xref: /netbsd/external/gpl3/gdb.old/dist/sim/arm/armsupp.c (revision 15d8e94a)

/*  armsupp.c -- ARMulator support code:  ARM6 Instruction Emulator.
    Copyright (C) 1994 Advanced RISC Machines Ltd.

    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 3 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, see <http://www.gnu.org/licenses/>. */

#include "armdefs.h"
#include "armemu.h"
#include "ansidecl.h"
#include "libiberty.h"
#include <math.h>

/* Definitions for the support routines.  */

static ARMword ModeToBank (ARMword);
static void    EnvokeList (ARMul_State *, unsigned long, unsigned long);

struct EventNode
{					/* An event list node.  */
  unsigned (*func) (ARMul_State *);	/* The function to call.  */
  struct EventNode *next;
};

/* This routine returns the value of a register from a mode.  */

ARMword
ARMul_GetReg (ARMul_State * state, unsigned mode, unsigned reg)
{
  mode &= MODEBITS;
  if (mode != state->Mode)
    return (state->RegBank[ModeToBank ((ARMword) mode)][reg]);
  else
    return (state->Reg[reg]);
}

/* This routine sets the value of a register for a mode.  */

void
ARMul_SetReg (ARMul_State * state, unsigned mode, unsigned reg, ARMword value)
{
  mode &= MODEBITS;
  if (mode != state->Mode)
    state->RegBank[ModeToBank ((ARMword) mode)][reg] = value;
  else
    state->Reg[reg] = value;
}

/* This routine returns the value of the PC, mode independently.  */

ARMword
ARMul_GetPC (ARMul_State * state)
{
  if (state->Mode > SVC26MODE)
    return state->Reg[15];
  else
    return R15PC;
}

/* This routine returns the value of the PC, mode independently.  */

ARMword
ARMul_GetNextPC (ARMul_State * state)
{
  if (state->Mode > SVC26MODE)
    return state->Reg[15] + isize;
  else
    return (state->Reg[15] + isize) & R15PCBITS;
}

/* This routine sets the value of the PC.  */

void
ARMul_SetPC (ARMul_State * state, ARMword value)
{
  if (ARMul_MODE32BIT)
    state->Reg[15] = value & PCBITS;
  else
    state->Reg[15] = R15CCINTMODE | (value & R15PCBITS);
  FLUSHPIPE;
}

/* This routine returns the value of register 15, mode independently.  */

ARMword
ARMul_GetR15 (ARMul_State * state)
{
  if (state->Mode > SVC26MODE)
    return (state->Reg[15]);
  else
    return (R15PC | ECC | ER15INT | EMODE);
}

/* This routine sets the value of Register 15.  */

void
ARMul_SetR15 (ARMul_State * state, ARMword value)
{
  if (ARMul_MODE32BIT)
    state->Reg[15] = value & PCBITS;
  else
    {
      state->Reg[15] = value;
      ARMul_R15Altered (state);
    }
  FLUSHPIPE;
}

/* This routine returns the value of the CPSR.  */

ARMword
ARMul_GetCPSR (ARMul_State * state)
{
  return (CPSR | state->Cpsr);
}

/* This routine sets the value of the CPSR.  */

void
ARMul_SetCPSR (ARMul_State * state, ARMword value)
{
  state->Cpsr = value;
  ARMul_CPSRAltered (state);
}

/* This routine does all the nasty bits involved in a write to the CPSR,
   including updating the register bank, given a MSR instruction.  */

void
ARMul_FixCPSR (ARMul_State * state, ARMword instr, ARMword rhs)
{
  state->Cpsr = ARMul_GetCPSR (state);

  if (state->Mode != USER26MODE
      && state->Mode != USER32MODE)
    {
      /* In user mode, only write flags.  */
      if (BIT (16))
	SETPSR_C (state->Cpsr, rhs);
      if (BIT (17))
	SETPSR_X (state->Cpsr, rhs);
      if (BIT (18))
	SETPSR_S (state->Cpsr, rhs);
    }
  if (BIT (19))
    SETPSR_F (state->Cpsr, rhs);
  ARMul_CPSRAltered (state);
}

/* Get an SPSR from the specified mode.  */

ARMword
ARMul_GetSPSR (ARMul_State * state, ARMword mode)
{
  ARMword bank = ModeToBank (mode & MODEBITS);

  if (! BANK_CAN_ACCESS_SPSR (bank))
    return ARMul_GetCPSR (state);

  return state->Spsr[bank];
}

/* This routine does a write to an SPSR.  */

void
ARMul_SetSPSR (ARMul_State * state, ARMword mode, ARMword value)
{
  ARMword bank = ModeToBank (mode & MODEBITS);

  if (BANK_CAN_ACCESS_SPSR (bank))
    state->Spsr[bank] = value;
}

/* This routine does a write to the current SPSR, given an MSR instruction.  */

void
ARMul_FixSPSR (ARMul_State * state, ARMword instr, ARMword rhs)
{
  if (BANK_CAN_ACCESS_SPSR (state->Bank))
    {
      if (BIT (16))
	SETPSR_C (state->Spsr[state->Bank], rhs);
      if (BIT (17))
	SETPSR_X (state->Spsr[state->Bank], rhs);
      if (BIT (18))
	SETPSR_S (state->Spsr[state->Bank], rhs);
      if (BIT (19))
	SETPSR_F (state->Spsr[state->Bank], rhs);
    }
}

/* This routine updates the state of the emulator after the Cpsr has been
   changed.  Both the processor flags and register bank are updated.  */

void
ARMul_CPSRAltered (ARMul_State * state)
{
  ARMword oldmode;

  if (state->prog32Sig == LOW)
    state->Cpsr &= (CCBITS | INTBITS | R15MODEBITS);

  oldmode = state->Mode;

  if (state->Mode != (state->Cpsr & MODEBITS))
    {
      state->Mode =
	ARMul_SwitchMode (state, state->Mode, state->Cpsr & MODEBITS);

      state->NtransSig = (state->Mode & 3) ? HIGH : LOW;
    }
  state->Cpsr &= ~MODEBITS;

