SDL_cpuinfo.c File Reference

#include "../SDL_internal.h"
#include "SDL_cpuinfo.h"
#include "SDL_assert.h"

Include dependency graph for SDL_cpuinfo.c:

Go to the source code of this file.

Macros
#define	CPU_HAS_RDTSC   (1 << 0)
#define	CPU_HAS_ALTIVEC   (1 << 1)
#define	CPU_HAS_MMX   (1 << 2)
#define	CPU_HAS_3DNOW   (1 << 3)
#define	CPU_HAS_SSE   (1 << 4)
#define	CPU_HAS_SSE2   (1 << 5)
#define	CPU_HAS_SSE3   (1 << 6)
#define	CPU_HAS_SSE41   (1 << 7)
#define	CPU_HAS_SSE42   (1 << 8)
#define	CPU_HAS_AVX   (1 << 9)
#define	CPU_HAS_AVX2   (1 << 10)
#define	CPU_HAS_NEON   (1 << 11)
#define	CPU_HAS_AVX512F   (1 << 12)
#define	CPU_HAS_ARM_SIMD   (1 << 13)
#define	cpuid(func, a, b, c, d)    do { a = b = c = d = 0; (void) a; (void) b; (void) c; (void) d; } while (0)
#define	CPU_haveRDTSC()   (CPU_CPUIDFeatures[3] & 0x00000010)
#define	CPU_haveMMX()   (CPU_CPUIDFeatures[3] & 0x00800000)
#define	CPU_haveSSE()   (CPU_CPUIDFeatures[3] & 0x02000000)
#define	CPU_haveSSE2()   (CPU_CPUIDFeatures[3] & 0x04000000)
#define	CPU_haveSSE3()   (CPU_CPUIDFeatures[2] & 0x00000001)
#define	CPU_haveSSE41()   (CPU_CPUIDFeatures[2] & 0x00080000)
#define	CPU_haveSSE42()   (CPU_CPUIDFeatures[2] & 0x00100000)
#define	CPU_haveAVX()   (CPU_OSSavesYMM && (CPU_CPUIDFeatures[2] & 0x10000000))
#define	CPU_FEATURE_AVAILABLE(f)   ((SDL_GetCPUFeatures() & f) ? SDL_TRUE : SDL_FALSE)

Functions
static int	CPU_haveCPUID (void)
static void	CPU_calcCPUIDFeatures (void)
static int	CPU_haveAltiVec (void)
static int	CPU_haveARMSIMD (void)
static int	CPU_haveNEON (void)
static int	CPU_have3DNow (void)
static int	CPU_haveAVX2 (void)
static int	CPU_haveAVX512F (void)
int	SDL_GetCPUCount (void)
static const char *	SDL_GetCPUType (void)
int	SDL_GetCPUCacheLineSize (void)
static Uint32	SDL_GetCPUFeatures (void)
SDL_bool	SDL_HasRDTSC (void)
SDL_bool	SDL_HasAltiVec (void)
SDL_bool	SDL_HasMMX (void)
SDL_bool	SDL_Has3DNow (void)
SDL_bool	SDL_HasSSE (void)
SDL_bool	SDL_HasSSE2 (void)
SDL_bool	SDL_HasSSE3 (void)
SDL_bool	SDL_HasSSE41 (void)
SDL_bool	SDL_HasSSE42 (void)
SDL_bool	SDL_HasAVX (void)
SDL_bool	SDL_HasAVX2 (void)
SDL_bool	SDL_HasAVX512F (void)
SDL_bool	SDL_HasARMSIMD (void)
SDL_bool	SDL_HasNEON (void)
int	SDL_GetSystemRAM (void)
size_t	SDL_SIMDGetAlignment (void)
	Report the alignment this system needs for SIMD allocations. More...
void *	SDL_SIMDAlloc (const size_t len)
	Allocate memory in a SIMD-friendly way. More...
void *	SDL_SIMDRealloc (void *mem, const size_t len)
	Reallocate memory obtained from SDL_SIMDAlloc. More...
void	SDL_SIMDFree (void *ptr)
	Deallocate memory obtained from SDL_SIMDAlloc. More...

Variables
static int	CPU_CPUIDFeatures [4]
static int	CPU_CPUIDMaxFunction = 0
static SDL_bool	CPU_OSSavesYMM = SDL_FALSE
static SDL_bool	CPU_OSSavesZMM = SDL_FALSE
static int	SDL_CPUCount = 0
static Uint32	SDL_CPUFeatures = 0xFFFFFFFF
static Uint32	SDL_SIMDAlignment = 0xFFFFFFFF
static int	SDL_SystemRAM = 0

Macro Definition Documentation

CPU_FEATURE_AVAILABLE

#define CPU_FEATURE_AVAILABLE

(

f

)

((SDL_GetCPUFeatures() & f) ? SDL_TRUE : SDL_FALSE)

Definition at line 798 of file SDL_cpuinfo.c.

CPU_HAS_3DNOW

#define CPU_HAS_3DNOW   (1 << 3)

Definition at line 106 of file SDL_cpuinfo.c.

CPU_HAS_ALTIVEC

#define CPU_HAS_ALTIVEC   (1 << 1)

Definition at line 104 of file SDL_cpuinfo.c.

CPU_HAS_ARM_SIMD

#define CPU_HAS_ARM_SIMD   (1 << 13)

Definition at line 116 of file SDL_cpuinfo.c.

CPU_HAS_AVX

#define CPU_HAS_AVX   (1 << 9)

Definition at line 112 of file SDL_cpuinfo.c.

