feat: Signed integer division and modulus in brillig gen

[sirasistant]

Removes the signed div opcode since the AVM won't support it and replaces it with the emulated version using unsigned division.

[AztecBot]

Benchmark results

No metrics with a significant change found.

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.

Values are compared against data from master at commit 86e1a864 and shown if the difference exceeds 1%.

L2 block published to L1

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

Metric	8 txs	32 txs	64 txs
l1_rollup_calldata_size_in_bytes	5,668	18,820	36,356
l1_rollup_calldata_gas	66,412	238,744	469,112
l1_rollup_execution_gas	647,510	929,102	1,305,292
l2_block_processing_time_in_ms	1,392 (+9%)	4,938 (+4%)	9,033 (+2%)
note_successful_decrypting_time_in_ms	197 (+11%)	499 (+3%)	954
note_trial_decrypting_time_in_ms	107 (+34%)	116 (+16%)	84.9 (+6%)
l2_block_building_time_in_ms	18,152 (+2%)	68,487	136,065 (+2%)
l2_block_rollup_simulation_time_in_ms	8,078	28,530 (-1%)	56,287 (+3%)
l2_block_public_tx_process_time_in_ms	10,053 (+3%)	39,899	79,680 (+1%)

L2 chain processing

Each column represents the number of blocks on the L2 chain where each block has 16 txs.

Metric	5 blocks	10 blocks
node_history_sync_time_in_ms	14,461 (+4%)	26,599 (-4%)
note_history_successful_decrypting_time_in_ms	1,241 (+1%)	2,442 (-2%)
note_history_trial_decrypting_time_in_ms	94.2 (+50%)	157 (-24%)
node_database_size_in_bytes	19,071,056	35,663,952 (-1%)
pxe_database_size_in_bytes	29,859	59,414

Circuits stats

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

Circuit	circuit_simulation_time_in_ms	circuit_input_size_in_bytes	circuit_output_size_in_bytes
private-kernel-init	282	44,366	28,244
private-kernel-ordering	216 (+1%)	52,868	14,326
base-parity	1,793 (+1%)	128	311
base-rollup	717 (+1%)	165,787	925
root-parity	1,554 (+2%)	1,244	311
root-rollup	63.0 (+1%)	4,487	789
private-kernel-inner	648 (+1%)	73,771	28,244
public-kernel-app-logic	449 (+2%)	35,260	28,215
public-kernel-tail	174 (+2%)	40,926	28,215
merge-rollup	8.32 (+1%)	2,696	925

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	512 leaves	1024 leaves	2048 leaves	4096 leaves	32 leaves
batch_insert_into_append_only_tree_16_depth_ms	10.0 (-1%)	16.0 (+1%)	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_count	16.8	31.6	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_16_depth_hash_ms	0.583	0.495 (+1%)	N/A	N/A	N/A	N/A	N/A	N/A	N/A
batch_insert_into_append_only_tree_32_depth_ms	N/A	N/A	47.0 (+1%)	72.4 (+1%)	234 (+2%)	445	880	1,718 (+4%)	N/A
batch_insert_into_append_only_tree_32_depth_hash_count	N/A	N/A	96.0	159	543	1,055	2,079	4,127	N/A
batch_insert_into_append_only_tree_32_depth_hash_ms	N/A	N/A	0.482 (+1%)	0.447 (+1%)	0.426 (+2%)	0.416	0.418	0.412 (+4%)	N/A
batch_insert_into_indexed_tree_20_depth_ms	N/A	N/A	53.8 (+2%)	107 (+1%)	337 (+1%)	660	1,315 (+1%)	2,598 (+3%)	N/A
batch_insert_into_indexed_tree_20_depth_hash_count	N/A	N/A	104	207	691	1,363	2,707	5,395	N/A
batch_insert_into_indexed_tree_20_depth_hash_ms	N/A	N/A	0.478 (+1%)	0.481 (+1%)	0.458 (+1%)	0.454	0.455 (+1%)	0.453 (+3%)	N/A
batch_insert_into_indexed_tree_40_depth_ms	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	61.1 (+1%)
batch_insert_into_indexed_tree_40_depth_hash_count	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	109
batch_insert_into_indexed_tree_40_depth_hash_ms	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.534 (+1%)

Miscellaneous

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

Metric	0 registered classes
tx_size_in_bytes	22,012

Transaction processing duration by data writes.

Metric	0 new note hashes	1 new note hashes
tx_pxe_processing_time_ms	3,239 (+2%)	1,755 (+1%)

Metric	0 public data writes	1 public data writes
tx_sequencer_processing_time_ms	11.5	1,251 (+2%)

[fcarreiro]

Not for now but it would be great to use RAII if possible in rust!

[sirasistant]

Yeah I've to think if I can use smart pointers to make the automatic drop() the compiler inserts at the end of lifetimes to release automatically scratch registers

[fcarreiro]

For the future: in a small-medium contract you'd be saving a lot of instructions if you just intern/pool the constants. That is, if you set them in a register the first time you see it and then just reuse them. (I guess you cannot know from the SSA if they will be modified, but you can do it for the Brillig-codegen ones).

[sirasistant]

It's a little complicated to do it for all internal functions due to linking the functions together, but still possible!