--- libecb/ecb.h 2011/05/26 16:41:12 1.1 +++ libecb/ecb.h 2011/06/11 17:34:57 1.40 @@ -1,7 +1,8 @@ /* - * libecb + * libecb - http://software.schmorp.de/pkg/libecb * - * Copyright (c) 2011 Marc Alexander Lehmann + * Copyright (©) 2009-2011 Marc Alexander Lehmann + * Copyright (©) 2011 Emanuele Giaquinta * All rights reserved. * * Redistribution and use in source and binary forms, with or without modifica- @@ -29,81 +30,209 @@ #ifndef ECB_H #define ECB_H -#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) +#include + +/* 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 + +#define ECB_C99 (__STDC_VERSION__ >= 199901L) + +#if __cplusplus + #define ECB_INLINE static inline +#elif ECB_GCC_VERSION(2,5) + #define ECB_INLINE static __inline__ +#elif ECB_C99 + #define ECB_INLINE static inline +#else + #define ECB_INLINE static +#endif + +#if ECB_GCC_VERSION(3,3) + #define ecb_restrict __restrict__ +#elif ECB_C99 + #define ecb_restrict restrict +#else + #define ecb_restrict +#endif + +typedef int ecb_bool; + +#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_function_ ECB_INLINE #if ECB_GCC_VERSION(3,1) -# define ecb_attribute(attrlist) __attribute__(attrlist) -# define ecb_is_constant(c) __builtin_constant_p (c) -# 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(c) 0 -# define ecb_expect(expr,value) (expr) -# define ecb_prefetch(addr,rw,locality) + #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) + #define ecb_decltype(x) __decltype(x) #elif ECB_GCC_VERSION(3,0) -# define ecb_decltype(x) typeof(x) + #define ecb_decltype(x) __typeof(x) #endif -#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 - -#if ECB_GCC_VERSION(4,5) -# define ecb_unreachable() __builtin_unreachable () +#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__)) + +#if ECB_GCC_VERSION(4,3) + #define ecb_artificial ecb_attribute ((__artificial__)) + #define ecb_hot ecb_attribute ((__hot__)) + #define ecb_cold ecb_attribute ((__cold__)) #else - // this seems to work fine, but gcc always emits a warning for it :/ - static inline void ecb_unreachable () ecb_attribute ((noreturn)); - static inline void ecb_unreachable () { } + #define ecb_artificial + #define ecb_hot + #define ecb_cold #endif -// put into ifs if you are very sure that the expression -// is mostly true or mosty false. note that these return -// booleans, not the expression. -#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0) -#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1) +/* put around conditional expressions 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) +/* for compatibility to the rest of the world */ +#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)) unreachable (); } while (0) +/* 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 +/* count trailing zero bits and count # of one bits */ #if ECB_GCC_VERSION(3,4) -static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } -static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); } + #define ecb_ctz32(x) __builtin_ctz (x) + #define ecb_popcount32(x) __builtin_popcount (x) #else -static int ecb_ctz (unsigned int x) ecb_const -{ - int r = 0; + ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const; + ecb_function_ 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_function_ int ecb_popcount32 (uint32_t x) ecb_const; + ecb_function_ int + ecb_popcount32 (uint32_t x) + { + x -= (x >> 1) & 0x55555555; + x = ((x >> 2) & 0x33333333) + (x & 0x33333333); + x = ((x >> 4) + x) & 0x0f0f0f0f; + x *= 0x01010101; - x &= -x; // this isolates the lowest bit + return x >> 24; + } +#endif - 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; +#if ECB_GCC_VERSION(4,3) + #define ecb_bswap32(x) __builtin_bswap32 (x) + #define ecb_bswap16(x) (__builtin_bswap32(x) >> 16) +#else + ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const; + ecb_function_ uint32_t + ecb_bswap32 (uint32_t x) + { + return (x >> 24) + | ((x >> 8) & 0x0000ff00) + | ((x << 8) & 0x00ff0000) + | (x << 24); + } + + ecb_function_ uint32_t ecb_bswap16 (uint32_t x) ecb_const; + ecb_function_ uint32_t + ecb_bswap16 (uint32_t x) + { + return ((x >> 8) & 0xff) + | ((x << 8) & 0x00ff0000) + | (x << 24); + } +#endif - return r; +#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_function_ void ecb_unreachable (void) ecb_noreturn; + ecb_function_ void ecb_unreachable (void) { } +#endif + +ecb_function_ unsigned char ecb_byteorder_helper (void) ecb_const; +ecb_function_ unsigned char +ecb_byteorder_helper (void) +{ + const uint32_t u = 0x11223344; + return *(unsigned char *)&u; } -static int ecb_popcount (unsigned int x) ecb_const +ecb_function_ ecb_bool ecb_big_endian (void) ecb_const; +ecb_function_ ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }; +ecb_function_ ecb_bool ecb_little_endian (void) ecb_const; +ecb_function_ ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }; + +#if ECB_GCC_VERSION(3,0) || ECB_C99 + #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 + 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) { - x -= (x >> 1) & 0x55555555; - x = ((x >> 2) & 0x33333333) + (x & 0x33333333); - x = ((x >> 4) + x) & 0x0f0f0f0f; - x *= 0x01010101; + return (x << (32 - count)) | (x >> count); +} - return x >> 24; +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 #endif