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Evex-byte1

Evex-byte1->x

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

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

Definitions and Theorems

Function: evex-byte1->x$inline

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

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

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

Theorem: evex-byte1->x$inline-of-evex-byte1-fix-byte1

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

Theorem: evex-byte1->x$inline-evex-byte1-equiv-congruence-on-byte1

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

Theorem: evex-byte1->x-of-evex-byte1

(defthm evex-byte1->x-of-evex-byte1
  (equal (evex-byte1->x (evex-byte1 mmm res r-prime b x r))
         (bfix x)))

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

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