cat /proc/cpuinfo | head -n 19 | tail -1 | grep -c rdtscp

execute_process(COMMAND cat /proc/cpuinfo
    COMMAND head -n 19
    COMMAND tail -1
    COMMAND grep -c rdtscp
    OUTPUT_VARIABLE OUT)

wp              : yes

execute_process(COMMAND grep -l '^flags[[:space:]]*:.*rdtscp' /proc/cpuinfo
    OUTPUT_VARIABLE OUT)