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Auto merge of #191 - est31:master, r=alexcrichton 

Small refactor to use associated consts

Yeey less chars.

r? @alexcrichton
This commit is contained in:
bors 2017-09-13 23:12:44 +00:00
parent 23f14d3f05 46cfa05650
commit 915293c528
9 changed files with 123 additions and 189 deletions
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4
src/float/add.rs
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@ -10,8 +10,8 @@ macro_rules! add {
let one = Wrapping(1 as <$ty as Float>::Int); let one = Wrapping(1 as <$ty as Float>::Int);
let zero = Wrapping(0 as <$ty as Float>::Int); let zero = Wrapping(0 as <$ty as Float>::Int);
let bits = Wrapping(<$ty>::bits() as <$ty as Float>::Int); let bits = Wrapping(<$ty>::BITS as <$ty as Float>::Int);
let significand_bits = Wrapping(<$ty>::significand_bits() as <$ty as Float>::Int); let significand_bits = Wrapping(<$ty>::SIGNIFICAND_BITS as <$ty as Float>::Int);
let exponent_bits = bits - significand_bits - one; let exponent_bits = bits - significand_bits - one;
let max_exponent = (one << exponent_bits.0 as usize) - one; let max_exponent = (one << exponent_bits.0 as usize) - one;

18
src/float/conv.rs
View File

@ -8,10 +8,10 @@ macro_rules! int_to_float {
return 0.0 return 0.0
} }
let mant_dig = <$fty>::significand_bits() + 1; let mant_dig = <$fty>::SIGNIFICAND_BITS + 1;
let exponent_bias = <$fty>::exponent_bias(); let exponent_bias = <$fty>::EXPONENT_BIAS;
let n = <$ity>::bits(); let n = <$ity>::BITS;
let (s, a) = i.extract_sign(); let (s, a) = i.extract_sign();
let mut a = a; let mut a = a;
@ -21,7 +21,7 @@ macro_rules! int_to_float {
// exponent // exponent
let mut e = sd - 1; let mut e = sd - 1;
if <$ity>::bits() < mant_dig { if <$ity>::BITS < mant_dig {
return <$fty>::from_parts(s, return <$fty>::from_parts(s,
(e + exponent_bias) as <$fty as Float>::Int, (e + exponent_bias) as <$fty as Float>::Int,
(a as <$fty as Float>::Int) << (mant_dig - e - 1)) (a as <$fty as Float>::Int) << (mant_dig - e - 1))
@ -142,12 +142,12 @@ macro_rules! float_to_int {
let f = $f; let f = $f;
let fixint_min = <$ity>::min_value(); let fixint_min = <$ity>::min_value();
let fixint_max = <$ity>::max_value(); let fixint_max = <$ity>::max_value();
let fixint_bits = <$ity>::bits() as usize; let fixint_bits = <$ity>::BITS as usize;
let fixint_unsigned = fixint_min == 0; let fixint_unsigned = fixint_min == 0;
let sign_bit = <$fty>::sign_mask(); let sign_bit = <$fty>::SIGN_MASK;
let significand_bits = <$fty>::significand_bits() as usize; let significand_bits = <$fty>::SIGNIFICAND_BITS as usize;
let exponent_bias = <$fty>::exponent_bias() as usize; let exponent_bias = <$fty>::EXPONENT_BIAS as usize;
//let exponent_max = <$fty>::exponent_max() as usize; //let exponent_max = <$fty>::exponent_max() as usize;
// Break a into sign, exponent, significand // Break a into sign, exponent, significand
@ -157,7 +157,7 @@ macro_rules! float_to_int {
// this is used to work around -1 not being available for unsigned // this is used to work around -1 not being available for unsigned
let sign = if (a_rep & sign_bit) == 0 { Sign::Positive } else { Sign::Negative }; let sign = if (a_rep & sign_bit) == 0 { Sign::Positive } else { Sign::Negative };
let mut exponent = (a_abs >> significand_bits) as usize; let mut exponent = (a_abs >> significand_bits) as usize;
let significand = (a_abs & <$fty>::significand_mask()) | <$fty>::implicit_bit(); let significand = (a_abs & <$fty>::SIGNIFICAND_MASK) | <$fty>::IMPLICIT_BIT;
// if < 1 or unsigned & negative // if < 1 or unsigned & negative
if exponent < exponent_bias || if exponent < exponent_bias ||

