So we should use XX3Form_Rcr to implement intrinsic Convert DP outs ins xscvdpsp No builtin are required Round &Convert QP DP(dword[1] is set to zero) No builtin are required Round to Quad Precision because you need to assign rounding mode in instruction Provide builtin(set f128:$vT,(int_ppc_vsx_xsrqpi f128:$vB))(set f128 yields< n x< ty > >< result > yields< ty >< result > No builtin are required Load Store load store see def memrix16 in PPCInstrInfo td Load Store Vector load store outs ins lxsdx set load store with conversion from to DP