sc_nbdefs.hh

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

  sc_nbdefs.h -- Top level header file for arbitrary precision signed/unsigned
                 arithmetic. This file defines all the constants needed.

  Original Author: Ali Dasdan, Synopsys, Inc.

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

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

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

      Name, Affiliation, Date: Torsten Maehne, Berner Fachhochschule,
                               2016-09-24
  Description of Modification: Move constant definitions to the header so that
                               that their value is known at compile time.

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

// $Log: sc_nbdefs.h,v $
// Revision 1.7  2011/02/18 20:19:15  acg
//  Andy Goodrich: updating Copyright notice.
//
// Revision 1.6  2011/02/18 20:09:34  acg
//  Philipp A. Hartmann: added alternative #define for Windows to guard.
//
// Revision 1.5  2011/01/20 16:52:20  acg
//  Andy Goodrich: changes for IEEE 1666 2011.
//
// Revision 1.4  2010/02/08 18:35:55  acg
//  Andy Goodrich: Philipp Hartmann's changes for Solaris and Linux 64.
//
// Revision 1.2  2009/05/22 16:06:29  acg
//  Andy Goodrich: process control updates.
//
// Revision 1.1.1.1  2006/12/15 20:20:05  acg
// SystemC 2.3
//
// 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 __SYSTEMC_EXT_DT_INT_SC_NBDEFS_HH__
#define __SYSTEMC_EXT_DT_INT_SC_NBDEFS_HH__

#include <stdint.h>

#include <climits>

namespace sc_dt
{

// ----------------------------------------------------------------------------
//  ENUM : sc_numrep
//
//  Enumeration of number representations for character string conversion.
// ----------------------------------------------------------------------------

enum sc_numrep
{
    SC_NOBASE = 0,
    SC_BIN = 2,
    SC_OCT = 8,
    SC_DEC = 10,
    SC_HEX = 16,
    SC_BIN_US,
    SC_BIN_SM,
    SC_OCT_US,
    SC_OCT_SM,
    SC_HEX_US,
    SC_HEX_SM,
    SC_CSD
};


// Sign of a number:
#define SC_NEG -1 // Negative number
#define SC_ZERO 0 // Zero
#define SC_POS 1 // Positive number
#define SC_NOSIGN 2 // Uninitialized sc_signed number

typedef unsigned char uchar;

// A small_type number is at least a char. Defining an int is probably
// better for alignment.
typedef int small_type;

// Attributes of a byte.
#define BITS_PER_BYTE 8
#define BYTE_RADIX 256
#define BYTE_MASK 255

// LOG2_BITS_PER_BYTE = log2(BITS_PER_BYTE), assuming that
// BITS_PER_BYTE is a power of 2.
#define LOG2_BITS_PER_BYTE 3

// Attributes of the unsigned long. These definitions are used mainly in
// the functions that are aware of the internal representation of
// digits, e.g., get/set_packed_rep().
#define BYTES_PER_DIGIT_TYPE 4
#define BITS_PER_DIGIT_TYPE 32

// Attributes of a digit, i.e., unsigned long less the overflow bits.
#define BYTES_PER_DIGIT 4
#define BITS_PER_DIGIT 30
#define DIGIT_RADIX (1ul << BITS_PER_DIGIT)
#define DIGIT_MASK (DIGIT_RADIX - 1)
// Make sure that BYTES_PER_DIGIT = ceil(BITS_PER_DIGIT / BITS_PER_BYTE).

// Similar attributes for the half of a digit. Note that
// HALF_DIGIT_RADIX is equal to the square root of DIGIT_RADIX. These
// definitions are used mainly in the multiplication routines.
#define BITS_PER_HALF_DIGIT (BITS_PER_DIGIT / 2)
#define HALF_DIGIT_RADIX (1ul << BITS_PER_HALF_DIGIT)
#define HALF_DIGIT_MASK (HALF_DIGIT_RADIX - 1)

// DIV_CEIL2(x, y) = ceil(x / y). x and y are positive numbers.
#define DIV_CEIL2(x, y) (((x) - 1) / (y) + 1)

// DIV_CEIL(x) = ceil(x / BITS_PER_DIGIT) = the number of digits to
// store x bits. x is a positive number.
#define DIV_CEIL(x) DIV_CEIL2(x, BITS_PER_DIGIT)

#ifdef SC_MAX_NBITS
static const int MAX_NDIGITS = DIV_CEIL(SC_MAX_NBITS) + 2;
// Consider a number with x bits another with y bits. The maximum
// number of bits happens when we multiply them. The result will have
// (x + y) bits. Assume that x + y <= SC_MAX_NBITS. Then, DIV_CEIL(x) +
// DIV_CEIL(y) <= DIV_CEIL(SC_MAX_NBITS) + 2. This is the reason for +2
// above. With this change, MAX_NDIGITS must be enough to hold the
// result of any operation.
#endif

// Support for "digit" vectors used to hold the values of sc_signed,
// sc_unsigned, sc_bv_base,  and sc_lv_base data types. This type is also used
// in the concatenation support. An sc_digit is currently an unsigned 32-bit
// quantity. The typedef used is an unsigned int, rather than an unsigned long,
// since the unsigned long data type varies in size between 32-bit and 64-bit
// machines.

typedef unsigned int sc_digit; // 32-bit unsigned integer

// Support for the long long type. This type is not in the standard
// but is usually supported by compilers.
#if defined(__x86_64__) || defined(__aarch64__)
typedef long long int64;
typedef unsigned long long uint64;
#else
typedef int64_t int64;
typedef uint64_t uint64;
#endif

static const uint64 UINT64_ZERO = 0ULL;
static const uint64 UINT64_ONE = 1ULL;
static const uint64 UINT64_32ONES = 0x00000000ffffffffULL;


// Bits per ...
// will be deleted in the future. Use numeric_limits instead
#define BITS_PER_CHAR 8
#define BITS_PER_INT (sizeof(int) * BITS_PER_CHAR)
#define BITS_PER_LONG (sizeof(long) * BITS_PER_CHAR)
#define BITS_PER_INT64 (sizeof(::sc_dt::int64) * BITS_PER_CHAR)
#define BITS_PER_UINT (sizeof(unsigned int) * BITS_PER_CHAR)
#define BITS_PER_ULONG (sizeof(unsigned long) * BITS_PER_CHAR)
#define BITS_PER_UINT64 (sizeof(::sc_dt::uint64) * BITS_PER_CHAR)

// Digits per ...
#define DIGITS_PER_CHAR 1
#define DIGITS_PER_INT ((BITS_PER_INT + 29) / 30)
#define DIGITS_PER_LONG ((BITS_PER_LONG + 29) / 30)
#define DIGITS_PER_INT64 ((BITS_PER_INT64 + 29) / 30)
#define DIGITS_PER_UINT ((BITS_PER_UINT + 29) / 30)
#define DIGITS_PER_ULONG ((BITS_PER_ULONG + 29) / 30)
#define DIGITS_PER_UINT64 ((BITS_PER_UINT64 + 29) / 30)

// Above, BITS_PER_X is mainly used for sc_signed, and BITS_PER_UX is
// mainly used for sc_unsigned.

static const small_type NB_DEFAULT_BASE = SC_DEC;

// For sc_int code:

typedef int64 int_type;
typedef uint64 uint_type;
#define SC_INTWIDTH 64
static const uint64 UINT_ZERO = UINT64_ZERO;
static const uint64 UINT_ONE = UINT64_ONE;

} // namespace sc_dt

#endif // __SYSTEMC_EXT_DT_INT_SC_NBDEFS_HH__