		Search-engine friendly clone of the ACL2 documentation.

Evex-prefixes

!evex-prefixes->byte1

Update the |X86ISA|::|BYTE1| field of a evex-prefixes bit structure.

Signature
(!evex-prefixes->byte1 byte1 x) → new-x
Arguments: byte1 — Guard (8bits-p byte1).; x — Guard (evex-prefixes-p x).
Returns: new-x — Type (evex-prefixes-p new-x).

Definitions and Theorems

Function: !evex-prefixes->byte1$inline

(defun !evex-prefixes->byte1$inline (byte1 x)
 (declare (xargs :guard (and (8bits-p byte1)
                             (evex-prefixes-p x))))
 (mbe
     :logic
     (b* ((byte1 (mbe :logic (8bits-fix byte1)
                      :exec byte1))
          (x (evex-prefixes-fix x)))
       (part-install byte1 x :width 8 :low 8))
     :exec (the (unsigned-byte 32)
                (logior (the (unsigned-byte 32)
                             (logand (the (unsigned-byte 32) x)
                                     (the (signed-byte 17) -65281)))
                        (the (unsigned-byte 16)
                             (ash (the (unsigned-byte 8) byte1)
                                  8))))))

Theorem: evex-prefixes-p-of-!evex-prefixes->byte1

(defthm evex-prefixes-p-of-!evex-prefixes->byte1
  (b* ((new-x (!evex-prefixes->byte1$inline byte1 x)))
    (evex-prefixes-p new-x))
  :rule-classes :rewrite)

Theorem: !evex-prefixes->byte1$inline-of-8bits-fix-byte1

(defthm !evex-prefixes->byte1$inline-of-8bits-fix-byte1
  (equal (!evex-prefixes->byte1$inline (8bits-fix byte1)
                                       x)
         (!evex-prefixes->byte1$inline byte1 x)))

Theorem: !evex-prefixes->byte1$inline-8bits-equiv-congruence-on-byte1

(defthm !evex-prefixes->byte1$inline-8bits-equiv-congruence-on-byte1
  (implies (8bits-equiv byte1 byte1-equiv)
           (equal (!evex-prefixes->byte1$inline byte1 x)
                  (!evex-prefixes->byte1$inline byte1-equiv x)))
  :rule-classes :congruence)

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

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

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

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

Theorem: !evex-prefixes->byte1-is-evex-prefixes

(defthm !evex-prefixes->byte1-is-evex-prefixes
  (equal (!evex-prefixes->byte1 byte1 x)
         (change-evex-prefixes x :byte1 byte1)))

Theorem: evex-prefixes->byte1-of-!evex-prefixes->byte1

(defthm evex-prefixes->byte1-of-!evex-prefixes->byte1
  (b* ((?new-x (!evex-prefixes->byte1$inline byte1 x)))
    (equal (evex-prefixes->byte1 new-x)
           (8bits-fix byte1))))

Theorem: !evex-prefixes->byte1-equiv-under-mask

(defthm !evex-prefixes->byte1-equiv-under-mask
  (b* ((?new-x (!evex-prefixes->byte1$inline byte1 x)))
    (evex-prefixes-equiv-under-mask new-x x -65281)))