dolphin/Source/Plugins/Plugin_DSP_LLE/Src/gdsp_condition_codes.cpp

159 lines
3.3 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/
// Additional copyrights go to Duddie and Tratax (c) 2004
// HELPER FUNCTIONS
#include "gdsp_condition_codes.h"
#include "gdsp_interpreter.h"
#include "DSPInterpreter.h"
namespace DSPInterpreter {
void Update_SR_Register64(s64 _Value)
{
g_dsp.r[DSP_REG_SR] &= ~SR_CMP_MASK;
if (_Value < 0)
{
g_dsp.r[DSP_REG_SR] |= 0x8;
}
if (_Value == 0)
{
g_dsp.r[DSP_REG_SR] |= 0x4;
}
// weird
if ((_Value >> 62) == 0)
{
g_dsp.r[DSP_REG_SR] |= 0x20;
}
}
void Update_SR_Register16(s16 _Value)
{
g_dsp.r[DSP_REG_SR] &= ~SR_CMP_MASK;
if (_Value < 0)
{
g_dsp.r[DSP_REG_SR] |= 0x8;
}
if (_Value == 0)
{
g_dsp.r[DSP_REG_SR] |= 0x4;
}
// weird
if ((_Value >> 14) == 0)
{
g_dsp.r[DSP_REG_SR] |= 0x20;
}
}
// If this always returns 1, Hermes' demo sounds better.
// However, most AX games are negatively affected.
int GetMultiplyModifier()
{
if (g_dsp.r[DSP_REG_SR] & (1 << 13))
return 1;
else
return 2;
}
// 0x02 - overflow????
// 0x04 - Zero bit
// 0x08 - Sign bit
// 0x40 - Logical Zero bit
bool CheckCondition(u8 _Condition)
{
bool taken = false;
switch (_Condition & 0xf)
{
case 0x0: //NS - NOT SIGN
if ((!(g_dsp.r[DSP_REG_SR] & 0x02)) && (!(g_dsp.r[DSP_REG_SR] & 0x08)))
taken = true;
break;
case 0x1: // S - SIGN
if ((!(g_dsp.r[DSP_REG_SR] & 0x02)) && (g_dsp.r[DSP_REG_SR] & 0x08))
taken = true;
break;
case 0x2: // G - GREATER
if ((!(g_dsp.r[DSP_REG_SR] & 0x02)) && (!(g_dsp.r[DSP_REG_SR] & 0x08)) && !((g_dsp.r[DSP_REG_SR] & 0x04))) // gets zelda stuck
taken = true;
break;
case 0x3: // LE - LESS EQUAL
if ((!(g_dsp.r[DSP_REG_SR] & 0x02)) && ((g_dsp.r[DSP_REG_SR] & 0x08) || (g_dsp.r[DSP_REG_SR] & 0x04)))
taken = true;
break;
case 0x4: // NZ - NOT ZERO
if (!(g_dsp.r[DSP_REG_SR] & 0x04))
taken = true;
break;
case 0x5: // Z - ZERO
if (g_dsp.r[DSP_REG_SR] & 0x04)
taken = true;
break;
case 0x6: // L - LESS
if (!(g_dsp.r[DSP_REG_SR] & 0x02) && (g_dsp.r[DSP_REG_SR] & 0x08))
taken = true;
break;
case 0x7: // GE - GREATER EQUAL
if ((!(g_dsp.r[DSP_REG_SR] & 0x02)) && (!(g_dsp.r[DSP_REG_SR] & 0x08) || (g_dsp.r[DSP_REG_SR] & 0x04)))
taken = true;
break;
case 0xc: // LNZ - LOGIC NOT ZERO
if (!(g_dsp.r[DSP_REG_SR] & 0x40))
taken = true;
break;
case 0xd: // LZ - LOGIC ZERO
if (g_dsp.r[DSP_REG_SR] & 0x40)
taken = true;
break;
case 0xf: // Empty
taken = true;
break;
default:
ERROR_LOG(DSPLLE, "Unknown condition check: 0x%04x\n", _Condition & 0xf);
break;
}
return taken;
}
} // namespace