/////////////////////////////////////////////////////////////////////////
// $Id: lazy_flags.h 13311 2017-10-15 22:01:32Z sshwarts $
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2001-2017  The Bochs Project
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library 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
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
//
/////////////////////////////////////////////////////////////////////////

#ifndef BX_LAZY_FLAGS_DEF
#define BX_LAZY_FLAGS_DEF

#if BX_SUPPORT_X86_64
  #define BX_LF_SIGN_BIT  63
#else
  #define BX_LF_SIGN_BIT  31
#endif

// These are the lazy flags bits in oszapc.auxbits which hold lazy state
// of zero flag, adjust flag, carry flag, and overflow flag.

enum {
  LF_BIT_SD  = 0,         /* lazy Sign Flag Delta            */
  LF_BIT_AF  = 3,         /* lazy Adjust flag                */
  LF_BIT_PDB = 8,         /* lazy Parity Delta Byte (8 bits) */
  LF_BIT_CF  = 31,        /* lazy Carry Flag                 */
  LF_BIT_PO  = 30         /* lazy Partial Overflow = CF ^ OF */
};

const Bit32u LF_MASK_SD  = (0x01 << LF_BIT_SD);
const Bit32u LF_MASK_AF  = (0x01 << LF_BIT_AF);
const Bit32u LF_MASK_PDB = (0xFF << LF_BIT_PDB);
const Bit32u LF_MASK_CF  = (0x01 << LF_BIT_CF);
const Bit32u LF_MASK_PO  = (0x01 << LF_BIT_PO);

#define ADD_COUT_VEC(op1, op2, result) \
  (((op1) & (op2)) | (((op1) | (op2)) & (~(result))))

#define SUB_COUT_VEC(op1, op2, result) \
  (((~(op1)) & (op2)) | (((~(op1)) ^ (op2)) & (result)))

#define GET_ADD_OVERFLOW(op1, op2, result, mask) \
  ((((op1) ^ (result)) & ((op2) ^ (result))) & (mask))

// *******************
// OSZAPC
// *******************

/* size, carries, result */
#define SET_FLAGS_OSZAPC_SIZE(size, lf_carries, lf_result) { \
  bx_address temp = ((lf_carries) & (LF_MASK_AF)) | \
        (((lf_carries) >> (size - 2)) << LF_BIT_PO); \
  BX_CPU_THIS_PTR oszapc.result = (bx_address)(Bit##size##s)(lf_result); \
  if ((size) == 32) temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \
  if ((size) == 16) temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \
  if ((size) == 8)  temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \
  BX_CPU_THIS_PTR oszapc.auxbits = (bx_address)(Bit32u)temp; \
}

/* carries, result */
#define SET_FLAGS_OSZAPC_8(carries, result) \
  SET_FLAGS_OSZAPC_SIZE(8, carries, result)
#define SET_FLAGS_OSZAPC_16(carries, result) \
  SET_FLAGS_OSZAPC_SIZE(16, carries, result)
#define SET_FLAGS_OSZAPC_32(carries, result) \
  SET_FLAGS_OSZAPC_SIZE(32, carries, result)
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAPC_64(carries, result) \
  SET_FLAGS_OSZAPC_SIZE(64, carries, result)
#endif

/* result */
#define SET_FLAGS_OSZAPC_LOGIC_8(result_8) \
   SET_FLAGS_OSZAPC_8(0, (result_8))
#define SET_FLAGS_OSZAPC_LOGIC_16(result_16) \
   SET_FLAGS_OSZAPC_16(0, (result_16))
#define SET_FLAGS_OSZAPC_LOGIC_32(result_32) \
   SET_FLAGS_OSZAPC_32(0, (result_32))
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAPC_LOGIC_64(result_64) \
   SET_FLAGS_OSZAPC_64(BX_CONST64(0), (result_64))
#endif

/* op1, op2, result */
#define SET_FLAGS_OSZAPC_ADD_8(op1_8, op2_8, sum_8) \
  SET_FLAGS_OSZAPC_8(ADD_COUT_VEC((op1_8), (op2_8), (sum_8)), (sum_8))
#define SET_FLAGS_OSZAPC_ADD_16(op1_16, op2_16, sum_16) \
  SET_FLAGS_OSZAPC_16(ADD_COUT_VEC((op1_16), (op2_16), (sum_16)), (sum_16))
#define SET_FLAGS_OSZAPC_ADD_32(op1_32, op2_32, sum_32) \
  SET_FLAGS_OSZAPC_32(ADD_COUT_VEC((op1_32), (op2_32), (sum_32)), (sum_32))
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAPC_ADD_64(op1_64, op2_64, sum_64) \
  SET_FLAGS_OSZAPC_64(ADD_COUT_VEC((op1_64), (op2_64), (sum_64)), (sum_64))
#endif

