Today's noteworthy upgrades include: Amdocs (DOX) upgraded to Buy from Neutral at BofA/Merrill... Cheesecake Factory (CAKE) upgraded to Overweight from Equal Weight at Stephens... Chemical Financial (CHFC) upgraded to Buy from Hold at Sandler O'Neill... Cimarex Energy (XEC) upgraded to Buy from Hold at Wunderlich... Cirrus Logic (CRUS) upgraded to Outperform from Perform at Oppenheimer... Citrix (CTXS) upgraded on Q4 results, valuation at JMP Securities... Comerica (CMA) upgraded to Market Perform from Underperform at BMO Capital... Community Health (CYH) upgraded to Market Perform from Underperform at Raymond James... Denny's (DENN) upgraded to Overweight from Equal Weight at Stephens... Dolby (DLB) upgraded to Buy from Neutral at Dougherty... EMC (EMC) upgraded to Buy from Neutral at Mizuho... Halliburton (HAL) upgraded to Buy from Accumulate at KLR Group... Hanmi Financial (HAFC) upgraded to Strong Buy from Outperform at Raymond James... Hawaiian Holdings (HA) upgraded to Neutral at BofA/Merrill... Hologic (HOLX) upgraded to Buy from Hold at Needham... Kinder Morgan (KMI) upgraded at Stifel... MGM China (MCHVF) upgraded to Overweight from Neutral at JPMorgan... Nimble Storage (NMBL) upgraded to Buy from Hold at Maxim... Patterson Companies (PDCO) upgraded to Buy from Neutral at UBS... PayPal (PYPL) upgraded to Outperform on core market share gains at Wedbush... Prosperity Bancshares (PB) upgraded to Buy from Neutral at DA Davidson... RPC, Inc. (RES) upgraded to Overweight from Equal Weight at Morgan Stanley... Rowan Companies (RDC) upgraded to Equal Weight from Underweight at Morgan Stanley... SanDisk (SNDK) upgraded to Buy from Neutral at Mizuho... Stillwater Mining (SWC) upgraded to Outperform from Market Perform at FBR Capital... Vantiv (VNTV) upgraded to Positive from Neutral at Susquehanna... Wilshire Bancorp (WIBC) upgraded to Outperform from Market Perform at Raymond James.