lib/common/compiler.h - third_party/zstd - Git at Google

 /*
  * Copyright (c) 2016-2021, 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

 #if defined(__GNUC__) || defined(__ICCARM__)
 #  define FORCE_INLINE_ATTR __attribute__((always_inline))
 #elif defined(_MSC_VER)
 #  define FORCE_INLINE_ATTR __forceinline
 #else
 #  define FORCE_INLINE_ATTR
 #endif

 #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.
 */
 #if  defined(_MSC_VER)
 #  define WIN_CDECL __cdecl
 #else
 #  define WIN_CDECL
 #endif

 /**
  * 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. */
 #if defined(__GNUC__)
 #  define UNUSED_ATTR __attribute__((unused))
 #else
 #  define UNUSED_ATTR
 #endif

 /* force no inlining */
 #ifdef _MSC_VER
 #  define FORCE_NOINLINE static __declspec(noinline)
 #else
 #  if defined(__GNUC__) || defined(__ICCARM__)
 #    define FORCE_NOINLINE static __attribute__((__noinline__))
 #  else
 #    define FORCE_NOINLINE static
 #  endif
 #endif


 /* target attribute */
 #ifndef __has_attribute
   #define __has_attribute(x) 0  /* Compatibility with non-clang compilers. */
 #endif
 #if defined(__GNUC__) || defined(__ICCARM__)
 #  define TARGET_ATTRIBUTE(target) __attribute__((__target__(target)))
 #else
 #  define TARGET_ATTRIBUTE(target)
 #endif

 /* 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 defined(NO_PREFETCH)
 #  define PREFETCH_L1(ptr)  (void)(ptr)  /* disabled */
 #  define PREFETCH_L2(ptr)  (void)(ptr)  /* disabled */
 #else
 #  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))  /* _mm_prefetch() is not defined outside of x86/x64 */
 #    include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
 #    define PREFETCH_L1(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
 #    define PREFETCH_L2(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T1)
 #  elif defined(__GNUC__) && ( (__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
 #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.
  */
 #if defined(__GNUC__)
 #define LIKELY(x) (__builtin_expect((x), 1))
 #define UNLIKELY(x) (__builtin_expect((x), 0))
 #else
 #define LIKELY(x) (x)
 #define UNLIKELY(x) (x)
 #endif

 /* disable warnings */
 #ifdef _MSC_VER    /* Visual Studio */
 #  include <intrin.h>                    /* For Visual 2005 */
 #  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */
 #  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
 #  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
 #  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
 #  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
 #endif

 /*Like DYNAMIC_BMI2 but for compile time determination of BMI2 support*/
 #ifndef STATIC_BMI2
 #  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))
 #    ifdef __AVX2__  //MSVC does not have a BMI2 specific flag, but every CPU that supports AVX2 also supports BMI2
 #       define STATIC_BMI2 1
 #    endif
 #  endif
 #endif

 #ifndef STATIC_BMI2
     #define STATIC_BMI2 0
 #endif

 /* 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

 /* detects whether we are being compiled under msan */
 #ifndef ZSTD_MEMORY_SANITIZER
 #  if __has_feature(memory_sanitizer)
 #    define ZSTD_MEMORY_SANITIZER 1
 #  else
 #    define ZSTD_MEMORY_SANITIZER 0
 #  endif
 #endif

 #if ZSTD_MEMORY_SANITIZER
 /* Not all platforms that support msan provide sanitizers/msan_interface.h.
  * We therefore declare the functions we need ourselves, rather than trying to
  * include the header file... */
 #include <stddef.h>  /* size_t */
 #define ZSTD_DEPS_NEED_STDINT
 #include "zstd_deps.h"  /* intptr_t */

 /* Make memory region fully initialized (without changing its contents). */
 void __msan_unpoison(const volatile void *a, size_t size);

 /* Make memory region fully uninitialized (without changing its contents).
    This is a legacy interface that does not update origin information. Use
    __msan_allocated_memory() instead. */
 void __msan_poison(const volatile void *a, size_t size);

 /* Returns the offset of the first (at least partially) poisoned byte in the
    memory range, or -1 if the whole range is good. */
 intptr_t __msan_test_shadow(const volatile void *x, size_t size);
 #endif

