jit/JIT.cpp

   1 /*
   2  * Copyright (C) 2008, 2009, 2012-2015 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
  28 #if ENABLE(JIT)
  29
  30 #include "JIT.h"
  31
  32 #include "ArityCheckFailReturnThunks.h"
  33 #include "CodeBlock.h"
  34 #include "CodeBlockWithJITType.h"
  35 #include "DFGCapabilities.h"
  36 #include "Interpreter.h"
  37 #include "JITInlines.h"
  38 #include "JITOperations.h"
  39 #include "JSArray.h"
  40 #include "JSFunction.h"
  41 #include "LinkBuffer.h"
  42 #include "MaxFrameExtentForSlowPathCall.h"
  43 #include "JSCInlines.h"
  44 #include "ProfilerDatabase.h"
  45 #include "RepatchBuffer.h"
  46 #include "ResultType.h"
  47 #include "SamplingTool.h"
  48 #include "SlowPathCall.h"
  49 #include "StackAlignment.h"
  50 #include "TypeProfilerLog.h"
  51 #include <wtf/CryptographicallyRandomNumber.h>
  52
  53 using namespace std;
  54
  55 namespace JSC {
  56
  57 void ctiPatchNearCallByReturnAddress(CodeBlock* codeblock, ReturnAddressPtr returnAddress, MacroAssemblerCodePtr newCalleeFunction)
  58 {
  59     RepatchBuffer repatchBuffer(codeblock);
  60     repatchBuffer.relinkNearCallerToTrampoline(returnAddress, newCalleeFunction);
  61 }
  62
  63 void ctiPatchCallByReturnAddress(CodeBlock* codeblock, ReturnAddressPtr returnAddress, MacroAssemblerCodePtr newCalleeFunction)
  64 {
  65     RepatchBuffer repatchBuffer(codeblock);
  66     repatchBuffer.relinkCallerToTrampoline(returnAddress, newCalleeFunction);
  67 }
  68
  69 void ctiPatchCallByReturnAddress(CodeBlock* codeblock, ReturnAddressPtr returnAddress, FunctionPtr newCalleeFunction)
  70 {
  71     RepatchBuffer repatchBuffer(codeblock);
  72     repatchBuffer.relinkCallerToFunction(returnAddress, newCalleeFunction);
  73 }
  74
  75 JIT::JIT(VM* vm, CodeBlock* codeBlock)
  76     : JSInterfaceJIT(vm, codeBlock)
  77     , m_interpreter(vm->interpreter)
  78     , m_labels(codeBlock ? codeBlock->numberOfInstructions() : 0)
  79     , m_bytecodeOffset(std::numeric_limits<unsigned>::max())
  80     , m_getByIdIndex(UINT_MAX)
  81     , m_putByIdIndex(UINT_MAX)
  82     , m_byValInstructionIndex(UINT_MAX)
  83     , m_callLinkInfoIndex(UINT_MAX)
  84     , m_randomGenerator(cryptographicallyRandomNumber())
  85     , m_canBeOptimized(false)
  86     , m_shouldEmitProfiling(false)
  87 {
  88 }
  89
  90 #if ENABLE(DFG_JIT)
  91 void JIT::emitEnterOptimizationCheck()
  92 {
  93     if (!canBeOptimized())
  94         return;
  95
  96     JumpList skipOptimize;
  97
  98     skipOptimize.append(branchAdd32(Signed, TrustedImm32(Options::executionCounterIncrementForEntry()), AbsoluteAddress(m_codeBlock->addressOfJITExecuteCounter())));
  99     ASSERT(!m_bytecodeOffset);
 100     callOperation(operationOptimize, m_bytecodeOffset);
 101     skipOptimize.append(branchTestPtr(Zero, returnValueGPR));
 102     move(returnValueGPR2, stackPointerRegister);
 103     jump(returnValueGPR);
 104     skipOptimize.link(this);
 105 }
 106 #endif
 107
 108 void JIT::emitNotifyWrite(WatchpointSet* set)
 109 {
 110     if (!set || set->state() == IsInvalidated)
 111         return;
 112
 113     addSlowCase(branch8(NotEqual, AbsoluteAddress(set->addressOfState()), TrustedImm32(IsInvalidated)));
 114 }
 115
 116 void JIT::assertStackPointerOffset()
 117 {
 118     if (ASSERT_DISABLED)
 119         return;
 120
 121     addPtr(TrustedImm32(stackPointerOffsetFor(m_codeBlock) * sizeof(Register)), callFrameRegister, regT0);
 122     Jump ok = branchPtr(Equal, regT0, stackPointerRegister);
 123     breakpoint();
 124     ok.link(this);
 125 }
 126
 127 #define NEXT_OPCODE(name) \
 128     m_bytecodeOffset += OPCODE_LENGTH(name); \
 129     break;
 130
 131 #define DEFINE_SLOW_OP(name) \
 132     case op_##name: { \
