[llvm] ConstraintElim: add dry-run routine to fail early (PR #99670)

Sun Jul 21 21:24:04 PDT 2024

dtcxzyw wrote:

> I've made one more optimization, which, according to Compile Time Tracker, is a small optimization: http://llvm-compile-time-tracker.com/compare.php?from=c5ee3c05ca61f3fae11337c5853aee7b450a9dc6&to=11b306fae6c365a152d8fb9b61846ca733ac87c1&stat=instructions%3Au. I'm running out of ideas to optimize the dry-run routine further.
> 
> @dtcxzyw Could you kindly re-check with the latest commit?

Top 5 improvements:
  darktable/FujiDecompressor.cpp.ll 3874209532 3011988604 -22.26%
  openjdk/ad_x86_gen.ll 20827921447 18378859574 -11.76%
  faiss/IndexIVFAdditiveQuantizerFastScan.cpp.ll 874177979 810966258 -7.23%
  php/metaphone.ll 3643053889 3456185042 -5.13%
  cmake/cmPolicies.cxx.ll 2196055101 2085039126 -5.06%
Top 5 regressions:
  faiss/utils.cpp.ll 1280148979 1316090722 +2.81%
  gromacs/pull.cpp.ll 3521897039 3617100314 +2.70%
  faiss/IndexBinaryHNSW.cpp.ll 1079192410 1105841398 +2.47%
  faiss/IndexIVFFlat.cpp.ll 1772139516 1815060287 +2.42%
  faiss/IndexAdditiveQuantizerFastScan.cpp.ll 412085733 421718533 +2.34%
Overall: 0.03707713%

https://github.com/llvm/llvm-project/pull/99670