After you have inserted the ILA core on a post-synthesized netlist it is possible for you to set
the number of comparators used to anywhere from 1 to 16. To do that in the Vivado IDE,
go to the Debug Core Options tab of the ILA core and set the
ALL_PROBE_SAME_MU_CNT
property to the desired number of
comparators.
Figure 1. Debug Core Options

Alternatively, you can set the ALL_PROBE_SAME_MU_CNT
property in the Tcl Console as follows:
set_property ALL_PROBE_SAME_MU_CNT 10 [get_debug_cores u_ila_0]
Tip: If Capture Control is enabled, you have a choice of using 1 to 15 comparators. One comparator is used by the capture control data filtering mechanism.
Important: It is not possible to set
different number of comparators for different probes in the ILA using the insertion
flow. AMD recommends that you use the HDL instantiation flow to
achieve that.