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 2006-2009 the V8 project authors. All rights reserved. 34 35 #ifndef V8_ASSEMBLER_H_ 36 #define V8_ASSEMBLER_H_ 37 38 #include "runtime.h" 39 #include "top.h" 40 #include "zone-inl.h" 41 #include "token.h" 42 43 namespace v8 { 44 namespace internal { 45 46 47 // ----------------------------------------------------------------------------- 48 // Labels represent pc locations; they are typically jump or call targets. 49 // After declaration, a label can be freely used to denote known or (yet) 50 // unknown pc location. Assembler::bind() is used to bind a label to the 51 // current pc. A label can be bound only once. 52 53 class Label BASE_EMBEDDED { 54 public: 55 INLINE(Label()) { Unuse(); } 56 INLINE(~Label()) { ASSERT(!is_linked()); } 57 58 INLINE(void Unuse()) { pos_ = 0; } 59 60 INLINE(bool is_bound() const) { return pos_ < 0; } 61 INLINE(bool is_unused() const) { return pos_ == 0; } 62 INLINE(bool is_linked() const) { return pos_ > 0; } 63 64 // Returns the position of bound or linked labels. Cannot be used 65 // for unused labels. 66 int pos() const; 67 68 private: 69 // pos_ encodes both the binding state (via its sign) 70 // and the binding position (via its value) of a label. 71 // 72 // pos_ < 0 bound label, pos() returns the jump target position 73 // pos_ == 0 unused label 74 // pos_ > 0 linked label, pos() returns the last reference position 75 int pos_; 76 77 void bind_to(int pos) { 78 pos_ = -pos - 1; 79 ASSERT(is_bound()); 80 } 81 void link_to(int pos) { 82 pos_ = pos + 1; 83 ASSERT(is_linked()); 84 } 85 86 friend class Assembler; 87 friend class RegexpAssembler; 88 friend class Displacement; 89 friend class ShadowTarget; 90 friend class RegExpMacroAssemblerIrregexp; 91 }; 92 93 94 // ----------------------------------------------------------------------------- 95 // Relocation information 96 97 98 // Relocation information consists of the address (pc) of the datum 99 // to which the relocation information applies, the relocation mode 100 // (rmode), and an optional data field. The relocation mode may be 101 // "descriptive" and not indicate a need for relocation, but simply 102 // describe a property of the datum. Such rmodes are useful for GC 103 // and nice disassembly output. 104 105 class RelocInfo BASE_EMBEDDED { 106 public: 107 // The constant kNoPosition is used with the collecting of source positions 108 // in the relocation information. Two types of source positions are collected 109 // "position" (RelocMode position) and "statement position" (RelocMode 110 // statement_position). The "position" is collected at places in the source 111 // code which are of interest when making stack traces to pin-point the source 112 // location of a stack frame as close as possible. The "statement position" is 113 // collected at the beginning at each statement, and is used to indicate 114 // possible break locations. kNoPosition is used to indicate an 115 // invalid/uninitialized position value. 116 static const int kNoPosition = -1; 117 118 enum Mode { 119 // Please note the order is important (see IsCodeTarget, IsGCRelocMode). 120 CONSTRUCT_CALL, // code target that is a call to a JavaScript constructor. 121 CODE_TARGET_CONTEXT, // code target used for contextual loads. 122 DEBUG_BREAK, 123 CODE_TARGET, // code target which is not any of the above. 124 EMBEDDED_OBJECT, 125 EMBEDDED_STRING, 126 127 // Everything after runtime_entry (inclusive) is not GC'ed. 128 RUNTIME_ENTRY, 129 JS_RETURN, // Marks start of the ExitJSFrame code. 130 COMMENT, 131 POSITION, // See comment for kNoPosition above. 132 STATEMENT_POSITION, // See comment for kNoPosition above. 