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authorAbseil Team <absl-team@google.com>2017-09-27T17·50-0700
committerDerek Mauro <dmauro@google.com>2017-09-27T20·03-0400
commitcdf20caa491f59c0a35a8d8fbec0d948e4bc7e4c (patch)
tree1d3dc27123440a6745c85bc6ae8265da0891a56b /absl/strings/internal/fastmem_test.cc
parent7a64d73e1ef61b15971f8cc90876a5128729b0d4 (diff)
Changes imported from Abseil "staging" branch:
  - 43853019b439efb32c79d5d50e24508588e1bbe0 Undo the not applying qualifications to absl types in enc... by Derek Mauro <dmauro@google.com>
  - 06d62a10621c9864279ee57097069cfe3cb7b42a fix capitalization by Abseil Team <absl-team@google.com>
  - 22adbfee340bb452ba38b68975ade6f072859c4a Fix indices in str_split.h comments. by Derek Mauro <dmauro@google.com>
  - ae5143a559ad8633a78cd76620e30a781006d088 Fix the inconsistent licenses directives in the BUILD fil... by Derek Mauro <dmauro@google.com>
  - 0a76a3653b2ecfdad433d3e2f5b651c4ecdcf74b Remove strip.cc, fastmem.h, and fastmem_test.cc from the ... by Derek Mauro <dmauro@google.com>
  - 77908cfce5927aabca1f8d62481106f22cfc1936 Internal change. by Derek Mauro <dmauro@google.com>
  - d3277b4171f37e22ab346becb5e295c36c7a0219 Be consistent in (not) applying qualifications for enclos... by Abseil Team <absl-team@google.com>
  - 9ec7f8164e7d6a5f64288a7360a346628393cc50 Add std:: qualification to isnan and isinf in duration_te... by Derek Mauro <dmauro@google.com>
  - 9f7c87d7764ddba05286fabca1f4f15285f3250a Fix typos in string_view comments. by Abseil Team <absl-team@google.com>
  - 281860804f8053143d969b99876e3dbc6deb1236 Fix typo in container.h docs. by Abseil Team <absl-team@google.com>
  - 0b0a9388c7a9d7f72349d44b5b46132f45bde56c Add bazel-* symlinks to gitignore. by Michael Pratt <mpratt@google.com>

GitOrigin-RevId: 43853019b439efb32c79d5d50e24508588e1bbe0
Change-Id: I9e74a5430816a34ecf1acb86486ed3b0bd12a1d6
Diffstat (limited to 'absl/strings/internal/fastmem_test.cc')
-rw-r--r--absl/strings/internal/fastmem_test.cc453
1 files changed, 0 insertions, 453 deletions
diff --git a/absl/strings/internal/fastmem_test.cc b/absl/strings/internal/fastmem_test.cc
deleted file mode 100644
index 7c670f967bb3..000000000000
--- a/absl/strings/internal/fastmem_test.cc
+++ /dev/null
@@ -1,453 +0,0 @@
-// Copyright 2017 The Abseil Authors.
