[llvm] [SLP] Add store-to-load forwarding conflict cost for widened store chains (PR #199606)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

1.Rebase
2. Did you use AI tool? Add to to the commit message
3. Add compile-time/runtime data

https://github.com/llvm/llvm-project/pull/199606