CPU_HAS_AVX2

#define CPU_HAS_AVX2   (1 << 10)

Definition at line 113 of file SDL_cpuinfo.c.

CPU_HAS_AVX512F

#define CPU_HAS_AVX512F   (1 << 12)

Definition at line 115 of file SDL_cpuinfo.c.

CPU_HAS_MMX

#define CPU_HAS_MMX   (1 << 2)

Definition at line 105 of file SDL_cpuinfo.c.

CPU_HAS_NEON

#define CPU_HAS_NEON   (1 << 11)

Definition at line 114 of file SDL_cpuinfo.c.

CPU_HAS_RDTSC

#define CPU_HAS_RDTSC   (1 << 0)

Definition at line 103 of file SDL_cpuinfo.c.

CPU_HAS_SSE

#define CPU_HAS_SSE   (1 << 4)

Definition at line 107 of file SDL_cpuinfo.c.

CPU_HAS_SSE2

#define CPU_HAS_SSE2   (1 << 5)

Definition at line 108 of file SDL_cpuinfo.c.

CPU_HAS_SSE3

#define CPU_HAS_SSE3   (1 << 6)

Definition at line 109 of file SDL_cpuinfo.c.

CPU_HAS_SSE41

#define CPU_HAS_SSE41   (1 << 7)

Definition at line 110 of file SDL_cpuinfo.c.

CPU_HAS_SSE42

#define CPU_HAS_SSE42   (1 << 8)

Definition at line 111 of file SDL_cpuinfo.c.

CPU_haveAVX

#define CPU_haveAVX

(

)

(CPU_OSSavesYMM && (CPU_CPUIDFeatures[2] & 0x10000000))

Definition at line 533 of file SDL_cpuinfo.c.

CPU_haveMMX

#define CPU_haveMMX

(

)

(CPU_CPUIDFeatures[3] & 0x00800000)

Definition at line 527 of file SDL_cpuinfo.c.

CPU_haveRDTSC

#define CPU_haveRDTSC

(

)

(CPU_CPUIDFeatures[3] & 0x00000010)

Definition at line 526 of file SDL_cpuinfo.c.

CPU_haveSSE

#define CPU_haveSSE

(

)

(CPU_CPUIDFeatures[3] & 0x02000000)

Definition at line 528 of file SDL_cpuinfo.c.

CPU_haveSSE2

#define CPU_haveSSE2

(

)

(CPU_CPUIDFeatures[3] & 0x04000000)

Definition at line 529 of file SDL_cpuinfo.c.

CPU_haveSSE3

#define CPU_haveSSE3

(

)

(CPU_CPUIDFeatures[2] & 0x00000001)

Definition at line 530 of file SDL_cpuinfo.c.

CPU_haveSSE41

#define CPU_haveSSE41

(

)

(CPU_CPUIDFeatures[2] & 0x00080000)

Definition at line 531 of file SDL_cpuinfo.c.

CPU_haveSSE42

#define CPU_haveSSE42

(

)

(CPU_CPUIDFeatures[2] & 0x00100000)

Definition at line 532 of file SDL_cpuinfo.c.

cpuid

#define cpuid	(		func,
			a,
			b,
			c,
			d
	)		do { a = b = c = d = 0; (void) a; (void) b; (void) c; (void) d; } while (0)

Definition at line 268 of file SDL_cpuinfo.c.

Function Documentation

CPU_calcCPUIDFeatures()

static void CPU_calcCPUIDFeatures ( void  )

static

Definition at line 278 of file SDL_cpuinfo.c.

{
    static SDL_bool checked = SDL_FALSE;
    if (!checked) {
        checked = SDL_TRUE;
        if (CPU_haveCPUID()) {
            int a, b, c, d;
            cpuid(0, a, b, c, d);
            CPU_CPUIDMaxFunction = a;
            if (CPU_CPUIDMaxFunction >= 1) {
                cpuid(1, a, b, c, d);
                CPU_CPUIDFeatures[0] = a;
                CPU_CPUIDFeatures[1] = b;
                CPU_CPUIDFeatures[2] = c;
                CPU_CPUIDFeatures[3] = d;
 
                /* Check to make sure we can call xgetbv */
                if (c & 0x08000000) {
                    /* Call xgetbv to see if YMM (etc) register state is saved */
#if defined(__GNUC__) && (defined(i386) || defined(__x86_64__))
                    __asm__(".byte 0x0f, 0x01, 0xd0" : "=a" (a) : "c" (0) : "%edx");
#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64)) && (_MSC_FULL_VER >= 160040219) /* VS2010 SP1 */
                    a = (int)_xgetbv(0);
#elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
                    __asm
                    {
                        xor ecx, ecx
                        _asm _emit 0x0f _asm _emit 0x01 _asm _emit 0xd0
                        mov a, eax
                    }
#endif
                    CPU_OSSavesYMM = ((a & 6) == 6) ? SDL_TRUE : SDL_FALSE;
                    CPU_OSSavesZMM = (CPU_OSSavesYMM && ((a & 0xe0) == 0xe0)) ? SDL_TRUE : SDL_FALSE;
                }
            }
        }
    }
}

References CPU_CPUIDFeatures, CPU_CPUIDMaxFunction, CPU_haveCPUID(), CPU_OSSavesYMM, CPU_OSSavesZMM, cpuid, d, int(), mov, SDL_FALSE, and SDL_TRUE.

Referenced by SDL_GetCPUFeatures(), and SDL_GetCPUType().

