trpfpe, fpecnt - trap and repair floating point faults
subroutine trpfpe (numesg, rtnval)
double precision rtnval
integer function fpecnt ()
common /fpeflt/ fperr
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 exceptions. If the
exception is due to a floating point arithmetic 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 excep-
tion that can't be repaired will result in the default action, typi-
cally 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.
This routine works only for faults, not traps. This is primarily 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.
4th Berkeley Distribution 26 July 1983 TRPFPE(3F)