GHC.Integer.GMP.Internals

integer-gmp-1.0.0.0: Integer library based on GMP

Copyright | (c) Herbert Valerio Riedel 2014
License | BSD3
Maintainer | ghc-devs@haskell.org
Stability | provisional
Portability | non-portable (GHC Extensions)
Safe Haskell | None
Language | Haskell2010

GHC.Integer.GMP.Internals

Contents

- The `Integer` type
  - Basic `Integer` operations
  - Additional `Integer` operations
  - Additional conversion operations to `Integer`
- The `BigNat` type
  - Conversions to/from `BigNat`
  - `BigNat` arithmetic operations
  - `BigNat` logic operations
  - `BigNat` comparision predicates
- Miscellaneous GMP-provided operations
- Primality tests
- Import/export functions
  - Compute size of serialisation
  - Export
  - Import

Description

This modules provides access to the `Integer` constructors and exposes some highly optimized GMP-operations.

Note that since `integer-gmp` does not depend on `base`, error reporting via exceptions, `error`, or `undefined` is not available. Instead, the low-level functions will crash the runtime if called with invalid arguments.

See also GHC Commentary: Libraries/Integer.

Synopsis

- data Integer
  - = S# !Int#
  - | Jp# !BigNat
  - | Jn# !BigNat
- isValidInteger# :: Integer -> Int#
- module GHC.Integer
- bitInteger :: Int# -> Integer
- popCountInteger :: Integer -> Int#
- gcdInteger :: Integer -> Integer -> Integer
- gcdExtInteger :: Integer -> Integer -> (#Integer, Integer#)
- lcmInteger :: Integer -> Integer -> Integer
- sqrInteger :: Integer -> Integer
- powModInteger :: Integer -> Integer -> Integer -> Integer
- recipModInteger :: Integer -> Integer -> Integer
- wordToNegInteger :: Word# -> Integer
- bigNatToInteger :: BigNat -> Integer
- bigNatToNegInteger :: BigNat -> Integer
- data BigNat = BN# ByteArray#
- type GmpLimb = Word
- type GmpLimb# = Word#
- type GmpSize = Int
- type GmpSize# = Int#
- isValidBigNat# :: BigNat -> Int#
- sizeofBigNat# :: BigNat -> GmpSize#
- zeroBigNat :: BigNat
- oneBigNat :: BigNat
- nullBigNat :: BigNat
- byteArrayToBigNat# :: ByteArray# -> GmpSize# -> BigNat
- wordToBigNat :: Word# -> BigNat
- wordToBigNat2 :: Word# -> Word# -> BigNat
- bigNatToInt :: BigNat -> Int#
- bigNatToWord :: BigNat -> Word#
- indexBigNat# :: BigNat -> GmpSize# -> GmpLimb#
- plusBigNat :: BigNat -> BigNat -> BigNat
- plusBigNatWord :: BigNat -> GmpLimb# -> BigNat
- minusBigNat :: BigNat -> BigNat -> BigNat
- minusBigNatWord :: BigNat -> GmpLimb# -> BigNat
- timesBigNat :: BigNat -> BigNat -> BigNat
- timesBigNatWord :: BigNat -> GmpLimb# -> BigNat
- sqrBigNat :: BigNat -> BigNat
- quotRemBigNat :: BigNat -> BigNat -> (#BigNat, BigNat#)
- quotRemBigNatWord :: BigNat -> GmpLimb# -> (#BigNat, GmpLimb##)
- quotBigNatWord :: BigNat -> GmpLimb# -> BigNat
- quotBigNat :: BigNat -> BigNat -> BigNat
- remBigNat :: BigNat -> BigNat -> BigNat
- remBigNatWord :: BigNat -> GmpLimb# -> Word#
- gcdBigNat :: BigNat -> BigNat -> BigNat
- gcdBigNatWord :: BigNat -> Word# -> Word#
- powModBigNat :: BigNat -> BigNat -> BigNat -> BigNat
- powModBigNatWord :: BigNat -> BigNat -> GmpLimb# -> GmpLimb#
- recipModBigNat :: BigNat -> BigNat -> BigNat
- shiftRBigNat :: BigNat -> Int# -> BigNat
- shiftLBigNat :: BigNat -> Int# -> BigNat
- testBitBigNat :: BigNat -> Int# -> Bool
- andBigNat :: BigNat -> BigNat -> BigNat
- xorBigNat :: BigNat -> BigNat -> BigNat
- popCountBigNat :: BigNat -> Int#
- orBigNat :: BigNat -> BigNat -> BigNat
- bitBigNat :: Int# -> BigNat
- isZeroBigNat :: BigNat -> Bool
- isNullBigNat# :: BigNat -> Int#
- compareBigNatWord :: BigNat -> GmpLimb# -> Ordering
- compareBigNat :: BigNat -> BigNat -> Ordering
- eqBigNatWord :: BigNat -> GmpLimb# -> Bool
- eqBigNatWord# :: BigNat -> GmpLimb# -> Int#
- eqBigNat :: BigNat -> BigNat -> Bool
- eqBigNat# :: BigNat -> BigNat -> Int#
- gtBigNatWord# :: BigNat -> GmpLimb# -> Int#
- gcdInt :: Int# -> Int# -> Int#
- gcdWord :: Word# -> Word# -> Word#
- powModWord :: GmpLimb# -> GmpLimb# -> GmpLimb# -> GmpLimb#
- recipModWord :: GmpLimb# -> GmpLimb# -> GmpLimb#
- testPrimeInteger :: Integer -> Int# -> Int#
- testPrimeBigNat :: BigNat -> Int# -> Int#
- testPrimeWord# :: GmpLimb# -> Int# -> Int#
- nextPrimeInteger :: Integer -> Integer
- nextPrimeBigNat :: BigNat -> BigNat
- nextPrimeWord# :: GmpLimb# -> GmpLimb#
- sizeInBaseBigNat :: BigNat -> Int# -> Word#
- sizeInBaseInteger :: Integer -> Int# -> Word#
- sizeInBaseWord# :: Word# -> Int# -> Word#
- exportBigNatToAddr :: BigNat -> Addr# -> Int# -> IO Word
- exportIntegerToAddr :: Integer -> Addr# -> Int# -> IO Word
- exportWordToAddr :: Word -> Addr# -> Int# -> IO Word
- exportBigNatToMutableByteArray :: BigNat -> MutableByteArray# RealWorld -> Word# -> Int# -> IO Word
- exportIntegerToMutableByteArray :: Integer -> MutableByteArray# RealWorld -> Word# -> Int# -> IO Word
- exportWordToMutableByteArray :: Word -> MutableByteArray# RealWorld -> Word# -> Int# -> IO Word
- importBigNatFromAddr :: Addr# -> Word# -> Int# -> IO BigNat
- importIntegerFromAddr :: Addr# -> Word# -> Int# -> IO Integer
- importBigNatFromByteArray :: ByteArray# -> Word# -> Word# -> Int# -> BigNat
- importIntegerFromByteArray :: ByteArray# -> Word# -> Word# -> Int# -> Integer

