rocksdb/util/crc32c.cc
Kefu Chai ba3c58cab6 specify SSE42 'target' attribute for Fast_CRC32()
Summary:
if we enable SSE42 globally when compiling the tree for preparing a
portable binary, which could be running on CPU w/o SSE42 instructions
even the GCC on the building host is able to emit SSE42 code, this leads
to illegal instruction errors on machines not supporting SSE42. to solve
this problem, crc32 detects the supported instruction at runtime, and
selects the supported CRC32 implementation according to the result of
`cpuid`. but intrinics like "_mm_crc32_u64()" will not be available
unless the "target" machine is appropriately specified in the command
line, like "-msse42", or using the "target" attribute.

we could pass "-msse42" only when compiling crc32c.cc, and allow the
compiler to generate the SSE42 instructions, but we are still at the
risk of executing illegal instructions on machines does not support
SSE42 if the compiler emits code that is not guarded by our runtime
detection. and we need to do the change in both Makefile and CMakefile.

or, we can use GCC's "target" attribute to enable the machine specific
instructions on certain function. in this way, we have finer grained
control of the used "target". and no need to change the makefiles. so
we don't need to duplicate the changes on both makefile and cmake as
the previous approach.

this problem surfaces when preparing a package for GNU/Linux distribution,
and we only applies to optimization for SSE42, so using a feature
only available on GCC/Clang is not that formidable.
Closes https://github.com/facebook/rocksdb/pull/2807

Differential Revision: D5786084

Pulled By: siying

fbshipit-source-id: bca5c0f877b8d6fb55f58f8f122254a26422843d
2017-09-07 12:40:57 -07:00

493 lines
18 KiB
C++

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
//
// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.
//
// A portable implementation of crc32c, optimized to handle
// four bytes at a time.
#include "util/crc32c.h"
#include <stdint.h>
#ifdef HAVE_SSE42
#include <nmmintrin.h>
#endif
#include "util/coding.h"
#ifdef __powerpc64__
#include "util/crc32c_ppc.h"
#include "util/crc32c_ppc_constants.h"
#if __linux__
#include <sys/auxv.h>
#ifndef PPC_FEATURE2_VEC_CRYPTO
#define PPC_FEATURE2_VEC_CRYPTO 0x02000000
#endif
#ifndef AT_HWCAP2
#define AT_HWCAP2 26
#endif
#endif /* __linux__ */
#endif
namespace rocksdb {
namespace crc32c {
#ifdef __powerpc64__
static int arch_ppc_crc32 = 0;
#endif
static const uint32_t table0_[256] = {
0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4,
0xc79a971f, 0x35f1141c, 0x26a1e7e8, 0xd4ca64eb,
0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b,
0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24,
0x105ec76f, 0xe235446c, 0xf165b798, 0x030e349b,
