Rigel: A Framework for OpenMP PerformanceTuning. - Piyumi Rameshka Amarasinghe Baragamage; Pasindu Senanayake; Thulana Kannangara; Praveen Seneviratne; Sanath Jayasena; Tharindu Rusira Patabandi; Mary W. Hall (HPCC/SmartCity/DSS, 2019)