vendor.xilinx_spartan_3_6: do not use retiming by default.

This was added in b404d603, probably by mistake, and is certainly
wrong given that we do not (yet) correctly mark CDC FFs.

diff --git a/nmigen/vendor/xilinx_spartan_3_6.py b/nmigen/vendor/xilinx_spartan_3_6.py
index be0f966f0cacf68bcae306e209f3c1c50b39d9c5..fd9ce2b61625fa887cdbcf9cb1d7690b19d331eb 100644 (file)
--- a/nmigen/vendor/xilinx_spartan_3_6.py
+++ b/nmigen/vendor/xilinx_spartan_3_6.py
@@ -101,7 +101,6 @@ class XilinxSpartan3Or6Platform(TemplatedPlatform):
             {% if platform.family in ["3", "3E", "3A"] %}
             -use_new_parser yes
             {% endif %}
-            -register_balancing yes
             -p {{platform.device}}{{platform.package}}-{{platform.speed}}
             {{get_override("script_after_run")|default("# (script_after_run placeholder)")}}
         """,