Only vectorize on block algo

src/targets/gpu/jit/fused_reduce.cpp

@@ -119,16 +119,14 @@ struct fused_reduce_compiler : compiler<fused_reduce_compiler>
         options.virtual_inputs = virtual_inputs;
         auto faxis             = find_fast_axis({options.virtual_inputs.front()});
         vectorize vec{};
-        // Vectorize if the axis is a reduction axis
-        if(options.virtual_inputs.back().lens()[faxis] == 1)
-        {
-            vec = vectorize::elements(ctx, faxis, options.virtual_inputs);
-        }
-        auto relements = reduced_shape.elements() / vec.size;
         auto nelements = options.virtual_inputs.back().elements();
         auto algo = v.get("algo", get_reduce_algo(options.virtual_inputs, reduced_shape.lens()));
         if(algo == "block")
         {
+            // Vectorize if the axis is a reduction axis
+            if(options.virtual_inputs.back().lens()[faxis] == 1)
+                vec = vectorize::elements(ctx, faxis, options.virtual_inputs);
+            auto relements = reduced_shape.elements() / vec.size;
             auto block_size = compute_block_size(relements, 256);
             options.set_launch_params(
                 v, compute_global_for(ctx, nelements * block_size, 256), block_size);