The DVCHK subroutine masks and detects divide by zero exceptions.

## Syntax

DVCHK (lflag)

*lflag* is an INTENT(IN) scalar of type LOGICAL.

*lflag* must be set to true on the first invocation.

On subsequent invocations *lflag* is assigned the value true if a divide-by-zero exception has occurred, and false otherwise.

The initial invocation of the DVCHK subroutine masks the divide-by-zero interrupt on the floating-point unit.

DVCHK will not check or mask zero divided by zero. Use INVALOP to check for a zero divided by zero.

## Example

logical :: lflag=.true. call dvchk(lflag) ! mask the divide-by-zero interrupt write(*,*) lflag ! writes F write(*,*) 1./0. ! writes Inf call dvchk (lflag) write(*,*) lflag ! writes T