[llvm] [SCEV] Use signed form of samesign compares when it tightens exit limits (PR #223514)

[Hao Ren via llvm-commits]

nvidia-moomoo wrote:

>From my reading of the current benchmark report, most of the regressions by smax / smin are gone, which makes unrolling regressions also gone. 

There are also no significant wins directly shown from the report because, like mentioned above, the wins are in backend LSR not captured in the benchmark.



https://github.com/llvm/llvm-project/pull/223514