Do not optimize away FFs in "prep" and Verific fron-end

Signed-off-by: Claire Wolf <claire@symbioticeda.com>

diff --git a/frontends/verific/verific.cc b/frontends/verific/verific.cc
index cb0368fd57ad05f6342efc75e1524a0ffbbdba1a..a753ca2892831151761eff75d9f2408836d974fc 100644 (file)
--- a/frontends/verific/verific.cc
+++ b/frontends/verific/verific.cc
@@ -2175,6 +2175,9 @@ struct VerificPass : public Pass {
                        RuntimeFlags::SetVar("vhdl_support_variable_slice", 1);
                        RuntimeFlags::SetVar("vhdl_ignore_assertion_statements", 0);
 
+                       RuntimeFlags::SetVar("veri_preserve_assignments", 1);
+                       RuntimeFlags::SetVar("vhdl_preserve_assignments", 1);
+
                        // Workaround for VIPER #13851
                        RuntimeFlags::SetVar("veri_create_name_for_unnamed_gen_block", 1);
 

diff --git a/passes/opt/opt.cc b/passes/opt/opt.cc
index 3968198832def0b71345ae8a948d77161fb114ad..b852e6ae8fcab7873e1d3fa7effced9289b00e5f 100644 (file)
--- a/passes/opt/opt.cc
+++ b/passes/opt/opt.cc
@@ -44,8 +44,8 @@ struct OptPass : public Pass {
                log("        opt_muxtree\n");
                log("        opt_reduce [-fine] [-full]\n");
                log("        opt_merge [-share_all]\n");
-               log("        opt_share (-full only)\n");
-               log("        opt_rmdff [-keepdc] [-sat]\n");
+               log("        opt_share  (-full only)\n");
+               log("        opt_rmdff [-keepdc] [-sat]  (except when called with -noff)\n");
                log("        opt_clean [-purge]\n");
                log("        opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc]\n");
                log("    while <changed design>\n");
@@ -55,7 +55,7 @@ struct OptPass : public Pass {
                log("    do\n");
                log("        opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc]\n");
                log("        opt_merge [-share_all]\n");
-               log("        opt_rmdff [-keepdc] [-sat]\n");
+               log("        opt_rmdff [-keepdc] [-sat]  (except when called with -noff)\n");
                log("        opt_clean [-purge]\n");
                log("    while <changed design in opt_rmdff>\n");
                log("\n");
@@ -73,6 +73,7 @@ struct OptPass : public Pass {
                std::string opt_rmdff_args;
                bool opt_share = false;
                bool fast_mode = false;
+               bool noff_mode = false;
 
                log_header(design, "Executing OPT pass (performing simple optimizations).\n");
                log_push();
@@ -127,6 +128,10 @@ struct OptPass : public Pass {
                                fast_mode = true;
                                continue;
                        }
+                       if (args[argidx] == "-noff") {
+                               noff_mode = true;
+                               continue;
+                       }
                        break;
                }
                extra_args(args, argidx, design);
@@ -137,7 +142,8 @@ struct OptPass : public Pass {
                                Pass::call(design, "opt_expr" + opt_expr_args);
                                Pass::call(design, "opt_merge" + opt_merge_args);
                                design->scratchpad_unset("opt.did_something");
-                               Pass::call(design, "opt_rmdff" + opt_rmdff_args);
+                               if (!noff_mode)
+                                       Pass::call(design, "opt_rmdff" + opt_rmdff_args);
                                if (design->scratchpad_get_bool("opt.did_something") == false)
                                        break;
                                Pass::call(design, "opt_clean" + opt_clean_args);
@@ -156,7 +162,8 @@ struct OptPass : public Pass {
                                Pass::call(design, "opt_merge" + opt_merge_args);
                                if (opt_share)
                                        Pass::call(design, "opt_share");
-                               Pass::call(design, "opt_rmdff" + opt_rmdff_args);
+                               if (!noff_mode)
+                                       Pass::call(design, "opt_rmdff" + opt_rmdff_args);
                                Pass::call(design, "opt_clean" + opt_clean_args);
                                Pass::call(design, "opt_expr" + opt_expr_args);
                                if (design->scratchpad_get_bool("opt.did_something") == false)

diff --git a/techlibs/common/prep.cc b/techlibs/common/prep.cc
index cdd21c3b328a675070333b58f20a39acc6f66a25..82e6126c62f57b9d2484cbfe6276a5f66d1326a6 100644 (file)
--- a/techlibs/common/prep.cc
+++ b/techlibs/common/prep.cc
@@ -192,7 +192,7 @@ struct PrepPass : public ScriptPass
                        run(nokeepdc ? "opt_expr" : "opt_expr -keepdc");
                        run("opt_clean");
                        run("check");
-                       run(nokeepdc ? "opt" : "opt -keepdc");
+                       run(nokeepdc ? "opt -noff" : "opt -noff -keepdc");
                        if (!ifxmode) {
                                if (help_mode)
                                        run("wreduce -keepdc [-memx]");
@@ -208,7 +208,7 @@ struct PrepPass : public ScriptPass
                                run("opt_clean");
                                run("memory_collect");
                        }
-                       run(nokeepdc ? "opt -fast" : "opt -keepdc -fast");
+                       run(nokeepdc ? "opt -noff -fast" : "opt -noff -keepdc -fast");
                }
 
                if (check_label("check"))