interp.c

这个是LINUX下的GDB调度工具的源码

	    break;

	  case SYS_stat:	/* added at hmsi */
	    /* stat system call */
	    {
	      struct stat host_stat;
	      int buf;
	      int len = strswaplen (regs[5]);

	      strnswap (regs[5], len);
	      regs[0] = stat (ptr (regs[5]), &host_stat);
	      strnswap (regs[5], len);

	      buf = regs[6];

	      WWAT (buf, host_stat.st_dev);
	      buf += 2;
	      WWAT (buf, host_stat.st_ino);
	      buf += 2;
	      WLAT (buf, host_stat.st_mode);
	      buf += 4;
	      WWAT (buf, host_stat.st_nlink);
	      buf += 2;
	      WWAT (buf, host_stat.st_uid);
	      buf += 2;
	      WWAT (buf, host_stat.st_gid);
	      buf += 2;
	      WWAT (buf, host_stat.st_rdev);
	      buf += 2;
	      WLAT (buf, host_stat.st_size);
	      buf += 4;
	      WLAT (buf, host_stat.st_atime);
	      buf += 4;
	      WLAT (buf, 0);
	      buf += 4;
	      WLAT (buf, host_stat.st_mtime);
	      buf += 4;
	      WLAT (buf, 0);
	      buf += 4;
	      WLAT (buf, host_stat.st_ctime);
	      buf += 4;
	      WLAT (buf, 0);
	      buf += 4;
	      WLAT (buf, 0);
	      buf += 4;
	      WLAT (buf, 0);
	      buf += 4;
	    }
	    break;

#ifndef _WIN32
	  case SYS_chown:
	    {
	      int len = strswaplen (regs[5]);

	      strnswap (regs[5], len);
	      regs[0] = chown (ptr (regs[5]), regs[6], regs[7]);
	      strnswap (regs[5], len);
	      break;
	    }
#endif /* _WIN32 */
	  case SYS_chmod:
	    {
	      int len = strswaplen (regs[5]);

	      strnswap (regs[5], len);
	      regs[0] = chmod (ptr (regs[5]), regs[6]);
	      strnswap (regs[5], len);
	      break;
	    }
	  case SYS_utime:
	    {
	      /* Cast the second argument to void *, to avoid type mismatch
		 if a prototype is present.  */
	      int len = strswaplen (regs[5]);

	      strnswap (regs[5], len);
	      regs[0] = utime (ptr (regs[5]), (void *) ptr (regs[6]));
	      strnswap (regs[5], len);
	      break;
	    }
	  case SYS_argc:
	    regs[0] = count_argc (prog_argv);
	    break;
	  case SYS_argnlen:
	    if (regs[5] < count_argc (prog_argv))
	      regs[0] = strlen (prog_argv[regs[5]]);
	    else
	      regs[0] = -1;
	    break;
	  case SYS_argn:
	    if (regs[5] < count_argc (prog_argv))
	      {
		/* Include the termination byte.  */
		int i = strlen (prog_argv[regs[5]]) + 1;
		regs[0] = sim_write (0, regs[6], prog_argv[regs[5]], i);
	      }
	    else
	      regs[0] = -1;
	    break;
	  case SYS_time:
	    regs[0] = get_now ();
	    break;
	  case SYS_ftruncate:
	    regs[0] = callback->ftruncate (callback, regs[5], regs[6]);
	    break;
	  case SYS_truncate:
	    {
	      int len = strswaplen (regs[5]);
	      strnswap (regs[5], len);
	      regs[0] = callback->truncate (callback, ptr (regs[5]), regs[6]);
	      strnswap (regs[5], len);
	      break;
	    }
	  default:
	    regs[0] = -1;
	    break;
	  }
	regs[1] = callback->get_errno (callback);
	errno = perrno;
      }
      break;

    case 13:	/* Set IBNR */
      IBNR = regs[0] & 0xffff;
      break;
    case 14:	/* Set IBCR */
      IBCR = regs[0] & 0xffff;
      break;
    case 0xc3:
    case 255:
      raise_exception (SIGTRAP);
      if (i == 0xc3)
	return -2;
      break;
    }
  return 0;
}

