path: root/deps/v8/src/ia32/code-stubs-ia32.cc

// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if V8_TARGET_ARCH_IA32

#include "src/api-arguments.h"
#include "src/assembler-inl.h"
#include "src/base/bits.h"
#include "src/bootstrapper.h"
#include "src/code-stubs.h"
#include "src/frame-constants.h"
#include "src/frames.h"
#include "src/heap/heap-inl.h"
#include "src/ic/ic.h"
#include "src/ic/stub-cache.h"
#include "src/isolate.h"
#include "src/regexp/jsregexp.h"
#include "src/regexp/regexp-macro-assembler.h"
#include "src/runtime/runtime.h"

namespace v8 {
namespace internal {

#define __ ACCESS_MASM(masm)

void ArrayNArgumentsConstructorStub::Generate(MacroAssembler* masm) {
  __ pop(ecx);
  __ mov(MemOperand(esp, eax, times_4, 0), edi);
  __ push(edi);
  __ push(ebx);
  __ push(ecx);
  __ add(eax, Immediate(3));
  __ TailCallRuntime(Runtime::kNewArray);
}


void DoubleToIStub::Generate(MacroAssembler* masm) {
  Register final_result_reg = this->destination();

  Label check_negative, process_64_bits, done;

  // Account for return address and saved regs.
  const int kArgumentOffset = 3 * kPointerSize;

  MemOperand mantissa_operand(MemOperand(esp, kArgumentOffset));
  MemOperand exponent_operand(
      MemOperand(esp, kArgumentOffset + kDoubleSize / 2));

  Register scratch1 = no_reg;
  {
    Register scratch_candidates[3] = { ebx, edx, edi };
    for (int i = 0; i < 3; i++) {
      scratch1 = scratch_candidates[i];
      if (final_result_reg != scratch1) break;
    }
  }
  // Since we must use ecx for shifts below, use some other register (eax)
  // to calculate the result if ecx is the requested return register.
  Register result_reg = final_result_reg == ecx ? eax : final_result_reg;
  // Save ecx if it isn't the return register and therefore volatile, or if it
  // is the return register, then save the temp register we use in its stead for
  // the result.
  Register save_reg = final_result_reg == ecx ? eax : ecx;
  __ push(scratch1);
  __ push(save_reg);

  __ mov(scratch1, mantissa_operand);
  if (CpuFeatures::IsSupported(SSE3)) {
    CpuFeatureScope scope(masm, SSE3);
    // Load x87 register with heap number.
    __ fld_d(mantissa_operand);
  }
  __ mov(ecx, exponent_operand);

  __ and_(ecx, HeapNumber::kExponentMask);
  __ shr(ecx, HeapNumber::kExponentShift);
  __ lea(result_reg, MemOperand(ecx, -HeapNumber::kExponentBias));
  __ cmp(result_reg, Immediate(HeapNumber::kMantissaBits));
  __ j(below, &process_64_bits);

  // Result is entirely in lower 32-bits of mantissa
  int delta = HeapNumber::kExponentBias + Double::kPhysicalSignificandSize;
  if (CpuFeatures::IsSupported(SSE3)) {
    __ fstp(0);
  }
  __ sub(ecx, Immediate(delta));
  __ xor_(result_reg, result_reg);
  __ cmp(ecx, Immediate(31));
  __ j(above, &done);
  __ shl_cl(scratch1);
  __ jmp(&check_negative);

  __ bind(&process_64_bits);
  if (CpuFeatures::IsSupported(SSE3)) {
    CpuFeatureScope scope(masm, SSE3);
    // Reserve space for 64 bit answer.
    __ sub(esp, Immediate(kDoubleSize));  // Nolint.
    // Do conversion, which cannot fail because we checked the exponent.
    __ fisttp_d(Operand(esp, 0));
    __ mov(result_reg, Operand(esp, 0));  // Load low word of answer as result
    __ add(esp, Immediate(kDoubleSize));
    __ jmp(&done);
  } else {
    // Result must be extracted from shifted 32-bit mantissa
    __ sub(ecx, Immediate(delta));
    __ neg(ecx);
    __ mov(result_reg, exponent_operand);
    __ and_(result_reg,
            Immediate(static_cast<uint32_t>(Double::kSignificandMask >> 32)));
    __ add(result_reg,
           Immediate(static_cast<uint32_t>(Double::kHiddenBit >> 32)));
    __ shrd_cl(scratch1, result_reg);
    __ shr_cl(result_reg);
    __ test(ecx, Immediate(32));
    __ cmov(not_equal, scratch1, result_reg);
  }

  // If the double was negative, negate the integer result.
  __ bind(&check_negative);
  __ mov(result_reg, scratch1);
  __ neg(result_reg);
  __ cmp(exponent_operand, Immediate(0));
  __ cmov(greater, result_reg, scratch1);

  // Restore registers
  __ bind(&done);
  if (final_result_reg != result_reg) {
    DCHECK(final_result_reg == ecx);
    __ mov(final_result_reg, result_reg);
  }
  __ pop(save_reg);
  __ pop(scratch1);
  __ ret(0);
}


void MathPowStub::Generate(MacroAssembler* masm) {
  const Register exponent = MathPowTaggedDescriptor::exponent();
  DCHECK(exponent == eax);
  const Register scratch = ecx;
  const XMMRegister double_result = xmm3;
  const XMMRegister double_base = xmm2;
  const XMMRegister double_exponent = xmm1;
  const XMMRegister double_scratch = xmm4;

  Label call_runtime, done, exponent_not_smi, int_exponent;

  // Save 1 in double_result - we need this several times later on.
  __ mov(scratch, Immediate(1));
  __ Cvtsi2sd(double_result, scratch);

  if (exponent_type() == TAGGED) {
    __ JumpIfNotSmi(exponent, &exponent_not_smi, Label::kNear);
    __ SmiUntag(exponent);
    __ jmp(&int_exponent);

