1 files changed, 108 insertions, 0 deletions
diff --git a/third-party/benchmark/src/benchmark_register.h b/third-party/benchmark/src/benchmark_register.h
new file mode 100644
index 000000000000..09496607f224
--- /dev/null
+++ b/third-party/benchmark/src/benchmark_register.h
@@ -0,0 +1,108 @@
+#ifndef BENCHMARK_REGISTER_H
+#define BENCHMARK_REGISTER_H
+
+#include <limits>
+#include <vector>
+
+#include "check.h"
+
+namespace benchmark {
+namespace internal {
+
+// Append the powers of 'mult' in the closed interval [lo, hi].
+// Returns iterator to the start of the inserted range.
+template <typename T>
+typename std::vector<T>::iterator
+AddPowers(std::vector<T>* dst, T lo, T hi, int mult) {
+  CHECK_GE(lo, 0);
+  CHECK_GE(hi, lo);
+  CHECK_GE(mult, 2);
+
+  const size_t start_offset = dst->size();
+
+  static const T kmax = std::numeric_limits<T>::max();
+
+  // Space out the values in multiples of "mult"
+  for (T i = static_cast<T>(1); i <= hi; i *= mult) {
+    if (i >= lo) {
+      dst->push_back(i);
+    }
+    // Break the loop here since multiplying by
+    // 'mult' would move outside of the range of T
+    if (i > kmax / mult) break;
+  }
+
+  return dst->begin() + start_offset;
+}
+
+template <typename T>
+void AddNegatedPowers(std::vector<T>* dst, T lo, T hi, int mult) {
+  // We negate lo and hi so we require that they cannot be equal to 'min'.
+  CHECK_GT(lo, std::numeric_limits<T>::min());
+  CHECK_GT(hi, std::numeric_limits<T>::min());
+  CHECK_GE(hi, lo);
+  CHECK_LE(hi, 0);
+
+  // Add positive powers, then negate and reverse.
+  // Casts necessary since small integers get promoted
+  // to 'int' when negating.
+  const auto lo_complement = static_cast<T>(-lo);
+  const auto hi_complement = static_cast<T>(-hi);
+
+  const auto it = AddPowers(dst, hi_complement, lo_complement, mult);
+
+  std::for_each(it, dst->end(), [](T& t) { t *= -1; });
+  std::reverse(it, dst->end());
+}
+
+template <typename T>
+void AddRange(std::vector<T>* dst, T lo, T hi, int mult) {
+  static_assert(std::is_integral<T>::value && std::is_signed<T>::value,
+                "Args type must be a signed integer");
+
+  CHECK_GE(hi, lo);
+  CHECK_GE(mult, 2);
+
+  // Add "lo"
+  dst->push_back(lo);
+
+  // Handle lo == hi as a special case, so we then know
+  // lo < hi and so it is safe to add 1 to lo and subtract 1
+  // from hi without falling outside of the range of T.
+  if (lo == hi) return;
+
+  // Ensure that lo_inner <= hi_inner below.
+  if (lo + 1 == hi) {
+    dst->push_back(hi);
+    return;
+  }
+
+  // Add all powers of 'mult' in the range [lo+1, hi-1] (inclusive).
+  const auto lo_inner = static_cast<T>(lo + 1);
+  const auto hi_inner = static_cast<T>(hi - 1);
+
+  // Insert negative values
+  if (lo_inner < 0) {
+    AddNegatedPowers(dst, lo_inner, std::min(hi_inner, T{-1}), mult);
+  }
+
+  // Treat 0 as a special case (see discussion on #762).
+  if (lo < 0 && hi >= 0) {
+    dst->push_back(0);
+  }
+
+  // Insert positive values
+  if (hi_inner > 0) {
+    AddPowers(dst, std::max(lo_inner, T{1}), hi_inner, mult);
+  }
+
+  // Add "hi" (if different from last value).
+  if (hi != dst->back()) {
+    dst->push_back(hi);
+  }
+}
+
+}  // namespace internal
+}  // namespace benchmark
+
+#endif  // BENCHMARK_REGISTER_H