SDL/include/SDL3/SDL_intrin.h

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/* WIKI CATEGORY: Intrinsics */

/**
 * # CategoryIntrinsics
 *
 * SDL does some preprocessor gymnastics to determine if any CPU-specific
 * compiler intrinsics are available, as this is not necessarily an easy thing
 * to calculate, and sometimes depends on quirks of a system, versions of
 * build tools, and other external forces.
 *
 * Apps including SDL's headers will be able to check consistent preprocessor
 * definitions to decide if it's safe to use compiler intrinsics for a
 * specific CPU architecture. This check only tells you that the compiler is
 * capable of using those intrinsics; at runtime, you should still check if
 * they are available on the current system with the
 * [CPU info functions](https://wiki.libsdl.org/SDL3/CategoryCPUInfo)
 * , such as SDL_HasSSE() or SDL_HasNEON(). Otherwise, the process might crash
 * for using an unsupported CPU instruction.
 *
 * SDL only sets preprocessor defines for CPU intrinsics if they are
 * supported, so apps should check with `#ifdef` and not `#if`.
 *
 * SDL will also include the appropriate instruction-set-specific support
 * headers, so if SDL decides to define SDL_SSE2_INTRINSICS, it will also
 * `#include <emmintrin.h>` as well.
 */

#ifndef SDL_intrin_h_
#define SDL_intrin_h_

#include <SDL3/SDL_stdinc.h>

#ifdef SDL_WIKI_DOCUMENTATION_SECTION

/**
 * Defined if (and only if) the compiler supports Loongarch LSX intrinsics.
 *
 * If this macro is defined, SDL will have already included `<lsxintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_LASX_INTRINSICS
 */
#define SDL_LSX_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Loongarch LSX intrinsics.
 *
 * If this macro is defined, SDL will have already included `<lasxintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_LASX_INTRINSICS
 */
#define SDL_LASX_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports ARM NEON intrinsics.
 *
 * If this macro is defined, SDL will have already included `<armintr.h>`
 * `<arm_neon.h>`, `<arm64intr.h>`, and `<arm64_neon.h>`, as appropriate.
 *
 * \since This macro is available since 3.1.3.
 */
#define SDL_NEON_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports PowerPC Altivec intrinsics.
 *
 * If this macro is defined, SDL will have already included `<altivec.h>`
 *
 * \since This macro is available since 3.1.3.
 */
#define SDL_ALTIVEC_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel MMX intrinsics.
 *
 * If this macro is defined, SDL will have already included `<mmintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_SSE_INTRINSICS
 */
#define SDL_MMX_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel SSE intrinsics.
 *
 * If this macro is defined, SDL will have already included `<xmmintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_SSE2_INTRINSICS
 * \sa SDL_SSE3_INTRINSICS
 * \sa SDL_SSE4_1_INTRINSICS
 * \sa SDL_SSE4_2_INTRINSICS
 */
#define SDL_SSE_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel SSE2 intrinsics.
 *
 * If this macro is defined, SDL will have already included `<emmintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_SSE_INTRINSICS
 * \sa SDL_SSE3_INTRINSICS
 * \sa SDL_SSE4_1_INTRINSICS
 * \sa SDL_SSE4_2_INTRINSICS
 */
#define SDL_SSE2_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel SSE3 intrinsics.
 *
 * If this macro is defined, SDL will have already included `<pmmintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_SSE_INTRINSICS
 * \sa SDL_SSE2_INTRINSICS
 * \sa SDL_SSE4_1_INTRINSICS
 * \sa SDL_SSE4_2_INTRINSICS
 */
#define SDL_SSE3_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel SSE4.1 intrinsics.
 *
 * If this macro is defined, SDL will have already included `<smmintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_SSE_INTRINSICS
 * \sa SDL_SSE2_INTRINSICS
 * \sa SDL_SSE3_INTRINSICS
 * \sa SDL_SSE4_2_INTRINSICS
 */
#define SDL_SSE4_1_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel SSE4.2 intrinsics.
 *
 * If this macro is defined, SDL will have already included `<nmmintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_SSE_INTRINSICS
 * \sa SDL_SSE2_INTRINSICS
 * \sa SDL_SSE3_INTRINSICS
 * \sa SDL_SSE4_1_INTRINSICS
 */
#define SDL_SSE4_2_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel AVX intrinsics.
 *
 * If this macro is defined, SDL will have already included `<immintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_AVX2_INTRINSICS
 * \sa SDL_AVX512F_INTRINSICS
 */
#define SDL_AVX_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel AVX2 intrinsics.
 *
 * If this macro is defined, SDL will have already included `<immintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_AVX_INTRINSICS
 * \sa SDL_AVX512F_INTRINSICS
 */
#define SDL_AVX2_INTRINSICS 1

