sc_nbutils.h

system C源码 一种替代verilog的语言

#ifdef DEBUG_SYSTEMC
  assert((n > 0) && (u != NULL) && (v != NULL));
#endif

  for (register int i = 0; i < n; ++i)
    u[i] = v[i];
}

// Copy v to u, where ulen >= vlen, and zero the rest of the digits in u.
inline
void
vec_copy_and_zero(int ulen, sc_digit *u, 
                  int vlen, const sc_digit *v)
{

#ifdef DEBUG_SYSTEMC
  assert((ulen > 0) && (u != NULL));
  assert((vlen > 0) && (v != NULL));
  assert(ulen >= vlen);
#endif

  vec_copy(vlen, u, v);
  vec_zero(vlen, ulen, u);

}

// 2's-complement the digits in u.
inline
void
vec_complement(int ulen, sc_digit *u)
{

#ifdef DEBUG_SYSTEMC
  assert((ulen > 0) && (u != NULL));
#endif

  register sc_digit carry = 1;

  for (register int i = 0; i < ulen; ++i) {
    carry += (~u[i] & DIGIT_MASK);
    u[i] = carry & DIGIT_MASK;
    carry >>= BITS_PER_DIGIT;
  }
  
}


// ----------------------------------------------------------------------------
//  Functions to handle built-in types or signs.
// ----------------------------------------------------------------------------

// u = v
// - v is an unsigned long or uint64, and positive integer.
template< class Type >
inline
void
from_uint(int ulen, sc_digit *u, Type v)
{

#ifdef DEBUG_SYSTEMC
  // assert((ulen <= 0) || (u != NULL));
  assert((ulen > 0) && (u != NULL));
  assert(v >= 0);
#endif

  register int i = 0;

  while (v && (i < ulen)) {
#ifndef WIN32
    u[i++] = static_cast<sc_digit>( v & DIGIT_MASK );
#else
    u[i++] = ((sc_digit) v) & DIGIT_MASK;
#endif
    v >>= BITS_PER_DIGIT;
  }

  vec_zero(i, ulen, u);

}


// Get u's sign and return its absolute value.
// u can be long, unsigned long, int64, or uint64.
template< class Type >
inline
small_type
get_sign(Type &u) 
{
  if (u > 0)
    return SC_POS;

  else if (u == 0)
    return SC_ZERO;

  else {
    u = -u;
    return SC_NEG;
  }
}


// Return us * vs:
// - Return SC_ZERO if either sign is SC_ZERO.
// - Return SC_POS if us == vs
// - Return SC_NEG if us != vs.
inline
small_type
mul_signs(small_type us, small_type vs)
{
  if ((us == SC_ZERO) || (vs == SC_ZERO))
    return SC_ZERO;

  if (us == vs)
    return SC_POS;

  return SC_NEG;
}


// ----------------------------------------------------------------------------
//  Functions to test for errors and print out error messages.
// ----------------------------------------------------------------------------

#ifdef SC_MAX_NBITS

inline
void
test_bound(int nb)
{
  if (nb > SC_MAX_NBITS) {
      char msg[BUFSIZ];
      std::sprintf( msg, "test_bound( int nb ) : "
	       "nb = %d > SC_MAX_NBITS = %d is not valid",
	       nb, SC_MAX_NBITS );
      SC_REPORT_ERROR( sc_core::SC_ID_OUT_OF_BOUNDS_, msg );
  }
}

#endif

template< class Type >
inline
void
div_by_zero(Type s)
{
  if (s == 0) {
      SC_REPORT_ERROR( sc_core::SC_ID_OPERATION_FAILED_,
		       "div_by_zero<Type>( Type ) : division by zero" );
  }
}


// ----------------------------------------------------------------------------
//  Functions to check if a given vector is zero or make one.
// ----------------------------------------------------------------------------

// If u[i] is zero for every i = 0,..., ulen - 1, return SC_ZERO,
// else return s.
inline
small_type 
check_for_zero(small_type s, int ulen, const sc_digit *u)
{

#ifdef DEBUG_SYSTEMC
  // assert(ulen >= 0);
  assert((ulen > 0) && (u != NULL));
#endif

  if (vec_find_first_nonzero(ulen, u) < 0)
    return SC_ZERO;  

  return s;

