Refactor the benchmark code.

Changes:
- Modify the benchmarks to derive from a single Benchmark object.
- Rewrite the main iteration code. This includes changing the iteration
  code to use the actual total time calculated by the benchmark as a basis
  for determining whether there are enough iterations instead of using
  the time it takes to run the benchmark.
- Allow benchmarks to take no argument, int, or double.
- Fix the PrettyInt printer for negative integers.
- Modify the max column width name to include the whole name including
  the arg part.
- Reformat property_benchmark.cpp in line with the rest of the code.
- Modify a few of the math benchmarks to take an argument instead of
  separate benchmarks for the same function with different args.
- Create a vector of regex_t structs to represent the args all at
  once instead of when running each benchmark.

This change is in preparation for adding new math based benchmarks.

Tested by running on a nexus flo running at max using the new code
and the old code and comparing. All of the numbers are similar, but
some of the iterations are different due to the slightly different
algorithm used.

Change-Id: I57ad1f3ff083282b9ffeb72e687cab369ce3523a

1 files changed, 0 insertions, 266 deletions

diff --git a/benchmarks/benchmark_main.cpp b/benchmarks/benchmark_main.cpp
deleted file mode 100644
index fae09bec4..000000000
--- a/benchmarks/benchmark_main.cpp
+++ /dev/null
@@ -1,266 +0,0 @@
-/*
- * Copyright (C) 2012 The Android Open Source Project
- *
- * 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 <benchmark.h>
-
-#include <regex.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-
-#include <string>
-#include <vector>
-
-#include <inttypes.h>
-
-static int64_t g_bytes_processed;
-static int64_t g_benchmark_total_time_ns;
-static int64_t g_benchmark_start_time_ns;
-static int g_name_column_width = 20;
-
-typedef std::vector<::testing::Benchmark*> BenchmarkList;
-
-static BenchmarkList& Benchmarks() {
-  static BenchmarkList benchmarks;
-  return benchmarks;
-}
-
-// Similar to the code in art, but supporting both binary and decimal prefixes.
-static std::string PrettyInt(uint64_t count, size_t base) {
-  if (base != 2 && base != 10) abort();
-
-  // The byte thresholds at which we display amounts. A count is displayed
-  // in unit U when kUnitThresholds[U] <= bytes < kUnitThresholds[U+1].
-  static const uint64_t kUnitThresholds2[] = {
-    1024*1024*1024 /* Gi */, 2*1024*1024 /* Mi */, 3*1024 /* Ki */, 0,
-  };
-  static const uint64_t kUnitThresholds10[] = {
-    1000*1000*1000 /* G */, 2*1000*1000 /* M */, 3*1000 /* k */, 0,
-  };
-  static const uint64_t kAmountPerUnit2[] = { 1024*1024*1024, 1024*1024, 1024, 1 };
-  static const uint64_t kAmountPerUnit10[] = { 1000*1000*1000, 1000*1000, 1000, 1 };
-  static const char* const kUnitStrings2[] = { "Gi", "Mi", "Ki", "" };
-  static const char* const kUnitStrings10[] = { "G", "M", "k", "" };
-
-  // Which set are we using?
-  const uint64_t* kUnitThresholds = ((base == 2) ? kUnitThresholds2 : kUnitThresholds10);
-  const uint64_t* kAmountPerUnit = ((base == 2) ? kAmountPerUnit2 : kAmountPerUnit10);
-  const char* const* kUnitStrings = ((base == 2) ? kUnitStrings2 : kUnitStrings10);
-
-  size_t i = 0;
-  for (; kUnitThresholds[i] != 0; ++i) {
-    if (count >= kUnitThresholds[i]) {
-      break;
-    }
-  }
-  char* s = NULL;
-  asprintf(&s, "%" PRId64 "%s", count / kAmountPerUnit[i], kUnitStrings[i]);
-  std::string result(s);
-  free(s);
-  return result;
-}
-
-static int Round(int n) {
-  int base = 1;
-  while (base*10 < n) {
-    base *= 10;
-  }
-  if (n < 2*base) {
-    return 2*base;
-  }
-  if (n < 5*base) {
-    return 5*base;
-  }
-  return 10*base;
-}
-
-static int64_t NanoTime() {
-  struct timespec t;
-  t.tv_sec = t.tv_nsec = 0;
-  clock_gettime(CLOCK_MONOTONIC, &t);
-  return static_cast<int64_t>(t.tv_sec) * 1000000000LL + t.tv_nsec;
-}
-
-namespace testing {
-
-Benchmark* Benchmark::Arg(int arg) {
-  args_.push_back(arg);
-  return this;
-}
-
-const char* Benchmark::Name() {
-  return name_;
-}
-
-bool Benchmark::ShouldRun(int argc, char* argv[]) {
-  if (argc == 1) {
-    return true;  // With no arguments, we run all benchmarks.
-  }