 /* detects whether we are being compiled under asan */
 #ifndef ZSTD_ADDRESS_SANITIZER
 #  if __has_feature(address_sanitizer)
 #    define ZSTD_ADDRESS_SANITIZER 1
 #  elif defined(__SANITIZE_ADDRESS__)
 #    define ZSTD_ADDRESS_SANITIZER 1
 #  else
 #    define ZSTD_ADDRESS_SANITIZER 0
 #  endif
 #endif

 #if ZSTD_ADDRESS_SANITIZER
 /* Not all platforms that support asan provide sanitizers/asan_interface.h.
  * We therefore declare the functions we need ourselves, rather than trying to
  * include the header file... */
 #include <stddef.h>  /* size_t */

 /**
  * Marks a memory region (<c>[addr, addr+size)</c>) as unaddressable.
  *
  * This memory must be previously allocated by your program. Instrumented
  * code is forbidden from accessing addresses in this region until it is
  * unpoisoned. This function is not guaranteed to poison the entire region -
  * it could poison only a subregion of <c>[addr, addr+size)</c> due to ASan
  * alignment restrictions.
  *
  * \note This function is not thread-safe because no two threads can poison or
  * unpoison memory in the same memory region simultaneously.
  *
  * \param addr Start of memory region.
  * \param size Size of memory region. */
 void __asan_poison_memory_region(void const volatile *addr, size_t size);

 /**
  * Marks a memory region (<c>[addr, addr+size)</c>) as addressable.
  *
  * This memory must be previously allocated by your program. Accessing
  * addresses in this region is allowed until this region is poisoned again.
  * This function could unpoison a super-region of <c>[addr, addr+size)</c> due
  * to ASan alignment restrictions.
  *
  * \note This function is not thread-safe because no two threads can
  * poison or unpoison memory in the same memory region simultaneously.
  *
  * \param addr Start of memory region.
  * \param size Size of memory region. */
 void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
 #endif

 #endif /* ZSTD_COMPILER_H */
	/*
	* Copyright (c) 2016-2021, 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

	#if defined(__GNUC__) \|\| defined(__ICCARM__)
	# define FORCE_INLINE_ATTR __attribute__((always_inline))
	#elif defined(_MSC_VER)
	# define FORCE_INLINE_ATTR __forceinline
	#else
	# define FORCE_INLINE_ATTR
	#endif

	#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.
	*/
	#if defined(_MSC_VER)
	# define WIN_CDECL __cdecl
	#else
	# define WIN_CDECL
	#endif

	/**
	* 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. */
	#if defined(__GNUC__)
	# define UNUSED_ATTR __attribute__((unused))
	#else
	# define UNUSED_ATTR
	#endif

	/* force no inlining */
	#ifdef _MSC_VER
	# define FORCE_NOINLINE static __declspec(noinline)
	#else
	# if defined(__GNUC__) \|\| defined(__ICCARM__)
	# define FORCE_NOINLINE static __attribute__((__noinline__))
	# else
	# define FORCE_NOINLINE static
	# endif
	#endif


	/* target attribute */
	#ifndef __has_attribute
	#define __has_attribute(x) 0 /* Compatibility with non-clang compilers. */
	#endif
	#if defined(__GNUC__) \|\| defined(__ICCARM__)
	# define TARGET_ATTRIBUTE(target) __attribute__((__target__(target)))
	#else
	# define TARGET_ATTRIBUTE(target)
	#endif

	/* 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 defined(NO_PREFETCH)
	# define PREFETCH_L1(ptr) (void)(ptr) /* disabled */
	# define PREFETCH_L2(ptr) (void)(ptr) /* disabled */
	#else
	# if defined(_MSC_VER) && (defined(_M_X64) \|\| defined(_M_I86)) /* _mm_prefetch() is not defined outside of x86/x64 */
	# include <mmintrin.h> /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
	# define PREFETCH_L1(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
	# define PREFETCH_L2(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T1)
	# elif defined(__GNUC__) && ( (__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
	#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.
	*/
	#if defined(__GNUC__)
	#define LIKELY(x) (__builtin_expect((x), 1))
	#define UNLIKELY(x) (__builtin_expect((x), 0))
	#else
	#define LIKELY(x) (x)
	#define UNLIKELY(x) (x)
	#endif