0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54,
0x5d1d08bf, 0xaf768bbc, 0xbc267848, 0x4e4dfb4b,
0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a,
0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35,
0xaa64d611, 0x580f5512, 0x4b5fa6e6, 0xb93425e5,
0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45,
0xf779deae, 0x05125dad, 0x1642ae59, 0xe4292d5a,
0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a,
0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595,
0x417b1dbc, 0xb3109ebf, 0xa0406d4b, 0x522bee48,
0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687,
0x0c38d26c, 0xfe53516f, 0xed03a29b, 0x1f682198,
0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927,
0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38,
0xdbfc821c, 0x2997011f, 0x3ac7f2eb, 0xc8ac71e8,
0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096,
0xa65c047d, 0x5437877e, 0x4767748a, 0xb50cf789,
0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859,
0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46,
0x7198540d, 0x83f3d70e, 0x90a324fa, 0x62c8a7f9,
0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36,
0x3cdb9bdd, 0xceb018de, 0xdde0eb2a, 0x2f8b6829,
0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c,
0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93,
0x082f63b7, 0xfa44e0b4, 0xe9141340, 0x1b7f9043,
0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3,
0x55326b08, 0xa759e80b, 0xb4091bff, 0x466298fc,
0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c,
0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033,
0xa24bb5a6, 0x502036a5, 0x4370c551, 0xb11b4652,
0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d,
0xef087a76, 0x1d63f975, 0x0e330a81, 0xfc588982,
0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d,
0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622,
0x38cc2a06, 0xcaa7a905, 0xd9f75af1, 0x2b9cd9f2,
0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530,
0x0417b1db, 0xf67c32d8, 0xe52cc12c, 0x1747422f,
0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff,
0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0,
0xd3d3e1ab, 0x21b862a8, 0x32e8915c, 0xc083125f,
0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90,
0x9e902e7b, 0x6cfbad78, 0x7fab5e8c, 0x8dc0dd8f,
0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee,
0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1,
0x69e9f0d5, 0x9b8273d6, 0x88d28022, 0x7ab90321,
0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81,
0x34f4f86a, 0xc69f7b69, 0xd5cf889d, 0x27a40b9e,
0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e,
0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351
};
static const uint32_t table1_[256] = {
0x00000000, 0x13a29877, 0x274530ee, 0x34e7a899,
0x4e8a61dc, 0x5d28f9ab, 0x69cf5132, 0x7a6dc945,
