By Rashika SinghAug 5 (Reuters) - Advanced Micro Devices shares tumbled on Wednesday as the chipmaker's revenue forecast failed to impress investors seeking ‌clearer signs that a multibillion-dollar AI spending boom will translate into ‌faster growth. Shares were last down 6.6% at $482.53, set to erase close to $59 billion from the company's ​market value. Shares of the AI bellwether gained 3.3% in early trading. AMD's stock has more than doubled this year on expectations that the company will ​emerge as the leading alternative ‌to Nvidia in AI chips, raising the ante for quarterly results. (Reporting ​by Rashika Singh and Purvi Agarwal in Bengaluru; Editing by ​Mrigank Dhaniwala, Devika Syamnath and Tasim Zahid)