[all-commits] [llvm/llvm-project] e1d4ca: [InstCombine] matchRotate - add support for matchi...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: e1d4ca00094a4267b6fd70f613f2e0390b2a8cbf
      https://github.com/llvm/llvm-project/commit/e1d4ca00094a4267b6fd70f613f2e0390b2a8cbf
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2020-10-08 (Thu, 08 Oct 2020)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    M llvm/test/Transforms/InstCombine/funnel.ll

  Log Message:
  -----------
  [InstCombine] matchRotate - add support for matching general funnel shifts with constant shift amounts (PR46896)

First step towards extending the existing rotation support to full funnel shift handling now that the backend legalization support has improved.

This enables us to match the shift by constant cases, which are pretty trivial to expand again if necessary.

D88420 will add non-uniform support for funnel shifts as well once its been finalized.

Differential Revision: https://reviews.llvm.org/D88834