[PATCH] D116039: [X86] Combine reduce(mul x, y) to VNNI instruction.

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

Any explicit checks for extension/truncation and their bitwidth delta instantly make me suspicious nowadays.
Does this deal with commutativity?
I think what you want to check is the number of known sign bits / known leading zero bits.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D116039/new/

https://reviews.llvm.org/D116039