update 3

calling-convention/Output-explanation.md

@@ -57,3 +57,42 @@ Arguments `g` and `h`, which are 64-bit values, have no registers left and
 are pushed onto the stack instead. `RS` points to 6, reflecting the 4
 caller-saved entries plus 2 stack parameters. After `undo_function_call`,
 all stack entries are cleaned and the result `99` is collected from `RA`.
+
+---
+
+## TEST 3: Boolean arguments
+
+**Function signature:** `ok = func(flag1, flag2, flag3, x)`
+
+**Output:**
+```
+
+===== TEST 3: Boolean arguments =====
+=== State after do_function_call ===
+Registers used: ['RA', 'RB']
+Stack: [{'type': 'caller_saved', 'reg': 'R0', 'value': 0}, {'type': 'caller_saved', 'reg': 'R1', 'value': 0}, {'type': 'caller_saved', 'reg': 'R2', 'value': 0}, {'type': 'caller_saved', 'reg': 'R3', 'value': 0}]
+...
+=== State after undo_function_call ===
+Clean stack: []
+RS: 0
+Collected result: {'ok': {'type': 'result', 'value': True}}
+```
+
+**Explanation:**
+Booleans (1-bit values) are not placed individually into registers.
+Instead they are accumulated into a queue and packed together before
+occupying a single register. The 3 boolean flags (flag1, flag2, flag3)
+are packed together and placed in `RB` as a `bool_pack_padded` entry.
+The regular argument `x` (8 bits) is placed in `RA` as normal.
+No arguments overflow to the stack. After `undo_function_call`, the result
+`True` is successfully collected from `RA`.
+
+---
+
+## General observations
+
+- The stack always starts and ends with the same state, proving the
+  algorithm correctly preserves the machine's previous context.
+- Caller-saved registers (R0-R3) are always pushed before the call
+  and restored after, regardless of the number of arguments.
+- `RS` accurately tracks the stack size at every step.