fix bug

extensions/native/compiler/src/constraints/halo2/baby_bear.rs

@@ -152,19 +152,16 @@ impl BabyBearChip {
             );
             // the inner product above must equal `a`
             ctx.constrain_equal(&a, &acc);
-            let r =
-                self.gate()
-                    .inner_product(ctx, limbs, self.cached_limbs_r[..num_limbs].to_vec());
             // we fetch the cells to lookup by getting the indices where `limbs` were assigned in `inner_product`. Because `limb_bases[0]` is 1, the progression of indices is 0,1,4,...,4+3*i
             self.add_cell_to_lookup(ctx, ctx.get(row_offset));
             for i in 0..num_limbs - 1 {
                 self.add_cell_to_lookup(ctx, ctx.get(row_offset + 1 + 3 * i as isize));
             }
-            (
-                ctx.get(row_offset + 1 + 3 * (num_limbs - 2) as isize),
-                r,
-                self.extra_bits + lookup_bits,
-            )
+            let last_limb = ctx.get(row_offset + 1 + 3 * (num_limbs - 2) as isize);
+            let r =
+                self.gate()
+                    .inner_product(ctx, limbs, self.cached_limbs_r[..num_limbs].to_vec());
+            (last_limb, r, self.extra_bits + lookup_bits)
         };
 
         // additional constraints for the last limb if rem_bits != 0