dolphin/Source/Core/Common/Src/Thunk.h

56 lines
1.7 KiB
C++

// Copyright (C) 2003-2009 Dolphin Project.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/
#ifndef _THUNK_H_
#define _THUNK_H_
#include <map>
#include "Common.h"
#include "x64Emitter.h"
// This simple class creates a wrapper around a C/C++ function that saves all fp state
// before entering it, and restores it upon exit. This is required to be able to selectively
// call functions from generated code, without inflicting the performance hit and increase
// of complexity that it means to protect the generated code from this problem.
// This process is called thunking.
// There will only ever be one level of thunking on the stack, plus,
// we don't want to pollute the stack, so we store away regs somewhere global.
// NOT THREAD SAFE. This may only be used from the CPU thread.
// Any other thread using this stuff will be FATAL.
class ThunkManager : public Gen::XCodeBlock
{
std::map<void *, const u8 *> thunks;
const u8 *save_regs;
const u8 *load_regs;
public:
void Init();
void Reset();
void Shutdown();
void *ProtectFunction(void *function, int num_params);
};
extern ThunkManager thunks;
#endif // _THUNK_H_