drt: pa on max spacing violations

Signed-off-by: osamahammad21 <[email protected]>

Author: osamahammad21

src/drt/include/drt/TritonRoute.h

@@ -54,6 +54,7 @@ struct FlexDRViaData;
 class frMarker;
 struct RouterConfiguration;
 class AbstractGraphicsFactory;
+class frViaDef;
 
 struct ParamStruct
 {
@@ -184,6 +185,7 @@ class TritonRoute
   void fixMaxSpacing(int num_threads);
   void deleteInstancePAData(frInst* inst, bool delete_inst = false);
   void addInstancePAData(frInst* inst);
+  void addAvoidViaDefPA(const frViaDef* via_def);
   void updateDirtyPAData();
 
  private:

src/drt/src/TritonRoute.cpp

@@ -26,6 +26,7 @@
 #include "db/obj/frVia.h"
 #include "db/tech/frLayer.h"
 #include "db/tech/frTechObject.h"
+#include "db/tech/frViaDef.h"
 #include "distributed/PinAccessJobDescription.h"
 #include "distributed/RoutingCallBack.h"
 #include "distributed/drUpdate.h"
@@ -59,7 +60,6 @@
 using odb::dbTechLayerType;
 
 namespace drt {
-
 TritonRoute::TritonRoute(odb::dbDatabase* db,
                          utl::Logger* logger,
                          utl::CallBackHandler* callback_handler,
@@ -1126,6 +1126,12 @@ void TritonRoute::addInstancePAData(frInst* inst)
   }
 }
 
+void TritonRoute::addAvoidViaDefPA(const frViaDef* via_def)
+{
+  if (pa_) {
+    pa_->addAvoidViaDef(via_def);
+  }
+}
 void TritonRoute::updateDirtyPAData()
 {
   if (pa_) {

src/drt/src/db/obj/frInstTerm.h

@@ -47,6 +47,8 @@ class frInstTerm : public frBlockObject
   odb::Rect getBBox() const;
   void setIndexInOwner(int in) { index_in_owner_ = in; }
   int getIndexInOwner() const { return index_in_owner_; }
+  bool isStubborn() const { return is_stubborn_; }
+  void setStubborn(bool in) { is_stubborn_ = in; }
 
  private:
   // Place this first so it is adjacent to "int id_" inherited from
@@ -56,6 +58,7 @@ class frInstTerm : public frBlockObject
   frMTerm* term_;
   frNet* net_{nullptr};
   std::vector<frAccessPoint*> ap_;  // follows pin index
+  bool is_stubborn_{false};
 };
 
 }  // namespace drt

src/drt/src/dr/FlexDR.cpp

@@ -1688,6 +1688,11 @@ void FlexDR::fixMaxSpacing()
         auto result = getLonelyVias(
             layer.get(), rule->getMaxSpacing(), rule->getCutClassIdx());
         lonely_vias.insert(lonely_vias.end(), result.begin(), result.end());
+        for (const auto via_def : layer->getViaDefs()) {
+          if (via_def->getCutClassIdx() == rule->getCutClassIdx()) {
+            router_->addAvoidViaDefPA(via_def);
+          }
+        }
       }
     }
   }
@@ -1722,7 +1727,27 @@ void FlexDR::fixMaxSpacing()
     region.set_xhi(tmp_box.xMax());
     region.set_yhi(tmp_box.yMax());
     lonely_vias_regions.emplace_back(region);
+    if (via->isBottomConnected() || via->isTopConnected()) {
+      // get pins connected to the via
+      frRegionQuery::Objects<frBlockObject> result;
+      getRegionQuery()->query(
+          via->isTopConnected() ? via->getLayer2BBox() : via->getLayer1BBox(),
+          via->isTopConnected() ? via->getViaDef()->getLayer2Num()
+                                : via->getViaDef()->getLayer1Num(),
+          result);
+      for (auto& [bx, obj] : result) {
+        if (obj->typeId() == frcInstTerm) {
+          auto inst_term = static_cast<frInstTerm*>(obj);
+          if (inst_term->getNet() != via->getNet()) {
+            continue;
+          }
+          inst_term->setStubborn(true);
+          router_->addInstancePAData(inst_term->getInst());
+        }
+      }
+    }
   }
+  router_->updateDirtyPAData();
   // merge intersecting regions
   std::sort(lonely_vias_regions.begin(),
             lonely_vias_regions.end(),

src/drt/src/pa/FlexPA.cpp

@@ -107,6 +107,11 @@ void FlexPA::addDirtyInst(frInst* inst)
   dirty_insts_.insert(inst);
 }
 
