sc_nbutils.h

system C源码 一种替代verilog的语言

/*****************************************************************************

  The following code is derived, directly or indirectly, from the SystemC
  source code Copyright (c) 1996-2006 by all Contributors.
  All Rights reserved.

  The contents of this file are subject to the restrictions and limitations
  set forth in the SystemC Open Source License Version 2.4 (the "License");
  You may not use this file except in compliance with such restrictions and
  limitations. You may obtain instructions on how to receive a copy of the
  License at http://www.systemc.org/. Software distributed by Contributors
  under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
  ANY KIND, either express or implied. See the License for the specific
  language governing rights and limitations under the License.

 *****************************************************************************/

/*****************************************************************************

  sc_nbutils.h -- External and friend functions for both sc_signed and
                  sc_unsigned classes.

  Original Author: Ali Dasdan, Synopsys, Inc.
 
 *****************************************************************************/

/*****************************************************************************

  MODIFICATION LOG - modifiers, enter your name, affiliation, date and
  changes you are making here.

      Name, Affiliation, Date:
  Description of Modification:

 *****************************************************************************/

// $Log: sc_nbutils.h,v $
// Revision 1.1.1.1  2006/12/15 20:31:36  acg
// SystemC 2.2
//
// Revision 1.3  2006/01/13 18:49:32  acg
// Added $Log command so that CVS check in comments are reproduced in the
// source.
//

#ifndef SC_NBUTILS_H
#define SC_NBUTILS_H


#if !defined(__ppc__) && !defined(_MSC_VER) && !defined(__x86_64__) && !defined(i386) && !defined(__hpux) && !defined( __BORLANDC__ )
#include <ieeefp.h>
#else
#include <cmath>
#endif

#include "sysc/datatypes/bit/sc_bit_ids.h"
#include "sysc/datatypes/int/sc_int_ids.h"
#include "sysc/datatypes/int/sc_nbdefs.h"
#include "sysc/utils/sc_string.h"
#include "sysc/utils/sc_report.h"


namespace sc_dt
{

inline
void
is_valid_base(sc_numrep base)
{
  switch (base) {
    case SC_NOBASE: case SC_BIN: 
    case SC_OCT: case SC_DEC: 
    case SC_HEX: 
        break;
    case SC_BIN_US: case SC_BIN_SM: 
    case SC_OCT_US: case SC_OCT_SM:
    case SC_HEX_US: case SC_HEX_SM:
      SC_REPORT_ERROR( sc_core::SC_ID_NOT_IMPLEMENTED_,
		       "is_valid_base( sc_numrep base ) : "
		       "base ending in _US and _SM is not supported yet" );
    default:
      char msg[BUFSIZ];
      std::sprintf( msg, "is_valid_base( sc_numrep base ) : "
	       "base = %s is not valid",
	       to_string( base ).c_str() );
      SC_REPORT_ERROR( sc_core::SC_ID_VALUE_NOT_VALID_, msg );
  }
}

// One transition of the FSM to find base and sign of a number.
extern
small_type 
fsm_move(char c, small_type &b, small_type &s, small_type &state);

// Parse a character string into its equivalent binary bits.
extern
void parse_binary_bits( 
    const char* src_p, int dst_n, sc_digit* data_p, sc_digit* ctrl_p=0
);


// Parse a character string into its equivalent hexadecimal bits.
extern
void parse_hex_bits( 
    const char* src_p, int dst_n, sc_digit* data_p, sc_digit* ctrl_p=0
);


// Find the base and sign of a number in v.
extern 
const char *
get_base_and_sign(const char *v, small_type &base, small_type &sign);

// Create a number out of v in base.
extern 
small_type 
vec_from_str(int unb, int und, sc_digit *u, 
             const char *v, sc_numrep base = SC_NOBASE) ;


// ----------------------------------------------------------------------------
//  Naming convention for the vec_ functions below:
//    vec_OP(u, v, w)  : computes w = u OP v.
//    vec_OP_on(u, v)  : computes u = u OP v if u has more digits than v.
//    vec_OP_on2(u, v) : computes u = u OP v if u has fewer digits than v.
//    _large           : parameters are vectors.
//    _small           : one of the parameters is a single digit.
//    Xlen             : the number of digits in X.
// ----------------------------------------------------------------------------

