Theory Native_Word.Uint64

(*  Title:      Uint64.thy
    Author:     Andreas Lochbihler, ETH Zurich
*)

chapter ‹Unsigned words of 64 bits›

theory Uint64 imports
  Word_Type_Copies
  Code_Target_Integer_Bit
begin

text ‹
  PolyML (in version 5.7) provides a Word64 structure only when run in 64-bit mode.
  Therefore, we by default provide an implementation of 64-bit words using \verb$IntInf.int$ and
  masking. The code target \texttt{SML\_word} replaces this implementation and maps the operations
  directly to the \verb$Word64$ structure provided by the Standard ML implementations.

  The \verb$Eval$ target used by @{command value} and @{method eval} dynamically tests at
  runtime for the version of PolyML and uses PolyML's Word64 structure if it detects a 64-bit 
  version which does not suffer from a division bug found in PolyML 5.6.
›

section ‹Type definition and primitive operations›

typedef uint64 = UNIV :: 64 word set ..

global_interpretation uint64: word_type_copy Abs_uint64 Rep_uint64
  using type_definition_uint64 by (rule word_type_copy.intro)

setup_lifting type_definition_uint64

declare uint64.of_word_of [code abstype]

declare Quotient_uint64 [transfer_rule]

instantiation uint64 :: {comm_ring_1, semiring_modulo, equal, linorder}
begin

lift_definition zero_uint64 :: uint64 is 0 .
lift_definition one_uint64 :: uint64 is 1 .
lift_definition plus_uint64 :: uint64  uint64  uint64 is (+) .
lift_definition uminus_uint64 :: uint64  uint64 is uminus .
lift_definition minus_uint64 :: uint64  uint64  uint64 is (-) .
lift_definition times_uint64 :: uint64  uint64  uint64 is (*) .
lift_definition divide_uint64 :: uint64  uint64  uint64 is (div) .
lift_definition modulo_uint64 :: uint64  uint64  uint64 is (mod) .
lift_definition equal_uint64 :: uint64  uint64  bool is HOL.equal .
lift_definition less_eq_uint64 :: uint64  uint64  bool is (≤) .
lift_definition less_uint64 :: uint64  uint64  bool is (<) .

global_interpretation uint64: word_type_copy_ring Abs_uint64 Rep_uint64
  by standard (fact zero_uint64.rep_eq one_uint64.rep_eq
    plus_uint64.rep_eq uminus_uint64.rep_eq minus_uint64.rep_eq
    times_uint64.rep_eq divide_uint64.rep_eq modulo_uint64.rep_eq
    equal_uint64.rep_eq less_eq_uint64.rep_eq less_uint64.rep_eq)+

instance proof -
  show OFCLASS(uint64, comm_ring_1_class)
    by (rule uint64.of_class_comm_ring_1)
  show OFCLASS(uint64, semiring_modulo_class)
    by (fact uint64.of_class_semiring_modulo)
  show OFCLASS(uint64, equal_class)
    by (fact uint64.of_class_equal)
  show OFCLASS(uint64, linorder_class)
    by (fact uint64.of_class_linorder)
qed

end

instantiation uint64 :: ring_bit_operations
begin

lift_definition bit_uint64 :: uint64  nat  bool is bit .
lift_definition not_uint64 :: uint64  uint64 is Bit_Operations.not .
lift_definition and_uint64 :: uint64  uint64  uint64 is Bit_Operations.and .
lift_definition or_uint64 :: uint64  uint64  uint64 is Bit_Operations.or .
lift_definition xor_uint64 :: uint64  uint64  uint64 is Bit_Operations.xor .
lift_definition mask_uint64 :: nat  uint64 is mask .
lift_definition push_bit_uint64 :: nat  uint64  uint64 is push_bit .
lift_definition drop_bit_uint64 :: nat  uint64  uint64 is drop_bit .
lift_definition signed_drop_bit_uint64 :: nat  uint64  uint64 is signed_drop_bit .
lift_definition take_bit_uint64 :: nat  uint64  uint64 is take_bit .
lift_definition set_bit_uint64 :: nat  uint64  uint64 is Bit_Operations.set_bit .
lift_definition unset_bit_uint64 :: nat  uint64  uint64 is unset_bit .
lift_definition flip_bit_uint64 :: nat  uint64  uint64 is flip_bit .

global_interpretation uint64: word_type_copy_bits Abs_uint64 Rep_uint64 signed_drop_bit_uint64
  by standard (fact bit_uint64.rep_eq not_uint64.rep_eq and_uint64.rep_eq or_uint64.rep_eq xor_uint64.rep_eq
    mask_uint64.rep_eq push_bit_uint64.rep_eq drop_bit_uint64.rep_eq signed_drop_bit_uint64.rep_eq take_bit_uint64.rep_eq
    set_bit_uint64.rep_eq unset_bit_uint64.rep_eq flip_bit_uint64.rep_eq)+

instance
  by (fact uint64.of_class_ring_bit_operations)

end

lift_definition uint64_of_nat :: nat  uint64
  is word_of_nat .

