[DebugInfo] Pack DILocation hash inputs (#196556)
Pack DILocation fields before hashing. Now that column is 16-bits
Line/Column/ImplicitCode fit in one 64-bit value (32 + 16 + 1 = 49 bits)
and AtomGroup and AtomRank also fit cleanly in one 64-bit value (61 + 3
= 64 bits).
Fewer hash_combine inputs on the hot DILocation path is a small
compile-time improvement.
CTMark geomean:
- stage1-ReleaseLTO-g: -0.10%
- stage1-O0-g: -0.23%
- stage1-aarch64-O0-g: -0.19%
- stage2-O0-g: -0.07%
https://llvm-compile-time-tracker.com/compare.php?from=71fef6d5a306d1adf8bf7d30d2fe9e286380fecf&to=1d80b5f5aa98561d2ba09adc3f20c3eacd24cb88&stat=instructions%3Au
Assisted-by: codex