174
src/float/mod.rs
View File

@ -1,5 +1,7 @@
use core::mem; use core::mem;
use super::int::Int;
pub mod conv; pub mod conv;
pub mod add; pub mod add;
pub mod pow; pub mod pow;
@ -8,39 +10,34 @@ pub mod sub;
/// Trait for some basic operations on floats /// Trait for some basic operations on floats
pub trait Float: Sized + Copy { pub trait Float: Sized + Copy {
/// A uint of the same with as the float /// A uint of the same with as the float
type Int; type Int: Int;
/// Returns the bitwidth of the float type /// The bitwidth of the float type
fn bits() -> u32; const BITS: u32;
/// Returns the bitwidth of the significand /// The bitwidth of the significand
fn significand_bits() -> u32; const SIGNIFICAND_BITS: u32;
/// Returns the bitwidth of the exponent /// The bitwidth of the exponent
fn exponent_bits() -> u32 { const EXPONENT_BITS: u32 = Self::BITS - Self::SIGNIFICAND_BITS - 1;
Self::bits() - Self::significand_bits() - 1
}
/// Returns the maximum value of the exponent
fn exponent_max() -> u32 {
(1 << Self::exponent_bits()) - 1
}
/// Returns the exponent bias value /// The maximum value of the exponent
fn exponent_bias() -> u32 { const EXPONENT_MAX: u32 = (1 << Self::EXPONENT_BITS) - 1;
Self::exponent_max() >> 1
}
/// Returns a mask for the sign bit /// The exponent bias value
fn sign_mask() -> Self::Int; const EXPONENT_BIAS: u32 = Self::EXPONENT_MAX >> 1;
/// Returns a mask for the significand /// A mask for the sign bit
fn significand_mask() -> Self::Int; const SIGN_MASK: Self::Int;
// Returns the implicit bit of the float format /// A mask for the significand
fn implicit_bit() -> Self::Int; const SIGNIFICAND_MASK: Self::Int;
/// Returns a mask for the exponent // The implicit bit of the float format
fn exponent_mask() -> Self::Int; const IMPLICIT_BIT: Self::Int;
/// A mask for the exponent
const EXPONENT_MASK: Self::Int;
/// Returns `self` transmuted to `Self::Int` /// Returns `self` transmuted to `Self::Int`
fn repr(self) -> Self::Int; fn repr(self) -> Self::Int;
@ -63,94 +60,45 @@ pub trait Float: Sized + Copy {
// FIXME: Some of this can be removed if RFC Issue #1424 is resolved // FIXME: Some of this can be removed if RFC Issue #1424 is resolved
// https://github.com/rust-lang/rfcs/issues/1424 // https://github.com/rust-lang/rfcs/issues/1424
impl Float for f32 { macro_rules! float_impl {
type Int = u32; ($ty:ident, $ity:ident, $bits:expr, $significand_bits:expr) => {
fn bits() -> u32 { impl Float for $ty {
32 type Int = $ity;
} const BITS: u32 = $bits;
fn significand_bits() -> u32 { const SIGNIFICAND_BITS: u32 = $significand_bits;
23
} const SIGN_MASK: Self::Int = 1 << (Self::BITS - 1);
fn implicit_bit() -> Self::Int { const SIGNIFICAND_MASK: Self::Int = (1 << Self::SIGNIFICAND_BITS) - 1;
1 << Self::significand_bits() const IMPLICIT_BIT: Self::Int = 1 << Self::SIGNIFICAND_BITS;
} const EXPONENT_MASK: Self::Int = !(Self::SIGN_MASK | Self::SIGNIFICAND_MASK);
fn sign_mask() -> Self::Int {
