Flat FRI layers array

m-kus · m-kus · commit 8a277fbe9f6f · 2025-09-25T13:27:17.000+01:00
diff --git a/stwo-verifier/Makefile b/stwo-verifier/Makefile
@@ -4,10 +4,10 @@ WIT_FILE=../target/proof.wit
 test:
 	bash ../scripts/unit_tests.sh --debug
 
-proof-simf:
+proof-test:
 	python3 scripts/generate_simf.py tests/data/proof.json > ../target/proof.simf
 
-proof-wit:
+proof:
 	python3 scripts/generate_wit.py tests/data/proof.json > $(WIT_FILE)
 
 build:
diff --git a/stwo-verifier/scripts/generate_simf.py b/stwo-verifier/scripts/generate_simf.py
@@ -146,9 +146,18 @@ def main() -> None:
     # FRI config and commitments
     fri = data["fri_proof"]
     # n_queries defined above
-    first_commitment_b = bytes32_from_list(fri["first_layer"]["commitment"]) if isinstance(fri["first_layer"]["commitment"], list) else bytes(fri["first_layer"]["commitment"])
-    inner_layers = fri.get("inner_layers", [])
-    inner_commitments_b = [bytes32_from_list(layer["commitment"]) for layer in inner_layers]
+    layers = fri.get("layers")
+    if layers is not None:
+        layer_commitments_b = [
+            bytes32_from_list(layer["commitment"]) if isinstance(layer["commitment"], list) else bytes(layer["commitment"])  # type: ignore[arg-type]
+            for layer in layers
+        ]
+    else:
+        # Backward compatibility: separate first + inner
+        first_commitment_b = bytes32_from_list(fri["first_layer"]["commitment"]) if isinstance(fri["first_layer"]["commitment"], list) else bytes(fri["first_layer"]["commitment"])  # type: ignore[arg-type]
+        inner_layers = fri.get("inner_layers", [])
+        inner_commitments_b = [bytes32_from_list(layer["commitment"]) for layer in inner_layers]
+        layer_commitments_b = [first_commitment_b] + inner_commitments_b
 
     # Last layer polynomial coefficients (QM31 list)
     last_layer_poly = fri["last_layer_poly"]
@@ -187,35 +196,27 @@ def main() -> None:
     cp_oods_str = "[" + ", ".join(fmt_qm31(q) for q in cp_oods_qm31) + "]"
     oods_evals_str = f"(\n        {trace_oods_str},\n        {cp_oods_str},\n    )"
 
-    # FRI commitments (no alphas): (u256, List<u256, MAX_FRI_LAYERS>, LinePoly)
-    first_commitment_str = u256_hex(u256_from_bytes_be(first_commitment_b))
-    inner_commitments_str = "[" + ", ".join(u256_hex(u256_from_bytes_be(c_b)) for c_b in inner_commitments_b) + "]"
+    # FRI commitments (unified): ([u256; NUM_FRI_LAYERS], LinePoly)
+    commitments_arr_str = "[" + ", ".join(u256_hex(u256_from_bytes_be(c_b)) for c_b in layer_commitments_b) + "]"
     last_layer_str = fmt_qm31(last_coeffs_qm31)
-    fri_commitments_str = f"(\n        {first_commitment_str},\n        {inner_commitments_str},\n        {last_layer_str},\n    )"
+    fri_commitments_str = f"(\n        {commitments_arr_str},\n        {last_layer_str},\n    )"
 
-    # FRI decommitments: (FriLayerDecommitment, [FriLayerDecommitment; NUM_FRI_LAYERS])
-    first_layer = fri["first_layer"]
-    first_layer_decommitment_str = indent(parse_fri_layer_decommitment(first_layer, n_queries), 8)
-    inner_layer_decommitments_strs = [parse_fri_layer_decommitment(layer, n_queries) for layer in inner_layers]
-    inner_layers_block = (
-        "[\n"
-        + ",\n".join(indent(s, 8) for s in inner_layer_decommitments_strs)
-        + "\n    ]"
-    )
+    # FRI decommitments (unified array)
+    fri_layers_list = layers if layers is not None else [fri["first_layer"]] + inner_layers
+    fri_layer_decommitments_strs = [parse_fri_layer_decommitment(layer, n_queries) for layer in fri_layers_list]
+    fri_decommitments_inner = ",\n".join(indent(s, 8) for s in fri_layer_decommitments_strs)
     fri_decommitments_str = (
-        "(\n"
-        + first_layer_decommitment_str
-        + ",\n"
-        + indent(inner_layers_block, 4)
-        + "\n    )"
+        "[\n"
+        + "        " + fri_decommitments_inner + "\n"
+        + "    ]"
     )
 
