jit/JIT.cpp

   1 /*
   2  * Copyright (C) 2008, 2009 Apple Inc. 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
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "JIT.h"
  28
  29 // This probably does not belong here; adding here for now as a quick Windows build fix.
  30 #if ENABLE(ASSEMBLER) && CPU(X86) && !OS(MAC_OS_X)
  31 #include "MacroAssembler.h"
  32 JSC::MacroAssemblerX86Common::SSE2CheckState JSC::MacroAssemblerX86Common::s_sse2CheckState = NotCheckedSSE2;
  33 #endif
  34
  35 #if ENABLE(JIT)
  36
  37 #include "CodeBlock.h"
  38 #include "Interpreter.h"
  39 #include "JITInlineMethods.h"
  40 #include "JITStubCall.h"
  41 #include "JSArray.h"
  42 #include "JSFunction.h"
  43 #include "LinkBuffer.h"
  44 #include "RepatchBuffer.h"
  45 #include "ResultType.h"
  46 #include "SamplingTool.h"
  47
  48 #ifndef NDEBUG
  49 #include <stdio.h>
  50 #endif
  51
  52 using namespace std;
  53
  54 namespace JSC {
  55
  56 void ctiPatchNearCallByReturnAddress(CodeBlock* codeblock, ReturnAddressPtr returnAddress, MacroAssemblerCodePtr newCalleeFunction)
  57 {
  58     RepatchBuffer repatchBuffer(codeblock);
  59     repatchBuffer.relinkNearCallerToTrampoline(returnAddress, newCalleeFunction);
  60 }
  61
  62 void ctiPatchCallByReturnAddress(CodeBlock* codeblock, ReturnAddressPtr returnAddress, MacroAssemblerCodePtr newCalleeFunction)
  63 {
  64     RepatchBuffer repatchBuffer(codeblock);
  65     repatchBuffer.relinkCallerToTrampoline(returnAddress, newCalleeFunction);
  66 }
  67
  68 void ctiPatchCallByReturnAddress(CodeBlock* codeblock, ReturnAddressPtr returnAddress, FunctionPtr newCalleeFunction)
  69 {
  70     RepatchBuffer repatchBuffer(codeblock);
  71     repatchBuffer.relinkCallerToFunction(returnAddress, newCalleeFunction);
  72 }
  73
  74 JIT::JIT(JSGlobalData* globalData, CodeBlock* codeBlock)
  75     : m_interpreter(globalData->interpreter)
  76     , m_globalData(globalData)
  77     , m_codeBlock(codeBlock)
  78     , m_labels(codeBlock ? codeBlock->instructions().size() : 0)
  79     , m_propertyAccessCompilationInfo(codeBlock ? codeBlock->numberOfStructureStubInfos() : 0)
  80     , m_callStructureStubCompilationInfo(codeBlock ? codeBlock->numberOfCallLinkInfos() : 0)
  81     , m_bytecodeIndex((unsigned)-1)
  82 #if USE(JSVALUE32_64)
  83     , m_jumpTargetIndex(0)
  84     , m_mappedBytecodeIndex((unsigned)-1)
  85     , m_mappedVirtualRegisterIndex((unsigned)-1)
  86     , m_mappedTag((RegisterID)-1)
  87     , m_mappedPayload((RegisterID)-1)
  88 #else
  89     , m_lastResultBytecodeRegister(std::numeric_limits<int>::max())
  90     , m_jumpTargetsPosition(0)
  91 #endif
  92 {
  93 }
  94
  95 #if USE(JSVALUE32_64)
  96 void JIT::emitTimeoutCheck()
  97 {
  98     Jump skipTimeout = branchSub32(NonZero, Imm32(1), timeoutCheckRegister);
  99     JITStubCall stubCall(this, cti_timeout_check);
 100     stubCall.addArgument(regT1, regT0); // save last result registers.
 101     stubCall.call(timeoutCheckRegister);
 102     stubCall.getArgument(0, regT1, regT0); // reload last result registers.