void
control_c (sig, code, scp, addr)
     int sig;
     int code;
     char *scp;
     char *addr;
{
  raise_exception (SIGINT);
}

static int
div1 (R, iRn2, iRn1/*, T*/)
     int *R;
     int iRn1;
     int iRn2;
     /* int T;*/
{
  unsigned long tmp0;
  unsigned char old_q, tmp1;

  old_q = Q;
  SET_SR_Q ((unsigned char) ((0x80000000 & R[iRn1]) != 0));
  R[iRn1] <<= 1;
  R[iRn1] |= (unsigned long) T;

  switch (old_q)
    {
    case 0:
      switch (M)
	{
	case 0:
	  tmp0 = R[iRn1];
	  R[iRn1] -= R[iRn2];
	  tmp1 = (R[iRn1] > tmp0);
	  switch (Q)
	    {
	    case 0:
	      SET_SR_Q (tmp1);
	      break;
	    case 1:
	      SET_SR_Q ((unsigned char) (tmp1 == 0));
	      break;
	    }
	  break;
	case 1:
	  tmp0 = R[iRn1];
	  R[iRn1] += R[iRn2];
	  tmp1 = (R[iRn1] < tmp0);
	  switch (Q)
	    {
	    case 0:
	      SET_SR_Q ((unsigned char) (tmp1 == 0));
	      break;
	    case 1:
	      SET_SR_Q (tmp1);
	      break;
	    }
	  break;
	}
      break;
    case 1:
      switch (M)
	{
	case 0:
	  tmp0 = R[iRn1];
	  R[iRn1] += R[iRn2];
	  tmp1 = (R[iRn1] < tmp0);
	  switch (Q)
	    {
	    case 0:
	      SET_SR_Q (tmp1);
	      break;
	    case 1:
	      SET_SR_Q ((unsigned char) (tmp1 == 0));
	      break;
	    }
	  break;
	case 1:
	  tmp0 = R[iRn1];
	  R[iRn1] -= R[iRn2];
	  tmp1 = (R[iRn1] > tmp0);
	  switch (Q)
	    {
	    case 0:
	      SET_SR_Q ((unsigned char) (tmp1 == 0));
	      break;
	    case 1:
	      SET_SR_Q (tmp1);
	      break;
	    }
	  break;
	}
      break;
    }
  /*T = (Q == M);*/
  SET_SR_T (Q == M);
  /*return T;*/
}

static void
dmul (sign, rm, rn)
     int sign;
     unsigned int rm;
     unsigned int rn;
{
  unsigned long RnL, RnH;
  unsigned long RmL, RmH;
  unsigned long temp0, temp1, temp2, temp3;
  unsigned long Res2, Res1, Res0;

  RnL = rn & 0xffff;
  RnH = (rn >> 16) & 0xffff;
  RmL = rm & 0xffff;
  RmH = (rm >> 16) & 0xffff;
  temp0 = RmL * RnL;
  temp1 = RmH * RnL;
  temp2 = RmL * RnH;
  temp3 = RmH * RnH;
  Res2 = 0;
  Res1 = temp1 + temp2;
  if (Res1 < temp1)
    Res2 += 0x00010000;
  temp1 = (Res1 << 16) & 0xffff0000;
  Res0 = temp0 + temp1;
  if (Res0 < temp0)
    Res2 += 1;
  Res2 += ((Res1 >> 16) & 0xffff) + temp3;
  
  if (sign)
    {
      if (rn & 0x80000000)
	Res2 -= rm;
      if (rm & 0x80000000)
	Res2 -= rn;
    }

