update Snappy 1.1.10

README.md

@@ -109,7 +109,7 @@ see the [CompFuzz Results](https://github.com/nemequ/compfuzz/wiki/Results) page
  - [quicklz 1.5.0](http://www.quicklz.com)
  - [shrinker 0.1](https://code.google.com/p/data-shrinker) - WARNING: it can throw SEGFAULT compiled with gcc 4.9+ -O3
  - [slz 1.2.0](http://www.libslz.org/) - only a compressor, uses zlib for decompression
- - [snappy 2020-07-11 (4dd277f)](https://github.com/google/snappy)
+ - [snappy 1.1.10](https://github.com/google/snappy)
  - [tornado 0.6a](http://freearc.org)
  - [ucl 1.03](http://www.oberhumer.com/opensource/ucl/)
  - [wflz 2015-09-16](https://github.com/ShaneWF/wflz) - WARNING: it can throw SEGFAULT compiled with gcc 4.9+ -O3

_lzbench/lzbench.h

@@ -190,7 +190,7 @@ static const compressor_desc_t comp_desc[LZBENCH_COMPRESSOR_COUNT] =
     { "slz_deflate","1.2.0",       1,   3,    2,       0, lzbench_slz_compress,        lzbench_slz_decompress,        NULL,                    NULL },
     { "slz_gzip",   "1.2.0",       1,   3,    1,       0, lzbench_slz_compress,        lzbench_slz_decompress,        NULL,                    NULL },
     { "slz_zlib",   "1.2.0",       1,   3,    0,       0, lzbench_slz_compress,        lzbench_slz_decompress,        NULL,                    NULL },
-    { "snappy",     "2020-07-11",  0,   0,    0,       0, lzbench_snappy_compress,     lzbench_snappy_decompress,     NULL,                    NULL },
+    { "snappy",     "1.1.10",  0,   0,    0,       0, lzbench_snappy_compress,     lzbench_snappy_decompress,     NULL,                    NULL },
     { "tornado",    "0.6a",        1,  16,    0,       0, lzbench_tornado_compress,    lzbench_tornado_decompress,    NULL,                    NULL },
     { "ucl_nrv2b",  "1.03",        1,   9,    0,       0, lzbench_ucl_nrv2b_compress,  lzbench_ucl_nrv2b_decompress,  NULL,                    NULL },
     { "ucl_nrv2d",  "1.03",        1,   9,    0,       0, lzbench_ucl_nrv2d_compress,  lzbench_ucl_nrv2d_decompress,  NULL,                    NULL },

snappy/snappy-internal.h

@@ -33,9 +33,84 @@
 
 #include "snappy-stubs-internal.h"
 
+#if SNAPPY_HAVE_SSSE3
+// Please do not replace with <x86intrin.h> or with headers that assume more
+// advanced SSE versions without checking with all the OWNERS.
+#include <emmintrin.h>
+#include <tmmintrin.h>
+#endif
+
+#if SNAPPY_HAVE_NEON
+#include <arm_neon.h>
+#endif
+
+#if SNAPPY_HAVE_SSSE3 || SNAPPY_HAVE_NEON
+#define SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE 1
+#else
+#define SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE 0
+#endif
+
 namespace snappy {
 namespace internal {
 
