refactor vm

fix-vm/src/instructions/variables.rs

@@ -0,0 +1,42 @@
+use crate::{BytecodeReader, Mutation, StepResult, Value};
+
+impl<'gc> crate::Vm<'gc> {
+    #[inline(always)]
+    pub(crate) fn op_load_local(&mut self, reader: &mut BytecodeReader<'_>) -> StepResult<'gc> {
+        let idx = reader.read_u32() as usize;
+        self.push_stack(self.env.borrow().locals[idx]);
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_load_outer(&mut self, reader: &mut BytecodeReader<'_>) -> StepResult<'gc> {
+        let layer = reader.read_u8();
+        let idx = reader.read_u32() as usize;
+        let mut cur = self.env;
+        for _ in 0..layer {
+            let prev = cur.borrow().prev.expect("LoadOuter: env chain too short");
+            cur = prev;
+        }
+        let val = cur.borrow().locals[idx];
+        self.push_stack(val);
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_store_local(&mut self, reader: &mut BytecodeReader<'_>, mc: &Mutation<'gc>) -> StepResult<'gc> {
+        let idx = reader.read_u32() as usize;
+        let val = self.pop_stack();
+        self.env.borrow_mut(mc).locals[idx] = val;
+        StepResult::Continue
+    }
+
+    #[inline(always)]
+    pub(crate) fn op_alloc_locals(&mut self, reader: &mut BytecodeReader<'_>, mc: &Mutation<'gc>) -> StepResult<'gc> {
+        let count = reader.read_u32() as usize;
+        self.env
+            .borrow_mut(mc)
+            .locals
+            .extend(std::iter::repeat_n(Value::default(), count));
+        StepResult::Continue
+    }
+}