From 8720cd14e530d6ec45f8a40634a7752cb852cca4 Mon Sep 17 00:00:00 2001
From: Jack O'Connor <jack@jackoconnor.dev>
Date: Fri, 15 Aug 2025 19:11:45 +0100
Subject: [PATCH 1/2] POC: Use Rust's `sort_by` instead of
 `timsort::try_sort_by_gt`
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## Time improvements
**rust-timsort**
(Timing from Linux laptop - I didn't repeat as 16 mins long)
```sh
✦ ❯ time cargo run --release -- -c "from random import random;
sorted([random() for i in range(1_000_000)]); print('DONE');"
    Finished `release` profile [optimized] target(s) in 0.16s
     Running `target/release/rustpython -c 'from random import random;
sorted([random() for i in range(1_000_000)]); print('\''DONE'\'');'`
DONE

real    16m52.217s
user    16m51.926s
sys     0m0.174s
```

**Built-in**
(Timing from MacOS laptop)
```sh
❯ time cargo run --release -- -c "from random import random;
sorted([random() for i in range(1_000_000)]); print('DONE');"
    Finished `release` profile [optimized] target(s) in 0.89s
     Running `target/release/rustpython -c 'from random import random;
sorted([random() for i in range(1_000_000)]); print('\''DONE'\'');'`
DONE
cargo run --release -- -c   0.96s user 0.23s system 54% cpu 2.196 total

```

## Verify list is sorted
```sh
❯ cargo run --release -- -c "from random import random; l =
sorted([random() for i in range(1_000_000)]); print(all(l[i] <= l[i+1]
for i in range(len(l) - 1))               ─╯
);"
TRUE
```

## TODO
- This uses `.unwrap` because I don't know how to handle the error case
- This doesn't use Ordering::Equal so it needs to either be confirmed
that this is a stable sorting algorithm, or else make it stable
---
 vm/src/builtins/list.rs | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/vm/src/builtins/list.rs b/vm/src/builtins/list.rs
index 9a7b589418..dd7b55af1c 100644
--- a/vm/src/builtins/list.rs
+++ b/vm/src/builtins/list.rs
@@ -504,6 +504,7 @@ impl Representable for PyList {
     }
 }
 
+use std::cmp::Ordering;
 fn do_sort(
     vm: &VirtualMachine,
     values: &mut Vec<PyObjectRef>,
@@ -515,17 +516,26 @@ fn do_sort(
     } else {
         PyComparisonOp::Gt
     };
-    let cmp = |a: &PyObjectRef, b: &PyObjectRef| a.rich_compare_bool(b, op, vm);
+    let cmp = |a: &PyObjectRef, b: &PyObjectRef| {
+        let res = a.rich_compare_bool(b, op, vm).unwrap();
+        if res {
+            Ordering::Greater
+        } else {
+            Ordering::Less
+        }
+    };
 
     if let Some(ref key_func) = key_func {
         let mut items = values
             .iter()
             .map(|x| Ok((x.clone(), key_func.call((x.clone(),), vm)?)))
             .collect::<Result<Vec<_>, _>>()?;
-        timsort::try_sort_by_gt(&mut items, |a, b| cmp(&a.1, &b.1))?;
+        // timsort::try_sort_by_gt(&mut items, |a, b| cmp(&a.1, &b.1))?;
+        items.sort_by(|a, b| cmp(&a.1, &b.1));
         *values = items.into_iter().map(|(val, _)| val).collect();
     } else {
-        timsort::try_sort_by_gt(values, cmp)?;
+        // timsort::try_sort_by_gt(values, cmp)?;
+        values.sort_by(|a, b| cmp(a, b));
     }
 
     Ok(())

From 8b909c36c2c228eba2cae91c85a7c61e616947bc Mon Sep 17 00:00:00 2001
From: Jack O'Connor <jack@jackoconnor.dev>
Date: Sat, 16 Aug 2025 17:40:31 +0100
Subject: [PATCH 2/2] POC: Return Ordering::Equal if exception and see what
 happens

---
 vm/src/builtins/list.rs | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/vm/src/builtins/list.rs b/vm/src/builtins/list.rs
index dd7b55af1c..738ded2a31 100644
--- a/vm/src/builtins/list.rs
+++ b/vm/src/builtins/list.rs
@@ -517,11 +517,9 @@ fn do_sort(
         PyComparisonOp::Gt
     };
     let cmp = |a: &PyObjectRef, b: &PyObjectRef| {
-        let res = a.rich_compare_bool(b, op, vm).unwrap();
-        if res {
-            Ordering::Greater
-        } else {
-            Ordering::Less
+        match a.rich_compare_bool(b, op, vm) {
+            Ok(res) => if res { Ordering::Greater } else { Ordering::Less },
+            Err(_) => Ordering::Equal,
         }
     };