    __ bind(&exponent_not_smi);
    __ movsd(double_exponent,
              FieldOperand(exponent, HeapNumber::kValueOffset));
  }

  if (exponent_type() != INTEGER) {
    Label fast_power, try_arithmetic_simplification;
    __ DoubleToI(exponent, double_exponent, double_scratch,
                 TREAT_MINUS_ZERO_AS_ZERO, &try_arithmetic_simplification,
                 &try_arithmetic_simplification,
                 &try_arithmetic_simplification);
    __ jmp(&int_exponent);

    __ bind(&try_arithmetic_simplification);
    // Skip to runtime if possibly NaN (indicated by the indefinite integer).
    __ cvttsd2si(exponent, Operand(double_exponent));
    __ cmp(exponent, Immediate(0x1));
    __ j(overflow, &call_runtime);

    // Using FPU instructions to calculate power.
    Label fast_power_failed;
    __ bind(&fast_power);
    __ fnclex();  // Clear flags to catch exceptions later.
    // Transfer (B)ase and (E)xponent onto the FPU register stack.
    __ sub(esp, Immediate(kDoubleSize));
    __ movsd(Operand(esp, 0), double_exponent);
    __ fld_d(Operand(esp, 0));  // E
    __ movsd(Operand(esp, 0), double_base);
    __ fld_d(Operand(esp, 0));  // B, E

    // Exponent is in st(1) and base is in st(0)
    // B ^ E = (2^(E * log2(B)) - 1) + 1 = (2^X - 1) + 1 for X = E * log2(B)
    // FYL2X calculates st(1) * log2(st(0))
    __ fyl2x();    // X
    __ fld(0);     // X, X
    __ frndint();  // rnd(X), X
    __ fsub(1);    // rnd(X), X-rnd(X)
    __ fxch(1);    // X - rnd(X), rnd(X)
    // F2XM1 calculates 2^st(0) - 1 for -1 < st(0) < 1
    __ f2xm1();    // 2^(X-rnd(X)) - 1, rnd(X)
    __ fld1();     // 1, 2^(X-rnd(X)) - 1, rnd(X)
    __ faddp(1);   // 2^(X-rnd(X)), rnd(X)
    // FSCALE calculates st(0) * 2^st(1)
    __ fscale();   // 2^X, rnd(X)
    __ fstp(1);    // 2^X
    // Bail out to runtime in case of exceptions in the status word.
    __ fnstsw_ax();
    __ test_b(eax,
              Immediate(0x5F));  // We check for all but precision exception.
    __ j(not_zero, &fast_power_failed, Label::kNear);
    __ fstp_d(Operand(esp, 0));
    __ movsd(double_result, Operand(esp, 0));
    __ add(esp, Immediate(kDoubleSize));
    __ jmp(&done);

    __ bind(&fast_power_failed);
    __ fninit();
    __ add(esp, Immediate(kDoubleSize));
    __ jmp(&call_runtime);
  }

  // Calculate power with integer exponent.
  __ bind(&int_exponent);
  const XMMRegister double_scratch2 = double_exponent;
  __ mov(scratch, exponent);  // Back up exponent.
  __ movsd(double_scratch, double_base);  // Back up base.
  __ movsd(double_scratch2, double_result);  // Load double_exponent with 1.

  // Get absolute value of exponent.
  Label no_neg, while_true, while_false;
  __ test(scratch, scratch);
  __ j(positive, &no_neg, Label::kNear);
  __ neg(scratch);
  __ bind(&no_neg);

  __ j(zero, &while_false, Label::kNear);
  __ shr(scratch, 1);
  // Above condition means CF==0 && ZF==0.  This means that the
  // bit that has been shifted out is 0 and the result is not 0.
  __ j(above, &while_true, Label::kNear);
  __ movsd(double_result, double_scratch);
  __ j(zero, &while_false, Label::kNear);

  __ bind(&while_true);
  __ shr(scratch, 1);
  __ mulsd(double_scratch, double_scratch);
  __ j(above, &while_true, Label::kNear);
  __ mulsd(double_result, double_scratch);
  __ j(not_zero, &while_true);

  __ bind(&while_false);
  // scratch has the original value of the exponent - if the exponent is
  // negative, return 1/result.
  __ test(exponent, exponent);
  __ j(positive, &done);
  __ divsd(double_scratch2, double_result);
  __ movsd(double_result, double_scratch2);
  // Test whether result is zero.  Bail out to check for subnormal result.
  // Due to subnormals, x^-y == (1/x)^y does not hold in all cases.
  __ xorps(double_scratch2, double_scratch2);
  __ ucomisd(double_scratch2, double_result);  // Result cannot be NaN.
  // double_exponent aliased as double_scratch2 has already been overwritten
  // and may not have contained the exponent value in the first place when the
  // exponent is a smi.  We reset it with exponent value before bailing out.
  __ j(not_equal, &done);
  __ Cvtsi2sd(double_exponent, exponent);

  // Returning or bailing out.
  __ bind(&call_runtime);
  {
    AllowExternalCallThatCantCauseGC scope(masm);
    __ PrepareCallCFunction(4, scratch);
    __ movsd(Operand(esp, 0 * kDoubleSize), double_base);
    __ movsd(Operand(esp, 1 * kDoubleSize), double_exponent);
    __ CallCFunction(ExternalReference::power_double_double_function(isolate()),
                     4);
  }
  // Return value is in st(0) on ia32.
  // Store it into the (fixed) result register.
  __ sub(esp, Immediate(kDoubleSize));
  __ fstp_d(Operand(esp, 0));
  __ movsd(double_result, Operand(esp, 0));
  __ add(esp, Immediate(kDoubleSize));

