Access the |X86ISA|::|G| field of a data-segment-descriptor-attributesbits bit structure.
(data-segment-descriptor-attributesbits->g x) → g
Function:
(defun data-segment-descriptor-attributesbits->g$inline (x) (declare (xargs :guard (data-segment-descriptor-attributesbits-p x))) (mbe :logic (let ((x (data-segment-descriptor-attributesbits-fix x))) (part-select x :low 11 :width 1)) :exec (the (unsigned-byte 1) (logand (the (unsigned-byte 1) 1) (the (unsigned-byte 5) (ash (the (unsigned-byte 16) x) -11))))))
Theorem:
(defthm bitp-of-data-segment-descriptor-attributesbits->g (b* ((g (data-segment-descriptor-attributesbits->g$inline x))) (bitp g)) :rule-classes :rewrite)
Theorem:
(defthm data-segment-descriptor-attributesbits->g$inline-of-data-segment-descriptor-attributesbits-fix-x (equal (data-segment-descriptor-attributesbits->g$inline (data-segment-descriptor-attributesbits-fix x)) (data-segment-descriptor-attributesbits->g$inline x)))
Theorem:
(defthm data-segment-descriptor-attributesbits->g$inline-data-segment-descriptor-attributesbits-equiv-congruence-on-x (implies (data-segment-descriptor-attributesbits-equiv x x-equiv) (equal (data-segment-descriptor-attributesbits->g$inline x) (data-segment-descriptor-attributesbits->g$inline x-equiv))) :rule-classes :congruence)
Theorem:
(defthm data-segment-descriptor-attributesbits->g-of-data-segment-descriptor-attributesbits (equal (data-segment-descriptor-attributesbits->g (data-segment-descriptor-attributesbits a w e msb-of-type s dpl p avl l d/b g unknownbits)) (bfix g)))
Theorem:
(defthm data-segment-descriptor-attributesbits->g-of-write-with-mask (implies (and (fty::bitstruct-read-over-write-hyps x data-segment-descriptor-attributesbits-equiv-under-mask) (data-segment-descriptor-attributesbits-equiv-under-mask x y fty::mask) (equal (logand (lognot fty::mask) 2048) 0)) (equal (data-segment-descriptor-attributesbits->g x) (data-segment-descriptor-attributesbits->g y))))