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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "src/v8.h"
      6 
      7 #if V8_TARGET_ARCH_X87
      8 
      9 #include "src/code-factory.h"
     10 #include "src/codegen.h"
     11 #include "src/deoptimizer.h"
     12 #include "src/full-codegen.h"
     13 
     14 namespace v8 {
     15 namespace internal {
     16 
     17 
     18 #define __ ACCESS_MASM(masm)
     19 
     20 
     21 void Builtins::Generate_Adaptor(MacroAssembler* masm,
     22                                 CFunctionId id,
     23                                 BuiltinExtraArguments extra_args) {
     24   // ----------- S t a t e -------------
     25   //  -- eax                : number of arguments excluding receiver
     26   //  -- edi                : called function (only guaranteed when
     27   //                          extra_args requires it)
     28   //  -- esi                : context
     29   //  -- esp[0]             : return address
     30   //  -- esp[4]             : last argument
     31   //  -- ...
     32   //  -- esp[4 * argc]      : first argument (argc == eax)
     33   //  -- esp[4 * (argc +1)] : receiver
     34   // -----------------------------------
     35 
     36   // Insert extra arguments.
     37   int num_extra_args = 0;
     38   if (extra_args == NEEDS_CALLED_FUNCTION) {
     39     num_extra_args = 1;
     40     Register scratch = ebx;
     41     __ pop(scratch);  // Save return address.
     42     __ push(edi);
     43     __ push(scratch);  // Restore return address.
     44   } else {
     45     DCHECK(extra_args == NO_EXTRA_ARGUMENTS);
     46   }
     47 
     48   // JumpToExternalReference expects eax to contain the number of arguments
     49   // including the receiver and the extra arguments.
     50   __ add(eax, Immediate(num_extra_args + 1));
     51   __ JumpToExternalReference(ExternalReference(id, masm->isolate()));
     52 }
     53 
     54 
     55 static void CallRuntimePassFunction(
     56     MacroAssembler* masm, Runtime::FunctionId function_id) {
     57   FrameScope scope(masm, StackFrame::INTERNAL);
     58   // Push a copy of the function.
     59   __ push(edi);
     60   // Function is also the parameter to the runtime call.
     61   __ push(edi);
     62 
     63   __ CallRuntime(function_id, 1);
     64   // Restore receiver.
     65   __ pop(edi);
     66 }
     67 
     68 
     69 static void GenerateTailCallToSharedCode(MacroAssembler* masm) {
     70   __ mov(eax, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
     71   __ mov(eax, FieldOperand(eax, SharedFunctionInfo::kCodeOffset));
     72   __ lea(eax, FieldOperand(eax, Code::kHeaderSize));
     73   __ jmp(eax);
     74 }
     75 
     76 
     77 static void GenerateTailCallToReturnedCode(MacroAssembler* masm) {
     78   __ lea(eax, FieldOperand(eax, Code::kHeaderSize));
     79   __ jmp(eax);
     80 }
     81 
     82 
     83 void Builtins::Generate_InOptimizationQueue(MacroAssembler* masm) {
     84   // Checking whether the queued function is ready for install is optional,
     85   // since we come across interrupts and stack checks elsewhere.  However,
     86   // not checking may delay installing ready functions, and always checking
     87   // would be quite expensive.  A good compromise is to first check against
     88   // stack limit as a cue for an interrupt signal.
     89   Label ok;
     90   ExternalReference stack_limit =
     91       ExternalReference::address_of_stack_limit(masm->isolate());
     92   __ cmp(esp, Operand::StaticVariable(stack_limit));
     93   __ j(above_equal, &ok, Label::kNear);
     94 
     95   CallRuntimePassFunction(masm, Runtime::kTryInstallOptimizedCode);
     96   GenerateTailCallToReturnedCode(masm);
     97 
     98   __ bind(&ok);
     99   GenerateTailCallToSharedCode(masm);
    100 }
    101 
    102 
    103 static void Generate_JSConstructStubHelper(MacroAssembler* masm,
    104                                            bool is_api_function,
    105                                            bool create_memento) {
    106   // ----------- S t a t e -------------
    107   //  -- eax: number of arguments
    108   //  -- edi: constructor function
    109   //  -- ebx: allocation site or undefined
    110   // -----------------------------------
    111 
    112   // Should never create mementos for api functions.
    113   DCHECK(!is_api_function || !create_memento);
    114 
    115   // Enter a construct frame.
    116   {
    117     FrameScope scope(masm, StackFrame::CONSTRUCT);
    118 
    119     if (create_memento) {
    120       __ AssertUndefinedOrAllocationSite(ebx);
    121       __ push(ebx);
    122     }
    123 
    124     // Store a smi-tagged arguments count on the stack.
    125     __ SmiTag(eax);
    126     __ push(eax);
    127 
    128     // Push the function to invoke on the stack.
    129     __ push(edi);
    130 
    131     // Try to allocate the object without transitioning into C code. If any of
    132     // the preconditions is not met, the code bails out to the runtime call.
    133     Label rt_call, allocated;
    134     if (FLAG_inline_new) {
    135       Label undo_allocation;
    136       ExternalReference debug_step_in_fp =
    137           ExternalReference::debug_step_in_fp_address(masm->isolate());
    138       __ cmp(Operand::StaticVariable(debug_step_in_fp), Immediate(0));
    139       __ j(not_equal, &rt_call);
    140 
    141       // Verified that the constructor is a JSFunction.
    142       // Load the initial map and verify that it is in fact a map.
    143       // edi: constructor
    144       __ mov(eax, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
    145       // Will both indicate a NULL and a Smi
    146       __ JumpIfSmi(eax, &rt_call);
    147       // edi: constructor
    148       // eax: initial map (if proven valid below)
    149       __ CmpObjectType(eax, MAP_TYPE, ebx);
    150       __ j(not_equal, &rt_call);
    151 
    152       // Check that the constructor is not constructing a JSFunction (see
    153       // comments in Runtime_NewObject in runtime.cc). In which case the
    154       // initial map's instance type would be JS_FUNCTION_TYPE.
    155       // edi: constructor
    156       // eax: initial map
    157       __ CmpInstanceType(eax, JS_FUNCTION_TYPE);
    158       __ j(equal, &rt_call);
    159 
    160       if (!is_api_function) {
    161         Label allocate;
    162         // The code below relies on these assumptions.
    163         STATIC_ASSERT(JSFunction::kNoSlackTracking == 0);
    164         STATIC_ASSERT(Map::ConstructionCount::kShift +
    165                       Map::ConstructionCount::kSize == 32);
    166         // Check if slack tracking is enabled.
    167         __ mov(esi, FieldOperand(eax, Map::kBitField3Offset));
    168         __ shr(esi, Map::ConstructionCount::kShift);
    169         __ j(zero, &allocate);  // JSFunction::kNoSlackTracking
    170         // Decrease generous allocation count.
    171         __ sub(FieldOperand(eax, Map::kBitField3Offset),
    172                Immediate(1 << Map::ConstructionCount::kShift));
    173 
    174         __ cmp(esi, JSFunction::kFinishSlackTracking);
    175         __ j(not_equal, &allocate);
    176 
    177         __ push(eax);
    178         __ push(edi);
    179 
    180         __ push(edi);  // constructor
    181         __ CallRuntime(Runtime::kFinalizeInstanceSize, 1);
    182 
    183         __ pop(edi);
    184         __ pop(eax);
    185         __ xor_(esi, esi);  // JSFunction::kNoSlackTracking
    186 
    187         __ bind(&allocate);
    188       }
    189 
    190       // Now allocate the JSObject on the heap.
    191       // edi: constructor
    192       // eax: initial map
    193       __ movzx_b(edi, FieldOperand(eax, Map::kInstanceSizeOffset));
    194       __ shl(edi, kPointerSizeLog2);
    195       if (create_memento) {
    196         __ add(edi, Immediate(AllocationMemento::kSize));
    197       }
    198 
    199       __ Allocate(edi, ebx, edi, no_reg, &rt_call, NO_ALLOCATION_FLAGS);
    200 
    201       Factory* factory = masm->isolate()->factory();
    202 
    203       // Allocated the JSObject, now initialize the fields.