-//
-// 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 "absl/strings/internal/fastmem.h"
-
-#include <memory>
-#include <random>
-#include <string>
-
-#include "base/init_google.h"
-#include "base/logging.h"
-#include "testing/base/public/benchmark.h"
-#include "gtest/gtest.h"
-
-namespace {
-
-using RandomEngine = std::minstd_rand0;
-
-void VerifyResults(const int r1, const int r2, const std::string& a,
-                   const std::string& b) {
-  CHECK_EQ(a.size(), b.size());
-  if (r1 == 0) {
-    EXPECT_EQ(r2, 0) << a << " " << b;
-  } else if (r1 > 0) {
-    EXPECT_GT(r2, 0) << a << " " << b;
-  } else {
-    EXPECT_LT(r2, 0) << a << " " << b;
-  }
-  if ((r1 == 0) == (r2 == 0)) {
-    EXPECT_EQ(r1 == 0,
-              absl::strings_internal::memeq(a.data(), b.data(), a.size()))
-        << r1 << " " << a << " " << b;
-  }
-}
-
-// Check correctness against glibc's memcmp implementation
-void CheckSingle(const std::string& a, const std::string& b) {
-  CHECK_EQ(a.size(), b.size());
-  const int r1 = memcmp(a.data(), b.data(), a.size());
-  const int r2 =
-      absl::strings_internal::fastmemcmp_inlined(a.data(), b.data(), a.size());
-  VerifyResults(r1, r2, a, b);
-}
-
-void GenerateString(size_t len, std::string* s) {
-  s->clear();
-  for (int i = 0; i < len; i++) {
-    *s += ('a' + (i % 26));
-  }
-}
-
-void CheckCompare(const std::string& a, const std::string& b) {
-  CheckSingle(a, b);
-  for (int common = 0; common <= 32; common++) {
-    std::string extra;
-    GenerateString(common, &extra);
-    CheckSingle(extra + a, extra + b);
-    CheckSingle(a + extra, b + extra);
-    for (char c1 = 'a'; c1 <= 'c'; c1++) {
-      for (char c2 = 'a'; c2 <= 'c'; c2++) {
-        CheckSingle(extra + c1 + a, extra + c2 + b);
-      }
-    }
-  }
-}
-
-TEST(FastCompare, Misc) {
-  CheckCompare("", "");
-
-  CheckCompare("a", "a");
-  CheckCompare("ab", "ab");
-  CheckCompare("abc", "abc");
-  CheckCompare("abcd", "abcd");
-  CheckCompare("abcde", "abcde");
-
-  CheckCompare("a", "x");
-  CheckCompare("ab", "xb");
-  CheckCompare("abc", "xbc");
-  CheckCompare("abcd", "xbcd");
-  CheckCompare("abcde", "xbcde");
-
-  CheckCompare("x", "a");
-  CheckCompare("xb", "ab");
-  CheckCompare("xbc", "abc");
-  CheckCompare("xbcd", "abcd");
-  CheckCompare("xbcde", "abcde");
-
-  CheckCompare("a", "x");
-  CheckCompare("ab", "ax");
-  CheckCompare("abc", "abx");
-  CheckCompare("abcd", "abcx");
-  CheckCompare("abcde", "abcdx");
-
-  CheckCompare("x", "a");
-  CheckCompare("ax", "ab");
-  CheckCompare("abx", "abc");
-  CheckCompare("abcx", "abcd");
-  CheckCompare("abcdx", "abcde");
-
-  for (int len = 0; len < 1000; len++) {
-    std::string p(len, 'z');
-    CheckCompare(p + "x", p + "a");
-    CheckCompare(p + "ax", p + "ab");
-    CheckCompare(p + "abx", p + "abc");
-    CheckCompare(p + "abcx", p + "abcd");
-    CheckCompare(p + "abcdx", p + "abcde");
-  }
-}
-
-TEST(FastCompare, TrailingByte) {
-  for (int i = 0; i < 256; i++) {
-    for (int j = 0; j < 256; j++) {
-      std::string a(1, i);
-      std::string b(1, j);
-      CheckSingle(a, b);
-    }
-  }
-}
-
-// Check correctness of memcpy_inlined.
