CSE2410 Fall 2014 Bounce

// Copyright 2006-2008 the V8 project authors. All rights reserved.

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

//       copyright notice, this list of conditions and the following

//       disclaimer in the documentation and/or other materials provided

//       with the distribution.

//     * Neither the name of Google Inc. nor the names of its

//       contributors may be used to endorse or promote products derived

//       from this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef V8_FRAMES_ARM_H_

#define V8_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:

static 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

static const int kNumRegs = 16;

// Caller-saved/arguments registers

static const RegList kJSCallerSaved =

  1 << 0 |  // r0 a1

  1 << 1 |  // r1 a2

  1 << 2 |  // r2 a3

  1 << 3;   // r3 a4

static const int kNumJSCallerSaved = 4;

typedef Object* JSCallerSavedBuffer[kNumJSCallerSaved];

// 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

static const RegList kCalleeSaved =

  1 <<  4 |  //  r4 v1

  1 <<  5 |  //  r5 v2

  1 <<  6 |  //  r6 v3

  1 <<  7 |  //  r7 v4

  1 <<  8 |  //  r8 v5 (cp in JavaScript code)

  kR9Available

    <<  9 |  //  r9 v6

  1 << 10 |  // r10 v7 (pp in JavaScript code)

  1 << 11;   // r11 v8 (fp in JavaScript code)

static const int kNumCalleeSaved = 7 + kR9Available;

// ----------------------------------------------------

class StackHandlerConstants : public AllStatic {

 public:

  // TODO(1233780): Get rid of the code slot in stack handlers.

  static const int kCodeOffset  = 0 * kPointerSize;

  static const int kNextOffset  = 1 * kPointerSize;

  static const int kStateOffset = 2 * kPointerSize;

  static const int kPPOffset    = 3 * kPointerSize;

  static const int kFPOffset    = 4 * kPointerSize;

  static const int kPCOffset    = 5 * kPointerSize;

  static const int kAddressDisplacement = -1 * kPointerSize;

  static const int kSize = kPCOffset + kPointerSize;

};

class EntryFrameConstants : public AllStatic {

 public:

  static const int kCallerFPOffset      = -3 * kPointerSize;

};

class ExitFrameConstants : public AllStatic {

 public:

  // Exit frames have a debug marker on the stack.

  static const int kSPDisplacement = -1 * kPointerSize;

  // The debug marker is just above the frame pointer.

  static const int kDebugMarkOffset = -1 * kPointerSize;

  static const int kSavedRegistersOffset = 0 * kPointerSize;

  // Let the parameters pointer for exit frames point just below the

  // frame structure on the stack.

  static const int kPPDisplacement = 3 * kPointerSize;

  // The caller fields are below the frame pointer on the stack.

  static const int kCallerFPOffset = +0 * kPointerSize;

  static const int kCallerPPOffset = +1 * kPointerSize;

  static const int kCallerPCOffset = +2 * kPointerSize;

};

class StandardFrameConstants : public AllStatic {

 public:

  static const int kExpressionsOffset = -3 * kPointerSize;

  static const int kMarkerOffset      = -2 * kPointerSize;

  static const int kContextOffset     = -1 * kPointerSize;

  static const int kCallerFPOffset    =  0 * kPointerSize;

  static const int kCallerPCOffset    = +1 * kPointerSize;

  static const int kCallerSPOffset    = +2 * kPointerSize;

};

class JavaScriptFrameConstants : public AllStatic {

 public:

  // FP-relative.

  static const int kLocal0Offset = StandardFrameConstants::kExpressionsOffset;

  static const int kSavedRegistersOffset = +2 * kPointerSize;

  static const int kFunctionOffset = StandardFrameConstants::kMarkerOffset;

  // PP-relative.

  static const int kParam0Offset   = -2 * kPointerSize;

  static const int kReceiverOffset = -1 * kPointerSize;

};

class ArgumentsAdaptorFrameConstants : public AllStatic {

 public:

  static const int kLengthOffset = StandardFrameConstants::kExpressionsOffset;

};

class InternalFrameConstants : public AllStatic {

 public:

  static const int kCodeOffset = StandardFrameConstants::kExpressionsOffset;

};

inline Object* JavaScriptFrame::function_slot_object() const {

  const int offset = JavaScriptFrameConstants::kFunctionOffset;

  return Memory::Object_at(fp() + offset);

}

// ----------------------------------------------------

  //    lower    |    Stack    |

  //  addresses  |      ^      |

  //             |      |      |

  //             |             |

  //             |  JS frame   |

  //             |             |

  //             |             |

  // ----------- +=============+ <--- sp (stack pointer)

  //             |  function   |

  //             +-------------+

  //             +-------------+

  //             |             |

  //             | expressions |

  //             |             |

  //             +-------------+

  //             |             |

  //      a      |   locals    |

  //      c      |             |

  //      t      +- - - - - - -+ <---

  //      i   -4 |   local0    |   ^

  //      v      +-------------+   |

  //      a   -3 |    code     |   |

  //      t      +-------------+   | kLocal0Offset

  //      i   -2 |   context   |   |

  //      o      +-------------+   |

  //      n   -1 | args_length |   v

  //             +-------------+ <--- fp (frame pointer)

  //           0 |  caller_pp  |

  //      f      +-------------+

  //      r    1 |  caller_fp  |

  //      a      +-------------+

  //      m    2 |  sp_on_exit |  (pp if return, caller_sp if no return)

