rmainz@derfwpc5131:~$ clang -E -dM -m32  -include time.h - < /dev/null | egrep '#[[:space:]]*define[[:space:]]+CLOCK_.+[[:space:]]+[[:digit:]]+'
#define CLOCK_BOOTTIME 7
#define CLOCK_BOOTTIME_ALARM 9
#define CLOCK_MONOTONIC 1
#define CLOCK_MONOTONIC_COARSE 6
#define CLOCK_MONOTONIC_RAW 4
#define CLOCK_PROCESS_CPUTIME_ID 2
#define CLOCK_REALTIME 0
#define CLOCK_REALTIME_ALARM 8
#define CLOCK_REALTIME_COARSE 5
#define CLOCK_TAI 11
#define CLOCK_THREAD_CPUTIME_ID 3