49 lines
1.3 KiB
C++
49 lines
1.3 KiB
C++
/*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Copyright 2010 Danny Robson <danny@nerdcruft.net>
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*/
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#include "bsdsum.hpp"
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#include "../debug.hpp"
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///////////////////////////////////////////////////////////////////////////////
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uint16_t
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bsdsum (const uint8_t *const restrict first, const uint8_t *const restrict last)
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{
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CHECK_LE (first, last);
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uint16_t accum = 0;
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for (auto cursor = first; cursor != last; ++cursor) {
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accum = (accum >> 1u) | ((accum & 0x01u) << 15u);
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accum += *cursor;
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}
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return accum;
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}
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///////////////////////////////////////////////////////////////////////////////
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uint16_t
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bsdsum (const void *restrict data, size_t size)
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{
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return bsdsum (
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static_cast<const uint8_t*> (data),
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static_cast<const uint8_t*> (data) + size
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);
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}
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