Oppenheimer upgraded SunPower Corporation to Outperform from Perform, saying the company’s challenging operating conditions are priced in to shares. The upgrade came after the company posted “strong” fourth quarter revenue and maintained 2017 guidance.SunPower, which has suffered from substantial module margin compression, reported fourth quarter non-GAAP EPS of $(0.64) versus consensus of $(0.46). Non-GAAP revenue was $1.097 billion versus Street view of $1.047 billion. Non-GAAP gross margin came in at (2 percent) compared to consensus of 3 percent.For the first quarter, the company guided to non-GAAP revenue of $370-$420 million versus consensus of $459 million.The company also maintained its FY2017 non-GAAP revenue outlook of $2.1-$2.6 billion versus consensus of $2.4 billion. Deployment guidance of 1.3-1.6 GW was also reiterated.via