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Two-byte-opcodes

X86-cmpxchg8b/16b

Signature
(x86-cmpxchg8b/16b 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-cmpxchg8b/16b

(defun x86-cmpxchg8b/16b
       (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-cmpxchg8b/16b))
  (declare (ignorable __function__))
  (b* ((?ctx 'x86-cmpxchg8b/16b)
       (?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*
    ((p2 (prefixes->seg prefixes))
     (p4? (equal 103 (prefixes->adr prefixes)))
     (rex-w? (logbitp 3 rex-byte))
     (reg-operand-size (if rex-w? 8 4))
     (mem-operand-size (* 2 reg-operand-size))
     (*ax (rgfi-size reg-operand-size *rax* rex-byte x86))
     (*dx (rgfi-size reg-operand-size *rdx* rex-byte x86))
     (dx-ax (logapp (* 8 reg-operand-size) *ax *dx))
     (*bx (rgfi-size reg-operand-size *rbx* rex-byte x86))
     (*cx (rgfi-size reg-operand-size *rcx* rex-byte x86))
     (cx-bx (logapp (* 8 reg-operand-size) *bx *cx))
     (seg-reg
         (select-segment-register proc-mode p2 p4? mod r/m sib x86))
     ((mv flg0 mem-operand
          (the (unsigned-byte 3) increment-rip-by)
          (the (signed-byte 64) addr)
          x86)
      (x86-operand-from-modr/m-and-sib-bytes
           proc-mode
           1 mem-operand-size t 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 temp-rip))
     (badlength? (check-instruction-length start-rip temp-rip 0))
     ((when badlength?)
      (!!fault-fresh :gp 0
                     :instruction-length badlength?))
     (compare (eql mem-operand dx-ax))
     ((the (unsigned-byte 32) input-rflags)
      (rflags x86))
     (output-rflags (!rflagsbits->zf (bool->bit compare)
                                     input-rflags))
     (undefined-flags 0)
     (x86 (write-user-rflags output-rflags undefined-flags x86))
     ((mv flg1 x86)
      (if compare (wme-size proc-mode mem-operand-size addr seg-reg
                            cx-bx (alignment-checking-enabled-p x86)
                            x86)
        (b* ((x86 (!rgfi-size reg-operand-size *rax*
                              (loghead (* 8 reg-operand-size)
                                       mem-operand)
                              rex-byte x86))
             (x86 (!rgfi-size reg-operand-size *rdx*
                              (logtail (* 8 reg-operand-size)
                                       mem-operand)
                              rex-byte x86)))
          (mv nil x86))))
     ((when flg1)
      (!!ms-fresh :wme-size flg1))
     (x86 (write-*ip proc-mode temp-rip x86)))
    x86))))

Theorem: x86p-of-x86-cmpxchg8b/16b

(defthm x86p-of-x86-cmpxchg8b/16b
 (implies
  (x86p x86)
  (b* ((x86 (x86-cmpxchg8b/16b proc-mode start-rip temp-rip prefixes
                               rex-byte opcode modr/m sib x86)))
    (x86p x86)))
 :rule-classes :rewrite)