[all-commits] [llvm/llvm-project] 9a75a8: [RISCV] Fix a codegen crash in getSetCCResultType

[Fraser Cormack via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 9a75a808c27f2d7a3ef4880be5f3febc97d5dcd2
      https://github.com/llvm/llvm-project/commit/9a75a808c27f2d7a3ef4880be5f3febc97d5dcd2
  Author: Fraser Cormack <fraser at codeplay.com>
  Date:   2021-01-27 (Wed, 27 Jan 2021)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.cpp
    A llvm/test/CodeGen/RISCV/vec3-setcc-crash.ll

  Log Message:
  -----------
  [RISCV] Fix a codegen crash in getSetCCResultType

This patch fixes some crashes coming from
`RISCVISelLowering::getSetCCResultType`, which would occasionally return
an EVT constructed from an invalid MVT, which has a null Type pointer.

The attached test shows this happening currently for some fixed-length
vectors, which hit this issue when the V extension was enabled, even
though they're not legal types under the V extension. The fix was also
pre-emptively extended to scalable vectors which can't be represented as
an MVT, even though a test case couldn't be found for them.

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D95434