Struct rustc_apfloat::ieee::X87DoubleExtendedS

pub struct X87DoubleExtendedS;

Trait Implementations

impl Semantics for X87DoubleExtendedS

const BITS: usize

BITS: usize = 80

Total number of bits in the in-memory format.

const PRECISION: usize

PRECISION: usize = 64

Number of bits in the significand. This includes the integer bit.

const MAX_EXP: ExpInt

MAX_EXP: ExpInt = (1 << 15 - 1) - 1

The largest E such that 2E is representable; this matches the definition of IEEE 754.

const QNAN_SIGNIFICAND: u128

QNAN_SIGNIFICAND: u128 = 3 << <Self>::QNAN_BIT

For x87 extended precision, we want to make a NaN, not a pseudo-NaN. Maybe we should expose the ability to make pseudo-NaNs?

fn from_bits(bits: u128) -> IeeeFloat<Self>

Integer bit is explicit in this format. Intel hardware (387 and later) does not support these bit patterns: exponent = all 1's, integer bit 0, significand 0 ("pseudoinfinity") exponent = all 1's, integer bit 0, significand nonzero ("pseudoNaN") exponent = 0, integer bit 1 ("pseudodenormal") exponent!=0 nor all 1's, integer bit 0 ("unnormal") At the moment, the first two are treated as NaNs, the second two as Normal.

fn to_bits(x: IeeeFloat<Self>) -> u128

const MIN_EXP: ExpInt

MIN_EXP: ExpInt = -<Self>::MAX_EXP + 1

The smallest E such that 2E is a normalized number; this matches the definition of IEEE 754.

const QNAN_BIT: usize

QNAN_BIT: usize = <Self>::PRECISION - 2

The significand bit that marks NaN as quiet.