+++ /dev/null
-/*
- * Copyright 2017 Facebook, Inc.
- *
- * 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.
- */
-
-#include <folly/Checksum.h>
-#include <boost/crc.hpp>
-#include <folly/CpuId.h>
-#include <folly/detail/ChecksumDetail.h>
-#include <algorithm>
-#include <stdexcept>
-
-#if FOLLY_SSE_PREREQ(4, 2)
-#include <nmmintrin.h>
-#endif
-
-namespace folly {
-
-namespace detail {
-
-uint32_t
-crc32c_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum);
-#if FOLLY_SSE_PREREQ(4, 2)
-
-uint32_t
-crc32_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum);
-
-// Fast SIMD implementation of CRC-32 for x86 with pclmul
-uint32_t
-crc32_hw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
- uint32_t sum = startingChecksum;
- size_t offset = 0;
-
- // Process unaligned bytes
- if ((uintptr_t)data & 15) {
- size_t limit = std::min(nbytes, -(uintptr_t)data & 15);
- sum = crc32_sw(data, limit, sum);
- offset += limit;
- nbytes -= limit;
- }
-
- if (nbytes >= 16) {
- sum = crc32_hw_aligned(sum, (const __m128i*)(data + offset), nbytes / 16);
- offset += nbytes & ~15;
- nbytes &= 15;
- }
-
- // Remaining unaligned bytes
- return crc32_sw(data + offset, nbytes, sum);
-}
-
-bool crc32c_hw_supported() {
- static folly::CpuId id;
- return id.sse42();
-}
-
-bool crc32_hw_supported() {
- static folly::CpuId id;
- return id.sse42();
-}
-
-#else
-
-uint32_t crc32_hw(const uint8_t *data, size_t nbytes,
- uint32_t startingChecksum) {
- throw std::runtime_error("crc32_hw is not implemented on this platform");
-}
-
-bool crc32c_hw_supported() {
- return false;
-}
-
-bool crc32_hw_supported() {
- return false;
-}
-#endif
-
-template <uint32_t CRC_POLYNOMIAL>
-uint32_t crc_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
- // Reverse the bits in the starting checksum so they'll be in the
- // right internal format for Boost's CRC engine.
- // O(1)-time, branchless bit reversal algorithm from
- // http://graphics.stanford.edu/~seander/bithacks.html
- startingChecksum = ((startingChecksum >> 1) & 0x55555555) |
- ((startingChecksum & 0x55555555) << 1);
- startingChecksum = ((startingChecksum >> 2) & 0x33333333) |
- ((startingChecksum & 0x33333333) << 2);
- startingChecksum = ((startingChecksum >> 4) & 0x0f0f0f0f) |
- ((startingChecksum & 0x0f0f0f0f) << 4);
- startingChecksum = ((startingChecksum >> 8) & 0x00ff00ff) |
- ((startingChecksum & 0x00ff00ff) << 8);
- startingChecksum = (startingChecksum >> 16) |
- (startingChecksum << 16);
-
- boost::crc_optimal<32, CRC_POLYNOMIAL, ~0U, 0, true, true> sum(
- startingChecksum);
- sum.process_bytes(data, nbytes);
- return sum.checksum();
-}
-
-uint32_t
-crc32c_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
- constexpr uint32_t CRC32C_POLYNOMIAL = 0x1EDC6F41;
- return crc_sw<CRC32C_POLYNOMIAL>(data, nbytes, startingChecksum);
-}
-
-uint32_t
-crc32_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
- constexpr uint32_t CRC32_POLYNOMIAL = 0x04C11DB7;
- return crc_sw<CRC32_POLYNOMIAL>(data, nbytes, startingChecksum);
-}
-
-} // namespace detail
-
-uint32_t crc32c(const uint8_t *data, size_t nbytes,
- uint32_t startingChecksum) {
- if (detail::crc32c_hw_supported()) {
- return detail::crc32c_hw(data, nbytes, startingChecksum);
- } else {
- return detail::crc32c_sw(data, nbytes, startingChecksum);
- }
-}
-
-uint32_t crc32(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
- if (detail::crc32_hw_supported()) {
- return detail::crc32_hw(data, nbytes, startingChecksum);
- } else {
- return detail::crc32_sw(data, nbytes, startingChecksum);
- }
-}
-
-uint32_t
-crc32_type(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
- return ~crc32(data, nbytes, startingChecksum);
-}
-
-} // namespace folly
+++ /dev/null
-/*
- * Copyright 2017 Facebook, Inc.
- *
- * 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.
- */
-
-#pragma once
-
-#include <stdint.h>
-#include <cstddef>
-
-/*
- * Checksum functions
- */
-
-namespace folly {
-
-/**
- * Compute the CRC-32C checksum of a buffer, using a hardware-accelerated
- * implementation if available or a portable software implementation as
- * a default.
- *
- * @note CRC-32C is different from CRC-32; CRC-32C starts with a different
- * polynomial and thus yields different results for the same input
- * than a traditional CRC-32.
- */
-uint32_t crc32c(const uint8_t* data, size_t nbytes,
- uint32_t startingChecksum = ~0U);
-
-/**
- * Compute the CRC-32 checksum of a buffer, using a hardware-accelerated
- * implementation if available or a portable software implementation as
- * a default.
- */
-uint32_t
-crc32(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
-
-/**
- * Compute the CRC-32 checksum of a buffer, using a hardware-accelerated
- * implementation if available or a portable software implementation as
- * a default.
- *
- * @note compared to crc32(), crc32_type() uses a different set of default
- * parameters to match the results returned by boost::crc_32_type and
- * php's built-in crc32 implementation
- */
-uint32_t
-crc32_type(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
-
-} // namespace folly
Bits.h \
CachelinePadded.h \
CallOnce.h \
- Checksum.h \
Chrono.h \
ClockGettimeWrappers.h \
ConcurrentSkipList.h \
detail/AtomicUnorderedMapUtils.h \
detail/AtomicUtils.h \
detail/BitIteratorDetail.h \
- detail/ChecksumDetail.h \
detail/DiscriminatedPtrDetail.h \
detail/FileUtilDetail.h \
detail/FingerprintPolynomial.h \
futures/detail/FSM.h \
futures/detail/Types.h \
futures/test/TestExecutor.h \
+ hash/Checksum.h \
+ hash/detail/ChecksumDetail.h \
hash/SpookyHashV1.h \
hash/SpookyHashV2.h \
gen/Base.h \
CLEANFILES += GroupVarintTables.cpp
libfollybasesse42_la_SOURCES = \
- detail/Crc32cDetail.cpp \
- detail/ChecksumDetail.cpp \
- detail/RangeSse42.cpp
+ detail/RangeSse42.cpp \
+ hash/detail/ChecksumDetail.cpp \
+ hash/detail/Crc32cDetail.cpp
libfollybase_la_SOURCES = \
Conv.cpp \
libfolly_la_SOURCES = \
Assume.cpp \
- Checksum.cpp \
ClockGettimeWrappers.cpp \
concurrency/CacheLocality.cpp \
concurrency/GlobalThreadPoolList.cpp \
experimental/hazptr/memory_resource.cpp \
GroupVarint.cpp \
GroupVarintTables.cpp \
+ hash/Checksum.cpp \
hash/SpookyHashV1.cpp \
hash/SpookyHashV2.cpp \
IPAddress.cpp \
+++ /dev/null
-/*
- * crc32_impl.h
- *
- * Copyright 2016 Eric Biggers
- *
- * Permission is hereby granted, free of charge, to any person
- * obtaining a copy of this software and associated documentation
- * files (the "Software"), to deal in the Software without
- * restriction, including without limitation the rights to use,
- * copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following
- * conditions:
- *
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
- * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
- * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
- * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
- * OTHER DEALINGS IN THE SOFTWARE.
- */
-
-/*
- * CRC-32 folding with PCLMULQDQ.
- *
- * The basic idea is to repeatedly "fold" each 512 bits into the next
- * 512 bits, producing an abbreviated message which is congruent the
- * original message modulo the generator polynomial G(x).
- *
- * Folding each 512 bits is implemented as eight 64-bit folds, each of
- * which uses one carryless multiplication instruction. It's expected
- * that CPUs may be able to execute some of these multiplications in
- * parallel.
- *
- * Explanation of "folding": let A(x) be 64 bits from the message, and
- * let B(x) be 95 bits from a constant distance D later in the
- * message. The relevant portion of the message can be written as:
- *
- * M(x) = A(x)*x^D + B(x)
- *
- * ... where + and * represent addition and multiplication,
- * respectively, of polynomials over GF(2). Note that when
- * implemented on a computer, these operations are equivalent to XOR
- * and carryless multiplication, respectively.
- *
- * For the purpose of CRC calculation, only the remainder modulo the
- * generator polynomial G(x) matters:
- *
- * M(x) mod G(x) = (A(x)*x^D + B(x)) mod G(x)
- *
- * Since the modulo operation can be applied anywhere in a sequence of
- * additions and multiplications without affecting the result, this is
- * equivalent to:
- *
- * M(x) mod G(x) = (A(x)*(x^D mod G(x)) + B(x)) mod G(x)
- *
- * For any D, 'x^D mod G(x)' will be a polynomial with maximum degree
- * 31, i.e. a 32-bit quantity. So 'A(x) * (x^D mod G(x))' is
- * equivalent to a carryless multiplication of a 64-bit quantity by a
- * 32-bit quantity, producing a 95-bit product. Then, adding
- * (XOR-ing) the product to B(x) produces a polynomial with the same
- * length as B(x) but with the same remainder as 'A(x)*x^D + B(x)'.
- * This is the basic fold operation with 64 bits.
- *
- * Note that the carryless multiplication instruction PCLMULQDQ
- * actually takes two 64-bit inputs and produces a 127-bit product in
- * the low-order bits of a 128-bit XMM register. This works fine, but
- * care must be taken to account for "bit endianness". With the CRC
- * version implemented here, bits are always ordered such that the
- * lowest-order bit represents the coefficient of highest power of x
- * and the highest-order bit represents the coefficient of the lowest
- * power of x. This is backwards from the more intuitive order.
- * Still, carryless multiplication works essentially the same either
- * way. It just must be accounted for that when we XOR the 95-bit
- * product in the low-order 95 bits of a 128-bit XMM register into
- * 128-bits of later data held in another XMM register, we'll really
- * be XOR-ing the product into the mathematically higher degree end of
- * those later bits, not the lower degree end as may be expected.
- *
- * So given that caveat and the fact that we process 512 bits per
- * iteration, the 'D' values we need for the two 64-bit halves of each
- * 128 bits of data are:
- *
- * D = (512 + 95) - 64 for the higher-degree half of each 128
- * bits, i.e. the lower order bits in
- * the XMM register
- *
- * D = (512 + 95) - 128 for the lower-degree half of each 128
- * bits, i.e. the higher order bits in
- * the XMM register
- *
- * The required 'x^D mod G(x)' values were precomputed.
- *
- * When <= 512 bits remain in the message, we finish up by folding
- * across smaller distances. This works similarly; the distance D is
- * just different, so different constant multipliers must be used.
- * Finally, once the remaining message is just 64 bits, it is is
- * reduced to the CRC-32 using Barrett reduction (explained later).