    204       // eax: initial map
    205       // ebx: JSObject
    206       // edi: start of next object (including memento if create_memento)
    207       __ mov(Operand(ebx, JSObject::kMapOffset), eax);
    208       __ mov(ecx, factory->empty_fixed_array());
    209       __ mov(Operand(ebx, JSObject::kPropertiesOffset), ecx);
    210       __ mov(Operand(ebx, JSObject::kElementsOffset), ecx);
    211       // Set extra fields in the newly allocated object.
    212       // eax: initial map
    213       // ebx: JSObject
    214       // edi: start of next object (including memento if create_memento)
    215       // esi: slack tracking counter (non-API function case)
    216       __ mov(edx, factory->undefined_value());
    217       __ lea(ecx, Operand(ebx, JSObject::kHeaderSize));
    218       if (!is_api_function) {
    219         Label no_inobject_slack_tracking;
    220 
    221         // Check if slack tracking is enabled.
    222         __ cmp(esi, JSFunction::kNoSlackTracking);
    223         __ j(equal, &no_inobject_slack_tracking);
    224 
    225         // Allocate object with a slack.
    226         __ movzx_b(esi,
    227                    FieldOperand(eax, Map::kPreAllocatedPropertyFieldsOffset));
    228         __ lea(esi,
    229                Operand(ebx, esi, times_pointer_size, JSObject::kHeaderSize));
    230         // esi: offset of first field after pre-allocated fields
    231         if (FLAG_debug_code) {
    232           __ cmp(esi, edi);
    233           __ Assert(less_equal,
    234                     kUnexpectedNumberOfPreAllocatedPropertyFields);
    235         }
    236         __ InitializeFieldsWithFiller(ecx, esi, edx);
    237         __ mov(edx, factory->one_pointer_filler_map());
    238         // Fill the remaining fields with one pointer filler map.
    239 
    240         __ bind(&no_inobject_slack_tracking);
    241       }
    242 
    243       if (create_memento) {
    244         __ lea(esi, Operand(edi, -AllocationMemento::kSize));
    245         __ InitializeFieldsWithFiller(ecx, esi, edx);
    246 
    247         // Fill in memento fields if necessary.
    248         // esi: points to the allocated but uninitialized memento.
    249         __ mov(Operand(esi, AllocationMemento::kMapOffset),
    250                factory->allocation_memento_map());
    251         // Get the cell or undefined.
    252         __ mov(edx, Operand(esp, kPointerSize*2));
    253         __ mov(Operand(esi, AllocationMemento::kAllocationSiteOffset),
    254                edx);
    255       } else {
    256         __ InitializeFieldsWithFiller(ecx, edi, edx);
    257       }
    258 
    259       // Add the object tag to make the JSObject real, so that we can continue
    260       // and jump into the continuation code at any time from now on. Any
    261       // failures need to undo the allocation, so that the heap is in a
    262       // consistent state and verifiable.
    263       // eax: initial map
    264       // ebx: JSObject
    265       // edi: start of next object
    266       __ or_(ebx, Immediate(kHeapObjectTag));
    267 
    268       // Check if a non-empty properties array is needed.
    269       // Allocate and initialize a FixedArray if it is.
    270       // eax: initial map
    271       // ebx: JSObject
    272       // edi: start of next object
    273       // Calculate the total number of properties described by the map.
    274       __ movzx_b(edx, FieldOperand(eax, Map::kUnusedPropertyFieldsOffset));
    275       __ movzx_b(ecx,
    276                  FieldOperand(eax, Map::kPreAllocatedPropertyFieldsOffset));
    277       __ add(edx, ecx);
    278       // Calculate unused properties past the end of the in-object properties.
    279       __ movzx_b(ecx, FieldOperand(eax, Map::kInObjectPropertiesOffset));
    280       __ sub(edx, ecx);
    281       // Done if no extra properties are to be allocated.
    282       __ j(zero, &allocated);
    283       __ Assert(positive, kPropertyAllocationCountFailed);
    284 
    285       // Scale the number of elements by pointer size and add the header for
    286       // FixedArrays to the start of the next object calculation from above.
    287       // ebx: JSObject
    288       // edi: start of next object (will be start of FixedArray)
    289       // edx: number of elements in properties array
    290       __ Allocate(FixedArray::kHeaderSize,
    291                   times_pointer_size,
    292                   edx,
    293                   REGISTER_VALUE_IS_INT32,
    294                   edi,
    295                   ecx,
    296                   no_reg,
    297                   &undo_allocation,
    298                   RESULT_CONTAINS_TOP);
    299 
    300       // Initialize the FixedArray.
    301       // ebx: JSObject
    302       // edi: FixedArray
    303       // edx: number of elements
    304       // ecx: start of next object
    305       __ mov(eax, factory->fixed_array_map());
    306       __ mov(Operand(edi, FixedArray::kMapOffset), eax);  // setup the map
    307       __ SmiTag(edx);
    308       __ mov(Operand(edi, FixedArray::kLengthOffset), edx);  // and length
    309 
    310       // Initialize the fields to undefined.
    311       // ebx: JSObject
    312       // edi: FixedArray
    313       // ecx: start of next object
    314       { Label loop, entry;
    315         __ mov(edx, factory->undefined_value());
    316         __ lea(eax, Operand(edi, FixedArray::kHeaderSize));
    317         __ jmp(&entry);
    318         __ bind(&loop);
    319         __ mov(Operand(eax, 0), edx);
    320         __ add(eax, Immediate(kPointerSize));
    321         __ bind(&entry);
    322         __ cmp(eax, ecx);
    323         __ j(below, &loop);
    324       }
    325 
    326       // Store the initialized FixedArray into the properties field of
    327       // the JSObject
    328       // ebx: JSObject
    329       // edi: FixedArray
    330       __ or_(edi, Immediate(kHeapObjectTag));  // add the heap tag
    331       __ mov(FieldOperand(ebx, JSObject::kPropertiesOffset), edi);
    332 
    333 
    334       // Continue with JSObject being successfully allocated
    335       // ebx: JSObject
    336       __ jmp(&allocated);
    337 
    338       // Undo the setting of the new top so that the heap is verifiable. For
    339       // example, the map's unused properties potentially do not match the
    340       // allocated objects unused properties.
    341       // ebx: JSObject (previous new top)
    342       __ bind(&undo_allocation);
    343       __ UndoAllocationInNewSpace(ebx);
    344     }
    345 
    346     // Allocate the new receiver object using the runtime call.
    347     __ bind(&rt_call);
    348     int offset = 0;
    349     if (create_memento) {
    350       // Get the cell or allocation site.
    351       __ mov(edi, Operand(esp, kPointerSize * 2));
    352       __ push(edi);
    353       offset = kPointerSize;
    354     }
    355 
    356     // Must restore esi (context) and edi (constructor) before calling runtime.
    357     __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
    358     __ mov(edi, Operand(esp, offset));
    359     // edi: function (constructor)
    360     __ push(edi);
    361     if (create_memento) {
    362       __ CallRuntime(Runtime::kNewObjectWithAllocationSite, 2);
    363     } else {
    364       __ CallRuntime(Runtime::kNewObject, 1);
    365     }
    366     __ mov(ebx, eax);  // store result in ebx
    367 
    368     // If we ended up using the runtime, and we want a memento, then the
    369     // runtime call made it for us, and we shouldn't do create count
    370     // increment.
    371     Label count_incremented;
    372     if (create_memento) {
    373       __ jmp(&count_incremented);
    374     }
    375 
    376     // New object allocated.
    377     // ebx: newly allocated object
    378     __ bind(&allocated);
    379 
    380     if (create_memento) {
    381       __ mov(ecx, Operand(esp, kPointerSize * 2));
    382       __ cmp(ecx, masm->isolate()->factory()->undefined_value());
    383       __ j(equal, &count_incremented);
    384       // ecx is an AllocationSite. We are creating a memento from it, so we
    385       // need to increment the memento create count.
    386       __ add(FieldOperand(ecx, AllocationSite::kPretenureCreateCountOffset),
    387              Immediate(Smi::FromInt(1)));
    388       __ bind(&count_incremented);
    389     }
    390 
    391     // Retrieve the function from the stack.
    392     __ pop(edi);
    393 
    394     // Retrieve smi-tagged arguments count from the stack.
    395     __ mov(eax, Operand(esp, 0));
    396     __ SmiUntag(eax);
    397 
    398     // Push the allocated receiver to the stack. We need two copies
    399     // because we may have to return the original one and the calling
    400     // conventions dictate that the called function pops the receiver.
    401     __ push(ebx);
    402     __ push(ebx);
    403 
    404     // Set up pointer to last argument.
    405     __ lea(ebx, Operand(ebp, StandardFrameConstants::kCallerSPOffset));
    406 
    407     // Copy arguments and receiver to the expression stack.
    408     Label loop, entry;
    409     __ mov(ecx, eax);
    410     __ jmp(&entry);
    411     __ bind(&loop);
    412     __ push(Operand(ebx, ecx, times_4, 0));
    413     __ bind(&entry);
    414     __ dec(ecx);
    415     __ j(greater_equal, &loop);
    416 
    417     // Call the function.
    418     if (is_api_function) {
    419       __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
    420       Handle<Code> code =
    421           masm->isolate()->builtins()->HandleApiCallConstruct();
    422       __ call(code, RelocInfo::CODE_TARGET);
    423     } else {
    424       ParameterCount actual(eax);
    425       __ InvokeFunction(edi, actual, CALL_FUNCTION,
    426                         NullCallWrapper());
    427     }
    428 
    429     // Store offset of return address for deoptimizer.
    430     if (!is_api_function) {
    431       masm->isolate()->heap()->SetConstructStubDeoptPCOffset(masm->pc_offset());
    432     }
    433 
    434     // Restore context from the frame.
    435     __ mov(esi, Operand(ebp, StandardFrameConstants::kContextOffset));
    436 
    437     // If the result is an object (in the ECMA sense), we should get rid
    438     // of the receiver and use the result; see ECMA-262 section 13.2.2-7
    439     // on page 74.
    440     Label use_receiver, exit;
    441 
    442     // If the result is a smi, it is *not* an object in the ECMA sense.
    443     __ JumpIfSmi(eax, &use_receiver);
    444 
    445     // If the type of the result (stored in its map) is less than
    446     // FIRST_SPEC_OBJECT_TYPE, it is not an object in the ECMA sense.
    447     __ CmpObjectType(eax, FIRST_SPEC_OBJECT_TYPE, ecx);
    448     __ j(above_equal, &exit);
    449 
    450     // Throw away the result of the constructor invocation and use the
    451     // on-stack receiver as the result.
    452     __ bind(&use_receiver);
    453     __ mov(eax, Operand(esp, 0));
    454 
    455     // Restore the arguments count and leave the construct frame.
    456     __ bind(&exit);
    457     __ mov(ebx, Operand(esp, kPointerSize));  // Get arguments count.
    458 
    459     // Leave construct frame.
    460   }
    461 
    462   // Remove caller arguments from the stack and return.
    463   STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
    464   __ pop(ecx);
    465   __ lea(esp, Operand(esp, ebx, times_2, 1 * kPointerSize));  // 1 ~ receiver
    466   __ push(ecx);
    467   __ IncrementCounter(masm->isolate()->counters()->constructed_objects(), 1);
    468   __ ret(0);
    469 }
    470 
    471 
    472 void Builtins::Generate_JSConstructStubGeneric(MacroAssembler* masm) {
    473   Generate_JSConstructStubHelper(masm, false, FLAG_pretenuring_call_new);
    474 }
    475 
    476 
    477 void Builtins::Generate_JSConstructStubApi(MacroAssembler* masm) {
    478   Generate_JSConstructStubHelper(masm, true, false);
    479 }
    480 
    481 
    482 static void Generate_JSEntryTrampolineHelper(MacroAssembler* masm,
    483                                              bool is_construct) {
    484   ProfileEntryHookStub::MaybeCallEntryHook(masm);
    485 
    486   // Clear the context before we push it when entering the internal frame.
    487   __ Move(esi, Immediate(0));
    488 
    489   {
    490     FrameScope scope(masm, StackFrame::INTERNAL);
    491 
    492     // Load the previous frame pointer (ebx) to access C arguments
    493     __ mov(ebx, Operand(ebp, 0));
    494 
    495     // Get the function from the frame and setup the context.
    496     __ mov(ecx, Operand(ebx, EntryFrameConstants::kFunctionArgOffset));
    497     __ mov(esi, FieldOperand(ecx, JSFunction::kContextOffset));
    498 
    499     // Push the function and the receiver onto the stack.
    500     __ push(ecx);
    501     __ push(Operand(ebx, EntryFrameConstants::kReceiverArgOffset));
    502 
    503     // Load the number of arguments and setup pointer to the arguments.
    504     __ mov(eax, Operand(ebx, EntryFrameConstants::kArgcOffset));
    505     __ mov(ebx, Operand(ebx, EntryFrameConstants::kArgvOffset));
    506 
    507     // Copy arguments to the stack in a loop.
    508     Label loop, entry;
    509     __ Move(ecx, Immediate(0));
    510     __ jmp(&entry);
    511     __ bind(&loop);
    512     __ mov(edx, Operand(ebx, ecx, times_4, 0));  // push parameter from argv
    513     __ push(Operand(edx, 0));  // dereference handle
    514     __ inc(ecx);
    515     __ bind(&entry);
    516     __ cmp(ecx, eax);
    517     __ j(not_equal, &loop);
    518 
    519     // Get the function from the stack and call it.
    520     // kPointerSize for the receiver.
    521     __ mov(edi, Operand(esp, eax, times_4, kPointerSize));
    522 
    523     // Invoke the code.
    524     if (is_construct) {
    525       // No type feedback cell is available
    526       __ mov(ebx, masm->isolate()->factory()->undefined_value());
    527       CallConstructStub stub(masm->isolate(), NO_CALL_CONSTRUCTOR_FLAGS);
    528       __ CallStub(&stub);
    529     } else {
    530       ParameterCount actual(eax);
    531       __ InvokeFunction(edi, actual, CALL_FUNCTION,
    532                         NullCallWrapper());
    533     }
    534 
    535     // Exit the internal frame. Notice that this also removes the empty.
    536     // context and the function left on the stack by the code
    537     // invocation.
    538   }
    539   __ ret(kPointerSize);  // Remove receiver.
    540 }
    541 
    542 
    543 void Builtins::Generate_JSEntryTrampoline(MacroAssembler* masm) {
    544   Generate_JSEntryTrampolineHelper(masm, false);
    545 }
    546 
    547 
    548 void Builtins::Generate_JSConstructEntryTrampoline(MacroAssembler* masm) {
    549   Generate_JSEntryTrampolineHelper(masm, true);
    550 }
    551 
    552 
    553 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
    554   CallRuntimePassFunction(masm, Runtime::kCompileLazy);
    555   GenerateTailCallToReturnedCode(masm);
    556 }
    557 
    558 
    559 
    560 static void CallCompileOptimized(MacroAssembler* masm, bool concurrent) {
    561   FrameScope scope(masm, StackFrame::INTERNAL);
    562   // Push a copy of the function.
    563   __ push(edi);
    564   // Function is also the parameter to the runtime call.
    565   __ push(edi);
    566   // Whether to compile in a background thread.
    567   __ Push(masm->isolate()->factory()->ToBoolean(concurrent));
    568 
    569   __ CallRuntime(Runtime::kCompileOptimized, 2);
    570   // Restore receiver.