0x9d14c3b8, 0x8eb65bcf, 0xba51f356, 0xa9f36b21,
0xd39ea264, 0xc03c3a13, 0xf4db928a, 0xe7790afd,
0x3fc5f181, 0x2c6769f6, 0x1880c16f, 0x0b225918,
0x714f905d, 0x62ed082a, 0x560aa0b3, 0x45a838c4,
0xa2d13239, 0xb173aa4e, 0x859402d7, 0x96369aa0,
0xec5b53e5, 0xfff9cb92, 0xcb1e630b, 0xd8bcfb7c,
0x7f8be302, 0x6c297b75, 0x58ced3ec, 0x4b6c4b9b,
0x310182de, 0x22a31aa9, 0x1644b230, 0x05e62a47,
0xe29f20ba, 0xf13db8cd, 0xc5da1054, 0xd6788823,
0xac154166, 0xbfb7d911, 0x8b507188, 0x98f2e9ff,
0x404e1283, 0x53ec8af4, 0x670b226d, 0x74a9ba1a,
0x0ec4735f, 0x1d66eb28, 0x298143b1, 0x3a23dbc6,
0xdd5ad13b, 0xcef8494c, 0xfa1fe1d5, 0xe9bd79a2,
0x93d0b0e7, 0x80722890, 0xb4958009, 0xa737187e,
0xff17c604, 0xecb55e73, 0xd852f6ea, 0xcbf06e9d,
0xb19da7d8, 0xa23f3faf, 0x96d89736, 0x857a0f41,
0x620305bc, 0x71a19dcb, 0x45463552, 0x56e4ad25,
0x2c896460, 0x3f2bfc17, 0x0bcc548e, 0x186eccf9,
0xc0d23785, 0xd370aff2, 0xe797076b, 0xf4359f1c,
0x8e585659, 0x9dface2e, 0xa91d66b7, 0xbabffec0,
0x5dc6f43d, 0x4e646c4a, 0x7a83c4d3, 0x69215ca4,
0x134c95e1, 0x00ee0d96, 0x3409a50f, 0x27ab3d78,
0x809c2506, 0x933ebd71, 0xa7d915e8, 0xb47b8d9f,
0xce1644da, 0xddb4dcad, 0xe9537434, 0xfaf1ec43,
0x1d88e6be, 0x0e2a7ec9, 0x3acdd650, 0x296f4e27,
0x53028762, 0x40a01f15, 0x7447b78c, 0x67e52ffb,
0xbf59d487, 0xacfb4cf0, 0x981ce469, 0x8bbe7c1e,
0xf1d3b55b, 0xe2712d2c, 0xd69685b5, 0xc5341dc2,
0x224d173f, 0x31ef8f48, 0x050827d1, 0x16aabfa6,
0x6cc776e3, 0x7f65ee94, 0x4b82460d, 0x5820de7a,
0xfbc3faf9, 0xe861628e, 0xdc86ca17, 0xcf245260,
0xb5499b25, 0xa6eb0352, 0x920cabcb, 0x81ae33bc,
0x66d73941, 0x7575a136, 0x419209af, 0x523091d8,
0x285d589d, 0x3bffc0ea, 0x0f186873, 0x1cbaf004,
0xc4060b78, 0xd7a4930f, 0xe3433b96, 0xf0e1a3e1,
0x8a8c6aa4, 0x992ef2d3, 0xadc95a4a, 0xbe6bc23d,
0x5912c8c0, 0x4ab050b7, 0x7e57f82e, 0x6df56059,
0x1798a91c, 0x043a316b, 0x30dd99f2, 0x237f0185,
0x844819fb, 0x97ea818c, 0xa30d2915, 0xb0afb162,
0xcac27827, 0xd960e050, 0xed8748c9, 0xfe25d0be,
0x195cda43, 0x0afe4234, 0x3e19eaad, 0x2dbb72da,
0x57d6bb9f, 0x447423e8, 0x70938b71, 0x63311306,
0xbb8de87a, 0xa82f700d, 0x9cc8d894, 0x8f6a40e3,
0xf50789a6, 0xe6a511d1, 0xd242b948, 0xc1e0213f,
0x26992bc2, 0x353bb3b5, 0x01dc1b2c, 0x127e835b,
0x68134a1e, 0x7bb1d269, 0x4f567af0, 0x5cf4e287,
0x04d43cfd, 0x1776a48a, 0x23910c13, 0x30339464,
0x4a5e5d21, 0x59fcc556, 0x6d1b6dcf, 0x7eb9f5b8,
0x99c0ff45, 0x8a626732, 0xbe85cfab, 0xad2757dc,
0xd74a9e99, 0xc4e806ee, 0xf00fae77, 0xe3ad3600,
0x3b11cd7c, 0x28b3550b, 0x1c54fd92, 0x0ff665e5,
0x759baca0, 0x663934d7, 0x52de9c4e, 0x417c0439,
0xa6050ec4, 0xb5a796b3, 0x81403e2a, 0x92e2a65d,
0xe88f6f18, 0xfb2df76f, 0xcfca5ff6, 0xdc68c781,
0x7b5fdfff, 0x68fd4788, 0x5c1aef11, 0x4fb87766,
0x35d5be23, 0x26772654, 0x12908ecd, 0x013216ba,
0xe64b1c47, 0xf5e98430, 0xc10e2ca9, 0xd2acb4de,
