Well, this seems to be working:
float[4] doSimd(float[4] values, float delta) { float4 v_delta = delta;float4 v_values = __simd(XMM.ADDPS, __simd(XMM.LODAPS, values[0]), v_delta); return [v_values[0], v_values[1],v_values[2],v_values[3]]; }
Not sure if it's correct though.