# The `Integer` type

data Integer

Invariant: `Jn#` and `Jp#` are used iff value doesn't fit in `S#`

Useful properties resulting from the invariants:

-     abs (S# _) <= abs (Jp# _)

-     abs (S# _) <  abs (Jn# _)

Constructors

S# !Int# | iff value in `[minBound::`Int`, maxBound::`Int`]` range
Jp# !BigNat | iff value in `]maxBound::`Int`, +inf[` range
Jn# !BigNat | iff value in `]-inf, minBound::`Int`[` range

Instances

Eq Integer |
Ord Integer |

isValidInteger# :: Integer -> Int#

Test whether all internal invariants are satisfied by `Integer` value

Returns `1#` if valid, `0#` otherwise.

This operation is mostly useful for test-suites and/or code which constructs `Integer` values directly.

## Basic `Integer` operations

module GHC.Integer

## Additional `Integer` operations

bitInteger :: Int# -> Integer

`Integer` for which only n-th bit is set. Undefined behaviour for negative n values.

popCountInteger :: Integer -> Int#

Count number of set bits. For negative arguments returns negative population count of negated argument.

gcdInteger :: Integer -> Integer -> Integer

Compute greatest common divisor.

gcdExtInteger :: Integer -> Integer -> (#Integer, Integer#)

Extended euclidean algorithm.

For `a` and `b`, compute their greatest common divisor `g` and the coefficient `s` satisfying `as + bt = g`.

Since: 0.5.1.0

lcmInteger :: Integer -> Integer -> Integer

Compute least common multiple.

sqrInteger :: Integer -> Integer

Square `Integer`

powModInteger :: Integer -> Integer -> Integer -> Integer

"``powModInteger` b e m`" computes base `b` raised to exponent `e` modulo `abs(m)`.