CPU_have3DNow()

static int CPU_have3DNow ( void  )

static

Definition at line 513 of file SDL_cpuinfo.c.

{
    if (CPU_CPUIDMaxFunction > 0) {  /* that is, do we have CPUID at all? */
        int a, b, c, d;
        cpuid(0x80000000, a, b, c, d);
        if (a >= 0x80000001) {
            cpuid(0x80000001, a, b, c, d);
            return (d & 0x80000000);
        }
    }
    return 0;
}

References CPU_CPUIDMaxFunction, cpuid, and d.

Referenced by SDL_GetCPUFeatures().

CPU_haveAltiVec()

static int CPU_haveAltiVec ( void  )

static

Definition at line 318 of file SDL_cpuinfo.c.

{
    volatile int altivec = 0;
#ifndef SDL_CPUINFO_DISABLED
#if (defined(__MACOSX__) && (defined(__ppc__) || defined(__ppc64__))) || (defined(__OpenBSD__) && defined(__powerpc__)) || (defined(__FreeBSD__) && defined(__powerpc__))
#ifdef __OpenBSD__
    int selectors[2] = { CTL_MACHDEP, CPU_ALTIVEC };
#elif defined(__FreeBSD__)
    int selectors[2] = { CTL_HW, PPC_FEATURE_HAS_ALTIVEC };
#else
    int selectors[2] = { CTL_HW, HW_VECTORUNIT };
#endif
    int hasVectorUnit = 0;
    size_t length = sizeof(hasVectorUnit);
    int error = sysctl(selectors, 2, &hasVectorUnit, &length, NULL, 0);
    if (0 == error)
        altivec = (hasVectorUnit != 0);
#elif SDL_ALTIVEC_BLITTERS && HAVE_SETJMP
    void (*handler) (int sig);
    handler = signal(SIGILL, illegal_instruction);
    if (setjmp(jmpbuf) == 0) {
        asm volatile ("mtspr 256, %0\n\t" "vand %%v0, %%v0, %%v0"::"r" (-1));
        altivec = 1;
    }
    signal(SIGILL, handler);
#endif
#endif
    return altivec;
}

References NULL, and void.

Referenced by SDL_GetCPUFeatures().

CPU_haveARMSIMD()

static int CPU_haveARMSIMD ( void  )

static

Definition at line 357 of file SDL_cpuinfo.c.

{
        return 0;
}

Referenced by SDL_GetCPUFeatures().

CPU_haveAVX2()

static int CPU_haveAVX2 ( void  )

static

Definition at line 536 of file SDL_cpuinfo.c.

{
    if (CPU_OSSavesYMM && (CPU_CPUIDMaxFunction >= 7)) {
        int a, b, c, d;
        (void) a; (void) b; (void) c; (void) d;  /* compiler warnings... */
        cpuid(7, a, b, c, d);
        return (b & 0x00000020);
    }
    return 0;
}

References CPU_CPUIDMaxFunction, CPU_OSSavesYMM, cpuid, d, and void.

Referenced by SDL_GetCPUFeatures().

CPU_haveAVX512F()

static int CPU_haveAVX512F ( void  )

static

Definition at line 548 of file SDL_cpuinfo.c.

{
    if (CPU_OSSavesZMM && (CPU_CPUIDMaxFunction >= 7)) {
        int a, b, c, d;
        (void) a; (void) b; (void) c; (void) d;  /* compiler warnings... */
        cpuid(7, a, b, c, d);
        return (b & 0x00010000);
    }
    return 0;
}

References CPU_CPUIDMaxFunction, CPU_OSSavesZMM, cpuid, d, and void.

Referenced by SDL_GetCPUFeatures().

CPU_haveCPUID()

static int CPU_haveCPUID ( void  )

static

Definition at line 131 of file SDL_cpuinfo.c.

{
    int has_CPUID = 0;
 
