[llvm] [SimplifyCFG] Skip phi scans when folded block shares no predecessors (PR #225647)

[Dominik Steenken via llvm-commits]

dominik-steenken wrote:

@nikic @fhahn could you please review this? The reproducer is using synthetic code, but i think the compile time reduction is still relevant in production code as well, and the change seems to me to just make the pass generally smarter about when to spend the effort, which should be a win in any case.

https://github.com/llvm/llvm-project/pull/225647