as.info: o

Go forward to R
Go backward to MD
Go up to Invoking
Go to the top op as

Name the Object File: `-o'

   There is always one object file output when you run `as'.  By
default it has the name `a.out' (or `b.out', for Intel 960 targets
only).  You use this option (which takes exactly one filename) to give
the object file a different name.
   Whatever the object file is called, `as' overwrites any existing
file of the same name.