added fallback and early termination based on r4 residual
added fallback and early termination based on r4 residual

Bryan-Peterson/chrono,hsu/chrono,projectchrono/chrono,Milad-Rakhsha/chrono,Bryan-Peterson/chrono,tjolsen/chrono,armanpazouki/chrono,projectchrono/chrono,jcmadsen/chrono,hsu/chrono,armanpazouki/chrono,andrewseidl/chrono,andrewseidl/chrono,jcmadsen/chrono,rserban/chrono,Milad-Rakhsha/chrono,tjolsen/chrono,jcmadsen/chrono,dariomangoni/chrono,jcmadsen/chrono,armanpazouki/chrono,rserban/chrono,jcmadsen/chrono,hsu/chrono,Bryan-Peterson/chrono,jcmadsen/chrono,Milad-Rakhsha/chrono,dariomangoni/chrono,projectchrono/chrono,armanpazouki/chrono,Milad-Rakhsha/chrono,Milad-Rakhsha/chrono,rserban/chrono,tjolsen/chrono,andrewseidl/chrono,rserban/chrono,hsu/chrono,amelmquist/chrono,projectchrono/chrono,hsu/chrono,PedroTrujilloV/chrono,rserban/chrono,armanpazouki/chrono,amelmquist/chrono,rserban/chrono,PedroTrujilloV/chrono,dariomangoni/chrono,andrewseidl/chrono,dariomangoni/chrono,projectchrono/chrono,Milad-Rakhsha/chrono,andrewseidl/chrono,Bryan-Peterson/chrono,jcmadsen/chrono,amelmquist/chrono,amelmquist/chrono,PedroTrujilloV/chrono,PedroTrujilloV/chrono,dariomangoni/chrono,rserban/chrono,Bryan-Peterson/chrono,amelmquist/chrono,projectchrono/chrono,PedroTrujilloV/chrono,armanpazouki/chrono,amelmquist/chrono,dariomangoni/chrono,tjolsen/chrono,tjolsen/chrono