  MACH = Res2;
  MACL = Res0;
}

static void
macw (regs, memory, n, m, endianw)
     int *regs;
     unsigned char *memory;
     int m, n;
     int endianw;
{
  long tempm, tempn;
  long prod, macl, sum;

  tempm=RSWAT (regs[m]); regs[m]+=2;
  tempn=RSWAT (regs[n]); regs[n]+=2;

  macl = MACL;
  prod = (long) (short) tempm * (long) (short) tempn;
  sum = prod + macl;
  if (S)
    {
      if ((~(prod ^ macl) & (sum ^ prod)) < 0)
	{
	  /* MACH's lsb is a sticky overflow bit.  */
	  MACH |= 1;
	  /* Store the smallest negative number in MACL if prod is
	     negative, and the largest positive number otherwise.  */
	  sum = 0x7fffffff + (prod < 0);
	}
    }
  else
    {
      long mach;
      /* Add to MACH the sign extended product, and carry from low sum.  */
      mach = MACH + (-(prod < 0)) + ((unsigned long) sum < prod);
      /* Sign extend at 10:th bit in MACH.  */
      MACH = (mach & 0x1ff) | -(mach & 0x200);
    }
  MACL = sum;
}

static void
macl (regs, memory, n, m)
     int *regs;
     unsigned char *memory;
     int m, n;
{
  long tempm, tempn;
  long prod, macl, mach, sum;
  long long ans,ansl,ansh,t;
  unsigned long long high,low,combine;
  union mac64
  {
    long m[2]; /* mach and macl*/
    long long m64; /* 64 bit MAC */
  }mac64;

  tempm = RSLAT (regs[m]);
  regs[m] += 4;

  tempn = RSLAT (regs[n]);
  regs[n] += 4;

  mach = MACH;
  macl = MACL;

  mac64.m[0] = macl;
  mac64.m[1] = mach;

  ans = (long long) tempm * (long long) tempn; /* Multiply 32bit * 32bit */

  mac64.m64 += ans; /* Accumulate   64bit + 64 bit */

  macl = mac64.m[0];
  mach = mac64.m[1];

  if (S)  /* Store only 48 bits of the result */
    {
      if (mach < 0) /* Result is negative */
        {
          mach = mach & 0x0000ffff; /* Mask higher 16 bits */
          mach |= 0xffff8000; /* Sign extend higher 16 bits */
        }
      else
        mach = mach & 0x00007fff; /* Postive Result */
    }

  MACL = macl;
  MACH = mach;
}

enum {
  B_BCLR = 0,
  B_BSET = 1,
  B_BST  = 2,
  B_BLD  = 3,
  B_BAND = 4,
  B_BOR  = 5,
  B_BXOR = 6,
  B_BLDNOT = 11,
  B_BANDNOT = 12,
  B_BORNOT = 13,
  
  MOVB_RM = 0x0000,
  MOVW_RM = 0x1000,
  MOVL_RM = 0x2000,
  FMOV_RM = 0x3000,
  MOVB_MR = 0x4000,
  MOVW_MR = 0x5000,
  MOVL_MR = 0x6000,
  FMOV_MR = 0x7000,
  MOVU_BMR = 0x8000,
  MOVU_WMR = 0x9000,
};

/* Do extended displacement move instructions.  */
void
do_long_move_insn (int op, int disp12, int m, int n, int *thatlock)
{
  int memstalls = 0;
  int thislock = *thatlock;
  int endianw = global_endianw;
  int *R = &(saved_state.asregs.regs[0]);
  unsigned char *memory = saved_state.asregs.memory;
  int maskb = ~((saved_state.asregs.msize - 1) & ~0);
  unsigned char *insn_ptr = PT2H (saved_state.asregs.pc);

