[PATCH] D111968: [TTI] Add OperandValueProperties::OP_NegatedPowerOf2 enum

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

Side note - we partly inverted canonicalization towards mul back to shl, so this pattern might come up less often after these patches:
0f32a5dea0e9 <https://reviews.llvm.org/rG0f32a5dea0e9ef5a52865f9fd285b394d46babaf>
ee0bf6472291 <https://reviews.llvm.org/rGee0bf6472291bd40687046ab2990f987a022a940>

We still change `-(X << C)` to `X * -2**C` for now since that replaces 2 IR instructions with 1.

If one form or the other is easier to deal with from the cost model perspective, that would help decide if we should change the canonicalization further.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D111968/new/

https://reviews.llvm.org/D111968