node/deps/v8/src/virtual-frame-inl.h

// Copyright 2008 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
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//
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#ifndef V8_VIRTUAL_FRAME_INL_H_
#define V8_VIRTUAL_FRAME_INL_H_

#include "virtual-frame.h"

namespace v8 {
namespace internal {


// On entry to a function, the virtual frame already contains the receiver,
// the parameters, and a return address.  All frame elements are in memory.
VirtualFrame::VirtualFrame()
    : elements_(parameter_count() + local_count() + kPreallocatedElements),
      stack_pointer_(parameter_count() + 1) {  // 0-based index of TOS.
  for (int i = 0; i <= stack_pointer_; i++) {
    elements_.Add(FrameElement::MemoryElement(NumberInfo::Unknown()));
  }
  for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) {
    register_locations_[i] = kIllegalIndex;
  }
}


// When cloned, a frame is a deep copy of the original.
VirtualFrame::VirtualFrame(VirtualFrame* original)
    : elements_(original->element_count()),
      stack_pointer_(original->stack_pointer_) {
  elements_.AddAll(original->elements_);
  // Copy register locations from original.
  memcpy(&register_locations_,
         original->register_locations_,
         sizeof(register_locations_));
}


void VirtualFrame::PushFrameSlotAt(int index) {
  elements_.Add(CopyElementAt(index));
}


void VirtualFrame::Push(Register reg, NumberInfo info) {
  if (is_used(reg)) {
    int index = register_location(reg);
    FrameElement element = CopyElementAt(index, info);
    elements_.Add(element);
  } else {
    Use(reg, element_count());
    FrameElement element =
        FrameElement::RegisterElement(reg, FrameElement::NOT_SYNCED, info);
    elements_.Add(element);
  }
}


void VirtualFrame::Push(Handle<Object> value) {
  FrameElement element =
      FrameElement::ConstantElement(value, FrameElement::NOT_SYNCED);
  elements_.Add(element);
}


void VirtualFrame::Push(Smi* value) {
  Push(Handle<Object> (value));
}


void VirtualFrame::Nip(int num_dropped) {
  ASSERT(num_dropped >= 0);
  if (num_dropped == 0) return;
  Result tos = Pop();
  if (num_dropped > 1) {
    Drop(num_dropped - 1);
  }
  SetElementAt(0, &tos);
}


bool VirtualFrame::Equals(VirtualFrame* other) {
#ifdef DEBUG
  for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) {
    if (register_location(i) != other->register_location(i)) {
      return false;
    }
  }
  if (element_count() != other->element_count()) return false;
#endif
  if (stack_pointer_ != other->stack_pointer_) return false;
  for (int i = 0; i < element_count(); i++) {
    if (!elements_[i].Equals(other->elements_[i])) return false;
  }

  return true;
}

} }  // namespace v8::internal

#endif  // V8_VIRTUAL_FRAME_INL_H_