133 EXTERNAL_REFERENCE, // The address of an external C++ function. 134 INTERNAL_REFERENCE, // An address inside the same function. 135 136 // add more as needed 137 // Pseudo-types 138 NUMBER_OF_MODES, // must be no greater than 14 - see RelocInfoWriter 139 NONE, // never recorded 140 LAST_CODE_ENUM = CODE_TARGET, 141 LAST_GCED_ENUM = EMBEDDED_STRING 142 }; 143 144 145 RelocInfo() {} 146 RelocInfo(byte* pc, Mode rmode, intptr_t data) 147 : pc_(pc), rmode_(rmode), data_(data) { 148 } 149 150 static inline bool IsConstructCall(Mode mode) { 151 return mode == CONSTRUCT_CALL; 152 } 153 static inline bool IsCodeTarget(Mode mode) { 154 return mode <= LAST_CODE_ENUM; 155 } 156 // Is the relocation mode affected by GC? 157 static inline bool IsGCRelocMode(Mode mode) { 158 return mode <= LAST_GCED_ENUM; 159 } 160 static inline bool IsJSReturn(Mode mode) { 161 return mode == JS_RETURN; 162 } 163 static inline bool IsComment(Mode mode) { 164 return mode == COMMENT; 165 } 166 static inline bool IsPosition(Mode mode) { 167 return mode == POSITION || mode == STATEMENT_POSITION; 168 } 169 static inline bool IsStatementPosition(Mode mode) { 170 return mode == STATEMENT_POSITION; 171 } 172 static inline bool IsExternalReference(Mode mode) { 173 return mode == EXTERNAL_REFERENCE; 174 } 175 static inline bool IsInternalReference(Mode mode) { 176 return mode == INTERNAL_REFERENCE; 177 } 178 static inline int ModeMask(Mode mode) { return 1 << mode; } 179 180 // Accessors 181 byte* pc() const { return pc_; } 182 void set_pc(byte* pc) { pc_ = pc; } 183 Mode rmode() const { return rmode_; } 184 intptr_t data() const { return data_; } 185 186 // Apply a relocation by delta bytes 187 INLINE(void apply(intptr_t delta)); 188 189 // Read/modify the code target in the branch/call instruction 190 // this relocation applies to; 191 // can only be called if IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY 192 INLINE(Address target_address()); 193 INLINE(void set_target_address(Address target)); 194 INLINE(Object* target_object()); 195 INLINE(Handle<Object> target_object_handle(Assembler* origin)); 196 INLINE(Object** target_object_address()); 197 INLINE(void set_target_object(Object* target)); 198 199 // Read the address of the word containing the target_address. Can only 200 // be called if IsCodeTarget(rmode_) || rmode_ == RUNTIME_ENTRY. 201 INLINE(Address target_address_address()); 202 203 // Read/modify the reference in the instruction this relocation 204 // applies to; can only be called if rmode_ is external_reference 205 INLINE(Address* target_reference_address()); 206 207 // Read/modify the address of a call instruction. This is used to relocate 208 // the break points where straight-line code is patched with a call 209 // instruction. 210 INLINE(Address call_address()); 211 INLINE(void set_call_address(Address target)); 212 INLINE(Object* call_object()); 213 INLINE(Object** call_object_address()); 214 INLINE(void set_call_object(Object* target)); 215 216 // Patch the code with some other code. 217 void PatchCode(byte* instructions, int instruction_count); 218 219 // Patch the code with a call. 220 void PatchCodeWithCall(Address target, int guard_bytes); 221 222 // Check whether this return sequence has been patched 223 // with a call to the debugger. 