}

// If u[i] is zero for every i = 0,..., ulen - 1, return true,
// else return false.
inline
bool
check_for_zero(int ulen, const sc_digit *u)
{

#ifdef DEBUG_SYSTEMC
  // assert(ulen >= 0);
  assert((ulen > 0) && (u != NULL));
#endif

  if (vec_find_first_nonzero(ulen, u) < 0)
    return true;

  return false;

}

inline
small_type
make_zero(int nd, sc_digit *d)
{
  vec_zero(nd, d);
  return SC_ZERO;
}


// ----------------------------------------------------------------------------
//  Functions for both signed and unsigned numbers to convert sign-magnitude
//  (SM) and 2's complement (2C) representations.
//  added = 1 => for signed.
//  added = 0 => for unsigned.
//  IF_SC_SIGNED can be used as 'added'.
// ----------------------------------------------------------------------------

// Trim the extra leading bits of a signed or unsigned number.
inline
void
trim(small_type added, int nb, int nd, sc_digit *d)
{
#ifdef DEBUG_SYSTEMC
  assert((nb > 0) && (nd > 0) && (d != NULL));
#endif

  d[nd - 1] &= one_and_ones(bit_ord(nb - 1) + added);    
}

// Convert an (un)signed number from sign-magnitude representation to
// 2's complement representation and trim the extra bits.
inline
void
convert_SM_to_2C_trimmed(small_type added, 
                         small_type s, int nb, int nd, sc_digit *d)
{
  if (s == SC_NEG) {
    vec_complement(nd, d);
    trim(added, nb, nd, d);
  }
}

// Convert an (un)signed number from sign-magnitude representation to
// 2's complement representation but do not trim the extra bits.
inline
void
convert_SM_to_2C(small_type s, int nd, sc_digit *d)
{
  if (s == SC_NEG)
    vec_complement(nd, d);
}


// ----------------------------------------------------------------------------
//  Functions to convert between sign-magnitude (SM) and 2's complement
//  (2C) representations of signed numbers.
// ----------------------------------------------------------------------------

// Trim the extra leading bits off a signed number.
inline
void
trim_signed(int nb, int nd, sc_digit *d)
{
#ifdef DEBUG_SYSTEMC
  assert((nb > 0) && (nd > 0) && (d != NULL));
#endif

  d[nd - 1] &= one_and_ones(bit_ord(nb - 1) + 1);
}

// Convert a signed number from 2's complement representation to
// sign-magnitude representation, and return its sign. nd is d's
// actual size, without zeros eliminated.
inline
small_type
convert_signed_2C_to_SM(int nb, int nd, sc_digit *d)
{

#ifdef DEBUG_SYSTEMC
  assert((nb > 0) && (nd > 0) && (d != NULL));
#endif

  small_type s;

  int xnb = bit_ord(nb - 1) + 1;

  // Test the sign bit.  
  if (d[nd - 1] & one_and_zeros(xnb - 1)) {
    s = SC_NEG;
    vec_complement(nd, d);
  }
  else
    s = SC_POS;

  // Trim the last digit.
  d[nd - 1] &= one_and_ones(xnb);

  // Check if the new number is zero.
  if (s == SC_POS)
    return check_for_zero(s, nd, d);

  return s;

}

// Convert a signed number from sign-magnitude representation to 2's
// complement representation, get its sign, convert back to
// sign-magnitude representation, and return its sign. nd is d's
// actual size, without zeros eliminated.
inline
small_type 
convert_signed_SM_to_2C_to_SM(small_type s, int nb, int nd, sc_digit *d)
{
  convert_SM_to_2C(s, nd, d);
  return convert_signed_2C_to_SM(nb, nd, d);
}

// Convert a signed number from sign-magnitude representation to 2's
// complement representation and trim the extra bits.
inline
void
convert_signed_SM_to_2C_trimmed(small_type s, int nb, int nd, sc_digit *d)
{
  convert_SM_to_2C_trimmed(1, s, nb, nd, d);
}

// Convert a signed number from sign-magnitude representation to 2's
// complement representation but do not trim the extra bits.
inline
void
convert_signed_SM_to_2C(small_type s, int nd, sc_digit *d)
{
  convert_SM_to_2C(s, nd, d);
}


