[Autoscheduler] Reduce task weight coercion overhead

Author: Peter Salas

python/tvm/auto_scheduler/relay_integration.py

@@ -171,7 +171,7 @@ def extract_tasks(
                 desc=",".join(func_names),
             )
         )
-        weights.append(weight)
+        weights.append(int(weight))
 
     if dump_workload_to_dag_log is not None:
         with open(dump_workload_to_dag_log, "w") as f:

src/node/reflection.cc

@@ -106,8 +106,11 @@ runtime::TVMRetValue ReflectionVTable::GetAttr(Object* self, const String& field
     }
   }
   if (!success) {
-    LOG(FATAL) << "AttributeError: " << self->GetTypeKey() << " object has no attributed "
-               << getter.skey;
+    // This exception is typically caught, sometimes in a loop. LOG(FATAL) is very
+    // expensive (it collects a backtrace) so throw an explicit exception instead.
+    std::ostringstream os;
+    os << "AttributeError: " << self->GetTypeKey() << " object has no attribute " << getter.skey;
+    throw dmlc::Error(os.str());
   }
   return ret;
 }