lift_definition nat_of_uint64 :: uint64  nat
  is unat .

lift_definition uint64_of_int :: int  uint64
  is word_of_int .

lift_definition int_of_uint64 :: uint64  int
  is uint .

context
  includes integer.lifting
begin

lift_definition Uint64 :: integer  uint64
  is word_of_int .

lift_definition integer_of_uint64 :: uint64  integer
  is uint .

end

global_interpretation uint64: word_type_copy_more Abs_uint64 Rep_uint64 signed_drop_bit_uint64
  uint64_of_nat nat_of_uint64 uint64_of_int int_of_uint64 Uint64 integer_of_uint64
  apply standard
       apply (simp_all add: uint64_of_nat.rep_eq nat_of_uint64.rep_eq
         uint64_of_int.rep_eq int_of_uint64.rep_eq
         Uint64.rep_eq integer_of_uint64.rep_eq integer_eq_iff)
  done

instantiation uint64 :: "{size, msb, set_bit, bit_comprehension}"
begin

lift_definition size_uint64 :: uint64  nat is size .

lift_definition msb_uint64 :: uint64  bool is msb .

text ‹Workaround: avoid name space clash by spelling out text‹lift_definition› explicitly.›

definition set_bit_uint64 :: uint64  nat  bool  uint64
  where set_bit_uint64_eq: set_bit_uint64 a n b = (if b then Bit_Operations.set_bit else unset_bit) n a

context
  includes lifting_syntax
begin

lemma set_bit_uint64_transfer [transfer_rule]:
  (cr_uint64 ===> (=) ===> (⟷) ===> cr_uint64) Generic_set_bit.set_bit Generic_set_bit.set_bit
  by (simp only: set_bit_eq [abs_def] set_bit_uint64_eq [abs_def]) transfer_prover

end

lift_definition set_bits_uint64 :: (nat  bool)  uint64 is set_bits .
lift_definition set_bits_aux_uint64 :: (nat  bool)  nat  uint64  uint64 is set_bits_aux .

global_interpretation uint64: word_type_copy_misc Abs_uint64 Rep_uint64 signed_drop_bit_uint64
  uint64_of_nat nat_of_uint64 uint64_of_int int_of_uint64 Uint64 integer_of_uint64 64 set_bits_aux_uint64
  by (standard; transfer) simp_all

instance using uint64.of_class_bit_comprehension
  uint64.of_class_set_bit
  by simp_all standard

end

section ‹Code setup›

text ‹ For SML, we generate an implementation of unsigned 64-bit words using \verb$IntInf.int$.
  If @{ML "LargeWord.wordSize > 63"} of the Isabelle/ML runtime environment holds, then we assume
  that there is also a Word64› structure available and accordingly replace the implementation
  for the target \verb$Eval$.
›
code_printing code_module "Uint64"  (SML) ‹(* Test that words can handle numbers between 0 and 63 *)
val _ = if 6 <= Word.wordSize then () else raise (Fail ("wordSize less than 6"));

structure Uint64 : sig
  eqtype uint64;
  val zero : uint64;
  val one : uint64;
  val fromInt : IntInf.int -> uint64;
  val toInt : uint64 -> IntInf.int;
  val toLarge : uint64 -> LargeWord.word;
  val fromLarge : LargeWord.word -> uint64
  val plus : uint64 -> uint64 -> uint64;
  val minus : uint64 -> uint64 -> uint64;
  val times : uint64 -> uint64 -> uint64;
  val divide : uint64 -> uint64 -> uint64;
  val modulus : uint64 -> uint64 -> uint64;
  val negate : uint64 -> uint64;
  val less_eq : uint64 -> uint64 -> bool;
  val less : uint64 -> uint64 -> bool;
  val notb : uint64 -> uint64;
  val andb : uint64 -> uint64 -> uint64;
  val orb : uint64 -> uint64 -> uint64;
  val xorb : uint64 -> uint64 -> uint64;
  val shiftl : uint64 -> IntInf.int -> uint64;
  val shiftr : uint64 -> IntInf.int -> uint64;
  val shiftr_signed : uint64 -> IntInf.int -> uint64;
  val set_bit : uint64 -> IntInf.int -> bool -> uint64;
  val test_bit : uint64 -> IntInf.int -> bool;
end = struct

type uint64 = IntInf.int;

val mask = 0xFFFFFFFFFFFFFFFF : IntInf.int;

val zero = 0 : IntInf.int;

val one = 1 : IntInf.int;

fun fromInt x = IntInf.andb(x, mask);

