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

// Copyright (C) 2003-2008 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 _JIT_ABI_H
#define _JIT_ABI_H

#include "x64Emitter.h"

// x86/x64 ABI:s, and helpers to help follow them when JIT-ing code.
// All convensions return values in EAX (+ possibly EDX).

// Linux 32-bit, Windows 32-bit (cdecl, System V):
// * Caller pushes left to right
// * Caller fixes stack after call
// * function subtract from stack for local storage only.
// Scratch:      EAX ECX EDX
// Callee-save:  EBX ESI EDI EBP
// Parameters:   -

// Windows 64-bit
// * 4-reg "fastcall" variant, very new-skool stack handling
// * Callee moves stack pointer, to make room for shadow regs for the biggest function _it itself calls_
// * Parameters passed in RCX, RDX, ... further parameters are MOVed into the allocated stack space.
// Scratch:      RAX RCX RDX R8 R9 R10 R11
// Callee-save:  RBX RSI RDI RBP R12 R13 R14 R15
// Parameters:   RCX RDX R8 R9, further MOV-ed

// Linux 64-bit
// * 6-reg "fastcall" variant, old skool stack handling (parameters are pushed)
// Scratch:      RAX RCX RDX RSI RDI R8 R9 R10 R11
// Callee-save:  RBX RBP R12 R13 R14 R15
// Parameters:   RDI RSI RDX RCX R8 R9

#ifdef _M_IX86
// 32 bit calling convention, shared by all

// 32-bit don't pass parameters in regs, but these are convenient to have anyway when we have to
// choose regs to put stuff in.
#define ABI_PARAM1 RCX
#define ABI_PARAM2 RDX

// There are no ABI_PARAM* here, since args are pushed.

// === 32-bit bog standard cdecl, shared between linux and windows ============================
// MacOSX 32-bit is same as System V with a few exceptions that we probably don't care much about.
#else
// 64 bit calling convention

#ifdef _WIN32
// === 64-bit Windows - the really exotic calling convention ==================================

#define ABI_PARAM1 RCX
#define ABI_PARAM2 RDX
#define ABI_PARAM3 R8
#define ABI_PARAM4 R9
#else
// === 64-bit Unix (hopefully MacOSX too) =====================================================

#define ABI_PARAM1 RDI
#define ABI_PARAM2 RSI
#define ABI_PARAM3 RDX
#define ABI_PARAM4 RCX
#define ABI_PARAM5 R8
#define ABI_PARAM6 R9

#endif

#endif

// Utility functions
// These only support u32 parameters, but that's enough for a lot of uses.
// These will destroy the 1 or 2 first "parameter regs".
void ABI_CallFunctionC(void *func, u32 param1);
void ABI_CallFunctionCC(void *func, u32 param1, u32 param2);
void ABI_CallFunctionAC(void *func, const Gen::OpArg &arg1, u32 param2);

// Pass a register as a paremeter.
void ABI_CallFunctionR(void *func, Gen::X64Reg reg1);
void ABI_CallFunctionRR(void *func, Gen::X64Reg reg1, Gen::X64Reg reg2);

// A function that doesn't have any control over what it will do to regs,
// such as the dispatcher, should be surrounded by these.
void ABI_PushAllCalleeSavedRegsAndAdjustStack();
void ABI_PopAllCalleeSavedRegsAndAdjustStack();

// A function that doesn't know anything about it's surroundings, should
// be surrounded by these to establish a safe environment, where it can roam free.
// An example is a backpatch injected function.
void ABI_PushAllCallerSavedRegsAndAdjustStack();
void ABI_PopAllCallerSavedRegsAndAdjustStack();

unsigned int ABI_GetAlignedFrameSize(unsigned int frameSize);
void ABI_AlignStack(unsigned int frameSize);
void ABI_RestoreStack(unsigned int frameSize);

// Sets up a __cdecl function.
// Only x64 really needs the parameter.
void ABI_EmitPrologue(int maxCallParams);
void ABI_EmitEpilogue(int maxCallParams);

#ifdef _M_IX86
inline int ABI_GetNumXMMRegs() { return 8; }
#else
inline int ABI_GetNumXMMRegs() { return 16; }
#endif

#endif  // _JIT_ABI_H