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| author | Jaroslav Sevcik <jarin@google.com> | 2020-01-22 15:19:44 +0100 |
|---|---|---|
| committer | Raphael Isemann <teemperor@gmail.com> | 2020-01-22 15:20:06 +0100 |
| commit | 4481eefbe8425c63289186dd13319aaa7043e67f (patch) | |
| tree | acdfe3c2b71e49054d3606b2407404a03c2c5059 /llvm/lib/CodeGen/MachineScheduler.cpp | |
| parent | e3b15ed376f3753d2a4e16281f8230e4ffed41ba (diff) | |
| download | llvm-4481eefbe8425c63289186dd13319aaa7043e67f.zip llvm-4481eefbe8425c63289186dd13319aaa7043e67f.tar.gz llvm-4481eefbe8425c63289186dd13319aaa7043e67f.tar.bz2 | |
[ASTImporter] Properly delete decls from SavedImportPaths
Summary:
We see a significant regression (~40% slower on large codebases) in expression evaluation after https://reviews.llvm.org/rL364771. A sampling profile shows the extra time is spent in SavedImportPathsTy::operator[] when called from ASTImporter::Import. I believe this is because ASTImporter::Import adds an element to the SavedImportPaths map for each decl unconditionally (see https://github.com/llvm/llvm-project/blob/7b81c3f8793d30a4285095a9b67dcfca2117916c/clang/lib/AST/ASTImporter.cpp#L8256).
To fix this, we call SavedImportPathsTy::erase on the declaration rather than clearing its value vector. That way we do not accidentally introduce new empty elements. (With this patch the performance is restored, and we do not see SavedImportPathsTy::operator[] in the profile anymore.)
Reviewers: martong, teemperor, a.sidorin, shafik
Reviewed By: martong
Subscribers: rnkovacs, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73166
Diffstat (limited to 'llvm/lib/CodeGen/MachineScheduler.cpp')
0 files changed, 0 insertions, 0 deletions