Additional bitwise arithmetic
Factor handbook > The language > Numbers > Arithmetic > Bitwise arithmetic

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The math.bitwise vocabulary provides bitwise arithmetic words extending Bitwise arithmetic. They are useful for efficiency, low-level programming, and interfacing with C libraries.

Setting and clearing bits:
set-bit ( x n -- y )

clear-bit ( x n -- y )


Testing if bits are set:
bit? ( x n -- ? )


Extracting bits from an integer:
bit-range ( x high low -- y )

bits ( m n -- m' )


Toggling a bit:
toggle-bit ( m n -- m' )


Operations with bitmasks:
mask ( x n -- y )

unmask ( x n -- y )

mask? ( x n -- ? )

unmask? ( x n -- ? )


Generating an integer with n set bits:
on-bits ( m -- n )


Counting the number of set bits:
bit-count ( obj -- n )


Testing the parity of an object:
even-parity? ( obj -- ? )

odd-parity? ( obj -- ? )


More efficient modding by powers of two:
wrap ( m n -- m' )


Bit-rolling:
bitroll ( x s w -- y )

bitroll-32 ( m s -- n )

bitroll-64 ( m s -- n )


32-bit arithmetic:
w+ ( x y -- z )

w- ( x y -- z )

w* ( x y -- z )


64-bit arithmetic:
W+ ( x y -- z )

W- ( x y -- z )

W* ( x y -- z )


Converting a number to the nearest even/odd/signed:
>even ( m -- n )

>odd ( m -- n )

>signed ( x n -- y )


Bitfields:
Constructing bit fields