From 7a541edb708abf8194ef43398489521dd08227bb Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@CerezoBook.local>
Date: Thu, 18 Jun 2026 09:15:32 -0700
Subject: [PATCH] levelize rm latch d->q handling

Signed-off-by: James Cherry <cherry@CerezoBook.local>
---
 search/Levelize.cc | 37 -------------------------------------
 search/Levelize.hh |  2 --
 2 files changed, 39 deletions(-)

diff --git a/search/Levelize.cc b/search/Levelize.cc
index 76788b40..bc1b5609 100644
--- a/search/Levelize.cc
+++ b/search/Levelize.cc
@@ -134,7 +134,6 @@ Levelize::findLevels()
   findBackEdges();
   VertexSeq topo_sorted = findTopologicalOrder();
   assignLevels(topo_sorted);
-  ensureLatchLevels();
 
   // Set level of stranded vertices (constants) to zero.
   VertexIterator vertex_iter2(graph_);
@@ -354,8 +353,6 @@ Levelize::findTopologicalOrder()
       Vertex *to_vertex = edge->to(graph_);
       if (searchThru(edge))
         in_degree[to_vertex] += 1;
-      if (edge->role() == TimingRole::latchDtoQ())
-        latch_d_to_q_edges_.insert(edge);
     }
     // Levelize bidirect driver as if it was a fanout of the bidirect load.
     const Pin *pin = vertex->pin();
@@ -507,27 +504,6 @@ Levelize::assignLevels(VertexSeq &topo_sorted)
 
 ////////////////////////////////////////////////////////////////
 
-// Make sure latch D input level is not the same as the Q level.
-// This is because the Q arrival depends on the D arrival and
-// to find them in parallel they have to be scheduled separately
-// to avoid a race condition.
-void
-Levelize::ensureLatchLevels()
-{
-  for (Edge *edge : latch_d_to_q_edges_) {
-    Vertex *from = edge->from(graph_);
-    Vertex *to = edge->to(graph_);
-    if (from->level() == to->level()) {
-      Level adjusted_level = from->level() + level_space_;
-      debugPrint(debug_, "levelize", 2, "latch {} {} (adjusted {}) -> {} {}",
-                 from->to_string(this), from->level(), adjusted_level,
-                 to->to_string(this), to->level());
-      setLevel(from, adjusted_level);
-    }
-  }
-  latch_d_to_q_edges_.clear();
-}
-
 void
 Levelize::setLevel(Vertex *vertex,
                    Level level)
@@ -604,7 +580,6 @@ Levelize::relevelize()
     EdgeSeq path;
     visit(vertex, nullptr, vertex->level(), 1, path_vertices, path);
   }
-  ensureLatchLevels();
   levels_valid_ = true;
   relevelize_from_.clear();
 }
@@ -635,18 +610,6 @@ Levelize::visit(Vertex *vertex,
         visit(to_vertex, edge, level + level_space, level_space, path_vertices,
               path);
     }
-
-    const TimingRole *role = edge->role();
-    if (role->isLatchDtoQ())
-      latch_d_to_q_edges_.insert(edge);
-    if (role->isLatchEnToQ()) {
-      VertexInEdgeIterator edge_iter2(to_vertex, graph_);
-      while (edge_iter2.hasNext()) {
-        Edge *edge2 = edge_iter2.next();
-        if (edge2->role()->isLatchDtoQ())
-          latch_d_to_q_edges_.insert(edge2);
-      }
-    }
   }
 
   // Levelize bidirect driver as if it was a fanout of the bidirect load.
diff --git a/search/Levelize.hh b/search/Levelize.hh
index 094e3d47..22b268b8 100644
--- a/search/Levelize.hh
+++ b/search/Levelize.hh
@@ -83,7 +83,6 @@ protected:
                   EdgeSeq &path);
   EdgeSeq *loopEdges(EdgeSeq &path,
                      Edge *closing_edge);
-  void ensureLatchLevels();
   void findBackEdges();
   EdgeSet findBackEdges(EdgeSeq &path,
                         FindBackEdgesStack &stack);
@@ -113,7 +112,6 @@ protected:
   GraphLoopSeq loops_;
   EdgeSet loop_edges_;
   EdgeSet disabled_loop_edges_;
-  EdgeSet latch_d_to_q_edges_;
   LevelizeObserver *observer_{nullptr};
 };