     # PoW nonce
     pow_nonce = int(data.get("proof_of_work", 0))
 
     # Assemble final proof
     proof_str = (
-        "let proof: Proof = (\n"
+        "let proof: StarkProof = (\n"
         f"    {commitments_str},\n"
         f"    {decommitments_str},\n"
         f"    {oods_evals_str},\n"
diff --git a/stwo-verifier/scripts/generate_wit.py b/stwo-verifier/scripts/generate_wit.py
@@ -87,9 +87,9 @@ def build_types(cols: int, col_offsets: int, cp_parts: int, n_queries: int, n_la
 
     FriQueryDecommitment = f"({QM31}, {MerkleProof32})"
     FriLayerDecommitment = f"[{FriQueryDecommitment}; {n_queries}]"
-    FriDecommitments = f"({FriLayerDecommitment}, [{FriLayerDecommitment}; {n_layers}])"
+    FriDecommitments = f"[{FriLayerDecommitment}; {n_layers}]"
 
-    FriCommitments = f"(u256, [u256; {n_layers}], {QM31})"
+    FriCommitments = f"([u256; {n_layers}], {QM31})"
 
     Commitments = "(u256, u256, u256)"
 
@@ -175,16 +175,25 @@ def build_witness_from_json(data: Dict[str, Any]) -> Dict[str, Dict[str, str]]:
         )
     decommitments_list_val = "[" + ", ".join(decommitment_items) + "]"
 
-    # FRI config and commitments
+    # FRI config and commitments (unified layers array with fallback)
     fri = data["fri_proof"]
-    # n_queries already determined above
-    first_commitment_b = bytes32_from_list(fri["first_layer"]["commitment"]) if isinstance(fri["first_layer"]["commitment"], list) else bytes(fri["first_layer"]["commitment"])
-    inner_layers = fri.get("inner_layers", [])
-    n_layers: int = len(inner_layers)
-    inner_commitments_b = [bytes32_from_list(layer["commitment"]) for layer in inner_layers]
-
-    first_commitment_val = u256_hex(u256_from_bytes_be(first_commitment_b))
-    inner_commitments_val = "[" + ", ".join(u256_hex(u256_from_bytes_be(c_b)) for c_b in inner_commitments_b) + "]"
+    layers = fri.get("layers")
+    if layers is not None:
+        n_layers: int = len(layers)
+        layer_commitments_b = [
+            bytes32_from_list(layer["commitment"]) if isinstance(layer["commitment"], list) else bytes(layer["commitment"])  # type: ignore[arg-type]
+            for layer in layers
+        ]
+        fri_layers_for_decomm = layers
+    else:
+        first_commitment_b = bytes32_from_list(fri["first_layer"]["commitment"]) if isinstance(fri["first_layer"]["commitment"], list) else bytes(fri["first_layer"]["commitment"])  # type: ignore[arg-type]
+        inner_layers = fri.get("inner_layers", [])
+        n_layers = 1 + len(inner_layers)
+        inner_commitments_b = [bytes32_from_list(layer["commitment"]) for layer in inner_layers]
+        layer_commitments_b = [first_commitment_b] + inner_commitments_b
+        fri_layers_for_decomm = [fri["first_layer"]] + inner_layers
+
+    commitments_arr_val = "[" + ", ".join(u256_hex(u256_from_bytes_be(c_b)) for c_b in layer_commitments_b) + "]"
 