-void CheckSingleMemcpyInlined(const std::string& a) {
-  std::unique_ptr<char[]> destination(new char[a.size() + 2]);
-  destination[0] = 'x';
-  destination[a.size() + 1] = 'x';
-  absl::strings_internal::memcpy_inlined(destination.get() + 1, a.data(),
-                                         a.size());
-  CHECK_EQ('x', destination[0]);
-  CHECK_EQ('x', destination[a.size() + 1]);
-  CHECK_EQ(0, memcmp(a.data(), destination.get() + 1, a.size()));
-}
-
-TEST(MemCpyInlined, Misc) {
-  CheckSingleMemcpyInlined("");
-  CheckSingleMemcpyInlined("0");
-  CheckSingleMemcpyInlined("012");
-  CheckSingleMemcpyInlined("0123");
-  CheckSingleMemcpyInlined("01234");
-  CheckSingleMemcpyInlined("012345");
-  CheckSingleMemcpyInlined("0123456");
-  CheckSingleMemcpyInlined("01234567");
-  CheckSingleMemcpyInlined("012345678");
-  CheckSingleMemcpyInlined("0123456789");
-  CheckSingleMemcpyInlined("0123456789a");
-  CheckSingleMemcpyInlined("0123456789ab");
-  CheckSingleMemcpyInlined("0123456789abc");
-  CheckSingleMemcpyInlined("0123456789abcd");
-  CheckSingleMemcpyInlined("0123456789abcde");
-  CheckSingleMemcpyInlined("0123456789abcdef");
-  CheckSingleMemcpyInlined("0123456789abcdefg");
-}
-
-template <typename Function>
-inline void CopyLoop(benchmark::State& state, int size, Function func) {
-  char* src = new char[size];
-  char* dst = new char[size];
-  memset(src, 'x', size);
-  memset(dst, 'y', size);
-  for (auto _ : state) {
-    func(dst, src, size);
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * size);
-  CHECK_EQ(dst[0], 'x');
-  delete[] src;
-  delete[] dst;
-}
-
-void BM_memcpy(benchmark::State& state) {
-  CopyLoop(state, state.range(0), memcpy);
-}
-BENCHMARK(BM_memcpy)->DenseRange(1, 18)->Range(32, 8 << 20);
-
-void BM_memcpy_inlined(benchmark::State& state) {
-  CopyLoop(state, state.range(0), absl::strings_internal::memcpy_inlined);
-}
-BENCHMARK(BM_memcpy_inlined)->DenseRange(1, 18)->Range(32, 8 << 20);
-
-// unaligned memcpy
-void BM_unaligned_memcpy(benchmark::State& state) {
-  const int n = state.range(0);
-  const int kMaxOffset = 32;
-  char* src = new char[n + kMaxOffset];
-  char* dst = new char[n + kMaxOffset];
-  memset(src, 'x', n + kMaxOffset);
-  int r = 0, i = 0;
-  for (auto _ : state) {
-    memcpy(dst + (i % kMaxOffset), src + ((i + 5) % kMaxOffset), n);
-    r += dst[0];
-    ++i;
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * n);
-  delete[] src;
-  delete[] dst;
-  benchmark::DoNotOptimize(r);
-}
-BENCHMARK(BM_unaligned_memcpy)->DenseRange(1, 18)->Range(32, 8 << 20);
-
-// memmove worst case: heavy overlap, but not always by the same amount.
-// Also, the source and destination will often be unaligned.
-void BM_memmove_worst_case(benchmark::State& state) {
-  const int n = state.range(0);
-  const int32_t kDeterministicSeed = 301;
-  const int kMaxOffset = 32;
-  char* src = new char[n + kMaxOffset];
-  memset(src, 'x', n + kMaxOffset);
-  size_t offsets[64];
-  RandomEngine rng(kDeterministicSeed);
-  std::uniform_int_distribution<size_t> random_to_max_offset(0, kMaxOffset);
-  for (size_t& offset : offsets) {
-    offset = random_to_max_offset(rng);
-  }
-  int r = 0, i = 0;
-  for (auto _ : state) {
-    memmove(src + offsets[i], src + offsets[i + 1], n);
-    r += src[0];
-    i = (i + 2) % arraysize(offsets);
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * n);
-  delete[] src;
-  benchmark::DoNotOptimize(r);
-}
-BENCHMARK(BM_memmove_worst_case)->DenseRange(1, 18)->Range(32, 8 << 20);
-
-// memmove cache-friendly: aligned and overlapping with 4k
-// between the source and destination addresses.
-void BM_memmove_cache_friendly(benchmark::State& state) {
-  const int n = state.range(0);
-  char* src = new char[n + 4096];
-  memset(src, 'x', n);
-  int r = 0;
-  while (state.KeepRunningBatch(2)) {  // count each memmove as an iteration
-    memmove(src + 4096, src, n);
-    memmove(src, src + 4096, n);
-    r += src[0];
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * n);
-  delete[] src;
-  benchmark::DoNotOptimize(r);
-}
-BENCHMARK(BM_memmove_cache_friendly)
-    ->Arg(5 * 1024)
-    ->Arg(10 * 1024)
-    ->Range(16 << 10, 8 << 20);
-
-// memmove best(?) case: aligned and non-overlapping.
