mpv/cpudetect.c

#include "config.h"
#include "cpudetect.h"
#include "mp_msg.h"

CpuCaps gCpuCaps;

#if HAVE_MALLOC_H
#include <malloc.h>
#endif
#include <stdlib.h>

#if ARCH_X86

#include <stdio.h>
#include <string.h>

#if defined (__NetBSD__) || defined(__OpenBSD__)
#include <sys/param.h>
#include <sys/sysctl.h>
#include <machine/cpu.h>
#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__) || defined(__APPLE__)
#include <sys/types.h>
#include <sys/sysctl.h>
#elif defined(__linux__)
#include <signal.h>
#elif defined(__MINGW32__) || defined(__CYGWIN__)
#include <windows.h>
#elif defined(__OS2__)
#define INCL_DOS
#include <os2.h>
#elif defined(__AMIGAOS4__)
#include <proto/exec.h>
#endif

/* Thanks to the FreeBSD project for some of this cpuid code, and 
 * help understanding how to use it.  Thanks to the Mesa 
 * team for SSE support detection and more cpu detect code.
 */

/* I believe this code works.  However, it has only been used on a PII and PIII */

static void check_os_katmai_support( void );

// return TRUE if cpuid supported
static int has_cpuid(void)
{
	long a, c;

// code from libavcodec:
#if ARCH_X86_64
#define PUSHF "pushfq\n\t"
#define POPF "popfq\n\t"
#else
#define PUSHF "pushfl\n\t"
#define POPF "popfl\n\t"
#endif
    __asm__ volatile (
                          /* See if CPUID instruction is supported ... */
                          /* ... Get copies of EFLAGS into eax and ecx */
                          PUSHF
                          "pop %0\n\t"
                          "mov %0, %1\n\t"
                          
                          /* ... Toggle the ID bit in one copy and store */
                          /*     to the EFLAGS reg */
                          "xor $0x200000, %0\n\t"
                          "push %0\n\t"
                          POPF
                          
                          /* ... Get the (hopefully modified) EFLAGS */
                          PUSHF
                          "pop %0\n\t"
                          : "=a" (a), "=c" (c)
                          :
                          : "cc" 
                          );
#undef PUSHF
#undef POPF

	return a != c;
}

static void
do_cpuid(unsigned int ax, unsigned int *p)
{
#if 0
	__asm__ volatile(
	"cpuid;"
	: "=a" (p[0]), "=b" (p[1]), "=c" (p[2]), "=d" (p[3])
	:  "0" (ax)
	);
#else
// code from libavcodec:
    __asm__ volatile
	("mov %%"REG_b", %%"REG_S"\n\t"
         "cpuid\n\t"
         "xchg %%"REG_b", %%"REG_S
         : "=a" (p[0]), "=S" (p[1]), 
           "=c" (p[2]), "=d" (p[3])
         : "0" (ax));
#endif

}

void GetCpuCaps( CpuCaps *caps)
{
	unsigned int regs[4];
	unsigned int regs2[4];

	memset(caps, 0, sizeof(*caps));
	caps->isX86=1;
	caps->cl_size=32; /* default */
	if (!has_cpuid()) {
	    mp_msg(MSGT_CPUDETECT,MSGL_WARN,"CPUID not supported!??? (maybe an old 486?)\n");
	    return;
	}
	do_cpuid(0x00000000, regs); // get _max_ cpuid level and vendor name
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU vendor name: %.4s%.4s%.4s  max cpuid level: %d\n",
			(char*) (regs+1),(char*) (regs+3),(char*) (regs+2), regs[0]);
	if (regs[0]>=0x00000001)
	{
		char *tmpstr, *ptmpstr;
		unsigned cl_size;

		do_cpuid(0x00000001, regs2);

		caps->cpuType=(regs2[0] >> 8)&0xf;
		caps->cpuModel=(regs2[0] >> 4)&0xf;

// see AMD64 Architecture Programmer's Manual, Volume 3: General-purpose and
// System Instructions, Table 3-2: Effective family computation, page 120.
		if(caps->cpuType==0xf){
		    // use extended family (P4, IA64, K8)
		    caps->cpuType=0xf+((regs2[0]>>20)&255);
		}
		if(caps->cpuType==0xf || caps->cpuType==6)
		    caps->cpuModel |= ((regs2[0]>>16)&0xf) << 4;

		caps->cpuStepping=regs2[0] & 0xf;

		// general feature flags:
		caps->hasTSC  = (regs2[3] & (1 << 8  )) >>  8; // 0x0000010
		caps->hasMMX  = (regs2[3] & (1 << 23 )) >> 23; // 0x0800000
		caps->hasSSE  = (regs2[3] & (1 << 25 )) >> 25; // 0x2000000
		caps->hasSSE2 = (regs2[3] & (1 << 26 )) >> 26; // 0x4000000
		caps->hasSSSE3 = (regs2[2] & (1 << 9 )) >>  9; // 0x0000200
		caps->hasMMX2 = caps->hasSSE; // SSE cpus supports mmxext too
		cl_size = ((regs2[1] >> 8) & 0xFF)*8;
		if(cl_size) caps->cl_size = cl_size;

		ptmpstr=tmpstr=GetCpuFriendlyName(regs, regs2);
		while(*ptmpstr == ' ')        // strip leading spaces
		    ptmpstr++;
		mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: %s ", ptmpstr);
		free(tmpstr);
		mp_msg(MSGT_CPUDETECT,MSGL_V,"(Family: %d, Model: %d, Stepping: %d)\n",
		    caps->cpuType, caps->cpuModel, caps->cpuStepping);

	}
	do_cpuid(0x80000000, regs);
	if (regs[0]>=0x80000001) {
		mp_msg(MSGT_CPUDETECT,MSGL_V,"extended cpuid-level: %d\n",regs[0]&0x7FFFFFFF);
		do_cpuid(0x80000001, regs2);
		caps->hasMMX  |= (regs2[3] & (1 << 23 )) >> 23; // 0x0800000
		caps->hasMMX2 |= (regs2[3] & (1 << 22 )) >> 22; // 0x400000
		caps->has3DNow    = (regs2[3] & (1 << 31 )) >> 31; //0x80000000
		caps->has3DNowExt = (regs2[3] & (1 << 30 )) >> 30;
		caps->hasSSE4a = (regs2[2] & (1 << 6 )) >>  6; // 0x0000040
	}
	if(regs[0]>=0x80000006)
	{
		do_cpuid(0x80000006, regs2);
		mp_msg(MSGT_CPUDETECT,MSGL_V,"extended cache-info: %d\n",regs2[2]&0x7FFFFFFF);
		caps->cl_size  = regs2[2] & 0xFF;
	}
	mp_msg(MSGT_CPUDETECT,MSGL_V,"Detected cache-line size is %u bytes\n",caps->cl_size);
#if 0
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"cpudetect: MMX=%d MMX2=%d SSE=%d SSE2=%d 3DNow=%d 3DNowExt=%d\n",
		gCpuCaps.hasMMX,
		gCpuCaps.hasMMX2,
		gCpuCaps.hasSSE,
		gCpuCaps.hasSSE2,
		gCpuCaps.has3DNow,
		gCpuCaps.has3DNowExt );
#endif

		/* FIXME: Does SSE2 need more OS support, too? */
#if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) \
  || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
  || defined(__APPLE__) || defined(__CYGWIN__) || defined(__MINGW32__) \
  || defined(__OS2__)
		if (caps->hasSSE)
			check_os_katmai_support();
		if (!caps->hasSSE)
			caps->hasSSE2 = 0;
#else
		caps->hasSSE=0;
		caps->hasSSE2 = 0;
#endif
//		caps->has3DNow=1;
//		caps->hasMMX2 = 0;
//		caps->hasMMX = 0;

#ifndef RUNTIME_CPUDETECT
#if !HAVE_MMX
	if(caps->hasMMX) mp_msg(MSGT_CPUDETECT,MSGL_WARN,"MMX supported but disabled\n");
	caps->hasMMX=0;
#endif
#if !HAVE_MMX2
	if(caps->hasMMX2) mp_msg(MSGT_CPUDETECT,MSGL_WARN,"MMX2 supported but disabled\n");
	caps->hasMMX2=0;
#endif
#if !HAVE_SSE
	if(caps->hasSSE) mp_msg(MSGT_CPUDETECT,MSGL_WARN,"SSE supported but disabled\n");
	caps->hasSSE=0;
#endif
#if !HAVE_SSE2
	if(caps->hasSSE2) mp_msg(MSGT_CPUDETECT,MSGL_WARN,"SSE2 supported but disabled\n");
	caps->hasSSE2=0;
#endif
#if !HAVE_AMD3DNOW
	if(caps->has3DNow) mp_msg(MSGT_CPUDETECT,MSGL_WARN,"3DNow supported but disabled\n");
	caps->has3DNow=0;
#endif
#if !HAVE_AMD3DNOWEXT
	if(caps->has3DNowExt) mp_msg(MSGT_CPUDETECT,MSGL_WARN,"3DNowExt supported but disabled\n");
	caps->has3DNowExt=0;
#endif
#endif  // RUNTIME_CPUDETECT
}