  __ bind(&done);
  __ ret(0);
}

Movability CEntryStub::NeedsImmovableCode() { return kMovable; }

void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
  CEntryStub::GenerateAheadOfTime(isolate);
  // It is important that the store buffer overflow stubs are generated first.
  CommonArrayConstructorStub::GenerateStubsAheadOfTime(isolate);
  StoreFastElementStub::GenerateAheadOfTime(isolate);
}


void CodeStub::GenerateFPStubs(Isolate* isolate) {
  // Generate if not already in cache.
  CEntryStub(isolate, 1, kSaveFPRegs).GetCode();
}


void CEntryStub::GenerateAheadOfTime(Isolate* isolate) {
  CEntryStub stub(isolate, 1, kDontSaveFPRegs);
  stub.GetCode();
}


void CEntryStub::Generate(MacroAssembler* masm) {
  // eax: number of arguments including receiver
  // ebx: pointer to C function  (C callee-saved)
  // ebp: frame pointer  (restored after C call)
  // esp: stack pointer  (restored after C call)
  // esi: current context (C callee-saved)
  // edi: JS function of the caller (C callee-saved)
  //
  // If argv_in_register():
  // ecx: pointer to the first argument

  ProfileEntryHookStub::MaybeCallEntryHook(masm);

  // Reserve space on the stack for the three arguments passed to the call. If
  // result size is greater than can be returned in registers, also reserve
  // space for the hidden argument for the result location, and space for the
  // result itself.
  int arg_stack_space = 3;

  // Enter the exit frame that transitions from JavaScript to C++.
  if (argv_in_register()) {
    DCHECK(!save_doubles());
    DCHECK(!is_builtin_exit());
    __ EnterApiExitFrame(arg_stack_space);

    // Move argc and argv into the correct registers.
    __ mov(esi, ecx);
    __ mov(edi, eax);
  } else {
    __ EnterExitFrame(
        arg_stack_space, save_doubles(),
        is_builtin_exit() ? StackFrame::BUILTIN_EXIT : StackFrame::EXIT);
  }

  // ebx: pointer to C function  (C callee-saved)
  // ebp: frame pointer  (restored after C call)
  // esp: stack pointer  (restored after C call)
  // edi: number of arguments including receiver  (C callee-saved)
  // esi: pointer to the first argument (C callee-saved)

  // Result returned in eax, or eax+edx if result size is 2.

  // Check stack alignment.
  if (FLAG_debug_code) {
    __ CheckStackAlignment();
  }
  // Call C function.
  __ mov(Operand(esp, 0 * kPointerSize), edi);  // argc.
  __ mov(Operand(esp, 1 * kPointerSize), esi);  // argv.
  __ mov(Operand(esp, 2 * kPointerSize),
         Immediate(ExternalReference::isolate_address(isolate())));
  __ call(ebx);

  // Result is in eax or edx:eax - do not destroy these registers!

  // Check result for exception sentinel.
  Label exception_returned;
  __ cmp(eax, isolate()->factory()->exception());
  __ j(equal, &exception_returned);

  // Check that there is no pending exception, otherwise we
  // should have returned the exception sentinel.
  if (FLAG_debug_code) {
    __ push(edx);
    __ mov(edx, Immediate(isolate()->factory()->the_hole_value()));
    Label okay;
    ExternalReference pending_exception_address(
        IsolateAddressId::kPendingExceptionAddress, isolate());
    __ cmp(edx, Operand::StaticVariable(pending_exception_address));
    // Cannot use check here as it attempts to generate call into runtime.
    __ j(equal, &okay, Label::kNear);
    __ int3();
    __ bind(&okay);
    __ pop(edx);
  }

  // Exit the JavaScript to C++ exit frame.
  __ LeaveExitFrame(save_doubles(), !argv_in_register());
  __ ret(0);

  // Handling of exception.
  __ bind(&exception_returned);

  ExternalReference pending_handler_context_address(
      IsolateAddressId::kPendingHandlerContextAddress, isolate());
  ExternalReference pending_handler_entrypoint_address(
      IsolateAddressId::kPendingHandlerEntrypointAddress, isolate());
  ExternalReference pending_handler_fp_address(
      IsolateAddressId::kPendingHandlerFPAddress, isolate());
  ExternalReference pending_handler_sp_address(
      IsolateAddressId::kPendingHandlerSPAddress, isolate());

  // Ask the runtime for help to determine the handler. This will set eax to
  // contain the current pending exception, don't clobber it.
  ExternalReference find_handler(Runtime::kUnwindAndFindExceptionHandler,
                                 isolate());
  {
    FrameScope scope(masm, StackFrame::MANUAL);
    __ PrepareCallCFunction(3, eax);
    __ mov(Operand(esp, 0 * kPointerSize), Immediate(0));  // argc.
    __ mov(Operand(esp, 1 * kPointerSize), Immediate(0));  // argv.
    __ mov(Operand(esp, 2 * kPointerSize),
           Immediate(ExternalReference::isolate_address(isolate())));
    __ CallCFunction(find_handler, 3);
  }

  // Retrieve the handler context, SP and FP.
  __ mov(esi, Operand::StaticVariable(pending_handler_context_address));
  __ mov(esp, Operand::StaticVariable(pending_handler_sp_address));
  __ mov(ebp, Operand::StaticVariable(pending_handler_fp_address));

  // If the handler is a JS frame, restore the context to the frame. Note that
  // the context will be set to (esi == 0) for non-JS frames.
  Label skip;
  __ test(esi, esi);
  __ j(zero, &skip, Label::kNear);
  __ mov(Operand(ebp, StandardFrameConstants::kContextOffset), esi);
  __ bind(&skip);

  // Compute the handler entry address and jump to it.
  __ mov(edi, Operand::StaticVariable(pending_handler_entrypoint_address));
  __ jmp(edi);
}


void JSEntryStub::Generate(MacroAssembler* masm) {
  Label invoke, handler_entry, exit;
  Label not_outermost_js, not_outermost_js_2;

