rsz: use adequate buffers for each operation

src/cts/src/TritonCTS.cpp

@@ -604,6 +604,8 @@ void TritonCTS::setBufferList(const char* buffers)
 
 void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
 {
+  sta::Vector<sta::LibertyCell*> selected_buffers;
+
   // first, look for buffers with "is_clock_cell: true" cell attribute
   sta::LibertyLibraryIterator* lib_iter = network_->libertyLibraryIterator();
   while (lib_iter->hasNext()) {
@@ -614,7 +616,7 @@ void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
     }
     for (sta::LibertyCell* buffer : *lib->buffers()) {
       if (buffer->isClockCell() && isClockCellCandidate(buffer)) {
-        buffers.emplace_back(buffer->name());
+        selected_buffers.emplace_back(buffer);
         // clang-format off
         debugPrint(logger_, CTS, "buffering", 1, "{} has clock cell attribute",
                    buffer->name());
@@ -625,7 +627,7 @@ void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
   delete lib_iter;
 
   // second, look for all buffers with name CLKBUF or clkbuf
-  if (buffers.empty()) {
+  if (selected_buffers.empty()) {
     sta::PatternMatch patternClkBuf(".*CLKBUF.*",
                                     /* is_regexp */ true,
                                     /* nocase */ true,
@@ -640,15 +642,15 @@ void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
       for (sta::LibertyCell* buffer :
            lib->findLibertyCellsMatching(&patternClkBuf)) {
         if (buffer->isBuffer() && isClockCellCandidate(buffer)) {
-          buffers.emplace_back(buffer->name());
+          selected_buffers.emplace_back(buffer);
         }
       }
     }
     delete lib_iter;
   }
 
   // third, look for all buffers with name BUF or buf
-  if (buffers.empty()) {
+  if (selected_buffers.empty()) {
     sta::PatternMatch patternBuf(".*BUF.*",
                                  /* is_regexp */ true,
                                  /* nocase */ true,
@@ -663,15 +665,15 @@ void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
       for (sta::LibertyCell* buffer :
            lib->findLibertyCellsMatching(&patternBuf)) {
         if (buffer->isBuffer() && isClockCellCandidate(buffer)) {
-          buffers.emplace_back(buffer->name());
+          selected_buffers.emplace_back(buffer);
         }
       }
     }
     delete lib_iter;
   }
 
   // abandon attributes & name patterns, just look for all buffers
-  if (buffers.empty()) {
+  if (selected_buffers.empty()) {
     lib_iter = network_->libertyLibraryIterator();
     while (lib_iter->hasNext()) {
       sta::LibertyLibrary* lib = lib_iter->next();
@@ -681,20 +683,26 @@ void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
       }
       for (sta::LibertyCell* buffer : *lib->buffers()) {
         if (isClockCellCandidate(buffer)) {
-          buffers.emplace_back(buffer->name());
+          selected_buffers.emplace_back(buffer);
         }
       }
     }
     delete lib_iter;
 
-    if (buffers.empty()) {
+    if (selected_buffers.empty()) {
       logger_->error(
           CTS,
           110,
           "No clock buffer candidates could be found from any libraries.");
     }
   }
 
+  resizer_->setClockBuffersList(selected_buffers);
+
+  for (sta::LibertyCell* buffer : selected_buffers) {
+    buffers.emplace_back(buffer->name());
+  }
+
   options_->setBufferListInferred(true);
   if (logger_->debugCheck(utl::CTS, "buffering", 1)) {
     for (const std::string& bufName : buffers) {

src/dbSta/include/db_sta/dbSta.hh

@@ -58,6 +58,7 @@ class dbStaReport;
 class dbStaCbk;
 class AbstractPathRenderer;
 class AbstractPowerDensityDataSource;
+class PatternMatch;
 
 using utl::Logger;
 
@@ -83,6 +84,23 @@ class dbStaState : public sta::StaState
   dbSta* sta_ = nullptr;
 };
 
+enum BufferUse
+{
+  DATA,
+  CLOCK
+};
+
+class BufferUseAnalyser
+{
+ public:
+  BufferUseAnalyser();
+
+  BufferUse getBufferUse(sta::LibertyCell* buffer);
+
+ private:
+  std::unique_ptr<sta::PatternMatch> clkbuf_pattern_;
+};
+
 class dbSta : public Sta, public ord::OpenRoadObserver
 {
  public:
@@ -172,6 +190,8 @@ class dbSta : public Sta, public ord::OpenRoadObserver
   InstType getInstanceType(odb::dbInst* inst);
   void report_cell_usage(bool verbose);
 
+  BufferUse getBufferUse(sta::LibertyCell* buffer);
+
   using Sta::netSlack;
   using Sta::replaceCell;
 
@@ -192,6 +212,8 @@ class dbSta : public Sta, public ord::OpenRoadObserver
   std::unique_ptr<dbStaCbk> db_cbk_;
   std::set<dbStaState*> sta_states_;
 
+  std::unique_ptr<BufferUseAnalyser> buffer_use_analyser_;
+
   std::unique_ptr<AbstractPathRenderer> path_renderer_;
   std::unique_ptr<AbstractPowerDensityDataSource> power_density_data_source_;
 };

src/dbSta/src/dbSta.cc

@@ -60,6 +60,7 @@
 #include "sta/Liberty.hh"
 #include "sta/PathExpanded.hh"
 #include "sta/PathRef.hh"
+#include "sta/PatternMatch.hh"
 #include "sta/ReportTcl.hh"
 #include "sta/Sdc.hh"
 #include "sta/Search.hh"
@@ -188,6 +189,7 @@ void dbSta::initVars(Tcl_Interp* tcl_interp,
   db_report_->setLogger(logger);
   db_network_->init(db, logger);
   db_cbk_ = std::make_unique<dbStaCbk>(this, logger);
+  buffer_use_analyser_ = std::make_unique<BufferUseAnalyser>();
 }
 
 void dbSta::updateComponentsState()
@@ -539,6 +541,11 @@ void dbSta::report_cell_usage(const bool verbose)
   }
 }
 
+BufferUse dbSta::getBufferUse(sta::LibertyCell* buffer)
+{
+  return buffer_use_analyser_->getBufferUse(buffer);
+}
+
 ////////////////////////////////////////////////////////////////
 
 // Network edit functions.
@@ -869,4 +876,26 @@ void dbSta::highlight(PathRef* path)
   path_renderer_->highlight(path);
 }
 
+////////////////////////////////////////////////////////////////
+
+BufferUseAnalyser::BufferUseAnalyser()
+{
+  clkbuf_pattern_
+      = std::make_unique<sta::PatternMatch>(".*CLKBUF.*",
+                                            /* is_regexp */ true,
+                                            /* nocase */ true,
+                                            /* Tcl_interp* */ nullptr);
+}
+
+BufferUse BufferUseAnalyser::getBufferUse(sta::LibertyCell* buffer)
+{
+  // is_clock_cell is a custom lib attribute that may not exist,
+  // so we also use the name pattern to help
+  if (buffer->isClockCell() || clkbuf_pattern_->match(buffer->name())) {
+    return CLOCK;
+  }
+
+  return DATA;
+}
+
 }  // namespace sta