- *
- * For more information see the original paper from Intel: "Fast CRC
- * Computation for Generic Polynomials Using PCLMULQDQ
- * Instruction" December 2009
- * http://www.intel.com/content/dam/www/public/us/en/documents/
- * white-papers/
- * fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
- */
-
-#include <folly/detail/ChecksumDetail.h>
-
-namespace folly {
-namespace detail {
-
-#if FOLLY_SSE_PREREQ(4, 2)
-
-uint32_t
-crc32_hw_aligned(uint32_t remainder, const __m128i* p, size_t vec_count) {
- /* Constants precomputed by gen_crc32_multipliers.c. Do not edit! */
- const __m128i multipliers_4 = _mm_set_epi32(0, 0x1D9513D7, 0, 0x8F352D95);
- const __m128i multipliers_2 = _mm_set_epi32(0, 0x81256527, 0, 0xF1DA05AA);
- const __m128i multipliers_1 = _mm_set_epi32(0, 0xCCAA009E, 0, 0xAE689191);
- const __m128i final_multiplier = _mm_set_epi32(0, 0, 0, 0xB8BC6765);
- const __m128i mask32 = _mm_set_epi32(0, 0, 0, 0xFFFFFFFF);
- const __m128i barrett_reduction_constants =
- _mm_set_epi32(0x1, 0xDB710641, 0x1, 0xF7011641);
-
- const __m128i* const end = p + vec_count;
- const __m128i* const end512 = p + (vec_count & ~3);
- __m128i x0, x1, x2, x3;
-
- /*
- * Account for the current 'remainder', i.e. the CRC of the part of
- * the message already processed. Explanation: rewrite the message
- * polynomial M(x) in terms of the first part A(x), the second part
- * B(x), and the length of the second part in bits |B(x)| >= 32:
- *
- * M(x) = A(x)*x^|B(x)| + B(x)
- *
- * Then the CRC of M(x) is:
- *
- * CRC(M(x)) = CRC(A(x)*x^|B(x)| + B(x))
- * = CRC(A(x)*x^32*x^(|B(x)| - 32) + B(x))
- * = CRC(CRC(A(x))*x^(|B(x)| - 32) + B(x))
- *
- * Note: all arithmetic is modulo G(x), the generator polynomial; that's
- * why A(x)*x^32 can be replaced with CRC(A(x)) = A(x)*x^32 mod G(x).
- *
- * So the CRC of the full message is the CRC of the second part of the
- * message where the first 32 bits of the second part of the message
- * have been XOR'ed with the CRC of the first part of the message.
- */
- x0 = *p++;
- x0 = _mm_xor_si128(x0, _mm_set_epi32(0, 0, 0, remainder));
-
- if (p > end512) /* only 128, 256, or 384 bits of input? */
- goto _128_bits_at_a_time;
- x1 = *p++;
- x2 = *p++;
- x3 = *p++;
-
- /* Fold 512 bits at a time */
- for (; p != end512; p += 4) {
- __m128i y0, y1, y2, y3;
-
- y0 = p[0];
- y1 = p[1];
- y2 = p[2];
- y3 = p[3];
-
- /*
- * Note: the immediate constant for PCLMULQDQ specifies which
- * 64-bit halves of the 128-bit vectors to multiply:
- *
- * 0x00 means low halves (higher degree polynomial terms for us)
- * 0x11 means high halves (lower degree polynomial terms for us)
- */
- y0 = _mm_xor_si128(y0, _mm_clmulepi64_si128(x0, multipliers_4, 0x00));
- y1 = _mm_xor_si128(y1, _mm_clmulepi64_si128(x1, multipliers_4, 0x00));
- y2 = _mm_xor_si128(y2, _mm_clmulepi64_si128(x2, multipliers_4, 0x00));
- y3 = _mm_xor_si128(y3, _mm_clmulepi64_si128(x3, multipliers_4, 0x00));
- y0 = _mm_xor_si128(y0, _mm_clmulepi64_si128(x0, multipliers_4, 0x11));
- y1 = _mm_xor_si128(y1, _mm_clmulepi64_si128(x1, multipliers_4, 0x11));
- y2 = _mm_xor_si128(y2, _mm_clmulepi64_si128(x2, multipliers_4, 0x11));
- y3 = _mm_xor_si128(y3, _mm_clmulepi64_si128(x3, multipliers_4, 0x11));
-
- x0 = y0;
- x1 = y1;
- x2 = y2;
- x3 = y3;
- }
-
- /* Fold 512 bits => 128 bits */
- x2 = _mm_xor_si128(x2, _mm_clmulepi64_si128(x0, multipliers_2, 0x00));
- x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x1, multipliers_2, 0x00));
- x2 = _mm_xor_si128(x2, _mm_clmulepi64_si128(x0, multipliers_2, 0x11));
- x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x1, multipliers_2, 0x11));
- x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x2, multipliers_1, 0x00));
- x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x2, multipliers_1, 0x11));
- x0 = x3;
-
-_128_bits_at_a_time:
- while (p != end) {
- /* Fold 128 bits into next 128 bits */
- x1 = *p++;
- x1 = _mm_xor_si128(x1, _mm_clmulepi64_si128(x0, multipliers_1, 0x00));
- x1 = _mm_xor_si128(x1, _mm_clmulepi64_si128(x0, multipliers_1, 0x11));
- x0 = x1;
- }
-
- /* Now there are just 128 bits left, stored in 'x0'. */
-
- /*
- * Fold 128 => 96 bits. This also implicitly appends 32 zero bits,
- * which is equivalent to multiplying by x^32. This is needed because
- * the CRC is defined as M(x)*x^32 mod G(x), not just M(x) mod G(x).
- */
- x0 = _mm_xor_si128(_mm_srli_si128(x0, 8), _mm_clmulepi64_si128(x0, multipliers_1, 0x10));
-
- /* Fold 96 => 64 bits */
- x0 = _mm_xor_si128(_mm_srli_si128(x0, 4),
- _mm_clmulepi64_si128(_mm_and_si128(x0, mask32), final_multiplier, 0x00));
-
- /*
- * Finally, reduce 64 => 32 bits using Barrett reduction.
- *
- * Let M(x) = A(x)*x^32 + B(x) be the remaining message. The goal is to
- * compute R(x) = M(x) mod G(x). Since degree(B(x)) < degree(G(x)):
- *
- * R(x) = (A(x)*x^32 + B(x)) mod G(x)
- * = (A(x)*x^32) mod G(x) + B(x)
- *
- * Then, by the Division Algorithm there exists a unique q(x) such that:
- *
- * A(x)*x^32 mod G(x) = A(x)*x^32 - q(x)*G(x)
- *
- * Since the left-hand side is of maximum degree 31, the right-hand side
- * must be too. This implies that we can apply 'mod x^32' to the
- * right-hand side without changing its value:
- *
- * (A(x)*x^32 - q(x)*G(x)) mod x^32 = q(x)*G(x) mod x^32
- *
- * Note that '+' is equivalent to '-' in polynomials over GF(2).
- *
- * We also know that:
- *
- * / A(x)*x^32 \
- * q(x) = floor ( --------- )
- * \ G(x) /
- *
- * To compute this efficiently, we can multiply the top and bottom by
- * x^32 and move the division by G(x) to the top:
- *
- * / A(x) * floor(x^64 / G(x)) \
- * q(x) = floor ( ------------------------- )
- * \ x^32 /
- *
- * Note that floor(x^64 / G(x)) is a constant.
- *
- * So finally we have:
- *
- * / A(x) * floor(x^64 / G(x)) \
- * R(x) = B(x) + G(x)*floor ( ------------------------- )
- * \ x^32 /
- */
- x1 = x0;
- x0 = _mm_clmulepi64_si128(_mm_and_si128(x0, mask32), barrett_reduction_constants, 0x00);
- x0 = _mm_clmulepi64_si128(_mm_and_si128(x0, mask32), barrett_reduction_constants, 0x10);
- return _mm_cvtsi128_si32(_mm_srli_si128(_mm_xor_si128(x0, x1), 4));
-}
-
-#endif
-}
-} // namespace
+++ /dev/null
-/*
- * Copyright 2017 Facebook, Inc.
- *
- * 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.
- */
-
-#pragma once
-
-#include <folly/Portability.h>
-
-#if FOLLY_SSE_PREREQ(4, 2)
-#include <immintrin.h>
-#endif
-
-#include <stdint.h>
-#include <cstddef>
-
-namespace folly { namespace detail {
-
-/**
- * Compute a CRC-32C checksum of a buffer using a hardware-accelerated
- * implementation.
- *
- * @note This function is exposed to support special cases where the
- * calling code is absolutely certain it ought to invoke a hardware-
- * accelerated CRC-32C implementation - unit tests, for example. For
- * all other scenarios, please call crc32c() and let it pick an
- * implementation based on the capabilities of the underlying CPU.
- */
-uint32_t crc32c_hw(const uint8_t* data, size_t nbytes,
- uint32_t startingChecksum = ~0U);
-
-/**
- * Check whether a hardware-accelerated CRC-32C implementation is
- * supported on the current CPU.
- */
-bool crc32c_hw_supported();
-
-/**
- * Compute a CRC-32C checksum of a buffer using a portable,
- * software-only implementation.
- *
- * @note This function is exposed to support special cases where the
- * calling code is absolutely certain it wants to use the software
- * implementation instead of the hardware-accelerated code - unit
- * tests, for example. For all other scenarios, please call crc32c()
- * and let it pick an implementation based on the capabilities of
- * the underlying CPU.
- */
-uint32_t crc32c_sw(const uint8_t* data, size_t nbytes,
- uint32_t startingChecksum = ~0U);
-
-/**
- * Compute a CRC-32 checksum of a buffer using a hardware-accelerated
- * implementation.
- *
- * @note This function is exposed to support special cases where the
- * calling code is absolutely certain it ought to invoke a hardware-
- * accelerated CRC-32 implementation - unit tests, for example. For
- * all other scenarios, please call crc32() and let it pick an
- * implementation based on the capabilities of the underlying CPU.
- */
-uint32_t
-crc32_hw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
-
-#if FOLLY_SSE_PREREQ(4, 2)
-uint32_t
-crc32_hw_aligned(uint32_t remainder, const __m128i* p, size_t vec_count);
-#endif
-
-/**
- * Check whether a hardware-accelerated CRC-32 implementation is
- * supported on the current CPU.
- */
-bool crc32_hw_supported();
-
-/**
- * Compute a CRC-32 checksum of a buffer using a portable,
- * software-only implementation.
- *
- * @note This function is exposed to support special cases where the
- * calling code is absolutely certain it wants to use the software
- * implementation instead of the hardware-accelerated code - unit
- * tests, for example. For all other scenarios, please call crc32()
- * and let it pick an implementation based on the capabilities of
- * the underlying CPU.
- */
-uint32_t
-crc32_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
-}} // folly::detail
+++ /dev/null
-/*
- * Copyright 2016 Ferry Toth, Exalon Delft BV, The Netherlands
- * This software is provided 'as-is', without any express or implied
- * warranty. In no event will the author be held liable for any damages
- * arising from the use of this software.
- * Permission is granted to anyone to use this software for any purpose,
- * including commercial applications, and to alter it and redistribute it
- * freely, subject to the following restrictions:
- * 1. The origin of this software must not be misrepresented; you must not
- * claim that you wrote the original software. If you use this software
- * in a product, an acknowledgment in the product documentation would be
- * appreciated but is not required.
- * 2. Altered source versions must be plainly marked as such, and must not be
- * misrepresented as being the original software.
- * 3. This notice may not be removed or altered from any source distribution.
- * Ferry Toth
- * ftoth@exalondelft.nl
- *
- * https://github.com/htot/crc32c
- *
- * Modified by Facebook
- *
- * Original intel whitepaper:
- * "Fast CRC Computation for iSCSI Polynomial Using CRC32 Instruction"
- * https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/crc-iscsi-polynomial-crc32-instruction-paper.pdf
- *
- * 32-bit support dropped
- * use intrinsics instead of inline asm
- * other code cleanup
- */
-
-#include <stdexcept>
-
-#include <folly/detail/ChecksumDetail.h>
-
-#include <folly/CppAttributes.h>
-
-#include <boost/preprocessor/arithmetic/add.hpp>
-#include <boost/preprocessor/arithmetic/sub.hpp>
-#include <boost/preprocessor/repetition/repeat_from_to.hpp>
-
-namespace folly {
-namespace detail {
-
-#if FOLLY_SSE_PREREQ(4, 2)
-
-namespace crc32_detail {
-
-#define CRCtriplet(crc, buf, offset) \
- crc##0 = _mm_crc32_u64(crc##0, *(buf##0 + offset)); \
- crc##1 = _mm_crc32_u64(crc##1, *(buf##1 + offset)); \
- crc##2 = _mm_crc32_u64(crc##2, *(buf##2 + offset)); \
- FOLLY_FALLTHROUGH;
-
-#define CRCduplet(crc, buf, offset) \
- crc##0 = _mm_crc32_u64(crc##0, *(buf##0 + offset)); \
- crc##1 = _mm_crc32_u64(crc##1, *(buf##1 + offset));
-
-#define CRCsinglet(crc, buf, offset) \
- crc = _mm_crc32_u64(crc, *(uint64_t*)(buf + offset)); \
- FOLLY_FALLTHROUGH;
-
-#define CASEREPEAT_TRIPLET(unused, count, total) \
- case BOOST_PP_ADD(1, BOOST_PP_SUB(total, count)): \
- CRCtriplet(crc, next, -BOOST_PP_ADD(1, BOOST_PP_SUB(total, count)));
-
-#define CASEREPEAT_SINGLET(unused, count, total) \
- case BOOST_PP_SUB(total, count): \
- CRCsinglet(crc0, next, -BOOST_PP_SUB(total, count) * 8);
-
-// Numbers taken directly from intel whitepaper.
