1 // Copyright 2012 the V8 project authors. All rights reserved.
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3 // modification, are permitted provided that the following conditions are
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5 //
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26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28 #ifndef V8_ARM_FRAMES_ARM_H_
29 #define V8_ARM_FRAMES_ARM_H_
30
31 namespace v8 {
32 namespace internal {
33
34
35 // The ARM ABI does not specify the usage of register r9, which may be reserved
36 // as the static base or thread register on some platforms, in which case we
37 // leave it alone. Adjust the value of kR9Available accordingly:
38 const int kR9Available = 1; // 1 if available to us, 0 if reserved
39
40
41 // Register list in load/store instructions
42 // Note that the bit values must match those used in actual instruction encoding
43 const int kNumRegs = 16;
44
45
46 // Caller-saved/arguments registers
47 const RegList kJSCallerSaved =
48 1 << 0 | // r0 a1
49 1 << 1 | // r1 a2
50 1 << 2 | // r2 a3
51 1 << 3; // r3 a4
52
53 const int kNumJSCallerSaved = 4;
54
55 typedef Object* JSCallerSavedBuffer[kNumJSCallerSaved];
56
57 // Return the code of the n-th caller-saved register available to JavaScript
58 // e.g. JSCallerSavedReg(0) returns r0.code() == 0
59 int JSCallerSavedCode(int n);
60
61
62 // Callee-saved registers preserved when switching from C to JavaScript
63 const RegList kCalleeSaved =
64 1 << 4 | // r4 v1
65 1 << 5 | // r5 v2
66 1 << 6 | // r6 v3
67 1 << 7 | // r7 v4
68 1 << 8 | // r8 v5 (cp in JavaScript code)
69 kR9Available << 9 | // r9 v6
70 1 << 10 | // r10 v7
71 1 << 11; // r11 v8 (fp in JavaScript code)
72
73 // When calling into C++ (only for C++ calls that can't cause a GC).
74 // The call code will take care of lr, fp, etc.
75 const RegList kCallerSaved =
76 1 << 0 | // r0
77 1 << 1 | // r1
78 1 << 2 | // r2
79 1 << 3 | // r3
80 1 << 9; // r9
81
82
83 const int kNumCalleeSaved = 7 + kR9Available;
84
85 // Double registers d8 to d15 are callee-saved.
86 const int kNumDoubleCalleeSaved = 8;
87
88
89 // Number of registers for which space is reserved in safepoints. Must be a
90 // multiple of 8.
91 // TODO(regis): Only 8 registers may actually be sufficient. Revisit.
92 const int kNumSafepointRegisters = 16;
93
94 // Define the list of registers actually saved at safepoints.
95 // Note that the number of saved registers may be smaller than the reserved
96 // space, i.e. kNumSafepointSavedRegisters <= kNumSafepointRegisters.
97 const RegList kSafepointSavedRegisters = kJSCallerSaved | kCalleeSaved;
98 const int kNumSafepointSavedRegisters = kNumJSCallerSaved + kNumCalleeSaved;
99
100 // ----------------------------------------------------
101
102
103 class StackHandlerConstants : public AllStatic {
104 public:
105 static const int kNextOffset = 0 * kPointerSize;
106 static const int kCodeOffset = 1 * kPointerSize;
107 static const int kStateOffset = 2 * kPointerSize;
108 static const int kContextOffset = 3 * kPointerSize;
109 static const int kFPOffset = 4 * kPointerSize;
110
111 static const int kSize = kFPOffset + kPointerSize;
112 };
113
114
115 class EntryFrameConstants : public AllStatic {
116 public:
117 static const int kCallerFPOffset = -3 * kPointerSize;
118 };
119
120
121 class ExitFrameConstants : public AllStatic {
122 public:
123 static const int kCodeOffset = -2 * kPointerSize;
124 static const int kSPOffset = -1 * kPointerSize;
125
126 // The caller fields are below the frame pointer on the stack.
127 static const int kCallerFPOffset = 0 * kPointerSize;
128 // The calling JS function is below FP.
129 static const int kCallerPCOffset = 1 * kPointerSize;
130
131 // FP-relative displacement of the caller's SP. It points just
132 // below the saved PC.
133 static const int kCallerSPDisplacement = 2 * kPointerSize;
134 };
135
136
137 class StandardFrameConstants : public AllStatic {
138 public:
139 // Fixed part of the frame consists of return address, caller fp,
140 // context and function.
141 static const int kFixedFrameSize = 4 * kPointerSize;
142 static const int kExpressionsOffset = -3 * kPointerSize;
143 static const int kMarkerOffset = -2 * kPointerSize;
144 static const int kContextOffset = -1 * kPointerSize;
145 static const int kCallerFPOffset = 0 * kPointerSize;
146 static const int kCallerPCOffset = 1 * kPointerSize;
147 static const int kCallerSPOffset = 2 * kPointerSize;
148 };
149
150
151 class JavaScriptFrameConstants : public AllStatic {
152 public:
153 // FP-relative.
154 static const int kLocal0Offset = StandardFrameConstants::kExpressionsOffset;
155 static const int kLastParameterOffset = +2 * kPointerSize;
156 static const int kFunctionOffset = StandardFrameConstants::kMarkerOffset;
157
158 // Caller SP-relative.
159 static const int kParam0Offset = -2 * kPointerSize;
160 static const int kReceiverOffset = -1 * kPointerSize;
161 };
162
163
164 class ArgumentsAdaptorFrameConstants : public AllStatic {
165 public:
166 static const int kLengthOffset = StandardFrameConstants::kExpressionsOffset;
167 static const int kFrameSize =
168 StandardFrameConstants::kFixedFrameSize + kPointerSize;
169 };
170
171
172 class InternalFrameConstants : public AllStatic {
173 public:
174 static const int kCodeOffset = StandardFrameConstants::kExpressionsOffset;
175 };
176
177
function_slot_object()178 inline Object* JavaScriptFrame::function_slot_object() const {
179 const int offset = JavaScriptFrameConstants::kFunctionOffset;
180 return Memory::Object_at(fp() + offset);
181 }
182
183
184 } } // namespace v8::internal
185
186 #endif // V8_ARM_FRAMES_ARM_H_
187