[llvm] [JumpThreading] Limit number of free instructions (PR #75671)

[Nick Terrell via llvm-commits]

terrelln wrote:

> this patch will cause the presence of debug info to affect codegen, which is something we don't want

Is this a hard requirement or a guideline? Currently, with the default settings, you'd need 500 "free" intrinsics for less than 14 non-free instructions to change the decision to duplicate. To me this seems like an extreme number that is unlikely to show up often in practice (but maybe I'm wrong). But if it is a hard requirement, then I get that.

If this isn't acceptable, do you have a suggestion for a path forward?

https://github.com/llvm/llvm-project/pull/75671