Use portable CRC32C from google/crc32c.

Benchmark results below. More results at
354d61ef97.

New, MacBookPro13,3 with Core i7 6920HQ:
LevelDB:    version 1.20
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
WARNING: Snappy compression is not enabled
------------------------------------------------
fillseq      :       2.952 micros/op;   37.5 MB/s
fillsync     :      43.932 micros/op;    2.5 MB/s (1000 ops)
fillrandom   :       3.856 micros/op;   28.7 MB/s
overwrite    :       4.053 micros/op;   27.3 MB/s
readrandom   :       4.234 micros/op; (1000000 of 1000000 found)
readrandom   :       3.923 micros/op; (1000000 of 1000000 found)
readseq      :       0.201 micros/op;  550.8 MB/s
readreverse  :       0.356 micros/op;  310.6 MB/s
compact      :  436800.000 micros/op;
readrandom   :       2.375 micros/op; (1000000 of 1000000 found)
readseq      :       0.151 micros/op;  734.3 MB/s
readreverse  :       0.298 micros/op;  370.7 MB/s
fill100K     :     554.075 micros/op;  172.1 MB/s (1000 ops)
crc32c       :       1.393 micros/op; 2805.0 MB/s (4K per op)
snappycomp   :    3902.000 micros/op; (snappy failure)
snappyuncomp :    3821.000 micros/op; (snappy failure)
acquireload  :      13.088 micros/op; (each op is 1000 loads)

Baseline, MacBookPro13,3 with Core i7 6920HQ:
LevelDB:    version 1.20
Keys:       16 bytes each
Values:     100 bytes each (50 bytes after compression)
Entries:    1000000
RawSize:    110.6 MB (estimated)
FileSize:   62.9 MB (estimated)
WARNING: Snappy compression is not enabled
------------------------------------------------
fillseq      :       3.000 micros/op;   36.9 MB/s
fillsync     :      46.721 micros/op;    2.4 MB/s (1000 ops)
fillrandom   :       3.922 micros/op;   28.2 MB/s
overwrite    :       4.080 micros/op;   27.1 MB/s
readrandom   :       4.409 micros/op; (1000000 of 1000000 found)
readrandom   :       3.895 micros/op; (1000000 of 1000000 found)
readseq      :       0.190 micros/op;  582.4 MB/s
readreverse  :       0.413 micros/op;  267.6 MB/s
compact      :  441076.000 micros/op;
readrandom   :       2.308 micros/op; (1000000 of 1000000 found)
readseq      :       0.170 micros/op;  651.2 MB/s
readreverse  :       0.302 micros/op;  366.2 MB/s
fill100K     :     614.289 micros/op;  155.3 MB/s (1000 ops)
crc32c       :       3.547 micros/op; 1101.2 MB/s (4K per op)
snappycomp   :    3393.000 micros/op; (snappy failure)
snappyuncomp :    3171.000 micros/op; (snappy failure)
acquireload  :      12.761 micros/op; (each op is 1000 loads)

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=170100372

util/crc32c.cc

@@ -2,11 +2,11 @@
 // 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.
+// A portable implementation of crc32c.
 
 #include "util/crc32c.h"
 
+#include <stddef.h>
 #include <stdint.h>
 
 #include "port/port.h"
@@ -15,276 +15,253 @@
 namespace leveldb {
 namespace crc32c {
 
-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
-};
+namespace {
 
-// 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));
+const uint32_t kByteExtensionTable[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};
+
+const uint32_t kStrideExtensionTable0[256] = {
+    0x00000000, 0x30d23865, 0x61a470ca, 0x517648af, 0xc348e194, 0xf39ad9f1,
+    0xa2ec915e, 0x923ea93b, 0x837db5d9, 0xb3af8dbc, 0xe2d9c513, 0xd20bfd76,
+    0x4035544d, 0x70e76c28, 0x21912487, 0x11431ce2, 0x03171d43, 0x33c52526,
+    0x62b36d89, 0x526155ec, 0xc05ffcd7, 0xf08dc4b2, 0xa1fb8c1d, 0x9129b478,
+    0x806aa89a, 0xb0b890ff, 0xe1ced850, 0xd11ce035, 0x4322490e, 0x73f0716b,
+    0x228639c4, 0x125401a1, 0x062e3a86, 0x36fc02e3, 0x678a4a4c, 0x57587229,
+    0xc566db12, 0xf5b4e377, 0xa4c2abd8, 0x941093bd, 0x85538f5f, 0xb581b73a,
+    0xe4f7ff95, 0xd425c7f0, 0x461b6ecb, 0x76c956ae, 0x27bf1e01, 0x176d2664,
+    0x053927c5, 0x35eb1fa0, 0x649d570f, 0x544f6f6a, 0xc671c651, 0xf6a3fe34,
+    0xa7d5b69b, 0x97078efe, 0x8644921c, 0xb696aa79, 0xe7e0e2d6, 0xd732dab3,
+    0x450c7388, 0x75de4bed, 0x24a80342, 0x147a3b27, 0x0c5c750c, 0x3c8e4d69,
+    0x6df805c6, 0x5d2a3da3, 0xcf149498, 0xffc6acfd, 0xaeb0e452, 0x9e62dc37,
+    0x8f21c0d5, 0xbff3f8b0, 0xee85b01f, 0xde57887a, 0x4c692141, 0x7cbb1924,
+    0x2dcd518b, 0x1d1f69ee, 0x0f4b684f, 0x3f99502a, 0x6eef1885, 0x5e3d20e0,
+    0xcc0389db, 0xfcd1b1be, 0xada7f911, 0x9d75c174, 0x8c36dd96, 0xbce4e5f3,
+    0xed92ad5c, 0xdd409539, 0x4f7e3c02, 0x7fac0467, 0x2eda4cc8, 0x1e0874ad,
+    0x0a724f8a, 0x3aa077ef, 0x6bd63f40, 0x5b040725, 0xc93aae1e, 0xf9e8967b,
+    0xa89eded4, 0x984ce6b1, 0x890ffa53, 0xb9ddc236, 0xe8ab8a99, 0xd879b2fc,
+    0x4a471bc7, 0x7a9523a2, 0x2be36b0d, 0x1b315368, 0x096552c9, 0x39b76aac,
+    0x68c12203, 0x58131a66, 0xca2db35d, 0xfaff8b38, 0xab89c397, 0x9b5bfbf2,
+    0x8a18e710, 0xbacadf75, 0xebbc97da, 0xdb6eafbf, 0x49500684, 0x79823ee1,
+    0x28f4764e, 0x18264e2b, 0x18b8ea18, 0x286ad27d, 0x791c9ad2, 0x49cea2b7,
+    0xdbf00b8c, 0xeb2233e9, 0xba547b46, 0x8a864323, 0x9bc55fc1, 0xab1767a4,
+    0xfa612f0b, 0xcab3176e, 0x588dbe55, 0x685f8630, 0x3929ce9f, 0x09fbf6fa,
+    0x1baff75b, 0x2b7dcf3e, 0x7a0b8791, 0x4ad9bff4, 0xd8e716cf, 0xe8352eaa,
+    0xb9436605, 0x89915e60, 0x98d24282, 0xa8007ae7, 0xf9763248, 0xc9a40a2d,
+    0x5b9aa316, 0x6b489b73, 0x3a3ed3dc, 0x0aecebb9, 0x1e96d09e, 0x2e44e8fb,
+    0x7f32a054, 0x4fe09831, 0xddde310a, 0xed0c096f, 0xbc7a41c0, 0x8ca879a5,
+    0x9deb6547, 0xad395d22, 0xfc4f158d, 0xcc9d2de8, 0x5ea384d3, 0x6e71bcb6,
+    0x3f07f419, 0x0fd5cc7c, 0x1d81cddd, 0x2d53f5b8, 0x7c25bd17, 0x4cf78572,
+    0xdec92c49, 0xee1b142c, 0xbf6d5c83, 0x8fbf64e6, 0x9efc7804, 0xae2e4061,
+    0xff5808ce, 0xcf8a30ab, 0x5db49990, 0x6d66a1f5, 0x3c10e95a, 0x0cc2d13f,
+    0x14e49f14, 0x2436a771, 0x7540efde, 0x4592d7bb, 0xd7ac7e80, 0xe77e46e5,
