Upon invoking "xepld" on a 9500 part, the following may be encountered if you have TIMESPECS in the design or in a constraints file:
hi604:[Warning]Unexpected TIMESPEC string FROM:PADS(PTOHP):TO:FFS=8.0, Ignored. Note that XC7000 devices support FROM:TO syntax and do not support the old-style P2P, C2S timing specifications.
The TIMESPEC is valid, and the signal "PTOHP" does indeed exist in the .xnf file.
The problem is that XEPLD calls a subprogram "xemake6", and this program has a bug. It will not accept any TIMESPEC string that references a signal with the string "TO" in it. Therefore, the signal "PTOHP" will need to be renamed to something else, such as "P2HP".