I think you need to explore in detail of your job functions.
If your current front end job is developing IP, then there is no point you move to Altera.
But if that is not the case, then you should consider Altera where they will offer you the chance to develop IP.
Working as a front end engineer is all about developing IP.
Another reason, if both company offer you the same job functions, then you should stick to your current company and develop your own skill. You can always move to Altera in the future. But if you leave Renesas and job Altera, then it is harder for you to work in Renesas in the future.