/* *INDENT-OFF* */
#ifndef SDL_CPUINFO_DISABLED
#if defined(__GNUC__) && defined(i386)
    __asm__ (
"        pushfl                      # Get original EFLAGS             \n"
"        popl    %%eax                                                 \n"
"        movl    %%eax,%%ecx                                           \n"
"        xorl    $0x200000,%%eax     # Flip ID bit in EFLAGS           \n"
"        pushl   %%eax               # Save new EFLAGS value on stack  \n"
"        popfl                       # Replace current EFLAGS value    \n"
"        pushfl                      # Get new EFLAGS                  \n"
"        popl    %%eax               # Store new EFLAGS in EAX         \n"
"        xorl    %%ecx,%%eax         # Can not toggle ID bit,          \n"
"        jz      1f                  # Processor=80486                 \n"
"        movl    $1,%0               # We have CPUID support           \n"
"1:                                                                    \n"
    : "=m" (has_CPUID)
    :
    : "%eax", "%ecx"
    );
#elif defined(__GNUC__) && defined(__x86_64__)
/* Technically, if this is being compiled under __x86_64__ then it has 
   CPUid by definition.  But it's nice to be able to prove it.  :)      */
    __asm__ (
"        pushfq                      # Get original EFLAGS             \n"
"        popq    %%rax                                                 \n"
"        movq    %%rax,%%rcx                                           \n"
"        xorl    $0x200000,%%eax     # Flip ID bit in EFLAGS           \n"
"        pushq   %%rax               # Save new EFLAGS value on stack  \n"
"        popfq                       # Replace current EFLAGS value    \n"
"        pushfq                      # Get new EFLAGS                  \n"
"        popq    %%rax               # Store new EFLAGS in EAX         \n"
"        xorl    %%ecx,%%eax         # Can not toggle ID bit,          \n"
"        jz      1f                  # Processor=80486                 \n"
"        movl    $1,%0               # We have CPUID support           \n"
"1:                                                                    \n"
    : "=m" (has_CPUID)
    :
    : "%rax", "%rcx"
    );
#elif (defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)
    __asm {
        pushfd                      ; Get original EFLAGS
        pop     eax
        mov     ecx, eax
        xor     eax, 200000h        ; Flip ID bit in EFLAGS
        push    eax                 ; Save new EFLAGS value on stack
        popfd                       ; Replace current EFLAGS value
        pushfd                      ; Get new EFLAGS
        pop     eax                 ; Store new EFLAGS in EAX
        xor     eax, ecx            ; Can not toggle ID bit,
        jz      done                ; Processor=80486
        mov     has_CPUID,1         ; We have CPUID support
done:
    }
#elif defined(_MSC_VER) && defined(_M_X64)
    has_CPUID = 1;
#elif defined(__sun) && defined(__i386)
    __asm (
"       pushfl                 \n"
"       popl    %eax           \n"
"       movl    %eax,%ecx      \n"
"       xorl    $0x200000,%eax \n"
"       pushl   %eax           \n"
"       popfl                  \n"
"       pushfl                 \n"
"       popl    %eax           \n"
"       xorl    %ecx,%eax      \n"
"       jz      1f             \n"
"       movl    $1,-8(%ebp)    \n"
"1:                            \n"
    );
#elif defined(__sun) && defined(__amd64)
    __asm (
"       pushfq                 \n"
"       popq    %rax           \n"
"       movq    %rax,%rcx      \n"
"       xorl    $0x200000,%eax \n"
"       pushq   %rax           \n"
"       popfq                  \n"
"       pushfq                 \n"
"       popq    %rax           \n"
"       xorl    %ecx,%eax      \n"
"       jz      1f             \n"
"       movl    $1,-8(%rbp)    \n"
"1:                            \n"
    );
#endif
#endif
/* *INDENT-ON* */
    return has_CPUID;
}

References done, mov, and pop.

Referenced by CPU_calcCPUIDFeatures().

CPU_haveNEON()

static int CPU_haveNEON ( void  )

static

Definition at line 446 of file SDL_cpuinfo.c.

{
/* The way you detect NEON is a privileged instruction on ARM, so you have
   query the OS kernel in a platform-specific way. :/ */
#if defined(SDL_CPUINFO_DISABLED)
   return 0; /* disabled */
#elif (defined(__WINDOWS__) || defined(__WINRT__)) && (defined(_M_ARM) || defined(_M_ARM64))
/* Visual Studio, for ARM, doesn't define __ARM_ARCH. Handle this first. */
/* Seems to have been removed */
#  if !defined(PF_ARM_NEON_INSTRUCTIONS_AVAILABLE)
#    define PF_ARM_NEON_INSTRUCTIONS_AVAILABLE 19
#  endif
/* All WinRT ARM devices are required to support NEON, but just in case. */
    return IsProcessorFeaturePresent(PF_ARM_NEON_INSTRUCTIONS_AVAILABLE) != 0;
#elif defined(__ARM_ARCH) && (__ARM_ARCH >= 8)
    return 1;  /* ARMv8 always has non-optional NEON support. */
#elif defined(__APPLE__) && defined(__ARM_ARCH) && (__ARM_ARCH >= 7)
    /* (note that sysctlbyname("hw.optional.neon") doesn't work!) */
    return 1;  /* all Apple ARMv7 chips and later have NEON. */
#elif defined(__APPLE__)
    return 0;  /* assume anything else from Apple doesn't have NEON. */
#elif defined(__OpenBSD__)
    return 1;  /* OpenBSD only supports ARMv7 CPUs that have NEON. */
#elif defined(HAVE_ELF_AUX_INFO) && defined(HWCAP_NEON)
    unsigned long hasneon = 0;
    if (elf_aux_info(AT_HWCAP, (void *)&hasneon, (int)sizeof(hasneon)) != 0)
        return 0;
    return ((hasneon & HWCAP_NEON) == HWCAP_NEON);
#elif !defined(__arm__)
    return 0;  /* not an ARM CPU at all. */
#elif defined(__QNXNTO__)
    return SYSPAGE_ENTRY(cpuinfo)->flags & ARM_CPU_FLAG_NEON;
#elif (defined(__LINUX__) || defined(__ANDROID__)) && defined(HAVE_GETAUXVAL)
    return ((getauxval(AT_HWCAP) & HWCAP_NEON) == HWCAP_NEON);
#elif defined(__LINUX__)
    return readProcAuxvForNeon();
#elif defined(__ANDROID__)
    /* Use NDK cpufeatures to read either /proc/self/auxv or /proc/cpuinfo */
    {
        AndroidCpuFamily cpu_family = android_getCpuFamily();
        if (cpu_family == ANDROID_CPU_FAMILY_ARM) {
            uint64_t cpu_features = android_getCpuFeatures();
            if ((cpu_features & ANDROID_CPU_ARM_FEATURE_NEON) != 0) {
                return 1;
            }
        }
        return 0;
    }
#elif defined(__RISCOS__)
    /* Use the VFPSupport_Features SWI to access the MVFR registers */
    {
        _kernel_swi_regs regs;
        regs.r[0] = 0;
        if (_kernel_swi(VFPSupport_Features, &regs, &regs) == NULL) {
            if ((regs.r[2] & 0xFFF000) == 0x111000) {
                return 1;
            }
        }
        return 0;
    }
#else
#warning SDL_HasNEON is not implemented for this ARM platform. Write me.
    return 0;
#endif
}

References NULL.

