Duckstation/src/core/cpu_pgxp.cpp

// SPDX-FileCopyrightText: 2016 iCatButler, 2019-2023 Connor McLaughlin <stenzek@gmail.com>
// SPDX-License-Identifier: GPL-2.0+

#include "cpu_pgxp.h"
#include "bus.h"
#include "cpu_core.h"
#include "settings.h"

#include "common/assert.h"
#include "common/log.h"

#include <climits>
#include <cmath>

Log_SetChannel(CPU::PGXP);

namespace CPU::PGXP {
namespace {

enum : u32
{
  VERTEX_CACHE_WIDTH = 0x800 * 2,
  VERTEX_CACHE_HEIGHT = 0x800 * 2,
  VERTEX_CACHE_SIZE = VERTEX_CACHE_WIDTH * VERTEX_CACHE_HEIGHT,
  PGXP_MEM_SIZE = (static_cast<u32>(Bus::RAM_8MB_SIZE) + static_cast<u32>(CPU::SCRATCHPAD_SIZE)) / 4,
  PGXP_MEM_SCRATCH_OFFSET = Bus::RAM_8MB_SIZE / 4
};

#define NONE 0
#define ALL 0xFFFFFFFF
#define VALID 1
#define VALID_0 (VALID << 0)
#define VALID_1 (VALID << 8)
#define VALID_2 (VALID << 16)
#define VALID_3 (VALID << 24)
#define VALID_01 (VALID_0 | VALID_1)
#define VALID_012 (VALID_0 | VALID_1 | VALID_2)
#define VALID_ALL (VALID_0 | VALID_1 | VALID_2 | VALID_3)
#define INV_VALID_ALL (ALL ^ VALID_ALL)

union psx_value
{
  struct
  {
    u8 l, h, h2, h3;
  } b;
  struct
  {
    u16 l, h;
  } w;
  struct
  {
    s8 l, h, h2, h3;
  } sb;
  struct
  {
    s16 l, h;
  } sw;
  u32 d;
  s32 sd;
};
} // namespace

static void PGXP_CacheVertex(s16 sx, s16 sy, const PGXP_value& vertex);
static PGXP_value* PGXP_GetCachedVertex(short sx, short sy);

static float TruncateVertexPosition(float p);
static bool IsWithinTolerance(float precise_x, float precise_y, int int_x, int int_y);

static void MakeValid(PGXP_value* pV, u32 psxV);

static void Validate(PGXP_value* pV, u32 psxV);
static void MaskValidate(PGXP_value* pV, u32 psxV, u32 mask, u32 validMask);

static double f16Sign(double in);
static double f16Unsign(double in);
static double f16Overflow(double in);

static PGXP_value* GetPtr(u32 addr);

static void ValidateAndCopyMem(PGXP_value* dest, u32 addr, u32 value);
static void ValidateAndCopyMem16(PGXP_value* dest, u32 addr, u32 value, bool sign);

static void CPU_MTC2_int(const PGXP_value& value, u32 reg);
static void CPU_BITWISE(u32 instr, u32 rdVal, u32 rsVal, u32 rtVal);

static void WriteMem(const PGXP_value* value, u32 addr);
static void WriteMem16(const PGXP_value* src, u32 addr);

static const PGXP_value PGXP_value_invalid = {0.f, 0.f, 0.f, {0}, 0};
static const PGXP_value PGXP_value_zero = {0.f, 0.f, 0.f, {VALID_ALL}, 0};

static PGXP_value* Mem = nullptr;
static PGXP_value* vertexCache = nullptr;
} // namespace CPU::PGXP

void CPU::PGXP::Initialize()
{
  std::memset(g_state.pgxp_gpr, 0, sizeof(g_state.pgxp_gpr));
  std::memset(g_state.pgxp_cop0, 0, sizeof(g_state.pgxp_cop0));

  std::memset(g_state.pgxp_gte, 0, sizeof(g_state.pgxp_gte));

  if (!Mem)
  {
    Mem = static_cast<PGXP_value*>(std::calloc(PGXP_MEM_SIZE, sizeof(PGXP_value)));
    if (!Mem)
      Panic("Failed to allocate PGXP memory");
  }

  if (g_settings.gpu_pgxp_vertex_cache && !vertexCache)
  {
    vertexCache = static_cast<PGXP_value*>(std::calloc(VERTEX_CACHE_SIZE, sizeof(PGXP_value)));
    if (!vertexCache)
    {
      Log_ErrorPrint("Failed to allocate memory for vertex cache, disabling.");
      g_settings.gpu_pgxp_vertex_cache = false;
    }
  }

  if (vertexCache)
    std::memset(vertexCache, 0, sizeof(PGXP_value) * VERTEX_CACHE_SIZE);
}

void CPU::PGXP::Reset()
{
  std::memset(g_state.pgxp_gpr, 0, sizeof(g_state.pgxp_gpr));
  std::memset(g_state.pgxp_cop0, 0, sizeof(g_state.pgxp_cop0));
  std::memset(g_state.pgxp_gte, 0, sizeof(g_state.pgxp_gte));

  if (Mem)
    std::memset(Mem, 0, sizeof(PGXP_value) * PGXP_MEM_SIZE);

  if (vertexCache)
    std::memset(vertexCache, 0, sizeof(PGXP_value) * VERTEX_CACHE_SIZE);
}

void CPU::PGXP::Shutdown()
{
  if (vertexCache)
  {
    std::free(vertexCache);
    vertexCache = nullptr;
  }
  if (Mem)
  {
    std::free(Mem);
    Mem = nullptr;
  }

  std::memset(g_state.pgxp_gte, 0, sizeof(g_state.pgxp_gte));

  std::memset(g_state.pgxp_gpr, 0, sizeof(g_state.pgxp_gpr));
  std::memset(g_state.pgxp_cop0, 0, sizeof(g_state.pgxp_cop0));
}

// Instruction register decoding
#define op(_instr) (_instr >> 26)          // The op part of the instruction register
#define func(_instr) ((_instr)&0x3F)       // The funct part of the instruction register
#define sa(_instr) ((_instr >> 6) & 0x1F)  // The sa part of the instruction register
#define rd(_instr) ((_instr >> 11) & 0x1F) // The rd part of the instruction register
#define rt(_instr) ((_instr >> 16) & 0x1F) // The rt part of the instruction register
#define rs(_instr) ((_instr >> 21) & 0x1F) // The rs part of the instruction register
#define imm(_instr) (_instr & 0xFFFF)      // The immediate part of the instruction register
#define cop2idx(_instr) (((_instr >> 11) & 0x1F) | ((_instr >> 17) & 0x20))

#define SX0 (g_state.pgxp_gte[12].x)
#define SY0 (g_state.pgxp_gte[12].y)
#define SX1 (g_state.pgxp_gte[13].x)
#define SY1 (g_state.pgxp_gte[13].y)
#define SX2 (g_state.pgxp_gte[14].x)
#define SY2 (g_state.pgxp_gte[14].y)

