Fix wreduce call (!!!), tweak muxcover costs

diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc
index 882ebe439434b560c6d2c19af226f17fbd743774..9724dff94efe8c0d10fb5ae68839982c63f219e9 100644 (file)
--- a/techlibs/xilinx/synth_xilinx.cc
+++ b/techlibs/xilinx/synth_xilinx.cc
@@ -229,7 +229,7 @@ struct SynthXilinxPass : public ScriptPass
                        if (help_mode)
                                run("wreduce [c:* t:$mux %d]", "(no selection if -nomux)");
                        else
-                               run("wreduce" + nomux ? "" : " c:* t:$mux %d");
+                               run("wreduce" + std::string(nomux ? "" : " c:* t:$mux %d"));
                        run("peepopt");
                        run("opt_clean");
                        run("alumacc");
@@ -271,10 +271,11 @@ struct SynthXilinxPass : public ScriptPass
                        run("dffsr2dff");
                        run("dff2dffe");
                        if (!nomux || help_mode) {
-                               run("simplemap t:$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("simplemap t:$mux", "                     (skip if -nomux)");
+                               // NB: Cost of mux2 is 100; mux8 should cost between 3 and 4
+                               //     of those so that 4:1 muxes and below are implemented
+                               //     out of mux2s
+                               run("muxcover -mux8=350 -mux16=400 -dmux=0", "(skip if -nomux)");
                        }
                        run("opt -full");