Merge pull request The-OpenROAD-Project#5051 from The-OpenROAD-Projec…

…t-staging/drt-cache-isSkipInstTerm

drt: cache the results of isSkipInstTerm for performance

src/drt/src/pa/FlexPA.cpp

@@ -92,6 +92,7 @@ void FlexPA::init()
   initTrackCoords();
 
   unique_insts_.init();
+  initSkipInstTerm();
 }
 
 void FlexPA::applyPatternsFile(const char* file_path)

src/drt/src/pa/FlexPA.h

@@ -99,6 +99,8 @@ class FlexPA
       uniqueInstPatterns_;
 
   UniqueInsts unique_insts_;
+  using UniqueMTerm = std::pair<const UniqueInsts::InstSet*, frMTerm*>;
+  std::map<UniqueMTerm, bool> skip_unique_inst_term_;
 
   // helper structures
   std::vector<std::map<frCoord, frAccessPointEnum>> trackCoords_;
@@ -121,13 +123,15 @@ class FlexPA
   }
   void applyPatternsFile(const char* file_path);
   void getViaRawPriority(frViaDef* viaDef, ViaRawPriorityTuple& priority);
+  bool isSkipInstTermLocal(frInstTerm* in);
   bool isSkipInstTerm(frInstTerm* in);
   bool isDistributed() const { return !remote_host_.empty(); }
 
   // init
   void init();
   void initTrackCoords();
   void initViaRawPriority();
+  void initSkipInstTerm();
   // prep
   void prep();
   void prepPoint();

src/drt/src/pa/FlexPA_init.cpp

@@ -159,4 +159,42 @@ void FlexPA::initTrackCoords()
   }
 }
 
+void FlexPA::initSkipInstTerm()
+{
+  const auto& unique = unique_insts_.getUnique();
+
+  // Populate the map single-threaded so no further resizing is needed.
+  for (frInst* inst : unique) {
+    for (auto& instTerm : inst->getInstTerms()) {
+      auto term = instTerm->getTerm();
+      auto instClass = unique_insts_.getClass(inst);
+      skip_unique_inst_term_[{instClass, term}] = false;
+    }
+  }
+
+  const int unique_size = unique.size();
+#pragma omp parallel for schedule(dynamic)
+  for (int uniqueInstIdx = 0; uniqueInstIdx < unique_size; uniqueInstIdx++) {
+    frInst* inst = unique[uniqueInstIdx];
+    for (auto& instTerm : inst->getInstTerms()) {
+      frMTerm* term = instTerm->getTerm();
+      const UniqueInsts::InstSet* instClass = unique_insts_.getClass(inst);
+
+      // We have to be careful that the skip conditions are true not only of
+      // the unique instance but also all the equivalent instances.
+      bool skip = isSkipInstTermLocal(instTerm.get());
+      if (skip) {
+        for (frInst* inst : *instClass) {
+          frInstTerm* it = inst->getInstTerm(instTerm->getIndexInOwner());
+          skip = isSkipInstTermLocal(it);
+          if (!skip) {
+            break;
+          }
+        }
+      }
+      skip_unique_inst_term_.at({instClass, term}) = skip;
+    }
+  }
+}
+
 }  // namespace drt

src/drt/src/pa/FlexPA_prep.cpp

@@ -2226,34 +2226,32 @@ void FlexPA::getInsts(std::vector<frInst*>& insts)
 }
 
 // Skip power pins, pins connected to special nets, and dangling pins
-// (since we won't route these).  We have to be careful that these
-// conditions are true not only of the unique instance but also all
-// the equivalent instances.
-bool FlexPA::isSkipInstTerm(frInstTerm* in)
+// (since we won't route these).
+//
+// Checks only this instTerm and not an equivalent ones.  This
+// is a helper to isSkipInstTerm and initSkipInstTerm.
+bool FlexPA::isSkipInstTermLocal(frInstTerm* in)
 {
-  if (in->getTerm()->getType().isSupply()) {
+  auto term = in->getTerm();
+  if (term->getType().isSupply()) {
     return true;
   }
   auto in_net = in->getNet();
   if (in_net && !in_net->isSpecial()) {
     return false;
   }
+  return true;
+}
+
+bool FlexPA::isSkipInstTerm(frInstTerm* in)
+{
   auto instClass = unique_insts_.getClass(in->getInst());
-  if (instClass != nullptr) {
-    for (auto& inst : *instClass) {
-      frInstTerm* it = inst->getInstTerm(in->getIndexInOwner());
-      if (!in_net) {
-        if (it->getNet()) {
-          return false;
-        }
-      } else if (in_net->isSpecial()) {
-        if (it->getNet() && !it->getNet()->isSpecial()) {
-          return false;
-        }
-      }
-    }
+  if (instClass == nullptr) {
+    return isSkipInstTermLocal(in);
   }
-  return true;
+
+  // This should be already computed in initSkipInstTerm()
+  return skip_unique_inst_term_.at({instClass, in->getTerm()});
 }
 
 // the input inst must be unique instance

src/drt/src/pa/FlexPA_unique.h

@@ -44,6 +44,7 @@ namespace drt {
 class UniqueInsts
 {
  public:
+  using InstSet = std::set<frInst*, frBlockObjectComp>;
   // if target_insts is non-empty then analysis is limited to
   // those instances.
   UniqueInsts(frDesign* design,
@@ -58,7 +59,7 @@ class UniqueInsts
   int getPAIndex(frInst* inst) const;
 
   // Gets the instances in the equivalence set of the given inst
-  std::set<frInst*, frBlockObjectComp>* getClass(frInst* inst) const;
+  InstSet* getClass(frInst* inst) const;
 
   const std::vector<frInst*>& getUnique() const;
   frInst* getUnique(int idx) const;
@@ -97,17 +98,14 @@ class UniqueInsts
   // Mapp all instances to their representative unique instance
   std::map<frInst*, frInst*, frBlockObjectComp> inst2unique_;
   // Maps all instances to the set of instances with the same unique inst
-  std::unordered_map<frInst*, std::set<frInst*, frBlockObjectComp>*>
-      inst2Class_;
+  std::unordered_map<frInst*, InstSet*> inst2Class_;
   // Maps a unique instance to its pin access index
   std::map<frInst*, int, frBlockObjectComp> unique2paidx_;
   // Maps a unique instance to its index in unique_
   std::map<frInst*, int, frBlockObjectComp> unique2Idx_;
   // master orient track-offset to instances
   std::map<frMaster*,
-           std::map<dbOrientType,
-                    std::map<std::vector<frCoord>,
-                             std::set<frInst*, frBlockObjectComp>>>,
+           std::map<dbOrientType, std::map<std::vector<frCoord>, InstSet>>,
            frBlockObjectComp>
       masterOT2Insts_;
 };