[PATCH] D155688: [PATCH] [llvm] [InstCombine] Canonicalise ADD+GEP

Mon Oct 9 05:29:17 PDT 2023

nikic added a comment.

In D155688#4653347 <https://reviews.llvm.org/D155688#4653347>, @fiigii wrote:

> How does this patch work with `visitGEPOfGEP` that does a reverse transformation?
>
>   // Replace: gep (gep %P, long B), long A, ...
>   // With:    T = long A+B; gep %P, T, ...

The reverse transform is only done if `A + B` simplifies.

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By the way, this change did cause some code size regressions: http://llvm-compile-time-tracker.com/compare.php?from=a16f6462d756804276d4b39267b3c19bcd6949fe&to=e13bed4c5f3544c076ce57e36d9a11eefa5a7815&stat=size-text

The one that stood out to me is that btGjkEpa2.cpp from bullet has become 13% larger.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D155688/new/

https://reviews.llvm.org/D155688