ppsspp/Common/Thunk.h
2016-05-01 11:40:00 +02:00

92 lines
2.8 KiB
C++

// Copyright (C) 2003 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 or later versions.
// 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/
#pragma once
#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.
// Only used for X86 right now.
// 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.
typedef Gen::XEmitter ThunkEmitter;
typedef Gen::XCodeBlock ThunkCodeBlock;
class ThunkManager : public ThunkCodeBlock
{
std::map<const void *, const u8 *> thunks;
const u8 *save_regs;
const u8 *load_regs;
public:
ThunkManager() {
Init();
}
~ThunkManager() {
Shutdown();
}
const void *ProtectFunction(const void *function, int num_params);
template <typename Tr>
const void *ProtectFunction(Tr (*func)()) {
return ProtectFunction((const void *)func, 0);
}
template <typename Tr, typename T1>
const void *ProtectFunction(Tr (*func)(T1)) {
return ProtectFunction((const void *)func, 1);
}
template <typename Tr, typename T1, typename T2>
const void *ProtectFunction(Tr (*func)(T1, T2)) {
return ProtectFunction((const void *)func, 2);
}
template <typename Tr, typename T1, typename T2, typename T3>
const void *ProtectFunction(Tr (*func)(T1, T2, T3)) {
return ProtectFunction((const void *)func, 3);
}
template <typename Tr, typename T1, typename T2, typename T3, typename T4>
const void *ProtectFunction(Tr (*func)(T1, T2, T3, T4)) {
return ProtectFunction((const void *)func, 4);
}
void Enter(ThunkEmitter *emit, bool withinCall = false);
void Leave(ThunkEmitter *emit, bool withinCall = false);
private:
void Init();
void Shutdown();
void Reset();
int ThunkStackOffset();
int ThunkBytesNeeded();
};