While this sort of thing is possible, it's unlikely. First, in almost all employment contracts the notice period is the same on both sides. Second, if the company did this sort of thing word would get around very quickly, resulting in a lot of employee dissatisfaction. Also companies rarely do this if they habitually take a 'gardening leave' approach. It doesn't pay them to have a long notice period if all they are going to do during it is pay you for not working.
If you believe you might be in this position, there is an easy way to deal with it, at least assuming that your intention is to move to another job. When the next job asks when you can start, say that you technically have to give three months notice, but you might be able to start in a month. Accept a start date in three months time, and if they fire you then call up the new company and say you can start early. They will probably be happy about that.
Incidentally it is often possible to negotiate down a long notice period. If you have another job to go to, and you are given three months gardening leave, go to the company and say you will take a month's pay instead of 3 months if they will let you start the new job immediately.