anchor.diff:                           :destination rhs-unboxed))
       (emit (make-instance 'x86-fake-three-operand-instruction
                            :opcode 'lap:addss
  +                         :result result-unboxed
  +                         :lhs lhs-unboxed
  +                         :rhs rhs-unboxed))
  +    (emit (make-instance 'box-single-float-instruction
  +                         :source result-unboxed
  +                         :destination result))))
  +
  +(define-builtin sys.int::%%single-float-- ((lhs rhs) result :early t)
  +  (let ((lhs-unboxed (make-instance 'virtual-register :kind :single-float))
  +        (rhs-unboxed (make-instance 'virtual-register :kind :single-float))
  +        (result-unboxed (make-instance 'virtual-register :kind :single-float)))
  +    (emit (make-instance 'unbox-single-float-instruction
  +                         :source lhs
  +                         :destination lhs-unboxed))
  +    (emit (make-instance 'unbox-single-float-instruction
  +                         :source rhs
  +                         :destination rhs-unboxed))
  +    (emit (make-instance 'x86-fake-three-operand-instruction
  +                         :opcode 'lap:subss
  +                         :result result-unboxed
  +                         :lhs lhs-unboxed
  +                         :rhs rhs-unboxed))
  +    (emit (make-instance 'box-single-float-instruction
  +                         :source result-unboxed
  +                         :destination result))))
  +
  +(define-builtin sys.int::%%single-float-* ((lhs rhs) result :early t)
  +  (let ((lhs-unboxed (make-instance 'virtual-register :kind :single-float))
  +        (rhs-unboxed (make-instance 'virtual-register :kind :single-float))
  +        (result-unboxed (make-instance 'virtual-register :kind :single-float)))
  +    (emit (make-instance 'unbox-single-float-instruction
  +                         :source lhs
  +                         :destination lhs-unboxed))
  +    (emit (make-instance 'unbox-single-float-instruction
  +                         :source rhs
  +                         :destination rhs-unboxed))
  +    (emit (make-instance 'x86-fake-three-operand-instruction
  +                         :opcode 'lap:mulss
  +                         :result result-unboxed
  +                         :lhs lhs-unboxed
  +                         :rhs rhs-unboxed))
  +    (emit (make-instance 'box-single-float-instruction
  +                         :source result-unboxed
  +                         :destination result))))
  +
  +(define-builtin sys.int::%%single-float-sqrt ((lhs rhs) result :early t)
  +  (let ((lhs-unboxed (make-instance 'virtual-register :kind :single-float))
  +        (rhs-unboxed (make-instance 'virtual-register :kind :single-float))
  +        (result-unboxed (make-instance 'virtual-register :kind :single-float)))
  +    (emit (make-instance 'unbox-single-float-instruction
  +                         :source lhs
  +                         :destination lhs-unboxed))
  +    (emit (make-instance 'unbox-single-float-instruction
  +                         :source rhs
  +                         :destination rhs-unboxed))
  +    (emit (make-instance 'x86-fake-three-operand-instruction
  +                         :opcode 'lap:sqrtss
                            :result result-unboxed
                            :lhs lhs-unboxed
                            :rhs rhs-unboxed))
  
positive.code:                          :destination temp))
      (emit (make-instance 'box-single-float-instruction
                           :source temp
                           :destination result))))
  
  (define-builtin sys.int::%%single-float-+ ((lhs rhs) result :early t)
  
negative.code:                        :lhs lhs
                         :rhs rhs)))
  
  (define-builtin sys.int::%single-float-as-integer ((value) result :early t)
    (let ((temp (make-instance 'virtual-register :kind :integer)))
      (emit (make-instance 'unbox-single-float-instruction
                           :source value
                           :destination temp))
      (emit (make-instance 'box-fixnum-instruction
                           :source temp
                           :destination result))))
  
  (define-builtin sys.int::%integer-as-single-float ((value) result :early t)
    (let ((temp (make-instance 'virtual-register :kind :integer)))
      (emit (make-instance 'unbox-fixnum-instruction
  