From 45da3ada7babc8f2b23a8b23ce25430a98e2e58e Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddie@fpgeh.com>
Date: Mon, 8 Jul 2019 23:49:16 -0700
Subject: [PATCH] Do not call opt -mux_undef (part of -full) before muxcover

---
 techlibs/xilinx/synth_xilinx.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc
index 15a37a439..6eab74a21 100644
--- a/techlibs/xilinx/synth_xilinx.cc
+++ b/techlibs/xilinx/synth_xilinx.cc
@@ -270,7 +270,11 @@ struct SynthXilinxPass : public ScriptPass
 		}
 
 		if (check_label("fine")) {
-			run("opt -fast -full");
+		        if (widemux > 0)
+				run("opt -fast -mux_bool -undriven -fine"); // Necessary to omit -mux_undef otherwise muxcover
+									    // performs less efficiently
+			else
+				run("opt -fast -full");
 			run("memory_map");
 			run("dffsr2dff");
 			run("dff2dffe");