    571   __ pop(edi);
    572 }
    573 
    574 
    575 void Builtins::Generate_CompileOptimized(MacroAssembler* masm) {
    576   CallCompileOptimized(masm, false);
    577   GenerateTailCallToReturnedCode(masm);
    578 }
    579 
    580 
    581 void Builtins::Generate_CompileOptimizedConcurrent(MacroAssembler* masm) {
    582   CallCompileOptimized(masm, true);
    583   GenerateTailCallToReturnedCode(masm);
    584 }
    585 
    586 
    587 static void GenerateMakeCodeYoungAgainCommon(MacroAssembler* masm) {
    588   // For now, we are relying on the fact that make_code_young doesn't do any
    589   // garbage collection which allows us to save/restore the registers without
    590   // worrying about which of them contain pointers. We also don't build an
    591   // internal frame to make the code faster, since we shouldn't have to do stack
    592   // crawls in MakeCodeYoung. This seems a bit fragile.
    593 
    594   // Re-execute the code that was patched back to the young age when
    595   // the stub returns.
    596   __ sub(Operand(esp, 0), Immediate(5));
    597   __ pushad();
    598   __ mov(eax, Operand(esp, 8 * kPointerSize));
    599   {
    600     FrameScope scope(masm, StackFrame::MANUAL);
    601     __ PrepareCallCFunction(2, ebx);
    602     __ mov(Operand(esp, 1 * kPointerSize),
    603            Immediate(ExternalReference::isolate_address(masm->isolate())));
    604     __ mov(Operand(esp, 0), eax);
    605     __ CallCFunction(
    606         ExternalReference::get_make_code_young_function(masm->isolate()), 2);
    607   }
    608   __ popad();
    609   __ ret(0);
    610 }
    611 
    612 #define DEFINE_CODE_AGE_BUILTIN_GENERATOR(C)                 \
    613 void Builtins::Generate_Make##C##CodeYoungAgainEvenMarking(  \
    614     MacroAssembler* masm) {                                  \
    615   GenerateMakeCodeYoungAgainCommon(masm);                    \
    616 }                                                            \
    617 void Builtins::Generate_Make##C##CodeYoungAgainOddMarking(   \
    618     MacroAssembler* masm) {                                  \
    619   GenerateMakeCodeYoungAgainCommon(masm);                    \
    620 }
    621 CODE_AGE_LIST(DEFINE_CODE_AGE_BUILTIN_GENERATOR)
    622 #undef DEFINE_CODE_AGE_BUILTIN_GENERATOR
    623 
    624 
    625 void Builtins::Generate_MarkCodeAsExecutedOnce(MacroAssembler* masm) {
    626   // For now, as in GenerateMakeCodeYoungAgainCommon, we are relying on the fact
    627   // that make_code_young doesn't do any garbage collection which allows us to
    628   // save/restore the registers without worrying about which of them contain
    629   // pointers.
    630   __ pushad();
    631   __ mov(eax, Operand(esp, 8 * kPointerSize));
    632   __ sub(eax, Immediate(Assembler::kCallInstructionLength));
    633   {  // NOLINT
    634     FrameScope scope(masm, StackFrame::MANUAL);
    635     __ PrepareCallCFunction(2, ebx);
    636     __ mov(Operand(esp, 1 * kPointerSize),
    637            Immediate(ExternalReference::isolate_address(masm->isolate())));
    638     __ mov(Operand(esp, 0), eax);
    639     __ CallCFunction(
    640         ExternalReference::get_mark_code_as_executed_function(masm->isolate()),
    641         2);
    642   }
    643   __ popad();
    644 
    645   // Perform prologue operations usually performed by the young code stub.
    646   __ pop(eax);   // Pop return address into scratch register.
    647   __ push(ebp);  // Caller's frame pointer.
    648   __ mov(ebp, esp);
    649   __ push(esi);  // Callee's context.
    650   __ push(edi);  // Callee's JS Function.
    651   __ push(eax);  // Push return address after frame prologue.
    652 
    653   // Jump to point after the code-age stub.
    654   __ ret(0);
    655 }
    656 
    657 
    658 void Builtins::Generate_MarkCodeAsExecutedTwice(MacroAssembler* masm) {
    659   GenerateMakeCodeYoungAgainCommon(masm);
    660 }
    661 
    662 
    663 static void Generate_NotifyStubFailureHelper(MacroAssembler* masm,
    664                                              SaveFPRegsMode save_doubles) {
    665   // Enter an internal frame.
    666   {
    667     FrameScope scope(masm, StackFrame::INTERNAL);
    668 
    669     // Preserve registers across notification, this is important for compiled
    670     // stubs that tail call the runtime on deopts passing their parameters in
    671     // registers.
    672     __ pushad();
    673     __ CallRuntime(Runtime::kNotifyStubFailure, 0, save_doubles);
    674     __ popad();
    675     // Tear down internal frame.
    676   }
    677 
    678   __ pop(MemOperand(esp, 0));  // Ignore state offset
    679   __ ret(0);  // Return to IC Miss stub, continuation still on stack.
    680 }
    681 
    682 
    683 void Builtins::Generate_NotifyStubFailure(MacroAssembler* masm) {
    684   Generate_NotifyStubFailureHelper(masm, kDontSaveFPRegs);
    685 }
    686 
    687 
    688 void Builtins::Generate_NotifyStubFailureSaveDoubles(MacroAssembler* masm) {
    689   Generate_NotifyStubFailureHelper(masm, kSaveFPRegs);
    690 }
    691 
    692 
    693 static void Generate_NotifyDeoptimizedHelper(MacroAssembler* masm,
    694                                              Deoptimizer::BailoutType type) {
    695   {
    696     FrameScope scope(masm, StackFrame::INTERNAL);
    697 
    698     // Pass deoptimization type to the runtime system.
    699     __ push(Immediate(Smi::FromInt(static_cast<int>(type))));
    700     __ CallRuntime(Runtime::kNotifyDeoptimized, 1);
    701 
    702     // Tear down internal frame.
    703   }
    704 
    705   // Get the full codegen state from the stack and untag it.
    706   __ mov(ecx, Operand(esp, 1 * kPointerSize));
    707   __ SmiUntag(ecx);
    708 
    709   // Switch on the state.
    710   Label not_no_registers, not_tos_eax;
    711   __ cmp(ecx, FullCodeGenerator::NO_REGISTERS);
    712   __ j(not_equal, &not_no_registers, Label::kNear);
    713   __ ret(1 * kPointerSize);  // Remove state.
    714 
    715   __ bind(&not_no_registers);
    716   __ mov(eax, Operand(esp, 2 * kPointerSize));
    717   __ cmp(ecx, FullCodeGenerator::TOS_REG);
    718   __ j(not_equal, &not_tos_eax, Label::kNear);
    719   __ ret(2 * kPointerSize);  // Remove state, eax.
    720 
    721   __ bind(&not_tos_eax);
    722   __ Abort(kNoCasesLeft);
    723 }
    724 
    725 
    726 void Builtins::Generate_NotifyDeoptimized(MacroAssembler* masm) {
    727   Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::EAGER);
    728 }
    729 
    730 
    731 void Builtins::Generate_NotifySoftDeoptimized(MacroAssembler* masm) {
    732   Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::SOFT);
    733 }
    734 
    735 
    736 void Builtins::Generate_NotifyLazyDeoptimized(MacroAssembler* masm) {
    737   Generate_NotifyDeoptimizedHelper(masm, Deoptimizer::LAZY);
    738 }
    739 
    740 
    741 void Builtins::Generate_FunctionCall(MacroAssembler* masm) {
    742   Factory* factory = masm->isolate()->factory();
    743 
    744   // 1. Make sure we have at least one argument.
    745   { Label done;
    746     __ test(eax, eax);
    747     __ j(not_zero, &done);
    748     __ pop(ebx);
    749     __ push(Immediate(factory->undefined_value()));
    750     __ push(ebx);
    751     __ inc(eax);
    752     __ bind(&done);
    753   }
    754 
    755   // 2. Get the function to call (passed as receiver) from the stack, check
    756   //    if it is a function.
    757   Label slow, non_function;
    758   // 1 ~ return address.
