CMake test for processor feature

Question

I am wondering if it is possible for CMake to run tests like one might run with a configure script. Specifically I want to test if the system I am compiling on has support for

Answer 1

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