release/src/router/dnscrypt/src/libnacl/cpucycles/amd64cpuspeed.c

   1 #include <stdio.h>
   2 #include <sys/types.h>
   3 #include <sys/param.h>
   4 #include <sys/sysctl.h>
   5
   6 long long cpucycles_amd64cpuspeed(void)
   7 {
   8   unsigned long long result;
   9   asm volatile(".byte 15;.byte 49;shlq $32,%%rdx;orq %%rdx,%%rax"
  10     : "=a" (result) ::  "%rdx");
  11   return result;
  12 }
  13
  14 long long cpucycles_amd64cpuspeed_persecond(void)
  15 {
  16   int oid[2];
  17   int val;
  18   size_t size;
  19   oid[0] = CTL_HW;
  20   oid[1] = HW_CPUSPEED;
  21   size = sizeof val;
  22   if (sysctl(oid,2,&val,&size,0,0) == -1) return 0;
  23   if (size != sizeof val) return 0;
  24   return val * 1000000LL;
  25 }