+    0xb6080e4a, 0x86da362f, 0x97992acd, 0xa74b12a8, 0xf63d5a07, 0xc6ef6262,
+    0x54d1cb59, 0x6403f33c, 0x3575bb93, 0x05a783f6, 0x17f38257, 0x2721ba32,
+    0x7657f29d, 0x4685caf8, 0xd4bb63c3, 0xe4695ba6, 0xb51f1309, 0x85cd2b6c,
+    0x948e378e, 0xa45c0feb, 0xf52a4744, 0xc5f87f21, 0x57c6d61a, 0x6714ee7f,
+    0x3662a6d0, 0x06b09eb5, 0x12caa592, 0x22189df7, 0x736ed558, 0x43bced3d,
+    0xd1824406, 0xe1507c63, 0xb02634cc, 0x80f40ca9, 0x91b7104b, 0xa165282e,
+    0xf0136081, 0xc0c158e4, 0x52fff1df, 0x622dc9ba, 0x335b8115, 0x0389b970,
+    0x11ddb8d1, 0x210f80b4, 0x7079c81b, 0x40abf07e, 0xd2955945, 0xe2476120,
+    0xb331298f, 0x83e311ea, 0x92a00d08, 0xa272356d, 0xf3047dc2, 0xc3d645a7,
+    0x51e8ec9c, 0x613ad4f9, 0x304c9c56, 0x009ea433};
+
+const uint32_t kStrideExtensionTable1[256] = {
+    0x00000000, 0x54075546, 0xa80eaa8c, 0xfc09ffca, 0x55f123e9, 0x01f676af,
+    0xfdff8965, 0xa9f8dc23, 0xabe247d2, 0xffe51294, 0x03eced5e, 0x57ebb818,
+    0xfe13643b, 0xaa14317d, 0x561dceb7, 0x021a9bf1, 0x5228f955, 0x062fac13,
+    0xfa2653d9, 0xae21069f, 0x07d9dabc, 0x53de8ffa, 0xafd77030, 0xfbd02576,
+    0xf9cabe87, 0xadcdebc1, 0x51c4140b, 0x05c3414d, 0xac3b9d6e, 0xf83cc828,
+    0x043537e2, 0x503262a4, 0xa451f2aa, 0xf056a7ec, 0x0c5f5826, 0x58580d60,
+    0xf1a0d143, 0xa5a78405, 0x59ae7bcf, 0x0da92e89, 0x0fb3b578, 0x5bb4e03e,
+    0xa7bd1ff4, 0xf3ba4ab2, 0x5a429691, 0x0e45c3d7, 0xf24c3c1d, 0xa64b695b,
+    0xf6790bff, 0xa27e5eb9, 0x5e77a173, 0x0a70f435, 0xa3882816, 0xf78f7d50,
+    0x0b86829a, 0x5f81d7dc, 0x5d9b4c2d, 0x099c196b, 0xf595e6a1, 0xa192b3e7,
+    0x086a6fc4, 0x5c6d3a82, 0xa064c548, 0xf463900e, 0x4d4f93a5, 0x1948c6e3,
+    0xe5413929, 0xb1466c6f, 0x18beb04c, 0x4cb9e50a, 0xb0b01ac0, 0xe4b74f86,
+    0xe6add477, 0xb2aa8131, 0x4ea37efb, 0x1aa42bbd, 0xb35cf79e, 0xe75ba2d8,
+    0x1b525d12, 0x4f550854, 0x1f676af0, 0x4b603fb6, 0xb769c07c, 0xe36e953a,
+    0x4a964919, 0x1e911c5f, 0xe298e395, 0xb69fb6d3, 0xb4852d22, 0xe0827864,
+    0x1c8b87ae, 0x488cd2e8, 0xe1740ecb, 0xb5735b8d, 0x497aa447, 0x1d7df101,
+    0xe91e610f, 0xbd193449, 0x4110cb83, 0x15179ec5, 0xbcef42e6, 0xe8e817a0,
+    0x14e1e86a, 0x40e6bd2c, 0x42fc26dd, 0x16fb739b, 0xeaf28c51, 0xbef5d917,
+    0x170d0534, 0x430a5072, 0xbf03afb8, 0xeb04fafe, 0xbb36985a, 0xef31cd1c,
+    0x133832d6, 0x473f6790, 0xeec7bbb3, 0xbac0eef5, 0x46c9113f, 0x12ce4479,
+    0x10d4df88, 0x44d38ace, 0xb8da7504, 0xecdd2042, 0x4525fc61, 0x1122a927,
+    0xed2b56ed, 0xb92c03ab, 0x9a9f274a, 0xce98720c, 0x32918dc6, 0x6696d880,
+    0xcf6e04a3, 0x9b6951e5, 0x6760ae2f, 0x3367fb69, 0x317d6098, 0x657a35de,
+    0x9973ca14, 0xcd749f52, 0x648c4371, 0x308b1637, 0xcc82e9fd, 0x9885bcbb,
+    0xc8b7de1f, 0x9cb08b59, 0x60b97493, 0x34be21d5, 0x9d46fdf6, 0xc941a8b0,