    759   __ mov(edi, Operand(esp, eax, times_4, 1 * kPointerSize));
    760   __ JumpIfSmi(edi, &non_function);
    761   __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
    762   __ j(not_equal, &slow);
    763 
    764 
    765   // 3a. Patch the first argument if necessary when calling a function.
    766   Label shift_arguments;
    767   __ Move(edx, Immediate(0));  // indicate regular JS_FUNCTION
    768   { Label convert_to_object, use_global_proxy, patch_receiver;
    769     // Change context eagerly in case we need the global receiver.
    770     __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
    771 
    772     // Do not transform the receiver for strict mode functions.
    773     __ mov(ebx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
    774     __ test_b(FieldOperand(ebx, SharedFunctionInfo::kStrictModeByteOffset),
    775               1 << SharedFunctionInfo::kStrictModeBitWithinByte);
    776     __ j(not_equal, &shift_arguments);
    777 
    778     // Do not transform the receiver for natives (shared already in ebx).
    779     __ test_b(FieldOperand(ebx, SharedFunctionInfo::kNativeByteOffset),
    780               1 << SharedFunctionInfo::kNativeBitWithinByte);
    781     __ j(not_equal, &shift_arguments);
    782 
    783     // Compute the receiver in sloppy mode.
    784     __ mov(ebx, Operand(esp, eax, times_4, 0));  // First argument.
    785 
    786     // Call ToObject on the receiver if it is not an object, or use the
    787     // global object if it is null or undefined.
    788     __ JumpIfSmi(ebx, &convert_to_object);
    789     __ cmp(ebx, factory->null_value());
    790     __ j(equal, &use_global_proxy);
    791     __ cmp(ebx, factory->undefined_value());
    792     __ j(equal, &use_global_proxy);
    793     STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
    794     __ CmpObjectType(ebx, FIRST_SPEC_OBJECT_TYPE, ecx);
    795     __ j(above_equal, &shift_arguments);
    796 
    797     __ bind(&convert_to_object);
    798 
    799     { // In order to preserve argument count.
    800       FrameScope scope(masm, StackFrame::INTERNAL);
    801       __ SmiTag(eax);
    802       __ push(eax);
    803 
    804       __ push(ebx);
    805       __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
    806       __ mov(ebx, eax);
    807       __ Move(edx, Immediate(0));  // restore
    808 
    809       __ pop(eax);
    810       __ SmiUntag(eax);
    811     }
    812 
    813     // Restore the function to edi.
    814     __ mov(edi, Operand(esp, eax, times_4, 1 * kPointerSize));
    815     __ jmp(&patch_receiver);
    816 
    817     __ bind(&use_global_proxy);
    818     __ mov(ebx,
    819            Operand(esi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
    820     __ mov(ebx, FieldOperand(ebx, GlobalObject::kGlobalProxyOffset));
    821 
    822     __ bind(&patch_receiver);
    823     __ mov(Operand(esp, eax, times_4, 0), ebx);
    824 
    825     __ jmp(&shift_arguments);
    826   }
    827 
    828   // 3b. Check for function proxy.
    829   __ bind(&slow);
    830   __ Move(edx, Immediate(1));  // indicate function proxy
    831   __ CmpInstanceType(ecx, JS_FUNCTION_PROXY_TYPE);
    832   __ j(equal, &shift_arguments);
    833   __ bind(&non_function);
    834   __ Move(edx, Immediate(2));  // indicate non-function
    835 
    836   // 3c. Patch the first argument when calling a non-function.  The
    837   //     CALL_NON_FUNCTION builtin expects the non-function callee as
    838   //     receiver, so overwrite the first argument which will ultimately
    839   //     become the receiver.
    840   __ mov(Operand(esp, eax, times_4, 0), edi);
    841 
    842   // 4. Shift arguments and return address one slot down on the stack
    843   //    (overwriting the original receiver).  Adjust argument count to make
    844   //    the original first argument the new receiver.
    845   __ bind(&shift_arguments);
    846   { Label loop;
    847     __ mov(ecx, eax);
    848     __ bind(&loop);
    849     __ mov(ebx, Operand(esp, ecx, times_4, 0));
    850     __ mov(Operand(esp, ecx, times_4, kPointerSize), ebx);
    851     __ dec(ecx);
    852     __ j(not_sign, &loop);  // While non-negative (to copy return address).
    853     __ pop(ebx);  // Discard copy of return address.
    854     __ dec(eax);  // One fewer argument (first argument is new receiver).
    855   }
    856 
    857   // 5a. Call non-function via tail call to CALL_NON_FUNCTION builtin,
    858   //     or a function proxy via CALL_FUNCTION_PROXY.
    859   { Label function, non_proxy;
    860     __ test(edx, edx);
    861     __ j(zero, &function);
    862     __ Move(ebx, Immediate(0));
    863     __ cmp(edx, Immediate(1));
    864     __ j(not_equal, &non_proxy);
    865 
    866     __ pop(edx);   // return address
    867     __ push(edi);  // re-add proxy object as additional argument
    868     __ push(edx);
    869     __ inc(eax);
    870     __ GetBuiltinEntry(edx, Builtins::CALL_FUNCTION_PROXY);
    871     __ jmp(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
    872            RelocInfo::CODE_TARGET);
    873 
    874     __ bind(&non_proxy);
    875     __ GetBuiltinEntry(edx, Builtins::CALL_NON_FUNCTION);
    876     __ jmp(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
    877            RelocInfo::CODE_TARGET);
    878     __ bind(&function);
    879   }
    880 
    881   // 5b. Get the code to call from the function and check that the number of
    882   //     expected arguments matches what we're providing.  If so, jump
    883   //     (tail-call) to the code in register edx without checking arguments.
    884   __ mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
    885   __ mov(ebx,
    886          FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
    887   __ mov(edx, FieldOperand(edi, JSFunction::kCodeEntryOffset));
    888   __ SmiUntag(ebx);
    889   __ cmp(eax, ebx);
    890   __ j(not_equal,
    891        masm->isolate()->builtins()->ArgumentsAdaptorTrampoline());
    892 
    893   ParameterCount expected(0);
    894   __ InvokeCode(edx, expected, expected, JUMP_FUNCTION, NullCallWrapper());
    895 }
    896 
    897 
    898 void Builtins::Generate_FunctionApply(MacroAssembler* masm) {
    899   static const int kArgumentsOffset = 2 * kPointerSize;
    900   static const int kReceiverOffset = 3 * kPointerSize;
    901   static const int kFunctionOffset = 4 * kPointerSize;
    902   {
    903     FrameScope frame_scope(masm, StackFrame::INTERNAL);
    904 
    905     __ push(Operand(ebp, kFunctionOffset));  // push this
    906     __ push(Operand(ebp, kArgumentsOffset));  // push arguments
    907     __ InvokeBuiltin(Builtins::APPLY_PREPARE, CALL_FUNCTION);
    908 
    909     // Check the stack for overflow. We are not trying to catch
    910     // interruptions (e.g. debug break and preemption) here, so the "real stack
    911     // limit" is checked.
    912     Label okay;
    913     ExternalReference real_stack_limit =
    914         ExternalReference::address_of_real_stack_limit(masm->isolate());
    915     __ mov(edi, Operand::StaticVariable(real_stack_limit));
    916     // Make ecx the space we have left. The stack might already be overflowed
    917     // here which will cause ecx to become negative.
    918     __ mov(ecx, esp);
    919     __ sub(ecx, edi);
    920     // Make edx the space we need for the array when it is unrolled onto the
    921     // stack.
    922     __ mov(edx, eax);
    923     __ shl(edx, kPointerSizeLog2 - kSmiTagSize);
    924     // Check if the arguments will overflow the stack.
    925     __ cmp(ecx, edx);
    926     __ j(greater, &okay);  // Signed comparison.
    927 
    928     // Out of stack space.
    929     __ push(Operand(ebp, 4 * kPointerSize));  // push this
    930     __ push(eax);
    931     __ InvokeBuiltin(Builtins::STACK_OVERFLOW, CALL_FUNCTION);
    932     __ bind(&okay);
    933     // End of stack check.
