DSP Builder version 17.1, attribute "preserve_syn_only"

Hello

I just updated my quartus version from 16.1 to 17.1, including the DSP builder. In my DSP builder design I use a division block. If I compile the *.vhd files from the DSP builder in my Quartus project, I receive the following warning:

Warning (10335): Unrecognized synthesis attribute "preserve_syn_only" at DSPbuilderFiles/completeSystem_wyssj_dut_prim.vhd(1391)

(and some more of the same typ). The corresponding line in the vhd file is

attribute preserve_syn_only of redist17_r_uid542_zCount_uid415_completeSystem_wyssj_dut_prim_dq2Mangle_getM_Divide2_x_q_17_sticky_ena_q : signal is true;

In the old file (created with DSP builder 16.1), the corresponding line reads

attribute preserve of redist4_r_uid542_zCount_uid415_completeSystem_wyssj_dut_prim_dq2Mangle_getM_Divide2_x_q_17_sticky_ena_q : signal is true;

So the change from 16.1 to 17.1 is that the attribute changes from "preserve" to "preserve_syn_only" which however is not recognized by Quartus. Therefore I'd like to ask:

1. Can I ignore this warning?

2. If not, can I just manually change all the attributes "preserve_syn_only" to "preserve"?

3. Why does DSP builder creates a file with instructions the quartus compiler does not recognize? The softwares are delivered in the same package and should be compatible!

All the best

Jonas