1 << (Self::bits() - 1) fn repr(self) -> Self::Int {
} unsafe { mem::transmute(self) }
fn significand_mask() -> Self::Int { }
(1 << Self::significand_bits()) - 1 #[cfg(test)]
} fn eq_repr(self, rhs: Self) -> bool {
fn exponent_mask() -> Self::Int { if self.is_nan() && rhs.is_nan() {
!(Self::sign_mask() | Self::significand_mask()) true
} } else {
fn repr(self) -> Self::Int { self.repr() == rhs.repr()
unsafe { mem::transmute(self) } }
} }
#[cfg(test)] fn from_repr(a: Self::Int) -> Self {
fn eq_repr(self, rhs: Self) -> bool { unsafe { mem::transmute(a) }
if self.is_nan() && rhs.is_nan() { }
true fn from_parts(sign: bool, exponent: Self::Int, significand: Self::Int) -> Self {
} else { Self::from_repr(((sign as Self::Int) << (Self::BITS - 1)) |
self.repr() == rhs.repr() ((exponent << Self::SIGNIFICAND_BITS) & Self::EXPONENT_MASK) |
(significand & Self::SIGNIFICAND_MASK))
}
fn normalize(significand: Self::Int) -> (i32, Self::Int) {
let shift = significand.leading_zeros()
.wrapping_sub((Self::Int::ONE << Self::SIGNIFICAND_BITS).leading_zeros());
(1i32.wrapping_sub(shift as i32), significand << shift as Self::Int)
}
} }
} }
fn from_repr(a: Self::Int) -> Self {
unsafe { mem::transmute(a) }
}
fn from_parts(sign: bool, exponent: Self::Int, significand: Self::Int) -> Self {
Self::from_repr(((sign as Self::Int) << (Self::bits() - 1)) |
((exponent << Self::significand_bits()) & Self::exponent_mask()) |
(significand & Self::significand_mask()))
}
fn normalize(significand: Self::Int) -> (i32, Self::Int) {
let shift = significand.leading_zeros()
.wrapping_sub((1u32 << Self::significand_bits()).leading_zeros());
(1i32.wrapping_sub(shift as i32), significand << shift as Self::Int)
}
}
impl Float for f64 {
type Int = u64;
fn bits() -> u32 {
64
}
fn significand_bits() -> u32 {
52
}
// Returns the implicit bit of the float format
fn implicit_bit() -> Self::Int {
1 << Self::significand_bits()
}
fn sign_mask() -> Self::Int {
1 << (Self::bits() - 1)
}
fn significand_mask() -> Self::Int {
(1 << Self::significand_bits()) - 1
}
fn exponent_mask() -> Self::Int {
!(Self::sign_mask() | Self::significand_mask())
}
fn repr(self) -> Self::Int {
unsafe { mem::transmute(self) }
}
#[cfg(test)]
fn eq_repr(self, rhs: Self) -> bool {
if self.is_nan() && rhs.is_nan() {
true
} else {
self.repr() == rhs.repr()
}
}
fn from_repr(a: Self::Int) -> Self {
unsafe { mem::transmute(a) }
}
fn from_parts(sign: bool, exponent: Self::Int, significand: Self::Int) -> Self {
Self::from_repr(((sign as Self::Int) << (Self::bits() - 1)) |
((exponent << Self::significand_bits()) & Self::exponent_mask()) |
(significand & Self::significand_mask()))
}
fn normalize(significand: Self::Int) -> (i32, Self::Int) {
let shift = significand.leading_zeros()
.wrapping_sub((1u64 << Self::significand_bits()).leading_zeros());
(1i32.wrapping_sub(shift as i32), significand << shift as Self::Int)
}
} }
float_impl!(f32, u32, 32, 23);
float_impl!(f64, u64, 64, 52);