     # Last layer polynomial coefficients (QM31 list of one)
     last_layer_poly = fri["last_layer_poly"]
@@ -193,14 +202,11 @@ def build_witness_from_json(data: Dict[str, Any]) -> Dict[str, Dict[str, str]]:
     last_coeffs_qm31 = parse_qm31_from_json(coeffs_json[0])
     last_layer_val = qm31_value_str(last_coeffs_qm31)
 
-    fri_commitments_val = f"({first_commitment_val}, {inner_commitments_val}, {last_layer_val})"
+    fri_commitments_val = f"({commitments_arr_val}, {last_layer_val})"
 
-    # FRI decommitments: first + inner
-    first_layer = fri["first_layer"]
-    first_layer_decommitment_val = parse_fri_layer_decommitment(first_layer, n_queries)
-    inner_layer_decommitments_vals = [parse_fri_layer_decommitment(layer, n_queries) for layer in inner_layers]
-    inner_layers_block_val = "[" + ", ".join(inner_layer_decommitments_vals) + "]"
-    fri_decommitments_val = f"({first_layer_decommitment_val}, {inner_layers_block_val})"
+    # FRI decommitments: unified array over layers
+    fri_layer_decommitments_vals = [parse_fri_layer_decommitment(layer, n_queries) for layer in fri_layers_for_decomm]
+    fri_decommitments_val = "[" + ", ".join(fri_layer_decommitments_vals) + "]"
 
     # PoW nonce
     pow_nonce = int(data.get("proof_of_work", 0))
diff --git a/stwo-verifier/src/config.simf b/stwo-verifier/src/config.simf
@@ -14,29 +14,29 @@
 #define NUM_COLUMNS 4
 
 #ifdef TESTING
-    #define TRACE_LOG_SIZE 3
+    #define TRACE_LOG_SIZE 2
 
     /// Log size of the extended evaluation domain.
     /// trace log size + log blowup factor
-    #define LDE_LOG_SIZE 4
+    #define LDE_LOG_SIZE 3
 
     /// Number of FRI queries.
     /// NOTE: must be power of 2 (temporarily, because array macros work for power of 2 sizes only)
-    #define NUM_FRI_QUERIES 1
+    #define NUM_FRI_QUERIES 2
     
-    /// Number of FRI inner layers (depends on the trace size).
+    /// Number of FRI layers except the last one (depends on the trace size).
     /// NOTE: must be power of 2 (temporarily, because array macros work for power of 2 sizes only)
     #define NUM_FRI_LAYERS 2
 
     /// The target for the proof of work.
     #define POW_TARGET_64 0x07ffffffffffffff // 5 bits
 
 #else
-    #define TRACE_LOG_SIZE 9
+    #define TRACE_LOG_SIZE 8
 
     /// Log size of the extended evaluation domain.
     /// trace log size + log blowup factor
-    #define LDE_LOG_SIZE 13
+    #define LDE_LOG_SIZE 12
 