  ASSIGNINT (state->Cpsr & INTBITS);
  state->Cpsr &= ~INTBITS;
  ASSIGNN ((state->Cpsr & NBIT) != 0);
  state->Cpsr &= ~NBIT;
  ASSIGNZ ((state->Cpsr & ZBIT) != 0);
  state->Cpsr &= ~ZBIT;
  ASSIGNC ((state->Cpsr & CBIT) != 0);
  state->Cpsr &= ~CBIT;
  ASSIGNV ((state->Cpsr & VBIT) != 0);
  state->Cpsr &= ~VBIT;
  ASSIGNS ((state->Cpsr & SBIT) != 0);
  state->Cpsr &= ~SBIT;
#ifdef MODET
  ASSIGNT ((state->Cpsr & TBIT) != 0);
  state->Cpsr &= ~TBIT;
#endif

  if (oldmode > SVC26MODE)
    {
      if (state->Mode <= SVC26MODE)
	{
	  state->Emulate = CHANGEMODE;
	  state->Reg[15] = ECC | ER15INT | EMODE | R15PC;
	}
    }
  else
    {
      if (state->Mode > SVC26MODE)
	{
	  state->Emulate = CHANGEMODE;
	  state->Reg[15] = R15PC;
	}
      else
	state->Reg[15] = ECC | ER15INT | EMODE | R15PC;
    }
}

/* This routine updates the state of the emulator after register 15 has
   been changed.  Both the processor flags and register bank are updated.
   This routine should only be called from a 26 bit mode.  */

void
ARMul_R15Altered (ARMul_State * state)
{
  if (state->Mode != R15MODE)
    {
      state->Mode = ARMul_SwitchMode (state, state->Mode, R15MODE);
      state->NtransSig = (state->Mode & 3) ? HIGH : LOW;
    }

  if (state->Mode > SVC26MODE)
    state->Emulate = CHANGEMODE;

  ASSIGNR15INT (R15INT);

  ASSIGNN ((state->Reg[15] & NBIT) != 0);
  ASSIGNZ ((state->Reg[15] & ZBIT) != 0);
  ASSIGNC ((state->Reg[15] & CBIT) != 0);
  ASSIGNV ((state->Reg[15] & VBIT) != 0);
}

/* This routine controls the saving and restoring of registers across mode
   changes.  The regbank matrix is largely unused, only rows 13 and 14 are
   used across all modes, 8 to 14 are used for FIQ, all others use the USER
   column.  It's easier this way.  old and new parameter are modes numbers.
   Notice the side effect of changing the Bank variable.  */

ARMword
ARMul_SwitchMode (ARMul_State * state, ARMword oldmode, ARMword newmode)
{
  unsigned i;
  ARMword  oldbank;
  ARMword  newbank;

  oldbank = ModeToBank (oldmode);
  newbank = state->Bank = ModeToBank (newmode);

  /* Do we really need to do it?  */
  if (oldbank != newbank)
    {
      /* Save away the old registers.  */
      switch (oldbank)
	{
	case USERBANK:
	case IRQBANK:
	case SVCBANK:
	case ABORTBANK:
	case UNDEFBANK:
	  if (newbank == FIQBANK)
	    for (i = 8; i < 13; i++)
	      state->RegBank[USERBANK][i] = state->Reg[i];
	  state->RegBank[oldbank][13] = state->Reg[13];
	  state->RegBank[oldbank][14] = state->Reg[14];
	  break;
	case FIQBANK:
	  for (i = 8; i < 15; i++)
	    state->RegBank[FIQBANK][i] = state->Reg[i];
	  break;
	case DUMMYBANK:
	  for (i = 8; i < 15; i++)
	    state->RegBank[DUMMYBANK][i] = 0;
	  break;
	default:
	  abort ();
	}

      /* Restore the new registers.  */
      switch (newbank)
	{
	case USERBANK:
	case IRQBANK:
	case SVCBANK:
	case ABORTBANK:
	case UNDEFBANK:
	  if (oldbank == FIQBANK)
	    for (i = 8; i < 13; i++)
	      state->Reg[i] = state->RegBank[USERBANK][i];
	  state->Reg[13] = state->RegBank[newbank][13];
	  state->Reg[14] = state->RegBank[newbank][14];
	  break;
	case FIQBANK:
	  for (i = 8; i < 15; i++)
	    state->Reg[i] = state->RegBank[FIQBANK][i];
	  break;
	case DUMMYBANK:
	  for (i = 8; i < 15; i++)
	    state->Reg[i] = 0;
	  break;
	default:
	  abort ();
	}
    }

  return newmode;
}

/* Given a processor mode, this routine returns the
   register bank that will be accessed in that mode.  */

static ARMword
ModeToBank (ARMword mode)
{
  static ARMword bankofmode[] =
  {
    USERBANK,  FIQBANK,   IRQBANK,   SVCBANK,
    DUMMYBANK, DUMMYBANK, DUMMYBANK, DUMMYBANK,
    DUMMYBANK, DUMMYBANK, DUMMYBANK, DUMMYBANK,
    DUMMYBANK, DUMMYBANK, DUMMYBANK, DUMMYBANK,
    USERBANK,  FIQBANK,   IRQBANK,   SVCBANK,
    DUMMYBANK, DUMMYBANK, DUMMYBANK, ABORTBANK,
    DUMMYBANK, DUMMYBANK, DUMMYBANK, UNDEFBANK,
    DUMMYBANK, DUMMYBANK, DUMMYBANK, SYSTEMBANK
  };

  if (mode >= ARRAY_SIZE (bankofmode))
    return DUMMYBANK;

  return bankofmode[mode];
}

/* Returns the register number of the nth register in a reg list.  */

unsigned
ARMul_NthReg (ARMword instr, unsigned number)
{
  unsigned bit, upto;

  for (bit = 0, upto = 0; upto <= number; bit ++)
    if (BIT (bit))
      upto ++;

  return (bit - 1);
}

/* Assigns the N and Z flags depending on the value of result.  */

void
ARMul_NegZero (ARMul_State * state, ARMword result)
{
  if (NEG (result))
    {
      SETN;
      CLEARZ;
    }
  else if (result == 0)
    {
      CLEARN;
      SETZ;
    }
  else
    {
      CLEARN;
      CLEARZ;
    }
}

