+;;; This function sets options controlling the floating-point
+;;; hardware. If a keyword is not supplied, then the current value is
+;;; preserved. Possible keywords:
+;;; :TRAPS
+;;; A list of the exception conditions that should cause traps.
+;;; Possible exceptions are :UNDERFLOW, :OVERFLOW, :INEXACT, :INVALID,
+;;; :DIVIDE-BY-ZERO, and on the X86 :DENORMALIZED-OPERAND. Initially
+;;; all traps except :INEXACT are enabled.
+;;;
+;;;:ROUNDING-MODE
+;;; The rounding mode to use when the result is not exact. Possible
+;;; values are :NEAREST, :POSITIVE-INFINITY, :NEGATIVE-INFINITY and
+;;; :ZERO. Initially, the rounding mode is :NEAREST.
+;;;
+;;;:CURRENT-EXCEPTIONS
+;;;:ACCRUED-EXCEPTIONS
+;;; These arguments allow setting of the exception flags. The main
+;;; use is setting the accrued exceptions to NIL to clear them.
+;;;
+;;;:FAST-MODE
+;;; Set the hardware's \"fast mode\" flag, if any. When set, IEEE
+;;; conformance or debuggability may be impaired. Some machines may not
+;;; have this feature, in which case the value is always NIL.
+;;;
+;;; GET-FLOATING-POINT-MODES may be used to find the floating point modes
+;;; currently in effect.