 103     skipTimeout.link(this);
 104 }
 105 #else
 106 void JIT::emitTimeoutCheck()
 107 {
 108     Jump skipTimeout = branchSub32(NonZero, Imm32(1), timeoutCheckRegister);
 109     JITStubCall(this, cti_timeout_check).call(timeoutCheckRegister);
 110     skipTimeout.link(this);
 111
 112     killLastResultRegister();
 113 }
 114 #endif
 115
 116 #define NEXT_OPCODE(name) \
 117     m_bytecodeIndex += OPCODE_LENGTH(name); \
 118     break;
 119
 120 #if USE(JSVALUE32_64)
 121 #define DEFINE_BINARY_OP(name) \
 122     case name: { \
 123         JITStubCall stubCall(this, cti_##name); \
 124         stubCall.addArgument(currentInstruction[2].u.operand); \
 125         stubCall.addArgument(currentInstruction[3].u.operand); \
 126         stubCall.call(currentInstruction[1].u.operand); \
 127         NEXT_OPCODE(name); \
 128     }
 129
 130 #define DEFINE_UNARY_OP(name) \
 131     case name: { \
 132         JITStubCall stubCall(this, cti_##name); \
 133         stubCall.addArgument(currentInstruction[2].u.operand); \
 134         stubCall.call(currentInstruction[1].u.operand); \
 135         NEXT_OPCODE(name); \
 136     }
 137
 138 #else // USE(JSVALUE32_64)
 139
 140 #define DEFINE_BINARY_OP(name) \
 141     case name: { \
 142         JITStubCall stubCall(this, cti_##name); \
 143         stubCall.addArgument(currentInstruction[2].u.operand, regT2); \
 144         stubCall.addArgument(currentInstruction[3].u.operand, regT2); \
 145         stubCall.call(currentInstruction[1].u.operand); \
 146         NEXT_OPCODE(name); \
 147     }
 148
 149 #define DEFINE_UNARY_OP(name) \
 150     case name: { \
 151         JITStubCall stubCall(this, cti_##name); \
 152         stubCall.addArgument(currentInstruction[2].u.operand, regT2); \
 153         stubCall.call(currentInstruction[1].u.operand); \
 154         NEXT_OPCODE(name); \
 155     }
 156 #endif // USE(JSVALUE32_64)
 157
 158 #define DEFINE_OP(name) \
 159     case name: { \
 160         emit_##name(currentInstruction); \
 161         NEXT_OPCODE(name); \
 162     }
 163
 164 #define DEFINE_SLOWCASE_OP(name) \
 165     case name: { \
 166         emitSlow_##name(currentInstruction, iter); \
 167         NEXT_OPCODE(name); \
 168     }
 169
 170 void JIT::privateCompileMainPass()
 171 {
 172     Instruction* instructionsBegin = m_codeBlock->instructions().begin();
 173     unsigned instructionCount = m_codeBlock->instructions().size();
 174
 175     m_propertyAccessInstructionIndex = 0;
 176     m_globalResolveInfoIndex = 0;
 177     m_callLinkInfoIndex = 0;
 178
 179     for (m_bytecodeIndex = 0; m_bytecodeIndex < instructionCount; ) {
 180         Instruction* currentInstruction = instructionsBegin + m_bytecodeIndex;
 181         ASSERT_WITH_MESSAGE(m_interpreter->isOpcode(currentInstruction->u.opcode), "privateCompileMainPass gone bad @ %d", m_bytecodeIndex);
 182
 183 #if ENABLE(OPCODE_SAMPLING)
 184         if (m_bytecodeIndex > 0) // Avoid the overhead of sampling op_enter twice.
