[PATCH] D42717: [JumpThreading] sync DT for LVI analysis (PR 36133)

Fri Feb 9 09:10:12 PST 2018

brzycki added a comment.

@dberlin thank you for the suggestion and I have implemented the change. The good news is `sqlite` is back to our original performance. The not-so-great news is this causes a regression for `tramp3d-v4`:

  brzycki at cc01 /work/brzycki/test-suite $ ~/git/me/llvm/litdiff build.upstream/results.json build.D42717_newpatch/results.json compile_time
  #  left column: build.upstream/results.json
  # right column: build.D42717_newpatch/results.json
  #  metric name: compile_time
      493.8600 <- 536.3320     [  8.60%]  CTMark/tramp3d-v4/tramp3d-v4.test
      336.3600 <- 343.2440     [  2.05%]  CTMark/sqlite3/sqlite3.test
      373.0960 -> 369.3400     [  1.02%]  CTMark/consumer-typeset/consumer-typeset.test
      256.1360 -> 253.9560     [  0.86%]  CTMark/mafft/pairlocalalign.test
      459.5960 <- 462.5360     [  0.64%]  CTMark/SPASS/SPASS.test
     1265.6800 <- 1270.5560    [  0.39%]  CTMark/7zip/7zip-benchmark.test
      589.8000 <- 591.7280     [  0.33%]  CTMark/lencod/lencod.test
      387.2960 <- 388.3840     [  0.28%]  CTMark/kimwitu++/kc.test
      924.1160 -> 921.7360     [  0.26%]  CTMark/Bullet/bullet.test
      497.1560 -> 496.2280     [  0.19%]  CTMark/ClamAV/clamscan.test
  brzycki at cc01 /work/brzycki/test-suite $ ~/git/me/llvm/litdiff build.upstream2/results.json build.D42717_newpatch/results.json compile_time
  #  left column: build.upstream2/results.json
  # right column: build.D42717_newpatch/results.json
  #  metric name: compile_time
      487.0560 <- 536.3320     [ 10.12%]  CTMark/tramp3d-v4/tramp3d-v4.test
      347.4120 -> 343.2440     [  1.21%]  CTMark/sqlite3/sqlite3.test
      256.1000 -> 253.9560     [  0.84%]  CTMark/mafft/pairlocalalign.test
      588.3840 <- 591.7280     [  0.57%]  CTMark/lencod/lencod.test
      498.5240 -> 496.2280     [  0.46%]  CTMark/ClamAV/clamscan.test
      389.8320 -> 388.3840     [  0.37%]  CTMark/kimwitu++/kc.test
     1267.2280 <- 1270.5560    [  0.26%]  CTMark/7zip/7zip-benchmark.test
      368.5280 <- 369.3400     [  0.22%]  CTMark/consumer-typeset/consumer-typeset.test
      921.2680 <- 921.7360     [  0.05%]  CTMark/Bullet/bullet.test
      462.5440 -> 462.5360     [  0.00%]  CTMark/SPASS/SPASS.test

The upstream and upstream2 builds both use DT for LVI analysis. In the case of `tramp3d-v4` we lucked out using DT analysis without causing a miscompile. I don't see a way to get that performance back.

This patch also invalidates my proposed fix for https://reviews.llvm.org/D34135 since we no longer have a valid DT before calling LVI in all instances.

https://reviews.llvm.org/D42717