#define SXY0 (g_state.pgxp_gte[12])
#define SXY1 (g_state.pgxp_gte[13])
#define SXY2 (g_state.pgxp_gte[14])
#define SXYP (g_state.pgxp_gte[15])

ALWAYS_INLINE_RELEASE void CPU::PGXP::MakeValid(PGXP_value* pV, u32 psxV)
{
  if (VALID_01 != (pV->flags & VALID_01))
  {
    pV->x = static_cast<float>(static_cast<s16>(Truncate16(psxV)));
    pV->y = static_cast<float>(static_cast<s16>(Truncate16(psxV >> 16)));
    pV->z = 0.f;
    pV->flags |= VALID_01;
    pV->value = psxV;
  }
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::Validate(PGXP_value* pV, u32 psxV)
{
  // assume pV is not NULL
  pV->flags &= (pV->value == psxV) ? ALL : INV_VALID_ALL;
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::MaskValidate(PGXP_value* pV, u32 psxV, u32 mask, u32 validMask)
{
  // assume pV is not NULL
  pV->flags &= ((pV->value & mask) == (psxV & mask)) ? ALL : (ALL ^ (validMask));
}

ALWAYS_INLINE_RELEASE double CPU::PGXP::f16Sign(double in)
{
  const s32 s = static_cast<s32>(static_cast<s64>(in * (USHRT_MAX + 1)));
  return static_cast<double>(s) / static_cast<double>(USHRT_MAX + 1);
}
ALWAYS_INLINE_RELEASE double CPU::PGXP::f16Unsign(double in)
{
  return (in >= 0) ? in : (in + (USHRT_MAX + 1));
}
ALWAYS_INLINE_RELEASE double CPU::PGXP::f16Overflow(double in)
{
  double out = 0;
  s64 v = ((s64)in) >> 16;
  out = (double)v;
  return out;
}

ALWAYS_INLINE_RELEASE CPU::PGXP_value* CPU::PGXP::GetPtr(u32 addr)
{
  if ((addr & SCRATCHPAD_ADDR_MASK) == SCRATCHPAD_ADDR)
    return &Mem[PGXP_MEM_SCRATCH_OFFSET + ((addr & SCRATCHPAD_OFFSET_MASK) >> 2)];

  const u32 paddr = (addr & PHYSICAL_MEMORY_ADDRESS_MASK);
  if (paddr < Bus::RAM_MIRROR_END)
    return &Mem[(paddr & Bus::g_ram_mask) >> 2];
  else
    return nullptr;
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::ValidateAndCopyMem(PGXP_value* dest, u32 addr, u32 value)
{
  PGXP_value* pMem = GetPtr(addr);
  if (pMem)
  {
    Validate(pMem, value);
    *dest = *pMem;
    return;
  }

  *dest = PGXP_value_invalid;
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::ValidateAndCopyMem16(PGXP_value* dest, u32 addr, u32 value, bool sign)
{
  u32 validMask = 0;
  psx_value val, mask;
  PGXP_value* pMem = GetPtr(addr);
  if (pMem)
  {
    mask.d = val.d = 0;
    // determine if high or low word
    if ((addr % 4) == 2)
    {
      val.w.h = static_cast<u16>(value);
      mask.w.h = 0xFFFF;
      validMask = VALID_1;
    }
    else
    {
      val.w.l = static_cast<u16>(value);
      mask.w.l = 0xFFFF;
      validMask = VALID_0;
    }

    // validate and copy whole value
    MaskValidate(pMem, val.d, mask.d, validMask);
    *dest = *pMem;

    // if high word then shift
    if ((addr % 4) == 2)
    {
      dest->x = dest->y;
      dest->compFlags[0] = dest->compFlags[1];
    }

    // truncate value
    dest->y = (dest->x < 0) ? -1.f * sign : 0.f; // 0.f;
    dest->value = value;
    dest->compFlags[1] = VALID; // iCB: High word is valid, just 0
    return;
  }

  *dest = PGXP_value_invalid;
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::WriteMem(const PGXP_value* value, u32 addr)
{
  PGXP_value* pMem = GetPtr(addr);

  if (pMem)
    *pMem = *value;
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::WriteMem16(const PGXP_value* src, u32 addr)
{
  PGXP_value* dest = GetPtr(addr);
  psx_value* pVal = nullptr;

  if (dest)
  {
    pVal = (psx_value*)&dest->value;
    // determine if high or low word
    if ((addr % 4) == 2)
    {
      dest->y = src->x;
      dest->compFlags[1] = src->compFlags[0];
      pVal->w.h = (u16)src->value;
    }
    else
    {
      dest->x = src->x;
      dest->compFlags[0] = src->compFlags[0];
      pVal->w.l = (u16)src->value;
    }

    // overwrite z/w if valid
    if (src->compFlags[2] == VALID)
    {
      dest->z = src->z;
      dest->compFlags[2] = src->compFlags[2];
    }

    // dest->valid = dest->valid && src->valid;
  }
}

void CPU::PGXP::GTE_PushSXYZ2f(float x, float y, float z, u32 v)
{
  // push values down FIFO
  SXY0 = SXY1;
  SXY1 = SXY2;

  SXY2.x = x;
  SXY2.y = y;
  SXY2.z = z;
  SXY2.value = v;
  SXY2.flags = VALID_ALL;

  if (g_settings.gpu_pgxp_vertex_cache)
    PGXP_CacheVertex(static_cast<s16>(Truncate16(v)), static_cast<s16>(Truncate16(v >> 16)), SXY2);
}

#define VX(n) (psxRegs.CP2D.p[n << 1].sw.l)
#define VY(n) (psxRegs.CP2D.p[n << 1].sw.h)
#define VZ(n) (psxRegs.CP2D.p[(n << 1) + 1].sw.l)

int CPU::PGXP::GTE_NCLIP_valid(u32 sxy0, u32 sxy1, u32 sxy2)
{
  Validate(&SXY0, sxy0);
  Validate(&SXY1, sxy1);
  Validate(&SXY2, sxy2);

  // Don't use accurate clipping for game-constructed values, which don't have a valid Z.
  return (((SXY0.flags & SXY1.flags & SXY2.flags & VALID_012) == VALID_012));
}

float CPU::PGXP::GTE_NCLIP()
{
  float nclip = ((SX0 * SY1) + (SX1 * SY2) + (SX2 * SY0) - (SX0 * SY2) - (SX1 * SY0) - (SX2 * SY1));

  // ensure fractional values are not incorrectly rounded to 0
  float nclipAbs = std::abs(nclip);
  if ((0.1f < nclipAbs) && (nclipAbs < 1.f))
    nclip += (nclip < 0.f ? -1 : 1);

  // float AX = SX1 - SX0;
  // float AY = SY1 - SY0;

  // float BX = SX2 - SX0;
  // float BY = SY2 - SY0;