-void BM_memmove_aligned_non_overlapping(benchmark::State& state) {
-  CopyLoop(state, state.range(0), memmove);
-}
-BENCHMARK(BM_memmove_aligned_non_overlapping)
-    ->DenseRange(1, 18)
-    ->Range(32, 8 << 20);
-
-// memset speed
-void BM_memset(benchmark::State& state) {
-  const int n = state.range(0);
-  char* dst = new char[n];
-  int r = 0;
-  for (auto _ : state) {
-    memset(dst, 'x', n);
-    r += dst[0];
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * n);
-  delete[] dst;
-  benchmark::DoNotOptimize(r);
-}
-BENCHMARK(BM_memset)->Range(8, 4096 << 10);
-
-// Bandwidth (vectorization?) test: the ideal generated code will be limited
-// by memory bandwidth.  Even so-so generated code will max out memory bandwidth
-// on some machines.
-void BM_membandwidth(benchmark::State& state) {
-  const int n = state.range(0);
-  CHECK_EQ(n % 32, 0);  // We will read 32 bytes per iter.
-  char* dst = new char[n];
-  int r = 0;
-  for (auto _ : state) {
-    const uint32_t* p = reinterpret_cast<uint32_t*>(dst);
-    const uint32_t* limit = reinterpret_cast<uint32_t*>(dst + n);
-    uint32_t x = 0;
-    while (p < limit) {
-      x += p[0];
-      x += p[1];
-      x += p[2];
-      x += p[3];
-      x += p[4];
-      x += p[5];
-      x += p[6];
-      x += p[7];
-      p += 8;
-    }
-    r += x;
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * n);
-  delete[] dst;
-  benchmark::DoNotOptimize(r);
-}
-BENCHMARK(BM_membandwidth)->Range(32, 16384 << 10);
-
-// Helper for benchmarks.  Repeatedly compares two strings that are
-// either equal or different only in one character.  If test_equal_strings
-// is false then position_to_modify determines where the difference will be.
-template <typename Function>
-ABSL_ATTRIBUTE_ALWAYS_INLINE inline void StringCompareLoop(
-    benchmark::State& state, bool test_equal_strings,
-    std::string::size_type position_to_modify, int size, Function func) {
-  const int kIterMult = 4;  // Iteration multiplier for better timing resolution
-  CHECK_GT(size, 0);
-  const bool position_to_modify_is_valid =
-      position_to_modify != std::string::npos && position_to_modify < size;
-  CHECK_NE(position_to_modify_is_valid, test_equal_strings);
-  if (!position_to_modify_is_valid) {
-    position_to_modify = 0;
-  }
-  std::string sa(size, 'a');
-  std::string sb = sa;
-  char last = sa[size - 1];
-  int num = 0;
-  for (auto _ : state) {
-    for (int i = 0; i < kIterMult; ++i) {
-      sb[position_to_modify] = test_equal_strings ? last : last ^ 1;
-      num += func(sa, sb);
-    }
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * size);
-  benchmark::DoNotOptimize(num);
-}
-
-// Helper for benchmarks.  Repeatedly compares two memory regions that are
-// either equal or different only in their final character.
