4.4BSD/usr/share/man/cat3f/trpfpe.0

F>=1  .if 3F<=8 .    if 3F>1 .if 3F<6 .ds an-extra3 "BSD Program-



TRPFPE(3F)             BSD Reference Manual            TRPFPE(3F)

mer's Manual
NNAAMMEE
       trpfpe, fpecnt - trap and repair floating point faults

SSYYNNOOPPSSIISS
       ssuubbrroouuttiinnee ttrrppffppee ((nnuummeessgg,, rrttnnvvaall))
       ddoouubbllee pprreecciissiioonn rrttnnvvaall

       iinntteeggeerr ffuunnccttiioonn ffppeeccnntt (())

       ccoommmmoonn //ffppeefflltt// ffppeerrrr
       llooggiiccaall ffppeerrrr

DDEESSCCRRIIPPTTIIOONN
       NNOOTTEE:: TThhiiss rroouuttiinnee aapppplliieess oonnllyy ttoo VVaaxx ccoommppuutteerrss..  It is a
       null routine on the PDP11.

       _T_r_p_f_p_e  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 _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 arith-
       metic 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.

       _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 ..ttrruuee..  each time a fault occurs.

FFIILLEESS
       /usr/lib/libF77.a

SSEEEE AALLSSOO
       signal(3F), range(3F)

BBUUGGSS
       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  June 5, 1993                         1