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Diffstat (limited to 'Utilities/cmliblzma/common/tuklib_integer.h')
| -rw-r--r-- | Utilities/cmliblzma/common/tuklib_integer.h | 514 |
1 files changed, 514 insertions, 0 deletions
diff --git a/Utilities/cmliblzma/common/tuklib_integer.h b/Utilities/cmliblzma/common/tuklib_integer.h new file mode 100644 index 0000000..5e8262a --- /dev/null +++ b/Utilities/cmliblzma/common/tuklib_integer.h @@ -0,0 +1,514 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file tuklib_integer.h +/// \brief Various integer and bit operations +/// +/// This file provides macros or functions to do some basic integer and bit +/// operations. +/// +/// Endianness related integer operations (XX = 16, 32, or 64; Y = b or l): +/// - Byte swapping: bswapXX(num) +/// - Byte order conversions to/from native: convXXYe(num) +/// - Aligned reads: readXXYe(ptr) +/// - Aligned writes: writeXXYe(ptr, num) +/// - Unaligned reads (16/32-bit only): unaligned_readXXYe(ptr) +/// - Unaligned writes (16/32-bit only): unaligned_writeXXYe(ptr, num) +/// +/// Since they can macros, the arguments should have no side effects since +/// they may be evaluated more than once. +/// +/// \todo PowerPC and possibly some other architectures support +/// byte swapping load and store instructions. This file +/// doesn't take advantage of those instructions. +/// +/// Bit scan operations for non-zero 32-bit integers: +/// - Bit scan reverse (find highest non-zero bit): bsr32(num) +/// - Count leading zeros: clz32(num) +/// - Count trailing zeros: ctz32(num) +/// - Bit scan forward (simply an alias for ctz32()): bsf32(num) +/// +/// The above bit scan operations return 0-31. If num is zero, +/// the result is undefined. +// +// Authors: Lasse Collin +// Joachim Henke +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef TUKLIB_INTEGER_H +#define TUKLIB_INTEGER_H + +#include "sysdefs.h" + +#if defined(__GNUC__) && defined(__GNUC_MINOR__) +# define TUKLIB_GNUC_REQ(major, minor) \ + ((__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)) \ + || __GNUC__ > (major)) +#else +# define TUKLIB_GNUC_REQ(major, minor) 0 +#endif + + +//////////////////////////////////////// +// Operating system specific features // +//////////////////////////////////////// + +#if defined(HAVE_BYTESWAP_H) + // glibc, uClibc, dietlibc +# include <byteswap.h> +# ifdef HAVE_BSWAP_16 +# define bswap16(num) bswap_16(num) +# endif +# ifdef HAVE_BSWAP_32 +# define bswap32(num) bswap_32(num) +# endif +# ifdef HAVE_BSWAP_64 +# define bswap64(num) bswap_64(num) +# endif + +#elif defined(HAVE_SYS_ENDIAN_H) + // *BSDs and Darwin +# include <sys/endian.h> + +#elif defined(HAVE_SYS_BYTEORDER_H) + // Solaris +# include <sys/byteorder.h> +# ifdef BSWAP_16 +# define bswap16(num) BSWAP_16(num) +# endif +# ifdef BSWAP_32 +# define bswap32(num) BSWAP_32(num) +# endif +# ifdef BSWAP_64 +# define bswap64(num) BSWAP_64(num) +# endif +# ifdef BE_16 +# define conv16be(num) BE_16(num) +# endif +# ifdef BE_32 +# define conv32be(num) BE_32(num) +# endif +# ifdef BE_64 +# define conv64be(num) BE_64(num) +# endif +# ifdef LE_16 +# define conv16le(num) LE_16(num) +# endif +# ifdef LE_32 +# define conv32le(num) LE_32(num) +# endif +# ifdef LE_64 +# define conv64le(num) LE_64(num) +# endif +#endif + + +/////////////////// +// Byte swapping // +/////////////////// + +#ifndef bswap16 +# define bswap16(num) \ + (((uint16_t)(num) << 8) | ((uint16_t)(num) >> 8)) +#endif + +#ifndef bswap32 +# define bswap32(num) \ + ( (((uint32_t)(num) << 24) ) \ + | (((uint32_t)(num) << 8) & UINT32_C(0x00FF0000)) \ + | (((uint32_t)(num) >> 8) & UINT32_C(0x0000FF00)) \ + | (((uint32_t)(num) >> 24) ) ) +#endif + +#ifndef bswap64 +# define bswap64(num) \ + ( (((uint64_t)(num) << 56) ) \ + | (((uint64_t)(num) << 40) & UINT64_C(0x00FF000000000000)) \ + | (((uint64_t)(num) << 24) & UINT64_C(0x0000FF0000000000)) \ + | (((uint64_t)(num) << 8) & UINT64_C(0x000000FF00000000)) \ + | (((uint64_t)(num) >> 8) & UINT64_C(0x00000000FF000000)) \ + | (((uint64_t)(num) >> 24) & UINT64_C(0x0000000000FF0000)) \ + | (((uint64_t)(num) >> 40) & UINT64_C(0x000000000000FF00)) \ + | (((uint64_t)(num) >> 56) ) ) +#endif + +// Define conversion macros using the basic byte swapping macros. +#ifdef WORDS_BIGENDIAN +# ifndef conv16be +# define conv16be(num) ((uint16_t)(num)) +# endif +# ifndef conv32be +# define conv32be(num) ((uint32_t)(num)) +# endif +# ifndef conv64be +# define conv64be(num) ((uint64_t)(num)) +# endif +# ifndef conv16le +# define conv16le(num) bswap16(num) +# endif +# ifndef conv32le +# define conv32le(num) bswap32(num) +# endif +# ifndef conv64le +# define conv64le(num) bswap64(num) +# endif +#else +# ifndef conv16be +# define conv16be(num) bswap16(num) +# endif +# ifndef conv32be +# define conv32be(num) bswap32(num) +# endif +# ifndef conv64be +# define conv64be(num) bswap64(num) +# endif +# ifndef conv16le +# define conv16le(num) ((uint16_t)(num)) +# endif +# ifndef conv32le +# define conv32le(num) ((uint32_t)(num)) +# endif +# ifndef conv64le +# define conv64le(num) ((uint64_t)(num)) +# endif +#endif + + +////////////////////////////// +// Aligned reads and writes // +////////////////////////////// + +static inline uint16_t +read16be(const uint8_t *buf) +{ + uint16_t num = *(const uint16_t *)buf; + return conv16be(num); +} + + +static inline uint16_t +read16le(const uint8_t *buf) +{ + uint16_t num = *(const uint16_t *)buf; + return conv16le(num); +} + + +static inline uint32_t +read32be(const uint8_t *buf) +{ + uint32_t num = *(const uint32_t *)buf; + return conv32be(num); +} + + +static inline uint32_t +read32le(const uint8_t *buf) +{ + uint32_t num = *(const uint32_t *)buf; + return conv32le(num); +} + + +static inline uint64_t +read64be(const uint8_t *buf) +{ + uint64_t num = *(const uint64_t *)buf; + return conv64be(num); +} + + +static inline uint64_t +read64le(const uint8_t *buf) +{ + uint64_t num = *(const uint64_t *)buf; + return conv64le(num); +} + + +// NOTE: Possible byte swapping must be done in a macro to allow GCC +// to optimize byte swapping of constants when using glibc's or *BSD's +// byte swapping macros. The actual write is done in an inline function +// to make type checking of the buf pointer possible similarly to readXXYe() +// functions. + +#define write16be(buf, num) write16ne((buf), conv16be(num)) +#define write16le(buf, num) write16ne((buf), conv16le(num)) +#define write32be(buf, num) write32ne((buf), conv32be(num)) +#define write32le(buf, num) write32ne((buf), conv32le(num)) +#define write64be(buf, num) write64ne((buf), conv64be(num)) +#define write64le(buf, num) write64ne((buf), conv64le(num)) + + +static inline void +write16ne(uint8_t *buf, uint16_t num) +{ + *(uint16_t *)buf = num; + return; +} + + +static inline void +write32ne(uint8_t *buf, uint32_t num) +{ + *(uint32_t *)buf = num; + return; +} + + +static inline void +write64ne(uint8_t *buf, uint64_t num) +{ + *(uint64_t *)buf = num; + return; +} + + +//////////////////////////////// +// Unaligned reads and writes // +//////////////////////////////// + +// NOTE: TUKLIB_FAST_UNALIGNED_ACCESS indicates only support for 16-bit and +// 32-bit unaligned integer loads and stores. It's possible that 64-bit +// unaligned access doesn't work or is slower than byte-by-byte access. +// Since unaligned 64-bit is probably not needed as often as 16-bit or +// 32-bit, we simply don't support 64-bit unaligned access for now. +#ifdef TUKLIB_FAST_UNALIGNED_ACCESS +# define unaligned_read16be read16be +# define unaligned_read16le read16le +# define unaligned_read32be read32be +# define unaligned_read32le read32le +# define unaligned_write16be write16be +# define unaligned_write16le write16le +# define unaligned_write32be write32be +# define