		Search-engine friendly clone of the ACL2 documentation.

Two-byte-opcodes

X86-two-byte-nop

Signature
(x86-two-byte-nop proc-mode start-rip temp-rip prefixes rex-byte opcode modr/m sib x86) → x86
Returns: x86 — Type (x86p x86), given (x86p x86).

Definitions and Theorems

Function: x86-two-byte-nop

(defun x86-two-byte-nop
       (proc-mode start-rip temp-rip
                  prefixes rex-byte opcode modr/m sib x86)
 (declare (xargs :stobjs (x86)))
 (declare (type (integer 0 4) proc-mode)
          (type (signed-byte 48) start-rip)
          (type (signed-byte 48) temp-rip)
          (type (unsigned-byte 52) prefixes)
          (type (unsigned-byte 8) rex-byte)
          (type (unsigned-byte 8) opcode)
          (type (unsigned-byte 8) modr/m)
          (type (unsigned-byte 8) sib))
 (declare (ignorable proc-mode start-rip temp-rip
                     prefixes rex-byte opcode modr/m sib))
 (declare (xargs :guard (and (prefixes-p prefixes)
                             (modr/m-p modr/m)
                             (sib-p sib)
                             (rip-guard-okp proc-mode temp-rip))))
 (let ((__function__ 'x86-two-byte-nop))
  (declare (ignorable __function__))
  (b* ((?ctx 'x86-two-byte-nop)
       (?r/m (the (unsigned-byte 3)
                  (modr/m->r/m modr/m)))
       (?mod (the (unsigned-byte 2)
                  (modr/m->mod modr/m)))
       (?reg (the (unsigned-byte 3)
                  (modr/m->reg modr/m))))
    (b*
      ((p4? (equal 103 (prefixes->adr prefixes)))
       ((mv flg0 (the (signed-byte 64) ?addr)
            (the (unsigned-byte 3) increment-rip-by)
            x86)
        (if (equal mod 3)
            (mv nil 0 0 x86)
          (x86-effective-addr proc-mode p4?
                              temp-rip rex-byte r/m mod sib 0 x86)))
       ((when flg0)
        (!!ms-fresh :x86-effective-addr flg0))
       ((mv flg (the (signed-byte 48) temp-rip))
        (add-to-*ip proc-mode
                    temp-rip increment-rip-by x86))
       ((when flg)
        (!!ms-fresh :next-rip-invalid temp-rip))
       (badlength? (check-instruction-length start-rip temp-rip 0))
       ((when badlength?)
        (!!fault-fresh :gp 0
                       :instruction-length badlength?))
       (x86 (write-*ip proc-mode temp-rip x86)))
      x86))))

Theorem: x86p-of-x86-two-byte-nop

(defthm x86p-of-x86-two-byte-nop
 (implies
   (x86p x86)
   (b* ((x86 (x86-two-byte-nop proc-mode start-rip temp-rip prefixes
                               rex-byte opcode modr/m sib x86)))
     (x86p x86)))
 :rule-classes :rewrite)