fun toInt x = x

fun toLarge x = LargeWord.fromLargeInt (IntInf.toLarge x);

fun fromLarge x = IntInf.fromLarge (LargeWord.toLargeInt x);

fun plus x y = IntInf.andb(IntInf.+(x, y), mask);

fun minus x y = IntInf.andb(IntInf.-(x, y), mask);

fun negate x = IntInf.andb(IntInf.~(x), mask);

fun times x y = IntInf.andb(IntInf.*(x, y), mask);

fun divide x y = IntInf.div(x, y);

fun modulus x y = IntInf.mod(x, y);

fun less_eq x y = IntInf.<=(x, y);

fun less x y = IntInf.<(x, y);

fun notb x = IntInf.andb(IntInf.notb(x), mask);

fun orb x y = IntInf.orb(x, y);

fun andb x y = IntInf.andb(x, y);

fun xorb x y = IntInf.xorb(x, y);

val maxWord = IntInf.pow (2, Word.wordSize);

fun shiftl x n = 
  if n < maxWord then IntInf.andb(IntInf.<< (x, Word.fromLargeInt (IntInf.toLarge n)), mask)
  else 0;

fun shiftr x n =
  if n < maxWord then IntInf.~>> (x, Word.fromLargeInt (IntInf.toLarge n))
  else 0;

val msb_mask = 0x8000000000000000 : IntInf.int;

fun shiftr_signed x i =
  if IntInf.andb(x, msb_mask) = 0 then shiftr x i
  else if i >= 64 then 0xFFFFFFFFFFFFFFFF
  else let
    val x' = shiftr x i
    val m' = IntInf.andb(IntInf.<<(mask, Word.max(0w64 - Word.fromLargeInt (IntInf.toLarge i), 0w0)), mask)
  in IntInf.orb(x', m') end;

fun test_bit x n =
  if n < maxWord then IntInf.andb (x, IntInf.<< (1, Word.fromLargeInt (IntInf.toLarge n))) <> 0
  else false;

fun set_bit x n b =
  if n < 64 then
    if b then IntInf.orb (x, IntInf.<< (1, Word.fromLargeInt (IntInf.toLarge n)))
    else IntInf.andb (x, IntInf.notb (IntInf.<< (1, Word.fromLargeInt (IntInf.toLarge n))))
  else x;

end
›
code_reserved SML Uint64

setup let
  val polyml64 = LargeWord.wordSize > 63;
  (* PolyML 5.6 has bugs in its Word64 implementation. We test for one such bug and refrain
     from using Word64 in that case. Testing is done with dynamic code evaluation such that
     the compiler does not choke on the Word64 structure, which need not be present in a 32bit
     environment. *)
  val error_msg = "Buggy Word64 structure";
  val test_code = 
   "val _ = if Word64.div (0w18446744073709551611 : Word64.word, 0w3) = 0w6148914691236517203 then ()\n" ^
   "else raise (Fail \"" ^ error_msg ^ "\");";
  val f = Exn.result (fn () => ML_Compiler.eval ML_Compiler.flags Position.none (ML_Lex.tokenize test_code))
  val use_Word64 = polyml64 andalso
    (case f () of 
       Exn.Res _ => true
     | Exn.Exn (e as ERROR m) => if String.isSuffix error_msg m then false else Exn.reraise e
     | Exn.Exn e => Exn.reraise e)
    ;

