Manual-sync mirror of chromium.googlesource.com/external/github.com/llvm/llvm-project (bare monorepo, no subtree suffix)
e9acb01904
This is a part of a series of patches that rework OpenMP cross-team
reductions.
This patch changes the cross-team reduction runtime to no longer work
through larger number of teams in chunks. Instead, we allocate a
suitable-sized global buffer for the team values and let all teams run
at once. The last team that finishes uses a strided loop to reduce the
team values from the global buffer.
We also use `mapping::getNumberOfThreadsInBlock()` instead of
`omp_get_num_threads()` because the reduction of the team values runs
outside of the parallel region device code, which would make
`omp_get_num_threads()` always return 1. For Generic-SPMD mode, we also
want to use all available threads, which means that we need to copy the
reduction data from LDS (where it lives in that mode by default) to
scratch in codegen before calling the cross-team reduction.
Performance:
All performance tests can be reproduced with
https://github.com/ro-i/xteam-test @ commit
2f09ae1f566f13189d20b414d8b83bf2986564d2. To reproduce, simply create a
`local.mk` file in the cloned directory with a suitable `OFFLOAD_ARCH`
for your machine and `CXX_trunk` + `CXX_trunk_dev` set to the paths of
the clang++ binaries for llvm/main and this patch. (llvm/main should
best be at the commit that is currently the base for this PR. At the
moment, this is
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| cmake | ||
| compiler-rt | ||
| cross-project-tests | ||
| flang | ||
| flang-rt | ||
| libc | ||
| libclc | ||
| libcxx | ||
| libcxxabi | ||
| libsycl | ||
| libunwind | ||
| lld | ||
| lldb | ||
| llvm | ||
| llvm-libgcc | ||
| mlir | ||
| offload | ||
| openmp | ||
| orc-rt | ||
| polly | ||
| runtimes | ||
| third-party | ||
| utils/bazel | ||
| .clang-format | ||
| .clang-format-ignore | ||
| .clang-tidy | ||
| .git-blame-ignore-revs | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| LICENSE.TXT | ||
| pyproject.toml | ||
| README.md | ||
| SECURITY.md | ||
The LLVM Compiler Infrastructure
Welcome to the LLVM project!
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