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llvm / llvm-project / 5850c44288cba01c75f8afb7cfcf3a2d47e2d5a4
commit5850c44288cba01c75f8afb7cfcf3a2d47e2d5a4[log] [tgz]
authorMingjie Xu <xumingjie.enna1@bytedance.com>Mon Sep 15 10:28:40 2025 +0800
committerGitHub <noreply@github.com>Mon Sep 15 10:28:40 2025 +0800
tree263985517e534cf057932834b9e19cd1dd1670c8
parentfef88d2ef21edc83660968e0134e28dda88d4a11 [diff]
[InstCombine] Improve `foldDeadPhiWeb` compile time (#158057)

The foldDeadPhiWeb function identifies and removes small dead PHI webs,
it bails out if the web size exceeds threshold (16).

In the current implementation, when there is a phi node has large number
of users that most of them are phi nodes, we still push them on the
`Stack` even if the number of phi nodes user exceeds the threshold.

This patch checks the early stop condition when we push an unvisited phi
node on the `Stack`.
With this change, the wall duration of total instcombine pass decreased
from 523,649.276 ms to 208,687.042 ms in an our internal case.
1 file changed
tree: 263985517e534cf057932834b9e19cd1dd1670c8
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. flang-rt/
  11. libc/
  12. libclc/
  13. libcxx/
  14. libcxxabi/
  15. libsycl/
  16. libunwind/
  17. lld/
  18. lldb/
  19. llvm/
  20. llvm-libgcc/
  21. mlir/
  22. offload/
  23. openmp/
  24. orc-rt/
  25. polly/
  26. runtimes/
  27. third-party/
  28. utils/
  29. .clang-format
  30. .clang-format-ignore
  31. .clang-tidy
  32. .git-blame-ignore-revs
  33. .gitattributes
  34. .gitignore
  35. .mailmap
  36. CODE_OF_CONDUCT.md
  37. CONTRIBUTING.md
  38. LICENSE.TXT
  39. pyproject.toml
  40. README.md
  41. SECURITY.md
README.md

The LLVM Compiler Infrastructure

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Welcome to the LLVM project!

This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.

C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

Consult the Getting Started with LLVM page for information on building and running LLVM.

For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting in touch

Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.

The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.