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android / toolchain / llvm-project / 7bcf4d63cf3b7bcc789808ea4e9c8369e94467dc
commit7bcf4d63cf3b7bcc789808ea4e9c8369e94467dc[log] [tgz]
authorJeffrey Byrnes <[email protected]>Thu Aug 22 11:38:24 2024 -0700
committerGitHub <[email protected]>Thu Aug 22 11:38:24 2024 -0700
tree1bcee76e0d74c33659f8fe2caa8e3c1c8104e230
parente5140aed275fe60b83188143f39011d5c0ee5bb0 [diff]
[AMDGPU] Correctly insert s_nops for dst forwarding hazard (#100276)

MI300 ISA section 4.5 states there is a hazard between "VALU op which
uses OPSEL or SDWA with changes the result’s bit position" and "VALU op
consumes result of that op"

This includes the case where the second op is SDWA with same dest and
dst_sel != DWORD && dst_unused == UNUSED_PRESERVE. In this case, there
is an implicit read of the first op dst and the compiler needs to
resolve this hazard. Confirmed with HW team.

We model dst_unused == UNUSED_PRESERVE as tied-def of implicit operand,
so this PR checks for that.

MI300_SP_MAS section 1.3.9.2 specifies that CVT_SR_FP8_F32 and
CVT_SR_BF8_F32 with opsel[3:2] !=0 have dest forwarding issue.
Currently, we only add check for CVT_SR_FP8_F32 with opsel[3] != 0 --
this PR adds support opsel[2] != 0 as well
8 files changed
tree: 1bcee76e0d74c33659f8fe2caa8e3c1c8104e230
  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!

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