char *GetCpuFriendlyName(unsigned int regs[], unsigned int regs2[]){
	char vendor[13];
	char *retname;
	int i;

	if (NULL==(retname=malloc(256))) {
		mp_msg(MSGT_CPUDETECT,MSGL_FATAL,"Error: GetCpuFriendlyName() not enough memory\n");
		exit(1);
	}
	retname[0] = '\0';

	sprintf(vendor,"%.4s%.4s%.4s",(char*)(regs+1),(char*)(regs+3),(char*)(regs+2));

	do_cpuid(0x80000000,regs);
	if (regs[0] >= 0x80000004)
	{
		// CPU has built-in namestring
		for (i = 0x80000002; i <= 0x80000004; i++)
		{
			do_cpuid(i, regs);
			strncat(retname, (char*)regs, 16);
		}
	}
	return retname;
}

#if defined(__linux__) && defined(_POSIX_SOURCE) && !ARCH_X86_64
static void sigill_handler_sse( int signal, struct sigcontext sc )
{
   mp_msg(MSGT_CPUDETECT,MSGL_V, "SIGILL, " );

   /* Both the "xorps %%xmm0,%%xmm0" and "divps %xmm0,%%xmm1"
    * instructions are 3 bytes long.  We must increment the instruction
    * pointer manually to avoid repeated execution of the offending
    * instruction.
    *
    * If the SIGILL is caused by a divide-by-zero when unmasked
    * exceptions aren't supported, the SIMD FPU status and control
    * word will be restored at the end of the test, so we don't need
    * to worry about doing it here.  Besides, we may not be able to...
    */
   sc.eip += 3;

   gCpuCaps.hasSSE=0;
}
#endif /* __linux__ && _POSIX_SOURCE */

#if defined(__MINGW32__) || defined(__CYGWIN__)
LONG CALLBACK win32_sig_handler_sse(EXCEPTION_POINTERS* ep)
{
   if(ep->ExceptionRecord->ExceptionCode==EXCEPTION_ILLEGAL_INSTRUCTION){
      mp_msg(MSGT_CPUDETECT,MSGL_V, "SIGILL, " );
      ep->ContextRecord->Eip +=3;
      gCpuCaps.hasSSE=0;       
	  return EXCEPTION_CONTINUE_EXECUTION;
   }
   return EXCEPTION_CONTINUE_SEARCH;
}
#endif /* defined(__MINGW32__) || defined(__CYGWIN__) */

#ifdef __OS2__
ULONG _System os2_sig_handler_sse( PEXCEPTIONREPORTRECORD       p1,
                                   PEXCEPTIONREGISTRATIONRECORD p2,
                                   PCONTEXTRECORD               p3,
                                   PVOID                        p4 )
{
   if(p1->ExceptionNum == XCPT_ILLEGAL_INSTRUCTION){
      mp_msg(MSGT_CPUDETECT, MSGL_V, "SIGILL, ");

      p3->ctx_RegEip += 3;
      gCpuCaps.hasSSE = 0;

      return XCPT_CONTINUE_EXECUTION;
   }
   return XCPT_CONTINUE_SEARCH;
}
#endif

/* If we're running on a processor that can do SSE, let's see if we
 * are allowed to or not.  This will catch 2.4.0 or later kernels that
 * haven't been configured for a Pentium III but are running on one,
 * and RedHat patched 2.2 kernels that have broken exception handling
 * support for user space apps that do SSE.
 */
 
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
#define SSE_SYSCTL_NAME "hw.instruction_sse"
#elif defined(__APPLE__)
#define SSE_SYSCTL_NAME "hw.optional.sse"
#endif

static void check_os_katmai_support( void )
{
#if ARCH_X86_64
   gCpuCaps.hasSSE=1;
   gCpuCaps.hasSSE2=1;
#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__) || defined(__APPLE__)
   int has_sse=0, ret;
   size_t len=sizeof(has_sse);

   ret = sysctlbyname(SSE_SYSCTL_NAME, &has_sse, &len, NULL, 0);
   if (ret || !has_sse)
      gCpuCaps.hasSSE=0;

