Struct LocalVarDecl 

pub struct LocalVarDecl {
    pub width: u32,
    pub signed: bool,
}

The declared type of one local-variable slot: every value stored in the slot is first cast to it (16.10 “the value of a local variable is a value of its declared type”; 16.8.2 “cast to the type of” for an input/inout formal’s initial value and for the value written back to an output/inout actual). The builder derives it from the variable’s declared integral type; a non-integral local variable is a loud build error, never a slot.

Fields

width: u32

Width in bits (>= 1).

signed: bool

Whether the type is signed: a signed value is sign-extended from its top bit after truncation, an unsigned one zero-extended.

Implementations

impl LocalVarDecl

pub fn is_wide(&self) -> bool

Whether the variable is wider than one frame slot (> 64 bits) and so occupies slots consecutive frame slots, see Automaton::new_local_var.

pub fn limbs(&self) -> usize

How many 64-bit limbs one plane (value or unknown) of the variable has: ceil(width / 64), and 1 for a narrow variable.

pub fn slots(&self) -> usize

How many consecutive frame slots the variable occupies: 1 when it fits an i64, else 2 * limbs() – the value limbs (least significant first), then the unknown-plane limbs (x/z bits, same order). A wide variable is four-state; a narrow one is the two-state i64 it always was.

pub fn cast(&self, value: i64) -> i64

value fitted to this type: truncated to width bits, then sign-extended when signed. A slot holds an i64, so a type of 64 bits or more is the identity here: a wider variable is stored limb by limb in several slots (slots, the helpers of crate::sva::wide fit it as a whole) and each limb slot is an ordinary 64-bit unsigned one.

Trait Implementations

impl Clone for LocalVarDecl

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for LocalVarDecl

impl Debug for LocalVarDecl

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for LocalVarDecl

impl Hash for LocalVarDecl

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for LocalVarDecl

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for LocalVarDecl