    934 
    935     // Push current index and limit.
    936     const int kLimitOffset =
    937         StandardFrameConstants::kExpressionsOffset - 1 * kPointerSize;
    938     const int kIndexOffset = kLimitOffset - 1 * kPointerSize;
    939     __ push(eax);  // limit
    940     __ push(Immediate(0));  // index
    941 
    942     // Get the receiver.
    943     __ mov(ebx, Operand(ebp, kReceiverOffset));
    944 
    945     // Check that the function is a JS function (otherwise it must be a proxy).
    946     Label push_receiver, use_global_proxy;
    947     __ mov(edi, Operand(ebp, kFunctionOffset));
    948     __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
    949     __ j(not_equal, &push_receiver);
    950 
    951     // Change context eagerly to get the right global object if necessary.
    952     __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
    953 
    954     // Compute the receiver.
    955     // Do not transform the receiver for strict mode functions.
    956     Label call_to_object;
    957     __ mov(ecx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
    958     __ test_b(FieldOperand(ecx, SharedFunctionInfo::kStrictModeByteOffset),
    959               1 << SharedFunctionInfo::kStrictModeBitWithinByte);
    960     __ j(not_equal, &push_receiver);
    961 
    962     Factory* factory = masm->isolate()->factory();
    963 
    964     // Do not transform the receiver for natives (shared already in ecx).
    965     __ test_b(FieldOperand(ecx, SharedFunctionInfo::kNativeByteOffset),
    966               1 << SharedFunctionInfo::kNativeBitWithinByte);
    967     __ j(not_equal, &push_receiver);
    968 
    969     // Compute the receiver in sloppy mode.
    970     // Call ToObject on the receiver if it is not an object, or use the
    971     // global object if it is null or undefined.
    972     __ JumpIfSmi(ebx, &call_to_object);
    973     __ cmp(ebx, factory->null_value());
    974     __ j(equal, &use_global_proxy);
    975     __ cmp(ebx, factory->undefined_value());
    976     __ j(equal, &use_global_proxy);
    977     STATIC_ASSERT(LAST_SPEC_OBJECT_TYPE == LAST_TYPE);
    978     __ CmpObjectType(ebx, FIRST_SPEC_OBJECT_TYPE, ecx);
    979     __ j(above_equal, &push_receiver);
    980 
    981     __ bind(&call_to_object);
    982     __ push(ebx);
    983     __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
    984     __ mov(ebx, eax);
    985     __ jmp(&push_receiver);
    986 
    987     __ bind(&use_global_proxy);
    988     __ mov(ebx,
    989            Operand(esi, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
    990     __ mov(ebx, FieldOperand(ebx, GlobalObject::kGlobalProxyOffset));
    991 
    992     // Push the receiver.
    993     __ bind(&push_receiver);
    994     __ push(ebx);
    995 
    996     // Copy all arguments from the array to the stack.
    997     Label entry, loop;
    998     Register receiver = LoadDescriptor::ReceiverRegister();
    999     Register key = LoadDescriptor::NameRegister();
   1000     __ mov(key, Operand(ebp, kIndexOffset));
   1001     __ jmp(&entry);
   1002     __ bind(&loop);
   1003     __ mov(receiver, Operand(ebp, kArgumentsOffset));  // load arguments
   1004 
   1005     // Use inline caching to speed up access to arguments.
   1006     if (FLAG_vector_ics) {
   1007       __ mov(VectorLoadICDescriptor::SlotRegister(),
   1008              Immediate(Smi::FromInt(0)));
   1009     }
   1010     Handle<Code> ic = CodeFactory::KeyedLoadIC(masm->isolate()).code();
   1011     __ call(ic, RelocInfo::CODE_TARGET);
   1012     // It is important that we do not have a test instruction after the
   1013     // call.  A test instruction after the call is used to indicate that
   1014     // we have generated an inline version of the keyed load.  In this
   1015     // case, we know that we are not generating a test instruction next.
   1016 
   1017     // Push the nth argument.
   1018     __ push(eax);
   1019 
   1020     // Update the index on the stack and in register key.
   1021     __ mov(key, Operand(ebp, kIndexOffset));
   1022     __ add(key, Immediate(1 << kSmiTagSize));
   1023     __ mov(Operand(ebp, kIndexOffset), key);
   1024 
   1025     __ bind(&entry);
   1026     __ cmp(key, Operand(ebp, kLimitOffset));
   1027     __ j(not_equal, &loop);
   1028 
   1029     // Call the function.
   1030     Label call_proxy;
   1031     ParameterCount actual(eax);
   1032     __ Move(eax, key);
   1033     __ SmiUntag(eax);
   1034     __ mov(edi, Operand(ebp, kFunctionOffset));
   1035     __ CmpObjectType(edi, JS_FUNCTION_TYPE, ecx);
   1036     __ j(not_equal, &call_proxy);
   1037     __ InvokeFunction(edi, actual, CALL_FUNCTION, NullCallWrapper());
   1038 
   1039     frame_scope.GenerateLeaveFrame();
   1040     __ ret(3 * kPointerSize);  // remove this, receiver, and arguments
   1041 
   1042     // Call the function proxy.
   1043     __ bind(&call_proxy);
   1044     __ push(edi);  // add function proxy as last argument
   1045     __ inc(eax);
   1046     __ Move(ebx, Immediate(0));
   1047     __ GetBuiltinEntry(edx, Builtins::CALL_FUNCTION_PROXY);
   1048     __ call(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
   1049             RelocInfo::CODE_TARGET);
   1050 
   1051     // Leave internal frame.
   1052   }
   1053   __ ret(3 * kPointerSize);  // remove this, receiver, and arguments
   1054 }
   1055 
   1056 
   1057 void Builtins::Generate_InternalArrayCode(MacroAssembler* masm) {
   1058   // ----------- S t a t e -------------
   1059   //  -- eax : argc
   1060   //  -- esp[0] : return address
   1061   //  -- esp[4] : last argument
   1062   // -----------------------------------
   1063   Label generic_array_code;
   1064 
   1065   // Get the InternalArray function.
   1066   __ LoadGlobalFunction(Context::INTERNAL_ARRAY_FUNCTION_INDEX, edi);
   1067 
   1068   if (FLAG_debug_code) {
   1069     // Initial map for the builtin InternalArray function should be a map.
   1070     __ mov(ebx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
   1071     // Will both indicate a NULL and a Smi.
   1072     __ test(ebx, Immediate(kSmiTagMask));
   1073     __ Assert(not_zero, kUnexpectedInitialMapForInternalArrayFunction);
   1074     __ CmpObjectType(ebx, MAP_TYPE, ecx);
   1075     __ Assert(equal, kUnexpectedInitialMapForInternalArrayFunction);
   1076   }
   1077 
   1078   // Run the native code for the InternalArray function called as a normal
   1079   // function.
   1080   // tail call a stub
   1081   InternalArrayConstructorStub stub(masm->isolate());
   1082   __ TailCallStub(&stub);
   1083 }
   1084 
   1085 
   1086 void Builtins::Generate_ArrayCode(MacroAssembler* masm) {
   1087   // ----------- S t a t e -------------
   1088   //  -- eax : argc
   1089   //  -- esp[0] : return address
   1090   //  -- esp[4] : last argument
   1091   // -----------------------------------
   1092   Label generic_array_code;
   1093 
   1094   // Get the Array function.
   1095   __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, edi);
   1096 
   1097   if (FLAG_debug_code) {
   1098     // Initial map for the builtin Array function should be a map.
   1099     __ mov(ebx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
   1100     // Will both indicate a NULL and a Smi.
   1101     __ test(ebx, Immediate(kSmiTagMask));
   1102     __ Assert(not_zero, kUnexpectedInitialMapForArrayFunction);
   1103     __ CmpObjectType(ebx, MAP_TYPE, ecx);
   1104     __ Assert(equal, kUnexpectedInitialMapForArrayFunction);
   1105   }
   1106 
   1107   // Run the native code for the Array function called as a normal function.
