1 files changed, 8 insertions, 0 deletions
diff --git a/src/block.rs b/src/block.rs
index bde60fc..0e64bbe 100644
--- a/src/block.rs
+++ b/src/block.rs
@@ -148,6 +148,14 @@ impl BitXor<Block> for Block {
 impl Shl<u32> for Block {
     type Output = Block;
     fn shl(self, rhs: u32) -> Block {
+        // We often use a shift by one, for example in the multiplication. We therefore optimize
+        // for this special case.
+        #[cfg(feature = "simd")]
+        {
+            if rhs == 1 {
+                return Block((self.0 << 1) | (self.0.shift_elements_left::<1>(0) >> 7));
+            }
+        }
         Block::from(self.to_int() << rhs)
     }
 }