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:
INLINE(Label ())55 INLINE(Label()) { Unuse(); }
INLINE(~Label ())56 INLINE(~Label()) { ASSERT(!is_linked()); }
57
INLINE(void Unuse ())58 INLINE(void Unuse()) { pos_ = 0; }
59
INLINE(bool is_bound ()const)60 INLINE(bool is_bound() const) { return pos_ < 0; }
INLINE(bool is_unused ()const)61 INLINE(bool is_unused() const) { return pos_ == 0; }
INLINE(bool is_linked ()const)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
bind_to(int pos)77 void bind_to(int pos) {
78 pos_ = -pos - 1;
79 ASSERT(is_bound());
80 }
link_to(int pos)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
RelocInfo()145 RelocInfo() {}
RelocInfo(byte * pc,Mode rmode,intptr_t data)146 RelocInfo(byte* pc, Mode rmode, intptr_t data)
147 : pc_(pc), rmode_(rmode), data_(data) {
148 }
149
IsConstructCall(Mode mode)150 static inline bool IsConstructCall(Mode mode) {
151 return mode == CONSTRUCT_CALL;
152 }
IsCodeTarget(Mode mode)153 static inline bool IsCodeTarget(Mode mode) {
154 return mode <= LAST_CODE_ENUM;
155 }
156 // Is the relocation mode affected by GC?
IsGCRelocMode(Mode mode)157 static inline bool IsGCRelocMode(Mode mode) {
158 return mode <= LAST_GCED_ENUM;
159 }
IsJSReturn(Mode mode)160 static inline bool IsJSReturn(Mode mode) {
161 return mode == JS_RETURN;
162 }
IsComment(Mode mode)163 static inline bool IsComment(Mode mode) {
164 return mode == COMMENT;
165 }
IsPosition(Mode mode)166 static inline bool IsPosition(Mode mode) {
167 return mode == POSITION || mode == STATEMENT_POSITION;
168 }
IsStatementPosition(Mode mode)169 static inline bool IsStatementPosition(Mode mode) {
170 return mode == STATEMENT_POSITION;
171 }
IsExternalReference(Mode mode)172 static inline bool IsExternalReference(Mode mode) {
173 return mode == EXTERNAL_REFERENCE;
174 }
IsInternalReference(Mode mode)175 static inline bool IsInternalReference(Mode mode) {
176 return mode == INTERNAL_REFERENCE;
177 }
ModeMask(Mode mode)178 static inline int ModeMask(Mode mode) { return 1 << mode; }
179
180 // Accessors
pc()181 byte* pc() const { return pc_; }
set_pc(byte * pc)182 void set_pc(byte* pc) { pc_ = pc; }
rmode()183 Mode rmode() const { return rmode_; }
data()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:
RelocInfoWriter()257 RelocInfoWriter() : pos_(NULL), last_pc_(NULL), last_data_(0) {}
RelocInfoWriter(byte * pos,byte * pc)258 RelocInfoWriter(byte* pos, byte* pc) : pos_(pos), last_pc_(pc),
259 last_data_(0) {}
260
pos()261 byte* pos() const { return pos_; }
last_pc()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.
Reposition(byte * pos,byte * pc)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
done()313 bool done() const { return done_; }
314 void next();
315
316 // Return pointer valid until next next().
rinfo()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.
SetMode(RelocInfo::Mode mode)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
address()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.
set_redirector(ExternalReferenceRedirector * redirector)476 static void set_redirector(ExternalReferenceRedirector* redirector) {
477 ASSERT(redirector_ == NULL); // We can't stack them.
478 redirector_ = redirector;
479 }
480
481 private:
ExternalReference(void * address)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
is_intn(int x,int n)508 static inline bool is_intn(int x, int n) {
509 return -(1 << (n-1)) <= x && x < (1 << (n-1));
510 }
511
is_int8(int x)512 static inline bool is_int8(int x) { return is_intn(x, 8); }
is_int16(int x)513 static inline bool is_int16(int x) { return is_intn(x, 16); }
is_int18(int x)514 static inline bool is_int18(int x) { return is_intn(x, 18); }
is_int24(int x)515 static inline bool is_int24(int x) { return is_intn(x, 24); }
516
is_uintn(int x,int n)517 static inline bool is_uintn(int x, int n) {
518 return (x & -(1 << n)) == 0;
519 }
520
is_uint2(int x)521 static inline bool is_uint2(int x) { return is_uintn(x, 2); }
is_uint3(int x)522 static inline bool is_uint3(int x) { return is_uintn(x, 3); }
is_uint4(int x)523 static inline bool is_uint4(int x) { return is_uintn(x, 4); }
is_uint5(int x)524 static inline bool is_uint5(int x) { return is_uintn(x, 5); }
is_uint6(int x)525 static inline bool is_uint6(int x) { return is_uintn(x, 6); }
is_uint8(int x)526 static inline bool is_uint8(int x) { return is_uintn(x, 8); }
is_uint10(int x)527 static inline bool is_uint10(int x) { return is_uintn(x, 10); }
is_uint12(int x)528 static inline bool is_uint12(int x) { return is_uintn(x, 12); }
is_uint16(int x)529 static inline bool is_uint16(int x) { return is_uintn(x, 16); }
is_uint24(int x)530 static inline bool is_uint24(int x) { return is_uintn(x, 24); }
is_uint26(int x)531 static inline bool is_uint26(int x) { return is_uintn(x, 26); }
is_uint28(int x)532 static inline bool is_uint28(int x) { return is_uintn(x, 28); }
533
NumberOfBitsSet(uint32_t x)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