// ----------------------------------------------------------------------------
//  Functions for vector addition: w = u + v or u += v.
// ----------------------------------------------------------------------------

extern 
void 
vec_add(int ulen, const sc_digit *u, 
        int vlen, const sc_digit *v, sc_digit *w);

extern 
void 
vec_add_on(int ulen, sc_digit *u, 
           int vlen, const sc_digit *v);

extern 
void 
vec_add_on2(int ulen, sc_digit *u, 
            int vlen, const sc_digit *v);

extern 
void 
vec_add_small(int ulen, const sc_digit *u,
              sc_digit v, sc_digit *w);

extern 
void 
vec_add_small_on(int ulen, sc_digit *u, sc_digit v);


// ----------------------------------------------------------------------------
//  Functions for vector subtraction: w = u - v, u -= v, or u = v - u.
// ----------------------------------------------------------------------------

extern 
void 
vec_sub(int ulen, const sc_digit *u, 
        int vlen, const sc_digit *v, sc_digit *w);

extern 
void 
vec_sub_on(int ulen, sc_digit *u, 
           int vlen, const sc_digit *v);

extern 
void 
vec_sub_on2(int ulen, sc_digit *u,
            int vlen, const sc_digit *v);

extern 
void 
vec_sub_small(int ulen, const sc_digit *u,
              sc_digit v, sc_digit *w);

extern 
void 
vec_sub_small_on(int ulen, sc_digit *u, sc_digit v);


// ----------------------------------------------------------------------------
//  Functions for vector multiplication: w = u * v or u *= v.
// ----------------------------------------------------------------------------

extern 
void 
vec_mul(int ulen, const sc_digit *u, 
        int vlen, const sc_digit *v, sc_digit *w);

extern 
void 
vec_mul_small(int ulen, const sc_digit *u,
              sc_digit v, sc_digit *w);

extern 
void 
vec_mul_small_on(int ulen, sc_digit *u, sc_digit v);


// ----------------------------------------------------------------------------
//  Functions for vector division: w = u / v.
// ----------------------------------------------------------------------------

extern 
void 
vec_div_large(int ulen, const sc_digit *u, 
              int vlen, const sc_digit *v, sc_digit *w);

extern 
void 
vec_div_small(int ulen, const sc_digit *u, 
              sc_digit v, sc_digit *w);


// ----------------------------------------------------------------------------
//  Functions for vector remainder: w = u % v or u %= v.
// ----------------------------------------------------------------------------

extern 
void 
vec_rem_large(int ulen, const sc_digit *u, 
              int vlen, const sc_digit *v, sc_digit *w);

extern 
sc_digit 
vec_rem_small(int ulen, const sc_digit *u, sc_digit v);

extern 
sc_digit 
vec_rem_on_small(int ulen, sc_digit *u, sc_digit v);


// ----------------------------------------------------------------------------
//  Functions to convert between vectors of char and sc_digit.
// ----------------------------------------------------------------------------

extern 
int 
vec_to_char(int ulen, const sc_digit *u, 
            int vlen, uchar *v);

extern 
void 
vec_from_char(int ulen, const uchar *u,
              int vlen, sc_digit *v);


// ----------------------------------------------------------------------------
//  Functions to shift left or right, or to create a mirror image of vectors.
// ----------------------------------------------------------------------------

extern 
void 
vec_shift_left(int ulen, sc_digit *u, int nsl);

extern 
void 
vec_shift_right(int vlen, sc_digit *u, int nsr, sc_digit fill = 0);

extern
void 
vec_reverse(int unb, int und, sc_digit *ud, 
            int l, int r = 0);


// ----------------------------------------------------------------------------
//  Various utility functions. 
// ----------------------------------------------------------------------------

// Return the low half part of d.
inline 
sc_digit 
low_half(sc_digit d) 
{
  return (d & HALF_DIGIT_MASK);
}

// Return the high half part of d. The high part of the digit may have
// more bits than BITS_PER_HALF_DIGIT due to, e.g., overflow in the
// multiplication. Hence, in other functions that use high_half(),
// make sure that the result contains BITS_PER_HALF_DIGIT if
// necessary. This is done by high_half_masked().
inline 
sc_digit 
high_half(sc_digit d) 
{
  return (d >> BITS_PER_HALF_DIGIT);
}

inline
sc_digit
high_half_masked(sc_digit d)
{
  return (high_half(d) & HALF_DIGIT_MASK);
}

