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clippy fix: remove manual PartialEq::ne #143377

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clippy fix: remove manual PartialEq::ne #143377

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2642b81
clippy fix: remove or annotate manual PartialEq::ne
hkBst Jul 3, 2025
9c60f35
reduce repetition with macros
hkBst Jul 4, 2025
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259 changes: 86 additions & 173 deletions library/core/src/cmp.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1813,8 +1813,6 @@ mod impls {
impl const PartialEq for $t {
#[inline]
fn eq(&self, other: &Self) -> bool { *self == *other }
#[inline]
fn ne(&self, other: &Self) -> bool { *self != *other }
Comment on lines -1816 to -1817
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Primitive ne isn't equivalent to !(*self == *other). This difference goes straight to MIR and codegen:

rust/compiler/rustc_codegen_ssa/src/mir/rvalue.rs

Lines 822 to 833 in 0fb279b

mir::BinOp::Ne
| mir::BinOp::Lt
| mir::BinOp::Gt
| mir::BinOp::Eq
| mir::BinOp::Le
| mir::BinOp::Ge => {
if is_float {
bx.fcmp(base::bin_op_to_fcmp_predicate(op), lhs, rhs)
} else {
bx.icmp(base::bin_op_to_icmp_predicate(op, is_signed), lhs, rhs)
}
}

Yes it can be trivially optimized away but why emit additional IR when you can emit less?

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Interesting! I suppose that treatment may be necessary in case these are implemented by inline assembly or via FFI.

Yes it can be trivially optimized away but why emit additional IR when you can emit less?

The documentation in this very file says that:

/// The default implementation of `ne` provides this consistency and is almost
/// always sufficient. It should not be overridden without very good reason.

Is the performance impact of emitting slightly more IR really a very good reason? I would expect it is on the edge of immeasurable.

}
)*)
}
Expand All @@ -1825,10 +1823,6 @@ mod impls {
fn eq(&self, _other: &()) -> bool {
true
}
#[inline]
fn ne(&self, _other: &()) -> bool {
false
}
}

partial_eq_impl! {
Expand Down Expand Up @@ -2014,179 +2008,98 @@ mod impls {
}
}

// & pointers
// reference types

#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
impl<A: PointeeSized, B: PointeeSized> const PartialEq<&B> for &A
where
A: ~const PartialEq<B>,
{
#[inline]
fn eq(&self, other: &&B) -> bool {
PartialEq::eq(*self, *other)
}
#[inline]
fn ne(&self, other: &&B) -> bool {
PartialEq::ne(*self, *other)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: PointeeSized, B: PointeeSized> PartialOrd<&B> for &A
where
A: PartialOrd<B>,
{
#[inline]
fn partial_cmp(&self, other: &&B) -> Option<Ordering> {
PartialOrd::partial_cmp(*self, *other)
}
#[inline]
fn lt(&self, other: &&B) -> bool {
PartialOrd::lt(*self, *other)
}
#[inline]
fn le(&self, other: &&B) -> bool {
PartialOrd::le(*self, *other)
}
#[inline]
fn gt(&self, other: &&B) -> bool {
PartialOrd::gt(*self, *other)
}
#[inline]
fn ge(&self, other: &&B) -> bool {
PartialOrd::ge(*self, *other)
}
#[inline]
fn __chaining_lt(&self, other: &&B) -> ControlFlow<bool> {
PartialOrd::__chaining_lt(*self, *other)
}
#[inline]
fn __chaining_le(&self, other: &&B) -> ControlFlow<bool> {
PartialOrd::__chaining_le(*self, *other)
}
#[inline]
fn __chaining_gt(&self, other: &&B) -> ControlFlow<bool> {
PartialOrd::__chaining_gt(*self, *other)
}
#[inline]
fn __chaining_ge(&self, other: &&B) -> ControlFlow<bool> {
PartialOrd::__chaining_ge(*self, *other)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: PointeeSized> Ord for &A
where
A: Ord,
{
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
Ord::cmp(*self, *other)
}
macro_rules! partial_eq_impl {
($(($ref_A:ty => $A:ident, $ref_B:ty => $B:ident))*) => ($(
#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
impl<$A, $B> const PartialEq<$ref_B> for $ref_A
where
$A: ~const PartialEq<$B> + PointeeSized,
$B: PointeeSized,
{
#[inline]
fn eq(&self, other: &$ref_B) -> bool {
PartialEq::eq(*self, *other)
}
// if <A as PartialEq<B>>::ne uses inline assembly or FFI, then
// this forwarding impl may be more efficient than the default impl
#[inline]
fn ne(&self, other: &$ref_B) -> bool {
PartialEq::ne(*self, *other)
}
}
)*)
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: PointeeSized> Eq for &A where A: Eq {}

// &mut pointers
partial_eq_impl!((&A => A, &B => B) (&A => A, &mut B => B) (&mut A => A, &B => B) (&mut A => A, &mut B => B));