4
src/float/sub.rs
View File

@ -3,11 +3,11 @@ use float::Float;
intrinsics! { intrinsics! {
#[arm_aeabi_alias = __aeabi_fsub] #[arm_aeabi_alias = __aeabi_fsub]
pub extern "C" fn __subsf3(a: f32, b: f32) -> f32 { pub extern "C" fn __subsf3(a: f32, b: f32) -> f32 {
a + f32::from_repr(b.repr() ^ f32::sign_mask()) a + f32::from_repr(b.repr() ^ f32::SIGN_MASK)
} }
#[arm_aeabi_alias = __aeabi_dsub] #[arm_aeabi_alias = __aeabi_dsub]
pub extern "C" fn __subdf3(a: f64, b: f64) -> f64 { pub extern "C" fn __subdf3(a: f64, b: f64) -> f64 {
a + f64::from_repr(b.repr() ^ f64::sign_mask()) a + f64::from_repr(b.repr() ^ f64::SIGN_MASK)
} }
} }

34
src/int/mod.rs
View File

@ -39,11 +39,11 @@ pub trait Int:
/// Unsigned version of Self /// Unsigned version of Self
type UnsignedInt: Int; type UnsignedInt: Int;
/// Returns the bitwidth of the int type /// The bitwidth of the int type
fn bits() -> u32; const BITS: u32;
fn zero() -> Self; const ZERO: Self;
fn one() -> Self; const ONE: Self;
/// Extracts the sign from self and returns a tuple. /// Extracts the sign from self and returns a tuple.
/// ///
@ -83,17 +83,10 @@ macro_rules! int_impl {
type OtherSign = $ity; type OtherSign = $ity;
type UnsignedInt = $uty; type UnsignedInt = $uty;
fn zero() -> Self { const BITS: u32 = $bits;
0
}
fn one() -> Self { const ZERO: Self = 0;
1 const ONE: Self = 1;
}
fn bits() -> u32 {
$bits
}
fn extract_sign(self) -> (bool, $uty) { fn extract_sign(self) -> (bool, $uty) {
(false, self) (false, self)
@ -140,17 +133,10 @@ macro_rules! int_impl {
type OtherSign = $uty; type OtherSign = $uty;
type UnsignedInt = $uty; type UnsignedInt = $uty;
fn bits() -> u32 { const BITS: u32 = $bits;
$bits
}
fn zero() -> Self { const ZERO: Self = 0;
0 const ONE: Self = 1;
}
fn one() -> Self {
1
}
fn extract_sign(self) -> (bool, $uty) { fn extract_sign(self) -> (bool, $uty) {
if self < 0 { if self < 0 {

