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Vex2-byte1

Vex2-byte1->l

Access the |ACL2|::|L| field of a vex2-byte1 bit structure.

Signature
(vex2-byte1->l x) → l
Arguments: x — Guard (vex2-byte1-p x).
Returns: l — Type (bitp l).

Definitions and Theorems

Function: vex2-byte1->l$inline

(defun vex2-byte1->l$inline (x)
 (declare (xargs :guard (vex2-byte1-p x)))
 (mbe
     :logic
     (let ((x (vex2-byte1-fix x)))
       (part-select x :low 2 :width 1))
     :exec (the (unsigned-byte 1)
                (logand (the (unsigned-byte 1) 1)
                        (the (unsigned-byte 6)
                             (ash (the (unsigned-byte 8) x) -2))))))

Theorem: bitp-of-vex2-byte1->l

(defthm bitp-of-vex2-byte1->l
  (b* ((l (vex2-byte1->l$inline x)))
    (bitp l))
  :rule-classes :rewrite)

Theorem: vex2-byte1->l$inline-of-vex2-byte1-fix-x

(defthm vex2-byte1->l$inline-of-vex2-byte1-fix-x
  (equal (vex2-byte1->l$inline (vex2-byte1-fix x))
         (vex2-byte1->l$inline x)))

Theorem: vex2-byte1->l$inline-vex2-byte1-equiv-congruence-on-x

(defthm vex2-byte1->l$inline-vex2-byte1-equiv-congruence-on-x
  (implies (vex2-byte1-equiv x x-equiv)
           (equal (vex2-byte1->l$inline x)
                  (vex2-byte1->l$inline x-equiv)))
  :rule-classes :congruence)

Theorem: vex2-byte1->l-of-vex2-byte1

(defthm vex2-byte1->l-of-vex2-byte1
  (equal (vex2-byte1->l (vex2-byte1 pp l vvvv r))
         (bfix l)))

Theorem: vex2-byte1->l-of-write-with-mask

(defthm vex2-byte1->l-of-write-with-mask
  (implies (and (fty::bitstruct-read-over-write-hyps
                     x vex2-byte1-equiv-under-mask)
                (vex2-byte1-equiv-under-mask x y fty::mask)
                (equal (logand (lognot fty::mask) 4) 0))
           (equal (vex2-byte1->l x)
                  (vex2-byte1->l y))))