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Update bounds and docs for the Float trait

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Add some bounds to integer types that allow our function trait bounds to
be slightly less verbose. Also clarify documentation and remove a
redundant operation.
This commit is contained in:
Trevor Gross 2024-08-19 15:35:49 -05:00
parent 44840a12bc
commit 23af8ca763
1 changed files with 5 additions and 5 deletions
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10
library/compiler-builtins/src/float/mod.rs
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@ -31,10 +31,10 @@ pub(crate) trait Float:
+ ops::Rem<Output = Self>
{
/// A uint of the same width as the float
type Int: Int;
type Int: Int<OtherSign = Self::SignedInt, UnsignedInt = Self::Int>;
/// A int of the same width as the float
type SignedInt: Int;
type SignedInt: Int + MinInt<OtherSign = Self::Int, UnsignedInt = Self::Int>;
/// An int capable of containing the exponent bits plus a sign bit. This is signed.
type ExpInt: Int;
@ -51,7 +51,7 @@ pub(crate) trait Float:
/// The bitwidth of the exponent
const EXPONENT_BITS: u32 = Self::BITS - Self::SIGNIFICAND_BITS - 1;
/// The maximum value of the exponent
/// The saturated value of the exponent (infinite representation), in the rightmost postiion.
const EXPONENT_MAX: u32 = (1 << Self::EXPONENT_BITS) - 1;
/// The exponent bias value
@ -83,7 +83,7 @@ pub(crate) trait Float:
/// Returns true if the sign is negative
fn is_sign_negative(self) -> bool;
/// Returns the exponent with bias
/// Returns the exponent, not adjusting for bias.
fn exp(self) -> Self::ExpInt;
/// Returns the significand with no implicit bit (or the "fractional" part)
@ -175,7 +175,7 @@ macro_rules! float_impl {
fn normalize(significand: Self::Int) -> (i32, Self::Int) {
let shift = significand
.leading_zeros()
.wrapping_sub((Self::Int::ONE << Self::SIGNIFICAND_BITS).leading_zeros());
.wrapping_sub(Self::EXPONENT_BITS);
(
1i32.wrapping_sub(shift as i32),
significand << shift as Self::Int,