#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
impl<A: PointeeSized, B: PointeeSized> const PartialEq<&mut B> for &mut A
where
A: ~const PartialEq<B>,
{
#[inline]
fn eq(&self, other: &&mut B) -> bool {
PartialEq::eq(*self, *other)
}
#[inline]
fn ne(&self, other: &&mut B) -> bool {
PartialEq::ne(*self, *other)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: PointeeSized, B: PointeeSized> PartialOrd<&mut B> for &mut A
where
A: PartialOrd<B>,
{
#[inline]
fn partial_cmp(&self, other: &&mut B) -> Option<Ordering> {
PartialOrd::partial_cmp(*self, *other)
}
#[inline]
fn lt(&self, other: &&mut B) -> bool {
PartialOrd::lt(*self, *other)
}
#[inline]
fn le(&self, other: &&mut B) -> bool {
PartialOrd::le(*self, *other)
}
#[inline]
fn gt(&self, other: &&mut B) -> bool {
PartialOrd::gt(*self, *other)
}
#[inline]
fn ge(&self, other: &&mut B) -> bool {
PartialOrd::ge(*self, *other)
}
#[inline]
fn __chaining_lt(&self, other: &&mut B) -> ControlFlow<bool> {
PartialOrd::__chaining_lt(*self, *other)
}
#[inline]
fn __chaining_le(&self, other: &&mut B) -> ControlFlow<bool> {
PartialOrd::__chaining_le(*self, *other)
}
#[inline]
fn __chaining_gt(&self, other: &&mut B) -> ControlFlow<bool> {
PartialOrd::__chaining_gt(*self, *other)
}
#[inline]
fn __chaining_ge(&self, other: &&mut B) -> ControlFlow<bool> {
PartialOrd::__chaining_ge(*self, *other)
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: PointeeSized> Ord for &mut A
where
A: Ord,
{
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
Ord::cmp(*self, *other)
}
macro_rules! partial_ord_impl {
($(($ref_A:ty => $A:ident, $ref_B:ty => $B:ident))*) => ($(
#[stable(feature = "rust1", since = "1.0.0")]
impl<$A, $B> PartialOrd<$ref_B> for $ref_A
where
$A: PartialOrd<$B> + PointeeSized,
$B: PointeeSized,
{
#[inline]
fn partial_cmp(&self, other: &$ref_B) -> Option<Ordering> {
PartialOrd::partial_cmp(*self, *other)
}
#[inline]
fn lt(&self, other: &$ref_B) -> bool {
PartialOrd::lt(*self, *other)
}
#[inline]
fn le(&self, other: &$ref_B) -> bool {
PartialOrd::le(*self, *other)
}
#[inline]
fn gt(&self, other: &$ref_B) -> bool {
PartialOrd::gt(*self, *other)
}
#[inline]
fn ge(&self, other: &$ref_B) -> bool {
PartialOrd::ge(*self, *other)
}
#[inline]
fn __chaining_lt(&self, other: &$ref_B) -> ControlFlow<bool> {
PartialOrd::__chaining_lt(*self, *other)
}
#[inline]
fn __chaining_le(&self, other: &$ref_B) -> ControlFlow<bool> {
PartialOrd::__chaining_le(*self, *other)
}
#[inline]
fn __chaining_gt(&self, other: &$ref_B) -> ControlFlow<bool> {
PartialOrd::__chaining_gt(*self, *other)
}
#[inline]
fn __chaining_ge(&self, other: &$ref_B) -> ControlFlow<bool> {
PartialOrd::__chaining_ge(*self, *other)
}
}
)*)
}
#[stable(feature = "rust1", since = "1.0.0")]
impl<A: PointeeSized> Eq for &mut A where A: Eq {}

#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
impl<A: PointeeSized, B: PointeeSized> const PartialEq<&mut B> for &A
where
A: ~const PartialEq<B>,
{
#[inline]
fn eq(&self, other: &&mut B) -> bool {
PartialEq::eq(*self, *other)
}
#[inline]
fn ne(&self, other: &&mut B) -> bool {
PartialEq::ne(*self, *other)
}
}
partial_ord_impl!((&A => A, &B => B) /*(&A => A, &mut B => B) (&mut A => A, &B => B)*/ (&mut A => A, &mut B => B));

#[stable(feature = "rust1", since = "1.0.0")]
#[rustc_const_unstable(feature = "const_cmp", issue = "143800")]
impl<A: PointeeSized, B: PointeeSized> const PartialEq<&B> for &mut A
where
A: ~const PartialEq<B>,
{
#[inline]
fn eq(&self, other: &&B) -> bool {
PartialEq::eq(*self, *other)
}
#[inline]
fn ne(&self, other: &&B) -> bool {
PartialEq::ne(*self, *other)
}
macro_rules! ord_eq_impl {
($($ref_A:ty => $A:ident),*) => ($(
#[stable(feature = "rust1", since = "1.0.0")]
impl<$A: Ord + PointeeSized> Ord for $ref_A
{
#[inline]
fn cmp(&self, other: &Self) -> Ordering {
Ord::cmp(*self, *other)
}
}

#[stable(feature = "rust1", since = "1.0.0")]
impl<$A: Eq + PointeeSized> Eq for $ref_A {}
)*)
}

ord_eq_impl!(&A => A, &mut A => A);
}
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