224 INLINE(bool IsPatchedReturnSequence()); 225 226 #ifdef ENABLE_DISASSEMBLER 227 // Printing 228 static const char* RelocModeName(Mode rmode); 229 void Print(); 230 #endif // ENABLE_DISASSEMBLER 231 #ifdef DEBUG 232 // Debugging 233 void Verify(); 234 #endif 235 236 static const int kCodeTargetMask = (1 << (LAST_CODE_ENUM + 1)) - 1; 237 static const int kPositionMask = 1 << POSITION | 1 << STATEMENT_POSITION; 238 static const int kDebugMask = kPositionMask | 1 << COMMENT; 239 static const int kApplyMask; // Modes affected by apply. Depends on arch. 240 241 private: 242 // On ARM, note that pc_ is the address of the constant pool entry 243 // to be relocated and not the address of the instruction 244 // referencing the constant pool entry (except when rmode_ == 245 // comment). 246 byte* pc_; 247 Mode rmode_; 248 intptr_t data_; 249 friend class RelocIterator; 250 }; 251 252 253 // RelocInfoWriter serializes a stream of relocation info. It writes towards 254 // lower addresses. 255 class RelocInfoWriter BASE_EMBEDDED { 256 public: 257 RelocInfoWriter() : pos_(NULL), last_pc_(NULL), last_data_(0) {} 258 RelocInfoWriter(byte* pos, byte* pc) : pos_(pos), last_pc_(pc), 259 last_data_(0) {} 260 261 byte* pos() const { return pos_; } 262 byte* last_pc() const { return last_pc_; } 263 264 void Write(const RelocInfo* rinfo); 265 266 // Update the state of the stream after reloc info buffer 267 // and/or code is moved while the stream is active. 268 void Reposition(byte* pos, byte* pc) { 269 pos_ = pos; 270 last_pc_ = pc; 271 } 272 273 // Max size (bytes) of a written RelocInfo. Longest encoding is 274 // ExtraTag, VariableLengthPCJump, ExtraTag, pc_delta, ExtraTag, data_delta. 275 // On ia32 and arm this is 1 + 4 + 1 + 1 + 1 + 4 = 12. 276 // On x64 this is 1 + 4 + 1 + 1 + 1 + 8 == 16; 277 // Here we use the maximum of the two. 278 static const int kMaxSize = 16; 279 280 private: 281 inline uint32_t WriteVariableLengthPCJump(uint32_t pc_delta); 282 inline void WriteTaggedPC(uint32_t pc_delta, int tag); 283 inline void WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag); 284 inline void WriteExtraTaggedData(intptr_t data_delta, int top_tag); 285 inline void WriteTaggedData(intptr_t data_delta, int tag); 286 inline void WriteExtraTag(int extra_tag, int top_tag); 287 288 byte* pos_; 289 byte* last_pc_; 290 intptr_t last_data_; 291 DISALLOW_COPY_AND_ASSIGN(RelocInfoWriter); 292 }; 293 294 295 // A RelocIterator iterates over relocation information. 296 // Typical use: 297 // 298 // for (RelocIterator it(code); !it.done(); it.next()) { 299 // // do something with it.rinfo() here 300 // } 301 // 302 // A mask can be specified to skip unwanted modes. 303 class RelocIterator: public Malloced { 304 public: 305 // Create a new iterator positioned at 306 // the beginning of the reloc info. 307 // Relocation information with mode k is included in the 308 // iteration iff bit k of mode_mask is set. 309 explicit RelocIterator(Code* code, int mode_mask = -1); 310 explicit RelocIterator(const CodeDesc& desc, int mode_mask = -1); 311 312 // Iteration 313 bool done() const { return done_; } 314 void next(); 315 316 // Return pointer valid until next next(). 317 RelocInfo* rinfo() { 318 ASSERT(!done()); 319 return &rinfo_; 320 } 321 322 private: 323 // Advance* moves the position before/after reading. 324 // *Read* reads from current byte(s) into rinfo_. 325 // *Get* just reads and returns info on current byte. 326 void Advance(int bytes = 1) { pos_ -= bytes; } 327 int AdvanceGetTag(); 328 int GetExtraTag(); 329 int GetTopTag(); 330 void ReadTaggedPC(); 331 void AdvanceReadPC(); 332 void AdvanceReadData(); 333 void AdvanceReadVariableLengthPCJump(); 334 int GetPositionTypeTag(); 335 void ReadTaggedData(); 336 337 static RelocInfo::Mode DebugInfoModeFromTag(int tag); 338 339 // If the given mode is wanted, set it in rinfo_ and return true. 340 // Else return false. Used for efficiently skipping unwanted modes. 