Referenced by SDL_GetCPUFeatures().

SDL_GetCPUCacheLineSize()

int SDL_GetCPUCacheLineSize

(

void

)

This function returns the L1 cache line size of the CPU

This is useful for determining multi-threaded structure padding or SIMD prefetch sizes.

Definition at line 712 of file SDL_cpuinfo.c.

{
    const char *cpuType = SDL_GetCPUType();
    int a, b, c, d;
    (void) a; (void) b; (void) c; (void) d;
   if (SDL_strcmp(cpuType, "GenuineIntel") == 0 || SDL_strcmp(cpuType, "CentaurHauls") == 0 || SDL_strcmp(cpuType, "  Shanghai  ") == 0) {
        cpuid(0x00000001, a, b, c, d);
        return (((b >> 8) & 0xff) * 8);
    } else if (SDL_strcmp(cpuType, "AuthenticAMD") == 0 || SDL_strcmp(cpuType, "HygonGenuine") == 0) {
        cpuid(0x80000005, a, b, c, d);
        return (c & 0xff);
    } else {
        /* Just make a guess here... */
        return SDL_CACHELINE_SIZE;
    }
}

References cpuid, d, SDL_CACHELINE_SIZE, SDL_GetCPUType(), SDL_strcmp, and void.

SDL_GetCPUCount()

int SDL_GetCPUCount

(

void

)

This function returns the number of CPU cores available.

Definition at line 562 of file SDL_cpuinfo.c.

{
    if (!SDL_CPUCount) {
#ifndef SDL_CPUINFO_DISABLED
#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_ONLN)
        if (SDL_CPUCount <= 0) {
            SDL_CPUCount = (int)sysconf(_SC_NPROCESSORS_ONLN);
        }
#endif
#ifdef HAVE_SYSCTLBYNAME
        if (SDL_CPUCount <= 0) {
            size_t size = sizeof(SDL_CPUCount);
            sysctlbyname("hw.ncpu", &SDL_CPUCount, &size, NULL, 0);
        }
#endif
#ifdef __WIN32__
        if (SDL_CPUCount <= 0) {
            SYSTEM_INFO info;
            GetSystemInfo(&info);
            SDL_CPUCount = info.dwNumberOfProcessors;
        }
#endif
#ifdef __OS2__
        if (SDL_CPUCount <= 0) {
            DosQuerySysInfo(QSV_NUMPROCESSORS, QSV_NUMPROCESSORS,
                            &SDL_CPUCount, sizeof(SDL_CPUCount) );
        }
#endif
#endif
        /* There has to be at least 1, right? :) */
        if (SDL_CPUCount <= 0) {
            SDL_CPUCount = 1;
        }
    }
    return SDL_CPUCount;
}

References int(), NULL, and SDL_CPUCount.

SDL_GetCPUFeatures()

static Uint32 SDL_GetCPUFeatures ( void  )

static

Definition at line 733 of file SDL_cpuinfo.c.

{
    if (SDL_CPUFeatures == 0xFFFFFFFF) {
        CPU_calcCPUIDFeatures();
        SDL_CPUFeatures = 0;
        SDL_SIMDAlignment = sizeof(void *);  /* a good safe base value */
        if (CPU_haveRDTSC()) {
            SDL_CPUFeatures |= CPU_HAS_RDTSC;
        }
        if (CPU_haveAltiVec()) {
            SDL_CPUFeatures |= CPU_HAS_ALTIVEC;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
        if (CPU_haveMMX()) {
            SDL_CPUFeatures |= CPU_HAS_MMX;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 8);
        }
        if (CPU_have3DNow()) {
            SDL_CPUFeatures |= CPU_HAS_3DNOW;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 8);
        }
        if (CPU_haveSSE()) {
            SDL_CPUFeatures |= CPU_HAS_SSE;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
        if (CPU_haveSSE2()) {
            SDL_CPUFeatures |= CPU_HAS_SSE2;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
        if (CPU_haveSSE3()) {
            SDL_CPUFeatures |= CPU_HAS_SSE3;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
        if (CPU_haveSSE41()) {
            SDL_CPUFeatures |= CPU_HAS_SSE41;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
        if (CPU_haveSSE42()) {
            SDL_CPUFeatures |= CPU_HAS_SSE42;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
        if (CPU_haveAVX()) {
            SDL_CPUFeatures |= CPU_HAS_AVX;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 32);
        }
        if (CPU_haveAVX2()) {
            SDL_CPUFeatures |= CPU_HAS_AVX2;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 32);
        }
        if (CPU_haveAVX512F()) {
            SDL_CPUFeatures |= CPU_HAS_AVX512F;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 64);
        }
        if (CPU_haveARMSIMD()) {
            SDL_CPUFeatures |= CPU_HAS_ARM_SIMD;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
        if (CPU_haveNEON()) {
            SDL_CPUFeatures |= CPU_HAS_NEON;
            SDL_SIMDAlignment = SDL_max(SDL_SIMDAlignment, 16);
        }
    }
    return SDL_CPUFeatures;
}

References CPU_calcCPUIDFeatures(), CPU_HAS_3DNOW, CPU_HAS_ALTIVEC, CPU_HAS_ARM_SIMD, CPU_HAS_AVX, CPU_HAS_AVX2, CPU_HAS_AVX512F, CPU_HAS_MMX, CPU_HAS_NEON, CPU_HAS_RDTSC, CPU_HAS_SSE, CPU_HAS_SSE2, CPU_HAS_SSE3, CPU_HAS_SSE41, CPU_HAS_SSE42, CPU_have3DNow(), CPU_haveAltiVec(), CPU_haveARMSIMD(), CPU_haveAVX, CPU_haveAVX2(), CPU_haveAVX512F(), CPU_haveMMX, CPU_haveNEON(), CPU_haveRDTSC, CPU_haveSSE, CPU_haveSSE2, CPU_haveSSE3, CPU_haveSSE41, CPU_haveSSE42, SDL_CPUFeatures, SDL_max, and SDL_SIMDAlignment.

