anchor.diff:  
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
  +;;; To a 32-bit GPR or memory location (destination), add an immediate
  +;;; 32-bit value (source), and store the result in the destination.
   ;;; Add imm32 to reg/mem32
   
  -;;; Add imm32 to reg32
  +;;; To a 32-bit GPR (destination), add an immediate 32-bit value
  +;;; (source), and store the result in the destination.
   (define-instruction "ADD"
     :modes (32 64)
     :operands ((gpr 32) (imm 32))
  
positive.code:   :encoding (modrm imm)
    :operand-size-override t)
  
  ;;; Add imm16 to mem16
  (define-instruction "ADD"
    :modes (32 64)
    :operands ((memory 16) (imm 16))
  
negative.code:   :opcode-extension 0
    :encoding (modrm imm))
  
  ;;; To a 32-bit memory location (destination), add an immediate 32-bit
  ;;; value (source), and store the result in the destination.
  (define-instruction "ADD"
    :modes (32 64)
    :operands ((memory 32) (imm 32))
  