[all-commits] [llvm/llvm-project] 69fac6: [Hexagon] Fix perfect shuffle generation for singl...

[Krzysztof Parzyszek via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 69fac677bc20ab2b3d8538f76aba81bf9630d6c4
      https://github.com/llvm/llvm-project/commit/69fac677bc20ab2b3d8538f76aba81bf9630d6c4
  Author: Krzysztof Parzyszek <kparzysz at quicinc.com>
  Date:   2020-08-30 (Sun, 30 Aug 2020)

  Changed paths:
    M llvm/lib/Target/Hexagon/HexagonISelDAGToDAGHVX.cpp
    A llvm/test/CodeGen/Hexagon/autohvx/isel-shuff-single.ll
    M llvm/test/CodeGen/Hexagon/isel-hvx-pred-bitcast-order.ll

  Log Message:
  -----------
  [Hexagon] Fix perfect shuffle generation for single vectors

Perfect shuffle instruction (vdealvdd/vshuffvdd) work on vector
pairs. When given a single input vector, half of it first needs
to be transposed into the other vector before the generated
shuffles can take effect. Also the first transpose needs to be
undone at the end (this last step was missing).