Referenced by SDL_SIMDGetAlignment().

SDL_GetCPUType()

static const char* SDL_GetCPUType ( void  )

static

Definition at line 601 of file SDL_cpuinfo.c.

{
    static char SDL_CPUType[13];
 
    if (!SDL_CPUType[0]) {
        int i = 0;
 
        CPU_calcCPUIDFeatures();
        if (CPU_CPUIDMaxFunction > 0) {  /* do we have CPUID at all? */
            int a, b, c, d;
            cpuid(0x00000000, a, b, c, d);
            (void) a;
            SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
            SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
            SDL_CPUType[i++] = (char)(b & 0xff); b >>= 8;
            SDL_CPUType[i++] = (char)(b & 0xff);
 
            SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
            SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
            SDL_CPUType[i++] = (char)(d & 0xff); d >>= 8;
            SDL_CPUType[i++] = (char)(d & 0xff);
 
            SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
            SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
            SDL_CPUType[i++] = (char)(c & 0xff); c >>= 8;
            SDL_CPUType[i++] = (char)(c & 0xff);
        }
        if (!SDL_CPUType[0]) {
            SDL_strlcpy(SDL_CPUType, "Unknown", sizeof(SDL_CPUType));
        }
    }
    return SDL_CPUType;
}

References CPU_calcCPUIDFeatures(), CPU_CPUIDMaxFunction, cpuid, d, i, SDL_strlcpy, and void.

Referenced by SDL_GetCPUCacheLineSize().

SDL_GetSystemRAM()

int SDL_GetSystemRAM

(

void

)

This function returns the amount of RAM configured in the system, in MB.

Definition at line 886 of file SDL_cpuinfo.c.

{
    if (!SDL_SystemRAM) {
#ifndef SDL_CPUINFO_DISABLED
#if defined(HAVE_SYSCONF) && defined(_SC_PHYS_PAGES) && defined(_SC_PAGESIZE)
        if (SDL_SystemRAM <= 0) {
            SDL_SystemRAM = (int)((Sint64)sysconf(_SC_PHYS_PAGES) * sysconf(_SC_PAGESIZE) / (1024*1024));
        }
#endif
#ifdef HAVE_SYSCTLBYNAME
        if (SDL_SystemRAM <= 0) {
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__NetBSD__) || defined(__DragonFly__)
#ifdef HW_REALMEM
            int mib[2] = {CTL_HW, HW_REALMEM};
#else
            /* might only report up to 2 GiB */
            int mib[2] = {CTL_HW, HW_PHYSMEM};
#endif /* HW_REALMEM */
#else
            int mib[2] = {CTL_HW, HW_MEMSIZE};
#endif /* __FreeBSD__ || __FreeBSD_kernel__ */
            Uint64 memsize = 0;
            size_t len = sizeof(memsize);
            
            if (sysctl(mib, 2, &memsize, &len, NULL, 0) == 0) {
                SDL_SystemRAM = (int)(memsize / (1024*1024));
            }
        }
#endif
#ifdef __WIN32__
        if (SDL_SystemRAM <= 0) {
            MEMORYSTATUSEX stat;
            stat.dwLength = sizeof(stat);
            if (GlobalMemoryStatusEx(&stat)) {
                SDL_SystemRAM = (int)(stat.ullTotalPhys / (1024 * 1024));
            }
        }
#endif
#ifdef __OS2__
        if (SDL_SystemRAM <= 0) {
            Uint32 sysram = 0;
            DosQuerySysInfo(QSV_TOTPHYSMEM, QSV_TOTPHYSMEM, &sysram, 4);
            SDL_SystemRAM = (int) (sysram / 0x100000U);
        }
#endif
#ifdef __RISCOS__
        if (SDL_SystemRAM <= 0) {
            _kernel_swi_regs regs;
            regs.r[0] = 0x108;
            if (_kernel_swi(OS_Memory, &regs, &regs) == NULL) {
                SDL_SystemRAM = (int)(regs.r[1] * regs.r[2] / (1024 * 1024));
            }
        }
#endif
#endif
    }
    return SDL_SystemRAM;
}

References int(), NULL, and SDL_SystemRAM.

SDL_Has3DNow()

SDL_bool SDL_Has3DNow

(

void

)

This function returns true if the CPU has 3DNow! features.

Definition at line 818 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_3DNOW);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_3DNOW.

SDL_HasAltiVec()

SDL_bool SDL_HasAltiVec

(

void

)

This function returns true if the CPU has AltiVec features.

Definition at line 806 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_ALTIVEC);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_ALTIVEC.

SDL_HasARMSIMD()

SDL_bool SDL_HasARMSIMD

(

void

)

This function returns true if the CPU has ARM SIMD (ARMv6) features.

