From 17b283135658b84a0dfeec8b35f7d2bfe782be19 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Wed, 2 Jan 2019 08:25:55 +0000
Subject: [PATCH] synth_ice40: use 4-LUT coarse synthesis mode.

---
 techlibs/ice40/synth_ice40.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/techlibs/ice40/synth_ice40.cc b/techlibs/ice40/synth_ice40.cc
index c2aed873b..4c4fdf7be 100644
--- a/techlibs/ice40/synth_ice40.cc
+++ b/techlibs/ice40/synth_ice40.cc
@@ -226,7 +226,7 @@ struct SynthIce40Pass : public ScriptPass
 
 		if (check_label("coarse"))
 		{
-			run("synth -run coarse");
+			run("synth -lut 4 -run coarse");
 		}
 
 		if (!nobram && check_label("bram", "(skip if -nobram)"))