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Rflagsbits

Rflagsbits->iopl

Access the |X86ISA|::|IOPL| field of a rflagsbits bit structure.

Signature
(rflagsbits->iopl x) → iopl
Arguments: x — Guard (rflagsbits-p x).
Returns: iopl — Type (2bits-p iopl).

Definitions and Theorems

Function: rflagsbits->iopl$inline

(defun rflagsbits->iopl$inline (x)
  (declare (xargs :guard (rflagsbits-p x)))
  (mbe :logic
       (let ((x (rflagsbits-fix x)))
         (part-select x :low 12 :width 2))
       :exec (the (unsigned-byte 2)
                  (logand (the (unsigned-byte 2) 3)
                          (the (unsigned-byte 20)
                               (ash (the (unsigned-byte 32) x)
                                    -12))))))

Theorem: 2bits-p-of-rflagsbits->iopl

(defthm 2bits-p-of-rflagsbits->iopl
  (b* ((iopl (rflagsbits->iopl$inline x)))
    (2bits-p iopl))
  :rule-classes :rewrite)

Theorem: rflagsbits->iopl$inline-of-rflagsbits-fix-x

(defthm rflagsbits->iopl$inline-of-rflagsbits-fix-x
  (equal (rflagsbits->iopl$inline (rflagsbits-fix x))
         (rflagsbits->iopl$inline x)))

Theorem: rflagsbits->iopl$inline-rflagsbits-equiv-congruence-on-x

(defthm rflagsbits->iopl$inline-rflagsbits-equiv-congruence-on-x
  (implies (rflagsbits-equiv x x-equiv)
           (equal (rflagsbits->iopl$inline x)
                  (rflagsbits->iopl$inline x-equiv)))
  :rule-classes :congruence)

Theorem: rflagsbits->iopl-of-rflagsbits

(defthm rflagsbits->iopl-of-rflagsbits
  (equal (rflagsbits->iopl
              (rflagsbits cf
                          res1 pf res2 af res3 zf sf tf intf df of
                          iopl nt res4 rf vm ac vif vip id res5))
         (2bits-fix iopl)))

Theorem: rflagsbits->iopl-of-write-with-mask

(defthm rflagsbits->iopl-of-write-with-mask
  (implies (and (fty::bitstruct-read-over-write-hyps
                     x rflagsbits-equiv-under-mask)
                (rflagsbits-equiv-under-mask x y fty::mask)
                (equal (logand (lognot fty::mask) 12288)
                       0))
           (equal (rflagsbits->iopl x)
                  (rflagsbits->iopl y))))