/**
 * Defined if (and only if) the compiler supports Intel AVX-512F intrinsics.
 *
 * AVX-512F is also sometimes referred to as "AVX-512 Foundation."
 *
 * If this macro is defined, SDL will have already included `<immintrin.h>`
 *
 * \since This macro is available since 3.1.3.
 *
 * \sa SDL_AVX_INTRINSICS
 * \sa SDL_AVX2_INTRINSICS
 */
#define SDL_AVX512F_INTRINSICS 1
#endif

/* Need to do this here because intrin.h has C++ code in it */
/* Visual Studio 2005 has a bug where intrin.h conflicts with winnt.h */
#if defined(_MSC_VER) && (_MSC_VER >= 1500) && (defined(_M_IX86) || defined(_M_X64))
#ifdef __clang__
/* As of Clang 11, '_m_prefetchw' is conflicting with the winnt.h's version,
   so we define the needed '_m_prefetch' here as a pseudo-header, until the issue is fixed. */
#ifndef __PRFCHWINTRIN_H
#define __PRFCHWINTRIN_H
static __inline__ void __attribute__((__always_inline__, __nodebug__))
_m_prefetch(void *__P)
{
  __builtin_prefetch (__P, 0, 3 /* _MM_HINT_T0 */);
}
#endif /* __PRFCHWINTRIN_H */
#endif /* __clang__ */
#include <intrin.h>

#elif defined(__MINGW64_VERSION_MAJOR)
#include <intrin.h>
#if defined(__ARM_NEON) && !defined(SDL_DISABLE_NEON)
#  define SDL_NEON_INTRINSICS 1
#  include <arm_neon.h>
#endif

#else
/* altivec.h redefining bool causes a number of problems, see bugs 3993 and 4392, so you need to explicitly define SDL_ENABLE_ALTIVEC to have it included. */
#if defined(__ALTIVEC__) && defined(SDL_ENABLE_ALTIVEC)
#define SDL_ALTIVEC_INTRINSICS 1
#include <altivec.h>
#endif
#ifndef SDL_DISABLE_NEON
#  ifdef __ARM_NEON
#    define SDL_NEON_INTRINSICS 1
#    include <arm_neon.h>
#  elif defined(SDL_PLATFORM_WINDOWS)
/* Visual Studio doesn't define __ARM_ARCH, but _M_ARM (if set, always 7), and _M_ARM64 (if set, always 1). */
#    ifdef _M_ARM
#      define SDL_NEON_INTRINSICS 1
#      include <armintr.h>
#      include <arm_neon.h>
#      define __ARM_NEON 1 /* Set __ARM_NEON so that it can be used elsewhere, at compile time */
#    endif
#    if defined (_M_ARM64)
#      define SDL_NEON_INTRINSICS 1
#      include <arm64intr.h>
#      include <arm64_neon.h>
#      define __ARM_NEON 1 /* Set __ARM_NEON so that it can be used elsewhere, at compile time */
#      define __ARM_ARCH 8
#    endif
#  endif
#endif
#endif /* compiler version */

#ifdef SDL_WIKI_DOCUMENTATION_SECTION
/**
 * A macro to decide if the compiler supports `__attribute__((target))`.
 *
 * Even though this is defined in SDL's public headers, it is generally not
 * used directly by apps. Apps should probably just use SDL_TARGETING
 * directly, instead.
 *
 * \since This macro is available since SDL 3.1.3.
 *
 * \sa SDL_TARGETING
 */
#define SDL_HAS_TARGET_ATTRIBS

#elif defined(__clang__) && defined(__has_attribute)
# if __has_attribute(target)
# define SDL_HAS_TARGET_ATTRIBS
# endif
#elif defined(__GNUC__) && (__GNUC__ + (__GNUC_MINOR__ >= 9) > 4) /* gcc >= 4.9 */
# define SDL_HAS_TARGET_ATTRIBS
#elif defined(__ICC) && __ICC >= 1600
# define SDL_HAS_TARGET_ATTRIBS
#endif


