Shares of global semiconductor firms rallied on Wednesday as they were boosted by some positive earnings in the sector and a report of potentially less severe U.S. export restrictions on China.AMD was among the morning's big winners with shares up more than 9% in U.S. premarket trading after the company reported a top and bottom line beat in its second-quarter financial report. AMD saw strong growth in its data center business, driven by sales of its graphics processing units (GPUs) which are used to train ...