[all-commits] [llvm/llvm-project] 66a3e4: [LoongArch] Override TargetLowering::isShuffleMask...

[wanglei via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 66a3e4fafb6eae19764f8a192ca3a116c0554211
      https://github.com/llvm/llvm-project/commit/66a3e4fafb6eae19764f8a192ca3a116c0554211
  Author: wanglei <wanglei at loongson.cn>
  Date:   2023-12-02 (Sat, 02 Dec 2023)

  Changed paths:
    M llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
    M llvm/lib/Target/LoongArch/LoongArchISelLowering.h
    M llvm/test/CodeGen/LoongArch/lsx/build-vector.ll

  Log Message:
  -----------
  [LoongArch] Override TargetLowering::isShuffleMaskLegal

 By default, `isShuffleMaskLegal` always returns true, which can result
 in the expansion of `BUILD_VECTOR` into a `VECTOR_SHUFFLE` node in
 certain situations. Subsequently, the `VECTOR_SHUFFLE` node is expanded
 again into a `BUILD_VECTOR`, leading to an infinite loop.
 To address this, we always return false, allowing the expansion of
 `BUILD_VECTOR` through the stack.