libecb/ecb.h

/*
 * libecb - http://software.schmorp.de/pkg/libecb
 *
 * Copyright (©) 2009-2012 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

/* 16 bits major, 16 bits minor */
#define ECB_VERSION 0x00010001

#ifdef _WIN32
  typedef   signed char   int8_t;
  typedef unsigned char  uint8_t;
  typedef   signed short  int16_t;
  typedef unsigned short uint16_t;
  typedef   signed int    int32_t;
  typedef unsigned int   uint32_t;
  #if __GNUC__
    typedef   signed long long int64_t;
    typedef unsigned long long uint64_t;
  #else /* _MSC_VER || __BORLANDC__ */
    typedef   signed __int64   int64_t;
    typedef unsigned __int64   uint64_t;
  #endif
  #ifdef _WIN64
    #define ECB_PTRSIZE 8
    typedef uint64_t uintptr_t;
    typedef  int64_t  intptr_t;
  #else
    #define ECB_PTRSIZE 4
    typedef uint32_t uintptr_t;
    typedef  int32_t  intptr_t;
  #endif
 typedef intptr_t ptrdiff_t;
#else
  #include <inttypes.h>
  #if UINTMAX_MAX > 0xffffffffU
    #define ECB_PTRSIZE 8
  #else
    #define ECB_PTRSIZE 4
  #endif
#endif

/* many compilers define _GNUC_ to some versions but then only implement
 * what their idiot authors think are the "more important" extensions,
 * causing enormous 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 __GNUC_MINOR__ || defined __INTEL_COMPILER || defined __SUNPRO_C || defined __SUNPRO_CC || defined __llvm__ || defined __clang__
    #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_C     (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
#define ECB_C99   (__STDC_VERSION__ >= 199901L)
#define ECB_C11   (__STDC_VERSION__ >= 201112L)
#define ECB_CPP   (__cplusplus+0)
#define ECB_CPP98 (__cplusplus >= 199711L)
#define ECB_CPP11 (__cplusplus >= 201103L)

/*****************************************************************************/

/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
/* ECB_NO_SMP     - ecb might be used in multiple threads, but only on a single cpu */

#if ECB_NO_THREADS
# define ECB_NO_SMP 1
#endif

#if ECB_NO_THREADS || ECB_NO_SMP
  #define ECB_MEMORY_FENCE do { } while (0)
#endif

#ifndef ECB_MEMORY_FENCE
  #if ECB_C11 && !defined __STDC_NO_ATOMICS__
    /* we assume that these memory fences work on all variables/all memory accesses, */
    /* not just C11 atomics and atomic accesses */
    #include <stdatomic.h>
    #define ECB_MEMORY_FENCE         atomic_thread_fence (memory_order_acq_rel)
    #define ECB_MEMORY_FENCE_ACQUIRE atomic_thread_fence (memory_order_acquire)
    #define ECB_MEMORY_FENCE_RELEASE atomic_thread_fence (memory_order_release)
  #endif
#endif

#ifndef ECB_MEMORY_FENCE
  #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
    #if __i386 || __i386__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
      #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */
      #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */
    #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("mfence" : : : "memory")
      #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
      #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */
    #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("sync" : : : "memory")
    #elif defined __ARM_ARCH_6__  || defined __ARM_ARCH_6J__  \
       || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
    #elif defined __ARM_ARCH_7__  || defined __ARM_ARCH_7A__  \
       || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__ 
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("dmb" : : : "memory")
    #elif __sparc || __sparc__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad | " : : : "memory")
      #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad"                               : : : "memory")
      #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore |             #StoreStore")
    #elif defined __s390__ || defined __s390x__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("bcr 15,0" : : : "memory")
    #elif defined __mips__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("sync" : : : "memory")
    #elif defined __alpha__
      #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("mb" : : : "memory")
    #endif
  #endif
#endif

