Unrecommended etime Function

Problem

The DTIME and ETIME functions are not standard Fortran functions. The functions are constructed using the intrinsic functions CPU_TIME and SYSTEM_CLOCK. Currently, Flang does not ensure the correctness of the result. Therefore, this function is not recommended.

Solution

Refer to cases on the Internet to manually write the DTIME or ETIME function.

! ETIME in standard Fortran. 
Real Function etime(time) 
  Real time(2) 
  Call Cpu_Time(etime) 
  time(1) = etime 
  time(2) = 0 
End Function