timing_opt: Make an optional pass controlled by command line

Signed-off-by: David Shah <dave@ds0.me>

2 files changed, 11 insertions, 3 deletions

diff --git a/ice40/arch.cc b/ice40/arch.cc
index 98e6d4c7..9dbc78bb 100644
--- a/ice40/arch.cc
+++ b/ice40/arch.cc
@@ -631,9 +631,14 @@ bool Arch::place()
 {
     if (!placer1(getCtx(), Placer1Cfg(getCtx())))
         return false;
-    TimingOptCfg tocfg(getCtx());
-    tocfg.cellTypes.insert(id_ICESTORM_LC);
-    return timing_opt(getCtx(), tocfg);
+    if(bool_or_default(settings, id("opt_timing"), false)) {
+        TimingOptCfg tocfg(getCtx());
+        tocfg.cellTypes.insert(id_ICESTORM_LC);
+        return timing_opt(getCtx(), tocfg);
+    } else {
+        return true;
+    }
+
 }
 
 bool Arch::route() { return router1(getCtx(), Router1Cfg(getCtx())); }
diff --git a/ice40/main.cc b/ice40/main.cc
index 4b6a9e42..543bd229 100644
--- a/ice40/main.cc
+++ b/ice40/main.cc
@@ -68,6 +68,7 @@ po::options_description Ice40CommandHandler::getArchOptions()
     specific.add_options()("promote-logic",
                            "enable promotion of 'logic' globals (in addition to clk/ce/sr by default)");
     specific.add_options()("no-promote-globals", "disable all global promotion");
+    specific.add_options()("opt-timing", "run post-placement timing optimisation pass (experimental)");
     specific.add_options()("tmfuzz", "run path delay estimate fuzzer");
     return specific;
 }
@@ -161,6 +162,8 @@ std::unique_ptr<Context> Ice40CommandHandler::createContext()
         ctx->settings[ctx->id("promote_logic")] = "1";
     if (vm.count("no-promote-globals"))
         ctx->settings[ctx->id("no_promote_globals")] = "1";
+    if (vm.count("opt-timing"))
+        ctx->settings[ctx->id("opt_timing")] = "1";
     return ctx;
 }