[llvm] [llvm-mca] Add optional identifier field to mca::Instruction (PR #97867)

[Chinmay Deshpande via llvm-commits]

chinmaydd wrote:

Hi @michaelmaitland, thank you for continuing to engage with this PR. I appreciate your time.

> It sounds like the value here is for llvm-mcad to explore whether receiving metadata is valuable

That is correct, but like my previous comment highlights -- we are also using MCAD to "provide" metadata rather than receiving it. This way, the client of the Broker can leverage hardware events, such as stalls and pipeline pressure events, which we store as a mapping from `{InstructionIdentifier: vector<HardwareEvents>}`.



https://github.com/llvm/llvm-project/pull/97867