Application note http://www.xilinx.com/txpatches/pub/documentation/M1/convergd_m1_5.pdf talks about the conversion of designs from Xact to M1.x. On page 20, there is a chart to compare the attributes from Xact and how to convert it into M1.x. There is a mention of the PRELOAD_OPT and the MRINPUT attributes which are not available as attributes for M1.x but can be found in the gui.
The MRINPUT and PRELOAD_OPT are only 7000 series attributes. These attributes are not supported on the 9500 family in M1.x.