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Diffstat (limited to 'lib/zstd/common/compiler.h')
| -rw-r--r-- | lib/zstd/common/compiler.h | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/lib/zstd/common/compiler.h b/lib/zstd/common/compiler.h new file mode 100644 index 0000000000..f5a9c70a22 --- /dev/null +++ b/lib/zstd/common/compiler.h @@ -0,0 +1,177 @@ +/* + * 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 + +/*-******************************************************* +* 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 inline +#else +# define INLINE_KEYWORD +#endif + +#define FORCE_INLINE_ATTR __attribute__((always_inline)) + +#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 explictly 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 static INLINE_KEYWORD FORCE_INLINE_ATTR +/* + * 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 static INLINE_KEYWORD +#else +# define HINT_INLINE static INLINE_KEYWORD FORCE_INLINE_ATTR +#endif + +/* UNUSED_ATTR tells the compiler it is okay if the function is unused. */ +#define UNUSED_ATTR __attribute__((unused)) + +/* force no inlining */ +#define FORCE_NOINLINE static __attribute__((__noinline__)) + + +/* target attribute */ +#ifndef __has_attribute + #define __has_attribute(x) 0 /* Compatibility with non-clang compilers. */ +#endif +#define TARGET_ATTRIBUTE(target) __attribute__((__target__(target))) + +/* Enable runtime BMI2 dispatch based on the CPU. + * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. + */ +#ifndef DYNAMIC_BMI2 + #if ((defined(__clang__) && __has_attribute(__target__)) \ + || (defined(__GNUC__) \ + && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \ + && (defined(__x86_64__) || defined(_M_X86)) \ + && !defined(__BMI2__) + # define DYNAMIC_BMI2 1 + #else + # define DYNAMIC_BMI2 0 + #endif +#endif + +/* prefetch + * can be disabled, by declaring NO_PREFETCH build macro */ +#if ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) ) +# define PREFETCH_L1(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */) +# define PREFETCH_L2(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */) +#elif defined(__aarch64__) +# define PREFETCH_L1(ptr) __asm__ __volatile__("prfm pldl1keep, %0" ::"Q"(*(ptr))) +# define PREFETCH_L2(ptr) __asm__ __volatile__("prfm pldl2keep, %0" ::"Q"(*(ptr))) +#else +# define PREFETCH_L1(ptr) (void)(ptr) /* disabled */ +# define PREFETCH_L2(ptr) (void)(ptr) /* disabled */ +#endif /* NO_PREFETCH */ + +#define CACHELINE_SIZE 64 + +#define PREFETCH_AREA(p, s) { \ + const char* const _ptr = (const char*)(p); \ + size_t const _size = (size_t)(s); \ + size_t _pos; \ + for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) { \ + PREFETCH_L2(_ptr + _pos); \ + } \ +} + +/* vectorization + * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax */ +#if !defined(__INTEL_COMPILER) && !defined(__clang__) && defined(__GNUC__) +# if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5) +# define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize"))) +# else +# define DONT_VECTORIZE _Pragma("GCC optimize(\"no-tree-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) (__builtin_expect((x), 1)) +#define UNLIKELY(x) (__builtin_expect((x), 0)) + +/* disable warnings */ + +/*Like DYNAMIC_BMI2 but for compile time determination of BMI2 support*/ + + +/* compat. with non-clang compilers */ +#ifndef __has_builtin +# define __has_builtin(x) 0 +#endif + +/* compat. with non-clang compilers */ +#ifndef __has_feature +# define __has_feature(x) 0 +#endif + +/* C-language Attributes are added in C23. */ +#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute) +# define ZSTD_HAS_C_ATTRIBUTE(x) __has_c_attribute(x) +#else +# define ZSTD_HAS_C_ATTRIBUTE(x) 0 +#endif + +/* Only use C++ attributes in C++. Some compilers report support for C++ + * attributes when compiling with C. + */ +#define ZSTD_HAS_CPP_ATTRIBUTE(x) 0 + +/* 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 fallthrough + +/* detects whether we are being compiled under msan */ + + +/* detects whether we are being compiled under asan */ + + +#endif /* ZSTD_COMPILER_H */ |