  val newline = "\n";
  val content = 
    "structure Uint64 : sig" ^ newline ^
    "  eqtype uint64;" ^ newline ^
    "  val zero : uint64;" ^ newline ^
    "  val one : uint64;" ^ newline ^
    "  val fromInt : IntInf.int -> uint64;" ^ newline ^
    "  val toInt : uint64 -> IntInf.int;" ^ newline ^
    "  val toLarge : uint64 -> LargeWord.word;" ^ newline ^
    "  val fromLarge : LargeWord.word -> uint64" ^ newline ^
    "  val plus : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val minus : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val times : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val divide : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val modulus : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val negate : uint64 -> uint64;" ^ newline ^
    "  val less_eq : uint64 -> uint64 -> bool;" ^ newline ^
    "  val less : uint64 -> uint64 -> bool;" ^ newline ^
    "  val notb : uint64 -> uint64;" ^ newline ^
    "  val andb : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val orb : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val xorb : uint64 -> uint64 -> uint64;" ^ newline ^
    "  val shiftl : uint64 -> IntInf.int -> uint64;" ^ newline ^
    "  val shiftr : uint64 -> IntInf.int -> uint64;" ^ newline ^
    "  val shiftr_signed : uint64 -> IntInf.int -> uint64;" ^ newline ^
    "  val set_bit : uint64 -> IntInf.int -> bool -> uint64;" ^ newline ^
    "  val test_bit : uint64 -> IntInf.int -> bool;" ^ newline ^
    "end = struct" ^ newline ^
    "" ^ newline ^
    "type uint64 = Word64.word;" ^ newline ^
    "" ^ newline ^
    "val zero = (0wx0 : uint64);" ^ newline ^
    "" ^ newline ^
    "val one = (0wx1 : uint64);" ^ newline ^
    "" ^ newline ^
    "fun fromInt x = Word64.fromLargeInt (IntInf.toLarge x);" ^ newline ^
    "" ^ newline ^
    "fun toInt x = IntInf.fromLarge (Word64.toLargeInt x);"  ^ newline ^
    "" ^ newline ^
    "fun fromLarge x = Word64.fromLarge x;" ^ newline ^
    "" ^ newline ^
    "fun toLarge x = Word64.toLarge x;"  ^ newline ^
    "" ^ newline ^
    "fun plus x y = Word64.+(x, y);" ^ newline ^
    "" ^ newline ^
    "fun minus x y = Word64.-(x, y);" ^ newline ^
    "" ^ newline ^
    "fun negate x = Word64.~(x);" ^ newline ^
    "" ^ newline ^
    "fun times x y = Word64.*(x, y);" ^ newline ^
    "" ^ newline ^
    "fun divide x y = Word64.div(x, y);" ^ newline ^
    "" ^ newline ^
    "fun modulus x y = Word64.mod(x, y);" ^ newline ^
    "" ^ newline ^
    "fun less_eq x y = Word64.<=(x, y);" ^ newline ^
    "" ^ newline ^
    "fun less x y = Word64.<(x, y);" ^ newline ^
    "" ^ newline ^
    "fun set_bit x n b =" ^ newline ^
    "  let val mask = Word64.<< (0wx1, Word.fromLargeInt (IntInf.toLarge n))" ^ newline ^
    "  in if b then Word64.orb (x, mask)" ^ newline ^
    "     else Word64.andb (x, Word64.notb mask)" ^ newline ^
    "  end" ^ newline ^
    "" ^ newline ^
    "fun shiftl x n =" ^ newline ^
    "  Word64.<< (x, Word.fromLargeInt (IntInf.toLarge n))" ^ newline ^
    "" ^ newline ^
    "fun shiftr x n =" ^ newline ^
    "  Word64.>> (x, Word.fromLargeInt (IntInf.toLarge n))" ^ newline ^
    "" ^ newline ^
    "fun shiftr_signed x n =" ^ newline ^
    "  Word64.~>> (x, Word.fromLargeInt (IntInf.toLarge n))" ^ newline ^
    "" ^ newline ^
    "fun test_bit x n =" ^ newline ^
    "  Word64.andb (x, Word64.<< (0wx1, Word.fromLargeInt (IntInf.toLarge n))) <> Word64.fromInt 0" ^ newline ^
    "" ^ newline ^
    "val notb = Word64.notb" ^ newline ^
    "" ^ newline ^
    "fun andb x y = Word64.andb(x, y);" ^ newline ^
    "" ^ newline ^
    "fun orb x y = Word64.orb(x, y);" ^ newline ^
    "" ^ newline ^
    "fun xorb x y = Word64.xorb(x, y);" ^ newline ^
    "" ^ newline ^
    "end (*struct Uint64*)"
  val target_SML64 = "SML_word";
in
  (if use_Word64 then Code_Target.set_printings (Code_Symbol.Module ("Uint64", [(Code_Runtime.target, SOME (content, []))])) else I)
  #> Code_Target.set_printings (Code_Symbol.Module ("Uint64", [(target_SML64, SOME (content, []))]))
end

code_printing code_module Uint64  (Haskell)
 ‹module Uint64(Int64, Word64) where

  import Data.Int(Int64)
  import Data.Word(Word64)›
code_reserved Haskell Uint64

text ‹
  OCaml and Scala provide only signed 64bit numbers, so we use these and 
  implement sign-sensitive operations like comparisons manually.
›
code_printing code_module "Uint64"  (OCaml)
‹module Uint64 : sig
  val less : int64 -> int64 -> bool
  val less_eq : int64 -> int64 -> bool
  val set_bit : int64 -> Z.t -> bool -> int64
  val shiftl : int64 -> Z.t -> int64
  val shiftr : int64 -> Z.t -> int64
  val shiftr_signed : int64 -> Z.t -> int64
  val test_bit : int64 -> Z.t -> bool
end = struct

