Access the |X86ISA|::|UNKNOWNBITS| field of a system-segment-descriptor-attributesbits bit structure.
(system-segment-descriptor-attributesbits->unknownbits x) → unknownbits
Function:
(defun system-segment-descriptor-attributesbits->unknownbits$inline (x) (declare (xargs :guard (system-segment-descriptor-attributesbits-p x))) (mbe :logic (let ((x (system-segment-descriptor-attributesbits-fix x))) (part-select x :low 10 :width 6)) :exec (the (unsigned-byte 6) (logand (the (unsigned-byte 6) 63) (the (unsigned-byte 6) (ash (the (unsigned-byte 16) x) -10))))))
Theorem:
(defthm 6bits-p-of-system-segment-descriptor-attributesbits->unknownbits (b* ((unknownbits (system-segment-descriptor-attributesbits->unknownbits$inline x))) (6bits-p unknownbits)) :rule-classes :rewrite)
Theorem:
(defthm system-segment-descriptor-attributesbits->unknownbits$inline-of-system-segment-descriptor-attributesbits-fix-x (equal (system-segment-descriptor-attributesbits->unknownbits$inline (system-segment-descriptor-attributesbits-fix x)) (system-segment-descriptor-attributesbits->unknownbits$inline x)))
Theorem:
(defthm system-segment-descriptor-attributesbits->unknownbits$inline-system-segment-descriptor-attributesbits-equiv-congruence-on-x (implies (system-segment-descriptor-attributesbits-equiv x x-equiv) (equal (system-segment-descriptor-attributesbits->unknownbits$inline x) (system-segment-descriptor-attributesbits->unknownbits$inline x-equiv))) :rule-classes :congruence)
Theorem:
(defthm system-segment-descriptor-attributesbits->unknownbits-of-system-segment-descriptor-attributesbits (equal (system-segment-descriptor-attributesbits->unknownbits (system-segment-descriptor-attributesbits type s dpl p avl g unknownbits)) (6bits-fix unknownbits)))
Theorem:
(defthm system-segment-descriptor-attributesbits->unknownbits-of-write-with-mask (implies (and (fty::bitstruct-read-over-write-hyps x system-segment-descriptor-attributesbits-equiv-under-mask) (system-segment-descriptor-attributesbits-equiv-under-mask x y fty::mask) (equal (logand (lognot fty::mask) 64512) 0)) (equal (system-segment-descriptor-attributesbits->unknownbits x) (system-segment-descriptor-attributesbits->unknownbits y))))