     /// Number of FRI queries.
     /// NOTE: must be power of 2 (temporarily, because array macros work for power of 2 sizes only)
diff --git a/stwo-verifier/src/evals/verify.simf b/stwo-verifier/src/evals/verify.simf
@@ -84,7 +84,7 @@ DEFINE_ZIP_ARR(query_decommitments, u32, Decommitment, 16, 8)
 /// Zip queries with decommitments to get query decommitments (u32, Decommitment).
 fn query_decommitments_zip_arr(queries: [u32; NUM_FRI_QUERIES], decommitments: [Decommitment; NUM_FRI_QUERIES]) -> [QueryDecommitment; NUM_FRI_QUERIES] {
 #ifdef TESTING
-    query_decommitments_zip_arr_1(queries, decommitments)
+    query_decommitments_zip_arr_2(queries, decommitments)
 #else
     query_decommitments_zip_arr_16(queries, decommitments)
 #endif // TESTING
@@ -101,7 +101,7 @@ DEFINE_MAP_ARR(QueryDecommitment, QueryResponse, QueryDecommitmentCtx, verify_qu
 /// Map query decommitments to query responses.
 fn verify_query_map_arr(query_decommitments: [QueryDecommitment; NUM_FRI_QUERIES], ctx: QueryDecommitmentCtx) -> ([QueryResponse; NUM_FRI_QUERIES], QueryDecommitmentCtx) {
 #ifdef TESTING
-    verify_query_map_arr_1(query_decommitments, ctx)
+    verify_query_map_arr_2(query_decommitments, ctx)
 #else
     verify_query_map_arr_16(query_decommitments, ctx)
 #endif // TESTING
diff --git a/stwo-verifier/src/fri/answers.simf b/stwo-verifier/src/fri/answers.simf
@@ -140,7 +140,7 @@ DEFINE_MAP_ARR(QueryResponse, FriAnswer, QueryResponseCtx, fri_answer, 16, 8)
 /// Map query responses to FRI answers.
 fn fri_answer_map_arr(responses: [QueryResponse; NUM_FRI_QUERIES], ctx: QueryResponseCtx) -> ([FriAnswer; NUM_FRI_QUERIES], QueryResponseCtx) {
 #ifdef TESTING
-    fri_answer_map_arr_1(responses, ctx)
+    fri_answer_map_arr_2(responses, ctx)
 #else
     fri_answer_map_arr_16(responses, ctx)
 #endif // TESTING
diff --git a/stwo-verifier/src/fri/commit.simf b/stwo-verifier/src/fri/commit.simf
@@ -13,10 +13,9 @@
 #include "macros/array_map.simf"
 
 /// FRI commitments:
-/// * first layer commitment
-/// * inner layers commitments
+/// * first and inner layers commitments
 /// * last layer: line polynomial coefficient (always degree 0)
-type FriCommitments = (u256, [u256; NUM_FRI_LAYERS], QM31);
+type FriCommitments = ([u256; NUM_FRI_LAYERS], QM31);
 
 /// FRI layer:
 /// * commitment
@@ -27,7 +26,7 @@ type FriLayer = (u256, QM31);
 /// * first layer
 /// * inner layers
 /// * last layer: line polynomial coefficient (always degree 0)
-type FriLayers = (FriLayer, [FriLayer; NUM_FRI_LAYERS], QM31);
+type FriLayers = ([FriLayer; NUM_FRI_LAYERS], QM31);
 
 /// Reads the FRI layer commitment and samples a random coefficient.
 /// Fails if the computed FRI layer evaluation does not match the pre-sampled FRI layer evaluation.
@@ -43,12 +42,12 @@ fn fri_layer_commit(root: u256, state: ChannelState) -> (FriLayer, ChannelState)
 }
 
 /// Mix line polynomial coefficients into the channel state.
-fn channel_mix_line_poly(state: ChannelState, last_layer: QM31) -> ChannelState {
+fn channel_mix_line_poly(state: ChannelState, line_poly_coeff: QM31) -> ChannelState {
     let (digest, _): ChannelState = state;
     let ctx: Ctx8 = jet::sha_256_ctx_8_init();
     let ctx: Ctx8 = jet::sha_256_ctx_8_add_32(ctx, digest);
     // Mix coefficients
-    let ctx: Ctx8 = hasher_add_qm31(last_layer, ctx);
+    let ctx: Ctx8 = hasher_add_qm31(line_poly_coeff, ctx);
     let res: u256 = jet::sha_256_ctx_8_finalize(ctx);
     // Reset the num_sent counter
     (res, 0)
@@ -70,38 +69,31 @@ fn fri_layer_commit_map_arr(commitments: [u256; NUM_FRI_LAYERS], state: ChannelS
 
 /// Commits the FRI layers.
 fn fri_commit(state: ChannelState, fri_commitments: FriCommitments) -> (ChannelState, FriLayers) {
-    let (first_commitment, inner_commitments, last_layer): FriCommitments = fri_commitments;
+    let (commitments, line_poly_coeff): FriCommitments = fri_commitments;
 
-    // Commit first layer
-    let (first_layer, state): (FriLayer, ChannelState) = fri_layer_commit(first_commitment, state);
-
-    // Commit inner layers
-    let (inner_layers, state): ([FriLayer; NUM_FRI_LAYERS], ChannelState) = fri_layer_commit_map_arr(inner_commitments, state);
+    // Commit first and inner layers
+    let (layers, state): ([FriLayer; NUM_FRI_LAYERS], ChannelState) = fri_layer_commit_map_arr(commitments, state);
 
