		Search-engine friendly clone of the ACL2 documentation.

Rflag-specifications

Sbb-af-spec8

Signature
(sbb-af-spec8 dst src cf) → *

Definitions and Theorems

Function: sbb-af-spec8$inline

(defun sbb-af-spec8$inline (dst src cf)
  (declare (type (unsigned-byte 8) dst)
           (type (unsigned-byte 8) src)
           (type (unsigned-byte 1) cf))
  (b* (((the (unsigned-byte 4) dst-3-0)
        (mbe :logic (part-select dst :low 0 :width 4)
             :exec (logand 15 dst)))
       ((the (unsigned-byte 4) src-3-0)
        (mbe :logic (part-select src :low 0 :width 4)
             :exec (logand 15 src)))
       ((the (unsigned-byte 6) sbb)
        (logand 63
                (- (the (unsigned-byte 4) dst-3-0)
                   (+ (the (unsigned-byte 4) src-3-0)
                      (the (unsigned-byte 4) cf)))))
       (af (the (unsigned-byte 1)
                (bool->bit (> sbb 15)))))
    af))

Theorem: n01p-sbb-af-spec8

(defthm n01p-sbb-af-spec8
 (unsigned-byte-p 1 (sbb-af-spec8 dst src cf))
 :rule-classes
 (:rewrite
  (:type-prescription
      :corollary (natp (sbb-af-spec8 dst src cf))
      :hints
      (("Goal" :in-theory '(unsigned-byte-p integer-range-p natp))))
  (:linear
   :corollary (and (<= 0 (sbb-af-spec8 dst src cf))
                   (< (sbb-af-spec8 dst src cf) 2))
   :hints
   (("Goal"
        :in-theory '(unsigned-byte-p integer-range-p (:e expt)))))))