  ProfileEntryHookStub::MaybeCallEntryHook(masm);

  // Set up frame.
  __ push(ebp);
  __ mov(ebp, esp);

  // Push marker in two places.
  StackFrame::Type marker = type();
  __ push(Immediate(StackFrame::TypeToMarker(marker)));  // marker
  ExternalReference context_address(IsolateAddressId::kContextAddress,
                                    isolate());
  __ push(Operand::StaticVariable(context_address));  // context
  // Save callee-saved registers (C calling conventions).
  __ push(edi);
  __ push(esi);
  __ push(ebx);

  // Save copies of the top frame descriptor on the stack.
  ExternalReference c_entry_fp(IsolateAddressId::kCEntryFPAddress, isolate());
  __ push(Operand::StaticVariable(c_entry_fp));

  // If this is the outermost JS call, set js_entry_sp value.
  ExternalReference js_entry_sp(IsolateAddressId::kJSEntrySPAddress, isolate());
  __ cmp(Operand::StaticVariable(js_entry_sp), Immediate(0));
  __ j(not_equal, &not_outermost_js, Label::kNear);
  __ mov(Operand::StaticVariable(js_entry_sp), ebp);
  __ push(Immediate(StackFrame::OUTERMOST_JSENTRY_FRAME));
  __ jmp(&invoke, Label::kNear);
  __ bind(&not_outermost_js);
  __ push(Immediate(StackFrame::INNER_JSENTRY_FRAME));

  // Jump to a faked try block that does the invoke, with a faked catch
  // block that sets the pending exception.
  __ jmp(&invoke);
  __ bind(&handler_entry);
  handler_offset_ = handler_entry.pos();
  // Caught exception: Store result (exception) in the pending exception
  // field in the JSEnv and return a failure sentinel.
  ExternalReference pending_exception(
      IsolateAddressId::kPendingExceptionAddress, isolate());
  __ mov(Operand::StaticVariable(pending_exception), eax);
  __ mov(eax, Immediate(isolate()->factory()->exception()));
  __ jmp(&exit);

  // Invoke: Link this frame into the handler chain.
  __ bind(&invoke);
  __ PushStackHandler();

  // Invoke the function by calling through JS entry trampoline builtin and
  // pop the faked function when we return. Notice that we cannot store a
  // reference to the trampoline code directly in this stub, because the
  // builtin stubs may not have been generated yet.
  __ Call(EntryTrampoline(), RelocInfo::CODE_TARGET);

  // Unlink this frame from the handler chain.
  __ PopStackHandler();

  __ bind(&exit);
  // Check if the current stack frame is marked as the outermost JS frame.
  __ pop(ebx);
  __ cmp(ebx, Immediate(StackFrame::OUTERMOST_JSENTRY_FRAME));
  __ j(not_equal, &not_outermost_js_2);
  __ mov(Operand::StaticVariable(js_entry_sp), Immediate(0));
  __ bind(&not_outermost_js_2);

  // Restore the top frame descriptor from the stack.
  __ pop(Operand::StaticVariable(
      ExternalReference(IsolateAddressId::kCEntryFPAddress, isolate())));

  // Restore callee-saved registers (C calling conventions).
  __ pop(ebx);
  __ pop(esi);
  __ pop(edi);
  __ add(esp, Immediate(2 * kPointerSize));  // remove markers

  // Restore frame pointer and return.
  __ pop(ebp);
  __ ret(0);
}

void ProfileEntryHookStub::MaybeCallEntryHookDelayed(TurboAssembler* tasm,
                                                     Zone* zone) {
  if (tasm->isolate()->function_entry_hook() != nullptr) {
    tasm->CallStubDelayed(new (zone) ProfileEntryHookStub(nullptr));
  }
}

void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
  if (masm->isolate()->function_entry_hook() != nullptr) {
    ProfileEntryHookStub stub(masm->isolate());
    masm->CallStub(&stub);
  }
}


void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
  // Save volatile registers.
  const int kNumSavedRegisters = 3;
  __ push(eax);
  __ push(ecx);
  __ push(edx);

  // Calculate and push the original stack pointer.
  __ lea(eax, Operand(esp, (kNumSavedRegisters + 1) * kPointerSize));
  __ push(eax);

  // Retrieve our return address and use it to calculate the calling
  // function's address.
  __ mov(eax, Operand(esp, (kNumSavedRegisters + 1) * kPointerSize));
  __ sub(eax, Immediate(Assembler::kCallInstructionLength));
  __ push(eax);

  // Call the entry hook.
  DCHECK_NOT_NULL(isolate()->function_entry_hook());
  __ call(FUNCTION_ADDR(isolate()->function_entry_hook()),
          RelocInfo::RUNTIME_ENTRY);
  __ add(esp, Immediate(2 * kPointerSize));

  // Restore ecx.
  __ pop(edx);
  __ pop(ecx);
  __ pop(eax);

  __ ret(0);
}


template<class T>
static void CreateArrayDispatch(MacroAssembler* masm,
                                AllocationSiteOverrideMode mode) {
  if (mode == DISABLE_ALLOCATION_SITES) {
    T stub(masm->isolate(),
           GetInitialFastElementsKind(),
           mode);
    __ TailCallStub(&stub);
  } else if (mode == DONT_OVERRIDE) {
    int last_index =
        GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
    for (int i = 0; i <= last_index; ++i) {
      Label next;
      ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
      __ cmp(edx, kind);
      __ j(not_equal, &next);
      T stub(masm->isolate(), kind);
      __ TailCallStub(&stub);
      __ bind(&next);
    }

