anchor.diff:    (def2 mezzano.simd::%movhlps/sse lap:movhlps)
     (def2 mezzano.simd::%movlhps/sse lap:movlhps)
     (def1 mezzano.simd::%movq/sse lap:movq)
  -  (def2 mezzano.simd::%movss/sse lap:movss)
  +  (def2 mezzano.simd::%movss/sse lap:movss :allow-memory-operand nil)
     (def2 mezzano.simd::%mulps/sse lap:mulps)
     (def2 mezzano.simd::%mulss/sse lap:mulss)
     (def2 mezzano.simd::%orps/sse lap:orps)
  
positive.code:   (def2 mezzano.simd::%maxsd/sse lap:maxsd)
    (def2 mezzano.simd::%minpd/sse lap:minpd)
    (def2 mezzano.simd::%minsd/sse lap:minsd)
    (def2 mezzano.simd::%movsd/sse lap:movsd)
    (def2 mezzano.simd::%mulpd/sse lap:mulpd)
    (def2 mezzano.simd::%mulsd/sse lap:mulsd)
    (def2 mezzano.simd::%orpd/sse lap:orpd)
  
negative.code:                          (emit (make-instance 'box-sse-vector-instruction
                                                :source result-unboxed
                                                :destination result)))))))
             (def2 (fn inst &key (allow-memory-operand t))
               `(define-builtin ,fn ((lhs rhs) result)
                  (cond ((and ',allow-memory-operand
                              (constant-value-p rhs 'mezzano.simd:sse-vector))
                         (let ((lhs-unboxed (make-instance 'ir:virtual-register :kind :sse))
                               (result-unboxed (make-instance 'ir:virtual-register :kind :sse)))
                           (emit (make-instance 'unbox-sse-vector-instruction
  