forked from OSchip/llvm-project
9dd96d73f7
The current approach isn't a long-term viable pattern. Given the set of architectures A, vendors V, operating systems O, and environments E, it does |A| * |V| * |O| * |E| * 4! tests. As LLVM grows, this test keeps getting slower, despite my working very hard to make it get some "optimizations" even in -O0 builds in order to lower the constant factors. Fundamentally, we're doing an unreasonable amount of work.i Looking at the specific thing being tested -- the goal seems very clearly to be testing the *permutations*, not the *combinations*. The combinations are driving up the complexity much more than anything else. Instead, test every possible value for a given triple entry in every permutation of *some* triple. This really seems to cover the core goal of the test. Every single possible triple component is tested in every position. But because we keep the rest of the triple constant, it does so in a dramatically more scalable amount of time. With this model we do (|A| + |V| + |O| + |E|) * 4! tests. For me on a debug build, this goes from running for 19 seconds to 19 milliseconds, or a 1000x improvement. This makes a world of difference for the critical path of 'ninja check-llvm' and other extremely common workflows. Thanks to Renato, Dean, and David for the helpful review comments and helping me refine the explanation of the change. Differential Revision: https://reviews.llvm.org/D23156 llvm-svn: 277912 |
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| cmake | ||
| docs | ||
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| include | ||
| lib | ||
| projects | ||
| resources | ||
| runtimes | ||
| test | ||
| tools | ||
| unittests | ||
| utils | ||
| .arcconfig | ||
| .clang-format | ||
| .clang-tidy | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CODE_OWNERS.TXT | ||
| CREDITS.TXT | ||
| LICENSE.TXT | ||
| LLVMBuild.txt | ||
| README.txt | ||
| RELEASE_TESTERS.TXT | ||
| configure | ||
| llvm.spec.in | ||
README.txt
Low Level Virtual Machine (LLVM) ================================ This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments. LLVM is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt. Please see the documentation provided in docs/ for further assistance with LLVM, and in particular docs/GettingStarted.rst for getting started with LLVM and docs/README.txt for an overview of LLVM's documentation setup. If you are writing a package for LLVM, see docs/Packaging.rst for our suggestions.