-// clang-format off
-const uint64_t clmul_constants[] = {
- 0x14cd00bd6, 0x105ec76f0, 0x0ba4fc28e, 0x14cd00bd6,
- 0x1d82c63da, 0x0f20c0dfe, 0x09e4addf8, 0x0ba4fc28e,
- 0x039d3b296, 0x1384aa63a, 0x102f9b8a2, 0x1d82c63da,
- 0x14237f5e6, 0x01c291d04, 0x00d3b6092, 0x09e4addf8,
- 0x0c96cfdc0, 0x0740eef02, 0x18266e456, 0x039d3b296,
- 0x0daece73e, 0x0083a6eec, 0x0ab7aff2a, 0x102f9b8a2,
- 0x1248ea574, 0x1c1733996, 0x083348832, 0x14237f5e6,
- 0x12c743124, 0x02ad91c30, 0x0b9e02b86, 0x00d3b6092,
- 0x018b33a4e, 0x06992cea2, 0x1b331e26a, 0x0c96cfdc0,
- 0x17d35ba46, 0x07e908048, 0x1bf2e8b8a, 0x18266e456,
- 0x1a3e0968a, 0x11ed1f9d8, 0x0ce7f39f4, 0x0daece73e,
- 0x061d82e56, 0x0f1d0f55e, 0x0d270f1a2, 0x0ab7aff2a,
- 0x1c3f5f66c, 0x0a87ab8a8, 0x12ed0daac, 0x1248ea574,
- 0x065863b64, 0x08462d800, 0x11eef4f8e, 0x083348832,
- 0x1ee54f54c, 0x071d111a8, 0x0b3e32c28, 0x12c743124,
- 0x0064f7f26, 0x0ffd852c6, 0x0dd7e3b0c, 0x0b9e02b86,
- 0x0f285651c, 0x0dcb17aa4, 0x010746f3c, 0x018b33a4e,
- 0x1c24afea4, 0x0f37c5aee, 0x0271d9844, 0x1b331e26a,
- 0x08e766a0c, 0x06051d5a2, 0x093a5f730, 0x17d35ba46,
- 0x06cb08e5c, 0x11d5ca20e, 0x06b749fb2, 0x1bf2e8b8a,
- 0x1167f94f2, 0x021f3d99c, 0x0cec3662e, 0x1a3e0968a,
- 0x19329634a, 0x08f158014, 0x0e6fc4e6a, 0x0ce7f39f4,
- 0x08227bb8a, 0x1a5e82106, 0x0b0cd4768, 0x061d82e56,
- 0x13c2b89c4, 0x188815ab2, 0x0d7a4825c, 0x0d270f1a2,
- 0x10f5ff2ba, 0x105405f3e, 0x00167d312, 0x1c3f5f66c,
- 0x0f6076544, 0x0e9adf796, 0x026f6a60a, 0x12ed0daac,
- 0x1a2adb74e, 0x096638b34, 0x19d34af3a, 0x065863b64,
- 0x049c3cc9c, 0x1e50585a0, 0x068bce87a, 0x11eef4f8e,
- 0x1524fa6c6, 0x19f1c69dc, 0x16cba8aca, 0x1ee54f54c,
- 0x042d98888, 0x12913343e, 0x1329d9f7e, 0x0b3e32c28,
- 0x1b1c69528, 0x088f25a3a, 0x02178513a, 0x0064f7f26,
- 0x0e0ac139e, 0x04e36f0b0, 0x0170076fa, 0x0dd7e3b0c,
- 0x141a1a2e2, 0x0bd6f81f8, 0x16ad828b4, 0x0f285651c,
- 0x041d17b64, 0x19425cbba, 0x1fae1cc66, 0x010746f3c,
- 0x1a75b4b00, 0x18db37e8a, 0x0f872e54c, 0x1c24afea4,
- 0x01e41e9fc, 0x04c144932, 0x086d8e4d2, 0x0271d9844,
- 0x160f7af7a, 0x052148f02, 0x05bb8f1bc, 0x08e766a0c,
- 0x0a90fd27a, 0x0a3c6f37a, 0x0b3af077a, 0x093a5f730,
- 0x04984d782, 0x1d22c238e, 0x0ca6ef3ac, 0x06cb08e5c,
- 0x0234e0b26, 0x063ded06a, 0x1d88abd4a, 0x06b749fb2,
- 0x04597456a, 0x04d56973c, 0x0e9e28eb4, 0x1167f94f2,
- 0x07b3ff57a, 0x19385bf2e, 0x0c9c8b782, 0x0cec3662e,
- 0x13a9cba9e, 0x0e417f38a, 0x093e106a4, 0x19329634a,
- 0x167001a9c, 0x14e727980, 0x1ddffc5d4, 0x0e6fc4e6a,
- 0x00df04680, 0x0d104b8fc, 0x02342001e, 0x08227bb8a,
- 0x00a2a8d7e, 0x05b397730, 0x168763fa6, 0x0b0cd4768,
- 0x1ed5a407a, 0x0e78eb416, 0x0d2c3ed1a, 0x13c2b89c4,
- 0x0995a5724, 0x1641378f0, 0x19b1afbc4, 0x0d7a4825c,
- 0x109ffedc0, 0x08d96551c, 0x0f2271e60, 0x10f5ff2ba,
- 0x00b0bf8ca, 0x00bf80dd2, 0x123888b7a, 0x00167d312,
- 0x1e888f7dc, 0x18dcddd1c, 0x002ee03b2, 0x0f6076544,
- 0x183e8d8fe, 0x06a45d2b2, 0x133d7a042, 0x026f6a60a,
- 0x116b0f50c, 0x1dd3e10e8, 0x05fabe670, 0x1a2adb74e,
- 0x130004488, 0x0de87806c, 0x000bcf5f6, 0x19d34af3a,
- 0x18f0c7078, 0x014338754, 0x017f27698, 0x049c3cc9c,
- 0x058ca5f00, 0x15e3e77ee, 0x1af900c24, 0x068bce87a,
- 0x0b5cfca28, 0x0dd07448e, 0x0ded288f8, 0x1524fa6c6,
- 0x059f229bc, 0x1d8048348, 0x06d390dec, 0x16cba8aca,
- 0x037170390, 0x0a3e3e02c, 0x06353c1cc, 0x042d98888,
- 0x0c4584f5c, 0x0d73c7bea, 0x1f16a3418, 0x1329d9f7e,
- 0x0531377e2, 0x185137662, 0x1d8d9ca7c, 0x1b1c69528,
- 0x0b25b29f2, 0x18a08b5bc, 0x19fb2a8b0, 0x02178513a,
- 0x1a08fe6ac, 0x1da758ae0, 0x045cddf4e, 0x0e0ac139e,
- 0x1a91647f2, 0x169cf9eb0, 0x1a0f717c4, 0x0170076fa,
-};
-// clang-format on
-
-/*
- * CombineCRC performs pclmulqdq multiplication of 2 partial CRC's and a well
- * chosen constant and xor's these with the remaining CRC.
- */
-uint64_t CombineCRC(
- size_t block_size,
- uint64_t crc0,
- uint64_t crc1,
- uint64_t crc2,
- const uint64_t* next2) {
- const auto multiplier =
- *(reinterpret_cast<const __m128i*>(clmul_constants) + block_size - 1);
- const auto crc0_xmm = _mm_set_epi64x(0, crc0);
- const auto res0 = _mm_clmulepi64_si128(crc0_xmm, multiplier, 0x00);
- const auto crc1_xmm = _mm_set_epi64x(0, crc1);
- const auto res1 = _mm_clmulepi64_si128(crc1_xmm, multiplier, 0x10);
- const auto res = _mm_xor_si128(res0, res1);
- crc0 = _mm_cvtsi128_si64(res);
- crc0 = crc0 ^ *((uint64_t*)next2 - 1);
- crc2 = _mm_crc32_u64(crc2, crc0);
- return crc2;
-}
-
-// Generates a block that will crc up to 7 bytes of unaligned data.
-// Always inline to avoid overhead on small crc sizes.
-FOLLY_ALWAYS_INLINE void align_to_8(
- size_t align,
- uint64_t& crc0, // crc so far, updated on return
- const unsigned char*& next) { // next data pointer, updated on return
- uint32_t crc32bit = static_cast<uint32_t>(crc0);
- if (align & 0x04) {
- crc32bit = _mm_crc32_u32(crc32bit, *(uint32_t*)next);
- next += sizeof(uint32_t);
- }
- if (align & 0x02) {
- crc32bit = _mm_crc32_u16(crc32bit, *(uint16_t*)next);
- next += sizeof(uint16_t);
- }
- if (align & 0x01) {
- crc32bit = _mm_crc32_u8(crc32bit, *(next));
- next++;
- }
- crc0 = crc32bit;
-}
-
-// The main loop for large crc sizes. Generates three crc32c
-// streams, of varying block sizes, using a duff's device.
-void triplet_loop(
- size_t block_size,
- uint64_t& crc0, // crc so far, updated on return
- const unsigned char*& next, // next data pointer, updated on return
- size_t n) { // block count
- uint64_t crc1 = 0, crc2 = 0;
- // points to the first byte of the next block
- const uint64_t* next0 = (uint64_t*)next + block_size;
- const uint64_t* next1 = next0 + block_size;
- const uint64_t* next2 = next1 + block_size;
-
- // Use Duff's device, a for() loop inside a switch()
- // statement. This needs to execute at least once, round len
- // down to nearest triplet multiple
- switch (block_size) {
- case 128:
- do {
- // jumps here for a full block of len 128
- CRCtriplet(crc, next, -128);
-
- // Generates case statements from 127 to 2 of form:
- // case 127:
- // CRCtriplet(crc, next, -127);
- //
- // MSVC has a max preprocessor expansion depth of 255, which is
- // exceeded if this is a single statement.
- BOOST_PP_REPEAT_FROM_TO(0, 64, CASEREPEAT_TRIPLET, 126);
- BOOST_PP_REPEAT_FROM_TO(0, 62, CASEREPEAT_TRIPLET, 62);
-
- // For the last byte, the three crc32c streams must be combined
- // using carry-less multiplication.
- case 1:
- CRCduplet(crc, next, -1); // the final triplet is actually only 2
- crc0 = CombineCRC(block_size, crc0, crc1, crc2, next2);
- if (--n > 0) {
- crc1 = crc2 = 0;
- block_size = 128;
- // points to the first byte of the next block
- next0 = next2 + 128;
- next1 = next0 + 128; // from here on all blocks are 128 long
- next2 = next1 + 128;
- }
- FOLLY_FALLTHROUGH;
- case 0:;
- } while (n > 0);
- }
-
- next = (const unsigned char*)next2;
-}
-
-} // namespace crc32c_detail
-
-/* Compute CRC-32C using the Intel hardware instruction. */
-FOLLY_TARGET_ATTRIBUTE("sse4.2")
-uint32_t crc32c_hw(const uint8_t* buf, size_t len, uint32_t crc) {
- const unsigned char* next = (const unsigned char*)buf;
- size_t count;
- uint64_t crc0;
- crc0 = crc;
-
- if (len >= 8) {
- // if len > 216 then align and use triplets
- if (len > 216) {
- size_t align = (8 - (uintptr_t)next) & 7;
- crc32_detail::align_to_8(align, crc0, next);
- len -= align;
-
- count = len / 24; // number of triplets
- len %= 24; // bytes remaining
- size_t n = count >> 7; // #blocks = first block + full blocks
- size_t block_size = count & 127;
- if (block_size == 0) {
- block_size = 128;
- } else {
- n++;
- }
-
- // This is a separate function call mainly to stop
- // clang from spilling registers.
