From 923458a2c90ee295cf6502a83ca6182d1d281f48 Mon Sep 17 00:00:00 2001
From: Arjen Roodselaar <arjen@oxide.computer>
Date: Tue, 20 Dec 2022 11:15:06 -0800
Subject: Allow setting cell placement timeout

---
 common/kernel/command.cc    |  8 +++++---
 common/place/placer_heap.cc | 19 ++++++++++---------
 common/place/placer_heap.h  |  2 +-
 3 files changed, 16 insertions(+), 13 deletions(-)

(limited to 'common')

diff --git a/common/kernel/command.cc b/common/kernel/command.cc
index 22000299..6d2dc939 100644
--- a/common/kernel/command.cc
+++ b/common/kernel/command.cc
@@ -189,7 +189,8 @@ po::options_description CommandHandler::getGeneralOptions()
     general.add_options()("placer-heap-critexp", po::value<int>(),
                           "placer heap criticality exponent (int, default: 2)");
     general.add_options()("placer-heap-timingweight", po::value<int>(), "placer heap timing weight (int, default: 10)");
-    general.add_options()("no-placer-timeout", "allow the placer to attempt placement without timeout");
+    general.add_options()("placer-heap-cell-placement-timeout", po::value<int>(),
+            "allow placer to attempt up to the given number of iterations to place the cell (int, default: design size^2 / 8, 0 for no timeout)");
 
 #if !defined(__wasm)
     general.add_options()("parallel-refine", "use new experimental parallelised engine for placement refinement");
@@ -329,8 +330,9 @@ void CommandHandler::setupContext(Context *ctx)
     if (vm.count("placer-heap-timingweight"))
         ctx->settings[ctx->id("placerHeap/timingWeight")] = std::to_string(vm["placer-heap-timingweight"].as<int>());
 
-    if (vm.count("no-placer-timeout"))
-        ctx->settings[ctx->id("placerHeap/noTimeout")] = true;
+    if (vm.count("placer-heap-cell-placement-timeout"))
+        ctx->settings[ctx->id("placerHeap/cellPlacementTimeout")] =
+            std::to_string(std::max(0, vm["placer-heap-cell-placement-timeout"].as<int>()));
 
     if (vm.count("parallel-refine"))
         ctx->settings[ctx->id("placerHeap/parallelRefine")] = true;
diff --git a/common/place/placer_heap.cc b/common/place/placer_heap.cc
index 69edd325..ae04118b 100644
--- a/common/place/placer_heap.cc
+++ b/common/place/placer_heap.cc
@@ -218,7 +218,10 @@ class HeAPPlacer
 
         heap_runs.push_back(all_buckets);
         // The main HeAP placer loop
-        log_info("Running main analytical placer.\n");
+        if (cfg.cell_placement_timeout > 0)
+            log_info("Running main analytical placer, max placement attempts per cell = %d.\n", cfg.cell_placement_timeout);
+        else
+            log_info("Running main analytical placer.\n");
         while (stalled < 5 && (solved_hpwl <= legal_hpwl * 0.8)) {
             // Alternate between particular bel types and all bels
             for (auto &run : heap_runs) {
@@ -828,11 +831,6 @@ class HeAPPlacer
     // Strict placement legalisation, performed after the initial HeAP spreading
     void legalise_placement_strict(bool require_validity = false)
     {
-        int placement_timeout = cfg.no_placement_timeout ? 0 :
-            // Set a conservative timeout. This is a rather large number and could probably be
-            // shaved down, but for now it will keep the process from running indefinite.
-            std::max(10000, (int(ctx->cells.size()) * int(ctx->cells.size()) / 8) + 1);
-
         auto startt = std::chrono::high_resolution_clock::now();
 
         // Unbind all cells placed in this solution
@@ -884,8 +882,8 @@ class HeAPPlacer
             }
 
             while (!placed) {
-                if (placement_timeout > 0 && total_iters_for_cell > placement_timeout)
-                    log_error("Unable to find legal placement for cell '%s' after %d attempts, check constraints and utilisation.\n",
+                if (cfg.cell_placement_timeout > 0 && total_iters_for_cell > cfg.cell_placement_timeout)
+                    log_error("Unable to find legal placement for cell '%s' after %d attempts, check constraints and utilisation. Use `--placer-heap-cell-placement-timeout` to change the number of attempts.\n",
                               ctx->nameOf(ci), total_iters_for_cell);
 
                 // Determine a search radius around the solver location (which increases over time) that is clamped to
@@ -1819,7 +1817,10 @@ PlacerHeapCfg::PlacerHeapCfg(Context *ctx)
     timing_driven = ctx->setting<bool>("timing_driven");
     solverTolerance = 1e-5;
     placeAllAtOnce = false;
-    no_placement_timeout = ctx->setting<bool>("placerHeap/noTimeout", false);
+    cell_placement_timeout = ctx->setting<int>("placerHeap/cellPlacementTimeout",
+            // Set a conservative default. This is a rather large number and could probably
+            // be shaved down, but for now it will keep the process from running indefinite.
+            std::max(10000, (int(ctx->cells.size()) * int(ctx->cells.size()) / 8) + 1));
 
     hpwl_scale_x = 1;
     hpwl_scale_y = 1;
diff --git a/common/place/placer_heap.h b/common/place/placer_heap.h
index 680e1dc7..e554a8e0 100644
--- a/common/place/placer_heap.h
+++ b/common/place/placer_heap.h
@@ -42,7 +42,7 @@ struct PlacerHeapCfg
     float solverTolerance;
     bool placeAllAtOnce;
     bool parallelRefine;
-    bool no_placement_timeout;
+    int cell_placement_timeout;
 
     int hpwl_scale_x, hpwl_scale_y;
     int spread_scale_x, spread_scale_y;
-- 
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