/* Compute whether an addition of A and B, giving RESULT, overflowed.  */

int
AddOverflow (ARMword a, ARMword b, ARMword result)
{
  return ((NEG (a) && NEG (b) && POS (result))
	  || (POS (a) && POS (b) && NEG (result)));
}

/* Compute whether a subtraction of A and B, giving RESULT, overflowed.  */

int
SubOverflow (ARMword a, ARMword b, ARMword result)
{
  return ((NEG (a) && POS (b) && POS (result))
	  || (POS (a) && NEG (b) && NEG (result)));
}

/* Assigns the C flag after an addition of a and b to give result.  */

void
ARMul_AddCarry (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
  ASSIGNC ((NEG (a) && NEG (b)) ||
	   (NEG (a) && POS (result)) || (NEG (b) && POS (result)));
}

/* Assigns the V flag after an addition of a and b to give result.  */

void
ARMul_AddOverflow (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
  ASSIGNV (AddOverflow (a, b, result));
}

/* Assigns the C flag after an subtraction of a and b to give result.  */

void
ARMul_SubCarry (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
  ASSIGNC ((NEG (a) && POS (b)) ||
	   (NEG (a) && POS (result)) || (POS (b) && POS (result)));
}

/* Assigns the V flag after an subtraction of a and b to give result.  */

void
ARMul_SubOverflow (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
  ASSIGNV (SubOverflow (a, b, result));
}

static void
handle_VFP_xfer (ARMul_State * state, ARMword instr)
{
  if (TOPBITS (28) == NV)
    {
      fprintf (stderr, "SIM: UNDEFINED VFP instruction\n");
      return;
    }

  if (BITS (25, 27) != 0x6)
    {
      fprintf (stderr, "SIM: ISE: VFP handler called incorrectly\n");
      return;
    }

  switch (BITS (20, 24))
    {
    case 0x04:
    case 0x05:
      {
	/* VMOV double precision to/from two ARM registers.  */
	int vm  = BITS (0, 3);
	int rt1 = BITS (12, 15);
	int rt2 = BITS (16, 19);

	/* FIXME: UNPREDICTABLE if rt1 == 15 or rt2 == 15.  */
	if (BIT (20))
	  {
	    /* Transfer to ARM.  */
	    /* FIXME: UPPREDICTABLE if rt1 == rt2.  */
	    state->Reg[rt1] = VFP_dword (vm) & 0xffffffff;
	    state->Reg[rt2] = VFP_dword (vm) >> 32;
	  }
	else
	  {
	    VFP_dword (vm) = state->Reg[rt2];
	    VFP_dword (vm) <<= 32;
	    VFP_dword (vm) |= (state->Reg[rt1] & 0xffffffff);
	  }
	return;
      }

    case 0x08:
    case 0x0A:
    case 0x0C:
    case 0x0E:
      {
	/* VSTM with PUW=011 or PUW=010.  */
	int n = BITS (16, 19);
	int imm8 = BITS (0, 7);

	ARMword address = state->Reg[n];
	if (BIT (21))
	  state->Reg[n] = address + (imm8 << 2);

	if (BIT (8))
	  {
	    int src = (BIT (22) << 4) | BITS (12, 15);
	    imm8 >>= 1;
	    while (imm8--)
	      {
		if (state->bigendSig)
		  {
		    ARMul_StoreWordN (state, address, VFP_dword (src) >> 32);
		    ARMul_StoreWordN (state, address + 4, VFP_dword (src));
		  }
		else
		  {
		    ARMul_StoreWordN (state, address, VFP_dword (src));
		    ARMul_StoreWordN (state, address + 4, VFP_dword (src) >> 32);
		  }
		address += 8;
		src += 1;
	      }
	  }
	else
	  {
	    int src = (BITS (12, 15) << 1) | BIT (22);
	    while (imm8--)
	      {
		ARMul_StoreWordN (state, address, VFP_uword (src));
		address += 4;
		src += 1;
	      }
	  }
      }
      return;

    case 0x10:
    case 0x14:
    case 0x18:
    case 0x1C:
      {
	/* VSTR */
	ARMword imm32 = BITS (0, 7) << 2;
	int base = state->Reg[LHSReg];
	ARMword address;
	int dest;

	if (LHSReg == 15)
	  base = (base + 3) & ~3;

	address = base + (BIT (23) ? imm32 : - imm32);

	if (CPNum == 10)
	  {
	    dest = (DESTReg << 1) + BIT (22);

	    ARMul_StoreWordN (state, address, VFP_uword (dest));
	  }
	else
	  {
	    dest = (BIT (22) << 4) + DESTReg;

	    if (state->bigendSig)
	      {
		ARMul_StoreWordN (state, address, VFP_dword (dest) >> 32);
		ARMul_StoreWordN (state, address + 4, VFP_dword (dest));
	      }
	    else
	      {
		ARMul_StoreWordN (state, address, VFP_dword (dest));
		ARMul_StoreWordN (state, address + 4, VFP_dword (dest) >> 32);
	      }
	  }
      }
      return;

    case 0x12:
    case 0x16:
      if (BITS (16, 19) == 13)
	{
	  /* VPUSH */
	  ARMword address = state->Reg[13] - (BITS (0, 7) << 2);
	  state->Reg[13] = address;

	  if (BIT (8))
	    {
	      int dreg = (BIT (22) << 4) | BITS (12, 15);
	      int num  = BITS (0, 7) >> 1;
	      while (num--)
		{
		  if (state->bigendSig)
		    {
		      ARMul_StoreWordN (state, address, VFP_dword (dreg) >> 32);
		      ARMul_StoreWordN (state, address + 4, VFP_dword (dreg));
		    }
		  else
		    {
		      ARMul_StoreWordN (state, address, VFP_dword (dreg));
		      ARMul_StoreWordN (state, address + 4, VFP_dword (dreg) >> 32);
		    }
		  address += 8;
		  dreg += 1;
		}
	    }
	  else
	    {
	      int sreg = (BITS (12, 15) << 1) | BIT (22);
	      int num  = BITS (0, 7);
	      while (num--)
		{
		  ARMul_StoreWordN (state, address, VFP_uword (sreg));
		  address += 4;
		  sreg += 1;
		}
	    }
	}
      else if (BITS (9, 11) != 0x5)
	break;
      else
	{
	  /* VSTM PUW=101 */
	  int n = BITS (16, 19);
	  int imm8 = BITS (0, 7);
	  ARMword address = state->Reg[n] - (imm8 << 2);
	  state->Reg[n] = address;