(* negative numbers have their highest bit set, 
   so they are greater than positive ones *)
let less x y =
  if Int64.compare x Int64.zero < 0 then
    Int64.compare y Int64.zero < 0 && Int64.compare x y < 0
  else Int64.compare y Int64.zero < 0 || Int64.compare x y < 0;;

let less_eq x y =
  if Int64.compare x Int64.zero < 0 then
    Int64.compare y Int64.zero < 0 && Int64.compare x y <= 0
  else Int64.compare y Int64.zero < 0 || Int64.compare x y <= 0;;

let set_bit x n b =
  let mask = Int64.shift_left Int64.one (Z.to_int n)
  in if b then Int64.logor x mask
     else Int64.logand x (Int64.lognot mask);;

let shiftl x n = Int64.shift_left x (Z.to_int n);;

let shiftr x n = Int64.shift_right_logical x (Z.to_int n);;

let shiftr_signed x n = Int64.shift_right x (Z.to_int n);;

let test_bit x n =
  Int64.compare 
    (Int64.logand x (Int64.shift_left Int64.one (Z.to_int n)))
    Int64.zero
  <> 0;;

end;; (*struct Uint64*)›
code_reserved OCaml Uint64

code_printing code_module Uint64  (Scala)
‹object Uint64 {

def less(x: Long, y: Long) : Boolean =
  x < 0 match {
    case true => y < 0 && x < y
    case false => y < 0 || x < y
  }

def less_eq(x: Long, y: Long) : Boolean =
  x < 0 match {
    case true => y < 0 && x <= y
    case false => y < 0 || x <= y
  }

def set_bit(x: Long, n: BigInt, b: Boolean) : Long =
  b match {
    case true => x | (1L << n.intValue)
    case false => x & (1L << n.intValue).unary_~
  }

def shiftl(x: Long, n: BigInt) : Long = x << n.intValue

def shiftr(x: Long, n: BigInt) : Long = x >>> n.intValue

def shiftr_signed(x: Long, n: BigInt) : Long = x >> n.intValue

def test_bit(x: Long, n: BigInt) : Boolean =
  (x & (1L << n.intValue)) != 0

} /* object Uint64 */›
code_reserved Scala Uint64

text ‹
  OCaml's conversion from Big\_int to int64 demands that the value fits int a signed 64-bit integer.
  The following justifies the implementation.
›

context
  includes bit_operations_syntax
begin

definition Uint64_signed :: "integer  uint64" 
where "Uint64_signed i = (if i < -(0x8000000000000000)  i  0x8000000000000000 then undefined Uint64 i else Uint64 i)"

lemma Uint64_code [code]:
  "Uint64 i = 
  (let i' = i AND 0xFFFFFFFFFFFFFFFF
   in if bit i' 63 then Uint64_signed (i' - 0x10000000000000000) else Uint64_signed i')"
  including undefined_transfer and integer.lifting unfolding Uint64_signed_def
  apply transfer
  apply (subst word_of_int_via_signed)
     apply (auto simp add: push_bit_of_1 mask_eq_exp_minus_1 word_of_int_via_signed cong del: if_cong)
  done

lemma Uint64_signed_code [code]:
  "Rep_uint64 (Uint64_signed i) = 
  (if i < -(0x8000000000000000)  i  0x8000000000000000 then Rep_uint64 (undefined Uint64 i) else word_of_int (int_of_integer_symbolic i))"
unfolding Uint64_signed_def Uint64_def int_of_integer_symbolic_def
by(simp add: Abs_uint64_inverse)

end

text ‹
  Avoid @{term Abs_uint64} in generated code, use @{term Rep_uint64'} instead. 
  The symbolic implementations for code\_simp use @{term Rep_uint64}.

  The new destructor @{term Rep_uint64'} is executable.
  As the simplifier is given the [code abstract] equations literally, 
  we cannot implement @{term Rep_uint64} directly, because that makes code\_simp loop.

  If code generation raises Match, some equation probably contains @{term Rep_uint64} 
  ([code abstract] equations for @{typ uint64} may use @{term Rep_uint64} because
  these instances will be folded away.)

  To convert @{typ "64 word"} values into @{typ uint64}, use @{term "Abs_uint64'"}.
›

definition Rep_uint64' where [simp]: "Rep_uint64' = Rep_uint64"

lemma Rep_uint64'_transfer [transfer_rule]:
  "rel_fun cr_uint64 (=) (λx. x) Rep_uint64'"
unfolding Rep_uint64'_def by(rule uint64.rep_transfer)

lemma Rep_uint64'_code [code]: "Rep_uint64' x = (BITS n. bit x n)"
  by transfer (simp add: set_bits_bit_eq)

lift_definition Abs_uint64' :: "64 word  uint64" is "λx :: 64 word. x" .

