The wall clock time is returned in seconds. The CPU time is measured in microseconds. However, the subroutine that returns CPU time divides the elapsed CPU time by 1000000 before returning it two you. The elapsed wall clock time since the last time rtc was called. It is replaced with the clock time of this call.
All subsequent calls return the elapsed time since the previous call to rtc.
It is replaced with the CPU time of this call. Linking with the Timing Routines These programs are installed in librtime.a. All you need to do to link them is to include -lrtime on the xlf, mpxlf, xlc, or mpcc command. The Fortran integer function Mclock also reports CPU time, but is only accurate to hundredths of a second, like the Unix time command, and is therefore not recommended for most timing purposes.