+    0x3548577a, 0x614f023c, 0x635599cd, 0x3752cc8b, 0xcb5b3341, 0x9f5c6607,
+    0x36a4ba24, 0x62a3ef62, 0x9eaa10a8, 0xcaad45ee, 0x3eced5e0, 0x6ac980a6,
+    0x96c07f6c, 0xc2c72a2a, 0x6b3ff609, 0x3f38a34f, 0xc3315c85, 0x973609c3,
+    0x952c9232, 0xc12bc774, 0x3d2238be, 0x69256df8, 0xc0ddb1db, 0x94dae49d,
+    0x68d31b57, 0x3cd44e11, 0x6ce62cb5, 0x38e179f3, 0xc4e88639, 0x90efd37f,
+    0x39170f5c, 0x6d105a1a, 0x9119a5d0, 0xc51ef096, 0xc7046b67, 0x93033e21,
+    0x6f0ac1eb, 0x3b0d94ad, 0x92f5488e, 0xc6f21dc8, 0x3afbe202, 0x6efcb744,
+    0xd7d0b4ef, 0x83d7e1a9, 0x7fde1e63, 0x2bd94b25, 0x82219706, 0xd626c240,
+    0x2a2f3d8a, 0x7e2868cc, 0x7c32f33d, 0x2835a67b, 0xd43c59b1, 0x803b0cf7,
+    0x29c3d0d4, 0x7dc48592, 0x81cd7a58, 0xd5ca2f1e, 0x85f84dba, 0xd1ff18fc,
+    0x2df6e736, 0x79f1b270, 0xd0096e53, 0x840e3b15, 0x7807c4df, 0x2c009199,
+    0x2e1a0a68, 0x7a1d5f2e, 0x8614a0e4, 0xd213f5a2, 0x7beb2981, 0x2fec7cc7,
+    0xd3e5830d, 0x87e2d64b, 0x73814645, 0x27861303, 0xdb8fecc9, 0x8f88b98f,
+    0x267065ac, 0x727730ea, 0x8e7ecf20, 0xda799a66, 0xd8630197, 0x8c6454d1,
+    0x706dab1b, 0x246afe5d, 0x8d92227e, 0xd9957738, 0x259c88f2, 0x719bddb4,
+    0x21a9bf10, 0x75aeea56, 0x89a7159c, 0xdda040da, 0x74589cf9, 0x205fc9bf,
+    0xdc563675, 0x88516333, 0x8a4bf8c2, 0xde4cad84, 0x2245524e, 0x76420708,
+    0xdfbadb2b, 0x8bbd8e6d, 0x77b471a7, 0x23b324e1};
+
+const uint32_t kStrideExtensionTable2[256] = {
+    0x00000000, 0x678efd01, 0xcf1dfa02, 0xa8930703, 0x9bd782f5, 0xfc597ff4,
+    0x54ca78f7, 0x334485f6, 0x3243731b, 0x55cd8e1a, 0xfd5e8919, 0x9ad07418,
+    0xa994f1ee, 0xce1a0cef, 0x66890bec, 0x0107f6ed, 0x6486e636, 0x03081b37,
+    0xab9b1c34, 0xcc15e135, 0xff5164c3, 0x98df99c2, 0x304c9ec1, 0x57c263c0,
+    0x56c5952d, 0x314b682c, 0x99d86f2f, 0xfe56922e, 0xcd1217d8, 0xaa9cead9,
+    0x020fedda, 0x658110db, 0xc90dcc6c, 0xae83316d, 0x0610366e, 0x619ecb6f,
+    0x52da4e99, 0x3554b398, 0x9dc7b49b, 0xfa49499a, 0xfb4ebf77, 0x9cc04276,
+    0x34534575, 0x53ddb874, 0x60993d82, 0x0717c083, 0xaf84c780, 0xc80a3a81,
+    0xad8b2a5a, 0xca05d75b, 0x6296d058, 0x05182d59, 0x365ca8af, 0x51d255ae,
+    0xf94152ad, 0x9ecfafac, 0x9fc85941, 0xf846a440, 0x50d5a343, 0x375b5e42,
+    0x041fdbb4, 0x639126b5, 0xcb0221b6, 0xac8cdcb7, 0x97f7ee29, 0xf0791328,
+    0x58ea142b, 0x3f64e92a, 0x0c206cdc, 0x6bae91dd, 0xc33d96de, 0xa4b36bdf,
+    0xa5b49d32, 0xc23a6033, 0x6aa96730, 0x0d279a31, 0x3e631fc7, 0x59ede2c6,
+    0xf17ee5c5, 0x96f018c4, 0xf371081f, 0x94fff51e, 0x3c6cf21d, 0x5be20f1c,
+    0x68a68aea, 0x0f2877eb, 0xa7bb70e8, 0xc0358de9, 0xc1327b04, 0xa6bc8605,
+    0x0e2f8106, 0x69a17c07, 0x5ae5f9f1, 0x3d6b04f0, 0x95f803f3, 0xf276fef2,
+    0x5efa2245, 0x3974df44, 0x91e7d847, 0xf6692546, 0xc52da0b0, 0xa2a35db1,
+    0x0a305ab2, 0x6dbea7b3, 0x6cb9515e, 0x0b37ac5f, 0xa3a4ab5c, 0xc42a565d,