unaligned_write32le write32le + +#else + +static inline uint16_t +unaligned_read16be(const uint8_t *buf) +{ + uint16_t num = ((uint16_t)buf[0] << 8) | (uint16_t)buf[1]; + return num; +} + + +static inline uint16_t +unaligned_read16le(const uint8_t *buf) +{ + uint16_t num = ((uint16_t)buf[0]) | ((uint16_t)buf[1] << 8); + return num; +} + + +static inline uint32_t +unaligned_read32be(const uint8_t *buf) +{ + uint32_t num = (uint32_t)buf[0] << 24; + num |= (uint32_t)buf[1] << 16; + num |= (uint32_t)buf[2] << 8; + num |= (uint32_t)buf[3]; + return num; +} + + +static inline uint32_t +unaligned_read32le(const uint8_t *buf) +{ + uint32_t num = (uint32_t)buf[0]; + num |= (uint32_t)buf[1] << 8; + num |= (uint32_t)buf[2] << 16; + num |= (uint32_t)buf[3] << 24; + return num; +} + + +static inline void +unaligned_write16be(uint8_t *buf, uint16_t num) +{ + buf[0] = num >> 8; + buf[1] = num; + return; +} + + +static inline void +unaligned_write16le(uint8_t *buf, uint16_t num) +{ + buf[0] = num; + buf[1] = num >> 8; + return; +} + + +static inline void +unaligned_write32be(uint8_t *buf, uint32_t num) +{ + buf[0] = num >> 24; + buf[1] = num >> 16; + buf[2] = num >> 8; + buf[3] = num; + return; +} + + +static inline void +unaligned_write32le(uint8_t *buf, uint32_t num) +{ + buf[0] = num; + buf[1] = num >> 8; + buf[2] = num >> 16; + buf[3] = num >> 24; + return; +} + +#endif + + +static inline uint32_t +bsr32(uint32_t n) +{ + // Check for ICC first, since it tends to define __GNUC__ too. +#if defined(__INTEL_COMPILER) + return _bit_scan_reverse(n); + +#elif TUKLIB_GNUC_REQ(3, 4) && UINT_MAX == UINT32_MAX + // GCC >= 3.4 has __builtin_clz(), which gives good results on + // multiple architectures. On x86, __builtin_clz() ^ 31U becomes + // either plain BSR (so the XOR gets optimized away) or LZCNT and + // XOR (if -march indicates that SSE4a instructions are supported). + return __builtin_clz(n) ^ 31U; + +#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) + uint32_t i; + __asm__("bsrl %1, %0" : "=r" (i) : "rm" (n)); + return i; + +#else + uint32_t i = 31; + + if ((n & UINT32_C(0xFFFF0000)) == 0) { + n <<= 16; + i = 15; + } + + if ((n & UINT32_C(0xFF000000)) == 0) { + n <<= 8; + i -= 8; + } + + if ((n & UINT32_C(0xF0000000)) == 0) { + n <<= 4; + i -= 4; + } + + if ((n & UINT32_C(0xC0000000)) == 0) { + n <<= 2; + i -= 2; + } + + if ((n & UINT32_C(0x80000000)) == 0) + --i; + + return i; +#endif +} + + +static inline uint32_t +clz32(uint32_t n) +{ +#if defined(__INTEL_COMPILER) + return _bit_scan_reverse(n) ^ 31U; + +#elif TUKLIB_GNUC_REQ(3, 4) && UINT_MAX == UINT32_MAX + return __builtin_clz(n); + +#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) + uint32_t i; + __asm__("bsrl %1, %0\n\t" + "xorl $31, %0" + : "=r" (i) : "rm" (n)); + return i; + +#else + uint32_t i = 0; + + if ((n & UINT32_C(0xFFFF0000)) == 0) { + n <<= 16; + i = 16; + } + + if ((n & UINT32_C(0xFF000000)) == 0) { + n <<= 8; + i += 8; + } + + if ((n & UINT32_C(0xF0000000)) == 0) { + n <<= 4; + i += 4; + } + + if ((n & UINT32_C(0xC0000000)) == 0) { + n <<= 2; + i += 2; + } + + if ((n & UINT32_C(0x80000000)) == 0) + ++i; + + return i; +#endif +} + + +static inline uint32_t +ctz32(uint32_t n) +{ +#if defined(__INTEL_COMPILER) + return _bit_scan_forward(n); + +#elif TUKLIB_GNUC_REQ(3, 4) && UINT_MAX >= UINT32_MAX + return __builtin_ctz(n); + +#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) + uint32_t i; + __asm__("bsfl %1, %0" : "=r" (i) : "rm" (n)); + return i; + +#else + uint32_t i = 0; + + if ((n & UINT32_C(0x0000FFFF)) == 0) { + n >>= 16; + i = 16; + } + + if ((n & UINT32_C(0x000000FF)) == 0) { + n >>= 8; + i += 8; + } + + if ((n & UINT32_C(0x0000000F)) == 0) { + n >>= 4; + i += 4; + } + + if ((n & UINT32_C(0x00000003)) == 0) { + n >>= 2; + i += 2; + } + + if ((n & UINT32_C(0x00000001)) == 0) + ++i; + + return i; +#endif +} + +#define bsf32 ctz32 + +#endif |