Cts add user clock buffer prefix for list inferring

src/cts/README.md

@@ -44,6 +44,7 @@ Perform clock tree synthesis.
 clock_tree_synthesis 
     [-wire_unit wire_unit]
     [-buf_list <list_of_buffers>]
+    [-buf_list_prefix prefix]\
     [-root_buf root_buf]
     [-clk_nets <list_of_clk_nets>]
     [-tree_buf <buf>]
@@ -71,6 +72,7 @@ clock_tree_synthesis
 | Switch Name | Description |
 | ----- | ----- |
 | `-buf_list` | Tcl list of master cells (buffers) that will be considered when making the wire segments (e.g. `{BUFXX, BUFYY}`). |
+| `-buf_list_prefix` | Prefix that will be used to infer the clock buffer list (e.g. `CLKBUF`). If no buffers are found using this prefix it will proceed with the normal buffer list inferring. Should not be used with `-buf_list` |
 | `-root_buffer` | The master cell of the buffer that serves as root for the clock tree. If this parameter is omitted, the first master cell from `-buf_list` is taken. |
 | `-wire_unit` | Minimum unit distance between buffers for a specific wire. If this parameter is omitted, the code gets the value from ten times the height of `-root_buffer`. |
 | `-distance_between_buffers` | Distance (in microns) between buffers that `cts` should use when creating the tree. When using this parameter, the clock tree algorithm is simplified and only uses a fraction of the segments from the LUT. |

src/cts/src/CtsOptions.h

@@ -43,6 +43,8 @@ class CtsOptions : public odb::dbBlockCallBackObj
   std::string getClockNets() const { return clockNets_; }
   void setRootBuffer(const std::string& buffer) { rootBuffer_ = buffer; }
   std::string getRootBuffer() const { return rootBuffer_; }
+  void setBufferListPrefix(const std::string& prefix) { bufferListPrefix_ = prefix; }
+  std::string getBufferListPrefix() const { return bufferListPrefix_; }
   void setBufferList(const std::vector<std::string>& buffers)
   {
     bufferList_ = buffers;
@@ -249,6 +251,7 @@ class CtsOptions : public odb::dbBlockCallBackObj
   std::string sinkBuffer_ = "";
   std::string treeBuffer_ = "";
   std::string metricFile_ = "";
+  std::string bufferListPrefix_ = "";
   int dbUnits_ = -1;
   unsigned wireSegmentUnit_ = 0;
   bool plotSolution_ = false;

src/cts/src/TritonCTS.cpp

@@ -667,7 +667,30 @@ void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
   }
   delete lib_iter;
 
-  // second, look for all buffers with name CLKBUF or clkbuf
+  // second, look for  buffers with name especified by the user
+  if (options_->getBufferListPrefix() != "") {
+    sta::PatternMatch patternClkBuf(options_->getBufferListPrefix().c_str(),
+                                    /* is_regexp */ true,
+                                    /* nocase */ true,
+                                    /* Tcl_interp* */ nullptr);
+    sta::LibertyLibraryIterator* lib_iter = network_->libertyLibraryIterator();
+    while (lib_iter->hasNext()) {
+      sta::LibertyLibrary* lib = lib_iter->next();
+      if (options_->isCtsLibrarySet()
+          && strcmp(lib->name(), options_->getCtsLibrary()) != 0) {
+        continue;
+      }
+      for (sta::LibertyCell* buffer :
+           lib->findLibertyCellsMatching(&patternClkBuf)) {
+        if (buffer->isBuffer() && isClockCellCandidate(buffer)) {
+          selected_buffers.emplace_back(buffer);
+        }
+      }
+    }
+    delete lib_iter;
+  }
+
+  // third, look for all buffers with name CLKBUF or clkbuf
   if (selected_buffers.empty()) {
     sta::PatternMatch patternClkBuf(".*CLKBUF.*",
                                     /* is_regexp */ true,
@@ -690,7 +713,7 @@ void TritonCTS::inferBufferList(std::vector<std::string>& buffers)
     delete lib_iter;
   }
 
-  // third, look for all buffers with name BUF or buf
+  // fourth, look for all buffers with name BUF or buf
   if (selected_buffers.empty()) {
     sta::PatternMatch patternBuf(".*BUF.*",
                                  /* is_regexp */ true,

src/cts/src/TritonCTS.i

@@ -3,6 +3,7 @@
 
 %{
 #include <cstdint>
+#include <iostream>
 
 #include "cts/TritonCTS.h"
 #include "CtsOptions.h"
@@ -70,6 +71,12 @@ set_root_buffer(const char* buffer)
   getTritonCts()->setRootBuffer(buffer);
 }
 
+void
+set_buffer_list_prefix(const char* prefix)
+{
+  getTritonCts()->getParms()->setBufferListPrefix(prefix);
+}
+
 void
 set_slew_steps(int steps)
 {

src/cts/src/TritonCTS.tcl

@@ -38,6 +38,7 @@ proc configure_cts_characterization { args } {
 
 sta::define_cmd_args "clock_tree_synthesis" {[-wire_unit unit]
                                              [-buf_list buflist] \
+                                             [-buf_list_prefix prefix]\
                                              [-root_buf buf] \
                                              [-clk_nets nets] \
                                              [-tree_buf buf] \
@@ -63,8 +64,8 @@ sta::define_cmd_args "clock_tree_synthesis" {[-wire_unit unit]
 
 proc clock_tree_synthesis { args } {
   sta::parse_key_args "clock_tree_synthesis" args \
-    keys {-root_buf -buf_list -wire_unit -clk_nets -sink_clustering_size \
-          -num_static_layers -sink_clustering_buffer \
+    keys {-root_buf -buf_list -wire_unit -clk_nets -buf_list_prefix\
+          -sink_clustering_size -num_static_layers -sink_clustering_buffer \
           -distance_between_buffers -branching_point_buffers_distance \
           -clustering_exponent \
           -clustering_unbalance_ratio -sink_clustering_max_diameter \
@@ -130,6 +131,14 @@ proc clock_tree_synthesis { args } {
     cts::set_clustering_unbalance_ratio $unbalance
   }
 
+  if { [info exists keys(-buf_list_prefix)] } {
+    set prefix $keys(-buf_list_prefix)
+    if { [info exists keys(-buf_list)] } {
+      utl::warn CTS 129 "-buf_list_prefix will not be used, as -buf_list was already declared"
+    }
+    cts::set_buffer_list_prefix ".*${prefix}.*"
+  }
+
   if { [info exists keys(-buf_list)] } {
     set buf_list $keys(-buf_list)
     cts::set_buffer_list $buf_list