+    0xf76ed3ab, 0x90e02eaa, 0x387329a9, 0x5ffdd4a8, 0x3a7cc473, 0x5df23972,
+    0xf5613e71, 0x92efc370, 0xa1ab4686, 0xc625bb87, 0x6eb6bc84, 0x09384185,
+    0x083fb768, 0x6fb14a69, 0xc7224d6a, 0xa0acb06b, 0x93e8359d, 0xf466c89c,
+    0x5cf5cf9f, 0x3b7b329e, 0x2a03aaa3, 0x4d8d57a2, 0xe51e50a1, 0x8290ada0,
+    0xb1d42856, 0xd65ad557, 0x7ec9d254, 0x19472f55, 0x1840d9b8, 0x7fce24b9,
+    0xd75d23ba, 0xb0d3debb, 0x83975b4d, 0xe419a64c, 0x4c8aa14f, 0x2b045c4e,
+    0x4e854c95, 0x290bb194, 0x8198b697, 0xe6164b96, 0xd552ce60, 0xb2dc3361,
+    0x1a4f3462, 0x7dc1c963, 0x7cc63f8e, 0x1b48c28f, 0xb3dbc58c, 0xd455388d,
+    0xe711bd7b, 0x809f407a, 0x280c4779, 0x4f82ba78, 0xe30e66cf, 0x84809bce,
+    0x2c139ccd, 0x4b9d61cc, 0x78d9e43a, 0x1f57193b, 0xb7c41e38, 0xd04ae339,
+    0xd14d15d4, 0xb6c3e8d5, 0x1e50efd6, 0x79de12d7, 0x4a9a9721, 0x2d146a20,
+    0x85876d23, 0xe2099022, 0x878880f9, 0xe0067df8, 0x48957afb, 0x2f1b87fa,
+    0x1c5f020c, 0x7bd1ff0d, 0xd342f80e, 0xb4cc050f, 0xb5cbf3e2, 0xd2450ee3,
+    0x7ad609e0, 0x1d58f4e1, 0x2e1c7117, 0x49928c16, 0xe1018b15, 0x868f7614,
+    0xbdf4448a, 0xda7ab98b, 0x72e9be88, 0x15674389, 0x2623c67f, 0x41ad3b7e,
+    0xe93e3c7d, 0x8eb0c17c, 0x8fb73791, 0xe839ca90, 0x40aacd93, 0x27243092,
+    0x1460b564, 0x73ee4865, 0xdb7d4f66, 0xbcf3b267, 0xd972a2bc, 0xbefc5fbd,
+    0x166f58be, 0x71e1a5bf, 0x42a52049, 0x252bdd48, 0x8db8da4b, 0xea36274a,
+    0xeb31d1a7, 0x8cbf2ca6, 0x242c2ba5, 0x43a2d6a4, 0x70e65352, 0x1768ae53,
+    0xbffba950, 0xd8755451, 0x74f988e6, 0x137775e7, 0xbbe472e4, 0xdc6a8fe5,
+    0xef2e0a13, 0x88a0f712, 0x2033f011, 0x47bd0d10, 0x46bafbfd, 0x213406fc,
+    0x89a701ff, 0xee29fcfe, 0xdd6d7908, 0xbae38409, 0x1270830a, 0x75fe7e0b,
+    0x107f6ed0, 0x77f193d1, 0xdf6294d2, 0xb8ec69d3, 0x8ba8ec25, 0xec261124,
+    0x44b51627, 0x233beb26, 0x223c1dcb, 0x45b2e0ca, 0xed21e7c9, 0x8aaf1ac8,
+    0xb9eb9f3e, 0xde65623f, 0x76f6653c, 0x1178983d};
+
+const uint32_t kStrideExtensionTable3[256] = {
+    0x00000000, 0xf20c0dfe, 0xe1f46d0d, 0x13f860f3, 0xc604aceb, 0x3408a115,
+    0x27f0c1e6, 0xd5fccc18, 0x89e52f27, 0x7be922d9, 0x6811422a, 0x9a1d4fd4,
+    0x4fe183cc, 0xbded8e32, 0xae15eec1, 0x5c19e33f, 0x162628bf, 0xe42a2541,
+    0xf7d245b2, 0x05de484c, 0xd0228454, 0x222e89aa, 0x31d6e959, 0xc3dae4a7,
+    0x9fc30798, 0x6dcf0a66, 0x7e376a95, 0x8c3b676b, 0x59c7ab73, 0xabcba68d,
+    0xb833c67e, 0x4a3fcb80, 0x2c4c517e, 0xde405c80, 0xcdb83c73, 0x3fb4318d,
+    0xea48fd95, 0x1844f06b, 0x0bbc9098, 0xf9b09d66, 0xa5a97e59, 0x57a573a7,
+    0x445d1354, 0xb6511eaa, 0x63add2b2, 0x91a1df4c, 0x8259bfbf, 0x7055b241,
+    0x3a6a79c1, 0xc866743f, 0xdb9e14cc, 0x29921932, 0xfc6ed52a, 0x0e62d8d4,
+    0x1d9ab827, 0xef96b5d9, 0xb38f56e6, 0x41835b18, 0x527b3beb, 0xa0773615,
+    0x758bfa0d, 0x8787f7f3, 0x947f9700, 0x66739afe, 0x5898a2fc, 0xaa94af02,