	/* disable warnings */
	#ifdef _MSC_VER /* Visual Studio */
	# include <intrin.h> /* For Visual 2005 */
	# pragma warning(disable : 4100) /* disable: C4100: unreferenced formal parameter */
	# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
	# pragma warning(disable : 4204) /* disable: C4204: non-constant aggregate initializer */
	# pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */
	# pragma warning(disable : 4324) /* disable: C4324: padded structure */
	#endif

	/Like DYNAMIC_BMI2 but for compile time determination of BMI2 support/
	#ifndef STATIC_BMI2
	# if defined(_MSC_VER) && (defined(_M_X64) \|\| defined(_M_I86))
	# ifdef __AVX2__ //MSVC does not have a BMI2 specific flag, but every CPU that supports AVX2 also supports BMI2
	# define STATIC_BMI2 1
	# endif
	# endif
	#endif

	#ifndef STATIC_BMI2
	#define STATIC_BMI2 0
	#endif

	/* 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

	/* detects whether we are being compiled under msan */
	#ifndef ZSTD_MEMORY_SANITIZER
	# if __has_feature(memory_sanitizer)
	# define ZSTD_MEMORY_SANITIZER 1
	# else
	# define ZSTD_MEMORY_SANITIZER 0
	# endif
	#endif

	#if ZSTD_MEMORY_SANITIZER
	/* Not all platforms that support msan provide sanitizers/msan_interface.h.
	* We therefore declare the functions we need ourselves, rather than trying to
	* include the header file... */
	#include <stddef.h> /* size_t */
	#define ZSTD_DEPS_NEED_STDINT
	#include "zstd_deps.h" /* intptr_t */

	/* Make memory region fully initialized (without changing its contents). */
	void __msan_unpoison(const volatile void *a, size_t size);

	/* Make memory region fully uninitialized (without changing its contents).
	This is a legacy interface that does not update origin information. Use
	__msan_allocated_memory() instead. */
	void __msan_poison(const volatile void *a, size_t size);

	/* Returns the offset of the first (at least partially) poisoned byte in the
	memory range, or -1 if the whole range is good. */
	intptr_t __msan_test_shadow(const volatile void *x, size_t size);
	#endif

	/* detects whether we are being compiled under asan */
	#ifndef ZSTD_ADDRESS_SANITIZER
	# if __has_feature(address_sanitizer)
	# define ZSTD_ADDRESS_SANITIZER 1
	# elif defined(__SANITIZE_ADDRESS__)
	# define ZSTD_ADDRESS_SANITIZER 1
	# else
	# define ZSTD_ADDRESS_SANITIZER 0
	# endif
	#endif

	#if ZSTD_ADDRESS_SANITIZER
	/* Not all platforms that support asan provide sanitizers/asan_interface.h.
	* We therefore declare the functions we need ourselves, rather than trying to
	* include the header file... */
	#include <stddef.h> /* size_t */

	/**
	* Marks a memory region (<c>[addr, addr+size)</c>) as unaddressable.
	*
	* This memory must be previously allocated by your program. Instrumented
	* code is forbidden from accessing addresses in this region until it is
	* unpoisoned. This function is not guaranteed to poison the entire region -
	* it could poison only a subregion of <c>[addr, addr+size)</c> due to ASan
	* alignment restrictions.
	*
	* \note This function is not thread-safe because no two threads can poison or
	* unpoison memory in the same memory region simultaneously.
	*
	* \param addr Start of memory region.
	* \param size Size of memory region. */
	void __asan_poison_memory_region(void const volatile *addr, size_t size);

	/**
	* Marks a memory region (<c>[addr, addr+size)</c>) as addressable.
	*
	* This memory must be previously allocated by your program. Accessing
	* addresses in this region is allowed until this region is poisoned again.
	* This function could unpoison a super-region of <c>[addr, addr+size)</c> due
	* to ASan alignment restrictions.
	*
	* \note This function is not thread-safe because no two threads can
	* poison or unpoison memory in the same memory region simultaneously.
	*
	* \param addr Start of memory region.
	* \param size Size of memory region. */
	void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
	#endif

	#endif /* ZSTD_COMPILER_H */