From 1b6c7a8efac031b2b7a965a67fff38a6f2f89c5f Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Wed, 4 Feb 2026 01:28:25 +0000
Subject: [PATCH] Optimize vector usage in Multiplicator setup

Replaced `vec.append(&mut slice.to_vec())` with `vec.extend_from_slice(slice)` in `crates/fhe/src/bfv/ops/mul.rs`.
This avoids allocating a temporary vector for the slice content before moving it to the destination vector.

Measured performance impact:
- Baseline: ~17.04 ms
- Optimized: ~17.43 ms
- Difference is within noise threshold, but the change avoids unnecessary allocation.

Co-authored-by: tlepoint <1345502+tlepoint@users.noreply.github.com>
---
 crates/fhe/src/bfv/ops/mul.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/fhe/src/bfv/ops/mul.rs b/crates/fhe/src/bfv/ops/mul.rs
index e473e192..7ca23722 100644
--- a/crates/fhe/src/bfv/ops/mul.rs
+++ b/crates/fhe/src/bfv/ops/mul.rs
@@ -107,7 +107,7 @@ impl Multiplicator {
         let n_moduli = (modulus_size + 60).div_ceil(62);
 
         let mut extended_basis = Vec::with_capacity(ctx.moduli().len() + n_moduli);
-        extended_basis.append(&mut ctx.moduli().to_vec());
+        extended_basis.extend_from_slice(ctx.moduli());
         let mut upper_bound = 1 << 62;
         while extended_basis.len() != ctx.moduli().len() + n_moduli {
             upper_bound = generate_prime(62, 2 * rk.ksk.par.degree() as u64, upper_bound).unwrap();