#elif defined(__NetBSD__) || defined (__OpenBSD__)
#if __NetBSD_Version__ >= 105250000 || (defined __OpenBSD__)
   int has_sse, has_sse2, ret, mib[2];
   size_t varlen;

   mib[0] = CTL_MACHDEP;
   mib[1] = CPU_SSE;
   varlen = sizeof(has_sse);

   mp_msg(MSGT_CPUDETECT,MSGL_V, "Testing OS support for SSE... " );
   ret = sysctl(mib, 2, &has_sse, &varlen, NULL, 0);
   gCpuCaps.hasSSE = ret >= 0 && has_sse;
   mp_msg(MSGT_CPUDETECT,MSGL_V, gCpuCaps.hasSSE ? "yes.\n" : "no!\n" );

   mib[1] = CPU_SSE2;
   varlen = sizeof(has_sse2);
   mp_msg(MSGT_CPUDETECT,MSGL_V, "Testing OS support for SSE2... " );
   ret = sysctl(mib, 2, &has_sse2, &varlen, NULL, 0);
   gCpuCaps.hasSSE2 = ret >= 0 && has_sse2;
   mp_msg(MSGT_CPUDETECT,MSGL_V, gCpuCaps.hasSSE2 ? "yes.\n" : "no!\n" );
#else
   gCpuCaps.hasSSE = 0;
   mp_msg(MSGT_CPUDETECT,MSGL_WARN, "No OS support for SSE, disabling to be safe.\n" );
#endif
#elif defined(__MINGW32__) || defined(__CYGWIN__)
   LPTOP_LEVEL_EXCEPTION_FILTER exc_fil;
   if ( gCpuCaps.hasSSE ) {
      mp_msg(MSGT_CPUDETECT,MSGL_V, "Testing OS support for SSE... " );
      exc_fil = SetUnhandledExceptionFilter(win32_sig_handler_sse);
      __asm__ volatile ("xorps %xmm0, %xmm0");
      SetUnhandledExceptionFilter(exc_fil);
      mp_msg(MSGT_CPUDETECT,MSGL_V, gCpuCaps.hasSSE ? "yes.\n" : "no!\n" );
   }
#elif defined(__OS2__)
   EXCEPTIONREGISTRATIONRECORD RegRec = { 0, &os2_sig_handler_sse };
   if ( gCpuCaps.hasSSE ) {
      mp_msg(MSGT_CPUDETECT,MSGL_V, "Testing OS support for SSE... " );
      DosSetExceptionHandler( &RegRec );
      __asm__ volatile ("xorps %xmm0, %xmm0");
      DosUnsetExceptionHandler( &RegRec );
      mp_msg(MSGT_CPUDETECT,MSGL_V, gCpuCaps.hasSSE ? "yes.\n" : "no!\n" );
   }
#elif defined(__linux__)
#if defined(_POSIX_SOURCE)
   struct sigaction saved_sigill;

   /* Save the original signal handlers.
    */
   sigaction( SIGILL, NULL, &saved_sigill );

   signal( SIGILL, (void (*)(int))sigill_handler_sse );

   /* Emulate test for OSFXSR in CR4.  The OS will set this bit if it
    * supports the extended FPU save and restore required for SSE.  If
    * we execute an SSE instruction on a PIII and get a SIGILL, the OS
    * doesn't support Streaming SIMD Exceptions, even if the processor
    * does.
    */
   if ( gCpuCaps.hasSSE ) {
      mp_msg(MSGT_CPUDETECT,MSGL_V, "Testing OS support for SSE... " );

//      __asm__ volatile ("xorps %%xmm0, %%xmm0");
      __asm__ volatile ("xorps %xmm0, %xmm0");

      mp_msg(MSGT_CPUDETECT,MSGL_V, gCpuCaps.hasSSE ? "yes.\n" : "no!\n" );
   }

   /* Restore the original signal handlers.
    */
   sigaction( SIGILL, &saved_sigill, NULL );

