synth_xilinx to call "synth -run coarse" with "-keepdc"

diff --git a/techlibs/xilinx/synth_xilinx.cc b/techlibs/xilinx/synth_xilinx.cc
index b404dc8e7d724f40ad0b3f28e8ed68026d142b10..15a37a439a4a77417a86cb3cdfc4595a979754b2 100644 (file)
--- a/techlibs/xilinx/synth_xilinx.cc
+++ b/techlibs/xilinx/synth_xilinx.cc
@@ -240,9 +240,9 @@ struct SynthXilinxPass : public ScriptPass
 
                if (check_label("coarse")) {
                        if (help_mode)
-                               run("synth -run coarse [-flatten]", "(with '-flatten')");
+                               run("synth -keepdc -run coarse [-flatten]", "(with '-flatten')");
                        else
-                               run("synth -run coarse" + std::string(flatten ? "" : " -flatten"), "(with '-flatten')");
+                               run("synth -keepdc -run coarse" + std::string(flatten ? "" : " -flatten"), "(with '-flatten')");
 
                        if (widemux > 0 || help_mode)
                                run("muxpack", "    ('-widemux' only)");