+void FlexPA::addAvoidViaDef(const frViaDef* via_def)
+{
+  avoid_via_defs_.insert(via_def);
+}
+
 void FlexPA::removeDirtyInst(frInst* inst)
 {
   dirty_insts_.erase(inst);

src/drt/src/pa/FlexPA.h

@@ -77,6 +77,8 @@ using frInstLocationSet = std::set<frInst*, frInstLocationComp>;
 class FlexPinAccessPattern;
 class FlexDPNode;
 class AbstractPAGraphics;
+class frViaDef;
+class frInstTerm;
 
 class FlexPA
 {
@@ -109,6 +111,7 @@ class FlexPA
 
   void deleteInst(frInst* inst);
   void addDirtyInst(frInst* inst);
+  void addAvoidViaDef(const frViaDef* via_def);
   void removeDirtyInst(frInst* inst);
   void updateDirtyInsts();
   void removeFromInstsSet(frInst* inst);
@@ -139,6 +142,7 @@ class FlexPA
       unique_inst_patterns_;
 
   UniqueInsts unique_insts_;
+  std::set<const frViaDef*> avoid_via_defs_;
 
   // helper structures
   std::vector<std::map<frCoord, frAccessPointEnum>> track_coords_;

src/drt/src/pa/FlexPA_acc_point.cpp

@@ -887,6 +887,10 @@ void FlexPA::filterViaAccess(
   if (via_defs.empty()) {  // no via map entry
     // hardcode first two single vias
     for (auto& [tup, via_def] : layer_num_to_via_defs_[layer_num + 1][1]) {
+      if (inst_term && inst_term->isStubborn()
+          && avoid_via_defs_.contains(via_def)) {
+        continue;
+      }
       via_defs.emplace_back(via_defs.size(), via_def);
       if (via_defs.size() >= max_num_via_trial && !deep_search) {
         break;

src/drt/src/pa/FlexPA_unique.cpp

@@ -197,7 +197,14 @@ UniqueClassKey UniqueInsts::computeUniqueClassKey(frInst* inst) const
   if (!router_cfg_->AUTO_TAPER_NDR_NETS && isNDRInst(inst)) {
     ndr_inst = inst;
   }
-  return UniqueClassKey(inst->getMaster(), orient, offset, ndr_inst);
+  std::set<frTerm*> stubborn_terms;
+  for (auto& term : inst->getInstTerms()) {
+    if (term->isStubborn()) {
+      stubborn_terms.insert(term->getTerm());
+    }
+  }
+  return UniqueClassKey(
+      inst->getMaster(), orient, offset, ndr_inst, stubborn_terms);
 }
 
 UniqueClass* UniqueInsts::computeUniqueClass(frInst* inst)

src/drt/src/pa/FlexPA_unique.h

@@ -29,29 +29,39 @@ struct UniqueClassKey
   odb::dbOrientType orient{odb::dbOrientType::R0};
   std::vector<frCoord> offsets;
   frInst* ndr_inst{nullptr};
+  std::set<frTerm*> stubborn_terms;
 
   UniqueClassKey(frMaster* master_in,
                  const odb::dbOrientType& orient_in,
                  std::vector<frCoord> offsets_in,
-                 frInst* ndr_inst_in = nullptr)
+                 frInst* ndr_inst_in = nullptr,
+                 std::set<frTerm*> stubborn_terms_in = {})
       : master(master_in),
         orient(orient_in),
         offsets(std::move(offsets_in)),
-        ndr_inst(ndr_inst_in)
+        ndr_inst(ndr_inst_in),
+        stubborn_terms(std::move(stubborn_terms_in))
   {
   }
 
   bool operator<(const UniqueClassKey& other) const
   {
-    return std::tie(master, orient, offsets, ndr_inst) < std::tie(
-               other.master, other.orient, other.offsets, other.ndr_inst);
+    return std::tie(master, orient, offsets, ndr_inst, stubborn_terms)
+           < std::tie(other.master,
+                      other.orient,
+                      other.offsets,
+                      other.ndr_inst,
+                      other.stubborn_terms);
   }
 
   bool operator==(const UniqueClassKey& other) const
   {
-    return std::tie(master, orient, offsets, ndr_inst)
-           == std::tie(
-               other.master, other.orient, other.offsets, other.ndr_inst);
+    return std::tie(master, orient, offsets, ndr_inst, stubborn_terms)
+           == std::tie(other.master,
+                       other.orient,
+                       other.offsets,
+                       other.ndr_inst,
+                       other.stubborn_terms);
   }
 };
 
@@ -66,6 +76,10 @@ class UniqueClass
   frMaster* getMaster() const { return key_.master; }
   odb::dbOrientType getOrient() const { return key_.orient; }
   const std::vector<frCoord>& getOffsets() const { return key_.offsets; }
+  const std::set<frTerm*>& getStubbornTerms() const
+  {
+    return key_.stubborn_terms;
+  }
   const InstSet& getInsts() const { return insts_; }
   int getPinAccessIdx() const { return pin_access_idx_; }
   void setPinAccessIdx(int idx) { pin_access_idx_ = idx; }