    // If we reached this point there is a problem.
    __ Abort(AbortReason::kUnexpectedElementsKindInArrayConstructor);
  } else {
    UNREACHABLE();
  }
}


static void CreateArrayDispatchOneArgument(MacroAssembler* masm,
                                           AllocationSiteOverrideMode mode) {
  // ebx - allocation site (if mode != DISABLE_ALLOCATION_SITES)
  // edx - kind (if mode != DISABLE_ALLOCATION_SITES)
  // eax - number of arguments
  // edi - constructor?
  // esp[0] - return address
  // esp[4] - last argument
  STATIC_ASSERT(PACKED_SMI_ELEMENTS == 0);
  STATIC_ASSERT(HOLEY_SMI_ELEMENTS == 1);
  STATIC_ASSERT(PACKED_ELEMENTS == 2);
  STATIC_ASSERT(HOLEY_ELEMENTS == 3);
  STATIC_ASSERT(PACKED_DOUBLE_ELEMENTS == 4);
  STATIC_ASSERT(HOLEY_DOUBLE_ELEMENTS == 5);

  if (mode == DISABLE_ALLOCATION_SITES) {
    ElementsKind initial = GetInitialFastElementsKind();
    ElementsKind holey_initial = GetHoleyElementsKind(initial);

    ArraySingleArgumentConstructorStub stub_holey(masm->isolate(),
                                                  holey_initial,
                                                  DISABLE_ALLOCATION_SITES);
    __ TailCallStub(&stub_holey);
  } else if (mode == DONT_OVERRIDE) {
    // is the low bit set? If so, we are holey and that is good.
    Label normal_sequence;
    __ test_b(edx, Immediate(1));
    __ j(not_zero, &normal_sequence);

    // We are going to create a holey array, but our kind is non-holey.
    // Fix kind and retry.
    __ inc(edx);

    if (FLAG_debug_code) {
      Handle<Map> allocation_site_map =
          masm->isolate()->factory()->allocation_site_map();
      __ cmp(FieldOperand(ebx, 0), Immediate(allocation_site_map));
      __ Assert(equal, AbortReason::kExpectedAllocationSite);
    }

    // Save the resulting elements kind in type info. We can't just store r3
    // in the AllocationSite::transition_info field because elements kind is
    // restricted to a portion of the field...upper bits need to be left alone.
    STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
    __ add(
        FieldOperand(ebx, AllocationSite::kTransitionInfoOrBoilerplateOffset),
        Immediate(Smi::FromInt(kFastElementsKindPackedToHoley)));

    __ bind(&normal_sequence);
    int last_index =
        GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
    for (int i = 0; i <= last_index; ++i) {
      Label next;
      ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
      __ cmp(edx, kind);
      __ j(not_equal, &next);
      ArraySingleArgumentConstructorStub stub(masm->isolate(), kind);
      __ TailCallStub(&stub);
      __ bind(&next);
    }

    // If we reached this point there is a problem.
    __ Abort(AbortReason::kUnexpectedElementsKindInArrayConstructor);
  } else {
    UNREACHABLE();
  }
}


template<class T>
static void ArrayConstructorStubAheadOfTimeHelper(Isolate* isolate) {
  int to_index =
      GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
  for (int i = 0; i <= to_index; ++i) {
    ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
    T stub(isolate, kind);
    stub.GetCode();
    if (AllocationSite::ShouldTrack(kind)) {
      T stub1(isolate, kind, DISABLE_ALLOCATION_SITES);
      stub1.GetCode();
    }
  }
}

void CommonArrayConstructorStub::GenerateStubsAheadOfTime(Isolate* isolate) {
  ArrayConstructorStubAheadOfTimeHelper<ArrayNoArgumentConstructorStub>(
      isolate);
  ArrayConstructorStubAheadOfTimeHelper<ArraySingleArgumentConstructorStub>(
      isolate);
  ArrayNArgumentsConstructorStub stub(isolate);
  stub.GetCode();

  ElementsKind kinds[2] = {PACKED_ELEMENTS, HOLEY_ELEMENTS};
  for (int i = 0; i < 2; i++) {
    // For internal arrays we only need a few things
    InternalArrayNoArgumentConstructorStub stubh1(isolate, kinds[i]);
    stubh1.GetCode();
    InternalArraySingleArgumentConstructorStub stubh2(isolate, kinds[i]);
    stubh2.GetCode();
  }
}

void ArrayConstructorStub::GenerateDispatchToArrayStub(
    MacroAssembler* masm, AllocationSiteOverrideMode mode) {
  Label not_zero_case, not_one_case;
  __ test(eax, eax);
  __ j(not_zero, &not_zero_case);
  CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);

  __ bind(&not_zero_case);
  __ cmp(eax, 1);
  __ j(greater, &not_one_case);
  CreateArrayDispatchOneArgument(masm, mode);

  __ bind(&not_one_case);
  ArrayNArgumentsConstructorStub stub(masm->isolate());
  __ TailCallStub(&stub);
}

void ArrayConstructorStub::Generate(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- eax : argc (only if argument_count() is ANY or MORE_THAN_ONE)
  //  -- ebx : AllocationSite or undefined
  //  -- edi : constructor
  //  -- edx : Original constructor
  //  -- esp[0] : return address
  //  -- esp[4] : last argument
  // -----------------------------------
  if (FLAG_debug_code) {
    // The array construct code is only set for the global and natives
    // builtin Array functions which always have maps.