  //// normalise A and B
  // float mA = sqrt((AX*AX) + (AY*AY));
  // float mB = sqrt((BX*BX) + (BY*BY));

  //// calculate AxB to get Z component of C
  // float CZ = ((AX * BY) - (AY * BX)) * (1 << 12);

  return nclip;
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::CPU_MTC2_int(const PGXP_value& value, u32 reg)
{
  switch (reg)
  {
    case 15:
      // push FIFO
      SXY0 = SXY1;
      SXY1 = SXY2;
      SXY2 = value;
      SXYP = SXY2;
      break;

    case 31:
      return;
  }

  g_state.pgxp_gte[reg] = value;
}

////////////////////////////////////
// Data transfer tracking
////////////////////////////////////

void CPU::PGXP::CPU_MFC2(u32 instr, u32 rdVal)
{
  // CPU[Rt] = GTE_D[Rd]
  const u32 idx = cop2idx(instr);
  Validate(&g_state.pgxp_gte[idx], rdVal);
  g_state.pgxp_gpr[rt(instr)] = g_state.pgxp_gte[idx];
  g_state.pgxp_gpr[rt(instr)].value = rdVal;
}

void CPU::PGXP::CPU_MTC2(u32 instr, u32 rtVal)
{
  // GTE_D[Rd] = CPU[Rt]
  const u32 idx = cop2idx(instr);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);
  CPU_MTC2_int(g_state.pgxp_gpr[rt(instr)], idx);
  g_state.pgxp_gte[idx].value = rtVal;
}

////////////////////////////////////
// Memory Access
////////////////////////////////////
void CPU::PGXP::CPU_LWC2(u32 instr, u32 addr, u32 rtVal)
{
  // GTE_D[Rt] = Mem[addr]
  PGXP_value val;
  ValidateAndCopyMem(&val, addr, rtVal);
  CPU_MTC2_int(val, rt(instr));
}

void CPU::PGXP::CPU_SWC2(u32 instr, u32 addr, u32 rtVal)
{
  //  Mem[addr] = GTE_D[Rt]
  Validate(&g_state.pgxp_gte[rt(instr)], rtVal);
  WriteMem(&g_state.pgxp_gte[rt(instr)], addr);
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::PGXP_CacheVertex(s16 sx, s16 sy, const PGXP_value& vertex)
{
  if (sx >= -0x800 && sx <= 0x7ff && sy >= -0x800 && sy <= 0x7ff)
  {
    // Write vertex into cache
    vertexCache[(sy + 0x800) * VERTEX_CACHE_WIDTH + (sx + 0x800)] = vertex;
  }
}

ALWAYS_INLINE_RELEASE CPU::PGXP_value* CPU::PGXP::PGXP_GetCachedVertex(short sx, short sy)
{
  if (sx >= -0x800 && sx <= 0x7ff && sy >= -0x800 && sy <= 0x7ff)
  {
    // Return pointer to cache entry
    return &vertexCache[(sy + 0x800) * VERTEX_CACHE_WIDTH + (sx + 0x800)];
  }

  return nullptr;
}

ALWAYS_INLINE_RELEASE float CPU::PGXP::TruncateVertexPosition(float p)
{
  const s32 int_part = static_cast<s32>(p);
  const float int_part_f = static_cast<float>(int_part);
  return static_cast<float>(static_cast<s16>(int_part << 5) >> 5) + (p - int_part_f);
}

ALWAYS_INLINE_RELEASE bool CPU::PGXP::IsWithinTolerance(float precise_x, float precise_y, int int_x, int int_y)
{
  const float tolerance = g_settings.gpu_pgxp_tolerance;
  if (tolerance < 0.0f)
    return true;

  return (std::abs(precise_x - static_cast<float>(int_x)) <= tolerance &&
          std::abs(precise_y - static_cast<float>(int_y)) <= tolerance);
}

bool CPU::PGXP::GetPreciseVertex(u32 addr, u32 value, int x, int y, int xOffs, int yOffs, float* out_x, float* out_y,
                                 float* out_w)
{
  const PGXP_value* vert = GetPtr(addr);
  if (vert && ((vert->flags & VALID_01) == VALID_01) && (vert->value == value))
  {
    // There is a value here with valid X and Y coordinates
    *out_x = TruncateVertexPosition(vert->x) + static_cast<float>(xOffs);
    *out_y = TruncateVertexPosition(vert->y) + static_cast<float>(yOffs);
    *out_w = vert->z / 32768.0f;

    if (IsWithinTolerance(*out_x, *out_y, x, y))
    {
      // check validity of z component
      return ((vert->flags & VALID_2) == VALID_2);
    }
  }

  if (g_settings.gpu_pgxp_vertex_cache)
  {
    const short psx_x = (short)(value & 0xFFFFu);
    const short psx_y = (short)(value >> 16);

    // Look in cache for valid vertex
    vert = PGXP_GetCachedVertex(psx_x, psx_y);
    if (vert && (vert->flags & VALID_01) == VALID_01)
    {
      *out_x = TruncateVertexPosition(vert->x) + static_cast<float>(xOffs);
      *out_y = TruncateVertexPosition(vert->y) + static_cast<float>(yOffs);
      *out_w = vert->z / 32768.0f;

      if (IsWithinTolerance(*out_x, *out_y, x, y))
        return false;
    }
  }

  // no valid value can be found anywhere, use the native PSX data
  *out_x = static_cast<float>(x);
  *out_y = static_cast<float>(y);
  *out_w = 1.0f;
  return false;
}

// Instruction register decoding
#define op(_instr) (_instr >> 26)          // The op part of the instruction register
#define func(_instr) ((_instr)&0x3F)       // The funct part of the instruction register
#define sa(_instr) ((_instr >> 6) & 0x1F)  // The sa part of the instruction register
#define rd(_instr) ((_instr >> 11) & 0x1F) // The rd part of the instruction register
#define rt(_instr) ((_instr >> 16) & 0x1F) // The rt part of the instruction register
#define rs(_instr) ((_instr >> 21) & 0x1F) // The rs part of the instruction register
#define imm(_instr) (_instr & 0xFFFF)      // The immediate part of the instruction register
#define imm_sext(_instr)                                                                                               \
  static_cast<s32>(static_cast<s16>(_instr & 0xFFFF)) // The immediate part of the instruction register

void CPU::PGXP::CPU_LW(u32 instr, u32 addr, u32 rtVal)
{
  // Rt = Mem[Rs + Im]
  ValidateAndCopyMem(&g_state.pgxp_gpr[rt(instr)], addr, rtVal);
}

void CPU::PGXP::CPU_LBx(u32 instr, u32 addr, u32 rtVal)
{
  g_state.pgxp_gpr[rt(instr)] = PGXP_value_invalid;
}

void CPU::PGXP::CPU_LH(u32 instr, u32 addr, u32 rtVal)
{
  // Rt = Mem[Rs + Im] (sign extended)
  ValidateAndCopyMem16(&g_state.pgxp_gpr[rt(instr)], addr, rtVal, true);
}

void CPU::PGXP::CPU_LHU(u32 instr, u32 addr, u32 rtVal)
{
  // Rt = Mem[Rs + Im] (zero extended)
  ValidateAndCopyMem16(&g_state.pgxp_gpr[rt(instr)], addr, rtVal, false);
}

void CPU::PGXP::CPU_SB(u32 instr, u32 addr, u32 rtVal)
{
  WriteMem(&PGXP_value_invalid, addr);
}

void CPU::PGXP::CPU_SH(u32 instr, u32 addr, u32 rtVal)
{
  PGXP_value* val = &g_state.pgxp_gpr[rt(instr)];