Negative exponents are supported if an inverse modulo `m` exists.

Warning: It's advised to avoid calling this primitive with negative exponents unless it is guaranteed the inverse exists, as failure to do so will likely cause program abortion due to a divide-by-zero fault. See also `recipModInteger`.

Future versions of `integer_gmp` may not support negative `e` values anymore.

Since: 0.5.1.0

recipModInteger :: Integer -> Integer -> Integer

"``recipModInteger` x m`" computes the inverse of `x` modulo `m`. If the inverse exists, the return value `y` will satisfy `0 < y < abs(m)`, otherwise the result is `0`.

Since: 0.5.1.0

## Additional conversion operations to `Integer`

wordToNegInteger :: Word# -> Integer

bigNatToInteger :: BigNat -> Integer

bigNatToNegInteger :: BigNat -> Integer

# The `BigNat` type

data BigNat

Type representing raw arbitrary-precision Naturals

This is common type used by `Natural` and `Integer`. As this type consists of a single constructor wrapping a `ByteArray#` it can be unpacked.

Essential invariants:

- `ByteArray#` size is an exact multiple of `Word#` size
- limbs are stored in least-significant-limb-first order,
- the most-significant limb must be non-zero, except for
- `0` which is represented as a 1-limb.

Constructors

BN# ByteArray# |

Instances

Eq BigNat |
Ord BigNat |

type GmpLimb = Word

Type representing a GMP Limb

type GmpLimb# = Word#

type GmpSize = Int

Count of `GmpLimb`s, must be positive (unless specified otherwise).

type GmpSize# = Int#

##

isValidBigNat# :: BigNat -> Int#

Test whether all internal invariants are satisfied by `BigNat` value

Returns `1#` if valid, `0#` otherwise.

This operation is mostly useful for test-suites and/or code which constructs `Integer` values directly.

sizeofBigNat# :: BigNat -> GmpSize#

Return number of limbs contained in `BigNat`.

zeroBigNat :: BigNat

CAF representing the value `0 :: BigNat`

oneBigNat :: BigNat

CAF representing the value `1 :: BigNat`

nullBigNat :: BigNat

Special 0-sized bigNat returned in case of arithmetic underflow

This is currently only returned by the following operations:

- `minusBigNat`
- `minusBigNatWord`

Other operations such as `quotBigNat` may return `nullBigNat` as well as a dummy/place-holder value instead of `undefined` since we can't throw exceptions. But that behaviour should not be relied upon.

NB: `isValidBigNat# nullBigNat` is false

## Conversions to/from `BigNat`

byteArrayToBigNat# :: ByteArray# -> GmpSize# -> BigNat

Construct `BigNat` from existing `ByteArray#` containing n `GmpLimb`s in least-significant-first order.

If possible `ByteArray#`, will be used directly (i.e. shared without cloning the `ByteArray#` into a newly allocated one)

Note: size parameter (times `sizeof(GmpLimb)`) must be less or equal to its `sizeofByteArray#`.

wordToBigNat :: Word# -> BigNat

Construct 1-limb `BigNat` from `Word#`

wordToBigNat2 :: Word# -> Word# -> BigNat

Construct BigNat from 2 limbs. The first argument is the most-significant limb.

bigNatToInt :: BigNat -> Int#

Equivalent to ``word2Int#` . `bigNatToWord``

bigNatToWord :: BigNat -> Word#

Same as ``indexBigNat#` bn 0#`

indexBigNat# :: BigNat -> GmpSize# -> GmpLimb#

Extract n-th (0-based) limb in `BigNat`. n must be less than size as reported by `sizeofBigNat#`.