    // Initial map for the builtin Array function should be a map.
    __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
    // Will both indicate a nullptr and a Smi.
    __ test(ecx, Immediate(kSmiTagMask));
    __ Assert(not_zero, AbortReason::kUnexpectedInitialMapForArrayFunction);
    __ CmpObjectType(ecx, MAP_TYPE, ecx);
    __ Assert(equal, AbortReason::kUnexpectedInitialMapForArrayFunction);

    // We should either have undefined in ebx or a valid AllocationSite
    __ AssertUndefinedOrAllocationSite(ebx);
  }

  Label subclassing;

  // Enter the context of the Array function.
  __ mov(esi, FieldOperand(edi, JSFunction::kContextOffset));

  __ cmp(edx, edi);
  __ j(not_equal, &subclassing);

  Label no_info;
  // If the feedback vector is the undefined value call an array constructor
  // that doesn't use AllocationSites.
  __ cmp(ebx, isolate()->factory()->undefined_value());
  __ j(equal, &no_info);

  // Only look at the lower 16 bits of the transition info.
  __ mov(edx,
         FieldOperand(ebx, AllocationSite::kTransitionInfoOrBoilerplateOffset));
  __ SmiUntag(edx);
  STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
  __ and_(edx, Immediate(AllocationSite::ElementsKindBits::kMask));
  GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);

  __ bind(&no_info);
  GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);

  // Subclassing.
  __ bind(&subclassing);
  __ mov(Operand(esp, eax, times_pointer_size, kPointerSize), edi);
  __ add(eax, Immediate(3));
  __ PopReturnAddressTo(ecx);
  __ Push(edx);
  __ Push(ebx);
  __ PushReturnAddressFrom(ecx);
  __ JumpToExternalReference(ExternalReference(Runtime::kNewArray, isolate()));
}


void InternalArrayConstructorStub::GenerateCase(
    MacroAssembler* masm, ElementsKind kind) {
  Label not_zero_case, not_one_case;
  Label normal_sequence;

  __ test(eax, eax);
  __ j(not_zero, &not_zero_case);
  InternalArrayNoArgumentConstructorStub stub0(isolate(), kind);
  __ TailCallStub(&stub0);

  __ bind(&not_zero_case);
  __ cmp(eax, 1);
  __ j(greater, &not_one_case);

  if (IsFastPackedElementsKind(kind)) {
    // We might need to create a holey array
    // look at the first argument
    __ mov(ecx, Operand(esp, kPointerSize));
    __ test(ecx, ecx);
    __ j(zero, &normal_sequence);

    InternalArraySingleArgumentConstructorStub
        stub1_holey(isolate(), GetHoleyElementsKind(kind));
    __ TailCallStub(&stub1_holey);
  }

  __ bind(&normal_sequence);
  InternalArraySingleArgumentConstructorStub stub1(isolate(), kind);
  __ TailCallStub(&stub1);

  __ bind(&not_one_case);
  ArrayNArgumentsConstructorStub stubN(isolate());
  __ TailCallStub(&stubN);
}


void InternalArrayConstructorStub::Generate(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- eax : argc
  //  -- edi : constructor
  //  -- esp[0] : return address
  //  -- esp[4] : last argument
  // -----------------------------------

  if (FLAG_debug_code) {
    // The array construct code is only set for the global and natives
    // builtin Array functions which always have maps.

    // Initial map for the builtin Array function should be a map.
    __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));
    // Will both indicate a nullptr and a Smi.
    __ test(ecx, Immediate(kSmiTagMask));
    __ Assert(not_zero, AbortReason::kUnexpectedInitialMapForArrayFunction);
    __ CmpObjectType(ecx, MAP_TYPE, ecx);
    __ Assert(equal, AbortReason::kUnexpectedInitialMapForArrayFunction);
  }

  // Figure out the right elements kind
  __ mov(ecx, FieldOperand(edi, JSFunction::kPrototypeOrInitialMapOffset));

  // Load the map's "bit field 2" into |result|. We only need the first byte,
  // but the following masking takes care of that anyway.
  __ mov(ecx, FieldOperand(ecx, Map::kBitField2Offset));
  // Retrieve elements_kind from bit field 2.
  __ DecodeField<Map::ElementsKindBits>(ecx);

  if (FLAG_debug_code) {
    Label done;
    __ cmp(ecx, Immediate(PACKED_ELEMENTS));
    __ j(equal, &done);
    __ cmp(ecx, Immediate(HOLEY_ELEMENTS));
    __ Assert(
        equal,
        AbortReason::kInvalidElementsKindForInternalArrayOrInternalPackedArray);
    __ bind(&done);
  }

  Label fast_elements_case;
  __ cmp(ecx, Immediate(PACKED_ELEMENTS));
  __ j(equal, &fast_elements_case);
  GenerateCase(masm, HOLEY_ELEMENTS);

  __ bind(&fast_elements_case);
  GenerateCase(masm, PACKED_ELEMENTS);
}

// Generates an Operand for saving parameters after PrepareCallApiFunction.
static Operand ApiParameterOperand(int index) {
  return Operand(esp, index * kPointerSize);
}


// Prepares stack to put arguments (aligns and so on). Reserves
// space for return value if needed (assumes the return value is a handle).
// Arguments must be stored in ApiParameterOperand(0), ApiParameterOperand(1)
// etc. Saves context (esi). If space was reserved for return value then
// stores the pointer to the reserved slot into esi.
static void PrepareCallApiFunction(MacroAssembler* masm, int argc) {
  __ EnterApiExitFrame(argc);
  if (__ emit_debug_code()) {
    __ mov(esi, Immediate(bit_cast<int32_t>(kZapValue)));
  }
}


// Calls an API function.  Allocates HandleScope, extracts returned value
// from handle and propagates exceptions.  Clobbers ebx, edi and
// caller-save registers.  Restores context.  On return removes
// stack_space * kPointerSize (GCed).
static void CallApiFunctionAndReturn(MacroAssembler* masm,
                                     Register function_address,
                                     ExternalReference thunk_ref,
                                     Operand thunk_last_arg, int stack_space,
                                     Operand* stack_space_operand,
                                     Operand return_value_operand) {
  Isolate* isolate = masm->isolate();

  ExternalReference next_address =
      ExternalReference::handle_scope_next_address(isolate);
  ExternalReference limit_address =
      ExternalReference::handle_scope_limit_address(isolate);
  ExternalReference level_address =
      ExternalReference::handle_scope_level_address(isolate);

