rea/experiments/atomic-codemode/native-engine.md

Native recovered IR experiment

Stock Kuna's diagnostic text omits CFG successors and does not encode operand or phi edge identities. kuna-native-ir.patch is a read-only exploratory exporter against Kuna v1.833. It is not an upstream release or an integrated REA capability. No upstream commit, PR or merge is being made.

decompile --json --atomic-facts captures the live function that produced C. The default path does not collect the facet. Graph records include ordered CFG edges, native value identities, indexed operands, outputs and phi input bindings to particular incoming edges. Duplicate instruction origins or predecessor blocks do not collapse identities. Values are local to one snapshot. Constant offsets remain hexadecimal u64 address-space offsets, with width and annotation status separate; they are not arbitrary-width computed bitvectors.

native-ir.mjs owns validation, immutable indexes and selected reads. control-dependence.mjs derives control dependence using immediate postdominators of the reversed graph, with linear retained graph state and a bounded work count. It treats zero-successor recovered blocks as exits and considers finite paths only. Exit-unreachable blocks, indirect-branch operations, missing definitions, runtime successors and memory alias limitations stay explicit. This is not a proof of feasible runtime paths.

The shared API adds values, blocks and relations(kind:"controllers"). Diagnostic SSA sessions report these missing capabilities explicitly. Native definition/use edges include operand and phi bindings; diagnostic printed occurrences retain their original, weaker semantics. CLI, SDK and both MCP adapters use the same owner. Ordinary source summaries are compact; evidence retains the exact command argv and separate display argv, complete output and digest. Earlier trials substituted display paths in arguments; they must not be retroactively claimed to have captured exact argv.

To reproduce, check out the pinned upstream revision in a disposable directory and apply this patch with git apply. Reuse already compiled .sla files from the corresponding stock release under the same relative specs/ paths; do not recompile specs or replace existing unrelated files. Build from the REA root:

env CARGO_INCREMENTAL=0 CARGO_PROFILE_RELEASE_DEBUG=0 \
  CARGO_PROFILE_RELEASE_OPT_LEVEL=1 CARGO_PROFILE_RELEASE_LTO=false \
  CARGO_PROFILE_RELEASE_CODEGEN_UNITS=16 \
  python3 experiments/analysis-efficiency/resource-run.py --observe-payload-exit -- \
  cargo build --manifest-path /absolute/kuna/decompiler/Cargo.toml \
  --locked --release -j1 -p kuna-cli --features embed-specs

Select that executable through REA_KUNA_COMMAND and explicitly pin its actual SHA-256 through REA_ATOMIC_NATIVE_IR_ENGINE_SHA256. Native IR requires embedded specs and rejects a caller-supplied --sleighpath; the provider creates a fresh owned engine cache per lease. The executable digest therefore covers its embedded assets, without reusing an unvalidated external spec cache. The current prototype uses optimization level 1, not the stock release's assumed optimization profile; comparisons must retain this difference or use the same engine in all lanes.

Native extraction bounds blocks/operations at 12,000, values at 36,000, input and CFG edges at 50,000 and display text at 2 MiB, before the 8 MiB transport bound. Capacity overflow makes this facet unavailable, preserving C and a reason. The provider retains at most two 8 MiB native indexes (two 2 MiB diagnostic indexes) and 64 MiB of complete source captures per lease. The outer observer still enforces one CPU, 4 GiB hard memory and early termination at 3 GiB.

Real Linux zlib verification produced 3,860 operations, 5,898 values, 472 blocks, 779 CFG edges and 790 phi operations. Its 5,533,649-byte native JSON has no omitted definitions or reported producer issues. C is byte-identical to the previously captured stock 1.833 JSON (52,431 characters), and line mappings are identical. The CLI composition independently discovers the string, owning function, store and its two local controllers. Its observed cold session takes 9.191 seconds, 8.887 process-family CPU seconds and 198.9 MiB kernel memory peak, with verified cleanup and zero OOM kills. This scripted lane is not a real-model cost result.

Targeted JS checks cover malformed/foreign identities, dangling relations, phi order, exact hex offsets, immutable facts, loop/exit coverage, resource failure, and all 64 four-node DAGs against an independent path-enumeration oracle. Upstream check-spec passes. The full upstream corpus, stages and workspace gates have not run; this patch is not declared upstream-ready. SQLite, more complex model tasks, paired warm runs and the revised actual model comparison remain required work.

The value-origin model comparison exposed a representation boundary: optimized recovered blocks can absorb a machine predecessor, so an IR edge is not an actual branch instruction target. The experimental API now names operation locations origin_address, their selector origin_addresses, and block locations origin_start; printed CFG targets use target_origin. These replace the old ambiguous fields without aliases. Historical captures retain their pinned old contracts. Raw upstream JSON is preserved unchanged in Evidence.

The added instructions method batches selected machine-address windows, using Kuna's existing disassemble CLI, with exact bytes, decoded text, extent, coverage and per-window errors. Kuna already has focused agent-oriented read surfaces; its port ancestry does not establish which primitives are missing. No assembly decoding or branch-target parser is duplicated in the MCP adapter.

Windows are capped at 4,096 decoded rows and 16 windows per call, sharing the 8 MiB capture and 64 MiB retained-source budgets. A real maximum-row CLI test returns 4,096 rows in an 842,106-byte source, taking 1.227 family wall seconds, 1.042 CPU seconds and 112.0 MiB kernel memory peak. Both real stock and patched MCP tests preserve good windows alongside an unmapped-address failure and report the actual JA 0xe26d / JMP 0xd9c9 bytes. Targeted tests now total 33; the representation fix still requires a fresh real-model task trial.