## `BigNat` arithmetic operations

plusBigNat :: BigNat -> BigNat -> BigNat

plusBigNatWord :: BigNat -> GmpLimb# -> BigNat

minusBigNat :: BigNat -> BigNat -> BigNat

Returns `nullBigNat` (see `isNullBigNat#`) in case of underflow

minusBigNatWord :: BigNat -> GmpLimb# -> BigNat

Returns `nullBigNat` (see `isNullBigNat#`) in case of underflow

timesBigNat :: BigNat -> BigNat -> BigNat

timesBigNatWord :: BigNat -> GmpLimb# -> BigNat

sqrBigNat :: BigNat -> BigNat

Square `BigNat`

quotRemBigNat :: BigNat -> BigNat -> (#BigNat, BigNat#)

If divisor is zero, `(# `nullBigNat`, `nullBigNat` #)` is returned

quotRemBigNatWord :: BigNat -> GmpLimb# -> (#BigNat, GmpLimb##)

Note: Result of div/0 undefined

quotBigNatWord :: BigNat -> GmpLimb# -> BigNat

quotBigNat :: BigNat -> BigNat -> BigNat

remBigNat :: BigNat -> BigNat -> BigNat

remBigNatWord :: BigNat -> GmpLimb# -> Word#

div/0 not checked

gcdBigNat :: BigNat -> BigNat -> BigNat

gcdBigNatWord :: BigNat -> Word# -> Word#

powModBigNat :: BigNat -> BigNat -> BigNat -> BigNat

Version of `powModInteger` operating on `BigNat`s

Since: 1.0.0.0

powModBigNatWord :: BigNat -> BigNat -> GmpLimb# -> GmpLimb#

Version of `powModInteger` for `Word#`-sized moduli

Since: 1.0.0.0

recipModBigNat :: BigNat -> BigNat -> BigNat

Version of `recipModInteger` operating on `BigNat`s

Since: 1.0.0.0

## `BigNat` logic operations

shiftRBigNat :: BigNat -> Int# -> BigNat

shiftLBigNat :: BigNat -> Int# -> BigNat

testBitBigNat :: BigNat -> Int# -> Bool

andBigNat :: BigNat -> BigNat -> BigNat

xorBigNat :: BigNat -> BigNat -> BigNat

popCountBigNat :: BigNat -> Int#

orBigNat :: BigNat -> BigNat -> BigNat

bitBigNat :: Int# -> BigNat

## `BigNat` comparision predicates

isZeroBigNat :: BigNat -> Bool

Test if `BigNat` value is equal to zero.

isNullBigNat# :: BigNat -> Int#

Test for special 0-sized `BigNat` representing underflows.

compareBigNatWord :: BigNat -> GmpLimb# -> Ordering

compareBigNat :: BigNat -> BigNat -> Ordering

eqBigNatWord :: BigNat -> GmpLimb# -> Bool

eqBigNatWord# :: BigNat -> GmpLimb# -> Int#

eqBigNat :: BigNat -> BigNat -> Bool

eqBigNat# :: BigNat -> BigNat -> Int#

gtBigNatWord# :: BigNat -> GmpLimb# -> Int#

# Miscellaneous GMP-provided operations

gcdInt :: Int# -> Int# -> Int#

Compute greatest common divisor.

Warning: result may become negative if (at least) one argument is `minBound`

gcdWord :: Word# -> Word# -> Word#

Compute greatest common divisor.

Since: 1.0.0.0

powModWord :: GmpLimb# -> GmpLimb# -> GmpLimb# -> GmpLimb#

Version of `powModInteger` operating on `Word#`s

Since: 1.0.0.0

recipModWord :: GmpLimb# -> GmpLimb# -> GmpLimb#

Version of `recipModInteger` operating on `Word#`s

Since: 1.0.0.0

# Primality tests

testPrimeInteger :: Integer -> Int# -> Int#

Probalistic Miller-Rabin primality test.

"``testPrimeInteger` n k`" determines whether `n` is prime and returns one of the following results:

- `2#` is returned if `n` is definitely prime,
- `1#` if `n` is a probable prime, or
- `0#` if `n` is definitely not a prime.

The `k` argument controls how many test rounds are performed for determining a probable prime. For more details, see GMP documentation for `mpz_probab_prime_p()`.

Since: 0.5.1.0

testPrimeBigNat :: BigNat -> Int# -> Int#

Version of `testPrimeInteger` operating on `BigNat`s

Since: 1.0.0.0

testPrimeWord# :: GmpLimb# -> Int# -> Int#

Version of `testPrimeInteger` operating on `Word#`s

Since: 1.0.0.0

nextPrimeInteger :: Integer -> Integer

Compute next prime greater than `n` probalistically.

According to the GMP documentation, the underlying function `mpz_nextprime()` "uses a probabilistic algorithm to identify primes. For practical purposes it's adequate, the chance of a composite passing will be extremely small."

