-/* Simple arithmetic for numbers greater than a long int, for GNU tar.
- Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+/* Long integers, for GNU tar.
+ Copyright 1999, 2007, 2013-2014 Free Software Foundation, Inc.
- This program is free software; you can redistribute it and/or modify
+ This file is part of GNU tar.
+
+ GNU tar is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
- This program is distributed in the hope that it will be useful,
+ GNU tar is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
-
-/* Also, see comments at beginning of arith.c. */
-
-#define BITS_PER_BYTE 8 /* number of bits in each sizeof unit */
-#define BITS_PER_TARLONG 42 /* wanted number of bits in each tarlong */
-
-/* In all cases, tarlong is the proper type for a big number.
-
- For simulated arithmetic, SUPERDIGIT is the base, TARLONG_FORMAT is the
- format to print a single super-digit filled with zeroes to the left, and
- BITS_PER_SUPERDIGIT is the smallest number of bits required to fully
- represent each super-digit. LONGS_PER_TARLONG says how many longs are
- required for a full tarlong, and SIZEOF_TARLONG is the size of a tarlong
- in bytes.
-
- For straight compiler arithmetic, SUPERDIGIT is zero and TARLONG_FORMAT
- is the format to directly print a tarlong (without zero-filling).
-
- The values of SIZEOF_LONG_LONG and SIZEOF_UNSIGNED_LONG, below, are
- obtained through the configuration process. */
-
-#if BITS_PER_BYTE * SIZEOF_UNSIGNED_LONG >= BITS_PER_TARLONG
-# define SUPERDIGIT 0
-# define TARLONG_FORMAT "%uld"
-typedef unsigned long tarlong;
-#else
-# if BITS_PER_BYTE * SIZEOF_LONG_LONG >= BITS_PER_TARLONG + 1
-# define SUPERDIGIT 0
-# define TARLONG_FORMAT "%lld"
-typedef long long tarlong;
-# else
-# if BITS_PER_BYTE * SIZEOF_UNSIGNED_LONG >= 64
-# define SUPERDIGIT 1000000000L
-# define BITS_PER_SUPERDIGIT 29
-# define TARLONG_FORMAT "%09uld"
-# else
-# if BITS_PER_BYTE * SIZEOF_UNSIGNED_LONG >= 32
-# define SUPERDIGIT 10000L
-# define BITS_PER_SUPERDIGIT 14
-# define TARLONG_FORMAT "%04uld"
-# endif
-# endif
-# endif
-#endif
-
-#if SUPERDIGIT
-
-# define LONGS_PER_TARLONG \
- ((BITS_PER_TARLONG + BITS_PER_SUPERDIGIT - 1) / BITS_PER_SUPERDIGIT)
-# define SIZEOF_TARLONG (LONGS_PER_TARLONG * sizeof (unsigned long))
-
-/* The NEC EWS 4.2 C compiler gets confused by a pointer to a typedef that
- is an array. So we wrap the array into a struct. (Pouah!) */
-
-struct tarlong
-{
- unsigned long digit[LONGS_PER_TARLONG];
-};
-
-typedef struct tarlong tarlong;
-
-int zerop_tarlong_helper PARAMS ((unsigned long *));
-int lessp_tarlong_helper PARAMS ((unsigned long *, unsigned long *));
-void clear_tarlong_helper PARAMS ((unsigned long *));
-void add_to_tarlong_helper PARAMS ((unsigned long *, int));
-void mult_tarlong_helper PARAMS ((unsigned long *, int));
-void print_tarlong_helper PARAMS ((unsigned long *, FILE *));
-
-# define zerop_tarlong(Accumulator) \
- zerop_tarlong_helper (&(Accumulator).digit[0])
-
-# define lessp_tarlong(First, Second) \
- lessp_tarlong_helper (&(First).digit[0], &(Second).digit[0])
-
-# define clear_tarlong(Accumulator) \
- clear_tarlong_helper (&(Accumulator).digit[0])
-
-# define add_to_tarlong(Accumulator, Value) \
- add_to_tarlong_helper (&(Accumulator).digit[0], (Value))
-
-# define mult_tarlong(Accumulator, Value) \
- mult_tarlong_helper (&(Accumulator).digit[0], (Value))
-
-# define print_tarlong(Accumulator, File) \
- print_tarlong_helper (&(Accumulator).digit[0], (File))
-
-#else /* not SUPERDIGIT */
-
-# define zerop_tarlong(Accumulator) \
- ((Accumulator) == 0)
-
-# define lessp_tarlong(First, Second) \
- ((First) < (Second))
-
-# define clear_tarlong(Accumulator) \
- ((Accumulator) = 0)
-
-# define add_to_tarlong(Accumulator, Value) \
- ((Accumulator) += (Value))
-
-# define mult_tarlong(Accumulator, Value) \
- ((Accumulator) *= (Value))
-
-# define print_tarlong(Accumulator, File) \
- (fprintf ((File), TARLONG_FORMAT, (Accumulator)))
-
-#endif /* not SUPERDIGIT */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+/* Handle large integers for calculating big tape lengths and the
+ like. In practice, double precision does for now. On the vast
+ majority of machines, it counts up to 2**52 bytes without any loss
+ of information, and counts up to 2**62 bytes if data are always
+ blocked in 1 kB boundaries. We'll need arbitrary precision
+ arithmetic anyway once we get into the 2**64 range, so there's no
+ point doing anything fancy before then. */
+
+#define TARLONG_FORMAT "%.0f"
+typedef double tarlong;
projects / chaz / tar / blobdiff