refactor: Symbol/Iter/Profiling 子结构方法下沉，IC helper 完成提取

crates/oxide_vm/src/ic_helper.rs

@@ -1,15 +1,26 @@
 //! Inline-cache (IC) bytecode-stream helpers.
 //!
-//! These operate purely on the bytecode `Instr` slice — they read/clear/write
-//! the IC extension words embedded after IC-bearing opcodes. They take no `Vm`
-//! state, so they live outside `Vm` for clearer ownership and to ease the future
-//! IC side-table migration.
+//! Contains ALL IC read/write/clear logic — property dispatch and member
+//! update handlers route through here, so IC format changes (like the future
+//! side-table migration) require editing only this file.
 
 use oxide_bytecode::opcode::{self, Instr};
+use oxide_types::object::JsObject;
+use oxide_types::value::JsValue;
+
+/// Read the three IC extension words at `pc` (the bytes following an
+/// IC-bearing opcode), advance `pc` past them, and return the decoded
+/// `(shape_id, slot)`.
+pub(crate) fn read_ic_entry(bytecode: &[Instr], pc: &mut usize) -> (u32, u32) {
+    let ext0 = bytecode[*pc];
+    let ext1 = bytecode[*pc + 1];
+    *pc += 3;
+    (ext0 & 0x00FF_FFFF, ext1)
+}
 
 /// Write a resolved `(shape_id, slot)` back into the three IC extension words
-/// that precede the current `pc`. Called on an IC miss after resolving a
-/// property, so the next execution of this site hits the cache.
+/// at `pc - 3` (they precede the current instruction). Called on an IC miss
+/// after resolving a property, so the next execution of this site hits the cache.
 pub(crate) fn write_ic_back(bytecode: &mut [Instr], pc: usize, shape_id: u32, slot_index: u32) {
     debug_assert!(pc >= 3, "IC write-back requires 3 extension words before pc");
     bytecode[pc - 3] = shape_id & 0x00FF_FFFF;
@@ -35,3 +46,22 @@ pub(crate) fn clear_ic_caches(bytecode: &mut [Instr]) {
         }
     }
 }
+
+#[inline(always)]
+pub(crate) fn ic_get_hit(obj: &JsObject, shape_id: u32, slot_index: u32) -> Option<JsValue> {
+    if shape_id != 0 && obj.shape_id() == shape_id && slot_index < obj.prop_vec_len() as u32 {
+        Some(obj.get_prop_at(slot_index))
+    } else {
+        None
+    }
+}
+
+#[inline(always)]
+pub(crate) fn ic_set_hit(obj: &mut JsObject, shape_id: u32, slot_index: u32, value: JsValue) -> bool {
+    if shape_id != 0 && obj.shape_id() == shape_id && slot_index < obj.prop_vec_len() as u32 {
+        obj.set_prop_at(slot_index, value);
+        true
+    } else {
+        false
+    }
+}