I don’t see why offsets larger than 16-bit are important. Are you implying that most fusion candidate pairs would need this? In tight inner loops why would you

I don’t see why offsets larger than 16-bit are important. Are you implying that most fusion candidate pairs would need this? In tight inner loops why would you need large offsets? Of course you discard architectural state changes in fusion. If I have a bunch of instructions which end up reading from memory into register x10, then I can fuse with all previous instructions which wrote into x10, as their results get clobbered anyway. Disclaimer: I may have misunderstood the point you made. However you don’t seem to make it clear how fusion is bad for performance. What performance tricks are you giving up by doing fusion?