GNU tar 1.12

src/arith.h

@@ -0,0 +1,123 @@
+/* Simple arithmetic for numbers greater than a long int, for GNU tar.
+   Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+
+   This program 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.
+
+   This program 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 */