[all-commits] [llvm/llvm-project] a701dc: [PowerPC] Remove undefs from splat input when chan...

[Nemanja Ivanovic via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: a701dc5510ab8e977dcb797035475e641d6a353a
      https://github.com/llvm/llvm-project/commit/a701dc5510ab8e977dcb797035475e641d6a353a
  Author: Nemanja Ivanovic <nemanja.i.ibm at gmail.com>
  Date:   2020-07-02 (Thu, 02 Jul 2020)

  Changed paths:
    M llvm/lib/Target/PowerPC/PPCISelLowering.cpp
    M llvm/test/CodeGen/PowerPC/canonical-merge-shuffles.ll

  Log Message:
  -----------
  [PowerPC] Remove undefs from splat input when changing shuffle mask

As of 1fed131660b2c5d3ea7007e273a7a5da80699445, we have code that
changes shuffle masks so that we can put the shuffle in a canonical
form that can be matched to a single instruction. However, it
does not properly account for undef elements in the BUILD_VECTOR
that is the RHS splat so we can end up with undefs where they
shouldn't be. This patch converts the splat input with undefs to
one without.