tree a48a463f819bd50e01ec33c42a166ba8b9dfc07b
parent cf184d6fe9720835a08f63594039a874a2d79b75
author Ellis Hoag <ellis.sparky.hoag@gmail.com> 1704413637 -0800
committer Copybara-Service <copybara-worker@google.com> 1704413731 -0800

[InstrProf] No linkage prefixes in IRPGO names (#76994)

Change the format of IRPGO counter names to
`[<filepath>;]<mangled-name>` which is computed by
`GlobalValue::getGlobalIdentifier()` to fix #74565.

In fe051934cbb0aaf25d960d7d45305135635d650b
(https://reviews.llvm.org/D156569) the format of IRPGO counter names was
changed to be `[<filepath>;]<linkage-name>` where `<linkage-name>` is
basically `F.getName()` with some prefix, e.g., `_` or `l_` on Mach-O
(yes, it is confusing that `<linkage-name>` is computed with
`Mangler().getNameWithPrefix()` while `<mangled-name>` is just
`F.getName()`). We discovered in #74565 that this causes some missed
import issues on some targets and #74008 is a partial fix.

Since `<mangled-name>` may not match the `<linkage-name>` on some
targets like Mach-O, we will need to post-process the output of
`llvm-profdata order` before passing to the linker via `-order_file`.

Profiles generated after fe051934cbb0aaf25d960d7d45305135635d650b will
become stale after this diff, but I think this is acceptable since that
patch landed after the LLVM 18 cut which hasn't been released yet.

GitOrigin-RevId: 9a2df55f47e4ec02a1efbf8efa776cfeed527df2