[LoopInterchange] Constrain number of  load/stores in a loop (#118973)

In the current state of the code, the transform computes entries for the
dependency matrix until `MaxMemInstrCount` which is 100. After 99th
entry, it terminates and thus overall wastes compile-time.

It would be nice if we can compute total number of entries upfront and
early exit if the number of entries > 100. However, computing the number
of entries is not always possible as it depends on two factors:
1. Number of load-store pairs in a loop.
2. Number of common loop levels for each of the pair.

This patch constrains the whole computation on the number of loads and
stores instructions in the loop.

In another approach, I experimented with computing 1 and constraining
the number of pairs, but that did not lead to any additional benefit in
terms of compile time. However, when other issues are fixed, I can
revisit this approach.
2 files changed
tree: 218e4e0b472d139c88c66dd181b691f0e5b68f74
  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
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