From 68d4426bf35874bca7300c4d8b7769d5406b7741 Mon Sep 17 00:00:00 2001
From: dsengupta0628 <dsengupta@precisioninno.com>
Date: Wed, 29 Apr 2026 19:20:56 +0000
Subject: [PATCH 1/2] fix for sta-1648 in read_spef

Signed-off-by: dsengupta0628 <dsengupta@precisioninno.com>
---
 parasitics/SpefReader.cc    | 39 ++++++++++++++++++++++++++++++++++++-
 parasitics/SpefReaderPvt.hh |  1 +
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/parasitics/SpefReader.cc b/parasitics/SpefReader.cc
index 05141673..35a99c51 100644
--- a/parasitics/SpefReader.cc
+++ b/parasitics/SpefReader.cc
@@ -133,10 +133,39 @@ SpefReader::setBusBrackets(char left,
   bus_brkt_right_ = right;
 }
 
+std::string
+SpefReader::stripped(std::string_view spef_name) const
+{
+  std::string out;
+  out.reserve(spef_name.size());
+  for (size_t i = 0; i < spef_name.size(); i++) {
+    char ch = spef_name[i];
+    if (ch == '\\' && i + 1 < spef_name.size())
+      out += spef_name[++i];
+    else
+      out += ch;
+  }
+  return out;
+}
+
 Instance *
 SpefReader::findInstanceRelative(std::string_view name)
 {
-  return sdc_network_->findInstanceRelative(instance_, name);
+  // Network::findInstanceRelative splits at unescaped '/' and walks
+  // hierarchy. That misses flat instance names with a literal '/' (e.g.
+  // post-CTS buffers like "u_x/g1234") because there is no parent module
+  // matching the pre-'/' segment; it also misses bracket-escaped names
+  // ("bus\[0\]") whose unescaped form is what the DEF reader stored.
+  // dbNetwork::findInstance has a flat block_->findInst() fallback that
+  // both cases need.
+  Instance *inst = sdc_network_->findInstanceRelative(instance_, name);
+  if (inst == nullptr)
+    inst = network_->findInstance(name);
+  if (inst == nullptr && name.find('\\') != std::string_view::npos)
+    inst = network_->findInstance(stripped(name));
+  debugPrint(debug_, "spef_lookup", 1, "findInstance '{}' -> {}", name,
+             inst ? "found" : "miss");
+  return inst;
 }
 
 Net *
@@ -147,6 +176,14 @@ SpefReader::findNetRelative(std::string_view name)
   // don't follow the rules.
   if (net == nullptr)
     net = sdc_network_->findNetRelative(instance_, name);
+  // dbNetwork::findNet at top scope does a literal block_->findNet() which
+  // finds flat names with '/' that findNetRelative cannot.
+  if (net == nullptr)
+    net = network_->findNet(instance_, name);
+  if (net == nullptr && name.find('\\') != std::string_view::npos)
+    net = network_->findNet(instance_, stripped(name));
+  debugPrint(debug_, "spef_lookup", 1, "findNet '{}' -> {}", name,
+             net ? "found" : "miss");
   return net;
 }
 
diff --git a/parasitics/SpefReaderPvt.hh b/parasitics/SpefReaderPvt.hh
index 4b1b90ff..22fa9b9d 100644
--- a/parasitics/SpefReaderPvt.hh
+++ b/parasitics/SpefReaderPvt.hh
@@ -121,6 +121,7 @@ private:
   Pin *findPortPinRelative(std::string_view name);
   Net *findNetRelative(std::string_view name);
   Instance *findInstanceRelative(std::string_view name);
+  std::string stripped(std::string_view spef_name) const;
   ParasiticNode *findParasiticNode(std::string_view name,
                                    bool local_only);
 

From 1e6e43bb48b5f370983bf3c643e1a2d519a2b316 Mon Sep 17 00:00:00 2001
From: dsengupta0628 <dsengupta@precisioninno.com>
Date: Thu, 30 Apr 2026 01:14:22 +0000
Subject: [PATCH 2/2] gemini feedback

Signed-off-by: dsengupta0628 <dsengupta@precisioninno.com>
---
 parasitics/SpefReader.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/parasitics/SpefReader.cc b/parasitics/SpefReader.cc
index 35a99c51..1c6a5f41 100644
--- a/parasitics/SpefReader.cc
+++ b/parasitics/SpefReader.cc
@@ -160,9 +160,9 @@ SpefReader::findInstanceRelative(std::string_view name)
   // both cases need.
   Instance *inst = sdc_network_->findInstanceRelative(instance_, name);
   if (inst == nullptr)
-    inst = network_->findInstance(name);
+    inst = network_->findChild(instance_, name);
   if (inst == nullptr && name.find('\\') != std::string_view::npos)
-    inst = network_->findInstance(stripped(name));
+    inst = network_->findChild(instance_, stripped(name));
   debugPrint(debug_, "spef_lookup", 1, "findInstance '{}' -> {}", name,
              inst ? "found" : "miss");
   return inst;