lemma Abs_uint64'_code [code]:
  "Abs_uint64' x = Uint64 (integer_of_int (uint x))"
including integer.lifting by transfer simp

declare [[code drop: "term_of_class.term_of :: uint64  _"]]

lemma term_of_uint64_code [code]:
  defines "TR  typerep.Typerep" and "bit0  STR ''Numeral_Type.bit0''" 
  shows
  "term_of_class.term_of x = 
   Code_Evaluation.App (Code_Evaluation.Const (STR ''Uint64.uint64.Abs_uint64'') (TR (STR ''fun'') [TR (STR ''Word.word'') [TR bit0 [TR bit0 [TR bit0 [TR bit0 [TR bit0 [TR bit0 [TR (STR ''Numeral_Type.num1'') []]]]]]]], TR (STR ''Uint64.uint64'') []]))
       (term_of_class.term_of (Rep_uint64' x))"
by(simp add: term_of_anything)

code_printing
  type_constructor uint64 
  (SML) "Uint64.uint64" and
  (Haskell) "Uint64.Word64" and
  (OCaml) "int64" and
  (Scala) "Long"
| constant Uint64 
  (SML) "Uint64.fromInt" and
  (Haskell) "(Prelude.fromInteger _ :: Uint64.Word64)" and
  (Haskell_Quickcheck) "(Prelude.fromInteger (Prelude.toInteger _) :: Uint64.Word64)" and
  (Scala) "_.longValue"
| constant Uint64_signed 
  (OCaml) "Z.to'_int64"
| constant "0 :: uint64" 
  (SML) "Uint64.zero" and
  (Haskell) "(0 :: Uint64.Word64)" and
  (OCaml) "Int64.zero" and
  (Scala) "0"
| constant "1 :: uint64" 
  (SML) "Uint64.one" and
  (Haskell) "(1 :: Uint64.Word64)" and
  (OCaml) "Int64.one" and
  (Scala) "1"
| constant "plus :: uint64  _ " 
  (SML) "Uint64.plus" and
  (Haskell) infixl 6 "+" and
  (OCaml) "Int64.add" and
  (Scala) infixl 7 "+"
| constant "uminus :: uint64  _" 
  (SML) "Uint64.negate" and
  (Haskell) "negate" and
  (OCaml) "Int64.neg" and
  (Scala) "!(- _)"
| constant "minus :: uint64  _" 
  (SML) "Uint64.minus" and
  (Haskell) infixl 6 "-" and
  (OCaml) "Int64.sub" and
  (Scala) infixl 7 "-"
| constant "times :: uint64  _  _" 
  (SML) "Uint64.times" and
  (Haskell) infixl 7 "*" and
  (OCaml) "Int64.mul" and
  (Scala) infixl 8 "*"
| constant "HOL.equal :: uint64  _  bool" 
  (SML) "!((_ : Uint64.uint64) = _)" and
  (Haskell) infix 4 "==" and
  (OCaml) "(Int64.compare _ _ = 0)" and
  (Scala) infixl 5 "=="
| class_instance uint64 :: equal 
  (Haskell) -
| constant "less_eq :: uint64  _  bool" 
  (SML) "Uint64.less'_eq" and
  (Haskell) infix 4 "<=" and
  (OCaml) "Uint64.less'_eq" and
  (Scala) "Uint64.less'_eq"
| constant "less :: uint64  _  bool" 
  (SML) "Uint64.less" and
  (Haskell) infix 4 "<" and
  (OCaml) "Uint64.less" and
  (Scala) "Uint64.less"
| constant "Bit_Operations.not :: uint64  _" 
  (SML) "Uint64.notb" and
  (Haskell) "Data'_Bits.complement" and
  (OCaml) "Int64.lognot" and
  (Scala) "_.unary'_~"
| constant "Bit_Operations.and :: uint64  _" 
  (SML) "Uint64.andb" and
  (Haskell) infixl 7 "Data_Bits..&." and
  (OCaml) "Int64.logand" and
  (Scala) infixl 3 "&"
| constant "Bit_Operations.or :: uint64  _" 
  (SML) "Uint64.orb" and
  (Haskell) infixl 5 "Data_Bits..|." and
  (OCaml) "Int64.logor" and
  (Scala) infixl 1 "|"
| constant "Bit_Operations.xor :: uint64  _" 
  (SML) "Uint64.xorb" and
  (Haskell) "Data'_Bits.xor" and
  (OCaml) "Int64.logxor" and
  (Scala) infixl 2 "^"

definition uint64_divmod :: "uint64  uint64  uint64 × uint64" where
  "uint64_divmod x y = 
  (if y = 0 then (undefined ((div) :: uint64  _) x (0 :: uint64), undefined ((mod) :: uint64  _) x (0 :: uint64)) 
  else (x div y, x mod y))"

definition uint64_div :: "uint64  uint64  uint64" 
where "uint64_div x y = fst (uint64_divmod x y)"

definition uint64_mod :: "uint64  uint64  uint64" 
where "uint64_mod x y = snd (uint64_divmod x y)"

lemma div_uint64_code [code]: "x div y = (if y = 0 then 0 else uint64_div x y)"
including undefined_transfer unfolding uint64_divmod_def uint64_div_def
by transfer (simp add: word_div_def)

