chore(l2): implement ecadd with substrate for ZisK and SP1 #5535
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Lines of code reportTotal lines added: Detailed view |
Benchmark Results ComparisonNo significant difference was registered for any benchmark run. Detailed ResultsBenchmark Results: BubbleSort
Benchmark Results: ERC20Approval
Benchmark Results: ERC20Mint
Benchmark Results: ERC20Transfer
Benchmark Results: Factorial
Benchmark Results: FactorialRecursive
Benchmark Results: Fibonacci
Benchmark Results: FibonacciRecursive
Benchmark Results: ManyHashes
Benchmark Results: MstoreBench
Benchmark Results: Push
Benchmark Results: SstoreBench_no_opt
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Pull request overview
This PR implements the ecadd precompile using substrate-bn for ZisK and SP1 zkVMs to improve performance. The benchmarks show a 0.13-0.48% reduction in steps across tested blocks.
- Refactors the existing
ecaddfunction to extract point addition logic into a newbn254_g1_addhelper function - Provides two feature-gated implementations of
bn254_g1_add: one usingarkworks(default) and one usingsubstrate-bn(for sp1/zisk features) - Updates coordinate validation to use helper functions (
parse_bn254_g1andvalidate_bn254_g1_coords)
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| #[cfg(any(feature = "sp1", feature = "zisk"))] | ||
| #[inline] | ||
| pub fn bn254_g1_add(first_point: G1, second_point: G1) -> Result<Bytes, VMError> { | ||
| use substrate_bn::{AffineG1, Fq, G1, Group}; |
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[nitpick] The import of substrate_bn::G1 shadows the custom G1 struct defined at line 946. While this works because the import is scoped to this function, it could be confusing for readers. Consider using a qualified import or type alias for clarity:
use substrate_bn::{AffineG1, Fq, Group};
use substrate_bn::G1 as SubstrateG1;Then use SubstrateG1 instead of G1 in the function body (lines 833, 837).
Comment on lines
+785
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+817
| if first_point.is_zero() { | ||
| let (g1_x, g1_y) = ( | ||
| Fq::from_slice(&second_point.0.to_big_endian()) | ||
| .map_err(|_| PrecompileError::ParsingInputError)?, | ||
| Fq::from_slice(&second_point.1.to_big_endian()) | ||
| .map_err(|_| PrecompileError::ParsingInputError)?, | ||
| ); | ||
| // Validate that the point is on the curve | ||
| AffineG1::new(g1_x, g1_y).map_err(|_| PrecompileError::InvalidPoint)?; | ||
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| let mut x_bytes = [0u8; 32]; | ||
| let mut y_bytes = [0u8; 32]; | ||
| g1_x.to_big_endian(&mut x_bytes); | ||
| g1_y.to_big_endian(&mut y_bytes); | ||
| return Ok(Bytes::from([x_bytes, y_bytes].concat())); | ||
| } | ||
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|
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| if second_point.is_zero() { | ||
| let (g1_x, g1_y) = ( | ||
| Fq::from_slice(&first_point.0.to_big_endian()) | ||
| .map_err(|_| PrecompileError::ParsingInputError)?, | ||
| Fq::from_slice(&first_point.1.to_big_endian()) | ||
| .map_err(|_| PrecompileError::ParsingInputError)?, | ||
| ); | ||
| // Validate that the point is on the curve | ||
| AffineG1::new(g1_x, g1_y).map_err(|_| PrecompileError::InvalidPoint)?; | ||
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| let mut x_bytes = [0u8; 32]; | ||
| let mut y_bytes = [0u8; 32]; | ||
| g1_x.to_big_endian(&mut x_bytes); | ||
| g1_y.to_big_endian(&mut y_bytes); | ||
| return Ok(Bytes::from([x_bytes, y_bytes].concat())); | ||
| } |
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The logic for handling first_point.is_zero() (lines 785-800) and second_point.is_zero() (lines 802-817) is duplicated. This could be extracted into a helper function that converts a G1 point to bytes while validating it's on the curve. This would reduce code duplication and improve maintainability.
Example:
fn g1_point_to_bytes(point: &G1) -> Result<Bytes, VMError> {
let (g1_x, g1_y) = (
Fq::from_slice(&point.0.to_big_endian())
.map_err(|_| PrecompileError::ParsingInputError)?,
Fq::from_slice(&point.1.to_big_endian())
.map_err(|_| PrecompileError::ParsingInputError)?,
);
// Validate that the point is on the curve
AffineG1::new(g1_x, g1_y).map_err(|_| PrecompileError::InvalidPoint)?;
let mut x_bytes = [0u8; 32];
let mut y_bytes = [0u8; 32];
g1_x.to_big_endian(&mut x_bytes);
g1_y.to_big_endian(&mut y_bytes);
Ok(Bytes::from([x_bytes, y_bytes].concat()))
}Then use:
if first_point.is_zero() {
return g1_point_to_bytes(&second_point);
}
if second_point.is_zero() {
return g1_point_to_bytes(&first_point);
}
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To use the patched substrate-bn of both zkVMs.
Benchmarks for ZisK:
main (7722c65):
zisk_ecadd:
diff in steps: