NAME

fperr − get floating-point error registers (2BSD)

SYNOPSIS

#include <pdp/fperr.h>
 struct fperr
{
shortf_fec;
caddr_tf_fea;
};
 fperr(fpe)
struct fperr ∗fpe;

DESCRIPTION

Fperr 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 fpe.

This call is required because the error registers in the PDP-11 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. 

ERRORS

[EINVAL] The kernel has not been compiled for a processor with floating point. 

SEE ALSO

Ed Gould, Jim Reeds, Vance Vaughan, UNIX Problems with Floating Point Processors

BUGS

Fperr is unique to the PDP-11 and 2BSD; its use is discouraged. 

2nd Berkeley Distribution  —  January 22, 1987