English
- /*
- * lbn.h - Low-level bignum header.
- * Defines various word sizes and useful macros.
- *
- * Copyright (c) 1995 Colin Plumb. All rights reserved.
- * For licensing and other legal details, see the file legal.c.
- */
- #ifndef LBN_H
- #define LBN_H
- #if HAVE_CONFIG_H
- #include "config.h"
- #endif
- #if !NO_LIMITS_H
- #include <limits.h>
- #if UCHAR_MAX != 0xff || CHAR_BIT != 8
- #error The bignum library requires 8-bit unsigned characters.
- #endif
- #endif
- #ifdef BNINCLUDE /* If this is defined as, say, foo.h */
- #define STR(x) #x /* STR(BNINCLUDE) -> "BNINCLUDE" */
- #define XSTR(x) STR(x) /* XSTR(BNINCLUDE) -> STR(foo.h) -> "foo.h" */
- #include XSTR(BNINCLUDE) /* #include "foo.h" */
- #undef XSTR
- #undef STR
- #endif
- /* Figure out the endianness */
- /* Error if more than one is defined */
- #if BN_BIG_ENDIAN && BN_LITTLE_ENDIAN
- #error Only one of BN_BIG_ENDIAN or BN_LITTLE_ENDIAN may be defined
- #endif
- /*
- * If no preference is stated, little-endian C code is slightly more
- * efficient, so prefer that. (The endianness here does NOT have to
- * match the machine's native byte sex; the library's C code will work
- * either way. The flexibility is allowed for assembly routines
- * that do care.
- */
- #if !defined(BN_BIG_ENDIAN) && !defined(BN_LITTLE_ENDIAN)
- #define BN_LITTLE_ENDIAN 1
- #endif /* !BN_BIG_ENDIAN && !BN_LITTLE_ENDIAN */
- /* Macros to choose between big and little endian */
- #if BN_BIG_ENDIAN
- #define BIG(b) b
- #define LITTLE(l) /*nothing*/
- #define BIGLITTLE(b,l) b
- #elif BN_LITTLE_ENDIAN
- #define BIG(b) /*nothing*/
- #define LITTLE(l) l
- #define BIGLITTLE(b,l) l
- #else
- #error One of BN_BIG_ENDIAN or BN_LITTLE_ENDIAN must be defined as 1
- #endif
- /*
- * Find a 16-bit unsigned type.
- * Unsigned short is preferred over unsigned int to make the type chosen
- * by this file more stable on platforms (such as many 68000 compilers)
- * which support both 16- and 32-bit ints.
- */
- #ifndef BNWORD16
- #ifndef USHRT_MAX /* No <limits.h> available - guess */
- typedef unsigned short bnword16;
- #define BNWORD16 bnword16
- #elif USHRT_MAX == 0xffff
- typedef unsigned short bnword16;
- #define BNWORD16 bnword16
- #elif UINT_MAX == 0xffff
- typedef unsigned bnword16;
- #define BNWORD16 bnword16
- #endif
- #endif /* BNWORD16 */
- /*
- * Find a 32-bit unsigned type.
- * Unsigned long is preferred over unsigned int to make the type chosen
- * by this file more stable on platforms (such as many 68000 compilers)
- * which support both 16- and 32-bit ints.
- */
- #ifndef BNWORD32
- #ifndef ULONG_MAX /* No <limits.h> available - guess */
- typedef unsigned long bnword32;
- #define BNWORD32 bnword32
- #elif ULONG_MAX == 0xffffffffu
- typedef unsigned long bnword32;
- #define BNWORD32 bnword32
- #elif UINT_MAX == 0xffffffffu
- typedef unsigned bnword32;
- #define BNWORD32 bnword32
- #elif USHRT_MAX == 0xffffffffu
- typedef unsigned short bnword32;
- #define BNWORD32 bnword32
- #endif
- #endif /* BNWORD16 */
- /*
- * Find a 64-bit unsigned type.
- * The conditions here are more complicated to avoid using numbers that
- * will choke lesser preprocessors (like 0xffffffffffffffff) unless
- * we're reasonably certain that they'll be acceptable.
- */
- #if !defined(BNWORD64) && ULONG_MAX > 0xffffffffu
- #if ULONG_MAX == 0xffffffffffffffffu
- typedef unsigned long bnword64;
- #define BNWORD64 bnword64
- #endif
- #endif
- /*
- * I would test the value of unsigned long long, but some *preprocessors*
- * don't constants that long even if the compiler can accept them, so it
- * doesn't work reliably. So cross our fingers and hope that it's a 64-bit
- * type.
- *
- * GCC uses ULONG_LONG_MAX. Solaris uses ULLONG_MAX. IRIX uses ULONGLONG_MAX.
- * Are there any other names for this?
- */
- #if !defined(BNWORD64) &&
- (defined(ULONG_LONG_MAX) || defined (ULLONG_MAX) || defined(ULONGLONG_MAX))
- typedef unsigned long long bnword64;
- #define BNWORD64 bnword64
- #endif
- /* We don't even try to find a 128-bit type at the moment */
- #endif /* !LBN_H */
