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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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