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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     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 (cp in JavaScript code)
     68   1 <<  8 |  //  r8 v5 (pp 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 EntryFrameConstants : public AllStatic {
    104  public:
    105   static const int kCallerFPOffset =
    106       -(StandardFrameConstants::kFixedFrameSizeFromFp + kPointerSize);
    107 };
    108 
    109 
    110 class ExitFrameConstants : public AllStatic {
    111  public:
    112   static const int kCodeOffset = -2 * kPointerSize;
    113   static const int kSPOffset = -1 * kPointerSize;
    114 
    115   // The caller fields are below the frame pointer on the stack.
    116   static const int kCallerFPOffset = 0 * kPointerSize;
    117   // The calling JS function is below FP.
    118   static const int kCallerPCOffset = 1 * kPointerSize;
    119 
    120   // FP-relative displacement of the caller's SP.  It points just
    121   // below the saved PC.
    122   static const int kCallerSPDisplacement = 2 * kPointerSize;
    123 };
    124 
    125 
    126 class JavaScriptFrameConstants : public AllStatic {
    127  public:
    128   // FP-relative.
    129   static const int kLocal0Offset = StandardFrameConstants::kExpressionsOffset;
    130   static const int kLastParameterOffset = +2 * kPointerSize;
    131   static const int kFunctionOffset = StandardFrameConstants::kMarkerOffset;
    132 
    133   // Caller SP-relative.
    134   static const int kParam0Offset   = -2 * kPointerSize;
    135   static const int kReceiverOffset = -1 * kPointerSize;
    136 };
    137 
    138 
    139 class ArgumentsAdaptorFrameConstants : public AllStatic {
    140  public:
    141   // FP-relative.
    142   static const int kLengthOffset = StandardFrameConstants::kExpressionsOffset;
    143 
    144   static const int kFrameSize =
    145       StandardFrameConstants::kFixedFrameSize + kPointerSize;
    146 };
    147 
    148 
    149 class ConstructFrameConstants : public AllStatic {
    150  public:
    151   // FP-relative.
    152   static const int kImplicitReceiverOffset = -6 * kPointerSize;
    153   static const int kConstructorOffset      = -5 * kPointerSize;
    154   static const int kLengthOffset           = -4 * kPointerSize;
    155   static const int kCodeOffset = StandardFrameConstants::kExpressionsOffset;
    156 
    157   static const int kFrameSize =
    158       StandardFrameConstants::kFixedFrameSize + 4 * kPointerSize;
    159 };
    160 
    161 
    162 class InternalFrameConstants : public AllStatic {
    163  public:
    164   // FP-relative.
    165   static const int kCodeOffset = StandardFrameConstants::kExpressionsOffset;
    166 };
    167 
    168 
    169 inline Object* JavaScriptFrame::function_slot_object() const {
    170   const int offset = JavaScriptFrameConstants::kFunctionOffset;
    171   return Memory::Object_at(fp() + offset);
    172 }
    173 
    174 
    175 inline void StackHandler::SetFp(Address slot, Address fp) {
    176   Memory::Address_at(slot) = fp;
    177 }
    178 
    179 
    180 } }  // namespace v8::internal
    181 
    182 #endif  // V8_ARM_FRAMES_ARM_H_
    183