0xa8c17d9b, 0xbb63e5ec, 0x8f844d75, 0x9c26d502,
0x449a2e7e, 0x5738b609, 0x63df1e90, 0x707d86e7,
0x0a104fa2, 0x19b2d7d5, 0x2d557f4c, 0x3ef7e73b,
0xd98eedc6, 0xca2c75b1, 0xfecbdd28, 0xed69455f,
0x97048c1a, 0x84a6146d, 0xb041bcf4, 0xa3e32483
};
static const uint32_t table2_[256] = {
0x00000000, 0xa541927e, 0x4f6f520d, 0xea2ec073,
0x9edea41a, 0x3b9f3664, 0xd1b1f617, 0x74f06469,
0x38513ec5, 0x9d10acbb, 0x773e6cc8, 0xd27ffeb6,
0xa68f9adf, 0x03ce08a1, 0xe9e0c8d2, 0x4ca15aac,
0x70a27d8a, 0xd5e3eff4, 0x3fcd2f87, 0x9a8cbdf9,
0xee7cd990, 0x4b3d4bee, 0xa1138b9d, 0x045219e3,
0x48f3434f, 0xedb2d131, 0x079c1142, 0xa2dd833c,
0xd62de755, 0x736c752b, 0x9942b558, 0x3c032726,
0xe144fb14, 0x4405696a, 0xae2ba919, 0x0b6a3b67,
0x7f9a5f0e, 0xdadbcd70, 0x30f50d03, 0x95b49f7d,
0xd915c5d1, 0x7c5457af, 0x967a97dc, 0x333b05a2,
0x47cb61cb, 0xe28af3b5, 0x08a433c6, 0xade5a1b8,
0x91e6869e, 0x34a714e0, 0xde89d493, 0x7bc846ed,
0x0f382284, 0xaa79b0fa, 0x40577089, 0xe516e2f7,
0xa9b7b85b, 0x0cf62a25, 0xe6d8ea56, 0x43997828,
0x37691c41, 0x92288e3f, 0x78064e4c, 0xdd47dc32,
0xc76580d9, 0x622412a7, 0x880ad2d4, 0x2d4b40aa,
0x59bb24c3, 0xfcfab6bd, 0x16d476ce, 0xb395e4b0,
0xff34be1c, 0x5a752c62, 0xb05bec11, 0x151a7e6f,
0x61ea1a06, 0xc4ab8878, 0x2e85480b, 0x8bc4da75,
0xb7c7fd53, 0x12866f2d, 0xf8a8af5e, 0x5de93d20,
0x29195949, 0x8c58cb37, 0x66760b44, 0xc337993a,
0x8f96c396, 0x2ad751e8, 0xc0f9919b, 0x65b803e5,
0x1148678c, 0xb409f5f2, 0x5e273581, 0xfb66a7ff,
0x26217bcd, 0x8360e9b3, 0x694e29c0, 0xcc0fbbbe,
0xb8ffdfd7, 0x1dbe4da9, 0xf7908dda, 0x52d11fa4,
0x1e704508, 0xbb31d776, 0x511f1705, 0xf45e857b,
0x80aee112, 0x25ef736c, 0xcfc1b31f, 0x6a802161,
0x56830647, 0xf3c29439, 0x19ec544a, 0xbcadc634,
0xc85da25d, 0x6d1c3023, 0x8732f050, 0x2273622e,
0x6ed23882, 0xcb93aafc, 0x21bd6a8f, 0x84fcf8f1,
0xf00c9c98, 0x554d0ee6, 0xbf63ce95, 0x1a225ceb,
0x8b277743, 0x2e66e53d, 0xc448254e, 0x6109b730,
0x15f9d359, 0xb0b84127, 0x5a968154, 0xffd7132a,
0xb3764986, 0x1637dbf8, 0xfc191b8b, 0x595889f5,
0x2da8ed9c, 0x88e97fe2, 0x62c7bf91, 0xc7862def,
0xfb850ac9, 0x5ec498b7, 0xb4ea58c4, 0x11abcaba,
0x655baed3, 0xc01a3cad, 0x2a34fcde, 0x8f756ea0,
0xc3d4340c, 0x6695a672, 0x8cbb6601, 0x29faf47f,
0x5d0a9016, 0xf84b0268, 0x1265c21b, 0xb7245065,
0x6a638c57, 0xcf221e29, 0x250cde5a, 0x804d4c24,
0xf4bd284d, 0x51fcba33, 0xbbd27a40, 0x1e93e83e,
0x5232b292, 0xf77320ec, 0x1d5de09f, 0xb81c72e1,
0xccec1688, 0x69ad84f6, 0x83834485, 0x26c2d6fb,
0x1ac1f1dd, 0xbf8063a3, 0x55aea3d0, 0xf0ef31ae,
0x841f55c7, 0x215ec7b9, 0xcb7007ca, 0x6e3195b4,
0x2290cf18, 0x87d15d66, 0x6dff9d15, 0xc8be0f6b,
0xbc4e6b02, 0x190ff97c, 0xf321390f, 0x5660ab71,
0x4c42f79a, 0xe90365e4, 0x032da597, 0xa66c37e9,
0xd29c5380, 0x77ddc1fe, 0x9df3018d, 0x38b293f3,
0x7413c95f, 0xd1525b21, 0x3b7c9b52, 0x9e3d092c,
0xeacd6d45, 0x4f8cff3b, 0xa5a23f48, 0x00e3ad36,
0x3ce08a10, 0x99a1186e, 0x738fd81d, 0xd6ce4a63,