/* op1, op2, result */
#define SET_FLAGS_OSZAPC_SUB_8(op1_8, op2_8, diff_8) \
  SET_FLAGS_OSZAPC_8(SUB_COUT_VEC((op1_8), (op2_8), (diff_8)), (diff_8))
#define SET_FLAGS_OSZAPC_SUB_16(op1_16, op2_16, diff_16) \
  SET_FLAGS_OSZAPC_16(SUB_COUT_VEC((op1_16), (op2_16), (diff_16)), (diff_16))
#define SET_FLAGS_OSZAPC_SUB_32(op1_32, op2_32, diff_32) \
  SET_FLAGS_OSZAPC_32(SUB_COUT_VEC((op1_32), (op2_32), (diff_32)), (diff_32))
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAPC_SUB_64(op1_64, op2_64, diff_64) \
  SET_FLAGS_OSZAPC_64(SUB_COUT_VEC((op1_64), (op2_64), (diff_64)), (diff_64))
#endif

// *******************
// OSZAP
// *******************

/* size, carries, result */
#define SET_FLAGS_OSZAP_SIZE(size, lf_carries, lf_result) { \
  bx_address temp = ((lf_carries) & (LF_MASK_AF)) | \
        (((lf_carries) >> (size - 2)) << LF_BIT_PO); \
  if ((size) == 32) temp = ((lf_carries) & ~(LF_MASK_PDB | LF_MASK_SD)); \
  if ((size) == 16) temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 16); \
  if ((size) == 8)  temp = ((lf_carries) & (LF_MASK_AF)) | ((lf_carries) << 24); \
  BX_CPU_THIS_PTR oszapc.result = (bx_address)(Bit##size##s)(lf_result); \
  bx_address delta_c = (BX_CPU_THIS_PTR oszapc.auxbits ^ temp) & LF_MASK_CF; \
  delta_c ^= (delta_c >> 1); \
  BX_CPU_THIS_PTR oszapc.auxbits = (bx_address)(Bit32u)(temp ^ delta_c); \
}

/* carries, result */
#define SET_FLAGS_OSZAP_8(carries, result) \
  SET_FLAGS_OSZAP_SIZE(8, carries, result)
#define SET_FLAGS_OSZAP_16(carries, result) \
  SET_FLAGS_OSZAP_SIZE(16, carries, result)
#define SET_FLAGS_OSZAP_32(carries, result) \
  SET_FLAGS_OSZAP_SIZE(32, carries, result)
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAP_64(carries, result) \
  SET_FLAGS_OSZAP_SIZE(64, carries, result)
#endif

/* op1, op2, result */
#define SET_FLAGS_OSZAP_ADD_8(op1_8, op2_8, sum_8) \
  SET_FLAGS_OSZAP_8(ADD_COUT_VEC((op1_8), (op2_8), (sum_8)), (sum_8))
#define SET_FLAGS_OSZAP_ADD_16(op1_16, op2_16, sum_16) \
  SET_FLAGS_OSZAP_16(ADD_COUT_VEC((op1_16), (op2_16), (sum_16)), (sum_16))
#define SET_FLAGS_OSZAP_ADD_32(op1_32, op2_32, sum_32) \
  SET_FLAGS_OSZAP_32(ADD_COUT_VEC((op1_32), (op2_32), (sum_32)), (sum_32))
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAP_ADD_64(op1_64, op2_64, sum_64) \
  SET_FLAGS_OSZAP_64(ADD_COUT_VEC((op1_64), (op2_64), (sum_64)), (sum_64))
#endif

/* op1, op2, result */
#define SET_FLAGS_OSZAP_SUB_8(op1_8, op2_8, diff_8) \
  SET_FLAGS_OSZAP_8(SUB_COUT_VEC((op1_8), (op2_8), (diff_8)), (diff_8))
#define SET_FLAGS_OSZAP_SUB_16(op1_16, op2_16, diff_16) \
  SET_FLAGS_OSZAP_16(SUB_COUT_VEC((op1_16), (op2_16), (diff_16)), (diff_16))
#define SET_FLAGS_OSZAP_SUB_32(op1_32, op2_32, diff_32) \
  SET_FLAGS_OSZAP_32(SUB_COUT_VEC((op1_32), (op2_32), (diff_32)), (diff_32))
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAP_SUB_64(op1_64, op2_64, diff_64) \
  SET_FLAGS_OSZAP_64(SUB_COUT_VEC((op1_64), (op2_64), (diff_64)), (diff_64))
#endif

