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ex: Add crc combine example for multiple polynomials
Change-Id: I55b6585f768877cffe1cbe16802456c8a12aea28 Signed-off-by: Greg Tucker <greg.b.tucker@intel.com>
This commit is contained in:
Greg Tucker
parent
ad39d7ccfd
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21
examples/crc/Makefile
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21
examples/crc/Makefile
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@ -0,0 +1,21 @@
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# Build examples from installed lib
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examples = crc_combine_example
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CFLAGS = -Wall -O2
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LDFLAGS = $(shell pkg-config --libs libisal)
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progs = $(notdir $(examples))
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ex: $(progs)
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run: $(addsuffix .run,$(progs))
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$(progs): % : %.c
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$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
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$(addsuffix .run,$(progs)): %.run : %
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./$<
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@echo Completed run: $<
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clean:
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$(RM) $(progs)
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442
examples/crc/crc_combine_example.c
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442
examples/crc/crc_combine_example.c
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@ -0,0 +1,442 @@
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/**********************************************************************
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Copyright(c) 2011-2023 Intel Corporation All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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distribution.
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* Neither the name of Intel Corporation nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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**********************************************************************/
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/**
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* @file crc_combine_example.c
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* @brief Example of CRC combine logic.
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*
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* Combine functions can produce the CRC from independent pieces as though they
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* were computed sequentially. The example includes combine functions that are
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* split into two parts; one that depends on length only, and another with
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* optimizations that uses the previous and individual CRCs to combine. By
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* splitting, the length-dependent constants can be pre-computed and the
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* remaining combine logic kept fast and simple.
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*
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*/
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// Compile as c++ for multi-function versions
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#include <stdio.h>
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#include <inttypes.h>
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#include <immintrin.h>
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#include <isa-l.h>
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int verbose; // Global for tests
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#if defined (_MSC_VER)
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# define __builtin_parity(x) (__popcnt64(x) & 1)
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#endif
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#if defined (__GNUC__) || defined (__clang__)
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# define ATTRIBUTE_TARGET(x) __attribute__((target(x)))
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#else
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# define ATTRIBUTE_TARGET(x)
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#endif
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struct crc64_desc {
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uint64_t poly;
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uint64_t k5;
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uint64_t k7;
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uint64_t k8;
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};
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void gen_crc64_refl_consts(uint64_t poly, struct crc64_desc *c)
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{
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uint64_t quotienth = 0;
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uint64_t div;
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uint64_t rem = 1ull;
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int i;
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for (i = 0; i < 64; i++) {
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div = (rem & 1ull) != 0;
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quotienth = (quotienth >> 1) | (div ? 0x8000000000000000ull : 0);
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rem = (div ? poly : 0) ^ (rem >> 1);
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}
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c->k5 = rem;
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c->poly = poly;
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c->k7 = quotienth;
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c->k8 = poly << 1;
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}
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void gen_crc64_norm_consts(uint64_t poly, struct crc64_desc *c)
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{
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uint64_t quotientl = 0;
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uint64_t div;
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uint64_t rem = 1ull << 63;
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int i;
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for (i = 0; i < 65; i++) {
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div = (rem & 0x8000000000000000ull) != 0;
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quotientl = (quotientl << 1) | div;
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rem = (div ? poly : 0) ^ (rem << 1);
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}