14
src/int/mul.rs
View File

@ -5,8 +5,8 @@ use int::Int;
trait Mul: LargeInt { trait Mul: LargeInt {
fn mul(self, other: Self) -> Self { fn mul(self, other: Self) -> Self {
let half_bits = Self::bits() / 4; let half_bits = Self::BITS / 4;
let lower_mask = !<<Self as LargeInt>::LowHalf>::zero() >> half_bits; let lower_mask = !<<Self as LargeInt>::LowHalf>::ZERO >> half_bits;
let mut low = (self.low() & lower_mask).wrapping_mul(other.low() & lower_mask); let mut low = (self.low() & lower_mask).wrapping_mul(other.low() & lower_mask);
let mut t = low >> half_bits; let mut t = low >> half_bits;
low &= lower_mask; low &= lower_mask;
@ -33,23 +33,23 @@ trait Mulo: Int + ops::Neg<Output = Self> {
*overflow = 0; *overflow = 0;
let result = self.wrapping_mul(other); let result = self.wrapping_mul(other);
if self == Self::min_value() { if self == Self::min_value() {
if other != Self::zero() && other != Self::one() { if other != Self::ZERO && other != Self::ONE {
*overflow = 1; *overflow = 1;
} }
return result; return result;
} }
if other == Self::min_value() { if other == Self::min_value() {
if self != Self::zero() && self != Self::one() { if self != Self::ZERO && self != Self::ONE {
*overflow = 1; *overflow = 1;
} }
return result; return result;
} }
let sa = self >> (Self::bits() - 1); let sa = self >> (Self::BITS - 1);
let abs_a = (self ^ sa) - sa; let abs_a = (self ^ sa) - sa;
let sb = other >> (Self::bits() - 1); let sb = other >> (Self::BITS - 1);
let abs_b = (other ^ sb) - sb; let abs_b = (other ^ sb) - sb;
let two = Self::one() + Self::one(); let two = Self::ONE + Self::ONE;
if abs_a < two || abs_b < two { if abs_a < two || abs_b < two {
return result; return result;
} }

10
src/int/sdiv.rs
View File

@ -3,9 +3,9 @@ use int::Int;
trait Div: Int { trait Div: Int {
/// Returns `a / b` /// Returns `a / b`
fn div(self, other: Self) -> Self { fn div(self, other: Self) -> Self {
let s_a = self >> (Self::bits() - 1); let s_a = self >> (Self::BITS - 1);
let s_b = other >> (Self::bits() - 1); let s_b = other >> (Self::BITS - 1);
// NOTE it's OK to overflow here because of the `as $uty` cast below // NOTE it's OK to overflow here because of the `.unsigned()` below.
// This whole operation is computing the absolute value of the inputs // This whole operation is computing the absolute value of the inputs
// So some overflow will happen when dealing with e.g. `i64::MIN` // So some overflow will happen when dealing with e.g. `i64::MIN`
// where the absolute value is `(-i64::MIN) as u64` // where the absolute value is `(-i64::MIN) as u64`
@ -25,10 +25,10 @@ impl Div for i128 {}
trait Mod: Int { trait Mod: Int {
/// Returns `a % b` /// Returns `a % b`
fn mod_(self, other: Self) -> Self { fn mod_(self, other: Self) -> Self {
let s = other >> (Self::bits() - 1); let s = other >> (Self::BITS - 1);
// NOTE(wrapping_sub) see comment in the `div` // NOTE(wrapping_sub) see comment in the `div`
let b = (other ^ s).wrapping_sub(s); let b = (other ^ s).wrapping_sub(s);
let s = self >> (Self::bits() - 1); let s = self >> (Self::BITS - 1);
let a = (self ^ s).wrapping_sub(s); let a = (self ^ s).wrapping_sub(s);
let r = a.unsigned().aborting_rem(b.unsigned()); let r = a.unsigned().aborting_rem(b.unsigned());