- crc32_detail::triplet_loop(block_size, crc0, next, n);
- }
-
- size_t count2 = len >> 3;
- len = len & 7;
- next += (count2 * 8);
-
- // Generates a duff device for the last 128 bytes of aligned data.
- switch (count2) {
- // Generates case statements of the form:
- // case 27:
- // CRCsinglet(crc0, next, -27 * 8);
- BOOST_PP_REPEAT_FROM_TO(0, 27, CASEREPEAT_SINGLET, 27);
- case 0:;
- }
- }
-
- // compute the crc for up to seven trailing bytes
- crc32_detail::align_to_8(len, crc0, next);
- return (uint32_t)crc0;
-}
-
-#else
-
-uint32_t crc32c_hw(const uint8_t* buf, size_t len, uint32_t crc) {
- throw std::runtime_error("crc32_hw is not implemented on this platform");
-}
-
-#endif
-
-} // namespace detail
-} // namespace folly
--- /dev/null
+/*
+ * Copyright 2017 Facebook, Inc.
+ *
+ * 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.
+ */
+
+#include <folly/hash/Checksum.h>
+#include <boost/crc.hpp>
+#include <folly/CpuId.h>
+#include <folly/hash/detail/ChecksumDetail.h>
+#include <algorithm>
+#include <stdexcept>
+
+#if FOLLY_SSE_PREREQ(4, 2)
+#include <nmmintrin.h>
+#endif
+
+namespace folly {
+
+namespace detail {
+
+uint32_t
+crc32c_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum);
+#if FOLLY_SSE_PREREQ(4, 2)
+
+uint32_t
+crc32_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum);
+
+// Fast SIMD implementation of CRC-32 for x86 with pclmul
+uint32_t
+crc32_hw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
+ uint32_t sum = startingChecksum;
+ size_t offset = 0;
+
+ // Process unaligned bytes
+ if ((uintptr_t)data & 15) {
+ size_t limit = std::min(nbytes, -(uintptr_t)data & 15);
+ sum = crc32_sw(data, limit, sum);
+ offset += limit;
+ nbytes -= limit;
+ }
+
+ if (nbytes >= 16) {
+ sum = crc32_hw_aligned(sum, (const __m128i*)(data + offset), nbytes / 16);
+ offset += nbytes & ~15;
+ nbytes &= 15;
+ }
+
+ // Remaining unaligned bytes
+ return crc32_sw(data + offset, nbytes, sum);
+}
+
+bool crc32c_hw_supported() {
+ static folly::CpuId id;
+ return id.sse42();
+}
+
+bool crc32_hw_supported() {
+ static folly::CpuId id;
+ return id.sse42();
+}
+
+#else
+
+uint32_t crc32_hw(const uint8_t *data, size_t nbytes,
+ uint32_t startingChecksum) {
+ throw std::runtime_error("crc32_hw is not implemented on this platform");
+}
+
+bool crc32c_hw_supported() {
+ return false;
+}
+
+bool crc32_hw_supported() {
+ return false;
+}
+#endif
+
+template <uint32_t CRC_POLYNOMIAL>
+uint32_t crc_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
+ // Reverse the bits in the starting checksum so they'll be in the
+ // right internal format for Boost's CRC engine.
+ // O(1)-time, branchless bit reversal algorithm from
+ // http://graphics.stanford.edu/~seander/bithacks.html
+ startingChecksum = ((startingChecksum >> 1) & 0x55555555) |
+ ((startingChecksum & 0x55555555) << 1);
+ startingChecksum = ((startingChecksum >> 2) & 0x33333333) |
+ ((startingChecksum & 0x33333333) << 2);
+ startingChecksum = ((startingChecksum >> 4) & 0x0f0f0f0f) |
+ ((startingChecksum & 0x0f0f0f0f) << 4);
+ startingChecksum = ((startingChecksum >> 8) & 0x00ff00ff) |
+ ((startingChecksum & 0x00ff00ff) << 8);
+ startingChecksum = (startingChecksum >> 16) |
+ (startingChecksum << 16);
+
+ boost::crc_optimal<32, CRC_POLYNOMIAL, ~0U, 0, true, true> sum(
+ startingChecksum);
+ sum.process_bytes(data, nbytes);
+ return sum.checksum();
+}
+
+uint32_t
+crc32c_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
+ constexpr uint32_t CRC32C_POLYNOMIAL = 0x1EDC6F41;
+ return crc_sw<CRC32C_POLYNOMIAL>(data, nbytes, startingChecksum);
+}
+
+uint32_t
+crc32_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
+ constexpr uint32_t CRC32_POLYNOMIAL = 0x04C11DB7;
+ return crc_sw<CRC32_POLYNOMIAL>(data, nbytes, startingChecksum);
+}
+
+} // namespace detail
+
+uint32_t crc32c(const uint8_t *data, size_t nbytes,
+ uint32_t startingChecksum) {
+ if (detail::crc32c_hw_supported()) {
+ return detail::crc32c_hw(data, nbytes, startingChecksum);
+ } else {
+ return detail::crc32c_sw(data, nbytes, startingChecksum);
+ }
+}
+
+uint32_t crc32(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
+ if (detail::crc32_hw_supported()) {
+ return detail::crc32_hw(data, nbytes, startingChecksum);
+ } else {
+ return detail::crc32_sw(data, nbytes, startingChecksum);
+ }
+}
+
+uint32_t
+crc32_type(const uint8_t* data, size_t nbytes, uint32_t startingChecksum) {
+ return ~crc32(data, nbytes, startingChecksum);
+}
+
+} // namespace folly
--- /dev/null
+/*
+ * Copyright 2017 Facebook, Inc.
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <cstddef>
+
+/*
+ * Checksum functions
+ */
+
+namespace folly {
+
+/**
+ * Compute the CRC-32C checksum of a buffer, using a hardware-accelerated
+ * implementation if available or a portable software implementation as
+ * a default.
+ *
+ * @note CRC-32C is different from CRC-32; CRC-32C starts with a different
+ * polynomial and thus yields different results for the same input
+ * than a traditional CRC-32.
+ */
+uint32_t crc32c(const uint8_t* data, size_t nbytes,
+ uint32_t startingChecksum = ~0U);
+
+/**
+ * Compute the CRC-32 checksum of a buffer, using a hardware-accelerated
+ * implementation if available or a portable software implementation as
+ * a default.
+ */
+uint32_t
+crc32(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
+
+/**
+ * Compute the CRC-32 checksum of a buffer, using a hardware-accelerated
+ * implementation if available or a portable software implementation as
+ * a default.
+ *
+ * @note compared to crc32(), crc32_type() uses a different set of default
+ * parameters to match the results returned by boost::crc_32_type and
+ * php's built-in crc32 implementation
+ */
+uint32_t
+crc32_type(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
+
+} // namespace folly
--- /dev/null
+/*
+ * crc32_impl.h
+ *
+ * Copyright 2016 Eric Biggers
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following
+ * conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * CRC-32 folding with PCLMULQDQ.
+ *
+ * The basic idea is to repeatedly "fold" each 512 bits into the next
+ * 512 bits, producing an abbreviated message which is congruent the
+ * original message modulo the generator polynomial G(x).
+ *
+ * Folding each 512 bits is implemented as eight 64-bit folds, each of
+ * which uses one carryless multiplication instruction. It's expected
+ * that CPUs may be able to execute some of these multiplications in
+ * parallel.
+ *
+ * Explanation of "folding": let A(x) be 64 bits from the message, and
+ * let B(x) be 95 bits from a constant distance D later in the
+ * message. The relevant portion of the message can be written as:
+ *
+ * M(x) = A(x)*x^D + B(x)
+ *
+ * ... where + and * represent addition and multiplication,
+ * respectively, of polynomials over GF(2). Note that when
+ * implemented on a computer, these operations are equivalent to XOR
+ * and carryless multiplication, respectively.
+ *
+ * For the purpose of CRC calculation, only the remainder modulo the
+ * generator polynomial G(x) matters:
+ *
+ * M(x) mod G(x) = (A(x)*x^D + B(x)) mod G(x)
+ *
+ * Since the modulo operation can be applied anywhere in a sequence of
+ * additions and multiplications without affecting the result, this is
+ * equivalent to:
+ *
+ * M(x) mod G(x) = (A(x)*(x^D mod G(x)) + B(x)) mod G(x)
+ *
+ * For any D, 'x^D mod G(x)' will be a polynomial with maximum degree
+ * 31, i.e. a 32-bit quantity. So 'A(x) * (x^D mod G(x))' is
+ * equivalent to a carryless multiplication of a 64-bit quantity by a
+ * 32-bit quantity, producing a 95-bit product. Then, adding
+ * (XOR-ing) the product to B(x) produces a polynomial with the same
+ * length as B(x) but with the same remainder as 'A(x)*x^D + B(x)'.
+ * This is the basic fold operation with 64 bits.
+ *
+ * Note that the carryless multiplication instruction PCLMULQDQ
+ * actually takes two 64-bit inputs and produces a 127-bit product in
+ * the low-order bits of a 128-bit XMM register. This works fine, but
+ * care must be taken to account for "bit endianness". With the CRC
+ * version implemented here, bits are always ordered such that the
+ * lowest-order bit represents the coefficient of highest power of x
+ * and the highest-order bit represents the coefficient of the lowest
+ * power of x. This is backwards from the more intuitive order.
+ * Still, carryless multiplication works essentially the same either
+ * way. It just must be accounted for that when we XOR the 95-bit
+ * product in the low-order 95 bits of a 128-bit XMM register into
+ * 128-bits of later data held in another XMM register, we'll really
+ * be XOR-ing the product into the mathematically higher degree end of
+ * those later bits, not the lower degree end as may be expected.
+ *
+ * So given that caveat and the fact that we process 512 bits per
+ * iteration, the 'D' values we need for the two 64-bit halves of each
+ * 128 bits of data are:
+ *
+ * D = (512 + 95) - 64 for the higher-degree half of each 128
+ * bits, i.e. the lower order bits in
+ * the XMM register
+ *
+ * D = (512 + 95) - 128 for the lower-degree half of each 128
+ * bits, i.e. the higher order bits in
+ * the XMM register
+ *
+ * The required 'x^D mod G(x)' values were precomputed.
+ *
+ * When <= 512 bits remain in the message, we finish up by folding
+ * across smaller distances. This works similarly; the distance D is
+ * just different, so different constant multipliers must be used.
+ * Finally, once the remaining message is just 64 bits, it is is
+ * reduced to the CRC-32 using Barrett reduction (explained later).
+ *
+ * For more information see the original paper from Intel: "Fast CRC
+ * Computation for Generic Polynomials Using PCLMULQDQ
+ * Instruction" December 2009
+ * http://www.intel.com/content/dam/www/public/us/en/documents/
+ * white-papers/
+ * fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
+ */
+
+#include <folly/hash/detail/ChecksumDetail.h>
+
+namespace folly {
+namespace detail {
+
+#if FOLLY_SSE_PREREQ(4, 2)
+
+uint32_t
+crc32_hw_aligned(uint32_t remainder, const __m128i* p, size_t vec_count) {
+ /* Constants precomputed by gen_crc32_multipliers.c. Do not edit! */
+ const __m128i multipliers_4 = _mm_set_epi32(0, 0x1D9513D7, 0, 0x8F352D95);
+ const __m128i multipliers_2 = _mm_set_epi32(0, 0x81256527, 0, 0xF1DA05AA);
+ const __m128i multipliers_1 = _mm_set_epi32(0, 0xCCAA009E, 0, 0xAE689191);
+ const __m128i final_multiplier = _mm_set_epi32(0, 0, 0, 0xB8BC6765);
+ const __m128i mask32 = _mm_set_epi32(0, 0, 0, 0xFFFFFFFF);
+ const __m128i barrett_reduction_constants =
+ _mm_set_epi32(0x1, 0xDB710641, 0x1, 0xF7011641);
+
+ const __m128i* const end = p + vec_count;
+ const __m128i* const end512 = p + (vec_count & ~3);
+ __m128i x0, x1, x2, x3;
+
+ /*
+ * Account for the current 'remainder', i.e. the CRC of the part of
+ * the message already processed. Explanation: rewrite the message
+ * polynomial M(x) in terms of the first part A(x), the second part
+ * B(x), and the length of the second part in bits |B(x)| >= 32:
+ *
+ * M(x) = A(x)*x^|B(x)| + B(x)
+ *
+ * Then the CRC of M(x) is:
+ *
+ * CRC(M(x)) = CRC(A(x)*x^|B(x)| + B(x))
+ * = CRC(A(x)*x^32*x^(|B(x)| - 32) + B(x))
+ * = CRC(CRC(A(x))*x^(|B(x)| - 32) + B(x))
+ *
+ * Note: all arithmetic is modulo G(x), the generator polynomial; that's
+ * why A(x)*x^32 can be replaced with CRC(A(x)) = A(x)*x^32 mod G(x).
