172 lines
6.7 KiB
OCaml
172 lines
6.7 KiB
OCaml
(***********************************************************************)
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(* *)
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(* Objective Caml *)
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(* *)
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(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
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(* *)
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(* Copyright 1996 Institut National de Recherche en Informatique et *)
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(* en Automatique. All rights reserved. This file is distributed *)
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(* under the terms of the GNU Library General Public License. *)
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(* *)
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(***********************************************************************)
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(* $Id$ *)
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(** Processor-native integers.
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This module provides operations on the type [nativeint] of
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signed 32-bit integers (on 32-bit platforms) or
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signed 64-bit integers (on 64-bit platforms).
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This integer type has exactly the same width as that of a [long]
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integer type in the C compiler. All arithmetic operations over
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[nativeint] are taken modulo 2{^32} or 2{^64} depending
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on the word size of the architecture.
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Performance notice: values of type [nativeint] occupy more memory
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space than values of type [int], and arithmetic operations on
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[nativeint] are generally slower than those on [int]. Use [nativeint]
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only when the application requires the extra bit of precision
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over the [int] type.
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*)
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(** The native integer 0.*)
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val zero: nativeint
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(** The native integer 1.*)
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val one: nativeint
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(** The native integer -1.*)
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val minus_one: nativeint
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(** Unary negation. *)
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external neg: nativeint -> nativeint = "%nativeint_neg"
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(** Addition. *)
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external add: nativeint -> nativeint -> nativeint = "%nativeint_add"
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(** Subtraction. *)
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external sub: nativeint -> nativeint -> nativeint = "%nativeint_sub"
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(** Multiplication. *)
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external mul: nativeint -> nativeint -> nativeint = "%nativeint_mul"
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(** Integer division. Raise [Division_by_zero] if the second
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argument is zero. *)
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external div: nativeint -> nativeint -> nativeint = "%nativeint_div"
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(** Integer remainder. If [x >= 0] and [y > 0], the result
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of [Nativeint.rem x y] satisfies the following properties:
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[0 <= Nativeint.rem x y < y] and
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[x = Nativeint.add (Nativeint.mul (Nativeint.div x y) y) (Nativeint.rem x y)].
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If [y = 0], [Nativeint.rem x y] raises [Division_by_zero].
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If [x < 0] or [y < 0], the result of [Nativeint.rem x y] is
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not specified and depends on the platform. *)
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external rem: nativeint -> nativeint -> nativeint = "%nativeint_mod"
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(** Successor.
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[Nativeint.succ x] is [Nativeint.add x Nativeint.one]. *)
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val succ: nativeint -> nativeint
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(** Predecessor.
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[Nativeint.pred x] is [Nativeint.sub x Nativeint.one]. *)
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val pred: nativeint -> nativeint
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(** Return the absolute value of its argument. *)
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val abs: nativeint -> nativeint
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(** The size in bits of a native integer. This is equal to [32]
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on a 32-bit platform and to [64] on a 64-bit platform. *)
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val size: int
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(** The greatest representable native integer,
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either 2{^31} - 1 on a 32-bit platform,
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or 2{^63} - 1 on a 64-bit platform. *)
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val max_int: nativeint
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(** The greatest representable native integer,
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either -2{^31} on a 32-bit platform,
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or -2{^63} on a 64-bit platform. *)
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val min_int: nativeint
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(** Bitwise logical and. *)
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external logand: nativeint -> nativeint -> nativeint = "%nativeint_and"
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(** Bitwise logical or. *)
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external logor: nativeint -> nativeint -> nativeint = "%nativeint_or"
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(** Bitwise logical exclusive or. *)
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external logxor: nativeint -> nativeint -> nativeint = "%nativeint_xor"
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(** Bitwise logical negation *)
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val lognot: nativeint -> nativeint
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(** [Nativeint.shift_left x y] shifts [x] to the left by [y] bits.
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The result is unspecified if [y < 0] or [y >= bitsize],
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where [bitsize] is [32] on a 32-bit platform and
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[64] on a 64-bit platform. *)
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external shift_left: nativeint -> int -> nativeint = "%nativeint_lsl"
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(** [Nativeint.shift_right x y] shifts [x] to the right by [y] bits.
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This is an arithmetic shift: the sign bit of [x] is replicated
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and inserted in the vacated bits.
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The result is unspecified if [y < 0] or [y >= bitsize]. *)
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external shift_right: nativeint -> int -> nativeint = "%nativeint_asr"
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(** [Nativeint.shift_right_logical x y] shifts [x] to the right
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by [y] bits.
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This is a logical shift: zeroes are inserted in the vacated bits
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regardless of the sign of [x].
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The result is unspecified if [y < 0] or [y >= bitsize]. *)
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external shift_right_logical: nativeint -> int -> nativeint = "%nativeint_lsr"
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(** Convert the given integer (type [int]) to a native integer
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(type [nativeint]). *)
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external of_int: int -> nativeint = "%nativeint_of_int"
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(** Convert the given native integer (type [nativeint]) to an
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integer (type [int]). The high-order bit is lost during
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the conversion. *)
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external to_int: nativeint -> int = "%nativeint_to_int"
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(** Convert the given floating-point number to a native integer,
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discarding the fractional part (truncate towards 0).
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The result of the conversion is undefined if, after truncation,
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the number is outside the range
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\[{!Nativeint.min_int}, {!Nativeint.max_int}\]. *)
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external of_float : float -> nativeint = "nativeint_of_float"
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(** Convert the given native integer to a floating-point number. *)
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external to_float : nativeint -> float = "nativeint_to_float"
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(** Convert the given 32-bit integer (type [int32])
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to a native integer. *)
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external of_int32: int32 -> nativeint = "%nativeint_of_int32"
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(** Convert the given native integer to a
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32-bit integer (type [int32]). On 64-bit platforms,
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the 64-bit native integer is taken modulo 2{^32},
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i.e. the top 32 bits are lost. On 32-bit platforms,
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the conversion is exact. *)
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external to_int32: nativeint -> int32 = "%nativeint_to_int32"
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(** Convert the given string to a native integer.
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The string is read in decimal (by default) or in hexadecimal,
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octal or binary if the string begins with [0x], [0o] or [0b]
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respectively.
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Raise [Failure "int_of_string"] if the given string is not
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a valid representation of an integer. *)
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external of_string: string -> nativeint = "nativeint_of_string"
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(** Return the string representation of its argument, in decimal. *)
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val to_string: nativeint -> string
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(** [Nativeint.format fmt n] return the string representation of the
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native integer [n] in the format specified by [fmt].
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[fmt] is a [Printf]-style format containing exactly
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one [%d], [%i], [%u], [%x], [%X] or [%o] conversion specification.
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See the documentation of the [Printf] module for more information, *)
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external format : string -> nativeint -> string = "nativeint_format"
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