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c->poly = poly;
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c->k5 = rem;
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c->k7 = quotientl;
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c->k8 = poly;
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}
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uint32_t calc_xi_mod(int n)
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{
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uint32_t rem = 0x1ul;
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int i, j;
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const uint32_t poly = 0x82f63b78;
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if (n < 16)
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return 0;
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for (i = 0; i < n - 8; i++)
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for (j = 0; j < 8; j++)
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rem = (rem & 0x1ul) ? (rem >> 1) ^ poly : (rem >> 1);
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return rem;
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}
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uint64_t calc64_refl_xi_mod(int n, struct crc64_desc *c)
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{
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uint64_t rem = 1ull;
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int i, j;
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const uint64_t poly = c->poly;
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if (n < 32)
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return 0;
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for (i = 0; i < n - 16; i++)
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for (j = 0; j < 8; j++)
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rem = (rem & 0x1ull) ? (rem >> 1) ^ poly : (rem >> 1);
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return rem;
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}
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uint64_t calc64_norm_xi_mod(int n, struct crc64_desc *c)
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{
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uint64_t rem = 1ull;
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int i, j;
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const uint64_t poly = c->poly;
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if (n < 32)
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return 0;
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for (i = 0; i < n - 8; i++)
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for (j = 0; j < 8; j++)
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rem = (rem & 0x8000000000000000ull ? poly : 0) ^ (rem << 1);
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return rem;
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}
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// Base function for crc32_iscsi_shiftx() if c++ multi-function versioning
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#ifdef __cplusplus
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static inline uint32_t bit_reverse32(uint32_t x)
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{
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x = (((x & 0xaaaaaaaa) >> 1) | ((x & 0x55555555) << 1));
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x = (((x & 0xcccccccc) >> 2) | ((x & 0x33333333) << 2));
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x = (((x & 0xf0f0f0f0) >> 4) | ((x & 0x0f0f0f0f) << 4));
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x = (((x & 0xff00ff00) >> 8) | ((x & 0x00ff00ff) << 8));
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return ((x >> 16) | (x << 16));
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}
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// Base function for crc32_iscsi_shiftx without clmul optimizations
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ATTRIBUTE_TARGET("default")
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uint32_t crc32_iscsi_shiftx(uint32_t crc1, uint32_t x)
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{
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int i;
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uint64_t xrev, q = 0;
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union {
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uint8_t a[8];
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uint64_t q;
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} qu;
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xrev = bit_reverse32(x);
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xrev <<= 32;
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for (i = 0; i < 64; i++, xrev >>= 1)
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q = (q << 1) | __builtin_parity(crc1 & xrev);
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qu.q = q;
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return crc32_iscsi(qu.a, 8, 0);
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}
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#endif // cplusplus
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ATTRIBUTE_TARGET("pclmul,sse4.2")
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uint32_t crc32_iscsi_shiftx(uint32_t crc1, uint32_t x)
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{
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__m128i crc1x, constx;
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uint64_t crc64;
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crc1x = _mm_setr_epi32(crc1, 0, 0, 0);
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constx = _mm_setr_epi32(x, 0, 0, 0);
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crc1x = _mm_clmulepi64_si128(crc1x, constx, 0);
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crc64 = _mm_cvtsi128_si64(crc1x);
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crc64 = _mm_crc32_u64(0, crc64);
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return crc64 & 0xffffffff;
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}
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ATTRIBUTE_TARGET("pclmul,sse4.2")
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uint64_t crc64_refl_shiftx(uint64_t crc1, uint64_t x, struct crc64_desc *c)
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{
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__m128i crc1x, crc2x, crc3x, constx;
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const __m128i rk5 = _mm_loadu_si64(&c->k5);
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const __m128i rk7 = _mm_loadu_si128((__m128i *) & c->k7);
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crc1x = _mm_cvtsi64_si128(crc1);
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constx = _mm_cvtsi64_si128(x);
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crc1x = _mm_clmulepi64_si128(crc1x, constx, 0x00);
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// Fold to 64b
