On 5/17/17 5:16 PM, David Miller wrote:
BTW, we track something similar already in reg->imm which tracks how many high order bits are known to be cleared in the register. It is used to avoid potential overflow for packet pointer accesses. I bet we can subsume that into this facility as well.
yeah, reg->imm tracks zero upper bits in very simplistic way. For alignment checking it seems we need to track lower zeros and ones. If Edward's algorithm can be adopted to track both that would be double win indeed.