/*

 * Copyright (c) 2016-present, 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 (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */

#  define INLINE_KEYWORD inline

#else

#  define INLINE_KEYWORD

#endif

#if defined(__GNUC__)

#  define FORCE_INLINE_ATTR __attribute__((always_inline))

#elif defined(_MSC_VER)

#  define FORCE_INLINE_ATTR __forceinline

#else

#  define FORCE_INLINE_ATTR

#endif

/**

 * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant

 * parameters. They must be inlined for the compiler to elimininate 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

/* force no inlining */

#ifdef _MSC_VER

#  define FORCE_NOINLINE static __declspec(noinline)

#else

#  ifdef __GNUC__

#    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__)

#  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 */

#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(ptr)   _mm_prefetch((const char*)ptr, _MM_HINT_T0)

#elif defined(__GNUC__)

#  define PREFETCH(ptr)   __builtin_prefetch(ptr, 0, 0)

#else

#  define PREFETCH(ptr)   /* disabled */

#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

#endif /* ZSTD_COMPILER_H */