NAME

fptrap − floating point interpreter

SYNOPSIS

syssignal; 4; fptrap

DESCRIPTION

Fptrap is a simulator of the 11/45 FP11-B floating point unit.  It works by intercepting illegal instruction traps and decoding and executing the floating point operation codes. 

Fptrap is not supported under the UNIX 3.0 system; it is included only to ease conversion to other machines. 

FILES

There is a fake routine in /lib/libc.a with this name; when simulation is desired, the real version should be put in /lib/libc.a. 

SEE ALSO

cc(1) (−f option), signal(2). 

DIAGNOSTICS

A breakpoint trap is given when a real illegal instruction trap occurs. 

BUGS

Rounding mode is not interpreted.  It’s slow. 

May 16, 1980  —  PDP-11 only