  switch (op) {
  case MOVB_RM:		/* signed */
    WBAT (disp12 * 1 + R[n], R[m]); 
    break;
  case MOVW_RM:
    WWAT (disp12 * 2 + R[n], R[m]); 
    break;
  case MOVL_RM:
    WLAT (disp12 * 4 + R[n], R[m]); 
    break;
  case FMOV_RM:		/* floating point */
    if (FPSCR_SZ) 
      {
        MA (1);
        WDAT (R[n] + 8 * disp12, m);
      }
    else 
      WLAT (R[n] + 4 * disp12, FI (m));
    break;
  case MOVB_MR:
    R[n] = RSBAT (disp12 * 1 + R[m]);
    L (n); 
    break;
  case MOVW_MR:
    R[n] = RSWAT (disp12 * 2 + R[m]);
    L (n); 
    break;
  case MOVL_MR:
    R[n] = RLAT (disp12 * 4 + R[m]);
    L (n); 
    break;
  case FMOV_MR:
    if (FPSCR_SZ) {
      MA (1);
      RDAT (R[m] + 8 * disp12, n);
    }
    else 
      SET_FI (n, RLAT (R[m] + 4 * disp12));
    break;
  case MOVU_BMR:	/* unsigned */
    R[n] = RBAT (disp12 * 1 + R[m]);
    L (n);
    break;
  case MOVU_WMR:
    R[n] = RWAT (disp12 * 2 + R[m]);
    L (n);
    break;
  default:
    RAISE_EXCEPTION (SIGINT);
    exit (1);
  }
  saved_state.asregs.memstalls += memstalls;
  *thatlock = thislock;
}

/* Do binary logical bit-manipulation insns.  */
void
do_blog_insn (int imm, int addr, int binop, 
	      unsigned char *memory, int maskb)
{
  int oldval = RBAT (addr);

  switch (binop) {
  case B_BCLR:	/* bclr.b */
    WBAT (addr, oldval & ~imm);
    break;
  case B_BSET:	/* bset.b */
    WBAT (addr, oldval | imm);
    break;
  case B_BST:	/* bst.b */
    if (T)
      WBAT (addr, oldval | imm);
    else
      WBAT (addr, oldval & ~imm);
    break;
  case B_BLD:	/* bld.b */
    SET_SR_T ((oldval & imm) != 0);
    break;
  case B_BAND:	/* band.b */
    SET_SR_T (T && ((oldval & imm) != 0));
    break;
  case B_BOR:	/* bor.b */
    SET_SR_T (T || ((oldval & imm) != 0));
    break;
  case B_BXOR:	/* bxor.b */
    SET_SR_T (T ^ ((oldval & imm) != 0));
    break;
  case B_BLDNOT:	/* bldnot.b */
    SET_SR_T ((oldval & imm) == 0);
    break;
  case B_BANDNOT:	/* bandnot.b */
    SET_SR_T (T && ((oldval & imm) == 0));
    break;
  case B_BORNOT:	/* bornot.b */
    SET_SR_T (T || ((oldval & imm) == 0));
    break;
  }
}
float
fsca_s (int in, double (*f) (double))
{
  double rad = ldexp ((in & 0xffff), -15) * 3.141592653589793238462643383;
  double result = (*f) (rad);
  double error, upper, lower, frac;
  int exp;

  /* Search the value with the maximum error that is still within the
     architectural spec.  */
  error = ldexp (1., -21);
  /* compensate for calculation inaccuracy by reducing error.  */
  error = error - ldexp (1., -50);
  upper = result + error;
  frac = frexp (upper, &exp);
  upper = ldexp (floor (ldexp (frac, 24)), exp - 24);
  lower = result - error;
  frac = frexp (lower, &exp);
  lower = ldexp (ceil (ldexp (frac, 24)), exp - 24);
  return abs (upper - result) >= abs (lower - result) ? upper : lower;
}

float
fsrra_s (float in)
{
  double result = 1. / sqrt (in);
  int exp;
  double frac, upper, lower, error, eps;

  /* refine result */
  result = result - (result * result * in - 1) * 0.5 * result;
  /* Search the value with the maximum error that is still within the
     architectural spec.  */
  frac = frexp (result, &exp);
  frac = ldexp (frac, 24);
  error = 4.0; /* 1 << 24-1-21 */
  /* use eps to compensate for possible 1 ulp error in our 'exact' result.  */
  eps = ldexp (1., -29);
  upper = floor (frac + error - eps);
  if (upper > 16777216.)
    upper = floor ((frac + error - eps) * 0.5) * 2.;
  lower = ceil ((frac - error + eps) * 2) * .5;
  if (lower > 8388608.)
    lower = ceil (frac - error + eps);
  upper = ldexp (upper, exp - 24);
  lower = ldexp (lower, exp - 24);