#ifndef ECB_MEMORY_FENCE
  #if ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
    #define ECB_MEMORY_FENCE         __sync_synchronize ()
    /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */
    /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release      (&dummy   ); }) */
  #elif _MSC_VER >= 1400 /* VC++ 2005 */
    #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
    #define ECB_MEMORY_FENCE         _ReadWriteBarrier ()
    #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
    #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
  #elif defined _WIN32
    #include <WinNT.h>
    #define ECB_MEMORY_FENCE         MemoryBarrier () /* actually just xchg on x86... scary */
  #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
    #include <mbarrier.h>
    #define ECB_MEMORY_FENCE         __machine_rw_barrier ()
    #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier  ()
    #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier  ()
  #elif __xlC__
    #define ECB_MEMORY_FENCE         __sync ()
  #endif
#endif

#ifndef ECB_MEMORY_FENCE
  #if !ECB_AVOID_PTHREADS
    /*
     * if you get undefined symbol references to pthread_mutex_lock,
     * or failure to find pthread.h, then you should implement
     * the ECB_MEMORY_FENCE operations for your cpu/compiler
     * OR provide pthread.h and link against the posix thread library
     * of your system.
     */
    #include <pthread.h>
    #define ECB_NEEDS_PTHREADS 1
    #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1

    static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
    #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
  #endif
#endif

#if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
  #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
#endif

#if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
  #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
#endif

/*****************************************************************************/

#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(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_noinline   ecb_attribute ((__noinline__))
#define ecb_unused     ecb_attribute ((__unused__))
#define ecb_const      ecb_attribute ((__const__))
#define ecb_pure       ecb_attribute ((__pure__))

#if ECB_C11
  #define ecb_noreturn   _Noreturn
#else
  #define ecb_noreturn   ecb_attribute ((__noreturn__))
#endif

#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
  #define ecb_artificial
  #define ecb_hot
  #define ecb_cold
#endif

/* 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)

/* count trailing zero bits and count # of one bits */
#if ECB_GCC_VERSION(3,4)
  /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
  #define ecb_ld32(x)      (__builtin_clz      (x) ^ 31)
  #define ecb_ld64(x)      (__builtin_clzll    (x) ^ 63)
  #define ecb_ctz32(x)      __builtin_ctz      (x)
  #define ecb_ctz64(x)      __builtin_ctzll    (x)
  #define ecb_popcount32(x) __builtin_popcount (x)
  /* no popcountll */
#else
  ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
  ecb_function_ int
  ecb_ctz32 (uint32_t x)
  {
    int r = 0;

    x &= ~x + 1; /* this isolates the lowest bit */

#if ECB_branchless_on_i386
    r += !!(x & 0xaaaaaaaa) << 0;
    r += !!(x & 0xcccccccc) << 1;
    r += !!(x & 0xf0f0f0f0) << 2;
    r += !!(x & 0xff00ff00) << 3;
    r += !!(x & 0xffff0000) << 4;
#else
    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;
#endif

    return r;
  }

  ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
  ecb_function_ int
  ecb_ctz64 (uint64_t x)
  {
    int shift = x & 0xffffffffU ? 0 : 32;
    return ecb_ctz32 (x >> shift) + shift;
  }

  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;

    return x >> 24;
  }

  ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
  ecb_function_ int ecb_ld32 (uint32_t x)
  {
    int r = 0;

    if (x >> 16) { x >>= 16; r += 16; }
    if (x >>  8) { x >>=  8; r +=  8; }
    if (x >>  4) { x >>=  4; r +=  4; }
    if (x >>  2) { x >>=  2; r +=  2; }
    if (x >>  1) {           r +=  1; }

    return r;
  }

  ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
  ecb_function_ int ecb_ld64 (uint64_t x)
  {
    int r = 0;

    if (x >> 32) { x >>= 32; r += 32; }

    return r + ecb_ld32 (x);
  }
#endif

ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }

ecb_function_ uint8_t  ecb_bitrev8  (uint8_t  x) ecb_const;
ecb_function_ uint8_t  ecb_bitrev8  (uint8_t  x)
{
  return (  (x * 0x0802U & 0x22110U)
          | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16; 
}

ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
{
  x = ((x >>  1) &     0x5555) | ((x &     0x5555) <<  1);
  x = ((x >>  2) &     0x3333) | ((x &     0x3333) <<  2);
  x = ((x >>  4) &     0x0f0f) | ((x &     0x0f0f) <<  4);
  x = ( x >>  8              ) | ( x               <<  8);

  return x;
}

ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
{
  x = ((x >>  1) & 0x55555555) | ((x & 0x55555555) <<  1);
  x = ((x >>  2) & 0x33333333) | ((x & 0x33333333) <<  2);
  x = ((x >>  4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) <<  4);
  x = ((x >>  8) & 0x00ff00ff) | ((x & 0x00ff00ff) <<  8);
  x = ( x >> 16              ) | ( x               << 16);

  return x;
}

/* popcount64 is only available on 64 bit cpus as gcc builtin */
/* so for this version we are lazy */
ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
ecb_function_ int
ecb_popcount64 (uint64_t x)
{
  return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
}

ecb_inline uint8_t  ecb_rotl8  (uint8_t  x, unsigned int count) ecb_const;
ecb_inline uint8_t  ecb_rotr8  (uint8_t  x, unsigned int count) ecb_const;
ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;

ecb_inline uint8_t  ecb_rotl8  (uint8_t  x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
ecb_inline uint8_t  ecb_rotr8  (uint8_t  x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }

#if ECB_GCC_VERSION(4,3)
  #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
  #define ecb_bswap32(x)  __builtin_bswap32 (x)
  #define ecb_bswap64(x)  __builtin_bswap64 (x)
#else
  ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
  ecb_function_ uint16_t
  ecb_bswap16 (uint16_t x)
  {
    return ecb_rotl16 (x, 8);
  }

  ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
  ecb_function_ uint32_t
  ecb_bswap32 (uint32_t x)
  {
    return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
  }

  ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
  ecb_function_ uint64_t
  ecb_bswap64 (uint64_t x)
  {
    return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
  }
#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_inline void ecb_unreachable (void) ecb_noreturn;
  ecb_inline void ecb_unreachable (void) { }
#endif

/* try to tell the compiler that some condition is definitely true */
#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)

ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
ecb_inline unsigned char
ecb_byteorder_helper (void)
{
  const uint32_t u = 0x11223344;
  return *(unsigned char *)&u;
}

ecb_inline ecb_bool ecb_big_endian    (void) ecb_const;
ecb_inline ecb_bool ecb_big_endian    (void) { return ecb_byteorder_helper () == 0x11; }
ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
ecb_inline 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 __cplusplus
  template<typename T>
  static inline T ecb_div_rd (T val, T div)
  {
    return val < 0 ? - ((-val + div - 1) / div) : (val          ) / div;
  }
  template<typename T>
  static inline T ecb_div_ru (T val, T div)
  {
    return val < 0 ? - ((-val          ) / div) : (val + div - 1) / div;
  }
#else
  #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val)            ) / (div))
  #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val)            ) / (div)) : ((val) + (div) - 1) / (div))
#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

