verinum.h

   1 #ifndef __verinum_H
   2 #define __verinum_H
   3 /*
   4  * Copyright (c) 1998 Stephen Williams (steve@icarus.com)
   5  *
   6  *    This source code is free software; you can redistribute it
   7  *    and/or modify it in source code form under the terms of the GNU
   8  *    General Public License as published by the Free Software
   9  *    Foundation; either version 2 of the License, or (at your option)
  10  *    any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  20  */
  21 #ifdef HAVE_CVS_IDENT
  22 #ident "$Id: verinum.h,v 1.33 2007/02/02 04:33:01 steve Exp $"
  23 #endif
  24
  25 # include  <string>
  26
  27 # include  "config.h"
  28 #ifdef HAVE_IOSFWD
  29 # include  <iosfwd>
  30 #else
  31 class ostream;
  32 #endif
  33
  34 using namespace std;
  35
  36 /*
  37  * Numbers in Verilog are multibit strings, where each bit has 4
  38  * possible values: 0, 1, x or z. The verinum number is store in
  39  * little-endian format. This means that if the long value is 2b'10,
  40  * get(0) is 0 and get(1) is 1.
  41  */
  42 class verinum {
  43
  44     public:
  45       enum V { V0 = 0, V1, Vx, Vz };
  46
  47       verinum();
  48       verinum(const string&str);
  49       verinum(const V*v, unsigned nbits, bool has_len =true);
  50       verinum(V, unsigned nbits =1, bool has_len =true);
  51       verinum(uint64_t val, unsigned bits);
  52       verinum(const verinum&);
  53
  54         // Create a signed number, with an unspecified number of bits.
  55       explicit verinum(int64_t val);
  56
  57         // Copy only the specified number of bits from the
  58         // source. Also mark this number as has_len.
  59       verinum(const verinum&, unsigned bits);
  60
  61       ~verinum();
  62       verinum& operator= (const verinum&);
  63
  64         // Number of significant bits in this number.
  65       unsigned len() const { return nbits_; }
  66
  67         // A number "has a length" if the length was specified fixed
  68         // in some way.
  69       bool has_len() const { return has_len_; }
  70
  71       bool has_sign(bool flag) { has_sign_ = flag; return has_sign_; }
  72       bool has_sign() const { return has_sign_; }
  73
  74         // A number is "defined" if there are no x or z bits in its value.
  75       bool is_defined() const;
  76       bool is_zero() const;
  77
  78         // A number is "a string" if its value came directly from
  79         // an ASCII description instead of a number value.
  80       bool is_string() const { return string_flag_; }
  81
  82         // Comparison for use in sorting algorithms.
  83       bool is_before(const verinum&that) const;
  84
  85         // Individual bits can be accessed with the get and set
  86         // methods.
  87       V get(unsigned idx) const;
  88       V set(unsigned idx, V val);
  89
  90       V operator[] (unsigned idx) const { return get(idx); }
  91
  92
  93       uint64_t as_ulong64() const;
  94       unsigned long as_ulong() const;
  95       signed long   as_long() const;
  96       string as_string() const;
  97
  98     private:
  99       V* bits_;
 100       unsigned nbits_;
 101       bool has_len_;
 102       bool has_sign_;
 103
 104         // These are some convenience flags that help us do a better
 105         // job of pretty-printing values.
 106       bool string_flag_;
 107 };
 108
 109 /* Return a verinum that has the same value as the input, but is at
 110    least as wide as the requested width. This may involve sign
 111    extension, if the value is signed. */
 112 extern verinum pad_to_width(const verinum&, unsigned width);
 113
 114 /* Return a verinum that is minimal. That is, it has only the length
 115    needed to accurately represent the contained value, signed or not. */
 116 extern verinum trim_vnum(const verinum&);
 117
 118 extern ostream& operator<< (ostream&, const verinum&);
 119 extern ostream& operator<< (ostream&, verinum::V);
 120
 121 extern verinum::V operator ~ (verinum::V l);
 122 extern verinum::V operator | (verinum::V l, verinum::V r);
 123 extern verinum::V operator & (verinum::V l, verinum::V r);
 124 extern verinum::V operator ^ (verinum::V l, verinum::V r);
 125
 126 extern verinum::V operator == (const verinum&left, const verinum&right);
 127 extern verinum::V operator <= (const verinum&left, const verinum&right);
 128 extern verinum::V operator <  (const verinum&left, const verinum&right);
 129
 130 inline verinum::V operator > (const verinum&left, const verinum&right)
 131 { return right < left; }
 132
 133 inline verinum::V operator >= (const verinum&left, const verinum&right)
 134 { return right <= left; }
 135
 136 inline verinum::V operator != (const verinum&left, const verinum&right)
 137 { return (left == right)? verinum::V0 : verinum::V1; }
 138
 139
 140 /* These are arithmetic operators. These generally work to produce
 141    results that do not overflow. That means the result may expand or
 142    contract to hold the bits needed to hold the operation results
 143    accurately. It is up to the caller to truncate or pad if a specific
 144    width is expected. */
 145 extern verinum operator + (const verinum&left, const verinum&right);
 146 extern verinum operator - (const verinum&left, const verinum&right);
 147 extern verinum operator * (const verinum&left, const verinum&right);
 148 extern verinum operator / (const verinum&left, const verinum&right);
 149 extern verinum operator % (const verinum&left, const verinum&right);
 150
 151 extern verinum pow(const verinum&left, const verinum&right);
 152
 153 extern verinum operator<< (const verinum&left, unsigned shift);
 154 extern verinum operator>> (const verinum&left, unsigned shift);
 155
 156 extern verinum concat(const verinum&left, const verinum&right);
 157
 158 /* Bitwise not returns the ones complement. */
 159 extern verinum v_not(const verinum&left);
 160
 161 /*
 162  * $Log: verinum.h,v $
 163  * Revision 1.33  2007/02/02 04:33:01  steve
 164  *  Use inttypes.h instead of stdint.h for portability.
