feat: Make Brillig do integer arithmetic operations using u128 instead of Bigint

[sirasistant]

This PR:

• Restricts Brillig bit sizes to the ones supported by noir and the AVM
• Avoids using BigInteger, using u128 to represent integers in brillig instead
• Fixes a bug in truncate discovered by making bit size an enum
• Removes truncation in brillig_directive_quotient that wasn't needed anymore

This generates a big performance boost, where this test spent 110 seconds running the ACVM before, and 34 seconds after this change.

Before:

After:

[fcarreiro]

LGTM for AVM

[guipublic]

here also I think the behaviour is different from Noir.
We should error if rhs >= bit_size

[sirasistant]

Cool, will change that!

[sirasistant]

Ah, no, we already check that in SSA:

unconstrained fn main(value: u32, shift_by: u8) -> pub u32 {
    value << shift_by
}

After Array Set Optimizations:
brillig fn main f0 {
  b0(v0: u32, v1: u8):
    v10 = shl v0, v1
    v11 = lt v1, u8 2⁵
    constrain v11 == u1 1 '"attempt to bit-shift with overflow"'
    return v10
}

This was probably not erroring before either in the brillig vm because the AVM has wrapping operations, not checked ones, so we check at the SSA level

[guipublic]

here too

[sirasistant]

Same as the above

[TomAFrench]

Will look at this a bit later.

[AztecBot]

⚠️ Performance Alert ⚠️

Possible performance regression was detected for benchmark 'C++ Benchmark'.
Benchmark result of this commit is worse than the previous benchmark result exceeding threshold 1.05.

Benchmark suite	Current: 456690b	Previous: 6efd2b4	Ratio
nativeconstruct_proof_ultrahonk_power_of_2/20	5479.907323000006 ms/iter	4754.443381000002 ms/iter	1.15
wasmconstruct_proof_ultrahonk_power_of_2/20	16378.270112999999 ms/iter	14250.740961999998 ms/iter	1.15

This comment was automatically generated by workflow using github-action-benchmark.

CC: @ludamad @codygunton

[AztecBot]

Benchmark results

Metrics with a significant change:

• app_circuit_witness_generation_time_in_ms (GasToken:deploy): 488 (-18%)
• protocol_circuit_simulation_time_in_ms (private-kernel-inner): 172 (-31%)
• protocol_circuit_simulation_time_in_ms (private-kernel-tail): 371 (-67%)
• protocol_circuit_simulation_time_in_ms (base-rollup): 3,255 (-23%)
• protocol_circuit_simulation_time_in_ms (public-kernel-setup): 101 (-49%)
• protocol_circuit_simulation_time_in_ms (public-kernel-app-logic): 106 (-30%)
• protocol_circuit_simulation_time_in_ms (public-kernel-tail): 627 (-30%)
• protocol_circuit_simulation_time_in_ms (private-kernel-reset-tiny): 227 (-23%)
• protocol_circuit_simulation_time_in_ms (public-kernel-teardown): 91.9 (-35%)
• avm_simulation_time_ms (Token:mint_public): 288 (+395%)
• avm_simulation_time_ms (Token:assert_minter_and_mint): 49.5 (-30%)
• avm_simulation_time_ms (AuthRegistry:set_authorized): 11.3 (-75%)
• avm_simulation_time_ms (FPC:prepare_fee): 140 (+36%)
• avm_simulation_time_ms (Token:transfer_public): 46.7 (+36%)
• avm_simulation_time_ms (Benchmarking:increment_balance): 994 (-24%)
• avm_simulation_time_ms (Token:_increase_public_balance): 87.5 (+370%)
• protocol_circuit_witness_generation_time_in_ms (private-kernel-tail-to-public): 1,366 (-53%)
• protocol_circuit_witness_generation_time_in_ms (private-kernel-tail): 830 (-67%)
• protocol_circuit_witness_generation_time_in_ms (base-parity): 639 (-23%)
• protocol_circuit_proving_time_in_ms (public-kernel-setup): 18,102 (+16%)
• protocol_circuit_proving_time_in_ms (public-kernel-app-logic): 10,120 (+16%)
• l2_block_building_time_in_ms (4): 10,293 (-22%)
• l2_block_building_time_in_ms (8): 20,030 (-22%)
• l2_block_building_time_in_ms (16): 39,518 (-22%)
• l2_block_rollup_simulation_time_in_ms (4): 10,293 (-22%)
• l2_block_rollup_simulation_time_in_ms (8): 20,030 (-22%)
• l2_block_rollup_simulation_time_in_ms (16): 39,517 (-22%)
• l2_block_public_tx_process_time_in_ms (4): 8,581 (-22%)
• l2_block_public_tx_process_time_in_ms (8): 18,132 (-22%)
• l2_block_public_tx_process_time_in_ms (16): 37,552 (-23%)