  // validate and copy half value
  MaskValidate(val, rtVal, 0xFFFF, VALID_0);
  WriteMem16(val, addr);
}

void CPU::PGXP::CPU_SW(u32 instr, u32 addr, u32 rtVal)
{
  // Mem[Rs + Im] = Rt
  PGXP_value* val = &g_state.pgxp_gpr[rt(instr)];
  Validate(val, rtVal);
  WriteMem(val, addr);
}

void CPU::PGXP::CPU_MOVE(u32 rd_and_rs, u32 rsVal)
{
  const u32 Rs = (rd_and_rs & 0xFFu);
  Validate(&g_state.pgxp_gpr[Rs], rsVal);
  g_state.pgxp_gpr[(rd_and_rs >> 8)] = g_state.pgxp_gpr[Rs];
}

void CPU::PGXP::CPU_ADDI(u32 instr, u32 rsVal)
{
  // Rt = Rs + Imm (signed)
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  PGXP_value ret = g_state.pgxp_gpr[rs(instr)];

  psx_value tempImm;
  tempImm.d = SignExtend32(static_cast<u16>(imm(instr)));

  if (tempImm.d != 0)
  {
    ret.x = (float)f16Unsign(ret.x);
    ret.x += (float)tempImm.w.l;

    // carry on over/underflow
    float of = (ret.x > USHRT_MAX) ? 1.f : (ret.x < 0) ? -1.f : 0.f;
    ret.x = (float)f16Sign(ret.x);
    // ret.x -= of * (USHRT_MAX + 1);
    ret.y += tempImm.sw.h + of;

    // truncate on overflow/underflow
    ret.y += (ret.y > SHRT_MAX) ? -(USHRT_MAX + 1) : (ret.y < SHRT_MIN) ? USHRT_MAX + 1 : 0.f;
  }

  g_state.pgxp_gpr[rt(instr)] = ret;
  g_state.pgxp_gpr[rt(instr)].value = rsVal + imm_sext(instr);
}

void CPU::PGXP::CPU_ANDI(u32 instr, u32 rsVal)
{
  // Rt = Rs & Imm
  const u32 rtVal = rsVal & imm(instr);
  psx_value vRt;
  PGXP_value ret;

  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  ret = g_state.pgxp_gpr[rs(instr)];

  vRt.d = rtVal;

  ret.y = 0.f; // remove upper 16-bits

  switch (imm(instr))
  {
    case 0:
      // if 0 then x == 0
      ret.x = 0.f;
      break;
    case 0xFFFF:
      // if saturated then x == x
      break;
    default:
      // otherwise x is low precision value
      ret.x = vRt.sw.l;
      ret.flags |= VALID_0;
  }

  ret.flags |= VALID_1;

  g_state.pgxp_gpr[rt(instr)] = ret;
  g_state.pgxp_gpr[rt(instr)].value = rtVal;
}

void CPU::PGXP::CPU_ORI(u32 instr, u32 rsVal)
{
  // Rt = Rs | Imm
  const u32 rtVal = rsVal | imm(instr);
  psx_value vRt;
  PGXP_value ret;

  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  ret = g_state.pgxp_gpr[rs(instr)];

  vRt.d = rtVal;

  switch (imm(instr))
  {
    case 0:
      // if 0 then x == x
      break;
    default:
      // otherwise x is low precision value
      ret.x = vRt.sw.l;
      ret.flags |= VALID_0;
  }

  ret.value = rtVal;
  g_state.pgxp_gpr[rt(instr)] = ret;
}

void CPU::PGXP::CPU_XORI(u32 instr, u32 rsVal)
{
  // Rt = Rs ^ Imm
  const u32 rtVal = rsVal ^ imm(instr);
  psx_value vRt;
  PGXP_value ret;

  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  ret = g_state.pgxp_gpr[rs(instr)];

  vRt.d = rtVal;

  switch (imm(instr))
  {
    case 0:
      // if 0 then x == x
      break;
    default:
      // otherwise x is low precision value
      ret.x = vRt.sw.l;
      ret.flags |= VALID_0;
  }

  ret.value = rtVal;
  g_state.pgxp_gpr[rt(instr)] = ret;
}

void CPU::PGXP::CPU_SLTI(u32 instr, u32 rsVal)
{
  // Rt = Rs < Imm (signed)
  psx_value tempImm;
  PGXP_value ret;

  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  ret = g_state.pgxp_gpr[rs(instr)];

  tempImm.w.h = imm(instr);
  ret.y = 0.f;
  ret.x = (g_state.pgxp_gpr[rs(instr)].x < tempImm.sw.h) ? 1.f : 0.f;
  ret.flags |= VALID_1;
  ret.value = BoolToUInt32(static_cast<s32>(rsVal) < imm_sext(instr));

  g_state.pgxp_gpr[rt(instr)] = ret;
}

void CPU::PGXP::CPU_SLTIU(u32 instr, u32 rsVal)
{
  // Rt = Rs < Imm (Unsigned)
  psx_value tempImm;
  PGXP_value ret;

  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  ret = g_state.pgxp_gpr[rs(instr)];

  tempImm.w.h = imm(instr);
  ret.y = 0.f;
  ret.x = (f16Unsign(g_state.pgxp_gpr[rs(instr)].x) < tempImm.w.h) ? 1.f : 0.f;
  ret.flags |= VALID_1;
  ret.value = BoolToUInt32(rsVal < imm(instr));

  g_state.pgxp_gpr[rt(instr)] = ret;
}

////////////////////////////////////
// Load Upper
////////////////////////////////////
void CPU::PGXP::CPU_LUI(u32 instr)
{
  // Rt = Imm << 16
  g_state.pgxp_gpr[rt(instr)] = PGXP_value_zero;
  g_state.pgxp_gpr[rt(instr)].y = (float)(s16)imm(instr);
  g_state.pgxp_gpr[rt(instr)].value = static_cast<u32>(imm(instr)) << 16;
  g_state.pgxp_gpr[rt(instr)].flags = VALID_01;
}