#endif

Revision:	1.91
Committed:	Tue May 29 14:30:44 2012 UTC (12 years ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.90:	+6 -2 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.17	* libecb - http://software.schmorp.de/pkg/libecb
3	root	1.1	*
4	root	1.72	* Copyright (©) 2009-2012 Marc Alexander Lehmann <libecb@schmorp.de>
5	root	1.7	* Copyright (©) 2011 Emanuele Giaquinta
6	root	1.1	* All rights reserved.
7			*
8			* Redistribution and use in source and binary forms, with or without modifica-
9			* tion, are permitted provided that the following conditions are met:
10			*
11			* 1. Redistributions of source code must retain the above copyright notice,
12			* this list of conditions and the following disclaimer.
13			*
14			* 2. Redistributions in binary form must reproduce the above copyright
15			* notice, this list of conditions and the following disclaimer in the
16			* documentation and/or other materials provided with the distribution.
17			*
18			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
19			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
20			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
21			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
22			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
26			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27			* OF THE POSSIBILITY OF SUCH DAMAGE.
28			*/
29
30			#ifndef ECB_H
31			#define ECB_H
32
33	root	1.87	/* 16 bits major, 16 bits minor */
34			#define ECB_VERSION 0x00010001
35
36	root	1.44	#ifdef _WIN32
37			typedef signed char int8_t;
38			typedef unsigned char uint8_t;
39			typedef signed short int16_t;
40			typedef unsigned short uint16_t;
41			typedef signed int int32_t;
42			typedef unsigned int uint32_t;
43			#if __GNUC__
44			typedef signed long long int64_t;
45			typedef unsigned long long uint64_t;
46	root	1.51	#else /* _MSC_VER \|\| __BORLANDC__ */
47	root	1.44	typedef signed __int64 int64_t;
48			typedef unsigned __int64 uint64_t;
49			#endif
50	root	1.87	#ifdef _WIN64
51			#define ECB_PTRSIZE 8
52			typedef uint64_t uintptr_t;
53			typedef int64_t intptr_t;
54			#else
55			#define ECB_PTRSIZE 4
56			typedef uint32_t uintptr_t;
57			typedef int32_t intptr_t;
58			#endif
59	root	1.89	typedef intptr_t ptrdiff_t;
60	root	1.44	#else
61			#include <inttypes.h>
62	root	1.87	#if UINTMAX_MAX > 0xffffffffU
63			#define ECB_PTRSIZE 8
64			#else
65			#define ECB_PTRSIZE 4
66			#endif
67	root	1.44	#endif
68	root	1.6
69	root	1.12	/* many compilers define _GNUC_ to some versions but then only implement
70			* what their idiot authors think are the "more important" extensions,
71	sf-exg	1.59	* causing enormous grief in return for some better fake benchmark numbers.
72	root	1.18	* or so.
73	root	1.12	* we try to detect these and simply assume they are not gcc - if they have
74			* an issue with that they should have done it right in the first place.
75			*/
76	root	1.14	#ifndef ECB_GCC_VERSION
77	root	1.85	#if !defined __GNUC_MINOR__ \|\| defined __INTEL_COMPILER \|\| defined __SUNPRO_C \|\| defined __SUNPRO_CC \|\| defined __llvm__ \|\| defined __clang__
78	root	1.37	#define ECB_GCC_VERSION(major,minor) 0
79			#else
80			#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) \|\| (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
81			#endif
82	root	1.12	#endif
83	root	1.1
84	root	1.91	#define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
85			#define ECB_C99 (__STDC_VERSION__ >= 199901L)
86			#define ECB_C11 (__STDC_VERSION__ >= 201112L)
87			#define ECB_CPP (__cplusplus+0)
88			#define ECB_CPP98 (__cplusplus >= 199711L)
89			#define ECB_CPP11 (__cplusplus >= 201103L)
90	root	1.90
91	root	1.52	/*****************************************************************************/
92
93	root	1.58	/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
94			/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
95
96	root	1.79	#if ECB_NO_THREADS
97			# define ECB_NO_SMP 1
98			#endif
99
100	root	1.58	#if ECB_NO_THREADS \|\| ECB_NO_SMP
101	root	1.64	#define ECB_MEMORY_FENCE do { } while (0)
