[llvm] [IR] Add `samesign` flag to icmp instruction (PR #111419)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> BTW, I believe we will encounter some miscompilation bugs as we don't drop poison-generating flags for icmp properly in some places. Please give me more time to do some testing before leveraging this flag to do more optimizations.

I cannot find more miscompilation bugs with mutation-based fuzzers. Feel free to go ahead :)


https://github.com/llvm/llvm-project/pull/111419