feat: move out_hash inside tx_effect_hash

[MirandaWood]

In the base rollup circuit, we currently sha hash l2 to l1 messages twice:

• In tree form, to create each tx's out_hash
• Flattened inside the tx_effect_hash

This PR takes the out_hash and inserts it into the tx_effect_hash preimage, to prevent doubling sha hashing. This saves approx 18k gates in base. It increases the gas cost (TBC) as we now have to calculate each tx's out_hash on-chain.
Note that to maintain simplicity of empty blocks/txs, an out_hash for a tx with no l2 to l1 messages is now zero (not H(0, 0) as previously).

[github-actions]

Changes to circuit sizes

Generated at commit: 015b06b58424d047acae7eac4b4a394989f1bd93, compared to commit: e29f042ccfb02f22ef63b3b82f43be2e4388902d

🧾 Summary (100% most significant diffs)

Program	ACIR opcodes (+/-)	%	Circuit size (+/-)	%
rollup_base	-501 ✅	-0.14%	-15,418 ✅	-0.17%

---

Full diff report 👇

Program	ACIR opcodes (+/-)	%	Circuit size (+/-)	%
rollup_base	348,922 (-501)	-0.14%	8,803,876 (-15,418)	-0.17%

[AztecBot]

Benchmark results

Metrics with a significant change:

• avm_simulation_time_ms (AuthRegistry:set_authorized): 6.93 (-38%)
• avm_simulation_time_ms (Token:_increase_public_balance): 51.5 (+320%)
• protocol_circuit_proving_time_in_ms (base-parity): 1,096 (-37%)

Detailed results

All benchmarks are run on txs on the Benchmarking contract on the repository. Each tx consists of a batch call to create_note and increment_balance, which guarantees that each tx has a private call, a nested private call, a public call, and a nested public call, as well as an emitted private note, an unencrypted log, and public storage read and write.

This benchmark source data is available in JSON format on S3 here.

Proof generation

Each column represents the number of threads used in proof generation.

Metric	1 threads	4 threads	16 threads	32 threads	64 threads
proof_construction_time_sha256_ms	5,794	1,566	711	739 (-6%)	774
proof_construction_time_sha256_30_ms	11,884	3,198	1,413	1,448	1,473 (+1%)
proof_construction_time_sha256_100_ms	44,274	12,542	5,705 (+1%)	5,625 (+1%)	5,489
proof_construction_time_poseidon_hash_ms	78.0	34.0	34.0	59.0 (+2%)	87.0 (-1%)
proof_construction_time_poseidon_hash_30_ms	1,536	422	201	234 (+4%)	268 (-1%)
proof_construction_time_poseidon_hash_100_ms	5,690	1,539	678 (-1%)	736 (-2%)	753

L2 block published to L1

Each column represents the number of txs on an L2 block published to L1.

Metric	4 txs	8 txs	16 txs
l1_rollup_calldata_size_in_bytes	4,324	7,844	14,852
l1_rollup_calldata_gas	49,660	92,480	177,548
l1_rollup_execution_gas	1,284,857 (-1%)	2,018,573 (-1%)	3,803,697 (-2%)
l2_block_processing_time_in_ms	259	454	833
l2_block_building_time_in_ms	9,494	18,747	37,096
l2_block_rollup_simulation_time_in_ms	9,493	18,746	37,096
l2_block_public_tx_process_time_in_ms	7,901	16,909	35,205

L2 chain processing

Each column represents the number of blocks on the L2 chain where each block has 8 txs.

Metric	3 blocks	5 blocks
node_history_sync_time_in_ms	3,006 (+1%)	4,003
node_database_size_in_bytes	12,738,640	16,937,040
pxe_database_size_in_bytes	16,254	26,813

Circuits stats

Stats on running time and I/O sizes collected for every kernel circuit run across all benchmarks.

Circuit	simulation_time_in_ms	witness_generation_time_in_ms	input_size_in_bytes	output_size_in_bytes	proving_time_in_ms	proof_size_in_bytes	num_public_inputs	size_in_gates
private-kernel-init	95.2 (-4%)	393	21,846	44,858	N/A	N/A	N/A	N/A
private-kernel-inner	175 (-1%)	691 (-1%)	72,545	45,005	N/A	N/A	N/A	N/A
private-kernel-tail	667 (-1%)	748 (-1%)	52,710	52,256	N/A	N/A	N/A	N/A
base-parity	5.97 (-2%)	570 (-5%)	160	96.0	⚠️ 1,096 (-37%)	13,188	19.0	65,536
root-parity	108 (-2%)	125 (-4%)	69,084	96.0	30,669 (-2%)	13,188	19.0	4,194,304
base-rollup	2,967	5,453 (-4%)	187,824	664	101,615 (+1%)	14,020	45.0	16,777,216
root-rollup	96.8 (-1%)	117 (+2%)	54,525	716	28,504 (+1%)	13,988	44.0	4,194,304
public-kernel-setup	90.9 (-3%)	2,790 (+1%)	104,025	71,222	17,984 (+2%)	129,220	3,645	2,097,152
public-kernel-app-logic	105 (-1%)	4,060 (-2%)	104,025	71,222	10,277 (+1%)	129,220	3,645	1,048,576
public-kernel-tail	567 (-1%)	30,575 (-1%)	409,190	16,414	106,844 (-2%)	34,308	679	16,777,216
private-kernel-reset-tiny	193 (-2%)	830 (-1%)	68,621	44,750	N/A	N/A	N/A	N/A
private-kernel-tail-to-public	2,277 (+1%)	1,512 (-1%)	931,564	1,697	N/A	N/A	N/A	N/A
public-kernel-teardown	85.8 (-4%)	4,171	104,025	71,222	18,907	129,220	3,645	2,097,152
merge-rollup	59.3 (-1%)	N/A	35,742	664	N/A	N/A	N/A	N/A
undefined	N/A	N/A	N/A	N/A	68,898 (-1%)	N/A	N/A	N/A

