[turbofan] move optimizer - CompressBlock cleanup.

I believe the code reads easier after this change. The original code
probably dates back to when we had 4 gap positions. Now that there
are only 2, the logic can be simpler by avoiding a loop and instead
treating each case explicitly: no gaps; gaps just at end; gaps at start and
maybe end. That way, it is also  easier to understand how the moves get
pushed downwards. This is what got me to make this change in the first
place: trying to work out a finer grained move optimization.

BUG=

Review URL: https://codereview.chromium.org/1543973002

Cr-Commit-Position: refs/heads/master@{#33016}
1 file changed
tree: 0d2235a15b8fc77ec6f27fc1c66e1f4abab98118
  1. benchmarks/
  2. build/
  3. docs/
  4. include/
  5. infra/
  6. samples/
  7. src/
  8. test/
  9. testing/
  10. third_party/
  11. tools/
  12. .clang-format
  13. .gitignore
  14. .ycm_extra_conf.py
  15. AUTHORS
  16. BUILD.gn
  17. ChangeLog
  18. codereview.settings
  19. DEPS
  20. LICENSE
  21. LICENSE.strongtalk
  22. LICENSE.v8
  23. LICENSE.valgrind
  24. Makefile
  25. Makefile.android
  26. Makefile.nacl
  27. OWNERS
  28. PRESUBMIT.py
  29. README.md
  30. snapshot_toolchain.gni
  31. WATCHLISTS
README.md

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

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V8 Project page: https://github.com/v8/v8/wiki

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Contributing

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