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Evex-byte2

Evex-byte2->res

Access the |X86ISA|::|RES| field of a evex-byte2 bit structure.

Signature
(evex-byte2->res x) → res
Arguments: x — Guard (evex-byte2-p x).
Returns: res — Type (bitp res).

Definitions and Theorems

Function: evex-byte2->res$inline

(defun evex-byte2->res$inline (x)
 (declare (xargs :guard (evex-byte2-p x)))
 (mbe
     :logic
     (let ((x (evex-byte2-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-evex-byte2->res

(defthm bitp-of-evex-byte2->res
  (b* ((res (evex-byte2->res$inline x)))
    (bitp res))
  :rule-classes :rewrite)

Theorem: evex-byte2->res$inline-of-evex-byte2-fix-x

(defthm evex-byte2->res$inline-of-evex-byte2-fix-x
  (equal (evex-byte2->res$inline (evex-byte2-fix x))
         (evex-byte2->res$inline x)))

Theorem: evex-byte2->res$inline-evex-byte2-equiv-congruence-on-x

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

Theorem: evex-byte2->res-of-evex-byte2

(defthm evex-byte2->res-of-evex-byte2
  (equal (evex-byte2->res (evex-byte2 pp res vvvv w))
         (bfix res)))

Theorem: evex-byte2->res-of-write-with-mask

(defthm evex-byte2->res-of-write-with-mask
  (implies (and (fty::bitstruct-read-over-write-hyps
                     x evex-byte2-equiv-under-mask)
                (evex-byte2-equiv-under-mask x y fty::mask)
                (equal (logand (lognot fty::mask) 4) 0))
           (equal (evex-byte2->res x)
                  (evex-byte2->res y))))