lemma mod_uint64_code [code]: "x mod y = (if y = 0 then x else uint64_mod x y)"
including undefined_transfer unfolding uint64_mod_def uint64_divmod_def
by transfer (simp add: word_mod_def)

definition uint64_sdiv :: "uint64  uint64  uint64"
where [code del]:
  "uint64_sdiv x y =
   (if y = 0 then undefined ((div) :: uint64  _) x (0 :: uint64)
    else Abs_uint64 (Rep_uint64 x sdiv Rep_uint64 y))"

definition div0_uint64 :: "uint64  uint64"
where [code del]: "div0_uint64 x = undefined ((div) :: uint64  _) x (0 :: uint64)"
declare [[code abort: div0_uint64]]

definition mod0_uint64 :: "uint64  uint64"
where [code del]: "mod0_uint64 x = undefined ((mod) :: uint64  _) x (0 :: uint64)"
declare [[code abort: mod0_uint64]]

lemma uint64_divmod_code [code]:
  "uint64_divmod x y =
  (if 0x8000000000000000  y then if x < y then (0, x) else (1, x - y)
   else if y = 0 then (div0_uint64 x, mod0_uint64 x)
   else let q = push_bit 1 (uint64_sdiv (drop_bit 1 x) y);
            r = x - q * y
        in if r  y then (q + 1, r - y) else (q, r))"
  including undefined_transfer unfolding uint64_divmod_def uint64_sdiv_def div0_uint64_def mod0_uint64_def
    less_eq_uint64.rep_eq
  apply transfer
  apply (simp add: divmod_via_sdivmod push_bit_eq_mult)
  done

lemma uint64_sdiv_code [code]:
  "Rep_uint64 (uint64_sdiv x y) =
   (if y = 0 then Rep_uint64 (undefined ((div) :: uint64  _) x (0 :: uint64))
    else Rep_uint64 x sdiv Rep_uint64 y)"
unfolding uint64_sdiv_def by(simp add: Abs_uint64_inverse)

text ‹
  Note that we only need a translation for signed division, but not for the remainder
  because @{thm uint64_divmod_code} computes both with division only.
›

code_printing
  constant uint64_div 
  (SML) "Uint64.divide" and
  (Haskell) "Prelude.div"
| constant uint64_mod 
  (SML) "Uint64.modulus" and
  (Haskell) "Prelude.mod"
| constant uint64_divmod 
  (Haskell) "divmod"
| constant uint64_sdiv 
  (OCaml) "Int64.div" and
  (Scala) "_ '/ _"

global_interpretation uint64: word_type_copy_target_language Abs_uint64 Rep_uint64 signed_drop_bit_uint64
  uint64_of_nat nat_of_uint64 uint64_of_int int_of_uint64 Uint64 integer_of_uint64 64 set_bits_aux_uint64 64 63
  defines uint64_test_bit = uint64.test_bit
    and uint64_shiftl = uint64.shiftl
    and uint64_shiftr = uint64.shiftr
    and uint64_sshiftr = uint64.sshiftr
    and uint64_set_bit = uint64.set_bit
  by standard simp_all

code_printing constant uint64_test_bit 
  (SML) "Uint64.test'_bit" and
  (Haskell) "Data'_Bits.testBitBounded" and
  (OCaml) "Uint64.test'_bit" and
  (Scala) "Uint64.test'_bit" and
  (Eval) "(fn x => fn i => if i < 0 orelse i >= 64 then raise (Fail \"argument to uint64'_test'_bit out of bounds\") else Uint64.test'_bit x i)"

code_printing constant uint64_set_bit 
  (SML) "Uint64.set'_bit" and
  (Haskell) "Data'_Bits.setBitBounded" and
  (OCaml) "Uint64.set'_bit" and
  (Scala) "Uint64.set'_bit" and
  (Eval) "(fn w => fn i => fn b => if i < 0 orelse i >= 64 then raise (Fail \"argument to uint64'_set'_bit out of bounds\") else Uint64.set'_bit w i b)"

code_printing constant uint64_shiftl 
  (SML) "Uint64.shiftl" and
  (Haskell) "Data'_Bits.shiftlBounded" and
  (OCaml) "Uint64.shiftl" and
  (Scala) "Uint64.shiftl" and
  (Eval) "(fn w => fn i => if i < 0 orelse i >= 64 then raise (Fail \"argument to uint64'_shiftl out of bounds\") else Uint64.shiftl w i)"

code_printing constant uint64_shiftr 
  (SML) "Uint64.shiftr" and
  (Haskell) "Data'_Bits.shiftrBounded" and
  (OCaml) "Uint64.shiftr" and
  (Scala) "Uint64.shiftr" and
  (Eval) "(fn w => fn i => if i < 0 orelse i >= 64 then raise (Fail \"argument to uint64'_shiftr out of bounds\") else Uint64.shiftr w i)"

