Improve performance of re-initialization logic

Keep track of shared libaries already discovered. Do not build HSA executables
for them.


[ROCm/hip commit: ece4539c1d]

projects/hip/src/program_state.cpp

@@ -180,21 +180,29 @@ const unordered_map<hsa_isa_t, vector<vector<char>>>& code_object_blobs(bool reb
     static once_flag f;
 
     auto cons = [rebuild]() {
+        // names of shared libraries who .kernel sections already loaded
+        static unordered_set<string> lib_names;
         static vector<vector<char>> blobs{code_object_blob_for_process()};
 
         if (rebuild) {
+            r.clear();
             blobs.clear();
-            blobs.push_back(code_object_blob_for_process());
         }
 
         dl_iterate_phdr(
             [](dl_phdr_info* info, std::size_t, void*) {
                 elfio tmp;
-                if (tmp.load(info->dlpi_name)) {
+                if ((lib_names.find(info->dlpi_name) == lib_names.end()) &&
+                    (tmp.load(info->dlpi_name))) {
                     const auto it = find_section_if(
                         tmp, [](const section* x) { return x->get_name() == ".kernel"; });
 
-                    if (it) blobs.emplace_back(it->get_data(), it->get_data() + it->get_size());
+                    if (it) {
+                        blobs.emplace_back(
+                            it->get_data(), it->get_data() + it->get_size());
+                        // register the shared library as already loaded
+                        lib_names.emplace(info->dlpi_name);
+                    }
                 }
                 return 0;
             },
@@ -338,7 +346,8 @@ executables(bool rebuild) {  // TODO: This leaks the hsa_executable_ts, it shoul
         static const auto accelerators = hc::accelerator::get_all();
 
         if (rebuild) {
-            r.clear();
+            // do NOT clear r so we reuse instances of hsa_executable_t
+            // created previously
             code_object_blobs(rebuild);
         }