HeAP: Make HeAP placer optional

A CMake option 'BUILD_HEAP' (default on) configures building of the
HeAP placer and the associated Eigen3 dependency.

Default for the iCE40 is SA placer, with --heap-placer to use HeAP

Default for the ECP5 is HeAP placer, as SA placer can take 1hr+ for
large ECP5 designs and HeAP tends to give better QoR. --sa-placer can
be used to use SA instead, and auto-fallback to SA if HeAP not built.

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

2 files changed, 25 insertions, 2 deletions

diff --git a/ecp5/arch.cc b/ecp5/arch.cc
index 5ea6a7c3..8385e57b 100644
--- a/ecp5/arch.cc
+++ b/ecp5/arch.cc
@@ -457,6 +457,7 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
     auto src_loc = est_location(src), dst_loc = est_location(dst);
 
     int dx = abs(src_loc.first - dst_loc.first), dy = abs(src_loc.second - dst_loc.second);
+
     return (130 - 25 * args.speed) *
            (6 + std::max(dx - 5, 0) + std::max(dy - 5, 0) + 2 * (std::min(dx, 5) + std::min(dy, 5)));
 
@@ -486,6 +487,7 @@ delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
     }
 
     int dx = abs(driver_loc.x - sink_loc.x), dy = abs(driver_loc.y - sink_loc.y);
+
     return (130 - 25 * args.speed) *
            (6 + std::max(dx - 5, 0) + std::max(dy - 5, 0) + 2 * (std::min(dx, 5) + std::min(dy, 5)));
 }
@@ -505,7 +507,22 @@ bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay
 
 // -----------------------------------------------------------------------
 
-bool Arch::place() { return placer_heap(getCtx()); }
+bool Arch::place()
+{
+    // HeAP is the default unless overriden or not built
+#ifdef WITH_HEAP
+    if (bool_or_default(settings, id("sa_placer"), false)) {
+#endif
+        if (!placer1(getCtx(), Placer1Cfg(getCtx())))
+            return false;
+#ifdef WITH_HEAP
+    } else {
+        if (!placer_heap(getCtx()))
+            return false;
+    }
+#endif
+    return true;
+}
 
 bool Arch::route()
 {
diff --git a/ecp5/main.cc b/ecp5/main.cc
index 15027a5a..de279e63 100644
--- a/ecp5/main.cc
+++ b/ecp5/main.cc
@@ -59,6 +59,8 @@ po::options_description ECP5CommandHandler::getArchOptions()
     specific.add_options()("um5g-45k", "set device type to LFE5UM5G-45F");
     specific.add_options()("um5g-85k", "set device type to LFE5UM5G-85F");
 
+    specific.add_options()("sa-placer", "use pure simulated annealing placer instead of HeAP analytic placer");
+
     specific.add_options()("package", po::value<std::string>(), "select device package (defaults to CABGA381)");
     specific.add_options()("speed", po::value<int>(), "select device speedgrade (6, 7 or 8)");
 
@@ -149,8 +151,12 @@ std::unique_ptr<Context> ECP5CommandHandler::createContext()
             chipArgs.speed = ArchArgs::SPEED_6;
         }
     }
+    auto ctx = std::unique_ptr<Context>(new Context(chipArgs));
+
+    if (vm.count("sa-placer"))
+        ctx->settings[ctx->id("sa_placer")] = "1";
 
-    return std::unique_ptr<Context>(new Context(chipArgs));
+    return ctx;
 }
 
 void ECP5CommandHandler::customAfterLoad(Context *ctx)