+    0xb96ccff1, 0x4b60c20f, 0x9e9c0e17, 0x6c9003e9, 0x7f68631a, 0x8d646ee4,
+    0xd17d8ddb, 0x23718025, 0x3089e0d6, 0xc285ed28, 0x17792130, 0xe5752cce,
+    0xf68d4c3d, 0x048141c3, 0x4ebe8a43, 0xbcb287bd, 0xaf4ae74e, 0x5d46eab0,
+    0x88ba26a8, 0x7ab62b56, 0x694e4ba5, 0x9b42465b, 0xc75ba564, 0x3557a89a,
+    0x26afc869, 0xd4a3c597, 0x015f098f, 0xf3530471, 0xe0ab6482, 0x12a7697c,
+    0x74d4f382, 0x86d8fe7c, 0x95209e8f, 0x672c9371, 0xb2d05f69, 0x40dc5297,
+    0x53243264, 0xa1283f9a, 0xfd31dca5, 0x0f3dd15b, 0x1cc5b1a8, 0xeec9bc56,
+    0x3b35704e, 0xc9397db0, 0xdac11d43, 0x28cd10bd, 0x62f2db3d, 0x90fed6c3,
+    0x8306b630, 0x710abbce, 0xa4f677d6, 0x56fa7a28, 0x45021adb, 0xb70e1725,
+    0xeb17f41a, 0x191bf9e4, 0x0ae39917, 0xf8ef94e9, 0x2d1358f1, 0xdf1f550f,
+    0xcce735fc, 0x3eeb3802, 0xb13145f8, 0x433d4806, 0x50c528f5, 0xa2c9250b,
+    0x7735e913, 0x8539e4ed, 0x96c1841e, 0x64cd89e0, 0x38d46adf, 0xcad86721,
+    0xd92007d2, 0x2b2c0a2c, 0xfed0c634, 0x0cdccbca, 0x1f24ab39, 0xed28a6c7,
+    0xa7176d47, 0x551b60b9, 0x46e3004a, 0xb4ef0db4, 0x6113c1ac, 0x931fcc52,
+    0x80e7aca1, 0x72eba15f, 0x2ef24260, 0xdcfe4f9e, 0xcf062f6d, 0x3d0a2293,
+    0xe8f6ee8b, 0x1afae375, 0x09028386, 0xfb0e8e78, 0x9d7d1486, 0x6f711978,
+    0x7c89798b, 0x8e857475, 0x5b79b86d, 0xa975b593, 0xba8dd560, 0x4881d89e,
+    0x14983ba1, 0xe694365f, 0xf56c56ac, 0x07605b52, 0xd29c974a, 0x20909ab4,
+    0x3368fa47, 0xc164f7b9, 0x8b5b3c39, 0x795731c7, 0x6aaf5134, 0x98a35cca,
+    0x4d5f90d2, 0xbf539d2c, 0xacabfddf, 0x5ea7f021, 0x02be131e, 0xf0b21ee0,
+    0xe34a7e13, 0x114673ed, 0xc4babff5, 0x36b6b20b, 0x254ed2f8, 0xd742df06,
+    0xe9a9e704, 0x1ba5eafa, 0x085d8a09, 0xfa5187f7, 0x2fad4bef, 0xdda14611,
+    0xce5926e2, 0x3c552b1c, 0x604cc823, 0x9240c5dd, 0x81b8a52e, 0x73b4a8d0,
+    0xa64864c8, 0x54446936, 0x47bc09c5, 0xb5b0043b, 0xff8fcfbb, 0x0d83c245,
+    0x1e7ba2b6, 0xec77af48, 0x398b6350, 0xcb876eae, 0xd87f0e5d, 0x2a7303a3,
+    0x766ae09c, 0x8466ed62, 0x979e8d91, 0x6592806f, 0xb06e4c77, 0x42624189,
+    0x519a217a, 0xa3962c84, 0xc5e5b67a, 0x37e9bb84, 0x2411db77, 0xd61dd689,
+    0x03e11a91, 0xf1ed176f, 0xe215779c, 0x10197a62, 0x4c00995d, 0xbe0c94a3,
+    0xadf4f450, 0x5ff8f9ae, 0x8a0435b6, 0x78083848, 0x6bf058bb, 0x99fc5545,
+    0xd3c39ec5, 0x21cf933b, 0x3237f3c8, 0xc03bfe36, 0x15c7322e, 0xe7cb3fd0,
+    0xf4335f23, 0x063f52dd, 0x5a26b1e2, 0xa82abc1c, 0xbbd2dcef, 0x49ded111,
+    0x9c221d09, 0x6e2e10f7, 0x7dd67004, 0x8fda7dfa};
+
+// CRCs are pre- and post- conditioned by xoring with all ones.
+static constexpr const uint32_t kCRC32Xor = static_cast<uint32_t>(0xffffffffU);
+
+// Reads a little-endian 32-bit integer from a 32-bit-aligned buffer.
+inline uint32_t ReadUint32LE(const uint8_t* buffer) {
+  return DecodeFixed32(reinterpret_cast<const char*>(buffer));
 }
 
