src/macro-assembler-arm.h

// 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
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//       with the distribution.
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//
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#ifndef V8_MACRO_ASSEMBLER_ARM_H_
#define V8_MACRO_ASSEMBLER_ARM_H_

#include "assembler.h"

namespace v8 { namespace internal {


// Give alias names to registers
extern Register cp;  // JavaScript context pointer
extern Register pp;  // parameter pointer


// Helper types to make boolean flag easier to read at call-site.
enum InvokeFlag {
  CALL_FUNCTION,
  JUMP_FUNCTION
};

enum InvokeJSFlags {
  CALL_JS,
  JUMP_JS
};

enum ExitJSFlag {
  RETURN,
  DO_NOT_RETURN
};

enum CodeLocation {
  IN_JAVASCRIPT,
  IN_JS_ENTRY,
  IN_C_ENTRY
};

enum HandlerType {
  TRY_CATCH_HANDLER,
  TRY_FINALLY_HANDLER,
  JS_ENTRY_HANDLER
};


// MacroAssembler implements a collection of frequently used macros.
class MacroAssembler: public Assembler {
 public:
  MacroAssembler(void* buffer, int size);

  // ---------------------------------------------------------------------------
  // Low-level helpers for compiler

  // Jump, Call, and Ret pseudo instructions implementing inter-working
 private:
  void Jump(intptr_t target, RelocInfo::Mode rmode, Condition cond = al);
  void Call(intptr_t target, RelocInfo::Mode rmode, Condition cond = al);
 public:
  void Jump(Register target, Condition cond = al);
  void Jump(byte* target, RelocInfo::Mode rmode, Condition cond = al);
  void Jump(Handle<Code> code, RelocInfo::Mode rmode, Condition cond = al);
  void Call(Register target, Condition cond = al);
  void Call(byte* target, RelocInfo::Mode rmode, Condition cond = al);
  void Call(Handle<Code> code, RelocInfo::Mode rmode, Condition cond = al);
  void Ret();


  // Sets the remembered set bit for [address+offset], where address is the
  // address of the heap object 'object'.  The address must be in the first 8K
  // of an allocated page. The 'scratch' register is used in the
  // implementation and all 3 registers are clobbered by the operation, as
  // well as the ip register.
  void RecordWrite(Register object, Register offset, Register scratch);

  // ---------------------------------------------------------------------------
  // Activation frames

  void EnterInternalFrame() { EnterFrame(StackFrame::INTERNAL); }
  void LeaveInternalFrame() { LeaveFrame(StackFrame::INTERNAL); }

  void EnterConstructFrame() { EnterFrame(StackFrame::CONSTRUCT); }
  void LeaveConstructFrame() { LeaveFrame(StackFrame::CONSTRUCT); }

  // Enter specific kind of exit frame; either EXIT or
  // EXIT_DEBUG. Expects the number of arguments in register r0 and
  // the builtin function to call in register r1. Exits with argc in
  // r4, argv in r6, and and the builtin function to call in r5.
  void EnterExitFrame(StackFrame::Type type);

  // Leave the current exit frame. Expects the return value in r0.
  void LeaveExitFrame(StackFrame::Type type);


  // ---------------------------------------------------------------------------
  // JavaScript invokes

  // Invoke the JavaScript function code by either calling or jumping.
  void InvokeCode(Register code,
                  const ParameterCount& expected,
                  const ParameterCount& actual,
                  InvokeFlag flag);

  void InvokeCode(Handle<Code> code,
                  const ParameterCount& expected,
                  const ParameterCount& actual,
                  RelocInfo::Mode rmode,
                  InvokeFlag flag);

  // Invoke the JavaScript function in the given register. Changes the
  // current context to the context in the function before invoking.
  void InvokeFunction(Register function,
                      const ParameterCount& actual,
                      InvokeFlag flag);


  // ---------------------------------------------------------------------------
  // Debugger Support

  void SaveRegistersToMemory(RegList regs);
  void RestoreRegistersFromMemory(RegList regs);
  void CopyRegistersFromMemoryToStack(Register base, RegList regs);
  void CopyRegistersFromStackToMemory(Register base,
                                      Register scratch,
                                      RegList regs);


  // ---------------------------------------------------------------------------
  // Exception handling

  // Push a new try handler and link into try handler chain.
  // The return address must be passed in register lr.
  // On exit, r0 contains TOS (code slot).
  void PushTryHandler(CodeLocation try_location, HandlerType type);


  // ---------------------------------------------------------------------------
  // Inline caching support