102	root	1.58	#endif
103
104	root	1.52	#ifndef ECB_MEMORY_FENCE
105	root	1.90	#if ECB_C11 && !defined __STDC_NO_ATOMICS__
106			/* we assume that these memory fences work on all variables/all memory accesses, */
107			/* not just C11 atomics and atomic accesses */
108			#include <stdatomic.h>
109			#define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_acq_rel)
110			#define ECB_MEMORY_FENCE_ACQUIRE atomic_thread_fence (memory_order_acquire)
111			#define ECB_MEMORY_FENCE_RELEASE atomic_thread_fence (memory_order_release)
112			#endif
113			#endif
114
115			#ifndef ECB_MEMORY_FENCE
116	root	1.85	#if ECB_GCC_VERSION(2,5) \|\| defined __INTEL_COMPILER \|\| (__llvm__ && __GNUC__) \|\| __SUNPRO_C >= 0x5110 \|\| __SUNPRO_CC >= 0x5110
117	root	1.73	#if __i386 \|\| __i386__
118	root	1.54	#define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
119	root	1.57	#define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */
120			#define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */
121	root	1.73	#elif __amd64 \|\| __amd64__ \|\| __x86_64 \|\| __x86_64__
122	root	1.52	#define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
123			#define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
124	root	1.57	#define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */
125	root	1.63	#elif __powerpc__ \|\| __ppc__ \|\| __powerpc64__ \|\| __ppc64__
126			#define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
127	root	1.85	#elif defined __ARM_ARCH_6__ \|\| defined __ARM_ARCH_6J__ \
128			\|\| defined __ARM_ARCH_6K__ \|\| defined __ARM_ARCH_6ZK__
129	root	1.84	#define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
130	root	1.85	#elif defined __ARM_ARCH_7__ \|\| defined __ARM_ARCH_7A__ \
131			\|\| defined __ARM_ARCH_7M__ \|\| defined __ARM_ARCH_7R__
132	root	1.65	#define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
133	root	1.73	#elif __sparc \|\| __sparc__
134	root	1.74	#define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore \| #LoadLoad \| #StoreStore \| #StoreLoad \| " : : : "memory")
135	root	1.77	#define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore \| #LoadLoad" : : : "memory")
136	root	1.74	#define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore \| #StoreStore")
137	root	1.85	#elif defined __s390__ \|\| defined __s390x__
138	root	1.77	#define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
139	root	1.85	#elif defined __mips__
140	root	1.80	#define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
141	root	1.86	#elif defined __alpha__
142			#define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
143	root	1.52	#endif
144			#endif
145			#endif
146
147			#ifndef ECB_MEMORY_FENCE
148	root	1.85	#if ECB_GCC_VERSION(4,4) \|\| defined __INTEL_COMPILER \|\| defined __clang__
149	root	1.52	#define ECB_MEMORY_FENCE __sync_synchronize ()
150	root	1.62	/#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) /
151			/#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) /
152	root	1.57	#elif _MSC_VER >= 1400 /* VC++ 2005 */
153			#pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
154			#define ECB_MEMORY_FENCE _ReadWriteBarrier ()
155			#define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
156			#define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
157	root	1.85	#elif defined _WIN32
158	root	1.55	#include <WinNT.h>
159	root	1.57	#define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
160	root	1.72	#elif __SUNPRO_C >= 0x5110 \|\| __SUNPRO_CC >= 0x5110
161			#include <mbarrier.h>
162			#define ECB_MEMORY_FENCE __machine_rw_barrier ()
163			#define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
164			#define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
165	root	1.82	#elif __xlC__
166	root	1.83	#define ECB_MEMORY_FENCE __sync ()
167	root	1.52	#endif
168			#endif
169
170	root	1.53	#ifndef ECB_MEMORY_FENCE
171	root	1.62	#if !ECB_AVOID_PTHREADS
172			/*
173			* if you get undefined symbol references to pthread_mutex_lock,
174			* or failure to find pthread.h, then you should implement
