I am receiving different synthesis reports between XST runs, even when I do not change any XST options or source code. More specifically, I am seeing the changes in the "Asynchronous Control Signal Information" section of the report.
Is my netlist changing?
XST selects one of the asynchronous control signals and reports it to the synthesis report. This reporting is not deterministic. This is only a reporting issue and there are no changes to the netlist.
This issue is fixed in 11.1.