From e3df9ad39a131f3b742460e2ace8c82d0c67cc4b Mon Sep 17 00:00:00 2001
From: Jan Bylicki <jbylicki@antmicro.com>
Date: Mon, 18 Nov 2024 15:26:14 +0100
Subject: [PATCH] odb: Add pointer caching to master terminal retrival

Signed-off-by: Jan Bylicki <jbylicki@antmicro.com>
---
 src/odb/include/odb/dbObject.h |  3 +++
 src/odb/src/db/dbITerm.cpp     | 21 ++++++++++++---------
 src/odb/src/db/dbInst.cpp      |  2 ++
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/odb/include/odb/dbObject.h b/src/odb/include/odb/dbObject.h
index 47676ee04c9..db493adb92d 100644
--- a/src/odb/include/odb/dbObject.h
+++ b/src/odb/include/odb/dbObject.h
@@ -176,6 +176,8 @@ enum dbObjectType
 
 class dbDatabase;
 
+class dbMTerm;
+
 class dbObject
 {
  public:
@@ -190,6 +192,7 @@ class dbObject
   // not exported.  They are for internal db convenience.
   _dbObject* getImpl();
   const _dbObject* getImpl() const;
+  mutable dbMTerm* mterm_cache;
 
  protected:
   dbObject() = default;
diff --git a/src/odb/src/db/dbITerm.cpp b/src/odb/src/db/dbITerm.cpp
index fdf571b01a9..8f821954f3b 100644
--- a/src/odb/src/db/dbITerm.cpp
+++ b/src/odb/src/db/dbITerm.cpp
@@ -263,15 +263,18 @@ dbNet* dbITerm::getNet()
 
 dbMTerm* dbITerm::getMTerm() const
 {
-  _dbITerm* iterm = (_dbITerm*) this;
-  _dbBlock* block = (_dbBlock*) iterm->getOwner();
-  _dbInst* inst = block->_inst_tbl->getPtr(iterm->_inst);
-  _dbInstHdr* inst_hdr = block->_inst_hdr_tbl->getPtr(inst->_inst_hdr);
-  _dbDatabase* db = iterm->getDatabase();
-  _dbLib* lib = db->_lib_tbl->getPtr(inst_hdr->_lib);
-  _dbMaster* master = lib->_master_tbl->getPtr(inst_hdr->_master);
-  dbId<_dbMTerm> mterm = inst_hdr->_mterms[iterm->_flags._mterm_idx];
-  return (dbMTerm*) master->_mterm_tbl->getPtr(mterm);
+  if (mterm_cache == nullptr) {
+    _dbITerm* iterm = (_dbITerm*) this;
+    _dbBlock* block = (_dbBlock*) iterm->getOwner();
+    _dbInst* inst = block->_inst_tbl->getPtr(iterm->_inst);
+    _dbInstHdr* inst_hdr = block->_inst_hdr_tbl->getPtr(inst->_inst_hdr);
+    _dbDatabase* db = iterm->getDatabase();
+    _dbLib* lib = db->_lib_tbl->getPtr(inst_hdr->_lib);
+    _dbMaster* master = lib->_master_tbl->getPtr(inst_hdr->_master);
+    dbId<_dbMTerm> mterm = inst_hdr->_mterms[iterm->_flags._mterm_idx];
+    mterm_cache = (dbMTerm*) master->_mterm_tbl->getPtr(mterm);
+  }
+  return mterm_cache;
 }
 
 dbBTerm* dbITerm::getBTerm()
diff --git a/src/odb/src/db/dbInst.cpp b/src/odb/src/db/dbInst.cpp
index 31afab66b8d..1d6aff4446d 100644
--- a/src/odb/src/db/dbInst.cpp
+++ b/src/odb/src/db/dbInst.cpp
@@ -1362,6 +1362,7 @@ bool dbInst::swapMaster(dbMaster* new_master_)
   uint i;
   for (i = 0; i < cnt; ++i) {
     _dbITerm* it = block->_iterm_tbl->getPtr(inst->_iterms[i]);
+    it->mterm_cache = nullptr;
     uint old_idx = it->_flags._mterm_idx;
     it->_flags._mterm_idx = idx_map[old_idx];
   }
@@ -1458,6 +1459,7 @@ dbInst* dbInst::create(dbBlock* block_,
   uint i;
   for (i = 0; i < mterm_cnt; ++i) {
     _dbITerm* iterm = block->_iterm_tbl->create();
+    iterm->mterm_cache = nullptr;
     inst->_iterms[i] = iterm->getOID();
     iterm->_flags._mterm_idx = i;
     iterm->_inst = inst->getOID();