compare_uc16(); // Function RegExpMacroAssembler*::CheckStackGuardState() static ExternalReference re_check_stack_guard_state(); // Function NativeRegExpMacroAssembler::GrowStack() static ExternalReference re_grow_stack(); // byte NativeRegExpMacroAssembler::word_character_bitmap static ExternalReference re_word_character_map(); #endif // This lets you register a function that rewrites all external references. // Used by the ARM simulator to catch calls to external references. static void set_redirector(ExternalReferenceRedirector* redirector) { ASSERT(redirector_ == NULL); // We can't stack them. redirector_ = redirector; } private: explicit ExternalReference(void* address) : address_(address) {} static ExternalReferenceRedirector* redirector_; static void* Redirect(void* address, bool fp_return = false) { if (redirector_ == NULL) return address; void* answer = (*redirector_)(address, fp_return); return answer; } static void* Redirect(Address address_arg, bool fp_return = false) { void* address = reinterpret_cast(address_arg); void* answer = (redirector_ == NULL) ? address : (*redirector_)(address, fp_return); return answer; } void* address_; }; // ----------------------------------------------------------------------------- // Position recording support struct PositionState { PositionState() : current_position(RelocInfo::kNoPosition), written_position(RelocInfo::kNoPosition), current_statement_position(RelocInfo::kNoPosition), written_statement_position(RelocInfo::kNoPosition) {} int current_position; int written_position; int current_statement_position; int written_statement_position; }; class PositionsRecorder BASE_EMBEDDED { public: explicit PositionsRecorder(Assembler* assembler) : assembler_(assembler) {} // Set current position to pos. void RecordPosition(int pos); // Set current statement position to pos. void RecordStatementPosition(int pos); // Write recorded positions to relocation information. bool WriteRecordedPositions(); int current_position() const { return state_.current_position; } int current_statement_position() const { return state_.current_statement_position; } private: Assembler* assembler_; PositionState state_; friend class PreservePositionScope; DISALLOW_COPY_AND_ASSIGN(PositionsRecorder); }; class PreservePositionScope BASE_EMBEDDED { public: explicit PreservePositionScope(PositionsRecorder* positions_recorder) : positions_recorder_(positions_recorder), saved_state_(positions_recorder->state_) {} ~PreservePositionScope() { positions_recorder_->state_ = saved_state_; } private: PositionsRecorder* positions_recorder_; const PositionState saved_state_; DISALLOW_COPY_AND_ASSIGN(PreservePositionScope); }; // ----------------------------------------------------------------------------- // Utility functions static inline bool is_intn(int x, int n) { return -(1 << (n-1)) <= x && x < (1 << (n-1)); } static inline bool is_int8(int x) { return is_intn(x, 8); } static inline bool is_int16(int x) { return is_intn(x, 16); } static inline bool is_int18(int x) { return is_intn(x, 18); } static inline bool is_int24(int x) { return is_intn(x, 24); } static inline bool is_uintn(int x, int n) { return (x & -(1 << n)) == 0; } static inline bool is_uint2(int x) { return is_uintn(x, 2); } static inline bool is_uint3(int x) { return is_uintn(x, 3); } static inline bool is_uint4(int x) { return is_uintn(x, 4); } static inline bool is_uint5(int x) { return is_uintn(x, 5); } static inline bool is_uint6(int x) { return is_uintn(x, 6); } static inline bool is_uint8(int x) { return is_uintn(x, 8); } static inline bool is_uint10(int x) { return is_uintn(x, 10); } static inline bool is_uint12(int x) { return is_uintn(x, 12); } static inline bool is_uint16(int x) { return is_uintn(x, 16); } static inline bool is_uint24(int x) { return is_uintn(x, 24); } static inline bool is_uint26(int x) { return is_uintn(x, 26); } static inline bool is_uint28(int x) { return is_uintn(x, 28); } static inline int NumberOfBitsSet(uint32_t x) { unsigned int num_bits_set; for (num_bits_set = 0; x; x >>= 1) { num_bits_set += x & 1; } return num_bits_set; } // Computes pow(x, y) with the special cases in the spec for Math.pow. double power_double_int(double x, int y); double power_double_double(double x, double y); } } // namespace v8::internal #endif // V8_ASSEMBLER_H_