code_printing constant uint64_sshiftr 
  (SML) "Uint64.shiftr'_signed" and
  (Haskell) 
    "(Prelude.fromInteger (Prelude.toInteger (Data'_Bits.shiftrBounded (Prelude.fromInteger (Prelude.toInteger _) :: Uint64.Int64) _)) :: Uint64.Word64)" and
  (OCaml) "Uint64.shiftr'_signed" and
  (Scala) "Uint64.shiftr'_signed" and
  (Eval) "(fn w => fn i => if i < 0 orelse i >= 64 then raise (Fail \"argument to uint64'_shiftr'_signed out of bounds\") else Uint64.shiftr'_signed w i)"

context
  includes bit_operations_syntax
begin

lemma uint64_msb_test_bit: "msb x  bit (x :: uint64) 63"
  by transfer (simp add: msb_word_iff_bit)

lemma msb_uint64_code [code]: "msb x  uint64_test_bit x 63"
  by (simp add: uint64.test_bit_def uint64_msb_test_bit)

lemma uint64_of_int_code [code]:
  "uint64_of_int i = Uint64 (integer_of_int i)"
  including integer.lifting by transfer simp

lemma int_of_uint64_code [code]:
  "int_of_uint64 x = int_of_integer (integer_of_uint64 x)"
  including integer.lifting by transfer simp

lemma uint64_of_nat_code [code]:
  "uint64_of_nat = uint64_of_int  int"
  by transfer (simp add: fun_eq_iff)

lemma nat_of_uint64_code [code]:
  "nat_of_uint64 x = nat_of_integer (integer_of_uint64 x)"
  unfolding integer_of_uint64_def including integer.lifting by transfer simp

definition integer_of_uint64_signed :: "uint64  integer"
where
  "integer_of_uint64_signed n = (if bit n 63 then undefined integer_of_uint64 n else integer_of_uint64 n)"

lemma integer_of_uint64_signed_code [code]:
  "integer_of_uint64_signed n =
  (if bit n 63 then undefined integer_of_uint64 n else integer_of_int (uint (Rep_uint64' n)))"
  by (simp add: integer_of_uint64_signed_def integer_of_uint64_def)

lemma integer_of_uint64_code [code]:
  "integer_of_uint64 n =
  (if bit n 63 then integer_of_uint64_signed (n AND 0x7FFFFFFFFFFFFFFF) OR 0x8000000000000000 else integer_of_uint64_signed n)"
proof -
  have integer_of_uint64_signed (n AND 0x7FFFFFFFFFFFFFFF) OR 0x8000000000000000 = Bit_Operations.set_bit 63 (integer_of_uint64_signed (take_bit 63 n))
    by (simp add: take_bit_eq_mask set_bit_eq_or push_bit_eq_mult mask_eq_exp_minus_1)
  moreover have integer_of_uint64 n = Bit_Operations.set_bit 63 (integer_of_uint64 (take_bit 63 n)) if bit n 63
  proof (rule bit_eqI)
    fix m
    from that show bit (integer_of_uint64 n) m = bit (Bit_Operations.set_bit 63 (integer_of_uint64 (take_bit 63 n))) m for m
      including integer.lifting by transfer (auto simp add: bit_simps dest: bit_imp_le_length)
  qed
  ultimately show ?thesis
    by simp (simp add: integer_of_uint64_signed_def bit_simps)
qed

end

code_printing
  constant "integer_of_uint64" 
  (SML) "Uint64.toInt" and
  (Haskell) "Prelude.toInteger"
| constant "integer_of_uint64_signed" 
  (OCaml) "Z.of'_int64" and
  (Scala) "BigInt"

section ‹Quickcheck setup›

definition uint64_of_natural :: "natural  uint64"
where "uint64_of_natural x  Uint64 (integer_of_natural x)"

instantiation uint64 :: "{random, exhaustive, full_exhaustive}" begin
definition "random_uint64  qc_random_cnv uint64_of_natural"
definition "exhaustive_uint64  qc_exhaustive_cnv uint64_of_natural"
definition "full_exhaustive_uint64  qc_full_exhaustive_cnv uint64_of_natural"
instance ..
end

instantiation uint64 :: narrowing begin

interpretation quickcheck_narrowing_samples
  "λi. let x = Uint64 i in (x, 0xFFFFFFFFFFFFFFFF - x)" "0"
  "Typerep.Typerep (STR ''Uint64.uint64'') []" .

definition "narrowing_uint64 d = qc_narrowing_drawn_from (narrowing_samples d) d"
declare [[code drop: "partial_term_of :: uint64 itself  _"]]
lemmas partial_term_of_uint64 [code] = partial_term_of_code

instance ..
end

end