// *******************
// OSZAxC
// *******************

/* size, carries, result */
#define SET_FLAGS_OSZAxC_LOGIC_SIZE(size, lf_result) { \
  bx_bool saved_PF = getB_PF(); \
  SET_FLAGS_OSZAPC_SIZE(size, (Bit##size##u)(0), lf_result); \
  set_PF(saved_PF); \
}

/* result */
#define SET_FLAGS_OSZAxC_LOGIC_32(result_32) \
   SET_FLAGS_OSZAxC_LOGIC_SIZE(32, (result_32))
#if BX_SUPPORT_X86_64
#define SET_FLAGS_OSZAxC_LOGIC_64(result_64) \
   SET_FLAGS_OSZAxC_LOGIC_SIZE(64, (result_64))
#endif

struct bx_lazyflags_entry {
  bx_address result;
  bx_address auxbits;

  BX_CPP_INLINE unsigned getB_OF(void) const;
  BX_CPP_INLINE unsigned get_OF(void) const;
  BX_CPP_INLINE void set_OF(bx_bool val);
  BX_CPP_INLINE void clear_OF(void);
  BX_CPP_INLINE void assert_OF(void);

  BX_CPP_INLINE unsigned getB_SF(void) const;
  BX_CPP_INLINE unsigned get_SF(void) const;
  BX_CPP_INLINE void set_SF(bx_bool val);
  BX_CPP_INLINE void clear_SF(void);
  BX_CPP_INLINE void assert_SF(void);

  BX_CPP_INLINE unsigned getB_ZF(void) const;
  BX_CPP_INLINE unsigned get_ZF(void) const;
  BX_CPP_INLINE void set_ZF(bx_bool val);
  BX_CPP_INLINE void clear_ZF(void);
  BX_CPP_INLINE void assert_ZF(void);

  BX_CPP_INLINE unsigned getB_AF(void) const;
  BX_CPP_INLINE unsigned get_AF(void) const;
  BX_CPP_INLINE void set_AF(bx_bool val);
  BX_CPP_INLINE void clear_AF(void);
  BX_CPP_INLINE void assert_AF(void);

  BX_CPP_INLINE unsigned getB_PF(void) const;
  BX_CPP_INLINE unsigned get_PF(void) const;
  BX_CPP_INLINE void set_PF(bx_bool val);
  BX_CPP_INLINE void clear_PF(void);
  BX_CPP_INLINE void assert_PF(void);

  BX_CPP_INLINE unsigned getB_CF(void) const;
  BX_CPP_INLINE unsigned get_CF(void) const;
  BX_CPP_INLINE void set_CF(bx_bool val);
  BX_CPP_INLINE void clear_CF(void);
  BX_CPP_INLINE void assert_CF(void);

  BX_CPP_INLINE void set_flags_OxxxxC(Bit32u new_of, Bit32u new_cf)
  {
    Bit32u temp_po = new_of ^ new_cf;
    auxbits &= ~(LF_MASK_PO | LF_MASK_CF);
    auxbits |= (temp_po << LF_BIT_PO) | (new_cf << LF_BIT_CF);
  }

  BX_CPP_INLINE void assert_flags_OxxxxC() { set_flags_OxxxxC(1,1); }
};

/// OF ////////////////////////////////////////
BX_CPP_INLINE unsigned bx_lazyflags_entry::getB_OF(void) const
{
  return ((auxbits + (1U << LF_BIT_PO)) >> LF_BIT_CF) & 1;
}

BX_CPP_INLINE unsigned bx_lazyflags_entry::get_OF(void) const
{
  return (auxbits + (1U << LF_BIT_PO)) & (1U << LF_BIT_CF);
}

BX_CPP_INLINE void bx_lazyflags_entry::set_OF(bx_bool val)
{
  bx_bool temp_cf = getB_CF();
  set_flags_OxxxxC(val, temp_cf);
}
 
BX_CPP_INLINE void bx_lazyflags_entry::clear_OF(void)
{
  bx_bool temp_cf = getB_CF();
  set_flags_OxxxxC(0, temp_cf);
}
 
BX_CPP_INLINE void bx_lazyflags_entry::assert_OF(void)
{
  unsigned temp_cf = getB_CF();
  set_flags_OxxxxC(1, temp_cf);
}

/// SF ////////////////////////////////////////
BX_CPP_INLINE unsigned bx_lazyflags_entry::getB_SF(void) const
{
  return ((result >> BX_LF_SIGN_BIT) ^ (auxbits >> LF_BIT_SD)) & 1;
}