0xa23e2e0a, 0x077fbc74, 0xed517c07, 0x4810ee79,
0x04b1b4d5, 0xa1f026ab, 0x4bdee6d8, 0xee9f74a6,
0x9a6f10cf, 0x3f2e82b1, 0xd50042c2, 0x7041d0bc,
0xad060c8e, 0x08479ef0, 0xe2695e83, 0x4728ccfd,
0x33d8a894, 0x96993aea, 0x7cb7fa99, 0xd9f668e7,
0x9557324b, 0x3016a035, 0xda386046, 0x7f79f238,
0x0b899651, 0xaec8042f, 0x44e6c45c, 0xe1a75622,
0xdda47104, 0x78e5e37a, 0x92cb2309, 0x378ab177,
0x437ad51e, 0xe63b4760, 0x0c158713, 0xa954156d,
0xe5f54fc1, 0x40b4ddbf, 0xaa9a1dcc, 0x0fdb8fb2,
0x7b2bebdb, 0xde6a79a5, 0x3444b9d6, 0x91052ba8
};
static const uint32_t table3_[256] = {
0x00000000, 0xdd45aab8, 0xbf672381, 0x62228939,
0x7b2231f3, 0xa6679b4b, 0xc4451272, 0x1900b8ca,
0xf64463e6, 0x2b01c95e, 0x49234067, 0x9466eadf,
0x8d665215, 0x5023f8ad, 0x32017194, 0xef44db2c,
0xe964b13d, 0x34211b85, 0x560392bc, 0x8b463804,
0x924680ce, 0x4f032a76, 0x2d21a34f, 0xf06409f7,
0x1f20d2db, 0xc2657863, 0xa047f15a, 0x7d025be2,
0x6402e328, 0xb9474990, 0xdb65c0a9, 0x06206a11,
0xd725148b, 0x0a60be33, 0x6842370a, 0xb5079db2,
0xac072578, 0x71428fc0, 0x136006f9, 0xce25ac41,
0x2161776d, 0xfc24ddd5, 0x9e0654ec, 0x4343fe54,
0x5a43469e, 0x8706ec26, 0xe524651f, 0x3861cfa7,
0x3e41a5b6, 0xe3040f0e, 0x81268637, 0x5c632c8f,
0x45639445, 0x98263efd, 0xfa04b7c4, 0x27411d7c,
0xc805c650, 0x15406ce8, 0x7762e5d1, 0xaa274f69,
0xb327f7a3, 0x6e625d1b, 0x0c40d422, 0xd1057e9a,
0xaba65fe7, 0x76e3f55f, 0x14c17c66, 0xc984d6de,
0xd0846e14, 0x0dc1c4ac, 0x6fe34d95, 0xb2a6e72d,
0x5de23c01, 0x80a796b9, 0xe2851f80, 0x3fc0b538,
0x26c00df2, 0xfb85a74a, 0x99a72e73, 0x44e284cb,
0x42c2eeda, 0x9f874462, 0xfda5cd5b, 0x20e067e3,
0x39e0df29, 0xe4a57591, 0x8687fca8, 0x5bc25610,
0xb4868d3c, 0x69c32784, 0x0be1aebd, 0xd6a40405,
0xcfa4bccf, 0x12e11677, 0x70c39f4e, 0xad8635f6,
0x7c834b6c, 0xa1c6e1d4, 0xc3e468ed, 0x1ea1c255,
0x07a17a9f, 0xdae4d027, 0xb8c6591e, 0x6583f3a6,
0x8ac7288a, 0x57828232, 0x35a00b0b, 0xe8e5a1b3,
0xf1e51979, 0x2ca0b3c1, 0x4e823af8, 0x93c79040,
0x95e7fa51, 0x48a250e9, 0x2a80d9d0, 0xf7c57368,
0xeec5cba2, 0x3380611a, 0x51a2e823, 0x8ce7429b,
0x63a399b7, 0xbee6330f, 0xdcc4ba36, 0x0181108e,
0x1881a844, 0xc5c402fc, 0xa7e68bc5, 0x7aa3217d,
0x52a0c93f, 0x8fe56387, 0xedc7eabe, 0x30824006,
0x2982f8cc, 0xf4c75274, 0x96e5db4d, 0x4ba071f5,
0xa4e4aad9, 0x79a10061, 0x1b838958, 0xc6c623e0,
0xdfc69b2a, 0x02833192, 0x60a1b8ab, 0xbde41213,
0xbbc47802, 0x6681d2ba, 0x04a35b83, 0xd9e6f13b,
0xc0e649f1, 0x1da3e349, 0x7f816a70, 0xa2c4c0c8,
0x4d801be4, 0x90c5b15c, 0xf2e73865, 0x2fa292dd,
0x36a22a17, 0xebe780af, 0x89c50996, 0x5480a32e,
0x8585ddb4, 0x58c0770c, 0x3ae2fe35, 0xe7a7548d,
0xfea7ec47, 0x23e246ff, 0x41c0cfc6, 0x9c85657e,
0x73c1be52, 0xae8414ea, 0xcca69dd3, 0x11e3376b,
0x08e38fa1, 0xd5a62519, 0xb784ac20, 0x6ac10698,
0x6ce16c89, 0xb1a4c631, 0xd3864f08, 0x0ec3e5b0,
0x17c35d7a, 0xca86f7c2, 0xa8a47efb, 0x75e1d443,