-  // Otherwise, we interpret each argument as a regular expression and
-  // see if any of our benchmarks match.
-  for (int i = 1; i < argc; i++) {
-    regex_t re;
-    if (regcomp(&re, argv[i], 0) != 0) {
-      fprintf(stderr, "couldn't compile \"%s\" as a regular expression!\n", argv[i]);
-      exit(EXIT_FAILURE);
-    }
-    int match = regexec(&re, name_, 0, NULL, 0);
-    regfree(&re);
-    if (match != REG_NOMATCH) {
-      return true;
-    }
-  }
-  return false;
-}
-
-void Benchmark::Register(const char* name, void (*fn)(int), void (*fn_range)(int, int)) {
-  name_ = name;
-  fn_ = fn;
-  fn_range_ = fn_range;
-
-  if (fn_ == NULL && fn_range_ == NULL) {
-    fprintf(stderr, "%s: missing function\n", name_);
-    exit(EXIT_FAILURE);
-  }
-
-  Benchmarks().push_back(this);
-}
-
-void Benchmark::Run() {
-  if (fn_ != NULL) {
-    RunWithArg(0);
-  } else {
-    if (args_.empty()) {
-      fprintf(stderr, "%s: no args!\n", name_);
-      exit(EXIT_FAILURE);
-    }
-    for (size_t i = 0; i < args_.size(); ++i) {
-      RunWithArg(args_[i]);
-    }
-  }
-}
-
-void Benchmark::RunRepeatedlyWithArg(int iterations, int arg) {
-  g_bytes_processed = 0;
-  g_benchmark_total_time_ns = 0;
-  g_benchmark_start_time_ns = NanoTime();
-  if (fn_ != NULL) {
-    fn_(iterations);
-  } else {
-    fn_range_(iterations, arg);
-  }
-  if (g_benchmark_start_time_ns != 0) {
-    g_benchmark_total_time_ns += NanoTime() - g_benchmark_start_time_ns;
-  }
-}
-
-void Benchmark::RunWithArg(int arg) {
-  // Run once in case it's expensive.
-  int iterations = 1;
-  int64_t realStartTime = NanoTime();
-  RunRepeatedlyWithArg(iterations, arg);
-  int64_t realTotalTime = NanoTime() - realStartTime;
-  while (realTotalTime < 1e9 && iterations < 1e8) {
-    int last = iterations;
-    if (realTotalTime/iterations == 0) {
-      iterations = 1e9;
-    } else {
-      iterations = 1e9 / (realTotalTime/iterations);
-    }
-    iterations = std::max(last + 1, std::min(iterations + iterations/2, 100*last));
-    iterations = Round(iterations);
-    realStartTime = NanoTime();
-    RunRepeatedlyWithArg(iterations, arg);
-    realTotalTime = NanoTime() - realStartTime;
-  }
-
-  char throughput[100];
-  throughput[0] = '\0';
-
-  if (g_benchmark_total_time_ns > 0 && g_bytes_processed > 0) {
-    double gib_processed = static_cast<double>(g_bytes_processed)/1e9;
-    double seconds = static_cast<double>(g_benchmark_total_time_ns)/1e9;
-    snprintf(throughput, sizeof(throughput), " %8.3f GiB/s", gib_processed/seconds);
-  }
-
-  char full_name[100];
-  if (fn_range_ != NULL) {
-    snprintf(full_name, sizeof(full_name), "%s/%s", name_, PrettyInt(arg, 2).c_str());
-  } else {
-    snprintf(full_name, sizeof(full_name), "%s", name_);
-  }
-
-  printf("%-*s %10s %10" PRId64 "%s\n",
-         g_name_column_width, full_name,
-         PrettyInt(iterations, 10).c_str(),
-         g_benchmark_total_time_ns/iterations,
-         throughput);
-  fflush(stdout);
-}
-
-}  // namespace testing
-
-void SetBenchmarkBytesProcessed(int64_t x) {
-  g_bytes_processed = x;
-}
-
-void StopBenchmarkTiming() {
-  if (g_benchmark_start_time_ns != 0) {
-    g_benchmark_total_time_ns += NanoTime() - g_benchmark_start_time_ns;
-  }
-  g_benchmark_start_time_ns = 0;
-}
-
-void StartBenchmarkTiming() {
-  if (g_benchmark_start_time_ns == 0) {
-    g_benchmark_start_time_ns = NanoTime();
-  }
-}
-
-int main(int argc, char* argv[]) {
-  if (Benchmarks().empty()) {
-    fprintf(stderr, "No benchmarks registered!\n");
-    exit(EXIT_FAILURE);
-  }
-
-  for (auto& b : Benchmarks()) {
-    int name_width = static_cast<int>(strlen(b->Name()));
-    g_name_column_width = std::max(g_name_column_width, name_width);
-  }
-
-  bool need_header = true;
-  for (auto& b : Benchmarks()) {
-    if (b->ShouldRun(argc, argv)) {
-      if (need_header) {
-        printf("%-*s %10s %10s\n", g_name_column_width, "", "iterations", "ns/op");
-        fflush(stdout);
-        need_header = false;
-      }
-      b->Run();
-    }
-  }
-
-  if (need_header) {
-    fprintf(stderr, "No matching benchmarks!\n");
-    fprintf(stderr, "Available benchmarks:\n");
-    for (auto& b : Benchmarks()) {
-      fprintf(stderr, "  %s\n", b->Name());
-    }
-    exit(EXIT_FAILURE);
-  }
-
-  return 0;
-}