--- libecb/ecb.h 2011/05/26 16:41:12 1.1 +++ libecb/ecb.h 2011/05/26 21:36:49 1.27 @@ -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- @@ -29,61 +30,89 @@ #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 + +#ifndef __cplusplus +# if __STDC_VERSION__ >= 199901L +# define ECB_INLINE inline +typedef _Bool ecb_bool; +# else +# define ECB_INLINE inline /* yeah! */ +typedef int ecb_bool; +# endif +#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 static 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_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(c) 0 +# 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_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 () -#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 () { } -#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) +#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 mosty false. note that these return */ +/* booleans, not the expression. */ +#define ecb_unlikely(expr) ecb_expect (!!(expr), 0) +#define ecb_likely(expr) ecb_expect (!!(expr), 1) -// 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 +ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) ecb_const; +ECB_HEADER_INLINE +ecb_ctz32 (uint32_t x) { int r = 0; - x &= -x; // this isolates the lowest bit + x &= -x; /* this isolates the lowest bit */ if (x & 0xaaaaaaaa) r += 1; if (x & 0xcccccccc) r += 2; @@ -94,7 +123,9 @@ return r; } -static int ecb_popcount (unsigned int x) ecb_const +ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) ecb_const; +ECB_HEADER_INLINE +ecb_popcount32 (uint32_t x) { x -= (x >> 1) & 0x55555555; x = ((x >> 2) & 0x33333333) + (x & 0x33333333); @@ -105,5 +136,77 @@ } #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; }; + +#define ecb_mod(m, n) ((m) < 0 ? ((n) - (-(m) % (n))) : ((m) % (n))) + +#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) +{ + 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