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author | root <root> | 2011-06-10 12:35:17 +0000 |
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committer | root <root> | 2011-06-10 12:35:17 +0000 |
commit | f7819174f1be7c8a58b9f751e1d3c9a41b081cdc (patch) | |
tree | af21bf1817220b491961c4dd0d70f9554a619d4f /ecb.h | |
parent | 5e8581f15bc308454846cb79c772083dab66b04f (diff) |
*** empty log message ***
Diffstat (limited to 'ecb.h')
-rw-r--r-- | ecb.h | 221 |
1 files changed, 221 insertions, 0 deletions
@@ -0,0 +1,221 @@ +/* + * libecb - http://software.schmorp.de/pkg/libecb + * + * Copyright (©) 2009-2011 Marc Alexander Lehmann <libecb@schmorp.de> + * Copyright (©) 2011 Emanuele Giaquinta + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modifica- + * tion, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- + * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO + * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- + * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- + * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef ECB_H +#define ECB_H + +#include <inttypes.h> + +/* many compilers define _GNUC_ to some versions but then only implement + * what their idiot authors think are the "more important" extensions, + * causing enourmous grief in return for some better fake benchmark numbers. + * or so. + * we try to detect these and simply assume they are not gcc - if they have + * an issue with that they should have done it right in the first place. + */ +#ifndef ECB_GCC_VERSION +# if defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__llvm__) +# define ECB_GCC_VERSION(major,minor) 0 +# else +# define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) +# endif +#endif + +#ifndef __cplusplus +# if __STDC_VERSION__ >= 199901L +# define ECB_INLINE static inline +typedef _Bool ecb_bool; +# else +# define ECB_INLINE static inline /* yeah! */ +typedef int ecb_bool; +# endif +#else +# define ECB_INLINE static inline +typedef bool ecb_bool; +#endif + +#define ECB_CONCAT_(a, b) a ## b +#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b) +#define ECB_STRINGIFY_(a) # a +#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a) + +#define ECB_HEADER_INLINE ECB_INLINE + +#if ECB_GCC_VERSION(3,1) +# define ecb_attribute(attrlist) __attribute__(attrlist) +# define ecb_is_constant(expr) __builtin_constant_p (expr) +# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) +# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) +#else +# define ecb_attribute(attrlist) +# define ecb_is_constant(expr) 0 +# define ecb_expect(expr,value) (expr) +# define ecb_prefetch(addr,rw,locality) +#endif + +/* no emulation for ecb_decltype */ +#if ECB_GCC_VERSION(4,5) +# define ecb_decltype(x) __decltype(x) +#elif ECB_GCC_VERSION(3,0) +# define ecb_decltype(x) typeof(x) +#endif + +#define ecb_artificial ecb_attribute ((__artificial__)) /* 4.3 */ +#define ecb_noinline ecb_attribute ((__noinline__)) +#define ecb_noreturn ecb_attribute ((__noreturn__)) +#define ecb_unused ecb_attribute ((__unused__)) +#define ecb_const ecb_attribute ((__const__)) +#define ecb_pure ecb_attribute ((__pure__)) +#define ecb_hot ecb_attribute ((__hot__)) /* 4.3 */ +#define ecb_cold ecb_attribute ((__cold__)) /* 4.3 */ + +/* put into if's if you are very sure that the expression */ +/* is mostly true or mostly false. note that these return */ +/* booleans, not the expression. */ +#define ecb_expect_false(expr) ecb_expect (!!(expr), 0) +#define ecb_expect_true(expr) ecb_expect (!!(expr), 1) +#define ecb_likely(expr) ecb_expect_true (expr) +#define ecb_unlikely(expr) ecb_expect_false (expr) + +/* try to tell the compiler that some condition is definitely true */ +#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0) + +/* count trailing zero bits and count # of one bits */ +#if ECB_GCC_VERSION(3,4) +#define ecb_ctz32(x) __builtin_ctz (x) +#define ecb_popcount32(x) __builtin_popcount (x) +#else +ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) ecb_const; +ECB_HEADER_INLINE int +ecb_ctz32 (uint32_t x) +{ + int r = 0; + + x &= -x; /* this isolates the lowest bit */ + + if (x & 0xaaaaaaaa) r += 1; + if (x & 0xcccccccc) r += 2; + if (x & 0xf0f0f0f0) r += 4; + if (x & 0xff00ff00) r += 8; + if (x & 0xffff0000) r += 16; + + return r; +} + +ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) ecb_const; +ECB_HEADER_INLINE int +ecb_popcount32 (uint32_t x) +{ + x -= (x >> 1) & 0x55555555; + x = ((x >> 2) & 0x33333333) + (x & 0x33333333); + x = ((x >> 4) + x) & 0x0f0f0f0f; + x *= 0x01010101; + + return x >> 24; +} +#endif + +#if ECB_GCC_VERSION(4,3) +# define ecb_bswap32(x) __builtin_bswap32 (x) +# define ecb_bswap16(x) (__builtin_bswap32(x) >> 16) +#else +ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) ecb_const; +ECB_HEADER_INLINE uint32_t +ecb_bswap32 (uint32_t x) +{ + return (x >> 24) + | ((x >> 8) & 0x0000ff00) + | ((x << 8) & 0x00ff0000) + | (x << 24); +} + +ECB_HEADER_INLINE uint32_t ecb_bswap16 (uint32_t x) ecb_const; +ECB_HEADER_INLINE uint32_t +ecb_bswap16 (uint32_t x) +{ + return ((x >> 8) & 0xff) + | ((x << 8) & 0x00ff0000) + | (x << 24); +} +#endif + +#if ECB_GCC_VERSION(4,5) +# define ecb_unreachable() __builtin_unreachable () +#else +/* this seems to work fine, but gcc always emits a warning for it :/ */ +ECB_HEADER_INLINE void ecb_unreachable (void) ecb_noreturn; +ECB_HEADER_INLINE void ecb_unreachable (void) { } +#endif + +ECB_HEADER_INLINE unsigned char ecb_byteorder_helper (void) ecb_const; +ECB_HEADER_INLINE unsigned char +ecb_byteorder_helper (void) +{ + const uint32_t u = 0x11223344; + return *(unsigned char *)&u; +} + +ECB_HEADER_INLINE ecb_bool ecb_big_endian (void) ecb_const; +ECB_HEADER_INLINE ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }; +ECB_HEADER_INLINE ecb_bool ecb_little_endian (void) ecb_const; +ECB_HEADER_INLINE ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }; + +#if ECB_GCC_VERSION(3,0) +# define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0)) +#else +# define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n))) +#endif + +#if ecb_cplusplus_does_not_suck +// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) +template<typename T, int N> +static inline int ecb_array_length (const T (&arr)[N]) +{ + return N; +} +#else +#define ecb_array_length(name) (sizeof (name) / sizeof (name [0])) +#endif + +ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const; +ECB_INLINE uint32_t +ecb_rotr32 (uint32_t x, unsigned int count) +{ + return (x << (32 - count)) | (x >> count); +} + +ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const; +ECB_INLINE uint32_t +ecb_rotl32 (uint32_t x, unsigned int count) +{ + return (x >> (32 - count)) | (x << count); +} + +#endif + |