Access the |FGL|::|BRANCH-ON-IFS| field of a interp-flags bit structure.
(interp-flags->branch-on-ifs x) → branch-on-ifs
Function:
(defun interp-flags->branch-on-ifs (x) (declare (xargs :guard (interp-flags-p x))) (mbe :logic (let ((x (interp-flags-fix x))) (bit->bool (acl2::part-select x :low 5 :width 1))) :exec (bit->bool (the (unsigned-byte 1) (logand (the (unsigned-byte 1) 1) (the (unsigned-byte 1) (ash (the (unsigned-byte 6) x) -5)))))))
Theorem:
(defthm booleanp-of-interp-flags->branch-on-ifs (b* ((branch-on-ifs (interp-flags->branch-on-ifs x))) (booleanp branch-on-ifs)) :rule-classes :rewrite)
Theorem:
(defthm interp-flags->branch-on-ifs-of-interp-flags-fix-x (equal (interp-flags->branch-on-ifs (interp-flags-fix x)) (interp-flags->branch-on-ifs x)))
Theorem:
(defthm interp-flags->branch-on-ifs-interp-flags-equiv-congruence-on-x (implies (interp-flags-equiv x x-equiv) (equal (interp-flags->branch-on-ifs x) (interp-flags->branch-on-ifs x-equiv))) :rule-classes :congruence)
Theorem:
(defthm interp-flags->branch-on-ifs-of-interp-flags (equal (interp-flags->branch-on-ifs (interp-flags intro-bvars intro-synvars simplify-logic trace-rewrites make-ites branch-on-ifs)) (bool-fix branch-on-ifs)))
Theorem:
(defthm interp-flags->branch-on-ifs-of-write-with-mask (implies (and (fty::bitstruct-read-over-write-hyps x interp-flags-equiv-under-mask) (interp-flags-equiv-under-mask x y fty::mask) (equal (logand (lognot fty::mask) 32) 0)) (equal (interp-flags->branch-on-ifs x) (interp-flags->branch-on-ifs y))))