  DCHECK(edx == function_address);
  // Allocate HandleScope in callee-save registers.
  __ mov(ebx, Operand::StaticVariable(next_address));
  __ mov(edi, Operand::StaticVariable(limit_address));
  __ add(Operand::StaticVariable(level_address), Immediate(1));

  if (FLAG_log_timer_events) {
    FrameScope frame(masm, StackFrame::MANUAL);
    __ PushSafepointRegisters();
    __ PrepareCallCFunction(1, eax);
    __ mov(Operand(esp, 0),
           Immediate(ExternalReference::isolate_address(isolate)));
    __ CallCFunction(ExternalReference::log_enter_external_function(isolate),
                     1);
    __ PopSafepointRegisters();
  }


  Label profiler_disabled;
  Label end_profiler_check;
  __ mov(eax, Immediate(ExternalReference::is_profiling_address(isolate)));
  __ cmpb(Operand(eax, 0), Immediate(0));
  __ j(zero, &profiler_disabled);

  // Additional parameter is the address of the actual getter function.
  __ mov(thunk_last_arg, function_address);
  // Call the api function.
  __ mov(eax, Immediate(thunk_ref));
  __ call(eax);
  __ jmp(&end_profiler_check);

  __ bind(&profiler_disabled);
  // Call the api function.
  __ call(function_address);
  __ bind(&end_profiler_check);

  if (FLAG_log_timer_events) {
    FrameScope frame(masm, StackFrame::MANUAL);
    __ PushSafepointRegisters();
    __ PrepareCallCFunction(1, eax);
    __ mov(Operand(esp, 0),
           Immediate(ExternalReference::isolate_address(isolate)));
    __ CallCFunction(ExternalReference::log_leave_external_function(isolate),
                     1);
    __ PopSafepointRegisters();
  }

  Label prologue;
  // Load the value from ReturnValue
  __ mov(eax, return_value_operand);

  Label promote_scheduled_exception;
  Label delete_allocated_handles;
  Label leave_exit_frame;

  __ bind(&prologue);
  // No more valid handles (the result handle was the last one). Restore
  // previous handle scope.
  __ mov(Operand::StaticVariable(next_address), ebx);
  __ sub(Operand::StaticVariable(level_address), Immediate(1));
  __ Assert(above_equal, AbortReason::kInvalidHandleScopeLevel);
  __ cmp(edi, Operand::StaticVariable(limit_address));
  __ j(not_equal, &delete_allocated_handles);

  // Leave the API exit frame.
  __ bind(&leave_exit_frame);
  if (stack_space_operand != nullptr) {
    __ mov(ebx, *stack_space_operand);
  }
  __ LeaveApiExitFrame();

  // Check if the function scheduled an exception.
  ExternalReference scheduled_exception_address =
      ExternalReference::scheduled_exception_address(isolate);
  __ cmp(Operand::StaticVariable(scheduled_exception_address),
         Immediate(isolate->factory()->the_hole_value()));
  __ j(not_equal, &promote_scheduled_exception);

#if DEBUG
  // Check if the function returned a valid JavaScript value.
  Label ok;
  Register return_value = eax;
  Register map = ecx;

  __ JumpIfSmi(return_value, &ok, Label::kNear);
  __ mov(map, FieldOperand(return_value, HeapObject::kMapOffset));

  __ CmpInstanceType(map, LAST_NAME_TYPE);
  __ j(below_equal, &ok, Label::kNear);

  __ CmpInstanceType(map, FIRST_JS_RECEIVER_TYPE);
  __ j(above_equal, &ok, Label::kNear);

  __ cmp(map, isolate->factory()->heap_number_map());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->undefined_value());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->true_value());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->false_value());
  __ j(equal, &ok, Label::kNear);

  __ cmp(return_value, isolate->factory()->null_value());
  __ j(equal, &ok, Label::kNear);

  __ Abort(AbortReason::kAPICallReturnedInvalidObject);

  __ bind(&ok);
#endif

  if (stack_space_operand != nullptr) {
    DCHECK_EQ(0, stack_space);
    __ pop(ecx);
    __ add(esp, ebx);
    __ jmp(ecx);
  } else {
    __ ret(stack_space * kPointerSize);
  }

  // Re-throw by promoting a scheduled exception.
  __ bind(&promote_scheduled_exception);
  __ TailCallRuntime(Runtime::kPromoteScheduledException);

  // HandleScope limit has changed. Delete allocated extensions.
  ExternalReference delete_extensions =
      ExternalReference::delete_handle_scope_extensions(isolate);
  __ bind(&delete_allocated_handles);
  __ mov(Operand::StaticVariable(limit_address), edi);
  __ mov(edi, eax);
  __ mov(Operand(esp, 0),
         Immediate(ExternalReference::isolate_address(isolate)));
  __ mov(eax, Immediate(delete_extensions));
  __ call(eax);
  __ mov(eax, edi);
  __ jmp(&leave_exit_frame);
}

void CallApiCallbackStub::Generate(MacroAssembler* masm) {
  // ----------- S t a t e -------------
  //  -- ebx                 : call_data
  //  -- ecx                 : holder
  //  -- edx                 : api_function_address
  //  -- esi                 : context
  //  --
  //  -- esp[0]              : return address
  //  -- esp[4]              : last argument
  //  -- ...
  //  -- esp[argc * 4]       : first argument
  //  -- esp[(argc + 1) * 4] : receiver
  // -----------------------------------

  Register call_data = ebx;
  Register holder = ecx;
  Register api_function_address = edx;
  Register return_address = eax;

  typedef FunctionCallbackArguments FCA;

  STATIC_ASSERT(FCA::kArgsLength == 6);
  STATIC_ASSERT(FCA::kNewTargetIndex == 5);
  STATIC_ASSERT(FCA::kDataIndex == 4);
  STATIC_ASSERT(FCA::kReturnValueOffset == 3);
  STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
  STATIC_ASSERT(FCA::kIsolateIndex == 1);
  STATIC_ASSERT(FCA::kHolderIndex == 0);

