message: [XLA:CPU] Don't switch vector-matrix dots to column major if the vector is tiny
  If the vector is too small tiling doesn't improve performance, so just stick with the
  default layout.
diff: @@ -736,12 +736,24 @@ DotOpEmitter::MatMultDims DotOpEmitter::GetMatMultDims() const {
  absl::optional<int64> ProfitableToMakeDotOperandColumnMajor(
  const HloInstruction& hlo) {
  if (hlo.opcode() == HloOpcode::kDot && hlo.shape().dimensions_size() <= 1) {
  - if (hlo.dot_dimension_numbers().rhs_contracting_dimensions(0) == 0) {
  - return 1;
  + if (hlo.operand(0)->shape().rank() != 1 ||
  + hlo.dot_dimension_numbers().rhs_contracting_dimensions(0) != 0) {
  + return {};
  }
  +
  + // Don't bother if the other operand is tiny, switching to column major
  + // wouldn't use tiling.
  + constexpr int kColumnMajorThresholdInBytes = 32;
  + int64 lhs_size =
  + ShapeUtil::ByteSizeOfPrimitiveType(hlo.shape().element_type()) *
  + ShapeUtil::ElementsIn(hlo.operand(0)->shape());
  + if (lhs_size < kColumnMajorThresholdInBytes) {
  return {};
  }
  + return 1;
  + }
  +
  if (hlo.IsOutputFusion()) {
  auto* fusion_root =
  hlo.fused_instructions_computation()->root_instruction();
  