Copyright	(c) 2025 Jared Tobin
License	MIT
Maintainer	Jared Tobin <jared@ppad.tech>
Safe Haskell	None
Language	Haskell2010

Data.Word.Wide

Contents

Wide Words
Construction, Conversion
Constant-time selection
Bit Manipulation
Comparison
Arithmetic
Unboxed Arithmetic

Description

Wide words, consisting of two Limbs.

Synopsis

data Wide = Wide !Limb2
wide :: Word -> Word -> Wide
to_vartime :: Integer -> Wide
from_vartime :: Wide -> Integer
select :: Wide -> Wide -> Choice -> Wide
or :: Wide -> Wide -> Wide
and :: Wide -> Wide -> Wide
xor :: Wide -> Wide -> Wide
not :: Wide -> Wide
eq :: Wide -> Wide -> Choice
eq_vartime :: Wide -> Wide -> Bool
add :: Wide -> Wide -> Wide
add_o :: Wide -> Wide -> (Wide, Word)
sub :: Wide -> Wide -> Wide
mul :: Wide -> Wide -> Wide
neg :: Wide -> Wide
add_o# :: Limb2 -> Limb2 -> (# Limb2, Limb #)
add_w# :: Limb2 -> Limb2 -> Limb2
sub_b# :: Limb2 -> Limb2 -> (# Limb2, Limb #)
sub_w# :: Limb2 -> Limb2 -> Limb2
mul_w# :: Limb2 -> Limb2 -> Limb2

Wide Words

data Wide Source #

Little-endian wide words.

Constructors

Wide !Limb2

Instances

Instances details

Num Wide Source #	Note that `fromInteger` necessarily runs in variable time due to conversion from the variable-size, potentially heap-allocated `Integer` type.
Instance details Defined in Data.Word.Wide Methods (+) :: Wide -> Wide -> Wide # (-) :: Wide -> Wide -> Wide # (*) :: Wide -> Wide -> Wide # negate :: Wide -> Wide # abs :: Wide -> Wide # signum :: Wide -> Wide # fromInteger :: Integer -> Wide #
Show Wide Source #
Instance details Defined in Data.Word.Wide Methods showsPrec :: Int -> Wide -> ShowS # show :: Wide -> String # showList :: [Wide] -> ShowS #
NFData Wide Source #
Instance details Defined in Data.Word.Wide Methods rnf :: Wide -> () #

Construction, Conversion

wide :: Word -> Word -> Wide Source #

Construct a Wide word from low and high Words.

to_vartime :: Integer -> Wide Source #

Convert an Integer to a Wide word in variable time.

>>> to_vartime 1
1

from_vartime :: Wide -> Integer Source #

Convert a Wide word to an Integer in variable time.

>>> from_vartime 1
1

Constant-time selection

select Source #

Arguments

:: Wide	a
-> Wide	b
-> Choice	c
-> Wide	result

Return a if c is truthy, otherwise return b.

>>> import qualified Data.Choice as C
>>> select 0 1 (C.true# ())
1

Bit Manipulation

or :: Wide -> Wide -> Wide Source #

Logical disjunction on Wide words.

and :: Wide -> Wide -> Wide Source #

Logical conjunction on Wide words.

xor :: Wide -> Wide -> Wide Source #

Logical exclusive-or on Wide words.

not :: Wide -> Wide Source #

Logical negation on Wide words.

Comparison

eq :: Wide -> Wide -> Choice Source #

Compare Wide words for equality in constant time.

>>> import qualified Data.Chocie as C
>>> C.decide (eq 1 1)
True

eq_vartime :: Wide -> Wide -> Bool Source #

Compare Wide words for equality in variable time.

>>> eq_vartime 1 1
True

Arithmetic

add :: Wide -> Wide -> Wide Source #

Wrapping addition on Wide words, computing 'a + b'.

add_o Source #

Arguments

:: Wide	augend
-> Wide	addend
-> (Wide, Word)	(sum, carry)

Overflowing addition on Wide words, computing 'a + b', returning the sum and carry bit.

sub :: Wide -> Wide -> Wide Source #

Wrapping subtraction on Wide words, computing 'a - b'.

mul :: Wide -> Wide -> Wide Source #

Wrapping multiplication on Wide words.

neg Source #

Arguments

:: Wide	argument
-> Wide	(wrapping) additive inverse

Wrapping negation on Wide words, producing an additive inverse.

>>> neg 1
340282366920938463463374607431768211455
>>> 1 + neg 1
>>> 0

Unboxed Arithmetic

add_o# Source #

Arguments

:: Limb2	augend
-> Limb2	addend
-> (# Limb2, Limb #)	(# sum, carry bit #)

Overflowing addition, computing 'a + b', returning the sum and a carry bit.

add_w# Source #

Arguments

:: Limb2	augend
-> Limb2	addend
-> Limb2	sum

Wrapping addition, computing 'a + b'.

sub_b# Source #

Arguments

:: Limb2	minuend
-> Limb2	subtrahend
-> (# Limb2, Limb #)	(# difference, borrow mask #)

Borrowing subtraction, computing 'a - b' and returning the difference with a borrow mask.

sub_w# Source #

Arguments

:: Limb2	minuend
-> Limb2	subtrahend
-> Limb2	difference

Wrapping subtraction, computing 'a - b'.

mul_w# Source #

Arguments

:: Limb2	multiplicand
-> Limb2	multiplier
-> Limb2	product

Wrapping multiplication, computing 'a b'.