 133         JITSlowPathCall slowPathCall(this, currentInstruction, slow_path_##name); \
 134         slowPathCall.call(); \
 135         NEXT_OPCODE(op_##name); \
 136     }
 137
 138 #define DEFINE_OP(name) \
 139     case name: { \
 140         emit_##name(currentInstruction); \
 141         NEXT_OPCODE(name); \
 142     }
 143
 144 #define DEFINE_SLOWCASE_OP(name) \
 145     case name: { \
 146         emitSlow_##name(currentInstruction, iter); \
 147         NEXT_OPCODE(name); \
 148     }
 149
 150 void JIT::privateCompileMainPass()
 151 {
 152     jitAssertTagsInPlace();
 153     jitAssertArgumentCountSane();
 154
 155     Instruction* instructionsBegin = m_codeBlock->instructions().begin();
 156     unsigned instructionCount = m_codeBlock->instructions().size();
 157
 158     m_callLinkInfoIndex = 0;
 159
 160     for (m_bytecodeOffset = 0; m_bytecodeOffset < instructionCount; ) {
 161         if (m_disassembler)
 162             m_disassembler->setForBytecodeMainPath(m_bytecodeOffset, label());
 163         Instruction* currentInstruction = instructionsBegin + m_bytecodeOffset;
 164         ASSERT_WITH_MESSAGE(m_interpreter->isOpcode(currentInstruction->u.opcode), "privateCompileMainPass gone bad @ %d", m_bytecodeOffset);
 165
 166 #if ENABLE(OPCODE_SAMPLING)
 167         if (m_bytecodeOffset > 0) // Avoid the overhead of sampling op_enter twice.
 168             sampleInstruction(currentInstruction);
 169 #endif
 170
 171         m_labels[m_bytecodeOffset] = label();
 172
 173 #if ENABLE(JIT_VERBOSE)
 174         dataLogF("Old JIT emitting code for bc#%u at offset 0x%lx.\n", m_bytecodeOffset, (long)debugOffset());
 175 #endif
 176
 177         OpcodeID opcodeID = m_interpreter->getOpcodeID(currentInstruction->u.opcode);
 178
 179         if (m_compilation) {
 180             add64(
 181                 TrustedImm32(1),
 182                 AbsoluteAddress(m_compilation->executionCounterFor(Profiler::OriginStack(Profiler::Origin(
 183                     m_compilation->bytecodes(), m_bytecodeOffset)))->address()));
 184         }
 185
 186         if (Options::eagerlyUpdateTopCallFrame())
 187             updateTopCallFrame();
 188
 189         switch (opcodeID) {
 190         DEFINE_SLOW_OP(del_by_val)
 191         DEFINE_SLOW_OP(in)
 192         DEFINE_SLOW_OP(less)
 193         DEFINE_SLOW_OP(lesseq)
 194         DEFINE_SLOW_OP(greater)
 195         DEFINE_SLOW_OP(greatereq)
 196         DEFINE_SLOW_OP(is_function)
 197         DEFINE_SLOW_OP(is_object_or_null)
 198         DEFINE_SLOW_OP(typeof)
 199
 200         DEFINE_OP(op_add)
 201         DEFINE_OP(op_bitand)
 202         DEFINE_OP(op_bitor)
 203         DEFINE_OP(op_bitxor)
 204         DEFINE_OP(op_call)
 205         DEFINE_OP(op_call_eval)
 206         DEFINE_OP(op_call_varargs)
 207         DEFINE_OP(op_construct_varargs)
 208         DEFINE_OP(op_catch)
 209         DEFINE_OP(op_construct)
 210         DEFINE_OP(op_create_this)
 211         DEFINE_OP(op_to_this)
 212         DEFINE_OP(op_create_direct_arguments)
 213         DEFINE_OP(op_create_scoped_arguments)
 214         DEFINE_OP(op_create_out_of_band_arguments)
 215         DEFINE_OP(op_check_tdz)
 216         DEFINE_OP(op_debug)
 217         DEFINE_OP(op_del_by_id)
 218         DEFINE_OP(op_div)
 219         DEFINE_OP(op_end)
 220         DEFINE_OP(op_enter)
 221         DEFINE_OP(op_create_lexical_environment)
 222         DEFINE_OP(op_get_scope)
 223         DEFINE_OP(op_eq)
 224         DEFINE_OP(op_eq_null)
 225         case op_get_by_id_out_of_line:
 226         case op_get_array_length:
 227         DEFINE_OP(op_get_by_id)
 228         DEFINE_OP(op_get_by_val)
 229         DEFINE_OP(op_check_has_instance)
 230         DEFINE_OP(op_instanceof)
 231         DEFINE_OP(op_is_undefined)
 232         DEFINE_OP(op_is_boolean)