 165  *
 166  * Revision 1.32  2006/08/08 05:11:37  steve
 167  *  Handle 64bit delay constants.
 168  *
 169  * Revision 1.31  2006/07/31 03:50:17  steve
 170  *  Add support for power in constant expressions.
 171  *
 172  * Revision 1.30  2006/06/02 04:48:50  steve
 173  *  Make elaborate_expr methods aware of the width that the context
 174  *  requires of it. In the process, fix sizing of the width of unary
 175  *  minus is context determined sizes.
 176  *
 177  * Revision 1.29  2006/06/01 03:54:51  steve
 178  *  Fix broken subtraction of small constants.
 179  *
 180  * Revision 1.28  2005/12/07 04:04:24  steve
 181  *  Allow constant concat expressions.
 182  *
 183  * Revision 1.27  2005/06/14 19:13:43  steve
 184  *  gcc3/4 compile errors.
 185  *
 186  * Revision 1.26  2004/02/17 06:52:55  steve
 187  *  Support unsigned divide of huge numbers.
 188  *
 189  * Revision 1.25  2003/10/26 04:54:56  steve
 190  *  Support constant evaluation of binary ^ operator.
 191  *
 192  * Revision 1.24  2003/04/14 03:40:21  steve
 193  *  Make some effort to preserve bits while
 194  *  operating on constant values.
 195  *
 196  * Revision 1.23  2003/04/03 04:30:00  steve
 197  *  Prevent overrun comparing verinums to zero.
 198  *
 199  * Revision 1.22  2003/01/30 16:23:08  steve
 200  *  Spelling fixes.
 201  *
 202  * Revision 1.21  2003/01/30 04:23:25  steve
 203  *  include config.h to get iosfwd flags.
 204  *
 205  * Revision 1.20  2002/08/12 01:35:01  steve
 206  *  conditional ident string using autoconfig.
 207  *
 208  * Revision 1.19  2002/06/03 04:04:24  steve
 209  *  Add verinum != operator.
 210  *
 211  * Revision 1.18  2001/02/10 20:29:39  steve
 212  *  In the context of range declarations, use elab_and_eval instead
 213  *  of the less robust eval_const methods.
 214  *
 215  * Revision 1.17  2001/02/09 05:44:23  steve
 216  *  support evaluation of constant < in expressions.
 217  *
 218  * Revision 1.16  2001/02/07 02:46:31  steve
 219  *  Support constant evaluation of / and % (PR#124)
 220  *
 221  * Revision 1.15  2001/01/16 02:44:18  steve
 222  *  Use the iosfwd header if available.
 223  *
 224  * Revision 1.14  2001/01/02 03:23:40  steve
 225  *  Evaluate constant &, | and unary ~.
 226  *
 227  * Revision 1.13  2000/12/10 22:01:36  steve
 228  *  Support decimal constants in behavioral delays.
 229  *
 230  * Revision 1.12  2000/09/27 18:28:37  steve
 231  *  multiply in parameter expressions.
 232  *
 233  * Revision 1.11  2000/02/23 04:43:43  steve
 234  *  Some compilers do not accept the not symbol.
 235  *
 236  * Revision 1.10  2000/02/23 02:56:56  steve
 237  *  Macintosh compilers do not support ident.
 238  *
 239  * Revision 1.9  2000/01/07 03:45:49  steve
 240  *  Initial support for signed constants.
 241  *
 242  * Revision 1.8  1999/11/06 16:00:17  steve
 243  *  Put number constants into a static table.
 244  *
 245  * Revision 1.7  1999/10/22 23:57:53  steve
 246  *  do the <= in bits, not numbers.
 247  *
 248  * Revision 1.6  1999/10/10 23:29:37  steve
 249  *  Support evaluating + operator at compile time.
 250  *
 251  * Revision 1.5  1999/05/13 04:02:09  steve
 252  *  More precise handling of verinum bit lengths.
 253  *
 254  * Revision 1.4  1998/12/20 02:05:41  steve
 255  *  Function to calculate wire initial value.
 256  *
 257  * Revision 1.3  1998/11/11 00:01:51  steve
 258  *  Check net ranges in declarations.
 259  *
 260  * Revision 1.2  1998/11/09 18:55:35  steve
 261  *  Add procedural while loops,
 262  *  Parse procedural for loops,
 263  *  Add procedural wait statements,
 264  *  Add constant nodes,
 265  *  Add XNOR logic gate,
 266  *  Make vvm output look a bit prettier.
 267  *
 268  * Revision 1.1  1998/11/03 23:29:08  steve
 269  *  Introduce verilog to CVS.
 270  *
 271  */
 272 #endif