  //      e      +-------------+

  //           3 |  caller_pc  |

  //             +-------------+ <--- caller_sp (incl. parameters)

  //             |             |

  //             | parameters  |

  //             |             |

  //             +- - - - - - -+ <---

  //          -2 | parameter0  |   ^

  //             +-------------+   | kParam0Offset

  //          -1 |  receiver   |   v

  // ----------- +=============+ <--- pp (parameter pointer, r10)

  //           0 |  function   |

  //             +-------------+

  //             |             |

  //             |caller-saved |  (must be valid JS values, traversed during GC)

  //             |    regs     |

  //             |             |

  //             +-------------+

  //             |             |

  //             |   caller    |

  //   higher    | expressions |

  //  addresses  |             |

  //             |             |

  //             |  JS frame   |

  // Handler frames (part of expressions of JS frames):

  //    lower    |    Stack    |

  //  addresses  |      ^      |

  //             |      |      |

  //             |             |

  //      h      | expressions |

  //      a      |             |

  //      n      +-------------+

  //      d   -1 |    code     |

  //      l      +-------------+ <--- handler sp

  //      e    0 |   next_sp   |  link to next handler (next handler's sp)

  //      r      +-------------+

  //           1 |    state    |

  //      f      +-------------+

  //      r    2 |     pp      |

  //      a      +-------------+

  //      m    3 |     fp      |

  //      e      +-------------+

  //           4 |     pc      |

  //             +-------------+

  //             |             |

  //   higher    | expressions |

  //  addresses  |             |

  // JS entry frames: When calling from C to JS, we construct two extra

  // frames: An entry frame (C) and a trampoline frame (JS). The

  // following pictures shows the two frames:

  //    lower    |    Stack    |

  //  addresses  |      ^      |

  //             |      |      |

  //             |             |

  //             |  JS frame   |

  //             |             |

  //             |             |

  // ----------- +=============+ <--- sp (stack pointer)

  //             |             |

  //             | parameters  |

  //      t      |             |

  //      r      +- - - - - - -+

  //      a      | parameter0  |

  //      m      +-------------+

  //      p      |  receiver   |

  //      o      +-------------+

  //      l      |  function   |

  //      i      +-------------+

  //      n   -3 |    code     |

  //      e      +-------------+

  //          -2 |    NULL     |  context is always NULL

  //             +-------------+

  //      f   -1 |      0      |  args_length is always zero

  //      r      +-------------+ <--- fp (frame pointer)

  //      a    0 |    NULL     |  caller pp is always NULL for entries

  //      m      +-------------+

  //      e    1 |  caller_fp  |

  //             +-------------+

  //           2 |  sp_on_exit |  (caller_sp)

  //             +-------------+

  //           3 |  caller_pc  |

  // ----------- +=============+ <--- caller_sp == pp

  //                    .          ^

  //                    .          |  try-handler, fake, not GC'ed

  //                    .          v

  //             +-------------+ <---

  //          -2 | next top pp |

  //             +-------------+

  //          -1 | next top fp |

  //             +-------------+ <--- fp

  //             |     r4      |  r4-r9 holding non-JS values must be preserved

  //             +-------------+

  //      J      |     r5      |  before being initialized not to confuse GC

  //      S      +-------------+

  //             |     r6      |

  //             +-------------+

  //      e      |     r7      |

  //      n      +-------------+

  //      t      |     r8      |

  //      r      +-------------+

  //      y    [ |     r9      | ]  only if r9 available

  //             +-------------+

  //             |     r10     |

  //      f      +-------------+

  //      r      |     r11     |

  //      a      +-------------+

  //      m      |  caller_sp  |

  //      e      +-------------+

  //             |  caller_pc  |

  //             +-------------+ <--- caller_sp

  //             |    argv     |    passed on stack from C code

  //             +-------------+

  //             |             |

  //   higher    |             |

  //  addresses  |   C frame   |

  // The first 4 args are passed from C in r0-r3 and are not spilled on entry:

  // r0: code entry

  // r1: function

  // r2: receiver

  // r3: argc

  // [sp+0]: argv

  // C entry frames: When calling from JS to C, we construct one extra

  // frame:

  //    lower    |    Stack    |

  //  addresses  |      ^      |

  //             |      |      |

  //             |             |

  //             |   C frame   |

  //             |             |

  //             |             |

  // ----------- +=============+ <--- sp (stack pointer)

  //             |             |

  //             | parameters  |  (first 4 args are passed in r0-r3)

  //             |             |

  //             +-------------+ <--- fp (frame pointer)

  //      f  4/5 |  caller_fp  |

  //      r      +-------------+

  //      a  5/6 |  sp_on_exit |  (pp)

  //      m      +-------------+

  //      e  6/7 |  caller_pc  |

  //             +-------------+ <--- caller_sp (incl. parameters)

  //         7/8 |             |

  //             | parameters  |

  //             |             |

  //             +- - - - - - -+ <---

  //          -2 | parameter0  |   ^

  //             +-------------+   | kParam0Offset

  //          -1 |  receiver   |   v

  // ----------- +=============+ <--- pp (parameter pointer, r10)

  //           0 |  function   |

  //             +-------------+

  //             |             |

  //             |caller-saved |

  //             |    regs     |

  //             |             |

  //             +-------------+

  //             |             |

  //             |   caller    |

  //             | expressions |

  //             |             |

  //   higher    |             |

  //  addresses  |  JS frame   |

} }  // namespace v8::internal

#endif  // V8_FRAMES_ARM_H_