 233         DEFINE_OP(op_is_number)
 234         DEFINE_OP(op_is_string)
 235         DEFINE_OP(op_is_object)
 236         DEFINE_OP(op_jeq_null)
 237         DEFINE_OP(op_jfalse)
 238         DEFINE_OP(op_jmp)
 239         DEFINE_OP(op_jneq_null)
 240         DEFINE_OP(op_jneq_ptr)
 241         DEFINE_OP(op_jless)
 242         DEFINE_OP(op_jlesseq)
 243         DEFINE_OP(op_jgreater)
 244         DEFINE_OP(op_jgreatereq)
 245         DEFINE_OP(op_jnless)
 246         DEFINE_OP(op_jnlesseq)
 247         DEFINE_OP(op_jngreater)
 248         DEFINE_OP(op_jngreatereq)
 249         DEFINE_OP(op_jtrue)
 250         DEFINE_OP(op_loop_hint)
 251         DEFINE_OP(op_lshift)
 252         DEFINE_OP(op_mod)
 253         DEFINE_OP(op_mov)
 254         DEFINE_OP(op_mul)
 255         DEFINE_OP(op_negate)
 256         DEFINE_OP(op_neq)
 257         DEFINE_OP(op_neq_null)
 258         DEFINE_OP(op_new_array)
 259         DEFINE_OP(op_new_array_with_size)
 260         DEFINE_OP(op_new_array_buffer)
 261         DEFINE_OP(op_new_func)
 262         DEFINE_OP(op_new_func_exp)
 263         DEFINE_OP(op_new_object)
 264         DEFINE_OP(op_new_regexp)
 265         DEFINE_OP(op_not)
 266         DEFINE_OP(op_nstricteq)
 267         DEFINE_OP(op_pop_scope)
 268         DEFINE_OP(op_dec)
 269         DEFINE_OP(op_inc)
 270         DEFINE_OP(op_profile_did_call)
 271         DEFINE_OP(op_profile_will_call)
 272         DEFINE_OP(op_profile_type)
 273         DEFINE_OP(op_profile_control_flow)
 274         DEFINE_OP(op_push_name_scope)
 275         DEFINE_OP(op_push_with_scope)
 276         case op_put_by_id_out_of_line:
 277         case op_put_by_id_transition_direct:
 278         case op_put_by_id_transition_normal:
 279         case op_put_by_id_transition_direct_out_of_line:
 280         case op_put_by_id_transition_normal_out_of_line:
 281         DEFINE_OP(op_put_by_id)
 282         DEFINE_OP(op_put_by_index)
 283         case op_put_by_val_direct:
 284         DEFINE_OP(op_put_by_val)
 285         DEFINE_OP(op_put_getter_by_id)
 286         DEFINE_OP(op_put_setter_by_id)
 287         DEFINE_OP(op_put_getter_setter)
 288         case op_init_global_const_nop:
 289             NEXT_OPCODE(op_init_global_const_nop);
 290         DEFINE_OP(op_init_global_const)
 291
 292         DEFINE_OP(op_ret)
 293         DEFINE_OP(op_rshift)
 294         DEFINE_OP(op_unsigned)
 295         DEFINE_OP(op_urshift)
 296         DEFINE_OP(op_strcat)
 297         DEFINE_OP(op_stricteq)
 298         DEFINE_OP(op_sub)
 299         DEFINE_OP(op_switch_char)
 300         DEFINE_OP(op_switch_imm)
 301         DEFINE_OP(op_switch_string)
 302         DEFINE_OP(op_throw)
 303         DEFINE_OP(op_throw_static_error)
 304         DEFINE_OP(op_to_number)
 305         DEFINE_OP(op_to_string)
 306         DEFINE_OP(op_to_primitive)
 307
 308         DEFINE_OP(op_resolve_scope)
 309         DEFINE_OP(op_get_from_scope)
 310         DEFINE_OP(op_put_to_scope)
 311         DEFINE_OP(op_get_from_arguments)
 312         DEFINE_OP(op_put_to_arguments)
 313
 314         DEFINE_OP(op_get_enumerable_length)
 315         DEFINE_OP(op_has_generic_property)
 316         DEFINE_OP(op_has_structure_property)
 317         DEFINE_OP(op_has_indexed_property)
 318         DEFINE_OP(op_get_direct_pname)
 319         DEFINE_OP(op_get_property_enumerator)
 320         DEFINE_OP(op_enumerator_structure_pname)
 321         DEFINE_OP(op_enumerator_generic_pname)
 322         DEFINE_OP(op_to_index_string)
 323         default:
 324             RELEASE_ASSERT_NOT_REACHED();
 325         }
 326     }
 327
 328     RELEASE_ASSERT(m_callLinkInfoIndex == m_callCompilationInfo.size());
 329
 330 #ifndef NDEBUG
 331     // Reset this, in order to guard its use with ASSERTs.