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	5,713	1,538 (-1%)	702 (-1%)	760	768 (-1%)
proof_construction_time_sha256_30_ms	11,673 (-1%)	3,129 (-1%)	1,402 (-1%)	1,433 (-1%)	1,463 (-1%)
proof_construction_time_sha256_100_ms	43,659 (-1%)	11,931	5,408 (-1%)	5,397	5,329 (-1%)
proof_construction_time_poseidon_hash_ms	78.0	34.0	34.0 (-21%)	57.0 (-12%)	86.0 (-4%)
proof_construction_time_poseidon_hash_30_ms	1,515	415	200	226 (-3%)	265 (-2%)
proof_construction_time_poseidon_hash_100_ms	5,595 (-1%)	1,513	689 (+1%)	740 (+2%)	747 (-1%)

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	708	708	708
l1_rollup_calldata_gas	6,588	6,592	6,600
l1_rollup_execution_gas	583,050	583,205	583,364
l2_block_processing_time_in_ms	765 (+2%)	1,427	2,730
l2_block_building_time_in_ms	⚠️ 10,293 (-22%)	⚠️ 20,030 (-22%)	⚠️ 39,518 (-22%)
l2_block_rollup_simulation_time_in_ms	⚠️ 10,293 (-22%)	⚠️ 20,030 (-22%)	⚠️ 39,517 (-22%)
l2_block_public_tx_process_time_in_ms	⚠️ 8,581 (-22%)	⚠️ 18,132 (-22%)	⚠️ 37,552 (-23%)

