felipecrv commented on code in PR #41373: URL: https://github.com/apache/arrow/pull/41373#discussion_r1626556729
########## cpp/src/arrow/util/gather_internal.h: ########## @@ -0,0 +1,287 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +#pragma once + +#include <cassert> +#include <cstddef> +#include <cstdint> +#include "arrow/array/data.h" +#include "arrow/util/bit_block_counter.h" +#include "arrow/util/bit_run_reader.h" +#include "arrow/util/bit_util.h" +#include "arrow/util/bitmap_ops.h" +#include "arrow/util/macros.h" + +// Implementation helpers for kernels that need to load/gather fixed-width +// data from multiple, arbitrary indices. +// +// https://en.wikipedia.org/wiki/Gather/scatter_(vector_addressing) + +namespace arrow::internal { +inline namespace gather_internal { Review Comment: > I guess I don't understand why using an inline namespace would open up more optimization opportunities. You understand that everything inside an anonymous namespace `namespace { ... }` has internal linkage. All the inline namespace symbols in a header when included in a `.cc` becomes internal to that compilation unit. The compiler doesn't have to expose internal linkage symbols, so the decision for inlining becomes easier: if it's called only once, it's binary-size economical to inline it. The compiler might not inline it if multiple calls are made in that compilation unit. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