////////////////////////////////////
// Register Arithmetic
////////////////////////////////////

void CPU::PGXP::CPU_ADD(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs + Rt (signed)
  PGXP_value ret;
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  if (rtVal == 0)
  {
    ret = g_state.pgxp_gpr[rs(instr)];
  }
  else if (rsVal == 0)
  {
    ret = g_state.pgxp_gpr[rt(instr)];
  }
  else
  {
    // iCB: Only require one valid input
    if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
        ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
    {
      MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
      MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
    }

    ret = g_state.pgxp_gpr[rs(instr)];

    ret.x = (float)f16Unsign(ret.x);
    ret.x += (float)f16Unsign(g_state.pgxp_gpr[rt(instr)].x);

    // carry on over/underflow
    float of = (ret.x > USHRT_MAX) ? 1.f : (ret.x < 0) ? -1.f : 0.f;
    ret.x = (float)f16Sign(ret.x);
    // ret.x -= of * (USHRT_MAX + 1);
    ret.y += g_state.pgxp_gpr[rt(instr)].y + of;

    // truncate on overflow/underflow
    ret.y += (ret.y > SHRT_MAX) ? -(USHRT_MAX + 1) : (ret.y < SHRT_MIN) ? USHRT_MAX + 1 : 0.f;

    // TODO: decide which "z/w" component to use

    ret.halfFlags[0] &= g_state.pgxp_gpr[rt(instr)].halfFlags[0];
  }

  if (!(ret.flags & VALID_2) && (g_state.pgxp_gpr[rt(instr)].flags & VALID_2))
  {
    ret.z = g_state.pgxp_gpr[rt(instr)].z;
    ret.flags |= VALID_2;
  }

  ret.value = rsVal + rtVal;

  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_SUB(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs - Rt (signed)
  PGXP_value ret;
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  // iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  ret = g_state.pgxp_gpr[rs(instr)];

  ret.x = (float)f16Unsign(ret.x);
  ret.x -= (float)f16Unsign(g_state.pgxp_gpr[rt(instr)].x);

  // carry on over/underflow
  float of = (ret.x > USHRT_MAX) ? 1.f : (ret.x < 0) ? -1.f : 0.f;
  ret.x = (float)f16Sign(ret.x);
  // ret.x -= of * (USHRT_MAX + 1);
  ret.y -= g_state.pgxp_gpr[rt(instr)].y - of;

  // truncate on overflow/underflow
  ret.y += (ret.y > SHRT_MAX) ? -(USHRT_MAX + 1) : (ret.y < SHRT_MIN) ? USHRT_MAX + 1 : 0.f;

  ret.halfFlags[0] &= g_state.pgxp_gpr[rt(instr)].halfFlags[0];

  ret.value = rsVal - rtVal;

  if (!(ret.flags & VALID_2) && (g_state.pgxp_gpr[rt(instr)].flags & VALID_2))
  {
    ret.z = g_state.pgxp_gpr[rt(instr)].z;
    ret.flags |= VALID_2;
  }

  g_state.pgxp_gpr[rd(instr)] = ret;
}

ALWAYS_INLINE_RELEASE void CPU::PGXP::CPU_BITWISE(u32 instr, u32 rdVal, u32 rsVal, u32 rtVal)
{
  // Rd = Rs & Rt
  psx_value vald, vals, valt;
  PGXP_value ret;

  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  // iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  vald.d = rdVal;
  vals.d = rsVal;
  valt.d = rtVal;

  //	CPU_reg[rd(instr)].valid = CPU_reg[rs(instr)].valid && CPU_reg[rt(instr)].valid;
  ret.flags = VALID_01;

  if (vald.w.l == 0)
  {
    ret.x = 0.f;
  }
  else if (vald.w.l == vals.w.l)
  {
    ret.x = g_state.pgxp_gpr[rs(instr)].x;
    ret.compFlags[0] = g_state.pgxp_gpr[rs(instr)].compFlags[0];
  }
  else if (vald.w.l == valt.w.l)
  {
    ret.x = g_state.pgxp_gpr[rt(instr)].x;
    ret.compFlags[0] = g_state.pgxp_gpr[rt(instr)].compFlags[0];
  }
  else
  {
    ret.x = (float)vald.sw.l;
    ret.compFlags[0] = VALID;
  }

  if (vald.w.h == 0)
  {
    ret.y = 0.f;
  }
  else if (vald.w.h == vals.w.h)
  {
    ret.y = g_state.pgxp_gpr[rs(instr)].y;
    ret.compFlags[1] &= g_state.pgxp_gpr[rs(instr)].compFlags[1];
  }
  else if (vald.w.h == valt.w.h)
  {
    ret.y = g_state.pgxp_gpr[rt(instr)].y;
    ret.compFlags[1] &= g_state.pgxp_gpr[rt(instr)].compFlags[1];
  }
  else
  {
    ret.y = (float)vald.sw.h;
    ret.compFlags[1] = VALID;
  }

  // iCB Hack: Force validity if even one half is valid
  // if ((ret.hFlags & VALID_HALF) || (ret.lFlags & VALID_HALF))
  //	ret.valid = 1;
  // /iCB Hack

  // Get a valid W
  if ((g_state.pgxp_gpr[rs(instr)].flags & VALID_2) == VALID_2)
  {
    ret.z = g_state.pgxp_gpr[rs(instr)].z;
    ret.compFlags[2] = g_state.pgxp_gpr[rs(instr)].compFlags[2];
  }
  else if ((g_state.pgxp_gpr[rt(instr)].flags & VALID_2) == VALID_2)
  {
    ret.z = g_state.pgxp_gpr[rt(instr)].z;
    ret.compFlags[2] = g_state.pgxp_gpr[rt(instr)].compFlags[2];
  }
  else
  {
    ret.z = 0.0f;
    ret.compFlags[2] = 0;
  }

  ret.value = rdVal;
  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_AND_(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs & Rt
  const u32 rdVal = rsVal & rtVal;
  CPU_BITWISE(instr, rdVal, rsVal, rtVal);
}

void CPU::PGXP::CPU_OR_(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs | Rt
  const u32 rdVal = rsVal | rtVal;
  CPU_BITWISE(instr, rdVal, rsVal, rtVal);
}

void CPU::PGXP::CPU_XOR_(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs ^ Rt
  const u32 rdVal = rsVal ^ rtVal;
  CPU_BITWISE(instr, rdVal, rsVal, rtVal);
}

void CPU::PGXP::CPU_NOR(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs NOR Rt
  const u32 rdVal = ~(rsVal | rtVal);
  CPU_BITWISE(instr, rdVal, rsVal, rtVal);
}

void CPU::PGXP::CPU_SLT(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs < Rt (signed)
  PGXP_value ret;
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  // iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  ret = g_state.pgxp_gpr[rs(instr)];
  ret.y = 0.f;
  ret.compFlags[1] = VALID;

  ret.x = (g_state.pgxp_gpr[rs(instr)].y < g_state.pgxp_gpr[rt(instr)].y)                       ? 1.f :
          (f16Unsign(g_state.pgxp_gpr[rs(instr)].x) < f16Unsign(g_state.pgxp_gpr[rt(instr)].x)) ? 1.f :
                                                                                                  0.f;

