Define word

The dw keyword compiles to a single field element of data directly in the code. For example:

dw 0x123

will be translated to the field element 0x123 in the bytecode. This is not really an instruction, and therefore should not be in any execution path. A common use for this is constant arrays:

from starkware.cairo.common.registers import get_label_location

# Returns a pointer to the values: [1, 22, 333, 4444].
func get_data() -> (data : felt*):
    let (data_address) = get_label_location(data_start)
    return (data=cast(data_address, felt*))

    data_start:
    dw 1
    dw 22
    dw 333
    dw 4444
end

func main():
    let (data) = get_data()
    tempvar value = data[2]
    assert value = 333
    return ()
end