ppsspp/Core/MIPS/MIPSCodeUtils.cpp
2015-04-12 13:16:01 -07:00

151 lines
3.3 KiB
C++

// Copyright (c) 2012- PPSSPP 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 git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
#include "Core/MIPS/MIPS.h"
#include "Core/MIPS/MIPSTables.h"
#include "Core/MIPS/MIPSCodeUtils.h"
#include "Core/Host.h"
#include "Core/MemMap.h"
namespace MIPSCodeUtils
{
#define OP_SYSCALL 0x0000000c
#define OP_SYSCALL_MASK 0xFC00003F
#define _RS ((op>>21) & 0x1F)
#define _RT ((op>>16) & 0x1F)
u32 GetJumpTarget(u32 addr)
{
MIPSOpcode op = Memory::Read_Instruction(addr, true);
if (op != 0)
{
MIPSInfo info = MIPSGetInfo(op);
if ((info & IS_JUMP) && (info & IN_IMM26))
{
u32 target = (addr & 0xF0000000) | ((op&0x03FFFFFF) << 2);
return target;
}
else
return INVALIDTARGET;
}
else
return INVALIDTARGET;
}
u32 GetBranchTarget(u32 addr)
{
MIPSOpcode op = Memory::Read_Instruction(addr, true);
if (op != 0)
{
MIPSInfo info = MIPSGetInfo(op);
if (info & IS_CONDBRANCH)
{
return addr + 4 + ((signed short)(op&0xFFFF)<<2);
}
else
return INVALIDTARGET;
}
else
return INVALIDTARGET;
}
u32 GetBranchTargetNoRA(u32 addr)
{
MIPSOpcode op = Memory::Read_Instruction(addr, true);
return GetBranchTargetNoRA(addr, op);
}
u32 GetBranchTargetNoRA(u32 addr, MIPSOpcode op)
{
if (op != 0)
{
MIPSInfo info = MIPSGetInfo(op);
if ((info & IS_CONDBRANCH) && !(info & OUT_RA))
{
return addr + 4 + ((signed short)(op&0xFFFF)<<2);
}
else
return INVALIDTARGET;
}
else
return INVALIDTARGET;
}
u32 GetSureBranchTarget(u32 addr)
{
MIPSOpcode op = Memory::Read_Instruction(addr, true);
if (op != 0)
{
MIPSInfo info = MIPSGetInfo(op);
if ((info & IS_CONDBRANCH) && !(info & (IN_FPUFLAG | IS_VFPU)))
{
bool sure;
bool takeBranch;
switch (info & CONDTYPE_MASK)
{
case CONDTYPE_EQ:
sure = _RS == _RT;
takeBranch = true;
break;
case CONDTYPE_NE:
sure = _RS == _RT;
takeBranch = false;
break;
case CONDTYPE_LEZ:
case CONDTYPE_GEZ:
sure = _RS == 0;
takeBranch = true;
break;
case CONDTYPE_LTZ:
case CONDTYPE_GTZ:
sure = _RS == 0;
takeBranch = false;
break;
default:
sure = false;
}
if (sure && takeBranch)
return addr + 4 + ((signed short)(op&0xFFFF)<<2);
else if (sure && !takeBranch)
return addr + 8;
else
return INVALIDTARGET;
}
else
return INVALIDTARGET;
}
else
return INVALIDTARGET;
}
bool IsVFPUBranch(MIPSOpcode op) {
return (MIPSGetInfo(op) & (IS_VFPU | IS_CONDBRANCH)) == (IS_VFPU | IS_CONDBRANCH);
}
bool IsBranch(MIPSOpcode op) {
return (MIPSGetInfo(op) & IS_CONDBRANCH) == IS_CONDBRANCH;
}
}