 332     m_bytecodeOffset = std::numeric_limits<unsigned>::max();
 333 #endif
 334 }
 335
 336 void JIT::privateCompileLinkPass()
 337 {
 338     unsigned jmpTableCount = m_jmpTable.size();
 339     for (unsigned i = 0; i < jmpTableCount; ++i)
 340         m_jmpTable[i].from.linkTo(m_labels[m_jmpTable[i].toBytecodeOffset], this);
 341     m_jmpTable.clear();
 342 }
 343
 344 void JIT::privateCompileSlowCases()
 345 {
 346     Instruction* instructionsBegin = m_codeBlock->instructions().begin();
 347
 348     m_getByIdIndex = 0;
 349     m_putByIdIndex = 0;
 350     m_byValInstructionIndex = 0;
 351     m_callLinkInfoIndex = 0;
 352
 353     // Use this to assert that slow-path code associates new profiling sites with existing
 354     // ValueProfiles rather than creating new ones. This ensures that for a given instruction
 355     // (say, get_by_id) we get combined statistics for both the fast-path executions of that
 356     // instructions and the slow-path executions. Furthermore, if the slow-path code created
 357     // new ValueProfiles then the ValueProfiles would no longer be sorted by bytecode offset,
 358     // which would break the invariant necessary to use CodeBlock::valueProfileForBytecodeOffset().
 359     unsigned numberOfValueProfiles = m_codeBlock->numberOfValueProfiles();
 360
 361     for (Vector<SlowCaseEntry>::iterator iter = m_slowCases.begin(); iter != m_slowCases.end();) {
 362         m_bytecodeOffset = iter->to;
 363
 364         unsigned firstTo = m_bytecodeOffset;
 365
 366         Instruction* currentInstruction = instructionsBegin + m_bytecodeOffset;
 367
 368         RareCaseProfile* rareCaseProfile = 0;
 369         if (shouldEmitProfiling())
 370             rareCaseProfile = m_codeBlock->addRareCaseProfile(m_bytecodeOffset);
 371
 372 #if ENABLE(JIT_VERBOSE)
 373         dataLogF("Old JIT emitting slow code for bc#%u at offset 0x%lx.\n", m_bytecodeOffset, (long)debugOffset());
 374 #endif
 375
 376         if (m_disassembler)
 377             m_disassembler->setForBytecodeSlowPath(m_bytecodeOffset, label());
 378
 379         switch (m_interpreter->getOpcodeID(currentInstruction->u.opcode)) {
 380         DEFINE_SLOWCASE_OP(op_add)
 381         DEFINE_SLOWCASE_OP(op_bitand)
 382         DEFINE_SLOWCASE_OP(op_bitor)
 383         DEFINE_SLOWCASE_OP(op_bitxor)
 384         DEFINE_SLOWCASE_OP(op_call)
 385         DEFINE_SLOWCASE_OP(op_call_eval)
 386         DEFINE_SLOWCASE_OP(op_call_varargs)
 387         DEFINE_SLOWCASE_OP(op_construct_varargs)
 388         DEFINE_SLOWCASE_OP(op_construct)
 389         DEFINE_SLOWCASE_OP(op_to_this)
 390         DEFINE_SLOWCASE_OP(op_check_tdz)
 391         DEFINE_SLOWCASE_OP(op_create_this)
 392         DEFINE_SLOWCASE_OP(op_div)
 393         DEFINE_SLOWCASE_OP(op_eq)
 394         case op_get_by_id_out_of_line:
 395         case op_get_array_length:
 396         DEFINE_SLOWCASE_OP(op_get_by_id)
 397         DEFINE_SLOWCASE_OP(op_get_by_val)
 398         DEFINE_SLOWCASE_OP(op_check_has_instance)
 399         DEFINE_SLOWCASE_OP(op_instanceof)
 400         DEFINE_SLOWCASE_OP(op_jfalse)
 401         DEFINE_SLOWCASE_OP(op_jless)
 402         DEFINE_SLOWCASE_OP(op_jlesseq)
 403         DEFINE_SLOWCASE_OP(op_jgreater)
 404         DEFINE_SLOWCASE_OP(op_jgreatereq)
 405         DEFINE_SLOWCASE_OP(op_jnless)
 406         DEFINE_SLOWCASE_OP(op_jnlesseq)
 407         DEFINE_SLOWCASE_OP(op_jngreater)
 408         DEFINE_SLOWCASE_OP(op_jngreatereq)
 409         DEFINE_SLOWCASE_OP(op_jtrue)
 410         DEFINE_SLOWCASE_OP(op_loop_hint)
 411         DEFINE_SLOWCASE_OP(op_lshift)
 412         DEFINE_SLOWCASE_OP(op_mod)
 413         DEFINE_SLOWCASE_OP(op_mul)