0x9aa50f6f, 0x47e0a5d7, 0x25c22cee, 0xf8878656,
0xe1873e9c, 0x3cc29424, 0x5ee01d1d, 0x83a5b7a5,
0xf90696d8, 0x24433c60, 0x4661b559, 0x9b241fe1,
0x8224a72b, 0x5f610d93, 0x3d4384aa, 0xe0062e12,
0x0f42f53e, 0xd2075f86, 0xb025d6bf, 0x6d607c07,
0x7460c4cd, 0xa9256e75, 0xcb07e74c, 0x16424df4,
0x106227e5, 0xcd278d5d, 0xaf050464, 0x7240aedc,
0x6b401616, 0xb605bcae, 0xd4273597, 0x09629f2f,
0xe6264403, 0x3b63eebb, 0x59416782, 0x8404cd3a,
0x9d0475f0, 0x4041df48, 0x22635671, 0xff26fcc9,
0x2e238253, 0xf36628eb, 0x9144a1d2, 0x4c010b6a,
0x5501b3a0, 0x88441918, 0xea669021, 0x37233a99,
0xd867e1b5, 0x05224b0d, 0x6700c234, 0xba45688c,
0xa345d046, 0x7e007afe, 0x1c22f3c7, 0xc167597f,
0xc747336e, 0x1a0299d6, 0x782010ef, 0xa565ba57,
0xbc65029d, 0x6120a825, 0x0302211c, 0xde478ba4,
0x31035088, 0xec46fa30, 0x8e647309, 0x5321d9b1,
0x4a21617b, 0x9764cbc3, 0xf54642fa, 0x2803e842
};
// Used to fetch a naturally-aligned 32-bit word in little endian byte-order
static inline uint32_t LE_LOAD32(const uint8_t *p) {
return DecodeFixed32(reinterpret_cast<const char*>(p));
}
#if defined(HAVE_SSE42) && (defined(__LP64__) || defined(_WIN64))
static inline uint64_t LE_LOAD64(const uint8_t *p) {
return DecodeFixed64(reinterpret_cast<const char*>(p));
}
#endif
static inline void Slow_CRC32(uint64_t* l, uint8_t const **p) {
uint32_t c = static_cast<uint32_t>(*l ^ LE_LOAD32(*p));
*p += 4;
*l = table3_[c & 0xff] ^
table2_[(c >> 8) & 0xff] ^
table1_[(c >> 16) & 0xff] ^
table0_[c >> 24];
// DO it twice.
c = static_cast<uint32_t>(*l ^ LE_LOAD32(*p));
*p += 4;
*l = table3_[c & 0xff] ^
table2_[(c >> 8) & 0xff] ^
table1_[(c >> 16) & 0xff] ^
table0_[c >> 24];
}
#if defined(HAVE_SSE42) && defined(__GNUC__)
#if defined(__clang__)
#if __has_cpp_attribute(gnu::target)
__attribute__ ((target ("sse4.2")))
#endif
#else // gcc supports this since 4.4
__attribute__ ((target ("sse4.2")))
#endif
#endif
static inline void Fast_CRC32(uint64_t* l, uint8_t const **p) {
#ifndef HAVE_SSE42
Slow_CRC32(l, p);
#elif defined(__LP64__) || defined(_WIN64)
*l = _mm_crc32_u64(*l, LE_LOAD64(*p));
*p += 8;
#else
*l = _mm_crc32_u32(static_cast<unsigned int>(*l), LE_LOAD32(*p));
*p += 4;
*l = _mm_crc32_u32(static_cast<unsigned int>(*l), LE_LOAD32(*p));
*p += 4;
#endif
}
template<void (*CRC32)(uint64_t*, uint8_t const**)>
uint32_t ExtendImpl(uint32_t crc, const char* buf, size_t size) {
const uint8_t *p = reinterpret_cast<const uint8_t *>(buf);
const uint8_t *e = p + size;
uint64_t l = crc ^ 0xffffffffu;
// Align n to (1 << m) byte boundary
#define ALIGN(n, m) ((n + ((1 << m) - 1)) & ~((1 << m) - 1))
#define STEP1 do { \
int c = (l & 0xff) ^ *p++; \
l = table0_[c] ^ (l >> 8); \
} while (0)
// Point x at first 16-byte aligned byte in string. This might be
// just past the end of the string.
