diff --git a/library/alloc/src/collections/binary_heap.rs b/library/alloc/src/collections/binary_heap.rs
index b67c72d7136..97ebc12175f 100644
--- a/library/alloc/src/collections/binary_heap.rs
+++ b/library/alloc/src/collections/binary_heap.rs
@@ -495,7 +495,14 @@ impl<T: Ord> BinaryHeap<T> {
         let mut end = self.len();
         while end > 1 {
             end -= 1;
-            self.data.swap(0, end);
+            // SAFETY: `end` goes from `self.len() - 1` to 1 (both included),
+            //  so it's always a valid index to access.
+            //  It is safe to access index 0 (i.e. `ptr`), because
+            //  1 <= end < self.len(), which means self.len() >= 2.
+            unsafe {
+                let ptr = self.data.as_mut_ptr();
+                ptr::swap(ptr, ptr.add(end));
+            }
             self.sift_down_range(0, end);
         }
         self.into_vec()
@@ -531,19 +538,19 @@ impl<T: Ord> BinaryHeap<T> {
         unsafe {
             let mut hole = Hole::new(&mut self.data, pos);
             let mut child = 2 * pos + 1;
-            while child < end {
-                let right = child + 1;
+            while child < end - 1 {
                 // compare with the greater of the two children
-                if right < end && hole.get(child) <= hole.get(right) {
-                    child = right;
-                }
+                child += (hole.get(child) <= hole.get(child + 1)) as usize;
                 // if we are already in order, stop.
                 if hole.element() >= hole.get(child) {
-                    break;
+                    return;
                 }
                 hole.move_to(child);
                 child = 2 * hole.pos() + 1;
             }
+            if child == end - 1 && hole.element() < hole.get(child) {
+                hole.move_to(child);
+            }
         }
     }
 
@@ -563,15 +570,14 @@ impl<T: Ord> BinaryHeap<T> {
         unsafe {
             let mut hole = Hole::new(&mut self.data, pos);
             let mut child = 2 * pos + 1;
-            while child < end {
-                let right = child + 1;
-                // compare with the greater of the two children
-                if right < end && hole.get(child) <= hole.get(right) {
-                    child = right;
-                }
+            while child < end - 1 {
+                child += (hole.get(child) <= hole.get(child + 1)) as usize;
                 hole.move_to(child);
                 child = 2 * hole.pos() + 1;
             }
+            if child == end - 1 {
+                hole.move_to(child);
+            }
             pos = hole.pos;
         }
         self.sift_up(start, pos);