Struct BarrelShifter

pub struct BarrelShifter {
    pub output: Col<B1, 32>,
    pub variant: ShiftVariant,
    /* private fields */
}

A gadget for performing a barrel shift circuit (https://en.wikipedia.org/wiki/Barrel_shifter).

The BarrelShifter gadget allows for left shifts, right shifts, and rotations on 32-bit inputs, with a configurable shift amount and direction.

Fields

output: Col<B1, 32>

The output column representing the result of the shift operation. This column is virtual or committed, depending on the flags

variant: ShiftVariant

The variant of the shift operation: logical left, logical right or circular left.

Implementations

impl BarrelShifter

pub fn new( table: &mut TableBuilder<'_>, input: Col<B1, 32>, shift_amount: Col<B1, 16>, variant: ShiftVariant, ) -> Self

Creates a new instance of the BarrelShifter gadget.

Arguments

• table - A mutable reference to the TableBuilder used to define the gadget.
• input - The input column of type Col<B1, 32>.
• shift_amount - The shift amount column of type Col<B1, 16>. The 11 most significant bits are ignored.
• variant - Indicates whether the circuits performs a logical left, logical right, or circular left shift.

Returns

A new instance of the BarrelShifter gadget.

pub fn populate<P>( &self, index: &mut TableWitnessSegment<'_, P>, ) -> Result<(), Error>

where P: PackedFieldIndexable<Scalar = B128> + PackedExtension<B1>,

Populates the table with witness values for the barrel shifter.

Arguments

• index - A mutable reference to the TableWitness used to populate the table.

Returns

A Result indicating success or failure.