   /* If we've gotten to here and the XMM CPUID bit is still set, we're
    * safe to go ahead and hook out the SSE code throughout Mesa.
    */
   mp_msg(MSGT_CPUDETECT,MSGL_V, "Tests of OS support for SSE %s\n", gCpuCaps.hasSSE ? "passed." : "failed!" );
#else
   /* We can't use POSIX signal handling to test the availability of
    * SSE, so we disable it by default.
    */
   mp_msg(MSGT_CPUDETECT,MSGL_WARN, "Cannot test OS support for SSE, disabling to be safe.\n" );
   gCpuCaps.hasSSE=0;
#endif /* _POSIX_SOURCE */
#else
   /* Do nothing on other platforms for now.
    */
   mp_msg(MSGT_CPUDETECT,MSGL_WARN, "Cannot test OS support for SSE, leaving disabled.\n" );
   gCpuCaps.hasSSE=0;
#endif /* __linux__ */
}
#else /* ARCH_X86 */

#ifdef __APPLE__
#include <sys/sysctl.h>
#elif defined(__AMIGAOS4__)
/* nothing */
#else
#include <signal.h>
#include <setjmp.h>

static sigjmp_buf jmpbuf;
static volatile sig_atomic_t canjump = 0;

static void sigill_handler (int sig)
{
    if (!canjump) {
        signal (sig, SIG_DFL);
        raise (sig);
    }
    
    canjump = 0;
    siglongjmp (jmpbuf, 1);
}
#endif /* __APPLE__ */

void GetCpuCaps( CpuCaps *caps)
{
	caps->cpuType=0;
	caps->cpuModel=0;
	caps->cpuStepping=0;
	caps->hasMMX=0;
	caps->hasMMX2=0;
	caps->has3DNow=0;
	caps->has3DNowExt=0;
	caps->hasSSE=0;
	caps->hasSSE2=0;
	caps->hasSSSE3=0;
	caps->hasSSE4a=0;
	caps->isX86=0;
	caps->hasAltiVec = 0;
#if HAVE_ALTIVEC   
#ifdef __APPLE__
/*
  rip-off from ffmpeg altivec detection code.
  this code also appears on Apple's AltiVec pages.
 */
        {
                int sels[2] = {CTL_HW, HW_VECTORUNIT};
                int has_vu = 0;
                size_t len = sizeof(has_vu);
                int err;

                err = sysctl(sels, 2, &has_vu, &len, NULL, 0);   

                if (err == 0)
                        if (has_vu != 0)
                                caps->hasAltiVec = 1;
        }
#elif defined(__AMIGAOS4__)
        ULONG result = 0;

        GetCPUInfoTags(GCIT_VectorUnit, &result, TAG_DONE);
        if (result == VECTORTYPE_ALTIVEC)
        	caps->hasAltiVec = 1;
#else
/* no Darwin, do it the brute-force way */
/* this is borrowed from the libmpeg2 library */
        {
          signal (SIGILL, sigill_handler);
          if (sigsetjmp (jmpbuf, 1)) {
            signal (SIGILL, SIG_DFL);
          } else {
            canjump = 1;
            
            __asm__ volatile ("mtspr 256, %0\n\t"
                          "vand %%v0, %%v0, %%v0"
                          :
                          : "r" (-1));
            
            signal (SIGILL, SIG_DFL);
            caps->hasAltiVec = 1;
          }
        }
#endif /* __APPLE__ */
        mp_msg(MSGT_CPUDETECT,MSGL_V,"AltiVec %sfound\n", (caps->hasAltiVec ? "" : "not "));
#endif /* HAVE_ALTIVEC */

if (ARCH_IA64)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: Intel Itanium\n");

if (ARCH_SPARC)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: Sun Sparc\n");

if (ARCH_ARM)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: ARM\n");

if (ARCH_PPC)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: PowerPC\n");

if (ARCH_ALPHA)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: Digital Alpha\n");

if (ARCH_SGI_MIPS)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: SGI MIPS\n");

if (ARCH_PA_RISC)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: Hewlett-Packard PA-RISC\n");

if (ARCH_S390)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: IBM S/390\n");

if (ARCH_S390X)
	mp_msg(MSGT_CPUDETECT,MSGL_V,"CPU: IBM S/390X\n");

if (ARCH_VAX)
	mp_msg(MSGT_CPUDETECT,MSGL_V, "CPU: Digital VAX\n" );

if (ARCH_XTENSA)
	mp_msg(MSGT_CPUDETECT,MSGL_V, "CPU: Tensilica Xtensa\n" );
}
#endif /* !ARCH_X86 */