include/SDL_cpuinfo.h
author Sam Lantinga <slouken@libsdl.org>
Sat, 19 Oct 2019 01:54:02 -0700
changeset 13150 29acbbbb41b2
parent 13004 ea71847e4e3c
permissions -rw-r--r--
Don't try to use the Xbox HID protocol with the NVIDIA Shield controllers
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 /**
    23  *  \file SDL_cpuinfo.h
    24  *
    25  *  CPU feature detection for SDL.
    26  */
    27 
    28 #ifndef SDL_cpuinfo_h_
    29 #define SDL_cpuinfo_h_
    30 
    31 #include "SDL_stdinc.h"
    32 
    33 /* Need to do this here because intrin.h has C++ code in it */
    34 /* Visual Studio 2005 has a bug where intrin.h conflicts with winnt.h */
    35 #if defined(_MSC_VER) && (_MSC_VER >= 1500) && (defined(_M_IX86) || defined(_M_X64))
    36 #ifdef __clang__
    37 /* Many of the intrinsics SDL uses are not implemented by clang with Visual Studio */
    38 #undef __MMX__
    39 #undef __SSE__
    40 #undef __SSE2__
    41 #else
    42 #include <intrin.h>
    43 #ifndef _WIN64
    44 #ifndef __MMX__
    45 #define __MMX__
    46 #endif
    47 #ifndef __3dNOW__
    48 #define __3dNOW__
    49 #endif
    50 #endif
    51 #ifndef __SSE__
    52 #define __SSE__
    53 #endif
    54 #ifndef __SSE2__
    55 #define __SSE2__
    56 #endif
    57 #endif /* __clang__ */
    58 #elif defined(__MINGW64_VERSION_MAJOR)
    59 #include <intrin.h>
    60 #else
    61 /* altivec.h redefining bool causes a number of problems, see bugs 3993 and 4392, so you need to explicitly define SDL_ENABLE_ALTIVEC_H to have it included. */
    62 #if defined(HAVE_ALTIVEC_H) && defined(__ALTIVEC__) && !defined(__APPLE_ALTIVEC__) && defined(SDL_ENABLE_ALTIVEC_H)
    63 #include <altivec.h>
    64 #endif
    65 #if !defined(SDL_DISABLE_ARM_NEON_H)
    66 #  if defined(__ARM_NEON)
    67 #    include <arm_neon.h>
    68 #  elif defined(__WINDOWS__) || defined(__WINRT__)
    69 /* Visual Studio doesn't define __ARM_ARCH, but _M_ARM (if set, always 7), and _M_ARM64 (if set, always 1). */
    70 #    if defined(_M_ARM)
    71 #      include <armintr.h>
    72 #      include <arm_neon.h>
    73 #      define __ARM_NEON 1 /* Set __ARM_NEON so that it can be used elsewhere, at compile time */
    74 #    endif
    75 #    if defined (_M_ARM64)
    76 #      include <arm64intr.h>
    77 #      include <arm64_neon.h>
    78 #      define __ARM_NEON 1 /* Set __ARM_NEON so that it can be used elsewhere, at compile time */
    79 #    endif
    80 #  endif
    81 #endif
    82 #if defined(__3dNOW__) && !defined(SDL_DISABLE_MM3DNOW_H)
    83 #include <mm3dnow.h>
    84 #endif
    85 #if defined(HAVE_IMMINTRIN_H) && !defined(SDL_DISABLE_IMMINTRIN_H)
    86 #include <immintrin.h>
    87 #else
    88 #if defined(__MMX__) && !defined(SDL_DISABLE_MMINTRIN_H)
    89 #include <mmintrin.h>
    90 #endif
    91 #if defined(__SSE__) && !defined(SDL_DISABLE_XMMINTRIN_H)
    92 #include <xmmintrin.h>
    93 #endif
    94 #if defined(__SSE2__) && !defined(SDL_DISABLE_EMMINTRIN_H)
    95 #include <emmintrin.h>
    96 #endif
    97 #if defined(__SSE3__) && !defined(SDL_DISABLE_PMMINTRIN_H)
    98 #include <pmmintrin.h>
    99 #endif
   100 #endif /* HAVE_IMMINTRIN_H */
   101 #endif /* compiler version */
   102 
   103 #include "begin_code.h"
   104 /* Set up for C function definitions, even when using C++ */
   105 #ifdef __cplusplus
   106 extern "C" {
   107 #endif
   108 
   109 /* This is a guess for the cacheline size used for padding.
   110  * Most x86 processors have a 64 byte cache line.
   111  * The 64-bit PowerPC processors have a 128 byte cache line.
   112  * We'll use the larger value to be generally safe.
   113  */
   114 #define SDL_CACHELINE_SIZE  128
   115 
   116 /**
   117  *  This function returns the number of CPU cores available.
   118  */
   119 extern DECLSPEC int SDLCALL SDL_GetCPUCount(void);
   120 
   121 /**
   122  *  This function returns the L1 cache line size of the CPU
   123  *
   124  *  This is useful for determining multi-threaded structure padding
   125  *  or SIMD prefetch sizes.
   126  */
   127 extern DECLSPEC int SDLCALL SDL_GetCPUCacheLineSize(void);
   128 
   129 /**
   130  *  This function returns true if the CPU has the RDTSC instruction.
   131  */
   132 extern DECLSPEC SDL_bool SDLCALL SDL_HasRDTSC(void);
   133 
   134 /**
   135  *  This function returns true if the CPU has AltiVec features.