 414         DEFINE_SLOWCASE_OP(op_negate)
 415         DEFINE_SLOWCASE_OP(op_neq)
 416         DEFINE_SLOWCASE_OP(op_new_object)
 417         DEFINE_SLOWCASE_OP(op_not)
 418         DEFINE_SLOWCASE_OP(op_nstricteq)
 419         DEFINE_SLOWCASE_OP(op_dec)
 420         DEFINE_SLOWCASE_OP(op_inc)
 421         case op_put_by_id_out_of_line:
 422         case op_put_by_id_transition_direct:
 423         case op_put_by_id_transition_normal:
 424         case op_put_by_id_transition_direct_out_of_line:
 425         case op_put_by_id_transition_normal_out_of_line:
 426         DEFINE_SLOWCASE_OP(op_put_by_id)
 427         case op_put_by_val_direct:
 428         DEFINE_SLOWCASE_OP(op_put_by_val)
 429         DEFINE_SLOWCASE_OP(op_rshift)
 430         DEFINE_SLOWCASE_OP(op_unsigned)
 431         DEFINE_SLOWCASE_OP(op_urshift)
 432         DEFINE_SLOWCASE_OP(op_stricteq)
 433         DEFINE_SLOWCASE_OP(op_sub)
 434         DEFINE_SLOWCASE_OP(op_to_number)
 435         DEFINE_SLOWCASE_OP(op_to_string)
 436         DEFINE_SLOWCASE_OP(op_to_primitive)
 437         DEFINE_SLOWCASE_OP(op_has_indexed_property)
 438         DEFINE_SLOWCASE_OP(op_has_structure_property)
 439         DEFINE_SLOWCASE_OP(op_get_direct_pname)
 440
 441         DEFINE_SLOWCASE_OP(op_resolve_scope)
 442         DEFINE_SLOWCASE_OP(op_get_from_scope)
 443         DEFINE_SLOWCASE_OP(op_put_to_scope)
 444
 445         default:
 446             RELEASE_ASSERT_NOT_REACHED();
 447         }
 448
 449         RELEASE_ASSERT_WITH_MESSAGE(iter == m_slowCases.end() || firstTo != iter->to, "Not enough jumps linked in slow case codegen.");
 450         RELEASE_ASSERT_WITH_MESSAGE(firstTo == (iter - 1)->to, "Too many jumps linked in slow case codegen.");
 451
 452         if (shouldEmitProfiling())
 453             add32(TrustedImm32(1), AbsoluteAddress(&rareCaseProfile->m_counter));
 454
 455         emitJumpSlowToHot(jump(), 0);
 456     }
 457
 458     RELEASE_ASSERT(m_getByIdIndex == m_getByIds.size());
 459     RELEASE_ASSERT(m_putByIdIndex == m_putByIds.size());
 460     RELEASE_ASSERT(m_callLinkInfoIndex == m_callCompilationInfo.size());
 461     RELEASE_ASSERT(numberOfValueProfiles == m_codeBlock->numberOfValueProfiles());
 462
 463 #ifndef NDEBUG
 464     // Reset this, in order to guard its use with ASSERTs.
 465     m_bytecodeOffset = std::numeric_limits<unsigned>::max();
 466 #endif
 467 }
 468
 469 CompilationResult JIT::privateCompile(JITCompilationEffort effort)
 470 {
 471     DFG::CapabilityLevel level = m_codeBlock->capabilityLevel();
 472     switch (level) {
 473     case DFG::CannotCompile:
 474         m_canBeOptimized = false;
 475         m_canBeOptimizedOrInlined = false;
 476         m_shouldEmitProfiling = false;
 477         break;
 478     case DFG::CanCompile:
 479     case DFG::CanCompileAndInline:
 480         m_canBeOptimized = true;
 481         m_canBeOptimizedOrInlined = true;
 482         m_shouldEmitProfiling = true;
 483         break;
 484     default:
 485         RELEASE_ASSERT_NOT_REACHED();
 486         break;
 487     }
 488
 489     switch (m_codeBlock->codeType()) {
 490     case GlobalCode:
 491     case EvalCode:
 492         m_codeBlock->m_shouldAlwaysBeInlined = false;
 493         break;
 494     case FunctionCode:
 495         // We could have already set it to false because we detected an uninlineable call.
 496         // Don't override that observation.
 497         m_codeBlock->m_shouldAlwaysBeInlined &= canInline(level) && DFG::mightInlineFunction(m_codeBlock);
 498         break;
 499     }
 500
 501     // This ensures that we have the most up to date type information when performing typecheck optimizations for op_profile_type.