+#if SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE
+#if SNAPPY_HAVE_SSSE3
+using V128 = __m128i;
+#elif SNAPPY_HAVE_NEON
+using V128 = uint8x16_t;
+#endif
+
+// Load 128 bits of integer data. `src` must be 16-byte aligned.
+inline V128 V128_Load(const V128* src);
+
+// Load 128 bits of integer data. `src` does not need to be aligned.
+inline V128 V128_LoadU(const V128* src);
+
+// Store 128 bits of integer data. `dst` does not need to be aligned.
+inline void V128_StoreU(V128* dst, V128 val);
+
+// Shuffle packed 8-bit integers using a shuffle mask.
+// Each packed integer in the shuffle mask must be in [0,16).
+inline V128 V128_Shuffle(V128 input, V128 shuffle_mask);
+
+// Constructs V128 with 16 chars |c|.
+inline V128 V128_DupChar(char c);
+
+#if SNAPPY_HAVE_SSSE3
+inline V128 V128_Load(const V128* src) { return _mm_load_si128(src); }
+
+inline V128 V128_LoadU(const V128* src) { return _mm_loadu_si128(src); }
+
+inline void V128_StoreU(V128* dst, V128 val) { _mm_storeu_si128(dst, val); }
+
+inline V128 V128_Shuffle(V128 input, V128 shuffle_mask) {
+  return _mm_shuffle_epi8(input, shuffle_mask);
+}
+
+inline V128 V128_DupChar(char c) { return _mm_set1_epi8(c); }
+
+#elif SNAPPY_HAVE_NEON
+inline V128 V128_Load(const V128* src) {
+  return vld1q_u8(reinterpret_cast<const uint8_t*>(src));
+}
+
+inline V128 V128_LoadU(const V128* src) {
+  return vld1q_u8(reinterpret_cast<const uint8_t*>(src));
+}
+
+inline void V128_StoreU(V128* dst, V128 val) {
+  vst1q_u8(reinterpret_cast<uint8_t*>(dst), val);
+}
+
+inline V128 V128_Shuffle(V128 input, V128 shuffle_mask) {
+  assert(vminvq_u8(shuffle_mask) >= 0 && vmaxvq_u8(shuffle_mask) <= 15);
+  return vqtbl1q_u8(input, shuffle_mask);
+}
+
+inline V128 V128_DupChar(char c) { return vdupq_n_u8(c); }
+#endif
+#endif  // SNAPPY_HAVE_VECTOR_BYTE_SHUFFLE
+
 // Working memory performs a single allocation to hold all scratch space
 // required for compression.
 class WorkingMemory {
@@ -95,8 +170,9 @@ char* CompressFragment(const char* input,
 // loading from s2 + n.
 //
 // Separate implementation for 64-bit, little-endian cpus.
-#if !defined(SNAPPY_IS_BIG_ENDIAN) && \
-    (defined(ARCH_K8) || defined(ARCH_PPC) || defined(ARCH_ARM))
+#if !SNAPPY_IS_BIG_ENDIAN && \
+    (defined(__x86_64__) || defined(_M_X64) || defined(ARCH_PPC) || \
+     defined(ARCH_ARM))
 static inline std::pair<size_t, bool> FindMatchLength(const char* s1,
                                                       const char* s2,
                                                       const char* s2_limit,
@@ -154,8 +230,9 @@ static inline std::pair<size_t, bool> FindMatchLength(const char* s1,
       uint64_t xorval = a1 ^ a2;
       int shift = Bits::FindLSBSetNonZero64(xorval);
       size_t matched_bytes = shift >> 3;
+      uint64_t a3 = UNALIGNED_LOAD64(s2 + 4);
 #ifndef __x86_64__
-      *data = UNALIGNED_LOAD64(s2 + matched_bytes);
+      a2 = static_cast<uint32_t>(xorval) == 0 ? a3 : a2;
 #else
       // Ideally this would just be
       //
@@ -166,13 +243,13 @@ static inline std::pair<size_t, bool> FindMatchLength(const char* s1,
       // use a conditional move (it's tuned to cut data dependencies). In this
       // case there is a longer parallel chain anyway AND this will be fairly
       // unpredictable.
-      uint64_t a3 = UNALIGNED_LOAD64(s2 + 4);
       asm("testl %k2, %k2\n\t"
           "cmovzq %1, %0\n\t"
           : "+r"(a2)
-          : "r"(a3), "r"(xorval));
-      *data = a2 >> (shift & (3 * 8));
+          : "r"(a3), "r"(xorval)
+          : "cc");
 #endif
+      *data = a2 >> (shift & (3 * 8));
       return std::pair<size_t, bool>(matched_bytes, true);
     } else {
       matched = 8;
@@ -194,16 +271,17 @@ static inline std::pair<size_t, bool> FindMatchLength(const char* s1,
       uint64_t xorval = a1 ^ a2;
       int shift = Bits::FindLSBSetNonZero64(xorval);
       size_t matched_bytes = shift >> 3;
+      uint64_t a3 = UNALIGNED_LOAD64(s2 + 4);
 #ifndef __x86_64__
-      *data = UNALIGNED_LOAD64(s2 + matched_bytes);
+      a2 = static_cast<uint32_t>(xorval) == 0 ? a3 : a2;
 #else
-      uint64_t a3 = UNALIGNED_LOAD64(s2 + 4);
       asm("testl %k2, %k2\n\t"
           "cmovzq %1, %0\n\t"
           : "+r"(a2)
-          : "r"(a3), "r"(xorval));
-      *data = a2 >> (shift & (3 * 8));
+          : "r"(a3), "r"(xorval)
+          : "cc");
 #endif
+      *data = a2 >> (shift & (3 * 8));
       matched += matched_bytes;
       assert(matched >= 8);
       return std::pair<size_t, bool>(matched, false);
@@ -274,7 +352,8 @@ static const int kMaximumTagLength = 5;  // COPY_4_BYTE_OFFSET plus the actual o
 // because of efficiency reasons:
 //      (1) Extracting a byte is faster than a bit-field
 //      (2) It properly aligns copy offset so we do not need a <<8
-static const uint16_t char_table[256] = {
+static constexpr uint16_t char_table[256] = {
+    // clang-format off
   0x0001, 0x0804, 0x1001, 0x2001, 0x0002, 0x0805, 0x1002, 0x2002,
   0x0003, 0x0806, 0x1003, 0x2003, 0x0004, 0x0807, 0x1004, 0x2004,
   0x0005, 0x0808, 0x1005, 0x2005, 0x0006, 0x0809, 0x1006, 0x2006,
@@ -306,7 +385,8 @@ static const uint16_t char_table[256] = {
   0x0039, 0x0f04, 0x1039, 0x2039, 0x003a, 0x0f05, 0x103a, 0x203a,
   0x003b, 0x0f06, 0x103b, 0x203b, 0x003c, 0x0f07, 0x103c, 0x203c,
   0x0801, 0x0f08, 0x103d, 0x203d, 0x1001, 0x0f09, 0x103e, 0x203e,
-  0x1801, 0x0f0a, 0x103f, 0x203f, 0x2001, 0x0f0b, 0x1040, 0x2040
+  0x1801, 0x0f0a, 0x103f, 0x203f, 0x2001, 0x0f0b, 0x1040, 0x2040,
+    // clang-format on
 };
 
