vm: add send_none fastpath for generator specialization

youknowone · youknowone · commit 3e92a7a07303 · 2026-03-05T20:37:16.000+09:00
diff --git a/crates/vm/src/coroutine.rs b/crates/vm/src/coroutine.rs
@@ -115,27 +115,12 @@ impl Coro {
         result
     }
 
-    pub fn send(
+    fn finalize_send_result(
         &self,
         jen: &PyObject,
-        value: PyObjectRef,
+        result: PyResult<ExecutionResult>,
         vm: &VirtualMachine,
     ) -> PyResult<PyIterReturn> {
-        if self.closed.load() {
-            return Ok(PyIterReturn::StopIteration(None));
-        }
-        self.frame.locals_to_fast(vm)?;
-        let value = if self.frame.lasti() > 0 {
-            Some(value)
-        } else if !vm.is_none(&value) {
-            return Err(vm.new_type_error(format!(
-                "can't send non-None value to a just-started {}",
-                gen_name(jen, vm),
-            )));
-        } else {
-            None
-        };
-        let result = self.run_with_context(jen, vm, |f| f.resume(value, vm));
         self.maybe_close(&result);
         match result {
             Ok(exec_res) => Ok(exec_res.into_iter_return(vm)),
@@ -158,6 +143,44 @@ impl Coro {
         }
     }
 
+    pub(crate) fn send_none(&self, jen: &PyObject, vm: &VirtualMachine) -> PyResult<PyIterReturn> {
+        if self.closed.load() {
+            return Ok(PyIterReturn::StopIteration(None));
+        }
+        self.frame.locals_to_fast(vm)?;
+        let value = if self.frame.lasti() > 0 {
+            Some(vm.ctx.none())
+        } else {
+            None
+        };
+        let result = self.run_with_context(jen, vm, |f| f.resume(value, vm));
+        self.finalize_send_result(jen, result, vm)
+    }
+
+    pub fn send(
+        &self,
+        jen: &PyObject,
+        value: PyObjectRef,
+        vm: &VirtualMachine,
+    ) -> PyResult<PyIterReturn> {
+        if self.closed.load() {
+            return Ok(PyIterReturn::StopIteration(None));
+        }
+        self.frame.locals_to_fast(vm)?;
+        let value = if self.frame.lasti() > 0 {
+            Some(value)
+        } else if !vm.is_none(&value) {
+            return Err(vm.new_type_error(format!(
+                "can't send non-None value to a just-started {}",
+                gen_name(jen, vm),
+            )));
+        } else {
+            None
+        };
+        let result = self.run_with_context(jen, vm, |f| f.resume(value, vm));
+        self.finalize_send_result(jen, result, vm)
+    }
+
     pub fn throw(
         &self,
         jen: &PyObject,
diff --git a/crates/vm/src/frame.rs b/crates/vm/src/frame.rs
@@ -3120,7 +3120,11 @@ impl ExecutingFrame<'_> {
                 let receiver = self.top_value();
                 let ret = if can_fast_send {
                     let coro = self.builtin_coro(receiver).unwrap();
-                    coro.send(receiver, val, vm)?
+                    if vm.is_none(&val) {
+                        coro.send_none(receiver, vm)?
+                    } else {
+                        coro.send(receiver, val, vm)?
+                    }
                 } else {
                     self._send(receiver, val, vm)?
                 };
@@ -5301,7 +5305,7 @@ impl ExecutingFrame<'_> {
                         self.execute_for_iter(vm, target)?;
                         return Ok(None);
                     }
-                    match generator.as_coro().send(iter, vm.ctx.none(), vm) {
+                    match generator.as_coro().send_none(iter, vm) {
                         Ok(PyIterReturn::Return(value)) => {
                             self.push_value(value);
                         }