   136  */
   137 extern DECLSPEC SDL_bool SDLCALL SDL_HasAltiVec(void);
   138 
   139 /**
   140  *  This function returns true if the CPU has MMX features.
   141  */
   142 extern DECLSPEC SDL_bool SDLCALL SDL_HasMMX(void);
   143 
   144 /**
   145  *  This function returns true if the CPU has 3DNow! features.
   146  */
   147 extern DECLSPEC SDL_bool SDLCALL SDL_Has3DNow(void);
   148 
   149 /**
   150  *  This function returns true if the CPU has SSE features.
   151  */
   152 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE(void);
   153 
   154 /**
   155  *  This function returns true if the CPU has SSE2 features.
   156  */
   157 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE2(void);
   158 
   159 /**
   160  *  This function returns true if the CPU has SSE3 features.
   161  */
   162 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE3(void);
   163 
   164 /**
   165  *  This function returns true if the CPU has SSE4.1 features.
   166  */
   167 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE41(void);
   168 
   169 /**
   170  *  This function returns true if the CPU has SSE4.2 features.
   171  */
   172 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE42(void);
   173 
   174 /**
   175  *  This function returns true if the CPU has AVX features.
   176  */
   177 extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX(void);
   178 
   179 /**
   180  *  This function returns true if the CPU has AVX2 features.
   181  */
   182 extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX2(void);
   183 
   184 /**
   185  *  This function returns true if the CPU has AVX-512F (foundation) features.
   186  */
   187 extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX512F(void);
   188 
   189 /**
   190  *  This function returns true if the CPU has NEON (ARM SIMD) features.
   191  */
   192 extern DECLSPEC SDL_bool SDLCALL SDL_HasNEON(void);
   193 
   194 /**
   195  *  This function returns the amount of RAM configured in the system, in MB.
   196  */
   197 extern DECLSPEC int SDLCALL SDL_GetSystemRAM(void);
   198 
   199 /**
   200  * \brief Report the alignment this system needs for SIMD allocations.
   201  *
   202  * This will return the minimum number of bytes to which a pointer must be
   203  *  aligned to be compatible with SIMD instructions on the current machine.
   204  *  For example, if the machine supports SSE only, it will return 16, but if
   205  *  it supports AVX-512F, it'll return 64 (etc). This only reports values for
   206  *  instruction sets SDL knows about, so if your SDL build doesn't have
   207  *  SDL_HasAVX512F(), then it might return 16 for the SSE support it sees and
   208  *  not 64 for the AVX-512 instructions that exist but SDL doesn't know about.
   209  *  Plan accordingly.
   210  */
   211 extern DECLSPEC size_t SDLCALL SDL_SIMDGetAlignment(void);
   212 
   213 /**
   214  * \brief Allocate memory in a SIMD-friendly way.
   215  *
   216  * This will allocate a block of memory that is suitable for use with SIMD
   217  *  instructions. Specifically, it will be properly aligned and padded for
   218  *  the system's supported vector instructions.
   219  *
   220  * The memory returned will be padded such that it is safe to read or write
   221  *  an incomplete vector at the end of the memory block. This can be useful
   222  *  so you don't have to drop back to a scalar fallback at the end of your
   223  *  SIMD processing loop to deal with the final elements without overflowing
   224  *  the allocated buffer.
   225  *
   226  * You must free this memory with SDL_FreeSIMD(), not free() or SDL_free()
   227  *  or delete[], etc.
   228  *
   229  * Note that SDL will only deal with SIMD instruction sets it is aware of;
   230  *  for example, SDL 2.0.8 knows that SSE wants 16-byte vectors
   231  *  (SDL_HasSSE()), and AVX2 wants 32 bytes (SDL_HasAVX2()), but doesn't
   232  *  know that AVX-512 wants 64. To be clear: if you can't decide to use an
   233  *  instruction set with an SDL_Has*() function, don't use that instruction
   234  *  set with memory allocated through here.
   235  *
   236  * SDL_AllocSIMD(0) will return a non-NULL pointer, assuming the system isn't
   237  *  out of memory.
   238  *
   239  *  \param len The length, in bytes, of the block to allocated. The actual
   240  *             allocated block might be larger due to padding, etc.
   241  * \return Pointer to newly-allocated block, NULL if out of memory.
   242  *
   243  * \sa SDL_SIMDAlignment
   244  * \sa SDL_SIMDFree
   245  */
   246 extern DECLSPEC void * SDLCALL SDL_SIMDAlloc(const size_t len);
   247 
   248 /**
   249  * \brief Deallocate memory obtained from SDL_SIMDAlloc
   250  *
   251  * It is not valid to use this function on a pointer from anything but
   252  *  SDL_SIMDAlloc(). It can't be used on pointers from malloc, realloc,
   253  *  SDL_malloc, memalign, new[], etc.
   254  *
   255  * However, SDL_SIMDFree(NULL) is a legal no-op.
   256  *
   257  * \sa SDL_SIMDAlloc
   258  */
   259 extern DECLSPEC void SDLCALL SDL_SIMDFree(void *ptr);
   260 
   261 /* vi: set ts=4 sw=4 expandtab: */
   262 /* Ends C function definitions when using C++ */
   263 #ifdef __cplusplus
   264 }
   265 #endif
   266 #include "close_code.h"
   267 
   268 #endif /* SDL_cpuinfo_h_ */
   269 
   270 /* vi: set ts=4 sw=4 expandtab: */