 }  // end namespace internal

snappy/snappy-sinksource.h

@@ -146,10 +146,10 @@ class Source {
 class ByteArraySource : public Source {
  public:
   ByteArraySource(const char* p, size_t n) : ptr_(p), left_(n) { }
-  virtual ~ByteArraySource();
-  virtual size_t Available() const;
-  virtual const char* Peek(size_t* len);
-  virtual void Skip(size_t n);
+  ~ByteArraySource() override;
+  size_t Available() const override;
+  const char* Peek(size_t* len) override;
+  void Skip(size_t n) override;
  private:
   const char* ptr_;
   size_t left_;
@@ -159,15 +159,15 @@ class ByteArraySource : public Source {
 class UncheckedByteArraySink : public Sink {
  public:
   explicit UncheckedByteArraySink(char* dest) : dest_(dest) { }
-  virtual ~UncheckedByteArraySink();
-  virtual void Append(const char* data, size_t n);
-  virtual char* GetAppendBuffer(size_t len, char* scratch);
-  virtual char* GetAppendBufferVariable(
+  ~UncheckedByteArraySink() override;
+  void Append(const char* data, size_t n) override;
+  char* GetAppendBuffer(size_t len, char* scratch) override;
+  char* GetAppendBufferVariable(
       size_t min_size, size_t desired_size_hint, char* scratch,
-      size_t scratch_size, size_t* allocated_size);
-  virtual void AppendAndTakeOwnership(
+      size_t scratch_size, size_t* allocated_size) override;
+  void AppendAndTakeOwnership(
       char* bytes, size_t n, void (*deleter)(void*, const char*, size_t),
-      void *deleter_arg);
+      void *deleter_arg) override;
 
   // Return the current output pointer so that a caller can see how
   // many bytes were produced.