[all-commits] [llvm/llvm-project] 21d8f6: [X86] Add test caes for pr46585. NFC

[topperc via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 21d8f66d20b813edadac84b12cc83b66eaeae630
      https://github.com/llvm/llvm-project/commit/21d8f66d20b813edadac84b12cc83b66eaeae630
  Author: Craig Topper <craig.topper at intel.com>
  Date:   2020-07-04 (Sat, 04 Jul 2020)

  Changed paths:
    A llvm/test/CodeGen/X86/pr46585.ll

  Log Message:
  -----------
  [X86] Add test caes for pr46585. NFC


  Commit: 120c5f1057dc50229f73bc75bbabf4df6ee50fef
      https://github.com/llvm/llvm-project/commit/120c5f1057dc50229f73bc75bbabf4df6ee50fef
  Author: Craig Topper <craig.topper at intel.com>
  Date:   2020-07-04 (Sat, 04 Jul 2020)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/test/CodeGen/X86/pr46585.ll

  Log Message:
  -----------
  [DAGCombiner] Don't fold zext_vector_inreg/sext_vector_inreg(undef) to undef. Fold to 0.

zext_vector_inreg needs to produces 0s in the extended bits and
sext_vector_inreg needs to produce upper bits that are all the
same. So we should fold them to a 0 vector instead of undef.

Fixes PR46585.


Compare: https://github.com/llvm/llvm-project/compare/11a3f040c710...120c5f1057dc