cpudetect.c

自己移植的linux下的流媒体播放器原代码,支持mms协议,支持ftp和http协议.

       */
      sc.fpstate->mxcsr |= 0x00000200;
      sc.fpstate->mxcsr &= 0xfffffffb;
   } else {
      /* If we ever get here, we're completely hosed.
       */
      mp_msg(MSGT_CPUDETECT,MSGL_V, "\n\n" );
      mp_msg(MSGT_CPUDETECT,MSGL_V, "SSE enabling test failed badly!" );
   }
}
#endif /* __linux__ && _POSIX_SOURCE && X86_FXSR_MAGIC */

#ifdef WIN32
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 /* WIN32 */

/* 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.
 */
static void check_os_katmai_support( void )
{
#ifdef ARCH_X86_64
   gCpuCaps.hasSSE=1;
   gCpuCaps.hasSSE2=1;
#elif defined(__FreeBSD__)
   int has_sse=0, ret;
   size_t len=sizeof(has_sse);

   ret = sysctlbyname("hw.instruction_sse", &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);
   if (ret < 0 || !has_sse) {
      gCpuCaps.hasSSE=0;
      mp_msg(MSGT_CPUDETECT,MSGL_V, "no!\n" );
   } else {
      gCpuCaps.hasSSE=1;
      mp_msg(MSGT_CPUDETECT,MSGL_V, "yes!\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);
   if (ret < 0 || !has_sse2) {
      gCpuCaps.hasSSE2=0;
      mp_msg(MSGT_CPUDETECT,MSGL_V, "no!\n" );
   } else {
      gCpuCaps.hasSSE2=1;
      mp_msg(MSGT_CPUDETECT,MSGL_V, "yes!\n" );
   }
#else
   gCpuCaps.hasSSE = 0;
   mp_msg(MSGT_CPUDETECT,MSGL_WARN, "No OS support for SSE, disabling to be safe.\n" );
#endif
#elif defined(WIN32)
   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);
      if ( gCpuCaps.hasSSE ) mp_msg(MSGT_CPUDETECT,MSGL_V, "yes.\n" );
      else mp_msg(MSGT_CPUDETECT,MSGL_V, "no!\n" );
   }
#elif defined(__linux__)
#if defined(_POSIX_SOURCE) && defined(X86_FXSR_MAGIC)
   struct sigaction saved_sigill;
   struct sigaction saved_sigfpe;

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

   signal( SIGILL, (void (*)(int))sigill_handler_sse );
   signal( SIGFPE, (void (*)(int))sigfpe_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");

      if ( gCpuCaps.hasSSE ) {
	 mp_msg(MSGT_CPUDETECT,MSGL_V, "yes.\n" );
      } else {
	 mp_msg(MSGT_CPUDETECT,MSGL_V, "no!\n" );
      }
   }

   /* Emulate test for OSXMMEXCPT in CR4.  The OS will set this bit if
    * it supports unmasked SIMD FPU exceptions.  If we unmask the
    * exceptions, do a SIMD divide-by-zero and get a SIGILL, the OS
    * doesn't support unmasked SIMD FPU exceptions.  If we get a SIGFPE
    * as expected, we're okay but we need to clean up after it.
    *
    * Are we being too stringent in our requirement that the OS support
    * unmasked exceptions?  Certain RedHat 2.2 kernels enable SSE by
    * setting CR4.OSFXSR but don't support unmasked exceptions.  Win98
    * doesn't even support them.  We at least know the user-space SSE
    * support is good in kernels that do support unmasked exceptions,
    * and therefore to be safe I'm going to leave this test in here.
    */
   if ( gCpuCaps.hasSSE ) {
      mp_msg(MSGT_CPUDETECT,MSGL_V, "Testing OS support for SSE unmasked exceptions... " );

//      test_os_katmai_exception_support();

      if ( gCpuCaps.hasSSE ) {
	 mp_msg(MSGT_CPUDETECT,MSGL_V, "yes.\n" );
      } else {
	 mp_msg(MSGT_CPUDETECT,MSGL_V, "no!\n" );
      }
   }

   /* Restore the original signal handlers.
    */
   sigaction( SIGILL, &saved_sigill, NULL );
   sigaction( SIGFPE, &saved_sigfpe, 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.
    */
   if ( gCpuCaps.hasSSE ) {
      mp_msg(MSGT_CPUDETECT,MSGL_V, "Tests of OS support for SSE passed.\n" );
   } else {
      mp_msg(MSGT_CPUDETECT,MSGL_V, "Tests of OS support for SSE failed!\n" );
   }
#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 && X86_FXSR_MAGIC */
#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 || ARCH_X86_64 */

#ifdef SYS_DARWIN
#include <sys/sysctl.h>
#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

void GetCpuCaps( CpuCaps *caps)
{
	caps->cpuType=0;
	caps->cpuStepping=0;
	caps->hasMMX=0;
	caps->hasMMX2=0;
	caps->has3DNow=0;
	caps->has3DNowExt=0;
	caps->hasSSE=0;
	caps->hasSSE2=0;
	caps->isX86=0;
	caps->hasAltiVec = 0;
#ifdef HAVE_ALTIVEC   
#ifdef SYS_DARWIN   
/*
  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;
        }
#else /* SYS_DARWIN */
/* 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 /* SYS_DARWIN */
        mp_msg(MSGT_CPUDETECT,MSGL_INFO,"AltiVec %sfound\n", (caps->hasAltiVec ? "" : "not "));
#endif /* HAVE_ALTIVEC */

#ifdef ARCH_IA64
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: Intel Itanium\n");
#endif

#ifdef ARCH_SPARC
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: Sun Sparc\n");
#endif

#ifdef ARCH_ARMV4L
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: ARM\n");
#endif

#ifdef ARCH_POWERPC
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: PowerPC\n");
#endif

#ifdef ARCH_ALPHA
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: Digital Alpha\n");
#endif

#ifdef ARCH_SGI_MIPS
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: SGI MIPS\n");
#endif

#ifdef ARCH_PA_RISC
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: Hewlett-Packard PA-RISC\n");
#endif

#ifdef ARCH_S390
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: IBM S/390\n");
#endif

#ifdef ARCH_S390X
	mp_msg(MSGT_CPUDETECT,MSGL_INFO,"CPU: IBM S/390X\n");
#endif

#ifdef ARCH_VAX
	mp_msg(MSGT_CPUDETECT,MSGL_INFO, "CPU: Digital VAX\n" );
#endif
}
#endif /* !ARCH_X86 */