 185             sampleInstruction(currentInstruction);
 186 #endif
 187
 188 #if !USE(JSVALUE32_64)
 189         if (m_labels[m_bytecodeIndex].isUsed())
 190             killLastResultRegister();
 191 #endif
 192
 193         m_labels[m_bytecodeIndex] = label();
 194
 195         switch (m_interpreter->getOpcodeID(currentInstruction->u.opcode)) {
 196         DEFINE_BINARY_OP(op_del_by_val)
 197 #if USE(JSVALUE32)
 198         DEFINE_BINARY_OP(op_div)
 199 #endif
 200         DEFINE_BINARY_OP(op_in)
 201         DEFINE_BINARY_OP(op_less)
 202         DEFINE_BINARY_OP(op_lesseq)
 203         DEFINE_BINARY_OP(op_urshift)
 204         DEFINE_UNARY_OP(op_is_boolean)
 205         DEFINE_UNARY_OP(op_is_function)
 206         DEFINE_UNARY_OP(op_is_number)
 207         DEFINE_UNARY_OP(op_is_object)
 208         DEFINE_UNARY_OP(op_is_string)
 209         DEFINE_UNARY_OP(op_is_undefined)
 210 #if !USE(JSVALUE32_64)
 211         DEFINE_UNARY_OP(op_negate)
 212 #endif
 213         DEFINE_UNARY_OP(op_typeof)
 214
 215         DEFINE_OP(op_add)
 216         DEFINE_OP(op_bitand)
 217         DEFINE_OP(op_bitnot)
 218         DEFINE_OP(op_bitor)
 219         DEFINE_OP(op_bitxor)
 220         DEFINE_OP(op_call)
 221         DEFINE_OP(op_call_eval)
 222         DEFINE_OP(op_call_varargs)
 223         DEFINE_OP(op_catch)
 224         DEFINE_OP(op_construct)
 225         DEFINE_OP(op_construct_verify)
 226         DEFINE_OP(op_convert_this)
 227         DEFINE_OP(op_init_arguments)
 228         DEFINE_OP(op_create_arguments)
 229         DEFINE_OP(op_debug)
 230         DEFINE_OP(op_del_by_id)
 231 #if !USE(JSVALUE32)
 232         DEFINE_OP(op_div)
 233 #endif
 234         DEFINE_OP(op_end)
 235         DEFINE_OP(op_enter)
 236         DEFINE_OP(op_enter_with_activation)
 237         DEFINE_OP(op_eq)
 238         DEFINE_OP(op_eq_null)
 239         DEFINE_OP(op_get_by_id)
 240         DEFINE_OP(op_get_by_val)
 241         DEFINE_OP(op_get_by_pname)
 242         DEFINE_OP(op_get_global_var)
 243         DEFINE_OP(op_get_pnames)
 244         DEFINE_OP(op_get_scoped_var)
 245         DEFINE_OP(op_instanceof)
 246         DEFINE_OP(op_jeq_null)
 247         DEFINE_OP(op_jfalse)
 248         DEFINE_OP(op_jmp)
 249         DEFINE_OP(op_jmp_scopes)
 250         DEFINE_OP(op_jneq_null)
 251         DEFINE_OP(op_jneq_ptr)
 252         DEFINE_OP(op_jnless)
 253         DEFINE_OP(op_jless)
 254         DEFINE_OP(op_jnlesseq)
 255         DEFINE_OP(op_jsr)
 256         DEFINE_OP(op_jtrue)
 257         DEFINE_OP(op_load_varargs)
 258         DEFINE_OP(op_loop)
 259         DEFINE_OP(op_loop_if_less)
 260         DEFINE_OP(op_loop_if_lesseq)
 261         DEFINE_OP(op_loop_if_true)
 262         DEFINE_OP(op_loop_if_false)
