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foundationdb/fdbrpc/libeio/ecb.h

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/*
* 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
#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
#else
#include <inttypes.h>
#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
/*****************************************************************************/
/* 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 || ECB_NO_SMP
#define ECB_MEMORY_FENCE do { } while (0)
#endif
#ifndef ECB_MEMORY_FENCE
#if ECB_GCC_VERSION(2,5) || defined(__INTEL_COMPILER) || defined(__clang__)
#if __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
#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")
#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 */
#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
/*****************************************************************************/
#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(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_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
#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
/* 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_function_ void ecb_unreachable (void) ecb_noreturn;
ecb_function_ 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_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;
}
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 __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
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