  ret.value = BoolToUInt32(static_cast<s32>(rsVal) < static_cast<s32>(rtVal));
  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_SLTU(u32 instr, u32 rsVal, u32 rtVal)
{
  // Rd = Rs < Rt (unsigned)
  PGXP_value ret;
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  // iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  ret = g_state.pgxp_gpr[rs(instr)];
  ret.y = 0.f;
  ret.compFlags[1] = VALID;

  ret.x = (f16Unsign(g_state.pgxp_gpr[rs(instr)].y) < f16Unsign(g_state.pgxp_gpr[rt(instr)].y)) ? 1.f :
          (f16Unsign(g_state.pgxp_gpr[rs(instr)].x) < f16Unsign(g_state.pgxp_gpr[rt(instr)].x)) ? 1.f :
                                                                                                  0.f;

  ret.value = BoolToUInt32(rsVal < rtVal);
  g_state.pgxp_gpr[rd(instr)] = ret;
}

////////////////////////////////////
// Register mult/div
////////////////////////////////////

void CPU::PGXP::CPU_MULT(u32 instr, u32 rsVal, u32 rtVal)
{
  // Hi/Lo = Rs * Rt (signed)
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  // iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  g_state.pgxp_lo = g_state.pgxp_hi = g_state.pgxp_gpr[rs(instr)];

  g_state.pgxp_lo.halfFlags[0] = g_state.pgxp_hi.halfFlags[0] =
    (g_state.pgxp_gpr[rs(instr)].halfFlags[0] & g_state.pgxp_gpr[rt(instr)].halfFlags[0]);

  double xx, xy, yx, yy;
  double lx = 0, ly = 0, hx = 0, hy = 0;

  // Multiply out components
  xx = f16Unsign(g_state.pgxp_gpr[rs(instr)].x) * f16Unsign(g_state.pgxp_gpr[rt(instr)].x);
  xy = f16Unsign(g_state.pgxp_gpr[rs(instr)].x) * (g_state.pgxp_gpr[rt(instr)].y);
  yx = (g_state.pgxp_gpr[rs(instr)].y) * f16Unsign(g_state.pgxp_gpr[rt(instr)].x);
  yy = (g_state.pgxp_gpr[rs(instr)].y) * (g_state.pgxp_gpr[rt(instr)].y);

  // Split values into outputs
  lx = xx;

  ly = f16Overflow(xx);
  ly += xy + yx;

  hx = f16Overflow(ly);
  hx += yy;

  hy = f16Overflow(hx);

  g_state.pgxp_lo.x = (float)f16Sign(lx);
  g_state.pgxp_lo.y = (float)f16Sign(ly);
  g_state.pgxp_hi.x = (float)f16Sign(hx);
  g_state.pgxp_hi.y = (float)f16Sign(hy);

  // compute PSX value
  const u64 result = static_cast<u64>(static_cast<s64>(SignExtend64(rsVal)) * static_cast<s64>(SignExtend64(rtVal)));
  g_state.pgxp_hi.value = Truncate32(result >> 32);
  g_state.pgxp_lo.value = Truncate32(result);
}

void CPU::PGXP::CPU_MULTU(u32 instr, u32 rsVal, u32 rtVal)
{
  // Hi/Lo = Rs * Rt (unsigned)
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  // iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  g_state.pgxp_lo = g_state.pgxp_hi = g_state.pgxp_gpr[rs(instr)];

  g_state.pgxp_lo.halfFlags[0] = g_state.pgxp_hi.halfFlags[0] =
    (g_state.pgxp_gpr[rs(instr)].halfFlags[0] & g_state.pgxp_gpr[rt(instr)].halfFlags[0]);

  double xx, xy, yx, yy;
  double lx = 0, ly = 0, hx = 0, hy = 0;

  // Multiply out components
  xx = f16Unsign(g_state.pgxp_gpr[rs(instr)].x) * f16Unsign(g_state.pgxp_gpr[rt(instr)].x);
  xy = f16Unsign(g_state.pgxp_gpr[rs(instr)].x) * f16Unsign(g_state.pgxp_gpr[rt(instr)].y);
  yx = f16Unsign(g_state.pgxp_gpr[rs(instr)].y) * f16Unsign(g_state.pgxp_gpr[rt(instr)].x);
  yy = f16Unsign(g_state.pgxp_gpr[rs(instr)].y) * f16Unsign(g_state.pgxp_gpr[rt(instr)].y);

  // Split values into outputs
  lx = xx;

  ly = f16Overflow(xx);
  ly += xy + yx;

  hx = f16Overflow(ly);
  hx += yy;

  hy = f16Overflow(hx);

  g_state.pgxp_lo.x = (float)f16Sign(lx);
  g_state.pgxp_lo.y = (float)f16Sign(ly);
  g_state.pgxp_hi.x = (float)f16Sign(hx);
  g_state.pgxp_hi.y = (float)f16Sign(hy);

  // compute PSX value
  const u64 result = ZeroExtend64(rsVal) * ZeroExtend64(rtVal);
  g_state.pgxp_hi.value = Truncate32(result >> 32);
  g_state.pgxp_lo.value = Truncate32(result);
}

void CPU::PGXP::CPU_DIV(u32 instr, u32 rsVal, u32 rtVal)
{
  // Lo = Rs / Rt (signed)
  // Hi = Rs % Rt (signed)
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  //// iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  g_state.pgxp_lo = g_state.pgxp_hi = g_state.pgxp_gpr[rs(instr)];

  g_state.pgxp_lo.halfFlags[0] = g_state.pgxp_hi.halfFlags[0] =
    (g_state.pgxp_gpr[rs(instr)].halfFlags[0] & g_state.pgxp_gpr[rt(instr)].halfFlags[0]);

  double vs = f16Unsign(g_state.pgxp_gpr[rs(instr)].x) + (g_state.pgxp_gpr[rs(instr)].y) * (double)(1 << 16);
  double vt = f16Unsign(g_state.pgxp_gpr[rt(instr)].x) + (g_state.pgxp_gpr[rt(instr)].y) * (double)(1 << 16);

  double lo = vs / vt;
  g_state.pgxp_lo.y = (float)f16Sign(f16Overflow(lo));
  g_state.pgxp_lo.x = (float)f16Sign(lo);

  double hi = fmod(vs, vt);
  g_state.pgxp_hi.y = (float)f16Sign(f16Overflow(hi));
  g_state.pgxp_hi.x = (float)f16Sign(hi);