16
src/int/shift.rs
View File

@ -1,13 +1,13 @@
use int::{Int, LargeInt}; use int::{Int, LargeInt};
trait Ashl: Int + LargeInt { trait Ashl: Int + LargeInt {
/// Returns `a << b`, requires `b < $ty::bits()` /// Returns `a << b`, requires `b < Self::BITS`
fn ashl(self, offset: u32) -> Self fn ashl(self, offset: u32) -> Self
where Self: LargeInt<HighHalf = <Self as LargeInt>::LowHalf>, where Self: LargeInt<HighHalf = <Self as LargeInt>::LowHalf>,
{ {
let half_bits = Self::bits() / 2; let half_bits = Self::BITS / 2;
if offset & half_bits != 0 { if offset & half_bits != 0 {
Self::from_parts(Int::zero(), self.low() << (offset - half_bits)) Self::from_parts(Int::ZERO, self.low() << (offset - half_bits))
} else if offset == 0 { } else if offset == 0 {
self self
} else { } else {
@ -22,11 +22,11 @@ impl Ashl for u64 {}
impl Ashl for u128 {} impl Ashl for u128 {}
trait Ashr: Int + LargeInt { trait Ashr: Int + LargeInt {
/// Returns arithmetic `a >> b`, requires `b < $ty::bits()` /// Returns arithmetic `a >> b`, requires `b < Self::BITS`
fn ashr(self, offset: u32) -> Self fn ashr(self, offset: u32) -> Self
where Self: LargeInt<LowHalf = <<Self as LargeInt>::HighHalf as Int>::UnsignedInt>, where Self: LargeInt<LowHalf = <<Self as LargeInt>::HighHalf as Int>::UnsignedInt>,
{ {
let half_bits = Self::bits() / 2; let half_bits = Self::BITS / 2;
if offset & half_bits != 0 { if offset & half_bits != 0 {
Self::from_parts((self.high() >> (offset - half_bits)).unsigned(), Self::from_parts((self.high() >> (offset - half_bits)).unsigned(),
self.high() >> (half_bits - 1)) self.high() >> (half_bits - 1))
@ -44,13 +44,13 @@ impl Ashr for i64 {}
impl Ashr for i128 {} impl Ashr for i128 {}
trait Lshr: Int + LargeInt { trait Lshr: Int + LargeInt {
/// Returns logical `a >> b`, requires `b < $ty::bits()` /// Returns logical `a >> b`, requires `b < Self::BITS`
fn lshr(self, offset: u32) -> Self fn lshr(self, offset: u32) -> Self
where Self: LargeInt<HighHalf = <Self as LargeInt>::LowHalf>, where Self: LargeInt<HighHalf = <Self as LargeInt>::LowHalf>,
{ {
let half_bits = Self::bits() / 2; let half_bits = Self::BITS / 2;
if offset & half_bits != 0 { if offset & half_bits != 0 {
Self::from_parts(self.high() >> (offset - half_bits), Int::zero()) Self::from_parts(self.high() >> (offset - half_bits), Int::ZERO)
} else if offset == 0 { } else if offset == 0 {
self self
} else { } else {

