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Vex3-byte2

Vex3-byte2->vvvv

Access the |X86ISA|::|VVVV| field of a vex3-byte2 bit structure.

Signature
(vex3-byte2->vvvv x) → vvvv
Arguments: x — Guard (vex3-byte2-p x).
Returns: vvvv — Type (4bits-p vvvv).

Definitions and Theorems

Function: vex3-byte2->vvvv$inline

(defun vex3-byte2->vvvv$inline (x)
 (declare (xargs :guard (vex3-byte2-p x)))
 (mbe
     :logic
     (let ((x (vex3-byte2-fix x)))
       (part-select x :low 3 :width 4))
     :exec (the (unsigned-byte 4)
                (logand (the (unsigned-byte 4) 15)
                        (the (unsigned-byte 5)
                             (ash (the (unsigned-byte 8) x) -3))))))

Theorem: 4bits-p-of-vex3-byte2->vvvv

(defthm 4bits-p-of-vex3-byte2->vvvv
  (b* ((vvvv (vex3-byte2->vvvv$inline x)))
    (4bits-p vvvv))
  :rule-classes :rewrite)

Theorem: vex3-byte2->vvvv$inline-of-vex3-byte2-fix-x

(defthm vex3-byte2->vvvv$inline-of-vex3-byte2-fix-x
  (equal (vex3-byte2->vvvv$inline (vex3-byte2-fix x))
         (vex3-byte2->vvvv$inline x)))

Theorem: vex3-byte2->vvvv$inline-vex3-byte2-equiv-congruence-on-x

(defthm vex3-byte2->vvvv$inline-vex3-byte2-equiv-congruence-on-x
  (implies (vex3-byte2-equiv x x-equiv)
           (equal (vex3-byte2->vvvv$inline x)
                  (vex3-byte2->vvvv$inline x-equiv)))
  :rule-classes :congruence)

Theorem: vex3-byte2->vvvv-of-vex3-byte2

(defthm vex3-byte2->vvvv-of-vex3-byte2
  (equal (vex3-byte2->vvvv (vex3-byte2 pp l vvvv w))
         (4bits-fix vvvv)))

Theorem: vex3-byte2->vvvv-of-write-with-mask

(defthm vex3-byte2->vvvv-of-write-with-mask
  (implies (and (fty::bitstruct-read-over-write-hyps
                     x vex3-byte2-equiv-under-mask)
                (vex3-byte2-equiv-under-mask x y fty::mask)
                (equal (logand (lognot fty::mask) 120)
                       0))
           (equal (vex3-byte2->vvvv x)
                  (vex3-byte2->vvvv y))))