175			* the ECB_MEMORY_FENCE operations for your cpu/compiler
176			* OR provide pthread.h and link against the posix thread library
177			* of your system.
178			*/
179			#include <pthread.h>
180			#define ECB_NEEDS_PTHREADS 1
181			#define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
182	root	1.52
183	root	1.62	static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
184			#define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
185			#endif
186			#endif
187
188	root	1.85	#if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
189	root	1.52	#define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
190	root	1.62	#endif
191
192	root	1.85	#if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
193	root	1.52	#define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
194			#endif
195
196			/*****************************************************************************/
197
198	root	1.39	#if __cplusplus
199	root	1.46	#define ecb_inline static inline
200	root	1.38	#elif ECB_GCC_VERSION(2,5)
201	root	1.46	#define ecb_inline static __inline__
202	root	1.39	#elif ECB_C99
203	root	1.46	#define ecb_inline static inline
204	root	1.29	#else
205	root	1.46	#define ecb_inline static
206	root	1.38	#endif
207
208			#if ECB_GCC_VERSION(3,3)
209			#define ecb_restrict __restrict__
210	root	1.39	#elif ECB_C99
211	root	1.38	#define ecb_restrict restrict
212			#else
213			#define ecb_restrict
214	root	1.4	#endif
215
216	root	1.38	typedef int ecb_bool;
217
218	root	1.8	#define ECB_CONCAT_(a, b) a ## b
219			#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
220			#define ECB_STRINGIFY_(a) # a
221			#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
222
223	root	1.46	#define ecb_function_ ecb_inline
224	root	1.3
225	root	1.1	#if ECB_GCC_VERSION(3,1)
226	root	1.37	#define ecb_attribute(attrlist) __attribute__(attrlist)
227			#define ecb_is_constant(expr) __builtin_constant_p (expr)
228			#define ecb_expect(expr,value) __builtin_expect ((expr),(value))
229			#define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
230			#else
231			#define ecb_attribute(attrlist)
232			#define ecb_is_constant(expr) 0
233			#define ecb_expect(expr,value) (expr)
234			#define ecb_prefetch(addr,rw,locality)
235	root	1.1	#endif
236
237	root	1.2	/* no emulation for ecb_decltype */
238	root	1.1	#if ECB_GCC_VERSION(4,5)
239	root	1.37	#define ecb_decltype(x) __decltype(x)
240	root	1.1	#elif ECB_GCC_VERSION(3,0)
241	root	1.39	#define ecb_decltype(x) __typeof(x)
242	root	1.1	#endif
243
244	root	1.24	#define ecb_noinline ecb_attribute ((__noinline__))
245			#define ecb_unused ecb_attribute ((__unused__))
246			#define ecb_const ecb_attribute ((__const__))
247			#define ecb_pure ecb_attribute ((__pure__))
248	root	1.35
249	root	1.90	#if ECB_C11
250			#define ecb_noreturn _Noreturn
251			#else
252			#define ecb_noreturn ecb_attribute ((__noreturn__))
253			#endif
254
255	root	1.35	#if ECB_GCC_VERSION(4,3)
256	root	1.39	#define ecb_artificial ecb_attribute ((__artificial__))
257			#define ecb_hot ecb_attribute ((__hot__))
258			#define ecb_cold ecb_attribute ((__cold__))
259	root	1.35	#else
260			#define ecb_artificial
261			#define ecb_hot
262			#define ecb_cold
263			#endif
264	root	1.1
265	root	1.39	/* put around conditional expressions if you are very sure that the */
266			/* expression is mostly true or mostly false. note that these return */
267			/* booleans, not the expression. */
268	root	1.33	#define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
269			#define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
270	root	1.36	/* for compatibility to the rest of the world */
271	root	1.33	#define ecb_likely(expr) ecb_expect_true (expr)
272			#define ecb_unlikely(expr) ecb_expect_false (expr)
273	root	1.1
274	root	1.3	/* count trailing zero bits and count # of one bits */
275	root	1.1	#if ECB_GCC_VERSION(3,4)
276	root	1.49	/* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
277			#define ecb_ld32(x) (__builtin_clz (x) ^ 31)
278			#define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