	  if (BIT (8))
	    {
	      int src = (BIT (22) << 4) | BITS (12, 15);

	      imm8 >>= 1;
	      while (imm8--)
		{
		  if (state->bigendSig)
		    {
		      ARMul_StoreWordN (state, address, VFP_dword (src) >> 32);
		      ARMul_StoreWordN (state, address + 4, VFP_dword (src));
		    }
		  else
		    {
		      ARMul_StoreWordN (state, address, VFP_dword (src));
		      ARMul_StoreWordN (state, address + 4, VFP_dword (src) >> 32);
		    }
		  address += 8;
		  src += 1;
		}
	    }
	  else
	    {
	      int src = (BITS (12, 15) << 1) | BIT (22);

	      while (imm8--)
		{
		  ARMul_StoreWordN (state, address, VFP_uword (src));
		  address += 4;
		  src += 1;
		}
	    }
	}
      return;

    case 0x13:
    case 0x17:
      /* VLDM PUW=101 */
    case 0x09:
    case 0x0D:
      /* VLDM PUW=010 */
	{
	  int n = BITS (16, 19);
	  int imm8 = BITS (0, 7);

	  ARMword address = state->Reg[n];
	  if (BIT (23) == 0)
	    address -= imm8 << 2;
	  if (BIT (21))
	    state->Reg[n] = BIT (23) ? address + (imm8 << 2) : address;

	  if (BIT (8))
	    {
	      int dest = (BIT (22) << 4) | BITS (12, 15);
	      imm8 >>= 1;
	      while (imm8--)
		{
		  if (state->bigendSig)
		    {
		      VFP_dword (dest) = ARMul_LoadWordN (state, address);
		      VFP_dword (dest) <<= 32;
		      VFP_dword (dest) |= ARMul_LoadWordN (state, address + 4);
		    }
		  else
		    {
		      VFP_dword (dest) = ARMul_LoadWordN (state, address + 4);
		      VFP_dword (dest) <<= 32;
		      VFP_dword (dest) |= ARMul_LoadWordN (state, address);
		    }

		  if (trace)
		    fprintf (stderr, " VFP: VLDM: D%d = %g\n", dest, VFP_dval (dest));

		  address += 8;
		  dest += 1;
		}
	    }
	  else
	    {
	      int dest = (BITS (12, 15) << 1) | BIT (22);

	      while (imm8--)
		{
		  VFP_uword (dest) = ARMul_LoadWordN (state, address);
		  address += 4;
		  dest += 1;
		}
	    }
	}
      return;

    case 0x0B:
    case 0x0F:
      if (BITS (16, 19) == 13)
	{
	  /* VPOP */
	  ARMword address = state->Reg[13];
	  state->Reg[13] = address + (BITS (0, 7) << 2);

	  if (BIT (8))
	    {
	      int dest = (BIT (22) << 4) | BITS (12, 15);
	      int num  = BITS (0, 7) >> 1;

	      while (num--)
		{
		  if (state->bigendSig)
		    {
		      VFP_dword (dest) = ARMul_LoadWordN (state, address);
		      VFP_dword (dest) <<= 32;
		      VFP_dword (dest) |= ARMul_LoadWordN (state, address + 4);
		    }
		  else
		    {
		      VFP_dword (dest) = ARMul_LoadWordN (state, address + 4);
		      VFP_dword (dest) <<= 32;
		      VFP_dword (dest) |= ARMul_LoadWordN (state, address);
		    }

		  if (trace)
		    fprintf (stderr, " VFP: VPOP: D%d = %g\n", dest, VFP_dval (dest));

		  address += 8;
		  dest += 1;
		}
	    }
	  else
	    {
	      int sreg = (BITS (12, 15) << 1) | BIT (22);
	      int num  = BITS (0, 7);

	      while (num--)
		{
		  VFP_uword (sreg) = ARMul_LoadWordN (state, address);
		  address += 4;
		  sreg += 1;
		}
	    }
	}
      else if (BITS (9, 11) != 0x5)
	break;
      else
	{
	  /* VLDM PUW=011 */
	  int n = BITS (16, 19);
	  int imm8 = BITS (0, 7);
	  ARMword address = state->Reg[n];
	  state->Reg[n] += imm8 << 2;

	  if (BIT (8))
	    {
	      int dest = (BIT (22) << 4) | BITS (12, 15);

	      imm8 >>= 1;
	      while (imm8--)
		{
		  if (state->bigendSig)
		    {
		      VFP_dword (dest) = ARMul_LoadWordN (state, address);
		      VFP_dword (dest) <<= 32;
		      VFP_dword (dest) |= ARMul_LoadWordN (state, address + 4);
		    }
		  else
		    {
		      VFP_dword (dest) = ARMul_LoadWordN (state, address + 4);
		      VFP_dword (dest) <<= 32;
		      VFP_dword (dest) |= ARMul_LoadWordN (state, address);
		    }

		  if (trace)
		    fprintf (stderr, " VFP: VLDM: D%d = %g\n", dest, VFP_dval (dest));

		  address += 8;
		  dest += 1;
		}
	    }
	  else
	    {
	      int dest = (BITS (12, 15) << 1) | BIT (22);
	      while (imm8--)
		{
		  VFP_uword (dest) = ARMul_LoadWordN (state, address);
		  address += 4;
		  dest += 1;
		}
	    }
	}
      return;

    case 0x11:
    case 0x15:
    case 0x19:
    case 0x1D:
      {
	/* VLDR */
	ARMword imm32 = BITS (0, 7) << 2;
	int base = state->Reg[LHSReg];
	ARMword address;
	int dest;

	if (LHSReg == 15)
	  base = (base + 3) & ~3;

	address = base + (BIT (23) ? imm32 : - imm32);

	if (CPNum == 10)
	  {
	    dest = (DESTReg << 1) + BIT (22);

