type stm = 
  | SEQ of stm * stm
  | EXP of exp
  | LABEL of Temp.label
  | JUMP of exp * Temp.label list
  | CJUMP of relop * exp * exp * Temp.label * Temp.label
	| MOVE of exp * exp

and exp = 
  | MEM of exp
  | BINOP of binop * exp * exp
  | ESEQ of stm * exp
  | CALL of exp * exp list
  | CONST of int
  | NAME of Temp.label
  | TEMP of Temp.temp

and binop = 
  | PLUS 
  | MINUS 
  | MUL 
  | DIV 
  | AND 
  | OR 
  | LSHIFT 
  | RSHIFT 
  | ARSHIFT 
  | XOR

and relop = 
  | EQ 
  | NE 
  | LT 
  | GT 
  | LE 
  | GE 
	| ULT 
  | ULE 
  | UGT 
  | UGE

let not_relop = function
  EQ -> NE
| NE -> EQ
| LT -> GE
| GT -> LE
| LE -> GT
| GE -> LT
| ULT -> UGE
| ULE -> UGT
| UGT -> ULE
| UGE -> ULT