   1108   // tail call a stub
   1109   __ mov(ebx, masm->isolate()->factory()->undefined_value());
   1110   ArrayConstructorStub stub(masm->isolate());
   1111   __ TailCallStub(&stub);
   1112 }
   1113 
   1114 
   1115 void Builtins::Generate_StringConstructCode(MacroAssembler* masm) {
   1116   // ----------- S t a t e -------------
   1117   //  -- eax                 : number of arguments
   1118   //  -- edi                 : constructor function
   1119   //  -- esp[0]              : return address
   1120   //  -- esp[(argc - n) * 4] : arg[n] (zero-based)
   1121   //  -- esp[(argc + 1) * 4] : receiver
   1122   // -----------------------------------
   1123   Counters* counters = masm->isolate()->counters();
   1124   __ IncrementCounter(counters->string_ctor_calls(), 1);
   1125 
   1126   if (FLAG_debug_code) {
   1127     __ LoadGlobalFunction(Context::STRING_FUNCTION_INDEX, ecx);
   1128     __ cmp(edi, ecx);
   1129     __ Assert(equal, kUnexpectedStringFunction);
   1130   }
   1131 
   1132   // Load the first argument into eax and get rid of the rest
   1133   // (including the receiver).
   1134   Label no_arguments;
   1135   __ test(eax, eax);
   1136   __ j(zero, &no_arguments);
   1137   __ mov(ebx, Operand(esp, eax, times_pointer_size, 0));
   1138   __ pop(ecx);
   1139   __ lea(esp, Operand(esp, eax, times_pointer_size, kPointerSize));
   1140   __ push(ecx);
   1141   __ mov(eax, ebx);
   1142 
   1143   // Lookup the argument in the number to string cache.
   1144   Label not_cached, argument_is_string;
   1145   __ LookupNumberStringCache(eax,  // Input.
   1146                              ebx,  // Result.
   1147                              ecx,  // Scratch 1.
   1148                              edx,  // Scratch 2.
   1149                              &not_cached);
   1150   __ IncrementCounter(counters->string_ctor_cached_number(), 1);
   1151   __ bind(&argument_is_string);
   1152   // ----------- S t a t e -------------
   1153   //  -- ebx    : argument converted to string
   1154   //  -- edi    : constructor function
   1155   //  -- esp[0] : return address
   1156   // -----------------------------------
   1157 
   1158   // Allocate a JSValue and put the tagged pointer into eax.
   1159   Label gc_required;
   1160   __ Allocate(JSValue::kSize,
   1161               eax,  // Result.
   1162               ecx,  // New allocation top (we ignore it).
   1163               no_reg,
   1164               &gc_required,
   1165               TAG_OBJECT);
   1166 
   1167   // Set the map.
   1168   __ LoadGlobalFunctionInitialMap(edi, ecx);
   1169   if (FLAG_debug_code) {
   1170     __ cmpb(FieldOperand(ecx, Map::kInstanceSizeOffset),
   1171             JSValue::kSize >> kPointerSizeLog2);
   1172     __ Assert(equal, kUnexpectedStringWrapperInstanceSize);
   1173     __ cmpb(FieldOperand(ecx, Map::kUnusedPropertyFieldsOffset), 0);
   1174     __ Assert(equal, kUnexpectedUnusedPropertiesOfStringWrapper);
   1175   }
   1176   __ mov(FieldOperand(eax, HeapObject::kMapOffset), ecx);
   1177 
   1178   // Set properties and elements.
   1179   Factory* factory = masm->isolate()->factory();
   1180   __ Move(ecx, Immediate(factory->empty_fixed_array()));
   1181   __ mov(FieldOperand(eax, JSObject::kPropertiesOffset), ecx);
   1182   __ mov(FieldOperand(eax, JSObject::kElementsOffset), ecx);
   1183 
   1184   // Set the value.
   1185   __ mov(FieldOperand(eax, JSValue::kValueOffset), ebx);
   1186 
   1187   // Ensure the object is fully initialized.
   1188   STATIC_ASSERT(JSValue::kSize == 4 * kPointerSize);
   1189 
   1190   // We're done. Return.
   1191   __ ret(0);
   1192 
   1193   // The argument was not found in the number to string cache. Check
   1194   // if it's a string already before calling the conversion builtin.
   1195   Label convert_argument;
   1196   __ bind(&not_cached);
   1197   STATIC_ASSERT(kSmiTag == 0);
   1198   __ JumpIfSmi(eax, &convert_argument);
   1199   Condition is_string = masm->IsObjectStringType(eax, ebx, ecx);
   1200   __ j(NegateCondition(is_string), &convert_argument);
   1201   __ mov(ebx, eax);
   1202   __ IncrementCounter(counters->string_ctor_string_value(), 1);
   1203   __ jmp(&argument_is_string);
   1204 
   1205   // Invoke the conversion builtin and put the result into ebx.
   1206   __ bind(&convert_argument);
   1207   __ IncrementCounter(counters->string_ctor_conversions(), 1);
   1208   {
   1209     FrameScope scope(masm, StackFrame::INTERNAL);
   1210     __ push(edi);  // Preserve the function.
   1211     __ push(eax);
   1212     __ InvokeBuiltin(Builtins::TO_STRING, CALL_FUNCTION);
   1213     __ pop(edi);
   1214   }
   1215   __ mov(ebx, eax);
   1216   __ jmp(&argument_is_string);
   1217 
   1218   // Load the empty string into ebx, remove the receiver from the
   1219   // stack, and jump back to the case where the argument is a string.
   1220   __ bind(&no_arguments);
   1221   __ Move(ebx, Immediate(factory->empty_string()));
   1222   __ pop(ecx);
   1223   __ lea(esp, Operand(esp, kPointerSize));
   1224   __ push(ecx);
   1225   __ jmp(&argument_is_string);
   1226 
   1227   // At this point the argument is already a string. Call runtime to
   1228   // create a string wrapper.
   1229   __ bind(&gc_required);
   1230   __ IncrementCounter(counters->string_ctor_gc_required(), 1);
   1231   {
   1232     FrameScope scope(masm, StackFrame::INTERNAL);
   1233     __ push(ebx);
   1234     __ CallRuntime(Runtime::kNewStringWrapper, 1);
   1235   }
   1236   __ ret(0);
   1237 }
   1238 
   1239 
   1240 static void ArgumentsAdaptorStackCheck(MacroAssembler* masm,
   1241                                        Label* stack_overflow) {
   1242   // ----------- S t a t e -------------
   1243   //  -- eax : actual number of arguments
   1244   //  -- ebx : expected number of arguments
   1245   //  -- edi : function (passed through to callee)
   1246   // -----------------------------------
   1247   // Check the stack for overflow. We are not trying to catch
   1248   // interruptions (e.g. debug break and preemption) here, so the "real stack
   1249   // limit" is checked.
   1250   ExternalReference real_stack_limit =
   1251       ExternalReference::address_of_real_stack_limit(masm->isolate());
   1252   __ mov(edx, Operand::StaticVariable(real_stack_limit));
   1253   // Make ecx the space we have left. The stack might already be overflowed
   1254   // here which will cause ecx to become negative.
   1255   __ mov(ecx, esp);
   1256   __ sub(ecx, edx);
   1257   // Make edx the space we need for the array when it is unrolled onto the
   1258   // stack.
   1259   __ mov(edx, ebx);
   1260   __ shl(edx, kPointerSizeLog2);
   1261   // Check if the arguments will overflow the stack.
   1262   __ cmp(ecx, edx);
   1263   __ j(less_equal, stack_overflow);  // Signed comparison.
   1264 }
   1265 
   1266 
   1267 static void EnterArgumentsAdaptorFrame(MacroAssembler* masm) {
   1268   __ push(ebp);
   1269   __ mov(ebp, esp);
   1270 
   1271   // Store the arguments adaptor context sentinel.
   1272   __ push(Immediate(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
   1273 
   1274   // Push the function on the stack.
