| // 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. |
| |
| #ifndef V8_ARM_FRAMES_ARM_H_ |
| #define V8_ARM_FRAMES_ARM_H_ |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| // The ARM ABI does not specify the usage of register r9, which may be reserved |
| // as the static base or thread register on some platforms, in which case we |
| // leave it alone. Adjust the value of kR9Available accordingly: |
| const int kR9Available = 1; // 1 if available to us, 0 if reserved |
| |
| |
| // Register list in load/store instructions |
| // Note that the bit values must match those used in actual instruction encoding |
| const int kNumRegs = 16; |
| |
| |
| // Caller-saved/arguments registers |
| const RegList kJSCallerSaved = |
| 1 << 0 | // r0 a1 |
| 1 << 1 | // r1 a2 |
| 1 << 2 | // r2 a3 |
| 1 << 3; // r3 a4 |
| |
| const int kNumJSCallerSaved = 4; |
| |
| // Return the code of the n-th caller-saved register available to JavaScript |
| // e.g. JSCallerSavedReg(0) returns r0.code() == 0 |
| int JSCallerSavedCode(int n); |
| |
| |
| // Callee-saved registers preserved when switching from C to JavaScript |
| const RegList kCalleeSaved = |
| 1 << 4 | // r4 v1 |
| 1 << 5 | // r5 v2 |
| 1 << 6 | // r6 v3 |
| 1 << 7 | // r7 v4 (cp in JavaScript code) |
| 1 << 8 | // r8 v5 (pp in JavaScript code) |
| kR9Available << 9 | // r9 v6 |
| 1 << 10 | // r10 v7 |
| 1 << 11; // r11 v8 (fp in JavaScript code) |
| |
| // When calling into C++ (only for C++ calls that can't cause a GC). |
| // The call code will take care of lr, fp, etc. |
| const RegList kCallerSaved = |
| 1 << 0 | // r0 |
| 1 << 1 | // r1 |
| 1 << 2 | // r2 |
| 1 << 3 | // r3 |
| 1 << 9; // r9 |
| |
| |
| const int kNumCalleeSaved = 7 + kR9Available; |
| |
| // Double registers d8 to d15 are callee-saved. |
| const int kNumDoubleCalleeSaved = 8; |
| |
| |
| // Number of registers for which space is reserved in safepoints. Must be a |
| // multiple of 8. |
| // TODO(regis): Only 8 registers may actually be sufficient. Revisit. |
| const int kNumSafepointRegisters = 16; |
| |
| // The embedded constant pool pointer (r8/pp) is not included in the safepoint |
| // since it is not tagged. This register is preserved in the stack frame where |
| // its value will be updated if GC code movement occurs. Including it in the |
| // safepoint (where it will not be relocated) would cause a stale value to be |
| // restored. |
| const RegList kConstantPointerRegMask = |
| FLAG_enable_embedded_constant_pool ? (1 << 8) : 0; |
| const int kNumConstantPoolPointerReg = |
| FLAG_enable_embedded_constant_pool ? 1 : 0; |
| |
| // Define the list of registers actually saved at safepoints. |
| // Note that the number of saved registers may be smaller than the reserved |
| // space, i.e. kNumSafepointSavedRegisters <= kNumSafepointRegisters. |
| const RegList kSafepointSavedRegisters = |
| kJSCallerSaved | (kCalleeSaved & ~kConstantPointerRegMask); |
| const int kNumSafepointSavedRegisters = |
| kNumJSCallerSaved + kNumCalleeSaved - kNumConstantPoolPointerReg; |
| |
| // ---------------------------------------------------- |
| |
| |
| class EntryFrameConstants : public AllStatic { |
| public: |
| static const int kCallerFPOffset = |
| -(StandardFrameConstants::kFixedFrameSizeFromFp + kPointerSize); |
| }; |
| |
| |
| class ExitFrameConstants : public AllStatic { |
| public: |
| static const int kFrameSize = |
| FLAG_enable_embedded_constant_pool ? 3 * kPointerSize : 2 * kPointerSize; |
| |
| static const int kConstantPoolOffset = |
| FLAG_enable_embedded_constant_pool ? -3 * kPointerSize : 0; |
| static const int kCodeOffset = -2 * kPointerSize; |
| static const int kSPOffset = -1 * kPointerSize; |
| |
| // The caller fields are below the frame pointer on the stack. |
| static const int kCallerFPOffset = 0 * kPointerSize; |
| // The calling JS function is below FP. |
| static const int kCallerPCOffset = 1 * kPointerSize; |
| |
| // FP-relative displacement of the caller's SP. It points just |
| // below the saved PC. |
| static const int kCallerSPDisplacement = 2 * kPointerSize; |
| }; |
| |
| |
| class JavaScriptFrameConstants : public AllStatic { |
| public: |
| // FP-relative. |
| static const int kLocal0Offset = StandardFrameConstants::kExpressionsOffset; |
| static const int kLastParameterOffset = +2 * kPointerSize; |
| static const int kFunctionOffset = StandardFrameConstants::kMarkerOffset; |
| |
| // Caller SP-relative. |
| static const int kParam0Offset = -2 * kPointerSize; |
| static const int kReceiverOffset = -1 * kPointerSize; |
| }; |
| |
| |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_ARM_FRAMES_ARM_H_ |