[llvm] [ProfileData] Preserve cross-image targets in concatenated raw profiles (PR #212715)

[Snehasish Kumar via llvm-commits]

snehasish wrote:

Thanks for narrowing the scope, but I do not think the benefit justifies this change.

The only demonstrated consumer is the hidden, non-default "-icp-allow-decls=true" mode. But the target remains an external declaration, the promotion cannot enable the primary benefits of ICP, such as inlining, specialization, constant propagation, or broader interprocedural optimization. At best, it replaces one indirect call with a guard and an external call, which is not clearly a consistent win.

The non-PIE case also needs validation: the profiled call operand may be the executable’s canonical PLT address rather than the DSO function entry, which may not match the DSO’s profile mapping.

Given the limited upside and the unconditional reader overhead, I do not think this should land.

https://github.com/llvm/llvm-project/pull/212715