Google Git
Sign in
llvm / llvm-project / 32cd18975d2e1de5a783e9b1c3c21a234d5723b4
commit32cd18975d2e1de5a783e9b1c3c21a234d5723b4[log] [tgz]
authorNikita Popov <npopov@redhat.com>Mon Jul 22 16:22:01 2024 +0200
committerGitHub <noreply@github.com>Mon Jul 22 16:22:01 2024 +0200
treef0b404e096878ff28fbc951b20ffe8ed79f4134d
parent091ec15bbebf5be42d10f05a393489732ce651e4 [diff]
[GVN] Look through select/phi when determining underlying object (#99509)

This addresses an optimization regression in Rust we have observed after
https://github.com/llvm/llvm-project/pull/82458. We now only perform
pointer replacement if they have the same underlying object. However,
getUnderlyingObject() by default only looks through linear chains, not
selects/phis. In particular, this means that we miss cases involving
involving pointer induction variables.

This patch fixes this by introducing a new helper
getUnderlyingObjectAggressive() which basically does what
getUnderlyingObjects() does, just specialized to the case where we must
arrive at a single underlying object in the end, and with a limit on the
number of inspected values.

Doing this more expensive underlying object check has no measurable
compile-time impact on CTMark.
4 files changed
tree: f0b404e096878ff28fbc951b20ffe8ed79f4134d
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. libc/
  11. libclc/
  12. libcxx/
  13. libcxxabi/
  14. libunwind/
  15. lld/
  16. lldb/
  17. llvm/
  18. llvm-libgcc/
  19. mlir/
  20. offload/
  21. openmp/
  22. polly/
  23. pstl/
  24. runtimes/
  25. third-party/
  26. utils/
  27. .clang-format
  28. .clang-tidy
  29. .git-blame-ignore-revs
  30. .gitattributes
  31. .gitignore
  32. .mailmap
  33. CODE_OF_CONDUCT.md
  34. CONTRIBUTING.md
  35. LICENSE.TXT
  36. pyproject.toml
  37. README.md
  38. SECURITY.md
README.md

The LLVM Compiler Infrastructure

OpenSSF Scorecard OpenSSF Best Practices libc++

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.