     // Commit last layer (line polynomial coefficients)
-    let state: ChannelState = channel_mix_line_poly(state, last_layer);
+    let state: ChannelState = channel_mix_line_poly(state, line_poly_coeff);
 
-    (state, (first_layer, inner_layers, last_layer))
+    (state, (layers, line_poly_coeff))
 }
 
 #ifdef TESTING
 
 fn test_fri_commit() {
-    let state: ChannelState = (0x44dff4effae0be493c21672683c892b3baeaa7d251e5e7153bc0e0b2da8a9d96, 0);
+    let state: ChannelState = (0x28583eb83f6fe4837a995243e8e5c2648edbfd9cdd06262edcbce47fe96e5e3c, 0);
     let fri_commitments: FriCommitments = (
-        0x768a89291d8db4be401f5545f1cc7f25a1b00753773a4b3789592badc33ecf3f,
-        [
-            0x3f2a2cb1b0384b1ddd57c16bb40b67a0b011c1449606196e959fdbff885a0280,
-            0xb03eededd1682fcab8c82d0d284ccf0f8ddc7d003708ecd12323adfd843f0f5f,
-        ],
-        qm31(1462473176, 2065988908, 1080482792, 1497677558),
+        [0x0bee0d98d63597a3b6725c885e77c23647585e29ae3ebd3b3b88bdba21f30f13, 0xd63312459c0bd0456789cce101ab292880c3bf103514eb22bd7457808388423e],
+        qm31(502777192, 1639915013, 504572960, 826242631),
     );
     let ((digest, _), layers): (ChannelState, FriLayers) = fri_commit(state, fri_commitments);
-    assert!(jet::eq_256(digest, 0xa906adfe1ac2b7cf283ae8a11e16a1c4c44834f259056eacd36d14044761266c));
+    assert!(jet::eq_256(digest, 0x3532bad0c22ceae1a8c9e137dfde35b18e8bd4a08ce6c5e64ea3d9465a517f82));
 
-    let (first_layer, _, _): FriLayers = layers;
-    let (_, first_alpha): FriLayer = first_layer;
-    assert!(qm31_eq(first_alpha, qm31(299390734, 1867715474, 641071780, 899293580)));
+    let (layers, _): FriLayers = layers;
+    let ((_, first_alpha), _): (FriLayer, FriLayer) = <[FriLayer; NUM_FRI_LAYERS]>::into(layers);
+    assert!(qm31_eq(first_alpha, qm31(766788992, 1201991280, 1148418600, 2122329945)));
 }
 
 #endif // TESTING
diff --git a/stwo-verifier/src/fri/queries.simf b/stwo-verifier/src/fri/queries.simf
@@ -31,7 +31,7 @@ fn fri_generate_queries(state: ChannelState, log_size: u8) -> (ChannelState, [u3
     let (state, (q0, q1, q2, q3, q4, q5, q6, q7)): (ChannelState, U32x8) = channel_draw_queries_8(state, query_mask);
 
 #ifdef TESTING
-    let queries: [u32; NUM_FRI_QUERIES] = dbg!([q0]);
+    let queries: [u32; NUM_FRI_QUERIES] = dbg!([q0, q1]);
 #else
     let (state, (q8, q9, q10, q11, q12, q13, q14, q15)): (ChannelState, U32x8) = channel_draw_queries_8(state, query_mask);
     // CONFIG: see NUM_FRI_QUERIES
diff --git a/stwo-verifier/src/fri/verify.simf b/stwo-verifier/src/fri/verify.simf
diff --git a/stwo-verifier/src/verifier.simf b/stwo-verifier/src/verifier.simf
diff --git a/stwo-verifier/tests/data/proof.json b/stwo-verifier/tests/data/proof.json
diff --git a/stwo-verifier/tests/data/proof_test.json b/stwo-verifier/tests/data/proof_test.json