+ *
+ * So the CRC of the full message is the CRC of the second part of the
+ * message where the first 32 bits of the second part of the message
+ * have been XOR'ed with the CRC of the first part of the message.
+ */
+ x0 = *p++;
+ x0 = _mm_xor_si128(x0, _mm_set_epi32(0, 0, 0, remainder));
+
+ if (p > end512) /* only 128, 256, or 384 bits of input? */
+ goto _128_bits_at_a_time;
+ x1 = *p++;
+ x2 = *p++;
+ x3 = *p++;
+
+ /* Fold 512 bits at a time */
+ for (; p != end512; p += 4) {
+ __m128i y0, y1, y2, y3;
+
+ y0 = p[0];
+ y1 = p[1];
+ y2 = p[2];
+ y3 = p[3];
+
+ /*
+ * Note: the immediate constant for PCLMULQDQ specifies which
+ * 64-bit halves of the 128-bit vectors to multiply:
+ *
+ * 0x00 means low halves (higher degree polynomial terms for us)
+ * 0x11 means high halves (lower degree polynomial terms for us)
+ */
+ y0 = _mm_xor_si128(y0, _mm_clmulepi64_si128(x0, multipliers_4, 0x00));
+ y1 = _mm_xor_si128(y1, _mm_clmulepi64_si128(x1, multipliers_4, 0x00));
+ y2 = _mm_xor_si128(y2, _mm_clmulepi64_si128(x2, multipliers_4, 0x00));
+ y3 = _mm_xor_si128(y3, _mm_clmulepi64_si128(x3, multipliers_4, 0x00));
+ y0 = _mm_xor_si128(y0, _mm_clmulepi64_si128(x0, multipliers_4, 0x11));
+ y1 = _mm_xor_si128(y1, _mm_clmulepi64_si128(x1, multipliers_4, 0x11));
+ y2 = _mm_xor_si128(y2, _mm_clmulepi64_si128(x2, multipliers_4, 0x11));
+ y3 = _mm_xor_si128(y3, _mm_clmulepi64_si128(x3, multipliers_4, 0x11));
+
+ x0 = y0;
+ x1 = y1;
+ x2 = y2;
+ x3 = y3;
+ }
+
+ /* Fold 512 bits => 128 bits */
+ x2 = _mm_xor_si128(x2, _mm_clmulepi64_si128(x0, multipliers_2, 0x00));
+ x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x1, multipliers_2, 0x00));
+ x2 = _mm_xor_si128(x2, _mm_clmulepi64_si128(x0, multipliers_2, 0x11));
+ x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x1, multipliers_2, 0x11));
+ x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x2, multipliers_1, 0x00));
+ x3 = _mm_xor_si128(x3, _mm_clmulepi64_si128(x2, multipliers_1, 0x11));
+ x0 = x3;
+
+_128_bits_at_a_time:
+ while (p != end) {
+ /* Fold 128 bits into next 128 bits */
+ x1 = *p++;
+ x1 = _mm_xor_si128(x1, _mm_clmulepi64_si128(x0, multipliers_1, 0x00));
+ x1 = _mm_xor_si128(x1, _mm_clmulepi64_si128(x0, multipliers_1, 0x11));
+ x0 = x1;
+ }
+
+ /* Now there are just 128 bits left, stored in 'x0'. */
+
+ /*
+ * Fold 128 => 96 bits. This also implicitly appends 32 zero bits,
+ * which is equivalent to multiplying by x^32. This is needed because
+ * the CRC is defined as M(x)*x^32 mod G(x), not just M(x) mod G(x).
+ */
+ x0 = _mm_xor_si128(_mm_srli_si128(x0, 8), _mm_clmulepi64_si128(x0, multipliers_1, 0x10));
+
+ /* Fold 96 => 64 bits */
+ x0 = _mm_xor_si128(_mm_srli_si128(x0, 4),
+ _mm_clmulepi64_si128(_mm_and_si128(x0, mask32), final_multiplier, 0x00));
+
+ /*
+ * Finally, reduce 64 => 32 bits using Barrett reduction.
+ *
+ * Let M(x) = A(x)*x^32 + B(x) be the remaining message. The goal is to
+ * compute R(x) = M(x) mod G(x). Since degree(B(x)) < degree(G(x)):
+ *
+ * R(x) = (A(x)*x^32 + B(x)) mod G(x)
+ * = (A(x)*x^32) mod G(x) + B(x)
+ *
+ * Then, by the Division Algorithm there exists a unique q(x) such that:
+ *
+ * A(x)*x^32 mod G(x) = A(x)*x^32 - q(x)*G(x)
+ *
+ * Since the left-hand side is of maximum degree 31, the right-hand side
+ * must be too. This implies that we can apply 'mod x^32' to the
+ * right-hand side without changing its value:
+ *
+ * (A(x)*x^32 - q(x)*G(x)) mod x^32 = q(x)*G(x) mod x^32
+ *
+ * Note that '+' is equivalent to '-' in polynomials over GF(2).
+ *
+ * We also know that:
+ *
+ * / A(x)*x^32 \
+ * q(x) = floor ( --------- )
+ * \ G(x) /
+ *
+ * To compute this efficiently, we can multiply the top and bottom by
+ * x^32 and move the division by G(x) to the top:
+ *
+ * / A(x) * floor(x^64 / G(x)) \
+ * q(x) = floor ( ------------------------- )
+ * \ x^32 /
+ *
+ * Note that floor(x^64 / G(x)) is a constant.
+ *
+ * So finally we have:
+ *
+ * / A(x) * floor(x^64 / G(x)) \
+ * R(x) = B(x) + G(x)*floor ( ------------------------- )
+ * \ x^32 /
+ */
+ x1 = x0;
+ x0 = _mm_clmulepi64_si128(_mm_and_si128(x0, mask32), barrett_reduction_constants, 0x00);
+ x0 = _mm_clmulepi64_si128(_mm_and_si128(x0, mask32), barrett_reduction_constants, 0x10);
+ return _mm_cvtsi128_si32(_mm_srli_si128(_mm_xor_si128(x0, x1), 4));
+}
+
+#endif
+}
+} // namespace
--- /dev/null
+/*
+ * Copyright 2017 Facebook, Inc.
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <folly/Portability.h>
+
+#if FOLLY_SSE_PREREQ(4, 2)
+#include <immintrin.h>
+#endif
+
+#include <stdint.h>
+#include <cstddef>
+
+namespace folly { namespace detail {
+
+/**
+ * Compute a CRC-32C checksum of a buffer using a hardware-accelerated
+ * implementation.
+ *
+ * @note This function is exposed to support special cases where the
+ * calling code is absolutely certain it ought to invoke a hardware-
+ * accelerated CRC-32C implementation - unit tests, for example. For
+ * all other scenarios, please call crc32c() and let it pick an
+ * implementation based on the capabilities of the underlying CPU.
+ */
+uint32_t crc32c_hw(const uint8_t* data, size_t nbytes,
+ uint32_t startingChecksum = ~0U);
+
+/**
+ * Check whether a hardware-accelerated CRC-32C implementation is
+ * supported on the current CPU.
+ */
+bool crc32c_hw_supported();
+
+/**
+ * Compute a CRC-32C checksum of a buffer using a portable,
+ * software-only implementation.
+ *
+ * @note This function is exposed to support special cases where the
+ * calling code is absolutely certain it wants to use the software
+ * implementation instead of the hardware-accelerated code - unit
+ * tests, for example. For all other scenarios, please call crc32c()
+ * and let it pick an implementation based on the capabilities of
+ * the underlying CPU.
+ */
+uint32_t crc32c_sw(const uint8_t* data, size_t nbytes,
+ uint32_t startingChecksum = ~0U);
+
+/**
+ * Compute a CRC-32 checksum of a buffer using a hardware-accelerated
+ * implementation.
+ *
+ * @note This function is exposed to support special cases where the
+ * calling code is absolutely certain it ought to invoke a hardware-
+ * accelerated CRC-32 implementation - unit tests, for example. For
+ * all other scenarios, please call crc32() and let it pick an
+ * implementation based on the capabilities of the underlying CPU.
+ */
+uint32_t
+crc32_hw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
+
+#if FOLLY_SSE_PREREQ(4, 2)
+uint32_t
+crc32_hw_aligned(uint32_t remainder, const __m128i* p, size_t vec_count);
+#endif
+
+/**
+ * Check whether a hardware-accelerated CRC-32 implementation is
+ * supported on the current CPU.
+ */
+bool crc32_hw_supported();
+
+/**
+ * Compute a CRC-32 checksum of a buffer using a portable,
+ * software-only implementation.
+ *
+ * @note This function is exposed to support special cases where the
+ * calling code is absolutely certain it wants to use the software
+ * implementation instead of the hardware-accelerated code - unit
+ * tests, for example. For all other scenarios, please call crc32()
+ * and let it pick an implementation based on the capabilities of
+ * the underlying CPU.
+ */
+uint32_t
+crc32_sw(const uint8_t* data, size_t nbytes, uint32_t startingChecksum = ~0U);
+}} // folly::detail
--- /dev/null
+/*
+ * Copyright 2016 Ferry Toth, Exalon Delft BV, The Netherlands
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the author be held liable for any damages
+ * arising from the use of this software.
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ * Ferry Toth
+ * ftoth@exalondelft.nl
+ *
+ * https://github.com/htot/crc32c
+ *
+ * Modified by Facebook
+ *
+ * Original intel whitepaper:
+ * "Fast CRC Computation for iSCSI Polynomial Using CRC32 Instruction"
+ * https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/crc-iscsi-polynomial-crc32-instruction-paper.pdf
+ *
+ * 32-bit support dropped
+ * use intrinsics instead of inline asm
+ * other code cleanup
+ */
+
+#include <stdexcept>
+
+#include <folly/hash/detail/ChecksumDetail.h>
+
+#include <folly/CppAttributes.h>
+
+#include <boost/preprocessor/arithmetic/add.hpp>
+#include <boost/preprocessor/arithmetic/sub.hpp>
+#include <boost/preprocessor/repetition/repeat_from_to.hpp>
+
+namespace folly {
+namespace detail {
+
+#if FOLLY_SSE_PREREQ(4, 2)
+
+namespace crc32_detail {
+
+#define CRCtriplet(crc, buf, offset) \
+ crc##0 = _mm_crc32_u64(crc##0, *(buf##0 + offset)); \
+ crc##1 = _mm_crc32_u64(crc##1, *(buf##1 + offset)); \
+ crc##2 = _mm_crc32_u64(crc##2, *(buf##2 + offset)); \
+ FOLLY_FALLTHROUGH;
+
+#define CRCduplet(crc, buf, offset) \
+ crc##0 = _mm_crc32_u64(crc##0, *(buf##0 + offset)); \
+ crc##1 = _mm_crc32_u64(crc##1, *(buf##1 + offset));
+
+#define CRCsinglet(crc, buf, offset) \
+ crc = _mm_crc32_u64(crc, *(uint64_t*)(buf + offset)); \
+ FOLLY_FALLTHROUGH;
+
+#define CASEREPEAT_TRIPLET(unused, count, total) \
+ case BOOST_PP_ADD(1, BOOST_PP_SUB(total, count)): \
+ CRCtriplet(crc, next, -BOOST_PP_ADD(1, BOOST_PP_SUB(total, count)));
+
+#define CASEREPEAT_SINGLET(unused, count, total) \
+ case BOOST_PP_SUB(total, count): \
+ CRCsinglet(crc0, next, -BOOST_PP_SUB(total, count) * 8);
+
+// Numbers taken directly from intel whitepaper.