279	root	1.35	#define ecb_ctz32(x) __builtin_ctz (x)
280	root	1.49	#define ecb_ctz64(x) __builtin_ctzll (x)
281	root	1.35	#define ecb_popcount32(x) __builtin_popcount (x)
282	root	1.49	/* no popcountll */
283	root	1.1	#else
284	root	1.39	ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
285			ecb_function_ int
286	root	1.35	ecb_ctz32 (uint32_t x)
287			{
288			int r = 0;
289
290	root	1.48	x &= ~x + 1; /* this isolates the lowest bit */
291	root	1.35
292	root	1.50	#if ECB_branchless_on_i386
293			r += !!(x & 0xaaaaaaaa) << 0;
294			r += !!(x & 0xcccccccc) << 1;
295			r += !!(x & 0xf0f0f0f0) << 2;
296			r += !!(x & 0xff00ff00) << 3;
297			r += !!(x & 0xffff0000) << 4;
298			#else
299	root	1.35	if (x & 0xaaaaaaaa) r += 1;
300			if (x & 0xcccccccc) r += 2;
301			if (x & 0xf0f0f0f0) r += 4;
302			if (x & 0xff00ff00) r += 8;
303			if (x & 0xffff0000) r += 16;
304	root	1.50	#endif
305	root	1.35
306			return r;
307			}
308
309	root	1.49	ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
310			ecb_function_ int
311			ecb_ctz64 (uint64_t x)
312			{
313			int shift = x & 0xffffffffU ? 0 : 32;
314	root	1.50	return ecb_ctz32 (x >> shift) + shift;
315	root	1.49	}
316
317	root	1.39	ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
318			ecb_function_ int
319	root	1.35	ecb_popcount32 (uint32_t x)
320			{
321			x -= (x >> 1) & 0x55555555;
322			x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
323			x = ((x >> 4) + x) & 0x0f0f0f0f;
324			x *= 0x01010101;
325	root	1.1
326	root	1.35	return x >> 24;
327			}
328	root	1.49
329			ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
330			ecb_function_ int ecb_ld32 (uint32_t x)
331			{
332	root	1.50	int r = 0;
333	root	1.49
334	root	1.50	if (x >> 16) { x >>= 16; r += 16; }
335			if (x >> 8) { x >>= 8; r += 8; }
336			if (x >> 4) { x >>= 4; r += 4; }
337			if (x >> 2) { x >>= 2; r += 2; }
338			if (x >> 1) { r += 1; }
339	root	1.49
340			return r;
341			}
342
343			ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
344			ecb_function_ int ecb_ld64 (uint64_t x)
345			{
346	root	1.50	int r = 0;
347	root	1.49
348	root	1.50	if (x >> 32) { x >>= 32; r += 32; }
349	root	1.49
350	root	1.50	return r + ecb_ld32 (x);
351	root	1.49	}
352	root	1.1	#endif
353
354	root	1.88	ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
355			ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
356			ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
357			ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
358
359	root	1.71	ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
360	root	1.70	ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
361			{
362			return ( (x * 0x0802U & 0x22110U)
363			\| (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
364			}
365
366	root	1.71	ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
367	root	1.70	ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
368			{
369			x = ((x >> 1) & 0x5555) \| ((x & 0x5555) << 1);
370			x = ((x >> 2) & 0x3333) \| ((x & 0x3333) << 2);
371			x = ((x >> 4) & 0x0f0f) \| ((x & 0x0f0f) << 4);
372			x = ( x >> 8 ) \| ( x << 8);
373
374			return x;
375			}
376
377	root	1.71	ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
378	root	1.70	ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
379			{
380			x = ((x >> 1) & 0x55555555) \| ((x & 0x55555555) << 1);
381			x = ((x >> 2) & 0x33333333) \| ((x & 0x33333333) << 2);
382			x = ((x >> 4) & 0x0f0f0f0f) \| ((x & 0x0f0f0f0f) << 4);
383			x = ((x >> 8) & 0x00ff00ff) \| ((x & 0x00ff00ff) << 8);
384			x = ( x >> 16 ) \| ( x << 16);
385
386			return x;
387			}
388
389	root	1.49	/* popcount64 is only available on 64 bit cpus as gcc builtin */
390			/* so for this version we are lazy */
391			ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
392			ecb_function_ int
393			ecb_popcount64 (uint64_t x)
394			{
395			return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
396			}
397
398	root	1.50	ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
399			ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
400			ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
