3 files changed, 8 insertions, 7 deletions
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index cb9feb074dd..167a9dd1c36 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -1012,9 +1012,11 @@ mod impls {
             impl Ord for $t {
                 #[inline]
                 fn cmp(&self, other: &$t) -> Ordering {
-                    if *self == *other { Equal }
-                    else if *self < *other { Less }
-                    else { Greater }
+                    // The order here is important to generate more optimal assembly.
+                    // See <https://github.com/rust-lang/rust/issues/63758> for more info.
+                    if *self < *other { Less }
+                    else if *self > *other { Greater }
+                    else { Equal }
                 }
             }
         )*)
diff --git a/src/libcore/iter/adapters/mod.rs b/src/libcore/iter/adapters/mod.rs
index a63434abd6c..f50781890ab 100644
--- a/src/libcore/iter/adapters/mod.rs
+++ b/src/libcore/iter/adapters/mod.rs
@@ -1309,7 +1309,7 @@ impl<I> DoubleEndedIterator for Peekable<I> where I: DoubleEndedIterator {
         Self: Sized, F: FnMut(B, Self::Item) -> R, R: Try<Ok=B>
     {
         match self.peeked.take() {
-            Some(None) => return Try::from_ok(init),
+            Some(None) => Try::from_ok(init),
             Some(Some(v)) => match self.iter.try_rfold(init, &mut f).into_result() {
                 Ok(acc) => f(acc, v),
                 Err(e) => {
@@ -1326,7 +1326,7 @@ impl<I> DoubleEndedIterator for Peekable<I> where I: DoubleEndedIterator {
         where Fold: FnMut(Acc, Self::Item) -> Acc,
     {
         match self.peeked {
-            Some(None) => return init,
+            Some(None) => init,
             Some(Some(v)) => {
                 let acc = self.iter.rfold(init, &mut fold);
                 fold(acc, v)
diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index bfbbb15c8d4..931768564ca 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -3026,8 +3026,7 @@ macro_rules! len {
         if size == 0 {
             // This _cannot_ use `unchecked_sub` because we depend on wrapping
             // to represent the length of long ZST slice iterators.
-            let diff = ($self.end as usize).wrapping_sub(start as usize);
-            diff
+            ($self.end as usize).wrapping_sub(start as usize)
         } else {
             // We know that `start <= end`, so can do better than `offset_from`,
             // which needs to deal in signed.  By setting appropriate flags here