  __ pop(return_address);

  // new target
  __ PushRoot(Heap::kUndefinedValueRootIndex);

  // call data
  __ push(call_data);

  // return value
  __ PushRoot(Heap::kUndefinedValueRootIndex);
  // return value default
  __ PushRoot(Heap::kUndefinedValueRootIndex);
  // isolate
  __ push(Immediate(ExternalReference::isolate_address(isolate())));
  // holder
  __ push(holder);

  Register scratch = call_data;

  __ mov(scratch, esp);

  // push return address
  __ push(return_address);

  // API function gets reference to the v8::Arguments. If CPU profiler
  // is enabled wrapper function will be called and we need to pass
  // address of the callback as additional parameter, always allocate
  // space for it.
  const int kApiArgc = 1 + 1;

  // Allocate the v8::Arguments structure in the arguments' space since
  // it's not controlled by GC.
  const int kApiStackSpace = 3;

  PrepareCallApiFunction(masm, kApiArgc + kApiStackSpace);

  // FunctionCallbackInfo::implicit_args_.
  __ mov(ApiParameterOperand(2), scratch);
  __ add(scratch, Immediate((argc() + FCA::kArgsLength - 1) * kPointerSize));
  // FunctionCallbackInfo::values_.
  __ mov(ApiParameterOperand(3), scratch);
  // FunctionCallbackInfo::length_.
  __ Move(ApiParameterOperand(4), Immediate(argc()));

  // v8::InvocationCallback's argument.
  __ lea(scratch, ApiParameterOperand(2));
  __ mov(ApiParameterOperand(0), scratch);

  ExternalReference thunk_ref =
      ExternalReference::invoke_function_callback(masm->isolate());

  // Stores return the first js argument
  int return_value_offset = 2 + FCA::kReturnValueOffset;
  Operand return_value_operand(ebp, return_value_offset * kPointerSize);
  const int stack_space = argc() + FCA::kArgsLength + 1;
  Operand* stack_space_operand = nullptr;
  CallApiFunctionAndReturn(masm, api_function_address, thunk_ref,
                           ApiParameterOperand(1), stack_space,
                           stack_space_operand, return_value_operand);
}


void CallApiGetterStub::Generate(MacroAssembler* masm) {
  // Build v8::PropertyCallbackInfo::args_ array on the stack and push property
  // name below the exit frame to make GC aware of them.
  STATIC_ASSERT(PropertyCallbackArguments::kShouldThrowOnErrorIndex == 0);
  STATIC_ASSERT(PropertyCallbackArguments::kHolderIndex == 1);
  STATIC_ASSERT(PropertyCallbackArguments::kIsolateIndex == 2);
  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueDefaultValueIndex == 3);
  STATIC_ASSERT(PropertyCallbackArguments::kReturnValueOffset == 4);
  STATIC_ASSERT(PropertyCallbackArguments::kDataIndex == 5);
  STATIC_ASSERT(PropertyCallbackArguments::kThisIndex == 6);
  STATIC_ASSERT(PropertyCallbackArguments::kArgsLength == 7);

  Register receiver = ApiGetterDescriptor::ReceiverRegister();
  Register holder = ApiGetterDescriptor::HolderRegister();
  Register callback = ApiGetterDescriptor::CallbackRegister();
  Register scratch = ebx;
  DCHECK(!AreAliased(receiver, holder, callback, scratch));

  __ pop(scratch);  // Pop return address to extend the frame.
  __ push(receiver);
  __ push(FieldOperand(callback, AccessorInfo::kDataOffset));
  __ PushRoot(Heap::kUndefinedValueRootIndex);  // ReturnValue
  // ReturnValue default value
  __ PushRoot(Heap::kUndefinedValueRootIndex);
  __ push(Immediate(ExternalReference::isolate_address(isolate())));
  __ push(holder);
  __ push(Immediate(Smi::kZero));  // should_throw_on_error -> false
  __ push(FieldOperand(callback, AccessorInfo::kNameOffset));
  __ push(scratch);  // Restore return address.

  // v8::PropertyCallbackInfo::args_ array and name handle.
  const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;

  // Allocate v8::PropertyCallbackInfo object, arguments for callback and
  // space for optional callback address parameter (in case CPU profiler is
  // active) in non-GCed stack space.
  const int kApiArgc = 3 + 1;

  // Load address of v8::PropertyAccessorInfo::args_ array.
  __ lea(scratch, Operand(esp, 2 * kPointerSize));

  PrepareCallApiFunction(masm, kApiArgc);
  // Create v8::PropertyCallbackInfo object on the stack and initialize
  // it's args_ field.
  Operand info_object = ApiParameterOperand(3);
  __ mov(info_object, scratch);

  // Name as handle.
  __ sub(scratch, Immediate(kPointerSize));
  __ mov(ApiParameterOperand(0), scratch);
  // Arguments pointer.
  __ lea(scratch, info_object);
  __ mov(ApiParameterOperand(1), scratch);
  // Reserve space for optional callback address parameter.
  Operand thunk_last_arg = ApiParameterOperand(2);

  ExternalReference thunk_ref =
      ExternalReference::invoke_accessor_getter_callback(isolate());

  __ mov(scratch, FieldOperand(callback, AccessorInfo::kJsGetterOffset));
  Register function_address = edx;
  __ mov(function_address,
         FieldOperand(scratch, Foreign::kForeignAddressOffset));
  // +3 is to skip prolog, return address and name handle.
  Operand return_value_operand(
      ebp, (PropertyCallbackArguments::kReturnValueOffset + 3) * kPointerSize);
  CallApiFunctionAndReturn(masm, function_address, thunk_ref, thunk_last_arg,
                           kStackUnwindSpace, nullptr, return_value_operand);
}

#undef __

}  // namespace internal
}  // namespace v8

#endif  // V8_TARGET_ARCH_IA32