lib/zstd/common/compiler.h - u-boot - Git at Google


            
            /*

            
             * 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 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 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 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 */

            
            #define TARGET_ATTRIBUTE(target) __attribute__((__target__(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 TARGET_ATTRIBUTE("lzcnt,bmi,bmi2")


            /* 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,

            
             * 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 __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))


            #if __has_builtin(__builtin_unreachable) || (defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)))

            
            #  define ZSTD_UNREACHABLE { assert(0), __builtin_unreachable(); }

            
            #else

            
            #  define ZSTD_UNREACHABLE { assert(0); }

            
            #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(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


            /*-**************************************************************

            
            *  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) __alignof(T)


            #endif /* ZSTD_ALIGNOF */


            /*-**************************************************************

            
            *  Sanitizer

            
            *****************************************************************/


            #endif /* ZSTD_COMPILER_H */
	/*
	* 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 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 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 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 */
	#define TARGET_ATTRIBUTE(target) __attribute__((__target__(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 TARGET_ATTRIBUTE("lzcnt,bmi,bmi2")

	/* 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,
	* 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 __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))

	#if __has_builtin(__builtin_unreachable) \|\| (defined(__GNUC__) && (__GNUC__ > 4 \|\| (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)))
	# define ZSTD_UNREACHABLE { assert(0), __builtin_unreachable(); }
	#else
	# define ZSTD_UNREACHABLE { assert(0); }
	#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(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

	/-*************************************************************
	* 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) __alignof(T)

	#endif /* ZSTD_ALIGNOF */

	/-*************************************************************
	* Sanitizer
	*****************************************************************/



	#endif /* ZSTD_COMPILER_H */