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/* IBM_PROLOG_BEGIN_TAG */
/* This is an automatically generated prolog. */
/* */
/* $Source: src/lib/crc32.C $ */
/* */
/* OpenPOWER HostBoot Project */
/* */
/* COPYRIGHT International Business Machines Corp. 2013,2014 */
/* */
/* Licensed 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. */
/* */
/* IBM_PROLOG_END_TAG */
#include <stdint.h>
#include <util/crc32.H>
namespace Util
{
static const uint64_t CRC32_POLY = 0x104C11DB7ull;
uint32_t crc32_calc(const void* ptr, size_t size)
{
const uint8_t* _ptr = (const uint8_t*)ptr;
uint64_t crc = 0;
while(size)
{
uint64_t data = 0;
for (int i = 0; i < 4; ++i)
{
data <<= 8;
if (size)
{
data |= *(_ptr++);
--size;
}
}
crc <<= 32;
crc ^= (data << 32);
int idx = 0;
do
{
idx = __builtin_clzl(crc);
if (idx < 32)
{
crc ^= (CRC32_POLY << (31 - idx));
}
} while (idx < 32);
}
return crc;
}
};
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