2.11BSD#431 - /usr/man/cat3f/trpfpe.0

TRPFPE(3F)	    UNIX Programmer's Manual	       TRPFPE(3F)


NAME
     trpfpe, fpecnt - trap and repair floating point faults

SYNOPSIS
     subroutine trpfpe (numesg, rtnval)
     double precision rtnval

     integer function fpecnt ()

     common /fpeflt/ fperr
     logical fperr

DESCRIPTION
     NOTE: This routine applies only to Vax computers.	It is a
     null routine on the PDP11.

     Trpfpe sets up a signal handler to trap arithmetic excep-
     tions.  If the exception is due to a floating point arith-
     metic fault, the result of the operation is replaced with
     the rtnval specified.  Rtnval must be a double precision
     value. For example, ``0d0'' or ``dflmax()''.

     The first numesg occurrences of a floating point arithmetic
     error will cause a message to be written to the standard
     error file.  Any exception that can't be repaired will
     result in the default action, typically an abort with core
     image.

     Fpecnt returns the number of faults since the last call to
     trpfpe.

     The logical value in the common block labelled fpeflt will
     be set to .true. each time a fault occurs.

FILES
     /usr/lib/libF77.a

SEE ALSO
     signal(3F), range(3F)

BUGS
     This routine works only for faults, not traps.  This is pri-
     marily due to the Vax architecture.

     If the operation involves changing the stack pointer, it
     can't be repaired.  This seldom should be a problem with the
     f77 compiler, but such an operation might be produced by the
     optimizer.

     The POLY and EMOD opcodes are not dealt with.


Printed 11/26/99	  May 15, 1985				1