Enum FpContract 

pub enum FpContract {
    Off,
    On,
    Fast,
}

How far a multiply and an addition may be fused into one rounding.

crate::Flags::CONTRACT is the same question asked about one instruction, and it is the one the optimizer reads. This is the one the code generator reads, because by the time it runs the two operations it might fuse may have arrived from different expressions and the flags that were on them are gone. off is the default here rather than the one C says, because the frontend is what knows what the command line asked for and a licence nobody granted should not be assumed.

Variants

Off

Never. Every rounding the source asked for happens.

On

Within one expression, which is what C’s FP_CONTRACT pragma allows.

Fast

Anywhere in the function, which is what -ffp-contract=fast means and what gcc does by default.

Implementations

impl FpContract

pub const fn name(self) -> &'static str

The textual form.

pub fn from_name(name: &str) -> Option<Self>

The setting with that name, if there is one.

pub fn all() -> impl Iterator<Item = Self>

Every setting, least permissive first.

Trait Implementations

impl Clone for FpContract

fn clone(&self) -> FpContract

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FpContract

impl Debug for FpContract

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

Formats the value using the given formatter.

impl Default for FpContract

fn default() -> FpContract

Returns the “default value” for a type.

impl Display for FpContract

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

Formats the value using the given formatter.

impl Eq for FpContract

impl Hash for FpContract

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 Ord for FpContract

fn cmp(&self, other: &FpContract) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for FpContract

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for FpContract

fn partial_cmp(&self, other: &FpContract) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for FpContract