	    VFP_uword (dest) = ARMul_LoadWordN (state, address);
	  }
	else
	  {
	    dest = (BIT (22) << 4) + DESTReg;

	    if (state->bigendSig)
	      {
		VFP_dword (dest) = ARMul_LoadWordN (state, address);
		VFP_dword (dest) <<= 32;
		VFP_dword (dest) |= ARMul_LoadWordN (state, address + 4);
	      }
	    else
	      {
		VFP_dword (dest) = ARMul_LoadWordN (state, address + 4);
		VFP_dword (dest) <<= 32;
		VFP_dword (dest) |= ARMul_LoadWordN (state, address);
	      }

	    if (trace)
	      fprintf (stderr, " VFP: VLDR: D%d = %g\n", dest, VFP_dval (dest));
	  }
      }
      return;
    }

  fprintf (stderr, "SIM: VFP: Unimplemented: %0x\n", BITS (20, 24));
}

/* This function does the work of generating the addresses used in an
   LDC instruction.  The code here is always post-indexed, it's up to the
   caller to get the input address correct and to handle base register
   modification. It also handles the Busy-Waiting.  */

void
ARMul_LDC (ARMul_State * state, ARMword instr, ARMword address)
{
  unsigned cpab;
  ARMword data;

  if (CPNum == 10 || CPNum == 11)
    {
      handle_VFP_xfer (state, instr);
      return;
    }

  UNDEF_LSCPCBaseWb;

  if (! CP_ACCESS_ALLOWED (state, CPNum))
    {
      ARMul_UndefInstr (state, instr);
      return;
    }

  if (ADDREXCEPT (address))
    INTERNALABORT (address);

  cpab = (state->LDC[CPNum]) (state, ARMul_FIRST, instr, 0);
  while (cpab == ARMul_BUSY)
    {
      ARMul_Icycles (state, 1, 0);

      if (IntPending (state))
	{
	  cpab = (state->LDC[CPNum]) (state, ARMul_INTERRUPT, instr, 0);
	  return;
	}
      else
	cpab = (state->LDC[CPNum]) (state, ARMul_BUSY, instr, 0);
    }
  if (cpab == ARMul_CANT)
    {
      CPTAKEABORT;
      return;
    }

  cpab = (state->LDC[CPNum]) (state, ARMul_TRANSFER, instr, 0);
  data = ARMul_LoadWordN (state, address);
  BUSUSEDINCPCN;

  if (BIT (21))
    LSBase = state->Base;
  cpab = (state->LDC[CPNum]) (state, ARMul_DATA, instr, data);

  while (cpab == ARMul_INC)
    {
      address += 4;
      data = ARMul_LoadWordN (state, address);
      cpab = (state->LDC[CPNum]) (state, ARMul_DATA, instr, data);
    }

  if (state->abortSig || state->Aborted)
    TAKEABORT;
}

/* This function does the work of generating the addresses used in an
   STC instruction.  The code here is always post-indexed, it's up to the
   caller to get the input address correct and to handle base register
   modification. It also handles the Busy-Waiting.  */

void
ARMul_STC (ARMul_State * state, ARMword instr, ARMword address)
{
  unsigned cpab;
  ARMword data;

  if (CPNum == 10 || CPNum == 11)
    {
      handle_VFP_xfer (state, instr);
      return;
    }

  UNDEF_LSCPCBaseWb;

  if (! CP_ACCESS_ALLOWED (state, CPNum))
    {
      ARMul_UndefInstr (state, instr);
      return;
    }

  if (ADDREXCEPT (address) || VECTORACCESS (address))
    INTERNALABORT (address);

  cpab = (state->STC[CPNum]) (state, ARMul_FIRST, instr, &data);
  while (cpab == ARMul_BUSY)
    {
      ARMul_Icycles (state, 1, 0);
      if (IntPending (state))
	{
	  cpab = (state->STC[CPNum]) (state, ARMul_INTERRUPT, instr, 0);
	  return;
	}
      else
	cpab = (state->STC[CPNum]) (state, ARMul_BUSY, instr, &data);
    }

  if (cpab == ARMul_CANT)
    {
      CPTAKEABORT;
      return;
    }
#ifndef MODE32
  if (ADDREXCEPT (address) || VECTORACCESS (address))
    INTERNALABORT (address);
#endif
  BUSUSEDINCPCN;
  if (BIT (21))
    LSBase = state->Base;
  cpab = (state->STC[CPNum]) (state, ARMul_DATA, instr, &data);
  ARMul_StoreWordN (state, address, data);

  while (cpab == ARMul_INC)
    {
      address += 4;
      cpab = (state->STC[CPNum]) (state, ARMul_DATA, instr, &data);
      ARMul_StoreWordN (state, address, data);
    }

  if (state->abortSig || state->Aborted)
    TAKEABORT;
}

/* This function does the Busy-Waiting for an MCR instruction.  */

void
ARMul_MCR (ARMul_State * state, ARMword instr, ARMword source)
{
  unsigned cpab;

  if (! CP_ACCESS_ALLOWED (state, CPNum))
    {
      ARMul_UndefInstr (state, instr);
      return;
    }

  cpab = (state->MCR[CPNum]) (state, ARMul_FIRST, instr, source);

  while (cpab == ARMul_BUSY)
    {
      ARMul_Icycles (state, 1, 0);

      if (IntPending (state))
	{
	  cpab = (state->MCR[CPNum]) (state, ARMul_INTERRUPT, instr, 0);
	  return;
	}
      else
	cpab = (state->MCR[CPNum]) (state, ARMul_BUSY, instr, source);
    }

  if (cpab == ARMul_CANT)
    ARMul_Abort (state, ARMul_UndefinedInstrV);
  else
    {
      BUSUSEDINCPCN;
      ARMul_Ccycles (state, 1, 0);
    }
}

