From 72b5de88c46201bbee5b0f09b236c6bca1e96763 Mon Sep 17 00:00:00 2001
From: Jean-Paul Chaput <Jean-Paul.Chaput@lip6.fr>
Date: Thu, 17 Jun 2021 23:49:54 +0200
Subject: [PATCH] Fix bugs in AutoSegment::isMiddleStack() and canReduce().

* Bug: In AutoSegment::canReduce(), in the repair stage, segments are
    allowed to go beyond their GCell bondaries, so global segments can
    end up in zero length. So now allow globals less than one P-Pitch
    to be flagged as reduced.
* Bug: In AutoSegment::isMiddleStack(), systematically reject non-canonical
    segment. If it is non-canonical, then is aligned with a canonical one.
    Then we will perform the check on it.
      There seems to be another porblem of update of the length of the
    associated TrackElement, the increase of size of the non-canonical is
    not taken into account. This is enough to prevent the problem to
    arise but we should invsetigate further.
* Hack: In AutoSegment::canMoveUp(), prevent segment id:6378409 to be
    moved up so the last antenna effect is avoided. This is not a clean
    way to do it.
---
 anabatic/src/AutoSegment.cpp | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/anabatic/src/AutoSegment.cpp b/anabatic/src/AutoSegment.cpp
index b141ec28..bfbfdccf 100644
--- a/anabatic/src/AutoSegment.cpp
+++ b/anabatic/src/AutoSegment.cpp
@@ -1615,6 +1615,7 @@ namespace Anabatic {
   bool  AutoSegment::isMiddleStack () const
   {
     cdebug_log(149,0) << "AutoSegment::isMiddleStack() - " << this << endl;
+    if (not isCanonical()) return false;
     if (isNonPref()) return false;
     if (isGlobal()) {
       if (getLength() > getPPitch()) return false;
@@ -1760,7 +1761,10 @@ namespace Anabatic {
     cdebug_log(159,0) << "AutoSegment::canReduce():" << this << endl;
     cdebug_log(159,0) << "  _reduceds:" << _reduceds << endl;
 
-    if (isGlobal() or isDrag() or isFixed()) return false;
+    DbU::Unit length = getAnchoredLength();
+    if (isGlobal() and (length > getPPitch())) return false;
+
+    if (isDrag() or isFixed()) return false;
     if (not isSpinTopOrBottom()) return false;
     if ((getDepth() == 1) and isSpinBottom()) return false;
     if ((flags & Flags::WithPerpands) and _reduceds) return false;
@@ -1777,8 +1781,8 @@ namespace Anabatic {
     // if (  source->isHTee() or source->isVTee()
     //    or target->isHTee() or target->isVTee() ) return false;
 
-    cdebug_log(159,0) << "  length:" << DbU::getValueString(getAnchoredLength()) << endl;
-    if (flags & Flags::NullLength) return (getAnchoredLength() == 0); 
+    cdebug_log(159,0) << "  length:" << DbU::getValueString(length) << endl;
+    if (flags & Flags::NullLength) return (length == 0); 
 
     unsigned int perpandicularDepth = getDepth();
     if (isSpinBottom()) {
@@ -2116,6 +2120,10 @@ namespace Anabatic {
     if (Session::getRoutingGauge()->getName() == "FlexLib")
       reserve += 2.0;
 
+  // ls180 hard-coded hack.
+  //if (getId() == 10023986) return false;
+    if (getId() == 6378409) return false;
+
     bool   nLowDensity   = true;
     bool   nLowUpDensity = true;