synth_xilinx to use shregmap with -minlen 3

diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc
index 5237cc4c640acdf76179b155c8bda4000e9c3b98..b6225a1a32e7eb242958b5bd9b5a27eff7723c84 100644 (file)
--- a/techlibs/xilinx/synth_xilinx.cc
+++ b/techlibs/xilinx/synth_xilinx.cc
@@ -114,7 +114,7 @@ struct SynthXilinxPass : public Pass
                log("        dff2dffe\n");
                log("        opt -full\n");
                log("        simplemap t:$dff* (only without -nosrl)\n");
-               log("        shregmap -tech xilinx (only without -nosrl)\n");
+               log("        shregmap -tech xilinx -minlen 3 (only without -nosrl)\n");
                log("        techmap -map +/techmap.v -map +/xilinx/arith_map.v -map +/xilinx/ff_map.v\n");
                log("        opt -fast\n");
                log("\n");
@@ -267,7 +267,7 @@ struct SynthXilinxPass : public Pass
 
                        if (!nosrl) {
                                Pass::call(design, "simplemap t:$dff*");
-                               Pass::call(design, "shregmap -tech xilinx");
+                               Pass::call(design, "shregmap -tech xilinx -minlen 3");
                        }
 
                        if (vpr) {