 263         DEFINE_OP(op_lshift)
 264         DEFINE_OP(op_method_check)
 265         DEFINE_OP(op_mod)
 266         DEFINE_OP(op_mov)
 267         DEFINE_OP(op_mul)
 268 #if USE(JSVALUE32_64)
 269         DEFINE_OP(op_negate)
 270 #endif
 271         DEFINE_OP(op_neq)
 272         DEFINE_OP(op_neq_null)
 273         DEFINE_OP(op_new_array)
 274         DEFINE_OP(op_new_error)
 275         DEFINE_OP(op_new_func)
 276         DEFINE_OP(op_new_func_exp)
 277         DEFINE_OP(op_new_object)
 278         DEFINE_OP(op_new_regexp)
 279         DEFINE_OP(op_next_pname)
 280         DEFINE_OP(op_not)
 281         DEFINE_OP(op_nstricteq)
 282         DEFINE_OP(op_pop_scope)
 283         DEFINE_OP(op_post_dec)
 284         DEFINE_OP(op_post_inc)
 285         DEFINE_OP(op_pre_dec)
 286         DEFINE_OP(op_pre_inc)
 287         DEFINE_OP(op_profile_did_call)
 288         DEFINE_OP(op_profile_will_call)
 289         DEFINE_OP(op_push_new_scope)
 290         DEFINE_OP(op_push_scope)
 291         DEFINE_OP(op_put_by_id)
 292         DEFINE_OP(op_put_by_index)
 293         DEFINE_OP(op_put_by_val)
 294         DEFINE_OP(op_put_getter)
 295         DEFINE_OP(op_put_global_var)
 296         DEFINE_OP(op_put_scoped_var)
 297         DEFINE_OP(op_put_setter)
 298         DEFINE_OP(op_resolve)
 299         DEFINE_OP(op_resolve_base)
 300         DEFINE_OP(op_resolve_global)
 301         DEFINE_OP(op_resolve_skip)
 302         DEFINE_OP(op_resolve_with_base)
 303         DEFINE_OP(op_ret)
 304         DEFINE_OP(op_rshift)
 305         DEFINE_OP(op_sret)
 306         DEFINE_OP(op_strcat)
 307         DEFINE_OP(op_stricteq)
 308         DEFINE_OP(op_sub)
 309         DEFINE_OP(op_switch_char)
 310         DEFINE_OP(op_switch_imm)
 311         DEFINE_OP(op_switch_string)
 312         DEFINE_OP(op_tear_off_activation)
 313         DEFINE_OP(op_tear_off_arguments)
 314         DEFINE_OP(op_throw)
 315         DEFINE_OP(op_to_jsnumber)
 316         DEFINE_OP(op_to_primitive)
 317
 318         case op_get_array_length:
 319         case op_get_by_id_chain:
 320         case op_get_by_id_generic:
 321         case op_get_by_id_proto:
 322         case op_get_by_id_proto_list:
 323         case op_get_by_id_self:
 324         case op_get_by_id_self_list:
 325         case op_get_string_length:
 326         case op_put_by_id_generic:
 327         case op_put_by_id_replace:
 328         case op_put_by_id_transition:
 329             ASSERT_NOT_REACHED();
 330         }
 331     }
 332
 333     ASSERT(m_propertyAccessInstructionIndex == m_codeBlock->numberOfStructureStubInfos());
 334     ASSERT(m_callLinkInfoIndex == m_codeBlock->numberOfCallLinkInfos());
 335
 336 #ifndef NDEBUG
 337     // Reset this, in order to guard its use with ASSERTs.
