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#ifndef BENCHMARK_REGISTER_H
#define BENCHMARK_REGISTER_H
#include <algorithm>
#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) {
BM_CHECK_GE(lo, 0);
BM_CHECK_GE(hi, lo);
BM_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 *= static_cast<T>(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() + static_cast<int>(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'.
BM_CHECK_GT(lo, std::numeric_limits<T>::min());
BM_CHECK_GT(hi, std::numeric_limits<T>::min());
BM_CHECK_GE(hi, lo);
BM_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");
BM_CHECK_GE(hi, lo);
BM_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
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