const uintptr_t pval = reinterpret_cast<uintptr_t>(p);
const uint8_t* x = reinterpret_cast<const uint8_t*>(ALIGN(pval, 4));
if (x <= e) {
// Process bytes until finished or p is 16-byte aligned
while (p != x) {
STEP1;
}
}
// Process bytes 16 at a time
while ((e-p) >= 16) {
CRC32(&l, &p);
CRC32(&l, &p);
}
// Process bytes 8 at a time
while ((e-p) >= 8) {
CRC32(&l, &p);
}
// Process the last few bytes
while (p != e) {
STEP1;
}
#undef STEP1
#undef ALIGN
return static_cast<uint32_t>(l ^ 0xffffffffu);
}
// Detect if SS42 or not.
#ifndef HAVE_POWER8
static bool isSSE42() {
#ifndef HAVE_SSE42
return false;
#elif defined(__GNUC__) && defined(__x86_64__) && !defined(IOS_CROSS_COMPILE)
uint32_t c_;
__asm__("cpuid" : "=c"(c_) : "a"(1) : "ebx", "edx");
return c_ & (1U << 20); // copied from CpuId.h in Folly.
#elif defined(_WIN64)
int info[4];
__cpuidex(info, 0x00000001, 0);
return (info[2] & ((int)1 << 20)) != 0;
#else
return false;
#endif
}
#endif
typedef uint32_t (*Function)(uint32_t, const char*, size_t);
#if defined(HAVE_POWER8) && defined(HAS_ALTIVEC)
uint32_t ExtendPPCImpl(uint32_t crc, const char *buf, size_t size) {
return crc32c_ppc(crc, (const unsigned char *)buf, size);
}
#if __linux__
static int arch_ppc_probe(void) {
arch_ppc_crc32 = 0;
#if defined(__powerpc64__)
if (getauxval(AT_HWCAP2) & PPC_FEATURE2_VEC_CRYPTO) arch_ppc_crc32 = 1;
#endif /* __powerpc64__ */
return arch_ppc_crc32;
}
#endif // __linux__
static bool isAltiVec() {
if (arch_ppc_probe()) {
return true;
} else {
return false;
}
}
#endif
static inline Function Choose_Extend() {
#ifndef HAVE_POWER8
return isSSE42() ? ExtendImpl<Fast_CRC32> : ExtendImpl<Slow_CRC32>;
#else
return isAltiVec() ? ExtendPPCImpl : ExtendImpl<Slow_CRC32>;
#endif
}
std::string IsFastCrc32Supported() {
bool has_fast_crc = false;
std::string fast_zero_msg;
std::string arch;
#ifdef HAVE_POWER8
#ifdef HAS_ALTIVEC
if (arch_ppc_probe()) {
has_fast_crc = true;
arch = "PPC";
}
#else
has_fast_crc = false;
arch = "PPC";
#endif
#else
has_fast_crc = isSSE42();
arch = "x86";
#endif
if (has_fast_crc){
fast_zero_msg.append("Supported on " + arch);
}
fast_zero_msg.append("Not supported on " + arch);
return fast_zero_msg;
}
static Function ChosenExtend = Choose_Extend();
uint32_t Extend(uint32_t crc, const char* buf, size_t size) {
return ChosenExtend(crc, buf, size);
}
} // namespace crc32c
} // namespace rocksdb