 338     m_bytecodeIndex = (unsigned)-1;
 339 #endif
 340 }
 341
 342
 343 void JIT::privateCompileLinkPass()
 344 {
 345     unsigned jmpTableCount = m_jmpTable.size();
 346     for (unsigned i = 0; i < jmpTableCount; ++i)
 347         m_jmpTable[i].from.linkTo(m_labels[m_jmpTable[i].toBytecodeIndex], this);
 348     m_jmpTable.clear();
 349 }
 350
 351 void JIT::privateCompileSlowCases()
 352 {
 353     Instruction* instructionsBegin = m_codeBlock->instructions().begin();
 354
 355     m_propertyAccessInstructionIndex = 0;
 356 #if USE(JSVALUE32_64)
 357     m_globalResolveInfoIndex = 0;
 358 #endif
 359     m_callLinkInfoIndex = 0;
 360
 361     for (Vector<SlowCaseEntry>::iterator iter = m_slowCases.begin(); iter != m_slowCases.end();) {
 362 #if !USE(JSVALUE32_64)
 363         killLastResultRegister();
 364 #endif
 365
 366         m_bytecodeIndex = iter->to;
 367 #ifndef NDEBUG
 368         unsigned firstTo = m_bytecodeIndex;
 369 #endif
 370         Instruction* currentInstruction = instructionsBegin + m_bytecodeIndex;
 371
 372         switch (m_interpreter->getOpcodeID(currentInstruction->u.opcode)) {
 373         DEFINE_SLOWCASE_OP(op_add)
 374         DEFINE_SLOWCASE_OP(op_bitand)
 375         DEFINE_SLOWCASE_OP(op_bitnot)
 376         DEFINE_SLOWCASE_OP(op_bitor)
 377         DEFINE_SLOWCASE_OP(op_bitxor)
 378         DEFINE_SLOWCASE_OP(op_call)
 379         DEFINE_SLOWCASE_OP(op_call_eval)
 380         DEFINE_SLOWCASE_OP(op_call_varargs)
 381         DEFINE_SLOWCASE_OP(op_construct)
 382         DEFINE_SLOWCASE_OP(op_construct_verify)
 383         DEFINE_SLOWCASE_OP(op_convert_this)
 384 #if !USE(JSVALUE32)
 385         DEFINE_SLOWCASE_OP(op_div)
 386 #endif
 387         DEFINE_SLOWCASE_OP(op_eq)
 388         DEFINE_SLOWCASE_OP(op_get_by_id)
 389         DEFINE_SLOWCASE_OP(op_get_by_val)
 390         DEFINE_SLOWCASE_OP(op_get_by_pname)
 391         DEFINE_SLOWCASE_OP(op_instanceof)
 392         DEFINE_SLOWCASE_OP(op_jfalse)
 393         DEFINE_SLOWCASE_OP(op_jnless)
 394         DEFINE_SLOWCASE_OP(op_jless)
 395         DEFINE_SLOWCASE_OP(op_jnlesseq)
 396         DEFINE_SLOWCASE_OP(op_jtrue)
 397         DEFINE_SLOWCASE_OP(op_loop_if_less)
 398         DEFINE_SLOWCASE_OP(op_loop_if_lesseq)
 399         DEFINE_SLOWCASE_OP(op_loop_if_true)
 400         DEFINE_SLOWCASE_OP(op_loop_if_false)
 401         DEFINE_SLOWCASE_OP(op_lshift)
 402         DEFINE_SLOWCASE_OP(op_method_check)
 403         DEFINE_SLOWCASE_OP(op_mod)
 404         DEFINE_SLOWCASE_OP(op_mul)
 405 #if USE(JSVALUE32_64)
 406         DEFINE_SLOWCASE_OP(op_negate)
 407 #endif
 408         DEFINE_SLOWCASE_OP(op_neq)
 409         DEFINE_SLOWCASE_OP(op_not)
 410         DEFINE_SLOWCASE_OP(op_nstricteq)
 411         DEFINE_SLOWCASE_OP(op_post_dec)
 412         DEFINE_SLOWCASE_OP(op_post_inc)
 413         DEFINE_SLOWCASE_OP(op_pre_dec)
 414         DEFINE_SLOWCASE_OP(op_pre_inc)
 415         DEFINE_SLOWCASE_OP(op_put_by_id)
 416         DEFINE_SLOWCASE_OP(op_put_by_val)
 417 #if USE(JSVALUE32_64)
 418         DEFINE_SLOWCASE_OP(op_resolve_global)
 419 #endif
 420         DEFINE_SLOWCASE_OP(op_rshift)
 421         DEFINE_SLOWCASE_OP(op_stricteq)
 422         DEFINE_SLOWCASE_OP(op_sub)
 423         DEFINE_SLOWCASE_OP(op_to_jsnumber)
 424         DEFINE_SLOWCASE_OP(op_to_primitive)
 425         default:
 426             ASSERT_NOT_REACHED();
 427         }
 428
 429         ASSERT_WITH_MESSAGE(iter == m_slowCases.end() || firstTo != iter->to,"Not enough jumps linked in slow case codegen.");
 430         ASSERT_WITH_MESSAGE(firstTo == (iter - 1)->to, "Too many jumps linked in slow case codegen.");
 431
 432         emitJumpSlowToHot(jump(), 0);
 433     }
 434
 435 #if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
 436     ASSERT(m_propertyAccessInstructionIndex == m_codeBlock->numberOfStructureStubInfos());
 437 #endif
 438     ASSERT(m_callLinkInfoIndex == m_codeBlock->numberOfCallLinkInfos());
 439
 440 #ifndef NDEBUG
 441     // Reset this, in order to guard its use with ASSERTs.
