llvm-project

f401a76d - [SampleProfileMatcher] Add direct basename early matching for orphan functions (#184409)

[SampleProfileMatcher] Add direct basename early matching for orphan functions (#184409) When user code changes function signatures (e.g., adding/removing parameters), the C++ mangled name changes while the base function name stays the same. The existing stale profile CG matching can only recover renamed functions when they appear as callees of already-matched callers. If the caller has no profile (e.g., fully inlined in the profiled binary, or from a different TU not loaded), the renamed callee is never discovered and gets zero profile data. Add `matchFunctionsWithoutProfileByBasename()` that pairs orphan IR functions (no profile) with unused top-level profile functions by demangled basename, without requiring a matched caller in the call graph. This direct basename matching runs before CG matching and writes to `FuncToProfileNameMap`. CG matching can later overwrite these entries (since `SymbolMap` is not updated until `UpdateWithSalvagedProfiles`), so a contextually better CG match is not blocked. An unambiguous 1:1 mapping is enforced: a basename is only matched when exactly one orphan IR function and exactly one profile candidate share it. This eliminates false positives from common/short basenames while preserving matches for unique function names that are the primary target of this optimization.