-template <typename Function>
-ABSL_ATTRIBUTE_ALWAYS_INLINE inline void CompareLoop(benchmark::State& state,
-                                                     bool test_equal_strings,
-                                                     int size, Function func) {
-  const int kIterMult = 4;  // Iteration multiplier for better timing resolution
-  CHECK_GT(size, 0);
-  char* data = static_cast<char*>(malloc(size * 2));
-  memset(data, 'a', size * 2);
-  char* a = data;
-  char* b = data + size;
-  char last = a[size - 1];
-  int num = 0;
-  for (auto _ : state) {
-    for (int i = 0; i < kIterMult; ++i) {
-      b[size - 1] = test_equal_strings ? last : last ^ 1;
-      num += func(a, b, size);
-    }
-  }
-  state.SetBytesProcessed(static_cast<int64_t>(state.iterations()) * size);
-  benchmark::DoNotOptimize(num);
-  free(data);
-}
-
-void BM_memcmp(benchmark::State& state) {
-  CompareLoop(state, false, state.range(0), memcmp);
-}
-BENCHMARK(BM_memcmp)->DenseRange(1, 9)->Range(32, 8 << 20);
-
-void BM_fastmemcmp_inlined(benchmark::State& state) {
-  CompareLoop(state, false, state.range(0),
-              absl::strings_internal::fastmemcmp_inlined);
-}
-BENCHMARK(BM_fastmemcmp_inlined)->DenseRange(1, 9)->Range(32, 8 << 20);
-
-void BM_memeq(benchmark::State& state) {
-  CompareLoop(state, false, state.range(0), absl::strings_internal::memeq);
-}
-BENCHMARK(BM_memeq)->DenseRange(1, 9)->Range(32, 8 << 20);
-
-void BM_memeq_equal(benchmark::State& state) {
-  CompareLoop(state, true, state.range(0), absl::strings_internal::memeq);
-}
-BENCHMARK(BM_memeq_equal)->DenseRange(1, 9)->Range(32, 8 << 20);
-
-bool StringLess(const std::string& x, const std::string& y) { return x < y; }
-bool StringEqual(const std::string& x, const std::string& y) { return x == y; }
-bool StdEqual(const std::string& x, const std::string& y) {
-  return x.size() == y.size() &&
-         std::equal(x.data(), x.data() + x.size(), y.data());
-}
-
-// Benchmark for x < y, where x and y are strings that differ in only their
-// final char.  That should be more-or-less the worst case for <.
-void BM_string_less(benchmark::State& state) {
-  StringCompareLoop(state, false, state.range(0) - 1, state.range(0),
-                    StringLess);
-}
-BENCHMARK(BM_string_less)->DenseRange(1, 9)->Range(32, 1 << 20);
-
-// Benchmark for x < y, where x and y are strings that differ in only their
-// first char.  That should be more-or-less the best case for <.
-void BM_string_less_easy(benchmark::State& state) {
-  StringCompareLoop(state, false, 0, state.range(0), StringLess);
-}
-BENCHMARK(BM_string_less_easy)->DenseRange(1, 9)->Range(32, 1 << 20);
-
-void BM_string_equal(benchmark::State& state) {
-  StringCompareLoop(state, false, state.range(0) - 1, state.range(0),
-                    StringEqual);
-}
-BENCHMARK(BM_string_equal)->DenseRange(1, 9)->Range(32, 1 << 20);
-
-void BM_string_equal_equal(benchmark::State& state) {
-  StringCompareLoop(state, true, std::string::npos, state.range(0), StringEqual);
-}
-BENCHMARK(BM_string_equal_equal)->DenseRange(1, 9)->Range(32, 1 << 20);
-
-void BM_std_equal(benchmark::State& state) {
-  StringCompareLoop(state, false, state.range(0) - 1, state.range(0), StdEqual);
-}
-BENCHMARK(BM_std_equal)->DenseRange(1, 9)->Range(32, 1 << 20);
-
-void BM_std_equal_equal(benchmark::State& state) {
-  StringCompareLoop(state, true, std::string::npos, state.range(0), StdEqual);
-}
-BENCHMARK(BM_std_equal_equal)->DenseRange(1, 9)->Range(32, 1 << 20);
-
-void BM_string_equal_unequal_lengths(benchmark::State& state) {
-  const int size = state.range(0);
-  std::string a(size, 'a');
-  std::string b(size + 1, 'a');
-  int count = 0;
-  for (auto _ : state) {
-    b[size - 1] = 'a';
-    count += (a == b);
-  }
-  benchmark::DoNotOptimize(count);
-}
-BENCHMARK(BM_string_equal_unequal_lengths)->Arg(1)->Arg(1 << 20);
-
-void BM_stdstring_equal_unequal_lengths(benchmark::State& state) {
-  const int size = state.range(0);
-  std::string a(size, 'a');
-  std::string b(size + 1, 'a');
-  int count = 0;
-  for (auto _ : state) {
-    b[size - 1] = 'a';
-    count += (a == b);
-  }
-  benchmark::DoNotOptimize(count);
-}
-BENCHMARK(BM_stdstring_equal_unequal_lengths)->Arg(1)->Arg(1 << 20);
-
-}  // namespace