+// Returns the smallest address >= the given address that is aligned to N bytes.
+//
+// N must be a power of two.
+template <int N>
+constexpr inline const uint8_t* RoundUp(const uint8_t* pointer) {
+  return reinterpret_cast<uint8_t*>(
+      (reinterpret_cast<uintptr_t>(pointer) + (N - 1))
+      & ~static_cast<uintptr_t>(N - 1));
+}
+
+}  // namespace
+
 // Determine if the CPU running this program can accelerate the CRC32C
 // calculation.
 static bool CanAccelerateCRC32C() {
@@ -302,48 +279,101 @@ uint32_t Extend(uint32_t crc, const char* buf, size_t size) {
     return port::AcceleratedCRC32C(crc, buf, size);
   }
 
-  const uint8_t *p = reinterpret_cast<const uint8_t *>(buf);
-  const uint8_t *e = p + size;
-  uint32_t l = crc ^ 0xffffffffu;
+  const uint8_t* p = reinterpret_cast<const uint8_t*>(buf);
+  const uint8_t* e = p + size;
+  uint32_t l = crc ^ kCRC32Xor;
+
+// Process one byte at a time.
+#define STEP1                              \
+  do {                                     \
+    int c = (l & 0xff) ^ *p++;             \
+    l = kByteExtensionTable[c] ^ (l >> 8); \
+  } while (0)
 