  // compute PSX value
  if (static_cast<s32>(rtVal) == 0)
  {
    // divide by zero
    g_state.pgxp_lo.value = (static_cast<s32>(rsVal) >= 0) ? UINT32_C(0xFFFFFFFF) : UINT32_C(1);
    g_state.pgxp_hi.value = static_cast<u32>(static_cast<s32>(rsVal));
  }
  else if (rsVal == UINT32_C(0x80000000) && static_cast<s32>(rtVal) == -1)
  {
    // unrepresentable
    g_state.pgxp_lo.value = UINT32_C(0x80000000);
    g_state.pgxp_hi.value = 0;
  }
  else
  {
    g_state.pgxp_lo.value = static_cast<u32>(static_cast<s32>(rsVal) / static_cast<s32>(rtVal));
    g_state.pgxp_hi.value = static_cast<u32>(static_cast<s32>(rsVal) % static_cast<s32>(rtVal));
  }
}

void CPU::PGXP::CPU_DIVU(u32 instr, u32 rsVal, u32 rtVal)
{
  // Lo = Rs / Rt (unsigned)
  // Hi = Rs % Rt (unsigned)
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  //// iCB: Only require one valid input
  if (((g_state.pgxp_gpr[rt(instr)].flags & VALID_01) != VALID_01) !=
      ((g_state.pgxp_gpr[rs(instr)].flags & VALID_01) != VALID_01))
  {
    MakeValid(&g_state.pgxp_gpr[rs(instr)], rsVal);
    MakeValid(&g_state.pgxp_gpr[rt(instr)], rtVal);
  }

  g_state.pgxp_lo = g_state.pgxp_hi = g_state.pgxp_gpr[rs(instr)];

  g_state.pgxp_lo.halfFlags[0] = g_state.pgxp_hi.halfFlags[0] =
    (g_state.pgxp_gpr[rs(instr)].halfFlags[0] & g_state.pgxp_gpr[rt(instr)].halfFlags[0]);

  double vs = f16Unsign(g_state.pgxp_gpr[rs(instr)].x) + f16Unsign(g_state.pgxp_gpr[rs(instr)].y) * (double)(1 << 16);
  double vt = f16Unsign(g_state.pgxp_gpr[rt(instr)].x) + f16Unsign(g_state.pgxp_gpr[rt(instr)].y) * (double)(1 << 16);

  double lo = vs / vt;
  g_state.pgxp_lo.y = (float)f16Sign(f16Overflow(lo));
  g_state.pgxp_lo.x = (float)f16Sign(lo);

  double hi = fmod(vs, vt);
  g_state.pgxp_hi.y = (float)f16Sign(f16Overflow(hi));
  g_state.pgxp_hi.x = (float)f16Sign(hi);

  if (rtVal == 0)
  {
    // divide by zero
    g_state.pgxp_lo.value = UINT32_C(0xFFFFFFFF);
    g_state.pgxp_hi.value = rsVal;
  }
  else
  {
    g_state.pgxp_lo.value = rsVal / rtVal;
    g_state.pgxp_hi.value = rsVal % rtVal;
  }
}

////////////////////////////////////
// Shift operations (sa)
////////////////////////////////////
void CPU::PGXP::CPU_SLL(u32 instr, u32 rtVal)
{
  // Rd = Rt << Sa
  const u32 rdVal = rtVal << sa(instr);
  PGXP_value ret;
  u32 sh = sa(instr);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  ret = g_state.pgxp_gpr[rt(instr)];

  // TODO: Shift flags
  double x = f16Unsign(g_state.pgxp_gpr[rt(instr)].x);
  double y = f16Unsign(g_state.pgxp_gpr[rt(instr)].y);
  if (sh >= 32)
  {
    x = 0.f;
    y = 0.f;
  }
  else if (sh == 16)
  {
    y = f16Sign(x);
    x = 0.f;
  }
  else if (sh >= 16)
  {
    y = x * (1 << (sh - 16));
    y = f16Sign(y);
    x = 0.f;
  }
  else
  {
    x = x * (1 << sh);
    y = y * (1 << sh);
    y += f16Overflow(x);
    x = f16Sign(x);
    y = f16Sign(y);
  }

  ret.x = (float)x;
  ret.y = (float)y;

  ret.value = rdVal;
  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_SRL(u32 instr, u32 rtVal)
{
  // Rd = Rt >> Sa
  const u32 rdVal = rtVal >> sa(instr);
  PGXP_value ret;
  u32 sh = sa(instr);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);

  ret = g_state.pgxp_gpr[rt(instr)];

  double x = g_state.pgxp_gpr[rt(instr)].x, y = f16Unsign(g_state.pgxp_gpr[rt(instr)].y);

  psx_value iX;
  iX.d = rtVal;
  psx_value iY;
  iY.d = rtVal;

  iX.sd = (iX.sd << 16) >> 16; // remove Y
  iY.sw.l = iX.sw.h;           // overwrite x with sign(x)

  // Shift test values
  psx_value dX;
  dX.sd = iX.sd >> sh;
  psx_value dY;
  dY.d = iY.d >> sh;

  if (dX.sw.l != iX.sw.h)
    x = x / (1 << sh);
  else
    x = dX.sw.l; // only sign bits left

  if (dY.sw.l != iX.sw.h)
  {
    if (sh == 16)
    {
      x = y;
    }
    else if (sh < 16)
    {
      x += y * (1 << (16 - sh));
      if (g_state.pgxp_gpr[rt(instr)].x < 0)
        x += 1 << (16 - sh);
    }
    else
    {
      x += y / (1 << (sh - 16));
    }
  }

  if ((dY.sw.h == 0) || (dY.sw.h == -1))
    y = dY.sw.h;
  else
    y = y / (1 << sh);

  x = f16Sign(x);
  y = f16Sign(y);

  ret.x = (float)x;
  ret.y = (float)y;

  ret.value = rdVal;
  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_SRA(u32 instr, u32 rtVal)
{
  // Rd = Rt >> Sa
  const u32 rdVal = static_cast<u32>(static_cast<s32>(rtVal) >> sa(instr));
  PGXP_value ret;
  u32 sh = sa(instr);
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);
  ret = g_state.pgxp_gpr[rt(instr)];

  double x = g_state.pgxp_gpr[rt(instr)].x, y = g_state.pgxp_gpr[rt(instr)].y;

  psx_value iX;
  iX.d = rtVal;
  psx_value iY;
  iY.d = rtVal;

  iX.sd = (iX.sd << 16) >> 16; // remove Y
  iY.sw.l = iX.sw.h;           // overwrite x with sign(x)

