1 files changed, 124 insertions, 0 deletions
diff --git a/third_party/crc32c/src/src/crc32c_arm64.cc b/third_party/crc32c/src/src/crc32c_arm64.cc
new file mode 100644
index 0000000000..9a988c1eed
--- /dev/null
+++ b/third_party/crc32c/src/src/crc32c_arm64.cc
@@ -0,0 +1,124 @@
+// Copyright 2017 The CRC32C 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.
+
+#include "./crc32c_arm64.h"
+
+// In a separate source file to allow this accelerated CRC32C function to be
+// compiled with the appropriate compiler flags to enable ARM NEON CRC32C
+// instructions.
+
+// This implementation is based on https://github.com/google/leveldb/pull/490.
+
+#include <cstddef>
+#include <cstdint>
+
+#include "./crc32c_internal.h"
+#include "crc32c/crc32c_config.h"
+
+#if HAVE_ARM64_CRC32C
+
+#include <arm_acle.h>
+#include <arm_neon.h>
+
+#define KBYTES 1032
+#define SEGMENTBYTES 256
+
+// compute 8bytes for each segment parallelly
+#define CRC32C32BYTES(P, IND)                                             \
+  do {                                                                    \
+    crc1 = __crc32cd(                                                     \
+        crc1, *((const uint64_t *)(P) + (SEGMENTBYTES / 8) * 1 + (IND))); \
+    crc2 = __crc32cd(                                                     \
+        crc2, *((const uint64_t *)(P) + (SEGMENTBYTES / 8) * 2 + (IND))); \
+    crc3 = __crc32cd(                                                     \
+        crc3, *((const uint64_t *)(P) + (SEGMENTBYTES / 8) * 3 + (IND))); \
+    crc0 = __crc32cd(                                                     \
+        crc0, *((const uint64_t *)(P) + (SEGMENTBYTES / 8) * 0 + (IND))); \
+  } while (0);
+
+// compute 8*8 bytes for each segment parallelly
+#define CRC32C256BYTES(P, IND)      \
+  do {                              \
+    CRC32C32BYTES((P), (IND)*8 + 0) \
+    CRC32C32BYTES((P), (IND)*8 + 1) \
+    CRC32C32BYTES((P), (IND)*8 + 2) \
+    CRC32C32BYTES((P), (IND)*8 + 3) \
+    CRC32C32BYTES((P), (IND)*8 + 4) \
+    CRC32C32BYTES((P), (IND)*8 + 5) \
+    CRC32C32BYTES((P), (IND)*8 + 6) \
+    CRC32C32BYTES((P), (IND)*8 + 7) \
+  } while (0);
+
+// compute 4*8*8 bytes for each segment parallelly
+#define CRC32C1024BYTES(P)   \
+  do {                       \
+    CRC32C256BYTES((P), 0)   \
+    CRC32C256BYTES((P), 1)   \
+    CRC32C256BYTES((P), 2)   \
+    CRC32C256BYTES((P), 3)   \
+    (P) += 4 * SEGMENTBYTES; \
+  } while (0)
+
+namespace crc32c {
+
+uint32_t ExtendArm64(uint32_t crc, const uint8_t *buf, size_t size) {
+  int64_t length = size;
+  uint32_t crc0, crc1, crc2, crc3;
+  uint64_t t0, t1, t2;
+
+  // k0=CRC(x^(3*SEGMENTBYTES*8)), k1=CRC(x^(2*SEGMENTBYTES*8)),
+  // k2=CRC(x^(SEGMENTBYTES*8))
+  const poly64_t k0 = 0x8d96551c, k1 = 0xbd6f81f8, k2 = 0xdcb17aa4;
+
+  crc = crc ^ kCRC32Xor;
+  const uint8_t *p = reinterpret_cast<const uint8_t *>(buf);
+
+  while (length >= KBYTES) {
+    crc0 = crc;
+    crc1 = 0;
+    crc2 = 0;
+    crc3 = 0;
+
+    // Process 1024 bytes in parallel.
+    CRC32C1024BYTES(p);
+
+    // Merge the 4 partial CRC32C values.
+    t2 = (uint64_t)vmull_p64(crc2, k2);
+    t1 = (uint64_t)vmull_p64(crc1, k1);
+    t0 = (uint64_t)vmull_p64(crc0, k0);
+    crc = __crc32cd(crc3, *(uint64_t *)p);
+    p += sizeof(uint64_t);
+    crc ^= __crc32cd(0, t2);
+    crc ^= __crc32cd(0, t1);
+    crc ^= __crc32cd(0, t0);
+
+    length -= KBYTES;
+  }
+
+  while (length >= 8) {
+    crc = __crc32cd(crc, *(uint64_t *)p);
+    p += 8;
+    length -= 8;
+  }
+
+  if (length & 4) {
+    crc = __crc32cw(crc, *(uint32_t *)p);
+    p += 4;
+  }
+
+  if (length & 2) {
+    crc = __crc32ch(crc, *(uint16_t *)p);
+    p += 2;
+  }
+
+  if (length & 1) {
+    crc = __crc32cb(crc, *p);
+  }
+
+  return crc ^ kCRC32Xor;
+}
+
+}  // namespace crc32c
+
+#endif  // HAVE_ARM64_CRC32C