// Concatenate the high part h and low part l. Assumes that h and l
// are less than or equal to HALF_DIGIT_MASK;
inline 
sc_digit 
concat(sc_digit h, sc_digit l) 
{
  return ((h << BITS_PER_HALF_DIGIT) | l);
}

// Create a number with n 1's.
inline
sc_digit
one_and_ones(int n)
{
  return (((sc_digit) 1 << n) - 1);
}

// Create a number with one 1 and n 0's.
inline
sc_digit
one_and_zeros(int n)
{
  return ((sc_digit) 1 << n);
}


// ----------------------------------------------------------------------------

// Find the digit that bit i is in.
inline
int 
digit_ord(int i)
{
  return (i / BITS_PER_DIGIT);
}

// Find the bit in digit_ord(i) that bit i corressponds to.
inline
int 
bit_ord(int i)
{
  return (i % BITS_PER_DIGIT);
}


// ----------------------------------------------------------------------------
//  Functions to compare, zero, complement vector(s).
// ----------------------------------------------------------------------------

// Compare u and v and return r
//  r = 0 if u == v
//  r < 0 if u < v
//  r > 0 if u > v
// - Assume that all the leading zero digits are already skipped.
// - ulen and/or vlen can be zero.
// - Every digit is less than or equal to DIGIT_MASK;
inline 
int
vec_cmp(int ulen, const sc_digit *u, 
        int vlen, const sc_digit *v)
{

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

  // ulen and vlen can be equal to 0 because vec_cmp can be called
  // after vec_skip_leading_zeros.
  assert((ulen >= 0) && (u != NULL));
  assert((vlen >= 0) && (v != NULL));
  // If ulen > 0, then the leading digit of u must be non-zero.
  assert((ulen <= 0) || (u[ulen - 1] != 0));
  assert((vlen <= 0) || (v[vlen - 1] != 0));
#endif

  if (ulen != vlen)
    return (ulen - vlen);

  // ulen == vlen >= 1
  while ((--ulen >= 0) && (u[ulen] == v[ulen]))
    ;

  if (ulen < 0)
    return 0;

#ifdef DEBUG_SYSTEMC
  // Test to see if the result is wrong due to the presence of
  // overflow bits.
  assert((u[ulen] & DIGIT_MASK) != (v[ulen] & DIGIT_MASK));
#endif

  return (int) (u[ulen] - v[ulen]);

}

// Find the index of the first non-zero digit.
// - ulen (before) = the number of digits in u.
// - the returned value = the index of the first non-zero digit. 
// A negative value of -1 indicates that every digit in u is zero.
inline
int
vec_find_first_nonzero(int ulen, const sc_digit *u)
{

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

  while ((--ulen >= 0) && (! u[ulen]))
    ;

  return ulen;
  
}

// Skip all the leading zero digits.  
// - ulen (before) = the number of digits in u.
// - the returned value = the number of non-zero digits in u.
// - the returned value is non-negative.
inline 
int
vec_skip_leading_zeros(int ulen, const sc_digit *u)
{

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

  return (1 + vec_find_first_nonzero(ulen, u));

}

// Compare u and v and return r
//  r = 0 if u == v
//  r < 0 if u < v
//  r > 0 if u > v
inline 
int 
vec_skip_and_cmp(int ulen, const sc_digit *u, 
                 int vlen, const sc_digit *v)
{

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

  ulen = vec_skip_leading_zeros(ulen, u);
  vlen = vec_skip_leading_zeros(vlen, v);
  // ulen and/or vlen can be equal to zero here.
  return vec_cmp(ulen, u, vlen, v);

}

// Set u[i] = 0 where i = from ... (ulen - 1).
inline
void
vec_zero(int from, int ulen, sc_digit *u)
{

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

  for(int i = from; i < ulen; i++)
    u[i] = 0;

}

// Set u[i] = 0 where i = 0 .. (ulen - 1).
inline
void
vec_zero(int ulen, sc_digit *u)
{
  vec_zero(0, ulen, u);
}

// Copy n digits from v to u.
inline
void
vec_copy(int n, sc_digit *u, const sc_digit *v)
{