From 7a236c38b77bc7155797df3fbc1ef724660b1b04 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Sat, 25 Apr 2026 10:35:42 -0700
Subject: [PATCH] flatten Clock::uncertainties

Signed-off-by: James Cherry <cherry@parallaxsw.com>
---
 include/sta/Clock.hh        |  4 ++--
 include/sta/MinMaxValues.hh |  5 +++++
 sdc/Clock.cc                | 23 ++++-------------------
 search/PathEnd.cc           |  2 +-
 search/Search.cc            |  6 +++---
 5 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/include/sta/Clock.hh b/include/sta/Clock.hh
index 8acc1e45..5a633ef0 100644
--- a/include/sta/Clock.hh
+++ b/include/sta/Clock.hh
@@ -90,7 +90,7 @@ public:
                  // Return values.
                  float &slew,
                  bool &exists) const;
-  ClockUncertainties *uncertainties() const { return uncertainties_; }
+  const ClockUncertainties &uncertainties() const { return uncertainties_; }
   void uncertainty(const SetupHold *setup_hold,
                    // Return values.
                    float &uncertainty,
@@ -180,7 +180,7 @@ protected:
   bool is_propagated_{false};
   RiseFallMinMax slews_;
   RiseFallMinMax slew_limits_[path_clk_or_data_count];
-  ClockUncertainties *uncertainties_{nullptr};
+  ClockUncertainties uncertainties_;
   bool is_generated_{false};
   // Generated clock variables.
   Pin *src_pin_{nullptr};
diff --git a/include/sta/MinMaxValues.hh b/include/sta/MinMaxValues.hh
index 8fb8eeea..c365d613 100644
--- a/include/sta/MinMaxValues.hh
+++ b/include/sta/MinMaxValues.hh
@@ -169,6 +169,11 @@ public:
   static int cmp(const MinMaxValues *values1,
                  const MinMaxValues *values2)
   {
+    if (!values1->exists_[MinMax::minIndex()]
+        && !values2->exists_[MinMax::minIndex()]
+        && !values1->exists_[MinMax::maxIndex()]
+        && !values2->exists_[MinMax::maxIndex()])
+      return 0;
     if (!values1->exists_[MinMax::minIndex()]
         && values2->exists_[MinMax::minIndex()])
       return -1;
diff --git a/sdc/Clock.cc b/sdc/Clock.cc
index c9d4d11a..21cd4d8d 100644
--- a/sdc/Clock.cc
+++ b/sdc/Clock.cc
@@ -240,42 +240,27 @@ Clock::uncertainty(const SetupHold *setup_hold,
                    float &uncertainty,
                    bool &exists) const
 {
-  if (uncertainties_)
-    uncertainties_->value(setup_hold, uncertainty, exists);
-  else {
-    uncertainty = 0.0F;
-    exists = false;
-  }
+  uncertainties_.value(setup_hold, uncertainty, exists);
 }
 
 void
 Clock::setUncertainty(const SetupHoldAll *setup_hold,
                       float uncertainty)
 {
-  if (uncertainties_ == nullptr)
-    uncertainties_ = new ClockUncertainties;
-  uncertainties_->setValue(setup_hold, uncertainty);
+  uncertainties_.setValue(setup_hold, uncertainty);
 }
 
 void
 Clock::setUncertainty(const SetupHold *setup_hold,
                       float uncertainty)
 {
-  if (uncertainties_ == nullptr)
-    uncertainties_ = new ClockUncertainties;
-  uncertainties_->setValue(setup_hold, uncertainty);
+  uncertainties_.setValue(setup_hold, uncertainty);
 }
 
 void
 Clock::removeUncertainty(const SetupHoldAll *setup_hold)
 {
-  if (uncertainties_) {
-    uncertainties_->removeValue(setup_hold);
-    if (uncertainties_->empty()) {
-      delete uncertainties_;
-      uncertainties_ = nullptr;
-    }
-  }
+  uncertainties_.removeValue(setup_hold);
 }
 
 void
diff --git a/search/PathEnd.cc b/search/PathEnd.cc
index 81920752..e917d89f 100644
--- a/search/PathEnd.cc
+++ b/search/PathEnd.cc
@@ -379,7 +379,7 @@ PathEnd::checkTgtClkUncertainty(const Path *tgt_clk_path,
   if (tgt_clk_path && tgt_clk_path->isClock(sta))
     uncertainties = tgt_clk_path->clkInfo(sta)->uncertainties();
   else if (tgt_clk_edge)
-    uncertainties = tgt_clk_edge->clock()->uncertainties();
+    uncertainties = &tgt_clk_edge->clock()->uncertainties();
   float uncertainty = 0.0;
   if (uncertainties) {
     bool exists;
diff --git a/search/Search.cc b/search/Search.cc
index d0d6b0ca..081daac8 100644
--- a/search/Search.cc
+++ b/search/Search.cc
@@ -1547,7 +1547,7 @@ Search::seedClkArrival(const Pin *pin,
 
   const ClockUncertainties *uncertainties = sdc->clockUncertainties(pin);
   if (uncertainties == nullptr)
-    uncertainties = clk->uncertainties();
+    uncertainties = &clk->uncertainties();
   // Propagate liberty "pulse_clock" transition to transitive fanout.
   LibertyPort *port = network_->libertyPort(pin);
   const RiseFall *pulse_clk_sense = (port ? port->pulseClkSense() : nullptr);
@@ -1914,13 +1914,13 @@ Search::inputDelayTag(const Pin *pin,
   const Pin *clk_pin = nullptr;
   const RiseFall *clk_rf = nullptr;
   bool is_propagated = false;
-  ClockUncertainties *clk_uncertainties = nullptr;
+  const ClockUncertainties *clk_uncertainties = nullptr;
   if (clk_edge) {
     clk = clk_edge->clock();
     clk_rf = clk_edge->transition();
     clk_pin = clk->defaultPin();
     is_propagated = clk->isPropagated();
-    clk_uncertainties = clk->uncertainties();
+    clk_uncertainties = &clk->uncertainties();
   }
 
   Sdc *sdc = scene->sdc();