xref: /third_party/node/deps/v8/src/compiler/frame.cc (revision 1cb0ef41) 
1// Copyright 2015 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/compiler/frame.h"
6
7#include "src/compiler/linkage.h"
8
9namespace v8 {
10namespace internal {
11namespace compiler {
12
13Frame::Frame(int fixed_frame_size_in_slots)
14    : fixed_slot_count_(fixed_frame_size_in_slots),
15      allocated_registers_(nullptr),
16      allocated_double_registers_(nullptr) {
17  slot_allocator_.AllocateUnaligned(fixed_frame_size_in_slots);
18}
19
20void Frame::AlignFrame(int alignment) {
21#if DEBUG
22  spill_slots_finished_ = true;
23  frame_aligned_ = true;
24#endif
25  // In the calculations below we assume that alignment is a power of 2.
26  DCHECK(base::bits::IsPowerOfTwo(alignment));
27  int alignment_in_slots = AlignedSlotAllocator::NumSlotsForWidth(alignment);
28
29  // We have to align return slots separately, because they are claimed
30  // separately on the stack.
31  const int mask = alignment_in_slots - 1;
32  int return_delta = alignment_in_slots - (return_slot_count_ & mask);
33  if (return_delta != alignment_in_slots) {
34    return_slot_count_ += return_delta;
35  }
36  int delta = alignment_in_slots - (slot_allocator_.Size() & mask);
37  if (delta != alignment_in_slots) {
38    slot_allocator_.Align(alignment_in_slots);
39    if (spill_slot_count_ != 0) {
40      spill_slot_count_ += delta;
41    }
42  }
43}
44
45void FrameAccessState::MarkHasFrame(bool state) {
46  has_frame_ = state;
47  SetFrameAccessToDefault();
48}
49
50void FrameAccessState::SetFrameAccessToDefault() {
51  if (has_frame() && !FLAG_turbo_sp_frame_access) {
52    SetFrameAccessToFP();
53  } else {
54    SetFrameAccessToSP();
55  }
56}
57
58
59FrameOffset FrameAccessState::GetFrameOffset(int spill_slot) const {
60  const int frame_offset = FrameSlotToFPOffset(spill_slot);
61  if (access_frame_with_fp()) {
62    return FrameOffset::FromFramePointer(frame_offset);
63  } else {
64    // No frame. Retrieve all parameters relative to stack pointer.
65    int sp_offset = frame_offset + GetSPToFPOffset();
66    return FrameOffset::FromStackPointer(sp_offset);
67  }
68}
69
70
71}  // namespace compiler
72}  // namespace internal
73}  // namespace v8
74