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Mxcsrbits

Mxcsrbits->im

Access the |X86ISA|::|IM| field of a mxcsrbits bit structure.

Signature
(mxcsrbits->im x) → im
Arguments: x — Guard (mxcsrbits-p x).
Returns: im — Type (bitp im).

Definitions and Theorems

Function: mxcsrbits->im$inline

(defun mxcsrbits->im$inline (x)
 (declare (xargs :guard (mxcsrbits-p x)))
 (mbe
    :logic
    (let ((x (mxcsrbits-fix x)))
      (part-select x :low 7 :width 1))
    :exec (the (unsigned-byte 1)
               (logand (the (unsigned-byte 1) 1)
                       (the (unsigned-byte 25)
                            (ash (the (unsigned-byte 32) x) -7))))))

Theorem: bitp-of-mxcsrbits->im

(defthm bitp-of-mxcsrbits->im
  (b* ((im (mxcsrbits->im$inline x)))
    (bitp im))
  :rule-classes :rewrite)

Theorem: mxcsrbits->im$inline-of-mxcsrbits-fix-x

(defthm mxcsrbits->im$inline-of-mxcsrbits-fix-x
  (equal (mxcsrbits->im$inline (mxcsrbits-fix x))
         (mxcsrbits->im$inline x)))

Theorem: mxcsrbits->im$inline-mxcsrbits-equiv-congruence-on-x

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

Theorem: mxcsrbits->im-of-mxcsrbits

(defthm mxcsrbits->im-of-mxcsrbits
 (equal
   (mxcsrbits->im (mxcsrbits ie de ze oe ue pe
                             daz im dm zm om um pm rc ftz reserved))
   (bfix im)))

Theorem: mxcsrbits->im-of-write-with-mask

(defthm mxcsrbits->im-of-write-with-mask
  (implies (and (fty::bitstruct-read-over-write-hyps
                     x mxcsrbits-equiv-under-mask)
                (mxcsrbits-equiv-under-mask x y fty::mask)
                (equal (logand (lognot fty::mask) 128)
                       0))
           (equal (mxcsrbits->im x)
                  (mxcsrbits->im y))))