scrypt-1.2.1/libcperciva/cpusupport/cpusupport_x86_aesni.c

   1 #include "cpusupport.h"
   2
   3 #ifdef CPUSUPPORT_X86_CPUID
   4 #include <cpuid.h>
   5
   6 #define CPUID_AESNI_BIT (1 << 25)
   7 #endif
   8
   9 CPUSUPPORT_FEATURE_DECL(x86, aesni)
  10 {
  11 #ifdef CPUSUPPORT_X86_CPUID
  12         unsigned int eax, ebx, ecx, edx;
  13
  14         /* Check if CPUID supports the level we need. */
  15         if (!__get_cpuid(0, &eax, &ebx, &ecx, &edx))
  16                 goto unsupported;
  17         if (eax < 1)
  18                 goto unsupported;
  19
  20         /* Ask about CPU features. */
  21         if (!__get_cpuid(1, &eax, &ebx, &ecx, &edx))
  22                 goto unsupported;
  23
  24         /* Return the relevant feature bit. */
  25         return ((ecx & CPUID_AESNI_BIT) ? 1 : 0);
  26
  27 unsupported:
  28 #endif
  29         return (0);
  30 }