 502     if (m_vm->typeProfiler())
 503         m_vm->typeProfilerLog()->processLogEntries(ASCIILiteral("Preparing for JIT compilation."));
 504
 505     if (Options::showDisassembly() || m_vm->m_perBytecodeProfiler)
 506         m_disassembler = std::make_unique<JITDisassembler>(m_codeBlock);
 507     if (m_vm->m_perBytecodeProfiler) {
 508         m_compilation = adoptRef(
 509             new Profiler::Compilation(
 510                 m_vm->m_perBytecodeProfiler->ensureBytecodesFor(m_codeBlock),
 511                 Profiler::Baseline));
 512         m_compilation->addProfiledBytecodes(*m_vm->m_perBytecodeProfiler, m_codeBlock);
 513     }
 514
 515     if (m_disassembler)
 516         m_disassembler->setStartOfCode(label());
 517
 518     // Just add a little bit of randomness to the codegen
 519     if (m_randomGenerator.getUint32() & 1)
 520         nop();
 521
 522     emitFunctionPrologue();
 523     emitPutImmediateToCallFrameHeader(m_codeBlock, JSStack::CodeBlock);
 524
 525     Label beginLabel(this);
 526
 527     sampleCodeBlock(m_codeBlock);
 528 #if ENABLE(OPCODE_SAMPLING)
 529     sampleInstruction(m_codeBlock->instructions().begin());
 530 #endif
 531
 532     if (m_codeBlock->codeType() == FunctionCode) {
 533         ASSERT(m_bytecodeOffset == std::numeric_limits<unsigned>::max());
 534         if (shouldEmitProfiling()) {
 535             for (int argument = 0; argument < m_codeBlock->numParameters(); ++argument) {
 536                 // If this is a constructor, then we want to put in a dummy profiling site (to
 537                 // keep things consistent) but we don't actually want to record the dummy value.
 538                 if (m_codeBlock->m_isConstructor && !argument)
 539                     continue;
 540                 int offset = CallFrame::argumentOffsetIncludingThis(argument) * static_cast<int>(sizeof(Register));
 541 #if USE(JSVALUE64)
 542                 load64(Address(callFrameRegister, offset), regT0);
 543 #elif USE(JSVALUE32_64)
 544                 load32(Address(callFrameRegister, offset + OBJECT_OFFSETOF(JSValue, u.asBits.payload)), regT0);
 545                 load32(Address(callFrameRegister, offset + OBJECT_OFFSETOF(JSValue, u.asBits.tag)), regT1);
 546 #endif
 547                 emitValueProfilingSite(m_codeBlock->valueProfileForArgument(argument));
 548             }
 549         }
 550     }
 551
 552     addPtr(TrustedImm32(stackPointerOffsetFor(m_codeBlock) * sizeof(Register)), callFrameRegister, regT1);
 553     Jump stackOverflow = branchPtr(Above, AbsoluteAddress(m_vm->addressOfStackLimit()), regT1);
 554
 555     move(regT1, stackPointerRegister);
 556     checkStackPointerAlignment();
 557
 558     privateCompileMainPass();
 559     privateCompileLinkPass();
 560     privateCompileSlowCases();
 561
 562     if (m_disassembler)
 563         m_disassembler->setEndOfSlowPath(label());
 564
 565     stackOverflow.link(this);
 566     m_bytecodeOffset = 0;
 567     if (maxFrameExtentForSlowPathCall)
 568         addPtr(TrustedImm32(-maxFrameExtentForSlowPathCall), stackPointerRegister);
 569     callOperationWithCallFrameRollbackOnException(operationThrowStackOverflowError, m_codeBlock);
 570
 571     Label arityCheck;
 572     if (m_codeBlock->codeType() == FunctionCode) {
 573         arityCheck = label();
 574         store8(TrustedImm32(0), &m_codeBlock->m_shouldAlwaysBeInlined);
 575         emitFunctionPrologue();
 576         emitPutImmediateToCallFrameHeader(m_codeBlock, JSStack::CodeBlock);
 577
 578         load32(payloadFor(JSStack::ArgumentCount), regT1);
 579         branch32(AboveOrEqual, regT1, TrustedImm32(m_codeBlock->m_numParameters)).linkTo(beginLabel, this);
 580
 581         m_bytecodeOffset = 0;
 582
 583         if (maxFrameExtentForSlowPathCall)
 584             addPtr(TrustedImm32(-maxFrameExtentForSlowPathCall), stackPointerRegister);
 585         callOperationWithCallFrameRollbackOnException(m_codeBlock->m_isConstructor ? operationConstructArityCheck : operationCallArityCheck);
 586         if (maxFrameExtentForSlowPathCall)
 587             addPtr(TrustedImm32(maxFrameExtentForSlowPathCall), stackPointerRegister);
 588         if (returnValueGPR != regT0)
 589             move(returnValueGPR, regT0);
 590         branchTest32(Zero, regT0).linkTo(beginLabel, this);
 591         GPRReg thunkReg;
 592 #if USE(JSVALUE64)
 593         thunkReg = GPRInfo::regT7;
 594 #else
 595         thunkReg = GPRInfo::regT5;
 596 #endif
 597         CodeLocationLabel* failThunkLabels =
 598             m_vm->arityCheckFailReturnThunks->returnPCsFor(*m_vm, m_codeBlock->numParameters());
 599         move(TrustedImmPtr(failThunkLabels), thunkReg);
 600         loadPtr(BaseIndex(thunkReg, regT0, timesPtr()), thunkReg);
 601         emitNakedCall(m_vm->getCTIStub(arityFixupGenerator).code());
 602
 603 #if !ASSERT_DISABLED
 604         m_bytecodeOffset = std::numeric_limits<unsigned>::max(); // Reset this, in order to guard its use with ASSERTs.
