2 files changed, 4 insertions, 2 deletions
diff --git a/Makefile b/Makefile
index fd4e90c15..f363be208 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 
-CONFIG := clang
-# CONFIG := gcc
+# CONFIG := clang
+CONFIG := gcc
 # CONFIG := gcc-4.8
 # CONFIG := afl-gcc
 # CONFIG := emcc
diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc
index ede2bda10..db3f5b7e4 100644
--- a/techlibs/xilinx/synth_xilinx.cc
+++ b/techlibs/xilinx/synth_xilinx.cc
@@ -275,6 +275,8 @@ struct SynthXilinxPass : public ScriptPass
 			run("dff2dffe");
 			if (!nomux || help_mode) {
 				run("simplemap t:$mux", "                     (skip if -nomux)");
+				              // FIXME: Must specify mux4, even if we don't need it,
+					      //        otherwise it will use mux8 as mux4
 				run("muxcover -mux4=150 -mux8=200 -mux16=250 -dmux=0", "(skip if -nomux)");
 			}
 			run("opt -full");