Update the |X86ISA|::|UNKNOWNBITS| field of a data-segment-descriptor-attributesbits bit structure.
(!data-segment-descriptor-attributesbits->unknownbits unknownbits x) → new-x
Function:
(defun !data-segment-descriptor-attributesbits->unknownbits$inline (unknownbits x) (declare (xargs :guard (and (4bits-p unknownbits) (data-segment-descriptor-attributesbits-p x)))) (mbe :logic (b* ((unknownbits (mbe :logic (4bits-fix unknownbits) :exec unknownbits)) (x (data-segment-descriptor-attributesbits-fix x))) (part-install unknownbits x :width 4 :low 12)) :exec (the (unsigned-byte 16) (logior (the (unsigned-byte 16) (logand (the (unsigned-byte 16) x) (the (signed-byte 17) -61441))) (the (unsigned-byte 16) (ash (the (unsigned-byte 4) unknownbits) 12))))))
Theorem:
(defthm data-segment-descriptor-attributesbits-p-of-!data-segment-descriptor-attributesbits->unknownbits (b* ((new-x (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x))) (data-segment-descriptor-attributesbits-p new-x)) :rule-classes :rewrite)
Theorem:
(defthm !data-segment-descriptor-attributesbits->unknownbits$inline-of-4bits-fix-unknownbits (equal (!data-segment-descriptor-attributesbits->unknownbits$inline (4bits-fix unknownbits) x) (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x)))
Theorem:
(defthm !data-segment-descriptor-attributesbits->unknownbits$inline-4bits-equiv-congruence-on-unknownbits (implies (4bits-equiv unknownbits unknownbits-equiv) (equal (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x) (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits-equiv x))) :rule-classes :congruence)
Theorem:
(defthm !data-segment-descriptor-attributesbits->unknownbits$inline-of-data-segment-descriptor-attributesbits-fix-x (equal (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits (data-segment-descriptor-attributesbits-fix x)) (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x)))
Theorem:
(defthm !data-segment-descriptor-attributesbits->unknownbits$inline-data-segment-descriptor-attributesbits-equiv-congruence-on-x (implies (data-segment-descriptor-attributesbits-equiv x x-equiv) (equal (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x) (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x-equiv))) :rule-classes :congruence)
Theorem:
(defthm !data-segment-descriptor-attributesbits->unknownbits-is-data-segment-descriptor-attributesbits (equal (!data-segment-descriptor-attributesbits->unknownbits unknownbits x) (change-data-segment-descriptor-attributesbits x :unknownbits unknownbits)))
Theorem:
(defthm data-segment-descriptor-attributesbits->unknownbits-of-!data-segment-descriptor-attributesbits->unknownbits (b* ((?new-x (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x))) (equal (data-segment-descriptor-attributesbits->unknownbits new-x) (4bits-fix unknownbits))))
Theorem:
(defthm !data-segment-descriptor-attributesbits->unknownbits-equiv-under-mask (b* ((?new-x (!data-segment-descriptor-attributesbits->unknownbits$inline unknownbits x))) (data-segment-descriptor-attributesbits-equiv-under-mask new-x x 4095)))