401			ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
402			ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
403			ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
404			ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
405			ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
406
407			ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) \| (x << count); }
408			ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) \| (x >> count); }
409			ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) \| (x << count); }
410			ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) \| (x >> count); }
411			ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) \| (x << count); }
412			ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) \| (x >> count); }
413			ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) \| (x << count); }
414			ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) \| (x >> count); }
415
416	root	1.13	#if ECB_GCC_VERSION(4,3)
417	root	1.49	#define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
418			#define ecb_bswap32(x) __builtin_bswap32 (x)
419			#define ecb_bswap64(x) __builtin_bswap64 (x)
420	root	1.13	#else
421	root	1.50	ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
422			ecb_function_ uint16_t
423			ecb_bswap16 (uint16_t x)
424	root	1.49	{
425	root	1.50	return ecb_rotl16 (x, 8);
426	root	1.49	}
427
428	root	1.39	ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
429			ecb_function_ uint32_t
430	root	1.35	ecb_bswap32 (uint32_t x)
431			{
432	root	1.50	return (((uint32_t)ecb_bswap16 (x)) << 16) \| ecb_bswap16 (x >> 16);
433	root	1.35	}
434
435	root	1.49	ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
436			ecb_function_ uint64_t
437			ecb_bswap64 (uint64_t x)
438	root	1.35	{
439	root	1.50	return (((uint64_t)ecb_bswap32 (x)) << 32) \| ecb_bswap32 (x >> 32);
440	root	1.35	}
441	root	1.13	#endif
442
443			#if ECB_GCC_VERSION(4,5)
444	root	1.35	#define ecb_unreachable() __builtin_unreachable ()
445	root	1.13	#else
446	root	1.35	/* this seems to work fine, but gcc always emits a warning for it :/ */
447	root	1.75	ecb_inline void ecb_unreachable (void) ecb_noreturn;
448			ecb_inline void ecb_unreachable (void) { }
449	root	1.13	#endif
450
451	root	1.41	/* try to tell the compiler that some condition is definitely true */
452			#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
453
454	root	1.76	ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
455			ecb_inline unsigned char
456	root	1.23	ecb_byteorder_helper (void)
457	root	1.3	{
458			const uint32_t u = 0x11223344;
459			return (unsigned char )&u;
460			}
461
462	root	1.76	ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
463			ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
464			ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
465			ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
466	root	1.3
467	root	1.39	#if ECB_GCC_VERSION(3,0) \|\| ECB_C99
468	root	1.35	#define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
469	root	1.31	#else
470	root	1.35	#define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
471	root	1.31	#endif
472	root	1.21
473	sf-exg	1.68	#if __cplusplus
474			template<typename T>
475			static inline T ecb_div_rd (T val, T div)
476			{
477			return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
478			}
479			template<typename T>
480			static inline T ecb_div_ru (T val, T div)
481			{
482			return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
483			}
484			#else
485			#define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
486			#define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
487			#endif
488	sf-exg	1.67
489	root	1.5	#if ecb_cplusplus_does_not_suck
490	root	1.40	/* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
491	root	1.35	template<typename T, int N>
492			static inline int ecb_array_length (const T (&arr)[N])
493			{
494			return N;
495			}
496	root	1.5	#else
497	root	1.35	#define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
498	root	1.5	#endif
499
500	root	1.1	#endif
501