请问ISE 中fifo编译MAP警告怎么消除？？？

windycraze

WARNINGack:2874 - Trimming timing constraints from pin
   gtx_module_inst/gtx_to_fifo_ip_inst/U0/xst_fifo_generator/gconvfifo.rf/grf.rf
   /gntv_or_sync_fifo.mem/gbm.gbmg.gbmga.ngecc.bmg/gnativebmg.native_blk_mem_gen
   /valid.cstr/ramloop[7].ram.r/v5_noinit.ram/SDP.SINGLE_PRIM36.TDP
   of frag REGCLKAL connected to power/ground net
   gtx_module_inst/gtx_to_fifo_ip_inst/U0/xst_fifo_generator/gconvfifo.rf/grf.rf
   /gntv_or_sync_fifo.mem/gbm.gbmg.gbmga.ngecc.bmg/gnativebmg.native_blk_mem_gen
   /valid.cstr/ramloop[7].ram.r/v5_noinit.ram/SDP.SINGLE_PRIM36.TDP_REGCLKAL_tie
   sig
WARNINGack:2874 - Trimming timing constraints from pin
   gtx_module_inst/gtx_to_fifo_ip_inst/U0/xst_fifo_generator/gconvfifo.rf/grf.rf
   /gntv_or_sync_fifo.mem/gbm.gbmg.gbmga.ngecc.bmg/gnativebmg.native_blk_mem_gen
   /valid.cstr/ramloop[7].ram.r/v5_noinit.ram/SDP.SINGLE_PRIM36.TDP
   of frag REGCLKBU connected to power/ground net
   gtx_module_inst/gtx_to_fifo_ip_inst/U0/xst_fifo_generator/gconvfifo.rf/grf.rf
   /gntv_or_sync_fifo.mem/gbm.gbmg.gbmga.ngecc.bmg/gnativebmg.native_blk_mem_gen
   /valid.cstr/ramloop[7].ram.r/v5_noinit.ram/SDP.SINGLE_PRIM36.TDP_REGCLKBU_tie
   sig
WARNINGack:2874 - Trimming timing constraints from pin
   gtx_module_inst/gtx_to_fifo_ip_inst/U0/xst_fifo_generator/gconvfifo.rf/grf.rf
   /gntv_or_sync_fifo.mem/gbm.gbmg.gbmga.ngecc.bmg/gnativebmg.native_blk_mem_gen
   /valid.cstr/ramloop[7].ram.r/v5_noinit.ram/SDP.SINGLE_PRIM36.TDP
   of frag REGCLKBL connected to power/ground net
   gtx_module_inst/gtx_to_fifo_ip_inst/U0/xst_fifo_generator/gconvfifo.rf/grf.rf
   /gntv_or_sync_fifo.mem/gbm.gbmg.gbmga.ngecc.bmg/gnativebmg.native_blk_mem_gen
   /valid.cstr/ramloop[7].ram.r/v5_noinit.ram/SDP.SINGLE_PRIM36.TDP_REGCLKBL_tie
   sig
虽然它们不影响设计性能，但是有消除此类警告的需求。。。