numam-spdk/lib/util/crc32c.c
Daniel Verkamp b483027aca util/crc32c: add SSE 4.2 CRC32 instruction support
Use the CRC32 CPU instruction, if available, to optimize the iSCSI
CRC-32C calculation.

Change-Id: Ifb706528c28f5e6921ebf525274b959d8cac85a0
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/370766
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-08-02 19:47:35 -04:00

90 lines
2.8 KiB
C

/*-
* BSD LICENSE
*
* Copyright (c) Intel Corporation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
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* the documentation and/or other materials provided with the
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* * Neither the name of Intel Corporation nor the names of its
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*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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*/
#include "spdk/crc32.h"
#if defined(__x86_64__) && defined(__SSE4_2__)
#include <x86intrin.h>
uint32_t
spdk_crc32c_update(const void *buf, size_t len, uint32_t crc)
{
uint64_t crc_tmp64;
size_t count;
/* _mm_crc32_u64() needs a 64-bit intermediate value */
crc_tmp64 = crc;
/* Process as much of the buffer as possible in 64-bit blocks. */
count = len / 8;
while (count--) {
uint64_t block;
/*
* Use memcpy() to avoid unaligned loads, which are undefined behavior in C.
* The compiler will optimize out the memcpy() in release builds.
*/
memcpy(&block, buf, sizeof(block));
crc_tmp64 = _mm_crc32_u64(crc_tmp64, block);
buf += sizeof(block);
}
crc = (uint32_t)crc_tmp64;
/* Handle any trailing bytes. */
count = len & 7;
while (count--) {
crc = _mm_crc32_u8(crc, *(const uint8_t *)buf);
buf++;
}
return crc;
}
#else /* SSE 4.2 (CRC32 instruction) not available */
static struct spdk_crc32_table g_crc32c_table;
__attribute__((constructor)) static void
spdk_crc32c_init(void)
{
spdk_crc32_table_init(&g_crc32c_table, SPDK_CRC32C_POLYNOMIAL_REFLECT);
}
uint32_t
spdk_crc32c_update(const void *buf, size_t len, uint32_t crc)
{
return spdk_crc32_update(&g_crc32c_table, buf, len, crc);
}
#endif