Archipelago » qemu

/*

    NetWinder Floating Point Emulator

    (c) Rebel.COM, 1998,1999

    Direct questions, comments to Scott Bambrough <scottb@netwinder.org>

    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; either version 2 of the License, or

    (at your option) any later version.

    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 for more details.

    You should have received a copy of the GNU General Public License

    along with this program; if not, write to the Free Software

    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include "fpa11.h"

#include "softfloat.h"

#include "fpopcode.h"

#include "fpsr.h"

//#include "fpmodule.h"

//#include "fpmodule.inl"

const floatx80 floatx80Constant[] = {

  { 0x0000000000000000ULL, 0x0000},        /* extended 0.0 */

  { 0x8000000000000000ULL, 0x3fff},        /* extended 1.0 */

  { 0x8000000000000000ULL, 0x4000},        /* extended 2.0 */

  { 0xc000000000000000ULL, 0x4000},        /* extended 3.0 */

  { 0x8000000000000000ULL, 0x4001},        /* extended 4.0 */

  { 0xa000000000000000ULL, 0x4001},        /* extended 5.0 */

  { 0x8000000000000000ULL, 0x3ffe},        /* extended 0.5 */

  { 0xa000000000000000ULL, 0x4002}        /* extended 10.0 */

}; 

const float64 float64Constant[] = {

  0x0000000000000000ULL,                /* double 0.0 */

  0x3ff0000000000000ULL,                /* double 1.0 */

  0x4000000000000000ULL,                /* double 2.0 */

  0x4008000000000000ULL,                /* double 3.0 */

  0x4010000000000000ULL,                /* double 4.0 */

  0x4014000000000000ULL,                /* double 5.0 */

  0x3fe0000000000000ULL,                /* double 0.5 */

  0x4024000000000000ULL                        /* double 10.0 */

}; 

const float32 float32Constant[] = {

  0x00000000,                                /* single 0.0 */

  0x3f800000,                                /* single 1.0 */

  0x40000000,                                /* single 2.0 */

  0x40400000,                                /* single 3.0 */

  0x40800000,                                /* single 4.0 */

  0x40a00000,                                /* single 5.0 */

  0x3f000000,                                /* single 0.5 */

  0x41200000                                /* single 10.0 */

}; 

unsigned int getTransferLength(const unsigned int opcode)

{

  unsigned int nRc;

  switch (opcode & MASK_TRANSFER_LENGTH)

  {

    case 0x00000000: nRc = 1; break; /* single precision */

    case 0x00008000: nRc = 2; break; /* double precision */

    case 0x00400000: nRc = 3; break; /* extended precision */

    default: nRc = 0;

  }

  return(nRc);

}

unsigned int getRegisterCount(const unsigned int opcode)

{

  unsigned int nRc;

  switch (opcode & MASK_REGISTER_COUNT)

  {

    case 0x00000000: nRc = 4; break;

    case 0x00008000: nRc = 1; break;

    case 0x00400000: nRc = 2; break;

    case 0x00408000: nRc = 3; break;

    default: nRc = 0;

  }

  return(nRc);

}

unsigned int getRoundingPrecision(const unsigned int opcode)

{

  unsigned int nRc;

  switch (opcode & MASK_ROUNDING_PRECISION)

  {

    case 0x00000000: nRc = 1; break;

    case 0x00000080: nRc = 2; break;

    case 0x00080000: nRc = 3; break;

    default: nRc = 0;

  }

  return(nRc);

}

unsigned int getDestinationSize(const unsigned int opcode)

{

  unsigned int nRc;

  switch (opcode & MASK_DESTINATION_SIZE)

  {

    case 0x00000000: nRc = typeSingle; break;

    case 0x00000080: nRc = typeDouble; break;

    case 0x00080000: nRc = typeExtended; break;

    default: nRc = typeNone;

  }

  return(nRc);

}

/* condition code lookup table

 index into the table is test code: EQ, NE, ... LT, GT, AL, NV

 bit position in short is condition code: NZCV */

static const unsigned short aCC[16] = {

    0xF0F0, // EQ == Z set

    0x0F0F, // NE

    0xCCCC, // CS == C set

    0x3333, // CC

    0xFF00, // MI == N set

    0x00FF, // PL

    0xAAAA, // VS == V set

    0x5555, // VC

    0x0C0C, // HI == C set && Z clear

    0xF3F3, // LS == C clear || Z set

    0xAA55, // GE == (N==V)

    0x55AA, // LT == (N!=V)

    0x0A05, // GT == (!Z && (N==V))

    0xF5FA, // LE == (Z || (N!=V))

    0xFFFF, // AL always

    0 // NV

};

unsigned int checkCondition(const unsigned int opcode, const unsigned int ccodes)

{

  return (aCC[opcode>>28] >> (ccodes>>28)) & 1;

}