/* * libecb - http://software.schmorp.de/pkg/libecb * * 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- * 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 /* 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 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