[PATCH] D122233: [AggressiveInstCombine] Add `shufflevector` instr support to `TruncInstCombine`

[Anton Afanasyev via Phabricator via llvm-commits]

anton-afanasyev added a comment.

In D122233#3513581 <https://reviews.llvm.org/D122233#3513581>, @RKSimon wrote:

> FWIW we might be able to perform something similar inside VectorCombine

Do you mean using `TTI.getShuffleCost()`? There's an issue here: we don't know the exact shuffle type at the moment we need to get its cost. We infer this type (given by `MinBitWidth`) after the expression graph has been built already. Need to refactor whole pass for this case, which looks redundant.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122233/new/

https://reviews.llvm.org/D122233