   1275   __ push(edi);
   1276 
   1277   // Preserve the number of arguments on the stack. Must preserve eax,
   1278   // ebx and ecx because these registers are used when copying the
   1279   // arguments and the receiver.
   1280   STATIC_ASSERT(kSmiTagSize == 1);
   1281   __ lea(edi, Operand(eax, eax, times_1, kSmiTag));
   1282   __ push(edi);
   1283 }
   1284 
   1285 
   1286 static void LeaveArgumentsAdaptorFrame(MacroAssembler* masm) {
   1287   // Retrieve the number of arguments from the stack.
   1288   __ mov(ebx, Operand(ebp, ArgumentsAdaptorFrameConstants::kLengthOffset));
   1289 
   1290   // Leave the frame.
   1291   __ leave();
   1292 
   1293   // Remove caller arguments from the stack.
   1294   STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
   1295   __ pop(ecx);
   1296   __ lea(esp, Operand(esp, ebx, times_2, 1 * kPointerSize));  // 1 ~ receiver
   1297   __ push(ecx);
   1298 }
   1299 
   1300 
   1301 void Builtins::Generate_ArgumentsAdaptorTrampoline(MacroAssembler* masm) {
   1302   // ----------- S t a t e -------------
   1303   //  -- eax : actual number of arguments
   1304   //  -- ebx : expected number of arguments
   1305   //  -- edi : function (passed through to callee)
   1306   // -----------------------------------
   1307 
   1308   Label invoke, dont_adapt_arguments;
   1309   __ IncrementCounter(masm->isolate()->counters()->arguments_adaptors(), 1);
   1310 
   1311   Label stack_overflow;
   1312   ArgumentsAdaptorStackCheck(masm, &stack_overflow);
   1313 
   1314   Label enough, too_few;
   1315   __ mov(edx, FieldOperand(edi, JSFunction::kCodeEntryOffset));
   1316   __ cmp(eax, ebx);
   1317   __ j(less, &too_few);
   1318   __ cmp(ebx, SharedFunctionInfo::kDontAdaptArgumentsSentinel);
   1319   __ j(equal, &dont_adapt_arguments);
   1320 
   1321   {  // Enough parameters: Actual >= expected.
   1322     __ bind(&enough);
   1323     EnterArgumentsAdaptorFrame(masm);
   1324 
   1325     // Copy receiver and all expected arguments.
   1326     const int offset = StandardFrameConstants::kCallerSPOffset;
   1327     __ lea(eax, Operand(ebp, eax, times_4, offset));
   1328     __ mov(edi, -1);  // account for receiver
   1329 
   1330     Label copy;
   1331     __ bind(&copy);
   1332     __ inc(edi);
   1333     __ push(Operand(eax, 0));
   1334     __ sub(eax, Immediate(kPointerSize));
   1335     __ cmp(edi, ebx);
   1336     __ j(less, &copy);
   1337     __ jmp(&invoke);
   1338   }
   1339 
   1340   {  // Too few parameters: Actual < expected.
   1341     __ bind(&too_few);
   1342     EnterArgumentsAdaptorFrame(masm);
   1343 
   1344     // Copy receiver and all actual arguments.
   1345     const int offset = StandardFrameConstants::kCallerSPOffset;
   1346     __ lea(edi, Operand(ebp, eax, times_4, offset));
   1347     // ebx = expected - actual.
   1348     __ sub(ebx, eax);
   1349     // eax = -actual - 1
   1350     __ neg(eax);
   1351     __ sub(eax, Immediate(1));
   1352 
   1353     Label copy;
   1354     __ bind(&copy);
   1355     __ inc(eax);
   1356     __ push(Operand(edi, 0));
   1357     __ sub(edi, Immediate(kPointerSize));
   1358     __ test(eax, eax);
   1359     __ j(not_zero, &copy);
   1360 
   1361     // Fill remaining expected arguments with undefined values.
   1362     Label fill;
   1363     __ bind(&fill);
   1364     __ inc(eax);
   1365     __ push(Immediate(masm->isolate()->factory()->undefined_value()));
   1366     __ cmp(eax, ebx);
   1367     __ j(less, &fill);
   1368   }
   1369 
   1370   // Call the entry point.
   1371   __ bind(&invoke);
   1372   // Restore function pointer.
   1373   __ mov(edi, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
   1374   __ call(edx);
   1375 
   1376   // Store offset of return address for deoptimizer.
   1377   masm->isolate()->heap()->SetArgumentsAdaptorDeoptPCOffset(masm->pc_offset());
   1378 
   1379   // Leave frame and return.
   1380   LeaveArgumentsAdaptorFrame(masm);
   1381   __ ret(0);
   1382 
   1383   // -------------------------------------------
   1384   // Dont adapt arguments.
   1385   // -------------------------------------------
   1386   __ bind(&dont_adapt_arguments);
   1387   __ jmp(edx);
   1388 
   1389   __ bind(&stack_overflow);
   1390   {
   1391     FrameScope frame(masm, StackFrame::MANUAL);
   1392     EnterArgumentsAdaptorFrame(masm);
   1393     __ InvokeBuiltin(Builtins::STACK_OVERFLOW, CALL_FUNCTION);
   1394     __ int3();
   1395   }
   1396 }
   1397 
   1398 
   1399 void Builtins::Generate_OnStackReplacement(MacroAssembler* masm) {
   1400   // Lookup the function in the JavaScript frame.
   1401   __ mov(eax, Operand(ebp, JavaScriptFrameConstants::kFunctionOffset));
   1402   {
   1403     FrameScope scope(masm, StackFrame::INTERNAL);
   1404     // Pass function as argument.
   1405     __ push(eax);
   1406     __ CallRuntime(Runtime::kCompileForOnStackReplacement, 1);
   1407   }
   1408 
   1409   Label skip;
   1410   // If the code object is null, just return to the unoptimized code.
   1411   __ cmp(eax, Immediate(0));
   1412   __ j(not_equal, &skip, Label::kNear);
   1413   __ ret(0);
   1414 
   1415   __ bind(&skip);
   1416 
   1417   // Load deoptimization data from the code object.
   1418   __ mov(ebx, Operand(eax, Code::kDeoptimizationDataOffset - kHeapObjectTag));
   1419 
   1420   // Load the OSR entrypoint offset from the deoptimization data.
   1421   __ mov(ebx, Operand(ebx, FixedArray::OffsetOfElementAt(
   1422       DeoptimizationInputData::kOsrPcOffsetIndex) - kHeapObjectTag));
   1423   __ SmiUntag(ebx);
   1424 
   1425   // Compute the target address = code_obj + header_size + osr_offset
   1426   __ lea(eax, Operand(eax, ebx, times_1, Code::kHeaderSize - kHeapObjectTag));
   1427 
   1428   // Overwrite the return address on the stack.
   1429   __ mov(Operand(esp, 0), eax);
   1430 
   1431   // And "return" to the OSR entry point of the function.
   1432   __ ret(0);
   1433 }
   1434 
   1435 
   1436 void Builtins::Generate_OsrAfterStackCheck(MacroAssembler* masm) {
   1437   // We check the stack limit as indicator that recompilation might be done.
   1438   Label ok;
   1439   ExternalReference stack_limit =
   1440       ExternalReference::address_of_stack_limit(masm->isolate());
   1441   __ cmp(esp, Operand::StaticVariable(stack_limit));
   1442   __ j(above_equal, &ok, Label::kNear);
   1443   {
   1444     FrameScope scope(masm, StackFrame::INTERNAL);
   1445     __ CallRuntime(Runtime::kStackGuard, 0);
   1446   }
   1447   __ jmp(masm->isolate()->builtins()->OnStackReplacement(),
   1448          RelocInfo::CODE_TARGET);
   1449 
   1450   __ bind(&ok);
   1451   __ ret(0);
   1452 }
   1453 
   1454 #undef __
   1455 }
   1456 }  // namespace v8::internal
   1457 
   1458 #endif  // V8_TARGET_ARCH_X87
   1459