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	7,059 (-1%)	10,013
node_database_size_in_bytes	12,746,832	16,941,136
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	94.8 (-18%)	392 (-5%)	21,744	54,085	N/A	N/A	N/A	N/A
private-kernel-inner	⚠️ 172 (-31%)	659 (-11%)	81,209	54,264	N/A	N/A	N/A	N/A
private-kernel-tail	⚠️ 371 (-67%)	⚠️ 830 (-67%)	61,565	62,127	N/A	N/A	N/A	N/A
base-parity	6.51 (-1%)	⚠️ 639 (-23%)	160	96.0	1,412 (+6%)	12,676	3.00	131,072
root-parity	106 (-3%)	120 (-2%)	64,860	96.0	30,694 (+10%)	12,676	3.00	4,194,304
base-rollup	⚠️ 3,255 (-23%)	4,970 (-4%)	181,083	632	45,133 (+10%)	13,476	28.0	4,194,304
root-rollup	151 (-2%)	124 (+11%)	51,261	652	28,712 (+13%)	13,412	26.0	4,194,304
public-kernel-setup	⚠️ 101 (-49%)	2,440 (+3%)	113,048	80,822	⚠️ 18,102 (+16%)	119,428	3,339	2,097,152
public-kernel-app-logic	⚠️ 106 (-30%)	3,365 (+1%)	113,048	80,822	⚠️ 10,120 (+16%)	119,428	3,339	1,048,576
public-kernel-tail	⚠️ 627 (-30%)	26,987 (+14%)	410,181	10,814	67,517 (+9%)	25,860	415	8,388,608
private-kernel-reset-tiny	⚠️ 227 (-23%)	894 (-14%)	77,005	53,954	N/A	N/A	N/A	N/A
private-kernel-tail-to-public	5,041 (+2%)	⚠️ 1,366 (-53%)	773,216	1,632	N/A	N/A	N/A	N/A
public-kernel-teardown	⚠️ 91.9 (-35%)	3,331 (+1%)	113,048	80,822	18,454 (+14%)	119,428	3,339	2,097,152
merge-rollup	57.4 (-1%)	N/A	33,566	632	N/A	N/A	N/A	N/A
undefined	N/A	N/A	N/A	N/A	174,193	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	1,312	9,344	360 (-10%)	N/A	N/A
ContractInstanceDeployer:deploy	1,376	9,344	24.9 (-2%)	N/A	N/A
MultiCallEntrypoint:entrypoint	1,888	9,344	564 (-12%)	N/A	N/A
GasToken:deploy	1,344	9,344	⚠️ 488 (-18%)	N/A	N/A
SchnorrAccount:constructor	1,280	9,344	430 (-8%)	N/A	N/A
SchnorrAccount:entrypoint	2,272	9,344	731 (-9%)	N/A	N/A
Token:privately_mint_private_note	1,248	9,344	509 (-10%)	N/A	N/A
FPC:fee_entrypoint_public	1,312	9,344	98.4 (-5%)	N/A	N/A
Token:transfer	1,280	9,344	1,350 (-12%)	N/A	N/A
AuthRegistry:set_authorized (avm)	19,222	N/A	N/A	95,392	2,193 (-10%)
FPC:prepare_fee (avm)	22,670	N/A	N/A	95,456	2,253 (-8%)
Token:transfer_public (avm)	42,914	N/A	N/A	95,456	3,128 (-1%)
AuthRegistry:consume (avm)	33,100	N/A	N/A	95,424	2,789 (-3%)
FPC:pay_refund (avm)	32,835	N/A	N/A	95,424	8,988 (+11%)
Benchmarking:create_note	1,312	9,344	421 (-7%)	N/A	N/A
SchnorrAccount:verify_private_authwit	1,248	9,344	41.4	N/A	N/A
Token:unshield	1,344	9,344	1,164 (-4%)	N/A	N/A
FPC:fee_entrypoint_private	1,344	9,344	1,527 (-5%)	N/A	N/A

AVM Simulation

Time to simulate various public functions in the AVM.

Function	time_ms	bytecode_size_in_bytes
GasToken:_increase_public_balance	101 (+1%)	13,790
GasToken:set_portal	11.5 (+1%)	3,339
Token:constructor	123 (-1%)	23,692
FPC:constructor	91.3 (-2%)	13,592
GasToken:mint_public	81.3 (-1%)	10,158
Token:mint_public	⚠️ 288 (+395%)	19,034
Token:assert_minter_and_mint	⚠️ 49.5 (-30%)	12,925
AuthRegistry:set_authorized	⚠️ 11.3 (-75%)	7,812
FPC:prepare_fee	⚠️ 140 (+36%)	11,068
Token:transfer_public	⚠️ 46.7 (+36%)	31,218
FPC:pay_refund	125 (+2%)	21,266
Benchmarking:increment_balance	⚠️ 994 (-24%)	11,281
Token:_increase_public_balance	⚠️ 87.5 (+370%)	15,006
FPC:pay_refund_with_shielded_rebate	176	22,361

Public DB Access

Time to access various public DBs.

Function	time_ms
get-nullifier-index	0.163 (+7%)

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	10.4	16.7	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	0.601 (-1%)	0.514 (-1%)	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_32_depth_ms	N/A	N/A	48.1 (-1%)	76.4 (+1%)	131	247 (+1%)	472
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	0.491 (-1%)	0.469 (+1%)	0.451 (+1%)	0.447 (+1%)	0.441 (+1%)
batch_insert_into_indexed_tree_20_depth_ms	N/A	N/A	60.0	111	183 (+1%)	354	701 (+1%)
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	0.506	0.499	0.484 (+1%)	0.479	0.482 (+1%)
batch_insert_into_indexed_tree_40_depth_ms	N/A	N/A	73.1	N/A	N/A	N/A	N/A
batch_insert_into_indexed_tree_40_depth_hash_count	N/A	N/A	133	N/A	N/A	N/A	N/A
batch_insert_into_indexed_tree_40_depth_hash_ms	N/A	N/A	0.520	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	77,362	668,542

Transaction size based on fee payment method

| Metric | |
| - | |