Re:Why is Rosetta 2 fast?
by vgatherps on Thursday November 10, 2022 @12:34AM
(#33542661)
I believe intel used to always predict forward branches not taken and backward branches always taken if it didn’t have any history.
Regardless, you can at least lay out code in a way that heavily favors one branch over the other, and potentially optimize for one branch (I.e. give one branch very expensive prelude/exit to make another branch very cheap). The last thing I’ve seen compilers greatly struggle with though…
Regardless, you can at least lay out code in a way that heavily favors one branch over the other, and potentially optimize for one branch (I.e. give one branch very expensive prelude/exit to make another branch very cheap). The last thing I’ve seen compilers greatly struggle with though…