[PATCH] D78069: [llvm][CodeGen] Fix issue for SVE gather prefetch.

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen accepted this revision.
sdesmalen added a comment.
This revision is now accepted and ready to land.

The patch LGTM.

I found the commit message quite confusing though. This is simply fixing an issue where the dagcombine incorrectly used an addressing mode with scaled offsets (indices), instead of unscaled offsets.
Because those addressing modes don't exist for prfh, prfw and prfd, we can reuse prfb because that has unscaled offsets, and because the pseudo-code in the XML spec suggests that the element size is not used for the amount of data that is prefetched by the instruction.

FWIW, GCC also emits a `prfb` for these cases.


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D78069