## PR-09 — HIP ISA Freeze v0: Opcode Table + Encoding Contract (Bytecode)

### Goal

Freeze the HIP-related opcode set and encoding so bytecode becomes stable.

### Required Changes

1. Update `prometeu-bytecode`:

* Define the canonical HIP opcode subset:

    * `PUSH_CONST`
    * `ALLOC(type_id, slots)`
    * `GATE_BEGIN_PEEK`, `GATE_END_PEEK`
    * `GATE_BEGIN_BORROW`, `GATE_END_BORROW`
    * `GATE_BEGIN_MUTATE`, `GATE_END_MUTATE`
    * `GATE_LOAD(offset)`
    * `GATE_STORE(offset)`
    * `GATE_RETAIN`, `GATE_RELEASE`
    * `FRAME_SYNC` (if included)

2. Define canonical encodings (normative in comments/doc):

* `GateId` encoding: `u32` little-endian
* `TypeId` encoding: `u32` little-endian
* `ConstId` encoding: `u32` little-endian
* `slots`: `u32` little-endian
* `offset`: `u32` little-endian

3. Update bytecode emitter so it emits these exact opcodes with these exact payloads.

### Non-goals

* No runtime execution changes

### Tests (Mandatory)

1. **Golden bytecode tests**:

* Given a minimal VM IR program using each HIP opcode, assert the exact emitted bytes.

2. **Opcode stability test**:

* Snapshot test of the opcode enum ordering and numeric values.

> If opcode numeric values already exist, DO NOT renumber. If new opcodes are added, append them.

---

## PR-10 — HIP ABI Freeze v0: Trap Conditions + Debug Surface

### Goal

Freeze the runtime-visible ABI behavior for HIP operations.

### Required Content (Normative)

Add a document (or module-level docs) defining traps:

* Invalid `GateId` → trap `TRAP_INVALID_GATE`
* Dead gate access → trap `TRAP_DEAD_GATE`
* Out-of-bounds offset (`offset >= slots`) → trap `TRAP_OOB`
* Type mismatch (if enforced) → trap `TRAP_TYPE`

Define what a trap includes:

* opcode
* message
* optional span (if debug info is present)

### Required Changes

* Add trap codes/constants in bytecode/VM interface.
* Ensure bytecode format reserves space / structure for propagating trap info.

### Tests (Mandatory)

* Unit tests verifying trap codes are stable (numeric values frozen).
* Doc tests or snapshot for ABI text.

---

## PR-11 — Cross-Layer Conformance Tests: Core→VM→Bytecode (HIP)

### Goal

Prove end-to-end determinism and stability.

### Required Tests

1. PBS snippet (or Core IR fixture) that:

* allocates a storage struct
* mutates a field
* peeks value

Assert:

* VM IR contains:

    * `Alloc(type_id, slots)`
    * `GateBeginMutate/EndMutate`
    * `GateStore(offset)`
    * `GateBeginPeek/EndPeek`
    * `GateLoad(offset)`
    * RC ops (retain/release)

2. Bytecode golden output for the same program:

* assert the exact bytes match the frozen ISA/ABI.

### Non-goals

* No runtime execution

---

## STOP POINT (Hard Gate)

* HIP access is fully deterministic
* RC events are explicit and testable
* HIP ISA/ABI v0 is frozen with golden bytecode tests

Only after this point may we implement/tune:

* Gate Pool
* Heap allocation
* RC counters + safe point reclaim
* Traps at runtime