diff options
| author | Richard Smith <richard-llvm@metafoo.co.uk> | 2018-10-10 23:13:35 +0000 |
|---|---|---|
| committer | Richard Smith <richard-llvm@metafoo.co.uk> | 2018-10-10 23:13:35 +0000 |
| commit | 58ae9852115b9cf05c3166cba9f4cffcfaa061e2 (patch) | |
| tree | 5949de0c96f7bb51d9d61af3a6e9122a4265b0a3 /docs/ReleaseNotes.rst | |
| parent | b6756678e3559c1304735550e28479a6289c4e52 (diff) | |
| download | clang-58ae9852115b9cf05c3166cba9f4cffcfaa061e2.tar.gz | |
Add a flag to remap manglings when reading profile data information.
This can be used to preserve profiling information across codebase
changes that have widespread impact on mangled names, but across which
most profiling data should still be usable. For example, when switching
from libstdc++ to libc++, or from the old libstdc++ ABI to the new ABI,
or even from a 32-bit to a 64-bit build.
The user can provide a remapping file specifying parts of mangled names
that should be treated as equivalent (eg, std::__1 should be treated as
equivalent to std::__cxx11), and profile data will be treated as
applying to a particular function if its name is equivalent to the name
of a function in the profile data under the provided equivalences. See
the documentation change for a description of how this is configured.
Remapping is supported for both sample-based profiling and instruction
profiling. We do not support remapping indirect branch target
information, but all other profile data should be remapped
appropriately.
Support is only added for the new pass manager. If someone wants to also
add support for this for the old pass manager, doing so should be
straightforward.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@344199 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/ReleaseNotes.rst')
| -rw-r--r-- | docs/ReleaseNotes.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index b3eb9d5e10..7e798492bb 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -46,6 +46,11 @@ sections with improvements to Clang's support for those languages. Major New Features ------------------ +- Clang supports use of a profile remapping file, which permits + profile data captured for one version of a program to be applied + when building another version where symbols have changed (for + example, due to renaming a class or namespace). + See the :doc:`UsersManual` for details. Improvements to Clang's diagnostics ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |