docs: Add bound method latency results to tracking doc.

Signed-off-by: Andrew Leech <[email protected]>

Author: pi-anl

docs/coroutine-implementation.md

@@ -724,27 +724,33 @@ TIM2 @ 10MHz (100ns/tick), NUCLEO_H563ZI @ 250MHz.
 | Callback Type | Counter Method | Avg Ticks | Avg ns |
 |---------------|---------------|-----------|--------|
 | **Direct Viper** |
-| **Viper direct** | **ptr32** | **16** | **1600** |
+| Viper direct | ptr32 | **16** | **1600** |
 | **Functions** |
-| Bytecode func | t.counter() | 27 | 2700 |
-| Bytecode func | mem32[] | 23 | 2300 |
-| Bytecode func | viper_read() | 27 | 2700 |
+| Bytecode func | t.counter() | 26 | 2600 |
+| Bytecode func | mem32[] | 25 | 2500 |
+| Bytecode func | viper_read() | 28 | 2800 |
 | **Generators** |
-| Bytecode gen | t.counter() | 28 | 2800 |
-| Native gen | t.counter() | 25 | 2500 |
+| Bytecode gen | t.counter() | 27 | 2700 |
+| Native gen | t.counter() | 24 | 2400 |
 | Bytecode gen | mem32[] | 24 | 2400 |
-| Native gen | mem32[] | 21 | 2100 |
+| Native gen | mem32[] | **20** | **2000** |
 | Bytecode gen | viper_read() | 28 | 2800 |
+| **Generic Callables** |
+| Bound method | t.counter() | 62 | 6200 |
 
 **Key findings:**
 
 1. **Direct `@viper` callback is fastest** at 16 ticks (1.6µs) - 24% faster than
    @native generators. Requires `array.array` + `uctypes.addressof()` for storage
    since viper can't access Python lists.
-2. **`@native` generator + `mem32[]`** at 21 ticks is fastest for code needing
+2. **`@native` generator + `mem32[]`** at 20 ticks is fastest for code needing
    Python data structure access.
 3. **Calling convention fix was critical** - Previous dispatch used wrong signature
    `(mp_obj_t)` instead of `(fun, n_args, n_kw, args)`. Fixed in 76b5665a07.
+4. **Bound methods are slowest** at 62 ticks (6.2µs) due to generic dispatch via
+   `mp_call_function_1()`. The extra ~36 ticks come from type lookups, args array
+   construction, and multiple function calls through the bound method machinery.
+   Use plain functions or generators when latency matters.
 
 For absolute minimum latency, use direct `@viper` callback with `ptr32()` and
 array-based storage. For easier Python interop, use `@native` generator with