  // Shift test values
  psx_value dX;
  dX.sd = iX.sd >> sh;
  psx_value dY;
  dY.sd = iY.sd >> sh;

  if (dX.sw.l != iX.sw.h)
    x = x / (1 << sh);
  else
    x = dX.sw.l; // only sign bits left

  if (dY.sw.l != iX.sw.h)
  {
    if (sh == 16)
    {
      x = y;
    }
    else if (sh < 16)
    {
      x += y * (1 << (16 - sh));
      if (g_state.pgxp_gpr[rt(instr)].x < 0)
        x += 1 << (16 - sh);
    }
    else
    {
      x += y / (1 << (sh - 16));
    }
  }

  if ((dY.sw.h == 0) || (dY.sw.h == -1))
    y = dY.sw.h;
  else
    y = y / (1 << sh);

  x = f16Sign(x);
  y = f16Sign(y);

  ret.x = (float)x;
  ret.y = (float)y;

  ret.value = rdVal;
  g_state.pgxp_gpr[rd(instr)] = ret;
}

////////////////////////////////////
// Shift operations variable
////////////////////////////////////
void CPU::PGXP::CPU_SLLV(u32 instr, u32 rtVal, u32 rsVal)
{
  // Rd = Rt << Rs
  const u32 rdVal = rtVal << rsVal;
  PGXP_value ret;
  u32 sh = rsVal & 0x1F;
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);

  ret = g_state.pgxp_gpr[rt(instr)];

  double x = f16Unsign(g_state.pgxp_gpr[rt(instr)].x);
  double y = f16Unsign(g_state.pgxp_gpr[rt(instr)].y);
  if (sh >= 32)
  {
    x = 0.f;
    y = 0.f;
  }
  else if (sh == 16)
  {
    y = f16Sign(x);
    x = 0.f;
  }
  else if (sh >= 16)
  {
    y = x * (1 << (sh - 16));
    y = f16Sign(y);
    x = 0.f;
  }
  else
  {
    x = x * (1 << sh);
    y = y * (1 << sh);
    y += f16Overflow(x);
    x = f16Sign(x);
    y = f16Sign(y);
  }

  ret.x = (float)x;
  ret.y = (float)y;

  ret.value = rdVal;
  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_SRLV(u32 instr, u32 rtVal, u32 rsVal)
{
  // Rd = Rt >> Sa
  const u32 rdVal = rtVal >> rsVal;
  PGXP_value ret;
  u32 sh = rsVal & 0x1F;
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);

  ret = g_state.pgxp_gpr[rt(instr)];

  double x = g_state.pgxp_gpr[rt(instr)].x, y = f16Unsign(g_state.pgxp_gpr[rt(instr)].y);

  psx_value iX;
  iX.d = rtVal;
  psx_value iY;
  iY.d = rtVal;

  iX.sd = (iX.sd << 16) >> 16; // remove Y
  iY.sw.l = iX.sw.h;           // overwrite x with sign(x)

  // Shift test values
  psx_value dX;
  dX.sd = iX.sd >> sh;
  psx_value dY;
  dY.d = iY.d >> sh;

  if (dX.sw.l != iX.sw.h)
    x = x / (1 << sh);
  else
    x = dX.sw.l; // only sign bits left

  if (dY.sw.l != iX.sw.h)
  {
    if (sh == 16)
    {
      x = y;
    }
    else if (sh < 16)
    {
      x += y * (1 << (16 - sh));
      if (g_state.pgxp_gpr[rt(instr)].x < 0)
        x += 1 << (16 - sh);
    }
    else
    {
      x += y / (1 << (sh - 16));
    }
  }

  if ((dY.sw.h == 0) || (dY.sw.h == -1))
    y = dY.sw.h;
  else
    y = y / (1 << sh);

  x = f16Sign(x);
  y = f16Sign(y);

  ret.x = (float)x;
  ret.y = (float)y;

  ret.value = rdVal;
  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_SRAV(u32 instr, u32 rtVal, u32 rsVal)
{
  // Rd = Rt >> Sa
  const u32 rdVal = static_cast<u32>(static_cast<s32>(rtVal) >> rsVal);
  PGXP_value ret;
  u32 sh = rsVal & 0x1F;
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);

  ret = g_state.pgxp_gpr[rt(instr)];

  double x = g_state.pgxp_gpr[rt(instr)].x, y = g_state.pgxp_gpr[rt(instr)].y;

  psx_value iX;
  iX.d = rtVal;
  psx_value iY;
  iY.d = rtVal;

  iX.sd = (iX.sd << 16) >> 16; // remove Y
  iY.sw.l = iX.sw.h;           // overwrite x with sign(x)

  // Shift test values
  psx_value dX;
  dX.sd = iX.sd >> sh;
  psx_value dY;
  dY.sd = iY.sd >> sh;

  if (dX.sw.l != iX.sw.h)
    x = x / (1 << sh);
  else
    x = dX.sw.l; // only sign bits left

  if (dY.sw.l != iX.sw.h)
  {
    if (sh == 16)
    {
      x = y;
    }
    else if (sh < 16)
    {
      x += y * (1 << (16 - sh));
      if (g_state.pgxp_gpr[rt(instr)].x < 0)
        x += 1 << (16 - sh);
    }
    else
    {
      x += y / (1 << (sh - 16));
    }
  }

  if ((dY.sw.h == 0) || (dY.sw.h == -1))
    y = dY.sw.h;
  else
    y = y / (1 << sh);

  x = f16Sign(x);
  y = f16Sign(y);

  ret.x = (float)x;
  ret.y = (float)y;

  ret.value = rdVal;
  g_state.pgxp_gpr[rd(instr)] = ret;
}

void CPU::PGXP::CPU_MFHI(u32 instr, u32 hiVal)
{
  // Rd = Hi
  Validate(&g_state.pgxp_hi, hiVal);

  g_state.pgxp_gpr[rd(instr)] = g_state.pgxp_hi;
}

void CPU::PGXP::CPU_MTHI(u32 instr, u32 rsVal)
{
  // Hi = Rd
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);

  g_state.pgxp_hi = g_state.pgxp_gpr[rd(instr)];
}

void CPU::PGXP::CPU_MFLO(u32 instr, u32 loVal)
{
  // Rd = Lo
  Validate(&g_state.pgxp_lo, loVal);

  g_state.pgxp_gpr[rd(instr)] = g_state.pgxp_lo;
}

void CPU::PGXP::CPU_MTLO(u32 instr, u32 rsVal)
{
  // Lo = Rd
  Validate(&g_state.pgxp_gpr[rs(instr)], rsVal);

  g_state.pgxp_lo = g_state.pgxp_gpr[rd(instr)];
}

void CPU::PGXP::CPU_MFC0(u32 instr, u32 rdVal)
{
  // CPU[Rt] = CP0[Rd]
  Validate(&g_state.pgxp_cop0[rd(instr)], rdVal);
  g_state.pgxp_gpr[rt(instr)] = g_state.pgxp_cop0[rd(instr)];
  g_state.pgxp_gpr[rt(instr)].value = rdVal;
}

void CPU::PGXP::CPU_MTC0(u32 instr, u32 rdVal, u32 rtVal)
{
  // CP0[Rd] = CPU[Rt]
  Validate(&g_state.pgxp_gpr[rt(instr)], rtVal);
  g_state.pgxp_cop0[rd(instr)] = g_state.pgxp_gpr[rt(instr)];
  g_state.pgxp_cop0[rd(instr)].value = rdVal;
}