 605 #endif
 606
 607         jump(beginLabel);
 608     }
 609
 610     ASSERT(m_jmpTable.isEmpty());
 611
 612     privateCompileExceptionHandlers();
 613
 614     if (m_disassembler)
 615         m_disassembler->setEndOfCode(label());
 616
 617     LinkBuffer patchBuffer(*m_vm, *this, m_codeBlock, effort);
 618     if (patchBuffer.didFailToAllocate())
 619         return CompilationFailed;
 620
 621     // Translate vPC offsets into addresses in JIT generated code, for switch tables.
 622     for (unsigned i = 0; i < m_switches.size(); ++i) {
 623         SwitchRecord record = m_switches[i];
 624         unsigned bytecodeOffset = record.bytecodeOffset;
 625
 626         if (record.type != SwitchRecord::String) {
 627             ASSERT(record.type == SwitchRecord::Immediate || record.type == SwitchRecord::Character);
 628             ASSERT(record.jumpTable.simpleJumpTable->branchOffsets.size() == record.jumpTable.simpleJumpTable->ctiOffsets.size());
 629
 630             record.jumpTable.simpleJumpTable->ctiDefault = patchBuffer.locationOf(m_labels[bytecodeOffset + record.defaultOffset]);
 631
 632             for (unsigned j = 0; j < record.jumpTable.simpleJumpTable->branchOffsets.size(); ++j) {
 633                 unsigned offset = record.jumpTable.simpleJumpTable->branchOffsets[j];
 634                 record.jumpTable.simpleJumpTable->ctiOffsets[j] = offset ? patchBuffer.locationOf(m_labels[bytecodeOffset + offset]) : record.jumpTable.simpleJumpTable->ctiDefault;
 635             }
 636         } else {
 637             ASSERT(record.type == SwitchRecord::String);
 638
 639             record.jumpTable.stringJumpTable->ctiDefault = patchBuffer.locationOf(m_labels[bytecodeOffset + record.defaultOffset]);
 640
 641             StringJumpTable::StringOffsetTable::iterator end = record.jumpTable.stringJumpTable->offsetTable.end();
 642             for (StringJumpTable::StringOffsetTable::iterator it = record.jumpTable.stringJumpTable->offsetTable.begin(); it != end; ++it) {
 643                 unsigned offset = it->value.branchOffset;
 644                 it->value.ctiOffset = offset ? patchBuffer.locationOf(m_labels[bytecodeOffset + offset]) : record.jumpTable.stringJumpTable->ctiDefault;
 645             }
 646         }
 647     }
 648
 649     for (size_t i = 0; i < m_codeBlock->numberOfExceptionHandlers(); ++i) {
 650         HandlerInfo& handler = m_codeBlock->exceptionHandler(i);
 651         handler.nativeCode = patchBuffer.locationOf(m_labels[handler.target]);
 652     }
 653
 654     for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
 655         if (iter->to)
 656             patchBuffer.link(iter->from, FunctionPtr(iter->to));
 657     }
 658
 659     for (unsigned i = m_getByIds.size(); i--;)
 660         m_getByIds[i].finalize(patchBuffer);
 661     for (unsigned i = m_putByIds.size(); i--;)
 662         m_putByIds[i].finalize(patchBuffer);
 663
 664     m_codeBlock->setNumberOfByValInfos(m_byValCompilationInfo.size());
 665     for (unsigned i = 0; i < m_byValCompilationInfo.size(); ++i) {
 666         CodeLocationJump badTypeJump = CodeLocationJump(patchBuffer.locationOf(m_byValCompilationInfo[i].badTypeJump));
 667         CodeLocationLabel doneTarget = patchBuffer.locationOf(m_byValCompilationInfo[i].doneTarget);
 668         CodeLocationLabel slowPathTarget = patchBuffer.locationOf(m_byValCompilationInfo[i].slowPathTarget);
 669         CodeLocationCall returnAddress = patchBuffer.locationOf(m_byValCompilationInfo[i].returnAddress);
 670
 671         m_codeBlock->byValInfo(i) = ByValInfo(
 672             m_byValCompilationInfo[i].bytecodeIndex,
 673             badTypeJump,
 674             m_byValCompilationInfo[i].arrayMode,
 675             differenceBetweenCodePtr(badTypeJump, doneTarget),
 676             differenceBetweenCodePtr(returnAddress, slowPathTarget));
 677     }
 678     for (unsigned i = 0; i < m_callCompilationInfo.size(); ++i) {
 679         CallCompilationInfo& compilationInfo = m_callCompilationInfo[i];
 680         CallLinkInfo& info = *compilationInfo.callLinkInfo;
 681         info.setCallLocations(patchBuffer.locationOfNearCall(compilationInfo.callReturnLocation),
