Reapply "[llvm-exegesis] Add AArch64 operand initializers, SetRegTo" (#174729) (#174944)

This reverts commit f68774fd1ad570fef850439ac163b61dc96b98f1. The
original PR broke the sanitizer-aarch64-linux-bootstrap-asan builder:
https://lab.llvm.org/buildbot/#/builders/24/builds/16298

The cause of the failure was exegesis producing inconsistent results
across libc++ implementations when seeded with
'--random-generator-seed=<seed>'. The failing Buildbot does a 2-stage
build, in the 1st stage it builds LLVMs libc++ then builds LLVM with it
in the 2nd stage. The exegesis implementation relies on
uniform_int_distribution which doesn't guarantee consistent results
across implementations.

The tests seeded the RNG because FileCheck can't handle the wrap around
constraint of the register pairs, e.g. { v31.1d, v0.1d }. The test is
updated to no longer rely on '--random-generator-seed'. Unfortunately
the tests aren't particularly good anymore, but not sure what else can
be done for now.
5 files changed
tree: 28ac61cc2660cc9a0320b717ad975d517b44e39e
  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

The LLVM Compiler Infrastructure

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