+// clang-format off
+const uint64_t clmul_constants[] = {
+ 0x14cd00bd6, 0x105ec76f0, 0x0ba4fc28e, 0x14cd00bd6,
+ 0x1d82c63da, 0x0f20c0dfe, 0x09e4addf8, 0x0ba4fc28e,
+ 0x039d3b296, 0x1384aa63a, 0x102f9b8a2, 0x1d82c63da,
+ 0x14237f5e6, 0x01c291d04, 0x00d3b6092, 0x09e4addf8,
+ 0x0c96cfdc0, 0x0740eef02, 0x18266e456, 0x039d3b296,
+ 0x0daece73e, 0x0083a6eec, 0x0ab7aff2a, 0x102f9b8a2,
+ 0x1248ea574, 0x1c1733996, 0x083348832, 0x14237f5e6,
+ 0x12c743124, 0x02ad91c30, 0x0b9e02b86, 0x00d3b6092,
+ 0x018b33a4e, 0x06992cea2, 0x1b331e26a, 0x0c96cfdc0,
+ 0x17d35ba46, 0x07e908048, 0x1bf2e8b8a, 0x18266e456,
+ 0x1a3e0968a, 0x11ed1f9d8, 0x0ce7f39f4, 0x0daece73e,
+ 0x061d82e56, 0x0f1d0f55e, 0x0d270f1a2, 0x0ab7aff2a,
+ 0x1c3f5f66c, 0x0a87ab8a8, 0x12ed0daac, 0x1248ea574,
+ 0x065863b64, 0x08462d800, 0x11eef4f8e, 0x083348832,
+ 0x1ee54f54c, 0x071d111a8, 0x0b3e32c28, 0x12c743124,
+ 0x0064f7f26, 0x0ffd852c6, 0x0dd7e3b0c, 0x0b9e02b86,
+ 0x0f285651c, 0x0dcb17aa4, 0x010746f3c, 0x018b33a4e,
+ 0x1c24afea4, 0x0f37c5aee, 0x0271d9844, 0x1b331e26a,
+ 0x08e766a0c, 0x06051d5a2, 0x093a5f730, 0x17d35ba46,
+ 0x06cb08e5c, 0x11d5ca20e, 0x06b749fb2, 0x1bf2e8b8a,
+ 0x1167f94f2, 0x021f3d99c, 0x0cec3662e, 0x1a3e0968a,
+ 0x19329634a, 0x08f158014, 0x0e6fc4e6a, 0x0ce7f39f4,
+ 0x08227bb8a, 0x1a5e82106, 0x0b0cd4768, 0x061d82e56,
+ 0x13c2b89c4, 0x188815ab2, 0x0d7a4825c, 0x0d270f1a2,
+ 0x10f5ff2ba, 0x105405f3e, 0x00167d312, 0x1c3f5f66c,
+ 0x0f6076544, 0x0e9adf796, 0x026f6a60a, 0x12ed0daac,
+ 0x1a2adb74e, 0x096638b34, 0x19d34af3a, 0x065863b64,
+ 0x049c3cc9c, 0x1e50585a0, 0x068bce87a, 0x11eef4f8e,
+ 0x1524fa6c6, 0x19f1c69dc, 0x16cba8aca, 0x1ee54f54c,
+ 0x042d98888, 0x12913343e, 0x1329d9f7e, 0x0b3e32c28,
+ 0x1b1c69528, 0x088f25a3a, 0x02178513a, 0x0064f7f26,
+ 0x0e0ac139e, 0x04e36f0b0, 0x0170076fa, 0x0dd7e3b0c,
+ 0x141a1a2e2, 0x0bd6f81f8, 0x16ad828b4, 0x0f285651c,
+ 0x041d17b64, 0x19425cbba, 0x1fae1cc66, 0x010746f3c,
+ 0x1a75b4b00, 0x18db37e8a, 0x0f872e54c, 0x1c24afea4,
+ 0x01e41e9fc, 0x04c144932, 0x086d8e4d2, 0x0271d9844,
+ 0x160f7af7a, 0x052148f02, 0x05bb8f1bc, 0x08e766a0c,
+ 0x0a90fd27a, 0x0a3c6f37a, 0x0b3af077a, 0x093a5f730,
+ 0x04984d782, 0x1d22c238e, 0x0ca6ef3ac, 0x06cb08e5c,
+ 0x0234e0b26, 0x063ded06a, 0x1d88abd4a, 0x06b749fb2,
+ 0x04597456a, 0x04d56973c, 0x0e9e28eb4, 0x1167f94f2,
+ 0x07b3ff57a, 0x19385bf2e, 0x0c9c8b782, 0x0cec3662e,
+ 0x13a9cba9e, 0x0e417f38a, 0x093e106a4, 0x19329634a,
+ 0x167001a9c, 0x14e727980, 0x1ddffc5d4, 0x0e6fc4e6a,
+ 0x00df04680, 0x0d104b8fc, 0x02342001e, 0x08227bb8a,
+ 0x00a2a8d7e, 0x05b397730, 0x168763fa6, 0x0b0cd4768,
+ 0x1ed5a407a, 0x0e78eb416, 0x0d2c3ed1a, 0x13c2b89c4,
+ 0x0995a5724, 0x1641378f0, 0x19b1afbc4, 0x0d7a4825c,
+ 0x109ffedc0, 0x08d96551c, 0x0f2271e60, 0x10f5ff2ba,
+ 0x00b0bf8ca, 0x00bf80dd2, 0x123888b7a, 0x00167d312,
+ 0x1e888f7dc, 0x18dcddd1c, 0x002ee03b2, 0x0f6076544,
+ 0x183e8d8fe, 0x06a45d2b2, 0x133d7a042, 0x026f6a60a,
+ 0x116b0f50c, 0x1dd3e10e8, 0x05fabe670, 0x1a2adb74e,
+ 0x130004488, 0x0de87806c, 0x000bcf5f6, 0x19d34af3a,
+ 0x18f0c7078, 0x014338754, 0x017f27698, 0x049c3cc9c,
+ 0x058ca5f00, 0x15e3e77ee, 0x1af900c24, 0x068bce87a,
+ 0x0b5cfca28, 0x0dd07448e, 0x0ded288f8, 0x1524fa6c6,
+ 0x059f229bc, 0x1d8048348, 0x06d390dec, 0x16cba8aca,
+ 0x037170390, 0x0a3e3e02c, 0x06353c1cc, 0x042d98888,
+ 0x0c4584f5c, 0x0d73c7bea, 0x1f16a3418, 0x1329d9f7e,
+ 0x0531377e2, 0x185137662, 0x1d8d9ca7c, 0x1b1c69528,
+ 0x0b25b29f2, 0x18a08b5bc, 0x19fb2a8b0, 0x02178513a,
+ 0x1a08fe6ac, 0x1da758ae0, 0x045cddf4e, 0x0e0ac139e,
+ 0x1a91647f2, 0x169cf9eb0, 0x1a0f717c4, 0x0170076fa,
+};
+// clang-format on
+
+/*
+ * CombineCRC performs pclmulqdq multiplication of 2 partial CRC's and a well
+ * chosen constant and xor's these with the remaining CRC.
+ */
+uint64_t CombineCRC(
+ size_t block_size,
+ uint64_t crc0,
+ uint64_t crc1,
+ uint64_t crc2,
+ const uint64_t* next2) {
+ const auto multiplier =
+ *(reinterpret_cast<const __m128i*>(clmul_constants) + block_size - 1);
+ const auto crc0_xmm = _mm_set_epi64x(0, crc0);
+ const auto res0 = _mm_clmulepi64_si128(crc0_xmm, multiplier, 0x00);
+ const auto crc1_xmm = _mm_set_epi64x(0, crc1);
+ const auto res1 = _mm_clmulepi64_si128(crc1_xmm, multiplier, 0x10);
+ const auto res = _mm_xor_si128(res0, res1);
+ crc0 = _mm_cvtsi128_si64(res);
+ crc0 = crc0 ^ *((uint64_t*)next2 - 1);
+ crc2 = _mm_crc32_u64(crc2, crc0);
+ return crc2;
+}
+
+// Generates a block that will crc up to 7 bytes of unaligned data.
+// Always inline to avoid overhead on small crc sizes.
+FOLLY_ALWAYS_INLINE void align_to_8(
+ size_t align,
+ uint64_t& crc0, // crc so far, updated on return
+ const unsigned char*& next) { // next data pointer, updated on return
+ uint32_t crc32bit = static_cast<uint32_t>(crc0);
+ if (align & 0x04) {
+ crc32bit = _mm_crc32_u32(crc32bit, *(uint32_t*)next);
+ next += sizeof(uint32_t);
+ }
+ if (align & 0x02) {
+ crc32bit = _mm_crc32_u16(crc32bit, *(uint16_t*)next);
+ next += sizeof(uint16_t);
+ }
+ if (align & 0x01) {
+ crc32bit = _mm_crc32_u8(crc32bit, *(next));
+ next++;
+ }
+ crc0 = crc32bit;
+}
+
+// The main loop for large crc sizes. Generates three crc32c
+// streams, of varying block sizes, using a duff's device.
+void triplet_loop(
+ size_t block_size,
+ uint64_t& crc0, // crc so far, updated on return
+ const unsigned char*& next, // next data pointer, updated on return
+ size_t n) { // block count
+ uint64_t crc1 = 0, crc2 = 0;
+ // points to the first byte of the next block
+ const uint64_t* next0 = (uint64_t*)next + block_size;
+ const uint64_t* next1 = next0 + block_size;
+ const uint64_t* next2 = next1 + block_size;
+
+ // Use Duff's device, a for() loop inside a switch()
+ // statement. This needs to execute at least once, round len
+ // down to nearest triplet multiple
+ switch (block_size) {
+ case 128:
+ do {
+ // jumps here for a full block of len 128
+ CRCtriplet(crc, next, -128);
+
+ // Generates case statements from 127 to 2 of form:
+ // case 127:
+ // CRCtriplet(crc, next, -127);
+ //
+ // MSVC has a max preprocessor expansion depth of 255, which is
+ // exceeded if this is a single statement.
+ BOOST_PP_REPEAT_FROM_TO(0, 64, CASEREPEAT_TRIPLET, 126);
+ BOOST_PP_REPEAT_FROM_TO(0, 62, CASEREPEAT_TRIPLET, 62);
+
+ // For the last byte, the three crc32c streams must be combined
+ // using carry-less multiplication.
+ case 1:
+ CRCduplet(crc, next, -1); // the final triplet is actually only 2
+ crc0 = CombineCRC(block_size, crc0, crc1, crc2, next2);
+ if (--n > 0) {
+ crc1 = crc2 = 0;
+ block_size = 128;
+ // points to the first byte of the next block
+ next0 = next2 + 128;
+ next1 = next0 + 128; // from here on all blocks are 128 long
+ next2 = next1 + 128;
+ }
+ FOLLY_FALLTHROUGH;
+ case 0:;
+ } while (n > 0);
+ }
+
+ next = (const unsigned char*)next2;
+}
+
+} // namespace crc32c_detail
+
+/* Compute CRC-32C using the Intel hardware instruction. */
+FOLLY_TARGET_ATTRIBUTE("sse4.2")
+uint32_t crc32c_hw(const uint8_t* buf, size_t len, uint32_t crc) {
+ const unsigned char* next = (const unsigned char*)buf;
+ size_t count;
+ uint64_t crc0;
+ crc0 = crc;
+
+ if (len >= 8) {
+ // if len > 216 then align and use triplets
+ if (len > 216) {
+ size_t align = (8 - (uintptr_t)next) & 7;
+ crc32_detail::align_to_8(align, crc0, next);
+ len -= align;
+
+ count = len / 24; // number of triplets
+ len %= 24; // bytes remaining
+ size_t n = count >> 7; // #blocks = first block + full blocks
+ size_t block_size = count & 127;
+ if (block_size == 0) {
+ block_size = 128;
+ } else {
+ n++;
+ }
+
+ // This is a separate function call mainly to stop
+ // clang from spilling registers.
