[PATCH] D68103: [InstCombine] Simplify shift-by-sext to shift-by-zext

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

In D68103#1686144 <https://reviews.llvm.org/D68103#1686144>, @lebedev.ri wrote:

> i can put the current-ish vaariant into aggressiveinstcombine; there it won't have O(N^2) problem, too.
>  It's just that the AIC IIRC only runs in -O3, not even -O2?


That's correct, but it was limited to -O3 only because that was the easy, non-controversial path forward. If someone is willing to quantify the perf vs. compile-time trade-off for AIC to show it's worth it, then it could be moved to -O2.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D68103/new/

https://reviews.llvm.org/D68103