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llvm / llvm-project / f47034cbe5c02b748742c733cf453b3b907687e5
commitf47034cbe5c02b748742c733cf453b3b907687e5[log] [tgz]
authorChangpeng Fang <changpeng.fang@amd.com>Fri Apr 04 21:19:43 2025 -0700
committerGitHub <noreply@github.com>Fri Apr 04 21:19:43 2025 -0700
tree59c93294eedf0b2efd6b1ab237559b54fb012e11
parenta07b37475ccbf6b718fdf64fd6f0756ea1958852 [diff]
AMDGPU: Add round-to-odd rounding during f64 to bf16 conversion (#133995)

f64 -> bf16 conversion can be lowered to f64 -> f32 followed by f32 ->
bf16:
   v_cvt_f32_f64_e32 v0, v[0:1]
   v_cvt_pk_bf16_f32 v0, v0, s0
Both conversion instructions will do round-to-even rounding, and thus we
will have double rounding issue which may generate incorrect result in
some data range. We need to add round-to-odd rounding during f64 -> f32
to avoid double rounding,.

NOTE: we are having the same issue with f64 -> f16 conversion. Will add
round-to-odd rounding for it in a separate patch, which fixes
SWDEV-523856

---------

Co-authored-by: Matt Arsenault <arsenm2@gmail.com>
3 files changed
tree: 59c93294eedf0b2efd6b1ab237559b54fb012e11
  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-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

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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.

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