mirror of
https://github.com/google/brotli.git
synced 2024-11-27 05:40:07 +00:00
143 lines
3.9 KiB
C
143 lines
3.9 KiB
C
/* Copyright 2013 Google Inc. All Rights Reserved.
|
|
|
|
Distributed under MIT license.
|
|
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
|
|
*/
|
|
|
|
// Macros for endianness, branch prediction and unaligned loads and stores.
|
|
|
|
#ifndef BROTLI_ENC_PORT_H_
|
|
#define BROTLI_ENC_PORT_H_
|
|
|
|
#include <assert.h>
|
|
#include <string.h>
|
|
#include "./types.h"
|
|
|
|
#if defined OS_LINUX || defined OS_CYGWIN
|
|
#include <endian.h>
|
|
#elif defined OS_FREEBSD
|
|
#include <machine/endian.h>
|
|
#elif defined OS_MACOSX
|
|
#include <machine/endian.h>
|
|
/* Let's try and follow the Linux convention */
|
|
#define __BYTE_ORDER BYTE_ORDER
|
|
#define __LITTLE_ENDIAN LITTLE_ENDIAN
|
|
#endif
|
|
|
|
// define the macro IS_LITTLE_ENDIAN
|
|
// using the above endian definitions from endian.h if
|
|
// endian.h was included
|
|
#ifdef __BYTE_ORDER
|
|
#if __BYTE_ORDER == __LITTLE_ENDIAN
|
|
#define IS_LITTLE_ENDIAN
|
|
#endif
|
|
|
|
#else
|
|
|
|
#if defined(__LITTLE_ENDIAN__)
|
|
#define IS_LITTLE_ENDIAN
|
|
#endif
|
|
#endif // __BYTE_ORDER
|
|
|
|
#if defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
|
|
#define IS_LITTLE_ENDIAN
|
|
#endif
|
|
|
|
// Enable little-endian optimization for x64 architecture on Windows.
|
|
#if (defined(_WIN32) || defined(_WIN64)) && defined(_M_X64)
|
|
#define IS_LITTLE_ENDIAN
|
|
#endif
|
|
|
|
/* Compatibility with non-clang compilers. */
|
|
#ifndef __has_builtin
|
|
#define __has_builtin(x) 0
|
|
#endif
|
|
|
|
#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ > 95) || \
|
|
(defined(__llvm__) && __has_builtin(__builtin_expect))
|
|
#define PREDICT_FALSE(x) (__builtin_expect(x, 0))
|
|
#define PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
|
|
#else
|
|
#define PREDICT_FALSE(x) (x)
|
|
#define PREDICT_TRUE(x) (x)
|
|
#endif
|
|
|
|
// Portable handling of unaligned loads, stores, and copies.
|
|
// On some platforms, like ARM, the copy functions can be more efficient
|
|
// then a load and a store.
|
|
|
|
#if defined(ARCH_PIII) || \
|
|
defined(ARCH_ATHLON) || defined(ARCH_K8) || defined(_ARCH_PPC)
|
|
|
|
// x86 and x86-64 can perform unaligned loads/stores directly;
|
|
// modern PowerPC hardware can also do unaligned integer loads and stores;
|
|
// but note: the FPU still sends unaligned loads and stores to a trap handler!
|
|
|
|
#define BROTLI_UNALIGNED_LOAD32(_p) (*reinterpret_cast<const uint32_t *>(_p))
|
|
#define BROTLI_UNALIGNED_LOAD64(_p) (*reinterpret_cast<const uint64_t *>(_p))
|
|
|
|
#define BROTLI_UNALIGNED_STORE32(_p, _val) \
|
|
(*reinterpret_cast<uint32_t *>(_p) = (_val))
|
|
#define BROTLI_UNALIGNED_STORE64(_p, _val) \
|
|
(*reinterpret_cast<uint64_t *>(_p) = (_val))
|
|
|
|
#elif defined(__arm__) && \
|
|
!defined(__ARM_ARCH_5__) && \
|
|
!defined(__ARM_ARCH_5T__) && \
|
|
!defined(__ARM_ARCH_5TE__) && \
|
|
!defined(__ARM_ARCH_5TEJ__) && \
|
|
!defined(__ARM_ARCH_6__) && \
|
|
!defined(__ARM_ARCH_6J__) && \
|
|
!defined(__ARM_ARCH_6K__) && \
|
|
!defined(__ARM_ARCH_6Z__) && \
|
|
!defined(__ARM_ARCH_6ZK__) && \
|
|
!defined(__ARM_ARCH_6T2__)
|
|
|
|
// ARMv7 and newer support native unaligned accesses, but only of 16-bit
|
|
// and 32-bit values (not 64-bit); older versions either raise a fatal signal,
|
|
// do an unaligned read and rotate the words around a bit, or do the reads very
|
|
// slowly (trip through kernel mode).
|
|
|
|
#define BROTLI_UNALIGNED_LOAD32(_p) (*reinterpret_cast<const uint32_t *>(_p))
|
|
#define BROTLI_UNALIGNED_STORE32(_p, _val) \
|
|
(*reinterpret_cast<uint32_t *>(_p) = (_val))
|
|
|
|
inline uint64_t BROTLI_UNALIGNED_LOAD64(const void *p) {
|
|
uint64_t t;
|
|
memcpy(&t, p, sizeof t);
|
|
return t;
|
|
}
|
|
|
|
inline void BROTLI_UNALIGNED_STORE64(void *p, uint64_t v) {
|
|
memcpy(p, &v, sizeof v);
|
|
}
|
|
|
|
#else
|
|
|
|
// These functions are provided for architectures that don't support
|
|
// unaligned loads and stores.
|
|
|
|
inline uint32_t BROTLI_UNALIGNED_LOAD32(const void *p) {
|
|
uint32_t t;
|
|
memcpy(&t, p, sizeof t);
|
|
return t;
|
|
}
|
|
|
|
inline uint64_t BROTLI_UNALIGNED_LOAD64(const void *p) {
|
|
uint64_t t;
|
|
memcpy(&t, p, sizeof t);
|
|
return t;
|
|
}
|
|
|
|
inline void BROTLI_UNALIGNED_STORE32(void *p, uint32_t v) {
|
|
memcpy(p, &v, sizeof v);
|
|
}
|
|
|
|
inline void BROTLI_UNALIGNED_STORE64(void *p, uint64_t v) {
|
|
memcpy(p, &v, sizeof v);
|
|
}
|
|
|
|
#endif
|
|
|
|
#endif // BROTLI_ENC_PORT_H_
|