Access the |ACL2|::|C| field of a code-segment-descriptor-attributesbits bit structure.
(code-segment-descriptor-attributesbits->c x) → c
Function:
(defun code-segment-descriptor-attributesbits->c$inline (x) (declare (xargs :guard (code-segment-descriptor-attributesbits-p x))) (mbe :logic (let ((x (code-segment-descriptor-attributesbits-fix x))) (part-select x :low 2 :width 1)) :exec (the (unsigned-byte 1) (logand (the (unsigned-byte 1) 1) (the (unsigned-byte 14) (ash (the (unsigned-byte 16) x) -2))))))
Theorem:
(defthm bitp-of-code-segment-descriptor-attributesbits->c (b* ((c (code-segment-descriptor-attributesbits->c$inline x))) (bitp c)) :rule-classes :rewrite)
Theorem:
(defthm code-segment-descriptor-attributesbits->c$inline-of-code-segment-descriptor-attributesbits-fix-x (equal (code-segment-descriptor-attributesbits->c$inline (code-segment-descriptor-attributesbits-fix x)) (code-segment-descriptor-attributesbits->c$inline x)))
Theorem:
(defthm code-segment-descriptor-attributesbits->c$inline-code-segment-descriptor-attributesbits-equiv-congruence-on-x (implies (code-segment-descriptor-attributesbits-equiv x x-equiv) (equal (code-segment-descriptor-attributesbits->c$inline x) (code-segment-descriptor-attributesbits->c$inline x-equiv))) :rule-classes :congruence)
Theorem:
(defthm code-segment-descriptor-attributesbits->c-of-code-segment-descriptor-attributesbits (equal (code-segment-descriptor-attributesbits->c (code-segment-descriptor-attributesbits a r c msb-of-type s dpl p avl l d g unknownbits)) (bfix c)))
Theorem:
(defthm code-segment-descriptor-attributesbits->c-of-write-with-mask (implies (and (fty::bitstruct-read-over-write-hyps x code-segment-descriptor-attributesbits-equiv-under-mask) (code-segment-descriptor-attributesbits-equiv-under-mask x y fty::mask) (equal (logand (lognot fty::mask) 4) 0)) (equal (code-segment-descriptor-attributesbits->c x) (code-segment-descriptor-attributesbits->c y))))