[TargetLowering] Add support for more constants to expandDIVREMByConstant. (#189286)

If we can find a chunk size k where 2^k mod divisor == -1, we can add
the even chunks and subtract the odd chunks. The resulting sum may be
negative, so we need to add 2^k + 1 (a multiple of divisor) for each odd
chunk to ensure the result is positive. We have enough extra bits
between the chunk size and HBitWidth to avoid overflow.

The idea here is similar to checking if a decimal number is divisible by
11. You can add the even digits and subtract the odd digits. If the
resulting sum is divisible by 11 the original number is divisible by 11.
6 files changed
tree: eb6e2cd457b93b60d11be418f3ea480f48a27b9e
  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. libsycl/
  16. libunwind/
  17. lld/
  18. lldb/
  19. llvm/
  20. llvm-libgcc/
  21. mlir/
  22. offload/
  23. openmp/
  24. orc-rt/
  25. polly/
  26. runtimes/
  27. third-party/
  28. utils/
  29. .clang-format
  30. .clang-format-ignore
  31. .clang-tidy
  32. .git-blame-ignore-revs
  33. .gitattributes
  34. .gitignore
  35. .mailmap
  36. CODE_OF_CONDUCT.md
  37. CONTRIBUTING.md
  38. LICENSE.TXT
  39. pyproject.toml
  40. README.md
  41. SECURITY.md
README.md

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