Access the |ACL2|::|W| field of a data-segment-descriptorbits bit structure.
(data-segment-descriptorbits->w x) → w
Function:
(defun data-segment-descriptorbits->w$inline (x) (declare (xargs :guard (data-segment-descriptorbits-p x))) (mbe :logic (let ((x (data-segment-descriptorbits-fix x))) (part-select x :low 41 :width 1)) :exec (the (unsigned-byte 1) (logand (the (unsigned-byte 1) 1) (the (unsigned-byte 23) (ash (the (unsigned-byte 64) x) -41))))))
Theorem:
(defthm bitp-of-data-segment-descriptorbits->w (b* ((w (data-segment-descriptorbits->w$inline x))) (bitp w)) :rule-classes :rewrite)
Theorem:
(defthm data-segment-descriptorbits->w$inline-of-data-segment-descriptorbits-fix-x (equal (data-segment-descriptorbits->w$inline (data-segment-descriptorbits-fix x)) (data-segment-descriptorbits->w$inline x)))
Theorem:
(defthm data-segment-descriptorbits->w$inline-data-segment-descriptorbits-equiv-congruence-on-x (implies (data-segment-descriptorbits-equiv x x-equiv) (equal (data-segment-descriptorbits->w$inline x) (data-segment-descriptorbits->w$inline x-equiv))) :rule-classes :congruence)
Theorem:
(defthm data-segment-descriptorbits->w-of-data-segment-descriptorbits (equal (data-segment-descriptorbits->w (data-segment-descriptorbits limit15-0 base15-0 base23-16 a w e msb-of-type s dpl p limit19-16 avl l d/b g base31-24)) (bfix w)))
Theorem:
(defthm data-segment-descriptorbits->w-of-write-with-mask (implies (and (fty::bitstruct-read-over-write-hyps x data-segment-descriptorbits-equiv-under-mask) (data-segment-descriptorbits-equiv-under-mask x y fty::mask) (equal (logand (lognot fty::mask) 2199023255552) 0)) (equal (data-segment-descriptorbits->w x) (data-segment-descriptorbits->w y))))