Since: 0.5.1.0

nextPrimeBigNat :: BigNat -> BigNat

Version of `nextPrimeInteger` operating on `BigNat`s

Since: 1.0.0.0

nextPrimeWord# :: GmpLimb# -> GmpLimb#

Version of `nextPrimeInteger` operating on `Word#`s

Since: 1.0.0.0

# Import/export functions

## Compute size of serialisation

sizeInBaseBigNat :: BigNat -> Int# -> Word#

Version of `sizeInBaseInteger` operating on `BigNat`

Since: 1.0.0.0

sizeInBaseInteger :: Integer -> Int# -> Word#

Compute number of digits (without sign) in given `base`.

This function wraps `mpz_sizeinbase()` which has some implementation pecularities to take into account:

- "``sizeInBaseInteger` 0 base = 1`" (see also comment in `exportIntegerToMutableByteArray`).
- This function is only defined if `base >= 2#` and `base <= 256#` (Note: the documentation claims that only `base <= 62#` is supported, however the actual implementation supports up to base 256).
- If `base` is a power of 2, the result will be exact. In other cases (e.g. for `base = 10#`), the result may be 1 digit too large sometimes.
- "``sizeInBaseInteger` i 2#`" can be used to determine the most significant bit of `i`.

Since: 0.5.1.0

sizeInBaseWord# :: Word# -> Int# -> Word#

Version of `sizeInBaseInteger` operating on `Word#`

Since: 1.0.0.0

## Export

exportBigNatToAddr :: BigNat -> Addr# -> Int# -> IO Word

Version of `exportIntegerToAddr` operating on `BigNat`s.

exportIntegerToAddr :: Integer -> Addr# -> Int# -> IO Word

Dump `Integer` (without sign) to `addr` in base-256 representation.

    exportIntegerToAddr i addr e

See description of `exportIntegerToMutableByteArray` for more details.

Since: 1.0.0.0

exportWordToAddr :: Word -> Addr# -> Int# -> IO Word

Version of `exportIntegerToAddr` operating on `Word`s.

exportBigNatToMutableByteArray :: BigNat -> MutableByteArray# RealWorld -> Word# -> Int# -> IO Word

Version of `exportIntegerToMutableByteArray` operating on `BigNat`s.

Since: 1.0.0.0

exportIntegerToMutableByteArray :: Integer -> MutableByteArray# RealWorld -> Word# -> Int# -> IO Word

Dump `Integer` (without sign) to mutable byte-array in base-256 representation.

The call

    exportIntegerToMutableByteArray i mba offset msbf

writes

- the `Integer` `i`
- into the `MutableByteArray#` `mba` starting at `offset`
- with most significant byte first if `msbf` is `1#` or least significant byte first if `msbf` is `0#`, and
- returns number of bytes written.

Use "``sizeInBaseInteger` i 256#`" to compute the exact number of bytes written in advance for `i /= 0`. In case of `i == 0`, `exportIntegerToMutableByteArray` will write and report zero bytes written, whereas `sizeInBaseInteger` report one byte.

It's recommended to avoid calling `exportIntegerToMutableByteArray` for small integers as this function would currently convert those to big integers in msbf to call `mpz_export()`.

Since: 1.0.0.0

exportWordToMutableByteArray :: Word -> MutableByteArray# RealWorld -> Word# -> Int# -> IO Word

Version of `exportIntegerToMutableByteArray` operating on `Word`s.

Since: 1.0.0.0

## Import

importBigNatFromAddr :: Addr# -> Word# -> Int# -> IO BigNat

Version of `importIntegerFromAddr` constructing a `BigNat`

importIntegerFromAddr :: Addr# -> Word# -> Int# -> IO Integer

Read `Integer` (without sign) from memory location at `addr` in base-256 representation.

    importIntegerFromAddr addr size msbf

See description of `importIntegerFromByteArray` for more details.

Since: 1.0.0.0

importBigNatFromByteArray :: ByteArray# -> Word# -> Word# -> Int# -> BigNat

Version of `importIntegerFromByteArray` constructing a `BigNat`

importIntegerFromByteArray :: ByteArray# -> Word# -> Word# -> Int# -> Integer

Read `Integer` (without sign) from byte-array in base-256 representation.

The call

    importIntegerFromByteArray ba offset size msbf

reads

- `size` bytes from the `ByteArray#` `ba` starting at `offset`
- with most significant byte first if `msbf` is `1#` or least significant byte first if `msbf` is `0#`, and
- returns a new `Integer`

Since: 1.0.0.0