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#ifndef V8_ARM_FRAMES_ARM_H_
6#define V8_ARM_FRAMES_ARM_H_
7
8namespace v8 {
9namespace internal {
10
11
12// The ARM ABI does not specify the usage of register r9, which may be reserved
13// as the static base or thread register on some platforms, in which case we
14// leave it alone. Adjust the value of kR9Available accordingly:
15const int kR9Available = 1;  // 1 if available to us, 0 if reserved
16
17
18// Register list in load/store instructions
19// Note that the bit values must match those used in actual instruction encoding
20const int kNumRegs = 16;
21
22
23// Caller-saved/arguments registers
24const RegList kJSCallerSaved =
25  1 << 0 |  // r0 a1
26  1 << 1 |  // r1 a2
27  1 << 2 |  // r2 a3
28  1 << 3;   // r3 a4
29
30const int kNumJSCallerSaved = 4;
31
32// Return the code of the n-th caller-saved register available to JavaScript
33// e.g. JSCallerSavedReg(0) returns r0.code() == 0
34int JSCallerSavedCode(int n);
35
36
37// Callee-saved registers preserved when switching from C to JavaScript
38const RegList kCalleeSaved =
39  1 <<  4 |  //  r4 v1
40  1 <<  5 |  //  r5 v2
41  1 <<  6 |  //  r6 v3
42  1 <<  7 |  //  r7 v4 (cp in JavaScript code)
43  1 <<  8 |  //  r8 v5 (pp in JavaScript code)
44  kR9Available <<  9 |  //  r9 v6
45  1 << 10 |  // r10 v7
46  1 << 11;   // r11 v8 (fp in JavaScript code)
47
48// When calling into C++ (only for C++ calls that can't cause a GC).
49// The call code will take care of lr, fp, etc.
50const RegList kCallerSaved =
51  1 <<  0 |  // r0
52  1 <<  1 |  // r1
53  1 <<  2 |  // r2
54  1 <<  3 |  // r3
55  1 <<  9;   // r9
56
57
58const int kNumCalleeSaved = 7 + kR9Available;
59
60// Double registers d8 to d15 are callee-saved.
61const int kNumDoubleCalleeSaved = 8;
62
63
64// Number of registers for which space is reserved in safepoints. Must be a
65// multiple of 8.
66// TODO(regis): Only 8 registers may actually be sufficient. Revisit.
67const int kNumSafepointRegisters = 16;
68
69// Define the list of registers actually saved at safepoints.
70// Note that the number of saved registers may be smaller than the reserved
71// space, i.e. kNumSafepointSavedRegisters <= kNumSafepointRegisters.
72const RegList kSafepointSavedRegisters = kJSCallerSaved | kCalleeSaved;
73const int kNumSafepointSavedRegisters = kNumJSCallerSaved + kNumCalleeSaved;
74
75// ----------------------------------------------------
76
77
78class EntryFrameConstants : public AllStatic {
79 public:
80  static const int kCallerFPOffset =
81      -(StandardFrameConstants::kFixedFrameSizeFromFp + kPointerSize);
82};
83
84
85class ExitFrameConstants : public AllStatic {
86 public:
87  static const int kFrameSize          = FLAG_enable_ool_constant_pool ?
88                                         3 * kPointerSize : 2 * kPointerSize;
89
90  static const int kConstantPoolOffset = FLAG_enable_ool_constant_pool ?
91                                         -3 * kPointerSize : 0;
92  static const int kCodeOffset         = -2 * kPointerSize;
93  static const int kSPOffset           = -1 * kPointerSize;
94
95  // The caller fields are below the frame pointer on the stack.
96  static const int kCallerFPOffset = 0 * kPointerSize;
97  // The calling JS function is below FP.
98  static const int kCallerPCOffset = 1 * kPointerSize;
99
100  // FP-relative displacement of the caller's SP.  It points just
101  // below the saved PC.
102  static const int kCallerSPDisplacement = 2 * kPointerSize;
103};
104
105
106class JavaScriptFrameConstants : public AllStatic {
107 public:
108  // FP-relative.
109  static const int kLocal0Offset = StandardFrameConstants::kExpressionsOffset;
110  static const int kLastParameterOffset = +2 * kPointerSize;
111  static const int kFunctionOffset = StandardFrameConstants::kMarkerOffset;
112
113  // Caller SP-relative.
114  static const int kParam0Offset   = -2 * kPointerSize;
115  static const int kReceiverOffset = -1 * kPointerSize;
116};
117
118
119class ArgumentsAdaptorFrameConstants : public AllStatic {
120 public:
121  // FP-relative.
122  static const int kLengthOffset = StandardFrameConstants::kExpressionsOffset;
123
124  static const int kFrameSize =
125      StandardFrameConstants::kFixedFrameSize + kPointerSize;
126};
127
128
129class ConstructFrameConstants : public AllStatic {
130 public:
131  // FP-relative.
132  static const int kImplicitReceiverOffset = -6 * kPointerSize;
133  static const int kConstructorOffset      = -5 * kPointerSize;
134  static const int kLengthOffset           = -4 * kPointerSize;
135  static const int kCodeOffset = StandardFrameConstants::kExpressionsOffset;
136
137  static const int kFrameSize =
138      StandardFrameConstants::kFixedFrameSize + 4 * kPointerSize;
139};
140
141
142class InternalFrameConstants : public AllStatic {
143 public:
144  // FP-relative.
145  static const int kCodeOffset = StandardFrameConstants::kExpressionsOffset;
146};
147
148
149inline Object* JavaScriptFrame::function_slot_object() const {
150  const int offset = JavaScriptFrameConstants::kFunctionOffset;
151  return Memory::Object_at(fp() + offset);
152}
153
154
155inline void StackHandler::SetFp(Address slot, Address fp) {
156  Memory::Address_at(slot) = fp;
157}
158
159
160} }  // namespace v8::internal
161
162#endif  // V8_ARM_FRAMES_ARM_H_
163