anchor.diff:    `(disasm-instr (list "dec" :op ,op)
        (set-af-on-sub (1+ (set-of-on-sub (set-pf-on-op (set-sf-on-op (set-zf-on-op (decf ,op)) ,is-word)) 1 ,is-word)) 1)))
   
  -;; One-byte opcodes on registers
  +;; Flag operations
   
   (defun clear-carry-flag ()
     (disasm-instr '("clc")
  
positive.code:     ((in-8-byte-block-p opcode #xb8) (with-one-byte-opcode-register opcode #'mov-word-to-register))
      ((= opcode #xf8) (clear-carry-flag))
      ((= opcode #xf9) (set-carry-flag))
      ((= opcode #xe9) (jmp-near))
      ((= opcode #xeb) (jmp-short))
      ((in-paired-byte-block-p opcode #x70) (jmp-short-conditionally opcode (flag-p :of) "o"))
  
negative.code: (defun set-carry-flag ()
    (disasm-instr '("stc")
      (setf (flag-p :cf) t)))
  
  (defun clear-direction-flag ()
    (disasm-instr '("cld")
      (setf (flag-p :df) nil)))
  
  (defun set-direction-flag ()
    (disasm-instr '("std")
      (setf (flag-p :df) t)))
  
  ;; One-byte opcodes on registers
  
  (defun push-register (reg)
    (disasm-instr (list "push" :src reg)
  