Stats on running time collected for app circuits

Function	input_size_in_bytes	output_size_in_bytes	witness_generation_time_in_ms	proof_size_in_bytes	proving_time_in_ms
ContractClassRegisterer:register	1,344	11,731	340 (-2%)	N/A	N/A
ContractInstanceDeployer:deploy	1,408	11,731	18.1 (-1%)	N/A	N/A
MultiCallEntrypoint:entrypoint	1,920	11,731	475 (-1%)	N/A	N/A
FeeJuice:deploy	1,376	11,731	388 (-1%)	N/A	N/A
SchnorrAccount:constructor	1,312	11,731	176 (-1%)	N/A	N/A
SchnorrAccount:entrypoint	2,304	11,731	535	N/A	N/A
Token:privately_mint_private_note	1,280	11,731	216 (-3%)	N/A	N/A
FPC:fee_entrypoint_public	1,344	11,731	27.3 (+19%)	N/A	N/A
Token:transfer	1,312	11,731	415 (+1%)	N/A	N/A
AuthRegistry:set_authorized (avm)	18,491	N/A	N/A	146,400	2,137
FPC:prepare_fee (avm)	22,958	N/A	N/A	146,464	2,516 (+2%)
Token:transfer_public (avm)	61,614	N/A	N/A	146,464	10,473 (+1%)
AuthRegistry:consume (avm)	41,719	N/A	N/A	146,432	5,002 (+1%)
FPC:pay_refund (avm)	26,227	N/A	N/A	146,432	4,802 (-2%)
Benchmarking:create_note	1,344	11,731	170 (+1%)	N/A	N/A
SchnorrAccount:verify_private_authwit	1,280	11,731	32.8 (+14%)	N/A	N/A
Token:unshield	1,376	11,731	631 (-12%)	N/A	N/A
FPC:fee_entrypoint_private	1,376	11,731	842 (-8%)	N/A	N/A

AVM Simulation

Time to simulate various public functions in the AVM.

Function	time_ms	bytecode_size_in_bytes
FeeJuice:_increase_public_balance	94.8	8,139
FeeJuice:set_portal	10.3 (-8%)	2,362
Token:constructor	120 (-7%)	31,107
FPC:constructor	94.0 (-3%)	22,380
FeeJuice:mint_public	78.3 (-5%)	6,150
Token:mint_public	92.7 (+10%)	11,720
Token:assert_minter_and_mint	79.4 (-13%)	8,028
AuthRegistry:set_authorized	⚠️ 6.93 (-38%)	4,537
FPC:prepare_fee	271 (-7%)	8,812
Token:transfer_public	39.4 (-11%)	47,374
FPC:pay_refund	63.2 (-5%)	12,114
Benchmarking:increment_balance	1,014	7,450
Token:_increase_public_balance	⚠️ 51.5 (+320%)	8,960
FPC:pay_refund_with_shielded_rebate	140 (-6%)	12,663

Public DB Access

Time to access various public DBs.

Function	time_ms
get-nullifier-index	0.161 (-3%)

Tree insertion stats

The duration to insert a fixed batch of leaves into each tree type.

Metric	1 leaves	16 leaves	64 leaves	128 leaves	256 leaves	512 leaves	1024 leaves
batch_insert_into_append_only_tree_16_depth_ms	2.15 (-2%)	3.87 (-1%)	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_count	16.8	31.7	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_ms	0.111 (-2%)	0.109 (-1%)	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_32_depth_ms	N/A	N/A	11.3 (-2%)	18.2 (+3%)	31.2 (+1%)	60.6	118 (+1%)
batch_insert_into_append_only_tree_32_depth_hash_count	N/A	N/A	95.9	159	287	543	1,055
batch_insert_into_append_only_tree_32_depth_hash_ms	N/A	N/A	0.108 (-2%)	0.106 (+3%)	0.101	0.104 (-1%)	0.105
batch_insert_into_indexed_tree_20_depth_ms	N/A	N/A	14.5	26.1 (-2%)	44.3 (+1%)	84.4 (+1%)	177 (+7%)
batch_insert_into_indexed_tree_20_depth_hash_count	N/A	N/A	109	207	355	691	1,363
batch_insert_into_indexed_tree_20_depth_hash_ms	N/A	N/A	0.109	0.105 (-1%)	0.102 (-4%)	0.105 (+1%)	0.113 (+10%)
batch_insert_into_indexed_tree_40_depth_ms	N/A	N/A	16.5 (-1%)	N/A	N/A	N/A	N/A
batch_insert_into_indexed_tree_40_depth_hash_count	N/A	N/A	132	N/A	N/A	N/A	N/A
batch_insert_into_indexed_tree_40_depth_hash_ms	N/A	N/A	0.106 (-1%)	N/A	N/A	N/A	N/A

Miscellaneous

Transaction sizes based on how many contract classes are registered in the tx.

Metric	0 registered classes	1 registered classes
tx_size_in_bytes	64,756	668,997

Transaction size based on fee payment method

| Metric | |
| - | |

[LeilaWang]

Nice!