nirandaperera commented on a change in pull request #10377: URL: https://github.com/apache/arrow/pull/10377#discussion_r637955569
########## File path: cpp/src/arrow/compute/kernels/scalar_if_else.cc ########## @@ -0,0 +1,285 @@ +// 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. + +#include <arrow/compute/api.h> +#include <arrow/util/bit_block_counter.h> +#include <arrow/util/bitmap_ops.h> + +#include "codegen_internal.h" + +namespace arrow { +using internal::BitBlockCount; +using internal::BitBlockCounter; + +namespace compute { + +namespace { + +// nulls will be promoted as follows +// cond.val && (cond.data && left.val || ~cond.data && right.val) +Status promote_nulls(KernelContext* ctx, const ArrayData& cond, const ArrayData& left, + const ArrayData& right, ArrayData* output) { + if (!cond.MayHaveNulls() && !left.MayHaveNulls() && !right.MayHaveNulls()) { + return Status::OK(); // no nulls to handle + } + const int64_t len = cond.length; + + ARROW_ASSIGN_OR_RAISE(std::shared_ptr<Buffer> out_validity, ctx->AllocateBitmap(len)); + arrow::internal::InvertBitmap(out_validity->data(), 0, len, + out_validity->mutable_data(), 0); + if (right.MayHaveNulls()) { + // out_validity = right.val && ~cond.data + arrow::internal::BitmapAndNot(right.buffers[0]->data(), right.offset, + cond.buffers[1]->data(), cond.offset, len, 0, + out_validity->mutable_data()); + } + + if (left.MayHaveNulls()) { + // tmp_buf = left.val && cond.data + ARROW_ASSIGN_OR_RAISE(std::shared_ptr<Buffer> temp_buf, + arrow::internal::BitmapAnd( + ctx->memory_pool(), left.buffers[0]->data(), left.offset, + cond.buffers[1]->data(), cond.offset, len, 0)); + // out_validity = cond.data && left.val || ~cond.data && right.val + arrow::internal::BitmapOr(out_validity->data(), 0, temp_buf->data(), 0, len, 0, + out_validity->mutable_data()); + } + + if (cond.MayHaveNulls()) { + // out_validity &= cond.val + ::arrow::internal::BitmapAnd(out_validity->data(), 0, cond.buffers[0]->data(), + cond.offset, len, 0, out_validity->mutable_data()); + } + + output->buffers[0] = std::move(out_validity); + output->GetNullCount(); // update null count + return Status::OK(); +} + +template <typename Type, bool swap = false, typename Enable = void> +struct IfElseFunctor {}; + +template <typename Type, bool swap> +struct IfElseFunctor<Type, swap, enable_if_t<is_number_type<Type>::value>> { + using T = typename TypeTraits<Type>::CType; + + static Status Call(KernelContext* ctx, const ArrayData& cond, const ArrayData& left, + const ArrayData& right, ArrayData* out) { + ARROW_RETURN_NOT_OK(promote_nulls(ctx, cond, left, right, out)); + + ARROW_ASSIGN_OR_RAISE(std::shared_ptr<Buffer> out_buf, + ctx->Allocate(cond.length * sizeof(T))); + T* out_values = reinterpret_cast<T*>(out_buf->mutable_data()); + + // copy right data to out_buff + const T* right_data = right.GetValues<T>(1); + std::memcpy(out_values, right_data, right.length * sizeof(T)); + + const auto* cond_data = cond.buffers[1]->data(); // this is a BoolArray + BitBlockCounter bit_counter(cond_data, cond.offset, cond.length); + + // selectively copy values from left data + const T* left_data = left.GetValues<T>(1); + int64_t offset = cond.offset; + + // todo this can be improved by intrinsics. ex: _mm*_mask_store_e* (vmovdqa*) Review comment: Do you mean, load with mask? -- 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. For queries about this service, please contact Infrastructure at: [email protected]