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crc2x = _mm_clmulepi64_si128(crc1x, rk5, 0x00);
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crc3x = _mm_bsrli_si128(crc1x, 8);
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crc1x = _mm_xor_si128(crc2x, crc3x);
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// Reduce
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crc2x = _mm_clmulepi64_si128(crc1x, rk7, 0x00);
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crc3x = _mm_clmulepi64_si128(crc2x, rk7, 0x10);
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crc2x = _mm_bslli_si128(crc2x, 8);
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crc1x = _mm_xor_si128(crc1x, crc2x);
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crc1x = _mm_xor_si128(crc1x, crc3x);
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return _mm_extract_epi64(crc1x, 1);
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}
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ATTRIBUTE_TARGET("pclmul,sse4.2")
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uint64_t crc64_norm_shiftx(uint64_t crc1, uint64_t x, struct crc64_desc *c)
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{
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__m128i crc1x, crc2x, crc3x, constx;
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const __m128i rk5 = _mm_loadu_si64(&c->k5);
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const __m128i rk7 = _mm_loadu_si128((__m128i *) & c->k7);
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crc1x = _mm_cvtsi64_si128(crc1);
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constx = _mm_cvtsi64_si128(x);
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crc1x = _mm_clmulepi64_si128(crc1x, constx, 0x00);
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// Fold to 64b
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crc2x = _mm_clmulepi64_si128(crc1x, rk5, 0x01);
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crc3x = _mm_bslli_si128(crc1x, 8);
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crc1x = _mm_xor_si128(crc2x, crc3x);
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// Reduce
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crc2x = _mm_clmulepi64_si128(crc1x, rk7, 0x01);
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crc2x = _mm_xor_si128(crc1x, crc2x);
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crc3x = _mm_clmulepi64_si128(crc2x, rk7, 0x11);
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crc1x = _mm_xor_si128(crc1x, crc3x);
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return _mm_extract_epi64(crc1x, 0);
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}
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uint32_t crc32_iscsi_combine_4k(uint32_t * crc_array, int n)
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{
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const uint32_t cn4k = 0x82f89c77; //calc_xi_mod(4*1024);
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int i;
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if (n < 1)
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return 0;
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uint32_t crc = crc_array[0];
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for (i = 1; i < n; i++)
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crc = crc32_iscsi_shiftx(crc, cn4k) ^ crc_array[i];
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return crc;
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}
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// Tests
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#define printv(...) {if (verbose) printf(__VA_ARGS__); else printf(".");}
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uint64_t test_combine64(uint8_t * inp, size_t len, uint64_t poly, int reflected,
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uint64_t(*func) (uint64_t, const uint8_t *, uint64_t))
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{
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uint64_t crc64_init, crc64, crc64a, crc64b;
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uint64_t crc64_1, crc64_2, crc64_3, crc64_n, err = 0;
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uint64_t xi_mod;
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struct crc64_desc crc64_c;
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size_t l1, l2, l3;
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l1 = len / 2;
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l2 = len - l1;
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crc64_init = rand();
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crc64 = func(crc64_init, inp, len);
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printv("\ncrc64 all = 0x%" PRIx64 "\n", crc64);
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// Do a sequential crc update
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crc64a = func(crc64_init, &inp[0], l1);
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crc64b = func(crc64a, &inp[l1], l2);
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printv("crc64 seq = 0x%" PRIx64 "\n", crc64b);
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// Split into 2 independent crc calc and combine
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crc64_1 = func(crc64_init, &inp[0], l1);
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crc64_2 = func(0, &inp[l1], l2);
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if (reflected) {
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gen_crc64_refl_consts(poly, &crc64_c);
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xi_mod = calc64_refl_xi_mod(l1, &crc64_c);
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crc64_1 = crc64_refl_shiftx(crc64_1, xi_mod, &crc64_c);
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} else {
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gen_crc64_norm_consts(poly, &crc64_c);
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xi_mod = calc64_norm_xi_mod(l1, &crc64_c);
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crc64_1 = crc64_norm_shiftx(crc64_1, xi_mod, &crc64_c);
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}
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crc64_n = crc64_1 ^ crc64_2;
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printv("crc64 combined2 = 0x%" PRIx64 "\n", crc64_n);
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err |= crc64_n ^ crc64;
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if (err)
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return err;
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// Split into 3 uneven segments and combine
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l1 = len / 3;
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l2 = (len / 3) - 3;
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l3 = len - l2 - l1;
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crc64_1 = func(crc64_init, &inp[0], l1);
