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llvm / llvm-project / 96b2e35a58819eb2fbe1821650e35a1f0e085bd7
commit96b2e35a58819eb2fbe1821650e35a1f0e085bd7[log] [tgz]
authorDavid Sherwood <57997763+david-arm@users.noreply.github.com>Wed Apr 24 14:31:06 2024 +0100
committerGitHub <noreply@github.com>Wed Apr 24 14:31:06 2024 +0100
tree7802fe4082699df975e9f8a7cb8895f2c9a3a7d0
parent3328ccf68985ed512d448890ee900ed5f4bdb620 [diff]
[CostModel][AArch64] Improve fixed-width vector costs for get.active.lane.mask (#89068)

When SVE is available we can lower calls to get.active.lane.mask using
the SVE whilelo instruction, however in practice since vXi1 types are
not legal for NEON we often end up expanding the predicate into a vector
of integers, e.g. v4i1 -> v4i32. This usually happens when we have to
keep the predicate live out of the block, for example when the predicate
is the incoming value to a PHI node in a tail-folded vector loop.
Currently in such cases the intrinsic call has a cost of 1, which is far
too low when considering the extra instructions required to expand the
predicate. This patch fixes that by basing the cost on the number of
lane moves required for expansion. This is required for a follow-on
patch that adds the cost of the intrinsic call to the vectorisation cost
model, so that we can teach the vectoriser to make better choices.
2 files changed
tree: 7802fe4082699df975e9f8a7cb8895f2c9a3a7d0
  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

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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.

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