[PATCH] D77523: Add CanonicalizeFreezeInLoops pass

[Juneyoung Lee via Phabricator via llvm-commits]

aqjune added a comment.

I investigated how this patch affects mcf_r , and the result was as follows:

(1) For the previous experimental result, I made a silly mistake :(
Actually, it brought speedup; I ran mcf_r with testsuite with LTO enabled, and applying this patch showed 4.7% speedup (91.86 sec -> 87.55 sec), which is much more than I expected.
To check whether it affects other benchmarks, I'm running SPEC 2017 (without using testsuite).

(2) For mcf_r, I investigated how many steps do we need to see from PHI to push all freezes out of the loop, and the maximum distance was 2.
>From this fact, we may not need very general algorithm at this point. Simple syntactic rules can be added if mcf_r shows slowdown again. If more general pattern is needed, we can revisit the general algorithm.

I can invest only a few hours for patches per a day, so updates might be a bit slow. Anyway, I'll attach the SPEC 2017 result after running is done.


Repository:
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https://reviews.llvm.org/D77523