From 35eeb79a7bba4ab092b797f2887d1c5cc836b018 Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Thu, 25 Mar 2021 15:29:56 -0700
Subject: [PATCH] fuzzyEqual handle zero better

---
 util/Fuzzy.cc | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/util/Fuzzy.cc b/util/Fuzzy.cc
index b3529d06..2c4ff893 100644
--- a/util/Fuzzy.cc
+++ b/util/Fuzzy.cc
@@ -26,19 +26,27 @@ namespace sta {
 using std::max;
 using std::abs;
 
+constexpr static float float_equal_tolerance = 1E-15F;
+
 bool
 fuzzyEqual(float v1,
 	   float v2)
 {
-  return v1 == v2
-    || abs(v1 - v2) < 1E-6F * max(abs(v1), abs(v2));
+  if (v1 == v2)
+    return true;
+  else if (v1 == 0.0)
+    return abs(v2) < float_equal_tolerance;
+  else if (v2 == 0.0)
+    return abs(v1) < float_equal_tolerance;
+  else
+    return abs(v1 - v2) < 1E-6F * max(abs(v1), abs(v2));
 }
 
 bool
 fuzzyZero(float v)
 {
   return v == 0.0
-    || abs(v) < 1E-15F;
+    || abs(v) < float_equal_tolerance;
 }
 
 bool