 442     m_bytecodeIndex = (unsigned)-1;
 443 #endif
 444 }
 445
 446 JITCode JIT::privateCompile()
 447 {
 448     sampleCodeBlock(m_codeBlock);
 449 #if ENABLE(OPCODE_SAMPLING)
 450     sampleInstruction(m_codeBlock->instructions().begin());
 451 #endif
 452
 453     // Could use a pop_m, but would need to offset the following instruction if so.
 454     preserveReturnAddressAfterCall(regT2);
 455     emitPutToCallFrameHeader(regT2, RegisterFile::ReturnPC);
 456
 457     Jump slowRegisterFileCheck;
 458     Label afterRegisterFileCheck;
 459     if (m_codeBlock->codeType() == FunctionCode) {
 460         // In the case of a fast linked call, we do not set this up in the caller.
 461         emitPutImmediateToCallFrameHeader(m_codeBlock, RegisterFile::CodeBlock);
 462
 463         peek(regT0, OBJECT_OFFSETOF(JITStackFrame, registerFile) / sizeof (void*));
 464         addPtr(Imm32(m_codeBlock->m_numCalleeRegisters * sizeof(Register)), callFrameRegister, regT1);
 465
 466         slowRegisterFileCheck = branchPtr(Above, regT1, Address(regT0, OBJECT_OFFSETOF(RegisterFile, m_end)));
 467         afterRegisterFileCheck = label();
 468     }
 469
 470     privateCompileMainPass();
 471     privateCompileLinkPass();
 472     privateCompileSlowCases();
 473
 474     if (m_codeBlock->codeType() == FunctionCode) {
 475         slowRegisterFileCheck.link(this);
 476         m_bytecodeIndex = 0;
 477         JITStubCall(this, cti_register_file_check).call();
 478 #ifndef NDEBUG
 479         m_bytecodeIndex = (unsigned)-1; // Reset this, in order to guard its use with ASSERTs.
 480 #endif
 481         jump(afterRegisterFileCheck);
 482     }
 483
 484     ASSERT(m_jmpTable.isEmpty());
 485
 486     LinkBuffer patchBuffer(this, m_globalData->executableAllocator.poolForSize(m_assembler.size()));
 487
 488     // Translate vPC offsets into addresses in JIT generated code, for switch tables.