+ crc32_detail::triplet_loop(block_size, crc0, next, n);
+ }
+
+ size_t count2 = len >> 3;
+ len = len & 7;
+ next += (count2 * 8);
+
+ // Generates a duff device for the last 128 bytes of aligned data.
+ switch (count2) {
+ // Generates case statements of the form:
+ // case 27:
+ // CRCsinglet(crc0, next, -27 * 8);
+ BOOST_PP_REPEAT_FROM_TO(0, 27, CASEREPEAT_SINGLET, 27);
+ case 0:;
+ }
+ }
+
+ // compute the crc for up to seven trailing bytes
+ crc32_detail::align_to_8(len, crc0, next);
+ return (uint32_t)crc0;
+}
+
+#else
+
+uint32_t crc32c_hw(const uint8_t* buf, size_t len, uint32_t crc) {
+ throw std::runtime_error("crc32_hw is not implemented on this platform");
+}
+
+#endif
+
+} // namespace detail
+} // namespace folly
--- /dev/null
+/*
+ * Copyright 2017 Facebook, Inc.
+ *
+ * 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.
+ */
+
+#include <folly/hash/Checksum.h>
+
+#include <boost/crc.hpp>
+
+#include <folly/Benchmark.h>
+#include <folly/Hash.h>
+#include <folly/hash/detail/ChecksumDetail.h>
+#include <folly/portability/GFlags.h>
+#include <folly/portability/GTest.h>
+
+namespace {
+const unsigned int BUFFER_SIZE = 512 * 1024 * sizeof(uint64_t);
+uint8_t buffer[BUFFER_SIZE];
+
+struct ExpectedResult {
+ size_t offset;
+ size_t length;
+ uint32_t crc32c;
+};
+
+ExpectedResult expectedResults[] = {
+ // Zero-byte input
+ { 0, 0, ~0U },
+ // Small aligned inputs to test special cases in SIMD implementations
+ { 8, 1, 1543413366 },
+ { 8, 2, 523493126 },
+ { 8, 3, 1560427360 },
+ { 8, 4, 3422504776 },
+ { 8, 5, 447841138 },
+ { 8, 6, 3910050499 },
+ { 8, 7, 3346241981 },
+ // Small unaligned inputs
+ { 9, 1, 3855826643 },
+ { 10, 2, 560880875 },
+ { 11, 3, 1479707779 },
+ { 12, 4, 2237687071 },
+ { 13, 5, 4063855784 },
+ { 14, 6, 2553454047 },
+ { 15, 7, 1349220140 },
+ // Larger inputs to test leftover chunks at the end of aligned blocks
+ { 8, 8, 627613930 },
+ { 8, 9, 2105929409 },
+ { 8, 10, 2447068514 },
+ { 8, 11, 863807079 },
+ { 8, 12, 292050879 },
+ { 8, 13, 1411837737 },
+ { 8, 14, 2614515001 },
+ { 8, 15, 3579076296 },
+ { 8, 16, 2897079161 },
+ { 8, 17, 675168386 },
+ // Much larger inputs
+ { 0, BUFFER_SIZE, 2096790750 },
+ { 1, BUFFER_SIZE / 2, 3854797577 },
+};
+
+void testCRC32C(
+ std::function<uint32_t(const uint8_t*, size_t, uint32_t)> impl) {
+ for (auto expected : expectedResults) {
+ uint32_t result = impl(buffer + expected.offset, expected.length, ~0U);
+ EXPECT_EQ(expected.crc32c, result);
+ }
+}
+
+void testCRC32CContinuation(
+ std::function<uint32_t(const uint8_t*, size_t, uint32_t)> impl) {
+ for (auto expected : expectedResults) {
+ size_t partialLength = expected.length / 2;
+ uint32_t partialChecksum = impl(
+ buffer + expected.offset, partialLength, ~0U);
+ uint32_t result = impl(
+ buffer + expected.offset + partialLength,
+ expected.length - partialLength, partialChecksum);
+ EXPECT_EQ(expected.crc32c, result);
+ }
+}
+
+void testMatchesBoost32Type() {
+ for (auto expected : expectedResults) {
+ boost::crc_32_type result;
+ result.process_bytes(buffer + expected.offset, expected.length);
+ const uint32_t boostResult = result.checksum();
+ const uint32_t follyResult =
+ folly::crc32_type(buffer + expected.offset, expected.length);
+ EXPECT_EQ(follyResult, boostResult);
+ }
+}
+
+} // namespace
+
+TEST(Checksum, crc32c_software) {
+ testCRC32C(folly::detail::crc32c_sw);
+}
+
+TEST(Checksum, crc32c_continuation_software) {
+ testCRC32CContinuation(folly::detail::crc32c_sw);
+}
+
+
+TEST(Checksum, crc32c_hardware) {
+ if (folly::detail::crc32c_hw_supported()) {
+ testCRC32C(folly::detail::crc32c_hw);
+ } else {
+ LOG(WARNING) << "skipping hardware-accelerated CRC-32C tests" <<
+ " (not supported on this CPU)";
+ }
+}
+
+TEST(Checksum, crc32c_hardware_eq) {
+ if (folly::detail::crc32c_hw_supported()) {
+ for (int i = 0; i < 1000; i++) {
+ auto sw = folly::detail::crc32c_sw(buffer, i, 0);
+ auto hw = folly::detail::crc32c_hw(buffer, i, 0);
+ EXPECT_EQ(sw, hw);
+ }
+ } else {
+ LOG(WARNING) << "skipping hardware-accelerated CRC-32C tests"
+ << " (not supported on this CPU)";
+ }
+}
+
+TEST(Checksum, crc32c_continuation_hardware) {
+ if (folly::detail::crc32c_hw_supported()) {
+ testCRC32CContinuation(folly::detail::crc32c_hw);
+ } else {
+ LOG(WARNING) << "skipping hardware-accelerated CRC-32C tests" <<
+ " (not supported on this CPU)";
+ }
+}
+
+TEST(Checksum, crc32c_autodetect) {
+ testCRC32C(folly::crc32c);
+}
+
+TEST(Checksum, crc32c_continuation_autodetect) {
+ testCRC32CContinuation(folly::crc32c);
+}
+
+TEST(Checksum, crc32) {
+ if (folly::detail::crc32c_hw_supported()) {
+ // Just check that sw and hw match
+ for (auto expected : expectedResults) {
+ uint32_t sw_res =
+ folly::detail::crc32_sw(buffer + expected.offset, expected.length, 0);
+ uint32_t hw_res =
+ folly::detail::crc32_hw(buffer + expected.offset, expected.length, 0);
+ EXPECT_EQ(sw_res, hw_res);
+ }
+ } else {
+ LOG(WARNING) << "skipping hardware-accelerated CRC-32 tests"
+ << " (not supported on this CPU)";
+ }
+}
+
+TEST(Checksum, crc32_continuation) {
+ if (folly::detail::crc32c_hw_supported()) {
+ // Just check that sw and hw match
+ for (auto expected : expectedResults) {
+ auto halflen = expected.length / 2;
+ uint32_t sw_res =
+ folly::detail::crc32_sw(buffer + expected.offset, halflen, 0);
+ sw_res = folly::detail::crc32_sw(
+ buffer + expected.offset + halflen, halflen, sw_res);
+ uint32_t hw_res =
+ folly::detail::crc32_hw(buffer + expected.offset, halflen, 0);
+ hw_res = folly::detail::crc32_hw(
+ buffer + expected.offset + halflen, halflen, hw_res);
+ EXPECT_EQ(sw_res, hw_res);
+ uint32_t sw_res2 =
+ folly::detail::crc32_sw(buffer + expected.offset, halflen * 2, 0);
+ EXPECT_EQ(sw_res, sw_res2);
+ uint32_t hw_res2 =
+ folly::detail::crc32_hw(buffer + expected.offset, halflen * 2, 0);
+ EXPECT_EQ(hw_res, hw_res2);
+ }
+ } else {
+ LOG(WARNING) << "skipping hardware-accelerated CRC-32 tests"
+ << " (not supported on this CPU)";
+ }
+}
+
+TEST(Checksum, crc32_type) {
+ // Test that crc32_type matches boost::crc_32_type
+ testMatchesBoost32Type();
+}
+
+void benchmarkHardwareCRC32C(unsigned long iters, size_t blockSize) {
+ if (folly::detail::crc32c_hw_supported()) {
+ uint32_t checksum;
+ for (unsigned long i = 0; i < iters; i++) {
+ checksum = folly::detail::crc32c_hw(buffer, blockSize);
+ folly::doNotOptimizeAway(checksum);
+ }
+ } else {
+ LOG(WARNING) << "skipping hardware-accelerated CRC-32C benchmarks" <<
+ " (not supported on this CPU)";
+ }
+}
+
+void benchmarkSoftwareCRC32C(unsigned long iters, size_t blockSize) {
+ uint32_t checksum;
+ for (unsigned long i = 0; i < iters; i++) {
+ checksum = folly::detail::crc32c_sw(buffer, blockSize);
+ folly::doNotOptimizeAway(checksum);
+ }
+}
+
+void benchmarkHardwareCRC32(unsigned long iters, size_t blockSize) {
+ if (folly::detail::crc32_hw_supported()) {
+ uint32_t checksum;
+ for (unsigned long i = 0; i < iters; i++) {
+ checksum = folly::detail::crc32_hw(buffer, blockSize);
+ folly::doNotOptimizeAway(checksum);
+ }
+ } else {
+ LOG(WARNING) << "skipping hardware-accelerated CRC-32 benchmarks"
+ << " (not supported on this CPU)";
+ }
+}
+
+void benchmarkSoftwareCRC32(unsigned long iters, size_t blockSize) {
+ uint32_t checksum;
+ for (unsigned long i = 0; i < iters; i++) {
+ checksum = folly::detail::crc32_sw(buffer, blockSize);
+ folly::doNotOptimizeAway(checksum);
+ }
+}
+
+// This test fits easily in the L1 cache on modern server processors,
+// and thus it mainly measures the speed of the checksum computation.
+BENCHMARK(crc32c_hardware_1KB_block, iters) {
+ benchmarkHardwareCRC32C(iters, 1024);
+}
+
+BENCHMARK(crc32c_software_1KB_block, iters) {
+ benchmarkSoftwareCRC32C(iters, 1024);
+}
+
+BENCHMARK(crc32_hardware_1KB_block, iters) {
+ benchmarkHardwareCRC32(iters, 1024);
+}
+
+BENCHMARK(crc32_software_1KB_block, iters) {
+ benchmarkSoftwareCRC32(iters, 1024);
+}
+
+BENCHMARK_DRAW_LINE();
+
+// This test is too big for the L1 cache but fits in L2
+BENCHMARK(crc32c_hardware_64KB_block, iters) {
+ benchmarkHardwareCRC32C(iters, 64 * 1024);
+}
+
+BENCHMARK(crc32c_software_64KB_block, iters) {
+ benchmarkSoftwareCRC32C(iters, 64 * 1024);
+}
+
+BENCHMARK(crc32_hardware_64KB_block, iters) {
+ benchmarkHardwareCRC32(iters, 64 * 1024);
+}
+
+BENCHMARK(crc32_software_64KB_block, iters) {
+ benchmarkSoftwareCRC32(iters, 64 * 1024);
+}
+
+BENCHMARK_DRAW_LINE();
+
+// This test is too big for the L2 cache but fits in L3
+BENCHMARK(crc32c_hardware_512KB_block, iters) {
+ benchmarkHardwareCRC32C(iters, 512 * 1024);
+}
+
+BENCHMARK(crc32c_software_512KB_block, iters) {
+ benchmarkSoftwareCRC32C(iters, 512 * 1024);
+}
+
+BENCHMARK(crc32_hardware_512KB_block, iters) {
+ benchmarkHardwareCRC32(iters, 512 * 1024);
+}
+
+BENCHMARK(crc32_software_512KB_block, iters) {
+ benchmarkSoftwareCRC32(iters, 512 * 1024);
+}
+
+int main(int argc, char** argv) {
+ testing::InitGoogleTest(&argc, argv);
+ gflags::ParseCommandLineFlags(&argc, &argv, true);
+
+ // Populate a buffer with a deterministic pattern
+ // on which to compute checksums
+ const uint8_t* src = buffer;
+ uint64_t* dst = (uint64_t*)buffer;
+ const uint64_t* end = (const uint64_t*)(buffer + BUFFER_SIZE);
+ *dst++ = 0;
+ while (dst < end) {
+ *dst++ = folly::hash::fnv64_buf((const char*)src, sizeof(uint64_t));
+ src += sizeof(uint64_t);
+ }
+
+ auto ret = RUN_ALL_TESTS();
+ if (!ret && FLAGS_benchmark) {
+ folly::runBenchmarks();
+ }
+ return ret;
+}
+++ /dev/null
-/*
- * Copyright 2017 Facebook, Inc.
