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llvm / llvm-project / b7d0c9b9d8e2b5c5d6677e368e3cdaf438df294e
commitb7d0c9b9d8e2b5c5d6677e368e3cdaf438df294e[log] [tgz]
authorCraig Topper <craig.topper@sifive.com>Sat Jun 21 18:56:00 2025 -0700
committerGitHub <noreply@github.com>Sat Jun 21 18:56:00 2025 -0700
treecd0fc93b94ed3f2ae930c083e85cf073661d5da0
parentf280d3b705de7f94ef9756e3ef2842b415a7c038 [diff]
[SelectionDAG][RISCV] Treat zext nneg as sext in PromoteIntOp_ZERO_EXTEND if the promoted input is sign extended. (#145120)

If the zext has the nneg flag and we can prove the promoted input
is sign extended, we can avoid generating an AND that we might not
be able to remove. RISC-V emits a lot of sext_inreg operations during
i32->i64 promotion that makes this likely.

I've restricted this to the case where the promoted type is the same
as the result type so we don't need to create an additional extend.

I've also restricted it to cases where the target has stated a
preference for sext like i32->i64 on RV64. This is largely to avoid
wasting time in computeNumSignBits until we have a test case that
benefits.
2 files changed
tree: cd0fc93b94ed3f2ae930c083e85cf073661d5da0
  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. pstl/
  25. runtimes/
  26. third-party/
  27. utils/
  28. .clang-format
  29. .clang-format-ignore
  30. .clang-tidy
  31. .git-blame-ignore-revs
  32. .gitattributes
  33. .gitignore
  34. .mailmap
  35. CODE_OF_CONDUCT.md
  36. CONTRIBUTING.md
  37. LICENSE.TXT
  38. pyproject.toml
  39. README.md
  40. 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.

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