 489     for (unsigned i = 0; i < m_switches.size(); ++i) {
 490         SwitchRecord record = m_switches[i];
 491         unsigned bytecodeIndex = record.bytecodeIndex;
 492
 493         if (record.type != SwitchRecord::String) {
 494             ASSERT(record.type == SwitchRecord::Immediate || record.type == SwitchRecord::Character);
 495             ASSERT(record.jumpTable.simpleJumpTable->branchOffsets.size() == record.jumpTable.simpleJumpTable->ctiOffsets.size());
 496
 497             record.jumpTable.simpleJumpTable->ctiDefault = patchBuffer.locationOf(m_labels[bytecodeIndex + record.defaultOffset]);
 498
 499             for (unsigned j = 0; j < record.jumpTable.simpleJumpTable->branchOffsets.size(); ++j) {
 500                 unsigned offset = record.jumpTable.simpleJumpTable->branchOffsets[j];
 501                 record.jumpTable.simpleJumpTable->ctiOffsets[j] = offset ? patchBuffer.locationOf(m_labels[bytecodeIndex + offset]) : record.jumpTable.simpleJumpTable->ctiDefault;
 502             }
 503         } else {
 504             ASSERT(record.type == SwitchRecord::String);
 505
 506             record.jumpTable.stringJumpTable->ctiDefault = patchBuffer.locationOf(m_labels[bytecodeIndex + record.defaultOffset]);
 507
 508             StringJumpTable::StringOffsetTable::iterator end = record.jumpTable.stringJumpTable->offsetTable.end();
 509             for (StringJumpTable::StringOffsetTable::iterator it = record.jumpTable.stringJumpTable->offsetTable.begin(); it != end; ++it) {
 510                 unsigned offset = it->second.branchOffset;
 511                 it->second.ctiOffset = offset ? patchBuffer.locationOf(m_labels[bytecodeIndex + offset]) : record.jumpTable.stringJumpTable->ctiDefault;
 512             }
 513         }
 514     }
 515
 516     for (size_t i = 0; i < m_codeBlock->numberOfExceptionHandlers(); ++i) {
 517         HandlerInfo& handler = m_codeBlock->exceptionHandler(i);
 518         handler.nativeCode = patchBuffer.locationOf(m_labels[handler.target]);
 519     }
 520
 521     for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
 522         if (iter->to)
 523             patchBuffer.link(iter->from, FunctionPtr(iter->to));
 524     }
 525
 526     if (m_codeBlock->hasExceptionInfo()) {
 527         m_codeBlock->callReturnIndexVector().reserveCapacity(m_calls.size());
 528         for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter)
 529             m_codeBlock->callReturnIndexVector().append(CallReturnOffsetToBytecodeIndex(patchBuffer.returnAddressOffset(iter->from), iter->bytecodeIndex));
 530     }
 531
 532     // Link absolute addresses for jsr
 533     for (Vector<JSRInfo>::iterator iter = m_jsrSites.begin(); iter != m_jsrSites.end(); ++iter)
 534         patchBuffer.patch(iter->storeLocation, patchBuffer.locationOf(iter->target).executableAddress());
 535
 536 #if ENABLE(JIT_OPTIMIZE_PROPERTY_ACCESS)
 537     for (unsigned i = 0; i < m_codeBlock->numberOfStructureStubInfos(); ++i) {
 538         StructureStubInfo& info = m_codeBlock->structureStubInfo(i);
 539         info.callReturnLocation = patchBuffer.locationOf(m_propertyAccessCompilationInfo[i].callReturnLocation);
 540         info.hotPathBegin = patchBuffer.locationOf(m_propertyAccessCompilationInfo[i].hotPathBegin);
 541     }
 542 #endif
 543 #if ENABLE(JIT_OPTIMIZE_CALL)
 544     for (unsigned i = 0; i < m_codeBlock->numberOfCallLinkInfos(); ++i) {
 545         CallLinkInfo& info = m_codeBlock->callLinkInfo(i);
 546         info.ownerCodeBlock = m_codeBlock;