/* This function does the Busy-Waiting for an MRC instruction.  */

ARMword
ARMul_MRC (ARMul_State * state, ARMword instr)
{
  unsigned cpab;
  ARMword result = 0;

  if (! CP_ACCESS_ALLOWED (state, CPNum))
    {
      ARMul_UndefInstr (state, instr);
      return result;
    }

  cpab = (state->MRC[CPNum]) (state, ARMul_FIRST, instr, &result);
  while (cpab == ARMul_BUSY)
    {
      ARMul_Icycles (state, 1, 0);
      if (IntPending (state))
	{
	  cpab = (state->MRC[CPNum]) (state, ARMul_INTERRUPT, instr, 0);
	  return (0);
	}
      else
	cpab = (state->MRC[CPNum]) (state, ARMul_BUSY, instr, &result);
    }
  if (cpab == ARMul_CANT)
    {
      ARMul_Abort (state, ARMul_UndefinedInstrV);
      /* Parent will destroy the flags otherwise.  */
      result = ECC;
    }
  else
    {
      BUSUSEDINCPCN;
      ARMul_Ccycles (state, 1, 0);
      ARMul_Icycles (state, 1, 0);
    }

  return result;
}

static void
handle_VFP_op (ARMul_State * state, ARMword instr)
{
  int dest;
  int srcN;
  int srcM;

  if (BITS (9, 11) != 0x5 || BIT (4) != 0)
    {
      fprintf (stderr, "SIM: VFP: Unimplemented: Float op: %08x\n", BITS (0,31));
      return;
    }

  if (BIT (8))
    {
      dest = BITS(12,15) + (BIT (22) << 4);
      srcN = LHSReg  + (BIT (7) << 4);
      srcM = BITS (0,3) + (BIT (5) << 4);
    }
  else
    {
      dest = (BITS(12,15) << 1) + BIT (22);
      srcN = (LHSReg << 1) + BIT (7);
      srcM = (BITS (0,3) << 1) + BIT (5);
    }

  switch (BITS (20, 27))
    {
    case 0xE0:
    case 0xE4:
      /* VMLA VMLS */
      if (BIT (8))
	{
	  ARMdval val = VFP_dval (srcN) * VFP_dval (srcM);

	  if (BIT (6))
	    {
	      if (trace)
		fprintf (stderr, " VFP: VMLS: %g = %g - %g * %g\n",
			 VFP_dval (dest) - val,
			 VFP_dval (dest), VFP_dval (srcN), VFP_dval (srcM));
	      VFP_dval (dest) -= val;
	    }
	  else
	    {
	      if (trace)
		fprintf (stderr, " VFP: VMLA: %g = %g + %g * %g\n",
			 VFP_dval (dest) + val,
			 VFP_dval (dest), VFP_dval (srcN), VFP_dval (srcM));
	      VFP_dval (dest) += val;
	    }
	}
      else
	{
	  ARMfval val = VFP_fval (srcN) * VFP_fval (srcM);

	  if (BIT (6))
	    {
	      if (trace)
		fprintf (stderr, " VFP: VMLS: %g = %g - %g * %g\n",
			 VFP_fval (dest) - val,
			 VFP_fval (dest), VFP_fval (srcN), VFP_fval (srcM));
	      VFP_fval (dest) -= val;
	    }
	  else
	    {
	      if (trace)
		fprintf (stderr, " VFP: VMLA: %g = %g + %g * %g\n",
			 VFP_fval (dest) + val,
			 VFP_fval (dest), VFP_fval (srcN), VFP_fval (srcM));
	      VFP_fval (dest) += val;
	    }
	}
      return;

    case 0xE1:
    case 0xE5:
      if (BIT (8))
	{
	  ARMdval product = VFP_dval (srcN) * VFP_dval (srcM);

	  if (BIT (6))
	    {
	      /* VNMLA */
	      if (trace)
		fprintf (stderr, " VFP: VNMLA: %g = -(%g + (%g * %g))\n",
			 -(VFP_dval (dest) + product),
			 VFP_dval (dest), VFP_dval (srcN), VFP_dval (srcM));
	      VFP_dval (dest) = -(product + VFP_dval (dest));
	    }
	  else
	    {
	      /* VNMLS */
	      if (trace)
		fprintf (stderr, " VFP: VNMLS: %g = -(%g + (%g * %g))\n",
			 -(VFP_dval (dest) + product),
			 VFP_dval (dest), VFP_dval (srcN), VFP_dval (srcM));
	      VFP_dval (dest) = product - VFP_dval (dest);
	    }
	}
      else
	{
	  ARMfval product = VFP_fval (srcN) * VFP_fval (srcM);

	  if (BIT (6))
	    /* VNMLA */
	    VFP_fval (dest) = -(product + VFP_fval (dest));
	  else
	    /* VNMLS */
	    VFP_fval (dest) = product - VFP_fval (dest);
	}
      return;

    case 0xE2:
    case 0xE6:
      if (BIT (8))
	{
	  ARMdval product = VFP_dval (srcN) * VFP_dval (srcM);

	  if (BIT (6))
	    {
	      if (trace)
		fprintf (stderr, " VFP: VMUL: %g = %g * %g\n",
			 - product, VFP_dval (srcN), VFP_dval (srcM));
	      /* VNMUL */
	      VFP_dval (dest) = - product;
	    }
	  else
	    {
	      if (trace)
		fprintf (stderr, " VFP: VMUL: %g = %g * %g\n",
			 product, VFP_dval (srcN), VFP_dval (srcM));
	      /* VMUL */
	      VFP_dval (dest) = product;
	    }
	}
      else
	{
	  ARMfval product = VFP_fval (srcN) * VFP_fval (srcM);

	  if (BIT (6))
	    {
	      if (trace)
		fprintf (stderr, " VFP: VNMUL: %g = %g * %g\n",
			 - product, VFP_fval (srcN), VFP_fval (srcM));

	      VFP_fval (dest) = - product;
	    }
	  else
	    {
	      if (trace)
		fprintf (stderr, " VFP: VMUL: %g = %g * %g\n",
			 product, VFP_fval (srcN), VFP_fval (srcM));

	      VFP_fval (dest) = product;
	    }
	}
      return;

    case 0xE3:
    case 0xE7:
      if (BIT (6) == 0)
	{
	  /* VADD */
	  if (BIT(8))
	    {
	      if (trace)
		fprintf (stderr, " VFP: VADD %g = %g + %g\n",
			 VFP_dval (srcN) + VFP_dval (srcM),
			 VFP_dval (srcN),
			 VFP_dval (srcM));
	      VFP_dval (dest) = VFP_dval (srcN) + VFP_dval (srcM);
	    }
	  else
	    VFP_fval (dest) = VFP_fval (srcN) + VFP_fval (srcM);

