[Sbcl-devel] possible bug in SB-C::DOMAIN-SUBTYPEP

[Alexey D. <ade...@co...>]

Hello,

--------
* (domain-subtypep (specifier-type '(double-float (0d0) *))
                   0d0 nil)
NIL
* (domain-subtypep (specifier-type '(double-float 0d0 *))
                   0d0 nil)
T
--------

Smaller segment is not a subdomain, but a larger is? If I understand
correctly, (DOMAIN-SUBTYPEP type low high) checks whether <type> is
a subset of a closed segment [low,high]. In this case the code,
checking the lower bound is not correct:

             (and arg-lo (>= arg-lo-val domain-low)
		  (not (and (zerop domain-low) (floatp domain-low)
			    (plusp (float-sign domain-low))
			    (zerop arg-lo-val) (floatp arg-lo-val)

			    (if (consp arg-lo)
				(plusp (float-sign arg-lo-val))
				(minusp (float-sign arg-lo-val))))))

I think the correct version is

             (and arg-lo (>= arg-lo-val domain-low)
		  (not (and (zerop domain-low) (floatp domain-low)
			    (plusp (float-sign domain-low))
			    (zerop arg-lo-val) (floatp arg-lo-val)

                            (not (consp arg-lo))
                            (minusp (float-sign arg-lo-val)))))

What do the FP experts think?

-- 
Regards,
Alexey Dejneka

"Alas, the spheres of truth are less transparent than those of
illusion." -- L.E.J. Brouwer