// ----------------------------------------------------------------------------
//  Functions to convert between sign-magnitude (SM) and 2's complement
//  (2C) representations of unsigned numbers.
// ----------------------------------------------------------------------------

// Trim the extra leading bits off an unsigned number.
inline
void
trim_unsigned(int nb, int nd, sc_digit *d)
{
#ifdef DEBUG_SYSTEMC
  assert((nb > 0) && (nd > 0) && (d != NULL));
#endif

  d[nd - 1] &= one_and_ones(bit_ord(nb - 1));    
}

// Convert an unsigned number from 2's complement representation to
// sign-magnitude representation, and return its sign. nd is d's
// actual size, without zeros eliminated.
inline
small_type
convert_unsigned_2C_to_SM(int nb, int nd, sc_digit *d)
{
  trim_unsigned(nb, nd, d);
  return check_for_zero(SC_POS, nd, d);
}

// Convert an unsigned number from sign-magnitude representation to
// 2's complement representation, get its sign, convert back to
// sign-magnitude representation, and return its sign. nd is d's
// actual size, without zeros eliminated.
inline
small_type
convert_unsigned_SM_to_2C_to_SM(small_type s, int nb, int nd, sc_digit *d)
{
  convert_SM_to_2C(s, nd, d);
  return convert_unsigned_2C_to_SM(nb, nd, d);
}

// Convert an unsigned number from sign-magnitude representation to
// 2's complement representation and trim the extra bits.
inline
void
convert_unsigned_SM_to_2C_trimmed(small_type s, int nb, int nd, sc_digit *d)
{
  convert_SM_to_2C_trimmed(0, s, nb, nd, d);
}

// Convert an unsigned number from sign-magnitude representation to
// 2's complement representation but do not trim the extra bits.
inline
void
convert_unsigned_SM_to_2C(small_type s, int nd, sc_digit *d)
{
  convert_SM_to_2C(s, nd, d);
}


// ----------------------------------------------------------------------------
//  Functions to copy one (un)signed number to another.
// ----------------------------------------------------------------------------

// Copy v to u.
inline
void
copy_digits_signed(small_type &us, 
                   int unb, int und, sc_digit *ud,
                   int vnb, int vnd, const sc_digit *vd)
{

  if (und <= vnd) {

    vec_copy(und, ud, vd);

    if (unb <= vnb)
      us = convert_signed_SM_to_2C_to_SM(us, unb, und, ud);

  }
  else // und > vnd
    vec_copy_and_zero(und, ud, vnd, vd);

}

// Copy v to u.
inline
void
copy_digits_unsigned(small_type &us, 
                     int unb, int und, sc_digit *ud,
                     int vnb, int vnd, const sc_digit *vd)
{

  if (und <= vnd)
    vec_copy(und, ud, vd);

  else // und > vnd
    vec_copy_and_zero(und, ud, vnd, vd);

  us = convert_unsigned_SM_to_2C_to_SM(us, unb, und, ud);

}


// ----------------------------------------------------------------------------
//  Faster set(i, v), without bound checking.
// ----------------------------------------------------------------------------

// A version of set(i, v) without bound checking.
inline
void
safe_set(int i, bool v, sc_digit *d)
{

#ifdef DEBUG_SYSTEMC
  assert((i >= 0) && (d != NULL));
#endif

  int bit_num = bit_ord(i);
  int digit_num = digit_ord(i);    
  
  if (v)
    d[digit_num] |= one_and_zeros(bit_num);      
  else
    d[digit_num] &= ~(one_and_zeros(bit_num));
  
}


// ----------------------------------------------------------------------------
//  Function to check if a double number is bad (NaN or infinite).
// ----------------------------------------------------------------------------

inline
void
is_bad_double(double v)
{
// Windows throws exception.
#if !defined(WIN32) && !defined(i386) && !defined(__x86_64__) && !defined( __EDG__ )
#if defined( __hpux ) && defined( isfinite )
  // HP-UX 11.00 does not have finite anymore
  if( ! isfinite( v ) ) {
#else
  if (! finite(v)) {
#endif
      SC_REPORT_ERROR( sc_core::SC_ID_VALUE_NOT_VALID_,
		       "is_bad_double( double v ) : "
		       "v is not finite - NaN or Inf" );
  }
#endif
}

} // namespace sc_dt


#endif