Definition at line 872 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_ARM_SIMD);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_ARM_SIMD.

SDL_HasAVX()

SDL_bool SDL_HasAVX

(

void

)

This function returns true if the CPU has AVX features.

Definition at line 854 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_AVX);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_AVX.

SDL_HasAVX2()

SDL_bool SDL_HasAVX2

(

void

)

This function returns true if the CPU has AVX2 features.

Definition at line 860 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_AVX2);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_AVX2.

SDL_HasAVX512F()

SDL_bool SDL_HasAVX512F

(

void

)

This function returns true if the CPU has AVX-512F (foundation) features.

Definition at line 866 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_AVX512F);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_AVX512F.

SDL_HasMMX()

SDL_bool SDL_HasMMX

(

void

)

This function returns true if the CPU has MMX features.

Definition at line 812 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_MMX);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_MMX.

SDL_HasNEON()

SDL_bool SDL_HasNEON

(

void

)

This function returns true if the CPU has NEON (ARM SIMD) features.

Definition at line 878 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_NEON);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_NEON.

SDL_HasRDTSC()

SDL_bool SDL_HasRDTSC

(

void

)

This function returns true if the CPU has the RDTSC instruction.

Definition at line 800 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_RDTSC);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_RDTSC.

SDL_HasSSE()

SDL_bool SDL_HasSSE

(

void

)

This function returns true if the CPU has SSE features.

Definition at line 824 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_SSE);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_SSE.

SDL_HasSSE2()

SDL_bool SDL_HasSSE2

(

void

)

This function returns true if the CPU has SSE2 features.

Definition at line 830 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_SSE2);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_SSE2.

SDL_HasSSE3()

SDL_bool SDL_HasSSE3

(

void

)

This function returns true if the CPU has SSE3 features.

Definition at line 836 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_SSE3);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_SSE3.

SDL_HasSSE41()

SDL_bool SDL_HasSSE41

(

void

)

This function returns true if the CPU has SSE4.1 features.

Definition at line 842 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_SSE41);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_SSE41.

SDL_HasSSE42()

SDL_bool SDL_HasSSE42

(

void

)

This function returns true if the CPU has SSE4.2 features.

Definition at line 848 of file SDL_cpuinfo.c.

{
    return CPU_FEATURE_AVAILABLE(CPU_HAS_SSE42);
}

References CPU_FEATURE_AVAILABLE, and CPU_HAS_SSE42.

SDL_SIMDAlloc()

void* SDL_SIMDAlloc

(

const size_t

len

)

Allocate memory in a SIMD-friendly way.

This will allocate a block of memory that is suitable for use with SIMD instructions. Specifically, it will be properly aligned and padded for the system's supported vector instructions.

The memory returned will be padded such that it is safe to read or write an incomplete vector at the end of the memory block. This can be useful so you don't have to drop back to a scalar fallback at the end of your SIMD processing loop to deal with the final elements without overflowing the allocated buffer.

You must free this memory with SDL_FreeSIMD(), not free() or SDL_free() or delete[], etc.

Note that SDL will only deal with SIMD instruction sets it is aware of; for example, SDL 2.0.8 knows that SSE wants 16-byte vectors (SDL_HasSSE()), and AVX2 wants 32 bytes (SDL_HasAVX2()), but doesn't know that AVX-512 wants 64. To be clear: if you can't decide to use an instruction set with an SDL_Has*() function, don't use that instruction set with memory allocated through here.

SDL_AllocSIMD(0) will return a non-NULL pointer, assuming the system isn't out of memory.

Parameters

len	The length, in bytes, of the block to allocated. The actual allocated block might be larger due to padding, etc.

Returns

Pointer to newly-allocated block, NULL if out of memory.

See also

SDL_SIMDAlignment

SDL_SIMDRealloc

SDL_SIMDFree

Definition at line 957 of file SDL_cpuinfo.c.

{
    const size_t alignment = SDL_SIMDGetAlignment();
    const size_t padding = alignment - (len % alignment);
    const size_t padded = (padding != alignment) ? (len + padding) : len;
    Uint8 *retval = NULL;
    Uint8 *ptr = (Uint8 *) SDL_malloc(padded + alignment + sizeof (void *));
    if (ptr) {
        /* store the actual malloc pointer right before our aligned pointer. */
        retval = ptr + sizeof (void *);
        retval += alignment - (((size_t) retval) % alignment);
        *(((void **) retval) - 1) = ptr;
    }
    return retval;
}

References NULL, ptr, retval, SDL_malloc, and SDL_SIMDGetAlignment().

SDL_SIMDFree()

void SDL_SIMDFree

(

void *

ptr

)

Deallocate memory obtained from SDL_SIMDAlloc.

It is not valid to use this function on a pointer from anything but SDL_SIMDAlloc(). It can't be used on pointers from malloc, realloc, SDL_malloc, memalign, new[], etc.

However, SDL_SIMDFree(NULL) is a legal no-op.

See also

SDL_SIMDAlloc

SDL_SIMDRealloc

Definition at line 1026 of file SDL_cpuinfo.c.

{
    if (ptr) {
        void **realptr = (void **) ptr;
        realptr--;
        SDL_free(*(((void **) ptr) - 1));
    }
}

References ptr, and SDL_free.

SDL_SIMDGetAlignment()

size_t SDL_SIMDGetAlignment

(

void

)

Report the alignment this system needs for SIMD allocations.

