let error_prefix = "MIPS interpret"
let error s = Error.global_error error_prefix (s ^ "\n")


let unop = function
  | MIPSOps.UOpAddi i -> Value.add (Value.Val_int i)
  | MIPSOps.UOpSlti i -> (fun v -> Value.cmp_lt v (Value.Val_int i))
  | MIPSOps.UOpSltiu i -> (fun v -> Value.cmp_lt_u v (Value.Val_int i))
  | MIPSOps.UOpAndi i -> Value.and_op (Value.Val_int i)
  | MIPSOps.UOpOri i -> Value.or_op (Value.Val_int i)
  | MIPSOps.UOpXori i -> Value.xor (Value.Val_int i)
  | MIPSOps.UOpNeg -> Value.negint
  | MIPSOps.UOpNot -> Value.notint

let binop = function
  | MIPSOps.OpAdd -> Value.add
  | MIPSOps.OpSub -> Value.sub
  | MIPSOps.OpMul -> Value.mul
  | MIPSOps.OpDiv -> Value.div
  | MIPSOps.OpDivu -> Value.divu
  | MIPSOps.OpModu -> Value.modulo
  | MIPSOps.OpLt -> Value.cmp_lt
  | MIPSOps.OpLtu -> Value.cmp_lt_u
  | MIPSOps.OpLe -> Value.cmp_le
  | MIPSOps.OpLeu -> Value.cmp_le_u
  | MIPSOps.OpGt -> Value.cmp_gt
  | MIPSOps.OpGtu -> Value.cmp_gt_u
  | MIPSOps.OpGe -> Value.cmp_ge
  | MIPSOps.OpGeu -> Value.cmp_ge_u
  | MIPSOps.OpEq -> Value.cmp_eq
  | MIPSOps.OpNe -> Value.cmp_ne
  | MIPSOps.OpSllv -> Value.shl
  | MIPSOps.OpSrav -> Value.shr
  | MIPSOps.OpSrlv -> Value.shru
  | MIPSOps.OpAnd -> Value.and_op
  | MIPSOps.OpOr -> Value.or_op
  | MIPSOps.OpXor -> Value.xor

let fun_of_uncon = function
  | MIPSOps.UConGez -> Value.cmp_ge
  | MIPSOps.UConGtz -> Value.cmp_gt
  | MIPSOps.UConLez -> Value.cmp_le
  | MIPSOps.UConLtz -> Value.cmp_lt

let uncon con = (fun_of_uncon con) (Value.Val_int 0l)
  

let bincon = function
  | MIPSOps.ConEq -> Value.cmp_eq
  | MIPSOps.ConNe -> Value.cmp_ne