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/*
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 "fpopcode.h"
//#include "fpmodule.h"
//#include "fpmodule.inl"
//#include <asm/system.h>
#include <stdio.h>
/* forward declarations */
unsigned int EmulateCPDO(const unsigned int);
unsigned int EmulateCPDT(const unsigned int);
unsigned int EmulateCPRT(const unsigned int);
FPA11* qemufpa=0;
unsigned int* user_registers=0;
/* Reset the FPA11 chip. Called to initialize and reset the emulator. */
void resetFPA11(void)
{
int i;
FPA11 *fpa11 = GET_FPA11();
/* initialize the register type array */
for (i=0;i<=7;i++)
{
fpa11->fType[i] = typeNone;
}
/* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
fpa11->fpsr = FP_EMULATOR | BIT_AC;
/* FPCR: set SB, AB and DA bits, clear all others */
#if MAINTAIN_FPCR
fpa11->fpcr = MASK_RESET;
#endif
}
void SetRoundingMode(const unsigned int opcode)
{
#if MAINTAIN_FPCR
FPA11 *fpa11 = GET_FPA11();
fpa11->fpcr &= ~MASK_ROUNDING_MODE;
#endif
switch (opcode & MASK_ROUNDING_MODE)
{
default:
case ROUND_TO_NEAREST:
float_rounding_mode = float_round_nearest_even;
#if MAINTAIN_FPCR
fpa11->fpcr |= ROUND_TO_NEAREST;
#endif
break;
case ROUND_TO_PLUS_INFINITY:
float_rounding_mode = float_round_up;
#if MAINTAIN_FPCR
fpa11->fpcr |= ROUND_TO_PLUS_INFINITY;
#endif
break;
case ROUND_TO_MINUS_INFINITY:
float_rounding_mode = float_round_down;
#if MAINTAIN_FPCR
fpa11->fpcr |= ROUND_TO_MINUS_INFINITY;
#endif
break;
case ROUND_TO_ZERO:
float_rounding_mode = float_round_to_zero;
#if MAINTAIN_FPCR
fpa11->fpcr |= ROUND_TO_ZERO;
#endif
break;
}
}
void SetRoundingPrecision(const unsigned int opcode)
{
#if MAINTAIN_FPCR
FPA11 *fpa11 = GET_FPA11();
fpa11->fpcr &= ~MASK_ROUNDING_PRECISION;
#endif
switch (opcode & MASK_ROUNDING_PRECISION)
{
case ROUND_SINGLE:
floatx80_rounding_precision = 32;
#if MAINTAIN_FPCR
fpa11->fpcr |= ROUND_SINGLE;
#endif
break;
case ROUND_DOUBLE:
floatx80_rounding_precision = 64;
#if MAINTAIN_FPCR
fpa11->fpcr |= ROUND_DOUBLE;
#endif
break;
case ROUND_EXTENDED:
floatx80_rounding_precision = 80;
#if MAINTAIN_FPCR
fpa11->fpcr |= ROUND_EXTENDED;
#endif
break;
default: floatx80_rounding_precision = 80;
}
}
/* Emulate the instruction in the opcode. */
unsigned int EmulateAll(unsigned int opcode, FPA11* qfpa, unsigned int* qregs)
{
unsigned int nRc = 0;
// unsigned long flags;
FPA11 *fpa11;
// save_flags(flags); sti();
qemufpa=qfpa;
user_registers=qregs;
#if 0
fprintf(stderr,"emulating FP insn 0x%08x, PC=0x%08x\n",
opcode, qregs[REG_PC]);
#endif
fpa11 = GET_FPA11();
if (fpa11->initflag == 0) /* good place for __builtin_expect */
{
resetFPA11();
SetRoundingMode(ROUND_TO_NEAREST);
SetRoundingPrecision(ROUND_EXTENDED);
fpa11->initflag = 1;
}
if (TEST_OPCODE(opcode,MASK_CPRT))
{
//fprintf(stderr,"emulating CPRT\n");
/* Emulate conversion opcodes. */
/* Emulate register transfer opcodes. */
/* Emulate comparison opcodes. */
nRc = EmulateCPRT(opcode);
}
else if (TEST_OPCODE(opcode,MASK_CPDO))
{
//fprintf(stderr,"emulating CPDO\n");
/* Emulate monadic arithmetic opcodes. */
/* Emulate dyadic arithmetic opcodes. */
nRc = EmulateCPDO(opcode);
}
else if (TEST_OPCODE(opcode,MASK_CPDT))
{
//fprintf(stderr,"emulating CPDT\n");
/* Emulate load/store opcodes. */
/* Emulate load/store multiple opcodes. */
nRc = EmulateCPDT(opcode);
}
else
{
/* Invalid instruction detected. Return FALSE. */
nRc = 0;
}
// restore_flags(flags);
//printf("returning %d\n",nRc);
return(nRc);
}
#if 0
unsigned int EmulateAll1(unsigned int opcode)
{
switch ((opcode >> 24) & 0xf)
{
case 0xc:
case 0xd:
if ((opcode >> 20) & 0x1)
{
switch ((opcode >> 8) & 0xf)
{
case 0x1: return PerformLDF(opcode); break;
case 0x2: return PerformLFM(opcode); break;
default: return 0;
}
}
else
{
switch ((opcode >> 8) & 0xf)
{
case 0x1: return PerformSTF(opcode); break;
case 0x2: return PerformSFM(opcode); break;
default: return 0;
}
}
break;
case 0xe:
if (opcode & 0x10)
return EmulateCPDO(opcode);
else
return EmulateCPRT(opcode);
break;
default: return 0;
}
}
#endif
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