動作周波数の取得 - processor name

CPUID から CPU 名を取得する関数 get_cpu_name() はこちら。

double get_cpuname_mfreq(void) {
  double freq = -1.0;
  int i, unit_size = 0;
  char name[48], buffer[8];
  strcpy(name, get_cpu_name());

  for (i = 0; i < 48-2; ++i) {
    if( name[i+1] == 'H' && name[i+2] == 'z' ) {
      if (name[i] == 'M') {
	  unit_size = 1;
      } else if (name[i] == 'G') {
	  unit_size = 1000;
      } else if (name[i] == 'T') {
	  unit_size = 1000000;
      }
    }

    /* parse "x.xxyHz" or "xxxxyHz" */
    if (unit_size > 0) {
      strncpy(buffer, &name[i-4], 7);
      buffer[7] = 0;
      if (name[i-3] == '.') {
	  freq  = (int)(name[i-4] - '0') * unit_size;
	  freq += (int)(name[i-2] - '0') * (unit_size/10);
	  freq += (int)(name[i-1] - '0') * (unit_size/100);
      } else {
	  freq  = (int)(name[i-4] - '0') * 1000;
	  freq += (int)(name[i-3] - '0') * 100;
	  freq += (int)(name[i-2] - '0') * 10;
	  freq += (int)(name[i-1] - '0');
	  freq *= unit_size;
      }
      break;
    }
  }
  return freq;
}

[参考] Intel(R) Processor Identification and the CPUID Instruction. 2009.