2.9BSD/usr/man/cat2/fperr.2

FPERR(2)            UNIX Programmer's Manual             FPERR(2)

NAME
     fperr - get floating-point error registers

SYNOPSIS
     #include <sys/fperr.h>

     fperr(fpe)
     struct fperr *fpe;

DESCRIPTION
     _F_p_e_r_r returns the contents of the floating-point processor's
     error registers as they were following the last floating
     exception generated by the calling process.  The registers
     are stored in the structure pointed to by _f_p_e.  The struc-
     ture defined in <sys/fperr.h> is as follows:

     /*
      * Structure of the floating point error register save/return
      */

     struct fperr
     {
             short   f_fec;
             caddr_t f_fea;
     };

     This call is required because the error registers in the
     floating-point processor are read-only.  Thus, they may be
     changed by some other process between the time that the
     current process generates an exception and the time that it
     reads the registers.  Therefore, the system saves their
     state at the time of an exception.

     The values returned are valid only after a floating-point
     exception.

SEE ALSO
     Ed Gould, Jim Reeds, Vance Vaughan, _U_N_I_X _P_r_o_b_l_e_m_s _w_i_t_h
     _F_l_o_a_t_i_n_g _P_o_i_n_t _P_r_o_c_e_s_s_o_r_s

ASSEMBLER
     (local = 58., fperr = 15.)
     sys local; 9f
     (fec in r0)
     (fea in r1)
     . . .
     .data
     9: sys fperr

Printed 5/17/83                                                 1