Google Git
Sign in
llvm / llvm-project / d74d841b65dc5ecc1adb87f94ee5c8073984e130
commitd74d841b65dc5ecc1adb87f94ee5c8073984e130[log] [tgz]
authorFlorian Hahn <flo@fhahn.com>Wed Jul 30 21:10:57 2025 +0100
committerGitHub <noreply@github.com>Wed Jul 30 21:10:57 2025 +0100
tree154c0a020248748485bd5a0e50cf3eed9c676197
parent8dd91996f008c47b986943499acf3e1abd4deaa8 [diff]
[SECV] Try to push the op into ZExt: A + zext (-A + B) -> zext (B) (#151227)

Try to push the constant operand into a ZExt:
A + zext (-A + B) -> zext (B), if trunc (A) + -A + B does not
unsigned-wrap.

The actual code supports ZExts with arbitrary number of arguments, hence
the getAddExpr in the return.

This helps SCEV reasoning in some cases, commonly when adding an offset
to a zero-extended SCEV that subtracts the same offset.

Note that this is restricted to cases where we can fold away an operand
of the inner Add. This is needed to avoid bad interactions with patterns
when forming ZExts, which try to push to ZExt to add operands.

https://alive2.llvm.org/ce/z/q7d303

PR: https://github.com/llvm/llvm-project/pull/151227
4 files changed
tree: 154c0a020248748485bd5a0e50cf3eed9c676197
  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. libunwind/
  16. lld/
  17. lldb/
  18. llvm/
  19. llvm-libgcc/
  20. mlir/
  21. offload/
  22. openmp/
  23. polly/
  24. runtimes/
  25. third-party/
  26. utils/
  27. .clang-format
  28. .clang-format-ignore
  29. .clang-tidy
  30. .git-blame-ignore-revs
  31. .gitattributes
  32. .gitignore
  33. .mailmap
  34. CODE_OF_CONDUCT.md
  35. CONTRIBUTING.md
  36. LICENSE.TXT
  37. pyproject.toml
  38. README.md
  39. 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.