Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
LTO: Apply global DCE to ThinLTO modules at LTO opt level 0.
This is necessary because DCE is applied to full LTO modules. Without this change, a reference from a dead ThinLTO global to a dead full LTO global will result in an undefined reference at link time. This problem is only observable when --gc-sections is disabled, or when targeting COFF, as the COFF port of lld requires all symbols to have a definition even if all references are dead (this is consistent with link.exe). This change also adds an EliminateAvailableExternally pass at -O0. This is necessary to handle the situation on Windows where a non-prevailing copy of a linkonce_odr function has an SEH filter function; any such filters must be DCE'd because they will contain a call to the llvm.localrecover intrinsic, passing as an argument the address of the function that the filter belongs to, and llvm.localrecover requires this function to be defined locally. Fixes PR35142. Differential Revision: https://reviews.llvm.org/D39484 llvm-svn: 317108
- Loading branch information
Showing
4 changed files
with
59 additions
and
32 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters