MCLOCK8 (The GNU Fortran Compiler)

### 8.200 `MCLOCK8` — Time function (64-bit) ¶

Synopsis:

  `RESULT = MCLOCK8()`

Description:

  Returns the number of clock ticks since the start of the process, based on the function `clock(3)` in the C standard library.

  Warning: this intrinsic does not increase the range of the timing values over that returned by `clock(3)`. On a system with a 32-bit `clock(3)`, `MCLOCK8` returns a 32-bit value, even though it is converted to a 64-bit `INTEGER(8)` value. That means overflows of the 32-bit value can still occur. Therefore, the values returned by this intrinsic might be or become negative or numerically less than previous values during a single run of the compiled program.

Class:

  Function

Return value:

  The return value is a scalar of type `INTEGER(8)`, equal to the number of clock ticks since the start of the process, or `-1` if the system does not support `clock(3)`.

Standard:

  GNU extension

See also:

  `CTIME` — Convert a time into a string,
  `GMTIME` — Convert time to GMT info,
  `LTIME` — Convert time to local time info,
  `MCLOCK` — Time function,
  `TIME8` — Time function (64-bit)