341 bool SetMode(RelocInfo::Mode mode) { 342 return (mode_mask_ & 1 << mode) ? (rinfo_.rmode_ = mode, true) : false; 343 } 344 345 byte* pos_; 346 byte* end_; 347 RelocInfo rinfo_; 348 bool done_; 349 int mode_mask_; 350 DISALLOW_COPY_AND_ASSIGN(RelocIterator); 351 }; 352 353 354 //------------------------------------------------------------------------------ 355 // External function 356 357 //---------------------------------------------------------------------------- 358 class IC_Utility; 359 class SCTableReference; 360 #ifdef ENABLE_DEBUGGER_SUPPORT 361 class Debug_Address; 362 #endif 363 364 365 typedef void* ExternalReferenceRedirector(void* original, bool fp_return); 366 367 368 // An ExternalReference represents a C++ address used in the generated 369 // code. All references to C++ functions and variables must be encapsulated in 370 // an ExternalReference instance. This is done in order to track the origin of 371 // all external references in the code so that they can be bound to the correct 372 // addresses when deserializing a heap. 373 class ExternalReference BASE_EMBEDDED { 374 public: 375 explicit ExternalReference(Builtins::CFunctionId id); 376 377 explicit ExternalReference(ApiFunction* ptr); 378 379 explicit ExternalReference(Builtins::Name name); 380 381 explicit ExternalReference(Runtime::FunctionId id); 382 383 explicit ExternalReference(Runtime::Function* f); 384 385 explicit ExternalReference(const IC_Utility& ic_utility); 386 387 #ifdef ENABLE_DEBUGGER_SUPPORT 388 explicit ExternalReference(const Debug_Address& debug_address); 389 #endif 390 391 explicit ExternalReference(StatsCounter* counter); 392 393 explicit ExternalReference(Top::AddressId id); 394 395 explicit ExternalReference(const SCTableReference& table_ref); 396 397 // One-of-a-kind references. These references are not part of a general 398 // pattern. This means that they have to be added to the 399 // ExternalReferenceTable in serialize.cc manually. 400 401 static ExternalReference perform_gc_function(); 402 static ExternalReference random_positive_smi_function(); 403 static ExternalReference transcendental_cache_array_address(); 404 405 // Static data in the keyed lookup cache. 406 static ExternalReference keyed_lookup_cache_keys(); 407 static ExternalReference keyed_lookup_cache_field_offsets(); 408 409 // Static variable Factory::the_hole_value.location() 410 static ExternalReference the_hole_value_location(); 411 412 // Static variable Heap::roots_address() 413 static ExternalReference roots_address(); 414 415 // Static variable StackGuard::address_of_jslimit() 416 static ExternalReference address_of_stack_limit(); 417 418 // Static variable StackGuard::address_of_real_jslimit() 419 static ExternalReference address_of_real_stack_limit(); 420 421 // Static variable RegExpStack::limit_address() 422 static ExternalReference address_of_regexp_stack_limit(); 423 424 // Static variables for RegExp. 425 static ExternalReference address_of_static_offsets_vector(); 426 static ExternalReference address_of_regexp_stack_memory_address(); 427 static ExternalReference address_of_regexp_stack_memory_size(); 428 429 // Static variable Heap::NewSpaceStart() 430 static ExternalReference new_space_start(); 431 static ExternalReference new_space_mask(); 432 static ExternalReference heap_always_allocate_scope_depth(); 433 434 // Used for fast allocation in generated code. 435 static ExternalReference new_space_allocation_top_address(); 436 static ExternalReference new_space_allocation_limit_address(); 437 438 static ExternalReference double_fp_operation(Token::Value operation); 439 static ExternalReference compare_doubles(); 440 441 static ExternalReference handle_scope_extensions_address(); 442 static ExternalReference handle_scope_next_address(); 