sc_nbdefs.hh revision 12837
1/***************************************************************************** 2 3 Licensed to Accellera Systems Initiative Inc. (Accellera) under one or 4 more contributor license agreements. See the NOTICE file distributed 5 with this work for additional information regarding copyright ownership. 6 Accellera licenses this file to you under the Apache License, Version 2.0 7 (the "License"); you may not use this file except in compliance with the 8 License. You may obtain a copy of the License at 9 10 http://www.apache.org/licenses/LICENSE-2.0 11 12 Unless required by applicable law or agreed to in writing, software 13 distributed under the License is distributed on an "AS IS" BASIS, 14 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 15 implied. See the License for the specific language governing 16 permissions and limitations under the License. 17 18 *****************************************************************************/ 19 20/***************************************************************************** 21 sc_nbdefs.h -- Top level header file for arbitrary precision signed/unsigned 22 arithmetic. This file defines all the constants needed. 23 *****************************************************************************/ 24 25#ifndef __SYSTEMC_DT_SC_NBDEFS_H__ 26#define __SYSTEMC_DT_SC_NBDEFS_H__ 27 28#include <stdint.h> 29 30#include <climits> 31 32namespace sc_dt 33{ 34 35// ---------------------------------------------------------------------------- 36// ENUM : sc_numrep 37// 38// Enumeration of number representations for character string conversion. 39// ---------------------------------------------------------------------------- 40 41enum sc_numrep 42{ 43 SC_NOBASE = 0, 44 SC_BIN = 2, 45 SC_OCT = 8, 46 SC_DEC = 10, 47 SC_HEX = 16, 48 SC_BIN_US, 49 SC_BIN_SM, 50 SC_OCT_US, 51 SC_OCT_SM, 52 SC_HEX_US, 53 SC_HEX_SM, 54 SC_CSD 55}; 56 57 58// Sign of a number: 59#define SC_NEG -1 // Negative number 60#define SC_ZERO 0 // Zero 61#define SC_POS 1 // Positive number 62#define SC_NOSIGN 2 // Uninitialized sc_signed number 63 64typedef unsigned char uchar; 65 66// A small_type number is at least a char. Defining an int is probably 67// better for alignment. 68typedef int small_type; 69 70// Attributes of a byte. 71#define BITS_PER_BYTE 8 72#define BYTE_RADIX 256 73#define BYTE_MASK 255 74 75// LOG2_BITS_PER_BYTE = log2(BITS_PER_BYTE), assuming that 76// BITS_PER_BYTE is a power of 2. 77#define LOG2_BITS_PER_BYTE 3 78 79// Attributes of the unsigned long. These definitions are used mainly in 80// the functions that are aware of the internal representation of digits, 81// e.g., get/set_packed_rep(). 82#define BYTES_PER_DIGIT_TYPE 4 83#define BITS_PER_DIGIT_TYPE 32 84 85// Attributes of a digit, i.e., unsigned long less the overflow bits. 86#define BYTES_PER_DIGIT 4 87#define BITS_PER_DIGIT 30 88#define DIGIT_RADIX (1ul << BITS_PER_DIGIT) 89#define DIGIT_MASK (DIGIT_RADIX - 1) 90// Make sure that BYTES_PER_DIGIT = ceil(BITS_PER_DIGIT / BITS_PER_BYTE). 91 92// Similar attributes for the half of a digit. Note that 93// HALF_DIGIT_RADIX is equal to the square root of DIGIT_RADIX. These 94// definitions are used mainly in the multiplication routines. 95#define BITS_PER_HALF_DIGIT (BITS_PER_DIGIT / 2) 96#define HALF_DIGIT_RADIX (1ul << BITS_PER_HALF_DIGIT) 97#define HALF_DIGIT_MASK (HALF_DIGIT_RADIX - 1) 98 99// DIV_CEIL2(x, y) = ceil(x / y). x and y are positive numbers. 100#define DIV_CEIL2(x, y) (((x) - 1) / (y) + 1) 101 102// DIV_CEIL(x) = ceil(x / BITS_PER_DIGIT) = the number of digits to 103// store x bits. x is a positive number. 104#define DIV_CEIL(x) DIV_CEIL2(x, BITS_PER_DIGIT) 105 106#ifdef SC_MAX_NBITS 107static const int MAX_NDIGITS = DIV_CEIL(SC_MAX_NBITS) + 2; 108// Consider a number with x bits another with y bits. The maximum 109// number of bits happens when we multiply them. The result will have 110// (x + y) bits. Assume that x + y <= SC_MAX_NBITS. Then, DIV_CEIL(x) + 111// DIV_CEIL(y) <= DIV_CEIL(SC_MAX_NBITS) + 2. This is the reason for +2 112// above. With this change, MAX_NDIGITS must be enough to hold the 113// result of any operation. 114#endif 115 116// Support for "digit" vectors used to hold the values of sc_signed, 117// sc_unsigned, sc_bv_base, and sc_lv_base data types. This type is also used 118// in the concatenation support. An sc_digit is currently an unsigned 32-bit 119// quantity. The typedef used is an unsigned int, rather than an unsigned long, 120// since the unsigned long data type varies in size between 32-bit and 64-bit 121// machines. 122 123typedef unsigned int sc_digit; // 32-bit unsigned integer 124 125// Support for the long long type. This type is not in the standard 126// but is usually supported by compilers. 127typedef int64_t int64; 128typedef uint64_t uint64; 129 130static const uint64 UINT64_ZERO = 0ULL; 131static const uint64 UINT64_ONE = 1ULL; 132static const uint64 UINT64_32ONES = 0x00000000ffffffffULL; 133 134// Bits per ... 135// will be deleted in the future. Use numeric_limits instead 136#define BITS_PER_CHAR 8 137#define BITS_PER_INT (sizeof(int) * BITS_PER_CHAR) 138#define BITS_PER_LONG (sizeof(long) * BITS_PER_CHAR) 139#define BITS_PER_INT64 (sizeof(::sc_dt::int64) * BITS_PER_CHAR) 140#define BITS_PER_UINT (sizeof(unsigned int) * BITS_PER_CHAR) 141#define BITS_PER_ULONG (sizeof(unsigned long) * BITS_PER_CHAR) 142#define BITS_PER_UINT64 (sizeof(::sc_dt::uint64) * BITS_PER_CHAR) 143 144// Digits per ... 145#define DIGITS_PER_CHAR 1 146#define DIGITS_PER_INT ((BITS_PER_INT+29)/30) 147#define DIGITS_PER_LONG ((BITS_PER_LONG+29)/30) 148#define DIGITS_PER_INT64 ((BITS_PER_INT64+29)/30) 149#define DIGITS_PER_UINT ((BITS_PER_UINT+29)/30) 150#define DIGITS_PER_ULONG ((BITS_PER_ULONG+29)/30) 151#define DIGITS_PER_UINT64 ((BITS_PER_UINT64+29)/30) 152 153// Above, BITS_PER_X is mainly used for sc_signed, and BITS_PER_UX is 154// mainly used for sc_unsigned. 155 156static const small_type NB_DEFAULT_BASE = SC_DEC; 157 158// For sc_int code: 159 160typedef int64 int_type; 161typedef uint64 uint_type; 162#define SC_INTWIDTH 64 163static const uint64 UINT_ZERO = UINT64_ZERO; 164static const uint64 UINT_ONE = UINT64_ONE; 165 166} // namespace sc_dt 167 168#endif 169