152 lines
4.1 KiB
C
152 lines
4.1 KiB
C
/*
|
|
* lbn.h - Low-level bignum header.
|
|
* Defines various word sizes and useful macros.
|
|
*
|
|
* Copyright (c) 1995 Colin Plumb. All rights reserved.
|
|
*/
|
|
#ifndef LBN_H
|
|
#define LBN_H
|
|
|
|
#ifndef HAVE_CONFIG_H
|
|
#define HAVE_CONFIG_H 0
|
|
#endif
|
|
#if HAVE_CONFIG_H
|
|
#include "bnconfig.h"
|
|
#endif
|
|
|
|
/*
|
|
* Some compilers complain about #if FOO if FOO isn't defined,
|
|
* so do the ANSI-mandated thing explicitly...
|
|
*/
|
|
#ifndef NO_LIMITS_H
|
|
#define NO_LIMITS_H 0
|
|
#endif
|
|
|
|
/* Make sure we have 8-bit bytes */
|
|
#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 /* !NO_LIMITS_H */
|
|
|
|
#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
|
|
|
|
/* Do we want bnYield()? */
|
|
#ifndef BNYIELD
|
|
#define BNYIELD 0
|
|
#endif
|
|
|
|
/* Figure out the endianness */
|
|
/* Error if more than one is defined */
|
|
#if defined(BN_BIG_ENDIAN) && defined(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 defined(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 == 0xfffffffful
|
|
typedef unsigned long bnword32;
|
|
#define BNWORD32 bnword32
|
|
#elif UINT_MAX == 0xffffffff
|
|
typedef unsigned bnword32;
|
|
#define BNWORD32 bnword32
|
|
#elif USHRT_MAX == 0xffffffff
|
|
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 > 0xfffffffful
|
|
#if ULONG_MAX == 0xffffffffffffffff
|
|
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
|
|
#else
|
|
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 */
|