38
src/int/udiv.rs
View File

@ -63,7 +63,7 @@ macro_rules! udivmod_inner {
sr = d.high().leading_zeros().wrapping_sub(n.high().leading_zeros()); sr = d.high().leading_zeros().wrapping_sub(n.high().leading_zeros());
// D > N // D > N
if sr > <hty!($ty)>::bits() - 2 { if sr > <hty!($ty)>::BITS - 2 {
if let Some(rem) = rem { if let Some(rem) = rem {
*rem = n; *rem = n;
} }
@ -72,8 +72,8 @@ macro_rules! udivmod_inner {
sr += 1; sr += 1;
// 1 <= sr <= <hty!($ty)>::bits() - 1 // 1 <= sr <= <hty!($ty)>::BITS - 1
q = n << (<$ty>::bits() - sr); q = n << (<$ty>::BITS - sr);
r = n >> sr; r = n >> sr;
} else if d.high() == 0 { } else if d.high() == 0 {
// K X // K X
@ -92,10 +92,10 @@ macro_rules! udivmod_inner {
}; };
} }
sr = 1 + <hty!($ty)>::bits() + d.low().leading_zeros() - n.high().leading_zeros(); sr = 1 + <hty!($ty)>::BITS + d.low().leading_zeros() - n.high().leading_zeros();
// 2 <= sr <= u64::bits() - 1 // 2 <= sr <= u64::BITS - 1
q = n << (<$ty>::bits() - sr); q = n << (<$ty>::BITS - sr);
r = n >> sr; r = n >> sr;
} else { } else {
// K X // K X
@ -104,7 +104,7 @@ macro_rules! udivmod_inner {
sr = d.high().leading_zeros().wrapping_sub(n.high().leading_zeros()); sr = d.high().leading_zeros().wrapping_sub(n.high().leading_zeros());
// D > N // D > N
if sr > <hty!($ty)>::bits() - 1 { if sr > <hty!($ty)>::BITS - 1 {
if let Some(rem) = rem { if let Some(rem) = rem {
*rem = n; *rem = n;
} }
@ -113,16 +113,16 @@ macro_rules! udivmod_inner {
sr += 1; sr += 1;
// 1 <= sr <= <hty!($ty)>::bits() // 1 <= sr <= <hty!($ty)>::BITS
q = n << (<$ty>::bits() - sr); q = n << (<$ty>::BITS - sr);
r = n >> sr; r = n >> sr;
} }
// Not a special case // Not a special case
// q and r are initialized with // q and r are initialized with
// q = n << (u64::bits() - sr) // q = n << (u64::BITS - sr)
// r = n >> sr // r = n >> sr
// 1 <= sr <= u64::bits() - 1 // 1 <= sr <= u64::BITS - 1
let mut carry = 0; let mut carry = 0;
// Don't use a range because they may generate references to memcpy in unoptimized code // Don't use a range because they may generate references to memcpy in unoptimized code
@ -131,7 +131,7 @@ macro_rules! udivmod_inner {
i += 1; i += 1;
// r:q = ((r:q) << 1) | carry // r:q = ((r:q) << 1) | carry
r = (r << 1) | (q >> (<$ty>::bits() - 1)); r = (r << 1) | (q >> (<$ty>::BITS - 1));
q = (q << 1) | carry as $ty; q = (q << 1) | carry as $ty;
// carry = 0 // carry = 0
@ -139,7 +139,7 @@ macro_rules! udivmod_inner {
// r -= d; // r -= d;
// carry = 1; // carry = 1;
// } // }
let s = (d.wrapping_sub(r).wrapping_sub(1)) as os_ty!($ty) >> (<$ty>::bits() - 1); let s = (d.wrapping_sub(r).wrapping_sub(1)) as os_ty!($ty) >> (<$ty>::BITS - 1);
carry = (s & 1) as hty!($ty); carry = (s & 1) as hty!($ty);
r -= d & s as $ty; r -= d & s as $ty;
} }
@ -169,19 +169,19 @@ intrinsics! {
let mut sr = d.leading_zeros().wrapping_sub(n.leading_zeros()); let mut sr = d.leading_zeros().wrapping_sub(n.leading_zeros());
// d > n // d > n
if sr > u32::bits() - 1 { if sr > u32::BITS - 1 {
return 0; return 0;
} }
// d == 1 // d == 1
if sr == u32::bits() - 1 { if sr == u32::BITS - 1 {
return n; return n;
} }
sr += 1; sr += 1;
// 1 <= sr <= u32::bits() - 1 // 1 <= sr <= u32::BITS - 1
let mut q = n << (u32::bits() - sr); let mut q = n << (u32::BITS - sr);
let mut r = n >> sr; let mut r = n >> sr;
let mut carry = 0; let mut carry = 0;
@ -192,7 +192,7 @@ intrinsics! {
i += 1; i += 1;
// r:q = ((r:q) << 1) | carry // r:q = ((r:q) << 1) | carry
r = (r << 1) | (q >> (u32::bits() - 1)); r = (r << 1) | (q >> (u32::BITS - 1));
q = (q << 1) | carry; q = (q << 1) | carry;
// carry = 0; // carry = 0;
@ -201,7 +201,7 @@ intrinsics! {
// carry = 1; // carry = 1;
// } // }
let s = (d.wrapping_sub(r).wrapping_sub(1)) as i32 >> (u32::bits() - 1); let s = (d.wrapping_sub(r).wrapping_sub(1)) as i32 >> (u32::BITS - 1);
carry = (s & 1) as u32; carry = (s & 1) as u32;
r -= d & s as u32; r -= d & s as u32;
} }