#ifdef SDL_WIKI_DOCUMENTATION_SECTION

/**
 * A macro to tag a function as targeting a specific CPU architecture.
 *
 * This is a hint to the compiler that a function should be built with support
 * for a CPU instruction set that might be different than the rest of the
 * program.
 *
 * The particulars of this are explained in the GCC documentation:
 *
 * https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-target-function-attribute
 *
 * An example of using this feature is to turn on SSE2 support for a specific
 * function, even if the rest of the source code is not compiled to use SSE2
 * code:
 *
 * ```c
 * #ifdef SDL_SSE2_INTRINSICS
 * static void SDL_TARGETING("sse2") DoSomethingWithSSE2(char *x) {
 *    ...use SSE2 intrinsic functions, etc...
 * }
 * #endif
 *
 * // later...
 * #ifdef SDL_SSE2_INTRINSICS
 * if (SDL_HasSSE2()) {
 *     DoSomethingWithSSE2(str);
 * }
 * #endif
 * ```
 *
 * The application is, on a whole, built without SSE2 instructions, so it will
 * run on Intel machines that don't support SSE2. But then at runtime, it
 * checks if the system supports the instructions, and then calls into a
 * function that uses SSE2 opcodes. The ifdefs make sure that this code isn't
 * used on platforms that don't have SSE2 at all.
 *
 * On compilers without target support, this is defined to nothing.
 *
 * This symbol is used by SDL internally, but apps and other libraries are
 * welcome to use it for their own interfaces as well.
 *
 * \since This macro is available since SDL 3.1.3.
 */
#define SDL_TARGETING(x) __attribute__((target(x)))

#elif defined(SDL_HAS_TARGET_ATTRIBS)
# define SDL_TARGETING(x) __attribute__((target(x)))
#else
# define SDL_TARGETING(x)
#endif

#ifdef __loongarch64
# ifndef SDL_DISABLE_LSX
#  define SDL_LSX_INTRINSICS 1
#  include <lsxintrin.h>
# endif
# ifndef SDL_DISABLE_LASX
#  define SDL_LASX_INTRINSICS 1
#  include <lasxintrin.h>
# endif
#endif

#if defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || defined(_M_IX86)
# if ((defined(_MSC_VER) && !defined(_M_X64)) || defined(__MMX__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(SDL_DISABLE_MMX)
#  define SDL_MMX_INTRINSICS 1
#  include <mmintrin.h>
# endif
# if (defined(_MSC_VER) || defined(__SSE__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(SDL_DISABLE_SSE)
#  define SDL_SSE_INTRINSICS 1
#  include <xmmintrin.h>
# endif
# if (defined(_MSC_VER) || defined(__SSE2__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(SDL_DISABLE_SSE2)
#  define SDL_SSE2_INTRINSICS 1
#  include <emmintrin.h>
# endif
# if (defined(_MSC_VER) || defined(__SSE3__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(SDL_DISABLE_SSE3)
#  define SDL_SSE3_INTRINSICS 1
#  include <pmmintrin.h>
# endif
# if (defined(_MSC_VER) || defined(__SSE4_1__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(SDL_DISABLE_SSE4_1)
#  define SDL_SSE4_1_INTRINSICS 1
#  include <smmintrin.h>
# endif
# if (defined(_MSC_VER) || defined(__SSE4_2__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(SDL_DISABLE_SSE4_2)
#  define SDL_SSE4_2_INTRINSICS 1
#  include <nmmintrin.h>
# endif
# if defined(__clang__) && (defined(_MSC_VER) || defined(__SCE__)) && !defined(__AVX__) && !defined(SDL_DISABLE_AVX)
#  define SDL_DISABLE_AVX       /* see https://reviews.llvm.org/D20291 and https://reviews.llvm.org/D79194 */
# endif
# if (defined(_MSC_VER) || defined(__AVX__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(_M_ARM64EC) && !defined(SDL_DISABLE_AVX)
#  define SDL_AVX_INTRINSICS 1
#  include <immintrin.h>
# endif
# if defined(__clang__) && (defined(_MSC_VER) || defined(__SCE__)) && !defined(__AVX2__) && !defined(SDL_DISABLE_AVX2)
#  define SDL_DISABLE_AVX2      /* see https://reviews.llvm.org/D20291 and https://reviews.llvm.org/D79194 */
# endif
# if (defined(_MSC_VER) || defined(__AVX2__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(_M_ARM64EC) && !defined(SDL_DISABLE_AVX2)
#  define SDL_AVX2_INTRINSICS 1
#  include <immintrin.h>
# endif
# if defined(__clang__) && (defined(_MSC_VER) || defined(__SCE__)) && !defined(__AVX512F__) && !defined(SDL_DISABLE_AVX512F)
#  define SDL_DISABLE_AVX512F   /* see https://reviews.llvm.org/D20291 and https://reviews.llvm.org/D79194 */
# endif
# if (defined(_MSC_VER) || defined(__AVX512F__) || defined(SDL_HAS_TARGET_ATTRIBS)) && !defined(_M_ARM64EC) && !defined(SDL_DISABLE_AVX512F)
#  define SDL_AVX512F_INTRINSICS 1
#  include <immintrin.h>
# endif
#endif /* defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || defined(_M_IX86) */

#endif /* SDL_intrin_h_ */