This will return the minimum number of bytes to which a pointer must be aligned to be compatible with SIMD instructions on the current machine. For example, if the machine supports SSE only, it will return 16, but if it supports AVX-512F, it'll return 64 (etc). This only reports values for instruction sets SDL knows about, so if your SDL build doesn't have SDL_HasAVX512F(), then it might return 16 for the SSE support it sees and not 64 for the AVX-512 instructions that exist but SDL doesn't know about. Plan accordingly.

Definition at line 947 of file SDL_cpuinfo.c.

{
    if (SDL_SIMDAlignment == 0xFFFFFFFF) {
        SDL_GetCPUFeatures();  /* make sure this has been calculated */
    }
    SDL_assert(SDL_SIMDAlignment != 0);
    return SDL_SIMDAlignment;
}

References SDL_assert, SDL_GetCPUFeatures(), and SDL_SIMDAlignment.

Referenced by SDL_SIMDAlloc(), and SDL_SIMDRealloc().

SDL_SIMDRealloc()

void* SDL_SIMDRealloc	(	void *	mem,
		const size_t	len
	)

Reallocate memory obtained from SDL_SIMDAlloc.

It is not valid to use this function on a pointer from anything but SDL_SIMDAlloc(). It can't be used on pointers from malloc, realloc, SDL_malloc, memalign, new[], etc.

Parameters

mem	The pointer obtained from SDL_SIMDAlloc. This function also accepts NULL, at which point this function is the same as calling SDL_realloc with a NULL pointer.
len	The length, in bytes, of the block to allocated. The actual allocated block might be larger due to padding, etc. Passing 0 will return a non-NULL pointer, assuming the system isn't out of memory.

Returns

Pointer to newly-reallocated block, NULL if out of memory.

See also

SDL_SIMDAlignment

SDL_SIMDAlloc

SDL_SIMDFree

Definition at line 974 of file SDL_cpuinfo.c.

{
    const size_t alignment = SDL_SIMDGetAlignment();
    const size_t padding = alignment - (len % alignment);
    const size_t padded = (padding != alignment) ? (len + padding) : len;
    Uint8 *retval = (Uint8*) mem;
    void *oldmem = mem;
    size_t memdiff = 0, ptrdiff;
    Uint8 *ptr;
 
    if (mem) {
        void **realptr = (void **) mem;
        realptr--;
        mem = *(((void **) mem) - 1);
 
        /* Check the delta between the real pointer and user pointer */
        memdiff = ((size_t) oldmem) - ((size_t) mem);
    }
 
    ptr = (Uint8 *) SDL_realloc(mem, padded + alignment + sizeof (void *));
 
    if (ptr == mem) {
        return retval; /* Pointer didn't change, nothing to do */
    }
    if (ptr == NULL) {
        return NULL; /* Out of memory, bail! */
    }
 
    /* Store the actual malloc pointer right before our aligned pointer. */
    retval = ptr + sizeof (void *);
    retval += alignment - (((size_t) retval) % alignment);
 
    /* Make sure the delta is the same! */
    if (mem) {
        ptrdiff = ((size_t) retval) - ((size_t) ptr);
        if (memdiff != ptrdiff) { /* Delta has changed, copy to new offset! */
            oldmem = (void*) (((size_t) ptr) + memdiff);
 
            /* Even though the data past the old `len` is undefined, this is the
             * only length value we have, and it guarantees that we copy all the
             * previous memory anyhow.
             */
            SDL_memmove(retval, oldmem, len);
        }
    }
 
    /* Actually store the malloc pointer, finally. */
    *(((void **) retval) - 1) = ptr;
    return retval;
}

References NULL, ptr, retval, SDL_memmove, SDL_realloc, and SDL_SIMDGetAlignment().

Variable Documentation

CPU_CPUIDFeatures

int CPU_CPUIDFeatures[4]

static

Definition at line 272 of file SDL_cpuinfo.c.

Referenced by CPU_calcCPUIDFeatures().

CPU_CPUIDMaxFunction

int CPU_CPUIDMaxFunction = 0

static

Definition at line 273 of file SDL_cpuinfo.c.

Referenced by CPU_calcCPUIDFeatures(), CPU_have3DNow(), CPU_haveAVX2(), CPU_haveAVX512F(), and SDL_GetCPUType().

CPU_OSSavesYMM

SDL_bool CPU_OSSavesYMM = SDL_FALSE

static

Definition at line 274 of file SDL_cpuinfo.c.

Referenced by CPU_calcCPUIDFeatures(), and CPU_haveAVX2().

CPU_OSSavesZMM

SDL_bool CPU_OSSavesZMM = SDL_FALSE

static

Definition at line 275 of file SDL_cpuinfo.c.

Referenced by CPU_calcCPUIDFeatures(), and CPU_haveAVX512F().

SDL_CPUCount

int SDL_CPUCount = 0

static

Definition at line 559 of file SDL_cpuinfo.c.

Referenced by SDL_GetCPUCount().

SDL_CPUFeatures

Uint32 SDL_CPUFeatures = 0xFFFFFFFF

static

Definition at line 729 of file SDL_cpuinfo.c.

Referenced by SDL_GetCPUFeatures().

SDL_SIMDAlignment

Uint32 SDL_SIMDAlignment = 0xFFFFFFFF

static

Definition at line 730 of file SDL_cpuinfo.c.

Referenced by SDL_GetCPUFeatures(), and SDL_SIMDGetAlignment().

SDL_SystemRAM

int SDL_SystemRAM = 0

static

Definition at line 883 of file SDL_cpuinfo.c.

Referenced by SDL_GetSystemRAM().