Node: System_Clock Intrinsic, Next: Tan Intrinsic, Previous: System Intrinsic (subroutine), Up: Table of Intrinsic Functions

CALL System_Clock(Count,Rate,Max)

`Count`: `INTEGER(KIND=1)`

; scalar; INTENT(OUT).

`Rate`: `INTEGER(KIND=1)`

; OPTIONAL; scalar; INTENT(OUT).

`Max`: `INTEGER(KIND=1)`

; OPTIONAL; scalar; INTENT(OUT).

Intrinsic groups: `f90`

.

Description:

Returns in `Count` the current value of the system clock; this is
the value returned by the UNIX function `times(2)`

in this implementation, but
isn't in general.
`Rate` is the number of clock ticks per second and
`Max` is the maximum value this can take, which isn't very useful
in this implementation since it's just the maximum C ```
unsigned
int
```

value.

On some systems, the underlying timings are represented using types with sufficiently small limits that overflows (wraparounds) are possible, such as 32-bit types. 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.