	}
      else
	{
	  /* VSUB */
	  if (BIT(8))
	    {
	      if (trace)
		fprintf (stderr, " VFP: VSUB %g = %g - %g\n",
			 VFP_dval (srcN) - VFP_dval (srcM),
			 VFP_dval (srcN),
			 VFP_dval (srcM));
	      VFP_dval (dest) = VFP_dval (srcN) - VFP_dval (srcM);
	    }
	  else
	    VFP_fval (dest) = VFP_fval (srcN) - VFP_fval (srcM);
	}
      return;

    case 0xE8:
    case 0xEC:
      if (BIT (6) == 1)
	break;

      /* VDIV */
      if (BIT (8))
	{
	  ARMdval res = VFP_dval (srcN) / VFP_dval (srcM);
	  if (trace)
	    fprintf (stderr, " VFP: VDIV (64bit): %g = %g / %g\n",
		     res, VFP_dval (srcN), VFP_dval (srcM));
	  VFP_dval (dest) = res;
	}
      else
	{
	  if (trace)
	    fprintf (stderr, " VFP: VDIV: %g = %g / %g\n",
		     VFP_fval (srcN) / VFP_fval (srcM),
		     VFP_fval (srcN), VFP_fval (srcM));

	  VFP_fval (dest) = VFP_fval (srcN) / VFP_fval (srcM);
	}
      return;

    case 0xEB:
    case 0xEF:
      if (BIT (6) != 1)
	break;

      switch (BITS (16, 19))
	{
	case 0x0:
	  if (BIT (7) == 0)
	    {
	      if (BIT (8))
		{
		  /* VMOV.F64 <Dd>, <Dm>.  */
		  VFP_dval (dest) = VFP_dval (srcM);
		  if (trace)
		    fprintf (stderr, " VFP: VMOV d%d, d%d: %g\n", dest, srcM, VFP_dval (srcM));
		}
	      else
		{
		  /* VMOV.F32 <Sd>, <Sm>.  */
		  VFP_fval (dest) = VFP_fval (srcM);
		  if (trace)
		    fprintf (stderr, " VFP: VMOV s%d, s%d: %g\n", dest, srcM, VFP_fval (srcM));
		}
	    }
	  else
	    {
	      /* VABS */
	      if (BIT (8))
		{
		  ARMdval src = VFP_dval (srcM);

		  VFP_dval (dest) = fabs (src);
		  if (trace)
		    fprintf (stderr, " VFP: VABS (%g) = %g\n", src, VFP_dval (dest));
		}
	      else
		{
		  ARMfval src = VFP_fval (srcM);

		  VFP_fval (dest) = fabsf (src);
		  if (trace)
		    fprintf (stderr, " VFP: VABS (%g) = %g\n", src, VFP_fval (dest));
		}
	    }
	  return;

	case 0x1:
	  if (BIT (7) == 0)
	    {
	      /* VNEG */
	      if (BIT (8))
		VFP_dval (dest) = - VFP_dval (srcM);
	      else
		VFP_fval (dest) = - VFP_fval (srcM);
	    }
	  else
	    {
	      /* VSQRT */
	      if (BIT (8))
		{
		  if (trace)
		    fprintf (stderr, " VFP: %g = root(%g)\n",
			     sqrt (VFP_dval (srcM)), VFP_dval (srcM));

		  VFP_dval (dest) = sqrt (VFP_dval (srcM));
		}
	      else
		{
		  if (trace)
		    fprintf (stderr, " VFP: %g = root(%g)\n",
			     sqrtf (VFP_fval (srcM)), VFP_fval (srcM));

		  VFP_fval (dest) = sqrtf (VFP_fval (srcM));
		}
	    }
	  return;

	case 0x4:
	case 0x5:
	  /* VCMP, VCMPE */
	  if (BIT(8))
	    {
	      ARMdval res = VFP_dval (dest);

	      if (BIT (16) == 0)
		{
		  ARMdval src = VFP_dval (srcM);

		  if (isinf (res) && isinf (src))
		    {
		      if (res > 0.0 && src > 0.0)
			res = 0.0;
		      else if (res < 0.0 && src < 0.0)
			res = 0.0;
		      /* else leave res alone.   */
		    }
		  else
		    res -= src;
		}

	      /* FIXME: Add handling of signalling NaNs and the E bit.  */

	      state->FPSCR &= 0x0FFFFFFF;
	      if (res < 0.0)
		state->FPSCR |= NBIT;
	      else
		state->FPSCR |= CBIT;
	      if (res == 0.0)
		state->FPSCR |= ZBIT;
	      if (isnan (res))
		state->FPSCR |= VBIT;

	      if (trace)
		fprintf (stderr, " VFP: VCMP (64bit) %g vs %g res %g, flags: %c%c%c%c\n",
			 VFP_dval (dest), BIT (16) ? 0.0 : VFP_dval (srcM), res,
			 state->FPSCR & NBIT ? 'N' : '-',
			 state->FPSCR & ZBIT ? 'Z' : '-',
			 state->FPSCR & CBIT ? 'C' : '-',
			 state->FPSCR & VBIT ? 'V' : '-');
	    }
	  else
	    {
	      ARMfval res = VFP_fval (dest);

	      if (BIT (16) == 0)
		{
		  ARMfval src = VFP_fval (srcM);

		  if (isinf (res) && isinf (src))
		    {
		      if (res > 0.0 && src > 0.0)
			res = 0.0;
		      else if (res < 0.0 && src < 0.0)
			res = 0.0;
		      /* else leave res alone.   */
		    }
		  else
		    res -= src;
		}

