		Search-engine friendly clone of the ACL2 documentation.

One-byte-opcodes

X86-xchg

Signature
(x86-xchg 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-xchg

(defun x86-xchg (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-xchg))
  (declare (ignorable __function__))
  (b* ((?ctx 'x86-xchg)
       (?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*
    (((when (and (equal opcode 144)
                 (not (logbitp *b* rex-byte))))
      (write-*ip proc-mode temp-rip x86))
     (p2 (prefixes->seg prefixes))
     (p4? (eql 103 (prefixes->adr prefixes)))
     (select-byte-operand (equal opcode 134))
     (reg/mem-size
        (select-operand-size proc-mode select-byte-operand
                             rex-byte nil prefixes nil nil nil x86))
     (seg-reg
         (select-segment-register proc-mode p2 p4? mod r/m sib x86))
     (inst-ac? t)
     ((mv flg0 val1
          (the (unsigned-byte 3) increment-rip-by)
          (the (signed-byte 64) addr)
          x86)
      (if (equal (ash opcode -4) 9)
          (mv nil
              (rgfi-size reg/mem-size *rax* rex-byte x86)
              0 0 x86)
        (x86-operand-from-modr/m-and-sib-bytes
             proc-mode
             0 reg/mem-size inst-ac? nil seg-reg p4?
             temp-rip rex-byte r/m mod sib 0 x86)))
     ((when flg0)
      (!!ms-fresh :x86-operand-from-modr/m-and-sib-bytes flg0))
     ((mv flg (the (signed-byte 48) temp-rip))
      (add-to-*ip proc-mode
                  temp-rip increment-rip-by x86))
     ((when flg)
      (!!ms-fresh :rip-increment-error flg))
     (badlength? (check-instruction-length start-rip temp-rip 0))
     ((when badlength?)
      (!!fault-fresh :gp 0
                     :instruction-length badlength?))
     (rw/rd (the (unsigned-byte 3)
                 (logand 7 opcode)))
     (val2 (if (equal (ash opcode -4) 9)
               (rgfi-size reg/mem-size
                          (reg-index rw/rd rex-byte 0)
                          rex-byte x86)
             (rgfi-size reg/mem-size (reg-index reg rex-byte 2)
                        rex-byte x86)))
     ((mv flg2 x86)
      (if
       (equal (ash opcode -4) 9)
       (let
          ((x86 (!rgfi-size reg/mem-size *rax* val2 rex-byte x86)))
         (mv nil x86))
       (x86-operand-to-reg/mem
            proc-mode reg/mem-size inst-ac? nil
            val2 seg-reg (the (signed-byte 64) addr)
            rex-byte r/m mod x86)))
     ((when flg2)
      (!!ms-fresh :x86-operand-to-reg/mem-error flg2))
     (x86 (if (equal (the (unsigned-byte 4) (ash opcode -4))
                     9)
              (!rgfi-size reg/mem-size
                          (reg-index rw/rd rex-byte 0)
                          val1 rex-byte x86)
            (!rgfi-size reg/mem-size (reg-index reg rex-byte 2)
                        val1 rex-byte x86)))
     (x86 (write-*ip proc-mode temp-rip x86)))
    x86))))

Theorem: x86p-of-x86-xchg

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