 682             patchBuffer.locationOf(compilationInfo.hotPathBegin),
 683             patchBuffer.locationOfNearCall(compilationInfo.hotPathOther));
 684     }
 685
 686     CompactJITCodeMap::Encoder jitCodeMapEncoder;
 687     for (unsigned bytecodeOffset = 0; bytecodeOffset < m_labels.size(); ++bytecodeOffset) {
 688         if (m_labels[bytecodeOffset].isSet())
 689             jitCodeMapEncoder.append(bytecodeOffset, patchBuffer.offsetOf(m_labels[bytecodeOffset]));
 690     }
 691     m_codeBlock->setJITCodeMap(jitCodeMapEncoder.finish());
 692
 693     MacroAssemblerCodePtr withArityCheck;
 694     if (m_codeBlock->codeType() == FunctionCode)
 695         withArityCheck = patchBuffer.locationOf(arityCheck);
 696
 697     if (Options::showDisassembly()) {
 698         m_disassembler->dump(patchBuffer);
 699         patchBuffer.didAlreadyDisassemble();
 700     }
 701     if (m_compilation) {
 702         m_disassembler->reportToProfiler(m_compilation.get(), patchBuffer);
 703         m_vm->m_perBytecodeProfiler->addCompilation(m_compilation);
 704     }
 705
 706     CodeRef result = FINALIZE_CODE(
 707         patchBuffer,
 708         ("Baseline JIT code for %s", toCString(CodeBlockWithJITType(m_codeBlock, JITCode::BaselineJIT)).data()));
 709
 710     m_vm->machineCodeBytesPerBytecodeWordForBaselineJIT.add(
 711         static_cast<double>(result.size()) /
 712         static_cast<double>(m_codeBlock->instructions().size()));
 713
 714     m_codeBlock->shrinkToFit(CodeBlock::LateShrink);
 715     m_codeBlock->setJITCode(
 716         adoptRef(new DirectJITCode(result, withArityCheck, JITCode::BaselineJIT)));
 717
 718 #if ENABLE(JIT_VERBOSE)
 719     dataLogF("JIT generated code for %p at [%p, %p).\n", m_codeBlock, result.executableMemory()->start(), result.executableMemory()->end());
 720 #endif
 721
 722     return CompilationSuccessful;
 723 }
 724
 725 void JIT::privateCompileExceptionHandlers()
 726 {
 727     if (!m_exceptionChecksWithCallFrameRollback.empty()) {
 728         m_exceptionChecksWithCallFrameRollback.link(this);
 729
 730         // lookupExceptionHandlerFromCallerFrame is passed two arguments, the VM and the exec (the CallFrame*).
 731
 732         move(TrustedImmPtr(vm()), GPRInfo::argumentGPR0);
 733         move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
 734
 735 #if CPU(X86)
 736         // FIXME: should use the call abstraction, but this is currently in the SpeculativeJIT layer!
 737         poke(GPRInfo::argumentGPR0);
 738         poke(GPRInfo::argumentGPR1, 1);
 739 #endif
 740         m_calls.append(CallRecord(call(), std::numeric_limits<unsigned>::max(), FunctionPtr(lookupExceptionHandlerFromCallerFrame).value()));
 741         jumpToExceptionHandler();
 742     }
 743
 744     if (!m_exceptionChecks.empty()) {
 745         m_exceptionChecks.link(this);
 746
 747         // lookupExceptionHandler is passed two arguments, the VM and the exec (the CallFrame*).
 748         move(TrustedImmPtr(vm()), GPRInfo::argumentGPR0);
 749         move(GPRInfo::callFrameRegister, GPRInfo::argumentGPR1);
 750
 751 #if CPU(X86)
 752         // FIXME: should use the call abstraction, but this is currently in the SpeculativeJIT layer!
 753         poke(GPRInfo::argumentGPR0);
 754         poke(GPRInfo::argumentGPR1, 1);
 755 #endif
 756         m_calls.append(CallRecord(call(), std::numeric_limits<unsigned>::max(), FunctionPtr(lookupExceptionHandler).value()));
 757         jumpToExceptionHandler();
 758     }
 759 }
 760
 761 unsigned JIT::frameRegisterCountFor(CodeBlock* codeBlock)
 762 {
 763     ASSERT(static_cast<unsigned>(codeBlock->m_numCalleeRegisters) == WTF::roundUpToMultipleOf(stackAlignmentRegisters(), static_cast<unsigned>(codeBlock->m_numCalleeRegisters)));
 764
 765     return roundLocalRegisterCountForFramePointerOffset(codeBlock->m_numCalleeRegisters + maxFrameExtentForSlowPathCallInRegisters);
 766 }
 767
 768 int JIT::stackPointerOffsetFor(CodeBlock* codeBlock)
 769 {
 770     return virtualRegisterForLocal(frameRegisterCountFor(codeBlock) - 1).offset();
 771 }
 772
 773 } // namespace JSC
 774
 775 #endif // ENABLE(JIT)