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crc64_2 = func(0, &inp[l1], l2);
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crc64_3 = func(0, &inp[l1 + l2], l3);
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if (reflected) {
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xi_mod = calc64_refl_xi_mod(l3, &crc64_c);
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crc64_2 = crc64_refl_shiftx(crc64_2, xi_mod, &crc64_c);
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xi_mod = calc64_refl_xi_mod(len - l1, &crc64_c);
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crc64_1 = crc64_refl_shiftx(crc64_1, xi_mod, &crc64_c);
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} else {
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xi_mod = calc64_norm_xi_mod(l3, &crc64_c);
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crc64_2 = crc64_norm_shiftx(crc64_2, xi_mod, &crc64_c);
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xi_mod = calc64_norm_xi_mod(len - l1, &crc64_c);
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crc64_1 = crc64_norm_shiftx(crc64_1, xi_mod, &crc64_c);
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}
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crc64_n = crc64_1 ^ crc64_2 ^ crc64_3;
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printv("crc64 combined3 = 0x%" PRIx64 "\n", crc64_n);
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err |= crc64_n ^ crc64;
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return err;
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}
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#define N (1024)
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#define B (2*N)
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#define T (3*N)
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#define N4k (4*1024)
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#define NMAX 32
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#define NMAX_SIZE (NMAX * N4k)
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int main(int argc, char *argv[])
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{
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int i;
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uint32_t crc, crca, crcb, crc1, crc2, crc3, crcn;
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uint32_t crc_init = rand();
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uint32_t err = 0;
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uint8_t *inp = (uint8_t *) malloc(NMAX_SIZE);
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verbose = argc - 1;
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if (NULL == inp)
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return -1;
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for (int i = 0; i < NMAX_SIZE; i++)
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inp[i] = rand();
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printf("crc_combine_test:");
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// Calc crc all at once
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crc = crc32_iscsi(inp, B, crc_init);
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printv("\ncrcB all = 0x%" PRIx32 "\n", crc);
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// Do a sequential crc update
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crca = crc32_iscsi(&inp[0], N, crc_init);
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crcb = crc32_iscsi(&inp[N], N, crca);
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printv("crcB seq = 0x%" PRIx32 "\n", crcb);
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// Split into 2 independent crc calc and combine
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crc1 = crc32_iscsi(&inp[0], N, crc_init);
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crc2 = crc32_iscsi(&inp[N], N, 0);
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crcn = crc32_iscsi_shiftx(crc1, calc_xi_mod(N)) ^ crc2;
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printv("crcB combined2 = 0x%" PRIx32 "\n", crcn);
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err |= crcn ^ crc;
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// Split into 3 uneven segments and combine
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crc1 = crc32_iscsi(&inp[0], 100, crc_init);
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crc2 = crc32_iscsi(&inp[100], 100, 0);
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crc3 = crc32_iscsi(&inp[200], B - 200, 0);
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crcn = crc3 ^
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crc32_iscsi_shiftx(crc2, calc_xi_mod(B - 200)) ^
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crc32_iscsi_shiftx(crc1, calc_xi_mod(B - 100));
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printv("crcB combined3 = 0x%" PRIx32 "\n\n", crcn);
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err |= crcn ^ crc;
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// Call all size T at once
|
||||
crc = crc32_iscsi(inp, T, crc_init);
|
||||
printv("crcT all = 0x%" PRIx32 "\n", crc);
|
||||
|
||||
// Split into 3 segments and combine with 2 consts
|
||||
crc1 = crc32_iscsi(&inp[0], N, crc_init);
|
||||
crc2 = crc32_iscsi(&inp[N], N, 0);
|
||||
crc3 = crc32_iscsi(&inp[2 * N], N, 0);
|
||||
crcn = crc3 ^
|
||||
crc32_iscsi_shiftx(crc2, calc_xi_mod(N)) ^
|
||||
crc32_iscsi_shiftx(crc1, calc_xi_mod(2 * N));
|
||||
printv("crcT combined3 = 0x%" PRIx32 "\n", crcn);
|
||||
err |= crcn ^ crc;
|
||||
|
||||
// Combine 3 segments with one const by sequential shift
|
||||
uint32_t xi_mod_n = calc_xi_mod(N);
|
||||
crcn = crc3 ^ crc32_iscsi_shiftx(crc32_iscsi_shiftx(crc1, xi_mod_n)
|
||||
^ crc2, xi_mod_n);
|
||||
printv("crcT comb3 seq = 0x%" PRIx32 "\n\n", crcn);
|
||||
err |= crcn ^ crc;
|
||||
|
||||
// Test 4k array function
|
||||
crc = crc32_iscsi(inp, NMAX_SIZE, crc_init);
|
||||
printv("crc 4k x n all = 0x%" PRIx32 "\n", crc);
|
||||
|
||||
// Test crc 4k array combine function
|
||||
uint32_t crcs[NMAX];
|
||||
crcs[0] = crc32_iscsi(&inp[0], N4k, crc_init);
|
||||
for (i = 1; i < NMAX; i++)
|
||||
crcs[i] = crc32_iscsi(&inp[i * N4k], N4k, 0);
|
||||
|
||||
crcn = crc32_iscsi_combine_4k(crcs, NMAX);
|
||||
printv("crc4k_array = 0x%" PRIx32 "\n", crcn);
|
||||
err |= crcn ^ crc;
|
||||
|
||||
// CRC64 generic poly tests - reflected
|
||||
uint64_t len = NMAX_SIZE;
|
||||
err |= test_combine64(inp, len, 0xc96c5795d7870f42ull, 1, crc64_ecma_refl);
|
||||
err |= test_combine64(inp, len, 0xd800000000000000ull, 1, crc64_iso_refl);
|
||||
err |= test_combine64(inp, len, 0x95ac9329ac4bc9b5ull, 1, crc64_jones_refl);
|
||||
|
||||
// CRC64 non-reflected polynomial tests
|
||||
err |= test_combine64(inp, len, 0x42f0e1eba9ea3693ull, 0, crc64_ecma_norm);
|
||||
err |= test_combine64(inp, len, 0x000000000000001bull, 0, crc64_iso_norm);
|
||||
err |= test_combine64(inp, len, 0xad93d23594c935a9ull, 0, crc64_jones_norm);
|
||||
|
||||
printf(err == 0 ? "pass\n" : "fail\n");
|
||||
free(inp);
|
||||
return err;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user