Changes in performance when the enable_noundef_analysis option is turned on.

Hello,
I’ve been working on making the “noundef” attribute be the default on all functions parameters. The reason for adding the “noundef” attribute to function arguments is to reduce performance degradation caused by the Freeze.
And I performed several tests to show that adding the “noundef” attribute to function arguments improves performance. I think the test results are pretty straightforward. When there is little Freeze, adding a “noundef” attribute does not degrade the performance.
However, in situations where the Freeze is added to solve the LoopUnswitch’s miscompilation problem, it is possible to alleviate performance degradation by adding the “noundef” attribute to function arguments. You can check the results and some more details at the below link.

https://reviews.llvm.org/D105169#2996754

Thanks.
Hyeongyu