forked from OSchip/llvm-project
46774df307
Reimplements MisExpect diagnostics from D66324 to reconstruct its original checking methodology only using MD_prof branch_weights metadata. New checks rely on 2 invariants: 1) For frontend instrumentation, MD_prof branch_weights will always be populated before llvm.expect intrinsics are lowered. 2) for IR and sample profiling, llvm.expect intrinsics will always be lowered before branch_weights are populated from the IR profiles. These invariants allow the checking to assume how the existing branch weights are populated depending on the profiling method used, and emit the correct diagnostics. If these invariants are ever invalidated, the MisExpect related checks would need to be updated, potentially by re-introducing MD_misexpect metadata, and ensuring it always will be transformed the same way as branch_weights in other optimization passes. Frontend based profiling is now enabled without using LLVM Args, by introducing a new CodeGen option, and checking if the -Wmisexpect flag has been passed on the command line. Reviewed By: tejohnson Differential Revision: https://reviews.llvm.org/D115907 |
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| bindings | ||
| cmake | ||
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| include | ||
| lib | ||
| runtime | ||
| test | ||
| tools | ||
| unittests | ||
| utils | ||
| www | ||
| .clang-format | ||
| .clang-tidy | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CODE_OWNERS.TXT | ||
| INSTALL.txt | ||
| LICENSE.TXT | ||
| ModuleInfo.txt | ||
| NOTES.txt | ||
| README.txt | ||
README.txt
//===----------------------------------------------------------------------===// // C Language Family Front-end //===----------------------------------------------------------------------===// Welcome to Clang. This is a compiler front-end for the C family of languages (C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM compiler infrastructure project. Unlike many other compiler frontends, Clang is useful for a number of things beyond just compiling code: we intend for Clang to be host to a number of different source-level tools. One example of this is the Clang Static Analyzer. If you're interested in more (including how to build Clang) it is best to read the relevant web sites. Here are some pointers: Information on Clang: http://clang.llvm.org/ Building and using Clang: http://clang.llvm.org/get_started.html Clang Static Analyzer: http://clang-analyzer.llvm.org/ Information on the LLVM project: http://llvm.org/ If you have questions or comments about Clang, a great place to discuss them is on the Clang forums: https://discourse.llvm.org/c/clang/ If you find a bug in Clang, please file it in the LLVM bug tracker: http://llvm.org/bugs/