perf(levm): remove duplicate subgroup check in ecpairing precompile

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 - Instead of lazy computation of blocklist, do greedy computation of allowlist and store the result, fetch it with the DB. [#4961](https://github.com/lambdaclass/ethrex/pull/4961)
 
+### 2025-10-20
+
+- Remove duplicate subgroup check in ecpairing precompile [#4960](https://github.com/lambdaclass/ethrex/pull/4960)
+
 ### 2025-10-17
 
 - Replaces incremental iteration with a one-time precompute method that scans the entire bytecode, building a `BitVec<u8, Msb0>` where bits mark valid `JUMPDEST` positions, skipping `PUSH1..PUSH32` data bytes.
@@ -17,7 +21,6 @@
 
 ### 2025-10-13
 
-
 - Remove explicit cache-related options from RocksDB configuration and reverted optimistic transactions to reduce RAM usage [#4853](https://github.com/lambdaclass/ethrex/pull/4853)
 - Remove unnecesary mul in ecpairing [#4843](https://github.com/lambdaclass/ethrex/pull/4843)
 

crates/vm/levm/src/errors.rs

@@ -198,8 +198,6 @@ pub enum PrecompileError {
     PointNotInTheCurve,
     #[error("The point is not in the subgroup")]
     PointNotInSubgroup,
-    #[error("BN254 ate pairing error")]
-    BN254AtePairingError,
     #[error("The G1 point is not in the curve")]
     BLS12381G1PointNotInCurve,
     #[error("The G2 point is not in the curve")]

crates/vm/levm/src/precompiles.rs

@@ -894,6 +894,8 @@ pub fn pairing_check(batch: &[(G1, G2)]) -> Result<bool, VMError> {
 #[cfg(not(feature = "sp1"))]
 #[inline]
 pub fn pairing_check(batch: &[(G1, G2)]) -> Result<bool, VMError> {
+    use lambdaworks_math::errors::PairingError;
+
     type Fq = BN254FieldElement;
     type Fq2 = BN254TwistCurveFieldElement;
     type LambdaworksG1 = BN254Curve;
@@ -936,18 +938,11 @@ pub fn pairing_check(batch: &[(G1, G2)]) -> Result<bool, VMError> {
             LambdaworksG2::create_point_from_affine(g2_x, g2_y)
                 .map_err(|_| PrecompileError::InvalidPoint)?
         };
-        if !g2.is_in_subgroup() {
-            return Err(PrecompileError::PointNotInSubgroup.into());
-        }
-
-        if g1.is_neutral_element() || g2.is_neutral_element() {
-            continue;
-        }
         valid_batch.push((g1, g2));
     }
     let valid_batch_refs: Vec<_> = valid_batch.iter().map(|(p1, p2)| (p1, p2)).collect();
     let result = BN254AtePairing::compute_batch(&valid_batch_refs)
-        .map_err(|_| PrecompileError::BN254AtePairingError)?;
+        .map_err(|PairingError::PointNotInSubgroup| PrecompileError::PointNotInSubgroup)?;
 
     Ok(result == QuadraticExtensionFieldElement::one())
 }