[llvm-branch-commits] [llvm][misexpect] Enable diagnostics for profitable llvm.expect annotations (PR #96523)

[Paul Kirth via llvm-branch-commits]

https://github.com/ilovepi created https://github.com/llvm/llvm-project/pull/96523

Issue #56502 describes an enhancement related to the use of llvm.expect.
The request is for a diagnostic mode that can identify branches that
would benefit from the use of llvm.expect based on the branch_weights
assigned from a PGO or sample profile.

To support identify branches(or switches) that would benefit from the
use of an llvm.expect intrinsic, we follow a similar checking pattern to
that used in MisExpect, but only in cases where MisExpect diagnostics
would not be used (i.e., when an llvm.expect intrinsic has already been
used).