Method GetCodegendComputeFnImpl

be/src/exprs/kudu-partition-expr.cc:240–321

Sample IR: To reproduce, run bin/impala-py.test tests/query_test/test_kudu.py:: TestKuduPartitioning::test_partitions_evenly_distributed define i64 @KuduPartitionExpr(%"class.impala::ScalarExprEvaluator"* %eval, %"class.impala::TupleRow"* %row) #47 { entry: %0 = alloca %"struct.impala::ColumnType" %status_ptr = alloca %"class.impala::Status" %1 = alloca i32 %kudu_partitioner_ptr_ptr = alloca %"

///   ret i64 %ret_val
/// }
Status KuduPartitionExpr::GetCodegendComputeFnImpl(
    LlvmCodeGen* codegen, llvm::Function** fn) {
  llvm::Function* const kudu_partition_row_fn =
      codegen->GetFunction(IRFunction::GET_KUDU_PARTITION_ROW, false);

  // Function prototype.
  llvm::LLVMContext& context = codegen->context();
  LlvmBuilder builder(context);

  // Parameters of the generated function (ScalarExprEvaluator*, TupleRow*).
  llvm::Value* args[2];
  llvm::Function* const function =
      CreateIrFunctionPrototype("KuduPartitionExpr", codegen, &args);

  // Codegen the initialisation of function context etc.
  llvm::BasicBlock* const entry_block =
      llvm::BasicBlock::Create(context, "entry", function);
  builder.SetInsertPoint(entry_block);

  llvm::Value* kudu_row_ptr = nullptr;
  llvm::Value* kudu_partitioner_ptr = nullptr;
  CodegenGetKuduPartialRowAndPartitioner(codegen, &builder, args[0], fn_ctx_idx_,
      &kudu_row_ptr, &kudu_partitioner_ptr);

  llvm::BasicBlock* current_eval_child_block = llvm::BasicBlock::Create(
      context, "eval_child", function);
  builder.CreateBr(current_eval_child_block);

  const int num_children = GetNumChildren();
  for (int i = 0; i < num_children; ++i) {
    ScalarExpr* const child_expr = GetChild(i);
    llvm::Function* child_fn = nullptr;
    RETURN_IF_ERROR(child_expr->GetCodegendComputeFn(codegen, false, &child_fn));

    builder.SetInsertPoint(current_eval_child_block);
    const ColumnType& child_type = child_expr->type();
    CodegenAnyVal child_wrapped = CodegenAnyVal::CreateCallWrapped(
        codegen, &builder, child_type, child_fn, {args[0], args[1]}, "child");

    CodegenAnyValReadWriteInfo rwi = child_wrapped.ToReadWriteInfo();
    rwi.entry_block().BranchTo(&builder);

    // Child is null.
    builder.SetInsertPoint(rwi.null_block());
    CodegenAnyVal error_ret_val =
        CodegenAnyVal::GetNonNullVal(codegen, &builder, type(), "error_ret_val");
    error_ret_val.SetVal(-1);
    builder.CreateRet(error_ret_val.GetLoweredValue());

    // Child is not null.
    builder.SetInsertPoint(rwi.non_null_block());
    const int col = tkudu_partition_expr_.referenced_columns[i];
    const ColumnDescriptor& col_desc = table_desc_->col_descs()[col];
    const ColumnType& type = col_desc.type();
    DCHECK_EQ(child_expr->type().type, type.type);

    llvm::Value* const child_native_val =
        SlotDescriptor::CodegenStoreNonNullAnyValToNewAlloca(rwi);