  // Generates code that verifies that the maps of objects in the
  // prototype chain of object hasn't changed since the code was
  // generated and branches to the miss label if any map has. If
  // necessary the function also generates code for security check
  // in case of global object holders. The scratch and holder
  // registers are always clobbered, but the object register is only
  // clobbered if it the same as the holder register. The function
  // returns a register containing the holder - either object_reg or
  // holder_reg.
  Register CheckMaps(JSObject* object, Register object_reg,
                     JSObject* holder, Register holder_reg,
                     Register scratch, Label* miss);

  // Generate code for checking access rights - used for security checks
  // on access to global objects across environments. The holder register
  // is left untouched, whereas both scratch registers are clobbered.
  void CheckAccessGlobalProxy(Register holder_reg,
                              Register scratch,
                              Label* miss);


  // ---------------------------------------------------------------------------
  // Support functions.

  // Generates code for reporting that an illegal operation has
  // occurred.
  void IllegalOperation(int num_arguments);


  // ---------------------------------------------------------------------------
  // Runtime calls

  // Call a code stub.
  void CallStub(CodeStub* stub);
  void CallJSExitStub(CodeStub* stub);

  // Return from a code stub after popping its arguments.
  void StubReturn(int argc);

  // Call a runtime routine.
  // Eventually this should be used for all C calls.
  void CallRuntime(Runtime::Function* f, int num_arguments);

  // Convenience function: Same as above, but takes the fid instead.
  void CallRuntime(Runtime::FunctionId fid, int num_arguments);

  // Tail call of a runtime routine (jump).
  // Like JumpToBuiltin, but also takes care of passing the number
  // of parameters.
  void TailCallRuntime(const ExternalReference& ext, int num_arguments);

  // Jump to the builtin routine.
  void JumpToBuiltin(const ExternalReference& builtin);

  // Invoke specified builtin JavaScript function. Adds an entry to
  // the unresolved list if the name does not resolve.
  void InvokeBuiltin(Builtins::JavaScript id, InvokeJSFlags flags);

  // Store the code object for the given builtin in the target register and
  // setup the function in r1.
  void GetBuiltinEntry(Register target, Builtins::JavaScript id);

  struct Unresolved {
    int pc;
    uint32_t flags;  // see Bootstrapper::FixupFlags decoders/encoders.
    const char* name;
  };
  List<Unresolved>* unresolved() { return &unresolved_; }


  // ---------------------------------------------------------------------------
  // StatsCounter support

  void SetCounter(StatsCounter* counter, int value,
                  Register scratch1, Register scratch2);
  void IncrementCounter(StatsCounter* counter, int value,
                        Register scratch1, Register scratch2);
  void DecrementCounter(StatsCounter* counter, int value,
                        Register scratch1, Register scratch2);


  // ---------------------------------------------------------------------------
  // Debugging

  // Calls Abort(msg) if the condition cc is not satisfied.
  // Use --debug_code to enable.
  void Assert(Condition cc, const char* msg);

  // Like Assert(), but always enabled.
  void Check(Condition cc, const char* msg);

  // Print a message to stdout and abort execution.
  void Abort(const char* msg);

  // Verify restrictions about code generated in stubs.
  void set_generating_stub(bool value) { generating_stub_ = value; }
  bool generating_stub() { return generating_stub_; }
  void set_allow_stub_calls(bool value) { allow_stub_calls_ = value; }
  bool allow_stub_calls() { return allow_stub_calls_; }

 private:
  List<Unresolved> unresolved_;
  bool generating_stub_;
  bool allow_stub_calls_;

  // Helper functions for generating invokes.
  void InvokePrologue(const ParameterCount& expected,
                      const ParameterCount& actual,
                      Handle<Code> code_constant,
                      Register code_reg,
                      Label* done,
                      InvokeFlag flag);

  // Get the code for the given builtin. Returns if able to resolve
  // the function in the 'resolved' flag.
  Handle<Code> ResolveBuiltin(Builtins::JavaScript id, bool* resolved);

  // Activation support.
  void EnterFrame(StackFrame::Type type);
  void LeaveFrame(StackFrame::Type type);
};


// -----------------------------------------------------------------------------
// Static helper functions.

// Generate a MemOperand for loading a field from an object.
static inline MemOperand FieldMemOperand(Register object, int offset) {
  return MemOperand(object, offset - kHeapObjectTag);
}



} }  // namespace v8::internal

#endif  // V8_MACRO_ASSEMBLER_ARM_H_