/* * Copyright (c) Yann Collet, Facebook, Inc. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). * You may select, at your option, one of the above-listed licenses. */ #ifndef ZSTD_COMPILER_H #define ZSTD_COMPILER_H #include "portability_macros.h" /*-******************************************************* * Compiler specifics *********************************************************/ /* force inlining */ #if !defined(ZSTD_NO_INLINE) #if (defined(__GNUC__) && !defined(__STRICT_ANSI__)) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ #define INLINE_KEYWORD … #else #define INLINE_KEYWORD #endif #define FORCE_INLINE_ATTR … #else #define INLINE_KEYWORD #define FORCE_INLINE_ATTR #endif /* On MSVC qsort requires that functions passed into it use the __cdecl calling conversion(CC). This explicitly marks such functions as __cdecl so that the code will still compile if a CC other than __cdecl has been made the default. */ #define WIN_CDECL /* * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant * parameters. They must be inlined for the compiler to eliminate the constant * branches. */ #define FORCE_INLINE_TEMPLATE … /* * HINT_INLINE is used to help the compiler generate better code. It is *not* * used for "templates", so it can be tweaked based on the compilers * performance. * * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the * always_inline attribute. * * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline * attribute. */ #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5 #define HINT_INLINE … #else #define HINT_INLINE … #endif /* UNUSED_ATTR tells the compiler it is okay if the function is unused. */ #define UNUSED_ATTR … /* force no inlining */ #define FORCE_NOINLINE … /* target attribute */ #define TARGET_ATTRIBUTE(target) … /* Target attribute for BMI2 dynamic dispatch. * Enable lzcnt, bmi, and bmi2. * We test for bmi1 & bmi2. lzcnt is included in bmi1. */ #define BMI2_TARGET_ATTRIBUTE … /* prefetch * can be disabled, by declaring NO_PREFETCH build macro */ #if ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) ) #define PREFETCH_L1(ptr) … #define PREFETCH_L2(ptr) … #elif defined(__aarch64__) #define PREFETCH_L1 … #define PREFETCH_L2 … #else #define PREFETCH_L1 … #define PREFETCH_L2 … #endif /* NO_PREFETCH */ #define CACHELINE_SIZE … #define PREFETCH_AREA(p, s) … /* vectorization * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax, * and some compilers, like Intel ICC and MCST LCC, do not support it at all. */ #if !defined(__INTEL_COMPILER) && !defined(__clang__) && defined(__GNUC__) && !defined(__LCC__) # if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5) #define DONT_VECTORIZE … # else #define DONT_VECTORIZE … # endif #else #define DONT_VECTORIZE #endif /* Tell the compiler that a branch is likely or unlikely. * Only use these macros if it causes the compiler to generate better code. * If you can remove a LIKELY/UNLIKELY annotation without speed changes in gcc * and clang, please do. */ #define LIKELY(x) … #define UNLIKELY(x) … #if __has_builtin(__builtin_unreachable) || (defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))) #define ZSTD_UNREACHABLE … #else #define ZSTD_UNREACHABLE … #endif /* disable warnings */ /*Like DYNAMIC_BMI2 but for compile time determination of BMI2 support*/ /* compile time determination of SIMD support */ /* C-language Attributes are added in C23. */ #if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute) #define ZSTD_HAS_C_ATTRIBUTE … #else #define ZSTD_HAS_C_ATTRIBUTE(x) … #endif /* Only use C++ attributes in C++. Some compilers report support for C++ * attributes when compiling with C. */ #define ZSTD_HAS_CPP_ATTRIBUTE(x) … /* Define ZSTD_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute. * - C23: https://en.cppreference.com/w/c/language/attributes/fallthrough * - CPP17: https://en.cppreference.com/w/cpp/language/attributes/fallthrough * - Else: __attribute__((__fallthrough__)) */ #define ZSTD_FALLTHROUGH … /*-************************************************************** * Alignment check *****************************************************************/ /* this test was initially positioned in mem.h, * but this file is removed (or replaced) for linux kernel * so it's now hosted in compiler.h, * which remains valid for both user & kernel spaces. */ #ifndef ZSTD_ALIGNOF /* covers gcc, clang & MSVC */ /* note : this section must come first, before C11, * due to a limitation in the kernel source generator */ #define ZSTD_ALIGNOF(T) … #endif /* ZSTD_ALIGNOF */ /*-************************************************************** * Sanitizer *****************************************************************/ #endif /* ZSTD_COMPILER_H */
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