Generally performance gets better mostly because x64 arch has more registers. That being said, I really wish the X32 ABI in linux had garnered more interest. T

Generally performance gets better mostly because x64 arch has more registers. That being said, I really wish the X32 ABI in linux had garnered more interest. The concept is that it's 64-bit code that runs with a 32-bit memory space. All your pointers can still be 32 bits but you also get all the architectural advantages of 64-bit mode too. In theory you should get the perf benefits of 64-bit without the perf costs. The ABI wasn't really used much, so it got removed. But it was a bit self fullfilling. We never wanted to switch to it because it had poor surport from distributions, but distributions didn't bother supporting it because nobody used it!