-#define STEP1 do {                              \
-    int c = (l & 0xff) ^ *p++;                  \
-    l = table0_[c] ^ (l >> 8);                  \
-} while (0)
-#define STEP4 do {                              \
-    uint32_t c = l ^ LE_LOAD32(p);              \
-    p += 4;                                     \
-    l = table3_[c & 0xff] ^                     \
-        table2_[(c >> 8) & 0xff] ^              \
-        table1_[(c >> 16) & 0xff] ^             \
-        table0_[c >> 24];                       \
-} while (0)
+// Process one of the 4 strides of 4-byte data.
+#define STEP4(s)                                                               \
+  do {                                                                         \
+    crc##s = ReadUint32LE(p + s * 4) ^ kStrideExtensionTable3[crc##s & 0xff] ^ \
+             kStrideExtensionTable2[(crc##s >> 8) & 0xff] ^                    \
+             kStrideExtensionTable1[(crc##s >> 16) & 0xff] ^                   \
+             kStrideExtensionTable0[crc##s >> 24];                             \
+  } while (0)
 
-  // Point x at first 4-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*>(((pval + 3) >> 2) << 2);
+// Process a 16-byte swath of 4 strides, each of which has 4 bytes of data.
+#define STEP16 \
+  do {         \
+    STEP4(0);  \
+    STEP4(1);  \
+    STEP4(2);  \
+    STEP4(3);  \
+    p += 16;   \
+  } while (0)
+
+// Process 4 bytes that were already loaded into a word.
+#define STEP4W(w)                                   \
+  do {                                              \
+    w ^= l;                                         \
+    for (size_t i = 0; i < 4; ++i) {                \
+      w = (w >> 8) ^ kByteExtensionTable[w & 0xff]; \
+    }                                               \
+    l = w;                                          \
+  } while (0)
+
+  // Point x at first 4-byte aligned byte in the buffer. This might be past the
+  // end of the buffer.
+  const uint8_t* x = RoundUp<4>(p);
   if (x <= e) {
-    // Process bytes until finished or p is 4-byte aligned
+    // Process bytes p is 4-byte aligned.
     while (p != x) {
       STEP1;
     }
   }
-  // Process bytes 16 at a time
-  while ((e-p) >= 16) {
-    STEP4; STEP4; STEP4; STEP4;
-  }
-  // Process bytes 4 at a time
-  while ((e-p) >= 4) {
-    STEP4;
+
+  if ((e - p) >= 16) {
+    // Load a 16-byte swath into the stride partial results.
+    uint32_t crc0 = ReadUint32LE(p + 0 * 4) ^ l;
+    uint32_t crc1 = ReadUint32LE(p + 1 * 4);
+    uint32_t crc2 = ReadUint32LE(p + 2 * 4);
+    uint32_t crc3 = ReadUint32LE(p + 3 * 4);
+    p += 16;
+
+    // It is possible to get better speeds (at least on x86) by interleaving
+    // prefetching 256 bytes ahead with processing 64 bytes at a time. See the
+    // portable implementation in https://github.com/google/crc32c/.
+
+    // Process one 16-byte swath at a time.
+    while ((e - p) >= 16) {
+      STEP16;
+    }
+
+    // Advance one word at a time as far as possible.
+    while ((e - p) >= 4) {
+      STEP4(0);
+      uint32_t tmp = crc0;
+      crc0 = crc1;
+      crc1 = crc2;
+      crc2 = crc3;
+      crc3 = tmp;
+      p += 4;
+    }
+
+    // Combine the 4 partial stride results.
+    l = 0;
+    STEP4W(crc0);
+    STEP4W(crc1);
+    STEP4W(crc2);
+    STEP4W(crc3);
   }
-  // Process the last few bytes
+
+  // Process the last few bytes.
   while (p != e) {
     STEP1;
   }
+#undef STEP4W
+#undef STEP16
 #undef STEP4
 #undef STEP1
-  return l ^ 0xffffffffu;
+  return l ^ kCRC32Xor;
 }
 
 }  // namespace crc32c