Method CodegenEvalConjuncts

be/src/exec/exec-node.cc:580–653

Codegen for EvalConjuncts. The generated signature is the same as EvalConjuncts(). For a node with two conjunct predicates: define i1 @EvalConjuncts(%"class.impala::ScalarExprEvaluator"** %evals, i32 %num_evals, %"class.impala::TupleRow"* %row) #34 { entry: %eval_ptr = getelementptr inbounds %"class.impala::ScalarExprEvaluator"*, %"class.impala::ScalarExprEvaluator"** %evals, i32 0 %eval = load

// }
//
Status ExecNode::CodegenEvalConjuncts(LlvmCodeGen* codegen,
    const vector<ScalarExpr*>& conjuncts, llvm::Function** fn, const char* name) {
  llvm::Function* conjunct_fns[conjuncts.size()];
  for (int i = 0; i < conjuncts.size(); ++i) {
    RETURN_IF_ERROR(conjuncts[i]->GetCodegendComputeFn(codegen, false, &conjunct_fns[i]));
    if (i >= LlvmCodeGen::CODEGEN_INLINE_EXPRS_THRESHOLD) {
      // Avoid bloating EvalConjuncts by inlining everything into it.
      codegen->SetNoInline(conjunct_fns[i]);
    }
  }

  // Construct function signature to match
  // bool EvalConjuncts(ScalarExprEvaluator**, int, TupleRow*)
  llvm::PointerType* tuple_row_ptr_type = codegen->GetStructPtrType<TupleRow>();
  llvm::Type* eval_type = codegen->GetStructType<ScalarExprEvaluator>();

  LlvmCodeGen::FnPrototype prototype(codegen, name, codegen->bool_type());
  prototype.AddArgument(
      LlvmCodeGen::NamedVariable("evals", codegen->GetPtrPtrType(eval_type)));
  prototype.AddArgument(
      LlvmCodeGen::NamedVariable("num_evals", codegen->i32_type()));
  prototype.AddArgument(LlvmCodeGen::NamedVariable("row", tuple_row_ptr_type));

  LlvmBuilder builder(codegen->context());
  llvm::Value* args[3];
  *fn = prototype.GeneratePrototype(&builder, args);
  llvm::Value* evals_arg = args[0];
  llvm::Value* tuple_row_arg = args[2];

  if (conjuncts.size() > 0) {
    llvm::LLVMContext& context = codegen->context();
    llvm::BasicBlock* false_block = llvm::BasicBlock::Create(context, "false", *fn);

    for (int i = 0; i < conjuncts.size(); ++i) {
      llvm::BasicBlock* true_block =
          llvm::BasicBlock::Create(context, "continue", *fn, false_block);
      llvm::Value* eval_arg_ptr = builder.CreateInBoundsGEP(
          NULL, evals_arg, codegen->GetI32Constant(i), "eval_ptr");
      llvm::Value* eval_arg = builder.CreateLoad(eval_arg_ptr, "eval");

      // Call conjunct_fns[i]
      CodegenAnyVal result = CodegenAnyVal::CreateCallWrapped(codegen, &builder,
          conjuncts[i]->type(), conjunct_fns[i], {eval_arg, tuple_row_arg},
          "result");

      // Return false if result.is_null || !result
      llvm::Value* is_null = result.GetIsNull();
      llvm::Value* is_false = builder.CreateNot(result.GetVal(), "is_false");
      llvm::Value* return_false = builder.CreateOr(is_null, is_false, "return_false");
      builder.CreateCondBr(return_false, false_block, true_block);

      // Set insertion point for continue/end
      builder.SetInsertPoint(true_block);
    }
    builder.CreateRet(codegen->true_value());

    builder.SetInsertPoint(false_block);
    builder.CreateRet(codegen->false_value());