TRPFPE(3F)                                                          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.

       _T_r_p_f_p_e 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 _r_t_n_v_a_l specified.  _R_t_n_v_a_l must be  a
       double precision value. For example, ‘‘0d0’’ or ‘‘dflmax()’’.

       The  first _n_u_m_e_s_g 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.

       _F_p_e_c_n_t returns the number of faults since the last call to _t_r_p_f_p_e.

       The logical value in the common block labelled _f_p_e_f_l_t 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 _f_a_u_l_t_s, not _t_r_a_p_s.  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.



4.2 Berkeley Distribution        May 15, 1985                       TRPFPE(3F)