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llvm / llvm-project / a91b0d27806226d52db90a4fe83bb73a95f412f4
commita91b0d27806226d52db90a4fe83bb73a95f412f4[log] [tgz]
authorzhijian lin <zhijian@ca.ibm.com>Thu Jun 05 09:41:51 2025 -0400
committerGitHub <noreply@github.com>Thu Jun 05 09:41:51 2025 -0400
tree25b4ff3867b2a3195f51061a3be01d4244c33f25
parent8830e3802a92dca1d08048ac1197d9b0542db048 [diff]
[PowerPC] hoist xxspltiw instruction out of the loop with FMA mutation pass. (#111696)

Summary: 
   
The patch fixes the issue [[PowerPC] missing VSX FMA Mutation optimize
in some case for option -schedule-ppc-vsx-fma-mutation-early
#111906](https://github.com/llvm/llvm-project/issues/111906)
   
In certain cases, the Register Coalescer pass—which eliminates COPY
instructions—can interfere with the PowerPC VSX FMA Mutation pass.
Specifically, it can prevent the mutation of a COPY adjacent to an
XSMADDADP into a single XSMADDMDP instruction. As a result, the xxspltiw
instruction is not hoisted out of the loop as expected, leading to
missed optimization opportunities.

To address this, the patch ensures that the `VSX FMA Mutation` pass runs
before the `Register Coalescer` pass when the
-schedule-ppc-vsx-fma-mutation-early option is enabled.
2 files changed
tree: 25b4ff3867b2a3195f51061a3be01d4244c33f25
  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

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