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So you're saying we should applaud reducing it by 1-2% right?

To answer the question of if it's worth it to add this specialized instruction, it really depends on how much die space it adds, but from the look of it, it's specialized handling of an existing operation to match an external spec; that can be not too hard to do and significantly reduce software complexity for tasks that do that operation. As a CE with no real hardware experience, it looks like a clear win to me.