BX_CPP_INLINE unsigned bx_lazyflags_entry::get_SF(void) const { return getB_SF(); }

BX_CPP_INLINE void bx_lazyflags_entry::set_SF(bx_bool val)
{
  bx_bool temp_sf = getB_SF();
  auxbits ^= (temp_sf ^ val) << LF_BIT_SD;
}

BX_CPP_INLINE void bx_lazyflags_entry::clear_SF  (void) { set_SF(0); }
BX_CPP_INLINE void bx_lazyflags_entry::assert_SF (void) { set_SF(1); }

/// ZF ////////////////////////////////////////
BX_CPP_INLINE unsigned bx_lazyflags_entry::getB_ZF(void) const
{
  return (0 == result);
}

BX_CPP_INLINE unsigned bx_lazyflags_entry::get_ZF(void) const { return getB_ZF(); }

BX_CPP_INLINE void bx_lazyflags_entry::set_ZF(bx_bool val)
{
  if (val) assert_ZF();
  else clear_ZF();
}

BX_CPP_INLINE void bx_lazyflags_entry::clear_ZF(void)
{
  result |= (1 << 8);
}

BX_CPP_INLINE void bx_lazyflags_entry::assert_ZF(void)
{
  // merge the sign bit into the Sign Delta
  auxbits ^= (((result >> BX_LF_SIGN_BIT) & 1) << LF_BIT_SD);

  // merge the parity bits into the Parity Delta Byte
  Bit32u temp_pdb = (255 & result);
  auxbits ^= (temp_pdb << LF_BIT_PDB);

  // now zero the .result value
  result = 0;
}

/// AF ////////////////////////////////////////

// AF - bit 4 in EFLAGS, represented by bit LF_BIT_AF of oszapc.auxbits
BX_CPP_INLINE unsigned bx_lazyflags_entry::getB_AF(void) const
{
  return (auxbits >> LF_BIT_AF) & 1;
}

BX_CPP_INLINE unsigned bx_lazyflags_entry::get_AF(void) const
{
  return (auxbits & LF_MASK_AF);
}

BX_CPP_INLINE void bx_lazyflags_entry::set_AF(bx_bool val)
{
  auxbits &= ~(LF_MASK_AF);
  auxbits |= (val) << LF_BIT_AF;
}
  
BX_CPP_INLINE void bx_lazyflags_entry::clear_AF(void)
{
  auxbits &= ~(LF_MASK_AF);
}

BX_CPP_INLINE void bx_lazyflags_entry::assert_AF(void)
{
  auxbits |=  (LF_MASK_AF);
}

/// PF ////////////////////////////////////////

// PF - bit 2 in EFLAGS, represented by lower 8 bits of oszapc.result
BX_CPP_INLINE unsigned bx_lazyflags_entry::getB_PF(void) const
{
  Bit32u temp = (255 & result);
  temp = temp ^ (255 & (auxbits >> LF_BIT_PDB));
  temp = (temp ^ (temp >> 4)) & 0x0F;
  return (0x9669U >> temp) & 1;
}

BX_CPP_INLINE unsigned bx_lazyflags_entry::get_PF(void) const { return getB_PF(); }

BX_CPP_INLINE void bx_lazyflags_entry::set_PF(bx_bool val)
{
    Bit32u temp_pdb = (255 & result) ^ (!val);
    auxbits &= ~(LF_MASK_PDB);
    auxbits |= (temp_pdb << LF_BIT_PDB);
}

BX_CPP_INLINE void bx_lazyflags_entry::clear_PF  (void) { set_PF(0); }
BX_CPP_INLINE void bx_lazyflags_entry::assert_PF (void) { set_PF(1); }

/// CF ////////////////////////////////////////

BX_CPP_INLINE unsigned bx_lazyflags_entry::getB_CF(void) const
{
  return (auxbits >> LF_BIT_CF) & 1;
}

BX_CPP_INLINE unsigned bx_lazyflags_entry::get_CF(void) const
{
  return (auxbits & LF_MASK_CF);
}

BX_CPP_INLINE void bx_lazyflags_entry::set_CF(bx_bool val)
{
  bx_bool temp_of = getB_OF();
  set_flags_OxxxxC(temp_of, val);
}

BX_CPP_INLINE void bx_lazyflags_entry::clear_CF(void)
{
  bx_bool temp_of = getB_OF();
  set_flags_OxxxxC(temp_of, 0);
}

BX_CPP_INLINE void bx_lazyflags_entry::assert_CF(void)
{
  bx_bool temp_of = getB_OF();
  set_flags_OxxxxC(temp_of, 1);
}

#endif // BX_LAZY_FLAGS_DEF
