From d61ffd6ae4bd93522ff3635097cc16c3fe474d78 Mon Sep 17 00:00:00 2001
From: Ryan Daum <ryan.daum@gmail.com>
Date: Sun, 14 Jan 2024 17:03:51 -0500
Subject: [PATCH] Missed the most important unnecessary .clone() in variable
 setting.

25-30% throughput improvement in for/range and list_append benches.
---
 crates/kernel/src/vm/activation.rs |  2 ++
 crates/kernel/src/vm/exec_state.rs |  2 +-
 crates/kernel/src/vm/vm_execute.rs | 14 ++++----------
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/crates/kernel/src/vm/activation.rs b/crates/kernel/src/vm/activation.rs
index 223b418b..cd8b61f7 100644
--- a/crates/kernel/src/vm/activation.rs
+++ b/crates/kernel/src/vm/activation.rs
@@ -323,6 +323,8 @@ impl Activation {
         assert!(self.pc < self.program.main_vector.len(), "pc out of bounds");
         let op = &self.program.main_vector[self.pc];
         self.pc += 1;
+        // TODO: It would be nice to avoid the clone here, and hold a reference in the execution loop, but
+        //   that leads to borrow issues.
         op.clone()
     }
 
diff --git a/crates/kernel/src/vm/exec_state.rs b/crates/kernel/src/vm/exec_state.rs
index 47ece204..33a069e3 100644
--- a/crates/kernel/src/vm/exec_state.rs
+++ b/crates/kernel/src/vm/exec_state.rs
@@ -205,6 +205,6 @@ impl VMExecState {
     /// Set the value of a local variable.
     #[inline]
     pub(crate) fn set_env(&mut self, id: &Name, v: Var) {
-        self.top_mut().environment.set(id.0 as usize, v.clone());
+        self.top_mut().environment.set(id.0 as usize, v);
     }
 }
diff --git a/crates/kernel/src/vm/vm_execute.rs b/crates/kernel/src/vm/vm_execute.rs
index 7a04fcf4..e85cfdf0 100644
--- a/crates/kernel/src/vm/vm_execute.rs
+++ b/crates/kernel/src/vm/vm_execute.rs
@@ -426,13 +426,13 @@ impl VM {
                     binary_bool_op!(state, <=);
                 }
                 Op::In => {
-                    let lhs = state.pop();
-                    let rhs = state.pop();
+                    let (lhs, rhs) = (state.pop(), state.peek_top());
                     let r = lhs.index_in(&rhs);
                     if let Variant::Err(e) = r.variant() {
+                        state.pop();
                         return self.push_error(state, *e);
                     }
-                    state.push(r);
+                    state.update(0, r);
                 }
                 Op::Mul => {
                     binary_var_op!(self, state, mul);
@@ -764,13 +764,7 @@ impl VM {
                     continue;
                 }
                 Op::Exit { stack, label } => {
-                    return self.unwind_stack(
-                        state,
-                        FinallyReason::Exit {
-                            stack,
-                            label,
-                        },
-                    );
+                    return self.unwind_stack(state, FinallyReason::Exit { stack, label });
                 }
                 Op::Scatter {
                     nargs,