- *
- * 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.
- */
-
-#include <folly/Checksum.h>
-
-#include <boost/crc.hpp>
-
-#include <folly/Benchmark.h>
-#include <folly/Hash.h>
-#include <folly/detail/ChecksumDetail.h>
-#include <folly/portability/GFlags.h>
-#include <folly/portability/GTest.h>
-
-namespace {
-const unsigned int BUFFER_SIZE = 512 * 1024 * sizeof(uint64_t);
-uint8_t buffer[BUFFER_SIZE];
-
-struct ExpectedResult {
- size_t offset;
- size_t length;
- uint32_t crc32c;
-};
-
-ExpectedResult expectedResults[] = {
- // Zero-byte input
- { 0, 0, ~0U },
- // Small aligned inputs to test special cases in SIMD implementations
- { 8, 1, 1543413366 },
- { 8, 2, 523493126 },
- { 8, 3, 1560427360 },
- { 8, 4, 3422504776 },
- { 8, 5, 447841138 },
- { 8, 6, 3910050499 },
- { 8, 7, 3346241981 },
- // Small unaligned inputs
- { 9, 1, 3855826643 },
- { 10, 2, 560880875 },
- { 11, 3, 1479707779 },
- { 12, 4, 2237687071 },
- { 13, 5, 4063855784 },
- { 14, 6, 2553454047 },
- { 15, 7, 1349220140 },
- // Larger inputs to test leftover chunks at the end of aligned blocks
- { 8, 8, 627613930 },
- { 8, 9, 2105929409 },
- { 8, 10, 2447068514 },
- { 8, 11, 863807079 },
- { 8, 12, 292050879 },
- { 8, 13, 1411837737 },
- { 8, 14, 2614515001 },
- { 8, 15, 3579076296 },
- { 8, 16, 2897079161 },
- { 8, 17, 675168386 },
- // Much larger inputs
- { 0, BUFFER_SIZE, 2096790750 },
- { 1, BUFFER_SIZE / 2, 3854797577 },
-};
-
-void testCRC32C(
- std::function<uint32_t(const uint8_t*, size_t, uint32_t)> impl) {
- for (auto expected : expectedResults) {
- uint32_t result = impl(buffer + expected.offset, expected.length, ~0U);
- EXPECT_EQ(expected.crc32c, result);
- }
-}
-
-void testCRC32CContinuation(
- std::function<uint32_t(const uint8_t*, size_t, uint32_t)> impl) {
- for (auto expected : expectedResults) {
- size_t partialLength = expected.length / 2;
- uint32_t partialChecksum = impl(
- buffer + expected.offset, partialLength, ~0U);
- uint32_t result = impl(
- buffer + expected.offset + partialLength,
- expected.length - partialLength, partialChecksum);
- EXPECT_EQ(expected.crc32c, result);
- }
-}
-
-void testMatchesBoost32Type() {
- for (auto expected : expectedResults) {
- boost::crc_32_type result;
- result.process_bytes(buffer + expected.offset, expected.length);
- const uint32_t boostResult = result.checksum();
- const uint32_t follyResult =
- folly::crc32_type(buffer + expected.offset, expected.length);
- EXPECT_EQ(follyResult, boostResult);
- }
-}
-
-} // namespace
-
-TEST(Checksum, crc32c_software) {
- testCRC32C(folly::detail::crc32c_sw);
-}
-
-TEST(Checksum, crc32c_continuation_software) {
- testCRC32CContinuation(folly::detail::crc32c_sw);
-}
-
-
-TEST(Checksum, crc32c_hardware) {
- if (folly::detail::crc32c_hw_supported()) {
- testCRC32C(folly::detail::crc32c_hw);
- } else {
- LOG(WARNING) << "skipping hardware-accelerated CRC-32C tests" <<
- " (not supported on this CPU)";
- }
-}
-
-TEST(Checksum, crc32c_hardware_eq) {
- if (folly::detail::crc32c_hw_supported()) {
- for (int i = 0; i < 1000; i++) {
- auto sw = folly::detail::crc32c_sw(buffer, i, 0);
- auto hw = folly::detail::crc32c_hw(buffer, i, 0);
- EXPECT_EQ(sw, hw);
- }
- } else {
- LOG(WARNING) << "skipping hardware-accelerated CRC-32C tests"
- << " (not supported on this CPU)";
- }
-}
-
-TEST(Checksum, crc32c_continuation_hardware) {
- if (folly::detail::crc32c_hw_supported()) {
- testCRC32CContinuation(folly::detail::crc32c_hw);
- } else {
- LOG(WARNING) << "skipping hardware-accelerated CRC-32C tests" <<
- " (not supported on this CPU)";
- }
-}
-
-TEST(Checksum, crc32c_autodetect) {
- testCRC32C(folly::crc32c);
-}
-
-TEST(Checksum, crc32c_continuation_autodetect) {
- testCRC32CContinuation(folly::crc32c);
-}
-
-TEST(Checksum, crc32) {
- if (folly::detail::crc32c_hw_supported()) {
- // Just check that sw and hw match
- for (auto expected : expectedResults) {
- uint32_t sw_res =
- folly::detail::crc32_sw(buffer + expected.offset, expected.length, 0);
- uint32_t hw_res =
- folly::detail::crc32_hw(buffer + expected.offset, expected.length, 0);
- EXPECT_EQ(sw_res, hw_res);
- }
- } else {
- LOG(WARNING) << "skipping hardware-accelerated CRC-32 tests"
- << " (not supported on this CPU)";
- }
-}
-
-TEST(Checksum, crc32_continuation) {
- if (folly::detail::crc32c_hw_supported()) {
- // Just check that sw and hw match
- for (auto expected : expectedResults) {
- auto halflen = expected.length / 2;
- uint32_t sw_res =
- folly::detail::crc32_sw(buffer + expected.offset, halflen, 0);
- sw_res = folly::detail::crc32_sw(
- buffer + expected.offset + halflen, halflen, sw_res);
- uint32_t hw_res =
- folly::detail::crc32_hw(buffer + expected.offset, halflen, 0);
- hw_res = folly::detail::crc32_hw(
- buffer + expected.offset + halflen, halflen, hw_res);
- EXPECT_EQ(sw_res, hw_res);
- uint32_t sw_res2 =
- folly::detail::crc32_sw(buffer + expected.offset, halflen * 2, 0);
- EXPECT_EQ(sw_res, sw_res2);
- uint32_t hw_res2 =
- folly::detail::crc32_hw(buffer + expected.offset, halflen * 2, 0);
- EXPECT_EQ(hw_res, hw_res2);
- }
- } else {
- LOG(WARNING) << "skipping hardware-accelerated CRC-32 tests"
- << " (not supported on this CPU)";
- }
-}
-
-TEST(Checksum, crc32_type) {
- // Test that crc32_type matches boost::crc_32_type
- testMatchesBoost32Type();
-}
-
-void benchmarkHardwareCRC32C(unsigned long iters, size_t blockSize) {
- if (folly::detail::crc32c_hw_supported()) {
- uint32_t checksum;
- for (unsigned long i = 0; i < iters; i++) {
- checksum = folly::detail::crc32c_hw(buffer, blockSize);
- folly::doNotOptimizeAway(checksum);
- }
- } else {
- LOG(WARNING) << "skipping hardware-accelerated CRC-32C benchmarks" <<
- " (not supported on this CPU)";
- }
-}
-
-void benchmarkSoftwareCRC32C(unsigned long iters, size_t blockSize) {
- uint32_t checksum;
- for (unsigned long i = 0; i < iters; i++) {
- checksum = folly::detail::crc32c_sw(buffer, blockSize);
- folly::doNotOptimizeAway(checksum);
- }
-}
-
-void benchmarkHardwareCRC32(unsigned long iters, size_t blockSize) {
- if (folly::detail::crc32_hw_supported()) {
- uint32_t checksum;
- for (unsigned long i = 0; i < iters; i++) {
- checksum = folly::detail::crc32_hw(buffer, blockSize);
- folly::doNotOptimizeAway(checksum);
- }
- } else {
- LOG(WARNING) << "skipping hardware-accelerated CRC-32 benchmarks"
- << " (not supported on this CPU)";
- }
-}
-
-void benchmarkSoftwareCRC32(unsigned long iters, size_t blockSize) {
- uint32_t checksum;
- for (unsigned long i = 0; i < iters; i++) {
- checksum = folly::detail::crc32_sw(buffer, blockSize);
- folly::doNotOptimizeAway(checksum);
- }
-}
-
-// This test fits easily in the L1 cache on modern server processors,
-// and thus it mainly measures the speed of the checksum computation.
-BENCHMARK(crc32c_hardware_1KB_block, iters) {
- benchmarkHardwareCRC32C(iters, 1024);
-}
-
-BENCHMARK(crc32c_software_1KB_block, iters) {
- benchmarkSoftwareCRC32C(iters, 1024);
-}
-
-BENCHMARK(crc32_hardware_1KB_block, iters) {
- benchmarkHardwareCRC32(iters, 1024);
-}
-
-BENCHMARK(crc32_software_1KB_block, iters) {
- benchmarkSoftwareCRC32(iters, 1024);
-}
-
-BENCHMARK_DRAW_LINE();
-
-// This test is too big for the L1 cache but fits in L2
-BENCHMARK(crc32c_hardware_64KB_block, iters) {
- benchmarkHardwareCRC32C(iters, 64 * 1024);
-}
-
-BENCHMARK(crc32c_software_64KB_block, iters) {
- benchmarkSoftwareCRC32C(iters, 64 * 1024);
-}
-
-BENCHMARK(crc32_hardware_64KB_block, iters) {
- benchmarkHardwareCRC32(iters, 64 * 1024);
-}
-
-BENCHMARK(crc32_software_64KB_block, iters) {
- benchmarkSoftwareCRC32(iters, 64 * 1024);
-}
-
-BENCHMARK_DRAW_LINE();
-
-// This test is too big for the L2 cache but fits in L3
-BENCHMARK(crc32c_hardware_512KB_block, iters) {
- benchmarkHardwareCRC32C(iters, 512 * 1024);
-}
-
-BENCHMARK(crc32c_software_512KB_block, iters) {
- benchmarkSoftwareCRC32C(iters, 512 * 1024);
-}
-
-BENCHMARK(crc32_hardware_512KB_block, iters) {
- benchmarkHardwareCRC32(iters, 512 * 1024);
-}
-
-BENCHMARK(crc32_software_512KB_block, iters) {
- benchmarkSoftwareCRC32(iters, 512 * 1024);
-}
-
-int main(int argc, char** argv) {
- testing::InitGoogleTest(&argc, argv);
- gflags::ParseCommandLineFlags(&argc, &argv, true);
-
- // Populate a buffer with a deterministic pattern
- // on which to compute checksums
- const uint8_t* src = buffer;
- uint64_t* dst = (uint64_t*)buffer;
- const uint64_t* end = (const uint64_t*)(buffer + BUFFER_SIZE);
- *dst++ = 0;
- while (dst < end) {
- *dst++ = folly::hash::fnv64_buf((const char*)src, sizeof(uint64_t));
- src += sizeof(uint64_t);
- }
-
- auto ret = RUN_ALL_TESTS();
- if (!ret && FLAGS_benchmark) {
- folly::runBenchmarks();
- }
- return ret;
-}
projects / folly.git / commitdiff