[AsmPrinter] Add generic support for verifying instruction sizes (#187703)

Many backends rely on TII reporting correct instruction sizes for MIR
level branch relaxation passes. Reporting a too small size can result in
MC fixup failures (or silent miscompiles for unvalidated fixups).

Some time ago I added validation to the PPC asm printer to verify that
the TII instruction size matches the actually emitted size. This was
very helpful to systematically fix all incorrectly reported instruction
sizes.

However, the same problem also exists in lots of other backends, so this
moves the validation into AsmPrinter, controlled by a new
getInstSizeVerifyMode() hook in TII, which is disabled by default.

The intention here is to gradually enable this validation for more
backends (which requires fixing them first).
5 files changed
tree: c318d5d3a089826808eaf3c064d5450ecb054172
  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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