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Vex3-byte1

Vex3-byte1->x

Access the |ACL2|::|X| field of a vex3-byte1 bit structure.

Signature
(vex3-byte1->x vex3byte1) → x
Arguments: vex3byte1 — Guard (vex3-byte1-p vex3byte1).
Returns: x — Type (bitp x).

Definitions and Theorems

Function: vex3-byte1->x$inline

(defun vex3-byte1->x$inline (vex3byte1)
 (declare (xargs :guard (vex3-byte1-p vex3byte1)))
 (mbe :logic
      (let ((vex3byte1 (vex3-byte1-fix vex3byte1)))
        (part-select vex3byte1 :low 6 :width 1))
      :exec (the (unsigned-byte 1)
                 (logand (the (unsigned-byte 1) 1)
                         (the (unsigned-byte 2)
                              (ash (the (unsigned-byte 8) vex3byte1)
                                   -6))))))

Theorem: bitp-of-vex3-byte1->x

(defthm bitp-of-vex3-byte1->x
  (b* ((x (vex3-byte1->x$inline vex3byte1)))
    (bitp x))
  :rule-classes :rewrite)

Theorem: vex3-byte1->x$inline-of-vex3-byte1-fix-vex3byte1

(defthm vex3-byte1->x$inline-of-vex3-byte1-fix-vex3byte1
  (equal (vex3-byte1->x$inline (vex3-byte1-fix vex3byte1))
         (vex3-byte1->x$inline vex3byte1)))

Theorem: vex3-byte1->x$inline-vex3-byte1-equiv-congruence-on-vex3byte1

(defthm
      vex3-byte1->x$inline-vex3-byte1-equiv-congruence-on-vex3byte1
  (implies (vex3-byte1-equiv vex3byte1 vex3byte1-equiv)
           (equal (vex3-byte1->x$inline vex3byte1)
                  (vex3-byte1->x$inline vex3byte1-equiv)))
  :rule-classes :congruence)

Theorem: vex3-byte1->x-of-vex3-byte1

(defthm vex3-byte1->x-of-vex3-byte1
  (equal (vex3-byte1->x (vex3-byte1 m-mmmm b x r))
         (bfix x)))

Theorem: vex3-byte1->x-of-write-with-mask

(defthm vex3-byte1->x-of-write-with-mask
  (implies (and (fty::bitstruct-read-over-write-hyps
                     vex3byte1 vex3-byte1-equiv-under-mask)
                (vex3-byte1-equiv-under-mask vex3byte1 y fty::mask)
                (equal (logand (lognot fty::mask) 64)
                       0))
           (equal (vex3-byte1->x vex3byte1)
                  (vex3-byte1->x y))))