brotli/common/port.h
2016-06-03 10:51:04 +02:00

108 lines
2.6 KiB
C

/* Copyright 2016 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
/* Macros for compiler / platform specific features and build options. */
#ifndef BROTLI_COMMON_PORT_H_
#define BROTLI_COMMON_PORT_H_
/* Compatibility with non-clang compilers. */
#ifndef __has_builtin
#define __has_builtin(x) 0
#endif
#ifndef __has_attribute
#define __has_attribute(x) 0
#endif
#ifndef __has_feature
#define __has_feature(x) 0
#endif
#if defined(__GNUC__) && defined(__GNUC_MINOR__)
#define BROTLI_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
#else
#define BROTLI_GCC_VERSION 0
#endif
#if defined(__ICC)
#define BROTLI_ICC_VERSION __ICC
#else
#define BROTLI_ICC_VERSION 0
#endif
#if defined(BROTLI_BUILD_MODERN_COMPILER)
#define BROTLI_MODERN_COMPILER 1
#elif BROTLI_GCC_VERSION > 300 || BROTLI_ICC_VERSION >= 1600
#define BROTLI_MODERN_COMPILER 1
#else
#define BROTLI_MODERN_COMPILER 0
#endif
/* Define "PREDICT_TRUE" and "PREDICT_FALSE" macros for capable compilers.
To apply compiler hint, enclose the branching condition into macros, like this:
if (PREDICT_TRUE(zero == 0)) {
// main execution path
} else {
// compiler should place this code outside of main execution path
}
OR:
if (PREDICT_FALSE(something_rare_or_unexpected_happens)) {
// compiler should place this code outside of main execution path
}
*/
#if BROTLI_MODERN_COMPILER || __has_builtin(__builtin_expect)
#define PREDICT_TRUE(x) (__builtin_expect(!!(x), 1))
#define PREDICT_FALSE(x) (__builtin_expect(x, 0))
#else
#define PREDICT_FALSE(x) (x)
#define PREDICT_TRUE(x) (x)
#endif
#if BROTLI_MODERN_COMPILER || __has_attribute(always_inline)
#define ATTRIBUTE_ALWAYS_INLINE __attribute__ ((always_inline))
#else
#define ATTRIBUTE_ALWAYS_INLINE
#endif
#if defined(_WIN32) || defined(__CYGWIN__)
#define ATTRIBUTE_VISIBILITY_HIDDEN
#elif BROTLI_MODERN_COMPILER || __has_attribute(visibility)
#define ATTRIBUTE_VISIBILITY_HIDDEN __attribute__ ((visibility ("hidden")))
#else
#define ATTRIBUTE_VISIBILITY_HIDDEN
#endif
#ifndef BROTLI_INTERNAL
#define BROTLI_INTERNAL ATTRIBUTE_VISIBILITY_HIDDEN
#endif
#ifndef _MSC_VER
#if defined(__cplusplus) || !defined(__STRICT_ANSI__) || \
__STDC_VERSION__ >= 199901L
#define BROTLI_INLINE inline ATTRIBUTE_ALWAYS_INLINE
#else
#define BROTLI_INLINE
#endif
#else /* _MSC_VER */
#define BROTLI_INLINE __forceinline
#endif /* _MSC_VER */
#if BROTLI_MODERN_COMPILER || __has_attribute(noinline)
#define BROTLI_NOINLINE __attribute__((noinline))
#else
#define BROTLI_NOINLINE
#endif
#define BROTLI_UNUSED(X) (void)(X)
#endif /* BROTLI_COMMON_PORT_H_ */