443 static ExternalReference handle_scope_limit_address(); 444 445 static ExternalReference scheduled_exception_address(); 446 447 Address address() const {return reinterpret_cast<Address>(address_);} 448 449 #ifdef ENABLE_DEBUGGER_SUPPORT 450 // Function Debug::Break() 451 static ExternalReference debug_break(); 452 453 // Used to check if single stepping is enabled in generated code. 454 static ExternalReference debug_step_in_fp_address(); 455 #endif 456 457 #ifdef V8_NATIVE_REGEXP 458 // C functions called from RegExp generated code. 459 460 // Function NativeRegExpMacroAssembler::CaseInsensitiveCompareUC16() 461 static ExternalReference re_case_insensitive_compare_uc16(); 462 463 // Function RegExpMacroAssembler*::CheckStackGuardState() 464 static ExternalReference re_check_stack_guard_state(); 465 466 // Function NativeRegExpMacroAssembler::GrowStack() 467 static ExternalReference re_grow_stack(); 468 469 // byte NativeRegExpMacroAssembler::word_character_bitmap 470 static ExternalReference re_word_character_map(); 471 472 #endif 473 474 // This lets you register a function that rewrites all external references. 475 // Used by the ARM simulator to catch calls to external references. 476 static void set_redirector(ExternalReferenceRedirector* redirector) { 477 ASSERT(redirector_ == NULL); // We can't stack them. 478 redirector_ = redirector; 479 } 480 481 private: 482 explicit ExternalReference(void* address) 483 : address_(address) {} 484 485 static ExternalReferenceRedirector* redirector_; 486 487 static void* Redirect(void* address, bool fp_return = false) { 488 if (redirector_ == NULL) return address; 489 void* answer = (*redirector_)(address, fp_return); 490 return answer; 491 } 492 493 static void* Redirect(Address address_arg, bool fp_return = false) { 494 void* address = reinterpret_cast<void*>(address_arg); 495 void* answer = (redirector_ == NULL) ? 496 address : 497 (*redirector_)(address, fp_return); 498 return answer; 499 } 500 501 void* address_; 502 }; 503 504 505 // ----------------------------------------------------------------------------- 506 // Utility functions 507 508 static inline bool is_intn(int x, int n) { 509 return -(1 << (n-1)) <= x && x < (1 << (n-1)); 510 } 511 512 static inline bool is_int8(int x) { return is_intn(x, 8); } 513 static inline bool is_int16(int x) { return is_intn(x, 16); } 514 static inline bool is_int18(int x) { return is_intn(x, 18); } 515 static inline bool is_int24(int x) { return is_intn(x, 24); } 516 517 static inline bool is_uintn(int x, int n) { 518 return (x & -(1 << n)) == 0; 519 } 520 521 static inline bool is_uint2(int x) { return is_uintn(x, 2); } 522 static inline bool is_uint3(int x) { return is_uintn(x, 3); } 523 static inline bool is_uint4(int x) { return is_uintn(x, 4); } 524 static inline bool is_uint5(int x) { return is_uintn(x, 5); } 525 static inline bool is_uint6(int x) { return is_uintn(x, 6); } 526 static inline bool is_uint8(int x) { return is_uintn(x, 8); } 527 static inline bool is_uint10(int x) { return is_uintn(x, 10); } 528 static inline bool is_uint12(int x) { return is_uintn(x, 12); } 529 static inline bool is_uint16(int x) { return is_uintn(x, 16); } 530 static inline bool is_uint24(int x) { return is_uintn(x, 24); } 531 static inline bool is_uint26(int x) { return is_uintn(x, 26); } 532 static inline bool is_uint28(int x) { return is_uintn(x, 28); } 533 534 static inline int NumberOfBitsSet(uint32_t x) { 535 unsigned int num_bits_set; 536 for (num_bits_set = 0; x; x >>= 1) { 537 num_bits_set += x & 1; 538 } 539 return num_bits_set; 540 } 541 542 } } // namespace v8::internal 543 544 #endif // V8_ASSEMBLER_H_ 545
