OpenMP有効時は omp_get_wtime、それ以外は system_clock を使う壁時計。
real(dp) function perf_wall_time_seconds() integer(int64) :: count, rate !$ perf_wall_time_seconds = omp_get_wtime() !$ return call system_clock(count=count, count_rate=rate) if (rate > 0_int64) then perf_wall_time_seconds = real(count, dp)/real(rate, dp) else call cpu_time(perf_wall_time_seconds) end if end function perf_wall_time_seconds