 547         info.callReturnLocation = patchBuffer.locationOfNearCall(m_callStructureStubCompilationInfo[i].callReturnLocation);
 548         info.hotPathBegin = patchBuffer.locationOf(m_callStructureStubCompilationInfo[i].hotPathBegin);
 549         info.hotPathOther = patchBuffer.locationOfNearCall(m_callStructureStubCompilationInfo[i].hotPathOther);
 550     }
 551 #endif
 552     unsigned methodCallCount = m_methodCallCompilationInfo.size();
 553     m_codeBlock->addMethodCallLinkInfos(methodCallCount);
 554     for (unsigned i = 0; i < methodCallCount; ++i) {
 555         MethodCallLinkInfo& info = m_codeBlock->methodCallLinkInfo(i);
 556         info.structureLabel = patchBuffer.locationOf(m_methodCallCompilationInfo[i].structureToCompare);
 557         info.callReturnLocation = m_codeBlock->structureStubInfo(m_methodCallCompilationInfo[i].propertyAccessIndex).callReturnLocation;
 558     }
 559
 560     return patchBuffer.finalizeCode();
 561 }
 562
 563 #if !USE(JSVALUE32_64)
 564 void JIT::emitGetVariableObjectRegister(RegisterID variableObject, int index, RegisterID dst)
 565 {
 566     loadPtr(Address(variableObject, OBJECT_OFFSETOF(JSVariableObject, d)), dst);
 567     loadPtr(Address(dst, OBJECT_OFFSETOF(JSVariableObject::JSVariableObjectData, registers)), dst);
 568     loadPtr(Address(dst, index * sizeof(Register)), dst);
 569 }
 570
 571 void JIT::emitPutVariableObjectRegister(RegisterID src, RegisterID variableObject, int index)
 572 {
 573     loadPtr(Address(variableObject, OBJECT_OFFSETOF(JSVariableObject, d)), variableObject);
 574     loadPtr(Address(variableObject, OBJECT_OFFSETOF(JSVariableObject::JSVariableObjectData, registers)), variableObject);
 575     storePtr(src, Address(variableObject, index * sizeof(Register)));
 576 }
 577 #endif
 578
 579 #if ENABLE(JIT_OPTIMIZE_CALL)
 580 void JIT::unlinkCall(CallLinkInfo* callLinkInfo)
 581 {
 582     // When the JSFunction is deleted the pointer embedded in the instruction stream will no longer be valid
 583     // (and, if a new JSFunction happened to be constructed at the same location, we could get a false positive
 584     // match).  Reset the check so it no longer matches.
 585     RepatchBuffer repatchBuffer(callLinkInfo->ownerCodeBlock.get());
 586 #if USE(JSVALUE32_64)
 587     repatchBuffer.repatch(callLinkInfo->hotPathBegin, 0);
 588 #else
 589     repatchBuffer.repatch(callLinkInfo->hotPathBegin, JSValue::encode(JSValue()));
 590 #endif
 591 }
 592
 593 void JIT::linkCall(JSFunction* callee, CodeBlock* callerCodeBlock, CodeBlock* calleeCodeBlock, JITCode& code, CallLinkInfo* callLinkInfo, int callerArgCount, JSGlobalData* globalData)
 594 {
 595     RepatchBuffer repatchBuffer(callerCodeBlock);
 596
 597     // Currently we only link calls with the exact number of arguments.
 598     // If this is a native call calleeCodeBlock is null so the number of parameters is unimportant
 599     if (!calleeCodeBlock || (callerArgCount == calleeCodeBlock->m_numParameters)) {
 600         ASSERT(!callLinkInfo->isLinked());
 601
 602         if (calleeCodeBlock)
 603             calleeCodeBlock->addCaller(callLinkInfo);
 604
 605         repatchBuffer.repatch(callLinkInfo->hotPathBegin, callee);
 606         repatchBuffer.relink(callLinkInfo->hotPathOther, code.addressForCall());
 607     }
 608
 609     // patch the call so we do not continue to try to link.
 610     repatchBuffer.relink(callLinkInfo->callReturnLocation, globalData->jitStubs.ctiVirtualCall());
 611 }
 612 #endif // ENABLE(JIT_OPTIMIZE_CALL)
 613
 614 } // namespace JSC
 615
 616 #endif // ENABLE(JIT)