	      /* FIXME: Add handling of signalling NaNs and the E bit.  */

	      state->FPSCR &= 0x0FFFFFFF;
	      if (res < 0.0)
		state->FPSCR |= NBIT;
	      else
		state->FPSCR |= CBIT;
	      if (res == 0.0)
		state->FPSCR |= ZBIT;
	      if (isnan (res))
		state->FPSCR |= VBIT;

	      if (trace)
		fprintf (stderr, " VFP: VCMP (32bit) %g vs %g res %g, flags: %c%c%c%c\n",
			 VFP_fval (dest), BIT (16) ? 0.0 : VFP_fval (srcM), res,
			 state->FPSCR & NBIT ? 'N' : '-',
			 state->FPSCR & ZBIT ? 'Z' : '-',
			 state->FPSCR & CBIT ? 'C' : '-',
			 state->FPSCR & VBIT ? 'V' : '-');
	    }
	  return;

	case 0x7:
	  if (BIT (8))
	    {
	      dest = (DESTReg << 1) + BIT (22);
	      VFP_fval (dest) = VFP_dval (srcM);
	    }
	  else
	    {
	      dest = DESTReg + (BIT (22) << 4);
	      VFP_dval (dest) = VFP_fval (srcM);
	    }
	  return;

	case 0x8:
	case 0xC:
	case 0xD:
	  /* VCVT integer <-> FP */
	  if (BIT (18))
	    {
	      /* To integer.  */
	      if (BIT (8))
		{
		  dest = (BITS(12,15) << 1) + BIT (22);
		  if (BIT (16))
		    VFP_sword (dest) = VFP_dval (srcM);
		  else
		    VFP_uword (dest) = VFP_dval (srcM);
		}
	      else
		{
		  if (BIT (16))
		    VFP_sword (dest) = VFP_fval (srcM);
		  else
		    VFP_uword (dest) = VFP_fval (srcM);
		}
	    }
	  else
	    {
	      /* From integer.  */
	      if (BIT (8))
		{
		  srcM = (BITS (0,3) << 1) + BIT (5);
		  if (BIT (7))
		    VFP_dval (dest) = VFP_sword (srcM);
		  else
		    VFP_dval (dest) = VFP_uword (srcM);
		}
	      else
		{
		  if (BIT (7))
		    VFP_fval (dest) = VFP_sword (srcM);
		  else
		    VFP_fval (dest) = VFP_uword (srcM);
		}
	    }
	  return;
	}

      fprintf (stderr, "SIM: VFP: Unimplemented: Float op3: %03x\n", BITS (16,27));
      return;
    }

  fprintf (stderr, "SIM: VFP: Unimplemented: Float op2: %02x\n", BITS (20, 27));
  return;
}

/* This function does the Busy-Waiting for an CDP instruction.  */

void
ARMul_CDP (ARMul_State * state, ARMword instr)
{
  unsigned cpab;

  if (CPNum == 10 || CPNum == 11)
    {
      handle_VFP_op (state, instr);
      return;
    }

  if (! CP_ACCESS_ALLOWED (state, CPNum))
    {
      ARMul_UndefInstr (state, instr);
      return;
    }

  cpab = (state->CDP[CPNum]) (state, ARMul_FIRST, instr);
  while (cpab == ARMul_BUSY)
    {
      ARMul_Icycles (state, 1, 0);
      if (IntPending (state))
	{
	  cpab = (state->CDP[CPNum]) (state, ARMul_INTERRUPT, instr);
	  return;
	}
      else
	cpab = (state->CDP[CPNum]) (state, ARMul_BUSY, instr);
    }
  if (cpab == ARMul_CANT)
    ARMul_Abort (state, ARMul_UndefinedInstrV);
  else
    BUSUSEDN;
}

/* This function handles Undefined instructions, as CP isntruction.  */

void
ARMul_UndefInstr (ARMul_State * state, ARMword instr ATTRIBUTE_UNUSED)
{
  ARMul_Abort (state, ARMul_UndefinedInstrV);
}

/* Return TRUE if an interrupt is pending, FALSE otherwise.  */

unsigned
IntPending (ARMul_State * state)
{
  if (state->Exception)
    {
      /* Any exceptions.  */
      if (state->NresetSig == LOW)
	{
	  ARMul_Abort (state, ARMul_ResetV);
	  return TRUE;
	}
      else if (!state->NfiqSig && !FFLAG)
	{
	  ARMul_Abort (state, ARMul_FIQV);
	  return TRUE;
	}
      else if (!state->NirqSig && !IFLAG)
	{
	  ARMul_Abort (state, ARMul_IRQV);
	  return TRUE;
	}
    }

  return FALSE;
}

/* Align a word access to a non word boundary.  */

ARMword
ARMul_Align (ARMul_State *state ATTRIBUTE_UNUSED, ARMword address, ARMword data)
{
  /* This code assumes the address is really unaligned,
     as a shift by 32 is undefined in C.  */

  address = (address & 3) << 3;	/* Get the word address.  */
  return ((data >> address) | (data << (32 - address)));	/* rot right */
}

/* This routine is used to call another routine after a certain number of
   cycles have been executed. The first parameter is the number of cycles
   delay before the function is called, the second argument is a pointer
   to the function. A delay of zero doesn't work, just call the function.  */

void
ARMul_ScheduleEvent (ARMul_State * state, unsigned long delay,
		     unsigned (*what) (ARMul_State *))
{
  unsigned long when;
  struct EventNode *event;

  if (state->EventSet++ == 0)
    state->Now = ARMul_Time (state);
  when = (state->Now + delay) % EVENTLISTSIZE;
  event = (struct EventNode *) malloc (sizeof (struct EventNode));
  event->func = what;
  event->next = *(state->EventPtr + when);
  *(state->EventPtr + when) = event;
}

/* This routine is called at the beginning of
   every cycle, to envoke scheduled events.  */

void
ARMul_EnvokeEvent (ARMul_State * state)
{
  static unsigned long then;

  then = state->Now;
  state->Now = ARMul_Time (state) % EVENTLISTSIZE;
  if (then < state->Now)
    /* Schedule events.  */
    EnvokeList (state, then, state->Now);
  else if (then > state->Now)
    {
      /* Need to wrap around the list.  */
      EnvokeList (state, then, EVENTLISTSIZE - 1L);
      EnvokeList (state, 0L, state->Now);
    }
}

/* Envokes all the entries in a range.  */

static void
EnvokeList (ARMul_State * state, unsigned long from, unsigned long to)
{
  for (; from <= to; from++)
    {
      struct EventNode *anevent;

      anevent = *(state->EventPtr + from);
      while (anevent)
	{
	  (anevent->func) (state);
	  state->EventSet--;
	  anevent = anevent->next;
	}
      *(state->EventPtr + from) = NULL;
    }
}

/* This routine is returns the number of clock ticks since the last reset.  */

unsigned long
ARMul_Time (ARMul_State * state)
{
  return (state->NumScycles + state->NumNcycles +
	  state->NumIcycles + state->NumCcycles + state->NumFcycles);
}